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Sample records for ph sensitive dye

  1. Influence of the pH value of anthocyanins on the electrical properties of dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Irén Juhász Junger

    2017-03-01

    Full Text Available In recent years the harvesting of renewable energies became of great importance. This led to a rapid development of dye-sensitized solar cells which can be produced from low-purity materials. The best electrical properties are provided by cells prepared using synthetical, ruthenium based dyes. Unfortunately, most of them are toxic and expensive. The anthocyanins extracted for example from hibiscus flowers yield a more cost-effective and eco-friendly alternative to toxic dyes, however, with a loss of solar cell efficiency. In this article the possibility of improvement of the conversion efficiency by modification of the pH value of the dye is investigated. By decrease of the pH value, an increase of efficiency by a factor of two was achieved.

  2. Dimerization of Organic Dyes on Luminescent Gold Nanoparticles for Ratiometric pH Sensing.

    Science.gov (United States)

    Sun, Shasha; Ning, Xuhui; Zhang, Greg; Wang, Yen-Chung; Peng, Chuanqi; Zheng, Jie

    2016-02-12

    Synergistic effects arising from the conjugation of organic dyes onto non-luminescent metal nanoparticles (NPs) have greatly broadened their applications in both imaging and sensing. Herein, we report that conjugation of a well-known pH-insensitive dye, tetramethyl-rhodamine (TAMRA), to pH-insensitive luminescent gold nanoparticles (AuNPs) can lead to an ultrasmall nanoindicator that can fluorescently report local pH in a ratiometric way. Such synergy originated from the dimerization of TAMRA on AuNPs, of which geometry was very sensitive to surface charges of the AuNPs and can be reversely modulated through protonation of surrounding glutathione ligands. Not limited to pH-insensitive dyes, this pH-dependent dimerization can also enhance the pH sensitivity of fluorescein, a well-known pH-sensitive dye, within a larger pH range, opening up a new pathway to design ultrasmall fluorescent ratiometric nanoindicators with tunable wavelengths and pH response ranges. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. A protein-dye hybrid system as a narrow range tunable intracellular pH sensor.

    Science.gov (United States)

    Anees, Palapuravan; Sudheesh, Karivachery V; Jayamurthy, Purushothaman; Chandrika, Arunkumar R; Omkumar, Ramakrishnapillai V; Ajayaghosh, Ayyappanpillai

    2016-11-18

    Accurate monitoring of pH variations inside cells is important for the early diagnosis of diseases such as cancer. Even though a variety of different pH sensors are available, construction of a custom-made sensor array for measuring minute variations in a narrow biological pH window, using easily available constituents, is a challenge. Here we report two-component hybrid sensors derived from a protein and organic dye nanoparticles whose sensitivity range can be tuned by choosing different ratios of the components, to monitor the minute pH variations in a given system. The dye interacts noncovalently with the protein at lower pH and covalently at higher pH, triggering two distinguishable fluorescent signals at 700 and 480 nm, respectively. The pH sensitivity region of the probe can be tuned for every unit of the pH window resulting in custom-made pH sensors. These narrow range tunable pH sensors have been used to monitor pH variations in HeLa cells using the fluorescence imaging technique.

  4. Dye-sensitized solar cell using natural dyes extracted from spinach and ipomoea

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H., E-mail: f10381@ntut.edu.t [Department of Mechanical Engineering, National Taipei University of Technology, No. 1. Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China); Wu, H.M. [Department of Materials Engineering, Tatung University, No. 40, Sec. 3, Jhongshan N. Rd. Jhongshan District, Taipei City 104, Taiwan (China); Chen, T.L. [Department of Industrial Design, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China); Huang, K.D. [Department of Vehicle Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China); Jwo, C.S. [Department of Energy and Air-Conditioning Refrigeration Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China); Lo, Y.J. [Department of Mechanical Engineering, National Taipei University of Technology, No. 1. Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China)

    2010-04-16

    This study used spinach extract, ipomoea leaf extract and their mixed extracts as the natural dyes for a dye-sensitized solar cell (DSSC). Spinach and ipomoea leaves were first placed separately in ethanol and the chlorophyll of these two kinds of plants was extracted to serve as the natural dyes for using in DSSCs. In addition, the self-developed nanofluid synthesis system prepared a TiO{sub 2} nanofluid with an average particle size of 50 nm. Electrophoresis deposition was performed to let the TiO{sub 2} deposit nanoparticles on the indium tin oxide (ITO) conductive glass, forming a TiO{sub 2} thin film with the thickness of 11.61 {mu}m. This TiO{sub 2} thin film underwent sintering at 450 {sup o}C to enhance the compactness of thin film. Finally, the sintered TiO{sub 2} thin film was immersed in the natural dye solutions extracted from spinach and ipomoea leaves, completing the production of the anode of DSSC. This study then further inspected the fill factor, photoelectric conversion efficiency and incident photon current efficiency of the encapsulated DSSC. According to the experimental results of current-voltage curve, the photoelectric conversion efficiency of the DSSCs prepared by natural dyes from ipomoea leaf extract is 0.318% under extraction temperature of 50 {sup o}C and pH value of extraction fluid at 1.0. This paper also investigated the influence of the temperature in the extraction process of this kind of natural dye and the influence of pH value of the dye solution on the UV-VIS patterns absorption spectra of the prepared natural dye solutions, and the influence of these two factors on the photoelectric conversion efficiency of DSSC.

  5. Theoretical study of indoline dyes for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Ham, Ho Wan; Kim, Young Sik

    2010-01-01

    Indoline dye sensitizers were designed and studied theoretically to increase molar extinction coefficients in the visible to near infrared region for solar-cell devices. To gain insight into dye sensitizers' structural, electronic, and optical properties, DFT/TDDFT calculations were performed on a series of dye sensitizers derived from the D149. The good agreement between the experimental and TDDFT calculated absorption spectra of the D149 sensitizer allowed us to provide a detailed assessment of the main spectral features of a series of dye sensitizers. Increase in the conjugation length resulted in a more red-shifted spectral response and less positive oxidation potential than that of the D149. The dye with the dimethylfluorene group showed stronger absorption bands due to a large dipole moment. The calculated dipoles for the dye series correlate well with the observed strong absorption bands of the electronic spectra. These results provided useful clues for the molecular engineering of efficient organic dye sensitizers.

  6. Effect of dye extracting solvents and sensitization time on photovoltaic performance of natural dye sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Md. Khalid Hossain

    Full Text Available In this study, natural dye sensitizer based solar cells were successfully fabricated and photovoltaic performance was measured. Sensitizer (turmeric sources, dye extraction process, and photoanode sensitization time of the fabricated cells were analyzed and optimized. Dry turmeric, verdant turmeric, and powder turmeric were used as dye sources. Five distinct types of solvents were used for extraction of natural dye from turmeric. Dyes were characterized by UV–Vis spectrophotometric analysis. The extracted turmeric dye was used as a sensitizer in the dye sensitized solar cell’s (DSSC photoanode assembly. Nano-crystalline TiO2 was used as a film coating semiconductor material of the photoanode. TiO2 films on ITO glass substrate were prepared by simple doctor blade technique. The influence of the different parameters VOC, JSC, power density, FF, and η% on the photovoltaic characteristics of DSSCs was analyzed. The best energy conversion performance was obtained for 2 h adsorption time of dye on TiO2 nano-porous surface with ethanol extracted dye from dry turmeric. Keywords: DSSC, Natural dye, TiO2 photoanode, Dye extracting solvent, Dye-adsorption time

  7. Effect of dye extracting solvents and sensitization time on photovoltaic performance of natural dye sensitized solar cells

    Science.gov (United States)

    Hossain, Md. Khalid; Pervez, M. Firoz; Mia, M. N. H.; Mortuza, A. A.; Rahaman, M. S.; Karim, M. R.; Islam, Jahid M. M.; Ahmed, Farid; Khan, Mubarak A.

    In this study, natural dye sensitizer based solar cells were successfully fabricated and photovoltaic performance was measured. Sensitizer (turmeric) sources, dye extraction process, and photoanode sensitization time of the fabricated cells were analyzed and optimized. Dry turmeric, verdant turmeric, and powder turmeric were used as dye sources. Five distinct types of solvents were used for extraction of natural dye from turmeric. Dyes were characterized by UV-Vis spectrophotometric analysis. The extracted turmeric dye was used as a sensitizer in the dye sensitized solar cell's (DSSC) photoanode assembly. Nano-crystalline TiO2 was used as a film coating semiconductor material of the photoanode. TiO2 films on ITO glass substrate were prepared by simple doctor blade technique. The influence of the different parameters VOC, JSC, power density, FF, and η% on the photovoltaic characteristics of DSSCs was analyzed. The best energy conversion performance was obtained for 2 h adsorption time of dye on TiO2 nano-porous surface with ethanol extracted dye from dry turmeric.

  8. Characteristics of dye-sensitized solar cells using natural dye

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Shoji, E-mail: furukawa@cse.kyutech.ac.j [Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka-ken 820-8502 (Japan); Iino, Hiroshi; Iwamoto, Tomohisa; Kukita, Koudai; Yamauchi, Shoji [Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka-ken 820-8502 (Japan)

    2009-11-30

    Dye-sensitized solar cells are expected to be used for future clean energy. Recently, most of the researchers in this field use Ruthenium complex as dye in the dye-sensitized solar cells. However, Ruthenium is a rare metal, so the cost of the Ruthenium complex is very high. In this paper, various dye-sensitized solar cells have been fabricated using natural dye, such as the dye of red-cabbage, curcumin, and red-perilla. As a result, it was found that the conversion efficiency of the solar cell fabricated using the mixture of red-cabbage and curcumin was about 0.6% (light source: halogen lamp), which was larger than that of the solar cells using one kind of dye. It was also found that the conversion efficiency was about 1.0% for the solar cell with the oxide semiconductor film fabricated using polyethylene glycol (PEG) whose molecular weight was 2,000,000 and red-cabbage dye. This indicates that the cost performance (defined by [conversion efficiency]/[cost of dye]) of the latter solar cell (dye: red-cabbage) is larger by more than 50 times than that of the solar cell using Ruthenium complex, even if the effect of the difference between the halogen lamp and the standard light source is taken into account.

  9. Increased light harvesting in dye-sensitized solar cells with energy relay dyes

    KAUST Repository

    Hardin, Brian E.

    2009-06-21

    Conventional dye-sensitized solar cells have excellent charge collection efficiencies, high open-circuit voltages and good fill factors. However, dye-sensitized solar cells do not completely absorb all of the photons from the visible and near-infrared domain and consequently have lower short-circuit photocurrent densities than inorganic photovoltaic devices. Here, we present a new design where high-energy photons are absorbed by highly photoluminescent chromophores unattached to the titania and undergo Förster resonant energy transfer to the sensitizing dye. This novel architecture allows for broader spectral absorption, an increase in dye loading, and relaxes the design requirements for the sensitizing dye. We demonstrate a 26% increase in power conversion efficiency when using an energy relay dye (PTCDI) with an organic sensitizing dye (TT1). We estimate the average excitation transfer efficiency in this system to be at least 47%. This system offers a viable pathway to develop more efficient dye-sensitized solar cells.

  10. Natural dyes as photosensitizers for dye-sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Sancun; Wu, Jihuai; Huang, Yunfang; Lin, Jianming [Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou, Fujian 362021 (China)

    2006-02-15

    The dye-sensitized solar cells (DSC) were assembled by using natural dyes extracted from black rice, capsicum, erythrina variegata flower, rosa xanthina, and kelp as sensitizers. The I{sub SC} from 1.142mA to 0.225mA, the V{sub OC} from 0.551V to 0.412V, the fill factor from 0.52 to 0.63, and P{sub max} from 58{mu}W to 327{mu}W were obtained from the DSC sensitized with natural dye extracts. In the extracts of natural fruit, leaves and flower chosen, the black rice extract performed the best photosensitized effect, which was due to the better interaction between the carbonyl and hydroxyl groups of anthocyanin molecule on black rice extract and the surface of TiO{sub 2} porous film. The blue-shift of absorption wavelength of the black rice extract in ethanol solution on TiO{sub 2} film and the blue-shift phenomenon from absorption spectrum to photoaction spectrum of DSC sensitized with black rice extract are discussed in the paper. Because of the simple preparation technique, widely available and low cheap cost natural dye as an alternative sensitizer for dye-sensitized solar cell is promising. (author)

  11. Incorporating Multiple Energy Relay Dyes in Liquid Dye-Sensitized Solar Cells

    KAUST Repository

    Yum, Jun-Ho

    2011-01-05

    Panchromatic response is essential to increase the light-harvesting efficiency in solar conversion systems. Herein we show increased light harvesting from using multiple energy relay dyes inside dye-sensitized solar cells. Additional photoresponse from 400-590 nm matching the optical window of the zinc phthalocyanine sensitizer was observed due to Förster resonance energy transfer (FRET) from the two energy relay dyes to the sensitizing dye. The complementary absorption spectra of the energy relay dyes and high excitation transfer efficiencies result in a 35% increase in photovoltaic performance. © 2011 Wiley-VCH Verlag GmbH& Co. KGaA.

  12. Ultra-bright red-emitting photostable perylene bisimide dyes: new indicators for ratiometric sensing of high pH or carbon dioxide.

    Science.gov (United States)

    Pfeifer, David; Klimant, Ingo; Borisov, Sergey M

    2018-05-08

    New pH sensitive perylene bisimide indicator dyes were synthesised and used for fabrication of optical sensors. The highly photostable dyes show absorption/emission bands in the red/near-infrared (NIR) region of the electromagnetic spectrum, high molar absorption coefficients (up to 100 000 M-1 cm-1) and fluorescence quantum yields close to unity. The absorption and emission spectra show strong bathochromic shift upon deprotonation of imidazole nitrogen which makes the dyes promising as ratiometric fluorescent indicators. Physical entrapment of the indicators into polyurethane hydrogel enables pH determination in alkaline pH. It is also shown that plastic carbon dioxide solid state sensor can be manufactured via immobilization of the pH indicator in a hydrophilic polymer, along with a quaternary ammonium base. The influence of plasticizer, different lipophilic bases and humidity on the sensitivity of the sensor material were systematically investigated. The disubstituted perylene, particularly, features two deprotonation equilibria enabling sensing over a very broad range from 0.5 to 1000 hPa pCO2. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Dye-sensitized solar cells using natural dyes as sensitizers from Malaysia local fruit `Buah Mertajam'

    Science.gov (United States)

    Hambali, N. A. M. Ahmad; Roshidah, N.; Hashim, M. Norhafiz; Mohamad, I. S.; Saad, N. Hidayah; Norizan, M. N.

    2015-05-01

    We experimentally demonstrate the high conversion efficiency, low cost, green technology and easy to fabricate dye-sensitized solar cells (DSSCs) using natural anthocyanin dyes as sensitizers. The DSSCs was fabricated by using natural anthocyanin dyes which were extracted from different parts of the plants inclusive `Buah Mertajam', `Buah Keriang Dot', `Bunga Geti', Hibiscus, Red Spinach and Henna. The natural anthocyanin dyes that found in flower, leaves and fruits were extracted by the simple procedures. This anthocyanin dye is used to replace the expensive chemical synthetic dyes due to its ability to effectively attach into the surface of Titanium dioxide (TiO2). A natural anthocyanin dyes molecule adsorbs to each particle of the TiO2 and acts as the absorber of the visible light. A natural anthocyanin dye from Buah Mertajam shows the best performance with the conversion efficiency of 5.948% and fill factor of 0.708 followed by natural anthocyanin dyes from `Buah Keriang Dot', `Bunga Geti', Hibiscus, Red Spinach and Henna. Buah Mertajam or scientifically known as eriglossum rubiginosum is a local Malaysia fruit.

  14. Dye-sensitized solar cells based on purple corn sensitizers

    Science.gov (United States)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-09-01

    Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  15. Homogeneous plate based antibody internalization assay using pH sensor fluorescent dye.

    Science.gov (United States)

    Nath, Nidhi; Godat, Becky; Zimprich, Chad; Dwight, Stephen J; Corona, Cesear; McDougall, Mark; Urh, Marjeta

    2016-04-01

    Receptor-mediated antibody internalization is a key mechanism underlying several anti-cancer antibody therapeutics. Delivering highly toxic drugs to cancer cells, as in the case of antibody drug conjugates (ADCs), efficient removal of surface receptors from cancer cells and changing the pharmacokinetics profile of the antibody drugs are some of key ways that internalization impacts the therapeutic efficacy of the antibodies. Over the years, several techniques have been used to study antibody internalization including radiolabels, fluorescent microscopy, flow cytometry and cellular toxicity assays. While these methods allow analysis of internalization, they have limitations including a multistep process and limited throughput and are generally endpoint assays. Here, we present a new homogeneous method that enables time and concentration dependent measurements of antibody internalization. The method uses a new hydrophilic and bright pH sensor dye (pHAb dye), which is not fluorescent at neutral pH but becomes highly fluorescent at acidic pH. For receptor mediated antibody internalization studies, antibodies against receptors are conjugated with the pHAb dye and incubated with the cells expressing the receptors. Upon binding to the receptor, the dyes conjugated to the antibody are not fluorescent because of the neutral pH of the media, but upon internalization and trafficking into endosomal and lysosomal vesicles the pH drops and dyes become fluorescent. The enabling attributes of the pHAb dyes are the hydrophilic nature to minimize antibody aggregation and bright fluorescence at acidic pH which allows development of simple plate based assays using a fluorescent reader. Using two different therapeutic antibodies--Trastuzumab (anti-HER2) and Cetuximab (anti-EGFR)--we show labeling with pHAb dye using amine and thiol chemistries and impact of chemistry and dye to antibody ration on internalization. We finally present two new approaches using the pHAb dye, which will be

  16. Dye-sensitized solar cells with natural dyes extracted from achiote seeds

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Ortiz, N.M.; Vazquez-Maldonado, I.A.; Azamar-Barrios, J.A.; Oskam, G. [Departamento de Fisica Aplicada, CINVESTAV-IPN, Merida, Yuc. 97310 (Mexico); Perez-Espadas, A.R.; Mena-Rejon, G.J. [Laboratorio de Quimica Organica de Investigacion, Facultad de Quimica, Universidad Autonoma de Yucatan, Merida, Yuc. 97150 (Mexico)

    2010-01-15

    We have explored the application of natural dyes extracted from the seeds of the achiote shrub (Bixa orellana L.) in dye-sensitized solar cells (DSCs). The main pigments are bixin and norbixin, which were obtained by separation and purification from the dark-red extract (annatto). The dyes were characterized using {sup 1}H-NMR, FTIR spectroscopy, and UV-Vis spectrophotometry. Solar cells were prepared using TiO{sub 2} and ZnO nanostructured, mesoporous films and the annatto, bixin, and norbixin as sensitizers. The best results were obtained with bixin-sensitized TiO{sub 2} solar cells with efficiencies of up to 0.53%, illustrating the importance of purification of dyes from natural extracts. (author)

  17. High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells

    KAUST Repository

    Hardin, Brian E.

    2010-08-11

    The energy relay dye, 4-(Dicyanomethylene)-2-methyl-6-(4- dimethylaminostyryl)-4H-pyran (DCM), was used with a near-infrared sensitizing dye, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3.5% to 4.5%. The unattached DCM dyes exhibit an average excitation transfer efficiency (EÌ?TE) of 96% inside TT1-covered, mesostructured TiO2 films. Further performance increases were limited by the solubility of DCM in an acetonitrile based electrolyte. This demonstration shows that energy relay dyes can be efficiently implemented in optimized dye-sensitized solar cells, but also highlights the need to design highly soluble energy relay dyes with high molar extinction coefficients. © 2010 American Chemical Society.

  18. Photostability of low cost dye-sensitized solar cells based on natural and synthetic dyes

    Science.gov (United States)

    Abdou, E. M.; Hafez, H. S.; Bakir, E.; Abdel-Mottaleb, M. S. A.

    2013-11-01

    This paper deals with the use of some natural pigments as well as synthetic dyes to act as sensitizers in dye-sensitized solar cells (DSSCs). Anthocyanin dye extracted from rosella (Hibiscus sabdariffa L.) flowers, the commercially available textile dye Remazole Red RB-133 (RR) and merocyanin-like dye based on 7-methyl coumarin are tested. The photostability of the three dyes is investigated under UV-Vis light exposure. The results show a relatively high stability of the three dyes. Moreover, the photostability of the solid dyes is studied over the TiO2 film electrodes. A very low decolorization rates are recorded as; rate constants k = 1.6, 2.1 and 1.9 × 10-3 min-1 for anthocyanin, RR and coumarin dyes, respectively. The stability results favor selecting anthocyanin as a promising sensitizer candidate in DSSCs based on natural products. Dyes-sensitized solar cells are fabricated and their conversion efficiency (η) is 0.27%, 0.14% and 0.001% for the anthocyanin, RR and coumarin dyes, respectively. Moreover, stability tests of the sealed cells based on anthocyanin and RR dyes are done under continuous light exposure of 100 mW cm-2, reveals highly stable DSSCs.

  19. High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells

    KAUST Repository

    Hardin, Brian E.; Yum, Jun-Ho; Hoke, Eric T.; Jun, Young Chul; Péchy, Peter; Torres, Tomás; Brongersma, Mark L.; Nazeeruddin, Md. Khaja; Grätzel, Michael; McGehee, Michael D.

    2010-01-01

    The energy relay dye, 4-(Dicyanomethylene)-2-methyl-6-(4- dimethylaminostyryl)-4H-pyran (DCM), was used with a near-infrared sensitizing dye, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3

  20. Synthesis and characterization of pH sensitive carboxySNARF-1 nanoreactors

    International Nuclear Information System (INIS)

    Chen Yenchi; Ostafin, Agnes; Mizukami, Hiroshi

    2010-01-01

    A rapid response dual wavelength emission pH sensor consisting of carboxySNARF-1 nanoreactors has been synthesized and shown to provide accurate pH measurements even in complex biological media, where the unprotected pH responsive dyes have failed. The carboxySNARF-1 nanoreactor is made of a calcium phosphate shell covering phosphatidylcholine liposomes filled with the dye. Its mean diameter is 150 nm with dynamic light scattering, the shell thickness is 5-7 nm with TEM, and it contains about 10 dyes/particle. The nanoreactor's response time to pH change nearly equals that of the dye in solution. Its pH titration curves at two different wavelengths are equivalent to those of the dye in solution and fluorescence intensity ratio dependent pH analysis is possible using the modified Henderson-Hasselbalch equation. However, the pH dependent fluorescence ratios of the dye in solution in the presence of plasma and albumin are distorted, and application of the Henderson-Hasselbalch equation is not possible. We have found that the distortions may be restored using cSNARF-1 nanoreactors and the pK a of the dye in the nanoreactor then equals that in solution. These results suggest that the interference to the dye for the pH analyses with the environmental molecules may be reduced or prohibited by usage of cSNARF-1 nanoreactors.

  1. Synthesis and characterization of pH sensitive carboxySNARF-1 nanoreactors

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yenchi; Ostafin, Agnes [Department of Materials Science, University of Utah, Salt Lake City, UT (United States); Mizukami, Hiroshi, E-mail: a.ostafin@utah.edu [Department of Biological Science, Wayne State University, Detroit, MI (United States)

    2010-05-28

    A rapid response dual wavelength emission pH sensor consisting of carboxySNARF-1 nanoreactors has been synthesized and shown to provide accurate pH measurements even in complex biological media, where the unprotected pH responsive dyes have failed. The carboxySNARF-1 nanoreactor is made of a calcium phosphate shell covering phosphatidylcholine liposomes filled with the dye. Its mean diameter is 150 nm with dynamic light scattering, the shell thickness is 5-7 nm with TEM, and it contains about 10 dyes/particle. The nanoreactor's response time to pH change nearly equals that of the dye in solution. Its pH titration curves at two different wavelengths are equivalent to those of the dye in solution and fluorescence intensity ratio dependent pH analysis is possible using the modified Henderson-Hasselbalch equation. However, the pH dependent fluorescence ratios of the dye in solution in the presence of plasma and albumin are distorted, and application of the Henderson-Hasselbalch equation is not possible. We have found that the distortions may be restored using cSNARF-1 nanoreactors and the pK{sub a} of the dye in the nanoreactor then equals that in solution. These results suggest that the interference to the dye for the pH analyses with the environmental molecules may be reduced or prohibited by usage of cSNARF-1 nanoreactors.

  2. Novel diyne-bridged dyes for efficient dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Jing-Kun, E-mail: fjk@njust.edu.cn [Department of Chemistry, School of Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei Street No. 200, Nanjing, 210094 (China); Sun, Tengxiao [Department of Chemistry, School of Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei Street No. 200, Nanjing, 210094 (China); Tian, Yi [Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Zhang, Yingjun, E-mail: ZhangYingjun@hec.cn [HEC Pharm Group, HEC R& D Center, Dongguan, 523871 (China); Jin, Chuanfei [HEC Pharm Group, HEC R& D Center, Dongguan, 523871 (China); Xu, Zhimin; Fang, Yu; Hu, Xiangyu; Wang, Haobin [Department of Chemistry, School of Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei Street No. 200, Nanjing, 210094 (China)

    2017-07-01

    Three new metal free organic dyes (FSD101-103) were synthesized to investigate the influence of diyne unit on dye molecules. FSD101 and FSD102 with diyne unit and FSD103 with monoyne unit were applied as sensitizers in the dye-sensitized solar cells (DSSCs). The optical and electrochemical properties, theoretical studies, and photovoltaic parameters of DSSCs sensitized by these dyes were systematically investigated. By replacing the monoyne unit with a diyne unit, FSD101 exhibited broader absorption spectrum, lower IP, higher EA, lower band gap energy, higher oscillator strength, more efficient electron injection ability, broader IPCE response range and higher τ{sub e} in comparison with FSD103. Hence, DSSC sensitized by FSD101 showed higher J{sub sc} and V{sub oc} values, and demonstrated a power conversion efficiency of 3.12%, about 2-fold as that of FSD103 (1.55%). FSD102 showed similar results as FSD101, with a power conversion efficiency of 2.98%, despite a stronger electron withdraw cyanoacrylic acid group was introduced. This may be due to the lower efficiency of the electron injection from dye to TiO{sub 2} and lower τ{sub e} of FSD102 than that of FSD101. These results indicate that the performance of DSSCs can be significantly improved by introducing a diyne unit into this type of organic dyes. - Highlights: • Diyne-bridge was introduced into dye molecules by a transition-metal-free protocol. • Power conversion efficiency grows from 1.55% to 3.12% by replacing monoyne unit with diyne unit. • FSD101 with diyne unit shows the highest electron lifetime resulting in a higher V{sub oc}.

  3. Photoelectrochemical studies of dye-sensitized solar cells using organic dyes

    Energy Technology Data Exchange (ETDEWEB)

    Marinado, Tannia

    2009-10-15

    The dye-sensitized solar cell (DSC) is a promising efficient low-cost molecular photovoltaic device. One of the key components in DSCs is the dye, as it is responsible for the capture of sunlight. State-of-the-art DSC devices, based on ruthenium dyes, show record efficiencies of 10-12 %. During the last decade, metal-free organic dyes have been extensively explored as sensitizers for DSC application. The use of organic dyes is particularly attractive as it enables easy structural modifications, due to fairly short synthetic routes and reduced material cost. Novel dye should in addition to the light-harvesting properties also be compatible with the DSC components. In this thesis, a series of new organic dyes are investigated, both when integrated in the DSC device and as individual components. The evaluation methods consisted of different electrochemical and photoelectrochemical techniques. Whereas the light-harvesting properties of the dyes were fairly easily improved, the behavior of the dye integrated in the DSC showed less predictable photovoltaic results. The dye series studied in Papers II and IV revealed that their dye energetics limited vital electron-transfer processes, the dye regeneration (Paper II) and injection quantum yield (Paper IV). Further, in Papers III-VI, it was observed that different dye structures seemed to alter the interfacial electron recombination with the electrolyte. In addition to the dye structure sterics, some organic dyes appear to enhance the interfacial recombination, possibly due to specific dye-redox acceptor interaction (Paper V). The impact of dye sterical modifications versus the use of coadsorbent was explored in Paper VI. The dye layer properties in the presence and absence of various coadsorbents were further investigated in Paper VII. The core of this thesis is the identification of the processes and properties limiting the performance of the DSC device, aiming at an overall understanding of the compatibility between the

  4. A panchromatic anthracene-fused porphyrin sensitizer for dye-sensitized solar cells

    KAUST Repository

    Ball, James M.

    2012-01-01

    The development of ruthenium-free sensitizers which absorb light over a broad range of the solar spectrum is important for improving the power conversion efficiency of dye-sensitized solar cells. Here we study three chemically tailored porphyrin-based dyes. We show that by fusing the porphyrin core to an anthracene unit, we can extend the conjugation length and lower the optical gap, shifting the absorption spectrum into the near-infrared (NIR). All three dyes were tested in dye-sensitized solar cells, using both titanium dioxide and tin dioxide as the electron-transport material. Solar cells incorporating the anthracene-fused porphyrin dye exhibit photocurrent collection at wavelengths up to about 1100 nm, which is the longest reported for a porphyrin-based system. Despite extending the photon absorption bandwidth, device efficiency is found to be low, which is a common property of cells based on porphyrin dyes with NIR absorption. We show that in the present case the efficiency is reduced by inefficient electron injection into the oxide, as opposed to dye regeneration, and highlight some important design considerations for panchromatic sensitizers. © 2012 The Royal Society of Chemistry.

  5. Increased light harvesting in dye-sensitized solar cells with energy relay dyes

    KAUST Repository

    Hardin, Brian E.; Hoke, Eric T.; Armstrong, Paul B.; Yum, Jun-Ho; Comte, Pascal; Torres, Tomá s; Fré chet, Jean M. J.; Nazeeruddin, Md Khaja; Grä tzel, Michael; McGehee, Michael D.

    2009-01-01

    Conventional dye-sensitized solar cells have excellent charge collection efficiencies, high open-circuit voltages and good fill factors. However, dye-sensitized solar cells do not completely absorb all of the photons from the visible and near

  6. Organic dye for highly efficient solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt-Mende, L.; Bach, U.; Humphry-Baker, R.; Ito, S.; Graetzel, M. [Institut des Sciences et Ingenierie Chimiques (ISIC), Laboratoire de Photonique et Interfaces (LPI), Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Horiuchi, T.; Miura, H. [Technology Research Laboratory, Corporate Research Center, Mitsubishi Paper Mills Limited, 46, Wadai, Tsukuba City, Ibaraki 300-4247 (Japan); Uchida, S. [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1-1 Katahira 2-chome, Aoba-ku, Sendai 980-8577 (Japan)

    2005-04-04

    The feasibility of solid-state dye-sensitized solar cells as a low-cost alternative to amorphous silicon cells is demonstrated. Such a cell with a record efficiency of over 4 % under simulated sunlight is reported, made possible by using a new organic metal-free indoline dye as the sensitizer with high absorption coefficient. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  7. Dye-sensitized solar cells based on purple corn sensitizers

    International Nuclear Information System (INIS)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-01-01

    Graphical abstract: - Highlights: • Extract from husk, cob and silk of purple corn was used as a photosensitizer in DSSC. • Effect of solvents i.e. acetone, ethanol and DI water on DSSC efficiency was studied. • The highest efficiency of 1.06% was obtained in DSSC based on acetone extraction. - Abstract: Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  8. Dye-sensitized solar cells based on purple corn sensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Phinjaturus, Kawin [Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Maiaugree, Wasan [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Suriharn, Bhalang [Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002 (Thailand); Pimanpaeng, Samuk; Amornkitbamrung, Vittaya [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Integrated Nanotechnology Research Center (INRC), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Swatsitang, Ekaphan, E-mail: ekaphan@kku.ac.th [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Integrated Nanotechnology Research Center (INRC), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage, Khon Kaen 40002 (Thailand)

    2016-09-01

    Graphical abstract: - Highlights: • Extract from husk, cob and silk of purple corn was used as a photosensitizer in DSSC. • Effect of solvents i.e. acetone, ethanol and DI water on DSSC efficiency was studied. • The highest efficiency of 1.06% was obtained in DSSC based on acetone extraction. - Abstract: Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  9. Incorporating Multiple Energy Relay Dyes in Liquid Dye-Sensitized Solar Cells

    KAUST Repository

    Yum, Jun-Ho; Hardin, Brian E.; Hoke, Eric T.; Baranoff, Etienne; Zakeeruddin, Shaik M.; Nazeeruddin, Mohammad K.; Torres, Tomas; McGehee, Michael D.; Grä tzel, Michael

    2011-01-01

    Panchromatic response is essential to increase the light-harvesting efficiency in solar conversion systems. Herein we show increased light harvesting from using multiple energy relay dyes inside dye-sensitized solar cells. Additional photoresponse

  10. Photoelectric characterization of fabricated dye-sensitized solar cell using dye extracted from red Siahkooti fruit as natural sensitizer

    Science.gov (United States)

    Mozaffari, Sayed Ahmad; Saeidi, Mahsa; Rahmanian, Reza

    2015-05-01

    Natural dye extracted from Siahkooti fruit with/without purification by solid phase extraction (SPE) technique was used in the fabrication of DSSC as natural sensitizer. The UV-Vis absorption spectroscopy and Fourier transform infrared (FTIR) were employed to indicate the presence of anthocyanins in the fruit of red Siahkooti. The photoelectrochemical performance and the efficiency of assembled DSSC using Siahkooti fruit dye extract were evaluated and efficiency enhancement was obtained by a preliminary purification of extracted dye. The efficiency and fill factor of the DSSC using purified Siahkooti fruit dye were 0.32% and 0.73%, respectively. The results successfully showed that the DSSC, using Siahkooti fruit extract as a dye sensitizer, is useful for the preparation of environmentally friendly, low-cost, renewable and clean sources of energy.

  11. BODIPYs for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Klfout, Hafsah; Stewart, Adam; Elkhalifa, Mahmoud; He, Hongshan

    2017-11-22

    BODIPY, abbreviation of boron-dipyrromethene, is one class of robust organic molecules that has been used widely in bioimaging, sensing, and logic gate design. Recently, BODIPY dyes have been explored for dye-sensitized solar cells (DSCs). Studies demonstrate their potential as light absorbers for the conversion of solar energy to electricity. However, their photovoltaic performance is inferior to many other dyes, including porphyrin dyes. In this review, several synthetic strategies of BODIPY dyes for DSCs and their further functionalization are described. The photophysical properties of dye molecules and their photovoltaic performances in DSCs are summarized. We aim to provide readers a clear picture of the field and expect to shed light on the next generation of BODIPY dyes for their applications in solar energy conversion.

  12. Enhancement of power conversion efficiency of dye-sensitized solar cells by co-sensitization of Phloxine B and Bromophenol blue dyes on ZnO photoanode

    Energy Technology Data Exchange (ETDEWEB)

    Kushwaha, Suman; Bahadur, Lal, E-mail: lbahadur@bhu.ac.in

    2015-05-15

    A single dye usually absorbs light only in a limited range of solar spectrum. In order to widen the absorption range, a combination of dyes, namely, Phloxine B and Bromophenol blue have been used as sensitizers in ZnO based dye sensitized solar cell (DSSC). It has been found that the DSSC sensitized by mixed dyes exhibited better photovoltaic performance than those observed with the DSSCs using test dyes individually. It has been ascribed to the enhanced absorption of light particularly in higher energy region (λ=400–550 nm) when both dyes were used together as was evident from the absorption spectra of dyes adsorbed onto ZnO electrode. The DSSC using ZnO electrode sensitized by mixed dyes provided J{sub SC}=5.6 mA cm{sup −2}, V{sub OC}=0.606 V, FF=0.53 and maximum energy conversion efficiency (η) of 1.35% on illuminating the cell with visible light of 150 mW cm{sup −2} intensity. - Highlights: • Phloxine B and Bromophenol blue have been used as sensitizers in ZnO based DSSC. • DSSC sensitized by mixed dyes exhibited better photovoltaic performance than those observed with the DSSCs using test dyes individually. • Enhanced absorption of light particularly in higher energy region (λ=400–550 nm) have been observed when both dyes were used together. • The DSSC using ZnO electrode sensitized by mixed dyes provided J{sub sc}=5.6 mA cm{sup −2}, V{sub oc}=0.606 V, FF=0.53. • Efficiency of 1.35% is achieved at visible light intensity of 150 mW cm{sup −2}.

  13. Photochemical solar cells based on dye-sensitization of nanocrystalline TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Deb, S.K.; Ellingson, R.; Ferrere, S.; Frank, A.J.; Gregg, B.A.; Nozik, A.J.; Park, N.; Schlichthoerl, G. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    A photoelectrochemical solar cell that is based on the dye-sensitization of thin nanocrystalline films of TiO{sub 2} (anatase) nanoparticles in contact with a non-aqueous liquid electrolyte is described. The cell, fabricated at NREL, shows a conversion efficiency of {approximately} 9.2% at AM1.5, which approaches the best reported value of 10--11% by Graetzel at EPFL in Lausanne, Switzerland. The femtosecond (fs) pump-probe spectroscopy has been used to time resolve the injection of electrons into the conduction band of nanocrystalline TiO{sub 2} films under ambient conditions following photoexcitation of the adsorbed Ru(II)-complex dye. The measurement indicates an instrument-limited {minus}50 fs upper limit on the electron injection time. The authors also report the sensitization of nanocrystalline TiO{sub 2} by a novel iron-based dye, CIS-[Fe{sup II}(2,2{prime}-bipyridine-4,4,{prime}-dicarboxylic acid){sub 2}(CN){sub 2}], a chromophore with an extremely short-lived, nonemissive excited state. The dye also exhibits a unique band selective sensitization through one of its two absorption bands. The operational principle of the device has been studied through the measurement of electric field distribution within the device structure and studies on the pH dependence of dye-redox potential. The incorporation of WO{sub 3}-based electrochromic layer into this device has led to a novel photoelectrochromic device structure for smart window application.

  14. Isolasi Dye Organik Alam dan Karakterisasinya Sebagai Sensitizer

    Directory of Open Access Journals (Sweden)

    Nurussaniah Nurussaniah

    2018-03-01

    Full Text Available Tujuan penelitian ini adalah untuk mengetahui cara mengisolasi dan karakteristik dye organik alam sebagai sensitizer. Penelitian ini dilakukan melalui beberapa tahap yaitu persiapan, isolasi dye organik alam, karakterisasi sifat optik, analisis dan menyimpulkan. Isolasi dye organic alam dilakukan untuk memperoleh sari dari bahan-bahan alam. Penelitian ini menggunakan bahan alam yaitu jagung (Zea mays dan labu kuning (Cucurbita moschata. Karakterisasi optik dye organik alam dalam penelitian ini dilihat dari spektrum absorbansi yang diukur menggunakan Spektrophotometer Uv-Vis. Spektrum absorbansi dye diukur dalam kuvet optik, pada panjang gelombang 350-800 . Hasil penelitian menunjukkan bahwa isolasi dye organik alam diperoleh melalui metode ekstraksi, yaitu suatu metode untuk memperoleh sari dari bahan-bahan alam. Proses ekstraksi dilakukan dengan melarutkan biji jagung (Zea mays dan daging buah labu kuning (Cucurbita moschata dalam pelarut etanol dengan konsentrasi 1:5. Karaktistik optik jagung (Zea mays dan labu kuning (Cucurbita moschata  menunjukkan panjang gelombang yaitu berada pada cahaya tampak dengan rentang panjang gelombang 350 – 500 nm.  Dengan demikian  dye  beta-karoten yang berasal dari jagung (Zea mays dan labu kuning (Cucurbita moschata dapat dimanfaatkan sebagai sensitizer dalam prototipe Dye Sensitized Solar Cell (DSSC.

  15. Modeling the efficiency of Förster resonant energy transfer from energy relay dyes in dye-sensitized solar cells

    KAUST Repository

    Hoke, Eric T.

    2010-02-11

    Förster resonant energy transfer can improve the spectral breadth, absorption and energy conversion efficiency of dye sensitized solar cells. In this design, unattached relay dyes absorb the high energy photons and transfer the excitation to sensitizing dye molecules by Förster resonant energy transfer. We use an analytic theory to calculate the excitation transfer efficiency from the relay dye to the sensitizing dye accounting for dynamic quenching and relay dye diffusion. We present calculations for pores of cylindrical and spherical geometry and examine the effects of the Förster radius, the pore size, sensitizing dye surface concentration, collisional quenching rate, and relay dye lifetime. We find that the excitation transfer efficiency can easily exceed 90% for appropriately chosen dyes and propose two different strategies for selecting dyes to achieve record power conversion efficiencies. © 2010 Optical Society of America.

  16. Effects of Taiwan Roselle anthocyanin treatment and single-walled carbon nanotube addition on the performance of dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Chou, C S; Huang, Y H; Chen, Y S; Tsai, P J; Wu, P; Shu, G G

    2014-01-01

    This study investigates the relationship between the performance of a dye-sensitized solar cell (DSSC) sensitized by a natural sensitizer of Taiwan Roselle anthocyanin (TRA) and fabrication process conditions of the DSSC. A set of systematic experiments has been carried out at various soaking temperatures, soaking periods, sensitizer concentrations, pH values, and additions of single-walled carbon nanotube (SWCNT). An absorption peak (520 nm) is found for TRA, and it is close to that of the N719 dye (518 nm). At a fixed concentration of TRA and a fixed soaking period, a lower pH of the extract or a lower soaking temperature is found favorable to the formation of pigment cations, which leads to an enhanced power conversion efficiency (η) of DSSC. For instance, by applying 17.53 mg/100ml TRA at 30 for 10 h, as the pH of the extract decreases to 2.00 from 2.33 (the original pH of TRA), the η of DSSC with TiO 2 +SWCNT electrode increases to 0.67% from 0.11% of a traditional DSSC with TiO 2 electrode. This performance improvement can be explained by the combined effect of the pH of sensitizer and the additions of SWCNT, a first investigation in DSSC using the natural sensitizer with SWCNT.

  17. Effects of Taiwan Roselle anthocyanin treatment and single-walled carbon nanotube addition on the performance of dye-sensitized solar cells

    Science.gov (United States)

    Chou, C. S.; Tsai, P. J.; Wu, P.; Shu, G. G.; Huang, Y. H.; Chen, Y. S.

    2014-04-01

    This study investigates the relationship between the performance of a dye-sensitized solar cell (DSSC) sensitized by a natural sensitizer of Taiwan Roselle anthocyanin (TRA) and fabrication process conditions of the DSSC. A set of systematic experiments has been carried out at various soaking temperatures, soaking periods, sensitizer concentrations, pH values, and additions of single-walled carbon nanotube (SWCNT). An absorption peak (520 nm) is found for TRA, and it is close to that of the N719 dye (518 nm). At a fixed concentration of TRA and a fixed soaking period, a lower pH of the extract or a lower soaking temperature is found favorable to the formation of pigment cations, which leads to an enhanced power conversion efficiency (η) of DSSC. For instance, by applying 17.53 mg/100ml TRA at 30 for 10 h, as the pH of the extract decreases to 2.00 from 2.33 (the original pH of TRA), the η of DSSC with TiO2+SWCNT electrode increases to 0.67% from 0.11% of a traditional DSSC with TiO2 electrode. This performance improvement can be explained by the combined effect of the pH of sensitizer and the additions of SWCNT, a first investigation in DSSC using the natural sensitizer with SWCNT.

  18. Characteristics of dye Rhoeo spathacea in dye sensitizer solar cell (DSSC)

    Science.gov (United States)

    Sumardiasih, Sri; Obina, Wilfrida M.; Cari; Supriyanto, Agus; Septiawan, Trio Y.; Khairuddin

    2017-01-01

    Dye-sensitized solar cell (DSSC) is a device that converts solar energy into electrical energy. The magnitude of the efficiency of DSSC is mainly based on the amount of dye absorbed by the surface of TiO2. In this work, used natural dye extracted from leaves Rhoeo spathacea. The dye partially used to immerse of TiO2 as working electrodes, and the rest are directly mixed TiO2 paste to obtain dye titanium dioxide.The paste TiO2 and dye titanium dioxide coated onto the fluorine-doped tin oxide (FTO) glass plate by spin coating method. The absorbance spectra of the dye, dye titanium dioxide and TiO2 were obtained by UV-Vis spectroscopy. The conductivity of the dye, dye titanium dioxide, and TiO2 was measured by two point probe El-Kahfi 100. The DSSC based on dye titanium dioxide that stirring for 5 hours the highest efficiency of 0,0520 % whereas those based on TiO2 immersed for 36 hours showed achieved 0,0501 % obtained from I-V characterization.

  19. Characteristics of dye Rhoeo spathacea in dye sensitizer solar cell (DSSC)

    International Nuclear Information System (INIS)

    Sumardiasih, Sri; Obina, Wilfrida M.; Cari; Supriyanto, Agus; Septiawan, Trio Y.; Khairuddin

    2017-01-01

    Dye-sensitized solar cell (DSSC) is a device that converts solar energy into electrical energy. The magnitude of the efficiency of DSSC is mainly based on the amount of dye absorbed by the surface of TiO 2 . In this work, used natural dye extracted from leaves Rhoeo spathacea. The dye partially used to immerse of TiO 2 as working electrodes, and the rest are directly mixed TiO 2 paste to obtain dye titanium dioxide.The paste TiO 2 and dye titanium dioxide coated onto the fluorine-doped tin oxide (FTO) glass plate by spin coating method. The absorbance spectra of the dye, dye titanium dioxide and TiO 2 were obtained by UV-Vis spectroscopy. The conductivity of the dye, dye titanium dioxide, and TiO 2 was measured by two point probe El-Kahfi 100. The DSSC based on dye titanium dioxide that stirring for 5 hours the highest efficiency of 0,0520 % whereas those based on TiO 2 immersed for 36 hours showed achieved 0,0501 % obtained from I-V characterization. (paper)

  20. Performance variation from triphenylamine- to carbazole-triphenylamine-rhodaniline-3-acetic acid dyes in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chien-Hsin, E-mail: yangch@nuk.edu.tw [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan (China); Lin, Wen-Churng [Department of Environmental Engineering, Kun Shan University, Tainan 710, Taiwan (China); Wang, Tzong-Liu; Shieh, Yeong-Tarng; Chen, Wen-Janq; Liao, Shao-Hong; Sun, Yu-Kuang [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)

    2011-10-17

    Highlights: {yields} We synthesized an organic dye of carbazole-rhodaniline-3-acetic acid-triphenylamine. {yields} A dye-sensitized solar cell is fabricated using this dye with efficiency of 4.64%. {yields} Carbazole donor in the dye molecule provides electron in increasing efficiency. {yields} Two rhodaniline-3-acetic acids play a key role in increasing efficiency. {yields} AC impedance proves this dye's effect on enhancing charge transfer in TiO{sub 2}. - Abstract: Organic dyes have been synthesized which contain an extra-electron donor (carbazole) and electron acceptors (rhodaniline-3-acetic acid) on triphenylamines (TPA). Photophysical, electrochemical, and theoretical computational methods have categorized these compounds. Nanocrystalline TiO{sub 2}-based dye-sensitized solar cells (DSSCs) are fabricated using these dye molecules as light-harvesting sensitizers. The overall efficiency of sensitized cells has 4.64% relative to a cis-di(thiocyanato)-bis(2,2'-bipyridyl)-4,4'-dicarboxylate ruthenium (II) (N3 dye)-sensitized device (7.83%) fabricated and measured under the same conditions. Carbazole-electron donation in the dye molecules plays a key role in the increased efficiency. Two rhodaniline-3-acetic acid groups appear to help convey the charge transfer from the excited dye molecules to the conduction band of TiO{sub 2}, leading to a higher efficiency of devices using such a dye. Electrochemical impedance supports this dye's effect on enhancing charge transfer in TiO{sub 2} (e{sup -}). Computations on this dye compound also indicate the larger charge transfer efficiency in the electronically excited state.

  1. Photoelectrode nanostructure dye-sensitized solar cell | Kimpa ...

    African Journals Online (AJOL)

    This study used carica papaya (pawpaw leaf) extracts as natural organic dye for dye sensitized solar cell (DSSC). Pawpaw leaf extract is rich in chlorophyll and was extracted using ethanol as the extracting solvent and serve as the sensitizer for DSSC. The specialty of the DSSC relative to other types of solar cells is the use ...

  2. Enhanced Photovoltaic Performances of Dye-Sensitized Solar Cells by Co-Sensitization of Benzothiadiazole and Squaraine-Based Dyes.

    Science.gov (United States)

    Islam, Ashraful; Akhtaruzzaman, Md; Chowdhury, Towhid H; Qin, Chuanjiang; Han, Liyuan; Bedja, Idriss M; Stalder, Romain; Schanze, Kirk S; Reynolds, John R

    2016-02-01

    Dye-sensitized solar cells (DSSCs) based on a donor-acceptor-donor oligothienylene dye containing benzothiadiazole (T4BTD-A) were cosensitized with dyes containing cis-configured squaraine rings (HSQ3 and HSQ4). The cosensitized dyes showed incident monochromatic photon-to-current conversion efficiency (IPCE) greater than 70% in the 300-850 nm wavelength region. The individual overall conversion efficiencies of the sensitizers T4BTD-A, HSQ3, and HSQ4 were 6.4%, 4.8%, and 5.8%, respectively. Improved power conversion efficiencies of 7.0% and 7.7% were observed when T4BTD-A was cosensitized with HSQ3 and HSQ4, respectively, thanks to a significant increase in current density (JSC) for the cosensitized DSSCs. Intensity-modulated photovoltage spectroscopy results showed a longer lifetime for cosensitized T4BTD-A+HSQ3 and T4BTD-A+HSQ4 compared to that of HSQ3 and HSQ4, respectively.

  3. Triphenylamine based organic dyes for dye sensitized solar cells: A theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Mohankumar, V.; Pandian, Muthu Senthil; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [SSN Research Centre, SSN College of Engineering, Chennai-603110, Tamilnadu (India)

    2016-05-23

    The geometry, electronic structure and absorption spectra for newly designed triphenylamine based organic dyes were investigated by density functional theory (DFT) and time dependent density functional theory (TD-DFT) with the Becke 3-Parameter-Lee-Yang-parr(B3LYP) functional, where the 6-31G(d,p) basis set was employed. All calculations were performed using the Gaussian 09 software package. The calculated HOMO and LUMO energies show that charge transfer occurs in the molecule. Ultraviolet–visible (UV–vis) spectrum was simulated by TD-DFT in gas phase. The calculation shows that all of the dyes can potentially be good sensitizers for DSSC. The LUMOs are just above the conduction band of TiO{sub 2} and their HOMOs are under the reduction potential energy of the electrolytes (I{sup −}/I{sub 3}{sup −}) which can facilitate electron transfer from the excited dye to TiO{sub 2} and charge regeneration process after photo oxidation respectively. The simulated absorption spectrum of dyes match with solar spectrum. Frontier molecular orbital results show that among all the three dyes, the “dye 3” can be used as potential sensitizer for DSSC.

  4. Comparative sensitizing potencies of fragrances, preservatives, and hair dyes

    DEFF Research Database (Denmark)

    Lidén, Carola; Yazar, Kerem; Johansen, Jeanne Duus

    2016-01-01

    the sensitizing potencies of fragrance substances, preservatives, and hair dye substances, which are skin sensitizers that frequently come into contact with the skin of consumers and workers, LLNA results and EC3 values for 72 fragrance substances, 25 preservatives and 107 hair dye substances were obtained from...... two published compilations of LLNA data and opinions by the Scientific Committee on Consumer Safety and its predecessors. The median EC3 values of fragrances (n = 61), preservatives (n = 19) and hair dyes (n = 59) were 5.9%, 0.9%, and 1.3%, respectively. The majority of sensitizing preservatives...... and hair dyes are thus strong or extreme sensitizers (EC3 value of ≤2%), and fragrances are mostly moderate sensitizers. Although fragrances are typically moderate sensitizers, they are among the most frequent causes of contact allergy. This indicates that factors other than potency need to be addressed...

  5. Dye-sensitized solar cells: a successful combination of materials

    Directory of Open Access Journals (Sweden)

    Longo Claudia

    2003-01-01

    Full Text Available Dye-sensitized TiO2 solar cells, DSSC, are a promising alternative for the development of a new generation of photovoltaic devices. DSSC are a successful combination of materials, consisting of a transparent electrode coated with a dye-sensitized mesoporous film of nanocrystalline particles of TiO2, an electrolyte containing a suitable redox-couple and a Pt coated counter-electrode. In general, Ru bipyridyl complexes are used as the dye sensitizers. The light-to-energy conversion performance of the cell depends on the relative energy levels of the semiconductor and dye and on the kinetics of the electron-transfer processes at the sensitized semiconductor | electrolyte interface. The rate of these processes depends on the properties of its components. This contribution presents a discussion on the influence of each of the materials which constitute the DSSC of the overall process for energy conversion. An overview of the results obtained for solid-state dye-sensitized TiO2 solar cells assembled with polymer electrolytes is also presented.

  6. Effect of Mixing Dyes and Solvent in Electrolyte Toward Characterization of Dye Sensitized Solar Cell Using Natural Dyes as The Sensitizer

    Science.gov (United States)

    Puspitasari, Nurrisma; Nurul Amalia, Silviyanti S.; Yudoyono, Gatut; Endarko

    2017-07-01

    Dye Sensitized Solar Cell (DSSC) using natural dyes (chlorophyll, curcumin from turmeric extract, and anthocyanin from mangosteen extract) have been successfully fabricated for determining the effect of variation natural dyes, mixing dyes and acetonitrile in electrolyte toward characterization of DSSC. DSSC consists of five parts namely ITO (Indium Tin Oxide) as a substrate; TiO2 as semiconductor materials; natural dyes as an electron donor; electrolyte as electron transfer; and carbon as a catalyst that can convert light energy into electric energy. Two types of gel electrolyte based on PEG that mixed with liquid electrolyte have utilized for analyzing the lifetime of DSSC. Type I used distilled water as a solvent whilst type II used acetonitrile as a solvent with addition of concentration of KI and iodine. The main purpose of study was to investigate influence of solvent in electrolyte, variation of natural dyes and mixing dyes toward an efficiency that resulted by DSSC. The result showed that electrolyte type II is generally better than type I with efficiency 0,0556 and 0,0456 %, respectively. An efficiency values which resulted from a variation of mixed three natural dyes showed the greatest efficiency compared to mixed two natural dyes and one dye, with an efficiency value can be achieved at 0,0194 % for chlorophyll; 0,111 % for turmeric; 0,0105 % for mangosteen; 0,0244% (mangosteen and chlorophyll); 0,0117 % (turmeric and mangosteen); 0,0158 % (turmeric and chlorophyll); and 0.0566 % (mixed three natural dyes).

  7. Dye sensitization of antimony-doped CdS photoelectrochemical solar cell

    Energy Technology Data Exchange (ETDEWEB)

    El Zayat, M.Y.; Saed, A.O.; El-Dessouki, M.S. [Department of Physics, Faculty of Science, Cairo University, Giza (Egypt)

    2002-01-31

    Sb-doped CdS single crystal was used as a photoanode to fabricate a photoelectrochemical solar (PECS) cell. The three organic dyes; eosin, thymol blue and rhodamin 6G were used as sensitizers in (PECS) cell. In the absence of the dye, the results showed that with Sb-doped CdS single crystal electrode, a higher power conversion efficiency 9.27% has been achieved compared to 5.7-7.4% for pure crystal. Application of the dye in PECS cell increases the efficiency to about 13%. The efficiency reaches its maximum value when the dye concentration is (2.5x10{sup -5})M, sufficient to cover the surface of the semiconductor electrode with a continuous monolayer of the dye. Exceeding this value resulted in a gradual decrease of the efficiency from its maximum value. Mott-Schottky plots gave a doping density of 3.14x10{sup 17}cm{sup -3} and a space charge width of 4.95x10{sup -6}cm for the sample used. A flat-band potential equal to -0.84V, independent of both frequency and pH, was also predicted. Cyclic voltammetry (c.v.) measurements showed an anodic current peak at 0.4V vs. SCE. The disappearance of this peak after excess addition of the reducing agent Na{sub 2}S, indicates that this peak is due to the PEC corrosion of the semiconductor electrode.

  8. Dye Sensitizers for Photodynamic Therapy

    Directory of Open Access Journals (Sweden)

    Harold S. Freeman

    2013-03-01

    Full Text Available Photofrin® was first approved in the 1990s as a sensitizer for use in treating cancer via photodynamic therapy (PDT. Since then a wide variety of dye sensitizers have been developed and a few have been approved for PDT treatment of skin and organ cancers and skin diseases such as acne vulgaris. Porphyrinoid derivatives and precursors have been the most successful in producing requisite singlet oxygen, with Photofrin® still remaining the most efficient sensitizer (quantum yield = 0.89 and having broad food and drug administration (FDA approval for treatment of multiple cancer types. Other porphyrinoid compounds that have received approval from US FDA and regulatory authorities in other countries include benzoporphyrin derivative monoacid ring A (BPD-MA, meta-tetra(hydroxyphenylchlorin (m-THPC, N-aspartyl chlorin e6 (NPe6, and precursors to endogenous protoporphyrin IX (PpIX: 1,5-aminolevulinic acid (ALA, methyl aminolevulinate (MAL, hexaminolevulinate (HAL. Although no non-porphyrin sensitizer has been approved for PDT applications, a small number of anthraquinone, phenothiazine, xanthene, cyanine, and curcuminoid sensitizers are under consideration and some are being evaluated in clinical trials. This review focuses on the nature of PDT, dye sensitizers that have been approved for use in PDT, and compounds that have entered or completed clinical trials as PDT sensitizers.

  9. Interplay between transparency and efficiency in dye sensitized solar cells.

    Science.gov (United States)

    Tagliaferro, Roberto; Colonna, Daniele; Brown, Thomas M; Reale, Andrea; Di Carlo, Aldo

    2013-02-11

    In this paper we analyze the interplay between transparency and efficiency in dye sensitized solar cells by varying fabrication parameters such as the thickness of the nano-crystalline TiO(2) layer, the dye loading and the dye type. Both transparency and efficiency show a saturation trend when plotted versus dye loading. By introducing the transparency-efficiency plot, we show that the relation between transparency and efficiency is linear and is almost independent on the TiO(2) thickness for a certain thickness range. On the contrary, the relation between transparency and efficiency depends strongly on the type of the dye. Moreover, we show that co-sensitization techniques can be effectively used to access regions of the transparency-efficiency space that are forbidden for single dye sensitization. The relation found between transparency and efficiency (T&E) can be the general guide for optimization of Dye Solar Cells in building integration applications.

  10. Novel organic dyes based on phenyl-substituted benzimidazole for dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Saltan, Gözde Murat [Department of Chemistry, Faculty of Arts and Science, Celal Bayar University, Yunus Emre, 45140 Manisa (Turkey); Dinçalp, Haluk, E-mail: haluk.dincalp@cbu.edu.tr [Department of Chemistry, Faculty of Arts and Science, Celal Bayar University, Yunus Emre, 45140 Manisa (Turkey); Kıran, Merve; Zafer, Ceylan [Solar Energy Institute, Ege University, Bornova, 35100 Izmir (Turkey); Erbaş, Seçil Çelik [Celal Bayar University, Materials Engineering Department, Faculty of Engineering, Yunus Emre, 45140 Manisa (Turkey)

    2015-08-01

    Two new sensitizers derived from benzimidazole core for dye-sensitized solar cell (DSSC) applications were designed and synthesized as D–π–A structures, in which two phenyl-substituted benzimidazole group, a phenyl ring and a cyanoacrylic acid were used as the electron donor, π-conjugated linkage and the electron acceptor, respectively. Effect of methoxy- and N,N-dimetylamino- moieties attached to the phenyl groups of benzimidazole were investigated by means of optical and photovoltaic measurements. The compounds exhibit broad absorption maximum at 387 nm with the tail extending up to 500 nm on TiO{sub 2}-coated thin film. The longer wavelength absorption band around 360 nm and the much longer decay components could be attributed to the existence of charge transfer state of the dyes in solutions. DSSC device fabricated by using methoxy substituted dye (BI5a) as a sensitizer shows much better incident photon-to-current conversion efficiency (IPCE) of 64% giving cell efficiency of 2.68%. - Graphical abstract: Display Omitted - Highlights: • Long decay times suggest the delayed fluorescence caused by the existence of ICT. • The best solar energy conversion efficiency was obtained for BI5a dye (2.68%). • More fluorescent BI5a dye gives higher photocurrent generation.

  11. Novel organic dyes based on phenyl-substituted benzimidazole for dye sensitized solar cells

    International Nuclear Information System (INIS)

    Saltan, Gözde Murat; Dinçalp, Haluk; Kıran, Merve; Zafer, Ceylan; Erbaş, Seçil Çelik

    2015-01-01

    Two new sensitizers derived from benzimidazole core for dye-sensitized solar cell (DSSC) applications were designed and synthesized as D–π–A structures, in which two phenyl-substituted benzimidazole group, a phenyl ring and a cyanoacrylic acid were used as the electron donor, π-conjugated linkage and the electron acceptor, respectively. Effect of methoxy- and N,N-dimetylamino- moieties attached to the phenyl groups of benzimidazole were investigated by means of optical and photovoltaic measurements. The compounds exhibit broad absorption maximum at 387 nm with the tail extending up to 500 nm on TiO 2 -coated thin film. The longer wavelength absorption band around 360 nm and the much longer decay components could be attributed to the existence of charge transfer state of the dyes in solutions. DSSC device fabricated by using methoxy substituted dye (BI5a) as a sensitizer shows much better incident photon-to-current conversion efficiency (IPCE) of 64% giving cell efficiency of 2.68%. - Graphical abstract: Display Omitted - Highlights: • Long decay times suggest the delayed fluorescence caused by the existence of ICT. • The best solar energy conversion efficiency was obtained for BI5a dye (2.68%). • More fluorescent BI5a dye gives higher photocurrent generation

  12. Assessment of the dye-sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, R. D. [Center for Basic Sciences, National Renewable Energy Laboratory, MIS 3211, 1617 Cole Boulevard, Golden, CO 80401 (United States)

    2002-09-01

    The field of solar electricity, or photovoltaics (PV), is rich in that there are many materials and concepts for converting sunlight into electricity. The technologies accepted as conventional are those well along in the process of commercialization. The dye-sensitized solar cell, developed in the 1990s, is a nonconventional solar electric technology that has attracted much attention, perhaps a result of its record cell efficiency above 10%. This paper reviews the technology, discusses new research results and approaches presented at a recent symposium of many of the world's important dye solar cell researchers, and presents an assessment of the dye-sensitized solar cell in a comparison with current conventional solar electric technologies. It concludes the dye solar cell has potential for becoming a cost-effective means for producing electricity, capable of competing with available solar electric technologies and, eventually, with today's conventional power technologies. But it is a relatively new technology and faces many hurdles on the path to commercialization. Because of its potential, this assessment recommends further funding for research and development (RandD) of the dye-sensitized solar cell technology on the basis of the promising technical characteristics of the technology, a strong US and worldwide research base, positive industry interest, and today's relatively small funding allocation for its RandD. (Author)

  13. Role of energy level alignment in solar cells sensitized with a metal-free organic dye: A combined experimental and theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Oprea, Corneliu I.; Lungu, Jeanina; Georgescu, Adrian; Moscalu, Florin; Oprea, Camelia; Girtu, Mihai A. [Department of Physics, Ovidius University of Constanta (Romania); Dumbrava, Anca [Department of Chemistry, Ovidius University of Constanta (Romania); Enache, Irina [Department of Chemistry, Ovidius University of Constanta (Romania); Department of Mathematics and Sciences, Constanta Maritime University (Romania)

    2011-10-15

    We report results of combined experimental and theoretical studies of dye-sensitized solar cells (DSSCs) using 5-(4-sulfophenylazo)salicylic acid disodium salt, known as Mordant Yellow 10 (MY-10), as TiO{sub 2} sensitizer. We focus on a single dye but vary the solvent and the pH of the solution as well as the photoelectrode preparation conditions to determine the conditions for best photovoltaic conversion efficiency. We found experimentally that the efficiency, measured under standard air mass 1.5 global (AM 1.5G) conditions, was higher in solutions of ethanol than of water, but still small (up to 0.174%), although the fill factor (FF) was large (up to 0.73). Of the dyes in ethanol, MY-10 in alkaline solution showed the best matching of the solar spectrum but displayed the lowest efficiency. Density functional theory (DFT) calculations provided the optimized geometry, electronic structure, and electronic spectrum of the dye in fully protonated as well as partially and totally deprotonated forms, in solution. The calculated optical spectra are consistent with the experimental data, with strong absorption in the visible range only for the alkaline dye solution. The low device efficiency is very likely related to the weak optical absorption in the visible range. The much higher photovoltaic conversion efficiency of the DSSCs fabricated using acid or roughly neutral pH solutions, corresponding to the protonated and partially deprotonated forms of MY-10, respectively, is likely caused by the better alignment of the ground state of the dye with the redox level of the electrolyte. The decrease with pH of the dye solution of the short-circuit current was linked to a weaker charge injection from the excited state of the dye to the conduction band of the oxide, which is correlated with the shifting of the excited state of the dye deeper into the CB edge of the semiconductor. The variation of the open-circuit voltage with the pH of the solution was linked to the adjustment

  14. Dye-Sensitized Approaches to Photovoltaics

    Science.gov (United States)

    Grätzel, Michael

    2008-03-01

    Sensitization of wide band-gap semiconductors to photons of energy less than the band-gap is a key step in two technically important processes - panchromatic photography and photoelectrochemical solar cells. In both cases the photosensitive species is not the semiconductor - silver halide or metal oxide - but rather an electrochemically active dye. The gap between the highest occupied molecular level (HOMO) and the lowest unoccupied molecular level (LUMO) is less than the band-gap of the semiconductor with which it is associated. It can therefore absorb light of a wavelength longer than that to which the semiconductor itself is sensitive. The electrochemical process is initiated when the dye molecule relaxes from its photoexcited level by electron injection into the semiconductor, which therefore acts as a photoanode. If the dye is in contact with a redox electrolyte, the negative charge represented by the lost electron can be recovered from the reduced state of the redox system, which in return is regenerated by charge transfer from a cathode. An external load completes the electrical circuit. The system therefore represents a conversion of the energy of absorbed photons into an electrical current by a regenerative device in every functional respect analogous to a solid-state photovoltaic cell. As in any engineering system, choice of materials, their optimization and their synergy are essential to efficient operation. While a semiconductor-electrolyte contact is analogous to a Schottky contact, in that a barrier is established between two materials of different conduction mechanism, with the possibility of optical absorption, charge carrier pair generation and separation, it should be remembered that the photogenerated valence band hole in the semiconductor represents a powerful oxidizing agent. Given that the band-gap is related to the strength and therefore the stability of chemical bonding within the semiconductor, for narrow-gap materials the most likely

  15. Panchromatic Response in Solid-State Dye-Sensitized Solar Cells Containing Phosphorescent Energy Relay Dyes

    KAUST Repository

    Yum, Jun-Ho

    2009-11-23

    Running relay: Incorporating an energyrelay dye (ERD) into the hole transporter of a dye-sensitized solar cell increased power-conversion efficiency by 29% by extending light harvesting into the blue region. In the operating mechanism (see picture), absorption of red photons by the sensitizer transfers an electron into TiO2 and a hole into the electrolyte. Blue photons absorbed by the ERD are transferred by FRET to the sensitizer. Chemical Equitation Presentation © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.

  16. Optical properties of anthocyanin dyes on TiO2 as photosensitizers for application of dye-sensitized solar cell (DSSC)

    Science.gov (United States)

    Ahliha, A. H.; Nurosyid, F.; Supriyanto, A.; Kusumaningsih, T.

    2018-03-01

    Dye-sensitized solar cell (DSSC) is one of the alternative energy that can convert light energy into electrical energy. The component of DSSC consists of FTO substrates, TiO2, electrolyte, dye sensitizer, and counter electrode. This study aim was to determine the effect of optical properties of anthocyanin dyes on efficiency of DSSC. The dye sensitizer used can be extracted from anthocyanin pigments such as dragon fruit, black rice, and red cabbage. The red cabbage sensitizer shows lower absorbance value in the visible range (450-580 nm), than dragon fruit and black rice. The chemical structure of each dye molecules has an R group (carbonyl and hydroxyl) that forms a bond with the oxide layer. Red cabbage dye cell has the highest efficiency, 0.06% then dragon fruit and black rice, 0.02% and 0.03%.

  17. Molecular design of new hydrazone dyes for dye-sensitized solar cells: Synthesis, characterization and DFT study

    KAUST Repository

    Al-Sehemi, Abdullah G.

    2012-07-01

    Three new sensitizers 2-{4-[2-(4-Nitrobenzylidene)hydrazino)]phenyl} ethylene-1,1,2-tricarbonitrile (NBHPET), 2-{4-[2-p-Chlorobenzylidenehydrazino] phenyl}- ethylene-1,1,2-tri carbonitrile (CBHPET) and 2-{4-[2-p- Bromobenzylidenehydrazino] phenyl}ethylene-1,1,2-tricarbonitrile (BBHPET) have been synthesized. The dyes showed pronounced solvatochromic effects as the polarity of the solvents increased. The structures have been optimized at B3LYP/6-31G(d) level of theory. The torsion in E-isomer is smaller than Z-isomer and azo isomers. The highest occupied molecular orbitals are delocalized on whole molecule while lowest unoccupied molecular orbitals are distributed on the tricarbonitrile. The lowest unoccupied molecular orbital energies are above the conduction band of titanium dioxide, highest occupied molecular orbitals of the dyes are below the redox couple of new synthesized dyes and small energy gap revealed these dyes would be better sensitizers for dye-sensitized solar cells. © 2012 Elsevier B.V. All rights reserved.

  18. Theoretical study on the application of double-donor branched organic dyes in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yan-Hong; Liu, Rui-Rui [Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory of Eco-environment-related Polymer Materials, Ministry of Education, Northwest Normal University, Lanzhou, 730070, Gansu (China); Zhu, Kai-Li [College of Chemistry and Life Science, Gansu Normal University for Nationalities, Hezuo, 747000, Gansu (China); Song, Yan-Lin [Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory of Eco-environment-related Polymer Materials, Ministry of Education, Northwest Normal University, Lanzhou, 730070, Gansu (China); Geng, Zhi-Yuan, E-mail: zhiyuangeng@126.com [Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory of Eco-environment-related Polymer Materials, Ministry of Education, Northwest Normal University, Lanzhou, 730070, Gansu (China)

    2016-09-15

    A novel organic dye with 2D-A structure has been designed and calculated whereby density functional theory (DFT) and time-dependent density functional theory (TD-DFT) for dye-sensitized solar cells. The double-donor branched dye which was consisted of two separated light-harvesting moieties was beneficial to photocurrent generation. First, we discussed the effects of different donor chains on photoelectric performance in the dye molecule, using the DTP-B8 which was a previously reported structure as the reference. Only to conclude that the suitable length can achieve the satisfactory efficiency. Secondly, to modify and sift potential sensitizers further, three series of dyes (BC-series, CB-series and CC-series) were designed and characterized. The increased molar extinction coefficient and the red-shifted λ{sub max} was attributed to an increasing in electron conjunction. This work presented a new route to design sensitizers that provide two channels for donating more electrons and improve the final efficiency. It is expected to provide some theoretical guidance on designing and synthetizing high efficiency photosensitive dye in the future experiments. - Highlights: • A novel organic dye with 2D-A structure was designed and characterized. • The double-donor branched dye was consisted of two separated light-harvesting paths. • The double-donor branched dye was beneficial to photocurrent generation. • The molar extinction coefficient was greatly improved in this novel structure. • Four promising candidates have been screened out.

