WorldWideScience

Sample records for cascade solar cells

  1. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.

    2011-09-27

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  2. Efficient cascade multiple heterojunction organic solar cells with inverted structure

    Science.gov (United States)

    Guo, Tingting; Li, Mingtao; Qiao, Zhenfang; Yu, Leiming; Zhao, Jianhong; Feng, Nianjun; Shi, Peiguang; Wang, Xiaoyan; Pu, Xiaoyun; Wang, Hai

    2018-05-01

    In this work, we demonstrate an efficient cascade multiple heterojunction organic solar cell with inverted structure. By using two donor materials, poly(3-hexylthiosphene) (P3HT) and titanyl phthalocyanine (TiOPc), as well as two acceptor materials, [6,6]-phenyl C61 butyric acid methyl ester (PCBM) and C60, the cascade multiple heterojunctions of P3HT:PCBM/TiOPc:C60/C60 have been constructed. Applying the optimized inverted configuration of FTO/Zinc Tin Oxide (ZTO)/C60 (30 nm)/TiOPc:C60 (1:1.5, 25 nm)/P3HT:PCBM (1:0.8, 100 nm)/MoO3 (4 nm)/Ag, the considerably enhanced open circuit voltage (VOC) and short circuit current (JSC) can be harvested together, and the power conversion efficiency (PCE) is three times higher than that of the control cell with conventional structure. The significant improvements of the inverted cell are mostly due to the broadened spectral absorption and high efficient multi-interface exciton dissociation in the cascade multiple heterojunctions, indicating that the optimized cascade heterojunctions match the inverted structure well.

  3. Design of cascaded low cost solar cell with CuO substrate

    International Nuclear Information System (INIS)

    Samson, Mil'shtein; Anup, Pillai; Shiv, Sharma; Garo, Yessayan

    2013-01-01

    For many years the main focus of R and D in solar cells was the development of high-efficiency solar convertors. However with solar technology beginning to be a part of national grids and stand-alone power supplies for variety of individual customers, the emphasis has changed, namely, the cost per kilowatt- hour (kW-hr) started to be an important figure of merit. Although Si does dominate the market of solar convertors, this material has total cost of kilowatt-hour much higher than what the power grid is providing presently to customers. It is well known that the cost of raw semiconductor material is a major factor in formulation of the final cost of a solar cell. That motivated us to search and design a novel solar cell using cheap materials. The new p-i-n solar cell consists of hetero-structure cascade of materials with step by step decreasing energy gap. Since the lattice constant of these three materials do differ not more than 2%, the more expensive epitaxial fabrication methods can be used as well. It should be emphasized that designed solar cell is not a cascade of three solar cells connected in series. Our market study shows that Si solar panel which costs $250–400 / m 2 leads to a cost of $0.12–0.30 / kW-hr. To the contrary, CuO based solar cells with Cadmium compounds on top, would cost $100 / m 2 . This will allow the novel solar cell to produce electricity at a cost of $0.06–0.08 / kW-hr

  4. Design of cascaded low cost solar cell with CuO substrate

    Energy Technology Data Exchange (ETDEWEB)

    Samson, Mil' shtein; Anup, Pillai; Shiv, Sharma; Garo, Yessayan [Advanced Electronic Technology Center, ECE Dept., University of Massachusetts, Lowell, MA-01851 (United States)

    2013-12-04

    For many years the main focus of R and D in solar cells was the development of high-efficiency solar convertors. However with solar technology beginning to be a part of national grids and stand-alone power supplies for variety of individual customers, the emphasis has changed, namely, the cost per kilowatt- hour (kW-hr) started to be an important figure of merit. Although Si does dominate the market of solar convertors, this material has total cost of kilowatt-hour much higher than what the power grid is providing presently to customers. It is well known that the cost of raw semiconductor material is a major factor in formulation of the final cost of a solar cell. That motivated us to search and design a novel solar cell using cheap materials. The new p-i-n solar cell consists of hetero-structure cascade of materials with step by step decreasing energy gap. Since the lattice constant of these three materials do differ not more than 2%, the more expensive epitaxial fabrication methods can be used as well. It should be emphasized that designed solar cell is not a cascade of three solar cells connected in series. Our market study shows that Si solar panel which costs $250–400 / m{sup 2} leads to a cost of $0.12–0.30 / kW-hr. To the contrary, CuO based solar cells with Cadmium compounds on top, would cost $100 / m{sup 2}. This will allow the novel solar cell to produce electricity at a cost of $0.06–0.08 / kW-hr.

  5. Design of cascaded low cost solar cell with CuO substrate

    Science.gov (United States)

    Samson, Mil'shtein; Anup, Pillai; Shiv, Sharma; Garo, Yessayan

    2013-12-01

    For many years the main focus of R&D in solar cells was the development of high-efficiency solar convertors. However with solar technology beginning to be a part of national grids and stand-alone power supplies for variety of individual customers, the emphasis has changed, namely, the cost per kilowatt- hour (kW-hr) started to be an important figure of merit. Although Si does dominate the market of solar convertors, this material has total cost of kilowatt-hour much higher than what the power grid is providing presently to customers. It is well known that the cost of raw semiconductor material is a major factor in formulation of the final cost of a solar cell. That motivated us to search and design a novel solar cell using cheap materials. The new p-i-n solar cell consists of hetero-structure cascade of materials with step by step decreasing energy gap. Since the lattice constant of these three materials do differ not more than 2%, the more expensive epitaxial fabrication methods can be used as well. It should be emphasized that designed solar cell is not a cascade of three solar cells connected in series. Our market study shows that Si solar panel which costs 250-400 / m2 leads to a cost of 0.12-0.30 / kW-hr. To the contrary, CuO based solar cells with Cadmium compounds on top, would cost 100 / m2. This will allow the novel solar cell to produce electricity at a cost of 0.06-0.08 / kW-hr.

  6. Cascading metallic gratings for broadband absorption enhancement in ultrathin plasmonic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Long; Sun, Fuhe [Key Laboratory of Nanodevices and Applications-CAS and Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123 (China); Chen, Qin, E-mail: qchen2012@sinano.ac.cn [Key Laboratory of Nanodevices and Applications-CAS and Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123 (China); Peking University Shenzhen SOC Key Laboratory, PKU-HKUST Shenzhen-Hong Kong Institute, Hi-Tech Industrial Park South, Shenzhen 518057 (China)

    2014-04-14

    The incorporation of plasmonic nanostructures in the thin-film solar cells (TFSCs) is a promising route to harvest light into the nanoscale active layer. However, the light trapping scheme based on the plasmonic effects intrinsically presents narrow-band resonant enhancement of light absorption. Here we demonstrate that by cascading metal nanogratings with different sizes atop the TFSCs, broadband absorption enhancement can be realized by simultaneously exciting multiple localized surface plasmon resonances and inducing strong coupling between the plasmonic modes and photonic modes. As a proof of concept, we demonstrate of 66.5% in the photocurrent in an ultrathin amorphous silicon TFSC with two-dimensional cascaded gratings over the reference cell without gratings.

  7. Cascading metallic gratings for broadband absorption enhancement in ultrathin plasmonic solar cells

    International Nuclear Information System (INIS)

    Wen, Long; Sun, Fuhe; Chen, Qin

    2014-01-01

    The incorporation of plasmonic nanostructures in the thin-film solar cells (TFSCs) is a promising route to harvest light into the nanoscale active layer. However, the light trapping scheme based on the plasmonic effects intrinsically presents narrow-band resonant enhancement of light absorption. Here we demonstrate that by cascading metal nanogratings with different sizes atop the TFSCs, broadband absorption enhancement can be realized by simultaneously exciting multiple localized surface plasmon resonances and inducing strong coupling between the plasmonic modes and photonic modes. As a proof of concept, we demonstrate of 66.5% in the photocurrent in an ultrathin amorphous silicon TFSC with two-dimensional cascaded gratings over the reference cell without gratings

  8. Interband Cascade Photovoltaic Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui Q. [Univ. of Oklahoma, Norman, OK (United States); Santos, Michael B. [Univ. of Oklahoma, Norman, OK (United States); Johnson, Matthew B. [Univ. of Oklahoma, Norman, OK (United States)

    2014-09-24

    In this project, we are performing basic and applied research to systematically investigate our newly proposed interband cascade (IC) photovoltaic (PV) cells [1]. These cells follow from the great success of infrared IC lasers [2-3] that pioneered the use of quantum-engineered IC structures. This quantum-engineered approach will enable PV cells to efficiently convert infrared radiation from the sun or other heat source, to electricity. Such cells will have important applications for more efficient use of solar energy, waste-heat recovery, and power beaming in combination with mid-infrared lasers. The objectives of our investigations are to: achieve extensive understanding of the fundamental aspects of the proposed PV structures, develop the necessary knowledge for making such IC PV cells, and demonstrate prototype working PV cells. This research will focus on IC PV structures and their segments for utilizing infrared radiation with wavelengths from 2 to 5 μm, a range well suited for emission by heat sources (1,000-2,000 K) that are widely available from combustion systems. The long-term goal of this project is to push PV technology to longer wavelengths, allowing for relatively low-temperature thermal sources. Our investigations address material quality, electrical and optical properties, and their interplay for the different regions of an IC PV structure. The tasks involve: design, modeling and optimization of IC PV structures, molecular beam epitaxial growth of PV structures and relevant segments, material characterization, prototype device fabrication and testing. At the end of this program, we expect to generate new cutting-edge knowledge in the design and understanding of quantum-engineered semiconductor structures, and demonstrate the concepts for IC PV devices with high conversion efficiencies.

  9. Cascaded Ga1-xAlxAs/GaAs solar cell with graded i-region

    Science.gov (United States)

    Mil'shtein, Sam; Halilov, Samed

    2018-02-01

    In current study we designed p-i-n junction with extended intrinsic layer, where linearly graded Alx Ga1-x As presents variable energy gap so needed for effective harvesting of sun radiation. The design realization involves two regions of compositional structure in the stacking direction. The top AlxGa1-xAs layer of 1 um total thickness has stoichiometric structure x=0.3-0.2d, where depth d runs from 0 to 1 um, topmost 200 nm of which is Be-doped. Bottom AlxGa1-xAs layer of 3 um total thickness has a variable composition of x=0.133-0.033d, d runs from 1 to 4 um, the very bottom of which with 10 nm thickness is Si-doped. On the top surface, there is a 50 nm layer of p+ doped GaAs as a spacer for growing AuGe/Ni anode electrode of 20% surface area, the bottom is coated with AuGe/Ni cathode electrode. The designed cell demonstrates 89% fill factor and 30% conversion efficiency without anti-reflection coating.

  10. An inverted AlGaAs/GaAs patterned-Ge tunnel junction cascade concentrator solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Venkatasubramanian, R. (Research Triangle Inst., Research Triangle Park, NC (United States))

    1993-01-01

    This report describes work to develop inverted-grown Al[sub 0.34]Ga[sub 0.66]As/GaAs cascades. Several significant developments are reported on as follows: (1) The AM1.5 1-sun total-area efficiency of the top Al[sub 0.34]Ga[sub 0.66]As cell for the cascade was improved from 11.3% to 13.2% (NREL measurement [total-area]). (2) The cycled'' organometallic vapor phase epitaxy growth (OMVPE) was studied in detail utilizing a combination of characterization techniques including Hall-data, photoluminescence, and secondary ion mass spectroscopy. (3) A technique called eutectic-metal-bonding (EMB) was developed by strain-free mounting of thin GaAs-AlGaAs films (based on lattice-matched growth on Ge substrates and selective plasma etching of Ge substrates) onto Si carrier substrates. Minority-carrier lifetime in an EMB GaAs double-heterostructure was measured as high as 103 nsec, the highest lifetime report for a freestanding GaAs thin film. (4) A thin-film, inverted-grown GaAs cell with a 1-sun AM1.5 active-area efficiency of 20.3% was obtained. This cell was eutectic-metal-bonded onto Si. (5) A thin-film inverted-grown, Al[sub 0.34]Ga[sub 0.66]As/GaAs cascade with AM1.5 efficiency of 19.9% and 21% at 1-sun and 7-suns, respectively, was obtained. This represents an important milestone in the development of an AlGaAs/GaAs cascade by OMVPE utilizing a tunnel interconnect and demonstrates a proof-of-concept for the inverted-growth approach.

  11. A cascaded QSAR model for efficient prediction of overall power conversion efficiency of all-organic dye-sensitized solar cells.

    Science.gov (United States)

    Li, Hongzhi; Zhong, Ziyan; Li, Lin; Gao, Rui; Cui, Jingxia; Gao, Ting; Hu, Li Hong; Lu, Yinghua; Su, Zhong-Min; Li, Hui

    2015-05-30

    A cascaded model is proposed to establish the quantitative structure-activity relationship (QSAR) between the overall power conversion efficiency (PCE) and quantum chemical molecular descriptors of all-organic dye sensitizers. The cascaded model is a two-level network in which the outputs of the first level (JSC, VOC, and FF) are the inputs of the second level, and the ultimate end-point is the overall PCE of dye-sensitized solar cells (DSSCs). The model combines quantum chemical methods and machine learning methods, further including quantum chemical calculations, data division, feature selection, regression, and validation steps. To improve the efficiency of the model and reduce the redundancy and noise of the molecular descriptors, six feature selection methods (multiple linear regression, genetic algorithms, mean impact value, forward selection, backward elimination, and +n-m algorithm) are used with the support vector machine. The best established cascaded model predicts the PCE values of DSSCs with a MAE of 0.57 (%), which is about 10% of the mean value PCE (5.62%). The validation parameters according to the OECD principles are R(2) (0.75), Q(2) (0.77), and Qcv2 (0.76), which demonstrate the great goodness-of-fit, predictivity, and robustness of the model. Additionally, the applicability domain of the cascaded QSAR model is defined for further application. This study demonstrates that the established cascaded model is able to effectively predict the PCE for organic dye sensitizers with very low cost and relatively high accuracy, providing a useful tool for the design of dye sensitizers with high PCE. © 2015 Wiley Periodicals, Inc.

  12. Solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, Moriaki; Hayashibara, Mitsuo

    1988-08-18

    Concerning the exsisting solar cell utilizing wavelength transition, the area of the solar cell element necessary for unit electric power output can be made small, but transition efficiency of the solar cell as a whole including a plastic plate with phosphor is not high. This invention concerns a solar cell which is appropriate for transferring the light within a wide spectrum range of the sunlight to electricilty efficiently, utilizes wavelength transition and has high efficiency per unit area. In other words, the solar cell of this invention has the feature of providing in parallel with a photoelectric transfer layer a layer of wavelength transitioning material (phosphor) which absorbs the light within the range of wavelength of low photoelectric transfer efficiency at the photoelectric transfer layer and emits the light within the range of wavelength in which the photoelectric transfer rate is high on the light incident side of the photoelectric transfer layer. (5 figs)

  13. Cascading pressure reactor and method for solar-thermochemical reactions

    Science.gov (United States)

    Ermanoski, Ivan

    2017-11-14

    Reactors and methods for solar thermochemical reactions are disclosed. The reactors and methods include a cascade of reduction chambers at successively lower pressures that leads to over an order of magnitude pressure decrease compared to a single-chambered design. The resulting efficiency gains are substantial, and represent an important step toward practical and efficient solar fuel production on a large scale.

  14. Solar cells

    International Nuclear Information System (INIS)

    1980-01-01

    A method of producing solar cells is described which consists of producing a substantially monocrystalline tubular body of silicon or other suitable semiconductor material, treating this body to form an annular rectifying junction and then cutting it longitudinally to form a number of nearly flat ribbons from which the solar cells are fabricated. The P=N rectifying junction produced by the formation of silicon dioxide on the layers at the inner and outer surfaces of the body can be formed by ion-implantation or diffusion. (U.K.)

  15. Ternary Nonfullerene Polymer Solar Cells with 12.16% Efficiency by Introducing One Acceptor with Cascading Energy Level and Complementary Absorption.

    Science.gov (United States)

    Jiang, Weigang; Yu, Runnan; Liu, Zhiyang; Peng, Ruixiang; Mi, Dongbo; Hong, Ling; Wei, Qiang; Hou, Jianhui; Kuang, Yongbo; Ge, Ziyi

    2018-01-01

    A novel small-molecule acceptor, (2,2'-((5E,5'E)-5,5'-((5,5'-(4,4,9,9-tetrakis(5-hexylthiophen-2-yl)-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-2,7-diyl)bis(4-(2-ethylhexyl)thiophene-5,2-diyl))bis(methanylylidene)) bis(3-hexyl-4-oxothiazolidine-5,2-diylidene))dimalononitrile (ITCN), end-capped with electron-deficient 2-(3-hexyl-4-oxothiazolidin-2-ylidene)malononitrile groups, is designed, synthesized, and used as the third component in fullerene-free ternary polymer solar cells (PSCs). The cascaded energy-level structure enabled by the newly designed acceptor is beneficial to the carrier transport and separation. Meanwhile, the three materials show a complementary absorption in the visible region, resulting in efficient light harvesting. Hence, the PBDB-T:ITCN:IT-M ternary PSCs possess a high short-circuit current density (J sc ) under an optimal weight ratio of donors and acceptors. Moreover, the open-circuit voltage (V oc ) of the ternary PSCs is enhanced with an increase of the third acceptor ITCN content, which is attributed to the higher lowest unoccupied molecular orbital energy level of ITCN than that of IT-M, thus exhibits a higher V oc in PBDB-T:ITCN binary system. Ultimately, the ternary PSCs achieve a power conversion efficiency of 12.16%, which is higher than the PBDB-T:ITM-based PSCs (10.89%) and PBDB-T:ITCN-based ones (2.21%). This work provides an effective strategy to improve the photovoltaic performance of PSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wendel, W.

    1977-03-03

    A solar collector is described. The absorber consists of a plate onto which the light is focussed through lenses. The heat is transported from the absorber to the heat accumulator via metallic heat conductors. In case of insufficient solar radiation, the heat transport from the collector to the accumulator may be interrupted by a disconnecting switch. The casing consists of Eternit.

  17. Experimental and theoretical study of cascade solar stills in Iran

    International Nuclear Information System (INIS)

    Tabrizi, F.F.; Sharak, A.Z.

    2009-01-01

    Due to low annual rainfall, most of Iran is dominated by arid and semi-arid areas. The solar radiation intensity is extremely high in most of the country. The need to produce fresh water from brackish water is considerably high, especially in dry regions. Desalination of brackish water may become a competitive potential water resource to meet potable water demand, and as the price of oil goes higher, using solar energy for water desalinisation becomes more economical. This paper presented a study that involved mathematical modeling of the first solar still in Iran. The cumulative fresh water production and water temperature were calculated as a function of time. The obtained results were verified by one month daily-based experimental data. The paper also provided background information on the Koshk village, situated in the south part of Iran near Badar Abbas city. Various investigations regarding meteorological conditions, economical considerations, and technical and operational appropriateness demonstrated that the cascade solar still is suitable for desalination of brackish water. 100 solar stills were installed at the site to provide potable water for a nearby village. It was concluded that the model could be used to simulate and optimize the effective design parameters in future studies. 6 refs., 7 figs

  18. Design Mining Microbial Fuel Cell Cascades

    OpenAIRE

    Preen, Richard J.; You, Jiseon; Bull, Larry; Ieropoulos, Ioannis A.

    2016-01-01

    Microbial fuel cells (MFCs) perform wastewater treatment and electricity production through the conversion of organic matter using microorganisms. For practical applications, it has been suggested that greater efficiency can be achieved by arranging multiple MFC units into physical stacks in a cascade with feedstock flowing sequentially between units. In this paper, we investigate the use of computational intelligence to physically explore and optimise (potentially) heterogeneous MFC designs ...

  19. OBSERVING CASCADES OF SOLAR BULLETS AT HIGH RESOLUTION. II

    Energy Technology Data Exchange (ETDEWEB)

    Scullion, E.; Engvold, O.; Lin, Y.; Voort, L. Rouppe van der, E-mail: scullie@tcd.ie [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, NO-0315 Oslo (Norway)

    2015-12-01

    High resolution observations from the Swedish 1-m Solar Telescope revealed bright, discrete, blob-like structures (which we refer to as solar bullets) in the Hα 656.28 nm line core that appear to propagate laterally across the solar atmosphere as clusters in active regions (ARs). These small-scale structures appear to be field aligned and many bullets become triggered simultaneously and traverse collectively as a cluster. Here, we conduct a follow-up study on these rapidly evolving structures with coincident observations from the Solar Dynamics Observatory/Atmospheric Imaging Assembly. With the co-aligned data sets, we reveal (a) an evolving multithermal structure in the bullet cluster ranging from chromospheric to at least transition region temperatures, (b) evidence for cascade-like behavior and corresponding bidirectional motions in bullets within the cluster, which indicate that there is a common source of the initial instability leading to bullet formation, and (c) a direct relationship between co-incident bullet velocities observed in Hα and He ii 30.4 nm and an inverse relationship with respect to bullet intensity in these channels. We find evidence supporting that bullets are typically composed of a cooler, higher density core detectable in Hα with a less dense, hotter, and fainter co-moving outer sheath. Bullets unequivocally demonstrate the finely structured nature of the AR corona. We have no clear evidence for bullets being associated with locally heated (or cooled), fast flowing plasma. Fast MHD pulses (such as solitons) could best describe the dynamic properties of bullets whereas the presence of a multithermal structure is new.

  20. Nanostructured Organic Solar Cells

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Rubahn, Horst-Günter; Madsen, Morten

    Recent forecasts for alternative energy generation predict emerging importance of supporting state of art photovoltaic solar cells with their organic equivalents. Despite their significantly lower efficiency, number of application niches are suitable for organic solar cells. This work reveals...... the principles of bulk heterojunction organic solar cells fabrication as well as summarises major differences in physics of their operation....

  1. Solar cells based on gallium antimonide

    International Nuclear Information System (INIS)

    Andreev, V. M.; Sorokina, S. V.; Timoshina, N. Kh.; Khvostikov, V. P.; Shvarts, M. Z.

    2009-01-01

    Liquid-phase epitaxy and diffusion from the gas phase have been used to create various kinds of GaSb-based solar cell structures intended for use in cascaded solar-radiation converters. A narrow-gap (GaSb) solar cell was studied in tandem based on a combination of semiconductors GaAs-GaSb (two p-n junctions) and GaInP/GaAs-GaSb (three p-n junctions). The maximum efficiency of photovoltaic conversion in GaSb behind the wide-gap cells is η = 6.5% (at sunlight concentration ratio of 275X, AM1.5D Low AOD spectrum).

  2. Solar cell concentrating system

    International Nuclear Information System (INIS)

    Garg, H.P.; Sharma, V.K.; Agarwal, R.K.

    1986-11-01

    This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

  3. Photovoltaic solar cell

    Science.gov (United States)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  4. Quantum cascade laser infrared spectroscopy of single cancer cells

    KAUST Repository

    Patel, Imran

    2017-03-27

    Quantum cascade laser infrared spectroscopy is a next generation novel imaging technique allowing high resolution spectral imaging of cells. We show after spectral pre-processing, identification of different cancer cell populations within minutes.

  5. Solar cell shingle

    Science.gov (United States)

    Forestieri, A. F.; Ratajczak, A. F.; Sidorak, L. G. (Inventor)

    1977-01-01

    A solar cell shingle was made of an array of solar cells on a lower portion of a substantially rectangular shingle substrate made of fiberglass cloth or the like. The solar cells may be encapsulated in flourinated ethylene propylene or some other weatherproof translucent or transparent encapsulant to form a combined electrical module and a roof shingle. The interconnected solar cells were connected to connectors at the edge of the substrate through a connection to a common electrical bus or busses. An overlap area was arranged to receive the overlap of a cooperating similar shingle so that the cell portion of the cooperating shingle may overlie the overlap area of the roof shingle. Accordingly, the same shingle serves the double function of an ordinary roof shingle which may be applied in the usual way and an array of cooperating solar cells from which electrical energy may be collected.