  19. Panchromatic Response in Solid-State Dye-Sensitized Solar Cells Containing Phosphorescent Energy Relay Dyes

    KAUST Repository

    Yum, Jun-Ho; Hardin, Brianâ E.; Moon, Soo-Jin; Baranoff, Etienne; Nà ¼ esch, Frank; McGehee, Michaelâ D.; Grà ¤ tzel, Michael; Nazeeruddin, Mohammadâ K.

    2009-01-01

    Running relay: Incorporating an energyrelay dye (ERD) into the hole transporter of a dye-sensitized solar cell increased power-conversion efficiency by 29% by extending light harvesting into the blue region. In the operating mechanism (see picture

  20. Ruthenium Sensitizers and Their Applications in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Yuancheng Qin

    2012-01-01

    Full Text Available Dye-sensitized solar cells (DSSCs have attracted considerable attention in recent years due to the possibility of low-cost conversion of photovoltaic energy. The DSSCs-based ruthenium complexes as sensitizers show high efficiency and excellent stability, implying potential practical applications. This review focuses on recent advances in design and preparation of efficient ruthenium sensitizers and their applications in DSSCs, including thiocyanate ruthenium sensitizers and thiocyanate-free ruthenium sensitizers.

  1. Influence of Dye Adsorbtion Time on TiO2 Dye-Sensitized Solar Cell with Krokot Extract (Portulaca Oleracea. L as A Natural Sensitizer

    Directory of Open Access Journals (Sweden)

    Didik Krisdiyanto

    2015-03-01

    Full Text Available Dye sensitized solar cells (DSSC photoelectrodes were fabricated using titanium oxide (TiO2 and sensitized with the krokot extract dye. This study investigated the effect of dye adsorption time to an efficiency of the solar cells. The fabrication cells immersed with krokot extract dye for 1, 8 and 26 hours. The photochemical performance of the DSSC showed that the open circuit voltage (Voc were 0.33, 0.036 and 0.27 V with short photocurrent density (Isc 8.00 x 10-5, 6.80 x 10-7 and 3.10 x 10-4. The photo-to-electric conversion efficiency of the DSSC reached 4.63 x 10-3 % for 26 hours adsorption time.

  2. Extension lifetime for dye-sensitized solar cells through multiple dye adsorption/desorption process

    Science.gov (United States)

    Chiang, Yi-Fang; Chen, Ruei-Tang; Shen, Po-Shen; Chen, Peter; Guo, Tzung-Fang

    2013-03-01

    In this study, we propose a novel concept of extending the lifetime of dye-sensitized solar cells (DSCs) and reducing the costs of re-conditioning DSCs by recycling the FTO/TiO2 substrates. The photovoltaic performances of DSCs using substrates with various cycles of dye uptake and rinse off history are tested. The results show that dye adsorption and Voc are significantly increased under multiple dye adsorption/desorption process and resulted in the improvement of power conversion efficiency. Moreover, the dyeing kinetics is faster after multiple recycling processes, which is favorable for the industrial application. With surface analysis and charge transport characteristics, we also demonstrate the optimal functionality of TiO2/dye interface for the improved Voc and efficiency. The results confirm that the improved performances are due to increased dye loading and dense packing of dye molecules. Our results are beneficial for the understanding on the extension of DSCs lifetime after long-term operation in the application of DSC modules. This approach may also be applied in the replacement of newly synthesized photosensitizes to the active cells.

  3. DFT Studies on the electronic structures of indoline dyes for dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    JIE XU

    2010-02-01

    Full Text Available A series of indoline dyes with promising efficiency for dye-sensitized solar cells (DSSCs were studied using the density functional theory at the B3LYP/6-31g (d level. The ground-state geometries, electronic structures and absorption spectra of these dyes are reported. The calculated results indicate that the energy levels of the HOMOs and LUMOs of these dyes are advantageous for electron injection. Their intense and broad absorption bands as well as favorable excited-state energy levels are key factor for their outstanding efficiencies in DSSCs.

  4. First principles DFT study of dye-sensitized CdS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Kalpna; Singh, Kh. S. [Department of Physics, D. J. College, Baraut -250611, U.P. (India); Kishor, Shyam, E-mail: shyam387@gmail.com [Department of Chemistry, J. V. College, Baraut -250611, U.P. (India); Josefesson, Ida; Odelius, Michael [Fysikum, Albanova University Center, Stockholm University, S-106 91 Stockholm (Sweden); Ramaniah, Lavanya M. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2014-04-24

    Dye-sensitized quantum dots (QDs) are considered promising candidates for dye-sensitized solar cells. In order to maximize their efficiency, detailed theoretical studies are important. Here, we report a first principles density functional theory (DFT) investigation of experimentally realized dye - sensitized QD / ligand systems, viz., Cd{sub 16}S{sub 16}, capped with acetate molecules and a coumarin dye. The hybrid B3LYP functional and a 6−311+G(d,p)/LANL2dz basis set are used to study the geometric, energetic and electronic properties of these clusters. There is significant structural rearrangement in all the clusters studied - on the surface for the bare QD, and in the positions of the acetate / dye ligands for the ligated QDs. The density of states (DOS) of the bare QD shows states in the band gap, which disappear on surface passivation with the acetate molecules. Interestingly, in the dye-sensitised QD, the HOMO is found to be localized mainly on the dye molecule, while the LUMO is on the QD, as required for photo-induced electron injection from the dye to the QD.

  5. Role of Dyestuff in Improving Dye-Sensitized Solar Cell Performance

    Directory of Open Access Journals (Sweden)

    Yehia Selim

    2017-03-01

    Full Text Available Dye-sensitized solar cells DSSCs have attracted great attention for their simple fabrication process, low production costs, relatively high conversion efficiency, and being environmental friendly.DSSC are a combination of materials, consisting of a transparent electrode coated with a dye-sensitized mesoporous film of nanocrystalline particles of TiO2, an electrolyte containing a suitable redox-couple and a electrode.DSSCs use organic dye assist to produce electricity in a wide range of light conditions, indoors and outdoors.The dye in the solar cell is the key element since it is responsible for light harvesting ability, photoelectron generation (the creation of free charges after injection of electrons into the nanostructured semi-conducting oxide and electron transfer.For this reason, this paper gives a background of dyestuff, types and limitations. The motivation of this work is to design a simple, easy and prepare an efficient organic dye sensitizer.Also, this paper investigates the important criteria which are considered for selecting dye to enhance DSSC efficiency. 

  6. Dye Sensitized Solar Cell, DSSC

    Directory of Open Access Journals (Sweden)

    Pongsatorn Amornpitoksuk

    2003-07-01

    Full Text Available A dye sensitized solar cell is a new type of solar cell. The operating system of this solar cell type is similar to plant’s photosynthesis process. The sensitizer is available for absorption light and transfer electrons to nanocrystalline metal oxide semiconductor. The ruthenium(II complexes with polypyridyl ligands are usually used as the sensitizers in solar cell. At the present time, the complex of [Ru(2,2',2'’-(COOH3- terpy(NCS3] is the most efficient sensitizer. The total photon to current conversion efficiency was approximately 10% at AM = 1.5.

  7. A panchromatic anthracene-fused porphyrin sensitizer for dye-sensitized solar cells

    KAUST Repository

    Ball, James M.; Davis, Nicola K. S.; Wilkinson, James D.; Kirkpatrick, James; Teuscher, Joë l; Gunning, Robert; Anderson, Harry L.; Snaith, Henry J.

    2012-01-01

    The development of ruthenium-free sensitizers which absorb light over a broad range of the solar spectrum is important for improving the power conversion efficiency of dye-sensitized solar cells. Here we study three chemically tailored porphyrin

  8. Rhodanine dyes for dye-sensitized solar cells : spectroscopy, energy levels and photovoltaic performance.

    Science.gov (United States)

    Marinado, Tannia; Hagberg, Daniel P; Hedlund, Maria; Edvinsson, Tomas; Johansson, Erik M J; Boschloo, Gerrit; Rensmo, Håkan; Brinck, Tore; Sun, Licheng; Hagfeldt, Anders

    2009-01-07

    Three new sensitizers for photoelectrochemical solar cells were synthesized consisting of a triphenylamine donor, a rhodanine-3-acetic acid acceptor and a polyene connection. The conjugation length was systematically increased, which resulted in two effects: first, it led to a red-shift of the optical absorption of the dyes, resulting in an improved spectral overlap with the solar spectrum. Secondly, the oxidation potential decreased systematically. The excited state levels were, however, calculated to be nearly stationary. The experimental trends were in excellent agreement with density functional theory (DFT) computations. The photovoltaic performance of this set of dyes as sensitizers in mesoporous TiO2 solar cells was investigated using electrolytes containing the iodide/triiodide redox couple. The dye with the best absorption characteristics showed the poorest solar cell efficiency, due to losses by recombination of electrons in TiO2 with triiodide. Addition of 4-tert butylpyridine to the electrolyte led to a strongly reduced photocurrent for all dyes due to a reduced electron injection efficiency, caused by a 0.15 V negative shift of the TiO2 conduction band potential.

  9. Synthesis and characterization of organic dyes with various electron-accepting substituents for p-type dye-sensitized solar cells.

    Science.gov (United States)

    Weidelener, Martin; Powar, Satvasheel; Kast, Hannelore; Yu, Ze; Boix, Pablo P; Li, Chen; Müllen, Klaus; Geiger, Thomas; Kuster, Simon; Nüesch, Frank; Bach, Udo; Mishra, Amaresh; Bäuerle, Peter

    2014-11-01

    Four new donor-π-acceptor dyes differing in their acceptor group have been synthesized and employed as model systems to study the influence of the acceptor groups on the photophysical properties and in NiO-based p-type dye-sensitized solar cells. UV/Vis absorption spectra showed a broad range of absorption coverage with maxima between 331 and 653 nm. Redox potentials as well as HOMO and LUMO energies of the dyes were determined from cyclic voltammetry measurements and evaluated concerning their potential use as sensitizers in p-type dye-sensitized solar cells (p-DSCs). Quantum-chemical density functional theory calculations gave further insight into the frontier orbital distributions, which are relevant for the electronic processes in p-DSCs. In p-DSCs using an iodide/triiodide-based electrolyte, the polycyclic 9,10-dicyano-acenaphtho[1,2-b]quinoxaline (DCANQ) acceptor-containing dye gave the highest power conversion efficiency of 0.08%, which is comparable to that obtained with the perylenemonoimide (PMI)-containing dye. Interestingly, devices containing the DCANQ-based dye achieve a higher V(OC) of 163 mV compared to 158 mV for the PMI-containing dye. The result was further confirmed by impedance spectroscopic analysis showing higher recombination resistance and thus a lower recombination rate for devices containing the DCANQ dye than for PMI dye-based devices. However, the use of the strong electron-accepting tricyanofurane (TCF) group played a negative role in the device performance, yielding an efficiency of only 0.01% due to a low-lying LUMO energy level, thus resulting in an insufficient driving force for efficient dye regeneration. The results demonstrate that a careful molecular design with a proper choice of the acceptor unit is essential for development of sensitizers for p-DSCs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Recording membrane potential changes through photoacoustic voltage sensitive dye

    DEFF Research Database (Denmark)

    Zhang, Haichong K.; Kang, Jeeun; Yan, Ping

    2017-01-01

    Monitoring of the membrane potential is possible using voltage sensitive dyes (VSD), where fluorescence intensity changes in response to neuronal electrical activity. However, fluorescence imaging is limited by depth of penetration and high scattering losses, which leads to low sensitivity in vivo...... systems for external detection. In contrast, photoacoustic (PA) imaging, an emerging modality, is capable of deep tissue, noninvasive imaging by combining near infrared light excitation and ultrasound detection. In this work, we develop the theoretical concept whereby the voltage-dependent quenching...... the experimental PA intensity change depends on fluorescence and absorbance properties of the dye. These results not only demonstrate the voltage sensing capability of the dye, but also indicate the necessity of considering both fluorescence and absorbance spectral sensitivities in order to optimize...

  11. Artificial evolution of coumarin dyes for dye sensitized solar cells.

    Science.gov (United States)

    Venkatraman, Vishwesh; Abburu, Sailesh; Alsberg, Bjørn Kåre

    2015-11-07

    The design and discovery of novel molecular structures with optimal properties has been an ongoing effort for materials scientists. This field has in general been dominated by experiment driven trial-and-error approaches that are often expensive and time-consuming. Here, we investigate if a de novo computational design methodology can be applied to the design of coumarin-based dye sensitizers with improved properties for use in Grätzel solar cells. To address the issue of synthetic accessibility of the designed compounds, a fragment-based assembly is employed, wherein the combination of chemical motifs (derived from the existing databases of structures) is carried out with respect to user-adaptable set of rules. Rather than using computationally intensive density functional theory (DFT)/ab initio methods to screen candidate dyes, we employ quantitative structure-property relationship (QSPR) models (calibrated from empirical data) for rapid estimation of the property of interest, which in this case is the product of short circuit current (Jsc) and open circuit voltage (Voc). Since QSPR models have limited validity, pre-determined applicability domain criteria are used to prevent unacceptable extrapolation. DFT analysis of the top-ranked structures provides supporting evidence of their potential for dye sensitized solar cell applications.

  12. Trihydroxytrioxatriangulene - An Extended Fluorescein and a Ratiometric pH Sensor

    DEFF Research Database (Denmark)

    Westerlund, Fredrik; Hildebrandt, Christoffer Boli; Sørensen, Thomas Just

    2010-01-01

    Fluorescein ver. 2.0: A new, highly fluorescent, pH-sensitive trihydroxytrioxatriangulenium dye (H-TOTA) has been synthesised and characterised. The dye is closely related to fluorescein and may be considered to be a two-dimensional extended version. This new dye can exist in four different proto...... protonation states (see graphic) depending on the pH, and its use as a sensitive fluorescent ratiometric pH probe in a physiological buffer is demonstrated....

  13. Green grasses as light harvesters in dye sensitized solar cells

    Science.gov (United States)

    Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A.; Anandan, Sambandam; Murugan, Ramaswamy

    2015-01-01

    Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

  14. Biophotovoltaics: Natural pigments in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Hug, Hubert; Bader, Michael; Mair, Peter; Glatzel, Thilo

    2014-01-01

    Highlights: • Natural pigments are photosensitizers in dye-sensitized solar cells (DSSCs). • Efficiency is still lower compared to synthetic pigments. • The use of natural pigments such as carotenoids and polyphenols is cheap. • General advantages of DSSCs are flexibility, color and transparency. • Usage under diffuse light and therefore, indoor applications are possible. - Abstract: Dye-sensitized solar cells (DSSCs) which are also called Graetzel cells are a novel type of solar cells. Their advantages are mainly low cost production, low energy payback time, flexibility, performance also at diffuse light and multicolor options. DSSCs become more and more interesting since a huge variety of dyes including also natural dyes can be used as light harvesting elements which provide the charge carriers. A wide band gap semiconductor like TiO 2 is used for charge separation and transport. Such a DSSC contains similarities to the photosynthetic apparatus. Therefore, we summarize current available knowledge on natural dyes that have been used in DSSCs which should provide reasonable light harvesting efficiency, sustainability, low cost and easy waste management. Promising natural compounds are carotenoids, polyphenols and chlorophylls

  15. Green grasses as light harvesters in dye sensitized solar cells.

    Science.gov (United States)

    Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A; Anandan, Sambandam; Murugan, Ramaswamy

    2015-01-25

    Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a). Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Development of Natural Anthocyanin Dye-Doped Silica Nanoparticles for pH and Borate-Sensing Applications

    Science.gov (United States)

    Ha, Chu T.; Lien, Nghiem T. Ha; Anh, Nguyen D.; Lam, Nguyen L.

    2017-12-01

    Anthocyanin belongs to a large group of phenolic compounds called flavonoids. It is found primarily in fruits, flowers, roots and other parts of higher plants. Within the black carrot, it has been found that the cyanidin component 1,2 diol was the major anthocyanine. Since the terminal thiols potentially display chemical interactions with borate additives, anthocyanin from the black carrot can act as a sensing material for detecting borate in the environment. As a natural dye, anthocyanin responds to pH change of the medium. Here, we present an application of black carrot dyes for pH sensing and for the detection of borate additives within meats. The dyes were encapsulated within a mesoporous silica (SiO2) matrix in order to prevent the sensing materials from dissolution into the aqueous medium. The encapsulation was done in situ during preparation of silica nanoparticles (size from 100 nm to 500 nm) following an advanced Stöber method. These anthocyanin-encapsulated silica nanoparticles show a clear color change from green in an aqueous solution free of borate to GRAY-red in the presence of borate additive and red (pH 2) to green (pH 10).

  17. Ionic liquid electrolytes for dye-sensitized solar cells.

    Science.gov (United States)

    Gorlov, Mikhail; Kloo, Lars

    2008-05-28

    The potential of room-temperature molten salts (ionic liquids) as solvents for electrolytes for dye-sensitized solar cells has been investigated during the last decade. The non-volatility, good solvent properties and high electrochemical stability of ionic liquids make them attractive solvents in contrast to volatile organic solvents. Despite this, the relatively high viscosity of ionic liquids leads to mass-transport limitations. Here we review recent developments in the application of different ionic liquids as solvents or components of liquid and quasi-solid electrolytes for dye-sensitized solar cells.

  18. The application of sensitizers from red frangipani flowers and star gooseberry leaves in dye-sensitized solar cells

    Science.gov (United States)

    Almaz Dhafina, Wan; Salleh, Hasiah; Zalani Daud, Muhamad; Ali, Nora’aini

    2018-05-01

    Nowadays natural based dyes for dye-sensitized solar cells (DSSCs) have been in research field attention due to its advantages over other type of dyes such as low-cost, low-toxicity, completely biodegradable and abundance of resources. Natural dyes can be produced via the simple extraction method of pigments from plant parts such as flower, fruits, leaves, tuber etc. In this feature article, the natural dyes which composed of anthocyanin pigment from red frangipani flowers and chlorophyll from star gooseberry leaves were applied in zinc oxide, (ZnO) based-DSSC. The ZnO photoanode of the DSSCs sample were sensitized in each dye with different duration. It was observed that DSSCs which has chlorophyll pigment as dye had better performance with power conversion efficiency (PCE) of 0.007%.

  19. Treatment of dyeing wastewater including reactive dyes (Reactive ...

    African Journals Online (AJOL)

    Fungal growth was not observed at pH 2. Maximum fungal decolourisation ocurred at pH 3 for anionic reactive dyes (RR, RBB, RB) and pH 6 for cationic MB dye. The fungal dye bioremoval was associated with the surface charge of the fungus due to electrostatic interactions. Growing R. arrhizus strain decolourised 100% of ...

  20. Rose bengal-sensitized nanocrystalline ceria photoanode for dye ...

    Indian Academy of Sciences (India)

    The bandgap of 2.93 eV is calculated using UV–visible ... Keywords. Wide bandgap; dye-sensitized solar cells; CeO2; rose bengal dye. 1. ... and renewable energy, its high-cost production and installa- tion excludes direct commercial use. It is an urgent require- .... surface leads to oxygen vacancies and defects, whose influ-.

  1. Voltage-sensitive dye recording from networks of cultured neurons

    Science.gov (United States)

    Chien, Chi-Bin

    This thesis describes the development and testing of a sensitive apparatus for recording electrical activity from microcultures of rat superior cervical ganglion (SCG) neurons by using voltage-sensitive fluorescent dyes.The apparatus comprises a feedback-regulated mercury arc light source, an inverted epifluorescence microscope, a novel fiber-optic camera with discrete photodiode detectors, and low-noise preamplifiers. Using an NA 0.75 objective and illuminating at 10 W/cm2 with the 546 nm mercury line, a typical SCG neuron stained with the styryl dye RH423 gives a detected photocurrent of 1 nA; the light source and optical detectors are quiet enough that the shot noise in this photocurrent--about.03% rms--dominates. The design, theory, and performance of this dye-recording apparatus are discussed in detail.Styryl dyes such as RH423 typically give signals of 1%/100 mV on these cells; the signals are linear in membrane potential, but do not appear to arise from a purely electrochromic mechanism. Given this voltage sensitivity and the noise level of the apparatus, it should be possible to detect both action potentials and subthreshold synaptic potentials from SCG cell bodies. In practice, dye recording can easily detect action potentials from every neuron in an SCG microculture, but small synaptic potentials are obscured by dye signals from the dense network of axons.In another microculture system that does not have such long and complex axons, this dye-recording apparatus should be able to detect synaptic potentials, making it possible to noninvasively map the synaptic connections in a microculture, and thus to study long-term synaptic plasticity.

  2. DYE-SENSITIZED PHOTOPOLYMERIZATION OF METHYL METHACRYLATE INITIATED BY COUMARIN DYE/IODONIUM SALT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Fang Gao; Yong-yuan Yang

    1999-01-01

    The photosensitive initiating system composed of 7-diethylamino-3-(2'-benzimidazolyl)coumarin dye (DEDC) and diphenyliodonium hexafluorophosphate (DIHP) which act as the sensitizer and the initiator respectively, can be used to initiate the polymerization of methyl methacrylate (MMA). The results showed that when exposed to visible light, coumarin dye/iodonium salt undergoes quick electron transfer from DEDC to DIHP and free radicals are produced. The visible light photoinduced reaction between DEDC and DIHP is mainly through the excited singlet state of DEDC and thus it is a little sensitive to O2. The influence of concentration of DEDC, DIHP and MMA on the rate of photopolymerization of MMA was also investigated.

  3. Inclusion of aggregation effect to evaluate the performance of organic dyes in dye-sensitized solar cells

    Science.gov (United States)

    Sun, Kenan; Zhang, Weiyi; Heng, Panpan; Wang, Li; Zhang, Jinglai

    2018-05-01

    Two new indoline-based D-A-π-A dyes, D3F and D3F2 (see Scheme 1), are developed on the basis of the reported D3 by insertion of one or two F atoms on benzothiadiazole group. Our central aim is to explore high-efficiency organic dyes applied in dye-sensitized solar cells by inclusion of a simple group rather than by employment of new complicated groups. The performance of two new designed organic dyes, D3F and D3F2, is compared with that of D3 from various aspects including absorption spectrum, light harvesting efficiency, driving force, and open-circuit voltage. Besides the isolated dye, the interfacial property between dye and TiO2 surface is studied. D3F and D3F2 do not show absolute superiority than D3 not only for the isolated dyes but also for the monomeric adsorption system. However, D3F and D3F2 would effectively reduce the influence of aggregation resulting in the much smaller intermolecular electronic coupling. Although the aggregation has attracted much attention recently, it is studied alone in most of studies. To comprehensively evaluate the performance of dye-sensitized solar cells, it is necessary to consider aggregation along with electron injection time from dye into TiO2 rather than only static items, such as, band gap and absorption region.

  4. An OFF–ON–OFF type of pH fluorescent sensor: Benzo[c,d]indole-based dimethine cyanine dye-synthesis, spectral properties and density functional theory studies

    International Nuclear Information System (INIS)

    Liu, Qi; Hong Su, Xiao; Ying Wang, Lan; Sun, Wei; Bo Lei, Yi; Yi Wen, Zhen

    2014-01-01

    We synthesized a novel OFF–ON–OFF type of pH-dependent fluorescent sensor: benzo[c,d]indole-based dimethine cyanine dye D1, with donor-π-acceptor (D-π-A) structure based on intramolecular charge transfer system (ICT), which employed dimethine cyanine dye as a fluorophore and pentavalent nitrogen NH + group as a pH modulator, respectively. The product was identified by 1 H NMR, 13 C NMR, IR, UV–vis and HRMS. The investigation of spectral properties found that dye D1 showed excellent spectroscopic properties and its absorption maxima and fluorescence quantum yield were basically larger in protic solvent than in aprotic solvent. Meanwhile, the absorption spectra of D1 were revealed to hypochromatic-shift and the absorption intensity was gradually decreased along with the increase of pH value. Interestingly, dye D1 showed remarkable fluorescence when pH value was in the range of 6.00–9.80 with the peak at 8.21, which was defined as an OFF–ON–OFF type of pH-dependent fluorescent sensors based on ICT. In addition, dye D1 exhibited a high selectivity for H + over other common ions, such as Cl − , K + , Fe 2+ etc. Theoretical calculations based on density functional theory (DFT) were employed to provide a better understanding of this particular dye sensor. These results indicated that D1 would be able to act as an efficient pH-sensor and had a potential to play an important role in biological and medical study. - Highlights: • A new benzo[c,d]indole-based pH fluorescent sensor was synthesized without adding catalyst. • The absorption spectra of dye D1 were associated with the solvents’ pK a value. • The sensor showed OFF–ON–OFF fluorescence in pH buffer, with the peak at 8.21. • The sensor had high sensitivity and selectivity

  5. Optical properties of natural dyes on the dye-sensitized solar cells (DSSC) performance

    International Nuclear Information System (INIS)

    Pratiwi, D. D.; Nurosyid, F.; Supriyanto, A.; Suryana, R.

    2016-01-01

    This study reported several natural dyes for application in dye-sensitized solar cells (DSSC). This study aims was to determine the effect of optical absorption properties of natural dyes on efficiency of DSSC. The sandwich structure of DSSC consist of TiO 2 as working electrode, carbon layer as counter electrode, natural dyes as photosensitizer, and electrolyte as electron transfer media. The natural dyes used in this experiment were extracted from dragon fruit anthocyanin, mangosteen peels anthocyanin, and red cabbage anthocyanin. The absorbance of dyes solutions and the adsorption of the dye on the surface of TiO 2 were characterized using UV-Vis spectrophotometer, the quantum efficiency versus wavelength was characterized using incident photon-to-current efficiency (IPCE) measurement system, and the efficiency of DSSC was calculated using I-V meter. UV-Vis characteristic curves showed that wavelength absorption of anthocyanin dye of red cabbage was 450 - 580 nm, anthocyanin of mangosteen peels was 400 - 480 nm, and anthocyanin of dragon fruit was 400 - 650 nm. Absorption spectra of the dye adsorption on the surface of TiO 2 which was resulted in the highest absorbance of red cabbage anthocyanin. IPCE characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted quantum efficiency of 0.058%; 0.047%; and 0.043%, respectively at wavelength maximum about 430 nm. I-V characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted efficiency of 0.054%; 0.042%; and 0.024%, respectively. (paper)

  6. Photoactive curcumin-derived dyes with surface anchoring moieties used in ZnO nanoparticle-based dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Ganesh, T.; Kim, Jong Hoon; Yoon, Seog Joon; Kil, Byung-Ho; Maldar, N.N.; Han, Jin Wook; Han, Sung-Hwan

    2010-01-01

    Photoactive, eco-friendly and high molar extinction coefficient, curcumin-derived dyes (BCMoxo and BCtCM) have been explored in ZnO nanoparticles (NPs)-based dye-sensitized solar cells (DSSCs). The boron complex curcumin dyes modified with di-carboxylic anchor groups (BCtCM) provided surface attachment with a strong UV-vis region absorption than the dye molecule without anchor groups (BCMoxo). Photoanodes primed with poly-dispersive ZnO NPs (∼80-50 nm) specifically devised for these dyes and optimized for the critical thickness, sensitization time and concentration using a solvent-free ionic electrolyte so as to get current density as high as 1.66 mA/cm 2 under 80 mW/cm 2 irradiation. Therefore, a successful conversion of visible light into electricity by using these curcumin-derived dyes (natural derived photoactive molecules) as photosensitizer in DSSCs would be a great interest in future studies for enhancing further conversion efficiencies.

  7. Electrophoresis-base dye adsorption into titanium dioxide film for dye sensitized solar cell application

    International Nuclear Information System (INIS)

    Ratno Nuryadi; Zico Alaia Akbar Junior; Lia Aprilia

    2010-01-01

    Dye Sensitized Solar Cell (DSSC) is one of renewable energy sources which has demanded a substitute non renewable energy sources. The most important factor influencing DSSC performance is dye adsorption into semiconductor nano-porous TiO 2 particles. The purpose of this work is to study the effect of dye eosin Y adsorption on DSSC characteristics by an electrophoresis method. As result, Open Circuit Voltage (V oc ) of DSSC increases as the applied voltage of electrophoresis increases. It is also found that the eosin Y absorbance at wavelength of around 500 nm increases when the electrophoresis voltage is increased. These results indicate that electrophoresis process plays an important role in dye adsorption. (author)

  8. Photochromic dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Noah M. Johnson

    2015-11-01

    Full Text Available We report the fabrication and characterization of photochromic dye sensitized solar cells that possess the ability to change color depending on external lighting conditions. This device can be used as a “smart” window shade that tints, collects the sun's energy, and blocks sunlight when the sun shines, and is completely transparent at night.

  9. A Triphenylamine-Based Conjugated Polymer with Donor-π-Acceptor Architecture as Organic Sensitizer for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Zhang, Wei; Fang, Zhen; Su, Mingjuan; Saeys, Mark; Liu, Bin

    2009-09-17

    A conjugated polymer containing an electron donating backbone (triphenylamine) and an electron accepting side chain (cyanoacetic acid) with conjugated thiophene units as the linkers has been synthesized. Dye-sensitized solar cells (DSSCs) are fabricated utilizing this material as the dye sensitizer, resulting a typical power conversion efficiency of 3.39% under AM 1.5 G illumination, which represents the highest efficiency for polymer dye-sensitized DSSCs reported so far. The results show the good promise of conjugated polymers as sensitizers for DSSC applications. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. A Study of Mixed Vegetable Dyes with Different Extraction Concentrations for Use as a Sensitizer for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Kun-Ching Cho

    2014-01-01

    Full Text Available Two vegetable dyes are used for the study: chlorophyll dye from sweet potato leaf extract and anthocyanin dye from extracts of blueberry, purple cabbage, and grape. The chlorophyll and anthocyanin dyes are blended in a cocktail in equal proportions, by volume. This study determines the effect of different extraction concentrations and different vegetable dyes on the photoelectric conversion efficiency of dye-sensitized solar cells. In order to make the electrode for the experiments, P25 TiO2 powder was coated on the ITO conducting surface, using a medical blade, to form a thin film with a thickness of around 35 μm. The experimental results show that the cocktail dye blended using extracts of sweet potato leaf and blueberries, in the volumetric proportion 1 : 1, at a weight concentration of 40%, using an extraction temperature of 50°C and an extraction heating time of 10 min produces the greatest photoelectric conversion efficiency (η of up to 1.57%, an open-circuit voltage (VOC of 0.61 V, and a short-circuit current density (JSC of 4.75 mA/cm2.

  11. Photoactive curcumin-derived dyes with surface anchoring moieties used in ZnO nanoparticle-based dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ganesh, T.; Kim, Jong Hoon; Yoon, Seog Joon; Kil, Byung-Ho; Maldar, N.N. [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sung-Dong-Ku, Haengdang-dong 17, Seoul (Korea, Republic of); Han, Jin Wook, E-mail: jwhan@hanyang.ac.kr [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sung-Dong-Ku, Haengdang-dong 17, Seoul (Korea, Republic of); Han, Sung-Hwan, E-mail: shhan@hanyang.ac.kr [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sung-Dong-Ku, Haengdang-dong 17, Seoul (Korea, Republic of)

    2010-09-01

    Photoactive, eco-friendly and high molar extinction coefficient, curcumin-derived dyes (BCMoxo and BCtCM) have been explored in ZnO nanoparticles (NPs)-based dye-sensitized solar cells (DSSCs). The boron complex curcumin dyes modified with di-carboxylic anchor groups (BCtCM) provided surface attachment with a strong UV-vis region absorption than the dye molecule without anchor groups (BCMoxo). Photoanodes primed with poly-dispersive ZnO NPs ({approx}80-50 nm) specifically devised for these dyes and optimized for the critical thickness, sensitization time and concentration using a solvent-free ionic electrolyte so as to get current density as high as 1.66 mA/cm{sup 2} under 80 mW/cm{sup 2} irradiation. Therefore, a successful conversion of visible light into electricity by using these curcumin-derived dyes (natural derived photoactive molecules) as photosensitizer in DSSCs would be a great interest in future studies for enhancing further conversion efficiencies.

  12. Vertically aligned ZnO nanowire arrays in Rose Bengal-based dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Basudev; Batabyal, Sudip K.; Pal, Amlan J. [Indian Association for the Cultivation of Science, Department of Solid State Physics, Kolkata 700032 (India)

    2007-05-23

    We fabricate dye-sensitized solar cells (DSSC) using vertically oriented, high density, and crystalline array of ZnO nanowires, which can be a suitable alternative to titanium dioxide nanoparticle films. The vertical nanowires provide fast routes or channels for electron transport to the substrate electrode. As an alternative to conventional ruthenium complex, we introduce Rose Bengal dye, which acts as a photosensitizer in the dye-sensitized solar cells. The dye energetically matches the ZnO with usual KI-I{sub 2} redox couple for dye-sensitized solar cell applications. (author)

  13. Studi Eksperimental Pengaruh Intensitas Cahaya terhadap Performa DSSC (Dye Sensitized Solar Cell dengan Ekstrak Buah dan Sayur Sebagai Dye Sensitizer

    Directory of Open Access Journals (Sweden)

    Khoiruz Zadit Taqwa

    2015-03-01

    Full Text Available Sel surya adalah peralatan yang dapat mengubah energi matahari menjadi energi listrik dengan menggunakan efek photovoltaic. Desain dan konstruksi dari solar cell mengalami perkembangan seiring dengan berkembangnya teknologi saat ini, hingga pada tahun 1991 ditemukan DSSC (Dye Sensitized Solar Cell. Sampai saat ini bahan yang umum digunakan sebagai dye pada pembuatan DSSC adalah ruthenium complex yang berharga mahal dan sulit untuk disintesa. Karena itu perlu dilakukannya penelitian tentang penggunaan bahan lain yang murah dan mudah untuk disintesa sebagai bahan dye, karena itu perlu diadakan pengujian terhadap performa yang dihasilkan dari DSSC dengan bahan dye tersebut dan apa saja variabel yang mempengaruhinya. Metode penelitian yang digunakan adalah studi eksperimental terhadap prototype DSSC dengan variasi bahan dye sensitizer dari ekstrak kulit manggis (Garcinia mangostana, ekstrak daun bayam (Amaranthus hybridus l. ekstrak buah naga merah (Hylocereus polyrhizus. Pengujian prototype DSSC dilakukan dengan cara menyinarinya menggunakan cahaya lampu halogen yang diatur tegangannya menggunakan sebuah dimmer untuk mengendalikan temperatur dari lampu, sehingga lampu tersebut menghasilkan variasi tintensitas cahaya sebesar 29 W/m2, 36 W/m2 dan 49 W/m2. Selanjutnya pengujian dilakukian dengan cara yang sama, tetapi dengan ditambahkan pendingin berupa air yang mengalir dibawah permukaan prototype DSSC. Penilitian ini menghasilkan kesimpulan bahwa semakin tinggi intensitas cahaya, maka semakin tinggi Pmax yang dihasilkan oleh prototype. Semakin bertambah temperatur pencahayaan maka semakin berkurang performa dari prototype DSSC. Efisiensi yang paling besar dihasilkan oleh prototype dengan bahan dye dari ekstrak kulit manggis pada intensitas 29 W/m2 sebesar 0,73%,Pendinginan yang diberikan kepada prototype mampu memperbaiki efisiensi dari prototype DSSC yang dibuat akan tetapi tidak signifikan.

  14. Carbon coated stainless steel as counter electrode for dye sensitized solar cells

    Science.gov (United States)

    Prakash, Shejale Kiran; Sharma, Rakesh K.; Roy, Mahesh S.; Kumar, Mahesh

    2014-10-01

    A new type of counter electrode for dye sensitized solar cells has been fabricated using a stainless steel sheet as substrate and graphite, graphene and multiwall carbon nanotubes as the catalytic material which applied by screen printing technique. The sheet resistances of the substrates and there influence on the dye sensitized solar cells has been studied. The fabricated counter electrodes i.e. SS-graphite, SS-graphene SS-MWCNT and SS-platinum were tested for their photovoltaic response in the form of dye sensitized solar cells.

  15. EH AND S ANALYSIS OF DYE-SENSITIZED PHOTOVOLTAIC SOLAR CELL PRODUCTION

    International Nuclear Information System (INIS)

    BOWERMAN, B.; FTHENAKIS, V.

    2001-01-01

    Photovoltaic solar cells based on a dye-sensitized nanocrystalline titanium dioxide photoelectrode have been researched and reported since the early 1990's. Commercial production of dye-sensitized photovoltaic solar cells has recently been reported in Australia. In this report, current manufacturing methods are described, and estimates are made of annual chemical use and emissions during production. Environmental, health and safety considerations for handling these materials are discussed. This preliminary EH and S evaluation of dye-sensitized titanium dioxide solar cells indicates that some precautions will be necessary to mitigate hazards that could result in worker exposure. Additional information required for a more complete assessment is identified

  16. Electrochemistry and dye-sensitized solar cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav

    2017-01-01

    Roč. 2, č. 1 (2017), s. 88-98 ISSN 2451-9103 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : electrochemistry * dye-sensitized cells * photoelectrode Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

  17. Spectral sensitization of TiO2 by new hemicyanine dyes in dye solar cell yielding enhanced photovoltage: Probing chain length effect on performance

    International Nuclear Information System (INIS)

    Fadadu, Kishan B.; Soni, Saurabh S.

    2013-01-01

    Graphical abstract: New hemicyanine dyes based on indolenine moiety were utilized as light harvesting materials in dye sensitized solar cell. Chain lengths of the molecules were varied in order to study its effect of chain length on the performance of DSSC. Electron transfer kinetic of the solar cell was studied and it was found that the chain length changes the electron transfer kinetic. We have achieved remarkable photovoltage and overall performance of DSSC. Highlights: ► New hemicyanine dyes based on indolenine moiety were utilized as light harvesting materials in dye sensitized solar cell. ► Chain lengths of the molecules were varied in order to study its effect of chain length on the performance of DSSC. ► Electron transfer kinetic of the solar cell was studied and it was found that the chain length changes the electron transfer kinetic. -- Abstract: New hemicyanine dyes having indole nucleus with different alkyl chain length were synthesized and characterized using 1 H NMR and mass spectroscopy. These dyes were used to sensitize the TiO 2 film in dye sensitized solar cell. Nanocrystalline dye solar cells were fabricated and characterized using various electrochemical techniques. It has been found that the alkyl chain length present in the dye molecules greatly affects the overall performance of dye solar cell. Molecules having longer alkyl chain are having better sensitizers which enhance V oc to significant extent. Chain length dependent performance was further investigated using Tafel polarization and impedance method. Hemicyanine dye having hexyl chain has outperformed by attaining 2.9% solar to electricity conversion efficiency

  18. Dye sensitized solar cells. How do they work?

    International Nuclear Information System (INIS)

    Laurie M, Peter

    2008-01-01

    Dye sensitized solar cells (DSC), also known as Gratzel cells, harvest sunlight using a dye adsorbed onto the high surface area of a porous nanocrystalline titanium dioxide film. Photoexcitation of the dye results in the injection of electrons into the conduction band of the oxide. The dye is regenerated in its original state by donation of electrons from iodide ions presenting an electrolyte that permeates the porous oxide film. The regeneration cycle is completed at a platinum coated cathode at which tri-iodide ions are reduced to iodide ions. DSC has achieved solar conversion efficiencies of over 10% in the laboratory, with best module efficiencies of around 8%. This lecture will describe the fabrication of the basic DSC and discuss the basic Physics and Chemistry of the cell. (Full text)

  19. Dye-sensitized solar cells: Out with both baby and bathwater

    Science.gov (United States)

    Elliott, C. Michael

    2011-03-01

    After two decades of research, the efficiency of dye-sensitized solar cells seems to have reached a plateau. Now, changing both electrolyte and dye opens up new opportunities that offer the hope that the efficiency ceiling can be broken.

  20. Molecular modification of coumarin dyes for more efficient dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-de-Armas, Rocio; San-Miguel, Miguel A.; Oviedo, Jaime; Sanz, Javier Fdez. [Department of Physical Chemistry, University of Seville, Seville (Spain)

    2012-05-21

    In this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (-OH, -NH{sub 2}, and -OCH{sub 3}) and two different substituents with steric effect: -CH{sub 2}-CH{sub 2}-CH{sub 2}- and -CH{sub 2}-HC=CH-. The electronic absorption spectra (position and width of the first band and absorption threshold) and the position of the LUMO level related to the conduction band have been used as theoretical criteria to evaluate the efficiency of the new dyes. The introduction of a -NH{sub 2} group produces a redshift of the absorption maximum position and the absorption threshold, which could improve the cell efficiency. In contrast, the introduction of -CH{sub 2}-CH{sub 2}-CH{sub 2}- does not modify significantly the electronic structure of NKX-2311, but it might prevent aggregation. Finally, -CH{sub 2}-HC=CH- produces important changes both in the electronic spectrum and in the electronic structure of the dye, and it would be expected as an improvement of cell efficiency for these dyes.

  1. Ultrafast Fabrication of Flexible Dye-Sensitized Solar Cells by Ultrasonic Spray-Coating Technology

    Science.gov (United States)

    Han, Hyun-Gyu; Weerasinghe, Hashitha C.; Min Kim, Kwang; Soo Kim, Jeong; Cheng, Yi-Bing; Jones, David J.; Holmes, Andrew B.; Kwon, Tae-Hyuk

    2015-09-01

    This study investigates novel deposition techniques for the preparation of TiO2 electrodes for use in flexible dye-sensitized solar cells. These proposed new methods, namely pre-dye-coating and codeposition ultrasonic spraying, eliminate the conventional need for time-consuming processes such as dye soaking and high-temperature sintering. Power conversion efficiencies of over 4.0% were achieved with electrodes prepared on flexible polymer substrates using this new deposition technology and N719 dye as a sensitizer.

  2. Efficient dye-sensitized solar cells from mesoporous zinc oxide nanostructures sensitized by N719 dye

    Science.gov (United States)

    Kumara, G. R. A.; Deshapriya, U.; Ranasinghe, C. S. K.; Jayaweera, E. N.; Rajapakse, R. M. G.

    2018-03-01

    Dye-sensitized solar cells (DSCs) have attracted a great deal of attention due to their low-cost and high power conversion efficiencies. They usually utilize an interconnected nanoparticle layer of TiO2 as the electron transport medium. From the fundamental point of view, faster mobility of electrons in ZnO is expected to contribute to better performance in DSCs than TiO2, though the actual practical situation is quite the opposite. In this research, we addressed this problem by first applying a dense layer of ZnO on FTO followed by a mesoporous layer of interconnected ZnO nanoparticle layer, both were prepared by spray pyrolysis technique. The best cell shows a power conversion efficiency of 5.2% when the mesoporous layer thickness is 14 μm and the concentration of the N719 dye in dye coating solution is 0.3 mM, while a cell without a dense layer shows 4.2% under identical conditions. The surface concentration of dye adsorbed in the cell with a dense layer and that without a dense layer are 5.00 × 10‑7 and 3.34 × 10‑7 mol/cm2, respectively. The cell with the dense layer has an electron lifetime of 54.81 ms whereas that without the dense layer is 11.08 ms. As such, the presence of the dense layer improves DSC characteristics of ZnO-based DSCs.

  3. Plasmonic Dye-Sensitized Solar Cells

    KAUST Repository

    Ding, I-Kang

    2010-12-14

    This image presents a scanning electron microscopy image of solid state dye-sensitized solar cell with a plasmonic back reflector, overlaid with simulated field intensity plots when monochromatic light is incident on the device. Plasmonic back reflectors, which consist of 2D arrays of silver nanodomes, can enhance absorption through excitation of plasmonic modes and increased light scattering, as reported by Michael D. McGehee, Yi Cui, and co-workers.

  4. Modeling the efficiency of Förster resonant energy transfer from energy relay dyes in dye-sensitized solar cells

    KAUST Repository

    Hoke, Eric T.; Hardin, Brian E.; McGehee, Michael D.

    2010-01-01

    Förster resonant energy transfer can improve the spectral breadth, absorption and energy conversion efficiency of dye sensitized solar cells. In this design, unattached relay dyes absorb the high energy photons and transfer the excitation

  5. Henna (Lawsonia inermis L.) Dye-Sensitized Nanocrystalline Titania Solar Cell

    International Nuclear Information System (INIS)

    Jasim, Kh.E.; Al-Dallal, Sh.; Hassan, A.M.

    2012-01-01

    Low-cost solar cells have been the subject of intensive research activities for over half century ago. More recently, dye-sensitized solar cells (DSSCs) emerged as a new class of low-cost solar cells that can be easily prepared. Natural-dye-sensitized solar cells (NDSSCs) are shown to be excellent examples of mimicking photosynthesis. The NDSSC acts as a green energy generator in which dyes molecules adsorbed to nanocrystalline layer of wide bandgap semiconductor material harvest photons. In this paper we investigate the structural, optical, electrical, and photovoltaic characterization of two types of natural dyes, namely, the Bahraini Henna and the Yemeni Henna, extracted using the Soxhlet extractor. Solar cells from both materials were prepared and characterized. It was found that the levels of open-circuit voltage and short-circuit current are concentration dependent. Further suggestions to improve the efficiency of NDSSC are discussed

  6. Henna (Lawsonia inermis L. Dye-Sensitized Nanocrystalline Titania Solar Cell

    Directory of Open Access Journals (Sweden)

    Khalil Ebrahim Jasim

    2012-01-01

    Full Text Available Low-cost solar cells have been the subject of intensive research activities for over half century ago. More recently, dye-sensitized solar cells (DSSCs emerged as a new class of low-cost solar cells that can be easily prepared. Natural-dye-sensitized solar cells (NDSSCs are shown to be excellent examples of mimicking photosynthesis. The NDSSC acts as a green energy generator in which dyes molecules adsorbed to nanocrystalline layer of wide bandgap semiconductor material harvest photons. In this paper we investigate the structural, optical, electrical, and photovoltaic characterization of two types of natural dyes, namely, the Bahraini Henna and the Yemeni Henna, extracted using the Soxhlet extractor. Solar cells from both materials were prepared and characterized. It was found that the levels of open-circuit voltage and short-circuit current are concentration dependent. Further suggestions to improve the efficiency of NDSSC are discussed.

  7. Perylene anhydride fused porphyrins as near-infrared sensitizers for dye-sensitized solar cells

    KAUST Repository

    Jiao, Chongjun

    2011-07-15

    Two perylene anhydride fused porphyrins 1 and 2 have been synthesized and employed successfully in dye-sensitized solar cells (DSCs). Both compounds showed broad incident monochromatic photon-to-current conversion efficiency spectra covering the entire visible spectral region and even extending into the near-infrared (NIR) region up to 1000 nm, which is impressive for ruthenium-free dyes in DSCs. © 2011 American Chemical Society.

  8. Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Di Wei

    2010-03-01

    Full Text Available Dye sensitized solar cell (DSSC is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  9. Dye-sensitized solar cells based on nanostructured zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Conradt, Jonas; Maier-Flaig, Florian; Sartor, Janos; Fallert, Johannes [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Szmytkowski, Jedrzej; Kalt, Heinz [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Reinhard, Manuel; Colsmann, Alexander [Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Lemmer, Uli [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Balaban, Teodor Silviu [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology, Karlsruhe (Germany)

    2009-07-01

    Hybrid solar cells represent a promising (cost-efficient) alternative to pure inorganic solar cells. We present dye-sensitized solar cells (DSSC) which are based on a zinc oxide (ZnO) electrode covered with a ruthenium dye. Our work focuses on the morphology of the ZnO electrode and its impact on the photovoltaic performance of the solar cell. Nanocrystalline ZnO powder layers and arrays of nanorods are incorporated into the DSSCs. The ZnO nanorods are grown by vapor transport deposition. The morphology and doping concentration of the rods can be controlled by the choice of substrate material, growth condition and catalytic metal layers. The nanorod arrays are expected to fasten the electron transport towards the anode and thereby improve the solar cell efficiency. In addition, novel self-assembling (porphyrin) dyes are tested as sensitizer within a DSSC.

  10. Photostability of the solar cell dye sensitizer N719

    DEFF Research Database (Denmark)

    Nour-Mohammadi, Farahnaz

    intensities. This light intensity dependency of the quantum yield was attributed to the back electron transfer reaction rate between the titanium dioxide conduction band electrons and the oxidized dye cation. Photoinduced absorption spectroscopy (PIA) was used to measure the back electron transfer reaction...... rate, kback at the same light intensities as used in the model experiments. The PIA measurements showed that kback increased with increasing light intensities. By applying the equation kdeg = Φdeg × kback to the experimentally obtained total quantum yields and back electron transfer rates......The photostability of the sensitizer dye [Ru(dcbpyH)2(NCS)2] (Bu4N)2 (referred to as N719) was investigated in a simple model system instead of a complete nanocrystaline dye sensitized titanium dioxide solar cells (nc-DSSC). The applied model system consisted of N719 dyed titanium dioxide...

  11. Novel D–π–A dye sensitizers of polymeric metal complexes with ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 38; Issue 2. Novel D––A dye sensitizers of polymeric metal complexes with triphenylamine derivatives as donor for dye-sensitized solar cells: synthesis, characterization and application. Guipeng Tang Jun Zhou Wei Zhang Jiaomei Hu Dahai Peng Qiufang Xie ...

  12. Ultrafast electron and energy transfer in dye-sensitized iron oxide and oxyhydroxide nanoparticles

    DEFF Research Database (Denmark)

    Gilbert, Benjamin; Katz, Jordan E.; Huse, Nils

    2013-01-01

    photo-initiated interfacial electron transfer. This approach enables time-resolved study of the fate and mobility of electrons within the solid phase. However, complete analysis of the ultrafast processes following dye photoexcitation of the sensitized iron(iii) oxide nanoparticles has not been reported....... We addressed this topic by performing femtosecond transient absorption (TA) measurements of aqueous suspensions of uncoated and DCF-sensitized iron oxide and oxyhydroxide nanoparticles, and an aqueous iron(iii)–dye complex. Following light absorption, excited state relaxation times of the dye of 115...... a four-state model of the dye-sensitized system, finding electron and energy transfer to occur on the same ultrafast timescale. The interfacial electron transfer rates for iron oxides are very close to those previously reported for DCF-sensitized titanium dioxide (for which dye–oxide energy transfer...

  13. A novel pH sensitive water soluble fluorescent nanomicellar sensor for potential biomedical applications.

    Science.gov (United States)

    Georgiev, Nikolai I; Bryaskova, Rayna; Tzoneva, Rumiana; Ugrinova, Iva; Detrembleur, Christophe; Miloshev, Stoyan; Asiri, Abdullah M; Qusti, Abdullah H; Bojinov, Vladimir B

    2013-11-01

    Herein we report on the synthesis and sensor activity of a novel pH sensitive probe designed as highly water-soluble fluorescent micelles by grafting of 1,8-naphthalimide-rhodamine bichromophoric FRET system (RNI) to the PMMA block of a well-defined amphiphilic diblock copolymer-poly(methyl methacrylate)-b-poly(methacrylic acid) (PMMA48-b-PMAA27). The RNI-PMMA48-b-PMAA27 adduct is capable of self-assembling into micelles with a hydrophobic PMMA core, containing the anchored fluorescent probe, and a hydrophilic shell composed of PMAA block. Novel fluorescent micelles are able to serve as a highly sensitive pH probe in water and to internalize successfully HeLa and HEK cells. Furthermore, they showed cell specificity and significantly higher photostability than that of a pure organic dye label such as BODIPY. The valuable properties of the newly prepared fluorescent micelles indicate the high potential of the probe for future biological and biomedical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Electrochemically Deposited Polypyrrole for Dye-Sensitized Solar Cell Counter Electrodes

    Directory of Open Access Journals (Sweden)

    Khamsone Keothongkham

    2012-01-01

    Full Text Available Polypyrrole films were coated on conductive glass by electrochemical deposition (alternative current or direct current process. They were then used as the dye-sensitized solar cell counter electrodes. Scanning electron microscopy revealed that polypyrrole forms a nanoparticle-like structure on the conductive glass. The amount of deposited polypyrrole (or film thickness increased with the deposition duration, and the performance of polypyrrole based-dye-sensitized solar cells is dependant upon polymer thickness. The highest efficiency of alternative current and direct current polypyrrole based-dye-sensitized solar cells (DSSCs is 4.72% and 4.02%, respectively. Electrochemical impedance spectroscopy suggests that the superior performance of alternative current polypyrrole solar cells is due to their lower charge-transfer resistance between counter electrode and electrolyte. The large charge-transfer resistance of direct current solar cells is attributed to the formation of unbounded polypyrrole chains minimizing the I3 − reduction rate.

  15. Recording membrane potential changes through photoacoustic voltage sensitive dye

    Science.gov (United States)

    Zhang, Haichong K.; Kang, Jeeun; Yan, Ping; Abou, Diane S.; Le, Hanh N. D.; Thorek, Daniel L. J.; Kang, Jin U.; Gjedde, Albert; Rahmim, Arman; Wong, Dean F.; Loew, Leslie M.; Boctor, Emad M.

    2017-03-01

    Monitoring of the membrane potential is possible using voltage sensitive dyes (VSD), where fluorescence intensity changes in response to neuronal electrical activity. However, fluorescence imaging is limited by depth of penetration and high scattering losses, which leads to low sensitivity in vivo systems for external detection. In contrast, photoacoustic (PA) imaging, an emerging modality, is capable of deep tissue, noninvasive imaging by combining near infrared light excitation and ultrasound detection. In this work, we develop the theoretical concept whereby the voltage-dependent quenching of dye fluorescence leads to a reciprocal enhancement of PA intensity. Based on this concept, we synthesized a novel near infrared photoacoustic VSD (PA-VSD) whose PA intensity change is sensitive to membrane potential. In the polarized state, this cyanine-based probe enhances PA intensity while decreasing fluorescence output in a lipid vesicle membrane model. With a 3-9 μM VSD concentration, we measured a PA signal increase in the range of 5.3 % to 18.1 %, and observed a corresponding signal reduction in fluorescence emission of 30.0 % to 48.7 %. A theoretical model successfully accounts for how the experimental PA intensity change depends on fluorescence and absorbance properties of the dye. These results not only demonstrate the voltage sensing capability of the dye, but also indicate the necessity of considering both fluorescence and absorbance spectral sensitivities in order to optimize the characteristics of improved photoacoustic probes. Together, our results demonstrate photoacoustic sensing as a potential new modality for sub-second recording and external imaging of electrophysiological and neurochemical events in the brain.

  16. Incorporation of Kojic Acid-Azo Dyes on TiO2 Thin Films for Dye Sensitized Solar Cells Applications

    Directory of Open Access Journals (Sweden)

    Carolynne Zie Wei Sie

    2017-01-01

    Full Text Available Sensitization of heavy metal free organic dyes onto TiO2 thin films has gained much attention in dye sensitized solar cells (DSSCs. A series of new kojic acid based organic dyes KA1–4 were synthesized via nucleophilic substitution of azobenzene bearing different vinyl chains A1–4 with kojyl chloride 4. Azo dyes KA1–4 were characterized for photophysical properties employing absorption spectrometry and photovoltaic characteristic in TiO2 thin film. The presence of vinyl chain in A1–4 improved the photovoltaic performance from 0.20 to 0.60%. The introduction of kojic acid obtained from sago waste further increases the efficiency to 0.82–1.54%. Based on photovoltaic performance, KA4 achieved the highest solar to electrical energy conversion efficiency (η = 1.54% in the series.

  17. Electrical characterization of dye sensitized nano solar cell using natural pomegranate juice as photosensitizer

    Science.gov (United States)

    Adithi, U.; Thomas, Sara; Uma, V.; Pradeep, N.

    2013-02-01

    This paper shows Electrical characterization of Dye Sensitized Solar Cell using natural dye, extracted from the pomegranate as a photo sensitizer and ZnO nanoparticles as semiconductor. The constituents of fabricated dye sensitized solar cell were working electrode, dye, electrolyte and counter electrode. ZnO nanoparticles were synthesized and used as semiconductor in working electrode. Carbon soot was used as counter electrode. The resistance of ZnO film on ITO film was found out. There was an increase in the resistance of the film and film changes from conducting to semiconducting. Photovoltaic parameters of the fabricated cell like Short circuit current, open circuit voltage, Fill factor and Efficiency were found out. This paper shows that usage of natural dyes like pomegranate juice as sensitizer enables faster and simpler production of cheaper and environmental friendly solar cell.

  18. Spectral Properties and Orientation of Voltage-Sensitive Dyes in Lipid Membranes

    KAUST Repository

    Matson, Maria; Carlsson, Nils; Beke-Somfai, Tamá s; Nordé n, Bengt

    2012-01-01

    Voltage-sensitive dyes are frequently used for probing variations in the electric potential across cell membranes. The dyes respond by changing their spectral properties: measured as shifts of wavelength of absorption or emission maxima

  19. Potential development in dye-sensitized solar cells for renewable energy

    CERN Document Server

    Pandikumar, Alagarsamy

    2013-01-01

    The development of photovoltaic technology is expected to solve problems related to energy shortages and environmental pollution caused by the use of fossil fuels. Dye-sensitizedsolar cells (DSSCs) are promising next-generation alternatives to conventional silicon-based photovoltaic devices owing to their low manufacturing cost and potentially high conversion efficiency. This special topic volume addresses recent advances in the research on dye-sensitized solar cells. The focus of this special topic volume is on materials development (sensitizers, nanostructured oxide films, and electrolyte),

  20. A novel "modularized" optical sensor for pH monitoring in biological matrixes.

    Science.gov (United States)

    Liu, Xun; Zhang, Shang-Qing; Wei, Xing; Yang, Ting; Chen, Ming-Li; Wang, Jian-Hua

    2018-06-30

    A novel core-shell structure optical pH sensor is developed with upconversion nanoparticles (UCNPs) serving as the core and silica as the shell, followed by grafting bovineserumalbumin (BSA) as another shell via glutaraldehyde cross-linking. The obtained core-shell-shell structure is shortly termed as UCNPs@SiO 2 @BSA, and its surface provides a platform for loading various pH sensitive dyes, which are alike "modules" to make it feasible for measuring pHs within different pH ranges by simply regulating the type of dyes. Generally, a single pH sensitive dye is adopted to respond within a certain pH range. This study employs bromothymol blue (BTB) and rhodamine B (RhB) to facilitate their responses to pH variations within two ranges, i.e., pH 5.99-8.09 and pH 4.98-6.40, respectively, with detection by ratio-fluorescence protocol. The core-shell-shell structure offers superior sensitivity, which is tens of times more sensitive than those achieved by ratio-fluorescence approaches based on various nanostructures, and favorable stability is achieved in high ionic strength medium. In addition, this sensor exhibits superior photostability under continuous excitation at 980 nm. Thanks to the near infrared excitation in the core-shell-shell structure, it effectively avoids the self-fluorescence from biological samples and thus facilitates accurate sensing of pH in various biological sample matrixes. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Calcium Sensitive Fluorescent Dyes Fluo-4 and Fura Red under Pressure: Behaviour of Fluorescence and Buffer Properties under Hydrostatic Pressures up to 200 MPa.

    Science.gov (United States)

    Schneidereit, D; Vass, H; Reischl, B; Allen, R J; Friedrich, O

    2016-01-01

    The fluorescent Ca2+ sensitive dyes Fura Red (ratiometric) and Fluo-4 (non-ratiometric) are widely utilized for the optical assessment of Ca2+ fluctuations in vitro as well as in situ. The fluorescent behavior of these dyes is strongly depends on temperature, pH, ionic strength and pressure. It is crucial to understand the response of these dyes to pressure when applying calcium imaging technologies in the field of high pressure bioscience. Therefore, we use an optically accessible pressure vessel to pressurize physiological Ca2+-buffered solutions at different fixed concentrations of free Ca2+ (1 nM to 25.6 μM) and a specified dye concentration (12 μM) to pressures of 200 MPa, and record dye fluorescence intensity. Our results show that Fluo-4 fluorescence intensity is reduced by 31% per 100 MPa, the intensity of Fura Red is reduced by 10% per 100 MPa. The mean reaction volume for the dissociation of calcium from the dye molecules [Formula: see text] is determined to -17.8 ml mol-1 for Fluo-4 and -21.3 ml mol-1 for Fura Red. Additionally, a model is presented that is used to correct for pressure-dependent changes in pH and binding affinity of Ca2+ to EGTA, as well as to determine the influence of these changes on dye fluorescence.

  2. Calcium Sensitive Fluorescent Dyes Fluo-4 and Fura Red under Pressure: Behaviour of Fluorescence and Buffer Properties under Hydrostatic Pressures up to 200 MPa

    Science.gov (United States)

    Vass, H.; Reischl, B.; Allen, R. J.; Friedrich, O.

    2016-01-01

    The fluorescent Ca2+ sensitive dyes Fura Red (ratiometric) and Fluo-4 (non-ratiometric) are widely utilized for the optical assessment of Ca2+ fluctuations in vitro as well as in situ. The fluorescent behavior of these dyes is strongly depends on temperature, pH, ionic strength and pressure. It is crucial to understand the response of these dyes to pressure when applying calcium imaging technologies in the field of high pressure bioscience. Therefore, we use an optically accessible pressure vessel to pressurize physiological Ca2+-buffered solutions at different fixed concentrations of free Ca2+ (1 nM to 25.6 μM) and a specified dye concentration (12 μM) to pressures of 200 MPa, and record dye fluorescence intensity. Our results show that Fluo-4 fluorescence intensity is reduced by 31% per 100 MPa, the intensity of Fura Red is reduced by 10% per 100 MPa. The mean reaction volume for the dissociation of calcium from the dye molecules Δdv¯ is determined to -17.8 ml mol-1 for Fluo-4 and -21.3 ml mol-1 for Fura Red. Additionally, a model is presented that is used to correct for pressure-dependent changes in pH and binding affinity of Ca2+ to EGTA, as well as to determine the influence of these changes on dye fluorescence. PMID:27764134

  3. Manipulation of pH induced sensitivity of a fluorescent probe in presence of silver nanoparticles

    International Nuclear Information System (INIS)

    Kacmaz, Sibel; Ertekin, Kadriye; Oter, Ozlem; Hizliateş, Cevher Gundogdu; Ergun, Yavuz; Celik, Erdal

    2015-01-01

    In this study, pH induced spectral response of the newly synthesized carbazole derivative (9-butyl-bis-3-(4-(dimethylamino) phenyl) allylidene)-9H-carbazole-3,6-diamine) has been declared. We utilized silver nanoparticles (AgNPs) along with ionic liquid as additives for manipulation of the spectral response. Plasticized ethyl cellulose (EC) was used as matrix material. Fibers and porous films were produced by electrospinning technique. The emission intensity at 631 nm has been followed as the analytical signal. Utilization of silver nanoparticles in electrospun polymeric fibers for pH sensing purposes resulted with many advantages such as tuned sensitivity, linear calibration plot for larger pH ranges, increased surface area and enhancement in all sensor dynamics. Additionally, we performed manipulation of the pKa within the same matrix exploiting the silver NPs. Characteristics of the pH induced response for the offered composition was superior with respect to the previously reported ones. When stored at the ambient air of the laboratory there was no significant drift in the signal intensity after 16 months. Our sensitivity and stability tests are still in progress. - Highlights: • A carbozole derivative was used for the first time for sensing of pH along with silver nanoparticles. • The sensor slides fabricated in form of nanofibers. • The Ag containing and Ag-free slides were produced by electrospinning technique. • pH Sensitivity of the dye was compared for both; Ag containing and Ag-free forms. • We performed manipulation of the pKa within the same matrix exploiting the silver NPs.

  4. Manipulation of pH induced sensitivity of a fluorescent probe in presence of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kacmaz, Sibel [Giresun University, Faculty of Engineering, Department of Food Engineering, 28200 Giresun (Turkey); Ertekin, Kadriye [University of Dokuz Eylul, Faculty of Sciences, Department of Chemistry, 35160 Izmir (Turkey); University of Dokuz Eylul, Center for Fabrication and Application of Electronic Materials (EMUM), 35160 Izmir (Turkey); Oter, Ozlem; Hizliateş, Cevher Gundogdu; Ergun, Yavuz [University of Dokuz Eylul, Faculty of Sciences, Department of Chemistry, 35160 Izmir (Turkey); Celik, Erdal [University of Dokuz Eylul, Faculty of Engineering, Department of Metallurgical and Materials Engineering, 35160 Izmir (Turkey); University of Dokuz Eylul, Center for Fabrication and Application of Electronic Materials (EMUM), 35160 Izmir (Turkey)

    2015-12-15

    In this study, pH induced spectral response of the newly synthesized carbazole derivative (9-butyl-bis-3-(4-(dimethylamino) phenyl) allylidene)-9H-carbazole-3,6-diamine) has been declared. We utilized silver nanoparticles (AgNPs) along with ionic liquid as additives for manipulation of the spectral response. Plasticized ethyl cellulose (EC) was used as matrix material. Fibers and porous films were produced by electrospinning technique. The emission intensity at 631 nm has been followed as the analytical signal. Utilization of silver nanoparticles in electrospun polymeric fibers for pH sensing purposes resulted with many advantages such as tuned sensitivity, linear calibration plot for larger pH ranges, increased surface area and enhancement in all sensor dynamics. Additionally, we performed manipulation of the pKa within the same matrix exploiting the silver NPs. Characteristics of the pH induced response for the offered composition was superior with respect to the previously reported ones. When stored at the ambient air of the laboratory there was no significant drift in the signal intensity after 16 months. Our sensitivity and stability tests are still in progress. - Highlights: • A carbozole derivative was used for the first time for sensing of pH along with silver nanoparticles. • The sensor slides fabricated in form of nanofibers. • The Ag containing and Ag-free slides were produced by electrospinning technique. • pH Sensitivity of the dye was compared for both; Ag containing and Ag-free forms. • We performed manipulation of the pKa within the same matrix exploiting the silver NPs.

  5. Zinc oxide based dye sensitized solar cell using eosin – Y as ...

    African Journals Online (AJOL)

    A zinc oxide based Dye sensitized Solar Cell (DSSC) has been fabricated, using Eosin-Y as the dye adsorbed on a nanocrystalline zinc oxide - fluorine doped tin oxide electrode, for the sensitization of the large band gap semiconductor. The absorption spectrum of Eosin-Y showed high absorption of visible light between ...

  6. Ultrafast photodynamics of the indoline dye D149 adsorbed to porous ZnO in dye-sensitized solar cells.

    Science.gov (United States)

    Rohwer, Egmont; Richter, Christoph; Heming, Nadine; Strauch, Kerstin; Litwinski, Christian; Nyokong, Tebello; Schlettwein, Derck; Schwoerer, Heinrich

    2013-01-14

    We investigate the ultrafast dynamics of the photoinduced electron transfer between surface-adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye-sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I(-)/I(3)(-) redox electrolyte typical for dye-sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert-butyl alcohol shows excited-state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge-transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Potential of roselle and blue pea in the dye-sensitized solar cell

    Science.gov (United States)

    Dayang, S.; Irwanto, M.; Gomesh, N.; Ismail, B.

    2017-09-01

    This paper discovers the use of natural dyes from Roselle flower and Blue Pea flower which act as a sensitizer in DSSC and in addition has a potential in absorbing visible light spectrum. The dyes were extracted using distilled water (DI) and ethanol (E) extract solvent in an ultrasonic cleaner for 30 minutes with a frequency of 37 Hz by using `degas' mode at the temperature of 30°C. Absorption spectra of roselle dye and blue pea dye with different extract solvent were tested using Evolution 201 UV-Vis Spectrophotometer. It was found that Roselle dye absorbs at a range of 400 nm - 620 nm and Blue Pea absorbs at the range of wavelength 500 nm - 680 nm. Fourier-Transform Infrared (FTIR) was used to identify the functional active group in extract dye. The concept of Dye-Sensitized Solar Cell (DSSC) similar to photosynthesis process has attracted much attention since it demonstrates a great potential due to the use of low-cost materials and environmentally friendly sources of technology.

  8. Fabrication of Two Columns Dye-Sensitized Solar-Cell

    International Nuclear Information System (INIS)

    Phyu Sin Khaing Oo; Su Su Hlaing; Khin Lay Thwe; Nwe Ni Khin

    2011-12-01

    A two columns dye-sensitized solar cell has been fabricated using dye extract form teak leaves. This solar cell was assembled with two 20-30 ohms conductive glasses (one for TiO2 coated electrode and another for carbon coated electrode), TiO2 nano-powder P25, iodide electrolyte solution and soft graphite pencil for carbon coating. It was found that the open circuit voltage Voc was 0.688V and the short circuit Isc was 0.724mA

  9. Nanostructured dye-sensitized solar cells

    OpenAIRE

    Palma, Giuseppina

    2014-01-01

    2012/2013 Dye-sensitized solar cells (DSSCs) represent a promising alternative to silicon-based technology. From the first publications about DSSCs in the 90s, they are considered an important breakthrough for achieving high efficiency by using relatively inexpensive and abundant materials. Stability and efficiency are two crucial points in the development of this new class of hybrid photovoltaic devices. Most of the DSSC studies carried out over the past twenty years are based on the o...

  10. In Situ Mapping of the Molecular Arrangement of Amphiphilic Dye Molecules at the TiO 2 Surface of Dye-Sensitized Solar Cells

    KAUST Repository

    Voï tchovsky, Kislon; Ashari-Astani, Negar; Tavernelli, Ivano; Té treault, Nicolas; Rothlisberger, Ursula; Stellacci, Francesco; Grä tzel, Michael; Harms, Hauke A.

    2015-01-01

    © 2015 American Chemical Society. Amphiphilic sensitizers are central to the function of dye-sensitized solar cells. It is known that the cell's performance depends on the molecular arrangement and the density of the dye on the semiconductor surface

  11. Listening to membrane potential: photoacoustic voltage-sensitive dye recording

    Science.gov (United States)

    Zhang, Haichong K.; Yan, Ping; Kang, Jeeun; Abou, Diane S.; Le, Hanh N. D.; Jha, Abhinav K.; Thorek, Daniel L. J.; Kang, Jin U.; Rahmim, Arman; Wong, Dean F.; Boctor, Emad M.; Loew, Leslie M.

    2017-04-01

    Voltage-sensitive dyes (VSDs) are designed to monitor membrane potential by detecting fluorescence changes in response to neuronal or muscle electrical activity. However, fluorescence imaging is limited by depth of penetration and high scattering losses, which leads to low sensitivity in vivo systems for external detection. By contrast, photoacoustic (PA) imaging, an emerging modality, is capable of deep tissue, noninvasive imaging by combining near-infrared light excitation and ultrasound detection. Here, we show that voltage-dependent quenching of dye fluorescence leads to a reciprocal enhancement of PA intensity. We synthesized a near-infrared photoacoustic VSD (PA-VSD), whose PA intensity change is sensitive to membrane potential. In the polarized state, this cyanine-based probe enhances PA intensity while decreasing fluorescence output in a lipid vesicle membrane model. A theoretical model accounts for how the experimental PA intensity change depends on fluorescence and absorbance properties of the dye. These results not only demonstrate PA voltage sensing but also emphasize the interplay of both fluorescence and absorbance properties in the design of optimized PA probes. Together, our results demonstrate PA sensing as a potential new modality for recording and external imaging of electrophysiological and neurochemical events in the brain.

  12. Hydroxy-Al and cell-surface negativity are responsible for the enhanced sensitivity of Rhodotorula taiwanensis to aluminum by increased medium pH.

    Science.gov (United States)

    Zhao, Xue Qiang; Bao, Xue Min; Wang, Chao; Xiao, Zuo Yi; Hu, Zhen Min; Zheng, Chun Li; Shen, Ren Fang

    2017-10-01

    Aluminum (Al) is ubiquitous and toxic to microbes. High Al 3+ concentration and low pH are two key factors responsible for Al toxicity, but our present results contradict this idea. Here, an Al-tolerant yeast strain Rhodotorula taiwanensis RS1 was incubated in glucose media containing Al with a continuous pH gradient from pH 3.1-4.2. The cells became more sensitive to Al and accumulated more Al when pH increased. Calculations using an electrostatic model Speciation Gouy Chapman Stern indicated that, the increased Al sensitivity of cells was associated with AlOH 2+ and Al(OH) 2 + rather than Al 3+ . The alcian blue (a positively charged dye) adsorption and zeta potential determination of cell surface indicated that, higher pH than 3.1 increased the negative charge and Al adsorption at the cell surface. Taken together, the enhanced sensitivity of R. taiwanensis RS1 to Al from pH 3.1-4.2 was associated with increased hydroxy-Al and cell-surface negativity.

  13. Nanobeads of zinc oxide with rhodamine B dye as a sensitizer for dye sensitized solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Baviskar, P.K. [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001, MS (India); Zhang, J.B. [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Gupta, V.; Chand, S. [Organic and Hybrid Solar Cell, Physics of Energy Harvesting Division, Dr. K. S. Krishnan Marg, National Physical Laboratory, New Delhi 110012 (India); Sankapal, B.R., E-mail: brsankapal@rediffmail.com [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001, MS (India)

    2012-01-05

    Highlights: > Synthesis of ZnO film was done at room temperature (27 deg. C). > Simple and inexpensive chemical bath deposition method was employed. > The as deposited film consists of mixed phases of hydroxide and oxide. > The post annealing was done at 200 deg. C in order to remove hydroxide phase. > Low-cost, metal free Rhodamine B dye was used for DSSC application. - Abstract: Cost effective, ruthenium metal free rhodamine B dye has been chemically adsorbed on ZnO films consisting of nanobeads to serve as a photo anode in dye sensitized solar cells. These ZnO films were chemically synthesized at room temperature (27 deg. C) on to fluorine doped tin oxide (FTO) coated glass substrates followed by annealing at 200 deg. C. These films consisting of inter connected nanobeads (20-40 nm) which are due to the agglomeration of very small size particles (3-5 nm) leading to high surface area. The film shows wurtzite structure having high crystallinity with optical direct band gap of 3.3 eV. Optical absorbance measurements for rhodamine B dye covered ZnO film revealed the good coverage in the visible region (460-590 nm) of the solar spectrum. With poly-iodide liquid as an electrolyte, device exhibits photon to electric energy conversion efficiency ({eta}) of 1.26% under AM 1.5G illumination at 100 mW/cm{sup 2}.

  14. Exploiting Nanocarbons in Dye-Sensitized Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav

    2014-01-01

    Roč. 348, č. 2014 (2014), s. 53-94 ISSN 0340-1022 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : Dye sensitized solar cells * Carbon nanotubes * Graphene Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.464, year: 2014

  15. Natural Dye-Sensitized Solar Cell Based on Nanocrystalline TiO2

    International Nuclear Information System (INIS)

    Jasim, K.E.

    2012-01-01

    During the last quarter of the twentieth century there have been intensive research activities looking for green sources of energy. The main aim of the green generators or converters of energy is to replace the conventional (fossil) energy sources, hence reducing further accumulation of the green house gasses GHGs. Conventional silicon and III-V semiconductor solar cell based on crystalline bulk, quantum well and quantum dots structure or amorphous and thin film structures provided a feasible solution. However, natural dye sensitized solar cells NDSSC are a promising class of photovoltaic cells with the capability of generating green energy at low production cost since no vacuum systems or expensive equipment are required in their fabrication. Also, natural dyes are abundant, easily extracted and safe materials. In NDSSC, once dye molecules exposed to light they become oxidized and transfer electrons to a nano structured layer of wide bandgap semiconductors such as TiO 2 . The generated electrons are drawn outside the cell through ohmic contact to a load. In this paper we review the structure and operation principles of the dye sensitized solar cell DSSC. We discuss preparation procedures, optical and electrical characterization of the NDSSC using local dyes extracted from Henna (Lawsonia inermis L.), pomegranate, cherries and Bahraini raspberries (Rubus spp.). These natural organic dyes are potential candidates to replace some of the man-made dyes used as sensitizer in many commercialized photoelectrochemical cells. Factors limiting the operation of the DSSC are discussed. NDSSCs are expected to be a favored choice in the building-integrated photovoltaic (BIPV) due to their robustness, therefore, requiring no special shielding from natural events such as tree strikes or hails. (author)

  16. Assessment of dye distribution in sensitized solar cells by microprobe techniques

    Energy Technology Data Exchange (ETDEWEB)

    Barreiros, M.A., E-mail: alexandra.barreiros@lneg.pt [Laboratório Nacional de Energia e Geologia, LEN/UES, Estrada do Paço do Lumiar, 22, 1649-038 Lisboa (Portugal); Corregidor, V. [IPFN, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2686-953 Sacavém (Portugal); Alves, L.C. [C2TN, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2686-953 Sacavém (Portugal); Guimarães, F. [Laboratório Nacional de Energia e Geologia, LGM/UCTM, Rua da Amieira, Apartado 1089, 4466-901 S. Mamede de Infesta (Portugal); Mascarenhas, J.; Torres, E.; Brites, M.J. [Laboratório Nacional de Energia e Geologia, LEN/UES, Estrada do Paço do Lumiar, 22, 1649-038 Lisboa (Portugal)

    2015-04-01

    Dye sensitized solar cells (DSCs) have received considerable attention once this technology offers economic and environmental advantages over conventional photovoltaic (PV) devices. The PV performance of a DSC relies on the characteristics of its photoanode, which typically consists of a nanocrystalline porous TiO{sub 2} film, enabled with a large adsorptive surface area. Dye molecules that capture photons from light during device operation are attached to the film nanoparticles. The effective loading of the dye in the TiO{sub 2} electrode is of paramount relevance for controlling and optimizing solar cell parameters. Relatively few methods are known today for quantitative evaluation of the total dye adsorbed on the film. In this context, microprobe techniques come out as suitable tools to evaluate the dye surface distribution and depth profile in sensitized films. Electron Probe Microanalysis (EPMA) and Ion Beam Analytical (IBA) techniques using a micro-ion beam were used to quantify and to study the distribution of the Ru organometallic dye in TiO{sub 2} films, making use of the different penetration depth and beam sizes of each technique. Different 1D nanostructured TiO{sub 2} films were prepared, morphologically characterized by SEM, sensitized and analyzed by the referred techniques. Dye load evaluation in different TiO{sub 2} films by three different techniques (PIXE, RBS and EPMA/WDS) provided similar results of Ru/Ti mass fraction ratio. Moreover, it was possible to assess dye surface distribution and its depth profile, by means of Ru signal, and to visualize the dye distribution in sample cross-section through X-ray mapping by EPMA/EDS. PIXE maps of Ru and Ti indicated an homogeneous surface distribution. The assessment of Ru depth profile by RBS showed that some films have homogeneous Ru depth distribution while others present different Ru concentration in the top layer (2 μm thickness). These results are consistent with the EPMA/EDS maps obtained.

  17. Co-encapsulation of enzyme and sensitive dye as a tool for fabrication of microcapsule based sensor for urea measuring.

    Science.gov (United States)

    Kazakova, Lyubov I; Shabarchina, Lyudmila I; Sukhorukov, Gleb B

    2011-06-21

    Enzyme based micron sized sensing system with optical readout was fabricated by co-encapsulation of urease and dextran couple with pH sensitive dye SNARF-1 into polyelectrolyte multilayer capsules. Co-precipitation of calcium carbonate, urease and dextran followed up by multilayer film coating and Ca-extracting by EDTA resulted in the formation of 3.5-4 micron capsules, what enable the calibrated fluorescence response to urea in concentration range from 10(-6) to 10(-1) M. The presence of urea can be monitored on a single capsule level as illustrated by confocal fluorescent microscopy. Variations in urease:dye ratio in capsules, applicability and limits of use of that type multi-component microencapsulated sensors are discussed.

  18. Radiation Degradation of some Commercial Dyes in Wastewater

    International Nuclear Information System (INIS)

    Dessouki, A.M.; Abdel-Aal, S.E.

    1999-01-01

    The degradation Kinetic due to irradiation of aqueous solutions of some commercial dyes, (Reactive Blue Brilliant, Reactive Yellow and Basic Blue 9 Dye (Methylene Blue 2 B), was studied. Factors affecting radiolysis of the dye such as dye concentration, irradiation dose, dose rate and ph of the solutions were studied. The effects of different additives such as nitrogen oxygen, hydrogen peroxide and sodium hypochlorite on the degradation process were investigated. The effect of irradiation dose on the different dye solutions at various concentrations, showed that the Reactive Yellow G. was very sensitive to gamma radiation. The effect of the ph of the dye solutions proved to very according type of the dye. Synergistic treatment of the dye solutions by irradiation and conventional method showed that saturation of the dye solutions with nitrogen did not enhance the radiation degradation of the dyes, while addition of oxygen resulted in a remarkable enhancement of the degradation of the dyes. Also, the addition of sodium hypochlorite (5%) and the oxidation by hydrogen peroxide resulted in more radiation degradation, Also, adsorption of the dyes onto Ga and some ion exchangers showed that Ga has the highest adsorption capacity. Radiation degradation of the toxic dye pollutants and their removal from wastewater down to concentrations not exceeding the maximum permissible concentration (Mpc) according to international standards, proved to be better than conventional methods of purification alone

  19. Optimization of dye extraction from Cordyline fruticosa via response surface methodology to produce a natural sensitizer for dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Mahmoud A.M. Al-Alwani

    Full Text Available In the present work, the application of response surface methodology (RSM for the optimization of process parameters in the chlorophyll extraction from Cordyline fruticosa leaves was performed. The absorbance of the extract obtained from the extraction process under different conditions was estimated using the D-optimal design in RSM. Three different process parameters such as the nature of organic solvent based on their boiling point (ethanol, methanol, and acetonitrile, pH (4–8 and extraction temperature (50–90 °C were optimized for chlorophyll extraction. The effects of these parameters on the absorbance or concentration of the extract were evaluated using ANOVA results of quadratic polynomial regression. The results showed a high R2 and adjusted R2 correlation coefficients of 0.9963 and 0.9921 respectively. Moreover, the analysis of the final quadric model based on the design experiments indicated an optimal extraction condition of pH of 7.99, extraction temperature of 78.33 °C, and a solvent boiling point, 78 °C. The predicted absorbance was 1.006, which is in good agreement with the experimentally obtained result of 1.04 at 665 nm wavelength. The application of pigment obtained under the optimal condition was further evaluated as a sensitizer for the dye sensitized solar cells. Maximum solar conversion efficiency (η of 0.5% was achieved for the C. fruticosa leaf extract obtained under the optimum extraction conditions. Furthermore, the exposure of the leaf pigment to 100 mW/cm2 simulated sunlight yielded a short circuit photocurrent density (Isc of 1.3 mA, open circuit voltage (Voc of 616 mV, and a fill factor (ff of 60.16%. Keywords: Optimization, Cordyline fruticosa, Chlorophyll, Process variables, D-optimal design, Solar cells

  20. Ranking of hair dye substances according to predicted sensitization potency

    DEFF Research Database (Denmark)

    Søsted, H; Basketter, D A; Estrada, E

    2004-01-01

    Allergic contact dermatitis following the use of hair dyes is well known. Many chemicals are used in hair dyes and it is unlikely that all cases of hair dye allergy can be diagnosed by means of patch testing with p-phenylenediamine (PPD). The objectives of this study are to identify all hair dye...... in order to help select a number of chemically diverse hair dye substances that could be used in subsequent clinical work. Various information sources, including the Inventory of Cosmetics Ingredients, new regulations on cosmetics, data on total use and ChemId (the Chemical Search Input website provided...... by the National Library of Medicine), were used in order to identify the names and structures of the hair dyes. A QSAR model, developed with the help of experimental local lymph node assay data and topological sub-structural molecular descriptors (TOPS-MODE), was used in order to predict the likely sensitization...

  1. Enhancement of dye-sensitized solar cells performances by improving electron density in conduction band of nanostructure TiO2 electrode with using a metalloporphyrin as additional dye

    International Nuclear Information System (INIS)

    Mojiri-Foroushani, M.; Dehghani, H.; Salehi-Vanani, N.

    2013-01-01

    Highlights: ► N719 and ZnTCPP dyes were used in a sequential adsorption process. ► By using two dyes, improved the performance of the cell. ► Density of electrons in the conduction band of TiO 2 electrodes improved. -- Abstract: A zinc(II)-porphyrin dye with four carboxyphenyl moiety of ancillary (ZnTCPP) was studied as a sensitizer in combination with a ruthenium complex (N719) in co-sensitized solar cells. The high molar extinction coefficient (ε) of porphyrin dyes leads to high light absorption in the dye-sensitized TiO 2 electrode. In spite of the high ε of porphyrin dyes, they usually have a narrow absorption band and also to suffer from dye aggregation due to their planar structural nature. This causes lower efficiencies of the DSSCs for the porphyrins than the ruthenium complexes. Co-sensitization of two or more dyes with complementary absorption spectra on TiO 2 film is an important method to further enhance the IPCE response and energy conversion efficiency of dye-sensitized solar cells. Interestingly, when the ZnTCPP electrode was used to assemble a co-sensitized solar cell by additional adsorption of N719 dye, the efficiency improved to 6.35% (in comparison to N719 that the efficiency was 4.74%). The results indicated that the co-sensitized device shows enhancements of photovoltaic performance not only in short-circuit current density (J SC ) but also in open-circuit voltage (V OC ). In the present study we have been shown that co-sensitization of a zinc(II)-porphyrin with N719 dye changes the energy levels of the TiO 2 electrode and in result produces further improvement for its device performance

  2. Recent Advances in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    F. O. Lenzmann

    2007-01-01

    Full Text Available This review describes recent advances in the research on dye-sensitized solar cells. After a brief discussion of the general operation principles and a presentation of record efficiencies, stability data and key technology drivers, current trends will be reviewed. The focus of this review is on materials development (sensitizers, nanostructured oxide films, and electrolyte, but commercialization aspects will also be briefly addressed. The review describes the most relevant characteristics and major trends in a compact way.

  3. Fabrication of triple-labeled polyelectrolyte microcapsules for localized ratiometric pH sensing.

    Science.gov (United States)

    Song, Xiaoxue; Li, Huanbin; Tong, Weijun; Gao, Changyou

    2014-02-15

    Encapsulation of pH sensitive fluorophores as reporting molecules provides a powerful approach to visualize the transportation of multilayer capsules. In this study, two pH sensitive dyes (fluorescein and oregon green) and one pH insensitive dye (rhodamine B) were simultaneously labeled on the microcapsules to fabricate ratiometric pH sensors. The fluorescence of the triple-labeled microcapsule sensors was robust and nearly independent of other intracellular species. With a dynamic pH measurement range of 3.3-6.5, the microcapsules can report their localized pH at a real time. Cell culture experiments showed that the microcapsules could be internalized by RAW 246.7 cells naturally and finally accumulated in acidic organelles with a pH value of 5.08 ± 0.59 (mean ± s.d.; n=162). Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Review of Polymer, Dye-Sensitized, and Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    S. N. F. Mohd-Nasir

    2014-01-01

    Full Text Available The combination of inorganic nanoparticles semiconductor, conjugated polymer, and dye-sensitized in a layer of solar cell is now recognized as potential application in developing flexible, large area, and low cost photovoltaic devices. Several conjugated low bandgap polymers, dyes, and underlayer materials based on the previous studies are quoted in this paper, which can provide guidelines in designing low cost photovoltaic solar cells. All of these materials are designed to help harvest more sunlight in a wider range of the solar spectrum besides enhancing the rate of charge transfer in a device structure. This review focuses on developing solid-state dye-synthesized, polymer, and hybrid solar cells.

  5. Hair dye dermatitis and p-phenylenediamine contact sensitivity: A preliminary report

    Directory of Open Access Journals (Sweden)

    Mrinal Gupta

    2015-01-01

    Full Text Available Background: The contact allergic reactions from p-phenylenediamine (PPD in hair dyes vary from mild contact dermatitis to severe life- threatening events (angioedema, bronchospasm, asthma, renal impairment. Objectives: To study the clinical patterns and PPD contact sensitivity in patients with hair-dye dermatitis. Materials and Methods: Eighty (M: F 47:33 consecutive patients aged between 18 and 74 years suspected to have contact allergy from hair dye were studied by patch testing with Indian Standard Series including p-phenylenediamine (PPD, 1.0% pet. Results: 54 Fifty-four (M: F 21:33 patients showed positive patch tests from PPD. Eight of these patients also showed positive patch test reaction from fragrance mix, thiuram mix, paraben mix, or colophony. Fifty-seven (71% patients affected were aged older than 40 years. The duration of dermatitis varied from 1 year with exacerbation following hair coloring. Forty-nine patients had dermatitis of scalp and/or scalp margins and 23 patients had face and neck dermatitis. Periorbital dermatitis, chronic actinic dermatitis, and erythema multiforme-like lesions were seen in 4, 2, and 1 patients, respectively. Conclusions: Hair dyes and PPD constitute a significant cause of contact dermatitis. There is an urgent need for creating consumer awareness regarding hair-dyes contact sensitivity and the significance of performing sensitivity testing prior to actual use.

  6. Alkyl Chain Barriers for Kinetic Optimization in Dye-Sensitized Solar Cells

    NARCIS (Netherlands)

    Kroeze, J.E.; Hirata, N.; Koops, S.; Nazeeruddin, M.K.; Schmidt-Mende, L.; Grätzel, M.; Durrant, J.R.

    2006-01-01

    The optimization of interfacial charge transfer is crucial to the design of dye-sensitized solar cells. In this paper we address the dynamics of the charge separation and recombination in liquid-electrolyte and solid-state cells employing a series of amphiphilic ruthenium dyes with varying

  7. The Effect of UV-Irradiation (under Short-Circuit Condition) on Dye-Sensitized Solar Cells Sensitized with a Ru-Complex Dye Functionalized with a (diphenylamino)Styryl-Thio phen Group

    International Nuclear Information System (INIS)

    Nonomura, K.; Xu, Y.; Marinado, T.; Hagberg, D.P.; Sun, L.; Boschloo, G.; Hagfeldt, A.; Rong Zhang, R.; Boschloo, G.; Hagfeldt, A.

    2009-01-01

    A new ruthenium complex, cis-di(thiocyanato)(2,2'-bipyridine-4,4'-dicarboxylic acid)(4,4'-bis (2-(5-(2-(4-diphenylaminophenyl)ethenyl) -thiophen-2-yl)ethenyl)-2,2'-bipyridine)ruthenium(II) (named E322) has been synthesized for use in dye-sensitized solar cells (DSCs). Higher extinction coefficient and a broader absorption compared to the standard Ru-dye, N719, were aimed. DSCs were fabricated with E322, and the efficiency was 0.12% initially. (4.06% for N719, as reference). The efficiency was enhanced to 1.83% by exposing the cell under simulated sunlight containing UV-irradiation at short-circuit condition. The reasons of this enhancement are (1) enhanceing electron injection from sensitizer to TiO 2 following a shift toward positive potentials of the conduction band of TiO 2 by the adsorption of protons or cations from the sensitizer, or from the redox electrolyte and (2) improving the regeneration reaction of the oxidized dye by the redox electrolyte by the dissolution of aggregated dye from the surface of TiO 2 following the treatment.

  8. Influence of polar solvents on photovoltaic performance of Monascusred dye-sensitized solar cell

    Science.gov (United States)

    Lee, Jae Wook; Kim, Tae Young; Ko, Hyun Seok; Han, Shin; Lee, Suk-Ho; Park, Kyung Hee

    Dye-sensitized solar cells (DSSCs) were assembled using natural dyes extracted from Monascus red pigment as a sensitizer. In this work, we studied the adsorption characteristics for harvesting sunlight and the electrochemical behavior for electron transfer in Monascus red DSSC using different solvents. The effect of polar aprotic and protic solvents including water, ethanol, and dimethylsulfoxide (DMSO) used in the sensitization process was investigated for the improvement in conversion efficiency of a cell. As for the Monascus red dye-sensitized electrode in DMSO solvent, the solar cell yields a short-circuit current density (Jsc) of 1.23 mA/cm2, a photovoltage (Voc) of 0.75 V, and a fill factor of 0.72, corresponding to an energy conversion efficiency (η) of 0.66%.

  9. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Directory of Open Access Journals (Sweden)

    Chih-Ping Yen

    2016-08-01

    Full Text Available The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP, and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE for application to dye-sensitized solar cell (DSSC is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  10. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Chih-Ping [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Yu, Pin-Feng [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China); Wang, Jyhpyng [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Central University, Taoyuan 320, Taiwan (China); Lin, Jiunn-Yuan [Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China); Chen, Yen-Mu [SuperbIN Co., Ltd., Taipei 114, Taiwan (China); Chen, Szu-yuan, E-mail: sychen@ltl.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Central University, Taoyuan 320, Taiwan (China)

    2016-08-15

    The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP), and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE) for application to dye-sensitized solar cell (DSSC) is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  11. Dye-sensitization of CdS nano-cage - A density functional theory approach

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Kalpna; Singh, Kh. S. [Department of Physics, D. J. College, Baraut, U.P.-250611 (India); Kishor, Shyam [Department of Chemistry, J. V. College, Baraut, U.P.-250611 (India); Josefsson, Ida; Odelius, Michael [Fysikum, Albanova University Center, Stockholm University, S-106 91 Stockholm (Sweden); Ramaniah, Lavanya M. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India)

    2016-05-23

    Quantum dots a few nanometer in size exhibit unique properties in comparison to bulk due to quantum confinement. Their properties can be tuned according to their sizes. Dye sensitized quantum dot (DSQD) solar cells are based on the same principle with surface dangling bonds as a challenge. Researches have shown the existence and stability of nano-cages which are assembled such as to minimize the surface dangling bonds and hence maximize stability. Here, we report a first principles DFT study of optical and electronic properties of CdS-cage (Cd{sub 34}S{sub 34}) sensitized with nkx-2388 dye in three different geometric configurations of dye attachment. A significant distortion is found to occur in the geometric structure of the cage when it interacts strongly with the dye. The relative positioning of dye and cage energy levels is found to be different in different configurations. The absorption spectrum has been analyzed with the help of natural transition orbitals (NTO).

  12. Porphyrin Dye-Sensitized Zinc Oxide Aggregated Anodes for Use in Solar Cells

    Directory of Open Access Journals (Sweden)

    Yu-Kai Syu

    2016-08-01

    Full Text Available Porphyrin YD2-o-C8-based dyes were employed to sensitize room-temperature (RT chemical-assembled ZnO aggregated anodes for use in dye-sensitized solar cells (DSSCs. To reduce the acidity of the YD2-o-C8 dye solution, the proton in the carboxyl group of a porphyrin dye was replaced with tetrabuthyl ammonium (TBA+ in this work. The short-circuit current density (Jsc of the YD2-o-C8-TBA-sensitized ZnO DSSCs is higher than that of the YD2-o-C8-sensitized cells, resulting in the improvement of the efficiency of the YD2-o-C8-based ZnO DSSCs. With an appropriate incorporation of chenodeoxycholic acid (CDCA as coadsorbate, the Jsc and efficiency of the YD2-o-C8-TBA-sensitized ZnO DSSC are enhanced due to the improvement of the incident-photon-to-current efficiency (IPCE values in the wavelength range of 400–450 nm. Moreover, a considerable increase in Jsc is achieved by the addition of a light scattering layer in the YD2-o-C8-TBA-sensitized ZnO photoanodes. Significant IPCE enhancement in the range 475–600 nm is not attainable by tuning the YD2-o-C8-TBA sensitization processes for the anodes without light scattering layers. Using the RT chemical-assembled ZnO aggregated anode with a light scattering layer, an efficiency of 3.43% was achieved in the YD2-o-C8-TBA-sensitized ZnO DSSC.

  13. Photo Degradation in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    T. J. Abodunrin

    2015-05-01

    Full Text Available Mesoporous TiO2 of 20nm diameter is prepared in-tandem with organic dyes and based on Fluorine –doped SnO2 (FTO, conducting base is produced by hydrothermal process. The prepared mesoporous Cola Acuminata (C.acuminata, Lupinus Arboreus (L.arboreus and Bougainvillea Spectabilis (B.spectabilis films (0.16 cm2 are applied; individually and in combination as interfacial layer in-between nanocrystalline TiO2 (NC- TiO2 and the FTO anode in the dye-sensitized solar cell (DSSC. Absorbance index (A.I of all three dyes was studied within wavelength range 200-900 nm for a period of 11 months, equivalent to 352 sun exposure. C.acuminata had A.I value 4.00 that decreased to 2.32 under exposure to AM1.5 global conditions. B.spectabilis A.I was 1.19 but decreased to 0.520 within same period of study. Combination of C.acuminata and B.spectabilis gave A.I value 1.40, dye cocktails of C.acuminata, B.spectabilis and L.arboreus gave 2.00 A.I value for same wavelength range. A UV/Vis photo spectrometer was used to determine the prominent peaks and absorbance at such wavelengths. This exponential relationship is subject of our explorative study.

  14. Dye-Sensitized Solar Cells Based on Bi4Ti3O12

    Directory of Open Access Journals (Sweden)

    Zeng Chen

    2011-01-01

    Full Text Available Bismuth titanate (Bi4Ti3O12 particles were synthesized by hydrothermal treatment and nanoporous thin films were prepared on conducting glass substrates. The structures and morphologies of the samples were examined with X-ray diffraction and scanning electron microscope (SEM. Significant absorbance spectra emerged in visible region which indicated the efficient sensitization of Bi4Ti3O12 with N3 dye. Surface photovoltaic properties of the samples were investigated by surface photovoltage. The results further indicate that N3 can extend the photovoltaic response range of Bi4Ti3O12 nanoparticles to the visible region, which shows potential application in dye-sensitized solar cell. As a working electrode in dye-sensitized solar cells (DSSCs, the overall efficiency reached 0.48% after TiO2 modification.

  15. Adsorption of dyes by ACs prepared from waste tyre reinforcing fibre. Effect of texture, surface chemistry and pH.

    Science.gov (United States)

    Acevedo, Beatriz; Rocha, Raquel P; Pereira, Manuel F R; Figueiredo, José L; Barriocanal, Carmen

    2015-12-01

    This paper compares the importance of the texture and surface chemistry of waste tyre activated carbons in the adsorption of commercial dyes. The adsorption of two commercial dyes, Basic Astrazon Yellow 7GLL and Reactive Rifafix Red 3BN on activated carbons made up of reinforcing fibres from tyre waste and low-rank bituminous coal was studied. The surface chemistry of activated carbons was modified by means of HCl-HNO3 treatment in order to increase the number of functional groups. Moreover, the influence of the pH on the process was also studied, this factor being of great importance due to the amphoteric characteristics of activated carbons. The activated carbons made with reinforcing fibre and coal had the highest SBET, but the reinforcing fibre activated carbon samples had the highest mesopore volume. The texture of the activated carbons was not modified upon acid oxidation treatment, unlike their surface chemistry which underwent considerable modification. The activated carbons made with a mixture of reinforcing fibre and coal experienced the largest degree of oxidation, and so had more acid surface groups. The adsorption of reactive dye was governed by the mesoporous volume, whilst surface chemistry played only a secondary role. However, the surface chemistry of the activated carbons and dispersive interactions played a key role in the adsorption of the basic dye. The adsorption of the reactive dye was more favored in a solution of pH 2, whereas the basic dye was adsorbed more easily in a solution of pH 12. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. QSPR study of absorption maxima of organic dyes for dye-sensitized solar cells based on 3D descriptors

    Science.gov (United States)

    Xu, Jie; Zhang, Hui; Wang, Lei; Liang, Guijie; Wang, Luoxin; Shen, Xiaolin; Xu, Weilin

    2010-07-01

    A quantitative structure-property relationship (QSPR) study was performed for the prediction of the absorption maxima ( λmax) of organic dyes for dye-sensitized solar cells (DSSCs). The entire set of 70 dyes was divided into a training set of 53 dyes and a test set of 17 dyes according to Kennard and Stones algorithm. Three-dimensional (3D) descriptors were calculated to represent the dye molecules. A ten-descriptor model, with a squared correlation coefficient ( R2) of 0.9543 and a standard error of estimation ( s) of 14.7 nm, was produced by using the stepwise multilinear regression analysis (MLRA) on the training set. The reliability of the proposed model was further illustrated using various evaluation techniques: leave-one-out cross-validation procedure, randomization tests, and validation through the external test set. All descriptors involved in the model were derived solely from the chemical structure of the dye molecules, which makes the model very useful to estimate the λmax of dyes before they are actually synthesized.

  17. Synthesis and characterization of natural dye and counter electrode thin films with different carbon materials for dye-sensitized solar cells.

    Science.gov (United States)

    Chang, Ho; Chen, Tien-Li; Kao, Mu-Jung; Chen, Chih-Hao; Chien, Shu-Hua; Jiang, Lii-Jenq

    2011-08-01

    This study aims to deal with the film of the counter electrode of dye-sensitized solar cells (DSSCs) and the preparation, structure and characteristics of the extract of natural dye. This study adopts different commercial carbon materials such as black lead, carbon black and self-made TiO2-MWCNT compound nanoparticle as the film of the counter electrodes. Moreover, for the preparation of natural dyes, anthocyanins and chlorophyll dyes are extracted from mulberry and pomegranate respectively. Furthermore, the extracted anthocyanins and chlorophyll are blended into cocktail dye to complete the preparation of natural dye. Results show that the photoelectric conversion efficiency of the single-layer TiO2-MWCNT counter electrode film and the cocktail dye of the DSSCs is 0.462%.

  18. Spectral Properties and Orientation of Voltage-Sensitive Dyes in Lipid Membranes

    KAUST Repository

    Matson, Maria

    2012-07-24

    Voltage-sensitive dyes are frequently used for probing variations in the electric potential across cell membranes. The dyes respond by changing their spectral properties: measured as shifts of wavelength of absorption or emission maxima or as changes of absorption or fluorescence intensity. Although such probes have been studied and used for decades, the mechanism behind their voltage sensitivity is still obscure. We ask whether the voltage response is due to electrochromism as a result of direct field interaction on the chromophore or to solvatochromism, which is the focus of this study, as result of changed environment or molecular alignment in the membrane. The spectral properties of three styryl dyes, di-4-ANEPPS, di-8-ANEPPS, and RH421, were investigated in solvents of varying polarity and in model membranes using spectroscopy. Using quantum mechanical calculations, the spectral dependence of monomer and dimer ANEPPS on solvent properties was modeled. Also, the kinetics of binding to lipid membranes and the binding geometry of the probe molecules were found relevant to address. The spectral properties of all three probes were found to be highly sensitive to the local environment, and the probes are oriented nearly parallel with the membrane normal. Slow binding kinetics and scattering in absorption spectra indicate, especially for di-8-ANEPPS, involvement of aggregation. On the basis of the experimental spectra and time-dependent density functional theory calculations, we find that aggregate formation may contribute to the blue-shifts seen for the dyes in decanol and when bound to membrane models. In conclusion, solvatochromic and other intermolecular interactions effects also need to be included when considering electrochromic response voltage-sensitive dyes. © 2012 American Chemical Society.

  19. Design of new metal-free dyes for dye-sensitized solar cells: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Xiong; Zhou, Le; Li, Yawei [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Sun, Qiang, E-mail: sunqiang@pku.edu.cn [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Jena, Puru [Department of Physics, Virginia Commonwealth University, Richmond, VA 23284 (United States)

    2012-08-06

    Five new metal-free dyes with acceptor–π–donor (A–π–D) structure are studied using first-principles calculation based on density functional theory. Benzothiadiazole (BTD) and triphenylamine (TPA) were chosen, respectively, as an acceptor and a donor with 4-(dicyanomethylene)-2-methyl-6-(4-dimethylamino-styryl)-4H-pyran (DCM) as a π linker. The linker was further modified by -CH=CH- resulting in a red-shift with improved absorption spectra caused by the smaller energy gap and the increased orbital hybridization. The designed dyes are found to exhibit wide absorption spectra, high molar extinction coefficients, desirable orbital distributions, and good energy levels alignment, and hence can have potential applications in dye-sensitized solar cells. -- Highlights: ► New metal-free dyes with A–π–D architecture. ► With wide absorption spectra and high molar extinction coefficients. ► With desirable orbital distribution and good energy levels alignment.

  20. Influence of polar solvents on photovoltaic performance of Monascusred dye-sensitized solar cell.

    Science.gov (United States)

    Lee, Jae Wook; Kim, Tae Young; Ko, Hyun Seok; Han, Shin; Lee, Suk-Ho; Park, Kyung Hee

    2014-05-21

    Dye-sensitized solar cells (DSSCs) were assembled using natural dyes extracted from Monascus red pigment as a sensitizer. In this work, we studied the adsorption characteristics for harvesting sunlight and the electrochemical behavior for electron transfer in Monascus red DSSC using different solvents. The effect of polar aprotic and protic solvents including water, ethanol, and dimethylsulfoxide (DMSO) used in the sensitization process was investigated for the improvement in conversion efficiency of a cell. As for the Monascus red dye-sensitized electrode in DMSO solvent, the solar cell yields a short-circuit current density (Jsc) of 1.23mA/cm(2), a photovoltage (Voc) of 0.75V, and a fill factor of 0.72, corresponding to an energy conversion efficiency (η) of 0.66%. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Alignment of the dye's molecular levels with the TiO2 band edges in dye-sensitized solar cells: a DFT-TDDFT study

    International Nuclear Information System (INIS)

    De Angelis, Filippo; Fantacci, Simona; Selloni, Annabella

    2008-01-01

    We present a theoretical study of the lineup of the LUMO of Ru(II)-polypyridyl (N3 and N719) molecular dyes with the conduction band edge of a TiO 2 anatase nanoparticle. We use density functional theory (DFT) and the Car-Parrinello scheme for efficient optimization of the dye-nanoparticle systems, followed by hybrid B3LYP functional calculations of the electronic structure and time-dependent DFT (TDDFT) determination of the lowest vertical excitation energies. The electronic structure and TDDFT calculations are performed in water solution, using a continuum model. Various approximate procedures to compute the excited state oxidation potential of dye sensitizers are discussed. Our calculations show that the level alignment for the interacting nanoparticle-sensitizer system is very similar, within about 0.1 eV, to that for the separated TiO 2 and dye. The excellent agreement of our results with available experimental data indicates that the approach of this work could be used as an efficient predictive tool to help the optimization of dye-sensitized solar cells.

  2. Molecular design of donor-acceptor dyes for efficient dye-sensitized solar cells I: a DFT study.

    Science.gov (United States)

    El-Shishtawy, Reda M; Asiri, Abdullah M; Aziz, Saadullah G; Elroby, Shaaban A K

    2014-06-01

    Dye-sensitized solar cells (DSSCs) have drawn great attention as low cost and high performance alternatives to conventional photovoltaic devices. The molecular design presented in this work is based on the use of pyran type dyes as donor based on frontier molecular orbitals (FMO) and theoretical UV-visible spectra in combination with squaraine type dyes as an acceptor. Density functional theory has been used to investigate several derivatives of pyran type dyes for a better dye design based on optimization of absorption, regeneration, and recombination processes in gas phase. The frontier molecular orbital (FMO) of the HOMO and LUMO energy levels plays an important role in the efficiency of DSSCs. These energies contribute to the generation of exciton, charge transfer, dissociation and exciton recombination. The computations of the geometries and electronic structures for the predicted dyes were performed using the B3LYP/6-31+G** level of theory. The FMO energies (EHOMO, ELUMO) of the studied dyes are calculated and analyzed in the terms of the UV-visible absorption spectra, which have been examined using time-dependent density functional theory (TD-DFT) techniques. This study examined absorption properties of pyran based on theoretical UV-visible absorption spectra, with comparisons between TD-DFT using B3LYP, PBE, and TPSSH functionals with 6-31+G (d) and 6-311++G** basis sets. The results provide a valuable guide for the design of donor-acceptor (D-A) dyes with high molar absorptivity and current conversion in DSSCs. The theoretical results indicated 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran dye (D2-Me) can be effectively used as a donor dye for DSSCs. This dye has a low energy gap by itself and a high energy gap with squaraine acceptor type dye, the design that reduces the recombination and improves the photocurrent generation in solar cell.

  3. Characterization and Performance Evaluation of Dye Sensitized Solar Cell Using Nanostructured TiO2 Electrode

    Directory of Open Access Journals (Sweden)

    Sule Erten-Ela

    2014-01-01

    Full Text Available Metal-free organic sensitizer consisting of donor, electron conducting, and anchoring anhydride groups was engineered at molecular level and synthesized. Dye sensitized solar cells based on conjugated naphthalene dye were fabricated using nanoporous electrode. Photoelectrodes with a 7 μm thick nanoporous layer and a 5 μm thick light-scattering layer were used to fabricate dye sensitized solar cells. DSSCs were fabricated in a FTO/nc-TiO2/organic dye/I-/I3-/Pt/FTO device geometry. Dye sensitized solar cell was characterized by current density-voltage (J-V measurement. All current-voltage (I-V measurements were done under 100 mW/cm2 light intensity and AM 1.5 conditions. The photovoltaic data revealed a short circuit photocurrent density of 1.86 mA/cm2, an open circuit voltage of 430 mV, and a fill factor of 0.63, corresponding to an overall conversion efficiency of 0.53%.

  4. Thiophene-bithiazole based metal-free dye as DSSC sensitizer ...

    Indian Academy of Sciences (India)

    aPhotosciences and Photonics Group, Chemical Sciences and Technology Division, CSIR-National. Institute ... Dye sensitized solar cell; Thiophenes; Bithiazoles, co-adsorbents; photoconversion .... After cooling, transparent TiO2 paste of par-.

  5. Development of carbon nanotube paste for dye-sensitized solar cells

    Science.gov (United States)

    Tsuji, Masaya; Sugiyama, Seiichi; Oya, Takahide

    2012-09-01

    We propose a new type of dye-sensitized solar cell (DSC) using carbon nanotubes (CNTs). Recently, global warming due to CO2 generated from power plants, cars, and so on has received much attention. Therefore, clean power, e.g., solar power, is gaining in importance. In this study, we focused on a DSC that uses CNTs. Generally, sensitized dyes on semiconducting and metallic electrodes are used for constructing DSCs. In contrast, CNTs have many excellent properties. In particular, they have metallic and semiconducting properties that are used for the electrodes of DSCs. Therefore, we applied CNTs for fabricating a new "painting-type" DSC with semiconducting and metallic electrodes. CNTs are dispersed in water with surfactant to prepare CNT-paste for painting. This resulting CNT-paste has the same properties as a normal CNT. A DSC is comprised of two electrodes. One is a semiconducting electrode with a sensitized dye and another is a metallic one, as mentioned above. We fabricated the two electrodes by painting the CNT-paste onto substrates. Thus, this type of DSC can be applied to various objects, for example, the wall and car and housetop. An electrolyte is required and must be put between the electrodes. The method for fabricating a painting type DSC is very simple. First, two versions of the paste are used. One is a semiconducting CNT-paste that adsorbs a dye and the other is a CNT-paste without a dye. Second, we paint each paste onto two substrates. Finally, the two substrates are stacked. We drip about 10μl of an electrolyte onto the stacked substrates and irradiate them with solar light (1300 W/m2). An electromotive force (EMF) is generated by excited electrons from the dye, which are adsorbed on the semiconducting electrode. The maximum EMF reached about 250 mV and the current reached about 10 μA. These results indicate that the proposed painting-type DSC can be used a new type of solar cell.

  6. Visible-Light-Driven, Dye-Sensitized TiO2 Photo-Catalyst for Self-Cleaning Cotton Fabrics

    Directory of Open Access Journals (Sweden)

    Ishaq Ahmad

    2017-11-01

    Full Text Available We report here the photo-catalytic properties of dye-sensitized TiO2-coated cotton fabrics. In this study, visible-light-driven, self-cleaning cotton fabrics were developed by coating the cotton fabrics with dye-sensitized TiO2. TiO2 nano-sol was prepared via the sol-gel method and the cotton fabric was coated with this nano-sol by the dip-pad–dry-cure method. In order to enhance the photo-catalytic properties of this TiO2-coated cotton fabric under visible light irradiation, the TiO2-coated cotton fabric was dyed with a phthalocyanine-based reactive dye, C.I. Reactive Blue 25 (RB-25, as a dye sensitizer for TiO2. The photo-catalytic self-cleaning efficiency of the resulting dye/TiO2-coated cotton fabrics was evaluated by degradation of Rhodamine B (RhB and color co-ordinate measurements. Dye/TiO2-coated cotton fabrics show very good photo-catalytic properties under visible light.

  7. Efficiency-limiting processes in cyclopentadithiophene-bridged donor-acceptor-type dyes for solid-state dye-sensitized solar cells

    KAUST Repository

    Hinkel, Felix

    2018-01-26

    The charge generation and recombination processes in three novel push-pull photosensitizers for dye-sensitized solar cells (DSSCs) are studied by ps–μs transient absorption (TA) and quasi-steady-state photoinduced absorption (PIA) spectroscopy. The three cyclopentadithiophene-based photosensitizer dye molecules exhibit comparably low power conversion efficiencies ranging from 0.8% to 1.7% in solid-state DSSCs. We find that the photocurrents increase in the presence of Li-salt additives. Both TA and PIA measurements observe long-lived dye cations created by electron injection from the dyes’ excited state for two dyes from the series. However, the third dye shows significantly lower performance as a consequence of the less efficient electron injection even after the addition of Li-salts and faster electron-hole recombination on the ns-μs time scale. In essence, the prerequisites for this class of donor-π bridge-acceptor photosensitizers to reach higher charge generation efficiencies are a combination of strong dipole moments and fine tuning of the electronic landscape at the titania-dye interface by Li-salt addition.

  8. Efficiency-limiting processes in cyclopentadithiophene-bridged donor-acceptor-type dyes for solid-state dye-sensitized solar cells

    KAUST Repository

    Hinkel, Felix; Kim, Yoojin M.; Zagraniarsky, Yulian; Schlü tter, Florian; Andrienko, Denis; Mü llen, Klaus; Laquai, Fré dé ric

    2018-01-01

    The charge generation and recombination processes in three novel push-pull photosensitizers for dye-sensitized solar cells (DSSCs) are studied by ps–μs transient absorption (TA) and quasi-steady-state photoinduced absorption (PIA) spectroscopy. The three cyclopentadithiophene-based photosensitizer dye molecules exhibit comparably low power conversion efficiencies ranging from 0.8% to 1.7% in solid-state DSSCs. We find that the photocurrents increase in the presence of Li-salt additives. Both TA and PIA measurements observe long-lived dye cations created by electron injection from the dyes’ excited state for two dyes from the series. However, the third dye shows significantly lower performance as a consequence of the less efficient electron injection even after the addition of Li-salts and faster electron-hole recombination on the ns-μs time scale. In essence, the prerequisites for this class of donor-π bridge-acceptor photosensitizers to reach higher charge generation efficiencies are a combination of strong dipole moments and fine tuning of the electronic landscape at the titania-dye interface by Li-salt addition.

  9. Vesicular perylene dye nanocapsules as supramolecular fluorescent pH sensor systems.

    Science.gov (United States)

    Zhang, Xin; Rehm, Stefanie; Safont-Sempere, Marina M; Würthner, Frank

    2009-11-01

    Water-soluble, self-assembled nanocapsules composed of a functional bilayer membrane and enclosed guest molecules can provide smart (that is, condition responsive) sensors for a variety of purposes. Owing to their outstanding optical and redox properties, perylene bisimide chromophores are interesting building blocks for a functional bilayer membrane in a water environment. Here, we report water-soluble perylene bisimide vesicles loaded with bispyrene-based energy donors in their aqueous interior. These loaded vesicles are stabilized by in situ photopolymerization to give nanocapsules that are stable over the entire aqueous pH range. On the basis of pH-tunable spectral overlap of donors and acceptors, the donor-loaded polymerized vesicles display pH-dependent fluorescence resonance energy transfer from the encapsulated donors to the bilayer dye membrane, providing ultrasensitive pH information on their aqueous environment with fluorescence colour changes covering the whole visible light range. At pH 9.0, quite exceptional white fluorescence could be observed for such water-soluble donor-loaded perylene vesicles.

  10. Rational Molecular Engineering of Indoline-Based D-A-π-A Organic Sensitizers for Long-Wavelength-Responsive Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Zhang, Weiwei; Wu, Yongzhen; Zhu, Haibo; Chai, Qipeng; Liu, Jingchuan; Li, Hui; Song, Xiongrong; Zhu, Wei-Hong

    2015-12-09

    Indoline-based D-A-π-A organic sensitizers are promising candidates for highly efficient and long-term stable dye-sensitized solar cells (DSSCs). In order to further broaden the spectral response of the known indoline dye WS-2, we rationally engineer the molecular structure through enhancing the electron donor and extending the π-bridge, resulting in two novel indoline-based D-A-π-A organic sensitizers WS-92 and WS-95. By replacing the 4-methylphenyl group on the indoline donor of WS-2 with a more electron-rich carbazole unit, the intramolecular charge transfer (ICT) absorption band of dye WS-92 is slightly red-shifted from 550 nm (WS-2) to 554 nm (WS-92). In comparison, the incorporation of a larger π-bridge of cyclopentadithiophene (CPDT) unit in dye WS-95 not only greatly bathochromatically tunes the absorption band to 574 nm but also largely enhances the molar extinction coefficients (ε), thus dramatically improving the light-harvesting capability. Under the standard global AM 1.5 solar light condition, the photovoltaic performances of both organic dyes have been evaluated in DSSCs on the basis of the iodide/triiodide electrolyte without any coadsorbent or cosensitizer. The DSSCs based on WS-95 display better device performance with power conversion efficiency (η) of 7.69%. The additional coadsorbent in the dye bath of WS-95 does not improve the photovoltaic performance, indicative of its negligible dye aggregation, which can be rationalized by the grafted dioctyl chains on the CPDT unit. The cosensitization of WS-95 with a short absorption wavelength dye S2 enhances the IPCE and improves the η to 9.18%. Our results indicate that extending the π-spacer is more rational than enhancing the electron donor in terms of broadening the spectral response of indoline-based D-A-π-A organic sensitizers.

  11. Formation of double-layered TiO2 structures with selectively-positioned molecular dyes for efficient flexible dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Kim, Eun Yi; Yu, Sora; Moon, Jeong Hoon; Yoo, Seon Mi; Kim, Chulhee; Kim, Hwan Kyu; Lee, Wan In

    2013-01-01

    Graphical abstract: A novel flexible tandem dye-sensitized solar cell, selectively loading different dyes in discrete layers, was successfully formed on a plastic substrate by transferring the high-temperature-processed N719/TiO 2 over an organic dye-adsorbed TiO 2 film by a typical compression process at room temperature. -- Highlights: • A novel flexible dye-sensitized solar cell, selectively loading two different dyes in discrete layers, was successfully formed on a plastic substrate. • η of the flexible tandem cell obtained by transferring the high-temperature-processed TiO 2 layer was enhanced from 2.91% to 6.86%. • Interface control between two TiO 2 layers is crucial for the efficient transport of photo-injected electrons from the top to bottom TiO 2 layer. -- Abstract: To fabricate flexible dye-sensitized solar cells (DSCs) utilizing full solar spectrum, the double-layered TiO 2 films, selectively loading two different dyes in discrete layers, were formed on a plastic substrate by transferring the high-temperature-processed N719/TiO 2 over an organic dye (TA-St-CA)-sensitized TiO 2 film by a typical compression process at room temperature. It was found that interface control between two TiO 2 layers is crucial for the efficient transport of photo-injected electrons from the N719/TiO 2 to the TA-St-CA/TiO 2 layer. Electron impedance spectra (EIS) and transient photoelectron spectroscopic analyses exhibited that introduction of a thin interfacial TiO 2 layer between the two TiO 2 layers remarkably decreased the resistance at the interface, while increasing the electron diffusion constant (D e ) by ∼10 times. As a result, the photovoltaic conversion efficiency (η) of the flexible tandem DSC was 6.64%, whereas that of the flexible cell derived from the single TA-St-CA/TiO 2 layer was only 2.98%. Another organic dye (HC-acid), absorbing a short wavelength region of solar spectrum, was also applied to fabricate flexible tandem DSC. The η of the cell

  12. Chitosan-edible oil based materials as upgraded adsorbents for textile dyes.

    Science.gov (United States)

    Dos Santos, Clayane Carvalho; Mouta, Rodolpho; Junior, Manoel Carvalho Castro; Santana, Sirlane Aparecida Abreu; Silva, Hildo Antonio Dos Santos; Bezerra, Cícero Wellington Brito

    2018-01-15

    Biopolymer chitosan is a low cost, abundant, environmentally friendly, very selective and efficient anionic dyes adsorbent, being a promising material for large-scale removal of dyes from wastewater. However, raw chitosan (CS) is an ineffective cationic dyes adsorbent and its performance is pH sensitive, thus, CS modifications that address these issues need to be developed. Here, we report the preparation and characterization of two new CS modifications using edible oils (soybean oil or babassu oil), and their adsorption performance for two dyes, one anionic (remazol red, RR) and one cationic (methylene blue, MB). Both modifications extended the pH range of RR adsorption. The babassu oil modification increased adsorption capacity of the cationic dye MB, whereas the soybean oil modification increased that of RR. Such improvements demonstrate the potential of these two new CS modifications as adsorbent candidates for controlling dyes pollution in effluents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Tuning the photovoltage of dye-sensitized solar cells based on electrodeposited ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Oekermann, Torsten [Institute of Physical Chemistry and Electrochemistry, Leibniz Universitaet Hannover, Callinstrasse 3- 3A, 30167 Hannover (Germany); Peter, Laurence [Department of Chemistry, University of Bath, Bath BA2 7AY (United Kingdom); Yoshida, Tsukasa [Graduate School of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193 (Japan)

    2007-07-01

    Nanoporous, fully crystalline ZnO films can be prepared by cathodic electrodeposition from aqueous solutions of Zn salts under the influence of structure-directing agents such as surfactants. Dye-sensitized solar cells (DSSC) based on such films have emerged as a possible alternative for nanocrystalline TiO2-based DSSC due to the very high porosity and good electron transport properties of the films. In this study, we have investigated the influence of the sensitizer dye molecules on the photovoltage of the ZnO-based DSSC. Impedance measurements show that the adsorbed dye molecules lead to a shift of the flatband potential of the ZnO. Electron pushing or withdrawing effects of the dye molecules and protonation or deprotonation of the ZnO surface are discussed as possible explanations. The shifts in the flatband potential partly explain the differences in the photovoltages caused by different dyes, however, differences in the electron injection efficiency and the blocking of electron back reaction by the dye molecules have to be taken into account, too, for a complete description.

  14. Piper Ornatum and Piper Betle as Organic Dyes for TiO2 and SnO2 Dye Sensitized Solar Cells

    Science.gov (United States)

    Hayat, Azwar; Putra, A. Erwin E.; Amaliyah, Novriany; Hayase, Shuzi; Pandey, Shyam. S.

    2018-03-01

    Dye sensitized solar cell (DSSC) mimics the principle of natural photosynthesis are now currently investigated due to low manufacturing cost as compared to silicon based solar cells. In this report, we utilized Piper ornatum (PO) and Piper betle (PB) as sensitizer to fabricate low cost DSSCs. We compared the photovoltaic performance of both sensitizers with Titanium dioxide (TiO2) and Tin dioxide (SnO2) semiconductors. The results show that PO and PB dyes have higher Short circuit current (Jsc) when applied in SnO2 compared to standard TiO2 photo-anode film even though the Open circuit voltage (Voc) was hampered on SnO2 device. In conclusion, from the result, higher electron injections can be achieved by choosing appropriate semiconductors with band gap that match with dyes energy level as one of strategy for further low cost solar cell.

  15. Novel nanostructures for next generation dye-sensitized solar cells

    KAUST Repository

    Té treault, Nicolas; Grä tzel, Michael

    2012-01-01

    Herein, we review our latest advancements in nanostructured photoanodes for next generation photovoltaics in general and dye-sensitized solar cells in particular. Bottom-up self-assembly techniques are developed to fabricate large-area 3D

  16. Photolysis of hexaarylbiimidazole sensitized by dyes and application in photopolymerization

    Institute of Scientific and Technical Information of China (English)

    GAO, Fang(高放); XU, Jin- Qi(徐锦棋); SONG, Xiao-You(宋晓友); LI, Li-Dong(李立东); YANG, Yong-Yuan(杨永源); FENG, Shu-Jing(冯树京)

    2000-01-01

    Kinetic studies on the near-UV photo-initiating polymerization of methylmethacrylate (MMA) sensitized by dye/hexaarylbiimidazole systems were carried out. When exposed to highpressure mercury lamp (filtered by Pyrex glass), dye/hexaarylbiimidazole system undergoes quick electron transfer and free radicals are produced. RSH, as hydrogen donor, can improve the polymerization efficiency of MMA. Comparisons of influence of different dyes and different RSH on the conversion of MMA photopolymerization were carried out. Excellent results have been obtained in photoimaging studies, e.g. a minimum exposure energy of the photosensitive systems of 8 mJ/cm2 can be reached and the resolution of presensitized printing plate was ca. 10μm.

  17. Effect of sintering time on the performance of turmeric dye-sensitized solar cells

    Science.gov (United States)

    Basuki, Hidajat, R. Lullus Lambang G.; Suyitno, Kristiawan, Budi; Rachmanto, Rendy Adhi

    2017-01-01

    This study reports the effect of sintering time on the performance of the dye-sensitized solar cells with turmeric dyes as sensitizers. Sintering TiO2 semiconductors were conducted at a temperature of 450°C for 30, 50, 90, 120, 150, and 180 minutes. The natural dye was extracted from dried turmeric powders with ethanol solvent. The results show that size of grains and the opening area of TiO2 semiconductor depended on the sintering time. The improvement of the properties of TiO2 semiconductor allowed more turmeric dyes were adsorbed by the semiconductors and then improved the performance of solar cells. The sintering time of 150 minutes produced large grains with an average diameter of 68.87 nm, and a porosity area of 26.51% caused the performance of DSSCs was the highest among other sintering time. The Voc, Jsc, and efficiency of DSSCs with turmeric-based natural dyes 0.64 V, 0.47 mA/cm2, and 0.2%, respectively.

  18. Fe-tannic acid complex dye as photo sensitizer for different morphological ZnO based DSSCs

    Science.gov (United States)

    Çakar, Soner; Özacar, Mahmut

    2016-06-01

    In this paper we have synthesized different morphological ZnO nanostructures via microwave hydrothermal methods at low temperature within a short time. We described different morphologies of ZnO at different Zn(NO3)2/KOH mole ratio. The ZnO nanostructures were characterized via X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and UV-vis spectrophotometry. All ZnO structures have hexagonal wurtzite type structures. The FESEM images showed various morphologies of ZnO such as plate, rod and nanoparticles. Dye sensitized solar cells have been assembled by these different morphological structures photo electrode and tannic acid or Fe-tannic acid complex dye as sensitizer. We have achieved at maximum efficiencies of photovoltaic cells prepared with ZnO plate in all dye systems. The conversion efficiencies of dye sensitized solar cells are 0.37% and 1.00% with tannic acid and Fe-tannic acid complex dye, respectively.

  19. Nanoparticle/Polymer assembled microcapsules with pH sensing property.

    Science.gov (United States)

    Zhang, Pan; Song, Xiaoxue; Tong, Weijun; Gao, Changyou

    2014-10-01

    The dual-labeled microcapsules via nanoparticle/polymer assembly based on polyamine-salt aggregates can be fabricated for the ratiometric intracellular pH sensing. After deposition of SiO2 nanoparticles on the poly(allylamine hydrochloride)/multivalent anionic salt aggregates followed by silicic acid treatment, the generated microcapsules are stable in a wide pH range (3.0 ∼ 8.0). pH sensitive dye and pH insensitive dye are simultaneously labeled on the capsules, which enable the ratiometric pH sensing. Due to the rough and positively charged surface, the microcapsules can be internalized by several kinds of cells naturally. Real-time measurement of intracellular pH in several living cells shows that the capsules are all located in acidic organelles after being taken up. Furthermore, the negatively charged DNA and dyes can be easily encapsulated into the capsules via charge interaction. The microcapsules with combination of localized pH sensing and drug loading abilities have many advantages, such as following the real-time transportation and processing of the carriers in cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. In Situ Mapping of the Molecular Arrangement of Amphiphilic Dye Molecules at the TiO 2 Surface of Dye-Sensitized Solar Cells

    KAUST Repository

    Voïtchovsky, Kislon

    2015-05-27

    © 2015 American Chemical Society. Amphiphilic sensitizers are central to the function of dye-sensitized solar cells. It is known that the cell\\'s performance depends on the molecular arrangement and the density of the dye on the semiconductor surface, but a molecular-level picture of the cell-electrolyte interface is still lacking. Here, we present subnanometer in situ atomic force microscopy images of the Z907 dye at the surface of TiO2 in a relevant liquid. Our results reveal changes in the conformation and the lateral arrangement of the dye molecules, depending on their average packing density on the surface. Complementary quantitative measurements on the ensemble of the film are obtained by the quartz-crystal microbalance with dissipation technique. An atomistic picture of the dye coverage-dependent packing, the effectiveness of the hydrophobic alkyl chains as blocking layer, and the solvent accessibility is obtained from molecular dynamics simulations. (Figure Presented).

  1. Fluorescent pH sensor based on Ag@SiO2 core-shell nanoparticle.

    Science.gov (United States)

    Bai, Zhenhua; Chen, Rui; Si, Peng; Huang, Youju; Sun, Handong; Kim, Dong-Hwan

    2013-06-26

    We have demonstrated a novel method for the preparation of a fluorescence-based pH sensor by combining the plasmon resonance band of Ag core and pH sensitive dye (HPTS). A thickness-variable silica shell is placed between Ag core and HPTS dye to achieve the maximum fluorescence enhancement. At the shell thickness of 8 nm, the fluorescence intensity increases 4 and 9 times when the sensor is excited at 405 and 455 nm, respectively. At the same time, the fluorescence intensity shows a good sensitivity toward pH value in the range of 5-9, and the ratio of emission intensity at 513 nm excited at 455 nm to that excited at 405 nm versus the pH value in the range of 5-9 is determined. It is believed that the present pH sensor has the potential for determining pH real time in the biological sample.

  2. Functional photoacoustic microscopy of pH.

    Science.gov (United States)

    Chatni, Muhammad Rameez; Yao, Junjie; Danielli, Amos; Favazza, Christopher P; Maslov, Konstantin I; Wang, Lihong V

    2011-10-01

    pH is a tightly regulated indicator of metabolic activity. In mammalian systems, an imbalance of pH regulation may result from or result in serious illness. In this paper, we report photoacoustic microscopy (PAM) of a commercially available pH-sensitive fluorescent dye (SNARF-5F carboxylic acid) in tissue phantoms. We demonstrated that PAM is capable of pH imaging in absolute values at tissue depths of up to 2.0 mm, greater than possible with other forms of optical microscopy.

  3. The chemical bonds effect of anthocyanin and chlorophyll dyes on TiO2 for dye-sensitized solar cell (DSSC)

    Science.gov (United States)

    Ahliha, A. H.; Nurosyid, F.; Supriyanto, A.; Kusumaningsih, T.

    2017-11-01

    Anthocyanin and chlorophyll dyes have been blended as the photosensitizer of Dye-Sensitized Solar Cell (DSSC). The results study showed the effect of chemical bond dyes on TiO2 and the efficiency of DSSC. Ratio blend of the anthocyanin and chlorophyll dyes are 1:1. The absorbance of dyes and TiO2 were characterized using UV-Vis Spectrophotometer. The chemical bonds contained in TiO2-dyes were characterized using FT-IR spectrophotometer. The efficiency of DSSC was calculated using I-V meter. The absorption spectra of chlorophyll: anthocyanin blend dye solutions and TiO2 films can increase after the dye adsorption. Absorbance characterization of anthocyanin and chlorophyll dye blend solutions showed three peaks at the wavelength of 412 nm; 535.5 nm; and 656.5 nm. Absorbance characterization of spinach before being blend with anthocyanin dyes solutions showed two peaks at the wavelength of 431 nm and 665.5 nm. The absorption spectra of TiO2 films can increase after the dyes adsorption at the wavelength of 400 nm. FT-IR spectra of TiO2 founded the functional groups C-Br, C=C, and O-H. The functional groups founded in anthocyanin: chlorophyll dye blended on the surface of TiO2 are C-Br, C-O, O-H, C-H, C=C, C=O, and O-H. The result showed that the greatest efficiency of 0.0544% at dye red cabbage-spinach. Adsorption blends of anthocyanin and chlorophyll dyes on the surface of TiO2 can be used as the photosensitizer for DSSC.

  4. Effect of composition of chlorophyll and ruthenium dyes mixture (hybrid) on the dye-sensitized solar cell performance

    Science.gov (United States)

    Pratiwi, D. D.; Nurosyid, F.; Kusumandari; Supriyanto, A.; Suryana, R.

    2018-03-01

    The fabrication of dye-sensitized solar cell (DSSC) has been conducted by varying the composition of natural dye from moss chlorophyll (Bryophyte) and synthesis dye from ruthenium complex N719. The sandwich structure of DSSC consists of the working electrode using TiO2, dye, electrolyte, and counter electrode using carbon. The composition of chlorophyll and synthesis dyes mixture were 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80%. The UV-Vis absorption spectra of moss chlorophyll showed the first peak in the wavelength range of 450-500 nm and the second peak at wavelength of 650-700 nm. The peak value of absorbance at wavelengths of 450-500 nm was 6.1004 and at wavelengths of 650-700 nm was 3.5835. The IPCE characteristic curves showed the absorption peak of photon for DSSCs occurred at wavelength of 550-650 nm. It considered that photon in this wavelength can contribute dominantly to produce the optimum electrons. The I-V characteristics of DSSCs with composition of chlorophyll and synthesis dyes mixture of 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80% resulted the efficiency of 0.0022; 0.0194; 0.0239; 0.0342; and 0.0414, respectively. It suggested that the addition of a little composition of the ruthenium complex dye into moss chlorophyll dye can increase the efficiency significantly.

  5. Numerical Procedure for Optimizing Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Mihai Razvan Mitroi

    2014-01-01

    Full Text Available We propose a numerical procedure consisting of a simplified physical model and a numerical method with the aim of optimizing the performance parameters of dye-sensitized solar cells (DSSCs. We calculate the real rate of absorbed photons (in the dye spectral range Grealx by introducing a factor β<1 in order to simplify the light absorption and reflection on TCO electrode. We consider the electrical transport to be purely diffusive and the recombination process only to occur between electrons from the TiO2 conduction band and anions from the electrolyte. The used numerical method permits solving the system of differential equations resulting from the physical model. We apply the proposed numerical procedure on a classical DSSC based on Ruthenium dye in order to validate it. For this, we simulate the J-V characteristics and calculate the main parameters: short-circuit current density Jsc, open circuit voltage Voc, fill factor FF, and power conversion efficiency η. We analyze the influence of the nature of semiconductor (TiO2 and dye and also the influence of different technological parameters on the performance parameters of DSSCs. The obtained results show that the proposed numerical procedure is suitable for developing a numerical simulation platform for improving the DSSCs performance by choosing the optimal parameters.

  6. Hyperbranched quasi-1D nanostructures for solid-state dye-sensitized solar cells.

    Science.gov (United States)

    Passoni, Luca; Ghods, Farbod; Docampo, Pablo; Abrusci, Agnese; Martí-Rujas, Javier; Ghidelli, Matteo; Divitini, Giorgio; Ducati, Caterina; Binda, Maddalena; Guarnera, Simone; Li Bassi, Andrea; Casari, Carlo Spartaco; Snaith, Henry J; Petrozza, Annamaria; Di Fonzo, Fabio

    2013-11-26

    In this work we demonstrate hyperbranched nanostructures, grown by pulsed laser deposition, composed of one-dimensional anatase single crystals assembled in arrays of high aspect ratio hierarchical mesostructures. The proposed growth mechanism relies on a two-step process: self-assembly from the gas phase of amorphous TiO2 clusters in a forest of tree-shaped hierarchical mesostructures with high aspect ratio; oriented crystallization of the branches upon thermal treatment. Structural and morphological characteristics can be optimized to achieve both high specific surface area for optimal dye uptake and broadband light scattering thanks to the microscopic feature size. Solid-state dye sensitized solar cells fabricated with arrays of hyperbranched TiO2 nanostructures on FTO-glass sensitized with D102 dye showed a significant 66% increase in efficiency with respect to a reference mesoporous photoanode and reached a maximum efficiency of 3.96% (among the highest reported for this system). This result was achieved mainly thanks to an increase in photogenerated current directly resulting from improved light harvesting efficiency of the hierarchical photoanode. The proposed photoanode overcomes typical limitations of 1D TiO2 nanostructures applied to ss-DSC and emerges as a promising foundation for next-generation high-efficiency solid-state devices comprosed of dyes, polymers, or quantum dots as sensitizers.

  7. Carbon Nanotubes Counter Electrode for Dye-Sensitized Solar Cells Application

    Directory of Open Access Journals (Sweden)

    Drygała A.

    2016-06-01

    Full Text Available The influence of the carbon nanotubes counter electrode deposited on the FTO glass substrates on the structure and optoelectrical properties of dye-sensitized solar cells counter electrode (CE was analysed. Carbon materials have been applied in DSSC s in order to produce low-cost solar cells with reasonable efficiency. Platinum is a preferred material for the counter electrode because of its high conductivity and catalytic activity. However, the costs of manufacturing of the platinum counter electrode limit its use to large-scale applications in solar cells. This paper presents the results of examining the structure and properties of the studied layers, defining optical properties of conductive layers and electrical properties of dye-sensitized solar cells manufactured with the use of carbon nanotubes.

  8. Design and synthesis of BODIPY sensitizers with long alkyl chains tethered to N-carbazole and their application for dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheema, Hammad [Polymer and Color Chemistry Program, North Carolina State University, Raleigh, NC, 27695 (United States); Younts, Robert; Gautam, Bhoj; Gundogdu, Kenan [Physics Department, North Carolina State University, Raleigh, NC, 27695 (United States); El-Shafei, Ahmed, E-mail: Ahmed_El-Shafei@ncsu.edu [Polymer and Color Chemistry Program, North Carolina State University, Raleigh, NC, 27695 (United States)

    2016-12-01

    In this study, three boron dipyrromethenes (BODIPY) dyes with extended conjugation and electron donating carbazole groups with different alkyl chain lengths tethered to N-carbazole were synthesized and characterized for dye-sensitized solar cells. The goal was to study the effect of different alkyl chain lengths on dye aggregation at TiO{sub 2} surface. The proposed molecular strategy resulted in BODIPY dyes which showed interesting electronic absorption and fluorescence properties. It was observed that intramolecular energy transfer decreases with the increase in alkyl chain length possibly due to induced changes in molecular geometry caused by long alkyl chains. Additionally, interface analysis by impedance spectroscopy in comparison to N719 sensitized TiO{sub 2} solar cell showed significant charge transport related losses (Nyquist plot) most likely due to impedance resulted from aggregated BODIPY dye on TiO{sub 2} surface. Femtosecond transient absorption studies showed the loss of excited electrons by recombination with oxidized ground state of the sensitizers. - Highlights: • BODIPY dyes with carbazole electron donating groups are characterized. • Photophysics is discussed based on transient and steady state spectroscopy results. • Impedance spectroscopy found huge charge transport related losses on TiO{sub 2.}.

  9. Design and synthesis of BODIPY sensitizers with long alkyl chains tethered to N-carbazole and their application for dye sensitized solar cells

    International Nuclear Information System (INIS)

    Cheema, Hammad; Younts, Robert; Gautam, Bhoj; Gundogdu, Kenan; El-Shafei, Ahmed

    2016-01-01

    In this study, three boron dipyrromethenes (BODIPY) dyes with extended conjugation and electron donating carbazole groups with different alkyl chain lengths tethered to N-carbazole were synthesized and characterized for dye-sensitized solar cells. The goal was to study the effect of different alkyl chain lengths on dye aggregation at TiO_2 surface. The proposed molecular strategy resulted in BODIPY dyes which showed interesting electronic absorption and fluorescence properties. It was observed that intramolecular energy transfer decreases with the increase in alkyl chain length possibly due to induced changes in molecular geometry caused by long alkyl chains. Additionally, interface analysis by impedance spectroscopy in comparison to N719 sensitized TiO_2 solar cell showed significant charge transport related losses (Nyquist plot) most likely due to impedance resulted from aggregated BODIPY dye on TiO_2 surface. Femtosecond transient absorption studies showed the loss of excited electrons by recombination with oxidized ground state of the sensitizers. - Highlights: • BODIPY dyes with carbazole electron donating groups are characterized. • Photophysics is discussed based on transient and steady state spectroscopy results. • Impedance spectroscopy found huge charge transport related losses on TiO_2_.

  10. High-resolution Imaging of pH in Alkaline Sediments and Water Based on a New Rapid Response Fluorescent Planar Optode

    Science.gov (United States)

    Han, Chao; Yao, Lei; Xu, Di; Xie, Xianchuan; Zhang, Chaosheng

    2016-05-01

    A new dual-lumophore optical sensor combined with a robust RGB referencing method was developed for two-dimensional (2D) pH imaging in alkaline sediments and water. The pH sensor film consisted of a proton-permeable polymer (PVC) in which two dyes with different pH sensitivities and emission colors: (1) chloro phenyl imino propenyl aniline (CPIPA) and (2) the coumarin dye Macrolex® fluorescence yellow 10 GN (MFY-10 GN) were entrapped. Calibration experiments revealed the typical sigmoid function and temperature dependencies. This sensor featured high sensitivity and fast response over the alkaline working ranges from pH 7.5 to pH 10.5. Cross-sensitivity towards ionic strength (IS) was found to be negligible for freshwater when IS applications.