  6. Hybrid Modulation Scheme for Cascaded H-Bridge Inverter Cells ...

    African Journals Online (AJOL)

    This work proposes a switching technique for cascaded H-Bridge (CHB) cells. Single carrier Sinusoidal PWM (SCSPWM) scheme is employed in the generation of the gating signals. A sequential switching and base PWM circulation schemes are presented for this fundamental cascaded multilevel inverter topology.

  7. Rectenna solar cells

    CERN Document Server

    Moddel, Garret

    2013-01-01

    Rectenna Solar Cells discusses antenna-coupled diode solar cells, an emerging technology that has the potential to provide ultra-high efficiency, low-cost solar energy conversion. This book will provide an overview of solar rectennas, and provide thorough descriptions of the two main components: the diode, and the optical antenna. The editors discuss the science, design, modeling, and manufacturing of the antennas coupled with the diodes. The book will provide concepts to understanding the challenges, fabrication technologies, and materials required to develop rectenna structures. Written by e

  8. Quantum dot solar cells

    CERN Document Server

    Wu, Jiang

    2013-01-01

    The third generation of solar cells includes those based on semiconductor quantum dots. This sophisticated technology applies nanotechnology and quantum mechanics theory to enhance the performance of ordinary solar cells. Although a practical application of quantum dot solar cells has yet to be achieved, a large number of theoretical calculations and experimental studies have confirmed the potential for meeting the requirement for ultra-high conversion efficiency. In this book, high-profile scientists have contributed tutorial chapters that outline the methods used in and the results of variou

  9. Solar cell array interconnects

    Science.gov (United States)

    Carey, Paul G.; Thompson, Jesse B.; Colella, Nicolas J.; Williams, Kenneth A.

    1995-01-01

    Electrical interconnects for solar cells or other electronic components using a silver-silicone paste or a lead-tin (Pb-Sn) no-clean fluxless solder cream, whereby the high breakage of thin (copper strips which are secured to the solar cells by a silver-silicone conductive paste which can be used at room temperature, or by a Pb-Sn solder cream which eliminates undesired residue on the active surfaces of the solar cells. Electrical testing using the interconnects of this invention has shown that no degradation of the interconnects developed under high current testing, while providing a very low contact resistance value.

  10. Solar cell radiation handbook

    Science.gov (United States)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  11. Conjugated Polymer Solar Cells

    National Research Council Canada - National Science Library

    Paraschuk, Dmitry Y

    2006-01-01

    This report results from a contract tasking Moscow State University as follows: Conjugated polymers are promising materials for many photonics applications, in particular, for photovoltaic and solar cell devices...

  12. Photovoltaic solar cell

    Science.gov (United States)

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

    2013-11-26

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  13. Experimental study of a cascade solar still coupled with a humidification–dehumidification system

    International Nuclear Information System (INIS)

    Farshchi Tabrizi, Farshad; Khosravi, Meisam; Shirzaei Sani, Iman

    2016-01-01

    Graphical abstract: In this study, coupling of a cascade solar still with a humidification–dehumidification system investigated experimentally. In addition, the effects of different operating conditions and configurations on thermal performance and productivity of the under investigation solar system were studied. - Highlights: • We investigate coupling of a cascade solar still with a humidification–dehumidification system. • The effects of different operating conditions on thermal performance were studied. • Temperature and flow rate of feed water as well as air process flow rate had undeniable effects on the productivity. • Coupling several CSS systems with just one HD system to maximize the productivity. • Enhancing daily productivity of coupling system from 28% to 141% for 40–150 ml/min flow rates, respectively. - Abstract: In this study, coupling of a cascade solar still with a humidification–dehumidification system was investigated experimentally under the climatological conditions of Zahedan (Latitude: 29.49, Longitude: 60.87), Iran. The inclined solar stills produce distillated and hot water simultaneously. In addition, the effects of different operating conditions and configurations on thermal performance and productivity of the solar system were studied. The effect of feed water and air flow rates on the daily productivity of HD system in different conditions such as feed water temperature has been investigated. The daily productivity of cascade solar still with and without HD system at different flow rates is investigated. Moreover, the end result of assembling the HD system with a cascade solar still was studied. The daily productivity of the system increases from 28% to 141% in the presence of humidification–dehumidification system. It also improves the thermal efficiency from 9% to 20% after using 40–150 ml/min of flow rate, respectively. The maximum productivity and efficiency were 5.4 kg/m 2 day and 39% for minimum flow rate.

  14. Nanocrystal Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gur, Ilan [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    This dissertation presents the results of a research agenda aimed at improving integration and stability in nanocrystal-based solar cells through advances in active materials and device architectures. The introduction of 3-dimensional nanocrystals illustrates the potential for improving transport and percolation in hybrid solar cells and enables novel fabrication methods for optimizing integration in these systems. Fabricating cells by sequential deposition allows for solution-based assembly of hybrid composites with controlled and well-characterized dispersion and electrode contact. Hyperbranched nanocrystals emerge as a nearly ideal building block for hybrid cells, allowing the controlled morphologies targeted by templated approaches to be achieved in an easily fabricated solution-cast device. In addition to offering practical benefits to device processing, these approaches offer fundamental insight into the operation of hybrid solar cells, shedding light on key phenomena such as the roles of electrode-contact and percolation behavior in these cells. Finally, all-inorganic nanocrystal solar cells are presented as a wholly new cell concept, illustrating that donor-acceptor charge transfer and directed carrier diffusion can be utilized in a system with no organic components, and that nanocrystals may act as building blocks for efficient, stable, and low-cost thin-film solar cells.

  15. Iron sulphide solar cells

    Science.gov (United States)

    Ennaoui, A.; Tributsch, H.

    1984-12-01

    The abundant, naturally occurring natural compound pyrite (FeS2) can be used as a semiconducting material for photoelectrochemical and photovoltaic solar cells. Unlike most of the intensively studied photoactive materials, pyrite solar cell production would never be limited by the availability of the elements or by their compatibility with the environment. An energy gap of 0.95 eV has been determined for pyrite, and it is noted that the theoretical efficiency limit for solar energy conversion in this material is of the order of 15-20 percent.

  16. Four-cell solar tracker

    Science.gov (United States)

    Berdahl, C. M.

    1981-01-01

    Forty cm Sun tracker, consisting of optical telescope and four solar cells, stays pointed at Sun throughout day for maximum energy collection. Each solar cell generates voltage proportional to part of solar image it receives; voltages drive servomotors that keep image centered. Mirrored portion of cylinder extends acquisition angle of device by reflecting Sun image back onto solar cells.

  17. Perovskite Solar Cell

    Indian Academy of Sciences (India)

    Organic–inorganic halide perovskite, a newcomerin the solar cell industry has proved its potential forincreasing efficiency rapidly from 3.8% in 2009 to 22.1% in2016. High efficiency, flexibility, and cell architecture of theemerging hybrid halide perovskite have caught the attentionof researchers and technologists in the field.

  18. Characterization of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, J.; Tuominen, E.; Nybergh, K.; Ezer, Y.; Yli-Koski, M.; Sinkkonen, J. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Electrical and Communications Engineering

    1998-10-01

    Photovoltaic research in the Electron Physics Laboratory started in 1993, when laboratory joined the national TEKES/NEMO 2 research program. Since the beginning of the project, characterization as well as experimentally orientated development of the fabrication process of the solar cells were carried out parallery. The process development research started by the initiatives of the Finnish industry. At the moment a large amount of the laboratory personnel works on solar cell research and the financing comes mainly from external projects. The funding for the research has come from TEKES, Ministry of Education, Finnish Academy, GETA graduate school, special equipment grants of the university, and from the laboratory

  19. Anisotropic third-moment estimates of the energy cascade in solar wind turbulence using multispacecraft data.

    Science.gov (United States)

    Osman, K T; Wan, M; Matthaeus, W H; Weygand, J M; Dasso, S

    2011-10-14

    The first direct determination of the inertial range energy cascade rate, using an anisotropic form of Yaglom's law for magnetohydrodynamic turbulence, is obtained in the solar wind with multispacecraft measurements. The two-point mixed third-order structure functions of Elsässer fluctuations are integrated over a sphere in magnetic field-aligned coordinates, and the result is consistent with a linear scaling. Therefore, volume integrated heating and cascade rates are obtained that, unlike previous studies, make only limited assumptions about the underlying spectral geometry of solar wind turbulence. These results confirm the turbulent nature of magnetic and velocity field fluctuations in the low frequency limit, and could supply the energy necessary to account for the nonadiabatic heating of the solar wind.

  20. Solution-Processed Nanocrystal Quantum Dot Tandem Solar Cells

    KAUST Repository

    Choi, Joshua J.

    2011-06-03

    Solution-processed tandem solar cells created from nanocrystal quantum dots with size-tuned energy levels are demonstrated. Prototype devices featuring interconnected quantum dot layers of cascaded energy gaps exhibit IR sensitivity and an open circuit voltage, V oc, approaching 1 V. The tandem solar cell performance depends critically on the optical and electrical properties of the interlayer. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. NASA Facts, Solar Cells.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    The design and function of solar cells as a source of electrical power for unmanned space vehicles is described in this pamphlet written for high school physical science students. The pamphlet is one of the NASA Facts Science Series (each of which consists of four pages) and is designed to fit in the standard size three-ring notebook. Review…

  2. Nature's Solar Cell

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. Nature's Solar Cell. Stephen Suresh Gautham Nadig. Research News Volume 1 Issue 2 February 1996 pp 102-104. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/02/0102-0104 ...

  3. Emerging Solar Technologies: Perovskite Solar Cell

    Indian Academy of Sciences (India)

    tus of hybrid perovskite solar cells. 1. Introduction. Gradually, primary energy resources such as fossil fuels, coal, and natural gas are depleting, while the global energy consump- tion is increasing. Solar energy, along with wind, biomass, tidal, and geothermal sources is emerging as an answer to our energy- starved planet.

  4. Energy Cascade Rate in Compressible Fast and Slow Solar Wind Turbulence

    International Nuclear Information System (INIS)

    Hadid, L. Z.; Sahraoui, F.; Galtier, S.

    2017-01-01

    Estimation of the energy cascade rate in the inertial range of solar wind turbulence has been done so far mostly within incompressible magnetohydrodynamics (MHD) theory. Here, we go beyond that approximation to include plasma compressibility using a reduced form of a recently derived exact law for compressible, isothermal MHD turbulence. Using in situ data from the THEMIS / ARTEMIS spacecraft in the fast and slow solar wind, we investigate in detail the role of the compressible fluctuations in modifying the energy cascade rate with respect to the prediction of the incompressible MHD model. In particular, we found that the energy cascade rate (1) is amplified particularly in the slow solar wind; (2) exhibits weaker fluctuations in spatial scales, which leads to a broader inertial range than the previous reported ones; (3) has a power-law scaling with the turbulent Mach number; (4) has a lower level of spatial anisotropy. Other features of solar wind turbulence are discussed along with their comparison with previous studies that used incompressible or heuristic (nonexact) compressible MHD models.

  5. Energy Cascade Rate in Compressible Fast and Slow Solar Wind Turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Hadid, L. Z.; Sahraoui, F.; Galtier, S., E-mail: lina.hadid@lpp.polytechnique.fr [LPP, CNRS, Ecole Polytechnique, UPMC Univ Paris 06, Univ. Paris-Sud, Observatoire de Paris, Université Paris-Saclay, Sorbonne Universités, PSL Research University, F-91128 Palaiseau (France)

    2017-03-20

    Estimation of the energy cascade rate in the inertial range of solar wind turbulence has been done so far mostly within incompressible magnetohydrodynamics (MHD) theory. Here, we go beyond that approximation to include plasma compressibility using a reduced form of a recently derived exact law for compressible, isothermal MHD turbulence. Using in situ data from the THEMIS / ARTEMIS spacecraft in the fast and slow solar wind, we investigate in detail the role of the compressible fluctuations in modifying the energy cascade rate with respect to the prediction of the incompressible MHD model. In particular, we found that the energy cascade rate (1) is amplified particularly in the slow solar wind; (2) exhibits weaker fluctuations in spatial scales, which leads to a broader inertial range than the previous reported ones; (3) has a power-law scaling with the turbulent Mach number; (4) has a lower level of spatial anisotropy. Other features of solar wind turbulence are discussed along with their comparison with previous studies that used incompressible or heuristic (nonexact) compressible MHD models.

  6. Characterization of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, J.; Tuominen, E.; Nybergh, K.; Ezer, Y.; Yli-Koski, M.; Sinkkonen, J. [Helsinki Univ. of Technology (Finland). Dept. of Electrical and Communications Engineering

    1998-12-31

    Photovoltaic research began at the Electron Physics Laboratory of the Helsinki University of Tehnology in 1993, when the laboratory joined the national NEMO 2 research program. During the early stages of the photovoltaic research the main objective was to establish necessary measurement and characterisation routines, as well as to develop the fabrication process. The fabrication process development work has been supported by characterisation and theoretical modelling of the solar cells. Theoretical investigations have been concerned with systematic studies of solar cell parameters, such as diffusion lengths, surface recombination velocities and junction depths. The main result of the modelling and characterisation work is a method which is based on a Laplace transform of the so-called spatial collection efficiency function of the cell. The basic objective of the research has been to develop a fabrication process cheap enough to be suitable for commercial production

  7. Nanostructures for Organic Solar Cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jarosław

    2016-01-01

    The experimental work in this thesis is focused on the fabrication of nanostructures that can be implemented in organic solar cell (OSC) architecture for enhancement of the device performance. Solar devices made from organic material are gaining increased attention, compared to their inorganic...... for organic solar cell applications, opening new patterning possibilities....

  8. Transparent solar cell window module

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Joseph Lik Hang; Chen, Ruei-Tang; Hwang, Gan-Lin; Tsai, Ping-Yuan [Nanopowder and Thin Film Technology Center, ITRI South, Industrial Technology Research Institute, Tainan County 709 (China); Lin, Chien-Chu [I-Lai Acrylic Corporation, Tainan City (China)

    2010-03-15

    A transparent solar cell window module based on the integration of traditional silicon solar cells and organic-inorganic nanocomposite material was designed and fabricated. The transparent solar cell window module was composed of a nanocomposite light-guide plate and traditional silicon solar cells. The preparation of the nanocomposite light-guide plate is easy without modification of the traditional casting process, the nanoparticles sol can be added directly to the polymethyl methacrylate (PMMA) monomer syrup during the process. The solar energy collected by this window can be used to power up small household electrical appliances. (author)

  9. Carbon Nanotube Solar Cells

    OpenAIRE

    Klinger, Colin; Patel, Yogeshwari; Postma, Henk W. Ch.

    2012-01-01

    We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabr...

  10. Silicon heterojunction solar cells

    CERN Document Server

    Fahrner, W R; Neitzert, H C

    2006-01-01

    The world of today must face up to two contradictory energy problems: on the one hand, there is the sharply growing consumer demand in countries such as China and India. On the other hand, natural resources are dwindling. Moreover, many of those countries which still possess substantial gas and oil supplies are politically unstable. As a result, renewable natural energy sources have received great attention. Among these, solar-cell technology is one of the most promising candidates. However, there still remains the problem of the manufacturing costs of such cells. Many attempts have been made

  11. Silicon Solar Cell Turns 50

    Energy Technology Data Exchange (ETDEWEB)

    Perlin, J.

    2004-08-01

    This short brochure describes a milestone in solar (or photovoltaic, PV) research-namely, the 50th anniversary of the invention of the first viable silicon solar cell by three researchers at Bell Laboratories.

  12. Emerging Solar Technologies: Perovskite Solar Cell

    Indian Academy of Sciences (India)

    Organic–inorganic halide perovskite, a newcomerin the solar cell industry has proved its potential forincreasing efficiency rapidly from 3.8% in 2009 to 22.1% in2016. High efficiency, flexibility, and cell architecture of theemerging hybrid halide perovskite have caught the attentionof researchers and technologists in the field.

  13. Emerging Solar Technologies: Perovskite Solar Cell

    Indian Academy of Sciences (India)

    High efficiency, flexibility, and cell architecture of the emerging hybrid halide perovskite have caught the attention of researchers and technologists in the field. This article fo- cuses on the emergence, properties, and current research sta- tus of hybrid perovskite solar cells. 1. Introduction. Gradually, primary energy resources ...

  14. Solar cell materials developing technologies

    CERN Document Server

    Conibeer, Gavin J

    2014-01-01

    This book presents a comparison of solar cell materials, including both new materials based on organics, nanostructures and novel inorganics and developments in more traditional photovoltaic materials. It surveys the materials and materials trends in the field including third generation solar cells (multiple energy level cells, thermal approaches and the modification of the solar spectrum) with an eye firmly on low costs, energy efficiency and the use of abundant non-toxic materials.

  15. Dye solar cell research

    CSIR Research Space (South Africa)

    Cummings, F

    2009-11-01

    Full Text Available Cummings Energy and Processes Materials Science and Manufacturing Council for Scientific and Industrial Research P.O. Box 395 Pretoria 0001, South Africa 27 November 2009 CONTENT head2rightBackground head2rightCSIR Dye Solar Cell Research head2... rightCollaborations and Links © CSIR 2007 www.csir.co.za head2rightAcknowledgements BACKGROUND head2rightSA is dry: Annual rainfall average of 450 mm compared with a world average of 860 mm head2rightOn upside, we have some...

  16. Space Solar Cell Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Measures, characterizes, and analyzes photovoltaic materials and devices. The primary focus is the measurement and characterization of solar cell response...

  17. 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.

  18. Quantum Junction Solar Cells

    KAUST Repository

    Tang, Jiang

    2012-09-12

    Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO 2); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. © 2012 American Chemical Society.

  19. An Arabidopsis kinase cascade influences auxin-responsive cell expansion.

    Science.gov (United States)

    Enders, Tara A; Frick, Elizabeth M; Strader, Lucia C

    2017-10-01

    Mitogen-activated protein kinase (MPK) cascades are conserved mechanisms of signal transduction across eukaryotes. Despite the importance of MPK proteins in signaling events, specific roles for many Arabidopsis MPK proteins remain unknown. Multiple studies have suggested roles for MPK signaling in a variety of auxin-related processes. To identify MPK proteins with roles in auxin response, we screened mpk insertional alleles and identified mpk1-1 as a mutant that displays hypersensitivity in auxin-responsive cell expansion assays. Further, mutants defective in the upstream MAP kinase kinase MKK3 also display hypersensitivity in auxin-responsive cell expansion assays, suggesting that this MPK cascade affects auxin-influenced cell expansion. We found that MPK1 interacts with and phosphorylates ROP BINDING PROTEIN KINASE 1 (RBK1), a protein kinase that interacts with members of the Rho-like GTPases from Plants (ROP) small GTPase family. Similar to mpk1-1 and mkk3-1 mutants, rbk1 insertional mutants display auxin hypersensitivity, consistent with a possible role for RBK1 downstream of MPK1 in influencing auxin-responsive cell expansion. We found that RBK1 directly phosphorylates ROP4 and ROP6, supporting the possibility that RBK1 effects on auxin-responsive cell expansion are mediated through phosphorylation-dependent modulation of ROP activity. Our data suggest a MKK3 • MPK1 • RBK1 phosphorylation cascade that may provide a dynamic module for altering cell expansion. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  20. Down-slope cascading modulated by day/night variations of solar heating

    Directory of Open Access Journals (Sweden)

    Irina P. Chubarenko

    2013-04-01

    Full Text Available Sloping sides of natural basins favour the formation of cross-shore temperature gradients (differential coastal heating/cooling, which cause significant littoral-pelagial water exchange. Autumnal denser water cascading along a sloping lake boundary, modulated by day/night variations of solar heating is considered numerically, in order to reveal the development of the cascading process in time, spatial structure of the exchange flows, and diurnal variations of volumetric flow-rate of littoral-pelagial exchange flow, as well as to compare its daily maxima at different depths/cross-sections, with known quasi-steady state predictions under constant buoyancy flux. The development of exchange flows progress through two phases: i appearance and adjustment to day/night buoyancy flux variations; and ii quasi-steady exchange, when variations of the flow rate in every next diurnal cycle are more or less the same as the previous day. The duration of the first phase depends on local depth (~1 day for depths of about 10 m, ~2 days for depths 15-25 m, and ~5 days down to 30 m for the considered initial linear vertical temperature stratification. Maximum horizontal exchange takes place in the cross-section where the thermocline meets the slope, and the cold down-slope currents detach from the bottom. The location of this cross-section advances off-shore with time, in accordance with the deepening of the upper mixed layer. The existence of a specific coastal circulation cell, with different water dynamics from those above the main part of the slope, is a characteristic feature of horizontal convective exchange. The mean value of the specific volumetric flow rate of the convective exchange, driven by day/night oscillations in its fully developed quasi-steady phase increases almost linearly with local depth, and is about twice as large as the quasi-steady exchange values, predicted by formula Q=0.0013·d1.37 (Q is measured in m2 s-1, and local depth above the

  1. An Introduction to Solar Cells

    Science.gov (United States)

    Feldman, Bernard J.

    2010-01-01

    Most likely, solar cells will play a significant role in this country's strategy to address the two interrelated issues of global warming and dependence on imported oil. The purpose of this paper is to present an explanation of how solar cells work at an introductory high school, college, or university physics course level. The treatment presented…

  2. Thin-film solar cell

    NARCIS (Netherlands)

    Metselaar, J.W.; Kuznetsov, V.I.

    1998-01-01

    The invention relates to a thin-film solar cell provided with at least one p-i-n junction comprising at least one p-i junction which is at an angle alpha with that surface of the thin-film solar cell which collects light during operation and at least one i-n junction which is at an angle beta with

  3. Cascade sensitization of triplet-triplet annihilation based photon upconversion at sub-solar irradiance.

    Science.gov (United States)

    Pedrini, Jacopo; Monguzzi, Angelo; Meinardi, Francesco

    2018-04-03

    In triplet-triplet annihilation based upconversion, high-energy photons are generated through the annihilation of fluorophore triplets, populated via energy transfer from a light-harvesting sensitizer. However, the absorption band of common sensitizers is narrow, limiting the fraction of recoverable photons. We overcome this issue using a third chromophore as an additional light-harvester in the transparency window between the upconverted luminescence and the sensitizer absorption. The third component transfers the extra-collected energy to sensitizers, realizing a cascade-sensitized upconversion that shows a 20% increment of the high-energy photon output and a conversion yield of 10% at solar irradiance.

  4. Upconversion in solar cells

    Science.gov (United States)

    2013-01-01

    The possibility to tune chemical and physical properties in nanosized materials has a strong impact on a variety of technologies, including photovoltaics. One of the prominent research areas of nanomaterials for photovoltaics involves spectral conversion. Modification of the spectrum requires down- and/or upconversion or downshifting of the spectrum, meaning that the energy of photons is modified to either lower (down) or higher (up) energy. Nanostructures such as quantum dots, luminescent dye molecules, and lanthanide-doped glasses are capable of absorbing photons at a certain wavelength and emitting photons at a different (shorter or longer) wavelength. We will discuss upconversion by lanthanide compounds in various host materials and will further demonstrate upconversion to work for thin-film silicon solar cells. PMID:23413889

  5. Photon management in solar cells

    CERN Document Server

    Rau, Uwe; Gombert, Andreas

    2015-01-01

    Written by renowned experts in the field of photon management in solar cells, this one-stop reference gives an introduction to the physics of light management in solar cells, and discusses the different concepts and methods of applying photon management. The authors cover the physics, principles, concepts, technologies, and methods used, explaining how to increase the efficiency of solar cells by splitting or modifying the solar spectrum before they absorb the sunlight. In so doing, they present novel concepts and materials allowing for the cheaper, more flexible manufacture of solar cells and systems. For educational purposes, the authors have split the reasons for photon management into spatial and spectral light management. Bridging the gap between the photonics and the photovoltaics communities, this is an invaluable reference for materials scientists, physicists in industry, experimental physicists, lecturers in physics, Ph.D. students in physics and material sciences, engineers in power technology, appl...

  6. Si Microwire Array Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Putnam, Morgan C.; Boettcher, Shannon W.; Kelzenberg, Michael D.; Turner-Evans, Daniel B.; Spurgeon, Joshua M.; Warren, Emily L.; Briggs, Ryan M.; Lewis, Nathan S.; Atwater, Harry A.

    2010-01-01

    Si microwire-array solar cells with Air Mass 1.5 Global conversion efficiencies of up to 7.9% have been fabricated using an active volume of Si equivalent to a 4 μm thick Si wafer. These solar cells exhibited open-circuit voltages of 500 mV, short-circuit current densities (J{sub sc}) of up to 24 mA cm{sup -2}, and fill factors >65% and employed Al{sub 2}O{sub 3} dielectric particles that scattered light incident in the space between the wires, a Ag back reflector that prevented the escape of incident illumination from the back surface of the solar cell, and an a-SiN{sub x}:H passivation/anti-reflection layer. Wire-array solar cells without some or all of these design features were also fabricated to demonstrate the importance of the light-trapping elements in achieving a high J{sub sc}. Scanning photocurrent microscopy images of the microwire-array solar cells revealed that the higher J{sub sc} of the most advanced cell design resulted from an increased absorption of light incident in the space between the wires. Spectral response measurements further revealed that solar cells with light-trapping elements exhibited improved red and infrared response, as compared to solar cells without light-trapping elements.

  7. MAGNETOHYDRODYNAMIC KINK WAVES IN NONUNIFORM SOLAR FLUX TUBES: PHASE MIXING AND ENERGY CASCADE TO SMALL SCALES

    Energy Technology Data Exchange (ETDEWEB)

    Soler, Roberto; Terradas, Jaume, E-mail: roberto.soler@uib.es [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain)

    2015-04-10

    Magnetohydrodynamic (MHD) kink waves are ubiquitously observed in the solar atmosphere. The propagation and damping of these waves may play relevant roles in the transport and dissipation of energy in the solar atmospheric medium. However, in the atmospheric plasma dissipation of transverse MHD wave energy by viscosity or resistivity needs very small spatial scales to be efficient. Here, we theoretically investigate the generation of small scales in nonuniform solar magnetic flux tubes due to phase mixing of MHD kink waves. We go beyond the usual approach based on the existence of a global quasi-mode that is damped in time due to resonant absorption. Instead, we use a modal expansion to express the MHD kink wave as a superposition of Alfvén continuum modes that are phase mixed as time evolves. The comparison of the two techniques evidences that the modal analysis is more physically transparent and describes both the damping of global kink motions and the building up of small scales due to phase mixing. In addition, we discuss that the processes of resonant absorption and phase mixing are closely linked. They represent two aspects of the same underlying physical mechanism: the energy cascade from large scales to small scales due to naturally occurring plasma and/or magnetic field inhomogeneities. This process may provide the necessary scenario for efficient dissipation of transverse MHD wave energy in the solar atmospheric plasma.

  8. Nanostructuring of Solar Cell Surfaces

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Schmidt, Michael Stenbæk

    Solar energy is by far the most abundant renewable energy source available, but the levelized cost of solar energy is still not competitive with that of fossil fuels. Therefore there is a need to improve the power conversion effciency of solar cells without adding to the production cost. The main...... objective of this PhD thesis is to develop nanostructured silicon (Si) solar cells with higher power conversion efficiency using only scalable and cost-efficient production methods. The nanostructures, known as 'black silicon', are fabricated by single-step, maskless reactive ion etching and used as front...... texturing of different Si solar cells. Theoretically the nanostructure topology may be described as a graded refractive index in a mean-field approximation between air and Si. The optical properties of the developed black Si were simulated and experimentally measured. Total AM1.5G-weighted average...

  9. Dust Removal from Solar Cells

    Science.gov (United States)

    Ashpis, David E. (Inventor)

    2015-01-01

    A solar panel cleaning device includes a solar panel having a plurality of photovoltaic cells arranged in rows and embedded in the solar panel with space between the rows. A transparent dielectric overlay is affixed to the solar panel. A plurality of electrode pairs each of which includes an upper and a lower electrode are arranged on opposite sides of the transparent dielectric and are affixed thereto. The electrodes may be transparent electrodes which may be arranged without concern for blocking sunlight to the solar panel. The solar panel may be a dielectric and its dielectric properties may be continuously and spatially variable. Alternatively the dielectric used may have dielectric segments which produce different electrical field and which affects the wind "generated."

  10. High Efficiency, Deployable Solar Cells

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultrathin, lightweight, flexible, and easily deployable solar cell (SC) capable of specific power greater than 1kW/kg is the target of this development and are at an...

  11. Solar cell module assembly jig

    Science.gov (United States)

    Ofarrell, H. W. (Inventor)

    1966-01-01

    The invention relates to the manufacture of solar cell modules and more particularly to a jig for assembling, positioning and maintaining the components under resilient pressure, while the entire assembly and the jig is subjected to heat for simultaneously soldering all of the various circuit connections; as well as structurally bonding the layers into a strong light weight structure which minimizes the tendency of the solar cells to crack and the other components and electrical connections to fracture.

  12. Solar cell with back side contacts

    Science.gov (United States)

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J; Wanlass, Mark Woodbury; Clews, Peggy J

    2013-12-24

    A III-V solar cell is described herein that includes all back side contacts. Additionally, the positive and negative electrical contacts contact compoud semiconductor layers of the solar cell other than the absorbing layer of the solar cell. That is, the positive and negative electrical contacts contact passivating layers of the solar cell.

  13. Industrial Silicon Wafer Solar Cells

    Directory of Open Access Journals (Sweden)

    Dirk-Holger Neuhaus

    2007-01-01

    Full Text Available In 2006, around 86% of all wafer-based silicon solar cells were produced using screen printing to form the silver front and aluminium rear contacts and chemical vapour deposition to grow silicon nitride as the antireflection coating onto the front surface. This paper reviews this dominant solar cell technology looking into state-of-the-art equipment and corresponding processes for each process step. The main efficiency losses of this type of solar cell are analyzed to demonstrate the future efficiency potential of this technology. In research and development, more various advanced solar cell concepts have demonstrated higher efficiencies. The question which arises is “why are new solar cell concepts not transferred into industrial production more frequently?”. We look into the requirements a new solar cell technology has to fulfill to have an advantage over the current approach. Finally, we give an overview of high-efficiency concepts which have already been transferred into industrial production.

  14. Solar electron source and thermionic solar cell

    Directory of Open Access Journals (Sweden)

    Parham Yaghoobi

    2012-12-01

    Full Text Available Common solar technologies are either photovoltaic/thermophotovoltaic, or use indirect methods of electricity generation such as boiling water for a steam turbine. Thermionic energy conversion based on the emission of electrons from a hot cathode into vacuum and their collection by an anode is also a promising route. However, thermionic solar conversion is extremely challenging as the sunlight intensity is too low for heating a conventional cathode to thermionic emission temperatures in a practical manner. Therefore, compared to other technologies, little has been done in this area, and the devices have been mainly limited to large experimental apparatus investigated for space power applications. Based on a recently observed “Heat Trap” effect in carbon nanotube arrays, allowing their efficient heating with low-power light, we report the first compact thermionic solar cell. Even using a simple off-the-shelf focusing lens, the device delivered over 1 V across a load. The device also shows intrinsic storage capacity.

  15. Radiation hard solar cell and array

    International Nuclear Information System (INIS)

    Russell, R.L.

    1975-01-01

    A power generating solar cell for a spacecraft solar array is hardened against transient response to nuclear radiation while permitting normal operation of the cell in a solar radiation environment by shunting the cell with a second solar cell whose contacts are reversed relative to the power cell to form a cell module, exposing the power cell only to the solar radiation in a solar radiation environment to produce an electrical output at the module terminals, and exposing both cells to the nuclear radiation in a nuclear radiation environment so that the radiation induced currents generated by the cells suppress one another

  16. Advances in Perovskite Solar Cells

    Science.gov (United States)

    Zuo, Chuantian; Bolink, Henk J.; Han, Hongwei; Huang, Jinsong

    2016-01-01

    Organolead halide perovskite materials possess a combination of remarkable optoelectronic properties, such as steep optical absorption edge and high absorption coefficients, long charge carrier diffusion lengths and lifetimes. Taken together with the ability for low temperature preparation, also from solution, perovskite‐based devices, especially photovoltaic (PV) cells have been studied intensively, with remarkable progress in performance, over the past few years. The combination of high efficiency, low cost and additional (non‐PV) applications provides great potential for commercialization. Performance and applications of perovskite solar cells often correlate with their device structures. Many innovative device structures were developed, aiming at large‐scale fabrication, reducing fabrication cost, enhancing the power conversion efficiency and thus broadening potential future applications. This review summarizes typical structures of perovskite solar cells and comments on novel device structures. The applications of perovskite solar cells are discussed. PMID:27812475

  17. Concentrator-solar-cell development

    Science.gov (United States)

    Grenon, L.

    1982-07-01

    A program is described which is a continuation of earlier programs for the development of high-efficiency, low-cost, silicon concentrator solar cells. The base-line process steps and process sequences identified in these earlier contracts were evaluated and specific processes reviewed. In particular, emphasis on the use of Czochralski-grown silicon wafers rather than float-zone wafers were examined. Additionally, a study of the trade-offs between textured and nontextured cells was initiated, and the limits within which the low-cost plated nickel copper metallization can be used in concentrator solar cell applications was identified.

  18. 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.

  19. Parametric Instability, Inverse Cascade, and the 1/f Range of Solar-Wind Turbulence.

    Science.gov (United States)

    Chandran, Benjamin D G

    2018-02-01

    In this paper, weak turbulence theory is used to investigate the nonlinear evolution of the parametric instability in 3D low- β plasmas at wavelengths much greater than the ion inertial length under the assumption that slow magnetosonic waves are strongly damped. It is shown analytically that the parametric instability leads to an inverse cascade of Alfvén wave quanta, and several exact solutions to the wave kinetic equations are presented. The main results of the paper concern the parametric decay of Alfvén waves that initially satisfy e + ≫ e - , where e + and e - are the frequency ( f ) spectra of Alfvén waves propagating in opposite directions along the magnetic field lines. If e + initially has a peak frequency f 0 (at which fe + is maximized) and an "infrared" scaling f p at smaller f with -1 scaling throughout a range of frequencies that spreads out in both directions from f 0 . At the same time, e - acquires an f -2 scaling within this same frequency range. If the plasma parameters and infrared e + spectrum are chosen to match conditions in the fast solar wind at a heliocentric distance of 0.3 astronomical units (AU), then the nonlinear evolution of the parametric instability leads to an e + spectrum that matches fast-wind measurements from the Helios spacecraft at 0.3 AU, including the observed f -1 scaling at f ≳ 3 × 10 -4 Hz. The results of this paper suggest that the f -1 spectrum seen by Helios in the fast solar wind at f ≳ 3 × 10 -4 Hz is produced in situ by parametric decay and that the f -1 range of e + extends over an increasingly narrow range of frequencies as r decreases below 0.3 AU. This prediction will be tested by measurements from the Parker Solar Probe .

  20. Photon upconversion for thin film solar cells

    NARCIS (Netherlands)

    de Wild, J.

    2012-01-01

    In this research one of the many possible methods to increase the efficiency of solar cells is described. The method investigated is based on adapting the solar light in such a way that the solar cell can convert more light into electricity. The part of the solar spectrum that is adapted is the part

  1. Solar cell circuit and method for manufacturing solar cells

    Science.gov (United States)

    Mardesich, Nick (Inventor)

    2010-01-01

    The invention is a novel manufacturing method for making multi-junction solar cell circuits that addresses current problems associated with such circuits by allowing the formation of integral diodes in the cells and allows for a large number of circuits to readily be placed on a single silicon wafer substrate. The standard Ge wafer used as the base for multi-junction solar cells is replaced with a thinner layer of Ge or a II-V semiconductor material on a silicon/silicon dioxide substrate. This allows high-voltage cells with multiple multi-junction circuits to be manufactured on a single wafer, resulting in less array assembly mass and simplified power management.

  2. Comparison of gas membrane separation cascades using conventional separation cell and two-unit separation cells

    International Nuclear Information System (INIS)

    Ohno, Masayoshi; Morisue, Tetsuo; Ozaki, Osamu; Miyauchi, Terukatsu.

    1978-01-01

    The adoption of two-unit separation cells in radioactive rare gas membrane separation equipment enhances the separation factor, but increases the required membrane area and compressive power. An analytical economic evaluation was undertaken to compare the conventional separation cell with the two-unit separation cells, adopting as parameters the number of cascade stages, the membrane area and the operating power requirements. This paper describes the models used for evaluating the separation performance and the economics of cascade embodying these different concepts of separation cell taken up for study, and the results obtained for the individual concepts are mutually compared. It proved that, in respect of the number required of cascade stages, of operating power requirements and of the annual expenditure, better performance could always be expected of the two-unit separation cells as compared with the conventional separation cell, at least in the range of parameters adopted in this study. As regards the minimum membrane area, the conventional separation cell and the series-type separation cell yielded almost the same values, with the parallel-type separation cell falling somewhat behind. (auth.)

  3. Comparative study of two weir type cascade solar stills with and without PCM storage using energy and exergy analysis

    International Nuclear Information System (INIS)

    Sarhaddi, Faramarz; Farshchi Tabrizi, Farshad; Aghaei Zoori, Halimeh; Mousavi, Seyed Amir Hossein Seyed

    2017-01-01

    Highlights: • Performance evaluation of cascade solar stills with PCM storage is carried out. • Model of cascade solar still is weir type. • Present study is based on numerical simulation. • Effect of operating parameters is studies on yield, energy and exergy efficiencies. - Abstract: In this paper, the comparative study of energy and exergy performance of two weir type cascade solar stills with and without PCM storage in sunny and semi-cloudy days is carried out. The governing equations of energy analysis include a set of nonlinear equations which is obtained by writing energy balance for the various components of a solar still (i.e. glass cover, brackish water, absorber plate, phase change materials). A detailed exergy analysis is carried out and various irreversibility rates in the solar still system and its exergy efficiency are introduced. In order to solve the governing equations a computer simulation program is developed. The results of a numerical simulation of the present study are in good agreement with the experimental data of previous literatures. The numerical results of the present study show that the energy and exergy performance of solar still without PCM storage is better than the solar still with PCM storage in sunny days. On the other hand, the solar still with PCM storage is preferred for semi-cloudy days due to its better energy and exergy performance. The maximum value of the energy and exergy efficiencies of the solar still without PCM for a typical sunny day are 76.69% and 6.53%, respectively. While, the maximum energy and exergy efficiencies of the solar still with PCM for a sample semi-cloudy day are 74.35% and 8.59%, respectively. Furthermore, it is observed that the highest irreversibility rate belongs to the absorber plate and its value for the solar still without PCM on typical sunny day and the solar still with PCM on semi-cloudy days is 83.1% and 78.8% of the whole of system irreversibility rates, respectively. Whereas, the

  4. Semi-transparent solar cells

    Science.gov (United States)

    Sun, J.; Jasieniak, J. J.

    2017-03-01

    Semi-transparent solar cells are a type of technology that combines the benefits of visible light transparency and light-to-electricity conversion. One of the biggest opportunities for such technologies is in their integration as windows and skylights within energy-sustainable buildings. Currently, such building integrated photovoltaics (BIPV) are dominated by crystalline silicon based modules; however, the opaque nature of silicon creates a unique opportunity for the adoption of emerging photovoltaic candidates that can be made truly semi-transparent. These include: amorphous silicon-, kesterite-, chalcopyrite-, CdTe-, dye-sensitized-, organic- and perovskite- based systems. For the most part, amorphous silicon has been the workhorse in the semi-transparent solar cell field owing to its established, low-temperature fabrication processes. Excitement around alternative classes, particularly perovskites and the inorganic candidates, has recently arisen because of the major efficiency gains exhibited by these technologies. Importantly, each of these presents unique opportunities and challenges within the context of BIPV. This topic review provides an overview into the broader benefits of semi-transparent solar cells as building-integrated features, as well as providing the current development status into all of the major types of semi-transparent solar cells technologies.

  5. Incineration of organic solar cells

    NARCIS (Netherlands)

    Søndergaard, Roar R.; Zimmermann, Yannick Serge; Espinosa, Nieves; Lenz, Markus; Krebs, Frederik

    2016-01-01

    Recovery of silver from the electrodes of roll-to-roll processed organic solar cells after incineration has been performed quantitatively by extraction with nitric acid. This procedure is more than 10 times faster than previous reports and the amount of acid needed for the extraction is reduced

  6. Graded bandgap perovskite solar cells

    Science.gov (United States)

    Ergen, Onur; Gilbert, S. Matt; Pham, Thang; Turner, Sally J.; Tan, Mark Tian Zhi; Worsley, Marcus A.; Zettl, Alex

    2017-05-01

    Organic-inorganic halide perovskite materials have emerged as attractive alternatives to conventional solar cell building blocks. Their high light absorption coefficients and long diffusion lengths suggest high power conversion efficiencies, and indeed perovskite-based single bandgap and tandem solar cell designs have yielded impressive performances. One approach to further enhance solar spectrum utilization is the graded bandgap, but this has not been previously achieved for perovskites. In this study, we demonstrate graded bandgap perovskite solar cells with steady-state conversion efficiencies averaging 18.4%, with a best of 21.7%, all without reflective coatings. An analysis of the experimental data yields high fill factors of ~75% and high short-circuit current densities up to 42.1 mA cm-2. The cells are based on an architecture of two perovskite layers (CH3NH3SnI3 and CH3NH3PbI3-xBrx), incorporating GaN, monolayer hexagonal boron nitride, and graphene aerogel.

  7. Organic and hybrid solar cells

    CERN Document Server

    Huang, Hui

    2014-01-01

    This book delivers a comprehensive evaluation of organic and hybrid solar cells and identifies their fundamental principles and numerous applications. Great attention is given to the charge transport mechanism, donor and acceptor materials, interfacial materials, alternative electrodes, device engineering and physics, and device stability. The authors provide an industrial perspective on the future of photovoltaic technologies.

  8. Surface Passivation for Silicon Heterojunction Solar Cells

    NARCIS (Netherlands)

    Deligiannis, D.

    2017-01-01

    Silicon heterojunction solar cells (SHJ) are currently one of the most promising solar cell technologies in the world. The SHJ solar cell is based on a crystalline silicon (c-Si) wafer, passivated on both sides with a thin intrinsic hydrogenated amorphous silicon (a-Si:H) layer. Subsequently, p-type

  9. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    TECS

    Abstract. A major issue encountered during fabrication of triple junction a-Si solar cells on polyimide sub- strates is the adhesion of the solar cell thin films to the substrates. Here, we present our study of film adhesion in amorphous silicon solar cells made on different polyimide substrates (Kapton VN, Upilex-S and ...

  10. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    A major issue encountered during fabrication of triple junction -Si solar cells on polyimide substrates is the adhesion of the solar cell thin films to the substrates. Here, we present our study of film adhesion in amorphous silicon solar cells made on different polyimide substrates (Kapton VN, Upilex-S and Gouldflex), and the ...

  11. Morphology of polymer solar cells

    DEFF Research Database (Denmark)

    Böttiger, Arvid P.L.

    the morphology of the active layer of the solar cells when produced with water based inks using R2R coating. Using a broad range of scattering and imaging techniques, cells coated with water based inks were investigated, and compared to their spin coated counterpart. Two challenges to be addressed were small...... cells. Ptychography offers desirable properties such as potentially high resolution, quantitative contrast and possibility for tomography. Both these X-ray imaging techniques were used to measure the samples with high spatial and chemical resolution. In addition, these experiments explored and reviewed...

  12. Transparent conductive oxides for thin-film silicon solar cells

    Science.gov (United States)

    Löffler, J.

    2005-04-01

    on ETP ZnO. The solar cells deposited on the first doped ZnO:Al layers suffered from collection problems reducing the fill factor, and from shunting. This is attributed to the steep trenches, sharp features and vertical steps that have been identified at the TCO surface. ZnO:Al layers with granular structure, deposited at higher argon flow through the cascaded arc plasma source, allowed for fill factors of the solar cells up to 0.70, comparable to cells on undoped ZnO. The best solar cell on doped ZnO:Al deposited by ETP CVD achieved an efficiency of 9.3 % which is comparable to the 9.4 % obtained on Asahi U-type SnO2:F. Fluorinated tin oxide has been deposited by Atmospheric Chemical Vapor Deposition (APCVD) on glass from three different tin precursors, tetramethyltin, monobutyltin trichloride, and tin tetrachloride (TTC). TTC is the Sn precursor which resulted in the TCO with the best performance of a-Si:H pin solar cells. In accordance with the conclusions from our experiments with solar cells on undoped and aluminum doped zinc oxide, a high surface roughness and haze do not necessarily lead to a lower diode quality, and vice versa.

  13. Hybrid emitter all back contact solar cell

    Science.gov (United States)

    Loscutoff, Paul; Rim, Seung

    2016-04-12

    An all back contact solar cell has a hybrid emitter design. The solar cell has a thin dielectric layer formed on a backside surface of a single crystalline silicon substrate. One emitter of the solar cell is made of doped polycrystalline silicon that is formed on the thin dielectric layer. The other emitter of the solar cell is formed in the single crystalline silicon substrate and is made of doped single crystalline silicon. The solar cell includes contact holes that allow metal contacts to connect to corresponding emitters.

  14. SLAM examination of solar cells and solar cell welds

    Science.gov (United States)

    Stella, P. M.; Vorres, C. L.; Yuhas, D. E.

    The scanning laser acoustic microscope (SLAM) has been evaluated for non-destructive examination of solar cells and interconnector bonds. Using this technique, it is possible to view through materials in order to reveal regions of discontinuity such as microcracks and voids. Of particular interest is the ability to evaluate, in a unique manner, the bonds produced by parallel gap welding. It is possible to not only determine the area and geometry of the bond between the tab and cell, but also to reveal any microcracks incurred during the welding. By correlating the SLAM results with conventional techniques of weld evaluation a more confident weld parameter optimization can be obtained.

  15. Three-Terminal Amorphous Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Cheng-Hung Tai

    2011-01-01

    Full Text Available Many defects exist within amorphous silicon since it is not crystalline. This provides recombination centers, thus reducing the efficiency of a typical a-Si solar cell. A new structure is presented in this paper: a three-terminal a-Si solar cell. The new back-to-back p-i-n/n-i-p structure increased the average electric field in a solar cell. A typical a-Si p-i-n solar cell was also simulated for comparison using the same thickness and material parameters. The 0.28 μm-thick three-terminal a-Si solar cell achieved an efficiency of 11.4%, while the efficiency of a typical a-Si p-i-n solar cell was 9.0%. Furthermore, an efficiency of 11.7% was achieved by thickness optimization of the three-terminal solar cell.

  16. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    . A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...

  17. Radiation performance of AlGaAs concentrator cells and expected performance of cascade structures

    International Nuclear Information System (INIS)

    Curtis, H.B.; Swartz, C.K.; Hart, R.E. Jr.