  11. Experimental elaboration and analysis of dye-sensitized TiO2 solar cells (DSSC) dyed by natural dyes and conductive polymers

    Science.gov (United States)

    KałuŻyński, P.; Maciak, E.; Herzog, T.; Wójcik, M.

    2016-09-01

    In this paper we propose low cost and easy in development fully working dye-sensitized solar cell module made with use of a different sensitizing dyes (various anthocyanins and P3HT) for increasing the absorption spectrum, transparent conducting substrates (vaccum spattered chromium and gold), nanometer sized TiO2 film, iodide and methyl viologen dichloride based electrolyte, and a counter electrode (vaccum spattered platinum or carbon). Moreover, some of the different technologies and optimization manufacturing processes were elaborated for energy efficiency increase and were presented in this paper.

  12. New triarylamine organic dyes containing the 9-hexyl-2-(hexyloxy)-9H-carbazole for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Su, Jianyang; Chen, Yu; Wu, Yungen; Ghimire, Raju Prasad; Xu, Yingjun; Liu, Xiujie; Wang, Zhihui; Liang, Mao

    2017-01-01

    Highlights: •9-hexyl-2-(hexyloxy)-9H-carbazole (HHCBZ) was synthesized for organic dyes. •Three new triarylamine sensitizers based on the HHCBZ unit were synthesized. •The HHCBZ unit outperforms the HCBZ when used as an electron donor. •An efficiency of 8.67% was achieved by M92 with the HHCBZ donor. -- Abstract: Developing carbazole derivatives as the electron donor for organic dyes have attracted extensive interest recently. Three organic dyes M92-94 based on the 9-hexyl-2-(hexyloxy)-9H-carbazole (HHCBZ) electron donor have been successfully designed and synthesized for dye-sensitized solar cells. M95 with the 9-hexyl-9H-carbazole (HCBZ) unit has also been synthesized for comparison. An introduction of the HHCBZ unit in triarylamine brings several advantages: (i) red shifting the absorption peak and increasing the maximum molar absorption coefficient of absorption bands; (ii) decreasing the charge recombination in cobalt cells as well as iodine cells; (iii) enhancing photocurrent/photovoltage and thus the power conversion efficiencies of cobalt cells as well as iodine cells. Devices prepared with M92 show consistently higher light-to-electric energy conversion efficiencies, with the champion device reaching 8.67%, surpassing M93-95.

  13. Influence of annealing temperature and organic dyes as sensitizers on sol–gel derived TiO{sub 2} films

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Mamta; Abbas, Saeed J.; Tripathi, S.K., E-mail: surya@pu.ac.in

    2014-09-15

    Highlights: • Preparation of rice shaped TiO{sub 2} nanorods with anatase structure by sol–gel method. • Effect of post deposition annealing on structural properties of TiO{sub 2} is studied. • Unlike individual dye, absorption of Cocktail dye with TiO{sub 2} nanorods is broader. • Cocktail dye sensitized TiO{sub 2} film has more photosensitivity than EY, RB, AO. • Increase in photosensitivity up to optimum temperature is due to hole passivation. - Abstract: Five different organic dyes and reported cocktail dye composed of these dyes are used as sensitizer for titanium dioxide (TiO{sub 2}). Rice shaped (TiO{sub 2}) nanorods are prepared by using sol–gel method. The films annealed at 673 K and above are crystalline with anatase structure. The effect of post annealing temperature is studied on various structural parameters. Cocktail dye shows broader absorption with TiO{sub 2} nanorods in visible region compared with five dyes. Maximum photosensitivity is obtained with RhB dye, followed by FGF and cocktail dye sensitized TiO{sub 2} films. Increase in photosensitivity is due to passivating some hole traps on the surface up to some optimum temperature, above which photosensitivity decreases due to a higher photo activation energy compared to dark conductivity in low temperature region and also may be due to damage of the dye molecule. This work may prove its worth for understanding the electron transport in dye sensitized nanodevices.

  14. Dye-sensitized solar cells using natural dye as light-harvesting materials extracted from Acanthus sennii chiovenda flower and Euphorbia cotinifolia leaf

    Directory of Open Access Journals (Sweden)

    Wuletaw Andargie Ayalew

    2016-12-01

    Full Text Available Natural dyes are environmentally and economically superior to ruthenium-based dyes because they are nontoxic and cheap. In this study, dye-sensitized solar cells (DSSCs were fabricated using natural dyes light harvesting materials. The natural dyes were extracted from Acanthus sennii chiovenda flower and Euphorbia cotinifolia leaf. In the as-prepared DSSC, a quasi-solid state electrolyte was sandwiched between the working electrode (photoanode and counter electrode (PEDOT-coated FTO glass. The photoelectrochemical performance of the as-prepared quasi-solid state DSSCs showed open-circuit voltages (VOC varied from 0.475 to 0.507 V, the short-circuit current densities (JSC ranged from 0.352 to 0.642 mA cm−2 and the fill factors (FF varied from 47 to 60% at 100 mWcm−2 light intensity. The dye extracted from A. sennii chiovenda flower, using acidified ethanol (in 1% HCl as extracting solvent, exhibited best conversion efficiency with a maximum open-circuit voltage (VOC of 0.507 V, short-circuit current density (JSC of 0.491 mA cm−2, fill factor (FF of 0.60 and an overall conversion efficiency (η of 0.15%. On the other hand, the maximum power conversion efficiency of the dye extracted from E. cotinifolia leaf was 0.136%. This is the first study that reports the fabrication of DSSC using natural dye sensitizers extracted from these plants in the presence of quasi-solid state electrolyte and PEDOT as a counter electrode.

  15. Performance Characterization of Dye-Sensitized Photovoltaics under Indoor Lighting.

    Science.gov (United States)

    Chen, Chia-Yuan; Jian, Zih-Hong; Huang, Shih-Han; Lee, Kun-Mu; Kao, Ming-Hsuan; Shen, Chang-Hong; Shieh, Jia-Min; Wang, Chin-Li; Chang, Chiung-Wen; Lin, Bo-Zhi; Lin, Ching-Yao; Chang, Ting-Kuang; Chi, Yun; Chi, Cheng-Yu; Wang, Wei-Ting; Tai, Yian; Lu, Ming-De; Tung, Yung-Liang; Chou, Po-Ting; Wu, Wen-Ti; Chow, Tahsin J; Chen, Peter; Luo, Xiang-Hao; Lee, Yuh-Lang; Wu, Chih-Chung; Chen, Chih-Ming; Yeh, Chen-Yu; Fan, Miao-Syuan; Peng, Jia-De; Ho, Kuo-Chuan; Liu, Yu-Nan; Lee, Hsiao-Yi; Chen, Chien-Yu; Lin, Hao-Wu; Yen, Chia-Te; Huang, Yu-Ching; Tsao, Cheng-Si; Ting, Yu-Chien; Wei, Tzu-Chien; Wu, Chun-Guey

    2017-04-20

    Indoor utilization of emerging photovoltaics is promising; however, efficiency characterization under room lighting is challenging. We report the first round-robin interlaboratory study of performance measurement for dye-sensitized photovoltaics (cells and mini-modules) and one silicon solar cell under a fluorescent dim light. Among 15 research groups, the relative deviation in power conversion efficiency (PCE) of the samples reaches an unprecedented 152%. On the basis of the comprehensive results, the gap between photometry and radiometry measurements and the response of devices to the dim illumination are identified as critical obstacles to the correct PCE. Therefore, we use an illuminometer as a prime standard with a spectroradiometer to quantify the intensity of indoor lighting and adopt the reverse-biased current-voltage (I-V) characteristics as an indicator to qualify the I-V sampling time for dye-sensitized photovoltaics. The recommendations can brighten the prospects of emerging photovoltaics for indoor applications.

  16. Vibrational Spectroscopy on Photoexcited Dye-Sensitized Films via Pump-Degenerate Four-Wave Mixing.

    Science.gov (United States)

    Abraham, Baxter; Fan, Hao; Galoppini, Elena; Gundlach, Lars

    2018-03-01

    Molecular sensitization of semiconductor films is an important technology for energy and environmental applications including solar energy conversion, photocatalytic hydrogen production, and water purification. Dye-sensitized films are also scientifically complex and interesting systems with a long history of research. In most applications, photoinduced heterogeneous electron transfer (HET) at the molecule/semiconductor interface is of critical importance, and while great progress has been made in understanding HET, many open questions remain. Of particular interest is the role of combined electronic and vibrational effects and coherence of the dye during HET. The ultrafast nature of the process, the rapid intramolecular vibrational energy redistribution, and vibrational cooling present complications in the study of vibronic coupling in HET. We present the application of a time domain vibrational spectroscopy-pump-degenerate four-wave mixing (pump-DFWM)-to dye-sensitized solid-state semiconductor films. Pump-DFWM can measure Raman-active vibrational modes that are triggered by excitation of the sample with an actinic pump pulse. Modifications to the instrument for solid-state samples and its application to an anatase TiO 2 film sensitized by a Zn-porphyrin dye are discussed. We show an effective combination of experimental techniques to overcome typical challenges in measuring solid-state samples with laser spectroscopy and observe molecular vibrations following HET in a picosecond time window. The cation spectrum of the dye shows modes that can be assigned to the linker group and a mode that is localized on the Zn-phorphyrin chromophore and that is connected to photoexcitation.

  17. Enhancing dye-sensitized solar cell efficiency by anode surface treatments

    International Nuclear Information System (INIS)

    Chang, Chao-Hsuan; Lin, Hsin-Han; Chen, Chin-Cheng; Hong, Franklin C.-N.

    2014-01-01

    In this study, titanium substrates treated with HF solution and KOH solution sequentially forming micro- and nano-structures were used for the fabrication of flexible dye-sensitized solar cells (DSSCs). After wet etching treatments, the titanium substrates were then exposed to the O 2 plasma treatment and further immersed in titanium tetrachloride (TiCl 4 ) solution. The process conditions for producing a very thin TiO 2 blocking layer were studied, in order to avoid solar cell current leakage for increasing the solar cell efficiency. Subsequently, TiO 2 nanoparticles were spin-coated on Ti substrates with varied thickness. The dye-sensitized solar cells on the titanium substrates were subjected to simulate AM 1.5 G irradiation of 100 mW/cm 2 using backside illumination mode. Surface treatments of Ti substrate and TiO 2 anode were found to play a significant role in improving the efficiency of DSSC. The efficiencies of the backside illumination solar cells were raised from 4.6% to 7.8% by integrating these surface treatments. - Highlights: • The flexible dye-sensitized solar cell (DSSC) device can be fabricated. • Many effective surface treatment methods to improve DSSC efficiency are elucidated. • The efficiency is dramatically enhanced by integrating surface treatment methods. • The back-illuminated DSSC efficiency was raised from 4.6% to 7.8%

  18. Photoanode Thickness Optimization and Impedance Spectroscopic Analysis of Dye-Sensitized Solar Cells based on a Carbazole-Containing Ruthenium Dye

    Science.gov (United States)

    Choi, Jongwan; Kim, Felix Sunjoo

    2018-03-01

    We studied the influence of photoanode thickness on the photovoltaic characteristics and impedance responses of the dye-sensitized solar cells based on a ruthenium dye containing a hexyloxyl-substituted carbazole unit (Ru-HCz). As the thickness of photoanode increases from 4.2 μm to 14.8 μm, the dye-loading amount and the efficiency increase. The device with thicker photoanode shows a decrease in the efficiency due to the higher probability of recombination of electron-hole pairs before charge extraction. We also analyzed the electron-transfer and recombination characteristics as a function of photoanode thickness through detailed electrochemical impedance spectroscopy analysis.

  19. Optical pH Sensor Covering the Range from pH 0-14 Compatible with Mobile-Device Readout and Based on a Set of Rationally Designed Indicator Dyes.

    Science.gov (United States)

    Gotor, Raúl; Ashokkumar, Pichandi; Hecht, Mandy; Keil, Karin; Rurack, Knut

    2017-08-15

    In this work, a family of pH-responsive fluorescent probes has been designed in a rational manner with the aid of quantum chemistry tools, covering the entire pH range from 0-14. Relying on the boron-dipyrromethene (BODIPY) core, all the probes as well as selected reference dyes display very similar spectroscopic properties with ON-OFF fluorescence switching responses, facilitating optical readout in simple devices used for detection and analysis. Embedding of the probes and reference dyes into hydrogel spots on a plastic strip yielded a test strip that reversibly indicates pH with a considerably small uncertainty of ∼0.1 pH units. These strips are not only reusable but, combined with a 3D-printed case that can be attached to a smartphone, the USB port of which drives the integrated LED used for excitation, allows for autonomous operation in on-site or in-the-field applications; the developed Android application software ("app") further simplifies operation for unskilled users.

  20. Theoretical Study of Ultrafast Electron Injection into a Dye/TiO2 System in Dye-Sensitized Solar Cells

    Science.gov (United States)

    Lin, Chundan; Xia, Qide; Li, Kuan; Li, Juan; Yang, Zhenqing

    2018-06-01

    The ultrafast injection of excited electrons in dye/TiO2 system plays a critical role, which determines the device's efficiency in large part. In this work, we studied the geometrical structures and electronic properties of a dye/TiO2 composite system for dye-sensitized solar cells (DSSCs) by using density functional theory, and we analyzed the mechanism of ultrafast electron injection with emphasis on the power conversion efficiency. The results show that the dye SPL103/TiO2 (101) surface is more stable than dye SPL101. The electron injection driving force of SPL103/TiO2 (101) is 3.55 times that of SPL101, indicating that SPL103/TiO2 (101) has a strong ability to transfer electrons. SPL103 and SPL101/TiO2 (101) both have fast electron transfer processes, and especially the electron injection time of SPL103/TiO2 (101) is only 1.875 fs. The results of this work are expected to provide a new understanding of the mechanism of electron injection in dyes/TiO2 systems for use in highly effective DSSCs.

  1. Fabrication of dye-sensitized solar cells with multilayer photoanodes

    Indian Academy of Sciences (India)

    Volume 39 Issue 6 October 2016 pp 1403-1410 ... Keywords. Dye-sensitized solar cells; hydrothermal method; TiO 2 nanocrystals; multilayer photoanodes; energy conversion efficiency. ... Higher energy conversion efficiencies were also attainable using two transparent sub-layers of hydrothermally grown TiO 2 NCs.

  2. OPTIMIZATION OF DYEING PARAMETERS TO DYE COTTON WITH CARROT EXTRACTION

    Directory of Open Access Journals (Sweden)

    MIRALLES Verónica

    2017-05-01

    Full Text Available Natural dyes derived from flora and fauna are believed to be safe because of non-toxic, non-carcinogenic and biodegradable nature. Furthermore, natural dyes do not cause pollution and waste water problems. Natural dyes as well as synthetic dyes need the optimum parameters to get a good dyeing. On some occasions, It is necessary the use of mordants to increase the affinity between cellulose fiber and natural dye, but there are other conditions to optimize in the dyeing process, like time, temperature, auxiliary porducts, etc. In addition, the optimum conditions are different depends on the type of dye and the fiber nature. The aim of this work is the use of carrot extract to dye cotton fabric by exhaustion at diverse dyeing conditions. Diffferent dyeing processes were carried out to study the effect of pH condition and the temperature, using 7, 6 and 4 pH values and 95 ºC and 130ºC for an hour. As a result some images of dyed samples are shown. Moreover, to evaluate the colour of each sample CIELAB parameters are analysed obtained by reflexion spectrophotometre. The results showed that the temperature used has an important influence on the colour of the dyed sample.

  3. Single-crystalline self-branched anatase titania nanowires for dye-sensitized solar cells

    Science.gov (United States)

    Li, Zhenquan; Yang, Huang; Wu, Fei; Fu, Jianxun; Wang, Linjun; Yang, Weiguang

    2017-03-01

    The morphology of the anatase titania plays an important role in improving the photovoltaic performance in dye-sensitized solar cells. In this work, single-crystalline self-branched anatase TiO2 nanowires have been synthesized by hydrothermal method using TBAH and CTAB as morphology controlling agents. The obtained self-branched TiO2 nanowires dominated by a large percentage of (010) facets. The photovoltaic conversion efficiency (6.37%) of dye-sensitized solar cell (DSSC) based on the self-branched TiO2 nanowires shows a significant improvement (26.6%) compared to that of P25 TiO2 (5.03%). The enhanced performance of the self-branched TiO2 nanowires-based DSSC is due to heir large percent of exposed (010) facets which have strong dye adsorption capacity and effective charge transport of the self-branched 1D nanostructures.

  4. Apoplastic pH in corn root gravitropism: a laser scanning confocal microscopy measurement

    International Nuclear Information System (INIS)

    Taylor, D.P.; Slattery, J.; Leopold, A.C.

    1996-01-01

    The ability to measure the pH of the apoplast in situ is of special interest as a test of the cell wall acidification theory. Optical sectioning of living seedlings of corn roots using the laser scanning confocal microscope (LSCM) permits us to make pH measurements in living tissue. The pH of the apoplast of corn roots was measured by this method after infiltration with CI-NERF, a pH-sensitive dye, along with Texas Red Dextran 3000, a pH-insensitive dye, as an internal standard. In the elongation zone of corn roots, the mean apoplastic pH was 4.9. Upon gravitropic stimulation, the pH on the convex side of actively bending roots was 4.5. The lowering of the apoplastic pH by 0.4 units appears to be sufficient to account for the increased growth on that side. This technique provides site-specific evidence for the acid growth theory of cell elongation. The LSCM permits measurements of the pH of living tissues, and has a sensitivity of approximately 0.2 pH units. (author)

  5. Insights into the Mechanism of a Covalently Linked Organic Dye-Cobaloxime Catalyst System for Dye-Sensitized Solar Fuel Devices.

    Science.gov (United States)

    Pati, Palas Baran; Zhang, Lei; Philippe, Bertrand; Fernández-Terán, Ricardo; Ahmadi, Sareh; Tian, Lei; Rensmo, Håkan; Hammarström, Leif; Tian, Haining

    2017-06-09

    A covalently linked organic dye-cobaloxime catalyst system based on mesoporous NiO is synthesized by a facile click reaction for mechanistic studies and application in a dye-sensitized solar fuel device. The system is systematically investigated by photoelectrochemical measurements, density functional theory, time-resolved fluorescence, transient absorption spectroscopy, and photoelectron spectroscopy. The results show that irradiation of the dye-catalyst on NiO leads to ultrafast hole injection into NiO from the excited dye, followed by a fast electron transfer process to reduce the catalyst. Moreover, the dye adopts different structures with different excited state energies, and excitation energy transfer occurs between neighboring molecules on the semiconductor surface. The photoelectrochemical experiments also show hydrogen production by this system. The axial chloride ligands of the catalyst are released during photocatalysis to create the active sites for proton reduction. A working mechanism of the dye-catalyst system on the photocathode is proposed on the basis of this study. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  6. [1]Benzothieno[3,2-b]benzothiophene-Based Organic Dyes for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Capodilupo, Agostina L; Fabiano, Eduardo; De Marco, Luisa; Ciccarella, Giuseppe; Gigli, Giuseppe; Martinelli, Carmela; Cardone, Antonio

    2016-04-15

    Three new metal-free organic dyes with the [1]benzothieno[3,2-b]benzothiophene (BTBT) π-bridge, having the structure donor-π-acceptor (D-π-A) and labeled as 19, 20 and 21, have been designed and synthesized for application in dye-sensitized solar cells (DSSC). Once the design of the π-acceptor block was fixed, containing the BTBT as the π-bridge and the cyanoacrylic group as the electron acceptor and anchoring unit, we selected three donor units with different electron-donor capacity, in order to assemble new chromophores with high molar extinction coefficients (ε), whose absorption features well reflect the good performance of the final DSSC devices. Starting with the 19 dye, which shows a molar extinction coefficient ε of over 14,000 M(-1) cm(-1) and takes into account the absorption maximun at the longer wavelength, the substitution of the BFT donor unit with the BFA yields a great enhancement of absorptivity (molar extinction coefficient ε > 42,000 M(-1) cm(-1)), until reaching the higher value (ε > 69,000 M(-1) cm(-1)) with the BFPhz donor unit. The good general photovoltaic performances obtained with the three dyes highlight the suitable properties of electron-transport of the BTBT as the π-bridge in organic chromophore for DSSC, making this very cheap and easy to synthesize molecule particularly attractive for efficient and low-cost photovoltaic devices.

  7. Dual-fluorophore Raspberry-like Nanohybrids for Ratiometric pH Sensing.

    Science.gov (United States)

    Acquah, Isaac; Roh, Jinkyu; Ahn, Dong June

    2017-07-18

    We report on the development of raspberry-like silica structures formed by the adsorption of 8-hydroxypyrene-1,3,6-trisulfonate (HPTS)@silica nanoparticles (NPs) on rhodamine B isothiocyanate (RBTIC)@silica NPs for ratiometric fluorescence-based pH sensing. To overcome the well-known problem of dye leaching which occurs during encapsulation of anionic HPTS dye in silica NPs, we utilized a polyelectrolyte-assisted incorporation of the anionic HPTS. The morphological and optical characterization of the as-synthesized dye-doped NPs and the resulting nanohybrids were carried out. The pH-sensitive dye, HPTS, incorporated in the HPTS-doped silica NPs provided a pH-dependent fluorescence response while the RBITC-doped silica provided the reference signal for ratiometric sensing. We evaluated the effectiveness of the nanohybrids for pH sensing; the ratio of the fluorescence emission intensity at 510 nm and 583 nm at excitation wavelengths of 454 nm and 555 nm, respectively. The results showed a dynamic response in the acidic pH range. With this approach, nanohybrids containing different dyes or receptors could be developed for multifunctioning and multiplexing applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Dye-sensitized solar cell with natural gel polymer electrolytes and f-MWCNT as counter-electrode

    Science.gov (United States)

    Nwanya, A. C.; Amaechi, C. I.; Ekwealor, A. B. C.; Osuji, R. U.; Maaza, M.; Ezema, F. I.

    2015-05-01

    Samples of DSSCs were made with gel polymer electrolytes using agar, gelatin and DNA as the polymer hosts. Anthocyanine dye from Hildegardia barteri flower is used to sensitize the TiO2 electrode, and the spectrum of the dye indicates strong absorptions in the blue region of the solar spectrum. The XRD pattern of the TiO2 shows that the adsorption of the dye did not affect the crystallinity of the electrode. The f-MWCNT indicates graphite structure of the MWCNTs were acid oxidized without significant damage. Efficiencies of 3.38 and 0.1% were obtained using gelatin and DNA gel polymer electrolytes, respectively, for the fabricated dye-sensitized solar cells.

  9. Charge Transfer Dynamics of Highly Efficient Cyanidin-3-O- Glucoside Sensitizer for Dye-Sensitized Solar Cells

    International Nuclear Information System (INIS)

    Prima, E C; Yuliarto, B; Suyatman; Dipojono, H K

    2016-01-01

    This paper reports the novel efficiency achievement of black rice-based natural dye- sensitized solar cells. The higher dye concentration, the longer dye extraction as well as dye immersion onto a TiO 2 film, and the co-adsorption addition are key strategies for improved-cell performance compared to the highest previous achievement. The black rice dye containing 1.38 mM cyanidin-3-O-glucoside has been extracted without purification for 3 weeks at dark condition and room temperature. The anatase TiO 2 photoanode was dipped into dye solution within 4 days. Its electrode was firmly sealed to be a cell and was filled by I - /I 3 - electrolyte using vacuum technique. As a result, the overall solar-to-energy conversion efficiency was 1.49% at AM 1.5 illumination (100 mW.cm -2 ). The voltametric analysis has reported the interfacial electronic band edges of TiO 2 -Dye-Electrolyte. Furthermore, electrochemical impedance spectroscopy has shown the kinetic of interfacial electron transfer dynamics among TiO 2 -dye-electrolyte. The cell has the transfer resistance (Rt) of 12.5 ω, the recombination resistance (Rr) of 266.8 ω, effective electron diffusion coefficients (Dn) of 1.4 × 10 -3 cm 2 /s, Dye-TiO 2 effective electron transfer (τ d ) of 26.6 μs, effective diffusion length (L n )of 33.78 μm, chemical capacitance (C μ ) of 12.43 μF, and electron lifetime (τ n ) of 3.32 ms. (paper)

  10. Effects of carboxyl and ester anchoring groups on solar conversion efficiencies of TiO2 dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sepehrifard, A.; Stublla, A.; Haftchenary, S.; Chen, S.; Potvin, P.; Morin, S. [York Univ., Toronto, ON (Canada). Dept. of Chemistry

    2008-07-01

    This paper reported on a study in which 2 new Ruthenium (Ru(2)) dyes bearing different anchoring groups were applied to sensitize TiO2 for dye-sensitized solar cells (DSSCs). The solar conversion efficiencies were measured. Results for 2 of the dyes which carried ester and carboxyl anchoring groups were presented. The extent and nature of the surface binding was studied using electrochemical, UV-visible, fluorescence and FTIR measurements. Solar cell performance was discussed in terms of surface concentration of chemisorbed dyes, electronic properties of the photoanodes and electrochemical properties of adsorbed dyes. The study showed that carboxylic acid groups offer better dye adsorption than ester groups. However, sensitization with warm solutions improved the adsorption of the esterified dye, most likely through transesterification. It was concluded that this may be a useful means of improving solar conversion efficiencies of ester-bearing dyes. 6 refs., 1 tab., 2 figs.

  11. Conducting polymers based counter electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Veerender, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Saxena, Vibha, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gusain, Abhay, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Jha, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Koiry, S. P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Chauhan, A. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Aswal, D. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gupta, S. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai - 400085 (India)

    2014-04-24

    Conducting polymer films were synthesized and employed as an alternative to expensive platinum counter electrodes for dye-sensitized solar cells. poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) thin films were spin-coated and polypyrrole films were electrochemically deposited via cyclic voltammetry method on ITO substrates. The morphology of the films were imaged by SEM and AFM. These films show good catalytic activity towards triiodide reduction as compared to Pt/FTO electrodes. Finally the photovoltaic performance of DSSC fabricated using N3 dye were compared with PT/FTO, PEDOT/ITO, and e-PPy counter electrodes.

  12. Power Conversion Efficiency of Arylamine Organic Dyes for Dye-Sensitized Solar Cells (DSSCs Explicit to Cobalt Electrolyte: Understanding the Structural Attributes Using a Direct QSPR Approach

    Directory of Open Access Journals (Sweden)

    Supratik Kar

    2016-12-01

    Full Text Available Post silicon solar cell era involves light-absorbing dyes for dye-sensitized solar systems (DSSCs. Therefore, there is great interest in the design of competent organic dyes for DSSCs with high power conversion efficiency (PCE to bypass some of the disadvantages of silicon-based solar cell technologies, such as high cost, heavy weight, limited silicon resources, and production methods that lead to high environmental pollution. The DSSC has the unique feature of a distance-dependent electron transfer step. This depends on the relative position of the sensitized organic dye in the metal oxide composite system. In the present work, we developed quantitative structure-property relationship (QSPR models to set up the quantitative relationship between the overall PCE and quantum chemical molecular descriptors. They were calculated from density functional theory (DFT and time-dependent DFT (TD-DFT methods as well as from DRAGON software. This allows for understanding the basic electron transfer mechanism along with the structural attributes of arylamine-organic dye sensitizers for the DSSCs explicit to cobalt electrolyte. The identified properties and structural fragments are particularly valuable for guiding time-saving synthetic efforts for development of efficient arylamine organic dyes with improved power conversion efficiency.

  13. Photosynthesis in a test tube- dye sensitized solar cells as a teaching tool

    Energy Technology Data Exchange (ETDEWEB)

    Raturi, Atul; Fepuleai, Yoheni [Division of Physics, School of Engineering and Physics, The University of the South Pacific, Suva (Fiji)

    2010-05-15

    Dye sensitized solar cells employing natural plant dyes as phosensitizers can be effectively used to train students in the science and technology of solar cells. This is especially relevant to developing countries where facilities for silicon cell fabrication are non-existent. The cross-disciplinary nature of this device makes it very attractive for student projects. The present work describes such a project where anthocyanin dye from hibiscus flowers has been used as the electron harvester. (author)

  14. Skin sensitization quantitative risk assessment for occupational exposure of hairdressers to hair dye ingredients.

    Science.gov (United States)

    Goebel, Carsten; Diepgen, Thomas L; Blömeke, Brunhilde; Gaspari, Anthony A; Schnuch, Axel; Fuchs, Anne; Schlotmann, Kordula; Krasteva, Maya; Kimber, Ian

    2018-06-01

    Occupational exposure of hairdressers to hair dyes has been associated with the development of allergic contact dermatitis (ACD) involving the hands. p-Phenylenediamine (PPD) and toluene-2,5-diamine (PTD) have been implicated as important occupational contact allergens. To conduct a quantitative risk assessment for the induction of contact sensitization to hair dyes in hairdressers, available data from hand rinsing studies following typical occupational exposure conditions to PPD, PTD and resorcinol were assessed. By accounting for wet work, uneven exposure and inter-individual variability for professionals, daily hand exposure concentrations were derived. Secondly, daily hand exposure was compared with the sensitization induction potency of the individual hair dye defined as the No Expected Sensitization Induction Levels (NESIL). For PPD and PTD hairdresser hand exposure levels were 2.7 and 5.9 fold below the individual NESIL. In contrast, hand exposure to resorcinol was 50 fold below the NESIL. Correspondingly, the risk assessment for PPD and PTD indicates that contact sensitization may occur, when skin protection and skin care are not rigorously applied. We conclude that awareness of health risks associated with occupational exposure to hair dyes, and of the importance of adequate protective measures, should be emphasized more fully during hairdresser education and training. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Adsorption of a reactive dye on chemically modified activated carbons--influence of pH.

    Science.gov (United States)

    Orfão, J J M; Silva, A I M; Pereira, J C V; Barata, S A; Fonseca, I M; Faria, P C C; Pereira, M F R

    2006-04-15

    The surface chemistry of a commercial activated carbon with a slightly basic nature was modified by appropriate treatments in order to obtain two additional samples, respectively with acidic and basic properties, without changing its textural parameters significantly. Different techniques (N2 adsorption at 77 K, temperature programmed desorption, and determination of acidity, basicity, and pH at the point of zero charge) were used to characterize the adsorbents. Kinetic and equilibrium adsorption data of a selected textile reactive dye (Rifafix Red 3BN, C.I. reactive red 241) on the mentioned materials were obtained at the pH values of 2, 7, and 12. The kinetic curves are fitted using the second-order model. The respective rate constants seem to diminish progressively with the initial concentration for the more diluted solutions tested, reaching a constant value at higher concentrations, which depends on the experimental system under consideration (adsorbent and pH). In general, the Langmuir model provides the best fit for the equilibrium data. The different uptakes obtained are discussed in relation to the surface chemical properties of the adsorbents. It is shown that the adsorption of the reactive (anionic) dye on the basic sample (prepared by thermal treatment under H2 flow at 700 degrees C) is favored. This conclusion is explained on the basis of the dispersive and electrostatic interactions involved. Moreover, it is also shown that the optimal adsorption condition for all the activated carbons tested corresponds to solution pH values not higher than the pH(pzc) of the adsorbents, which may be interpreted by taking into account the electrostatic forces present.

  16. Nanowire-templated microelectrodes for high-sensitivity pH detection

    DEFF Research Database (Denmark)

    Antohe, V.A.; Radu, Adrian; Mátéfi-Tempfli, Mária

    2009-01-01

    A highly sensitive pH capacitive sensor has been designed by confined growth of vertically aligned nanowire arrays on interdigited microelectrodes. The active surface of the device has been functionalized with an electrochemical pH transducer (polyaniline). We easily tune the device features...... by combining lithographic techniques with electrochemical synthesis. The reported electrical LC resonance measurements show considerable sensitivity enhancement compared to conventional capacitive pH sensors realized with microfabricated interdigited electrodes. The sensitivity can be easily improved...

  17. Pomegranate leaves and mulberry fruit as natural sensitizers for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ho; Lo, Yu-Jen [Department of Mechanical Engineering, National Taipei University of Technology (China)

    2010-10-15

    This study employs chlorophyll extract from pomegranate leaf and anthocyanin extract from mulberry fruit as the natural dyes for a dye-sensitized solar cell (DSSC). A self-developed nanofluid synthesis system is employed to prepare TiO{sub 2} nanofluid with an average particle size of 25 nm. Electrophoresis deposition was performed to deposit TiO{sub 2} nanoparticles on the indium tin oxide (ITO) conductive glass, forming a TiO{sub 2} thin film with the thickness of 11 {mu}m. Furthermore, this TiO{sub 2} thin film was sintered at 450 C to enhance the thin film compactness. Sputtering was used to prepare counter electrode by depositing Pt thin film on FTO glass at a thickness of 20 nm. The electrodes, electrolyte (I{sub 3}{sup -}), and dyes were assembled into a cell module and illuminated by a light source simulating AM 1.5 with a light strength of 100 mW/cm{sup 2} to measure the photoelectric conversion efficiency of the prepared DSSCs. According to experimental results, the conversion efficiency of the DSSCs prepared by chlorophyll dyes from pomegranate leaf extract is 0.597%, with open-circuit voltage (V{sub OC}) of 0.56 V, short-circuit current density (J{sub SC}) of 2.05 mA/cm{sup 2}, and fill factor (FF) of 0.52. The conversion efficiency of the DSSCs prepared by anthocyanin dyes from mulberry extract is 0.548%, with V{sub OC} of 0.555 V and J{sub SC} of 1.89 mA/cm{sup 2} and FF of 0.53. The conversion efficiency is 0.722% for chlorophyll and anthocyanin as the dye mixture, with V{sub OC} of 0.53 V, J{sub SC} of 2.8 mA/cm{sup 2}, and FF of 0.49. (author)

  18. Molecularly Engineered Ru(II) Sensitizers Compatible with Cobalt(II/III) Redox Mediators for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Wu, Kuan-Lin; Huckaba, Aron J; Clifford, John N; Yang, Ya-Wen; Yella, Aswani; Palomares, Emilio; Grätzel, Michael; Chi, Yun; Nazeeruddin, Mohammad Khaja

    2016-08-01

    Thiocyanate-free isoquinazolylpyrazolate Ru(II) complexes were synthesized and applied as sensitizers in dye-sensitized solar cells (DSCs). Unlike most other successful Ru sensitizers, Co-based electrolytes were used, and resulting record efficiency of 9.53% was obtained under simulated sunlight with an intensity of 100 mW cm(-2). Specifically, dye 51-57dht.1 and an electrolyte based on Co(phen)3 led to measurement of a JSC of 13.89 mA cm(-2), VOC of 900 mV, and FF of 0.762 to yield 9.53% efficiency. The improved device performances were achieved by the inclusion of 2-hexylthiophene units onto the isoquinoline subunits, in addition to lengthening the perfluoroalkyl chain on the pyrazolate chelating group, which worked to increase light absorption and decrease recombination effects when using the Co-based electrolyte. As this study shows, Ru(II) sensitizers bearing sterically demanding ligands can allow successful utilization of important Co electrolytes and high performance.

  19. Fabrication of dye sensitized solar cells with a double layer photoanode

    Directory of Open Access Journals (Sweden)

    M. Pirhadi

    2016-01-01

    Full Text Available Dye sensitized solar cell was fabricated from a double layer photoanode. First, TiO2 nanoparticles  were synthesized by hydrothermal method. These TiO2 NPs were deposited on FTO glasses by electrophoretic deposition  method in applied voltage of 5 V and EPD time of 2.5-10 min. Then TiO2 hollow spheres (HSs were synthesized by sacrificed template method with Carbon Spheres as template and TTIP as precursor. Then these template scarified and the hollow structures found. Since the HSs paste was prepared as same method of prepared TiO2 nano particles and this paste was deposited on last layer by Dr. Blade method. The prepared photoanodes was soaped in N-719 dye after sintering in 500 ÚC. The dye sensitized solar cells  were fabricated with the finalized double layer photoanodes. The best photovoltaic characteristics of the optimized cell were 734 mV, 13.16 mA/cm2, 62% and 5.96% for Voc, Jsc, F.F. and efficiency respectively.

  20. Bioremediation of coractive blue dye by using Pseudomonas spp. isolated from the textile dye wastewater

    Science.gov (United States)

    Sunar, N. M.; Mon, Z. K.; Rahim, N. A.; Leman, A. M.; Airish, N. A. M.; Khalid, A.; Ali, R.; Zaidi, E.; Azhar, A. T. S.

    2018-04-01

    Wastewater released from the textile industry contains variety substances, mainly dyes that contains a high concentration of color and organic. In this study the potential for bacterial decolorization of coractive blue dye was examined that isolated from textile wastewater. The optimum conditions were determined for pH, temperature and initial concentration of the dye. The bacteria isolated was Pseudomonas spp. The selected bacterium shows high decolorization in static condition at an optimum of pH 7.0. The Pseudomonas spp. could decolorize coractive blue dye by 70% within 24 h under static condition, with the optimum of pH 7.0. Decolorization was confirmed by using UV-VIS spectrophotometer. This present study suggests the potential of Pseudomonas spp. as an approach in sustainable bioremediation that provide an efficient method for decolorizing coractive blue dye.

  1. Changes in inorganic matrices of dye sensitized solar cells during preparation

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Harald; Baumgaertel, Thomas; Luettich, Franziska; Kehr, Mirko [Institute of Physics, University of Technology Chemnitz (Germany); Maedler, Carsten [Institute of Physics, University of Technology Chemnitz (Germany); Department of Physics, Boston University, Boston, MA (United States); Oekermann, Thorsten [Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover (Germany)

    2010-07-01

    Dye-sensitized solar cells (DSSC) containing zinc oxide (ZnO) as the inorganic semiconductor and organic dye molecules as the sensitizer are well known devices with high efficiency. Such DSSC are prepared by electrochemical deposition of an aqueous zinc salt solution including organic molecules as templates. The template is desorbed in a second step to obtain a porous ZnO network. As a final step the sensitizing organic molecules were re-adsorped from solution. Within these different processing steps the structure of the ZnO can be influenced. We will discuss the growth mechanism during film deposition e.g. due to different template molecules. Also the crystal structure changes accompanying the desorption process, which is performed in an alkaline aqueous solution. Different techniques as X-ray investigations, optical absorption and scanning probe methods are used to identify the variations in different cells and within the production process.

  2. Versatile ruthenium(II) dye towards blue-light emitter and dye-sensitizer for solar cells

    Science.gov (United States)

    Zanoni, Kassio P. S.; Amaral, Ronaldo C.; Murakami Iha, Neyde Y.; Abreu, Felipe D.; de Carvalho, Idalina M. M.

    2018-06-01

    A versatile Ru(II) complex bearing an anthracene moiety was synthesized in our search for suitable compounds towards efficient molecular devices. The new engineered dye, cis‑[Ru(dcbH2)(NCS)2(mbpy‑anth)] (dcbH2 = 2,2‧‑bipyridyl‑4,4‧‑dicarboxylic acid, mbpy‑anth = 4‑[N‑(2‑anthryl)carbamoyl]‑4‧‑methyl‑2,2‧‑bipyridine), exhibits a blueish emission in a vibronically structured spectrum ascribed to the fluorescence of a 1LCAnth (ligand centered) excited state in the anthracene and has a potential to be exploited in the fields of smart lighting and displays. This complex was also employed in dye-sensitized solar cells with fairly efficient solar energy conversion with the use of self-assembled TiO2 compact layers beneath the TiO2 mesoporous film to prevent meso‑TiO2/dye back reactions. Further photoelectrochemical investigations through incident photon-to-current efficiency and electrochemical impedance spectra showed that the all-nano-TiO2 compact layer acts as contact layers that increase the electron harvesting in the external circuit, enhancing efficiencies up to 50%.

  3. The influence of local electric fields on photoinduced absorption in dye-sensitized solar cells.

    Science.gov (United States)

    Cappel, Ute B; Feldt, Sandra M; Schöneboom, Jan; Hagfeldt, Anders; Boschloo, Gerrit

    2010-07-07

    The dye-sensitized solar cell (DSC) challenges conventional photovoltaics with its potential for low-cost production and its flexibility in terms of color and design. Transient absorption spectroscopy is widely used to unravel the working mechanism of DSCs. A surprising, unexplained feature observed in these studies is an apparent bleach of the ground-state absorption of the dye, under conditions where the dye is in the ground state. Here, we demonstrate that this feature can be attributed to a change of the local electric field affecting the absorption spectrum of the dye, an effect related to the Stark effect first reported in 1913. We present a method for measuring the effect of an externally applied electric field on the absorption of dye monolayers adsorbed on flat TiO(2) substrates. The measured signal has the shape of the first derivative of the absorption spectra of the dyes and reverses sign along with the reversion of the direction of the change in dipole moment upon excitation relative to the TiO(2) surface. A very similar signal is observed in photoinduced absorption spectra of dye-sensitized TiO(2) electrodes under solar cell conditions, demonstrating that the electric field across the dye molecules changes upon illumination. This result has important implications for the analysis of transient absorption spectra of DSCs and other molecular optoelectronic devices and challenges the interpretation of many previously published results.

  4. Dye-sensitized solar cells: Atomic scale investigation of interface structure and dynamics

    International Nuclear Information System (INIS)

    Ma Wei; Zhang Fan; Meng Sheng

    2014-01-01

    Recent progress in dye-sensitized solar cells (DSC) research is reviewed, focusing on atomic-scale investigations of the interface electronic structures and dynamical processes, including the structure of dye adsorption onto TiO 2 , ultrafast electron injection, hot-electron injection, multiple-exciton generation, and electron—hole recombination. Advanced experimental techniques and theoretical approaches are briefly summarized, and then progressive achievements in photovoltaic device optimization based on insights from atomic scale investigations are introduced. Finally, some challenges and opportunities for further improvement of dye solar cells are presented. (invited review — international conference on nanoscience and technology, china 2013)

  5. Performance and stability analysis of curcumin dye as a photo sensitizer used in nanostructured ZnO based DSSC

    Science.gov (United States)

    Sinha, D.; De, D.; Ayaz, A.

    2018-03-01

    Environmental friendly natural dye curcumin extracted from low-cost Curcumina longa stem is used as a photo-sensitizer for the fabrication of ZnO-based dye-sensitized solar cells (DSSC). Nanostructured ZnO is fabricated on a transparent conducting glass (TCO), using a cost-effective chemical bath deposition technique. Scanning electron microscopic images show hexagonal patterned ZnO nano-towers decorated with several nanosteps. The average length of ZnO nano-tower is 5 μm and diameter is 1.2 μm. The UV-Vis spectroscopic study of the curcumin dye is used to understand the light absorption behavior as well as band gap energy of the extracted natural dye. The dye shows wider absorption band-groups over 350-470 nm and 500-600 nm with two peaks positioned at 425 nm and 525 nm. The optical band gap energy and energy band position of the dye is derived which supports its stability and high electron affinity that makes it suitable for light harvesting and effortless electron transfer from dye to the semiconductor or interface between them. FTIR spectrum of curcumin dye-sensitized ZnO-based DSSC shows the presence of anchoring groups and colouring constitutes. The I-V and P-V curves of the fabricated DSSC are measured under simulated light (100 mW/cm2). The highest visible light to electric conversion efficiency of 0.266% (using ITO) and 0.33% (using FTO) is achieved from the curcumin dye-sensitized cell.

  6. Acid-base indicator properties of dyes from local plants I: Dyes from ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    Acid-base indicator properties of dyes from local plants I: Dyes from Basella alba. (Indian spinach) and ... solution, which change colour immediately after the equivalence point has .... The pH ranges over which the dyes change colour were ...

  7. CdSe/ZnS quantum dots conjugated with a fluorescein derivative: a FRET-based pH sensor for physiological alkaline conditions.

    Science.gov (United States)

    Kurabayashi, Tomokazu; Funaki, Nayuta; Fukuda, Takeshi; Akiyama, Shinnosuke; Suzuki, Miho

    2014-01-01

    Dual pH-dependent fluorescence peaks from a semiconductor quantum dot (QD) and a pH-dependent fluorescent dye can be measured by irradiating with a single wavelength light, and the pH can be estimated from the ratio of the fluorescent intensity of the two peaks. In this work, ratiometric pH sensing was achieved in an aqueous environment by a fluorescent CdSe/ZnS QD appended with a pH-sensitive organic dye, based on fluorescence resonance energy transfer (FRET). By functionalizing the CdSe/ZnS QD with 5-(and 6)-carboxynaphthofluorescein succinimidyl ester as a pH-dependent fluorescent dye, we succeeded in fabricating sensitive nanocomplexes with a linear response to a broad range of physiological pH levels (7.5-9.5) when excited at 450 nm. We found that a purification process is important for increasing the high-fluorescence intensity ratio of a ratiometric fluorescence pH-sensor, and the fluorescence intensity ratio was improved up to 1.0 at pH 8.0 after the purification process to remove unreacted CdSe/ZnS QDs even though the fluorescence of the dye could not be observed without the purification process. The fluorescence intensity ratio corresponds to the fluorescence intensity of the dye, and this fluorescent dye exhibited pH-dependent fluorescence intensity changes. These facts indicate that the fluorescence intensity ratio linearly increased with increasing pH value of the buffer solution containing the QD and the dye. The FRET efficiencies changed from 0.3 (pH 7.5) to 6.2 (pH 9.5).

  8. Dye sensitized solar cell based on environmental friendly eosin Y dye and Al doped titanium dioxide nano particles

    Science.gov (United States)

    Kulkarni, Swati S.; Bodkhe, Gajanan A.; Shirsat, Sumedh M.; Hussaini, S. S.; Shejwal, N. N.; Shirsat, Mahendra D.

    2018-03-01

    Present communication deals with the development of cost effective dye sensitized solar cell (DSSC) with eco-friendly materials. Eco-friendly Eosin Y dye was used to sensitize photo anode which was fabricated using undoped and Aluminium doped titanium dioxide (TiO2) nanoparticles. Undoped and Aluminium doped TiO2 nanoparticles were synthesized by simple and cost effective sol-gel method. Aluminium doped and undoped TiO2 nanoparticles were characterized using UV-visible, FT-IR spectroscopy, x-ray Diffraction, and Scanning Electron Micrograph with EDX. The photo-voltaic activity of the cell was studied under light irradiation of 100 milliwatt cm-2. Aluminium doped TiO2 nanoparticle photo electrode exhibits more than 60% increase in cell efficiency as compared to the undoped TiO2 nanoparticle photo electrode.

  9. Three-in-one approach towards efficient organic dye-sensitized solar cells: aggregation suppression, panchromatic absorption and resonance energy transfer

    Directory of Open Access Journals (Sweden)

    Jayita Patwari

    2017-08-01

    Full Text Available In the present study, protoporphyrin IX (PPIX and squarine (SQ2 have been used in a co-sensitized dye-sensitized solar cell (DSSC to apply their high absorption coefficients in the visible and NIR region of the solar spectrum and to probe the possibility of Förster resonance energy transfer (FRET between the two dyes. FRET from the donor PPIX to acceptor SQ2 was observed from detailed investigation of the excited-state photophysics of the dye mixture, using time-resolved fluorescence decay measurements. The electron transfer time scales from the dyes to TiO2 have also been characterized for each dye. The current–voltage (I–V characteristics and the wavelength-dependent photocurrent measurements of the co-sensitized DSSCs reveal that FRET between the two dyes increase the photocurrent as well as the efficiency of the device. From the absorption spectra of the co-sensitized photoanodes, PPIX was observed to be efficiently acting as a co-adsorbent and to reduce the dye aggregation problem of SQ2. It has further been proven by a comparison of the device performance with a chenodeoxycholic acid (CDCA added to a SQ2-sensitized DSSC. Apart from increasing the absorption window, the FRET-induced enhanced photocurrent and the anti-aggregating behavior of PPIX towards SQ2 are crucial points that improve the performance of the co-sensitized DSSC.

  10. Fibrous flexible solid-type dye-sensitized solar cells without transparent conducting oxide

    International Nuclear Information System (INIS)

    Fan Xing; Chu Zengze; Chen Lin; Zhang Chao; Wang Fuzhi; Tang Yanwei; Sun Jianliang; Zou Dechun

    2008-01-01

    We have explored a type of all-solid fibrous flexible dye-sensitized solar cells without transparent conducting oxide based on a CuI electrolyte. The working electrode's substrate is a metal wire. Cu wire counterelectrode is twisted with the dye-sensitized and CuI-coated working electrode. The cell's apparent diameter is about 150 μm. The cell's current-voltage output depends little on the incident angle of light. A 4-cm-long fibrous cell's open-circuit voltage and short-circuit current generate 304 mV and 0.032 mA, respectively. The interfacial interaction between the two electrodes has a significant influence on the inner charge transfer of the cell

  11. Fabrication of dye-sensitized solar cell (DSSC) using annato seeds (Bixa orellana Linn)

    Energy Technology Data Exchange (ETDEWEB)

    Haryanto, Ditia Allindira; Landuma, Suarni; Purwanto, Agus [Department of Chemical Engineering, Sebelas Maret University, Surakarta 632112 (Indonesia)

    2014-02-24

    The Fabrication of dye sensitized solar cell (DSSC) using Annato seeds has been conducted in this study. Annato seeds (Bixa orellana Linn) used as a sensitizer for dye sensitized solar cell. The experimental parameter was concentration of natural dye. Annato seeds was extracted using etanol solution and the concentration was controlled by varying mass of Annato seeds. A semiconductor TiO{sub 2} was prepared by a screen printing method for coating glass use paste of TiO{sub 2}. Construction DSSC used layered systems (sandwich) consists of working electrode (TiO{sub 2} semiconductor-dye) and counter electrode (platina). Both are placed on conductive glass and electrolytes that occur electrons cycle. The characterization of thin layer of TiO{sub 2} was conducted using SEM (Scanning Electron Microscpy) analysis showed the surface morphology of TiO{sub 2} thin layer and the cross section of a thin layer of TiO{sub 2} with a thickness of 15–19 μm. Characterization of natural dye extract was determined using UV-Vis spectrometry analysis shows the wavelength range annato seeds is 328–515 nm, and the voltage (V{sub oc}) and electric current (I{sub sc}) resulted in keithley test for 30 gram, 40 gram, and 50 gram were 0,4000 V; 0,4251 V; 0,4502 V and 0,000074 A; 0,000458 A; 0,000857 A, respectively. The efficiencies of the fabricated solar cells using annato seeds as senstizer for each varying mass are 0,00799%, 0,01237%, and 0,05696%.

  12. High-Efficiency Dye-Sensitized Solar Cell with Three-Dimensional Photoanode

    KAUST Repository

    Tétreault, Nicolas

    2011-11-09

    Herein, we present a straightforward bottom-up synthesis of a high electron mobility and highly light scattering macroporous photoanode for dye-sensitized solar cells. The dense three-dimensional Al/ZnO, SnO2, or TiO 2 host integrates a conformal passivation thin film to reduce recombination and a large surface-area mesoporous anatase guest for high dye loading. This novel photoanode is designed to improve the charge extraction resulting in higher fill factor and photovoltage for DSCs. An increase in photovoltage of up to 110 mV over state-of-the-art DSC is demonstrated. © 2011 American Chemical Society.

  13. High-Efficiency Dye-Sensitized Solar Cell with Three-Dimensional Photoanode

    KAUST Repository

    Té treault, Nicolas; Arsenault, É ric; Heiniger, Leo-Philipp; Soheilnia, Navid; Brillet, Jé ré mie; Moehl, Thomas; Zakeeruddin, Shaik; Ozin, Geoffrey A.; Grä tzel, Michael

    2011-01-01

    Herein, we present a straightforward bottom-up synthesis of a high electron mobility and highly light scattering macroporous photoanode for dye-sensitized solar cells. The dense three-dimensional Al/ZnO, SnO2, or TiO 2 host integrates a conformal passivation thin film to reduce recombination and a large surface-area mesoporous anatase guest for high dye loading. This novel photoanode is designed to improve the charge extraction resulting in higher fill factor and photovoltage for DSCs. An increase in photovoltage of up to 110 mV over state-of-the-art DSC is demonstrated. © 2011 American Chemical Society.

  14. Influence of structural variations in push-pull zinc porphyrins on photovoltaic performance of dye-sensitized solar cells.

    Science.gov (United States)

    Yi, Chenyi; Giordano, Fabrizio; Cevey-Ha, Ngoc-Le; Tsao, Hoi Nok; Zakeeruddin, Shaik M; Grätzel, Michael

    2014-04-01

    We designed and synthesized two new zinc porphyrin dyes for dye-sensitized solar cells (DSCs). Subtle molecular structural variation in the dyes significantly influenced the performance of the DSC devices. By utilizing these dyes in combination with a cobalt-based redox electrolyte using a photoanode made of mesoporous TiO2 , we achieved a power conversion efficiency (PCE) of up to 12.0 % under AM 1.5 G (100 mW cm(-2)) simulated solar light. Moreover, we obtained a high PCE of 6.4 % for solid-state dye-sensitized solar cells by using 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene as a hole-transporting material. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. pH- and ion-sensitive polymers for drug delivery

    Science.gov (United States)

    Yoshida, Takayuki; Lai, Tsz Chung; Kwon, Glen S; Sako, Kazuhiro

    2013-01-01

    Introduction Drug delivery systems (DDSs) are important for effective, safe, and convenient administration of drugs. pH- and ion-responsive polymers have been widely employed in DDS for site-specific drug release due to their abilities to exploit specific pH- or ion-gradients in the human body. Areas covered Having pH-sensitivity, cationic polymers can mask the taste of drugs and release drugs in the stomach by responding to gastric low pH. Anionic polymers responsive to intestinal high pH are used for preventing gastric degradation of drug, colon drug delivery and achieving high bioavailability of weak basic drugs. Tumor-targeted DDSs have been developed based on polymers with imidazole groups or poly(β-amino ester) responsive to tumoral low pH. Polymers with pH-sensitive chemical linkages, such as hydrazone, acetal, ortho ester and vinyl ester, pH-sensitive cell-penetrating peptides and cationic polymers undergoing pH-dependent protonation have been studied to utilize the pH gradient along the endocytic pathway for intracellular drug delivery. As ion-sensitive polymers, ion-exchange resins are frequently used for taste-masking, counterion-responsive drug release and sustained drug release. Polymers responding to ions in the saliva and gastrointestinal fluids are also used for controlled drug release in oral drug formulations. Expert opinion Stimuli-responsive DDSs are important for achieving site-specific and controlled drug release; however, intraindividual, interindividual and intercellular variations of pH should be considered when designing DDSs or drug products. Combination of polymers and other components, and deeper understanding of human physiology are important for development of pH- and ion-sensitive polymeric DDS products for patients. PMID:23930949

  16. pH- and ion-sensitive polymers for drug delivery.

    Science.gov (United States)

    Yoshida, Takayuki; Lai, Tsz Chung; Kwon, Glen S; Sako, Kazuhiro

    2013-11-01

    Drug delivery systems (DDSs) are important for effective, safe, and convenient administration of drugs. pH- and ion-responsive polymers have been widely employed in DDS for site-specific drug release due to their abilities to exploit specific pH- or ion-gradients in the human body. Having pH-sensitivity, cationic polymers can mask the taste of drugs and release drugs in the stomach by responding to gastric low pH. Anionic polymers responsive to intestinal high pH are used for preventing gastric degradation of drug, colon drug delivery and achieving high bioavailability of weak basic drugs. Tumor-targeted DDSs have been developed based on polymers with imidazole groups or poly(β-amino ester) responsive to tumoral low pH. Polymers with pH-sensitive chemical linkages, such as hydrazone, acetal, ortho ester and vinyl ester, pH-sensitive cell-penetrating peptides and cationic polymers undergoing pH-dependent protonation have been studied to utilize the pH gradient along the endocytic pathway for intracellular drug delivery. As ion-sensitive polymers, ion-exchange resins are frequently used for taste-masking, counterion-responsive drug release and sustained drug release. Polymers responding to ions in the saliva and gastrointestinal fluids are also used for controlled drug release in oral drug formulations. Stimuli-responsive DDSs are important for achieving site-specific and controlled drug release; however, intraindividual, interindividual and intercellular variations of pH should be considered when designing DDSs or drug products. Combination of polymers and other components, and deeper understanding of human physiology are important for development of pH- and ion-sensitive polymeric DDS products for patients.

  17. The application of electrospun titania nanofibers in dye-sensitized solar cells.

    Science.gov (United States)

    Krysova, Hana; Zukal, Arnost; Trckova-Barakova, Jana; Chandiran, Aravind Kumar; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Kavan, Ladislav

    2013-01-01

    Titania nanofibers were fabricated using the industrial Nanospider(TM) technology. The preparative protocol was optimized by screening various precursor materials to get pure anatase nanofibers. Composite films were prepared by mixing a commercial paste of nanocrystalline anatase particles with the electrospun nanofibers, which were shortened by milling. The composite films were sensitized by Ru-bipyridine dye (coded C106) and the solar conversion efficiency was tested in a dye-sensitized solar cell filled with iodide-based electrolyte solution (coded Z960). The solar conversion efficiency of a solar cell with the optimized composite electrode (η = 7.53% at AM 1.5 irradiation) outperforms that of a solar cell with pure nanoparticle film (η = 5.44%). Still larger improvement was found for lower light intensities. At 10% sun illumination, the best composite electrode showed η = 7.04%, referenced to that of pure nanoparticle film (η = 4.69%). There are non-monotonic relations between the film's surface area, dye sorption capacity and solar performance of nanofiber-containing composite films, but the beneficial effect of the nanofiber morphology for enhancement of the solar efficiency has been demonstrated.

  18. Control of interfacial charge-transfer interaction of dye and p-CuI in solid-state dye-sensitized solar cells

    Science.gov (United States)

    Moribe, Shinya; Kato, Naohiko; Higuchi, Kazuo; Mizumoto, Katsuyoshi; Toyoda, Tatsuo

    2017-04-01

    We systematically investigated the photovoltaic and absorption characteristics of solid-state dye-sensitized solar cells with CuI to elucidate the impact of the interaction between the dye and CuI. For the ruthenium complex N719, the incident photon-to-current conversion efficiency (IPCE) on the longer-wavelength side decreased owing to the change of the metal-to-ligand charge transfer (CT) of N719 due to the interaction between the thiocyanate groups of N719 and CuI. In contrast, when D149 — which included rhodanine groups — was used, the interaction with CuI and the resultant CT increased the IPCE. The results provide a new strategy for improving the photovoltaic performance by controlling the interfacial CT between the dye and CuI.

  19. Optically Transparent FTO-Free Cathode for Dye-Sensitized Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Liska, P.; Zakeeruddin, S. M.; Grätzel, M.

    2014-01-01

    Roč. 6, č. 24 (2014), s. 22343-22350 ISSN 1944-8244 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : Dye sensitized solar cells * electrochemical impendance spectroscopy * tungsten electrode Subject RIV: CG - Electrochemistry Impact factor: 6.723, year: 2014

  20. Natural dye sensitizer from cassava (Manihot utilissima) leaves extract and its adsorption onto TiO2 photo-anode

    Science.gov (United States)

    Nurlela; Wibowo, R.; Gunlazuardi, J.

    2017-04-01

    Interaction between TiO2 and dyes sensitizer have been studied. The chlorophyll presents in the crude leave extract (CLE-dye) from cassava (Manihot utilissima) was immobilized on to the photo-anode, consists of TiO2 supported by fluor doped Tin oxide (SnO2-F) Glass. The TiO2 was prepared by Rapid Breakdown Anodization (RBA) method then immobilized on to glass coated by SnO2-F using doctor blade technique, to give CLE-dye/TiO2/SnO2-F/Glass photo-anode. The prepared photo-anode was characterized by UV-Vis-DRS, FTIR, XRD, SEM, electrochemical and spectro-electrochemical systems. In this study, the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy level of the CLE-dye were empirically determined by cyclic voltammetry method, while spectro-electro-chemistry method was used to determine the coefficient of degradation and formation of the dyes, and diffusion coefficient of the hole recombination as well. Good anchoring between TiO2 with dye extracts (CLE-dye) can be seen from value of dye LUMO energy level (-4.26 eV), which is approaching the conduction band of TiO2 (-4.3 eV). The coefficient of degradation and formation of the CLE-dye showed a quasi reversible and diffusion coefficient hole recombination values were small, indicated that it is quite suitable as a sensitizer in a dyes sensitized solar cell.

  1. Performance comparison between silicon solar panel and dye-sensitized solar panel in Malaysia

    Science.gov (United States)

    Hamed, N. K. A.; Ahmad, M. K.; Urus, N. S. T.; Mohamad, F.; Nafarizal, N.; Ahmad, N.; Soon, C. F.; Ameruddin, A. S.; Faridah, A. B.; Shimomura, M.; Murakami, K.

    2017-09-01

    In carrying out experimental research in performance between silicon solar panel and dye-sensitive solar panel, we have been developing a device and a system. This system has been developed consisting of controllers, hardware and software. This system is capable to get most of the input sources. If only need to change the main circuit and coding for a different source input value. This device is able to get the ambient temperature, surface temperature, surrounding humidity, voltage with load, current with load, voltage without load and current without load and save the data into external memory. This device is able to withstand the heat and rain as it was fabricated in a waterproof box. This experiment was conducted to examine the performance of both the solar panels which are capable to maintain their stability and performance. A conclusion based on data populated, the distribution of data for dye-sensitized solar panel is much better than silicon solar panel as dye-sensitized solar panel is very sensitive to heat and not depend only on midday where is that is the maximum ambient temperature for both solar panel as silicon solar panel only can give maximum and high output only when midday.

  2. Enhanced Light Harvesting in Dye-Sensitized Solar Cell Using External Lightguide

    Directory of Open Access Journals (Sweden)

    Chi-Hui Chien

    2011-01-01

    Full Text Available An external lightguide (EL for enhancing the light-harvesting efficiency of dye-sensitized solar cells (DSSCs was designed and developed. The EL attached to the exterior of a DSSC photoelectrode directed light on a dye-covered nanoporous TiO2 film (D-NTF of the photoelectrode. Experimental tests confirmed that the EL increased the light-harvesting efficiency of a DSSC with an active area of 0.25 cm2 by 30.69%. Photocurrent density and the power conversion efficiency were also increased by 38.12% and 25.09%, respectively.

  3. Fabrication and Characterization of Dye-Sensitized Solar Cells

    OpenAIRE

    Mohamed FATHALLAH; Ahmed TORCHANI; Rached GHARBI

    2014-01-01

    Dye-sensitized solar cell (DSSC) constitutes a real revolution in the conversion of solar energy into electricity after 40 years of the invention of silicon solar cells. The working mechanism is based on a photoelectrochemical system, similar to the photosynthesis in plant leaves. The efficiencies of the DSSC are high as those obtained from amorphous silicon solar cells (10-11 %) and intensive efforts are done in different directions to improve this efficiency.

  4. Fabrication and Characterization of Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Mohamed FATHALLAH

    2014-05-01

    Full Text Available Dye-sensitized solar cell (DSSC constitutes a real revolution in the conversion of solar energy into electricity after 40 years of the invention of silicon solar cells. The working mechanism is based on a photoelectrochemical system, similar to the photosynthesis in plant leaves. The efficiencies of the DSSC are high as those obtained from amorphous silicon solar cells (10-11 % and intensive efforts are done in different directions to improve this efficiency.

  5. Brief Overview of Dye-Sensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hagfeldt, Anders (Dept. of Chemistry, Aangstroem, Uppsala Univ., Uppsala (Sweden); Center for Molecular Devices, KTH-Royal Inst. of Technology, Stockholm (Sweden)), E-mail: anders.hagfeldt@kemi.uu.se

    2012-03-15

    Dye-sensitized solar cells (DSC) are based on molecular and nanometer-scale components. Record cell efficiencies of 12%, promising stability data and means of energy-efficient production methods have been accomplished. As selling points for the DSC technology the prospect of low-cost investments and fabrication are key features. DSCs offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency. The basic principles of the operation of DSC, the state-of-the-art as well as the potentials for future development are described

  6. Ratiometric Imaging of Extracellular pH in Dental Biofilms Using C-SNARF-4

    DEFF Research Database (Denmark)

    Dige, Irene

    pH in dental biofilms plays a central role for the development of caries lesions. For decades, pH measurements in biofilms have been limited to recording pH with electrodes/microelectrodes that do not permit monitoring horizontal pH gradients in biofilms in real-time. Quantitative fluorescent...... microscopy can overcome these problems. Objective: The aim of this demonstration study was to monitor extracellular biofilm pH microscopically with the ratiometric pH-sensitive dye C-SNARF-4 in in-situ-grown dental biofilms. Methods: Using confocal microscopy, the dye C-SNARF-4 was employed both as p...... the microscopic images in order to exclusively determine extracellular pH. We monitored the pH drop at the biofilm-substratum interface in six microscopic fields of view per biofilm for 1h after exposure to 0.4% glucose. Results: Extracellular pH dropped rapidly in all specimens. In both individuals, analysis...

  7. Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L.

    Science.gov (United States)

    Agustia, Yuda Virgantara; Suyitno, Arifin, Zainal; Sutanto, Bayu

    2016-03-01

    The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, EHOMO and ELUMO was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where Ered = -0.37V, ELUMO = -4.28 eV, Eox = 1.15V, EHOMO = -5.83 eV, and Eband gap = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

  8. Efficiencies of Dye-Sensitized Solar Cells using Ferritin-Encapsulated Quantum Dots with Various Staining Methods

    Science.gov (United States)

    Perez, Luis

    Dye-sensitized solar cells (DSSC) have the potential to replace traditional and cost-inefficient crystalline silicon or ruthenium solar cells. This can only be accomplished by optimizing DSSC's energy efficiency. One of the major components in a dye-sensitized solar cell is the porous layer of titanium dioxide. This layer is coated with a molecular dye that absorbs sunlight. The research conducted for this paper focuses on the different methods used to dye the porous TiO2 layer with ferritin-encapsulated quantum dots. Multiple anodes were dyed using a method known as SILAR which involves deposition through alternate immersion in two different solutions. The efficiencies of DSSCs with ferritin-encapsulated lead sulfide dye deposited using SILAR were subsequently compared against the efficiencies produced by cells using the traditional immersion method. It was concluded that both methods resulted in similar efficiencies (? .074%) however, the SILAR method dyed the TiO2 coating significantly faster than the immersion method. On a related note, our experiments concluded that conducting 2 SILAR cycles yields the highest possible efficiency for this particular binding method. National Science Foundation.

  9. One pot synthesis of multi-functional tin oxide nanostructures for high efficiency dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wali, Qamar; Fakharuddin, Azhar; Yasin, Amina; Ab Rahim, Mohd Hasbi; Ismail, Jamil; Jose, Rajan, E-mail: rjose@ump.edu.my

    2015-10-15

    Photoanode plays a key role in dye sensitized solar cells (DSSCs) as a scaffold for dye molecules, transport medium for photogenerated electrons, and scatters light for improved absorption. Herein, tin oxide nanostructures unifying the above three characteristics were optimized by a hydrothermal process and used as photoanode in DSSCs. The optimized morphology is a combination of hollow porous nanoparticles of size ∼50 nm and micron sized spheres with BET surface area (up to 29 m{sup 2}/g) to allow large dye-loading and light scattering as well as high crystallinity to support efficient charge transport. The optimized morphology gave the highest photovoltaic conversion efficiency (∼7.5%), so far achieved in DSSCs with high open circuit voltage (∼700 mV) and short circuit current density (∼21 mA/cm{sup 2}) employing conventional N3 dye and iodide/triiodide electrolyte. The best performing device achieved an incident photon to current conversion efficiency of ∼90%. The performance of the optimized tin oxide nanostructures was comparable to that of conventional titanium based DSSCs fabricated at similar conditions. - Graphical abstract: Tin oxide hollow nanostructure simultaneously supporting improved light scattering, dye-loading, and charge transport yielded high photovoltaic conversion efficiency in dye-sensitized solar cells. - Highlights: • Uniformly and bimodelly distributed tin oxide hollow nanospheres (HNS) are synthesized. • Uniform HNS are of size ∼10 nm; bimodel HNS has additional size up to ∼800 nm. • They are evaluated as photoelectrodes in dye-sensitized solar cells (DSSCs). • The uniform HNS increase dye-loading and the larger increase light scattering in DSSCs. • Photo conversion efficiency ∼7.5% is achieved using bimodel HNS.

  10. Change of Dye Bath for Sensitisation of Nanocrystalline TiO Films: Enhances Performance of Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Malapaka Chandrasekharam

    2011-01-01

    Full Text Available The photovoltaic performance of the heteroleptic H102 and HRD2 sensitizers was measured in DSSC and compared with that of reference N719 under similar fabrication and evaluation conditions. The Dye-Sensitised TiO2 electrodes were prepared by staining the electrodes in ethanol bath and 1/1 v/v acetonitrile/tert-butanol (binary liquid mixture bath separately and the DSSCs based on these sensitizers show that the change of dye bath from ethanol to the binary liquid mixture enhances the photocurrent action spectrum and solar-to-electricity conversion efficiencies, (η. Using ethanol for sensitisation of TiO2 electrodes, the efficiencies obtained for H102, HRD2 and N719 are 4.31%, 4.62%, and 5.46%, respectively, while in binary liquid mixture bath, the corresponding values are enhanced to 5.89%, 4.87%, and 7.23%, respectively, under comparable conditions.

  11. Precise identification and manipulation of adsorption geometry of donor-π-acceptor dye on nanocrystalline TiO₂ films for improved photovoltaics.

    Science.gov (United States)

    Zhang, Fan; Ma, Wei; Jiao, Yang; Wang, Jingchuan; Shan, Xinyan; Li, Hui; Lu, Xinghua; Meng, Sheng

    2014-12-24

    Adsorption geometry of dye molecules on nanocrystalline TiO2 plays a central role in dye-sensitized solar cells, enabling effective sunlight absorption, fast electron injection, optimized interface band offsets, and stable photovoltaic performance. However, precise determination of dye binding geometry and proportion has been challenging due to complexity and sensitivity at interfaces. Here employing combined vibrational spectrometry and density functional calculations, we identify typical adsorption configurations of widely adopted cyanoacrylic donor-π bridge-acceptor dyes on nanocrystalline TiO2. Binding mode switching from bidentate bridging to hydrogen-bonded monodentate configuration with Ti-N bonding has been observed when dye-sensitizing solution becomes more basic. Raman and infrared spectroscopy measurements confirm this configuration switch and determine quantitatively the proportion of competing binding geometries, with vibration peaks assigned using density functional theory calculations. We further found that the proportion of dye-binding configurations can be manipulated by adjusting pH value of dye-sensitizing solutions. Controlling molecular adsorption density and configurations led to enhanced energy conversion efficiency from 2.4% to 6.1% for the fabricated dye-sensitized solar cells, providing a simple method to improve photovoltaic performance by suppressing unfavorable binding configurations in solar cell applications.

  12. DYE-SENSITIZED PHOTOLYSIS OF o-Cl-HEXAARYLBIIMIDAZOLE AND PHOTOPOLYMERIZATION KINETICS STUDY OF THE LONG WAVE-LENGTH DYE/HEXAARYLBIIMIDAZOLE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Fang Gao; Chun-ying Zhao; Li-dong Li; Shu-jing Feng; Yong-yuan Yang

    2000-01-01

    o-Chloro-hexaarylbiimidazole (o-Cl-HABI) can be sensitized efficiently by the dyes 1-ethyl-3'-methyl thiacyanine bromide (C1), 3,3'-diethyl thiacarbocyanine iodide (C2), and cyclopentanone 2,5-bis[2-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)ethylidene] (C3) through electron transfer proceses. When exposed to a xenon lamp (filtered by Pyrex glass),the photosensitive systems composed of o-Cl-HABI and the above dyes can produce free radicals which initiate the polymerization of MMA. The photopolymerization kinetics equation was obtained for the o-Cl-HABI/C2 system, Rp =K [C2]0.75[o-Cl-HABI]0.44[MTA]0.12[MMA]1.0. A comparison of the influence of different dyes on the conversion of MMA photopolymerization was conducted.

  13. "Spider"-shaped porphyrins with conjugated pyridyl anchoring groups as efficient sensitizers for dye-sensitized solar cells.

    Science.gov (United States)

    Stangel, Christina; Bagaki, Anthi; Angaridis, Panagiotis A; Charalambidis, Georgios; Sharma, Ganesh D; Coutsolelos, Athanasios G

    2014-11-17

    Two novel "spider-shaped" porphyrins, meso-tetraaryl-substituted 1PV-Por and zinc-metalated 1PV-Zn-Por, bearing four oligo(p-phenylenevinylene) (oPPV) pyridyl groups with long dodecyloxy chains on the phenyl groups, have been synthesized. The presence of four pyridyl groups in both porphyrins, which allow them to act as anchoring groups upon coordination to various Lewis acid sites, the conjugated oPPV bridges, which offer the possibility of electronic communication between the porphyrin core and the pyridyl groups, and the dodecyloxy groups, which offer the advantage of high solubility in a variety of organic solvents of different polarities and could prevent porphyrin aggregation, renders porphyrins 1PV-Por and 1PV-Zn-Por very promising sensitizers for dye-sensitized solar cells (DSSCs). Photophysical measurements, together with electrochemistry experiments and density functional theory calculations, suggest that both porphyrins have frontier molecular orbital energy levels that favor electron injection and dye regeneration in DSSCs. Solar cells sensitized by 1PV-Por and 1PV-Zn-Por were fabricated, and it was found that they show power conversion efficiencies (PCEs) of 3.28 and 5.12%, respectively. Photovoltaic measurements (J-V curves) together with incident photon-to-electron conversion efficiency spectra of the two cells reveal that the higher PCE value of the DSSC based on 1PV-Zn-Por is ascribed to higher short-circuit current (Jsc), open-circuit voltage (Voc), and dye loading values. Emission spectra and electrochemistry experiments suggest a greater driving force for injection of the photogenerated electrons into the TiO2 conduction band for 1PV-Zn-Por rather than its free-base analogue. Furthermore, electrochemical impedance spectroscopy measurements prove that the utilization of 1PV-Zn-Por as a sensitizer offers a high charge recombination resistance and, therefore, leads to a longer electron lifetime.

  14. Theoretical study of electronic transfer current rate at dye-sensitized solar cells

    Science.gov (United States)

    AL-Agealy, Hadi J. M.; AlMaadhede, Taif Saad; Hassooni, Mohsin A.; Sadoon, Abbas K.; Ashweik, Ahmed M.; Mahdi, Hind Abdlmajeed; Ghadhban, Rawnaq Qays

    2018-05-01

    In this research, we present a theoretical study of electronic transfer kinetics rate in N719/TiO2 and N719/ZnO dye-sensitized solar cells (DSSC) systems using a simple model depending on the postulate of quantum mechanics theory. The evaluation of the electronic transition current rate in DSSC systems are function of many parameters such that; the reorientation transition energies ΛSe m D y e , the transition coupling parameter ℂT(0), potential exponential effect e-(E/C-EF ) kBT , unit cell volume VSem, and temperature T. Furthermore, the analysis of electronic transfer current rate in N719/TiO2 and N719/ZnO systems show that the rate upon dye-sensitization solar cell increases with increases of transition coupling parameter, decreasing potential that building at interface a results of different material in this devices and increasing with reorientation transition energy. On the other hand, we can find the electronic transfer behavior is dependent of the dye absorption spectrum and mainly depending on the reorientation of transition energy. The replacement of the solvents in both DSSC system caused increasing of current rates dramatically depending on polarity of solvent in subset devices. This change in current rate of electron transfer were attributed to much more available of recombination sites introduced by the solvents medium. The electronic transfer current dynamics are shown to occurs in N719/TiO2 system faster many time compare to ocuures at N719/ZnO system, this indicate that TiO2 a is a good and active material compare with ZnO to using in dye sensitized solar cell devices. In contrast, the large current rate in N719/TiO2 comparing to ZnO of N719/ZnO systems indicate that using TiO2 with N719 dye lead to increasing the efficiency of DSSC.

  15. Nitrogen-Doped Graphene/Platinum Counter Electrodes for Dye-Sensitized Solar Cells

    KAUST Repository

    Lin, Chinan; Lee, Chuanpei; Ho, Shute; Wei, Tzuchiao; Chi, Yuwen; Huang, Kunping; He, Jr-Hau

    2014-01-01

    Nitrogen-doped graphene (NGR) was utilized in dye-sensitized solar cells for energy harvesting. NGR on a Pt-sputtered fluorine-doped tin oxide substrate (NGR/Pt/FTO) as counter electrodes (CEs) achieves the high efficiency of 9.38% via the nitrogen

  16. Optoelectronic and Photovoltaic Performances of Pyridine Based Monomer and Polymer Capped ZnO Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Singh, Satbir; Raj, Tilak; Singh, Amarpal; Kaur, Navneet

    2016-06-01

    The present research work describes the comparative analysis and performance characteristics of 4-pyridine based monomer and polymer capped ZnO dye-sensitized solar cells. The N, N-dimethyl-N4-((pyridine-4yl)methylene) propaneamine (4,monomer) and polyamine-4-pyridyl Schiff base (5, polymer) dyes were synthesized through one step condensation reaction between 4-pyridinecarboxaldehyde 1 and N, N-dimethylpropylamine 2/polyamine 3. Products obtained N, N-dimethyl-N4-((pyridine-4yl)methylene)propaneamine (4) and polyamine-4-pyridyl Schiff base (5) were purified and characterized using 1H, 13C NMR, mass, IR and CHN spectroscopy. Both the dyes 4 and 5 were further coated over ZnO nanoparticles and characterized using SEM, DLS and XRD analysis. Absorption profile and emission profile was monitored using fluorescence and UV-Vis absorption spectroscopy. A thick layer of these inbuilt dye linked ZnO nanoparticles of dyes (4) and (5) was pasted on one of the conductive side of ITO glass followed with a liquid electrolyte and counter electrode of the same conductive glass. Polyamine-4-pyridyl Schiff base polymer (5) decorated dye sensitized solar cell has shown better exciting photovoltaic properties in the form of short circuit current density (J(sc) = 6.3 mA/cm2), open circuit photo voltage (V(oc) = 0.7 V), fill factor (FF = 0.736) than monomer decorated dye sensitized solar cell. Polymer dye (5) based ZnO solar cell has shown a maximum solar power to electrical conversion efficiency of 3.25%, which is enhanced by 2.16% in case of monomer dye based ZnO solar cell under AM 1.5 sun illuminations.

  17. Dye-sensitized photopolymerization of N,N ...

    Indian Academy of Sciences (India)

    Unknown

    and a primary radical derived from the reducing agent. This radical initiates the vinyl polymerization. (scheme 1). In scheme 1, D is the dye, 1D the first excited singlet state, 3D the triplet state, DH. • the semi- quinone dye, DH2 the leuco dye, RH the reducing agent and R. • the initiating radical. Similar schemes. 1D → 3D,.

  18. Self-assembled ultra small ZnO nanocrystals for dye-sensitized solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Patra, Astam K.; Dutta, Arghya; Bhaumik, Asim, E-mail: msab@iacs.res.in

    2014-07-01

    We demonstrate a facile chemical approach to produce self-assembled ultra-small mesoporous zinc oxide nanocrystals using sodium salicylate (SS) as a template under hydrothermal conditions. These ZnO nanomaterials have been successfully fabricated as a photoanode for the dye-sensitized solar cell (DSSC) in the presence of N719 dye and iodine–triiodide electrolyte. The structural features, crystallinity, purity, mesophase and morphology of the nanostructure ZnO are investigated by several characterization tools. N{sub 2} sorption analysis revealed high surface areas (203 m{sup 2} g{sup −1}) and narrow pore size distributions (5.1–5.4 nm) for different samples. The mesoporous structure and strong photoluminescence facilitates the high dye loading at the mesoscopic void spaces and light harvesting in DSSC. By utilizing this ultra-small ZnO photoelectrode with film thickness of about 7 μm in the DSSC with an open-circuit voltage (V{sub OC}) of 0.74 V, short-circuit current density (J{sub SC}) of 3.83 mA cm{sup −2} and an overall power conversion efficiency of 1.12% has been achieved. - Graphical abstract: Ultra-small ZnO nanocrystals have been synthesized with sodium salicylate as a template and using it as a photoanode in a dye-sensitized solar cell 1.12% power conversion efficiency has been observed. - Highlights: • Synthesis of self-assembled ultra-small mesoporous ZnO nanocrystals by using sodium salicylate as a template. • Mesoporous ZnO materials have high BET surface areas and void space. • ZnO nanoparticles serve as a photoanode for the dye-sensitized solar cell (DSSC). • Using ZnO nanocrystals as photoelectrode power conversion efficiency of 1.12% has been achieved.

  19. Dye-sensitized solar cells using Aloe Vera and Cladode of Cactus extracts as natural sensitizers

    Science.gov (United States)

    Ganta, D.; Jara, J.; Villanueva, R.

    2017-07-01

    The purpose of this study is to develop dye-sensitized solar cells (DSSCs) from natural plant-based dyes, extracted from the Cladode (nopal) of the Thornless Prickly Pear Cactus (Opuntia ficus-indica), the gel of Aloe Vera (Aloe barbadensis miller), and the combination of Cladode and Aloe Vera extracts on side-by-side configuration. Optical properties were analyzed using UV-Vis Absorption and Fourier Transform Infrared Spectroscopy. Open circuit voltages (Voc) varied from 0.440 to 0.676 V, fill factors (FF) were greater than 40%, short-circuit photocurrent densities (Jsc) ranged from 0.112 to 0.290 mA/cm2 and highest conversion efficiency of 0.740% was reported for the Cladode DSSC.

  20. Computational screening of functionalized zinc porphyrins for dye sensitized solar cells

    DEFF Research Database (Denmark)

    Ørnsø, Kristian Baruël; García Lastra, Juan Maria; Thygesen, Kristian Sommer

    2013-01-01

    separation, and high output voltage. Here we demonstrate an extensive computational screening of zinc porphyrins functionalized with electron donating side groups and electron accepting anchoring groups. The trends in frontier energy levels versus side groups are analyzed and a no-loss DSSC level alignment...... quality is estimated. Out of the initial 1029 molecules, we find around 50 candidates with level alignment qualities within 5% of the optimal limit. We show that the level alignment of five zinc porphyrin dyes which were recently used in DSSCs with high efficiencies can be further improved by simple side......An efficient dye sensitized solar cell (DSSC) is one possible solution to meet the world's rapidly increasing energy demands and associated climate challenges. This requires inexpensive and stable dyes with well-positioned frontier energy levels for maximal solar absorption, efficient charge...

  1. Effect of electrolytes on the photovoltaic performance of a hybrid dye sensitized ZnO solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Suri, Poonam; Mehra, R.M. [Department of Electronic Science, University of Delhi South Campus, New Delhi 110021 (India)

    2007-03-23

    The efficiency of dye sensitized solar cell depends on the number of factors such as impedance due to anions in the electrolytes, oxidation-reduction process of anions and size of cations of the electrolyte. This paper reports the effect of electrolytes on the photovoltaic performance of hybrid dye sensitized ZnO solar cells based on Eosin Y dye. The size of the cations has been varied by choosing different electrolytes such as LiBr+Br{sub 2}, LiI+I{sub 2}, tetrapropylammonium iodide +I{sub 2} in mixed solvent of acetronitrile and ethylene carbonate. The impedance of anions has been determined by electrochemical impedance spectra. It is observed that Br{sup -}/Br{sub 3}{sup -} offers high impedance as compared to I{sup -}/I{sub 3}{sup -} couple. The oxidation-reduction reactions of electrolytes are measured by linear sweep voltammogram. It is found that Br{sup -}/Br{sub 3}{sup -} is more suitable than an I{sup -}/I{sub 3}{sup -} couple in dye sensitized solar cell (DSSC) in terms of higher open-circuit photovoltage production and higher overall energy conversion efficiency. This is attributed to more positive potential of the dye sensitizer than that of Br{sup -}/Br{sub 3}{sup -}. The gain in V{sub oc} was due to the enlarged energy level difference between the redox potential of the electrolyte and the Fermi level (E{sub f}) of ZnO and the suppressed charge recombination as well. (author)

  2. Revealing the influence of Cyano in Anchoring Groups of Organic Dyes on Adsorption Stability and Photovoltaic Properties for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Chen, Wei-Chieh; Nachimuthu, Santhanamoorthi; Jiang, Jyh-Chiang

    2017-07-10

    Determining an ideal adsorption configuration for a dye on the semiconductor surface is an important task in improving the overall efficiency of dye-sensitized solar cells. Here, we present a detailed investigation of different adsorption configurations of designed model dyes on TiO 2 anatase (101) surface using first principles methods. Particularly, we aimed to investigate the influence of cyano group in the anchoring part of dye on its adsorption stability and the overall photovoltaic properties such as open circuit voltage, electron injection ability to the surface. Our results indicate that the inclusion of cyano group increases the stability of adsorption only when it adsorbs via CN with the surface and it decreases the photovoltaic properties when it does not involve in binding. In addition, we also considered full dyes based on the results of model dyes and investigated the different strength of acceptor abilities on stability and electron injection ability. Among the various adsorption configurations considered here, the bidentate bridging mode (A3) is more appropriate one which has higher electron injection ability, larger V OC value and more importantly it has higher dye loading on the surface.

  3. Efficiency enhancement of dye-sensitized solar cells with addition of ...

    Indian Academy of Sciences (India)

    Abstract. The effect of addition of single and binary additives on the performance of dye-sensitized TiO2 solar cells based on electrolytes containing an ionic liquid (IL), 1,2-dimethyl-3-propylimidazolium iodide (DMPII) has been studied. Among the seven additives used, the addition of 2-(dimethylamino)-pyridine (DMAP) to ...

  4. Pt-graphene electrodes for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Hoshi, Hajime; Tanaka, Shumpei; Miyoshi, Takashi

    2014-01-01

    Highlights: • Graphene films with Pt nanoparticles were prepared from commercial graphene. • Pt consumption can be reduced by using Pt-graphene films. • The film showed improved catalytic activity for the reaction I 3 − /I − . • The film can be used as the counter electrode of dye-sensitized solar cells (DSSCs). • The performance of DSSC was superior to that of the Pt electrode. - Abstract: A simple paste method for fabricating graphene films with Pt nanoparticles was developed. First, graphene pastes with Pt nanoparticles were prepared from commercially available graphene. The resulting films of graphene nanoplatelet aggregates with Pt nanoparticles (Pt-GNA) contained Pt nanoparticles distributed over the entire three-dimensional surface of the GNA. Then, the catalytic activity for the I 3 − /I − redox reaction was evaluated by cyclic voltammetry. The GNA electrode exhibited higher activity than a graphene nanoplatelet electrode because of its higher effective surface area. Addition of Pt nanoparticles to the electrodes improved the catalytic activity. In particular, a large Faradaic current for the I 3 − /I − reaction was observed for the Pt-GNA electrode. As the counter electrodes of dye-sensitized solar cells (DSSCs), their performance was consistent with the cyclic voltammetry results. In particular, the DSSC performance of the Pt-GNA electrode was superior to that of the Pt electrodes commonly used in DSSCs

  5. Paper-based quasi-solid dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Bella, Federico; Pugliese, Diego; Zolin, Lorenzo; Gerbaldi, Claudio

    2017-01-01

    Highlights: • Natural cellulose fibres as photoanode and electrolyte for dye-sensitized solar cells. • TiO_2-laden paper foils as photoanodes obtained by papermaking. • Nanoscale microfibrillated cellulose as polymer electrolyte. • Efficiencies as high as 3.55% under 1 sun irradiation. • Stability equal to 96% after 1000 h of accelerated aging test. - Abstract: Natural cellulose fibres are proposed as promising components for bioderived photoanodes and polymer electrolytes in dye-sensitized solar cells (DSSCs). In particular, TiO_2-laden paper foils, prepared by simple papermaking, can be applied to several substrates (conductive glass or plastics) instead of the high-temperature sintered traditional commercial pastes. In addition, nanoscale microfibrillated cellulose is used as reinforcing filler in acrylate/methacrylate-based thermo-set polymer electrolyte membranes prepared by means of fast, low-cost and green UV-induced free-radical photopolymerization. The laboratory-scale quasi-solid state paper-DSSCs assembled with cellulose-based electrodes and electrolytes guarantee sunlight conversion efficiencies as high as 3.55 and 5.20% at simulated light intensities of 1 and 0.2 sun, respectively, along with an excellent efficiency retention of 96% after 1000 h of accelerated aging test. The simple, low cost and green approach here specifically developed opens up intriguing prospects in the design of bio-inspired energy conversion devices showing high performance, outstanding durability and truly sustainable characteristics.

  6. Dye-sensitized solar cell architecture based on indium-tin oxide nanowires coated with titanium dioxide

    International Nuclear Information System (INIS)

    Joanni, Ednan; Savu, Raluca; Sousa Goes, Marcio de; Bueno, Paulo Roberto; Nei de Freitas, Jilian; Nogueira, Ana Flavia; Longo, Elson; Varela, Jose Arana

    2007-01-01

    A new architecture for dye-sensitized solar cells is employed, based on a nanostructured transparent conducting oxide protruding from the substrate, covered with a separate active oxide layer. The objective is to decrease electron-hole recombination. The concept was tested by growing branched indium-tin oxide nanowires on glass using pulsed laser deposition followed by deposition of a sputtered titanium dioxide layer covering the wires. The separation of charge generation and charge transport functions opens many possibilities for dye-sensitized solar cell optimization

  7. First Principle Modelling of Materials and Processes in Dye-Sensitized Photoanodes for Solar Energy and Solar Fuels

    Directory of Open Access Journals (Sweden)

    Mariachiara Pastore

    2017-01-01

    Full Text Available In the context of solar energy exploitation, dye-sensitized solar cells and dye-sensitized photoelectrosynthetic cells offer the promise of low-cost sunlight conversion and storage, respectively. In this perspective we discuss the main successes and limitations of modern computational methodologies, ranging from hybrid and long-range corrected density functionals, GW approaches and multi-reference perturbation theories, in describing the electronic and optical properties of isolated components and complex interfaces relevant to these devices. While computational modelling has had a crucial role in the development of the dye-sensitized solar cells technology, the theoretical characterization of the interface structure and interfacial processes in water splitting devices is still at its infancy, especially concerning the electron and hole transfer phenomena. Quantitative analysis of interfacial charge separation and recombination reactions in multiple metal-oxide/dye/catalyst heterointerfaces, thus, undoubtedly represents the compelling challenge in the field of modern computational material science.

  8. An Organic D-π-A Dye for Record Efficiency Solid-State Sensitized Heterojunction Solar Cells

    KAUST Repository

    Cai, Ning; Moon, Soo-Jin; Cevey-Ha, Lê; Moehl, Thomas; Humphry-Baker, Robin; Wang, Peng; Zakeeruddin, Shaik M.; Grätzel, Michael

    2011-01-01

    The high molar absorption coefficient organic D-π-A dye C220 exhibits more than 6% certified electric power conversion efficiency at AM 1.5G solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis

  9. Titanium dioxide nanoparticles biosynthesis for dye sensitized solar cells application: review

    CSIR Research Space (South Africa)

    Mbonyiryivuze, A

    2015-08-01

    Full Text Available has been made by Professor Michael Grätzel and co-workers at the Swiss Federal Institute of Technology (EPFL). They have developed a state solid version of DSSC called perovskite-sensitized solar cells that is fabricated by a sequential deposition.... Gao, M. K. Nazzeeruddin and M. Gratzel, “Sequential deposition as route to high performance perovskite-sensitized solar cells.” Nature, vol. 499, pp. 316-319, 2013. [21] K. H. a. H. Arakawa, Dye-sensitized solar cells, Tsukuba, Japan: National...

  10. ph Sensitive hydrogel as colon specific drug delivery

    International Nuclear Information System (INIS)

    Alarifi, A.S.

    2011-01-01

    γ-radiation induced graft copolymerization and crosslinking was for the synthesis of ph-sensitive hydrogels composed of poly (vinyl pyrrolidone) acrylic acid. The prepared hydrogels were subjected to swelling test to evaluate the effects of ph and ionic strength of the surrounding solution. Drastic changes in the swelling parameters where observed by changing the surrounding solution ph values. The release of ibuprofen from hydrogels was monitored as a function of time at ph 1 and ph 7 in order to evaluate the prepared copolymer ability for colon- specific drug carrier uses.

  11. Development of a novel pH sensor based upon Janus Green B immobilized on triacetyl cellulose membrane: Experimental design and optimization

    Science.gov (United States)

    Chamkouri, Narges; Niazi, Ali; Zare-Shahabadi, Vali

    2016-03-01

    A novel pH optical sensor was prepared by immobilizing an azo dye called Janus Green B on the triacetylcellulose membrane. Condition of the dye solution used in the immobilization step, including concentration of the dye, pH, and duration were considered and optimized using the Box-Behnken design. The proposed sensor showed good behavior and precision (RSD < 5%) in the pH range of 2.0-10.0. Advantages of this optical sensor include on-line applicability, no leakage, long-term stability (more than 6 months), fast response time (less than 1 min), high selectivity and sensitivity as well as good reversibility and reproducibility.

  12. Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells.

    Science.gov (United States)

    Cherrington, Ruth; Wood, Benjamin Michael; Salaoru, Iulia; Goodship, Vannessa

    2016-05-04

    Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less environmentally damaging with lower processing temperatures presenting a viable and low cost alternative to conventional production. This paper further enhances these environmental credentials by evaluating the digital printing and therefore additive production route for these cells. This is achieved here by investigating the formation and performance of a metal oxide photoelectrode using nanoparticle sized titanium dioxide. An ink-jettable material was formulated, characterized and printed with a piezoelectric inkjet head to produce a 2.6 µm thick layer. The resultant printed layer was fabricated into a functioning cell with an active area of 0.25 cm(2) and a power conversion efficiency of 3.5%. The binder-free formulation resulted in a reduced processing temperature of 250 °C, compatible with flexible polyamide substrates which are stable up to temperatures of 350 ˚C. The authors are continuing to develop this process route by investigating inkjet printing of other layers within dye sensitized solar cells.

  13. Surface Design in Solid-State Dye Sensitized Solar Cells: Effects of Zwitterionic Co-adsorbents on Photovoltaic Performance

    KAUST Repository

    Wang, Mingkui

    2009-07-10

    In solid-state dye sensitized solar cells (SSDSCs) charge recombination at the dye-hole transporting material interface plays a critical role in the cell efficiency. For the first time we report on the influence of dipolar coadsorbents on the photovoltaic performance of sensitized hetero-junction solar cells. In the present study, we investigated the effect of two zwitterionic butyric acid derivatives differing only in the polar moiety attached to their common 4 carbon-chain acid, i.e., 4-guanidinobutyric acid (GBA) and 4-aminobutyric acid (ABA). These two molecules were implemented as coadsorbents in conjunction with Z907Na dye on the SSDSC. It was found that a Z907Na/GBA dye/co-adsorbent combination increases both the open circuit voltage (V oc) and short-circuit current density ( Jsc) as compared to using Z907Na dye alone. The Z907Na/ABA dye/co-adsorbent combination increases the Jsc. Impedance and transient photovoltage investigations elucidate the cause of these remarkable observations. ©2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. A UV-prepared linear polymer electrolyte membrane for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Imperiyka, M., E-mail: imperiyka@gmail.com [Faculty of Arts and Sciences, Kufra Campus, University of Benghazi, Al Kufrah (Libya); Ahmad, A.; Hanifah, S.A. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Bella, F. [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Department of Applied Science and Technology – DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2014-10-01

    The effects of LiClO{sub 4} and LiFS{sub 3}SO{sub 3} on poly(glycidyl methacrylate)-based solid polymer electrolyte and its photoelectrochemical performance in a dye sensitized solar cell consisting of FTO/TiO{sub 2}–dye/P(GMA)–LiClO{sub 4}–EC/Pt were investigated. The electrochemical stability of films was studied by cyclic voltammetry (CV). The highest ionic conductivities obtained were 4.2×10{sup −5} and 3.7×10{sup −6} S cm{sup −1} for the film containing 30 wt% LiClO{sub 4} and 25 wt% LiCF{sub 3}SO{sub 3}, respectively. The polymer electrolytes showed electrochemical stability windows up to 3 V and 2.8 V for LiClO{sub 4} and LiCF{sub 3}SO{sub 3}, respectively. The assembled dye-sensitized solar cell showed a sunlight conversion efficiency of 0.679% (J{sub sc}=3 mA cm{sup −2}, V{sub oc}=0.48 V and FF=0.47), under light intensity of 100 mW cm{sup −2}.

  15. N -annulated perylene as an efficient electron donor for porphyrin-based dyes: Enhanced light-harvesting ability and high-efficiency Co(II/III)-based dye-sensitized solar cells

    KAUST Repository

    Luo, Jie; Xu, Mingfei; Li, Renzhi; Huang, Kuo-Wei; Jiang, Changyun; Qi, Qingbiao; Zeng, Wangdong; Zhang, Jie; Chi, Chunyan; Wang, Peng; Wu, Jishan

    2014-01-01

    Porphyrin-based dyes recently have become good candidates for dye-sensitized solar cells (DSCs). However, the bottleneck is how to further improve their light-harvesting ability. In this work, N-annulated perylene (NP) was used to functionalize

  16. Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L

    Energy Technology Data Exchange (ETDEWEB)

    Agustia, Yuda Virgantara, E-mail: yuda.mechanical.engineer@student.uns.ac.id; Suyitno,, E-mail: suyitno@uns.ac.id; Sutanto, Bayu, E-mail: bayu.sutanto@student.uns.ac.id [Department of Mechanical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta (Indonesia); Arifin, Zainal, E-mail: zainal-a@uns.ac.id [Department of Mechanical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta (Indonesia); Department of Mechanical Engineering, Brawijaya University, Malang (Indonesia)

    2016-03-29

    The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, E{sub HOMO} and E{sub LUMO} was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where E{sub red} = −0.37V, E{sub LUMO} = −4.28 eV, E{sub ox} = 1.15V, E{sub HOMO} = −5.83 eV, and E{sub band} {sub gap} = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

  17. Dye-Sensitized Solar Cells with Optimal Gel Electrolyte Using the Taguchi Design Method

    Directory of Open Access Journals (Sweden)

    Jenn-Kai Tsai

    2013-01-01

    Full Text Available The Taguchi method was adopted to determine the optimal gel electrolyte used in dye-sensitized solar cells (DSSCs. Since electrolyte is a very important factor in fabrication of high performance and long-term stability DSSCs, to find the optimal composition of gel electrolyte is desired. In this paper, the common ingredients used in the liquid electrolyte were chosen. The ingredients then mixed with cheap ionic liquids and poly(vinylidenefluoride-co-hexafluoropropylene (PVDF-HFP were added to form colloidal electrolyte (gel. The optimal composition of each materials in the gel electrolyte determined by Taguchi method consists of 0.03 M I2, 0.15 M KI, 0.6 M LiI, 0.5 M 4-tertbutylpyridine (TBP, and 10% PVDF-HFP dissolved in the acetonitrile and 3-methoxypropionitrile (MPN solution with volume ratio of 2 : 1. The short circuit current density of 14.11 mA/cm2, the conversion efficiency (η of 5.52%, and the lifetime of over 110 days were observed for the dye-sensitized solar cell assembled with optimal gel electrolyte. The lifetime increases 10 times when compared with the conventional dye-sensitized solar cell assembled with liquid electrolyte.

  18. Stability of dye-sensitized solar cells under extended thermal stress.

    Science.gov (United States)

    Yadav, Surendra K; Ravishankar, Sandheep; Pescetelli, Sara; Agresti, Antonio; Fabregat-Santiago, Francisco; Di Carlo, Aldo

    2017-08-23

    In the last few decades, dye-sensitized solar cell (DSC) technology has been demonstrated to be a promising candidate for low cost energy production due to cost-effective materials and fabrication processes. Arguably, DSC stability is the biggest challenge for making this technology appealing for industrial exploitation. This work provides further insight into the stability of DSCs by considering specific dye-electrolyte systems characterized by Raman and impedance spectroscopy analysis. In particular, two ruthenium-based dyes, Z907 and Ru505, and two commercially available electrolytes, namely, the high stability electrolyte (HSE) and solvent-free Livion 12 (L-12), were tested. After 4700 h of thermal stress at 85 °C, the least stable device composed of Z907/HSE showed an efficiency degradation rate of ∼14%/1000 h, while the Ru505/L-12 system retained 96% of its initial efficiency by losing ∼1% each 1000 h. The present results show a viable route to stabilize the DSC technology under prolonged annealing conditions complying with the IEC standard requirements.

  19. Novel D–π–A dye sensitizers of polymeric metal complexes with ...

    Indian Academy of Sciences (India)

    triphenylamine derivatives as donor for dye-sensitized solar cells: synthesis .... a saturated calomel electrode (SCE) were used as work- ing electrode, auxiliary ..... mechanisms, materials and devices (Boca Raton, FL: CRC). 35. Li X Z, Zeng ...

  20. Effects of Introducing Methoxy Groups into the Ancillary Ligands in Bis(diimine Copper(I Dyes for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Annika Büttner

    2018-04-01

    Full Text Available A systematic investigation of four heteroleptic bis(diimine copper(I dyes in n-type Dye-Sensitized Solar Cells (DSSCs is presented. The dyes are assembled using a stepwise, on-surface assembly. The dyes contain a phosphonic acid-functionalized 2,2′-bipyridine (bpy anchoring domain (5 and ancillary bpy ligands that bear peripheral phenyl (1, 4-methoxyphenyl (2, 3,5-dimethoxyphenyl (3, or 3,4,5-trimethoxyphenyl (4 substituents. In masked DSSCs, the best overall photoconversion efficiency was obtained with the dye [Cu(5(4]+ (1.96% versus 5.79% for N719. Values of JSC for both [Cu(5(2]+ (in which the 4-MeO group is electron releasing and [Cu(5(4]+ (which combines electron-releasing and electron-withdrawing effects of the 4- and 3,5-substituents and are enhanced with respect to [Cu(5(1]+. DSSCs with [Cu(5(3]+ show the lowest JSC. Solid-state absorption spectra and external quantum efficiency spectra reveal that [Cu(5(4]+ benefits from an extended spectral range at higher energies. Values of VOC are in the order [Cu(5(4]+ > [Cu(5(1]+ > [Cu(5(2]+ > [Cu(5(3]+. Density functional theory calculations suggest that methoxyphenyl character in MOs within the HOMO manifold in [Cu(5(2]+ and [Cu(5(4]+ may contribute to the enhanced performances of these dyes with respect to [Cu(5(1]+.

  1. Novel methylene-blue-sensitized photopolymers for holographic recording: a comparison

    Science.gov (United States)

    Ushamani, Mythili; Sreekumar, K.; Sudha Kartha, C.; Joseph, Rani

    2004-06-01

    Polymer matrices like PVC and a blend of PVA/PAA is introduced as new holographic media that cause red sensitivity with methylene blue. Unlike methylene blue sensitized polymers like PVA, PMMA, gelatin etc, the change of state occurring for methylene blue on laser irradiation on PVC matrix was found to be permanent. No recovery of dye on the irradiated spot was observed on storage. The outstanding properties of this material are its excellent optical clarity, insensitive to humidity, economical, ease of fabrication, absence of dark room storage etc. The recovery of dye in conventional MBPVA matrix can be delayed by blending PVA with PAA. Optimization of the ratio of PVA/PAA, the sensitizer concentration, pH, energy, diffraction efficiency measurements etc are done. pH is found to have a great influence on the recovery of the dye in this matrix. The effect of monomers in improving the diffraction efficiency on these dye doped polymer system is also evaluated. A comparative study is done on these polymer matrices and holographic gratings were recorded on these films from a He- Ne laser operating at 632.8 nm.

  2. Self-testing for contact sensitization to hair dyes--scientific considerations and clinical concerns of an industry-led screening programme

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Søsted, Heidi; Uter, Wolfgang

    2012-01-01

    The cosmetic industry producing hair dyes has, for many years, recommended that their consumers perform 'a hair dye allergy self-test' or similar prior to hair dyeing, to identify individuals who are likely to react upon subsequent hair dyeing. This review offers important information...... on the requirements for correct validation of screening tests, and concludes that, in its present form, the hair dye self-test has severe limitations: (i) it is not a screening test but a diagnostic test; (ii) it has not been validated according to basic criteria defined by scientists; (iii) it has been evaluated...... in the wrong population group; (iv) skin reactions have been read by dermatologists and not by the targeted group (consumers and hairdressers); (v) hair dyes contain strong and extreme sensitizers that are left on the skin in high concentrations, potentially resulting in active sensitization; and (vi...

  3. A novel high-performance counter electrode for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wang Guiqiang; Lin Ruifeng; Lin Yuan; Li Xueping; Zhou Xiaowen; Xiao Xurui

    2005-01-01

    A novel Pt counter electrode for dye-sensitized solar cells (DSC) was prepared by thermal decomposition of H 2 PtCl 6 on NiP-plated glass substrate. The charge-transfer kinetic properties of the platinized NiP-plated glass electrode (Pt/NiP electrode) for triiodide reduction were studied by electrochemical impedance spectroscopy. Pt/NiP electrode has the advantage over the platinized FTO conducting glass electrode (Pt/FTO electrode) in increasing the light reflectance and reducing the sheet resistance leading to improve the light harvest efficiency and the fill factor of the dye-sensitized solar cells effectively. The photon-to-current efficiency and the overall conversion efficiency of DSC using Pt/NiP counter electrode is increased by 20% and 33%, respectively, compared to that of using Pt/FTO counter electrode. Examination of the anodic dissolution and the long-term test on the variation of charge-transfer resistance indicates the good stability of the Pt/NiP electrode in the electrolyte containing iodide/triiodide

  4. Towards Sustainable H2 Production: Rational Design of Hydrophobic Triphenylamine-based Dyes for Sensitized Ethanol Photoreforming.

    Science.gov (United States)

    Dessì, Alessio; Monai, Matteo; Bessi, Matteo; Montini, Tiziano; Calamante, Massimo; Mordini, Alessandro; Reginato, Gianna; Trono, Cosimo; Fornasiero, Paolo; Zani, Lorenzo

    2018-02-22

    Donor-acceptor dyes are a well-established class of photosensitizers, used to enhance visible-light harvesting in solar cells and in direct photocatalytic reactions, such as H 2 production by photoreforming of sacrificial electron donors (SEDs). Amines-typically triethanolamine (TEOA)-are commonly employed as SEDs in such reactions. Dye-sensitized photoreforming of more sustainable, biomass-derived alcohols, on the other hand, was only recently reported by using methanol as the electron donor. In this work, several rationally designed donor-acceptor dyes were used as sensitizers in H 2 photocatalytic production, comparing the efficiency of TEOA and EtOH as SEDs. In particular, the effect of hydrophobic chains in the spacer and/or the donor unit of the dyes was systematically studied. The H 2 production rates were higher when TEOA was used as SED, whereas the activity trends depended on the SED used. The best performance was obtained with TEOA by using a sensitizer with just one bulky hydrophobic moiety, propylenedioxythiophene, placed on the spacer unit. In the case of EtOH, the best-performing sensitizers were the ones featuring a thiazolo[5,4-d]thiazole internal unit, needed for enhancing light harvesting, and carrying alkyl chains on both the donor part and the spacer unit. The results are discussed in terms of reaction mechanism, interaction with the SED, and structural/electrochemical properties of the sensitizers. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Economical wireless optical ratiometric pH sensor

    International Nuclear Information System (INIS)

    Vuppu, Sandeep; Kostov, Yordan; Rao, Govind

    2009-01-01

    The development and application of a portable, wireless fluorescence-based optical pH sensor is presented. The design incorporates the MSP430 microcontroller as the control unit, an RF transceiver for wireless communication, digital filters and amplifiers and a USB-based communication module for data transmission. The pH sensor is based on ratiometric fluorescence detection from pH sensitive dye incorporated in a peel-and-stick patch. The ability of the instrument to detect the pH of the solution with contact only between the sensor patch and the solution makes it partially non-invasive. The instrument also has the ability to transmit data wirelessly, enabling its use in processes that entail stringent temperature control and sterility. The use of the microcontroller makes it a reliable, low-cost and low-power device. The luminous intensity of the light source can be digitally controlled to maximize the sensitivity of the instrument. It has a resolution of 0.05 pH. The sensor is accurate and reversible over the pH range of 6.5–9

  6. Dye stability and performances of dye-sensitized solar cells with different nitrogen additives at elevated temperatures - Can sterically hindered pyridines prevent dye degradation?

    Energy Technology Data Exchange (ETDEWEB)

    Tuyet Nguyen, Phuong; Lund, Torben [Department of Science, Systems and Models, Roskilde University, 4000 Roskilde (Denmark); Rand Andersen, Anders [University of Southern Denmark, Institute of Sensors, Signals and Electrotechnics (SENSE), Niels Bohrs Alle 1, 5230 Odense M (Denmark); Danish Technological Institute, Plastics Technology, Gregersensvej 2630 Taastrup (Denmark); Morten Skou, Eivind [University of Southern Denmark, Department of Chemical Engineering, Biotechnology and Enviromental Technology, Niels Bohrs Alle 1, 5230 Odense M (Denmark)

    2010-10-15

    The homogeneous kinetics of the nucleophilic substitution reactions between the ruthenium dye N719 and eight pyridines and 1-methylbenzimidazole have been investigated in 3-methoxypropionitrile at 100 C. The half lives of N719 with the additives 4-tert-butylpyridine (0.5 M) and 1-methylbenzimidazole (0.5 M) were 57 and 160 h, respectively. Sterically hindered pyridines like 2,6-lutidine did not react with N719. The efficiencies of dye-sensitized solar cells (DSC, area=8.0 cm{sup 2}) prepared with 1-methylbenzimidazole (MBI), 4-tert-butylpyridine (4-TBP), 2,6-lutidine and without any additive were 7.1%, 6.2%, 6.0% and 4.8%, respectively. The cells were stored in dark at 85 C and their I-V curves and impedance spectra were measured at regular time intervals. The N719 dye degradation in the cells were monitored by a new dye extraction protocol combined with analysis of the dye extract by HPLC coupled to mass spectrometry. After 300 h storage in dark at 85 C 40% of the initial amount of N719 dye was degraded in DSC cells prepared with MBI and the efficiency was decreased to 40% of its initial value. DSC cells prepared with 2,6-lutidine or no additives showed smaller thermal dye and efficiency stability at elevated temperatures than DSC cells prepared with the none sterically hindered additives MBI and 4-TBP. In the cells prepared with 2,6-lutidine or no additive higher contents of the iodo products [RuL{sub 2}(NCS)(iodide)]{sup +} and [RuL{sub 2}(3-MPN)(iodide)]{sup +} were found than in cells prepared with 4-TBP and MBI. It is suggested that sterically hindered pyridines have smaller complexation constants with I{sub 3}{sup -} than unsterically hindered additives. This may explain the observed faster nucleophilic substitution rates of uncomplexed I{sub 3}{sup -} with N719 in DSC cells prepared with sterically hindered pyridines. The EIS analysis showed that the lifetime of the injected electrons in the TiO{sub 2}{tau}{sub eff} is reduced by a thermally induced change

  7. Dye-sensitized solar cells based on different nano-oxides on plastic PET substrate

    Science.gov (United States)

    Mikula, Milan; Gemeiner, Pavol; Beková, Zuzana; Dvonka, Vladimír; Búc, Dalibor

    2015-01-01

    Polyethylene-terephthalate (PET) foils and glass slides coated with thin conductive layers were used as substrates for TiO2 or ZnO based photoactive electrodes of dye-sensitized solar cells (DSSC) with organo-metallic Ru-dye, standard iodine electrolyte and Pt coated FTO/glass counterelectrode (CE). Different compositions of nanoparticle oxides in forms of alcohol pastes as well as the CE paste were applied onto the substrates by screen printing or by doctor blade techniques. Photocurrents and I-V loading characteristics were measured depending on the solar cell structure and preparation, including the oxide composition, electrode conductivity and the dye type. The influence of thin TiO2 blocking layer prepared by sol-gel technique is also discussed.

  8. Pt-graphene electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, Hajime, E-mail: hoshi@ed.tus.ac.jp; Tanaka, Shumpei; Miyoshi, Takashi

    2014-12-15

    Highlights: • Graphene films with Pt nanoparticles were prepared from commercial graphene. • Pt consumption can be reduced by using Pt-graphene films. • The film showed improved catalytic activity for the reaction I{sub 3}{sup −}/I{sup −}. • The film can be used as the counter electrode of dye-sensitized solar cells (DSSCs). • The performance of DSSC was superior to that of the Pt electrode. - Abstract: A simple paste method for fabricating graphene films with Pt nanoparticles was developed. First, graphene pastes with Pt nanoparticles were prepared from commercially available graphene. The resulting films of graphene nanoplatelet aggregates with Pt nanoparticles (Pt-GNA) contained Pt nanoparticles distributed over the entire three-dimensional surface of the GNA. Then, the catalytic activity for the I{sub 3}{sup −}/I{sup −} redox reaction was evaluated by cyclic voltammetry. The GNA electrode exhibited higher activity than a graphene nanoplatelet electrode because of its higher effective surface area. Addition of Pt nanoparticles to the electrodes improved the catalytic activity. In particular, a large Faradaic current for the I{sub 3}{sup −}/I{sup −} reaction was observed for the Pt-GNA electrode. As the counter electrodes of dye-sensitized solar cells (DSSCs), their performance was consistent with the cyclic voltammetry results. In particular, the DSSC performance of the Pt-GNA electrode was superior to that of the Pt electrodes commonly used in DSSCs.

  9. Design of butterfly type organic dye sensitizers with double electron donors: The first principle study

    Science.gov (United States)

    Yang, Zhenqing; Shao, Di; Li, Juan; Tang, Lian; Shao, Changjin

    2018-05-01

    In this work, we designed a series of butterfly type organic dyes, named ME07-ME13 by introducing such as triphenylamine, phenothiazine, coumarin groups etc. as electron donors and further investigated their absorption spectra using density functional theory (DFT) and time-dependent DFT (TDDFT). All designed dyes cover the entire visible absorption spectrum from 300 to 800 nm. It's fascinating that ME13 molecule has two absorption peak and the molar coefficient of two absorption peaks are above 4.645 × 104 M-1·cm-1. The light absorption area of ME13 exhibits an increment of 16.5-19.1% compared to ME07-ME12. Furthermore, we performed a detailed analysis on their geometrical and electronic properties, including molecular structures, energy levels, light harvesting efficiency (LHE), driving force (ΔGinject), regeneration (ΔGregen),electron dipole moments (μnormal), intermolecular electron transfer and dye/(TiO2)38 system electron transitions. The results of calculation reveal that double coumarin donors in ME13 are promising functional groups for butterfly type organic dye sensitizers. It is expected that the design of double donors can provide a new strategy and guidance for the investigation in high efficiency dye-sensitized devices.

  10. New Components for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Stefano Caramori

    2010-01-01

    Full Text Available Dye-Sensitized Solar Cells (DSSCs are among the most promising solar energy conversion devices of new generation, since coupling ease of fabrication and low cost offer the possibility of building integration in photovoltaic windows and facades. Although in their earliest configuration these systems are close to commercialization, fundamental studies are still required for developing new molecules and materials with more desirable properties as well as improving our understanding of the fundamental processes at the basis of the functioning of photoactive heterogeneous interfaces. In this contribution, some recent advances, made in the effort of improving DSSC devices by finding alternative materials and configurations, are reviewed.

  11. Optical and Photovoltaic Properties of Thieno[3,2-b]thiophene-Based Push-Pull Organic Dyes with Different Anchoring Groups for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Fernandes, Sara S M; Castro, M Cidália R; Pereira, Ana Isabel; Mendes, Adélio; Serpa, Carlos; Pina, João; Justino, Licínia L G; Burrows, Hugh D; Raposo, M Manuela M

    2017-12-31

    The effect of anchoring groups on the optical and electrochemical properties of triphenylamine-thienothiophenes, and on the photovoltaic performance of DSSCs photosensitized with the prepared dyes, was studied using newly synthesized compounds with cyanoacetic acid or rhodanine-3-acetic acid groups. Precursor aldehydes were synthesized through Suzuki cross-coupling, whereas Knoevenagel condensation of these with 2-cyanoacetic acid or rhodanine-3-acetic acid afforded the final push-pull dyes. A comprehensive photophysical study was performed in solution and in the solid state. The femtosecond time-resolved transient absorption spectra for the synthesized dyes were obtained following photoexcitation in solution and for the dyes adsorbed to TiO 2 mesoporous films. Information on conformation, electronic structure, and electron distribution was obtained by density functional theory (DFT) and time-dependent DFT calculations. Triphenylamine-thienothiophene functionalized with a cyanoacetic acid anchoring group displayed the highest conversion efficiency (3.68%) as the dye sensitizer in nanocrystalline TiO 2 solar cells. Coadsorption studies were performed for this dye with the ruthenium-based N719 dye, and they showed dye power conversion efficiencies enhanced by 20-64%. The best cell performance obtained with the coadsorbed N719 and cyanoacetic dye showed an efficiency of 6.05%.

  12. Optical and Photovoltaic Properties of Thieno[3,2-b]thiophene-Based Push–Pull Organic Dyes with Different Anchoring Groups for Dye-Sensitized Solar Cells

    Science.gov (United States)

    2017-01-01

    The effect of anchoring groups on the optical and electrochemical properties of triphenylamine-thienothiophenes, and on the photovoltaic performance of DSSCs photosensitized with the prepared dyes, was studied using newly synthesized compounds with cyanoacetic acid or rhodanine-3-acetic acid groups. Precursor aldehydes were synthesized through Suzuki cross-coupling, whereas Knoevenagel condensation of these with 2-cyanoacetic acid or rhodanine-3-acetic acid afforded the final push–pull dyes. A comprehensive photophysical study was performed in solution and in the solid state. The femtosecond time-resolved transient absorption spectra for the synthesized dyes were obtained following photoexcitation in solution and for the dyes adsorbed to TiO2 mesoporous films. Information on conformation, electronic structure, and electron distribution was obtained by density functional theory (DFT) and time-dependent DFT calculations. Triphenylamine–thienothiophene functionalized with a cyanoacetic acid anchoring group displayed the highest conversion efficiency (3.68%) as the dye sensitizer in nanocrystalline TiO2 solar cells. Coadsorption studies were performed for this dye with the ruthenium-based N719 dye, and they showed dye power conversion efficiencies enhanced by 20–64%. The best cell performance obtained with the coadsorbed N719 and cyanoacetic dye showed an efficiency of 6.05%. PMID:29302638

  13. A protein?dye hybrid system as a narrow range tunable intracellular pH sensor? ?Electronic supplementary information (ESI) available: Figures depicting various photophysical properties, cytotoxicity studies and confocal fluorescence images. See DOI: 10.1039/c6sc02659a Click here for additional data file.

    OpenAIRE

    Anees, Palapuravan; Sudheesh, Karivachery V.; Jayamurthy, Purushothaman; Chandrika, Arunkumar R.; Omkumar, Ramakrishnapillai V.; Ajayaghosh, Ayyappanpillai

    2016-01-01

    Accurate monitoring of pH variations inside cells is important for the early diagnosis of diseases such as cancer. Even though a variety of different pH sensors are available, construction of a custom-made sensor array for measuring minute variations in a narrow biological pH window, using easily available constituents, is a challenge. Here we report two-component hybrid sensors derived from a protein and organic dye nanoparticles whose sensitivity range can be tuned by choosing different rat...

  14. Indoor Light Performance of Coil Type Cylindrical Dye Sensitized Solar Cells.

    Science.gov (United States)

    Kapil, Gaurav; Ogomi, Yuhei; Pandey, Shyam S; Ma, Tingli; Hayase, Shuzi

    2016-04-01

    A very good performance under low/diffused light intensities is one of the application areas in which dye-sensitized solar cells (DSSCs) can be utilized effectively compared to their inorganic silicon solar cell counterparts. In this article, we have investigated the 1 SUN and low intensity fluorescent light performance of Titanium (Ti)-coil based cylindrical DSSC (C-DSSC) using ruthenium based N719 dye and organic dyes such as D205 and Y123. Electrochemical impedance spectroscopic results were analyzed for variable solar cell performances. Reflecting mirror with parabolic geometry as concentrator was also utilized to tap diffused light for indoor applications. Fluorescent light at relatively lower illumination intensities (0.2 mW/cm2 to 0.5 mW/cm2) were used for the investigation of TCO-less C-DSSC performance with and without reflector geometry. Furthermore, the DSSC performances were analyzed and compared with the commercially available amorphous silicon based solar cell for indoor applications.

  15. Surface Design in Solid-State Dye Sensitized Solar Cells: Effects of Zwitterionic Co-adsorbents on Photovoltaic Performance

    KAUST Repository

    Wang, Mingkui; Grä tzel, Carole; Moon, Soo-Jin; Humphry-Baker, Robin; Rossier-Iten, Nathalie; Zakeeruddin, Shaik M.; Grä tzel, Michael

    2009-01-01

    In solid-state dye sensitized solar cells (SSDSCs) charge recombination at the dye-hole transporting material interface plays a critical role in the cell efficiency. For the first time we report on the influence of dipolar coadsorbents

  16. Solid polymeric electrolyte based dye-sensitized solar cell with improved stability

    Science.gov (United States)

    Prasad, Narottam; Kumar, Manish; Patel, K. R.; Roy, M. S.

    2018-05-01

    The impact of polymeric electrolyte was investigated over the performance of dye-sensitized solar cell made with Rose Bengal as sensitizer. Further, the selective influence of TiCl4 treatment and pre-sensitizer deoxycholic acid on nc-TiO2 photoanode was determined in terms of improvement in conversion efficiency of the cell. It is found that the effect of TiCl4 treatment was comparatively more than pre-sensitization with de-oxy cholic acid towards improving the efficiency of the cell. The conversion efficiency on TiCl4 treatment was 0.2% whereas on pre-sensitization with deoxy chollic acid it was 0.1%. The combined effect of both TiCl4 treatment & pre-sensitization with deoxycholic acid leads conversion efficiency to 0.33%.

  17. Morphology dependent dye-sensitized solar cell properties of nanocrystalline zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.K., E-mail: sanjeevlrs732000@yahoo.co.in [Department of Information and Communication, Cheju Halla College, Jeju City 690 708 (Korea, Republic of); Inamdar, A.I.; Im, Hyunsik [Department of Semiconductor Science, Dongguk University, Seoul 100 715 (Korea, Republic of); Kim, B.G. [Department of Information and Communication, Cheju Halla College, Jeju City 690 708 (Korea, Republic of); Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India)

    2011-02-03

    Research highlights: > Nano-crystalline zinc oxide thin films were electrosynthesized from an aqueous zinc acetate [Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O] solution onto FTO coated conducting glass substrates using two different electrochemical routes, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) or SDS (sodium dodecyl sulfate). > The reproducibility of the catalytic activity of the SDS and PVA surfactants in the modification of the morphologies was observed. > Vertically aligned nest-like and compact structures were observed from the SDS and PVA mediated films, respectively, while the grain size in the ZnO thin films without an organic surfactant was observed to be {approx}150 nm. > The dye sensitized ZnO electrodes displayed excellent properties in the conversion process from light to electricity. The efficiencies of the surfactant mediated nanocrystalline ZnO thin films, viz. ZnO:SDS and ZnO:PVA, sensitized with ruthenium-II (N3) dye were observed to be 0.49% and 0.27%, respectively. - Abstract: Nano-crystalline zinc oxide thin films were electrosynthesized with an aqueous zinc acetate [Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O] solution on to FTO coated glass substrates. Two different electrochemical baths were used, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) and SDS (sodium dodecyl sulfate). The organic surfactants played an important role in modifying the surface morphology, which influenced the size of the crystallites and dye-sensitized solar cell (DSSC) properties. The vertically aligned thin and compact hexagonal crystallites were observed with SDS mediated films, while the grain size in the films without an organic surfactant was observed to be {approx}150 nm. The conversion efficiencies of the ZnO:SDS:Dye and ZnO:PVA:Dye thin films were observed to be 0.49% and 0.27%, respectively.

  18. Exploiting quantum interference in dye sensitized solar cells

    DEFF Research Database (Denmark)

    Maggio, Emanuele; Solomon, Gemma C.; Troisi, Alessandro

    2014-01-01

    A strategy to hinder the charge recombination process in dye sensitized solar cells is developed in analogy with similar approaches to modulate charge transport across nanostructures. The system studied is a TiO2 (anatase)-chromophore interface, with an unsaturated carbon bridge connecting the two...... of the possible tunnelling path. Calculations carried out on realistic molecules at the DFT level of theory show how the recombination lifetime can be modulated by changes in the electron-withdrawing (donating) character of the groups connected to the cross-conjugated bridge. Tight binding calculations...

  19. pH sensitive quantum dot-anthraquinone nanoconjugates

    Science.gov (United States)

    Ruedas-Rama, Maria Jose; Hall, Elizabeth A. H.

    2014-05-01

    Semiconductor quantum dots (QDs) have been shown to be highly sensitive to electron or charge transfer processes, which may alter their optical properties. This feature can be exploited for different sensing applications. Here, we demonstrate that QD-anthraquinone conjugates can function as electron transfer-based pH nanosensors. The attachment of the anthraquinones on the surface of QDs results in the reduction of electron hole recombination, and therefore a quenching of the photoluminescence intensity. For some anthraquinone derivatives tested, the quenching mechanism is simply caused by an electron transfer process from QDs to the anthraquinone, functioning as an electron acceptor. For others, electron transfer and energy transfer (FRET) processes were found. A detailed analysis of the quenching processes for CdSe/ZnS QD of two different sizes is presented. The photoluminescence quenching phenomenon of QDs is consistent with the pH sensitive anthraquinone redox chemistry. The resultant family of pH nanosensors shows pKa ranging ˜5-8, being ideal for applications of pH determination in physiological samples like blood or serum, for intracellular pH determination, and for more acidic cellular compartments such as endosomes and lysosomes. The nanosensors showed high selectivity towards many metal cations, including the most physiologically important cations which exist at high concentration in living cells. The reversibility of the proposed systems was also demonstrated. The nanosensors were applied in the determination of pH in samples mimicking the intracellular environment. Finally, the possibility of incorporating a reference QD to achieve quantitative ratiometric measurements was investigated.

  20. pH sensitive quantum dot–anthraquinone nanoconjugates

    International Nuclear Information System (INIS)

    Ruedas-Rama, Maria Jose; Hall, Elizabeth A H

    2014-01-01

    Semiconductor quantum dots (QDs) have been shown to be highly sensitive to electron or charge transfer processes, which may alter their optical properties. This feature can be exploited for different sensing applications. Here, we demonstrate that QD-anthraquinone conjugates can function as electron transfer-based pH nanosensors. The attachment of the anthraquinones on the surface of QDs results in the reduction of electron hole recombination, and therefore a quenching of the photoluminescence intensity. For some anthraquinone derivatives tested, the quenching mechanism is simply caused by an electron transfer process from QDs to the anthraquinone, functioning as an electron acceptor. For others, electron transfer and energy transfer (FRET) processes were found. A detailed analysis of the quenching processes for CdSe/ZnS QD of two different sizes is presented. The photoluminescence quenching phenomenon of QDs is consistent with the pH sensitive anthraquinone redox chemistry. The resultant family of pH nanosensors shows pK a ranging ∼5–8, being ideal for applications of pH determination in physiological samples like blood or serum, for intracellular pH determination, and for more acidic cellular compartments such as endosomes and lysosomes. The nanosensors showed high selectivity towards many metal cations, including the most physiologically important cations which exist at high concentration in living cells. The reversibility of the proposed systems was also demonstrated. The nanosensors were applied in the determination of pH in samples mimicking the intracellular environment. Finally, the possibility of incorporating a reference QD to achieve quantitative ratiometric measurements was investigated

  1. Rehydrating dye sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Christian Hellert

    2017-05-01

    Full Text Available Dye sensitized solar cells (DSSCs are silicon free, simply producible solar cells. Longevity, however, is a longstanding problem for DSSCs. Due to liquid electrolytes being commonly used, evaporation of the electrolyte causes a dramatic drop in electric output as cells continue to be used unmaintained. Stopping evaporation has been tried in different ways in the past, albeit with differing degrees of success. In a recent project, a different route was chosen, exploring ways of revitalizing DSSCs after varying periods of usage. For this, we focused on rehydration of the cells using distilled water as well as the electrolyte contained in the cells. The results show a significant influence of these rehydration procedures on the solar cell efficiency. In possible applications of DSSCs in tents etc., morning dew may thus be used for rehydration of solar cells. Refillable DSSCs can also be used in tropical climates or specific types of farms and greenhouses where high humidity serves the purpose of rehydrating DSSCs.

  2. [pH sensors based on rubbery ormosils preparation and their spectrum studies].

    Science.gov (United States)

    Chen, Xi; Dai, Yuan-jing; Li, Wei; Zhuang, Zhi-xia; Wang, Xiao-ru

    2002-02-01

    A new type of methyl substituted ormosils as a matrix for bromophenol blue (BPhB) and bromocresol green (BCG) is described. The new ormosils combine features of classical TEOS sol-gel material such as solvability in organic solvent and those of sol-gel glasses such as transparent and a porous structure, the ormosils also make a good mechanical stability. The influence of the conditions during the polymerisation process on the photochemical properties of BPhB and BCG has been studied. This sol-gel material was wed to immobilize pH-sensitive absorption dyes, bromothymol blue and bromocresol green, to prepare pH sensing films. The several aspects of the sensing films, including the leaching of the dye from gel, response time to different pH buffer solution, absorption spectra and the improvement of the immobilization of the dyes to filmo, were also discussed.

  3. Crossflow Ultrafiltration for Removing Direct-15 Dye from Wastewater of Textile Industry

    Directory of Open Access Journals (Sweden)

    A.L. Ahmad

    2017-11-01

    Full Text Available Ultrafiltration membrane was used to treat the effluent from textile industries. Crossflow ultrafiltration using GN polymeric membrane was used to remove the dye from textile effluent. A synthetic textile effluent of Direct-15 dye was used. The study focused through the effect of feed concentration, transmembrane pressure and solution’s pH on the permeate flux and percentage of dye removal were investigated. Dye concentration had significant effects on flux values. Under the fixed pressures and pH, the flux decreased while the dye rejection increased with increasing feed concentration. Transmembrane pressure also had significant effect on flux values. Under the fixed feed concentration and pH, the flux increased while dye rejection decreased with increasing pressure. Experiment data showed that the highest flux was observed at pH 4 (acidic condition while the highest dye removal observed at pH 7. Data collection could be used to improve the effectiveness of dye removal from textile industry wastewater using membrane technology.

  4. Color-sensitive photoconductivity of nanostructured ZnO/dye hybrid films prepared by one-step electrodeposition

    International Nuclear Information System (INIS)

    Oekermann, T.; Yoshida, T.; Tada, H.; Minoura, H.

    2006-01-01

    Nanostructured ZnO/dye hybrid films prepared by one-step electrodeposition have been investigated in conductivity and photoconductivity measurements in view of applications in dye-sensitized solar cells (DSSC) and in optoelectronics. Highly porous ZnO/eosin Y films, which were obtained at potentials < - 0.9 V vs. SCE, were found to have a very high conductivity already in the dark, probably because of a higher n-doping, which is due to a higher concentration of Zn atoms in the film. On the other hand, less porous or non-porous films, which were obtained at more positive potentials and in which the dye molecules are located within the ZnO crystals, were found to show a much higher sensitivity to illumination with visible light in photoconductivity measurements due to a higher absolute photoconductivity and a lower conductivity in the dark

  5. Color-sensitive photoconductivity of nanostructured ZnO/dye hybrid films prepared by one-step electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Oekermann, T. [Gifu University, Graduate School of Engineering, Yanagido 1-1, Gifu 501-1193 (Japan) and University of Hannover, Institute of Physical Chemistry and Electrochemistry, Callinstrasse 3-3A, 30167 Hannover (Germany)]. E-mail: torsten.oekermann@pci.uni-hannover.de; Yoshida, T. [Gifu University, Graduate School of Engineering, Yanagido 1-1, Gifu 501-1193 (Japan)]. E-mail: yoshida@apchem.gifu-u.ac.jp; Tada, H. [Institute for Molecular Science, Okazaki National Research Institutes, Myodaiji, Okazaki 444-8585 (Japan); Minoura, H. [Gifu University, Graduate School of Engineering, Yanagido 1-1, Gifu 501-1193 (Japan)

    2006-07-26

    Nanostructured ZnO/dye hybrid films prepared by one-step electrodeposition have been investigated in conductivity and photoconductivity measurements in view of applications in dye-sensitized solar cells (DSSC) and in optoelectronics. Highly porous ZnO/eosin Y films, which were obtained at potentials < - 0.9 V vs. SCE, were found to have a very high conductivity already in the dark, probably because of a higher n-doping, which is due to a higher concentration of Zn atoms in the film. On the other hand, less porous or non-porous films, which were obtained at more positive potentials and in which the dye molecules are located within the ZnO crystals, were found to show a much higher sensitivity to illumination with visible light in photoconductivity measurements due to a higher absolute photoconductivity and a lower conductivity in the dark.

  6. Mediator-assisted decolorization and detoxification of textile dyes/dye mixture by Cyathus bulleri laccase.

    Science.gov (United States)

    Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, T R

    2008-12-01

    Laccase from basidiomycete fungus Cyathus bulleri was evaluated for its ability to decolorize a number of reactive and acidic dyes in the presence of natural and synthetic mediators. The extent of decolorization was monitored at different mediator/dye concentrations and incubation time. Among the synthetic mediators, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) was effective at low mediator/dye ratios and resulted in 80-95% decolorization at rates that varied from 226 +/- 4 nmol min(-1) mg(-1) for Reactive Orange 1 to 1,333 +/- 15 nmol min(-1) mg(-1) for Reactive Red 198. Other synthetic mediators like 1-hydroxybenzotriazole and violuric acid showed both concentration- and time-dependent increases in percent decolorization. Natural mediators like vanillin, on the other hand, were found to be less effective on all the dyes except Reactive Orange 1. Computed rates of decolorization were about twofold lower than that with ABTS. The laccase-ABTS system also led to nearly 80% decolorization for the simulated dye mixture. No clear correlation between laccase activity on the mediator and its ability to decolorize dyes was found, but pH had a significant effect: Optimum pH for decolorization coincided with the optimum pH for mediator oxidation. The treated samples were also evaluated for toxicity in model microbial systems. The laccase-mediator system appears promising for treatment of textile wastewaters.

  7. Optimized adsorption of sulfonated phthalocyanines on ZnO electrodes and their characterization in dye- sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Falgenhauer, Jane; Loewenstein, Thomas; Schlettwein, Derck [Institute of Applied Physics, Justus-Liebig-University Giessen (Germany)

    2010-07-01

    Phthalocyanines belong to the most stable industrial dyes and show some of the highest molar extinction coefficients in the visible range. ZnO is known as a wide band gap semiconductor material which can be conveniently prepared as a porous electrode from solution-based processes. Sulfonated phthalocyanines were adsorbed at such electrodeposited porous ZnO thin films to work as a photosensitizer in a dye sensitized solar cell (DSSC). The adsorption solution of the phthalocyanine was modified in its composition and by adding different detergents in different concentrations. The adsorption solutions and the sensitized ZnO films were investigated by UV/Vis spectroscopy to characterize the aggregation of the dye molecules. Most of the detergents used could minimize the aggregation of the dye molecules in the adsorption solution without hindering the adsorption of the phthalocyanine on the ZnO surface. The photoelectrochemical characteristics of the resulting test cells were determined using a standard liquid electrolyte. The efficiency of the cells did not reach the expected level and reasons for this are discussed based on film morphology, amount of adsorbed dye molecules, competition by detergent adsorption, the optical absorbance of the dyes in the film and aggregate formation.

  8. Power Conversion Efficiency of Arylamine Organic Dyes for Dye-Sensitized Solar Cells (DSSCs) Explicit to Cobalt Electrolyte: Understanding the Structural Attributes Using a Direct QSPR Approach

    OpenAIRE

    Supratik Kar; Juganta K. Roy; Danuta Leszczynska; Jerzy Leszczynski

    2016-01-01

    Post silicon solar cell era involves light-absorbing dyes for dye-sensitized solar systems (DSSCs). Therefore, there is great interest in the design of competent organic dyes for DSSCs with high power conversion efficiency (PCE) to bypass some of the disadvantages of silicon-based solar cell technologies, such as high cost, heavy weight, limited silicon resources, and production methods that lead to high environmental pollution. The DSSC has the unique feature of a distance-dependent electron...

  9. Photo-electrochemical solar cells with a SnO/sub 2/-liquid junction sensitized with highly concentrated dyes

    Energy Technology Data Exchange (ETDEWEB)

    Shimura, Michiko; Shakushiro, Kiyoaki; Shimura, Yukio

    1986-09-01

    The sensitization of a SnO/sub 2/-liquid junction cell with highly concentrated dyes was investigated. The dyes used were Crystal Violet, Methyl Violet B, Malachite Green, Pararosaniline, and Rhodamine B. Anomalous or positive photovoltages were obtained in the system when Fe(CN)/sub 6//sup 3 -/ was added. The performance of the photovoltaic cells showed an open-circuit photovoltage, Vsub(oc), of 175 mV, a short-circuit photocurrent, Isub(sc), of 12 ..mu..A, and a fill factor of 0.42. The action spectra resembled the absorption spectra of the aggregated dyes. A D-D mechanism is introduced to explain the anomaly of the photovoltage of the SnO/sub 2/ electrode sensitized with the dyes. This behaviour is relevant to the practical usage of such photo-electrochemical cells and merits further investigation.

  10. Dye adsorption mechanisms in TiO2 films, and their effects on the photodynamic and photovoltaic properties in dye-sensitized solar cells.

    Science.gov (United States)

    Hwang, Kyung-Jun; Shim, Wang-Geun; Kim, Youngjin; Kim, Gunwoo; Choi, Chulmin; Kang, Sang Ook; Cho, Dae Won

    2015-09-14

    The adsorption mechanism for the N719 dye on a TiO2 electrode was examined by the kinetic and diffusion models (pseudo-first order, pseudo-second order, and intra-particle diffusion models). Among these methods, the observed adsorption kinetics are well-described using the pseudo-second order model. Moreover, the film diffusion process was the main controlling step of adsorption, which was analysed using a diffusion-based model. The photodynamic properties in dye-sensitized solar cells (DSSCs) were investigated using time-resolved transient absorption techniques. The photodynamics of the oxidized N719 species were shown to be dependent on the adsorption time, and also the adsorbed concentration of N719. The photovoltaic parameters (Jsc, Voc, FF and η) of this DSSC were determined in terms of the dye adsorption amounts. The solar cell performance correlates significantly with charge recombination and dye regeneration dynamics, which are also affected by the dye adsorption amounts. Therefore, the photovoltaic performance of this DSSC can be interpreted in terms of the adsorption kinetics and the photodynamics of oxidized N719.

  11. Adsorption of Dyes in Studying the Surface Chemistry of Ultradispersed Diamond

    Science.gov (United States)

    Khokhlova, T. D.; Yunusova, G. R.; Lanin, S. N.

    2018-05-01

    The effect the surface chemistry of ultradispersed diamond (UDD) has on the adsorption of watersoluble dyes is considered. A comparison is made to adsorption on graphitized thermal carbon black (GTCB), which has a homogeneous and nonporous surface. The adsorption isotherms of dyes and the dependence of the adsorption on the pH of solutions are measured. It is found that UDD adsorbs acid (anionic) dyes—acid orange (AO) and acid anthraquinone blue (AAB)—but barely adsorbs a basic (cationic) dye, methylene blue (MB), because of the predominance of positively charged basic groups on the surface of UDD. The maximum adsorption of AO is much lower on UDD than on GTCB, while the maximum adsorption of AAB is similar for both surfaces. The adsorption of AO on UDD depends strongly on the pH of the solution, while the adsorption of AAB is independent of this parameter. It is suggested that the adsorption of AAB is determined not only by ionic and hydrophobic interactions but also by coordination interactions with impurity metal ions on a UDD surface. It is concluded that the adsorption of dyes characterizes the chemistry of a UDD surface with high sensitivity.

  12. Efficiency enhancement in dye-sensitized solar cells by in situ passivation of the sensitized nanoporous electrode with Li2CO3

    International Nuclear Information System (INIS)

    Zhang Jingbo; Zaban, Arie

    2008-01-01

    This work entails a method to improve the performance of dye-sensitized nanocrystalline TiO 2 solar cells by adding surface passivating elements to the electrolyte. The presence of either CO 2 , Li 2 CO 3 or K 2 CO 3 in electrolyte increases both the photocurrent and the photovoltage, resulting in higher overall conversion efficiency of these solar cells. The additives are used to form a passivation layer of lithium carbonate on the dye free surface of the TiO 2 nanoparticles and the conductive substrate. This layer suppresses the rate of the main recombination reaction between the photoinjected electrons and the oxidized ions in the electrolyte solution. While blocking part of the recombination, the lithium carbonate layer allows motion of the Li + ions towards the TiO 2 surface for charge screening. Consequently using this simple treatment, the conversion efficiency of dye-sensitized solar cell most improved by 17.2% (from 6.4% to 7.5%)

  13. Nitrogen-doped graphene as transparent counter electrode for efficient dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wang, Guiqiang; Fang, Yanyan; Lin, Yuan; Xing, Wei; Zhuo, Shuping

    2012-01-01

    Graphical abstract: Display Omitted Highlights: ► NG sheets are prepared through a hydrothermal reduction of graphite oxide. ► The transparent NG counter electrodes of DSCs are fabricated at room temperature. ► Transparent NG electrode exhibits excellent catalytic activity for the reduction of I 3 − . ► The DSC with NG electrode achieves a comparable efficiency to that of the Pt-based cell. ► The efficiency of rear illumination is about 85% that of front illumination. -- Abstract: Nitrogen-doped graphene sheets are prepared through a hydrothermal reduction of graphite oxide in the presence of ammonia and applied to fabricate the transparent counter electrode of dye-sensitized solar cells. The atomic percentage of nitrogen in doped graphene sample is about 2.5%, and the nitrogen bonds display pyridine and pyrrole-like configurations. Cyclic voltammetry studies demonstrate a much higher electrocatalytic activity toward I − /I 3 − redox reaction for nitrogen-doped graphene, as compared with pristine graphene. The dye-sensitized solar cell with this transparent nitrogen-doped graphene counter electrode shows conversion efficiencies of 6.12% and 5.23% corresponding to front-side and rear-side illumination, respectively. Meanwhile, the cell with a Pt counter electrode shows a conversion efficiency of 6.97% under the same experimental condition. These promising results highlight the potential application of nitrogen-doped graphene in cost-effective, transparent dye-sensitized solar cells.