    1987-01-01

    Aluminum gallium arsenide, GaAs, silicon and InGaAs cells have been irradiated with 1 MeV electrons and 37 MeV protons. These cells are candidates for individual cells in a cascade structure. Data is presented for both electron and proton irradiation studies for one sun and a concentration level of 100X AMO. Results of calculations on the radiation resistance of cascade cell structures based on the individual cell data are also presented. Both series connected and separately connected structures are investigated

  18. Recent Advances in Solar Cell Technology

    Science.gov (United States)

    Landis, Geoffrey A.; Bailey, Sheila G.; Piszczor, Michael F., Jr.

    1996-01-01

    The advances in solar cell efficiency, radiation tolerance, and cost over the last decade are reviewed. Potential performance of thin-film solar cells in space are discussed, and the cost and the historical trends in production capability of the photovoltaics industry are considered with respect to the requirements of space power systems. Concentrator cells with conversion efficiency over 30%, and nonconcentrating solar cells with efficiency over 25% are now available, and advanced radiation-tolerant cells and lightweight, thin-film arrays are both being developed. Nonsolar applications of solar cells, including thermophotovoltaics, alpha- and betavoltaics, and laser power receivers, are also discussed.

  19. Simulating characteristics of Si/Ge tandem monolithic solar cell with Si1-xGex buffer layer

    Directory of Open Access Journals (Sweden)

    Gnilenko A. B.

    2015-12-01

    Full Text Available In spite of many efforts to propose new semiconductor materials and sophisticated constructions of solar cells, crystalline silicone remains the main photovoltaic material widely used up to now. There are various methods to enhance the efficiency of silicone solar cells. One of them is to combine silicone with an additional semiconductor material with the different bandgap to form a tandem construction. For example, the germanium sub-cell used as the bottom cascade for the silicone sub-cell in the tandem monolithic solar cell makes it possible to utilize the "red" sub-band of solar spectra increasing overall solar cell efficiency. The problem of the 4.2% mismatch in lattice constant between Si and Ge can be resolved in such a case by the use of SiGe buffer layer. In the paper the results of the computer simulation for Si/Ge tandem monolithic solar cell with Si1-xGex buffer layer are presented. In the solar cell under consideration, the step graded Si1-xGex buffer layer is located between the top silicone and the bottom germanium cascades to reduce the threading dislocation density in mismatched materials. The cascades are commutated by the use of the germanium tunnel diode between the bottom sub-cell and the buffer layer. For the solar cell modeling, the physically-based device simulator ATLAS of Silvaco TCAD software is employed to predict the electrical behavior of the semiconductor structure and to provide a deep insight into the internal physical processes. The voltage-current characteristic, photovoltaic parameters and the distribution of basic physical values are obtained for the investigated tandem solar cell. The influence of layer thicknesses on the photovoltaic parameters is studied. The calculated efficiency of the tandem solar cell reaches 13% which is a quarter more than the efficiency of a simple silicone solar cell with the same constructive parameters and under the same illumination conditions.

  20. Supramolecular photochemistry and solar cells

    Directory of Open Access Journals (Sweden)

    IHA NEYDE YUKIE MURAKAMI

    2000-01-01

    Full Text Available Supramolecular photochemistry as well as solar cells are fascinating topics of current interest in Inorganic Photochemistry and very active research fields which have attracted wide attention in last two decades. A brief outline of the investigations in these fields carried out in our Laboratory of Inorganic Photochemistry and Energy Conversion is given here with no attempt of an exhaustive coverage of the literature. The emphasis is placed on recent work and information on the above mentioned subjects. Three types of supramolecular systems have been the focus of this work: (i cage-type coordination compounds; (ii second-sphere coordination compounds, exemplified by ion-pair photochemistry of cobalt complexes and (iii covalently-linked systems. In the latter, modulation of the photoluminescence and photochemistry of some rhenium complexes are discussed. Solar energy conversion and development of thin-layer photoelectrochemical solar cells based on sensitization of nanocrystalline semiconductor films by some ruthenium polypyridyl complexes are presented as an important application that resulted from specifically engineered artificial assemblies.

  1. Semiconductor materials for solar photovoltaic cells

    CERN Document Server

    Wong-Ng, Winnie; Bhattacharya, Raghu

    2016-01-01

    This book reviews the current status of semiconductor materials for conversion of sunlight to electricity, and highlights advances in both basic science and manufacturing.  Photovoltaic (PV) solar electric technology will be a significant contributor to world energy supplies when reliable, efficient PV power products are manufactured in large volumes at low cost.  Expert chapters cover the full range of semiconductor materials for solar-to-electricity conversion, from crystalline silicon and amorphous silicon to cadmium telluride, copper indium gallium sulfide selenides, dye sensitized solar cells, organic solar cells, and environmentally friendly copper zinc tin sulfide selenides. The latest methods for synthesis and characterization of solar cell materials are described, together with techniques for measuring solar cell efficiency. Semiconductor Materials for Solar Photovoltaic Cells presents the current state of the art as well as key details about future strategies to increase the efficiency and reduce ...

  2. Energy Conversion: Nano Solar Cell

    Science.gov (United States)

    Yahaya, Muhammad; Yap, Chi Chin; Mat Salleh, Muhamad

    2009-09-01

    Problems of fossil-fuel-induced climate change have sparked a demand for sustainable energy supply for all sectors of economy. Most laboratories continue to search for new materials and new technique to generate clean energy at affordable cost. Nanotechnology can play a major role in solving the energy problem. The prospect for solar energy using Si-based technology is not encouraging. Si photovoltaics can produce electricity at 20-30 c//kWhr with about 25% efficiency. Nanoparticles have a strong capacity to absorb light and generate more electrons for current as discovered in the recent work of organic and dye-sensitized cell. Using cheap preparation technique such as screen-printing and self-assembly growth, organic cells shows a strong potential for commercialization. Thin Films research group at National University Malaysia has been actively involved in these areas, and in this seminar, we will present a review works on nanomaterials for solar cells and particularly on hybrid organic solar cell based on ZnO nanorod arrays. The organic layer consisting of poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV) and [6, 6]-phenyl C61-butyric acid 3-ethylthiophene ester (PCBE) was spin-coated on ZnO nanorod arrays. ZnO nanorod arrays were grown on FTO glass substrates which were pre-coated with ZnO nanoparticles using a low temperature chemical solution method. A gold electrode was used as the top contact. The device gave a short circuit current density of 2.49×10-4 mA/cm2 and an open circuit voltage of 0.45 V under illumination of a projector halogen light at 100 mW/cm2.

  3. Dye solar cells: a different approach to solar energy

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2008-11-01

    Full Text Available An attractive and cheaper alternative to siliconbased photovoltaic (PV) cells for the conversion of solar light into electrical energy is to utilise dyeadsorbed, large-band-gap metal oxide materials such as TiO2 to absorb the solar light...

  4. Bypass diode for a solar cell

    Science.gov (United States)

    Rim, Seung Bum [Palo Alto, CA; Kim, Taeseok [San Jose, CA; Smith, David D [Campbell, CA; Cousins, Peter J [Menlo Park, CA

    2012-03-13

    Bypass diodes for solar cells are described. In one embodiment, a bypass diode for a solar cell includes a substrate of the solar cell. A first conductive region is disposed above the substrate, the first conductive region of a first conductivity type. A second conductive region is disposed on the first conductive region, the second conductive region of a second conductivity type opposite the first conductivity type.

  5. Solar Cells Using Quantum Funnels

    KAUST Repository

    Kramer, Illan J.

    2011-09-14

    Colloidal quantum dots offer broad tuning of semiconductor bandstructure via the quantum size effect. Devices involving a sequence of layers comprised of quantum dots selected to have different diameters, and therefore bandgaps, offer the possibility of funneling energy toward an acceptor. Here we report a quantum funnel that efficiently conveys photoelectrons from their point of generation toward an intended electron acceptor. Using this concept we build a solar cell that benefits from enhanced fill factor as a result of this quantum funnel. This concept addresses limitations on transport in soft condensed matter systems and leverages their advantages in large-area optoelectronic devices and systems. © 2011 American Chemical Society.

  6. Cascade and Dissipation of Solar Wind Turbulence at Electron Scales: Whistlers or Kinetic Alfv\\'en Waves?

    Science.gov (United States)

    Sahraoui, Fouad; Goldstein, Melvyn L.

    2010-01-01

    Over the past few decades, large-scales solar wind (SW) turbulence has been studied extensively, both theoretically and observationally. Observed power spectra of the low frequency turbulence, which can be described in the magnetohydrodynamic (MHD) limit, are shown to obey the Kolmogorov scaling, $k"{ -5/3 }$, down the local proton gyrofrequency ($C{ci} \\sim O.l$-Hz). Turbulence at frequencies above $C{ci}$ has not been thoroughly investigated and remains far less well understood. Above $C{ ci}$ the spectrum steepens to $\\sim f"{ -2.5}$ and a debate exists as to whether the turbulence has become dominated by dispersive kinetic Alfven waves (KA W) or by whistler waves, before it is dissipated at small scales, In a case study Sahraoui et al., PRL (2009) have reported the first direct determination of the dissipation range of solar wind turbulence near the electron gyroscale using the high resolution Cluster magnetic and electric field data (up to $10"2$-Hz in the spacecraft reference frame). Above the Doppler-shifted proton scale $C{\\rho i}$ a new inertial range with a scaling $\\sim f"{ -2.3}$ has been evidenced and shown to remarkably agree with theoretical predictions of a quasi-two-dimensional cascade into KA W turbulence. Here, we use a wider sample of data sets of small scale SW turbulence under different plasma conditions, and investigate under which physical criteria the KA W (or the whistler) turbulence may be observed to carry out the cascade at small scales, These new observations/criteria are compared to the predictions on the cascade and the (kinetic) dissipation from the Vlasov theory. Implications of the results on the heating problem of the solar wind will be discussed.

  7. Device operation of organic tandem solar cells

    NARCIS (Netherlands)

    Hadipour, A.; de Boer, B.; Blom, P. W. M.

    2008-01-01

    A generalized methodology is developed to obtain the current-voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and

  8. Integration of Solar Cells on Top of CMOS Chips - Part II: CIGS Solar Cells

    NARCIS (Netherlands)

    Lu, J.; Liu, Wei; Kovalgin, Alexeij Y.; Sun, Yun; Schmitz, Jurriaan

    2011-01-01

    We present the monolithic integration of deepsubmicrometer complementary metal–oxide–semiconductor (CMOS) microchips with copper indium gallium (di)selenide (CIGS) solar cells. Solar cells are manufactured directly on unpackaged CMOS chips. The microchips maintain comparable electronic performance,

  9. Theoretical investigation on heterojunction solar cell

    International Nuclear Information System (INIS)

    Prema, K.; Geetha, K.

    1986-11-01

    The study of thin film solar cells has proved that the surface is rough. A two-dimensional method based on the integral equation technique to analyse thin film solar cells has been developed by DeMey et al. In this paper we present our analysis of a thin film solar cell using the above techniques. Variation of the minority carrier concentration, the saturation current and the junction current of the solar cell with surface roughness is presented. (author). 8 refs, 4 figs

  10. Nanostructured organic and hybrid solar cells.

    Science.gov (United States)

    Weickert, Jonas; Dunbar, Ricky B; Hesse, Holger C; Wiedemann, Wolfgang; Schmidt-Mende, Lukas

    2011-04-26

    This Progress Report highlights recent developments in nanostructured organic and hybrid solar cells. The authors discuss novel approaches to control the film morphology in fully organic solar cells and the design of nanostructured hybrid solar cells. The motivation and recent results concerning fabrication and effects on device physics are emphasized. The aim of this review is not to give a summary of all recent results in organic and hybrid solar cells, but rather to focus on the fabrication, device physics, and light trapping properties of nanostructured organic and hybrid devices. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Machine for welding solar cell connections

    Energy Technology Data Exchange (ETDEWEB)

    Lorans, D.Y.

    1977-08-09

    A machine for welding a connection wire over a solar cell electrode is described which comprises a base, a welding mount for the solar cell which is supported on the base, means for holding the solar cell on the welding mount, welding electrodes, means to lower the welding electrodes over the solar cell and the connection wire superimposed thereon, means for applying electric current pulses to said welding electrodes. It is characterized by the fact that it further comprises means for imparting to said mount an alternating transverse movement in relation to said base before and during the welding operation.

  12. Integration of Solar Cells on Top of CMOS Chips Part I: a-Si Solar Cells

    NARCIS (Netherlands)

    Lu, J.; Kovalgin, Alexeij Y.; van der Werf, Karine H.M.; Schropp, Ruud E.I.; Schmitz, Jurriaan

    2011-01-01

    We present the monolithic integration of deepsubmicrometer complementary metal–oxide–semiconductor (CMOS) microchips with a-Si:H solar cells. Solar cells are manufactured directly on the CMOS chips. The microchips maintain comparable electronic performance, and the solar cells show efficiency values

  13. Effects of indirect bandgap top cells in a monolithic cascade cell structure

    Science.gov (United States)

    Curtis, H. B.; Godlewski, M. P.

    1982-01-01

    The effect of having a slightly indirect top cell in a three junction cascade monolithic stack is calculated. The minority carrier continuity equations are utilized to calculate individual junction performance. Absorption coefficient curves for general III-V compounds are calculated for a variety of direct and indirect gap materials. The results indicate that for a small excursion into the indirect region, (about 0.1 eV), the loss of efficiency is acceptably small (less than 2.5 percent) and considerably less than attempting to make the top junction a smaller direct bandgap.

  14. Monolithic cells for solar fuels.

    Science.gov (United States)

    Rongé, Jan; Bosserez, Tom; Martel, David; Nervi, Carlo; Boarino, Luca; Taulelle, Francis; Decher, Gero; Bordiga, Silvia; Martens, Johan A

    2014-12-07

    Hybrid energy generation models based on a variety of alternative energy supply technologies are considered the best way to cope with the depletion of fossil energy resources and to limit global warming. One of the currently missing technologies is the mimic of natural photosynthesis to convert carbon dioxide and water into chemical fuel using sunlight. This idea has been around for decades, but artificial photosynthesis of organic molecules is still far away from providing real-world solutions. The scientific challenge is to perform in an efficient way the multi-electron transfer reactions of water oxidation and carbon dioxide reduction using holes and single electrons generated in an illuminated semiconductor. In this tutorial review the design of photoelectrochemical (PEC) cells that combine solar water oxidation and CO2 reduction is discussed. In such PEC cells simultaneous transport and efficient use of light, electrons, protons and molecules has to be managed. It is explained how efficiency can be gained by compartmentalisation of the water oxidation and CO2 reduction processes by proton exchange membranes, and monolithic concepts of artificial leaves and solar membranes are presented. Besides transferring protons from the anode to the cathode compartment the membrane serves as a molecular barrier material to prevent cross-over of oxygen and fuel molecules. Innovative nano-organized multimaterials will be needed to realise practical artificial photosynthesis devices. This review provides an overview of synthesis techniques which could be used to realise monolithic multifunctional membrane-electrode assemblies, such as Layer-by-Layer (LbL) deposition, Atomic Layer Deposition (ALD), and porous silicon (porSi) engineering. Advances in modelling approaches, electrochemical techniques and in situ spectroscopies to characterise overall PEC cell performance are discussed.

  15. Perovskite Solar Cells with Large-Area CVD-Graphene for Tandem Solar Cells.

    Science.gov (United States)

    Lang, Felix; Gluba, Marc A; Albrecht, Steve; Rappich, Jörg; Korte, Lars; Rech, Bernd; Nickel, Norbert H

    2015-07-16

    Perovskite solar cells with transparent contacts may be used to compensate for thermalization losses of silicon solar cells in tandem devices. This offers a way to outreach stagnating efficiencies. However, perovskite top cells in tandem structures require contact layers with high electrical conductivity and optimal transparency. We address this challenge by implementing large-area graphene grown by chemical vapor deposition as a highly transparent electrode in perovskite solar cells, leading to identical charge collection efficiencies. Electrical performance of solar cells with a graphene-based contact reached those of solar cells with standard gold contacts. The optical transmission by far exceeds that of reference devices and amounts to 64.3% below the perovskite band gap. Finally, we demonstrate a four-terminal tandem device combining a high band gap graphene-contacted perovskite top solar cell (Eg = 1.6 eV) with an amorphous/crystalline silicon bottom solar cell (Eg = 1.12 eV).

  16. Achieving 15% Tandem Polymer Solar Cells

    Science.gov (United States)

    2015-06-23

    final support also enabled us to explore novel hybrid perovskite solar cells in depth. For example, single junction cell efficiency of 19.3% under...novel hybrid perovskite solar cells in depth. For example, single junction cell efficiency of 19.3% under reverse bias was achieved and the results...solar cells with 10.2% power conversion efficiency via stacking two PDTP-DFBT:PC71BM bulk heterojunctions, connected by MoO3/PEDOT:PSS/ ZnO as an

  17. Towards upconversion for amorphous silicon solar cells

    NARCIS (Netherlands)

    de Wild, J.; Meijerink, A.; Rath, J.K.; van Sark, W.G.J.H.M.; Schropp, R.E.I.

    2010-01-01

    Upconversion of subbandgap light of thin film single junction amorphous silicon solar cells may enhance their performance in the near infrared (NIR). In this paper we report on the application of the NIR–vis upconverter β-NaYF4:Yb3+(18%) Er3+(2%) at the back of an amorphous silicon solar cell in

  18. Dye-sensitised solar cell (artificial photosynthesis)

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2005-07-01

    Full Text Available A novel system that harnesses solar energy is the nano-crystalline TiO dye-sensitised solar cell (DSC), in conjunction with several new concepts, such as nanotechnology and molecular devices. An efficient and low-cost cell can be produced by using...

  19. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    TECS

    flexible triple junction, amorphous silicon solar cells. At the Malaysia Energy Centre (MEC), we fabricated triple junction amorphous silicon solar cells (up to 12⋅7% efficiency (Wang et al 2002)) and laser-interconnected modules on steel, glass and polyimide substrates. A major issue encountered is the adhesion of thin film ...

  20. Scaling up ITO-Free solar cells

    NARCIS (Netherlands)

    Galagan, Y.O.; Coenen, E.W.C.; Zimmermann, B.; Slooff, L.H.; Verhees, W.J.H.; Veenstra, S.C.; Kroon, J.M.; Jørgensen, M.; Krebs, F.C.; Andriessen, H.A.J.M.

    2014-01-01

    Indium-tin-oxide-free (ITO-free) polymer solar cells with composite electrodes containing current-collecting grids and a semitransparent poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) (PEDOT:PSS) conductor are demonstrated. The up-scaling of the length of the solar cell from 1 to 6 cm and

  1. Predicted solar cell edge radiation effects

    International Nuclear Information System (INIS)

    Gates, M.T.

    1993-01-01

    The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

  2. Fullerene surfactants and their use in polymer solar cells

    Science.gov (United States)

    Jen, Kwan-Yue; Yip, Hin-Lap; Li, Chang-Zhi

    2015-12-15

    Fullerene surfactant compounds useful as interfacial layer in polymer solar cells to enhance solar cell efficiency. Polymer solar cell including a fullerene surfactant-containing interfacial layer intermediate cathode and active layer.

  3. Organic Based Solar Cells with Morphology Control

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks

    The field of organic solar cells has in the last years gone through an impressive development with efficiencies reported up to 12 %. For organic solar cells to take the leap from primarily being a laboratory scale technology to being utilized as renewable energy source, several issues need...... Microscopy and as solar cells in a blend with PCBM. It was concluded that these particles did not show a potential large enough for continuous work due to a high material loss and low efficiency when applied in solar cells. The second method to achieve was preparation of pre-arranged morphology organic...... nanoparticles consisting of a blend of donor and acceptor in an aqueous dispersion, thereby addressing two of the issues remaining in the field of organic solar cells. This approach was used on six different polymers, which all had the ability to prepare aqueous nanoparticle inks. The morphology...

  4. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

  5. Improved CMX solar cell coverglasses and optical solar reflectors

    Science.gov (United States)

    Whalley, A. M.; Jones, D. P.; Dollery, A. A.; Murphy, N.; Porter, D. A.

    Recent development programs have demonstrated that considerable improvements in optical and thermooptical performance as well as mechanical properties of CMX solar cell coverglasses and optical solar reflectors (OSRs) can be achieved. Optical coatings can increase infrared emittance by 4 percent and decrease solar absorptance by 50 percent. Chemical treatments can be used to increase glass strength to four times its untreated value or to provide integral antireflection layers which reduce reflection to 0.5 percent per surface. Automated test equipment for proving the strength of each coverglass and mirror has been designed and manufactured.

  6. Coating Processes Boost Performance of Solar Cells

    Science.gov (United States)

    2012-01-01

    NASA currently has spacecraft orbiting Mercury (MESSENGER), imaging the asteroid Vesta (Dawn), roaming the red plains of Mars (the Opportunity rover), and providing a laboratory for humans to advance scientific research in space (the International Space Station, or ISS). The heart of the technology that powers those missions and many others can be held in the palm of your hand - the solar cell. Solar, or photovoltaic (PV), cells are what make up the panels and arrays that draw on the Sun s light to generate electricity for everything from the Hubble Space Telescope s imaging equipment to the life support systems for the ISS. To enable NASA spacecraft to utilize the Sun s energy for exploring destinations as distant as Jupiter, the Agency has invested significant research into improving solar cell design and efficiency. Glenn Research Center has been a national leader in advancing PV technology. The Center s Photovoltaic and Power Technologies Branch has conducted numerous experiments aimed at developing lighter, more efficient solar cells that are less expensive to manufacture. Initiatives like the Forward Technology Solar Cell Experiments I and II in which PV cells developed by NASA and private industry were mounted outside the ISS have tested how various solar technologies perform in the harsh conditions of space. While NASA seeks to improve solar cells for space applications, the results are returning to Earth to benefit the solar energy industry.

  7. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    Science.gov (United States)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  8. Solar Cell Panel and the Method for Manufacturing the Same

    Science.gov (United States)

    Richards, Benjamin C. (Inventor); Sarver, Charles F. (Inventor); Naidenkova, Maria (Inventor)

    2016-01-01

    According to an aspect of an embodiment of the present disclosure, there is provided a solar cell panel and a method for manufacturing the same. The solar cell panel comprises: a solar cell for generating electric power from sunlight; a coverglass for covering the solar cell; transparent shims, which are disposed between the solar cell and the coverglass at the points where the distance between the solar cell and the coverglass needs to be controlled, and form a space between the solar cell and the coverglass; and adhesive layer, which fills the space between the solar cell and the coverglass and has the thickness the same as that of the transparent shims.

  9. Nanocomposite enables sensitized solar cell

    Science.gov (United States)

    Phuyal, Dibya D.