  14. A Gold Nanoparticle Bio-Optical Transponder to Dynamically Monitor Intracellular pH.

    Science.gov (United States)

    Carnevale, Kate J F; Riskowski, Ryan A; Strouse, Geoffrey F

    2018-06-13

    A pH-sensitive bio-optical transponder (pH-BOT) capable of simultaneously reporting the timing of intracellular DNA cargo release from a gold nanoparticle (AuNP) and the evolving intracellular pH (pH i) during endosomal maturation is demonstrated. The pH-BOT is designed with a triple-dye-labeled duplex DNA appended to a 6.6 nm AuNP, utilizing pH-responsive fluorescein paired with DyLight405 as a surface energy transfer (SET) coupled dye pair to ratiometrically report the pH at and after cargo release. A non-SET-coupled dye, DyLight 700, is used to provide dynamic tracking throughout the experiment. The pH-BOT beacon of the cargo uptake, release, and processing was visualized using live-cell confocal fluorescent microscopy in Chinese hamster ovary cells, and it was observed that while maturation of endosomes carrying pH-BOT is slowed significantly, the pH-BOT is distributed throughout the endolysosomal system while remaining at pH ∼6. This observed decoupling of endosomal maturation from acidification lends support to those models that propose that pH alone is not sufficient to explain endosomal maturation and may enable greater insight into our understanding of the fundamental processes of biology.

  15. Effects of the aspect ratio on the dye adsorption of ZnO nanorods grown by using a sonochemical method for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Choi, Seok Cheol; Yun, Won Suk; Sohn, Sang Ho; Oh, Sang Jin

    2012-01-01

    Well-aligned ZnO nanorods for the photoelectrode of dye-sensitized solar cells (DSSCs) were grown via a sonochemical method, and the effects of their aspect ratios on the dye adsorption in DSSCs were studied. The control of the aspect ratio of well-aligned ZnO nanorods was performed by tuning the mole concentration of zinc acetate dehydrate in the range of 0.04 ∼ 0.06M. The dye amounts adsorbed in the ZnO nanorods were estimated from the UV-Visible absorbance by using the Beer-Lambert law. The efficiency of DSSCs with ZnO nanorods was measured to investigate the effects of the aspect ratio of the ZnO nanorods on the dye adsorption properties. A change in the aspect ratio of the ZnO nanorods was founded to yield a change in their dye adsorption ability, resulting in a change in the efficiency of the DSSCs.

  16. Solid State Polymer Electrolytes for Dye-sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction Over the past decade,Dye-sensitized solar cells (DSSCs) have been intensively investigated as potential alternatives to conventional inorganic photovoltaic devices due to their low production cost and high energy conversion[1-4]. This type of solar cell has achieved an impressive energy conversion efficiency of over 10%,whose electrolyte is a voltaic organic liquid solvent containing iodide/triiodide as redox couple.However,the use of a liquid electrolyte brings difficulties in the practi...

  17. Magnetic and fluorescent core-shell nanoparticles for ratiometric pH sensing

    International Nuclear Information System (INIS)

    Lapresta-Fernandez, Alejandro; Doussineau, Tristan; Moro, Artur J; Dutz, Silvio; Steiniger, Frank; Mohr, Gerhard J

    2011-01-01

    This paper describes the preparation of nanoparticles composed of a magnetic core surrounded by two successive silica shells embedding two fluorophores, showing uniform nanoparticle size (50-60 nm in diameter) and shape, which allow ratiometric pH measurements in the pH range 5-8. Uncoated iron oxide magnetic nanoparticles (∼10 nm in diameter) were formed by the coprecipitation reaction of ferrous and ferric salts. Then, they were added to a water-in-oil microemulsion where the hydrophilic silica shells were obtained through hydrolysis and condensation of tetraethoxyorthosilicate together with the corresponding silylated dye derivatives-a sulforhodamine was embedded in the inner silica shell and used as the reference dye while a pH-sensitive fluorescein was incorporated in the outer shell as the pH indicator. The magnetic nanoparticles were characterized using vibrating sample magnetometry, dynamic light scattering, transmission electron microscopy, x-ray diffraction and Fourier transform infrared spectroscopy. The relationship between the analytical parameter, that is, the ratio of fluorescence between the sensing and reference dyes versus the pH was adjusted to a sigmoidal fit using a Boltzmann type equation giving an apparent pK a value of 6.8. The fluorescence intensity of the reference dye did not change significantly (∼3.0%) on modifying the pH of the nanoparticle dispersion. Finally, the proposed method was statistically validated against a reference procedure using samples of water and physiological buffer with 2% of horse serum, indicating that there are no significant statistical differences at a 95% confidence level.

  18. Nicotinic acid as a new co-adsorbent in dye-sensitized solar cells

    DEFF Research Database (Denmark)

    Nguyen, Phuong Tuyet; Nguyen, Vinh Son; Pham Phan, Thu Anh

    2017-01-01

    With the aim of introduction a new inexpensive co-adsorbent to improve solar cell performance, the influence of nicotinic acid (NTA) used as a co-adsorbent in dye-sensitized solar cells (DSCs) was investigated. The findings showed that low concentrations of NTA (

  19. Incorporation of graphene into SnO2 photoanodes for dye-sensitized solar cells

    Science.gov (United States)

    Batmunkh, Munkhbayar; Dadkhah, Mahnaz; Shearer, Cameron J.; Biggs, Mark J.; Shapter, Joseph G.

    2016-11-01

    In dye-sensitized solar cell (DSSC) photoanodes, tin dioxide (SnO2) structures present a promising alternative semiconducting oxide to the conventional titania (TiO2), but they suffer from poor photovoltaic (PV) efficiency caused by insufficient dye adsorption and low energy value of the conduction band. A hybrid structure consisting of SnO2 and reduced graphene oxide (SnO2-RGO) was synthesized via a microwave-assisted method and has been employed as a photoanode in DSSCs. Incorporation of RGO into the SnO2 photoanode enhanced the power conversion efficiency of DSSC device by 91.5%, as compared to the device assembled without RGO. This efficiency improvement can be attributed to increased dye loading, enhanced electron transfer and addition of suitable energy levels in the photoanode. Finally, the use of RGO addresses the major shortcoming of SnO2 when employed as a DSSC photoanode, namely poor dye adsorption and slow electron transfer rate.

  20. Effect of gamma-irradiation on basic dye maxilon blue in aqueous solution

    International Nuclear Information System (INIS)

    Andayani, Winarti; Bagyo, Agustin S.M.; Winarno, Ermin K.; Winarno, Hendig

    1998-01-01

    The effects of radiation of basic dye maxilon blue have been studied. Irradiation was done at various pH (3, 5, 7, 9, and 12) with doses of 0 - 4 kGy/h. at pH 5 irradiation of dye solution with variation of concentration i.e. 10; 25; 50.8; 78.2 and 106 ppm were done. Bubbling of air were done during irradiation of dye solution. Parameters examined were the change of the spectrum by spectrophotometer, the decrease of pH by pH meter and degradation products such as organic acids by HPLC. The results showed that the percentage of degradation at acid pH is higher than that basic and neutral pH. G value (degradation) of the dye at pH 5 was 0.876 with a dose rate of 5 kGy/h. Percentage of decoloration of dye solution at initial concentration 10 and 25 ppm were higher than 90% at dose of 0.5 kGy, dye solution at initial concentration between 50 to 106 ppm were higher than 90% at 2 kGy. The equation of degradation rate of the dye was V=-d(dye)/dt = 1.4 x 10 -2 [dye] 1,1107 ppm/min. Degradation of the dye has first order pseudo with the rate constant of 1.4 x 10 -2 min -1 . Degradation products that could be detected was oxalic acid. (authors)

  1. Photovoltaic characteristics of natural light harvesting dye sensitized solar cells

    Science.gov (United States)

    Hafez, H. S.; Shenouda, S. S.; Fadel, M.

    2018-03-01

    In this work of research, anthocyanin as a natural dye obtained from raspberry fruits, was used and tested as a photon harvesting/electron donating dye in titanium dioxide nanoparticle-based DSSCs. A working photoelectrode made from TiO2 nanoparticles with an average particle size (10-40 nm) that is coated on Florine doped tin-oxide substrate, was prepared via a simple and low cost hydrothermal method. A detailed structural and morphological analysis of the TiO2 photoactive electrode was investigated by X-ray diffraction (XRD), diffuse reflectance spectrometer, transmission electron microscope (TEM) and scanning electron microscope (SEM). Complete photovoltaic characteristics including (current, voltage, outpower, and responsivity) of the natural anthocyanin based dye sensitized solar cell have been investigated under different illumination intensity ranging from 10 to 100 mW.cm- 2. The cell responsivity and efficiency of the fabricated solar cell under different illumination intensity were found to be in the range (R = 15.6-23.8 mA.W- 1 and η = 0.13-0.25) at AM = 1.5 conditions. This study is important for enhancing the future applications of the promising DSSC technology.

  2. Photovoltaic characteristics of natural light harvesting dye sensitized solar cells.

    Science.gov (United States)

    Hafez, H S; Shenouda, S S; Fadel, M

    2018-03-05

    In this work of research, anthocyanin as a natural dye obtained from raspberry fruits, was used and tested as a photon harvesting/electron donating dye in titanium dioxide nanoparticle-based DSSCs. A working photoelectrode made from TiO 2 nanoparticles with an average particle size (10-40nm) that is coated on Florine doped tin-oxide substrate, was prepared via a simple and low cost hydrothermal method. A detailed structural and morphological analysis of the TiO 2 photoactive electrode was investigated by X-ray diffraction (XRD), diffuse reflectance spectrometer, transmission electron microscope (TEM) and scanning electron microscope (SEM). Complete photovoltaic characteristics including (current, voltage, outpower, and responsivity) of the natural anthocyanin based dye sensitized solar cell have been investigated under different illumination intensity ranging from 10 to 100mW.cm -2 . The cell responsivity and efficiency of the fabricated solar cell under different illumination intensity were found to be in the range (R=15.6-23.8mA.W -1 and η=0.13-0.25) at AM=1.5 conditions. This study is important for enhancing the future applications of the promising DSSC technology. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Ground and excited state properties of high performance anthocyanidin dyes-sensitized solar cells in the basic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Prima, Eka Cahya [Advanced Functional Material Laboratory, Engineering Physics, Institut Teknologi Bandung (Indonesia); Computational Material Design and Quantum Engineering Laboratory, Engineering Physics, Institut Teknologi Bandung (Indonesia); International Program on Science Education, Universitas Pendidikan Indonesia (Indonesia); Yuliarto, Brian; Suyatman, E-mail: yatman@tf.itb.ac.id [Advanced Functional Material Laboratory, Engineering Physics, Institut Teknologi Bandung (Indonesia); Dipojono, Hermawan Kresno [Computational Material Design and Quantum Engineering Laboratory, Engineering Physics, Institut Teknologi Bandung (Indonesia)

    2015-09-30

    The aglycones of anthocyanidin dyes were previously reported to form carbinol pseudobase, cis-chalcone, and trans-chalcone due to the basic levels. The further investigations of ground and excited state properties of the dyes were characterized using density functional theory with PCM(UFF)/B3LYP/6-31+G(d,p) level in the basic solutions. However, to the best of our knowledge, the theoretical investigation of their potential photosensitizers has never been reported before. In this paper, the theoretical photovoltaic properties sensitized by dyes have been successfully investigated including the electron injections, the ground and excited state oxidation potentials, the estimated open circuit voltages, and the light harvesting efficiencies. The results prove that the electronic properties represented by dyes’ LUMO-HOMO levels will affect to the photovoltaic performances. Cis-chalcone dye is the best anthocyanidin aglycone dye with the electron injection spontaneity of −1.208 eV, the theoretical open circuit voltage of 1.781 V, and light harvesting efficiency of 56.55% due to the best HOMO-LUMO levels. Moreover, the ethanol solvent slightly contributes to the better cell performance than the water solvent dye because of the better oxidation potential stabilization in the ground state as well as in the excited state. These results are in good agreement with the known experimental report that the aglycones of anthocyanidin dyes in basic solvent are the high potential photosensitizers for dye-sensitized solar cell.

  4. A novel pH optical sensor using methyl orange based on triacetylcellulose membranes as support.

    Science.gov (United States)

    Hosseini, Mohammad; Heydari, Rouhollah; Alimoradi, Mohammad

    2014-07-15

    A novel pH optical sensor based on triacetylcellulose membrane as solid support was developed by using immobilization of methyl orange indicator. The prepared optical sensor was fixed into a flow cell for on-line pH monitoring. Variables affecting sensor performance, such as pH of dye bonding to triacetylcellulose membrane and dye concentration have been fully evaluated and optimized. The calibration curve showed good behavior and precision (RSDpH range of 4.0-12.0. No significant variation was observed on sensor response with increasing the ionic strength in the range of 0.0-0.5M of sodium chloride. Determination of pH by using the proposed optical sensor is on-line, quick, inexpensive, selective and sensitive in the pH range of 4.0-12.0. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Application of graphene-based nanostructures in dye-sensitized solar cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Yum, J. H.; Graetzel, M.

    2013-01-01

    Roč. 250, č. 12 (2013), s. 2643-2648 ISSN 0370-1972 R&D Projects: GA ČR GA13-07724S; GA ČR GA13-31783S Grant - others:European Commission CORDIS(XE) FP7-ENERGY-2010-FET, projekt 256617 Institutional support: RVO:61388955 Keywords : counter electrode * dye-sensitized solar cells * electrocatalysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.605, year: 2013

  6. Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L

    International Nuclear Information System (INIS)

    Agustia, Yuda Virgantara; Suyitno,; Sutanto, Bayu; Arifin, Zainal

    2016-01-01

    The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, E_H_O_M_O and E_L_U_M_O was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where E_r_e_d = −0.37V, E_L_U_M_O = −4.28 eV, E_o_x = 1.15V, E_H_O_M_O = −5.83 eV, and E_b_a_n_d _g_a_p = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

  7. Normalization of voltage-sensitive dye signal with functional activity measures.

    Directory of Open Access Journals (Sweden)

    Kentaroh Takagaki

    Full Text Available In general, signal amplitude in optical imaging is normalized using the well-established DeltaF/F method, where functional activity is divided by the total fluorescent light flux. This measure is used both directly, as a measure of population activity, and indirectly, to quantify spatial and spatiotemporal activity patterns. Despite its ubiquitous use, the stability and accuracy of this measure has not been validated for voltage-sensitive dye imaging of mammalian neocortex in vivo. In this report, we find that this normalization can introduce dynamic biases. In particular, the DeltaF/F is influenced by dye staining quality, and the ratio is also unstable over the course of experiments. As methods to record and analyze optical imaging signals become more precise, such biases can have an increasingly pernicious impact on the accuracy of findings, especially in the comparison of cytoarchitechtonic areas, in area-of-activation measurements, and in plasticity or developmental experiments. These dynamic biases of the DeltaF/F method may, to an extent, be mitigated by a novel method of normalization, DeltaF/DeltaF(epileptiform. This normalization uses as a reference the measured activity of epileptiform spikes elicited by global disinhibition with bicuculline methiodide. Since this normalization is based on a functional measure, i.e. the signal amplitude of "hypersynchronized" bursts of activity in the cortical network, it is less influenced by staining of non-functional elements. We demonstrate that such a functional measure can better represent the amplitude of population mass action, and discuss alternative functional normalizations based on the amplitude of synchronized spontaneous sleep-like activity. These findings demonstrate that the traditional DeltaF/F normalization of voltage-sensitive dye signals can introduce pernicious inaccuracies in the quantification of neural population activity. They further suggest that normalization

  8. Fabrication and characterization of mixed dye: Natural and synthetic organic dye

    Science.gov (United States)

    Richhariya, Geetam; Kumar, Anil

    2018-05-01

    Mixed dye from hibiscus sabdariffa and eosin Y was employed in the fabrication of dye sensitized solar cell (DSSC). Nanostructured mesoporous film was prepared from the titanium dioxide (TiO2). The energy conversion efficiency of hibiscus, eosin Y and mixed dye was obtained as 0.41%, 1.53% and 2.02% respectively. Mixed DSSC has shown improvement in the performance of the cell as compared to hibiscus and eosin Y dye due to addition of synthetic organic dye. This illustrates the effect of synthetic organic dyes in performance enhancement of natural dyes. It has been credited to the improved absorption of light mainly in higher energy state (λ = 440-560 nm) when two dyes were employed simultaneously as was obvious from the absorption spectra of dyes adsorbed onto TiO2 electrode. The cell with TiO2 electrode sensitized by mixed dye gives short circuit current density (Jsc) = 4.01 mA/cm2, open circuit voltage (Voc) = 0.67 V, fill factor (FF) = 0.60 and energy conversion efficiency (η) of 2.02%.

  9. Solution Processed Silver Nanoparticles in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Marko Berginc

    2014-01-01

    Full Text Available A plasmonic effect of silver nanoparticles (Ag NPs in dye-sensitized solar cells (DSSCs is studied. The solutions of silver nitrate in isopropanol, ethylene glycol, or in TiO2 sol were examined as possible precursors for Ag NPs formation. The solutions were dip-coated on the top of the porous TiO2 layer. The results of optical measurements confirmed the formation of Ag NPs throughout the porous TiO2 layer after the heat treatment of the layers above 100°C. Heat treatment at 220°C was found to be optimal regarding the formation of the Ag NPs. The porous TiO2 layers with Ag NPs have been evaluated also in DSSC by measuring current-voltage characteristics and the external quantum efficiency of the cells. In addition, the amount of adsorbed dye has been determined to prove the plasmonic effect in the cells. The I-V characterization of the DSSCs revealed an increase of the short circuit current in the presence of Ag NPs although the amount of the attached dye molecules decreased. These results confirm that the performance enhancement is related to the plasmonic effect. However, neither a thin sol-gel TiO2 layer nor poly(4-vinylpyridine shells provide effective protection for the long term stability of the Ag NPs against the corrosion of I3-/I- based electrolyte.

  10. Copper Bipyridyl Redox Mediators for Dye-Sensitized Solar Cells with High Photovoltage

    Czech Academy of Sciences Publication Activity Database

    Saygili, Y.; Söderberg, M.; Pellet, N.; Giordano, F.; Cao, Y.; Munoz-García, A. B.; Zakeeruddin, S. M.; Vlachopoulos, N.; Pavone, M.; Boschloo, G.; Kavan, Ladislav; Moser, J. E.; Grätzel, M.; Hagfeldt, A.; Freitag, M.

    2016-01-01

    Roč. 138, č. 45 (2016), s. 15087-15096 ISSN 0002-7863 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : Conversion efficiency * Copper * Dye-sensitized solar cells Subject RIV: CG - Electrochemistry Impact factor: 13.858, year: 2016

  11. ISFET pH Sensitivity: Counter-Ions Play a Key Role.

    Science.gov (United States)

    Parizi, Kokab B; Xu, Xiaoqing; Pal, Ashish; Hu, Xiaolin; Wong, H S Philip

    2017-02-02

    The Field Effect sensors are broadly used for detecting various target analytes in chemical and biological solutions. We report the conditions under which the pH sensitivity of an Ion Sensitive Field Effect transistor (ISFET) sensor can be significantly enhanced. Our theory and simulations show that by using pH buffer solutions containing counter-ions that are beyond a specific size, the sensor shows significantly higher sensitivity which can exceed the Nernst limit. We validate the theory by measuring the pH response of an extended gate ISFET pH sensor. The consistency and reproducibility of the measurement results have been recorded in hysteresis free and stable operations. Different conditions have been tested to confirm the accuracy and validity of our experiment results such as using different solutions, various oxide dielectrics as the sensing layer and off-the-shelf versus IC fabricated transistors as the basis of the ISFET sensor.

  12. The Function of TiO2 with Respect to Sensitizer Stability in Nanocrystalline Dye Solar Cells

    Directory of Open Access Journals (Sweden)

    A. Barkschat

    2008-01-01

    Full Text Available Dyes of characteristically different composition have been tested with respect to long-term stability in operating standardized dye sensitized cells during a time period of up to 3600 hours. Selective solar illumination, the use of graded filters, and imaging of photocurrents revealed that degradation is linked to the density of photocurrent passed. Photoelectrochemical degradation was observed with all sensitizers investigated. Sensitization was less efficient and sensitizers were less photostable with nanostructured ZnO compared to nanostructured TiO2. The best performance was confirmed for cis-RuII(dcbpyH22(NCS2 on TiO2. However, it was 7–10 times less stable under other identical conditions on ZnO. Stability is favored by carboxylate anchoring and metal-centred electron transfer. In presence of TiO2, it is enhanced by formation of a stabilizing charge-transfer complex between oxidized Ru dye and back-bonding interfacial Ti3+ states. This is considered to be the main reason for the ongoing use of expensive Ru complexes in combination with TiO2. The local surface chemistry of the nanocrystalline TiO2 turned out to be a crucial factor for sensitizer stability and requires further investigation.

  13. Photoelectrochemical characterization of squaraine-sensitized nickel oxide cathodes deposited via screen-printing for p-type dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Naponiello, Gaia; Venditti, Iole [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Zardetto, Valerio [Centre for Hybrid and Organic Solar Energy, Department of Electronic Engineering, University of Rome - Tor Vergata, via del Politecnico 1, 00133 Rome (Italy); Saccone, Davide [Department of Chemistry and NIS, Interdepartmental Centre of Excellence, University of Torino, via Pietro Giuria 7, I-10125 Torino (Italy); Di Carlo, Aldo [Centre for Hybrid and Organic Solar Energy, Department of Electronic Engineering, University of Rome - Tor Vergata, via del Politecnico 1, 00133 Rome (Italy); Fratoddi, Ilaria [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Center for Nanotechnology for Engineering (CNIS), Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Barolo, Claudia [Department of Chemistry and NIS, Interdepartmental Centre of Excellence, University of Torino, via Pietro Giuria 7, I-10125 Torino (Italy); Dini, Danilo, E-mail: danilo.dini@uniroma1.it [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy)

    2015-11-30

    Graphical abstract: Screen-printing method has been adopted for the deposition of nickel oxide thin film electrodes with mesoporous features. Nickel oxide was sensitized with three newly synthesized squaraines (VG1C8,VG10C8 and DS2/35) and employed as photoelectroactive cathode of p-type dye-sensitized solar cells. Colorant erythrosine b (EB) was taken as commercial benchmark for comparative purposes. Sensitization was successful with the attainment of overall conversion efficiencies in the order of 0.025% when the mesoporous surface of nickel oxide was alkali treated. The prolongation of nickel oxide sensitization time up to 16 h led to a general increase of the open circuit voltage in the corresponding solar cells. - Highlights: • We deposited nickel oxide with screen-printing technique utilizing nickel oxide nanoparticles. • We employed screen-printed nickel oxide as cathodes of p-DSCs. • We employed new squaraine as sensitizers of screen-printed nickel oxide. • Further progress is expected when the formulation of the screen-printing paste will be optimized. - Abstract: In the present paper we report on the employment of the screen-printing method for the deposition of nickel oxide (NiO{sub x}) layers when preformed nanoparticles of the metal oxide (diameter < 50 nm) constitute the precursors in the paste. The applicative purpose of this study is the deposition of mesoporous NiO{sub x} electrodes in the configuration of thin films (thickness, l ≤ 4 μm) for the realization of p-type dye-sensitized solar cells (p-DSCs). Three different squaraine-based dyes (here indicated with VG1C8, VG10C8 and DS2/35), have been used for the first time as sensitizers of a p-type DSC electrode. VG1C8 and VG10C8 present two carboxylic groups as anchoring moieties, whereas DS2/35 sensitizer possesses four acidic anchoring groups. All three squaraines are symmetrical and differ mainly for the extent of electronic conjugation. The colorant erythrosine b (ERY B) was taken as

  14. Novelionic Polymer Electrolytes for Dye Sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    Li Wang; Shibi Fang; Yuan Lin

    2005-01-01

    @@ 1Introduction In recent years, dye-sensitized solar cells(DSC) based on nanocrystalline porous TiO2 films have attracted much attention because of their relatively higher efficiency and low cost compared with conventional inorganic photovoltaic devices[1]. This type of solar cell has achieved an impressive photo-to-energy conversion efficiency of over 10% where the electrolyte is volatile organic liquid solvents containing I-/I-3- as redox couple. Because of high volatilities, solvent losses occur during long-term operations, resulting in lowered DSC performances.And leakage of liquid electrolyte also limits the durability of DSC.

  15. Ytterbium oxide nanodots via block copolymer self-assembly and their efficacy to dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwang-Won; Ahn, Sungwoo; Lim, Sung-Hwan; Jin, Ming Hao; Song, Jeemin; Yun, Seung-Young [Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Kim, Hyeon Mo; Kim, Gi Jeong [Sooyang Chemtec Co., Ltd., Digital-ro 32-gil, Guro-gu, Seoul 152-777 (Korea, Republic of); Ok, Kang Min [Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Hong, Jongin, E-mail: hongj@cau.ac.kr [Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756 (Korea, Republic of)

    2016-02-28

    Graphical abstract: - Highlights: • A novel phosphor, Yb{sub 2}O{sub 3}, was developed as a UV-absorbing spectral converter for dye-sensitized solar cells (DSSCs). • The ordered Yb{sub 2}O{sub 3} nanodots trap more light and prevent charge recombination at the interfaces. • Their multifunctionality improves DSSC performance for both Ru-based and organic dyes. - Abstract: In this study, we develop a novel phosphor, Yb{sub 2}O{sub 3}, to be used as the spectral converter in dye-sensitized solar cells (DSSCs) for the efficient capture of ultraviolet light via down-conversion. These zero-dimensional nanodots with a high refractive index also allow more light to be trapped and can prevent charge recombination at the interfaces in the DSSCs. Compared to DSSCs without the nanodots, the DSSCs fabricated with the Yb{sub 2}O{sub 3} nanodots exhibits higher power-conversion efficiencies for both the N719 (10.5%) and CSD-01 (20.5%) dyes. The multifunctionality of the Yb{sub 2}O{sub 3} nanodots provides a new route for improving the performance of DSSCs.

  16. The Application of Electrospun Titania Nanofibers in Dye-sensitized Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Krýsová, Hana; Zukal, Arnošt; Trčková-Baraková, J.; Chandiran, A. K.; Nazeeruddin, M. K.; Grätzel, M.; Kavan, Ladislav

    2013-01-01

    Roč. 67, č. 3 (2013), s. 149-154 ISSN 0009-4293 R&D Projects: GA AV ČR IAA400400804; GA AV ČR KAN200100801; GA ČR GA203/08/0604 Institutional support: RVO:61388955 Keywords : dye-sensitized solar cells * electrospinning * titanium dioxide Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.091, year: 2013

  17. Magnetic field effects in dye-sensitized solar cells controlled by different cell architecture.

    Science.gov (United States)

    Klein, M; Pankiewicz, R; Zalas, M; Stampor, W

    2016-07-21

    The charge recombination and exciton dissociation are generally recognized as the basic electronic processes limiting the efficiency of photovoltaic devices. In this work, we propose a detailed mechanism of photocurrent generation in dye-sensitized solar cells (DSSCs) examined by magnetic field effect (MFE) technique. Here we demonstrate that the magnitude of the MFE on photocurrent in DSSCs can be controlled by the radius and spin coherence time of electron-hole (e-h) pairs which are experimentally modified by the photoanode morphology (TiO2 nanoparticles or nanotubes) and the electronic orbital structure of various dye molecules (ruthenium N719, dinuclear ruthenium B1 and fully organic squaraine SQ2 dyes). The observed MFE is attributed to magnetic-field-induced spin-mixing of (e-h) pairs according to the Δg mechanism.

  18. Mesoporous anatase TiO_2 microspheres with interconnected nanoparticles delivering enhanced dye-loading and charge transport for efficient dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Chu, Liang; Qin, Zhengfei; Zhang, Qiaoxia; Chen, Wei; Yang, Jian; Yang, Jianping; Li, Xing’ao

    2016-01-01

    Graphical abstract: The photoelectrodes of DSSCs consisted of mesoporous anatase TiO_2 microspheres with interconnected nanoparticles. The interconnected nanoparticles enhance dye-loading capacity and charge transport. - Highlights: • The mesoporous anatase TiO_2 microspheres were synthesized by a template-free, one-step fast solvothermal process. • The mesoporous anatase TiO_2 microspheres with interconnected nanoparticles have the advantages of large surface area and connected-structure for electron transfer. • The mesoporous anatase TiO_2 microspheres were further utilized as efficient photoelectrodes for dye-sensitized solar cells. - Abstract: Mesoporous anatase TiO_2 microspheres with interconnected nanostructures meet both large surface area and connected-structure for electron transfer as ideal nano/micromaterials for application in solar cells, energy storage, catalysis, water splitting and gas sensing. In this work, mesoporous anatase TiO_2 microspheres consisting of interconnected nanoparticles were synthesized by template-free, one-step fast solvothermal process, where urea was used as capping agent to control phase and promote oriented growth. The morphology was assembled by nucleation-growth-assembly-mechanism. The mesoporous anatase TiO_2 microspheres with interconnected nanoparticles were further utilized as efficient photoelectrodes of dye-sensitized solar cells (DSSCs), which were beneficial to capacity of dye loading and charge transfer. The power conversion efficiency (PCE) based on the optimized thickness of TiO_2 photoelectrodes was up to 7.13% under standard AM 1.5 G illumination (100 mW/cm"2).

  19. Dye-sensitized solar cells with ZnO nanoparticles fabricated at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sungjae; Moon, Byungjoon; Son, Dongick [Korea Institute of Science and Technology, Wanju (Korea, Republic of); Kwon, Byoungwook; Choi, Wonkook [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2014-11-15

    The authors investigated the microstructural and the electrical properties of ZnO based dyesensitized solar cells (DSSCs) fabricated using a low-temperature-processed(200 .deg. C) dye-sensitized ZnO-nanoparticle thin film and a Pt catalyst deposited on ITO/glass by using RF magnetron sputtering. A hydropolymer containing PEG (poly(ethylene glycol)) and PEO (poly ethylene oxide) was used to make uniformly-distributed ZnO nanoparticle layer that form a nano-porous ZnO network after heat treatment and was then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short circuit current density (J{sub sc}), the open circuit potential(V{sub oc}), the fill factor(FF), and the power conversion efficiency (η), of the DSSC fabricated under optimized conditions were observed to be 4.93 mA/cm{sup 2}, 0.56 V, 0.40, and 1.12%, respectively.

  20. Pemanfaatan Antosianin dari Ekstrak Kol Merah (Brassica oleracea var sebagai Pewarna Dye-Sensitized Solar Cells (DSSC

    Directory of Open Access Journals (Sweden)

    Dinasti Dwi Pratiwi

    2016-09-01

    Full Text Available A prototype of Dye-Sensitized Solar Cells (DSSC utilizing anthocyanin extract from red cabbage was fabricated. This study aims to determine the wavelength absorption of dye contributed in highest efficiency. The sandwich structure of DSSC consists of TiO2 as working electrode, carbon layer as counter electrode, anthocyanin dye as photosensitizer, and electrolyte as electron transfer media. The absorbance of dye was characterized using UV-Vis spectrophotometer, the efficiency of DSSC was calculated using I-V Meter Keithley, and the quantum efficiency was characterized using IPCE Measurement System. The absorption of dye anthocyanin of red cabbage is 450 nm–580 nm wavelengths, I-V characteristic curves resulted efficiency of 0,029%, and IPCE characteristic resulted highest efficiency at wavelength of 420 nm with efficiency of 0,099%.

  1. Incorporation of graphene into SnO2 photoanodes for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Batmunkh, Munkhbayar; Dadkhah, Mahnaz; Shearer, Cameron J.; Biggs, Mark J.; Shapter, Joseph G.

    2016-01-01

    Graphical abstract: Incorporation of a graphene structure into SnO 2 dye-sensitized solar cell photoanode films has been demonstrated for the first time. The use of graphene in the SnO 2 has been found to be a promising strategy to address many problems of photovoltaic cells based on SnO 2 photoanodes. - Highlights: • SnO 2 -reduced graphene oxide (RGO) hybrid is prepared using a microwave technique. • The first SnO 2 -RGO photoanode based DSSC is fabricated. • Use of RGO addresses the major shortcoming of SnO 2 when employed as a DSSC photoanode. • RGO significantly improved the electron transport rate within the DSSC devices. • Incorporation of RGO into the SnO 2 photoanode enhanced the DSSC efficiency by 91.5%. - Abstract: In dye-sensitized solar cell (DSSC) photoanodes, tin dioxide (SnO 2 ) structures present a promising alternative semiconducting oxide to the conventional titania (TiO 2 ), but they suffer from poor photovoltaic (PV) efficiency caused by insufficient dye adsorption and low energy value of the conduction band. A hybrid structure consisting of SnO 2 and reduced graphene oxide (SnO 2 -RGO) was synthesized via a microwave-assisted method and has been employed as a photoanode in DSSCs. Incorporation of RGO into the SnO 2 photoanode enhanced the power conversion efficiency of DSSC device by 91.5%, as compared to the device assembled without RGO. This efficiency improvement can be attributed to increased dye loading, enhanced electron transfer and addition of suitable energy levels in the photoanode. Finally, the use of RGO addresses the major shortcoming of SnO 2 when employed as a DSSC photoanode, namely poor dye adsorption and slow electron transfer rate.

  2. Metal-free indoline dye sensitized solar cells based on nanocrystalline Zn{sub 2}SnO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lihua [Institute of New Energy Technology and Nano-Materials, Fuzhou University, Fuzhou, Fujian 350002 (China); Jiang, Lilong; Wei, Mingding [Institute of New Energy Technology and Nano-Materials, Fuzhou University, Fuzhou, Fujian 350002 (China); National Engineering Research Center for Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, Fujian 350002 (China)

    2010-02-15

    Zn{sub 2}SnO{sub 4} nanocrystals were synthesized and first used as the electrode materials for the metal-free indoline dyes sensitized solar cells (DSSCs). The highest efficiency of 3.08% was achieved for a D131 DSSC. This might be attributed to the fact that the D131 dye has a greater positive oxidation potential, which can lead to rapid dye regeneration, avoiding the geminate charge recombination between oxidized dye molecules and injected electrons in the Zn{sub 2}SnO{sub 4} film. The efficiency can be improved significantly using a mixture solution of D131 and N719 dyes for which an efficiency of 3.6% was obtained. (author)

  3. Cyanidin-Based Novel Organic Sensitizer for Efficient Dye-Sensitized Solar Cells: DFT/TDDFT Study

    Directory of Open Access Journals (Sweden)

    Kalpana Galappaththi

    2017-01-01

    Full Text Available Cyanidin is widely considered as a potential natural sensitizer in dye-sensitized solar cells due to its promising electron-donating and electron-accepting abilities and cheap availability. We consider modifications of cyanidin structure in order to obtain broader UV-Vis absorption and hence to achieve better performance in DSSC. The modified molecule consists of cyanidin and the benzothiadiazolylbenzoic acid group, where the benzothiadiazolylbenzoic acid group is attached to the cyanidin molecule by replacing one hydroxyl group. The resulting structure was then computationally simulated by using the Spartan’10 software package. The molecular geometries, electronic structures, absorption spectra, and electron injections of the newly designed organic sensitizer were investigated in this work through density functional theory (DFT and time-dependent density functional theory (TDDFT calculations using the Gaussian’09W software package. Furthermore, TDDFT computational calculations were performed on cyanadin and benzothiadiazolylbenzoic acid separately, as reference. The computational studies on the new sensitizer have shown a reduced HOMO-LUMO gap; bathochromic and hyperchromic shifts of absorption spectra range up to near-infrared region revealing its enhanced ability to sensitize DSSCs.

  4. Peripheral Hole Acceptor Moieties on an Organic Dye Improve Dye‐Sensitized Solar Cell Performance

    Science.gov (United States)

    Hao, Yan; Gabrielsson, Erik; Lohse, Peter William; Yang, Wenxing; Johansson, Erik M. J.; Hagfeldt, Anders

    2015-01-01

    Investigation of charge transfer dynamics in dye‐sensitized solar cells is of fundamental interest and the control of these dynamics is a key factor for developing more efficient solar cell devices. One possibility for attenuating losses through recombination between injected electrons and oxidized dye molecules is to move the positive charge further away from the metal oxide surface. For this purpose, a metal‐free dye named E6 is developed, in which the chromophore core is tethered to two external triphenylamine (TPA) units. After photoinduced electron injection into TiO2, the remaining hole is rapidly transferred to a peripheral TPA unit. Electron–hole recombination is slowed down by 30% compared to a reference dye without peripheral TPA units. Furthermore, it is found that the added TPA moieties improve the electron blocking effect of the dye, retarding recombination of electrons from TiO2 to the cobalt‐based electrolyte. PMID:27722076

  5. Towards Renewable Iodide Sources for Electrolytes in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Iryna Sagaidak

    2016-03-01

    Full Text Available A novel family of iodide salts and ionic liquids based on different carbohydrate core units is herein described for application in dye-sensitized solar cell (DSC. The influence of the molecular skeleton and the cationic structure on the electrolyte properties, device performance and on interfacial charge transfer has been investigated. In combination with the C106 polypyridyl ruthenium sensitizer, power conversion efficiencies lying between 5.0% and 7.3% under standard Air Mass (A.M. 1.5G conditions were obtained in association with a low volatile methoxypropionitrile (MPN-based electrolyte.

  6. A home-made system for IPCE measurement of standard and dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Palma, Giuseppina; Cozzarini, Luca; Capria, Ennio [Organic OptoElectronics Laboratory, Sincrotrone Trieste SCpA—SS 14.5, km 163.5, 34149 Basovizza (TS) (Italy); Fraleoni-Morgera, Alessandro, E-mail: alessandro.fraleoni@elettra.trieste.it, E-mail: afraleoni@units.it [Organic OptoElectronics Laboratory, Sincrotrone Trieste SCpA—SS 14.5, km 163.5, 34149 Basovizza (TS) (Italy); Flextronics Laboratory, Department of Engineering and Architecture, University of Trieste. V. Valerio 10, 34100 Trieste (TS) (Italy)

    2015-01-15

    A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

  7. A home-made system for IPCE measurement of standard and dye-sensitized solar cells.

    Science.gov (United States)

    Palma, Giuseppina; Cozzarini, Luca; Capria, Ennio; Fraleoni-Morgera, Alessandro

    2015-01-01

    A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

  8. Sculptured platinum nanowire counter electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeonseok [Department of Electrical Engineering, Pennsylvania State University, University Park 16802 (United States); Horn, Mark W., E-mail: MHorn@engr.psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park 16802-6812 (United States)

    2013-07-01

    Sculptured platinum nanowire thin films were formed by oblique angle electron beam evaporation with a 5° vapor incidence angle and incorporated as counter electrodes for dye-sensitized solar cells (DSSCs). For the comparison of the performance, bare fluorine doped tin oxide, planar Pt electrodes and counter electrodes treated with chloroplatinic acid were prepared. The sculptured Pt nanowire electrodes showed five times lower charge transfer resistance (0.121 [Ω∗cm{sup 2}]) than that of Pt planar electrode (0.578 [Ω∗cm{sup 2}]) and when the Pt nanowire electrodes are treated with an H{sub 2}PtCl{sub 6} solution have more than ten times lower charge transfer resistance (0.04025 [Ω∗cm{sup 2}]). Moreover, Pt nanowire films used as a counter electrode lead to enhancement in current density and efficiency in comparison with Pt planar counter electrodes. The conversion efficiency with planar electrodes was 5.1 [%] while the efficiency of DSSC with platinum nanowire counter electrodes reached to 5.63 [%] under AM 1.5 illumination. - Highlights: • Pt sculptured thin films (STFs) fabricated by electron beam evaporator. • The STFs featured higher roughness and lower charge transfer resistance. • Improved performance of dye-sensitized solar cells by Pt STFs counter electrodes.

  9. Dye-sensitized Pt@TiO2 core–shell nanostructures for the efficient photocatalytic generation of hydrogen

    Directory of Open Access Journals (Sweden)

    Jun Fang

    2014-03-01

    Full Text Available Pt@TiO2 core–shell nanostructures were prepared through a hydrothermal method. The dye-sensitization of these Pt@TiO2 core–shell structures allows for a high photocatalytic activity for the generation of hydrogen from proton reduction under visible-light irradiation. When the dyes and TiO2 were co-excited through the combination of two irradiation beams with different wavelengths, a synergic effect was observed, which led to a greatly enhanced H2 generation yield. This is attributed to the rational spatial distribution of the three components (dye, TiO2, Pt, and the vectored transport of photogenerated electrons from the dye to the Pt particles via the TiO2 particle bridge.

  10. Preparation and surface modification of hierarchical nanosheets-based ZnO microstructures for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Yongming; Lin, Yu, E-mail: linyuyrr@163.com; Lin, Yibing; Yang, Jiyuan

    2014-02-15

    This paper reports a simple one-step hydrothermal route for the preparation of hierarchical nanosheets-based ZnO microstructures and their application to dye-sensitized solar cells. The morphologies of the products were controlled by the dosage of the reactants. Their physical characteristics were detected by X-ray diffraction, a field-emission scanning electron microscope and a surface analyzer. It is proved that the sample of ZnO microspheres with larger surface area and stronger light-trapping capacity since the superiority of their entirely spherical structures exhibits better photoelectrochemical properties than the mixtures of ZnO microspheres and ZnO microflowers. A dye-sensitized solar cell assembled by the ZnO microspheres as photoanode shows an energy conversion efficiency of 2.94% after surface modification by tetrabutyl titanate solution at 90 {sup °}C. This result is over 1.6 times higher than the non-modified cell fabricated by the ZnO microspheres on the basis of the external improvement and the stability enhancement for the dye-sensitized ZnO photoanode. - Graphical abstract: Influences on energy conversion efficiency of the dye-sensitized solar cells assembled by decorating hierarchical nanosheets-based ZnO microstructures with tetrabutyl titanate solution at different temperatures. Display Omitted - Highlights: • Hierarchical nanosheets-based ZnO microstructures were controllably synthesized. • The ZnO microspheres show good optical and electrochemical properties. • The ZnO microspheres were modified by C{sub 16}H{sub 36}O{sub 4}Ti solution. • Remarkable increase of conversion efficiency is observed after surface modification.

  11. Effect of Isotopic Substitution on Elementary Processes in Dye-Sensitized Solar Cells: Deuterated Amino-Phenyl Acid Dyes on TiO2

    Directory of Open Access Journals (Sweden)

    Sergei Manzhos

    2013-03-01

    Full Text Available We present the first computational study of the effects of isotopic substitution on the operation of dye-sensitized solar cells. Ab initio molecular dynamics is used to study the effect of deuteration on light absorption, dye adsorption dynamics, the averaged over vibrations driving force to injection (∆Gi and regeneration (∆Gr, as well as on promotion of electron back-donation in dyes NK1 (2E,4E-2-cyano-5-(4-dimethylaminophenylpenta-2,4-dienoic acid and NK7 (2E,4E-2-cyano-5-(4-diphenylaminophenylpenta-2,4-dienoic acid adsorbed in monodentate molecular and bidentate bridging dissociative configurations on the anatase (101 surface of TiO2. Deuteration causes a red shift of the absorption spectrum of the dye/TiO2 complex by about 5% (dozens of nm, which can noticeably affect the overlap with the solar spectrum in real cells. The dynamics effect on the driving force to injection and recombination (the difference between the averaged <∆Gi,r> and ∆Gi,requil at the equilibrium configuration is strong, yet there is surprisingly little isotopic effect: the average driving force to injection <∆Gi> and to regeneration <∆Gr> changes by only about 10 meV upon deuteration. The nuclear dynamics enhance recombination to the dye ground state due to the approach of the electron-donating group to TiO2, yet this effect is similar for deuterated and non-deuterated dyes. We conclude that the nuclear dynamics of the C-H(D bonds, mostly affected by deuteration, might not be important for the operation of photoelectrochemical cells based on organic dyes. As the expectation value of the ground state energy is higher than its optimum geometry value (by up to 0.1 eV in the present case, nuclear motions will affect dye regeneration by recently proposed redox shuttle-dye combinations operating at low driving forces.

  12. Electrochemical Characterization of TiO 2 Blocking Layers for Dye-Sensitized Solar Cells

    KAUST Repository

    Kavan, Ladislav; Té treault, Nicolas; Moehl, Thomas; Grä tzel, Michael

    2014-01-01

    Thin compact layers of TiO2 are grown by thermal oxidation of Ti, by spray pyrolysis, by electrochemical deposition, and by atomic layer deposition. These layers are used in dye-sensitized solar cells to prevent recombination of electrons from

  13. Biocompatibility Research of a Novel pH Sensitive Ion Exchange Resin Microsphere.

    Science.gov (United States)

    Liu, Hongfei; Shi, Shuangshuang; Pan, Weisan; Sun, Changshan; Zou, Xiaomian; Fu, Min; Feng, Yingshu; Ding, Hui

    2014-01-01

    The main objective of this study was to investigate biocompatibility and provide in-vivo pharmacological and toxicological evidence for further investigation of the possibility of pH sensitive ion exchange resin microsphere for clinical utilizations. Acute toxicity study and general pharmacological studies were conducted on the pH sensitive ion exchange resin microsphere we prepared. The general pharmacological studies consist of the effects of the pH sensitive ion exchange resin microsphere on the nervous system of mice, the functional coordination of mice, the hypnosis of mice treated with nembutal at subliminal dose, the autonomic activities of tested mice, and the heart rate, blood pressure, ECG and breathing of the anesthetic cats. The LD50 of pH sensitive ion exchange resin microsphere after oral administration was more than 18.84 g·Kg(-1). Mice were orally administered with 16 mg·Kg(-1), 32 mg·Kg(-1) and 64 mg·Kg(-1) of pH sensitive ion exchange resin microsphere and there was no significant influence on mice nervous system, general behavior, function coordination, hypnotic effect treated with nembutal at subliminal dose and frequency of autonomic activities. Within the 90 min after 5 mg·Kg(-1), 10 mg·Kg(-1), 20 mg·Kg(-1) pH sensitive ion exchange resin microsphere was injected to cat duodenum, the heart rate, blood pressure, breathing and ECG of the cats didn't make significant changes in each experimental group compared with the control group. The desirable pharmacological and toxicological behaviors of the pH sensitive ion exchange resin microsphere exhibited that it has safe biocompatibility and is possible for clinical use.

  14. Identification of changes in the inorganic matrix of dye sensitized solar cells during preparation

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Harald; Maedler, Carsten; Kehr, Mirko; Baumgaertel, Thomas [Institute of Physics, Chemnitz University of Technology, Reichenhainer Str. 70, 09126 Chemnitz (Germany); Oekermann, Torsten [Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, 30167 Hannover (Germany)

    2009-12-15

    Nanoporous zinc oxide films can be prepared by electrochemical co-deposition with the dye eosin Y (EY) as template. A subsequent desorption of the dye with aqueous KOH is a key step for the increased efficiency of such dye sensitized solar cells (DSSC). In this contribution, the partial dissolving and reorganization of the zinc oxide film during the desorption step has been studied in detail by X-ray diffraction, Kelvin probe force microscopy, and atomic force microscopy (AFM) as well as scanning electron microscopy. It is found that the reorganization leads to an enhancement of crystal orientation and a reduction of the defect concentration at the surface of zinc oxide, being a possible reason for suppressed recombination of electrons in these films. Also, an increased defect concentration in ZnO was found when co-deposited with EY. For these co-deposited films, AFM investigations showed a coverage of the surface with dye aggregates. High resolution AFM investigations revealed the nanocrystalline and highly porous structure of the inorganic matrix after desorption of the dye. Photographs of the organic/inorganic hybrid thin film material were investigated in this study. Left side: film directly after deposition, right side: after desorption of the organic dye. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  15. Electrochemical design of ZnO hierarchical structures for dye-sensitized solar cells

    Czech Academy of Sciences Publication Activity Database

    Guerin, V. M.; Rathouský, Jiří; Pauporté, T.

    2012-01-01

    Roč. 102, JUL 2012 (2012), s. 8-14 ISSN 0927-0248 R&D Projects: GA AV ČR KAN100400702 Institutional research plan: CEZ:AV0Z40400503 Keywords : ZnO hierarchical structures * epitaxy * dye-sensitized solar cell Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.630, year: 2012

  16. Photocurrent enhanced by singlet fission in a dye-sensitized solar cell.

    Science.gov (United States)

    Schrauben, Joel N; Zhao, Yixin; Mercado, Candy; Dron, Paul I; Ryerson, Joseph L; Michl, Josef; Zhu, Kai; Johnson, Justin C

    2015-02-04

    Investigations of singlet fission have accelerated recently because of its potential utility in solar photoconversion, although only a few reports definitively identify the role of singlet fission in a complete solar cell. Evidence of the influence of singlet fission in a dye-sensitized solar cell using 1,3-diphenylisobenzofuran (DPIBF, 1) as the sensitizer is reported here. Self-assembly of the blue-absorbing 1 with co-adsorbed oxidation products on mesoporous TiO2 yields a cell with a peak internal quantum efficiency of ∼70% and a power conversion efficiency of ∼1.1%. Introducing a ZrO2 spacer layer of thickness varying from 2 to 20 Å modulates the short-circuit photocurrent such that it is initially reduced as thickness increases but 1 with 10-15 Å of added ZrO2. This rise can be explained as being due to a reduced rate of injection of electrons from the S1 state of 1 such that singlet fission, known to occur with a 30 ps time constant in polycrystalline films, has the opportunity to proceed efficiently and produce two T1 states per absorbed photon that can subsequently inject electrons into TiO2. Transient spectroscopy and kinetic simulations confirm this novel mode of dye-sensitized solar cell operation and its potential utility for enhanced solar photoconversion.

  17. Development of a novel pH sensor based upon Janus Green B immobilized on triacetyl cellulose membrane: Experimental design and optimization.

    Science.gov (United States)

    Chamkouri, Narges; Niazi, Ali; Zare-Shahabadi, Vali

    2016-03-05

    A novel pH optical sensor was prepared by immobilizing an azo dye called Janus Green B on the triacetylcellulose membrane. Condition of the dye solution used in the immobilization step, including concentration of the dye, pH, and duration were considered and optimized using the Box-Behnken design. The proposed sensor showed good behavior and precision (RSDpH range of 2.0-10.0. Advantages of this optical sensor include on-line applicability, no leakage, long-term stability (more than 6 months), fast response time (less than 1 min), high selectivity and sensitivity as well as good reversibility and reproducibility. Copyright © 2015. Published by Elsevier B.V.

  18. The reversal constituent structure of photo-electrode in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Ting, Chen-Ching; Chao, Wei-Shi

    2011-01-01

    Highlights: → The new structure of photo-electrode in DSSC increases absorption of incident photons. → The substrate of copper mesh as photo-electrode reduces electric resistance. → Application of the copper mesh as substrate reduces the fabricating cost. → There are ca. 3 times increment of photoelectric conversion efficiency. → Application of the copper mesh as substrate can achieve the flexible DSSCs. - Abstract: This article presents significant experimental data about the dye-sensitized nano solar cells (DSSCs) using the new developed photo-electrode with reversal constituent structure in our CCT laboratory. The conventional constituent structure of a photo-electrode arranged in sequence from the incident light is the transparent conductive glass, the nano TiO 2 semi-conductive porous film, and the dye. In process, the photons energy of the incident light is mainly absorbed by the dye for DSSCs. This causes excited electrons in the dye to jump into conductive band of the TiO 2 and further to transfer into the outer circuit through the conductive glass. That is, a correct constituent structure of the photo-electrode arranged in sequence from the incident light in terms of the working principle should be the dye, the nano TiO 2 film, and the conductive substrate. The conventional constituent structure of the photo-electrode causes the incident light to be hindered by the TiO 2 layer. To reduce the light hindrance for the dye, this work used copper mesh as the conductive substrate and the nano TiO 2 was coated on it. In this way, the copper mesh connects the nano TiO 2 layer with the outer circuit and the holes of the copper mesh also allow the dye to contact with the electrolyte. The new developed constituent structure of the photo-electrode arranged in sequence from the incident light is the dye, the nano TiO 2 film, and the copper mesh. This new constituent structure, which increases amounts of the absorption light in the dye and further improved the

  19. TASK-2 Channels Contribute to pH Sensitivity of Retrotrapezoid Nucleus Chemoreceptor Neurons

    Science.gov (United States)

    Wang, Sheng; Benamer, Najate; Zanella, Sébastien; Kumar, Natasha N.; Shi, Yingtang; Bévengut, Michelle; Penton, David; Guyenet, Patrice G.; Lesage, Florian

    2013-01-01

    Phox2b-expressing glutamatergic neurons of the retrotrapezoid nucleus (RTN) display properties expected of central respiratory chemoreceptors; they are directly activated by CO2/H+ via an unidentified pH-sensitive background K+ channel and, in turn, facilitate brainstem networks that control breathing. Here, we used a knock-out mouse model to examine whether TASK-2 (K2P5), an alkaline-activated background K+ channel, contributes to RTN neuronal pH sensitivity. We made patch-clamp recordings in brainstem slices from RTN neurons that were identified by expression of GFP (directed by the Phox2b promoter) or β-galactosidase (from the gene trap used for TASK-2 knock-out). Whereas nearly all RTN cells from control mice were pH sensitive (95%, n = 58 of 61), only 56% of GFP-expressing RTN neurons from TASK-2−/− mice (n = 49 of 88) could be classified as pH sensitive (>30% reduction in firing rate from pH 7.0 to pH 7.8); the remaining cells were pH insensitive (44%). Moreover, none of the recorded RTN neurons from TASK-2−/− mice selected based on β-galactosidase activity (a subpopulation of GFP-expressing neurons) were pH sensitive. The alkaline-activated background K+ currents were reduced in amplitude in RTN neurons from TASK-2−/− mice that retained some pH sensitivity but were absent from pH-insensitive cells. Finally, using a working heart–brainstem preparation, we found diminished inhibition of phrenic burst amplitude by alkalization in TASK-2−/− mice, with apneic threshold shifted to higher pH levels. In conclusion, alkaline-activated TASK-2 channels contribute to pH sensitivity in RTN neurons, with effects on respiration in situ that are particularly prominent near apneic threshold. PMID:24107938

  20. Eosin Yellowish Dye-Sensitized ZnO Nanostructure-Based Solar Cells Employing Solid PEO Redox Couple Electrolyte

    Directory of Open Access Journals (Sweden)

    S. S. Kanmani

    2012-01-01

    Full Text Available ZnO nanostructures are synthesized by low-temperature methods, and they possess polycrystalline hexagonal wurtzite structure with preferential c-axial growth. Morphological study by SEM shows the presence of ~30 nm sized spherical-shaped ZnO nanoparticle, the branched flower-like ZnO composed of many nanorods (length: 1.2 to 4.2 μm and diameter: 0.3 to 0.4 μm, and ~50 nm diameter of individual ZnO nanorods. Reduction in photoemission intensity of nanorods infers the decrease in electron-hole recombination rate, which offers better photovoltaic performance. The dye-sensitized solar cell (DSSC based on ZnO nanorods sensitized with Eosin yellowish dye exhibits a maximum optimal energy conversion efficiency of 0.163% compared to that of nanoparticles and nanoflowers, due to better dye loading and direct conduction pathway for electron transport.

  1. Electronic structure of the indium tin oxide/nanocrystalline anatase (TiO2)/ruthenium-dye interfaces in dye-sensitized solar cells

    Science.gov (United States)

    Lyon, J. E.; Rayan, M. K.; Beerbom, M. M.; Schlaf, R.

    2008-10-01

    The electronic structure of two interfaces commonly found in dye-sensitized photovoltaic cells based on nanocrystalline anatase TiO2 ("Grätzel cells") was investigated using photoemission spectroscopy (PES). X-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) measurements were carried out on the indium tin oxide (ITO)/TiO2 and the TiO2/cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)-ruthenium(II)bis-tetrabutylammonium dye ("N719" or "Ruthenium 535-bisTBA") interfaces. Both contacts were investigated using a multistep deposition procedure where the entire structure was prepared in vacuum using electrospray deposition. In between deposition steps the surface was characterized with XPS and UPS resulting in a series of spectra, allowing the determination of the orbital and band lineup at the interfaces. The results of these efforts confirm previous PES measurements on TiO2/dye contacts prepared under ambient conditions, suggesting that ambient contamination might not have significant influence on the electronic structure at the dye/TiO2 interface. The results also demonstrate that there may be a significant barrier for electron injection at the sputtered ITO/TiO2 interface and that this interface should be viewed as a semiconductor heterojunction rather than as metal-semiconductor (Schottky) contact.

  2. Dye-sensitized solar cells using graphene-based carbon nano composite as counter electrode

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyonkwang; Kim, Hyunkook; Hwang, Sookhyun; Jeon, Minhyon [Department of Nano Systems Engineering, Center of Nano Manufacturing, Inje University, Obang, Gimhae, Gyungnam 621-749 (Korea, Republic of); Choi, Wonbong [Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States)

    2011-01-15

    We demonstrated a counter electrode in dye-sensitized solar cells (DSSCs) using the graphene-based multi-walled carbon nanotubes (GMWNTs) structure. Graphene layers were prepared by drop casting on a SiO{sub 2}/Si substrate and multi-walled carbon nanotubes (MWNTs) were synthesized on graphene layers using iron catalyst by chemical vapor deposition. The structural properties of GMWNTs were investigated by transmission electron microscope and field-emission scanning electron microscopy. The GMWNTs sheets were lifted off from the Si substrate by buffered oxide etching and were transplanted on fluorine-doped tin oxide glass by Van der Waals force as a counter electrode. From the electrochemical impedance spectroscopy and energy conversion efficiencies, electrochemical properties of GMWNTs were comparable with those of MWNTs counter electrode. The results suggested that GMWNTs were one of the candidates for a counter electrode for dye-sensitized solar cells. (author)

  3. Block copolymer directed synthesis of mesoporous TiO 2 for dye-sensitized solar cells

    KAUST Repository

    Nedelcu, Mihaela

    2009-01-01

    The morphology of TiO2 plays an important role in the operation of solid-state dye-sensitized solar cells. By using polyisoprene-block- ethyleneoxide (PI-b-PEO) copolymers as structure directing agents for a sol-gel based synthesis of mesoporous TiO2, we demonstrate a strategy for the detailed control of the semiconductor morphology on the 10 nm length scale. The careful adjustment of polymer molecular weight and titania precursor content is used to systematically vary the material structure and its influence upon solar cell performance is investigated. Furthermore, the use of a partially sp 2 hybridized structure directing polymer enables the crystallization of porous TiO2 networks at high temperatures without pore collapse, improving its performance in solid-state dye-sensitized solar cells. © 2009 The Royal Society of Chemistry.

  4. Accurate Quantitative Sensing of Intracellular pH based on Self-ratiometric Upconversion Luminescent Nanoprobe.

    Science.gov (United States)

    Li, Cuixia; Zuo, Jing; Zhang, Li; Chang, Yulei; Zhang, Youlin; Tu, Langping; Liu, Xiaomin; Xue, Bin; Li, Qiqing; Zhao, Huiying; Zhang, Hong; Kong, Xianggui

    2016-12-09

    Accurate quantitation of intracellular pH (pH i ) is of great importance in revealing the cellular activities and early warning of diseases. A series of fluorescence-based nano-bioprobes composed of different nanoparticles or/and dye pairs have already been developed for pH i sensing. Till now, biological auto-fluorescence background upon UV-Vis excitation and severe photo-bleaching of dyes are the two main factors impeding the accurate quantitative detection of pH i . Herein, we have developed a self-ratiometric luminescence nanoprobe based on förster resonant energy transfer (FRET) for probing pH i , in which pH-sensitive fluorescein isothiocyanate (FITC) and upconversion nanoparticles (UCNPs) were served as energy acceptor and donor, respectively. Under 980 nm excitation, upconversion emission bands at 475 nm and 645 nm of NaYF 4 :Yb 3+ , Tm 3+ UCNPs were used as pH i response and self-ratiometric reference signal, respectively. This direct quantitative sensing approach has circumvented the traditional software-based subsequent processing of images which may lead to relatively large uncertainty of the results. Due to efficient FRET and fluorescence background free, a highly-sensitive and accurate sensing has been achieved, featured by 3.56 per unit change in pH i value 3.0-7.0 with deviation less than 0.43. This approach shall facilitate the researches in pH i related areas and development of the intracellular drug delivery systems.

  5. Improve photovoltaic performance of titanium dioxide nanorods based dye-sensitized solar cells by Ca-doping

    International Nuclear Information System (INIS)

    Li, Weixin; Yang, Junyou; Zhang, Jiaqi; Gao, Sheng; Luo, Yubo; Liu, Ming

    2014-01-01

    Highlights: • TiO 2 nanorods doped with Ca ions were synthesized by one-step hydrothermal method. • The flat band edge of rutile TiO 2 shifted positively via Ca-doping. • The photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs) based on TiO 2 electrode was much enhanced by Ca-doping. • A relatively high open circuit voltage was obtained by adopting Ca-doped TiO 2 nanorods electrode. - Abstract: Ca-doped TiO 2 nanorod arrays were prepared via the one-step hydrothermal method successfully, and the effect of Ca ions content on the photovoltaic conversion efficiency of dye-sensitized solar cells has been fully discussed in the paper. Although no obvious change on the microstructure and morphology was observed by field emission scanning electron microscope and transmission electron microscope for the Ca-doped samples, the results of X-ray diffraction and X-ray photoelectron spectroscopy confirmed that Ti 4+ was substituted with Ca 2+ successfully. UV–vis spectroscopy results revealed that the flat band edge shifted positively by Ca ions doping. The photovoltaic conversion efficiency of the dye-sensitized solar cells based on the 2 mol% Ca-doped TiO 2 electrode was 43% higher than that of the undoped one due to the less recombination possibility

  6. Optimizations of large area quasi-solid-state dye-sensitized solar cells

    DEFF Research Database (Denmark)

    Biancardo, M.; West, K.; Krebs, Frederik C

    2006-01-01

    In this paper, we address optimizations of dye sensitized solar cells (DSSCs) through the combination of important issues like semi-transparency, quasi-solid-state constructions and low-cost realization of serially connected modules. DSSCs with a transparency of 50% in the visible region, moderate...... encouraging results. A short circuit current (I-sc) of 4.45 mA cm(-2) with an open circuit voltage (V-oc) of 0.5 V were recorded in standard solar cells sensitized by cis-bis(thiocyano) ruthenium(II)-bis-2, 2'-bipyridine-4, 4'-dicarboxylate. Up-scaling tests demonstrate the easy realization of a 625 cm(2...

  7. Sol–Gel Titanium Dioxide Blocking Layers for Dye- Sensitized Solar Cells: Electrochemical Characterization

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Zukalová, Markéta; Vik, O.; Havlíček, D.

    2014-01-01

    Roč. 15, č. 6 (2014), s. 1056-1061 ISSN 1439-4235 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : TiO2 * electrochemistry * dye-sensitized solar cell Subject RIV: CG - Electrochemistry Impact factor: 3.419, year: 2014

  8. Fast, Highly-Sensitive, and Wide-Dynamic-Range Interdigitated Capacitor Glucose Biosensor Using Solvatochromic Dye-Containing Sensing Membrane.

    Science.gov (United States)

    Khan, Md Rajibur Rahaman; Khalilian, Alireza; Kang, Shin-Won

    2016-02-20

    In this paper, we proposed an interdigitated capacitor (IDC)-based glucose biosensor to measure different concentrations of glucose from 1 μM to 1 M. We studied four different types of solvatochromic dyes: Auramine O, Nile red, Rhodamine B, and Reichardt's dye (R-dye). These dyes were individually incorporated into a polymer [polyvinyl chloride (PVC)] and N,N-Dimethylacetamide (DMAC) solution to make the respective dielectric/sensing materials. To the best of our knowledge, we report for the first time an IDC glucose biosensing system utilizing a solvatochromic-dye-containing sensing membrane. These four dielectric or sensing materials were individually placed into the interdigitated electrode (IDE) by spin coating to make four IDC glucose biosensing elements. The proposed IDC glucose biosensor has a high sensing ability over a wide dynamic range and its sensitivity was about 23.32 mV/decade. It also has fast response and recovery times of approximately 7 s and 5 s, respectively, excellent reproducibility with a standard deviation of approximately 0.023, highly stable sensing performance, and real-time monitoring capabilities. The proposed IDC glucose biosensor was compared with an IDC, potentiometric, FET, and fiber-optic glucose sensor with respect to response time, dynamic range width, sensitivity, and linearity. We observed that the designed IDC glucose biosensor offered excellent performance.

  9. Insight into the effects of modifying chromophores on the performance of quinoline-based dye-sensitized solar cells

    Science.gov (United States)

    Mao, Mao; Wang, Jian-Bo; Liu, Xiu-Lin; Wu, Guo-Hua; Fang, Xia-Qin; Song, Qin-Hua

    2018-02-01

    A series of organic dyes based on quinoline as an electron-deficient π-linker, were designed and synthesized for dye sensitized solar cells (DSSC) application. These push-pull conjugated dyes, sharing same anchoring group with distinctive electron-rich donating groups such as N,N-diethyl (DEA-Q), 3,6-dimethoxy carbazole (CBZ-Q), bis(4-butoxyphenyl)amine (BPA-Q), were synthesized by Riley oxidation of sbnd CH3 followed by Knoevenagel condensation of the corresponding aldehyde precursors 2a-c with cyanoacrylic acid. The optical, electrochemical, theoretical calculation and photovoltaic properties with these three dyes were systematically investigated. Compared to DEA-Q and CBZ-Q, BPA-Q possesses better light harvesting properties with regard to extended conjugate length, red-shifted intramolecular charge transfer band absorption and broaden light-responsive IPCE spectrum, resulting in a greater short circuit photocurrent density output. BPA-Q also has improved open-circuit voltage due to the apparent large charge recombination resistance. Consequently, assembled with iodine redox electrolytes, the device with BPA-Q achieved the best overall conversion efficiency value of 3.07% among three dyes under AM 1.5G standard conditions. This present investigation demonstrates the importance of various N-substituent chromophores in the prevalent D-π-A type organic sensitizers for tuning the photovoltaic performance of their DSSCs.

  10. pH triggered superior selective adsorption and separation of both cationic and anionic dyes and photocatalytic activity on a fully exfoliated titanate layer-natural polymer based nanocomposite.

    Science.gov (United States)

    Sarkar, Amit Kumar; Saha, Arka; Panda, Asit Baran; Pal, Sagar

    2015-11-18

    A fully exfoliated titanate layer-natural polymer amylopectin based nanocomposite, with pH responsive superior selective adsorption, separation of both cationic (MB: 599 mg g(-1) at pH 9) and anionic (MO: 558 mg g(-1) at pH 3) dyes and photodegradation properties, has been realized through simultaneous in situ layered titanate formation, exfoliation and polymerization.

  11. High Molar Extinction Coefficient Ru(II-Mixed Ligand Polypyridyl Complexes for Dye Sensitized Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Malapaka Chandrasekharam

    2011-01-01

    Full Text Available Two new ruthenium(II mixed ligand terpyridine complexes, “Ru(Htcterpy(NCS(L1 (N(C4H94, mLBD1” and Ru(Htcterpy(NCS(L2(N(C4H94, mLBD2 were synthesized and fully characterized by UV-Vis, emission, cyclic voltammogram, and other spectroscopic means, and the structures of the compounds are confirmed by 1H-NMR, ESI-MASS, and FT-IR spectroscopes. The influence of the substitution of L1 and L2 on solar-to-electrical energy conversion efficiency (η of dye-sensitized solar cells (DSSCs was evaluated relative to reference black dye. The dyes showed molar extinction coefficients of 17600 M−1 cm−1 for mLBD1 and 21300 M−1 cm−1 for mLBD2 both at λ maximum of 512 nm, while black dye has shown 8660 M−1 cm−1 at λ maximum of 615 nm. The monochromatic incident photon-to-collected electron conversion efficiencies of 60.71% and 75.89% were obtained for mLBD1 and mLBD2 dyes, respectively. The energy conversion efficiencies of mLBD1 and mLBD2 dyes are 3.15% (SC=11.86 mA/cm2, OC=613 mV, ff=0.4337 and 3.36% (SC=12.71 mA/cm2, OC=655 mV, ff=0.4042, respectively, measured at the AM1.5G conditions, the reference black dye-sensitized solar cell, fabricated and evaluated under identical conditions exhibited η-value of 2.69% (SC=10.95 mA/cm2, OC=655 mV, ff=0.3750.

  12. Statistical identification of stimulus-activated network nodes in multi-neuron voltage-sensitive dye optical recordings.

    Science.gov (United States)

    Fathiazar, Elham; Anemuller, Jorn; Kretzberg, Jutta

    2016-08-01

    Voltage-Sensitive Dye (VSD) imaging is an optical imaging method that allows measuring the graded voltage changes of multiple neurons simultaneously. In neuroscience, this method is used to reveal networks of neurons involved in certain tasks. However, the recorded relative dye fluorescence changes are usually low and signals are superimposed by noise and artifacts. Therefore, establishing a reliable method to identify which cells are activated by specific stimulus conditions is the first step to identify functional networks. In this paper, we present a statistical method to identify stimulus-activated network nodes as cells, whose activities during sensory network stimulation differ significantly from the un-stimulated control condition. This method is demonstrated based on voltage-sensitive dye recordings from up to 100 neurons in a ganglion of the medicinal leech responding to tactile skin stimulation. Without relying on any prior physiological knowledge, the network nodes identified by our statistical analysis were found to match well with published cell types involved in tactile stimulus processing and to be consistent across stimulus conditions and preparations.

  13. Tuning the Electron-Transport and Electron-Accepting Abilities of Dyes through Introduction of Different π-Conjugated Bridges and Acceptors for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Li, Yuanzuo; Sun, Chaofan; Song, Peng; Ma, Fengcai; Yang, Yanhui

    2017-02-17

    A series of dyes, containing thiophene and thieno[3,2-b]thiophene as π-conjugated bridging units and six kinds of groups as electron acceptors, were designed for dye-sensitized solar cells (DSSCs). The ground- and excited-state properties of the designed dyes were investigated by using density functional theory (DFT) and time-dependent DFT, respectively. Moreover, the parameters affecting the short-circuit current density and open-circuit voltage were calculated to predict the photoelectrical performance of each dye. In addition, the charge difference density was presented through a three-dimensional (3D) real-space analysis method to investigate the electron-injection mechanism in the complexes. Our results show that the longer conjugated bridge would inhibit the intramolecular charge transfer, thereby affecting the photoelectrical properties of DSSCs. Similarly, owing to the lowest chemical hardness, largest electron-accepting ability, dipole moment (μnormal ) and the change in the energy of the TiO 2 conduction band (ΔECB ), the dye with a (E)-3-(4-(benzo[c][1,2,5]thiadiazol-4-yl)phenyl)-2-cyanoacrylic acid (TCA) acceptor group would exhibit the most significant photoelectrical properties among the designed dyes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. [Contents mensuration of total alkaloid in Uncaria rhynchophylla by acid dye colorimetry].

    Science.gov (United States)

    Zeng, Chang-qing; Luo, Bei-liang

    2007-08-01

    To investigate the method of determination of total alkaloids Uncaria rhynchophylla. The Contents of total Alkaloid were determined by Acid dye Colorimetry. Acid dye color conditions: pH3.6 buffer 5.0 ml, bromocresol green liquid 5.0 ml; chloroform extraction three times, each time was exeracted for 2 minutes, put it aside for at least 5 minutes for the determination of the best method. Rhynchophylline 6.018 microg - 108.324 microg in the linear range, Recoveriys rate was 97.19%, RSD was 1.34% (n = 6). The method is simple, highly sensitive and reproducible.

  15. In Vitro Polarized Resonance Raman Study of N719 and N719-TBP in Dye Sensitized Solar Cells

    DEFF Research Database (Denmark)

    Hassing, Søren; Jernshøj, Kit Drescher; Nguyen, Phuong Tuyet

    2016-01-01

    Abstract: The working efficiency of dye-sensitized solar cells (DSCs) depends on the long-term stability of the dye itself and on the microscopic structure of the dye-semiconductor interface. Previous experimental studies of DSCs based on ruthenium dye with bipyridine ligands (N719) adsorbed...... to the TiO2substrate applied FTIR,un-polarized Raman (RS) and un-polarized resonance Raman (RRS) spectroscopy. In the un-polarized RRS studies of N719/TiO2 – DSCs the discussion of the adsorption of N719 was based on the rather weak carbonyl or carboxyl group stretching vibrations and on minor spectral...

  16. A quantum-mechanical study of ZnO and TiO2 based dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cicero, Giancarlo [Chemical Engineering and Materials Science Department, Politecnico of Torino, Torino (Italy); Mallia, Giuseppe; Liborio, Leandro [Imperial College London, Thomas Young Centre, Chemistry Department, London (United Kingdom); Harrison, Nicholas M. [Imperial College London, Thomas Young Centre, Chemistry Department, London (United Kingdom); STFC, Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom)

    2010-07-01

    Since the pioneering work of Regan and Graetzel, a great attention has been paid to dye sensitized solar cell (DSC) as cheap, effective and environmentally benign candidates for a new generation solar power devices. Optimization of the DSC is still a challenging task as it is a highly complex interacting molecular system. Surface properties of the oxide and in particular proper sensitization with dye molecules may highly affect the efficiency of these cells. Aim of this study is to address the binding of cathecol and isonicotinic acid to oxide surfaces usually employed in DSC, namely ZnO and TiO{sub 2}, in terms of geometry, stability, electronic structure and band alignment. To this end, we employ quantum mechanical simulations based on hybrid density functional theory. Our analysis helps understanding whether the difference between ZnO and TiO{sub 2} in photoeletricity generation efficiency is due to the changes in the bonding geometry of the dye anchoring groups or to electronic effects.

  17. Removal of some basic dyes by poly (Vinyl Alcohol/ acrylic acid)Hydrogel

    International Nuclear Information System (INIS)

    Hegazy, S.A.; Abdel-AAl, S.E.; Abdel-Rehim, H.A.; Khalifa, N.A.; El-Hosseiny, E.M.

    2000-01-01

    A study has made on the preparation and properties of poly (vinyl alcohol/ acrylic acid) hydrogel for the purpose of removal of cationic dyes from aqueous solutions. The effect of dose and monomer concentration on the uptake property of the hydrogel toward dye was studied. The uptake of basic methylene blue-9 dye with PVA/AAc was studied by the batch adsorption technique. The effect of pH on the dye uptake was demonstrated to find out that the suitable pH for maximum uptake occurred at pH 5. It was observed that as the concentration of dye is increased the dye uptake decreased. Furthermore, the uptake of dye by hydrogels increased as the temperature was elevated. The recovery of dye adsorbed is possible by treating the hydrogel with 5% HCl. The results obtained suggested this hydrogel possessed good removal properties towards basic methylene blue-9 dye, and this suggests that such hydrogels could be acceptable for practical uses

  18. Incorporation of graphene into SnO{sub 2} photoanodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Batmunkh, Munkhbayar [School of Chemical Engineering, The University of Adelaide, Adelaide, South Australia 5005 (Australia); Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, Adelaide, South Australia 5042 (Australia); Dadkhah, Mahnaz; Shearer, Cameron J. [Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, Adelaide, South Australia 5042 (Australia); Biggs, Mark J. [School of Chemical Engineering, The University of Adelaide, Adelaide, South Australia 5005 (Australia); School of Science, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom); Shapter, Joseph G., E-mail: joe.shapter@flinders.edu.au [Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, Adelaide, South Australia 5042 (Australia)

    2016-11-30

    Graphical abstract: Incorporation of a graphene structure into SnO{sub 2} dye-sensitized solar cell photoanode films has been demonstrated for the first time. The use of graphene in the SnO{sub 2} has been found to be a promising strategy to address many problems of photovoltaic cells based on SnO{sub 2} photoanodes. - Highlights: • SnO{sub 2}-reduced graphene oxide (RGO) hybrid is prepared using a microwave technique. • The first SnO{sub 2}-RGO photoanode based DSSC is fabricated. • Use of RGO addresses the major shortcoming of SnO{sub 2} when employed as a DSSC photoanode. • RGO significantly improved the electron transport rate within the DSSC devices. • Incorporation of RGO into the SnO{sub 2} photoanode enhanced the DSSC efficiency by 91.5%. - Abstract: In dye-sensitized solar cell (DSSC) photoanodes, tin dioxide (SnO{sub 2}) structures present a promising alternative semiconducting oxide to the conventional titania (TiO{sub 2}), but they suffer from poor photovoltaic (PV) efficiency caused by insufficient dye adsorption and low energy value of the conduction band. A hybrid structure consisting of SnO{sub 2} and reduced graphene oxide (SnO{sub 2}-RGO) was synthesized via a microwave-assisted method and has been employed as a photoanode in DSSCs. Incorporation of RGO into the SnO{sub 2} photoanode enhanced the power conversion efficiency of DSSC device by 91.5%, as compared to the device assembled without RGO. This efficiency improvement can be attributed to increased dye loading, enhanced electron transfer and addition of suitable energy levels in the photoanode. Finally, the use of RGO addresses the major shortcoming of SnO{sub 2} when employed as a DSSC photoanode, namely poor dye adsorption and slow electron transfer rate.

  19. Development of pH sensitive polymeric nanoparticles of erythromycin stearate

    Directory of Open Access Journals (Sweden)

    Sulekha Bhadra

    2016-01-01

    Full Text Available Context: Bioavailability of conventional tablet of erythromycin stearate is low as it is unstable at acidic pH and also shows a low dissolution rate. Objective: It was proposed to protect it from the acidic condition of the stomach along with an increase in dissolution rate by formulating pH sensitive nanoparticles. Materials and Methods: The nanoparticles were prepared by the solvent evaporation technique using different quantities of Eudragit L100-55 and polyvinyl alcohol (PVA. Size reduction was achieved by high speed homogenization technique using Digital Ultra Turrax homogenizer. The formulation was optimized using 32 factorial design, keeping drug polymer ratio and surfactant concentration as independent variables. Particle size, entrapment efficiency, and drug-release (DR were studied as dependent variables. Results: Optimized batch containing 1:0.3 erythromycin stearate: Eudragit L100-55 ratio and 1.0% PVA showed 8.24 ± 0.71% DR in pH 1.2 in 1-h and 90.38 ± 5.97% in pH 5.5 and pH 6.8 within 2-h, respectively. Discussion: The optimized batch exhibited lower release in acidic pH and faster release in higher pH compared to the marketed preparation. Conclusion: Thus the present study concludes that pH sensitive nanoparticles of erythromycin stearate increases the dissolution of the drug in intestinal pH and also protect it from acidic pH, which may help in improving the bioavailability of erythromycin.

  20. High energy irradiation treatment of dye containing wastewater. Steady state gamma radiolysis experiments

    International Nuclear Information System (INIS)

    Solpan, D.; Gueven, O.

    2002-01-01

    Complete text of publication follows. The degradation and decoloration of three textile (JGB, Janus Green B, RB5, Reactive Black 5 and AR, Apollofix Red) dyes by gamma irradiation have been studied. Colour and pH of the dye solutions were found to decrease with irradiation, The change of absorption spectra, the degree of decoloration, the change of pH, COD (chemical oxygen demand), BOD (biological oxygen demand) were measured as a function of irradiation dose, dose rate and dye concentration. In all cases the absorbance of the dye compounds was found to decrease with the increase of the dose. The effect of pH, N2, N2O on the degradation and decoloration process was studied. The degradation and decoloration in the presence of nitrous oxide occurred faster than in air and nitrogen-saturated solutions. The degree of decoloration for AR and RB5 increased with the increasing irradiation dose and dose rate but above 2 kGy/h dose rate, the degree of decoloration is independent of the dose rate and irradiation dose. The degree of decoloration increased up to 100% for the nitrous oxide-saturated RB5 solution from 80% for the nitrogen-saturated RB5 solution at 0.8 kGy irradiation dose and at 2 kGy/h dose rate. For AR aqueous solution in air and nitrogen-saturated and nitrous oxide-saturated AR solution, the degrees of decoloration were very similar to each other. Although the absorptions at maximum wavelength (596 nm) decreased with increasing irradiation dose for nitrogen-saturated RB5 aqueous solutions, for nitrous oxide-saturated RB5 aqueous solutions they decreased and shifted to lower wavelength. This suggests that the skeleton of the RB5 molecule is mainly destroyed by the attack of the OH radicals. AR and RB5 dyes are destroyed in the pH range from 7 to 4 with a reduced sensitivity at lower and higher pH range

  1. Highly efficient and stable dye-sensitized solar cells based on nanographite/polypyrrole counter electrode

    International Nuclear Information System (INIS)

    Yue, Gentian; Zhang, Xin’an; Wang, Lei; Tan, Furui; Wu, Jihuai; Jiang, Qiwei; Lin, Jianming; Huang, Miaoliang; Lan, Zhang

    2014-01-01

    Graphical abstract: Much higher photovoltaic performance of dye-sensitized solar cell with nanographite/PPy counter electrode as well as that of Pt configuration device. - Highlights: • Pt-free dye-sensitized solar cells. • The nanographite/PPy composite film showed high catalytic activity as well as Pt electrode. • The enhanced catalytic activity was attributed to increased active sites. • The DSSC based on the nanographite/PPy electrode showed a high photovoltaic performance. - Abstract: Nanographite/polypyrrole (NG/PPy) composite film was successfully prepared via in situ polymerization on rigid fluorine-doped tin oxide substrate and served as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The surface morphology and composition of the composite film were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra and Fourier transform infrared spectroscopy (FTIR). The electrochemical performance of the NG/PPy electrode was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results of CV and EIS revealed that the NG/PPy electrode possessed excellent electrocatalytic activity for the reduction reaction of triiodide to iodide and low charge transfer resistance at the interface between electrolyte and CE, respectively. The DSSC assembled with the novel NG/PPy CE exhibited an enhanced power conversion efficiency of 7.40% under full sunlight illumination as comparing to that of the DSSC based on sputtered-Pt electrode. Thus, the NG/PPy CE could be premeditated as a promising alternative CE for low-cost and high- efficient DSSCs

  2. Synthesis and characterization of Ag nanowires: Improved performance in dye sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Safia A. Kazmi

    2016-09-01

    Full Text Available Development of highly efficient dye-sensitized solar cells (DSSCs with good photovoltaic parameters is an active research area of current global interest. Recently, one dimensional nanomaterial, such as nanorods and nanotubes has replaced the nanoparticles used in DSSCs anode because of their ability to improve the electron transport leading to enhanced electron collection efficiency. In the present work, rapid synthesis of silver nanowires (AgNWs was done. The XRD characterization was performed to confirm the formation and size of synthesized AgNWs. It was observed that FWHM of the diffraction peaks was increased with AgNWs concentration in TiO2. The synthesized TiO2AgNWs nanocomposite was used as the photo anode of Dye sensitized solar cell. The I–V characteristics of the solar cell were drawn using standard conditions. It was observed that TiO2AgNWs based solar cells have significantly increased photocurrent density resulting in improved conversion efficiency as compared to pure TiO2 based DSSC.

  3. Graphene Nanoplatelet Cathode for Co(III)/(II) Mediated Dye-Sensitized Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Yum, J. H.; Nazeeruddin, M. K.; Grätzel, M.

    2011-01-01

    Roč. 5, č. 11 (2011), s. 9171-9178 ISSN 1936-0851 R&D Projects: GA MŠk LC510; GA AV ČR IAA400400804; GA AV ČR KAN200100801 Institutional research plan: CEZ:AV0Z40400503 Keywords : graphene * dye sensitized solar cell * cobalt redox shuttle Subject RIV: CG - Electrochemistry Impact factor: 10.774, year: 2011

  4. Optically Transparent Cathode for Dye-Sensitized Solar Cells Based on Graphene Nanoplatelets

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Yum, J. H.; Graetzel, M.

    2011-01-01

    Roč. 5, č. 1 (2011), s. 165-172 ISSN 1936-0851 R&D Projects: GA MŠk LC510; GA AV ČR IAA400400804; GA AV ČR KAN200100801 Institutional research plan: CEZ:AV0Z40400503 Keywords : graphene * dye sensitized solar cells * electrochemical impendance Subject RIV: CG - Electrochemistry Impact factor: 10.774, year: 2011

  5. See-Through Dye-Sensitized Solar Cells: Photonic Reflectors for Tandem and Building Integrated Photovoltaics

    KAUST Repository

    Heiniger, Leo-Philipp; O'Brien, Paul G.; Soheilnia, Navid; Yang, Yang; Kherani, Nazir P.; Grä tzel, Michael; Ozin, Geoffrey A.; Té treault, Nicolas

    2013-01-01

    See-through dye-sensitized solar cells with 1D photonic crystal Bragg reflector photoanodes show an increase in peak external quantum efficiency of 47% while still maintaining high fill factors, resulting in an almost 40% increase in power

  6. Preparation of a novel pH optical sensor using orange (II) based on agarose membrane as support.

    Science.gov (United States)

    Heydari, Rouhollah; Hosseini, Mohammad; Amraei, Ahmadreza; Mohammadzadeh, Ali

    2016-04-01

    A novel and cost effective optical pH sensor was prepared using covalent immobilization of orange (II) indicator on the agarose membrane as solid support. The fabricated optical sensor was fixed into a sample holder of a spectrophotometer instrument for pH monitoring. Variables affecting sensor performance including pH of dye bonding to agarose membrane and dye concentration were optimized. The sensor responds to the pH changes in the range of 3.0-10.0 with a response time of 2.0 min and appropriate reproducibility (RSD ≤ 0.9%). No significant variation was observed on sensor response after increasing the ionic strength in the range of 0.0-0.5M of sodium chloride. Determination of pH using the proposed optical sensor is quick, simple, inexpensive, selective and sensitive in the pH range of 3.0-10.0. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Molecular and Material Approaches to Overcome Kinetic and Energetic Constraints in Dye-Sensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hamann, Thomas [Michigan State Univ., East Lansing, MI (United States)

    2016-08-14

    Dye-sensitized solar cells (DSSCs) have attracted a lot of interest as they proffer the possibility of extremely inexpensive and efficient solar energy conversion. The excellent performance of the most efficient DSSCs relies on two main features: 1) a high surface area nanoparticle semiconductor photoanode to allow for excellent light absorption with moderate extinction molecular dyes and 2) slow recombination rates from the photoanode to I3- allowing good charge collection. The I3-/I- couple, however, has some disadvantages, notably the redox potential limits the maximum open-circuit voltage, and the dye regeneration requires a large driving force which constrains the light harvesting ability. Thus, the design features that allow DSSCs to perform as well as they do also prevent further significant improvements in performance. As a consequence, the most efficient device configuration, and the maximum efficiency, has remained essentially unchanged over the last 16 years. Significant gains in performance are possible; however it will likely require a substantial paradigm shift. The general goal of this project is to understand the fundamental role of dye-sensitized solar cell, DSSC, components (sensitizer, redox shuttle, and photoanode) involved in key processes in order to overcome the kinetic and energetic constraints of current generation DSSCs. For example, the key to achieving high energy conversion efficiency DSSCs is the realization of a redox shuttle which fulfills the dual requirements of 1) efficient dye regeneration with a minimal driving force and 2) efficient charge collection. In current generation DSSCs, however, only one or the other of these requirements is met. We are currently primarily interested in understanding the physical underpinnings of the regeneration and recombination reactions. Our approach is to systematically vary the components involved in reactions and interrogate them with a

  8. Dye-sensitized PS-b-P2VP-templated nickel oxide films for photoelectrochemical applications.

    Science.gov (United States)

    Massin, Julien; Bräutigam, Maximilian; Kaeffer, Nicolas; Queyriaux, Nicolas; Field, Martin J; Schacher, Felix H; Popp, Jürgen; Chavarot-Kerlidou, Murielle; Dietzek, Benjamin; Artero, Vincent

    2015-06-06

    Moving from homogeneous water-splitting photocatalytic systems to photoelectrochemical devices requires the preparation and evaluation of novel p-type transparent conductive photoelectrode substrates. We report here on the sensitization of polystyrene-block-poly-(2-vinylpyridine) (PS-b-P2VP) diblock copolymer-templated NiO films with an organic push-pull dye. The potential of these new templated NiO film preparations for photoelectrochemical applications is compared with NiO material templated by F108 triblock copolymers. We conclude that NiO films are promising materials for the construction of dye-sensitized photocathodes to be inserted into photoelectrochemical (PEC) cells. However, a combined effort at the interface between materials science and molecular chemistry, ideally funded within a Global Artificial Photosynthesis Project, is still needed to improve the overall performance of the photoelectrodes and progress towards economically viable PEC devices.

  9. Nanographite-TiO2 photoanode for dye sensitized solar cells

    Science.gov (United States)

    Sharma, S. S.; Sharma, Khushboo; Sharma, Vinay

    2016-05-01

    Nanographite-TiO2 (NG-TiO2) composite was successfully synthesized by the hydrothermal method and its performance as the photoanode for dye-sensitized solar cells (DSSCs) was investigated. Environmental Scanning electron microscope (E-SEM) micrographs show the uniform distribution of TiO2 nanoflowers deposited over nanographite sheets. The average performance characteristics of the assembled cell in terms of short-ciruit current density (JSC), open circuit voltage (VOC), fill factor (FF) and photoelectric conversion efficiency (η) were measured.

  10. Genetically Targeted Ratiometric and Activated pH Indicator Complexes (TRApHIC) for Receptor Trafficking.

    Science.gov (United States)

    Perkins, Lydia A; Yan, Qi; Schmidt, Brigitte F; Kolodieznyi, Dmytro; Saurabh, Saumya; Larsen, Mads Breum; Watkins, Simon C; Kremer, Laura; Bruchez, Marcel P

    2018-02-06

    Fluorescent protein-based pH sensors are useful tools for measuring protein trafficking through pH changes associated with endo- and exocytosis. However, commonly used pH-sensing probes are ubiquitously expressed with their protein of interest throughout the cell, hindering our ability to focus on specific trafficking pools of proteins. We developed a family of excitation ratiometric, activatable pH responsive tandem dyes, consisting of a pH sensitive Cy3 donor linked to a fluorogenic malachite green acceptor. These cell-excluded dyes are targeted and activated upon binding to a genetically expressed fluorogen-activating protein and are suitable for selective labeling of surface proteins for analysis of endocytosis and recycling in live cells using both confocal and superresolution microscopy. Quantitative profiling of the endocytosis and recycling of tagged β2-adrenergic receptor (B2AR) at a single-vesicle level revealed differences among B2AR agonists, consistent with more detailed pharmacological profiling.

  11. Waste metal hydroxide sludge as adsorbent for a reactive dye.

    Science.gov (United States)

    Santos, Sílvia C R; Vílar, Vítor J P; Boaventura, Rui A R

    2008-05-30

    An industrial waste sludge mainly composed by metal hydroxides was used as a low-cost adsorbent for removing a reactive textile dye (Remazol Brilliant Blue) in solution. Characterization of this waste material included chemical composition, pH(ZPC) determination, particle size distribution, physical textural properties and metals mobility under different pH conditions. Dye adsorption equilibrium isotherms were determined at 25 and 35 degrees C and pH of 4, 7 and 10 revealing reasonably fits to Langmuir and Freundlich models. At 25 degrees C and pH 7, Langmuir fit indicates a maximum adsorption capacity of 91.0mg/g. An adsorptive ion-exchange mechanism was identified from desorption studies. Batch kinetic experiments were also conducted at different initial dye concentration, temperature, adsorbent dosage and pH. A pseudo-second-order model showed good agreement with experimental data. LDF approximation model was used to estimate homogeneous solid diffusion coefficients and the effective pore diffusivities. Additionally, a simulated real effluent containing the selected dye, salts and dyeing auxiliary chemicals, was also used in equilibrium and kinetic experiments and the adsorption performance was compared with aqueous dye solutions.

  12. Recent advances in plasmonic dye-sensitized solar cells

    Science.gov (United States)

    Rho, Won-Yeop; Song, Da Hyun; Yang, Hwa-Young; Kim, Ho-Sub; Son, Byung Sung; Suh, Jung Sang; Jun, Bong-Hyun

    2018-02-01

    Dye-sensitized solar cells (DSSCs) are among the best devices in generating electrons from solar light energy due to their high efficiency, low-cost in processing and transparency in building integrated photovoltaics. There are several ways to improve their energy-conversion efficiency, such as increasing light harvesting and electron transport, of which plasmon and 3-dimensional nanostructures are greatly capable. We review recent advances in plasmonic effects which depend on optimizing sizes, shapes, alloy compositions and integration of metal nanoparticles. Different methods to integrate metal nanoparticles into 3-dimensional nanostructures are also discussed. This review presents a guideline for enhancing the energy-conversion efficiency of DSSCs by utilizing metal nanoparticles that are incorporated into 3-dimensional nanostructures.

  13. Synthesis of new low band gap dyes with BF{sub 2}-azopyrrole complex and their use for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mikroyannidis, John A. [Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR-26500 Patras (Greece); Roy, M.S. [Defence Laboratory, Jodhpur (Raj.) (India); Sharma, G.D. [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur (Raj.) 342005 (India); Jaipur Engineering College, Kukas, Jaipur (Raj.) (India)

    2010-08-15

    The diazonium salt derived from 4-aminobenzoic acid, 4-aminophenol or 2-aminophenol reacted with half equivalent of pyrrole to afford symmetrical 2,5-bisazopyrroles. They reacted subsequently with boron trifluoride in the presence of triethylamine to afford the corresponding BF{sub 2}-azopyrrole complexes D1, D2 and D3 respectively. They were soluble and stable in nonprotic solvents such as chloroform, dichloromethane and tetrahydrofuran but unstable in protic solvents such as ethanol. Their absorption spectra were broad with optical band gap of 1.49-1.70 eV. Among these dyes D2 displayed the broader absorption spectrum with low band gap E{sub g}{sup opt} of 1.49 eV. We have utilized these complexes as photosensitizers for quasi solid state dye-sensitized solar cells (DSSCs) and achieved power conversion efficiency in the range of 4.0-6.0%. We have also found that the co-adsorption of citric acid hindered the formation of dye aggregates and might improve the electron injection efficiency leading to an enhancement in short circuit photocurrent. This work suggests that metal-free dyes based on BF{sub 2}-azopyrrole complex are promising candidates for improvement of the DSSC performance. (author)

  14. Novel nanostructures for next generation dye-sensitized solar cells

    KAUST Repository

    Tétreault, Nicolas

    2012-01-01

    Herein, we review our latest advancements in nanostructured photoanodes for next generation photovoltaics in general and dye-sensitized solar cells in particular. Bottom-up self-assembly techniques are developed to fabricate large-area 3D nanostructures that enable enhanced charge extraction and light harvesting through optical scattering or photonic crystal effects to improve photocurrent, photovoltage and fill factor. Using generalized techniques to fabricate specialized nanostructures enables specific optoelectronic and physical characteristics like conduction, charge extraction, injection, recombination and light harvesting but also helps improve mechanical flexibility and long-term stability in low cost materials. © 2012 The Royal Society of Chemistry.

  15. Weavable dye sensitized solar cells exploiting carbon nanotube yarns

    Science.gov (United States)

    Velten, Josef; Kuanyshbekova, Zharkynay; Göktepe, Özer; Göktepe, Fatma; Zakhidov, Anvar

    2013-05-01

    Weavable Dye Sensitized Solar Cells (DSSC) made with flexible yarns of conductive multiwalled carbon nanotubes (MWNTs) were produced having a power conversion efficiency above 3%. This was achieved with a specific design and careful consideration of the yarn function in the DSSC. Fermat yarns of MWNTs individually coated with mesoporous TiO2 layer were twisted together and coated with more mesoporous TiO2 to create a 3 dimensional photo electrode to overcome electron diffusion length issues. Archimedian yarns of MWNTs coated with a thin layer of platinum worked as a counter electrode to complete the architecture used in this DSSC.

  16. Effects of nano anatase-rutile TiO2 volume fraction with natural dye containing anthocyanin on the dye sensitized solar cell performance

    Science.gov (United States)

    Agustini, S.; Wahyuono, R. A.; Sawitri, D.; Risanti, D. D.

    2013-09-01

    Since its first development, efforts to improve efficiency of Dye Sensitized Solar Cell (DSSC) are continuously carried out, either through selection of dye materials, the type of semiconductor, counter electrode design or the sandwiched structure. It is widely known that anatase and rutile are phases of TiO2 that often being used for fabrication of DSSC. Rutile is thermodynamically more stable phase having band-gap suitable for absorption of sunlight spectrum. On the other hand, anatase has higher electrical conductivity, capability to adsorp dye as well as higher electron diffusion coefficient than those of rutile. Present research uses mangosteen pericarp and Rhoeo spathacea extracted in ethanol as natural dye containing anthocyanin. These dyes were characterized by using UV-Vis and FTIR, showing that the absorption maxima peaks obtained at 389 nm and 413 nm, for mangosteen and Rhoeo spathacea, respectively. The nano TiO2 was prepared by means of co-precipitation method. The particle size were 9-11 nm and 54.5 nm for anatase and rutile, respectively, according to Scherrer's equation. DSSCs were fabricated in various volume fractions of anatase and rutile TiO2. The fabricated DSSCs were tested under 17 mW/cm2 of solar irradiation. The current-voltage (I-V) characteristic of DSSCs employing 75%: 25% volume fraction of anatase and rutile TiO2 have outstanding result than others. The highest conversion efficiencies of 0.037% and 0.013% are obtained for DSSC employing natural dye extract from mangosteen pericarp and Rhoeo spathacea, respectively.

  17. Laminating solution-processed silver nanowire mesh electrodes onto solid-state dye-sensitized solar cells

    KAUST Repository

    Hardin, Brian E.; Gaynor, Whitney; Ding, I-Kang; Rim, Seung-Bum; Peumans, Peter; McGehee, Michael D.

    2011-01-01

    Solution processed silver nanowire meshes (Ag NWs) were laminated on top of solid-state dye-sensitized solar cells (ss-DSCs) as a reflective counter electrode. Ag NWs were deposited in <1 min and were less reflective compared to evaporated Ag

  18. Microstructure characterization of onion (A.cepa) peels and thin films for dye sensitized solar cells

    Science.gov (United States)

    Abodunrin, T.; Boyo, A.; Usikalu, M.; Obafemi, L.; Oladapo, O.; Kotsedi, L.; Yenus, Z.; Maaza, M.

    2017-03-01

    A.cepa peels are obtained from mature onion bulbs. Because of the continuous need for energy, alternative avenues for producing energy are gaining importance. The motivation for this work is based on an urgent need to source energy from readily available waste materials like domestic onion peels. Dye sensitized solar cells (DSSCs) fabricated via doctor blade method and high temperature sintering from waste (onion peels) are investigated for their ability to convert solar to electrical energy. The charge carriers were revealed under phytochemical screening. Functional groups of compounds present in A.cepa peel were analyzed with Fourier transform in infrared (FTIR). The influence of different electrolyte sensitizer is observed on the DSSCs under standard air mass conditions of 1.5 AM. The microstructure properties of these A.cepa DSSCs were explored using scanning electron microscope with energy dispersive spectroscopy (SEM/EDS), x-ray diffraction and Fluorecence spectroscopy (XRF). The interfacial boundary between A.cepa dye, TiO2 framework of TiO2 and indium doped tin oxide (ITO) reveals several prominent anatase and rutile peaks. Photoelectric results, revealed dye-sensitized solar cells with a maximum power output of 126 W and incident photon to conversion energy (IPCE) of 0.13%.This work has established that A.cepa peels can be used as a source of micro-energy generation.

  19. A study of charge transfer kinetics in dye-sensitized surface conductivity solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Dennis

    2011-05-15

    The efficiency of the quasi-solid-state dye-sensitized solar cell developed by Junghaenel and Tributsch, the so-called Nano Surface Conductivity Solar Cell (NSCSC), was improved from 2% to 3.5% introducing a compact TiO{sub 2} underlayer, modifying the surface of the mesoporous TiO{sub 2} electrode, optimizing the deposition process of the electrolyte film, and replacing the platinum counter electrode by a carbon layer. Space-resolved photocurrent images revealed the importance of a homogeneous distribution of the electrolyte film. An uneven dispersion led to localized areas of high and low photocurrents, whereas the latter were attributed to an insufficient concentration of the redox couple. Impedance spectroscopy was performed on cells containing different concentrations of the redox couple. By modeling the spectra using an equivalent circuit with a transmission line of resistive and capacitive elements, the characteristic parameters of electron transport in the TiO{sub 2}, such as diffusion length and electron lifetime were obtained. The measurements indicated that the transport of the positive charge to the counter electrode is the main process limiting the efficiency of the cells. Excess charge carrier decay in functioning devices was analyzed by contactless transient photoconductance measurements in the microwave frequency range (TRMC). The lifetime of the photogenerated charge carriers was observed to decrease with increasing applied potential, reaching its maximum close to the opencircuit potential of the cell, where the photocurrent density was minimal, i.e. the potential dependent decay observed was limited by the injection of electrons into the front contact. The functioning of this NSCSC indicated that the transport of the positive charge occurs by solid-state diffusion at the surface of the TiO{sub 2} particles. TRMC measurements on subset devices in the form of sensitized TiO{sub 2} layers revealed charge carrier kinetics strongly dependent on the

  20. Investigation on the Tunable-Length Zinc Oxide Nanowire Arrays for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Shou-Yi Kuo

    2014-01-01

    Full Text Available We had successfully fabricated ZnO-based nanowires by vapor transport method in the furnace tube. ZnO nanowire arrays grown in 600°C for 30 minutes, 60 minutes, 90 minutes, and 120 minutes had applied to the dye-sensitized solar cells. The dye loading is proportional to the total equivalent surface area of ZnO nanowire arrays in the cells and plays an important role in improving power conversion efficiency. The highest efficiency was observed in DSSC sample with ZnO nanowires grown for 90 minutes, which had the largest equivalent surface area and also the highest dye loading. According to our experimental results, the enhancement in power conversion efficiency is attributed to the higher light harvesting and reduction of carrier recombination. In addition, ZnO nanowires also contribute to the photocurrent in the UV region.

  1. Effect of microwave exposure on the photo anode of DSSC sensitized with natural dye

    Science.gov (United States)

    Swathi, K. E.; Jinchu, I.; Sreelatha, K. S.; Sreekala, C. O.; Menon, Sreedevi K.

    2018-02-01

    Dye Sensitized solar cells (DSSC) are also referred to as dye sensitised cells (DSC) or Graetzel cell are the device that converts solar energy in to electricity by the photovoltaic effect. This is the class of advanced cell that mimics the artificial photosynthesis. DSSC fabrication is simple and can be done using readily available low cost materials that are nontoxic, environment friendly and works even under low flux of sunlight. DSSC exhibits good efficiency of ~ 10-14 %. This paper emphasis on the study of enhancing the efficiency of DSSC by exposing the photo anode to microwave frequency. Effect of duration of microwave exposure at 2.6 GHz on energy efficiency of solar cell is studied in detail. The SEM analysis and dye desorption studies of the photo anode confirms an increased solar energy conversion efficiency of the DSSC.

  2. Fast, Highly-Sensitive, and Wide-Dynamic-Range Interdigitated Capacitor Glucose Biosensor Using Solvatochromic Dye-Containing Sensing Membrane

    Directory of Open Access Journals (Sweden)

    Md. Rajibur Rahaman Khan

    2016-02-01

    Full Text Available In this paper, we proposed an interdigitated capacitor (IDC-based glucose biosensor to measure different concentrations of glucose from 1 μM to 1 M. We studied four different types of solvatochromic dyes: Auramine O, Nile red, Rhodamine B, and Reichardt’s dye (R-dye. These dyes were individually incorporated into a polymer [polyvinyl chloride (PVC] and N,N-Dimethylacetamide (DMAC solution to make the respective dielectric/sensing materials. To the best of our knowledge, we report for the first time an IDC glucose biosensing system utilizing a solvatochromic-dye-containing sensing membrane. These four dielectric or sensing materials were individually placed into the interdigitated electrode (IDE by spin coating to make four IDC glucose biosensing elements. The proposed IDC glucose biosensor has a high sensing ability over a wide dynamic range and its sensitivity was about 23.32 mV/decade. It also has fast response and recovery times of approximately 7 s and 5 s, respectively, excellent reproducibility with a standard deviation of approximately 0.023, highly stable sensing performance, and real-time monitoring capabilities. The proposed IDC glucose biosensor was compared with an IDC, potentiometric, FET, and fiber-optic glucose sensor with respect to response time, dynamic range width, sensitivity, and linearity. We observed that the designed IDC glucose biosensor offered excellent performance.

  3. Dynamics of Interfacial Charge Transfer States and Carriers Separation in Dye-Sensitized Solar Cells: A Time-Resolved Terahertz Spectroscopy Study

    OpenAIRE

    Brauer, Jan C.; Marchioro, Arianna; Paraecattil, Arun A.; Oskouei, Ahmad A.; Moser, Jacques-E.

    2015-01-01

    Electron injection from a photoexcited molecular sensitizer into a wide-bandgap semiconductor is the primary step toward charge separation in dye-sensitized solar cells (DSSCs). According to the current understanding of DSSCs functioning mechanism, charges are separated directly during this primary electron transfer process, yielding hot conduction band electrons in the semiconductor and positive holes localized on oxidized dye molecules at the surface. Comparing results of ultrafast transien...

  4. Bifacial dye-sensitized solar cells: A strategy to enhance overall efficiency based on transparent polyaniline electrode

    OpenAIRE

    Wu, Jihuai; Li, Yan; Tang, Qunwei; Yue, Gentian; Lin, Jianming; Huang, Miaoliang; Meng, Lijian

    2014-01-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its clean, low-cost, high efficiency, good durability, and easy fabrication. However, enhancing the efficiency of the DSSC still is an important issue. Here we devise a bifacial DSSC based on a transparent polyaniline (PANI) counter electrode (CE). Owing to the sunlight irradiation simultaneously from the front and the rear sides, more dye molecules are excited and more ...

  5. Debundling and Selective Enrichment of SWNTs for Applications in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    F. Bonaccorso

    2010-01-01

    Full Text Available We present an overview of the recent developments in de-bundling and sorting of Single-Wall Carbon Nanotubes (SWNTs, which are useful for hi-tech applications in dye sensitized solar cells (DSSCs. Applications of SWNTs as transparent and conductive films, catalyst, and scaffold in DSSCs are also reviewed.

  6. Stability of a fiber optic pH sensor at 100 degree F

    International Nuclear Information System (INIS)

    Angel, S.M.; Northrup, M.A.

    1993-02-01

    A simple ratiometric fiber-optic pH sensor was developed and accelerated aging studies were performed in 100 degree F distilled water. A ph-sensitive fluorescent indicator dye, HPTS (hydroxypyrenetrisulfonic acid) was convalently attached, using a procedure that was developed during this work, to a polyacrylamide polymer that was subsequently immobilized at the end of an optical fiber. Different immobilization techniques were compared and it was found that physically attaching the indicator gels to the fibers gave the most reproducible long-term results. These fiber-optic sensors were found to give linear pH responses, between pH 6 and 8, and resolution greater than 0.25 pH unit with useful lifetimes exceeding one year

  7. Polyamine/salt-assembled microspheres coated with hyaluronic acid for targeting and pH sensing.

    Science.gov (United States)

    Zhang, Pan; Yang, Hui; Wang, Guojun; Tong, Weijun; Gao, Changyou

    2016-06-01

    The poly(allylamine hydrochloride)/trisodium citrate aggregates were fabricated and further covalently crosslinked via the coupling reaction of carboxylic sites on trisodium citrate with the amine groups on polyamine, onto which poly-L-lysine and hyaluronic acid were sequentially assembled, forming stable microspheres. The pH sensitive dye and pH insensitive dye were further labeled to enable the microspheres with pH sensing property. Moreover, these microspheres could be specifically targeted to HeLa tumor cells, since hyaluronic acid can specifically recognize and bind to CD44, a receptor overexpressed on many tumor cells. Quantitative pH measurement by confocal laser scanning microscopy demonstrated that the microspheres were internalized into HeLa cells, and accumulated in acidic compartments. By contrast, only a few microspheres were adhered on the NIH 3T3 cells surface. The microspheres with combined pH sensing property and targeting ability can enhance the insight understanding of the targeted drug vehicles trafficking after cellular internalization. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Nanographite-TiO_2 photoanode for dye sensitized solar cells

    International Nuclear Information System (INIS)

    Sharma, S. S.; Sharma, Khushboo; Sharma, Vinay

    2016-01-01

    Nanographite-TiO_2 (NG-TiO_2) composite was successfully synthesized by the hydrothermal method and its performance as the photoanode for dye-sensitized solar cells (DSSCs) was investigated. Environmental Scanning electron microscope (E-SEM) micrographs show the uniform distribution of TiO_2 nanoflowers deposited over nanographite sheets. The average performance characteristics of the assembled cell in terms of short-ciruit current density (J_S_C), open circuit voltage (V_O_C), fill factor (FF) and photoelectric conversion efficiency (η) were measured.

  9. Block copolymer directed synthesis of mesoporous TiO 2 for dye-sensitized solar cells

    KAUST Repository

    Nedelcu, Mihaela; Lee, Jinwoo; Crossland, Edward J. W.; Warren, Scott C.; Orilall, M. Christopher; Guldin, Stefan; Hü ttner, Sven; Ducati, Catarina; Eder, Dominik; Wiesner, Ulrich; Steiner, Ullrich; Snaith, Henry J.

    2009-01-01

    The morphology of TiO2 plays an important role in the operation of solid-state dye-sensitized solar cells. By using polyisoprene-block- ethyleneoxide (PI-b-PEO) copolymers as structure directing agents for a sol-gel based synthesis of mesoporous TiO

  10. Barium Staminate as Semiconductor Working Electrodes for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Fu-an Guo

    2010-01-01

    Full Text Available Dye-sensitized solar cells (DSSCs are fabricated with perovskite-type BaSnO3 as the photoelectrode materials. Different preparation methods including coprecipitation, hydrothermal, and solid state reaction are employed to synthesize BaSnO3 particles to optimize the photoelectric activities of electrode materials. The photoelectric properties of BaSnO3 particles and the performances of DSSCs are investigated by surface photovoltage spectroscopy and current-voltage measurements. The light-to-electricity conversion of 1.1% is preliminarily reached on the DSSC made of the coprecipitation-derived BaSnO3 particles. Large current density of hole injection into the HOMO level of N719 dye from the valence band of BaSnO3 and reduced photogenerated charge recombination in BaSnO3 could be responsible for the observed solar cell performance of the DSSC fabricated from the coprecipitation-derived BaSnO3 particles.

  11. An Organic D-π-A Dye for Record Efficiency Solid-State Sensitized Heterojunction Solar Cells

    KAUST Repository

    Cai, Ning

    2011-04-13

    The high molar absorption coefficient organic D-π-A dye C220 exhibits more than 6% certified electric power conversion efficiency at AM 1.5G solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis(N,N-dimethoxyphenylamine)-9,9′- spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This contributes to a new record (6.08% by NREL) for this type of sensitized heterojunction photovoltaic device. Efficient charge generation is proved by incident photon-to-current conversion efficiency spectra. Transient photovoltage and photocurrent decay measurements showed that the enhanced performance achieved with C220 partially stems from the high charge collection efficiency over a wide potential range. © 2011 American Chemical Society.

  12. Deposition of hole-transport materials in solid-state dye-sensitized solar cells by doctor-blading

    KAUST Repository

    Ding, I-Kang

    2010-07-01

    We report using doctor-blading to replace conventional spin coating for the deposition of the hole-transport material spiro-OMeTAD (2,20,7,70-tetrakis-(N, N-di-p-methoxyphenylamine)- 9,90-spirobifluorene) in solid-state dye-sensitized solar cells. Doctor-blading is a roll-to-roll compatible, large-area coating technique, is capable of achieving the same spiro-OMeTAD pore filling fraction as spin coating, and uses much less material. The average power conversion efficiency of solid-state dye-sensitized solar cells made from doctorblading is 3.0% for 2-lm thick films and 2.0% for 5-lm thick films, on par with devices made with spin coating. Directions to further improve the filling fraction are also suggested. © 2010 Elsevier B.V. All rights reserved.

  13. Simplifying the construction of dye-sensitized solar cells to increase their accessibility for community education

    Energy Technology Data Exchange (ETDEWEB)

    Appleyard, Steve [Department of Environment and Conservation, PO Box K822, Perth, WA 6842 (Australia)

    2010-01-15

    Simple dye-sensitized solar cells were developed using blackboard chalk as a substrate for mixed ZnO and SnO{sub 2} films that were sensitized with Mercurochrome (Merbromine) dye. Graphite pencil 'leads' were used as counter electrodes for the cells and the electrolyte consisted of an aqueous solution of iodine and potassium iodide that was gelled with a disinfectant containing quaternary ammonium compounds and cyanoacrylate adhesive (Superglue {sup registered}). The open circuit potential of constructed cells was typically 0.50-0.64 V and the short circuit current varied between 0.5 and 2.0 mA cm{sup -2}. The cells were developed as an educational resource that could be simply and safely constructed in a home or school environment with readily accessible materials. (author)

  14. Influence of polyoxyethylene phytosterol addition in ionic liquid-based electrolyte on photovoltaic performance of dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Takahashi, Masashi; Sato, Kei; Sakurai, Sho; Kobayashi, Koichi

    2016-01-01

    Highlights: • The ionic liquid solution of less solvophilic BPS exhibits a better surface active property and a weaker dye-desorption effect. • Photovoltaic performances of the N719- and NKX2677-sensitized DSSCs can be improved by the BPS addition to the IL-based electrolyte. • BPS added to the electrolyte plays a key role in reducing charge-transfer resistance and increasing electron lifetime in the TiO 2 electrode. - Abstract: In this work, we studied influence of polyoxyethylene phytosterol (BPS) addition in ionic liquid (IL)-based electrolyte on photovoltaic performance of dye-sensitized solar cells (DSSCs) using 1-methyl-3-propylimidazolium iodide as an IL. Surface tension, photocurrent density-voltage characteristics and electrochemical impedance spectra were measured to clarify the role of BPS in the DSSCs using three different dyes. The results showed that the IL solution of less solvophilic BPS-EO5 exhibited a better surface active property and a weaker dye-desorption effect than BPS-EO30 and BPS-PO7/EO30. Short-circuit current densities of the N719- and NKX2677-sensitized cells were found to be noticeably increased by the addition of either BPS-EO5 or BPS-EO30 to the IL-based electrolyte in the concentration range of 0.001–0.01 mol dm −3 . Enhanced photovoltaic conversion efficiencies were obtained for these DSSCs, which most likely resulted from the effects of BPS on reducing charge-transfer resistance at the TiO 2 /dye/electrolyte interface and on increasing electron lifetime within the TiO 2 photoanode.

  15. One-Dimensional TiO2 Nanostructures as Photoanodes for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Jie Qu

    2013-01-01

    Full Text Available Titanium dioxide (TiO2 is star materials due to its remarkable optical and electronic properties, resulting in various applications, especially in the fields of dye-sensitized solar cells (DSSCs. Photoanode is the most important part of the DSSCs, which help to adsorb dye molecules and transport the injected electrons. The size, structure, and morphology of TiO2 photoanode have been found to show significant influence on the photovoltaic performance of DSSCs. In this paper, we briefly summarize the synthesis and properties of one-dimensional (1D TiO2 nanomaterials (bare 1D TiO2 nanomaterial and 1D hierarchical TiO2 and their photovoltaic performance in DSSCs.

  16. Ultrasonic assisted dyeing: dyeing of acrylic fabrics C.I. Astrazon Basic Red 5BL 200%.

    Science.gov (United States)

    Kamel, M M; Helmy, H M; Mashaly, H M; Kafafy, H H

    2010-01-01

    The dyeing of acrylic fabrics using C.I. Astrazon Basic Red 5BL 200% has been studied with both conventional and ultrasonic techniques. The effect of dye concentration, dye bath pH, ultrasonic power, dyeing time and temperature were studied and the resulting shades obtained by dyeing with both techniques were compared. Colour strength values obtained were found to be higher with ultrasonic than with conventional heating. The results of fastness properties of the dyed fabrics were studied. X-ray and Scanning Electron Microscope SEM were carried out on dyed samples using both methods of dyeing to find out an explanation for the better dyeability of acrylic fabrics with (US) method. Dyeing kinetics of acrylic fabrics using C.I. Astrazon Basic Red 5BL 200% using conventional and ultrasonic conditions were compared. The time/dye-uptake isotherms are revealing the enhanced dye-uptake in the second phase of dyeing. The values of dyeing rate constant, half-time of dyeing and standard affinity and ultrasonic efficiency have been calculated and discussed.

  17. Krokot (Portulaca oleracea L As a Natural Sensitizer for TiO2 Dye-sensitized Solar Cells: The Effect of Temperature Extract

    Directory of Open Access Journals (Sweden)

    Reyza Anni Mufidah

    2015-10-01

    Full Text Available The solar cell is formed by a sandwich structure, in which two electrodes flank the primary electrolyte that is containing redox I-/based on PEG (Polyethylene Glycol. The working-electrode which is TiO2 layer on an ITO glass substrate is sensitized with krokot dye as the electron donor. The counter electrode is a layer of carbon. The fabrication cell is immersed with the krokot dye with 40°C, 50°C, 60°C extract temperature. The result of the UV-Vis shows that the absorption of wave-length from dye extract of krokot is located in the visible region with the absorbance peak in 420,5 nm and 665,5 nm which are the peak of chlorophyll. For the UV-Vis solid system, there are the highest band gap  in  50°C extract temperature that make the capability of absorption toward UV spectrum is large. Furthermore, in the functional group analysed by FT-IR, there are shiften-carbonil and hydroxyl group after they are sensitized. From the current and voltage test with I-V meter keithley 2400 is resulted that on the 50°C extract temperature produces the highest efficiency of reaches which is 2.63 x 10-3 %.

  18. The enhanced cyan fluorescent protein: a sensitive pH sensor for fluorescence lifetime imaging.

    Science.gov (United States)

    Poëa-Guyon, Sandrine; Pasquier, Hélène; Mérola, Fabienne; Morel, Nicolas; Erard, Marie

    2013-05-01

    pH is an important parameter that affects many functions of live cells, from protein structure or function to several crucial steps of their metabolism. Genetically encoded pH sensors based on pH-sensitive fluorescent proteins have been developed and used to monitor the pH of intracellular compartments. The quantitative analysis of pH variations can be performed either by ratiometric or fluorescence lifetime detection. However, most available genetically encoded pH sensors are based on green and yellow fluorescent proteins and are not compatible with multicolor approaches. Taking advantage of the strong pH sensitivity of enhanced cyan fluorescent protein (ECFP), we demonstrate here its suitability as a sensitive pH sensor using fluorescence lifetime imaging. The intracellular ECFP lifetime undergoes large changes (32 %) in the pH 5 to pH 7 range, which allows accurate pH measurements to better than 0.2 pH units. By fusion of ECFP with the granular chromogranin A, we successfully measured the pH in secretory granules of PC12 cells, and we performed a kinetic analysis of intragranular pH variations in living cells exposed to ammonium chloride.

  19. Hydrothermal synthesis of hierarchical WO3 nanostructures for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Rashad, M.M.; Shalan, A.E.

    2014-01-01

    Hierarchical architectures consisting of one-dimensional (1D) nanostructures are of great interest for potential use in energy and environmental applications in recent years. In this work, hierarchical tungsten oxide (WO 3 ) has been synthesized via a facile hydrothermal route from ammonium metatungstate hydrate and implemented as photoelectrode for dye-sensitized solar cells. The urchin-like WO 3 micro-patterns are constructed by self-organized nanoscale length 1D building blocks, which are single crystalline in nature, grown along (001) direction and confirm an orthorhombic crystal phase. The obtained powders were investigated by XRD, SEM, TEM and UV-Vis Spectroscopy. The photovoltaic performance of dye-sensitized solar cells based on WO 3 photoanodes was investigated. With increasing the calcination temperature of the prepared nanopowders, the light-electricity conversion efficiency (η) was increased. The results were attributed to increase the crystallinity of the particles and ease of electron movement. The DSSC based on hierarchical WO 3 showed a short-circuit current, an open-circuit voltage, a fill factor, and a conversion efficiency of 4.241 mA/cm 2 , 0.656 V, 66.74, and 1.85 %, respectively. (orig.)

  20. pH effect on decolorization of raw textile wastewater polluted with reactive dyes by advanced oxidation with uv/h2o2

    NARCIS (Netherlands)

    Racyte, J.; Rimeika, M.; Bruning, H.

    2009-01-01

    The effectiveness of the advanced oxidation process (UV/H2O2) in decolorizing real textile wastewater polluted with commercial reactive dyes - Reactive Yellow 84 and Reactive Red 141 was investigated. All the experiments were performed in a lab-scale reactor with the original high pH of the

  1. (Invited) Atomic Layer Deposition for Novel Dye-Sensitized Solar Cells

    KAUST Repository

    Tétreault, Nicolas

    2011-01-01

    Herein we present the latest fabrication and characterization techniques for atomic layer deposition of Al 2O 3, ZnO, SnO 2, Nb 2O 5, HfO 2, Ga 2O 3 and TiO 2 for research on dye-sensitized solar cell. In particular, we review the fabrication of state-of-the-art 3D host-passivation-guest photoanodes and ZnO nanowires as well as characterize the deposited thin films using spectroscopic ellipsometry, X-ray diffraction, Hall effect, J-V curves and electrochemical impedance spectroscopy. ©The Electrochemical Society.

  2. Hybrid Dye-Sensitized Solar Cells Consisting of Double Titania Layers for Harvesting Light with Wide Range of Wavelengths

    Science.gov (United States)

    Sadamasu, Kengo; Inoue, Takafumi; Ogomi, Yuhei; Pandey, Shyam S.; Hayase, Shuzi

    2011-02-01

    We report a hybrid dye-sensitized solar cell consisting of double titania layers (top and bottom layers) stained with two dyes. A top layer fabricated on a glass was mechanically pressed with a bottom layer fabricated on a glass cloth. The glass cloth acts as a supporter of a porous titania layer as well as a holder of electrolyte. The incident photon to current efficiency (IPCE) curve had two peaks corresponding to those of the two dyes, which demonstrates that electrons are collected from both the top and bottom layers.

  3. Dye sensitized photovoltaic cells: Attaching conjugated polymers to zwitterionic ruthenium dyes

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Biancardo, M.

    2006-01-01

    The synthesis of a zwitterionic ruthenium dye that binds to anatase surfaces and has a built-in functionality that allows for the attachment of a conjugated polymer chain is presented. The system was found to adsorb on the surface of anatase anchored by the ruthenium dye. Two types of devices were...... prepared: standard photoelectrochemical (PEC) solar cells and polymer solar cells. The PEC solar cells employed a sandwich geometry between TiO2 nanoporous photoanodes and Pt counter electrodes using LiI/I-2 in CH3CN as an electrolyte. The polymer solar cells employed planar anatase electrodes...

  4. Decolorization of reactive textile dyes using water falling film dielectric barrier discharge

    International Nuclear Information System (INIS)

    Dojcinovic, Biljana P.; Roglic, Goran M.; Obradovic, Bratislav M.; Kuraica, Milorad M.; Kostic, Mirjana M.; Nesic, Jelena; Manojlovic, Dragan D.

    2011-01-01

    Highlights: → Decolorization of four reactive textile dyes using non-thermal plasma reactor. → Influence of applied energy on decolorization. → Effects of initial pH and addition of homogeneous catalysts. → Toxicity evaluation using the brine shrimp as a test organism. - Abstract: Decolorization of reactive textile dyes Reactive Black 5, Reactive Blue 52, Reactive Yellow 125 and Reactive Green 15 was studied using advanced oxidation processes (AOPs) in a non-thermal plasma reactor, based on coaxial water falling film dielectric barrier discharge (DBD). Used initial dye concentrations in the solution were 40.0 and 80.0 mg/L. The effects of different initial pH of dye solutions, and addition of homogeneous catalysts (H 2 O 2 , Fe 2+ and Cu 2+ ) on the decolorization during subsequent recirculation of dye solution through the DBD reactor, i.e. applied energy density (45-315 kJ/L) were studied. Influence of residence time was investigated over a period of 24 h. Change of pH values and effect of pH adjustments of dye solution after each recirculation on the decolorization was also tested. It was found that the initial pH of dye solutions and pH adjustments of dye solution after each recirculation did not influence the decolorization. The most effective decolorization of 97% was obtained with addition of 10 mM H 2 O 2 in a system of 80.0 mg/L Reactive Black 5 with applied energy density of 45 kJ/L, after residence time of 24 h from plasma treatment. Toxicity was evaluated using the brine shrimp Artemia salina as a test organism.

  5. Decolorization of reactive textile dyes using water falling film dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Dojcinovic, Biljana P. [Institute of Chemistry, Technology and Metallurgy, Center of Chemistry, Studentski trg 12-16, 11000 Belgrade (Serbia); Roglic, Goran M. [Faculty of Chemistry, University of Belgrade, P.O. Box 158, 11000 Belgrade (Serbia); Obradovic, Bratislav M., E-mail: obrat@ff.bg.ac.rs [Faculty of Physics, University of Belgrade, P.O. Box 368, 11000 Belgrade (Serbia); Kuraica, Milorad M. [Faculty of Physics, University of Belgrade, P.O. Box 368, 11000 Belgrade (Serbia); Kostic, Mirjana M. [Faculty of Technology and Metallurgy, Department of Textile Engineering, Karnegijeva 4, 11000 Belgrade (Serbia); Nesic, Jelena; Manojlovic, Dragan D. [Faculty of Chemistry, University of Belgrade, P.O. Box 158, 11000 Belgrade (Serbia)

    2011-08-30

    Highlights: {yields} Decolorization of four reactive textile dyes using non-thermal plasma reactor. {yields} Influence of applied energy on decolorization. {yields} Effects of initial pH and addition of homogeneous catalysts. {yields} Toxicity evaluation using the brine shrimp as a test organism. - Abstract: Decolorization of reactive textile dyes Reactive Black 5, Reactive Blue 52, Reactive Yellow 125 and Reactive Green 15 was studied using advanced oxidation processes (AOPs) in a non-thermal plasma reactor, based on coaxial water falling film dielectric barrier discharge (DBD). Used initial dye concentrations in the solution were 40.0 and 80.0 mg/L. The effects of different initial pH of dye solutions, and addition of homogeneous catalysts (H{sub 2}O{sub 2}, Fe{sup 2+} and Cu{sup 2+}) on the decolorization during subsequent recirculation of dye solution through the DBD reactor, i.e. applied energy density (45-315 kJ/L) were studied. Influence of residence time was investigated over a period of 24 h. Change of pH values and effect of pH adjustments of dye solution after each recirculation on the decolorization was also tested. It was found that the initial pH of dye solutions and pH adjustments of dye solution after each recirculation did not influence the decolorization. The most effective decolorization of 97% was obtained with addition of 10 mM H{sub 2}O{sub 2} in a system of 80.0 mg/L Reactive Black 5 with applied energy density of 45 kJ/L, after residence time of 24 h from plasma treatment. Toxicity was evaluated using the brine shrimp Artemia salina as a test organism.

  6. A Review on Current Status of Stability and Knowledge on Liquid Electrolyte-Based Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Frédéric Sauvage

    2014-01-01

    Full Text Available The purpose of this review is to gather the current background in materials development and provide the reader with an accurate image of today’s knowledge regarding the stability of dye-sensitized solar cells. This contribution highlights the literature from the 1970s to the present day on nanostructured TiO2, dye, Pt counter electrode, and liquid electrolyte for which this review is focused on.

  7. Multiwall Carbon Nanotube Coated with Conducting Polyaniline Nanocomposites for Quasi-Solid-State Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaul Karim

    2013-01-01

    Full Text Available Multiwalled carbon nanotube (MWNT coated with conducting polyaniline (PAni nanocomposites has been enforced as for quasi-solid-state electrolyte layer in the dye-sensitized solar cells (DSSCs, and the incorporation of MWNT-PAni nanoparticles on the cell performance has been examined. The MWNT-PAni nanoparticles exploited as the extended electron transfer materials, which can reduce charge diffusion length and serve simultaneously as catalyst for the electrochemical reduction of I3-. An ionic liquid of 1-methyl-3-propyl-imidazolium iodide (PMII together with the hybrid MWNT-PAni nanocomposites was placed between the dye-sensitized porous TiO2 and the Pt counter electrode without adding iodine and achieved a moderately higher cell efficiency (3.15%, as compared to that containing bare PMII (0.26%.

  8. Influence of thin film thickness of working electrodes on photovoltaic characteristics of dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Lai Yeong-Lin

    2017-01-01

    Full Text Available This paper presents the study of the influence of thin film thickness of working electrodes on the photovoltaic characteristics of dye-sensitized solar cells. Titanium dioxide (TiO2 thin films, with the thickness from 7.67 to 24.3 μm, were used to fabricate the working electrodes of dye-sensitized solar cells (DSSCs. A TiO2 film was coated on a fluorine-doped tin oxide (FTO conductive glass substrate and then sintered in a high-temperature furnace. On the other hand, platinum (Pt solution was coated onto an FTO substrate for the fabrication of the counter electrode of a DSSC. The working electrode immersed in a dye, the counter electrode, and the electrolyte were assembled to complete a sandwich-structure DSSC. The material analysis of the TiO2 films of DSSCs was carried out by scanning electron microscopy (SEM and ultraviolet-visible (UV-Vis spectroscopy, while the photovoltaic characteristics of DSSCs were measured by an AM-1.5 sunlight simulator. The light transmittance characteristics of the TiO2 working electrode depend on the TiO2 film thickness. The thin film thickness of the working electrode also affects the light absorption of a dye and results in the photovoltaic characteristics of the DSSC, including open-circuited voltage (VOC, short-circuited current density (JSC, fill factor, and photovoltaic conversion efficiency.

  9. Ultrafine fibers of zein and anthocyanins as natural pH indicator.

    Science.gov (United States)

    Prietto, Luciana; Pinto, Vania Zanella; El Halal, Shanise Lisie Mello; de Morais, Michele Greque; Costa, Jorge Alberto Vieira; Lim, Loong-Tak; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

    2018-05-01

    pH-sensitive indicator membranes, which are useful for pharmaceutical, food, and packaging applications, can be formed by encapsulating halochromic compounds within various solid supports. Accordingly, electrospinning is a versatile technique for the development of these indicators, by entrapping pH dyes within ultrafine polymer fibers. The ultrafine zein fibers, containing 5% (w/v) anthocyanins, had an average diameter of 510 nm. The pH-sensitive membrane exhibited color changes from pink to green when exposed to acidic and alkaline buffers, respectively. The contact angle was negligible after 10 and 2 s for neat and 5% anthocyanin-loaded zein membranes, respectively. The pH membranes exhibited color changes in a board pH range, which can potentially be used in various active packaging applications. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Performance engineering of dye sensitized solar cells (DSSC) using Ag modified titania as photoanode

    Science.gov (United States)

    Nair, Ranjith G.; Mathan Kumar, P.; Samdarshi, S. K.

    2018-01-01

    Present work reports the fabrication of silver (Ag) modified titania photoanode as an efficient photoanode for Dye Sensitized Solar Cell (DSSC). Pristine and Ag modified Titania nanomaterials were prepared using sol gel method. The structural analyses confirm the high crystallinity of the samples with crystallite size distribution in nanorange. TEM micrograph confirms that the synthesized nanomaterials are in uniform size. A red shift is observed in the UV DRS spectra compared to pristine Titania and which confirm the incorporation of Ag inside titania. A prototype DSSC was fabricated using the pristine and modified Titania as photoanode, Ruthenium dye as sensitizer, I-/I-3 as redox electrolyte and platinum counter electrode. The cell with Ag modified titania photoanode showed 15 times enhanced photoconversion efficiency (PCE) than the pristine one. This improved performance of the Ag modified DSSC can be ascribed to reduced recombination and improved charge carrier transport of electrons/holes at the interfaces.

  11. Dye-Sensitized Solar Cells: The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells (Adv. Mater. 20/2016).

    Science.gov (United States)

    Briscoe, Joe; Dunn, Steve

    2016-05-01

    Sustainability is an important concept generating traction in the research community. To be really sustainable the full life cycle of a product needs to be carefully considered. A key aspect of this is using elements that are either readily recycled or accessible in the Earth's biosphere. Jigsawing these materials together in compounds to address our future energy needs represents a great opportunity for the current generation of researchers. On page 3802, S. Dunn and J. Briscoe summarize the performance of a selection of alternative materials to replace platinum in the counter electrodes of dye-sensitized solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Feasibility of using local tanguile dye as chemical desimeter

    International Nuclear Information System (INIS)

    Cojuangco, J.G.; Juan, N.B.

    1976-05-01

    This is a part of a study on the feasibility of using local materials as radiation dosemeters. The characteristic responses of aqueous tanguile dye with different pH irradiated at various doses of Co-60 are being determined. The effects of different factors light, temperature and pH on the stability of unirradiated dye solutions are also investigated

  13. Theoretical insight into electronic structure and optoelectronic properties of heteroleptic Cu(I)-based complexes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shuxian; Li, Ke; Lu, Xiaoqing, E-mail: luxq@upc.edu.cn; Zhao, Zigang; Shao, Yang; Dang, Yong; Li, Shaoren; Guo, Wenyue, E-mail: wyguo@upc.edu.cn

    2016-04-15

    A series of heteroleptic Cu(I)-based dyes were investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT). Results showed that Cu(I)-based dyes were inclined to form distorted pseudo-trigonal pyramidal configurations with four-coordinated geometry index τ{sub 4} ranging from 0.905 to 0.914. The absorption spectra of Cu(I)-based dyes covered ∼300.0–600.0 nm region, and the lowest excitation states were crucial for efficient electron excitation and separation. Suitable energy levels of Cu(I)-based dyes rendered them thermodynamically favorable for efficient electron injection into semiconductor and regeneration from electrolyte. Relative to π-conjugation, heteroaromatic groups introduced into ancillary ligands could significantly improve the property of Cu(I)-based dyes by decreasing HOMO-LUMO gaps, red-shifting spectral range, strengthening absorption intensity, boosting light-harvesting efficiency, and promoting interfacial electron injection. Specifically, Cu(I)-based dye with dithiole-functionalized group exhibited outstanding optoelectronic property. - Highlights: • Assessment of heteroleptic Cu(I) dyes for dye-sensitized solar cells. • Suitable energy levels render Cu(I) dyes ideal candidates for electron injection. • Heteroaromatic groups efficiently improve Cu(I) dyes light-harvesting properties. • Dye with dithiole group exhibits ideal photoelectronic property.

  14. Pengaruh Temperatur Kalsinasi pada Kaca FTO yang di-coating ZnO terhadap Efisiensi DSSC (Dye Sensitized Solar Cell yang Menggunakan Dye dari Buah Terung Belanda (Solanum betaceum

    Directory of Open Access Journals (Sweden)

    Akbar Nur Prasetya

    2013-09-01

    Full Text Available Penelitian mengenai dye sensitized solar cell dilakukan dengan dye dari ekstrak buah terung belanda sebagai sumber energi alternatif dari tenaga surya. Dye sensitized solar cell (DSSC dibuat dengan menggunakan semikonduktor ZnO yang dilapiskan pada kaca konduktif Fluorine Doped Tin Oxide (FTO dan dikalsinasi  dengan variasi temperatur 5000C, 5500C, dan 6000C, dengan waktu tahan 30 menit pada tiap temperaturnya. Lapisan ZnO pada substrat dikarakterisasi dengan menggunakan SEM dan XRD. Luas permukaan aktif diukur dengan pengujian BET. Hasil SEM menunjukkan ukuran bentuk partikel ZnO berupa hexagonal. Hasil XRD menunjukkan struktur kristal ZnO adalah Wurthzite. Luas permukaan aktif dibandingkan dengan hasil kelistrikan DSSC, yang selaras meningkat dari temperatur 5000C ke 5500C, namun menurun pada 6000C. Densitas arus dan voltase maksimum diperoleh pada variasi temperatur 550oC yaitu sebesar 0,591 mA/cm2 dan 1140 mV. Efisiensi maksimum yang diperoleh sebesar 0,150%. Karena sampel 550oC memiliki luas permukaan aktif paling besar 146,185 m2/gr.

  15. Color removal from dye-containing wastewater by magnesium chloride.

    Science.gov (United States)

    Gao, Bao-Yu; Yue, Qin-Yan; Wang, Yan; Zhou, Wei-Zhi

    2007-01-01

    Color removal by MgCl(2) when treating synthetic waste containing pure dyes was studied. The color removal efficiency of MgCl(2)/Ca(OH)(2) was compared with that of Al(2)(SO(4))(3), polyaluminum chloride (PAC) and FeSO(4)/Ca(OH)(2). The mechanism of color removal by MgCl(2) was also investigated. The experimental results show that the color removal efficiency of MgCl(2) is related to the type of dye and depends on the pH of the waste and the dosage of the coagulants used. Treatment of waste containing reactive dye or dispersed dye with MgCl(2) yielded an optimum color removal ratio when the pH of the solution was equal to or above 12.0. For both the reactive and dispersed dye waste, MgCl(2)/Ca(OH)(2) was shown to be superior to MgCl(2)/NaOH, Al(2)(SO(4))(3), PAC and FeSO(4)/Ca(OH)(2) for color removal. A magnesium hydroxide precipitate formed at pH values greater than 12.0, which provided a large adsorptive surface area and a positive electrostatic surface charge, enabling it to remove the dyes through charge neutralization and an adsorptive coagulating mechanism. So, the MgCl(2)/Ca(OH)(2) system is a viable alternative to some of the more conventional forms of chemical treatment, especially for treating actual textile waste with high natural pH.

  16. Stability of the elderberry dye in vodkas

    International Nuclear Information System (INIS)

    Pizlo, A.; Jankowska, D.

    2001-01-01

    The effect of light, pH, strength of vodkas and by-products on Sambucus nigra pigments stability was tested in this paper. The elderberry dye was unstable in vodkas during light action in general. It was stated that low strength of vodkas and high pH effected an increase of the vodkas colour stability. The presence of vitamin C caused discolouring effect on elderberry dye but chockeberry distillate effected an increase of the vodkas colour stability

  17. Time dependent – density functional theory characterization of organic dyes for dye-sensitized solar cells

    KAUST Repository

    Hilal, Rifaat

    2017-06-19

    We aim at providing better insight into the parameters that govern the intramolecular charge transfer (ICT) and photo-injection processes in dyes for dye-sensitised solar cells (DSSC). Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations are utilized to study the geometry, electronic structure, electrostatic potential (ESP) and absorption spectrum, for a representative donor-π bridge-acceptor (D–π–A) dye for DSSC. The coplanar geometry of the dye (D1) facilitates strong conjugation and considerable delocalization originating the π CT interaction from donor to acceptor orbitals and the hyper-conjugative interactions involving Rydberg states. A model simulating the adsorption of the dye on the TiO surface is utilized to estimate binding energies. The effect of fluorine substituents in the π-spacer on the quantum efficiency of DSSCs was investigated. Gibb’s free energy values, redox potentials, excited state lifetime, non-linear optical properties (NLO) and driving forces for D1 and its fluorinated derivatives were computed.

  18. Deposition of hole-transport materials in solid-state dye-sensitized solar cells by doctor-blading

    KAUST Repository

    Ding, I-Kang; Melas-Kyriazi, John; Cevey-Ha, Ngoc-Le; Chittibabu, Kethinni G.; Zakeeruddin, Shaik M.; Grä tzel, Michael; McGehee, Michael D.

    2010-01-01

    We report using doctor-blading to replace conventional spin coating for the deposition of the hole-transport material spiro-OMeTAD (2,20,7,70-tetrakis-(N, N-di-p-methoxyphenylamine)- 9,90-spirobifluorene) in solid-state dye-sensitized solar cells

  19. Dithiafulvene-based organic sensitizers using pyridine as the acceptor for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jun; Cao, Yaxiong; Liang, Xiaozhong; Zheng, Jingxia; Zhang, Fang [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Wei, Shuxian; Lu, Xiaoqing [College of Science, China University of Petroleum, Qingdao, Shandong 266555 (China); Guo, Kunpeng, E-mail: guokunpeng@tyut.edu.cn [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Yang, Shihe, E-mail: chsyang@ust.hk [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

    2017-05-01

    Three dithiafulvene-based metal-free organic sensitizers all using pyridine as the acceptor but with different π-bridges of phenyl (DTF-Py1), thienyl (DTF-Py2) and phenyl-thienyl (DTF-Py3) have been designed, synthesized and used as photosensitizers for dye-sensitized solar cells (DSCs). Introducing thienyl unit into the π-bridge, as well as extension of the π-bridge can dramatically improve their light harvesting ability and suppress the electron recombination, thus uplifting the performance of DSCs. The overall power conversion efficiency of DSC based on DTF-Py3 shows the highest efficiency of 2.61% with a short-circuit photocurrent density of 7.99 mA cm{sup -2}, an open-circuit photovoltage of 630 mV, and a fill factor of 0.52, under standard global AM 1.5 solar light condition. More importantly, the long-term stability of the DTF-Py3 based DSCs under 500 h light-soaking has been demonstrated. - Highlights: • Dithiafulvene sensitizers using pyridine ring as the acceptor were synthesized for the first time. • The power conversion efficiency of 2.61% was obtained for DTF-Py3 sensitized cell. • DTF-Py3 loaded TiO{sub 2} film shows improved light harvesting ability and suppressed electron recombination.