    Dye Sensitized solar cells (DSSCs) are a promising candidate for next generation photovoltaic panels due to their low cost, easy fabrication process, and relative high efficiency. Despite considerable effort on the advancement of DSSCs, the efficiency has been stalled for nearly a decade due to the complex interplay among various DSSC components. DSSCs consist of a photoanode on a conducting substrate, infiltrated dye for light absorption and electron injection, and an electrolyte to regenerate the dye. On the photoanode is a high band-gap semiconducting material, primarily of a nanostructure morphology of titanium (II) dioxide (TiO2), dye molecules whose molar absorption is typically in the visible spectrum, are adsorbed onto the surface of TiO 2. To improve the current DSSCs, there are many parameters that can be investigated. In a conventional DSSC, a thick semiconducting layer such as the nanoparticle TiO2 layer induces charge separation efficiently while concurrently increasing the charge transport distance, leading the cell to suffer from more charge recombination and deterioration in charge collection efficiency. To improve on this limitation, TiO2 nanowires (NW) and nanotubes (NT) are explored to replace the nanoparticle photoanode. One-dimensional nanostructures are known for the excellent electron transport properties as well as maintaining a relatively high surface area. Hence one of the focuses of this thesis explores at using different morphologies and composition of TiO2 nanostructures to enhance electron collection efficiency. Another challenge in conventional DSSCs is the limit in light absorption of solar irradiation. Dyes are limited to absorption only in the visible range, and have a low molar absorption coefficient in the near infrared (NIR). Tuning dyes is extremely complicated and may have more disadvantages than simply by extending light harvesting. Therefore our strategy is to incorporate quantum dots to replace the dye, as well as prepare a

  10. Recent Advances in Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Thomas Kietzke

    2007-01-01

    Full Text Available Solar cells based on organic semiconductors have attracted much attention. The thickness of the active layer of organic solar cells is typically only 100 nm thin, which is about 1000 times thinner than for crystalline silicon solar cells and still 10 times thinner than for current inorganic thin film cells. The low material consumption per area and the easy processing of organic semiconductors offer a huge potential for low cost large area solar cells. However, to compete with inorganic solar cells the efficiency of organic solar cells has to be improved by a factor of 2-3. Several organic semiconducting materials have been investigated so far, but the optimum material still has to be designed. Similar as for organic light emitting devices (OLED small molecules are competing with polymers to become the material of choice. After a general introduction into the device structures and operational principles of organic solar cells the three different basic types (all polymer based, all small molecules based and small molecules mixed with polymers are described in detail in this review. For each kind the current state of research is described and the best of class reported efficiencies are listed.

  11. Automatic Detection of Cervical Cancer Cells by a Two-Level Cascade Classification System

    Directory of Open Access Journals (Sweden)

    Jie Su

    2016-01-01

    Full Text Available We proposed a method for automatic detection of cervical cancer cells in images captured from thin liquid based cytology slides. We selected 20,000 cells in images derived from 120 different thin liquid based cytology slides, which include 5000 epithelial cells (normal 2500, abnormal 2500, lymphoid cells, neutrophils, and junk cells. We first proposed 28 features, including 20 morphologic features and 8 texture features, based on the characteristics of each cell type. We then used a two-level cascade integration system of two classifiers to classify the cervical cells into normal and abnormal epithelial cells. The results showed that the recognition rates for abnormal cervical epithelial cells were 92.7% and 93.2%, respectively, when C4.5 classifier or LR (LR: logical regression classifier was used individually; while the recognition rate was significantly higher (95.642% when our two-level cascade integrated classifier system was used. The false negative rate and false positive rate (both 1.44% of the proposed automatic two-level cascade classification system are also much lower than those of traditional Pap smear review.

  12. Integrated cascade of photovoltaic cells as a power supply for integrated circuits

    NARCIS (Netherlands)

    Mouthaan, A.J.

    1984-01-01

    ICs can be powered directly when a supply voltage source capable of generating a multiple of the open circuit voltage of one pn-junction is available on a chip. Two schemes have been investigated for cascading photovoltaic cells on the chip. The structures can be made compatible with standard

  13. Coupling of Luminescent Solar Concentrators to Plasmonic Solar Cells

    Science.gov (United States)

    Wang, Shu-Yi

    To make inexpensive solar cells is a continuous goal for solar photovoltaic (PV) energy industry. Thin film solar cells of various materials have been developed and continue to emerge in order to replace bulk silicon solar cells. A thin film solar cell not only uses less material but also requires a less expensive refinery process. In addition, other advantages coming along with small thickness are higher open circuit voltage and higher conversion efficiency. However, thin film solar cells, especially those made of silicon, have significant optical losses. In order to address this problem, this thesis investigates the spectral coupling of thin films PV to luminescent solar concentrators (LSC). LSC are passive devices, consisting of plastic sheets embedded with fluorescent dyes which absorb part of the incoming radiation spectrum and emit at specific wavelength. The emitted light is concentrated by total internal reflection to the edge of the sheet, where the PVs are placed. Since the light emitted from the LSC edge is usually in a narrow spectral range, it is possible to employ diverse strategies to enhance PV absorption at the peak of the emission wavelength. Employing plasmonic nanostructures has been shown to enhance absorption of thin films via forward scattering, diffraction and localized surface plasmon. These two strategies are theoretically investigated here for improving the absorption and elevating the output power of a thin film solar cell. First, the idea of spectral coupling of luminescent solar concentrators to plasmonic solar cells is introduced to assess its potential for increasing the power output. This study is carried out employing P3HT/PC60BM organic solar cells and LSC with Lumogen Red dyes. A simplified spectral coupling analysis is employed to predict the power density, considering the output spectrum of the LSC equivalent to the emission spectrum of the dye and neglecting any angular dependence. Plasmonic tuning is conducted to enhance

  14. Characterising dye-sensitized solar cells

    Science.gov (United States)

    Tobin, Laura L.; O'Reilly, Thomas; Zerulla, Dominic; Sheridan, John T.

    2009-08-01

    With growing energy and environmental concerns due to fossil fuel depletion and global warming there is an increasing attention being attracted by alternative and/or renewable sources of power such as biomass, hydropower, geothermal, wind and solar energy. In today's society there is a vast and in many cases not fully appreciated dependence on electrical power for everyday life and therefore devices such as PV cells are of enormous importance. The more widely used and commercially available silicon (semiconductor) based cells currently have the greatest efficiencies, however the manufacturing of these cells is complex and costly due to the cost and difficulty of producing and processing pure silicon. One new direction being explored is the development of dye-sensitised solar cells (DSSC). The SFI Strategic Research Centre for Solar Energy Conversion is a new research cluster based in Ireland, formed with the express intention of bringing together industry and academia to produce renewable energy solutions. Our specific area of research is in biomimetic dye sensitised solar cells and their electrical properties. We are currently working to develop test equipment, and optoelectronic models describing the performance and behaviors of dye-sensitised solar cells (Grätzel Cells). In this paper we describe some of the background to our work and also some of our initial experimental results. Based on these results we intend to characterise the opto-electrical properties and bulk characteristics of simple dye-sensitised solar cells and then to proceed to test new cell compositions.

  15. Recent Advances in Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Umer Mehmood

    2014-01-01

    Full Text Available Solar energy is an abundant and accessible source of renewable energy available on earth, and many types of photovoltaic (PV devices like organic, inorganic, and hybrid cells have been developed to harness the energy. PV cells directly convert solar radiation into electricity without affecting the environment. Although silicon based solar cells (inorganic cells are widely used because of their high efficiency, they are rigid and manufacturing costs are high. Researchers have focused on organic solar cells to overcome these disadvantages. DSSCs comprise a sensitized semiconductor (photoelectrode and a catalytic electrode (counter electrode with an electrolyte sandwiched between them and their efficiency depends on many factors. The maximum electrical conversion efficiency of DSSCs attained so far is 11.1%, which is still low for commercial applications. This review examines the working principle, factors affecting the efficiency, and key challenges facing DSSCs.

  16. Development and Prospect of Nanoarchitectured Solar Cells

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2015-01-01

    Full Text Available This paper gives an overview of the development and prospect of nanotechnologies utilized in the solar cell applications. Even though it is not clearly pointed out, nanostructures indeed have been used in the fabrication of conventional solar cells for a long time. However, in those circumstances, only very limited benefits of nanostructures have been used to improve cell performance. During the last decade, the development of the photovoltaic device theory and nanofabrication technology enables studies of more complex nanostructured solar cells with higher conversion efficiency and lower production cost. The fundamental principles and important features of these advanced solar cell designs are systematically reviewed and summarized in this paper, with a focus on the function and role of nanostructures and the key factors affecting device performance. Among various nanostructures, special attention is given to those relying on quantum effect.

  17. Solar cell with a gallium nitride electrode

    Science.gov (United States)

    Pankove, Jacques I.

    1979-01-01

    A solar cell which comprises a body of silicon having a P-N junction therein with a transparent conducting N-type gallium nitride layer as an ohmic contact on the N-type side of the semiconductor exposed to solar radiation.

  18. Multijunction Solar Cells Optimized for the Mars Surface Solar Spectrum

    Science.gov (United States)

    Edmondson, Kenneth M.; Fetzer, Chris; Karam, Nasser H.; Stella, Paul; Mardesich, Nick; Mueller, Robert

    2007-01-01

    This paper gives an update on the performance of the Mars Exploration Rovers (MER) which have been continually performing for more than 3 years beyond their original 90-day missions. The paper also gives the latest results on the optimization of a multijunction solar cell that is optimized to give more power on the surface of Mars.

  19. Multicompartment Artificial Organelles Conducting Enzymatic Cascade Reactions inside Cells

    DEFF Research Database (Denmark)

    Gallardo, Maria Godoy; Labay, Cédric Pierre; Trikalitis, Vasileios

    2017-01-01

    Cell organelles are subcellular structures entrapping a set of enzymes to achieve a specific functionality. The incorporation of artificial organelles into cells is a novel medical paradigm which might contribute to the treatment of various cell disorders by replacing malfunctioning organelles....... In particular, artificial organelles are expected to be a powerful solution in the context of enzyme replacement therapy since enzymatic malfunction is the primary cause of organelle dysfunction. Although several attempts have been made to encapsulate enzymes within a carrier vehicle, only few intracellularly...

  20. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....

  1. Advanced Silicon Space Solar Cells Using Nanotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Gee, J.M.; Ruby, D.S.; Zaidi, S.H.

    1999-03-31

    Application of nanotechnology and advanced optical structures offer new possibilities for improved radiation tolerance in silicon solar cells. We describe the application of subwavelength diffractive structures to enhance optical absorption near the surface, and thereby improve the radiation tolerance.

  2. Solar cell efficiency tables (version 50)

    Energy Technology Data Exchange (ETDEWEB)

    Green, Martin A. [Australian Centre for Advanced Photovoltaics, University of New South Wales, Sydney 2052 Australia; Hishikawa, Yoshihiro [National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Photovoltaics (RCPV), Central 2, Umezono 1-1-1, Ibaraki Tsukuba 305-8568 Japan; Warta, Wilhelm [Department: Characterisation and Simulation/CalLab Cells, Fraunhofer-Institute for Solar Energy Systems, Heidenhofstr. 2 Freiburg D-79110 Germany; Dunlop, Ewan D. [European Commission-Joint Research Centre, Directorate C-Energy, Transport and Climate, Via E. Fermi 2749 Ispra IT-21027 VA Italy; Levi, Dean H. [National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA; Hohl-Ebinger, Jochen [Department: Characterisation and Simulation/CalLab Cells, Fraunhofer-Institute for Solar Energy Systems, Heidenhofstr. 2 Freiburg D-79110 Germany; Ho-Baillie, Anita W. H. [Australian Centre for Advanced Photovoltaics, University of New South Wales, Sydney 2052 Australia

    2017-06-21

    Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined, and new entries since January 2017 are reviewed.

  3. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  4. Silicon Germanium Quantum Well Solar Cell

    Data.gov (United States)

    National Aeronautics and Space Administration — A single crystal SiGe has enormous potentials for high performance chips and solar cells. This project seeks to fabricate a rudimentary but 1st cut quantum-well...

  5. Electrospun Polymer-Fiber Solar Cell

    Directory of Open Access Journals (Sweden)

    Shinobu Nagata

    2013-01-01

    Full Text Available A novel electrospun polymer-fiber solar cell was synthesized by electrospinning a 1 : 2.5 weight% ratio mixture of poly[2-methoxy-5-(2-ethylhexyloxy-1,4-phenylenevinylene] (MEH-PPV and [6,6]-phenyl C61 butyric acid methyl ester (PCBM resulting in bulk heterojunctions. Electrospinning is introduced as a technique that may increase polymer solar cell efficiency, and a list of advantages of the technique applied to solar cells is discussed. The device achieved a power conversion efficiency of %. The absorption and photoluminescence of MEH-PPV nanofibers are compared to thin films of the same material. Electrospun nanofibers are discussed as a favorable structure for application in polymer solar cells.

  6. Modeling and Simulation of Monolithic AlGaAs/InGaAs Tandem Solar Cell

    Directory of Open Access Journals (Sweden)

    Samia SLIMANI

    2015-06-01

    Full Text Available Employing conventional III-V junctions we report a classical calculation of conduction and valence band edge and the electron and hole densities. It is shown that the optimum performance can be achieved by employing AlGaAs /AlGaAs/InGaAs monolithic cascade solar cells, we have established these calculations by solving the Poisson equation within the framework of the Nextnano.

  7. Investigating dye-sensitised solar cells

    Science.gov (United States)

    Tobin, Laura L.; O'Reilly, Thomas; Zerulla, Dominic; Sheridan, John T.

    2010-05-01

    At present there is considerable global concern in relation to environmental issues and future energy supplies, for instance climate change (global warming) and the rapid depletion of fossil fuel resources. This trepidation has initiated a more critical investigation into alternative and renewable sources of power such as geothermal, biomass, hydropower, wind and solar energy. The immense dependence on electrical power in today's society has prompted the manufacturing of devices such as photovoltaic (PV) cells to help alleviate and replace current electrical demands of the power grid. The most popular and commercially available PV cells are silicon solar cells which have to date the greatest efficiencies for PV cells. The drawback however is that the manufacturing of these cells is complex and costly due to the expense and difficulty of producing and processing pure silicon. One relatively inexpensive alternative to silicon PV cells that we are currently studying are dye-sensitised solar cells (DSSC or Grätzel Cells). DSSC are biomimetic solar cells which are based on the process of photosynthesis. The SFI Strategic Research Centre for Solar Energy Conversion is a research cluster based in Ireland formed with the express intention of bringing together industry and academia to produce renewable energy solutions. Our specific research area is in DSSC and their electrical properties. We are currently developing testing equipment for arrays of DSSC and developing optoelectronic models which todescribe the performance and behaviour of DSSCs.

  8. Perovskite Solar Cells: Progress and Advancements

    Directory of Open Access Journals (Sweden)

    Naveen Kumar Elumalai

    2016-10-01

    Full Text Available Organic–inorganic hybrid perovskite solar cells (PSCs have emerged as a new class of optoelectronic semiconductors that revolutionized the photovoltaic research in the recent years. The perovskite solar cells present numerous advantages include unique electronic structure, bandgap tunability, superior charge transport properties, facile processing, and low cost. Perovskite solar cells have demonstrated unprecedented progress in efficiency and its architecture evolved over the period of the last 5–6 years, achieving a high power conversion efficiency of about 22% in 2016, serving as a promising candidate with the potential to replace the existing commercial PV technologies. This review discusses the progress of perovskite solar cells focusing on aspects such as superior electronic properties and unique features of halide perovskite materials compared to that of conventional light absorbing semiconductors. The review also presents a brief overview of device architectures, fabrication methods, and interface engineering of perovskite solar cells. The last part of the review elaborates on the major challenges such as hysteresis and stability issues in perovskite solar cells that serve as a bottleneck for successful commercialization of this promising PV technology.

  9. Improved protection for silicon solar cells

    Science.gov (United States)

    Broder, J. D.

    1970-01-01

    Fluorinated ethylene propylene /FEP/ film is substituted for epoxy cement in bonding glass covers to silicon solar cells. Insensitivity of FEP to ultraviolet radiation reduces requirement for filtering and does not impair cell performance. Cell costs are reduced and cover mounting is simplified.

  10. Method to manufacture solar cells

    International Nuclear Information System (INIS)

    Hanschmann, H.

    1978-01-01

    An attempt has been made to outwit physics and to improve the solar energy utilization in households and space ships by means of power storers, gravitational drive and other futuristic means. (DG) [de

  11. HYBRID FUEL CELL-SOLAR CELL SPACE POWER SUBSYSTEM CAPABILITY.

    Science.gov (United States)

    This report outlines the capabilities and limitations of a hybrid solar cell- fuel cell space power subsystem by comparing the proposed hybrid system...to conventional power subsystem devices. The comparisons are based on projected 1968 capability in the areas of primary and secondary battery, fuel ... cell , solar cell, and chemical dynamic power subsystems. The purpose of the investigation was to determine the relative merits of a hybrid power

  12. Nanoparticle Solar Cell Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Breeze, Alison, J; Sahoo, Yudhisthira; Reddy, Damoder; Sholin, Veronica; Carter, Sue

    2008-06-17

    The purpose of this work was to demonstrate all-inorganic nanoparticle-based solar cells with photovoltaic performance extending into the near-IR region of the solar spectrum as a pathway towards improving power conversion efficiencies. The field of all-inorganic nanoparticle-based solar cells is very new, with only one literature publication in the prior to our project. Very little is understood regarding how these devices function. Inorganic solar cells with IR performance have previously been fabricated using traditional methods such as physical vapor deposition and sputtering, and solution-processed devices utilizing IR-absorbing organic polymers have been investigated. The solution-based deposition of nanoparticles offers the potential of a low-cost manufacturing process combined with the ability to tune the chemical synthesis and material properties to control the device properties. This work, in collaboration with the Sue Carter research group at the University of California, Santa Cruz, has greatly expanded the knowledge base in this field, exploring multiple material systems and several key areas of device physics including temperature, bandgap and electrode device behavior dependence, material morphological behavior, and the role of buffer layers. One publication has been accepted to Solar Energy Materials and Solar Cells pending minor revision and another two papers are being written now. While device performance in the near-IR did not reach the level anticipated at the beginning of this grant, we did observe one of the highest near-IR efficiencies for a nanoparticle-based solar cell device to date. We also identified several key parameters of importance for improving both near-IR performance and nanoparticle solar cells in general, and demonstrated multiple pathways which showed promise for future commercialization with further research.

  13. 24% efficient PERL structure silicon solar cells

    International Nuclear Information System (INIS)

    Zhao, J.; Wang, A.; Green, M.A.

    1990-01-01

    This paper reports that the performance of silicon solar cells have been significantly improved using an improved PERL (passivated emitter, rear locally-diffused) cell structure. This structure overcomes deficiencies in an earlier PERC (passivated emitter and rear cell) cell structure by locally diffusing boron into contact areas at the rear of the cells. Terrestrial energy conversion efficiencies up to 24% are reported for silicon cells for the first time. Air Mass O efficiencies approach 21%. The first batches of concentrator cells using the new structure have demonstrated significant improvement with 29% efficient concentrator silicon cells expected in the near future

  14. Third Working Meeting on Gallium Arsenide Solar Cells

    Science.gov (United States)

    Walker, G. H. (Compiler)

    1976-01-01

    Research results are reported for GaAs Schottky barrier solar cells, GaAlAs/GaAs heteroface solar cells, and GaAlAs graded band gap solar cells. Related materials studies are presented. A systems study for GaAs and Si solar concentrator systems is given.

  15. Plastic Schottky-barrier solar cells

    Science.gov (United States)

    Waldrop, J.R.; Cohen, M.J.

    1981-12-30

    A photovoltaic cell structure is fabricated from an active medium including an undoped polyacetylene, organic semiconductor. When a film of such material is in rectifying contact with a metallic area electrode, a Schottky-barrier junction is obtained within the body of the cell structure. Also, a gold overlayer passivates a magnesium layer on the undoped polyacetylene film. With the proper selection and location of elements a photovoltaic cell structure and solar cell are obtained.

  16. Origin of Open-Circuit Voltage Loss in Polymer Solar Cells and Perovskite Solar Cells.

    Science.gov (United States)

    Kim, Hyung Do; Yanagawa, Nayu; Shimazaki, Ai; Endo, Masaru; Wakamiya, Atsushi; Ohkita, Hideo; Benten, Hiroaki; Ito, Shinzaburo

    2017-06-14

    Herein, the open-circuit voltage (V OC ) loss in both polymer solar cells and perovskite solar cells is quantitatively analyzed by measuring the temperature dependence of V OC to discuss the difference in the primary loss mechanism of V OC between them. As a result, the photon energy loss for polymer solar cells is in the range of about 0.7-1.4 eV, which is ascribed to temperature-independent and -dependent loss mechanisms, while that for perovskite solar cells is as small as about 0.5 eV, which is ascribed to a temperature-dependent loss mechanism. This difference is attributed to the different charge generation and recombination mechanisms between the two devices. The potential strategies for the improvement of V OC in both solar cells are further discussed on the basis of the experimental data.

  17. Solar heating of GaAs nanowire solar cells.

    Science.gov (United States)

    Wu, Shao-Hua; Povinelli, Michelle L

    2015-11-30

    We use a coupled thermal-optical approach to model the operating temperature rise in GaAs nanowire solar cells. We find that despite more highly concentrated light absorption and lower thermal conductivity, the overall temperature rise in a nanowire structure is no higher than in a planar structure. Moreover, coating the nanowires with a transparent polymer can increase the radiative cooling power by 2.2 times, lowering the operating temperature by nearly 7 K.

  18. Amorphous silicon crystalline silicon heterojunction solar cells

    CERN Document Server

    Fahrner, Wolfgang Rainer

    2013-01-01

    Amorphous Silicon/Crystalline Silicon Solar Cells deals with some typical properties of heterojunction solar cells, such as their history, the properties and the challenges of the cells, some important measurement tools, some simulation programs and a brief survey of the state of the art, aiming to provide an initial framework in this field and serve as a ready reference for all those interested in the subject. This book helps to "fill in the blanks" on heterojunction solar cells. Readers will receive a comprehensive overview of the principles, structures, processing techniques and the current developmental states of the devices. Prof. Dr. Wolfgang R. Fahrner is a professor at the University of Hagen, Germany and Nanchang University, China.

  19. Scaling Up ITO-free solar cells

    DEFF Research Database (Denmark)

    Galagan, Yulia; Coenen, Erica W. C.; Zimmermann, Birger

    2014-01-01

    Indium-tin-oxide-free (ITO-free) polymer solar cells with composite electrodes containing current-collecting grids and a semitransparent poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) (PEDOT:PSS) conductor are demonstrated. The up-scaling of the length of the solar cell from 1 to 6 cm...... and the effect of the grid line resistance are explored for a series of devices. Laser-beam-induced current (LBIC) mapping is used for quality control of the devices. A theoretical modeling study is presented that enables the identification of the most rational cell dimension for the grids with different...... resistances. The performance of ITO-free organic solar cells with different dimensions and different electrode resistances are evaluated for different light intensities. The current generation and electric potential distribution are found to not be uniformly distributed in large-area devices at simulated 1...

  20. Microscopic optoelectronic defectoscopy of solar cells

    Directory of Open Access Journals (Sweden)

    Dallaeva D.

    2013-05-01

    Full Text Available Scanning probe microscopes are powerful tool for micro- or nanoscale diagnostics of defects in crystalline silicon solar cells. Solar cell is a large p-n junction semiconductor device. Its quality is strongly damaged by the presence of defects. If the cell works under low reverse-biased voltage, defects emit a light in visible range. The suggested method combines three different measurements: electric noise measurement, local topography and near-field optical beam induced current and thus provides more complex information. To prove its feasibility, we have selected one defect (truncated pyramid in the sample, which emitted light under low reverse-biased voltage.

  1. Organic solar cells fundamentals, devices, and upscaling

    CERN Document Server

    Rand, Barry P

    2014-01-01

    Solution-Processed DonorsB. Burkhart, B. C. ThompsonSmall-Molecule and Vapor-Deposited Organic Photovoltaics R. R. Lunt, R. J. HolmesAcceptor Materials for Solution-Processed Solar Cells Y. HeInterfacial Layers R. Po, C. Carbonera, A. BernardiElectrodes in Organic Photovoltaic Cells S. Yoo, J.-Y. Lee, H. Kim, J. LeeTandem and Multi-Junction Organic Solar Cells J. Gilot, R. A. J. JanssenBulk Heterojunction Morphology Control and Characterization T. Wang, D. G. LidzeyOptical Modeling and Light Management

  2. High-efficiency concentrator silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

    1990-11-01

    This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

  3. Dye-sensitised solar cell (artificial photosynthesis)

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2006-02-01

    Full Text Available is the nano- crystalline TiO2dye- sensitised solar cell (DSC), in conjunction with several new concepts, such as nanotechnology and molecular devices. An efficient and low-cost cell can be produced by using simple materials. The production process generates...

  4. Thermal stability of gallium arsenide solar cells

    Science.gov (United States)

    Papež, Nikola; Škvarenina, Ľubomír.; Tofel, Pavel; Sobola, Dinara

    2017-12-01

    This article summarizes a measurement of gallium arsenide (GaAs) solar cells during their thermal processing. These solar cells compared to standard silicon cells have better efficiency and high thermal stability. However, their use is partly limited due to high acquisition costs. For these reasons, GaAs cells are deployed only in the most demanding applications where their features are needed, such as space applications. In this work, GaAs solar cells were studied in a high temperature range within 30-650 °C where their functionality and changes in surface topology were monitored. These changes were recorded using an electron microscope which determined the position of the defects; using an atomic force microscope we determined the roughness of the surface and an infrared camera that showed us the thermal radiated places of the defected parts of the cell. The electrical characteristics of the cells during processing were determined by its current-voltage characteristics. Despite the occurrence of subtle changes on the solar cell with newly created surface features after 300 °C thermal processing, its current-voltage characteristic remained without a significant change.

  5. Radiation resistant passivation of silicon solar cells

    International Nuclear Information System (INIS)

    Swanson, R.M.; Gan, J.Y.; Gruenbaum, P.E.

    1991-01-01

    This patent describes a silicon solar cell having improved stability when exposed to concentrated solar radiation. It comprises a body of silicon material having a major surface for receiving radiation, a plurality of p and n conductivity regions in the body for collecting electrons and holes created by impinging radiation, and a passivation layer on the major surface including a first layer of silicon oxide in contact with the body and a polycrystalline silicon layer on the first layer of silicon oxide

  6. Microbial solar cells: applying photosynthetic and electrochemically active organisms

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Timmers, R.A.; Helder, M.; Steinbusch, K.J.J.; Hamelers, H.V.M.; Buisman, C.J.N.

    2011-01-01

    Microbial solar cells (MSCs) are recently developed technologies that utilize solar energy to produce electricity or chemicals. MSCs use photoautotrophic microorganisms or higher plants to harvest solar energy, and use electrochemically active microorganisms in the bioelectrochemical system to

  7. Light-trapping in perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Du, Qing Guo, E-mail: duqi0001@e.ntu.edu.sg [Department of Physics, University of Toronto, 60 ST. George St., Toronto, Ontario, M5S 1A7 (Canada); Institute of High Performance Computing, A* STAR, Singapore, 138632 (Singapore); Shen, Guansheng [Department of Physics, University of Toronto, 60 ST. George St., Toronto, Ontario, M5S 1A7 (Canada); School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); John, Sajeev [Department of Physics, University of Toronto, 60 ST. George St., Toronto, Ontario, M5S 1A7 (Canada); Department of Physics, Soochow University, Suzhou (China)

    2016-06-15

    We numerically demonstrate enhanced light harvesting efficiency in both CH{sub 3}NH{sub 3}PbI{sub 3} and CH(NH{sub 2}){sub 2}PbI{sub 3}-based perovskite solar cells using inverted vertical-cone photonic-crystal nanostructures. For CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells, the maximum achievable photocurrent density (MAPD) reaches 25.1 mA/cm{sup 2}, corresponding to 92% of the total available photocurrent in the absorption range of 300 nm to 800 nm. Our cell shows 6% absorption enhancement compared to the Lambertian limit (23.7 mA/cm{sup 2}) and has a projected power conversion efficiency of 12.9%. Excellent solar absorption is numerically demonstrated over a broad angular range from 0 to 60 degree for both S- and P- polarizations. For the corresponding CH(NH{sub 2}){sub 2}PbI{sub 3} based perovskite solar cell, with absorption range of 300 nm to 850 nm, we find a MAPD of 29.1 mA/cm{sup 2}, corresponding to 95.4% of the total available photocurrent. The projected power conversion efficiency of the CH(NH{sub 2}){sub 2}PbI{sub 3} based photonic crystal solar cell is 23.4%, well above the current world record efficiency of 20.1%.

  8. Space Radiation Effect on Si Solar Cells

    Directory of Open Access Journals (Sweden)

    Jae-Jin Lee

    2008-12-01

    Full Text Available High energy charged particles are trapped by geomagnetic field in the region named Van Allen Belt. These particles can move to low altitude along magnetic field and threaten even low altitude spacecraft. Space Radiation can cause equipment failures and on occasions can even destroy operations of satellites in orbit. Sun sensors aboard Science and Technology Satellite (STSAT-1 was designed to detect sun light with silicon solar cells which performance was degraded during satellite operation. In this study, we try to identify which particle contribute to the solar cell degradation with ground based radiation facilities. We measured the short circuit current after bombarding electrons and protons on the solar cells same as STSAT-1 sun sensors. Also we estimated particle flux on the STSAT-1 orbit with analyzing NOAA POES particle data. Our result clearly shows STSAT-1 solar cell degradation was caused by energetic protons which energy is about 700 keV to 1.5 MeV. Our result can be applied to estimate solar cell conditions of other satellites.

  9. Neutral Color Semitransparent Microstructured Perovskite Solar Cells

    KAUST Repository

    Eperon, Giles E.

    2014-01-28

    Neutral-colored semitransparent solar cells are commercially desired to integrate solar cells into the windows and cladding of buildings and automotive applications. Here, we report the use of morphological control of perovskite thin films to form semitransparent planar heterojunction solar cells with neutral color and comparatively high efficiencies. We take advantage of spontaneous dewetting to create microstructured arrays of perovskite "islands", on a length-scale small enough to appear continuous to the eye yet large enough to enable unattenuated transmission of light between the islands. The islands are thick enough to absorb most visible light, and the combination of completely absorbing and completely transparent regions results in neutral transmission of light. Using these films, we fabricate thin-film solar cells with respectable power conversion efficiencies. Remarkably, we find that such discontinuous films still have good rectification behavior and relatively high open-circuit voltages due to the inherent rectification between the n- and p-type charge collection layers. Furthermore, we demonstrate the ease of "color-tinting" such microstructured perovksite solar cells with no reduction in performance, by incorporation of a dye within the hole transport medium. © 2013 American Chemical Society.

  10. Development of large area, high efficiency amorphous silicon solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K.S.; Kim, S.; Kim, D.W. [Yu Kong Taedok Institute of Technology (Korea, Republic of)

    1996-02-01

    The objective of the research is to develop the mass-production technologies of high efficiency amorphous silicon solar cells in order to reduce the costs of solar cells and dissemination of solar cells. Amorphous silicon solar cell is the most promising option of thin film solar cells which are relatively easy to reduce the costs. The final goal of the research is to develop amorphous silicon solar cells having the efficiency of 10%, the ratio of light-induced degradation 15% in the area of 1200 cm{sup 2} and test the cells in the form of 2 Kw grid-connected photovoltaic system. (author) 35 refs., 8 tabs., 67 figs.

  11. Turbulent cascade in the solar wind at kinetic scales and quasi-parallel whistler waves

    Science.gov (United States)

    Alexandrova, O.; Lacombe, C.; Mangeney, A.; Grappin, R.; Maksimovic, M.; Matteini, L.; Santolik, O.; Cornilleau-Wehrlin, N.; de Conchy, Y.

    2014-12-01

    The nature of the magnetic field fluctuations in the solar wind between the ion and electron scales is still under debate. Using the Cluster/STAFF instrument, we make a survey of the power spectral density and of the polarization of these fluctuations at frequencies 1-400 Hz, during five years (2001-2005) when Cluster was in the free solar wind, i.e. not magnetically connected to the Earth's bow-shock.In most of the analyzed time intervals, the fluctuations are non-polarized and they have a general spectral shape between the ion scales and a fraction of electron scales. The intensity of these spectra is well correlated to the ion thermal pressure. These non-polarized fluctuations seem to have a negligible frequency in the solar wind frame, and a wavevector anisotropy kperp>>k||. In the rest ~10% of the selected data, we observe narrow-band, right-handed, circularly polarized fluctuations, with wave vectors quasi-parallel to the mean magnetic field, superimposed on the spectrum of the permanent background turbulence. We interpret these coherent fluctuations as whistler mode waves. The life time of such waves varies between a few seconds and several hours. We analyze in details the long-lived whistler waves, i.e. with a life time longer than five minutes. We find several conditions for the appearance of such waves: (1) a low level of the background turbulence; (2) a low ion thermal pressure; (3) a slow solar wind speed; (4) an electron heat flux Qe>4μW/m2; (5) an electron mean free path larger than 0.5 AU, i.e., a low collisional frequency; (6) a change in the magnetic field direction. When the level of the background turbulence is high, we cannot affirm that whistler waves do not exist: they can be just masked by the turbulence. The six above conditions for the presence of parallel whistlers in the free solar wind are necessary but are not sufficient. When the electron parallel beta factor βe is larger than 3, the whistler waves are seen along the heat flux

  12. Silicon MIS/inversion-layer solar cells

    Science.gov (United States)

    Olsen, L. C.

    1982-10-01

    Silicon Metal-Insulator-Semiconductor/Inversion-Layer (MIS-IL) solar cells were investigated as an approach to low cost terrestrial photovoltaics. Considerable progress was made concerning the development of procedures for SiO deposition for inversion-layer formation, the characterization of the fixed charge in deposited SiO layers, surface state density at the Si-SiO interface, fabrication and characterization of MIS-IL solar cells. Improvements were also made in the theory of MIS-IL solar cells, and utilized to calculate cell performance for a range of insulator charge and base resistivities. Inversion layer formation was studied in several ways. MOS devices was analyzed to determine the magnitude of the net positive charge, Q/sub POS/, vensus surface potential, Psi/sub S/. In situ sheet resistance measurements was made to determine the charge distribution within the deposited SiO layer. Finally, estimates of Q/sub POS/ obtained by comparing experimental results for MIS-IL cells and theory are compared with values of Q/sub POS/ determined for MOS structures fabricated simultaneously with the solar cells. Cell fabrication procedures emphasized low temperature processing.

  13. Fabricating solar cells with silicon nanoparticles

    Science.gov (United States)

    Loscutoff, Paul; Molesa, Steve; Kim, Taeseok

    2014-09-02

    A laser contact process is employed to form contact holes to emitters of a solar cell. Doped silicon nanoparticles are formed over a substrate of the solar cell. The surface of individual or clusters of silicon nanoparticles is coated with a nanoparticle passivation film. Contact holes to emitters of the solar cell are formed by impinging a laser beam on the passivated silicon nanoparticles. For example, the laser contact process may be a laser ablation process. In that case, the emitters may be formed by diffusing dopants from the silicon nanoparticles prior to forming the contact holes to the emitters. As another example, the laser contact process may be a laser melting process whereby portions of the silicon nanoparticles are melted to form the emitters and contact holes to the emitters.

  14. Doctor Blade-Coated Polymer Solar Cells

    KAUST Repository

    Cho, Nam Chul

    2016-10-25

    In this work, we report polymer solar cells based on blade-coated P3HT:PC71BM and PBDTTT-EFT:PC71BM bulk heterojunction photoactive layers. Enhanced power conversion efficiency of 2.75 (conventional structure) and 3.03% (inverted structure) with improved reproducibility was obtained from blade-coated P3HT:PC71BM solar cells, compared to spin-coated ones. Furthermore, by demonstrating 3.10% efficiency flexible solar cells using blade-coated PBDTTT-EFT:PC71BM films on the plastic substrates, we suggest the potential applicability of blade coating technique to the high throughput roll-to-roll fabrication systems.

  15. Questionable effects of antireflective coatings on inefficiently cooled solar cells

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Galster, Georg; Larsen, Esben

    1998-01-01

    A model for temperature effects in p-n junction solar cells is introduced. The temperature of solar cells and the losses in the solar cell junction region caused by elevating temperature are discussed. The model developed is examined for low-cost silicon solar cells. In order to improve the shape...... of the output power and efficiency curves throughout the day the coherence between technical parameters of the solar cells and the climate in the operation region is observed and examined. It is shown how the drop in output power around noon can be avoided by fitting technical parameters of the solar cells...

  16. Solar Cells Having a Nanostructured Antireflection Layer

    DEFF Research Database (Denmark)

    2013-01-01

    An solar cell having a surface in a first material is provided, the optical device having a non-periodic nanostructure formed in the surface, the nanostructure comprising a plurality of cone -haped structures wherein the cones are distributed non-periodically on the surface and have a random height...... distribution, at least a part of the cone-shaped structures having a height of at least 100 nm. The first material may be SiC or GaN. A method of manufacturing a non-periodic nanostructured surface on a solar cell, is furthermore provided, the method comprising the steps of providing a surface comprising Si...

  17. High throughput solar cell ablation system

    Science.gov (United States)

    Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

    2012-09-11

    A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

  18. Origami-enabled deformable silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Rui; Huang, Hai; Liang, Hanshuang; Liang, Mengbing [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Tu, Hongen; Xu, Yong [Electrical and Computer Engineering, Wayne State University, 5050 Anthony Wayne Dr., Detroit, Michigan 48202 (United States); Song, Zeming; Jiang, Hanqing, E-mail: hanqing.jiang@asu.edu [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Yu, Hongyu, E-mail: hongyu.yu@asu.edu [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287 (United States)

    2014-02-24

    Deformable electronics have found various applications and elastomeric materials have been widely used to reach flexibility and stretchability. In this Letter, we report an alternative approach to enable deformability through origami. In this approach, the deformability is achieved through folding and unfolding at the creases while the functional devices do not experience strain. We have demonstrated an example of origami-enabled silicon solar cells and showed that this solar cell can reach up to 644% areal compactness while maintaining reasonable good performance upon cyclic folding/unfolding. This approach opens an alternative direction of producing flexible, stretchable, and deformable electronics.

  19. Origami-enabled deformable silicon solar cells

    International Nuclear Information System (INIS)

    Tang, Rui; Huang, Hai; Liang, Hanshuang; Liang, Mengbing; Tu, Hongen; Xu, Yong; Song, Zeming; Jiang, Hanqing; Yu, Hongyu

    2014-01-01

    Deformable electronics have found various applications and elastomeric materials have been widely used to reach flexibility and stretchability. In this Letter, we report an alternative approach to enable deformability through origami. In this approach, the deformability is achieved through folding and unfolding at the creases while the functional devices do not experience strain. We have demonstrated an example of origami-enabled silicon solar cells and showed that this solar cell can reach up to 644% areal compactness while maintaining reasonable good performance upon cyclic folding/unfolding. This approach opens an alternative direction of producing flexible, stretchable, and deformable electronics

  20. Flexible ITO-Free Polymer Solar Cells

    DEFF Research Database (Denmark)

    Angmo, Dechan; Krebs, Frederik C

    2013-01-01

    Indium tin oxide (ITO) is the material-of-choice for transparent conductors in any optoelectronic application. However, scarce resources of indium and high market demand of ITO have created large price fluctuations and future supply concerns. In polymer solar cells (PSCs), ITO is the single......-most cost driving factor due to expensive raw materials and processing. Given the limited lifetime and stability of PSCs as compared with other mature technologies such as silicon-based solar cells, the technological future of PSCs beyond that of academic interests rests in reducing cost of production...

  1. Advances in solar cell welding technology

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, L.G.; Lott, D.R.

    1982-09-01

    In addition to developing the rigid substrate welded conventional cell panels for an earlier U.S. flight program, LMSC recently demonstrated a welded lightweight array system using both 2 x 4 and 5.9 x 5.9 cm wraparound solar cells. This weld system uses infrared sensing of weld joint temperature at the cell contact metalization interface to precisely control weld energy on each joint. Modules fabricated using this weld control system survived lowearth-orbit simulated 5-year tests (over 30,000 cycles) without joint failure. The data from these specifically configured modules, printed circuit substrate with copper interconnect and dielectric wraparound solar cells, can be used as a basis for developing weld schedules for additional cell array panel types.

  2. Calculation of the Performance of Solar Cells With Spectral Down Shifters Using Realistic Outdoor Solar Spectra

    NARCIS (Netherlands)

    van Sark, W.G.J.H.M.

    2007-01-01

    Spectral down converters and shifters have been proposed as a good means to enhance the efficiency of underlying solar cells. In this paper, we focus on the simulation of the outdoor performance of solar cells with spectral down shifters, i.e., multicrystalline silicon solar cells with semiconductor

  3. Cyclic AMP activates the mitogen-activated protein kinase cascade in PC12 cells

    DEFF Research Database (Denmark)

    Frödin, M; Peraldi, P; Van Obberghen, E

    1994-01-01

    reported. In rat pheochromocytoma PC12 cells, we demonstrate here a stimulation of the MAP kinase isozyme extracellular signal-regulated kinase 1 (ERK1) following elevation of intracellular cAMP after exposure of the cells to isobutylmethylxanthine, cholera toxin, forskolin, or cAMP-analogues. cAMP acted...... upstream activator of ERK1 in the MAP kinase cascade. Supporting this view, forskolin and a cAMP analogue were found to increase the activity of MAP kinase kinase in PC12 cells, alone as well as in combination with phorbol ester. PACAP38 also stimulated in vivo 32P-labeling of ERK1 and MAP kinase kinase...... activity. Finally, cAMP or PACAP38 increased by 3-fold nerve growth factor-stimulated neurite formation in PC12 cells, which may be correlated with the potentiating effect of these agents on nerve growth factor-stimulated ERK1 activity....

  4. 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.

  5. Assembly jig assures reliable solar cell modules

    Science.gov (United States)

    Ofarrell, H. O.

    1966-01-01

    Assembly jig holds the components for a solar cell module in place as the assembly is soldered and bonded by the even heat of an oven. The jig is designed to the configuration of the planned module. It eliminates uneven thermal conditions caused by hand soldering methods.

  6. Energy. From firewood to solar cell

    International Nuclear Information System (INIS)

    Reijnders, L.

    2006-01-01

    An outline is given of the development of energy and the options to secure the energy supply for the future. Much information is given about energy efficiency, the exploitation of tar sands, reopening of the coal mines in the Netherlands, nuclear fusion and fission, wave energy and solar cells, etc [nl

  7. Baselines for Lifetime of Organic Solar Cells

    DEFF Research Database (Denmark)

    Gevorgyan, Suren; Espinosa Martinez, Nieves; Ciammaruchi, Laura

    2016-01-01

    The process of accurately gauging lifetime improvements in organic photovoltaics (OPVs) or other similar emerging technologies, such as perovskites solar cells is still a major challenge. The presented work is part of a larger effort of developing a worldwide database of lifetimes that can help...

  8. CPV solar cell modeling and metallization optimization

    NARCIS (Netherlands)

    Gupta, D.K.; Barink, M.; Langelaar, M.

    2018-01-01

    Concentrated photovoltaics (CPV) has recently gained popularity due to its ability to deliver significantly more power at relatively lower absorber material costs. In CPVs, lenses and mirrors are used to concentrate illumination over a small solar cell, thereby increasing the incident light by

  9. Stability and Degradation of Polymer Solar cells

    DEFF Research Database (Denmark)

    Norrman, Kion

    The current state-of-the-art allows for roll-to-roll manufacture of polymer solar cells in high volume with stability and efficiency sufficient to grant success in low-energy applications. However, further improvement is needed for the successful application of the devices in real life applications...

  10. CPV solar cell modeling and metallization optimization

    NARCIS (Netherlands)

    Gupta, D.K.; Barink, Marco; Langelaar, M.

    2018-01-01

    Concentrated photovoltaics (CPV) has recently gained popularity due to its ability to deliver significantly more power at relatively lower absorber material costs. In CPVs, lenses and mirrors are used to concentrate illumination over a small solar cell, thereby increasing the incident light by

  11. Hybrid Silicon Nanocone–Polymer Solar Cells

    KAUST Repository

    Jeong, Sangmoo

    2012-06-13

    Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm 2, which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution. © 2012 American Chemical Society.

  12. PHOTOELECTROCHEMICAL SOLAR CELLS BASED ON DYE ...

    African Journals Online (AJOL)

    conventional solid-state solar cells convert light into electricity by ... network via diffusion [2] due to electron scattering to the conductive .... The surface network morphology of these film layers was examined with an atomic force microscope in contact mode. (AFM: Nanoscope Illa from digital instruments version 4.42r4).

  13. Upconverter solar cells: materials and applications

    NARCIS (Netherlands)

    de Wild, J.; Meijerink, A.; Rath, J.K.; van Sark, W.G.J.H.M.; Schropp, R.E.I.

    2011-01-01

    Spectral conversion of sunlight is a promising route to reduce spectral mismatch losses that are responsible for the major part of the efficiency losses in solar cells. Both upconversion and downconversion materials are presently explored. In an upconversion process, photons with an energy lower

  14. Distributed series resistance effects in solar cells

    DEFF Research Database (Denmark)

    Nielsen, Lars Drud

    1982-01-01

    A mathematical treatment is presented of the effects of one-dimensional distributed series resistance in solar cells. A general perturbation theory is developed, including consistently the induced spatial variation of diode current density and leading to a first-order equivalent lumped resistance...

  15. Solar Cell Efficiency Tables (Version 51)

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Dean H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Green, Martin A. [University of New South Wales; Hishikawa, Yoshihiro [National Institute of Advanced Industrial Science and Technology (AIST); Dunlop, Ewan D. [European Commission-Joint Research Centre; Hohl-Ebinger, Jochen [Fraunhofer Institute for Solar Energy Systems; Ho-Baillie, Anita W. Y. [University of New South Wales

    2017-12-14

    Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since July 2017 are reviewed, together with progress over the last 25 years. Appendices are included documenting area definitions and also listing recognised test centres.

  16. Floating-Emitter Solar-Cell Transistor

    Science.gov (United States)

    Sah, C. T.; Cheng, L. J.

    1986-01-01

    Conceptual transistor embedded in photovoltaic diode promises to increase efficiency to more than 20 percent. Solar-cell transistor has front-surface contact, rear contact, and floating emitter. Variety of other contact and junction configurations possible, but do not offer ease of fabrication in combination with high performance.

  17. Passivated emitters in silicon solar cells

    International Nuclear Information System (INIS)

    King, R.R.; Gruenbaum, P.E.; Sinton, R.A.; Swanson, R.M.

    1990-01-01

    In high-efficiency silicon solar cells with low metal contact coverage fractions and high bulk lifetimes, cell performance is often dominated by recombination in the oxide-passivated diffusions on the cell surface. Measurements of the emitter saturation current density, J o , of oxide-passivated, boron and phosphorus diffusions are presented, and from these measurements, the dependence of surface recombination velocity on dopant concentration was extracted. The lowest observed values of J o which are stable under UV light are given for both boron- and phosphorus-doped, oxide-passivated diffusions, for both textured and untextured surfaces. Contour plots which incorporate the above data have been applied to two types of backside-contact solar cells with large area (37.5 cm 2 ) and one-sun efficiencies up to 22.7%

  18. How the relative permittivity of solar cell materials influences solar cell performance

    DEFF Research Database (Denmark)

    Crovetto, Andrea; Huss-Hansen, Mathias K.; Hansen, Ole

    2017-01-01

    The relative permittivity of the materials constituting heterojunction solar cells is usually not considered as a design parameter when searching for novel combinations of heterojunction materials. In this work, we investigate the validity of such an approach. Specifically, we show the effect...... of the materials permittivity on the physics and performance of the solar cell by means of numerical simulation supported by analytical relations. We demonstrate that, depending on the specific solar cell configuration and materials properties, there are scenarios where the relative permittivity has a major...... the heterojunction partner has a high permittivity, solar cells are consistently more robust against several non-idealities that are especially likely to occur in early-stage development, when the device is not yet optimized....