  20. Rationalization of dye uptake on titania slides for dye-sensitized solar cells by a combined chemometric and structural approach.

    Science.gov (United States)

    Gianotti, Valentina; Favaro, Giada; Bonandini, Luca; Palin, Luca; Croce, Gianluca; Boccaleri, Enrico; Artuso, Emma; van Beek, Wouter; Barolo, Claudia; Milanesio, Marco

    2014-11-01

    A model photosensitizer (D5) for application in dye-sensitized solar cells has been studied by a combination of XRD, theoretical calculations, and spectroscopic/chemometric methods. The conformational stability and flexibility of D5 and molecular interactions between adjacent molecules were characterized to obtain the driving forces that govern D5 uptake and grafting and to infer the most likely arrangement of the molecules on the surface of TiO2. A spectroscopic/chemometric approach was then used to yield information about the correlations between three variables that govern the uptake itself: D5 concentration, dispersant (chenodeoxycholic acid; CDCA) concentration, and contact time. The obtained regression model shows that large uptakes can be obtained at high D5 concentrations in the presence of CDCA with a long contact time, or in absence of CDCA if the contact time is short, which suggests how dye uptake and photovoltaic device preparation can be optimized. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Modified Multiwalled Carbon Nanotubes for Treatment of Some Organic Dyes in Wastewater

    Directory of Open Access Journals (Sweden)

    M. I. Mohammed

    2014-01-01

    Full Text Available In Iraq, a large quantity of basic orange and methyl violet dyes contaminated wastewater from textile industries is discharged into Tigris River. So the aim of this work is to found an efficient and fast technique that can be applied directly for removal of such dyes from the wastewater before discharging into river. Accordingly, CNTs as a new approach prepared by CCVD technique were purified, functionalized, and used as adsorption material to remove dyes from wastewater. The effect of pH, contact time, CNTs dosage, and dyes concentration on removal of pollutants was studied. The removal percentage of both dyes was proportional to the contact time, CNTs dosage, and pH and inversely proportional to the dyes concentration. The results show that the equilibrium time was 20 and 30 min for basic orange and methyl violet dyes, respectively, and the maximum removal percentage for all dyes concentrations was at pH = 8.5 and CNTs dosage of 0.25 g/L and 0.3 g/L for methyl violet and basic orange dye, respectively. The adsorption isotherm shows that the correlation coefficient of Freundlich model was higher than Langmuir model for both dyes, indicating that the Freundlich model is more appropriate to describe the adsorption characteristics of organic pollutants.

  2. Molecular Design of Efficient Organic D-A-pi-A Dye Featuring Triphenylamine as Donor Fragment for Application in Dye-Sensitized Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Ferdowsi, P.; Saygili, Y.; Zhang, W.; Edvinson, T.; Kavan, Ladislav; Mokhtari, J.; Zakeerudin, S. M.; Grätzel, M.; Hagfeldt, A.

    2018-01-01

    Roč. 11, č. 2 (2018), s. 494-502 ISSN 1864-5631 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : Dye-Sensitized Solar Cells * Electrolytes * Donor-acceptor systems Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 7.226, year: 2016

  3. Optical and structural characterization od titanium dioxide films used for construction of dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Ivanovska, Tanja

    2012-01-01

    The dye-sensitized solar cells are the most serious concept that could replace the silicon solar cells. These are low-cost photovoltaic, and represent a technology which could seriously decrease the cost of the electrical energy they produce. The dye-sensitized solar cells are composed of several layers of materials that belong to the group of inorganic semiconductors. For the efficiency improvement of these cells, there are two basic concepts of research regarding the construction materials. On one side, investigation of new materials that will, as a result of their physical and electrochemical characteristics, increase the cell efficiency, and on the other side, use of materials that will contribute to the long term stability of the cell in atmospheric conditions. As a part of this Master thesis, compact and meso porous Ti(>2 films for dye- sensitized solar cells have been prepared. The compact Ti0 2 films were deposited with the technique of spray pyrolysis, and the preparation of the meso porous films was made with a blade casting technique. The optical and structural analysis and characterization of the films was done with optical spectroscopy in the visible and ultraviolet spectral region (UV- Vis), Raman spectroscopy and atomic force microscopy (AFM). The crystal structure of the films, surface uniformity, thickness and grain size dependence on the deposition parameters was investigated, this led to calculation of the optical constants for the compact films, as well as the determination of the electron transitions and the determination of the bang gap energy. Also regarding the structure and porosity of the meso porous films, characterization of the quality of the film depending on the chemical composition of the paste used for deposition was made. As a result of the preformed investigations, through defining the structural and optical parameters of quality compact and meso porous TiC>2 films for dye-sensitized solar cells, the optimal parameters for film

  4. Pristine and Al-doped hematite printed films as photoanodes of p-type dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Congiu, Mirko, E-mail: mirko.congiu@fc.unesp.br [UNESP–Univ. Estadual Paulista, POSMAT-Programa de Pós-Graduação em Ciência e Tecnologia de Materiais (Brazil); De Marco, Maria L.; Bonomo, Matteo [DC-FC-UNESP–Univ. Estadual Paulista (Brazil); Nunes-Neto, Oswaldo [UNESP–Univ. Estadual Paulista, POSMAT-Programa de Pós-Graduação em Ciência e Tecnologia de Materiais (Brazil); Dini, Danilo [DC-FC-UNESP–Univ. Estadual Paulista (Brazil); Graeff, Carlos F.O. [UNESP–Univ. Estadual Paulista, POSMAT-Programa de Pós-Graduação em Ciência e Tecnologia de Materiais (Brazil)

    2017-01-15

    We hereby propose a non-expensive method for the deposition of pure and Al-doped hematite photoanodes in the configuration of thin films for the application of dye-sensitized solar cells (DSSC). The electrodes have been prepared from hematite nanoparticles that were obtained by thermal degradation of a chemical precursor. The particles have been used in the preparation of a paste, suitable for both screen printing and doctor blade deposition. The paste was then spread on fluorine-doped tin oxide (FTO) to obtain porous hematite electrodes. The electrodes have been sensitized using N3 and D5 dyes and were characterized through current/voltage curves under simulated sun light (1 sun, AM 1.5) with a Pt counter electrode. Al-doping of hematite showed interesting changes in the physical and electrochemical characteristics of sensitized photoanodes since we could notice the growth of AlFe{sub 2}O{sub 4} (hercynite) as a secondary crystal phase into the oxides obtained by firing the mixtures of two chemical precursors at different molar ratios. Pure and Al-doped hematite electrodes have been used in a complete n-type DSSCs. The kinetics of charge transfer through the interface dye/electrolyte was studied and compared to that of a typical p-type DSSC based on NiO photocathodes sensitized with erythrosine B. The results suggest a potential application of both Fe{sub 2}O{sub 3} and Fe{sub 2}O{sub 3}/AlFe{sub 2}O{sub 4} as photoanodes of a tandem DSSC.

  5. Post-deposition annealing temperature dependence TiO_2-based EGFET pH sensor sensitivity

    International Nuclear Information System (INIS)

    Zulkefle, M. A.; Rahman, R. A.; Yusoff, K. A.; Abdullah, W. F. H.; Rusop, M.; Herman, S. H.

    2016-01-01

    EGFET pH sensor is one type of pH sensor that is used to measure and determine pH of a solution. The sensing membrane of EGFET pH sensor plays vital role in the overall performance of the sensor. This paper studies the effects of different annealing temperature of the TiO_2 sensing membranes towards sensitivity of EGFET pH sensor. Sol-gel spin coating was chosen as TiO_2 deposition techniques since it is cost-effective and produces thin film with uniform thickness. Deposited TiO_2 thin films were then annealed at different annealing temperatures and then were connected to the gate of MOSFET as a part of the EGFET pH sensor structure. The thin films now act as sensing membranes of the EGFET pH sensor and sensitivity of each sensing membrane towards pH was measured. From the results it was determined that sensing membrane annealed at 300 °C gave the highest sensitivity followed by sample annealed at 400 °C and 500 °C.

  6. Variasi Temperatur dan Waktu Tahan Kalsinasi terhadap Unjuk Kerja Semikonduktor TiO2 sebagai Dye Sensitized Solar Cell (DSSC dengan Dye dari Ekstrak Buah Naga Merah

    Directory of Open Access Journals (Sweden)

    Sahat M. R. Nadaek

    2012-09-01

    Full Text Available Salah satu energi alternatif yang mempunyai potensi sumber energi yang sangat besar untuk mencegah terjadinya krisis energi namun sering kali terabaikan adalah sinar matahari. Oleh karena itu, penelitian ini dilakukan untuk  menghasilkan prototype dalam mengkonversi energi cahaya matahari menjadi energi listrik. Dye Sensitized Solar Cell (DSSC telah difabrikasi dengan menggunakan serbuk Titanium Dioksida (TiO2 yang dilapisi ke kaca Indium Tin Oxide dan diberi variasi temperatur 350oC, 450oC, dan 550oC dengan waktu tahan kalsinasi 30 dan 60 menit yang kemudian disensitisasi ke dalam larutan dye ekstrak buah naga merah (Hylocereus polyrhizus. DSSC di-assembling dengan coating Pd/Au yang telah di-sputtering ke kaca Indium Tin Oxide yang selanjutnya ditetesi dengan larutan elektrolit. Kemudian lapisan TiO2 tersebut dikarakterisasi menggunakan uji (SEM dan (XRD. Luas permukaan aktif partikel diidentifikasi dengan menggunakan BET analyzer. Dari hasil XRD dapat diketahui struktur kristalnya tetragonal. Hasil SEM menunjukkan bahwa bentuk partikel TiO2 adalah spherical. Untuk luas permukaan aktif yang dihasilkan menunjukkan nilai yang berbanding lurus dengan kenaikan nilai kelistrikan DSSC buah naga. Dari uji kelistrikan didapatkan hasil optimum pada temperatur 550oC dan waktu tahan 60 menit dengan voltase 562 mV, kuat arus 0.307 mA, dan memiliki efisiensi sebesar 0.089%. Kata kunci: Dye ekstrak buah naga merah, dye sensitized solar cell, temperatur kalsinasi, TiO2, waktu tahan kalsinasi.

  7. Optimizing TiO2 nanotube top geometry for use in dye-sensitized solar cells.

    Science.gov (United States)

    Mir, Nooshin; Lee, Kiyoung; Paramasivam, Indhumati; Schmuki, Patrik

    2012-09-17

    Recombination dynamics: For TiO(2) nanotube-based dye-sensitized solar cells, the efficiency can be drastically enhanced by a synergetic effect that occurs when using nanowire-ended nanotubes in combination with an adequate nanoparticle decoration (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Improvement of N-phthaloylchitosan based gel polymer electrolyte in dye-sensitized solar cells using a binary salt system.

    Science.gov (United States)

    Yusuf, S N F; Azzahari, A D; Selvanathan, V; Yahya, R; Careem, M A; Arof, A K

    2017-02-10

    A binary salt system utilizing lithium iodide (LiI) as the auxiliary component has been introduced to the N-phthaloylchitosan (PhCh) based gel polymer electrolyte consisting of ethylene carbonate (EC), dimethylformamide (DMF), tetrapropylammonium iodide (TPAI), and iodine (I 2 ) in order to improve the performance of dye-sensitized solar cell (DSSC) with efficiency of 6.36%, photocurrent density, J SC of 17.29mAcm -2 , open circuit voltage, V OC of 0.59V and fill factor, FF of 0.62. This efficiency value is an improvement from the 5.00% performance obtained by the DSSC consisting of only TPAI single salt system. The presence of the LiI in addition to the TPAI improves the charge injection rates and increases the iodide contribution to the total conductivity and both factors contribute to the increase in efficiency of the DSSC. The interaction behavior between polymer-plasticizer-salt was thoroughly investigated using EIS, FTIR spectroscopy and XRD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Parameters influencing charge separation in solid-state dye-sensitized solar cells using novel hole conductors

    NARCIS (Netherlands)

    Kroeze, J.E.; Hirata, N.; Schmidt-Mende, L.; Orizu, C.; Ogier, S.D.; Carr, K.; Grätzel, M.; Durrant, J.R.

    2006-01-01

    Solid-state dye-sensitized solar cells employing a solid organic hole-transport material (HTM) are currently under intensive investigation, since they offer a number of practical advantages over liquid-electrolyte junction devices. Of particular importance to the design of such devices is the

  10. Isolation and screening of azo dye decolorizing bacterial isolates from dye-contaminated textile wastewater

    Directory of Open Access Journals (Sweden)

    Shahid Mahmood

    2011-04-01

    Full Text Available Azo dyes are released into wastewater streams without any pretreatment and pollute water and soilenvironments. To prevent contamination of our vulnerable resources, removal of these dye pollutants is of greatimportance. For this purpose, wastewater samples were collected from dye-contaminated sites of Faisalabad. About200 bacterial isolates were isolated through enrichment and then tested for their potential to remove RemazolBlack-B azo dye in liquid medium. Five bacterial isolates capable of degrading Remazol Black-B azo dye efficientlywere screened through experimentation on modified mineral salt medium. Isolate SS1 (collected from wastewater ofSupreme Textile Industry was able to completely remove the Remazol Black-B dye from the liquid medium in 18 h.Further, the isolate showed the best performance at the dye concentration of 100 mg L-1 medium (pH 7 and attemperature 35oC. Similarly, yeast extract proved to be the best carbon source for decolorization purpose. Theresults imply that the isolate SS1 could be used for the removal of the reactive dyes from textile effluents.

  11. Green dyeing process of modified cotton fibres using natural dyes extracted from Tamarix aphylla (L.) Karst. leaves.

    Science.gov (United States)

    Baaka, Noureddine; Mahfoudhi, Adel; Haddar, Wafa; Mhenni, Mohamed Farouk; Mighri, Zine

    2017-01-01

    This research work involves an eco-friendly dyeing process of modified cotton with the aqueous extract of Tamarix aphylla leaves. During this process, the dyeing step was carried out on modified cotton by several cationising agents in order to improve its dyeability. The influence of the main dyeing conditions (dye bath pH, dyeing time, dyeing temperature, salt addition) on the performances of this dyeing process were studied. The dyeing performances of this process were appreciated by measuring the colour yield (K/S) and the fastness properties of the dyed samples. The effect of mordant type with different mordanting methods on dyeing quality was also studied. The results showed that mordanting gave deeper shades and enhanced fastness properties. In addition, environmental indicators (BOD 5 , COD and COD/BOD 5 ) were used to describe potential improvements in the biodegradability of the dyebath wastewater. Further, HPLC was used to identify the major phenolic compounds in the extracted dye.

  12. Monolithic route to efficient dye-sensitized solar cells employing diblock copolymers for mesoporous TiO 2

    KAUST Repository

    Nedelcu, Mihaela; Guldin, Stefan; Orilall, M. Christopher; Lee, Jinwoo; Hü ttner, Sven; Crossland, Edward J. W.; Warren, Scott C.; Ducati, Caterina; Laity, Pete R.; Eder, Dominik; Wiesner, Ulrich; Steiner, Ullrich; Snaith, Henry J.

    2010-01-01

    We present a material and device based study on the fabrication of mesoporous TiO2 and its integration into dye-sensitized solar cells. Poly(isoprene-block-ethyleneoxide) (PI-b-PEO) copolymers were used as structure directing agents for the sol-gel based synthesis of nanoporous monolithic TiO2 which was subsequently ground down to small particles and processed into a paste. The TiO2 synthesis and the formation of tens of micrometre thick films from the paste is a scalable approach for the manufacture of dye sensitised solar cells (DSCs). In this study, we followed the self-assembly of the material through the various processing stages of DSC manufacture. Since this approach enables high annealing temperatures while maintaining porosity, excellent crystallinity was achieved. Internal TiO 2 structures ranging from the nanometre to micrometre scale combine a high internal surface area with the strong scattering of light, which results in high light absorption and an excellent full-sun power conversion efficiency of up to 6.4% in a robust, 3 μm thick dye-sensitized solar cell. © 2010 The Royal Society of Chemistry.

  13. Plasma dye coating as straightforward and widely applicable procedure for dye immobilization on polymeric materials.

    Science.gov (United States)

    De Smet, Lieselot; Vancoillie, Gertjan; Minshall, Peter; Lava, Kathleen; Steyaert, Iline; Schoolaert, Ella; Van De Walle, Elke; Dubruel, Peter; De Clerck, Karen; Hoogenboom, Richard

    2018-03-16

    Here, we introduce a novel concept for the fabrication of colored materials with significantly reduced dye leaching through covalent immobilization of the desired dye using plasma-generated surface radicals. This plasma dye coating (PDC) procedure immobilizes a pre-adsorbed layer of a dye functionalized with a radical sensitive group on the surface through radical addition caused by a short plasma treatment. The non-specific nature of the plasma-generated surface radicals allows for a wide variety of dyes including azobenzenes and sulfonphthaleins, functionalized with radical sensitive groups to avoid significant dye degradation, to be combined with various materials including PP, PE, PA6, cellulose, and PTFE. The wide applicability, low consumption of dye, relatively short procedure time, and the possibility of continuous PDC using an atmospheric plasma reactor make this procedure economically interesting for various applications ranging from simple coloring of a material to the fabrication of chromic sensor fabrics as demonstrated by preparing a range of halochromic materials.

  14. Solidification of liquid electrolyte with imidazole polymers for quasi-solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wang Miao; Lin Yuan; Zhou Xiaowen; Xiao Xurui; Yang Lei; Feng Shujing; Li Xueping

    2008-01-01

    Quasi-solid-state electrolytes were prepared by employing the imidazole polymers to solidify the liquid electrolyte containing lithium iodide, iodine and ethylene carbonate (EC)/propylene carbonate (PC) mixed solvent. The ionic conductivity and diffusion behavior of triiodide in the quasi-solid-state electrolytes were examined in terms of the polymer content. Application of the quasi-solid-state electrolytes to the dye-sensitized solar cells, the maximum energy conversion efficiency of 7.6% (AM 1.5, 100 mW cm -2 ) was achieved. The dependence of the photovoltaic performance on the polymer content and on the different anions of the imidazole polymers was studied by electrochemical impedance spectroscopy and cyclic voltammetry. The results indicate the charge transfer behaviors occurred at nanocrystalline TiO 2 /electrolyte and Pt/electrolyte interface play an important role in influencing the photovoltaic performance of quasi-solid-state dye-sensitized solar cells

  15. Structure of electron collection electrode in dye-sensitized nanocrystalline TiO2

    International Nuclear Information System (INIS)

    Yanagida, Masatoshi; Numata, Youhei; Yoshimatsu, Keiichi; Ochiai, Masayuki; Naito, Hiroyoshi; Han, Liyuan

    2013-01-01

    As part of the effort to control electron transport in the TiO 2 films of dye-sensitized solar cells (DSCs), the structure of the electron collection electrode on the films has been investigated. Here, we report the comparison between a sandwich-type dye-sensitized solar cell (SW-DSC), in which the TiO 2 film is sandwiched between a TCO glass front electron collection electrode and a sputtered Ti back charge collection electrode, and a normal DSC (N-DSC), which has no back electrode. In N-DSCs, electrons in TiO 2 that are far from the front electrode have to diffuse for a long distance (ca. 10 μm), and therefore, the photocurrent cannot rapidly respond to light with a modulation frequency >100 Hz. In SW-DSCs, the photocurrent response was enhanced at frequencies between 10 and 500 Hz because electrons in TiO 2 can be extracted by both front and back electrodes, which can be also explained by an electron diffusion model. Calculations based on the electron diffusion model suggested that a high short-circuit photocurrent could be maintained in SW-DSCs even when the electron diffusion length in the TiO 2 film was shortened.

  16. Transparent platinum counter electrode for efficient semi-transparent dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Iefanova, Anastasiia; Nepal, Jeevan; Poudel, Prashant; Davoux, Daren; Gautam, Umesh [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Mallam, Venkataiah [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Qiao, Qiquan [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Logue, Brian [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Baroughi, Mahdi Farrokh, E-mail: m.farrokhbaroughi@sdstate.edu [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States)

    2014-07-01

    A method for fabrication of highly transparent platinum counter electrodes (CEs) has been developed based on spray coating of Pt nanoparticles (NPs) on hot substrates. This method leads to 86% reduction in Pt consumption reducing the Pt cost per peak watt of counter electrode from $0.79/Wp down to $0.11/Wp compared to the conventional Pt counter electrodes made by sputter deposition. The simplicity and low cost of this method provide a basis for an up-scalable fabrication process. The Pt NP layer is over 88% transparent, leading to overall transparency of 80% when incorporated with indium tin oxide/glass substrates for functional counter electrodes. This counter electrode exhibits a large surface area and high catalytic activity, comparable to that of the conventional opaque CEs. Semi-transparent dye-sensitized solar cells fabricated based on this counter electrode showed 6.17% power conversion efficiency. - Highlights: • Counter electrode (CE) prepared by spraying nanoparticle (NP) Pt on hot substrate. • Low cost and scalable fabrication process of CE. • The spray deposited CE uses 10 times less Pt compared to the sputtering method. • The CE is 80% transparent and exhibits a large surface and high catalytic activity. • A semitransparent dye-sensitized solar cell with Pt NP CE was 6.17% efficient.

  17. Industrial sheet metals for nanocrystalline dye-sensitized solar cell structures

    Energy Technology Data Exchange (ETDEWEB)

    Toivola, Minna; Ahlskog, Fredrik; Lund, Peter [Laboratory of Advanced Energy Systems, Department of Engineering Physics and Mathematics, Helsinki University of Technology, P.O. Box 4100, FIN-02015 TKK (Finland)

    2006-11-06

    Direct integration of dye-sensitized solar cells (DSSC) onto industrial sheet metals has been studied. The stability of the metals, including zinc-coated and plain carbon steel, stainless steel and copper in a standard iodine electrolyte was investigated with soaking and encapsulation tests. Stainless and carbon steel showed sufficient stability and were used as the cell counter-electrodes, yielding cells with energy conversion efficiencies of 3.6% and 3.1%, respectively. A DSSC built on flexible steel substrates is a promising approach especially from the viewpoint of large-scale, cost-effective industrial manufacturing of the cells. (author)

  18. Eosin yellowish dye sensitized TiO2 solar cell with PEG/PEO/LiI/I2 as electrolyte

    Science.gov (United States)

    Kanmani, S. S.; Umapathy, S.; Ramachandran, K.

    2012-06-01

    Eosin Yellowish dye sensitized TiO2 nanoparticles (NP) and nanowires (NW) are employed as photo anodes in dye sensitized solar cells with PEO/PEG/LiI/I2 as electrolyte. Material characterization by XRD and SEM confirms the formation of anatase phased TiO2 NP and NW. Effective quenching of UV emission in TiO2 NW than NP is a consequence of reduction in recombination rate, which directly favours for better solar conversion efficiency. The photovoltaic performance of TiO2 NW with an overall conversion efficiency of 0.31 % is better than NP, which is the outcome of improved electron transport in NW.

  19. Quasi Solid-State Dye-Sensitized Solar Cell Incorporating Highly Conducting Polythiophene-Coated Carbon Nanotube Composites in Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaul Karim

    2011-01-01

    Full Text Available Conducting polythiophene (PTh composites with the host filler multiwalled carbon nanotube (MWNT have been used, for the first time, in the dye-sensitized solar cells (DSCs. A quasi solid-state DSCs with the hybrid MWNT-PTh composites, an ionic liquid of 1-methyl-3-propyl imidazolium iodide (PMII, was placed between the dye-sensitized porous TiO2 and the Pt counter electrode without adding iodine and higher cell efficiency (4.76% was achieved, as compared to that containing bare PMII (0.29%. The MWNT-PTh nanoparticles are exploited as the extended electron transfer materials and serve simultaneously as catalyst for the electrochemical reduction of I−3.

  20. Facile preparation of squarylium dye sensitized TiO{sub 2} nanoparticles and their enhanced visible-light photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhongyu, E-mail: zhongyuli@mail.tsinghua.edu.cn [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Changzhou Expansion New Stuff Technology Limited Company, Changzhou 213122 (China); Fang, Yongling [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Zhan, Xueqiu [Department of Basic Courses, Wuxi Institute of Technology, Wuxi 214121 (China); Xu, Song [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China)

    2013-07-05

    Highlights: •ISQ dye sensitized TiO{sub 2} nanoparticles were prepared via a facile solution method. •ISQ/TiO{sub 2} nanoparticles exhibited significantly enhanced visible light activity. •ISQ/TiO{sub 2} showed high visible light photocatalytic activity over MB decomposition. •ISQ/TiO{sub 2} nanoparticles exhibited good photocatalytic stability. -- Abstract: A squarylium dye, 1,3-bis[(3,3-dimethylindolin-2-ylidene)methyl]squaraine (ISQ) sensitized TiO{sub 2} nanoparticles photocatalysts with different mass ratio of ISQ to TiO{sub 2} were facilely prepared by blending ISQ and TiO{sub 2} in ethanol solution. The resulting composite photocatalysts were characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectra (FT-IR) and UV–vis diffuse reflectance spectroscope (DRS). The visible light photocatalytic activities of ISQ sensitized TiO{sub 2} nanoparticles were evaluated using the degradation of methylene blue (MB) as a photodegradation target. The results showed that photo-response of the ISQ sensitized TiO{sub 2} nanoparticles were remarkably extended to visible-light region, and the ISQ dye sensitized TiO{sub 2} exhibited significantly enhanced photocatalytic activity under visible light irradiation. The maximum photocatalytic activity of the ISQ sensitized TiO{sub 2} was found at a composite photocatalyst (mass ratio of ISQ to TiO{sub 2} was 1:3), and its degradation efficiency of MB reached approximately 98% in 2 h under visible light irradiation. Furthermore, a possible mechanism for the photocatalytic oxidative degradation was also proposed.

  1. Graphene Oxide Based Nanocarrier Combined with a pH-Sensitive Tracer: A Vehicle for Concurrent pH Sensing and pH-Responsive Oligonucleotide Delivery.

    Science.gov (United States)

    Hsieh, Chia-Jung; Chen, Yu-Cheng; Hsieh, Pei-Ying; Liu, Shi-Rong; Wu, Shu-Pao; Hsieh, You-Zung; Hsu, Hsin-Yun

    2015-06-03

    We chemically tuned the oxidation status of graphene oxide (GO) and constructed a GO-based nanoplatform combined with a pH-sensitive fluorescence tracer that is designed for both pH sensing and pH-responsive drug delivery. A series of GOs oxidized to distinct degrees were examined to optimize the adsorption of the model drug, poly dT30. We determined that highly oxidized GO was a superior drug-carrier candidate in vitro when compared to GOs oxidized to lesser degrees. In the cell experiment, the synthesized pH-sensitive rhodamine dye was first applied to monitor cellular pH; under acidic conditions, protonated rhodamine fluoresces at 588 nm (λex=561 nm). When the dT30-GO nanocarrier was introduced into cells, a rhodamine-triggered competition reaction occurred, and this led to the release of the oligonucleotides and the quenching of rhodamine fluorescence by GO. Our results indicate high drug loading (FAM-dT30/GO=25/50 μg/mL) and rapid cellular uptake (<0.5 h) of the nanocarrier which can potentially be used for targeted RNAi delivery to the acidic milieu of tumors.

  2. A new sight towards dye-sensitized solar cells material and theoretical

    CERN Document Server

    Lin, Hong

    2010-01-01

    Dye-sensitized solar cell (DSC) technology is emerging, against the current background of drastic consumption-rates of irreplaceable natural resources, as the Cinderella solution to many energy-related problems, Almost since its first appearance, it has been regarded as being the most promising alternative to conventional silicon solar cell technology due to the tremendous advantages of low cost and high theoretical energy-conversion efficiency. Review from Book News Inc.: Eight invited and peer-reviewed papers comprise this special-topic volume on a possible alternative to conventional silico

  3. Copper Complexes with Tetradentate Ligands for Enhanced Charge Transport in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Hannes Michaels

    2018-05-01

    Full Text Available In dye-sensitized solar cells (DSCs, the redox mediator is responsible for the regeneration of the oxidized dye and for the hole transport towards the cathode. Here, we introduce new copper complexes with tetradentate 6,6′-bis(4-(S-isopropyl-2-oxazolinyl-2,2′-bipyridine ligands, Cu(oxabpy, as redox mediators. Copper coordination complexes with a square-planar geometry show low reorganization energies and thus introduce smaller losses in photovoltage. Slow recombination kinetics of excited electrons between the TiO2 and CuII(oxabpy species lead to an exceptionally long electron lifetime, a high Fermi level in the TiO2, and a high photovoltage of 920 mV with photocurrents of 10 mA∙cm−2 and 6.2% power conversion efficiency. Meanwhile, a large driving force remains for the dye regeneration of the Y123 dye with high efficiencies. The square-planar Cu(oxabpy complexes yield viscous gel-like solutions. The unique charge transport characteristics are attributed to a superposition of diffusion and electronic conduction. An enhancement in charge transport performance of 70% despite the higher viscosity is observed upon comparison of Cu(oxabpy to the previously reported Cu(tmby2 redox electrolyte.

  4. Sensitivity improvement of a fibre Bragg grating pH sensor with elastomeric coating

    Science.gov (United States)

    Yulianti, Ian; Supa'at, A. S. M.; Idrus, Sevia M.; Kurdi, Ojo; Anwar, M. R. S.

    2012-01-01

    A new optical pH sensor based on fibre Bragg grating (FBG) is demonstrated. The sensor consists of a FBG coated with pH sensitive hydrogel. The sensing was performed through the detection of wavelength shifts resulting from the induced strain on the FBG due to mechanical expansion of the hydrogel. An elastomeric coating was applied before the hydrogel coating to improve the sensitivity. The sensor performance was investigated by simulating the hydrogel swelling and the strain induced on the FBG. The swelling of hydrogel due to pH change was modelled using a free-energy function and was solved using the finite element method. With silicone rubber as the elastomer material, the results show that the sensitivity was improved by up to 66% compared to that of the FBG pH sensor without elastomeric coating.

  5. Sensitivity improvement of a fibre Bragg grating pH sensor with elastomeric coating

    International Nuclear Information System (INIS)

    Yulianti, Ian; Supa'at, A S M; Idrus, Sevia M; Anwar, M R S; Kurdi, Ojo

    2012-01-01

    A new optical pH sensor based on fibre Bragg grating (FBG) is demonstrated. The sensor consists of a FBG coated with pH sensitive hydrogel. The sensing was performed through the detection of wavelength shifts resulting from the induced strain on the FBG due to mechanical expansion of the hydrogel. An elastomeric coating was applied before the hydrogel coating to improve the sensitivity. The sensor performance was investigated by simulating the hydrogel swelling and the strain induced on the FBG. The swelling of hydrogel due to pH change was modelled using a free-energy function and was solved using the finite element method. With silicone rubber as the elastomer material, the results show that the sensitivity was improved by up to 66% compared to that of the FBG pH sensor without elastomeric coating

  6. An equivalent circuit approach to the modelling of the dynamics of dye sensitized solar cells

    DEFF Research Database (Denmark)

    Bay, L.; West, K.

    2005-01-01

    A model that can be used to interpret the response of a dye-sensitized photo electrode to intensity-modulated light (intensity modulated voltage spectroscopy, IMVS and intensity modulated photo-current spectroscopy, IMPS) is presented. The model is based on an equivalent circuit approach involvin...

  7. Structurally stabilized mesoporous TiO2 nanofibres for efficient dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Fargol Hasani Bijarbooneh

    2013-09-01

    Full Text Available One-dimensional (1D TiO2 nanostructures are very desirable for providing fascinating properties and features, such as high electron mobility, quantum confinement effects, and high specific surface area. Herein, 1D mesoporous TiO2 nanofibres were prepared using the electrospinning method to verify their potential for use as the photoelectrode of dye-sensitized solar cells (DSSCs. The 1D mesoporous nanofibres, 300 nm in diameter and 10-20 μm in length, were aggregated from anatase nanoparticles 20-30 nm in size. The employment of these novel 1D mesoporous nanofibres significantly improved dye loading and light scattering of the DSSC photoanode, and resulted in conversion cell efficiency of 8.14%, corresponding to an ∼35% enhancement over the Degussa P25 reference photoanode.

  8. Sensitivity of early-life-stage golden trout to low pH and elevated aluminum

    International Nuclear Information System (INIS)

    DeLonay, A.J.; Little, E.E.; Woodward, F.; Brumbaugh, W.G.; Farag, A.M.; Rabeni, C.F.

    1993-01-01

    Early-life-stage golden trout (Oncorhynchus aguabonita) were exposed to acid and Al to examine the response and determine the sensitivity of a western, alpine salmonid to conditions simulating an episodic pH depression. Freshly fertilized eggs, alevins, and swim-up larvae were exposed for 7 d to one of 12 combinations of pH and Al, and surviving fish were held to 40 d post-hatch to determine the effect of exposure on subsequent survival and recovery. Golden trout are sensitive to conditions simulating episodic acidification events typically observed in the field. Significant mortality occurred when the pH of test waters was below 5.0 in the absence of Al or when pH was 5.5 in the presence of 100 μg/L total Al. Behavioral impairments were sensitive indicators of low pH and Al stress. Impaired locomotory and feeding behavior occurred at pH 5.5 without Al and at Al concentrations ≥ μg/L. In contrast, growth, RNA-to-DNA ratio, and whole-body ion concentration were relatively less sensitive indicators of sublethal acid and Al stress

  9. Using Eggshell in Acid Orange 2 Dye Removal from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Yari

    2015-05-01

    Full Text Available Background and purpose: Generated dye wastewater by the textile industry is usually toxic, non-biodegradable and resistant in the environment. Eggshell is one of the inexpensive material and for the reason the vesicular structures can be used as a proper adsorbent for pollutants removal. The aim of this study is to investigate the efficiency of eggshell for removal of acid orange 2 dye from aqueous solution. Materials and Methods: In the experimental study was determined the efficacy of variant variables such as contact time (15, 30, 60, 90 and 120 min, pH (3, 7 and 11, adsorbent dose (10, 25, 50 and 75 g/L, and initial dye concentration (25, 50 and 100 mg/L. The concentration of dye by spectrophotometer ultraviolet/visible in the wavelength 483 nm was examined. Results: The results showed that with increasing contact time and adsorbent dose, the dye removal efficiency was increased, but with increasing pH and initial dye concentration the removal efficiency was decreased. The maximum of removal efficiency of acid orange 2 dye got in the optimum pH: 3, contact time: 90 min, adsorbent dose: 50 g/L and initial dye concentration: 25 mg/L. Adsorption of acid orange 2 dye (R2 = 0.87 follow the Freundlich isotherm. Conclusion: Eggshells can be used as an inexpensive and effective adsorbent for the removal of acid orange 2 dye.

  10. Measuring interstitial pH and pO2 in mouse tumors.

    Science.gov (United States)

    Jain, Rakesh K; Munn, Lance L; Fukumura, Dai

    2013-07-01

    This protocol outlines methods to measure two extravascular parameters, interstitial pH and partial pressure of oxygen (pO2), in mouse tumors. The method for measuring interstitial pH uses fluorescence ratio imaging microscopy (FRIM) of the pH-sensitive fluorescent dye 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF). The method for measuring interstitial pO2 is based on the oxygen-dependent quenching of the phosphorescence of albumin-bound palladium meso-tetra(4-carboxyphenyl)porphyrin, and can be used to measure microvascular as well as interstitial pO2. In addition, the two methods can be used sequentially to measure both pH and pO2 in the same tissues.

  11. Adsorption Equilibrium and Kinetics of Gardenia Blue on TiO2 Photoelectrode for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Tae-Young Kim

    2014-01-01

    Full Text Available Nanostructured porous TiO2 paste was deposited on the FTO conductive glass using squeeze printing technique in order to obtain a TiO2 thin film with a thickness of 10 μm and an area of 4 cm2. Gardenia blue (GB extracted from Gardenia jasminode Ellis was employed as the natural dye for a dye-sensitized solar cell (DSSC. Adsorption studies indicated that the maximum adsorption capacity of GB on the surface of TiO2 thin film was approximately 417 mg GB/g TiO2 photoelectrode. The commercial and natural dyes, N-719 and GB, respectively, were employed to measure the adsorption kinetic data, which were analyzed by pseudo-first-order and pseudo-second-order models. The energy conversion efficiency of the TiO2 electrode with successive adsorptions of GB dye was about 0.2%.

  12. Fabrication and Characterization of Sansevieria trifasciata, Pandanus amaryllifolius and Cassia angustifolia as Photosensitizer for Dye Sensitized Solar Cells

    International Nuclear Information System (INIS)

    Cari; Supriyanto, Agus; Fadli, Ulfa Mahfudli; Prasada, Ashari Bayu

    2016-01-01

    Dye sensitized Solar Cells (DSSC) is one of the electric cells photochemical consisting of photoelectrode, dye, counter electrode, and electrolyte. The aims of the research to determine of the optical and electrical characteristic of the extract Sansevieria trifasciata, Pandanus amaryllifolius, and Cassia angustifolia. The study is also aimed to determine the effect of natural dyes extract to increase the efficiency of solar cells based DSSC. Sandwich structures formed in the sample consisted of working electrode pair Titanium dioxide (TiO 2 ) and the counter electrode platinum (Pt). Dye extraction process is performed by stirring for 1 hour and then allowed to stand for 24 hours. Absorbance test is measure by using UV-Vis spectrophotometer Lambda 25, conductivity test by using a two-point probes Elkahfi 100, and characterization of current and voltage (I-V) by using a Keithley 2602A. The results showed that the greatest efficiency of 0.160% at Dye Pandanus amaryllifolius. (paper)

  13. Fabrication and Characterization of Sansevieria trifasciata, Pandanus amaryllifolius and Cassia angustifolia as Photosensitizer for Dye Sensitized Solar Cells

    Science.gov (United States)

    Cari; Supriyanto, Agus; Mahfudli Fadli, Ulfa; Bayu Prasada, Ashari

    2016-04-01

    Dye sensitized Solar Cells (DSSC) is one of the electric cells photochemical consisting of photoelectrode, dye, counter electrode, and electrolyte. The aims of the research to determine of the optical and electrical characteristic of the extract Sansevieria trifasciata, Pandanus amaryllifolius, and Cassia angustifolia. The study is also aimed to determine the effect of natural dyes extract to increase the efficiency of solar cells based DSSC. Sandwich structures formed in the sample consisted of working electrode pair Titanium dioxide (TiO2) and the counter electrode platinum (Pt). Dye extraction process is performed by stirring for 1 hour and then allowed to stand for 24 hours. Absorbance test is measure by using UV-Vis spectrophotometer Lambda 25, conductivity test by using a two-point probes Elkahfi 100, and characterization of current and voltage (I-V) by using a Keithley 2602A. The results showed that the greatest efficiency of 0.160% at Dye Pandanus amaryllifolius.

  14. Hydrothermal synthesis of hierarchical WO{sub 3} nanostructures for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rashad, M.M. [Central Metallurgical Research and Development Institute (CMRDI), Helwan, P.O. Box 87, Cairo (Egypt); Shalan, A.E. [Central Metallurgical Research and Development Institute (CMRDI), Helwan, P.O. Box 87, Cairo (Egypt); Friedrich-Alexander-University of Erlangen-Nuremberg, Institute of Materials for Electronics and Energy Technology (i-MEET), Erlangen (Germany)

    2014-08-15

    Hierarchical architectures consisting of one-dimensional (1D) nanostructures are of great interest for potential use in energy and environmental applications in recent years. In this work, hierarchical tungsten oxide (WO{sub 3}) has been synthesized via a facile hydrothermal route from ammonium metatungstate hydrate and implemented as photoelectrode for dye-sensitized solar cells. The urchin-like WO{sub 3} micro-patterns are constructed by self-organized nanoscale length 1D building blocks, which are single crystalline in nature, grown along (001) direction and confirm an orthorhombic crystal phase. The obtained powders were investigated by XRD, SEM, TEM and UV-Vis Spectroscopy. The photovoltaic performance of dye-sensitized solar cells based on WO{sub 3} photoanodes was investigated. With increasing the calcination temperature of the prepared nanopowders, the light-electricity conversion efficiency (η) was increased. The results were attributed to increase the crystallinity of the particles and ease of electron movement. The DSSC based on hierarchical WO{sub 3} showed a short-circuit current, an open-circuit voltage, a fill factor, and a conversion efficiency of 4.241 mA/cm{sup 2}, 0.656 V, 66.74, and 1.85 %, respectively. (orig.)

  15. Improving the photovoltaic performance of dye-sensitized solar cell by graphene/titania photoanode

    International Nuclear Information System (INIS)

    Zhao, Junchang; Wu, Jihuai; Zheng, Ming; Huo, Jinghao; Tu, Yongguang

    2015-01-01

    Highlights: • A colloid of graphene/titania is prepared, and thus a graphene/titania film is made. • The film shows high porosity, large surface area and small transfer resistance. • The cell with graphene/titania photoanode obtains a conversion efficiency of 7.52%. • Which is increased by 18% compared to the cell with pristine titania electrode. - Abstract: A mixed colloid of graphene and titania is synthesized by a one-step hydrothermal reaction, thus a graphene/titania film photoanode is prepared. The graphene/titania film shows high porosity and large specific surface area, which favors a full adsorption of sensitized dye. On the other hand, the graphene/titania electrode has smaller charge transfer resistance than the pristine titania electrode, which replies that the graphene/titania electrode accelerates electronic transportation and suppresses the charge recombination. Under an optimal condition, the dye-sensitized solar cell based on graphene/titania photoanode achieve a power conversion efficiency of 7.52%, which is increased by 17.7% compared to the cell based on the pristine titania electrode under a simulated solar light irradiation of 100 mW·cm −2

  16. Exploring the critical dependence of adsorption of various dyes on the degradation rate using Ln3+-TiO2 surface under UV/solar light

    International Nuclear Information System (INIS)

    Devi, L. Gomathi; Kumar, S. Girish

    2012-01-01

    Graphical abstract: The surface reactive acidic sites enhances on doping with rare earth ions which facilitates efficient adsorption of the dye molecules on the catalyst surface. In addition, the nature of the dopant, its concentration and electronic configuration additionally contributes to the overall efficiency. Highlights: ► The degradation of structurally different anionic dyes under different pH conditions is reported. ► Pre adsorption of pollutant on catalyst surface is vital for efficient photocatalysis. ► Adsorption of dye on the catalyst surface depends on the substituent's attached to it. ► The dopant with half filled electronic configuration served as shallow traps for charge carriers. - Abstract: The degradation of structurally different anionic dyes like Alizarin Red S (ARS) Amaranth (AR), Brilliant Yellow (BY), Congo Red (CR), Fast Red (FR), Methyl Orange (MO), and Methyl Red (MR) were carried out using Ln 3+ (Ln 3+ = La 3+ , Ce 3+ and Gd 3+ ) doped TiO 2 at different pH conditions under UV/solar light. All the anionic dyes underwent rapid degradation at acidic pH, while resisted at alkaline conditions due to the adsorptive tendency of these dyes on the catalyst surface at different pH conditions. Gd 3+ (0.15 mol%)-TiO 2 exhibited better activity compared to other photocatalyst ascribed to half filled electronic configuration of Gd 3+ ions. It is proposed that Ln 3+ serves only as charge carrier traps under UV light, while it also act as visible light sensitizers under solar light. Irrespective of the catalyst and excitation source, the dye degradation followed the order: AR > FR > MO > MR > ARS > BY > CR. The results suggest that pre-adsorption of the pollutant is vital for efficient photocatalysis which is dependent on the nature of the substituent's group attached to the dye molecule.

  17. Removal of dyes using immobilized titanium dioxide illuminated by fluorescent lamps

    International Nuclear Information System (INIS)

    Zainal, Zulkarnain; Hui, Lee Kong; Hussein, Mohd Zobir; Taufiq-Yap, Yun Hin; Abdullah, Abdul Halim; Ramli, Irmawati

    2005-01-01

    The photodegradation of various dyes in aqueous solution was studied. Experiments were carried out using glass coated titanium dioxide thin film as photocatalyst. Photodegradation processes of methylene blue (MB), methyl orange (MO), indigo carmine (IC), chicago sky blue 6B (CSB), and mixed dye (MD, mixture of the four mentioned single dye) were reported. As each photodegradation system is pH dependent, the photodegradation experiment was carried out in each dye photodegradation reactive pH range at ∼28 deg C. The dyes removal efficiency was studied and compared using UV-vis spectrophotometer analysis. The total removal of each dye was: methylene blue (90.3%), methyl orange (98.5%), indigo carmine (92.4%), chicago sky blue 6B (60.3%), and mixed dyes (70.1%), respectively. The characteristic of the photocatalyst was investigated using X-ray diffractometer (XRD). The amount of each dye intermediate produced in the photodegradation process was also determined with the help of total organic carbon (TOC) analysis

  18. Three dimensional graphene transistor for ultra-sensitive pH sensing directly in biological media

    International Nuclear Information System (INIS)

    Ameri, Shideh Kabiri; Singh, Pramod K.; Sonkusale, Sameer R.

    2016-01-01

    In this work, pH sensing directly in biological media using three dimensional liquid gated graphene transistors is presented. The sensor is made of suspended network of graphene coated all around with thin layer of hafnium oxide (HfO_2), showing high sensitivity and sensing beyond the Debye-screening limit. The performance of the pH sensor is validated by measuring the pH of isotonic buffered, Dulbecco's phosphate buffered saline (DPBS) solution, and of blood serum derived from Sprague-Dawley rat. The pH sensor shows high sensitivity of 71 ± 7 mV/pH even in high ionic strength media with molarities as high as 289 ± 1 mM. High sensitivity of this device is owing to suspension of three dimensional graphene in electrolyte which provides all around liquid gating of graphene, leading to higher electrostatic coupling efficiency of electrolyte to the channel and higher gating control of transistor channel by ions in the electrolyte. Coating graphene with hafnium oxide film (HfO_2) provides binding sites for hydrogen ions, which results in higher sensitivity and sensing beyond the Debye-screening limit. The 3D graphene transistor offers the possibility of real-time pH measurement in biological media without the need for desaltation or sample preparation. - Graphical abstract: (a) Test setup – Direct rat blood serum pH measurements (b) Measured transfer characteristics of the transistor for blood serum at different pH values, and (c) Zoomed in version around direct point. - Highlights: • A three-dimensional graphene transistor for pH sensing is presented. • It shows sensitivity of 71 ± 7 mV/pH even in high ionic strength media. • High sensitivity attributed to 3D foam structure and all-around liquid gating. • Enables real-time pH sensing in biological media without need of desaltation.

  19. Three dimensional graphene transistor for ultra-sensitive pH sensing directly in biological media

    Energy Technology Data Exchange (ETDEWEB)

    Ameri, Shideh Kabiri; Singh, Pramod K.; Sonkusale, Sameer R., E-mail: sameer@ece.tufts.edu

    2016-08-31

    In this work, pH sensing directly in biological media using three dimensional liquid gated graphene transistors is presented. The sensor is made of suspended network of graphene coated all around with thin layer of hafnium oxide (HfO{sub 2}), showing high sensitivity and sensing beyond the Debye-screening limit. The performance of the pH sensor is validated by measuring the pH of isotonic buffered, Dulbecco's phosphate buffered saline (DPBS) solution, and of blood serum derived from Sprague-Dawley rat. The pH sensor shows high sensitivity of 71 ± 7 mV/pH even in high ionic strength media with molarities as high as 289 ± 1 mM. High sensitivity of this device is owing to suspension of three dimensional graphene in electrolyte which provides all around liquid gating of graphene, leading to higher electrostatic coupling efficiency of electrolyte to the channel and higher gating control of transistor channel by ions in the electrolyte. Coating graphene with hafnium oxide film (HfO{sub 2}) provides binding sites for hydrogen ions, which results in higher sensitivity and sensing beyond the Debye-screening limit. The 3D graphene transistor offers the possibility of real-time pH measurement in biological media without the need for desaltation or sample preparation. - Graphical abstract: (a) Test setup – Direct rat blood serum pH measurements (b) Measured transfer characteristics of the transistor for blood serum at different pH values, and (c) Zoomed in version around direct point. - Highlights: • A three-dimensional graphene transistor for pH sensing is presented. • It shows sensitivity of 71 ± 7 mV/pH even in high ionic strength media. • High sensitivity attributed to 3D foam structure and all-around liquid gating. • Enables real-time pH sensing in biological media without need of desaltation.

  20. Electrochemical Properties of Cu(II/I)-Based Redox Mediators for Dye-Sensitized Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Saygili, Y.; Freitag, M.; Zakeeruddin, S. M.; Hagfeldt, A.; Grätzel, M.

    2017-01-01

    Roč. 227, FEB 2017 (2017), s. 194-202 ISSN 0013-4686 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : Graphene * Dye sensitized solar cell * Cu-complexes Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 4.798, year: 2016

  1. Time dependent – density functional theory characterization of organic dyes for dye-sensitized solar cells

    KAUST Repository

    Hilal, Rifaat; Aziz, Saadullah G.; Osman, Osman I.; Bredas, Jean-Luc

    2017-01-01

    We aim at providing better insight into the parameters that govern the intramolecular charge transfer (ICT) and photo-injection processes in dyes for dye-sensitised solar cells (DSSC). Density functional theory (DFT) and time-dependent DFT (TD

  2. Efficiency enhancement using voltage biasing for ferroelectric polarization in dye-sensitized solar cells

    Science.gov (United States)

    Kim, Sangmo; Song, Myoung Geun; Bark, Chung Wung

    2018-01-01

    Dye-sensitized solar cells (DSSCs) are one of the most promising third generation solar cells that have been extensively researched over the past decade as alternative to silicon-based solar cells, due to their low production cost and high energy-conversion efficiency. In general, a DSSC consists of a transparent electrode, a counter electrode, and an electrolyte such as dye. To achieve high power-conversion efficiency in cells, many research groups have focused their efforts on developing efficient dyes for liquid electrolytes. In this work, we report on the photovoltaic properties of DSSCs fabricated using a mixture of TiO2 with nanosized Fe-doped bismuth lanthanum titanate (nFe-BLT) powder). Firstly, nFe-BLT powders were prepared using a high-energy ball milling process and then, TiO2 and nFe-BLT powders were stoichiometrically blended. Direct current (DC) bias of 20 MV/m was applied to lab-made DSSCs. With the optimal concentration of nFe-BLT doped in the electrode, their light-to-electricity conversion efficiency could be improved by ∼64% compared with DSSCs where no DC bias was applied.

  3. Aplikasi Semikonduktor TiO2 dengan Variasi Temperatur dan Waktu Tahan Kalsinasi sebagai Dye Sensitized Solar Cell (DSSC dengan Dye dari Ekstrak Buah Terung Belanda (Solanum betaceum

    Directory of Open Access Journals (Sweden)

    Maula Nafi

    2013-03-01

    Full Text Available Penelitian mengenai dye sensitized solar cell dilakukan dengan dye dari ekstrak buah terung belanda sebagai sumber energi alternatif dari tenaga surya. Dye sensitized solar cell (DSSC dibuat dengan menggunakan semikonduktor TiO2 yang dilapiskan pada kaca konduktif Fluorine Doped Tin Oxide (FTO dan dikalsinasi  dengan variasi temperatur 5500C, 6500C, dan 7500C, dengan waktu tahan 60 dan 120 menit pada tiap temperaturnya. Lapisan TiO2 pada substrat dikarakterisasi dengan menggunakan SEM dan XRD. Luas permukaan aktif diukur dengan pengujian BET. Hasil SEM menunjukkan ukuran bentuk partikel TiO2 berupa sphere. Hasil XRD menunjukkan struktur kristal TiO2 adalah body centered tetragonal. Luas permukaan aktif dibandingkan dengan hasil kelistrikan DSSC, yang selaras meningkat dari temperatur 5500C ke 6500C, namun menurun pada 7500C. Densitas arus dan voltase maksimum diperoleh pada variasi temperatur 650oC dengan waktu tahan 60 menit yaitu sebesar 0,356 mA/cm2 dan 593,1 mV. Efisiensi maksimum yang diperoleh sebesar 0,469208%. DSSC dimodifikasi dengan menambahkan pembungkus plastik, sehingga dapat memperlambat penurunan daya yang terjadi saat DSSC bekerja.

  4. Lessons learned: from dye-sensitized solar cells to all-solid-state hybrid devices.

    Science.gov (United States)

    Docampo, Pablo; Guldin, Stefan; Leijtens, Tomas; Noel, Nakita K; Steiner, Ullrich; Snaith, Henry J

    2014-06-25

    The field of solution-processed photovoltaic cells is currently in its second spring. The dye-sensitized solar cell is a widely studied and longstanding candidate for future energy generation. Recently, inorganic absorber-based devices have reached new record efficiencies, with the benefits of all-solid-state devices. In this rapidly changing environment, this review sheds light on recent developments in all-solid-state solar cells in terms of electrode architecture, alternative sensitizers, and hole-transporting materials. These concepts are of general applicability to many next-generation device platforms. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Hydrazone based molecular glasses for solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Aich, R.; Tran-Van, F.; Goubard, F.; Beouch, L.; Michaleviciute, A.; Grazulevicius, J.V.; Ratier, B.; Chevrot, C.

    2008-01-01

    Biscarbazole and terthiophene based molecular glasses with hydrazone functional goups (named respectively 2CzMPH and 3TDPH) have been synthesized and the thermal, optical and electrochemical properties have been studied. Differential scanning calorimetry characterizations confirm the metastable amorphous properties of these molecules with glass transition temperatures at 80 deg. C for the 3TDPH and 93 deg. C for the 2CzMPH. Their electrochemical properties have been studied and showed the effect of the conjugated hydrazone groups on the electronic delocalization of the structures. The concept of solid state dye-sensitized solar cells using hydrazone based molecular glasses has been verified with the elaboration of a SnO 2 : F/nc-TiO 2 /Ru-dye/2CzMPH /Au devices. Under full sunlight (98 mW/cm 2 , air mass 1.5) the I-V characterization of the device give a short circuit photocurrents I sc = 0.42 mA/cm 2 , open circuit voltage V oc = 500 mV with a fill factor of 0.35

  6. Hydrazone based molecular glasses for solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Aich, R. [Laboratoire de Physicochimie des Polymeres et des Interfaces (EA 2528), Universite de Cergy-Pontoise, 5 mail Gay Lussac, 95031 Cergy Pontoise (France); Ecole Electricite de Production et Methodes Industrielles, Cergy Pontoise (France); Tran-Van, F. [Laboratoire de Physicochimie des Polymeres et des Interfaces (EA 2528), Universite de Cergy-Pontoise, 5 mail Gay Lussac, 95031 Cergy Pontoise (France)], E-mail: francois.tran-van@u-cergy.fr; Goubard, F.; Beouch, L. [Laboratoire de Physicochimie des Polymeres et des Interfaces (EA 2528), Universite de Cergy-Pontoise, 5 mail Gay Lussac, 95031 Cergy Pontoise (France); Michaleviciute, A.; Grazulevicius, J.V. [Department of Organic Technology, Kaunas University of Technology, Radvilenu Plentas 19, Kaunas LT-50254 (Lithuania); Ratier, B. [X-LIM., departement MINACOM, UMR 6172, Faculte des Sciences, 123 av. Albert Thomas 87060 Limoges cedex France (France); Chevrot, C. [Laboratoire de Physicochimie des Polymeres et des Interfaces (EA 2528), Universite de Cergy-Pontoise, 5 mail Gay Lussac, 95031 Cergy Pontoise (France)

    2008-08-30

    Biscarbazole and terthiophene based molecular glasses with hydrazone functional goups (named respectively 2CzMPH and 3TDPH) have been synthesized and the thermal, optical and electrochemical properties have been studied. Differential scanning calorimetry characterizations confirm the metastable amorphous properties of these molecules with glass transition temperatures at 80 deg. C for the 3TDPH and 93 deg. C for the 2CzMPH. Their electrochemical properties have been studied and showed the effect of the conjugated hydrazone groups on the electronic delocalization of the structures. The concept of solid state dye-sensitized solar cells using hydrazone based molecular glasses has been verified with the elaboration of a SnO{sub 2}: F/nc-TiO{sub 2}/Ru-dye/2CzMPH /Au devices. Under full sunlight (98 mW/cm{sup 2}, air mass 1.5) the I-V characterization of the device give a short circuit photocurrents I{sub sc} = 0.42 mA/cm{sup 2}, open circuit voltage V{sub oc} = 500 mV with a fill factor of 0.35.

  7. Nitrogen-Doped Graphene/Platinum Counter Electrodes for Dye-Sensitized Solar Cells

    KAUST Repository

    Lin, Chinan

    2014-12-17

    Nitrogen-doped graphene (NGR) was utilized in dye-sensitized solar cells for energy harvesting. NGR on a Pt-sputtered fluorine-doped tin oxide substrate (NGR/Pt/FTO) as counter electrodes (CEs) achieves the high efficiency of 9.38% via the nitrogen doping into graphene. This is due to (i) the hole-cascading transport at the interface of electrolyte/CEs via controlling the valence band maximum of NGR located between the redox potential of the I-/I- redox couple and the Fermi level of Pt by nitrogen doping, (ii) the extended electron transfer surface effect provided by large-surface-area NGR, (iii) the high charge transfer efficiency due to superior catalytic characteristics of NGR via nitrogen doping, and (iv) the superior light-reflection effect of NGR/Pt/FTO CEs, facilitating the electron transfer from CEs to I3 - ions of the electrolyte and light absorption of dye. The result demonstrated that the NGR/Pt hybrid structure is promising in the catalysis field. (Chemical Presented). © 2014 American Chemical Society.

  8. A cell-surface-anchored ratiometric fluorescent probe for extracellular pH sensing.

    Science.gov (United States)

    Ke, Guoliang; Zhu, Zhi; Wang, Wei; Zou, Yuan; Guan, Zhichao; Jia, Shasha; Zhang, Huimin; Wu, Xuemeng; Yang, Chaoyong James

    2014-09-10

    Accurate sensing of the extracellular pH is a very important yet challenging task in biological and clinical applications. This paper describes the development of an amphiphilic lipid-DNA molecule as a simple yet useful cell-surface-anchored ratiometric fluorescent probe for extracellular pH sensing. The lipid-DNA probe, which consists of a hydrophobic diacyllipid tail and a hydrophilic DNA strand, is modified with two fluorescent dyes; one is pH-sensitive as pH indicator and the other is pH-insensitive as an internal reference. The lipid-DNA probe showed sensitive and reversible response to pH change in the range of 6.0-8.0, which is suitable for most extracellular studies. In addition, based on simple hydrophobic interactions with the cell membrane, the lipid-DNA probe can be easily anchored on the cell surface with negligible cytotoxicity, excellent stability, and unique ratiometric readout, thus ensuring its accurate sensing of extracellular pH. Finally, this lipid-DNA-based ratiometric pH indicator was successfully used for extracellular pH sensing of cells in 3D culture environment, demonstrating the potential applications of the sensor in biological and medical studies.

  9. Transition Metal Polypyridine Complexes: Studies of Mediation in Dye-Sensitized Solar Cells and Charge Separation

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, C. Michael [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry; Prieto, Amy L. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry

    2017-02-08

    The Elliott group has long been supported by DOE for studies of cobalt(II/III) trisbypiridine (DTB) mediator complexes in dye sensitized solar cells. Previous work demonstrated that Co(II/III) chemistry is sensitive to the environment, showing unprecedented electrode-surface and electrolyte dependant voltammetry. In electrolytes that have large lipophilic cations, voltammetry of the [Co(DTB)3]2+/3+ couple is nearly Nernstian in appearance on nominally oxide-free metal surfaces. In contrast, on semiconductor electrodes in electrolytes with small, hard cations such as Li+, the electron transfer rates are so slow that it is difficult to measure any Faradaic current even at overpotentials of ±1 V. These studies are of direct relevance to the operation of cobalt-based mediators in solar cells. The research has also shown that these mediators are compatible with copper phenantroline based dyes, in contrast to I- due to the insolubility of CuI.

  10. In-situ Decolorization of Residual Dye Effluent in Textile Jet Dyeing Machine by Ozone

    Directory of Open Access Journals (Sweden)

    Irfan Ahmed Shaikh

    2014-12-01

    Full Text Available In this study, a new idea of decolourization was investigated in which residual dyeing effluent from textile dyeing process was treated using O3 in the same machine where it was generated. The novelty comes from the idea of doing dyeing and treatment simultaneously. At the completion of dyeing process, O3 gas was injected directly into the machine to remove colour and COD from the wastewater. To evaluate the effectiveness of new method, pilot-scale studies were performed, and decolourization of residual dyeing effluents containing C.I. Reactive Orange 7, C.I. Reactive Blue 19, and C.I. Reactive Black 5 was carried out in specially built textile jet dyeing machine. The results showed that almost 100% colour removal and 90% COD reduction were achieved when process conditions such as pH, dye concentration (mg/L, ozone production rate (g/hr, and temperature were optimized. The study concludes that new method has a great potential to eliminate the need of a separate end-of-the-pipe wastewater treatment system, thus offering an on-site and cost-effective solution.

  11. Label-Free Carbon-Dots-Based Ratiometric Fluorescence pH Nanoprobes for Intracellular pH Sensing.

    Science.gov (United States)

    Shangguan, Jingfang; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Xu, Fengzhou; Liu, Jinquan; Tang, Jinlu; Yang, Xue; Huang, Jin

    2016-08-02

    Measuring pH in living cells is of great importance for better understanding cellular functions as well as providing pivotal assistance for early diagnosis of diseases. In this work, we report the first use of a novel kind of label-free carbon dots for intracellular ratiometric fluorescence pH sensing. By simple one-pot hydrothermal treatment of citric acid and basic fuchsin, the carbon dots showing dual emission bands at 475 and 545 nm under single-wavelength excitation were synthesized. It is demonstrated that the fluorescence intensities of the as-synthesized carbon dots at the two emissions are pH-sensitive simultaneously. The intensity ratio (I475 nm/I545 nm) is linear against pH values from 5.2 to 8.8 in buffer solution, affording the capability as ratiometric probes for intracellular pH sensing. It also displays that the carbon dots show excellent reversibility and photostability in pH measurements. With this nanoprobe, quantitative fluorescence imaging using the ratio of two emissions (I475 nm/I545 nm) for the detection of intracellular pH were successfully applied in HeLa cells. In contrast to most of the reported nanomaterials-based ratiometric pH sensors which rely on the attachment of additional dyes, these carbon-dots-based ratiometric probes are low in toxicity, easy to synthesize, and free from labels.

  12. Current distribution evaluation of dye-sensitized solar cell using HTS-SQUID-based magnetic measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Kenji, E-mail: Sakai-k@okayama-u.ac.jp; Tanaka, Kohei; Kiwa, Toshihiko; Tsukada, Keiji

    2016-11-15

    Highlights: • Current distribution and direction of dye-sensitized solar cell (DSSC) was measured. • Electrical current flowing in the indium tin oxide (ITO) glass substrate was uniform. • The distribution of electrical current depended on I–V characteristic. • Current direction changed when the performance of DSSC is low. - Abstract: The current flowing inside a dye-sensitized solar cell (DSSC) was measured using a high-temperature superconductor superconducting quantum interference device (HTS-SQUID)-based magnetic measurement system. Further, a new evaluation method of the DSSC, which is difficult to measure using the conventional method, was investigated to improve the characteristics of the DSSC. The tangential components of the magnetic field generated from the DSSC were measured using two HTS-SQUIDs, and the intensity and direction related to the electrical current were obtained by the measured magnetic field. The DSSCs prepared with different dyes and catalytic substances showed different current-intensity mapping. The current direction was different for the DSSC with low performance. In addition, the current flowing in the ITO layer of the ITO glass substrate was also measured and the results confirmed that it had uniform distribution. These results show that the current mapping and the direction of the electrical current depend on the internal factors of the DSSC, and the detection of the magnetic field distribution generated from it is expected to lead to its new evaluation method.

  13. Electrodeposited Nanoporous versus Nanoparticulate ZnO Films of Similar Roughness for Dye-Sensitized Solar Cell Applications

    Czech Academy of Sciences Publication Activity Database

    Guerin, V. M.; Magne, C.; Pauporté, T.; Le Bahers, T.; Rathouský, Jiří

    2010-01-01

    Roč. 2, č. 12 (2010), s. 3677-3685 ISSN 1944-8244 Institutional research plan: CEZ:AV0Z40400503 Keywords : ZnO * dye sensitized solar cells * electrodeposition Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.925, year: 2010

  14. Annealing effects of ZnO nanorods on dye-sensitized solar cell efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jooyoung; Lee, Juneyoung [Department of Chemical and Biomolecular Engineering, Yonsei University, 134 Shinchon-dong, Seodaemoon-gu, Seoul 120-749 (Korea, Republic of); Lim, Sangwoo, E-mail: swlim@yonsei.ac.k [Department of Chemical and Biomolecular Engineering, Yonsei University, 134 Shinchon-dong, Seodaemoon-gu, Seoul 120-749 (Korea, Republic of)

    2010-06-01

    Dye-sensitized solar cells (DSSCs) were fabricated using ZnO nanorod arrays vertically grown on fluorine-doped tin oxide (FTO) glass using a low-temperature hydrothermal method. When the ZnO seed layer was annealed, greater DSSC efficiency was obtained. This may be attributed to the improvement of adhesion between the FTO and the seed layer and the corresponding effective growth of the ZnO nanorods. The DSSCs fabricated using ZnO nanorods which underwent annealing were more efficient than those that did not undergo annealing. The ZnO nanorods which were annealed in N{sub 2}/H{sub 2} or O{sub 2} had increased dye loadings due to higher OH concentrations on the hydrophilic surface, which contributed to the improved DSSC efficiency. The fill factor increased after the annealing of the ZnO nanorods, potentially due to the improved crystallinity of the ZnO nanorods. In this study, annealing of both the seed layer and the ZnO nanorods resulted in the greatest DSSC efficiency.

  15. Influence of Different Surface Modifications on the Photovoltaic Performance and Dark Current of Dye-Sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    XU Weiwei; DAI Songyuan; HU Linhua; ZHANG Changneng; XIAO Shangfeng; LUO Xiangdong; JING Weiping; WANG Kongjia

    2007-01-01

    The TiO2 nanoporous film photoelectrode, as a crucial component of dye-sensitized solar cells, has been investigated. The photovoltaic properties and the dark current were studied by two surface modification methods. One was to apply a compact layer between the conductive glass substrate and nanoporous TiO2 film. Another was to produce TiO2 nanoparticles among the microstructure by TiCU treatment. A suitable concentration and number of times for TiCU treatment were found in our experiment. The dark current is suppressed by surface modifications, leading to a significant improvement in the solar cells performance. An excessive concentration of TiCU will produce more surface states and introduce a larger dark current reversely. The dye is also regarded as a source of charge recombination in dark to some extent, due to an amount of surface protonations introduced by the interfacial link in the conductive glass substrate/dye interface and dye/TiO2 interface.

  16. Solid-state dye-sensitized solar cells based on ZnO nanoparticle and nanorod array hybrid photoanodes

    Directory of Open Access Journals (Sweden)

    Sue Hung-Jue

    2011-01-01

    Full Text Available Abstract The effect of ZnO photoanode morphology on the performance of solid-state dye-sensitized solar cells (DSSCs is reported. Four different structures of dye-loaded ZnO layers have been fabricated in conjunction with poly(3-hexylthiophene. A significant improvement in device efficiency with ZnO nanorod arrays as photoanodes has been achieved by filling the interstitial voids of the nanorod arrays with ZnO nanoparticles. The overall power conversion efficiency increases from 0.13% for a nanorod-only device to 0.34% for a device with combined nanoparticles and nanorod arrays. The higher device efficiency in solid-state DSSCs with hybrid nanorod/nanoparticle photoanodes is originated from both large surface area provided by nanoparticles for dye adsorption and efficient charge transport provided by the nanorod arrays to reduce the recombinations of photogenerated carriers.

  17. Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

    International Nuclear Information System (INIS)

    Franzi, J.J.

    1985-01-01

    Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal

  18. Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Franzi, J.J.

    1985-01-01

    Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal.

  19. Effects of gamma irradiation on the degradation of dyes

    International Nuclear Information System (INIS)

    Piccinini, N.; Ferrero, F.

    1975-01-01

    To investigate the degradation kinetics of aqueous solutions of dyes of several classes, we studied the effects of gamma irradiation versus the dose (up to 80 krad), the dye concentration, the pH and the oxygen content of these solutions. To study the influence of some of the above-mentioned parameters, anthraquinonic dyes have been irradiated in a wide range of doses (up to 5 Mrad). Furthermore these dyes were acted upon in order to investigate the complex reactions of molecular alteration through chromatographic separations and spectrophotometric analyses. Experimental results agreed with a first order kinetics for dye concentrations lower than 0.04 g/1, and with a zero order one for higher concentrations. The pH was found to have a different influence according to the type of dye; for example we found that the degradation efficiency for anthraquinonic dyes has higher values for basic ranges. The dissolved oxygen supports the degradation in comparison with de-aerated solutions, though its influence varies according to the dye type and the pH. The oxygen action is particularly evident with high doses; in fact, tests on anthraquinonic dyes with doses up to 5 Mrad showed a marked decrease in the kinetic constants caused by the oxygen disappearance. Radiochemical degradation yields (Gd), never greater than a few units, show that the radical reactions responsible for the decolorization effect, are limited to a few transfer sequences. COD decrease, on the other hand, confirms the presence of oxidation phenomena which correspond to computed radiochemical yields (Gsub(ox)) markedly higher than those spectrophotometrically measured; such a difference is enhanced in the case of irradiation with aeration of solutions. The theoretical considerations are also described that were developed for outlining a general scheme involving the experimental results of both the kinetics and the radiochemical yield. (author)

  20. Mesoporous multi-shelled ZnO microspheres for the scattering layer of dye sensitized solar cell with a high efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Weiwei; Mei, Chao; Zeng, Xianghua, E-mail: xhzeng@yzu.edu.cn; Wu, Guoqing; Shen, Xiaoshuang [College of Physics Science and Technology and Institute of Optoelectronic Technology, Yangzhou University, Yangzhou 225002 (China); Chang, Shuai [Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)

    2016-03-14

    Both light scattering and dye adsorbing are important for the power conversion efficiency PCE performance of dye sensitized solar cell (DSSC). Nanostructured scattering layers with a large specific surface area are regarded as an efficient way to improve the PCE by increasing dye adsorbing, but excess adsorbed dye will hinder light scattering and light penetration. Thus, how to balance the dye adsorbing and light penetration is a key problem to improve the PCE performance. Here, multiple-shelled ZnO microspheres with a mesoporous surface are fabricated by a hydrothermal method and are used as scattering layers on the TiO{sub 2} photoanode of the DSSC in the presence of N719 dye and iodine–based electrolyte, and the results reveal that the DSSCs based on triple shelled ZnO microsphere with a mesoporous surface exhibit an enhanced PCE of 7.66%, which is 13.0% higher than those without the scattering layers (6.78%), indicating that multiple-shelled microspheres with a mesoporous surface can ensure enough light scattering between the shells, and a favorable concentration of the adsorbed dye can improve the light penetration. These results may provide a promising pathway to obtain the high efficient DSSCs.