  19. Local Structure Analysis of Materials for Solar Cell Absorber Layer

    OpenAIRE

    Jewell, Leila Elizabeth

    2016-01-01

    This dissertation examines solar cell absorber materials that have the potential to replace silicon in solar cells, including several copper-based sulfides and perovskites. Earth-abundant absorbers such as these become even more cost-effective when used in a nanostructured solar cell. Atomic layer deposition (ALD) and chemical vapor deposition (CVD) deposit highly conformal films and hence are important tools for developing extremely thin absorber solar cells with scalability. Thus, the prima...

  20. Review of Recent Progress in Dye-Sensitized Solar Cells

    OpenAIRE

    Fan-Tai Kong; Song-Yuan Dai; Kong-Jia Wang

    2007-01-01

    We introduced the structure and the principle of dye-sensitized solar cell (DSC). The latest results about the critical technology and the industrialization research on dye-sensitized solar cells were reviewed. The development of key components, including nanoporous semiconductor films, dye sensitizers, redox electrolyte, counter electrode, and conducting substrate in dye-sensitized solar cells was reviewed in detail. The developing progress and prospect of dye-sensitized solar cells from sma...

  1. Plastic Schottky barrier solar cells

    Science.gov (United States)

    Waldrop, James R.; Cohen, Marshall J.

    1984-01-24

    A photovoltaic cell structure is fabricated from an active medium including an undoped, intrinsically p-type organic semiconductor comprising polyacetylene. When a film of such material is in rectifying contact with a magnesium electrode, a Schottky-barrier junction is obtained within the body of the cell structure. Also, a gold overlayer passivates the magnesium layer on the undoped polyacetylene film.

  2. Expression Analysis of the Hippo Cascade Indicates a Role in Pituitary Stem Cell Development

    Directory of Open Access Journals (Sweden)

    Emily J Lodge

    2016-03-01

    Full Text Available The pituitary gland is a primary endocrine organ that controls major physiological processes. Abnormal development or homeostatic disruptions can lead to human disorders such as hypopituitarism or tumours. Multiple signalling pathways, including WNT, BMP, FGF and SHH regulate pituitary development but the role of the Hippo-YAP1/TAZ cascade is currently unknown. In multiple tissues, the Hippo kinase cascade underlies neoplasias; it influences organ size through the regulation of proliferation and apoptosis, and has roles in determining stem cell potential. We have used a sensitive mRNA in situ hybridisation method (RNAscope to determine the expression patterns of the Hippo pathway components during mouse pituitary development. We have also carried out immunolocalisation studies to determine when YAP1 and TAZ, the transcriptional effectors of the Hippo pathway, are active. We find that YAP1/TAZ are active in the stem/progenitor cell population throughout development and at postnatal stages, consistent with their role in promoting the stem cell state. Our results demonstrate for the first time the collective expression of major components of the Hippo pathway during normal embryonic and postnatal development of the pituitary gland.

  3. Metal nanoparticles for thin film solar cells

    DEFF Research Database (Denmark)

    Gritti, Claudia

    Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution in the infr......Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution...... characterized. Spectral responses are measured and in two types of measured GaAs solar cells (with Au and Ag nanoparticles) there was no clear efficiency enhancement in the NIR spectral range. In the case of Au nanoparticles it could be explained in similar way to the absorption data: the effect being broad...... cells spectral response to longer wavelengths, through possibly cheap and simple technologies: EBL can be substituted by colloidal solutions implementation and electroless plating is not expensive and results to be effective within a broad set of parameters (size, shape, density). Another application...

  4. Flexible thermal cycle test equipment for concentrator solar cells

    Science.gov (United States)

    Hebert, Peter H [Glendale, CA; Brandt, Randolph J [Palmdale, CA

    2012-06-19

    A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

  5. Review of Recent Progress in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Fan-Tai Kong

    2007-01-01

    Full Text Available We introduced the structure and the principle of dye-sensitized solar cell (DSC. The latest results about the critical technology and the industrialization research on dye-sensitized solar cells were reviewed. The development of key components, including nanoporous semiconductor films, dye sensitizers, redox electrolyte, counter electrode, and conducting substrate in dye-sensitized solar cells was reviewed in detail. The developing progress and prospect of dye-sensitized solar cells from small cells in the laboratory to industrialization large-scale production were reviewed. At last, the future development of DSC was prospective for the tendency of dye-sensitized solar cells.

  6. Segregation of the anodic microbial communities in a microbial fuel cell cascade

    Directory of Open Access Journals (Sweden)

    Douglas eHodgson

    2016-05-01

    Full Text Available Metabolic interactions within microbial communities are essential for the efficient degradation of complex organic compounds, and underpin natural phenomena driven by microorganisms, such as the recycling of carbon-, nitrogen-, and sulphur-containing molecules. These metabolic interactions ultimately determine the function, activity and stability of the community, and therefore their understanding would be essential to steer processes where microbial communities are involved. This is exploited in the design of microbial fuel cells (MFCs, bioelectrochemical devices that convert the chemical energy present in substrates into electrical energy through the metabolic activity of microorganisms, either single species or communities. In this work, we analysed the evolution of the microbial community structure in a cascade of microbial fuel cells (MFCs inoculated with an anaerobic microbial community and continuously fed with a complex medium. The analysis of the composition of the anodic communities revealed the establishment of different communities in the anodes of the hydraulically connected MFCs, with a decrease in the abundance of fermentative taxa and a concurrent increase in respiratory taxa along the cascade. The analysis of the metabolites in the anodic suspension showed a metabolic shift between the first and last MFC, confirming the segregation of the anodic communities. Those results suggest a metabolic interaction mechanism between the predominant fermentative bacteria at the first stages of the cascade and the anaerobic respiratory electrogenic population in the latter stages, which is reflected in the observed increase in power output. We show that our experimental system represents an ideal platform for optimization of processes where the degradation of complex substrates is involved, as well as a potential tool for the study of metabolic interactions in complex microbial communities.

  7. Hedgehog signaling acts with the temporal cascade to promote neuroblast cell cycle exit.

    Directory of Open Access Journals (Sweden)

    Phing Chian Chai

    Full Text Available In Drosophila postembryonic neuroblasts, transition in gene expression programs of a cascade of transcription factors (also known as the temporal series acts together with the asymmetric division machinery to generate diverse neurons with distinct identities and regulate the end of neuroblast proliferation. However, the underlying mechanism of how this "temporal series" acts during development remains unclear. Here, we show that Hh signaling in the postembryonic brain is temporally regulated; excess (earlier onset of Hh signaling causes premature neuroblast cell cycle exit and under-proliferation, whereas loss of Hh signaling causes delayed cell cycle exit and excess proliferation. Moreover, the Hh pathway functions downstream of Castor but upstream of Grainyhead, two components of the temporal series, to schedule neuroblast cell cycle exit. Interestingly, hh is likely a target of Castor. Hence, Hh signaling provides a link between the temporal series and the asymmetric division machinery in scheduling the end of neurogenesis.

  8. Spatio-temporal dynamcis of a cell signal cascade with negative feedback

    Science.gov (United States)

    Maya Bernal, Jose Luis; Ramirez-Santiago, Guillermo

    2014-03-01

    We studied the spatio-temporal dynamics of a system of reactio-diffusion equations that models a cell signal transduction pathway with six cycles and negative feedback. The basic cycle consists of the phosphorylation-dephosphorylation of two antagonic proteins. We found two regimes of saturation of the enzimatic reaction in the kinetic parameters space and determined the conditions for the signal propagation in the steady state. The trajectories for which transduction occurs are defined in terms of the ratio of the enzimatic activities. We found that in spite of the negative feedback the cell signal cascade behaves as an amplifier and produces phosphoprotein concentration gradients within the cell. This model behaves also as a noise filter and as a switch. Supported by DGAPA-UNAM Contract IN118410-3.

  9. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Glatkowski, P. J.; Landis, D. A.

    2013-04-16

    Todays solar cells are fabricated using metal oxide based transparent conductive coatings (TCC) or metal wires with optoelectronic performance exceeding that currently possible with Carbon Nanotube (CNT) based TCCs. The motivation for replacing current TCC is their inherent brittleness, high deposition cost, and high deposition temperatures; leading to reduced performance on thin substrates. With improved processing, application and characterization techniques Nanofiber and/or CNT based TCCs can overcome these shortcomings while offering the ability to be applied in atmospheric conditions using low cost coating processes At todays level of development, CNT based TCC are nearing commercial use in touch screens, some types of information displays (i.e. electronic paper), and certain military applications. However, the resistivity and transparency requirements for use in current commercial solar cells are more stringent than in many of these applications. Therefore, significant research on fundamental nanotube composition, dispersion and deposition are required to reach the required performance commanded by photovoltaic devices. The objective of this project was to research and develop transparent conductive coatings based on novel nanomaterial composite coatings, which comprise nanotubes, nanofibers, and other nanostructured materials along with binder materials. One objective was to show that these new nanomaterials perform at an electrical resistivity and optical transparency suitable for use in solar cells and other energy-related applications. A second objective was to generate new structures and chemistries with improved resistivity and transparency performance. The materials also included the binders and surface treatments that facilitate the utility of the electrically conductive portion of these composites in solar photovoltaic devices. Performance enhancement venues included: CNT purification and metallic tube separation techniques, chemical doping, CNT

  10. Solar Airplanes and Regenerative Fuel Cells

    Science.gov (United States)

    Bents, David J.

    2007-01-01

    A solar electric aircraft with the potential to "fly forever" has captured NASA's interest, and the concept for such an aircraft was pursued under Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project. Feasibility of this aircraft happens to depend on the successful development of solar power technologies critical to NASA's Exploration Initiatives; hence, there was widespread interest throughout NASA to bring these technologies to a flight demonstration. The most critical is an energy storage system to sustain mission power during night periods. For the solar airplane, whose flight capability is already limited by the diffuse nature of solar flux and subject to latitude and time of year constraints, the feasibility of long endurance flight depends on a storage density figure of merit better than 400-600 watt-hr per kilogram. This figure of merit is beyond the capability of present day storage technologies (other than nuclear) but may be achievable in the hydrogen-oxygen regenerative fuel cell (RFC). This potential has led NASA to undertake the practical development of a hydrogen-oxygen regenerative fuel cell, initially as solar energy storage for a high altitude UAV science platform but eventually to serve as the primary power source for NASAs lunar base and other planet surface installations. Potentially the highest storage capacity and lowest weight of any non-nuclear device, a flight-weight RFC aboard a solar-electric aircraft that is flown continuously through several successive day-night cycles will provide the most convincing demonstration that this technology's widespread potential has been realized. In 1998 NASA began development of a closed cycle hydrogen oxygen PEM RFC under the Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project and continued its development, originally for a solar electric airplane flight, through FY2005 under the Low Emissions Alternative Power (LEAP) project. Construction of

  11. Laser scanning of experimental solar cells

    Science.gov (United States)

    Plunkett, B. C.; Lasswell, P. G.

    1980-01-01

    A description is presented of a laser scanning instrument which makes it possible to display and measure the spatial response of a solar cell. Examples are presented to illustrate the use of generated micrographs in the isolation of flaws and features of the cell. The laser scanner system uses a 4 mW, CW helium-neon laser, operating a wavelength of 0.633 micrometers. The beam is deflected by two mirror galvanometers arranged to scan in orthogonal directions. After being focused on the solar cell by the beam focusing lens, the moving light spot raster scans the specimen. The current output of the photovoltaic device under test, as a function of the scan dot position, can be displayed in several modes. The laser scanner has proved to be a very useful diagnostic tool in optimizing the process design of transparent metal film photovoltaic devices on Zn3P2, a relatively new photovoltaic material.

  12. Microstructured extremely thin absorber solar cells

    DEFF Research Database (Denmark)

    Biancardo, Matteo; Krebs, Frederik C

    2007-01-01

    In this paper we present the realization of extremely thin absorber (ETA) solar cells employing conductive glass substrates functionalized with TiO2 microstructures produced by embossing. Nanocrystalline or compact TiO2 films on Indium doped tin oxide (ITO) glass substrates were embossed by press......In this paper we present the realization of extremely thin absorber (ETA) solar cells employing conductive glass substrates functionalized with TiO2 microstructures produced by embossing. Nanocrystalline or compact TiO2 films on Indium doped tin oxide (ITO) glass substrates were embossed...... by pressing a silicon stamp containing a mu m size raised grid structure into the TiO2 by use of a hydraulic press (1 ton/50 cm(2)). The performance of these microstructured substrates in a ETA cell sensitized by a thermally evaporated or chemical bath deposited PbS film and completed by a PEDOT:PSS hole...

  13. Space solar cell technology development - A perspective

    Science.gov (United States)

    Scott-Monck, J.

    1982-01-01

    The developmental history of photovoltaics is examined as a basis for predicting further advances to the year 2000. Transistor technology was the precursor of solar cell development. Terrestrial cells were modified for space through changes in geometry and size, as well as the use of Ag-Ti contacts and manufacture of a p-type base. The violet cell was produced for Comsat, and involved shallow junctions, new contacts, and an enhanced antireflection coating for better radiation tolerance. The driving force was the desire by private companies to reduce cost and weight for commercial satellite power supplies. Liquid phase epitaxial (LPE) GaAs cells are the latest advancement, having a 4 sq cm area and increased efficiency. GaAs cells are expected to be flight ready in the 1980s. Testing is still necessary to verify production techniques and the resistance to electron and photon damage. Research will continue in CVD cell technology, new panel technology, and ultrathin Si cells.

  14. Proton irradiation effects of amorphous silicon solar cell for solar power satellite

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

    1997-03-01

    Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

  15. Superstrate sub-cell voltage-matched multijunction solar cells

    Science.gov (United States)

    Mascarenhas, Angelo; Alberi, Kirstin

    2016-03-15

    Voltage-matched thin film multijunction solar cell and methods of producing cells having upper CdTe pn junction layers formed on a transparent substrate which in the completed device is operatively positioned in a superstate configuration. The solar cell also includes a lower pn junction formed independently of the CdTe pn junction and an insulating layer between CdTe and lower pn junctions. The voltage-matched thin film multijunction solar cells further include a parallel connection between the CdTe pn junction and lower pn junctions to form a two-terminal photonic device. Methods of fabricating devices from independently produced upper CdTe junction layers and lower junction layers are also disclosed.

  16. Semiconductor Nanocrystals as Light Harvesters in Solar Cells

    Directory of Open Access Journals (Sweden)

    Lioz Etgar

    2013-02-01

    Full Text Available Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered.

  17. Semiconductor Nanocrystals as Light Harvesters in Solar Cells.

    Science.gov (United States)

    Etgar, Lioz

    2013-02-04

    Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG) capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered.

  18. Rational Strategies for Efficient Perovskite Solar Cells.

    Science.gov (United States)

    Seo, Jangwon; Noh, Jun Hong; Seok, Sang Il

    2016-03-15

    A long-standing dream in the large scale application of solar energy conversion is the fabrication of solar cells with high-efficiency and long-term stability at low cost. The realization of such practical goals depends on the architecture, process and key materials because solar cells are typically constructed from multilayer heterostructures of light harvesters, with electron and hole transporting layers as a major component. Recently, inorganic-organic hybrid lead halide perovskites have attracted significant attention as light absorbers for the fabrication of low-cost and high-efficiency solar cells via a solution process. This mainly stems from long-range ambipolar charge transport properties, low exciton binding energies, and suitable band gap tuning by managing the chemical composition. In our pioneering work, a new photovoltaic platform for efficient perovskite solar cells (PSCs) was proposed, which yielded a high power conversion efficiency (PCE) of 12%. The platform consisted of a pillared architecture of a three-dimensional nanocomposite of perovskites fully infiltrating mesoporous TiO2, resulting in the formation of continuous phases and perovskite domains overlaid with a polymeric hole conductor. Since then, the PCE of our PSCs has been rapidly increased from 3% to over 20% certified efficiency. The unprecedented increase in the PCE can be attributed to the effective integration of the advantageous attributes of the refined bicontinuous architecture, deposition process, and composition of perovskite materials. Specifically, the bicontinuous architectures used in the high efficiency comprise a layer of perovskite sandwiched between mesoporous metal-oxide layer, which is a very thinner than that of used in conventional dye-sensitized solar cells, and hole-conducting contact materials with a metal back contact. The mesoporous scaffold can affect the hysteresis under different scan direction in measurements of PSCs. The hysteresis also greatly depends on

  19. Accelerated stress testing of terrestrial solar cells

    Science.gov (United States)

    Prince, J. L.; Lathrop, J. W.

    1979-01-01

    A program to investigate the reliability characteristics of unencapsulated low-cost terrestrial solar cells using accelerated stress testing is described. Reliability (or parametric degradation) factors appropriate to the cell technologies and use conditions were studied and a series of accelerated stress tests was synthesized. An electrical measurement procedure and a data analysis and management system was derived, and stress test fixturing and material flow procedures were set up after consideration was given to the number of cells to be stress tested and measured and the nature of the information to be obtained from the process. Selected results and conclusions are presented.

  20. 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.

  1. Gallium Arsenide solar cell radiation damage experiment

    Science.gov (United States)

    Maurer, R. H.; Kinnison, J. D.; Herbert, G. A.; Meulenberg, A.

    1991-01-01

    Gallium arsenide (GaAs) solar cells for space applications from three different manufactures were irradiated with 10 MeV protons or 1 MeV electrons. The electrical performance of the cells was measured at several fluence levels and compared. Silicon cells were included for reference and comparison. All the GaAs cell types performed similarly throughout the testing and showed a 36 to 56 percent power areal density advantage over the silicon cells. Thinner (8-mil versus 12-mil) GaAs cells provide a significant weight reduction. The use of germanium (Ge) substrates to improve mechanical integrity can be implemented with little impact on end of life performance in a radiation environment.

  2. Highly efficient light management for perovskite solar cells

    Science.gov (United States)

    Wang, Dong-Lin; Cui, Hui-Juan; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2016-01-01

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells. PMID:26733112

  3. Interface engineering of Graphene-Silicon heterojunction solar cells

    Science.gov (United States)

    Xu, Dikai; Yu, Xuegong; Yang, Lifei; Yang, Deren

    2016-11-01

    Graphene has attracted great research interests due to its unique mechanical, electrical and optical properties, which opens up a huge number of opportunities for applications. Recently, Graphene-Silicon (Grsbnd Si) solar cell has been recognized as one interesting candidate for the future photovoltaic. Since the first Grsbnd Si solar cell reported in 2010, Grsbnd Si solar cell has been intensively investigated and the power converse efficiency (PCE) of it has been developed to 15.6%. This review presents and discusses current development of Grsbnd Si solar cell. Firstly, the basic concept and mechanism of Grsbnd Si solar cell are introduced. Then, several key technologies are introduced to improve the performance of Grsbnd Si solar cells, such as chemical doping, annealing, Si surface passivation and interlayer insertion. Particular emphasis is placed on strategies for Grsbnd Si interface engineering. Finally, new pathways and opportunities of "MIS-like structure" Grsbnd Si solar cells are described.

  4. METHOD AND APPARATUS FOR CHARACTERIZATION OF A SOLAR CELL

    DEFF Research Database (Denmark)

    2017-01-01

    ; and estimating variations in the solar cell, thereby electrically characterizing the solar cell. The disclosure further relates to a solar cell characterization apparatus for characterization of a solar cell, comprising: a light source for generating an optical probe light; a modulation unit, configured......The present disclosure relates to a method for characterization of a solar cell, comprising the steps of: providing an optical probe light; modulating the optical probe light with a modulation frequency of between 100 kHz and 50 MHz, thereby obtaining a modulated probe light; scanning the modulated...... probe light such that said modulated probe light is incident on at least a part of the surface of the solar cell, and such that the part of the solar cell exposed to the modulated probe light converts the modulated probe light to an electrical signal; detecting and analyzing said electrical signal...

  5. A Bicontinuous Double Gyroid Hybrid Solar Cell

    KAUST Repository

    Crossland, Edward J. W.

    2009-08-12

    We report the first successful application of an ordered bicontinuous gyroid semiconducting network in a hybrid bulk heterojunction solar cell. The freestanding gyroid network is fabricated by electrochemical deposition into the 10 nm wide voided channels of a self-assembled, selectively degradable block copolymer film. The highly ordered pore structure is ideal for uniform infiltration of an organic hole transporting material, and solid-state dye-sensitized solar cells only 400 nm thick exhibit up to 1.7% power conversion efficiency. This patterning technique can be readily extended to other promising heterojunction systems and is a major step toward realizing the full potential of self-assembly in the next generation of device technologies. © 2009 American Chemical Society.

  6. Thin-film polycrystalline silicon solar cells

    Science.gov (United States)

    Funghnan, B. W.; Blanc, J.; Phillips, W.; Redfield, D.

    1980-08-01

    Thirty-four new solar cells were fabricated on Wacker Sislo substrates and the AM-1 parameters were measured. A detailed comparison was made between the measurement of minority carrier diffusion length by the OE method and the penetrating light laser scan grain boundary photoresponse linewidth method. The laser scan method has more experimental uncertainty and agrees within 10 to 50% with the QE method. It allows determination of L over a large area. Atomic hydrogen passivation studies continued on Wacker material by three techniques. A method of determining surface recombination velocity, s, from laser scan data was developed. No change in s in completed solar cells after H-plasma treatment was observed within experimental error. H-passivation of bare silicon cars as measured by the new laser scan photoconductivity technique showed very large effects.

  7. Perovskite Materials: Solar Cell and Optoelectronic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bin [ORNL; Geohegan, David B [ORNL; Xiao, Kai [ORNL

    2017-01-01

    Hybrid organometallic trihalide perovskites are promising candidates in the applications for next-generation, high-performance, low-cost optoelectronic devices, including photovoltaics, light emitting diodes, and photodetectors. Particularly, the solar cells based on this type of materials have reached 22% lab scale power conversion efficiency in only about seven years, comparable to the other thin film photovoltaic technologies. Hybrid perovskite materials not only exhibit superior optoelectronic properties, but also show many interesting physical properties such as ion migration and defect physics, which may allow the exploration of more device functionalities. In this article, the fundamental understanding of the interrelationships between crystal structure, electronic structure, and material properties is discussed. Various chemical synthesis and processing methods for superior device performance in solar cells and optoelectronic devices are reviewed.

  8. Promises and challenges of perovskite solar cells

    Science.gov (United States)

    Correa-Baena, Juan-Pablo; Saliba, Michael; Buonassisi, Tonio; Grätzel, Michael; Abate, Antonio; Tress, Wolfgang; Hagfeldt, Anders

    2017-11-01

    The efficiencies of perovskite solar cells have gone from single digits to a certified 22.1% in a few years’ time. At this stage of their development, the key issues concern how to achieve further improvements in efficiency and long-term stability. We review recent developments in the quest to improve the current state of the art. Because photocurrents are near the theoretical maximum, our focus is on efforts to increase open-circuit voltage by means of improving charge-selective contacts and charge carrier lifetimes in perovskites via processes such as ion tailoring. The challenges associated with long-term perovskite solar cell device stability include the role of testing protocols, ionic movement affecting performance metrics over extended periods of time, and determination of the best ways to counteract degradation mechanisms.

  9. The photophysics of perovskite solar cells

    Science.gov (United States)

    Sum, Tze Chien

    2014-09-01

    Solution-processed hybrid organic-inorganic perovskite solar cells, a newcomer to the photovoltaic arena, have taken the field by storm with their extraordinary power conversion efficiencies exceeding 17%. In this paper, the photophysics and the latest findings on the carrier dynamics and charge transfer mechanisms in this new class of photovoltaic material will be examined and distilled. Some open photophysics questions will also be discussed.

  10. 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.

  11. PbSe Nanocrystal Excitonic Solar Cells

    KAUST Repository

    Choi, Joshua J.

    2009-11-11

    We report the design, fabrication, and characterization of colloidal PbSe nanocrystal (NC)-based photovoltaic test structures that exhibit an excitonic solar cell mechanism. Charge extraction from the NC active layer is driven by a photoinduced chemical potential energy gradient at the nanostructured heterojunction. By minimizing perturbation to PbSe NC energy levels and thereby gaining insight into the "intrinsic" photovoltaic properties and charge transfer mechanism of PbSe NC, we show a direct correlation between interfacial energy level offsets and photovoltaic device performance. Size dependent PbSe NC energy levels were determined by cyclic voltammetry and optical spectroscopy and correlated to photovoltaic measurements. Photovoltaic test structures were fabricated from PbSe NC films sandwiched between layers of ZnO nanoparticles and PEDOT:PSS as electron and hole transporting elements, respectively. The device current-voltage characteristics suggest a charge separation mechanism that Is distinct from previously reported Schottky devices and consistent with signatures of excitonic solar cells. Remarkably, despite the limitation of planar junction structure, and without film thickness optimization, the best performing device shows a 1-sun power conversion efficiency of 3.4%, ranking among the highest performing NC-based solar cells reported to date. © 2009 American Chemical Society.

  12. Thin-film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.

    1987-10-01

    Cadmium telluride, with a room-temperature band-gap energy of 1.5 eV, is a promising thin-film photovoltaic material. The major objective of this research has been to demonstrate thin-film CdTe heterojunction solar cells with a total area greater than 1 sq cm and photovoltaic efficiencies of 13 percent or more. Thin-film p-CdTe/CdS/SnO2:F/glass solar cells with an AM1.5 efficiency of 10.5 percent have been reported previously. This report contains results of work done on: (1) the deposition, resistivity control, and characterization of p-CdTe films by the close-spaced sublimation process; (2) the deposition of large-band-gap window materials; (3) the electrical properties of CdS/CdTe heterojunctions; (4) the formation of stable, reproducible, ohmic contacts (such as p-HgTe) to p-CdTe; and (5) the preparation and evaluation of heterojunction solar cells.

  13. Accelerated stress testing of terrestrial solar cells

    Science.gov (United States)

    Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.

    1982-01-01

    The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.

  14. Gallium arsenide solar cell radiation damage study

    Science.gov (United States)

    Maurer, R. H.; Herbert, G. A.; Kinnison, J. D.; Meulenberg, A.

    1989-01-01

    A thorough analysis has been made of electron- and proton- damaged GaAs solar cells suitable for use in space. It is found that, although some electrical parametric data and spectral response data are quite similar, the type of damage due to the two types of radiation is different. An I-V analysis model shows that electrons damage the bulk of the cell and its currents relatively more, while protons damage the junction of the cell and its voltages more. It is suggested that multiple defects due to protons in a strong field region such as a p/n junction cause the greater degradation in cell voltage, whereas the individual point defects in the quasi-neutral minority-carrier-diffusion regions due to electrons cause the greater degradation in cell current and spectral response.

  15. [Sizes of bacterial cells in soils determined by cascade filtration technique].

    Science.gov (United States)

    Polianskaia, L M; Gorodnichev, R B; Zviagintsev, D G

    2013-01-01

    This paper studies the number of bacteria in typical chernozem and mountain-meadow soil by the traditional method and the cascade filtration technique. The total number of bacteria in these soils, which was obtained in filters of different diameters during filtering the suspension of a certain amount, is 1.5-5 times higher than that obtained by the traditional method. In the structure of the bacterial biomass in both soils, the biomass of bacterial cells with a diameter of 0.38-0.43 microm was dominating by 8-90%. In the typical chernozem, the biomass of cells with a diameter of 0.17 microm was slightly more than 1%; in the mountain-meadow soil, the percentage of the biomass of cells with a diameter of 0.17 microm increased by 5%. The average volume and diameter of the bacteria in the studied soils were calculated. In typical chernozem, the average volume of bacterial cells was equal to 0.0046 microm3 and the diameter was 0.206 microm. In the mountain-meadow soils, these values were slightly lower, 0.0038 microm3 and 0.194 microm, respectively. The biomass of the bacterial cells, which is usually calculated based on the cell volume of 0.1 microm3, is overestimated by about five times when counting the number on the filters. The percentage of the real biomass of soil bacteria is traditionally much lower than that estimated.

  16. Development of gallium arsenide solar cells

    Science.gov (United States)

    1973-01-01

    The potential of ion implantation as a means to the development of high efficiency gallium arsenide solar cells is investigated. Summaries are included of the results of computer calculations of GaAs cell characteristics, based on a model which includes the effects of surface recombination, junction space-charge region recombination, and built-in fields produced by nonuniform doping in the region; of the fabrication technology developed under the program; and of the results of electrical and optical measurements on the samples produced during the program. It was determined that measured AMO efficiencies were more than a factor of two lower than the calculated values.

  17. Solar energy powered microbial fuel cell with a reversible bioelectrode

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Hamelers, H.V.M.; Buisman, C.J.N.

    2010-01-01

    The solar energy powered microbial fuel cell is an emerging technology for electricity generation via electrochemically active microorganisms fueled by solar energy via in situ photosynthesized metabolites from algae, cyanobacteria, or living higher plants. A general problem with microbial fuel

  18. High Temperature InGaN-based Solar Cells

    Data.gov (United States)

    National Aeronautics and Space Administration — An efficient generation of solar power in a space environment is an enduring challenging for all NASA missions. The current available solar cells, however, suffer...

  19. Transparent antennas for solar cell integration

    Science.gov (United States)

    Yasin, Tursunjan

    Transparent patch antennas are microstrip patch antennas that have a certain level of optical transparency. Highly transparent patch antennas are potentially suitable for integration with solar panels of small satellites, which are becoming increasingly important in space exploration. Traditional patch antennas employed on small satellites compete with solar cells for surface area. However, a transparent patch antenna can be placed directly on top of solar cells and resolve the issue of competing for limited surface real estate. For such an integration, a high optical transparency of the patch antenna is required from the solar cells' point of view. On the other hand, the antenna should possess at least acceptable radiation properties at the same time. This dissertation focuses on some of the most important concerns from the perspective of small satellite applications. For example, an optimization method to simultaneously improve both optical transparency and radiation efficiency of the antenna is studied. Active integrated antenna design method is extended to meshed patch applications in an attempt to improve the overall power efficiency of the front end communication subsystem. As is well known, circular polarization is immune from Faraday rotation effect in the ionosphere and thus can avoid a 3-dB loss in geo-satellite communication. Therefore, this research also aims to present design methods for circularly polarized meshed patch antennas. Moreover, a meshed patch antenna capable of supporting a high communication data rate is investigated. Lastly, other types of transparent patch antennas are also analyzed and compared to meshed patches. In summary, many properties of transparent patch antennas are examined in order to meet different design requirements.

  20. Performance Study of CdS/Co-Doped-CdSe Quantum Dot Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Xiaoping Zou

    2014-01-01

    Full Text Available In order to optimize the charge transfer path in quantum dot sensitized solar cells (QDSCs, we employed successive ionic layer adsorption and reaction method to dope CdSe with Co for fabricating CdS/Co-doped-CdSe QDSCs constructed with CdS/Co-doped-CdSe deposited on mesoscopic TiO2 film as photoanode, Pt counter electrode, and sulfide/polysulfide electrolyte. After Co doping, the bandgap of CdSe quantum dot decreases, and the conduction band and valence band all improve, forming a cascade energy level which is more conducive to charge transport inside the solar cell and reducing the recombination of electron-hole thus improving the photocurrent and ultimately improving the power conversion efficiency. This work has not been found in the literature.

  1. Photovoltaic Technology: The Case for Thin-Film Solar Cells

    OpenAIRE

    Shah, Arvind; Torres, Pedro; Tscharner, Reto; Wyrsch, Nicolas; Keppner, Herbert

    2013-01-01

    The advantages and limitations of photovoltaic solar modules for energy generation are reviewed with their operation principles and physical efficiency limits. Although the main materials currently used or investigated and the associated fabrication technologies are individually described, emphasis is on silicon-based solar cells. Wafer-based crystalline silicon solar modules dominate in terms of production, but amorphous silicon solar cells have the potential to undercut costs owing, for exa...

  2. The Signaling Cascades of Ginkgolide B-Induced Apoptosis in MCF-7 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Wen-Hsiung Chan

    2007-11-01

    Full Text Available Ginkgolide B, the major active component of Ginkgo biloba extracts, can bothstimulate and inhibit apoptotic signaling. Here, we demonstrate that ginkgolide B caninduce the production of reactive oxygen species in MCF-7 breast cancer cells, leading toan increase in the intracellular concentrations of cytoplasmic free Ca2+ and nitric oxide(NO, loss of mitochondrial membrane potential (MMP, activation of caspase-9 and -3,and increase the mRNA expression levels of p53 and p21, which are known to be involvedin apoptotic signaling. In addition, prevention of ROS generation by pretreatment withN-acetyl cysteine (NAC could effectively block intracellular Ca2+ concentrationsincreases and apoptosis in ginkgolide B-treated MCF-7 cells. Moreover, pretreatment withnitric oxide (NO scavengers could inhibit ginkgolide B-induced MMP change andsequent apoptotic processes. Overall, our results signify that both ROS and NO playedimportant roles in ginkgolide B-induced apoptosis of MCF-7 cells. Based on these studyresults, we propose a model for ginkgolide B-induced cell apoptosis signaling cascades inMCF-7 cells.

  3. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  4. OPTEC: A Cubesat for Solar Cell Calibration

    Science.gov (United States)

    Landis, Geoffrey; Hepp, Aloysius; Arutyunov, Dennis; White, Kelsey; Witsberger, Paul

    2014-01-01

    A new type of small spacecraft, the cubesat, has introduced a new concept for extremely small, low-cost missions into space. Cubesats are designed to be launched as secondary payloads on other missions, and are made up of unit elements (U) of size 10 cm by 10 cm by 10 cm, with a nominal mass of no more than 1.33 kg per U. We have designed a cubesat, OPTEC (Orbital Photovoltaic Testbed Cubesat) as a low-cost testbed to demonstrate, calibrate, and test solar cell technologies in space. Size of the cubesat is 2U (10x10x20cm, and the mass 2.66 kg. The cubesat deploys from the International Space Station into Low Earth Orbit at an altitude of about 420 km. Up to two 4x8cm test solar panels can be flown, with full I-V curves and temperature measurements taken.

  5. Enhancing Solar Cell Efficiency Using Photon Upconversion Materials

    Directory of Open Access Journals (Sweden)

    Yunfei Shang

    2015-10-01

    Full Text Available Photovoltaic cells are able to convert sunlight into electricity, providing enough of the most abundant and cleanest energy to cover our energy needs. However, the efficiency of current photovoltaics is significantly impeded by the transmission loss of sub-band-gap photons. Photon upconversion is a promising route to circumvent this problem by converting these transmitted sub-band-gap photons into above-band-gap light, where solar cells typically have high quantum efficiency. Here, we summarize recent progress on varying types of efficient upconversion materials as well as their outstanding uses in a series of solar cells, including silicon solar cells (crystalline and amorphous, gallium arsenide (GaAs solar cells, dye-sensitized solar cells, and other types of solar cells. The challenge and prospect of upconversion materials for photovoltaic applications are also discussed

  6. Organic Solar Cells: Understanding the Role of Förster Resonance Energy Transfer

    Science.gov (United States)

    Feron, Krishna; Belcher, Warwick J.; Fell, Christopher J.; Dastoor, Paul C.

    2012-01-01

    Organic solar cells have the potential to become a low-cost sustainable energy source. Understanding the photoconversion mechanism is key to the design of efficient organic solar cells. In this review, we discuss the processes involved in the photo-electron conversion mechanism, which may be subdivided into exciton harvesting, exciton transport, exciton dissociation, charge transport and extraction stages. In particular, we focus on the role of energy transfer as described by Förster resonance energy transfer (FRET) theory in the photoconversion mechanism. FRET plays a major role in exciton transport, harvesting and dissociation. The spectral absorption range of organic solar cells may be extended using sensitizers that efficiently transfer absorbed energy to the photoactive materials. The limitations of Förster theory to accurately calculate energy transfer rates are discussed. Energy transfer is the first step of an efficient two-step exciton dissociation process and may also be used to preferentially transport excitons to the heterointerface, where efficient exciton dissociation may occur. However, FRET also competes with charge transfer at the heterointerface turning it in a potential loss mechanism. An energy cascade comprising both energy transfer and charge transfer may aid in separating charges and is briefly discussed. Considering the extent to which the photo-electron conversion efficiency is governed by energy transfer, optimisation of this process offers the prospect of improved organic photovoltaic performance and thus aids in realising the potential of organic solar cells. PMID:23235328

  7. Solar cells based on the poly(N-vinylcarbazole): porphyrin: tris(8-hydroxyquinolinato) aluminium blend system

    International Nuclear Information System (INIS)

    Tian-Hui, Zhang; Su-Ling, Zhao; Zheng, Xu; Xiao-Dong, Liu; Chao, Kong; Xu-Rong, Xu; Ling-Yu, Piao; Si-Ting, Ju

    2011-01-01

    Organic solar cells based on poly(N-vinylcarbazole) (PVK): porphyrin: tris (8-hydroxyquinolinato) aluminium (Alq3) blend p-n junction systems have been fabricated in this work. The roles of the different components in the blend system and of the amount of porphyrin have been investigated. The 5, 10, 15, 20-tetraphenylporphyrin (TPP) and 5, 10, 15, 20-tetra(o-chloro)phenylporphyrinato-copper (CuTClPP) are used in the solar cells. The results show that TPP is better than CuTCIPP in enhancing the performance of PVK:Alq3 solar cells. When the weight ratio of PVK:TPP:Alq3 is 1:1.5:1, the best performance of solar cell is obtained. The open circuit voltage (V oc ) is 0.87 V, and the short circuit current (J sc ) is 17.5 μA·cm −2 . In the ternary bulk hereojunction system, the device may be regarded as a cascade of three devices of PVK:TPP, TPP:Alq3 and PVK:Alq3. PVK, TPP and Alq3 can improve the hole mobility, light absorption intensity and electron mobility of the ternary bulk hereojunction system, respectively. (interdisciplinary physics and related areas of science and technology)

  8. Solar cells based on the poly(N-vinylcarbazole): porphyrin: tris(8-hydroxyquinolinato) aluminium blend system

    Science.gov (United States)

    Zhang, Tian-Hui; Zhao, Su-Ling; Piao, Ling-Yu; Xu, Zheng; Ju, Si-Ting; Liu, Xiao-Dong; Kong, Chao; Xu, Xu-Rong

    2011-03-01

    Organic solar cells based on poly(N-vinylcarbazole) (PVK): porphyrin: tris (8-hydroxyquinolinato) aluminium (Alq3) blend p-n junction systems have been fabricated in this work. The roles of the different components in the blend system and of the amount of porphyrin have been investigated. The 5, 10, 15, 20-tetraphenylporphyrin (TPP) and 5, 10, 15, 20-tetra(o-chloro)phenylporphyrinato-copper (CuTClPP) are used in the solar cells. The results show that TPP is better than CuTCIPP in enhancing the performance of PVK:Alq3 solar cells. When the weight ratio of PVK:TPP:Alq3 is 1:1.5:1, the best performance of solar cell is obtained. The open circuit voltage (Voc) is 0.87 V, and the short circuit current (Jsc) is 17.5 μA·cm-2. In the ternary bulk hereojunction system, the device may be regarded as a cascade of three devices of PVK:TPP, TPP:Alq3 and PVK:Alq3. PVK, TPP and Alq3 can improve the hole mobility, light absorption intensity and electron mobility of the ternary bulk hereojunction system, respectively. Project supported by the National Natural Science Foundation of China (Grant Nos. 60978060 and 50602008), the Beijing Municipal Science & Technology Commission (Grant No. Z090803044009001), and the Excellent Doctor's Science and Technology Innovation Foundation of Beijing Jiaotong University of China (Grant No. 141107522).

  9. Organic solar cells: understanding the role of Förster resonance energy transfer.

    Science.gov (United States)

    Feron, Krishna; Belcher, Warwick J; Fell, Christopher J; Dastoor, Paul C

    2012-12-12

    Organic solar cells have the potential to become a low-cost sustainable energy source. Understanding the photoconversion mechanism is key to the design of efficient organic solar cells. In this review, we discuss the processes involved in the photo-electron conversion mechanism, which may be subdivided into exciton harvesting, exciton transport, exciton dissociation, charge transport and extraction stages. In particular, we focus on the role of energy transfer as described by F¨orster resonance energy transfer (FRET) theory in the photoconversion mechanism. FRET plays a major role in exciton transport, harvesting and dissociation. The spectral absorption range of organic solar cells may be extended using sensitizers that efficiently transfer absorbed energy to the photoactive materials. The limitations of F¨orster theory to accurately calculate energy transfer rates are discussed. Energy transfer is the first step of an efficient two-step exciton dissociation process and may also be used to preferentially transport excitons to the heterointerface, where efficient exciton dissociation may occur. However, FRET also competes with charge transfer at the heterointerface turning it in a potential loss mechanism. An energy cascade comprising both energy transfer and charge transfer may aid in separating charges and is briefly discussed. Considering the extent to which the photo-electron conversion efficiency is governed by energy transfer, optimisation of this process offers the prospect of improved organic photovoltaic performance and thus aids in realising the potential of organic solar cells.

  10. Organic Solar Cells: Understanding the Role of Förster Resonance Energy Transfer

    Directory of Open Access Journals (Sweden)

    Paul C. Dastoor

    2012-12-01

    Full Text Available Organic solar cells have the potential to become a low-cost sustainable energy source. Understanding the photoconversion mechanism is key to the design of efficient organic solar cells. In this review, we discuss the processes involved in the photo-electron conversion mechanism, which may be subdivided into exciton harvesting, exciton transport, exciton dissociation, charge transport and extraction stages. In particular, we focus on the role of energy transfer as described by F¨orster resonance energy transfer (FRET theory in the photoconversion mechanism. FRET plays a major role in exciton transport, harvesting and dissociation. The spectral absorption range of organic solar cells may be extended using sensitizers that efficiently transfer absorbed energy to the photoactive materials. The limitations of F¨orster theory to accurately calculate energy transfer rates are discussed. Energy transfer is the first step of an efficient two-step exciton dissociation process and may also be used to preferentially transport excitons to the heterointerface, where efficient exciton dissociation may occur. However, FRET also competes with charge transfer at the heterointerface turning it in a potential loss mechanism. An energy cascade comprising both energy transfer and charge transfer may aid in separating charges and is briefly discussed. Considering the extent to which the photo-electron conversion efficiency is governed by energy transfer, optimisation of this process offers the prospect of improved organic photovoltaic performance and thus aids in realising the potential of organic solar cells.

  11. Simulation of an electrowetting solar concentration cell

    Science.gov (United States)

    Khan, Iftekhar; Rosengarten, Gary

    2015-09-01

    Electrowetting control of liquid lenses has emerged as a novel approach for solar tracking and concentration. Recent studies have demonstrated the concept of steering sunlight using thin electrowetting cells without the use of any bulky mechanical equipment. Effective application of this technique may facilitate designing thin and flat solar concentrators. Understanding the behavior of liquid-liquid and liquid-solid interface of the electrowetting cell through trial and error experimental processes is not efficient and is time consuming. In this paper, we present a simulation model to predict the liquid-liquid and liquid-solid interface behavior of electrowetting cell as a function of various parameters such as applied voltage, dielectric constant, cell size etc. We used Comsol Multiphysics simulations incorporating experimental data of different liquids. We have designed both two dimensional and three dimensional simulation models, which predict the shape of the liquid lenses. The model calculates the contact angle using the Young-Lippman equation and uses a moving mesh interface to solve the Navier-stokes equation with Navier slip wall boundary condition. Simulation of the electric field from the electrodes is coupled to the Young-Lippman equation. The model can also be used to determine operational characteristics of other MEMS electrowetting devices such as electrowetting display, optical switches, electronic paper, electrowetting Fresnel lens etc.

  12. Nanorods and nanotubes for solar cells.

    Science.gov (United States)

    Kislyuk, V V; Dimitriev, O P

    2008-01-01

    Nanorods and nanotubes as photoactive materials as well as electrodes in photovoltaic cells have been launched a few years ago, and the literature in this field started to appear only recently. The first steps have shown both advantages and disadvantages of their application, and the main expectation associated with their effective charge transport has not been realized completely. This article aims to review both the first and the recent tendencies in the development and application of nanorod and nanotube materials in photovoltaic cells. Two basic techniques of synthesis of crystalline nanorod structures are described, the top-down and bottom-up approaches, respectively. Design and photovoltaic performance of solar cells based on various semiconductor nanorod materials, such as TiO2, ZnO, CdS, CdSe, CdTe, CuO, Si are presented and compared with respective solar cells based on semiconductor nanoparticles. Specific of synthesis and application of carbon nanotubes in photovoltaic devices is also reviewed.

  13. Si Wire-Array Solar Cells

    Science.gov (United States)

    Boettcher, Shannon

    2010-03-01

    Micron-scale Si wire arrays are three-dimensional photovoltaic absorbers that enable orthogonalization of light absorption and carrier collection and hence allow for the utilization of relatively impure Si in efficient solar cell designs. The wire arrays are grown by a vapor-liquid-solid-catalyzed process on a crystalline (111) Si wafer lithographically patterned with an array of metal catalyst particles. Following growth, such arrays can be embedded in polymethyldisiloxane (PDMS) and then peeled from the template growth substrate. The result is an unusual photovoltaic material: a flexible, bendable, wafer-thickness crystalline Si absorber. In this paper I will describe: 1. the growth of high-quality Si wires with controllable doping and the evaluation of their photovoltaic energy-conversion performance using a test electrolyte that forms a rectifying conformal semiconductor-liquid contact 2. the observation of enhanced absorption in wire arrays exceeding the conventional light trapping limits for planar Si cells of equivalent material thickness and 3. single-wire and large-area solid-state Si wire-array solar cell results obtained to date with directions for future cell designs based on optical and device physics. In collaboration with Michael Kelzenberg, Morgan Putnam, Joshua Spurgeon, Daniel Turner-Evans, Emily Warren, Nathan Lewis, and Harry Atwater, California Institute of Technology.

  14. An interim report on the NTS-2 solar cell experiment

    Science.gov (United States)

    Statler, R. L.; Walker, D. H.

    1979-01-01

    Data obtained from the fourteen solar cell modules on the NTS-2 satellite are presented together with a record of panel temperature and sun inclination. The following flight data are discussed: (1) state of the art solar cell configurations which embody improvements in solar cell efficiency through new silicon surface and bulk technology, (2) improved coverslip materials and coverslip bonding techniques, (3) short and long term effects of ultraviolet rejection filters vs. no filters on the cells, (4) degradation on a developmental type of liquid epitaxy gallium-aluminum-arsenide solar cell, and (5) space radiation effects.

  15. Photovoltaic characteristics of porous silicon /(n+ - p) silicon solar cells

    International Nuclear Information System (INIS)

    Dzhafarov, T.D.; Aslanov, S.S.; Ragimov, S.H.; Sadigov, M.S.; Nabiyeva, A.F.; Yuksel, Aydin S.

    2012-01-01

    Full text : The purpose of this work is to improve the photovoltaic parameters of the screen-printed silicon solar cells by formation the nano-porous silicon film on the frontal surface of the cell. The photovoltaic characteristics of two type silicon solar cells with and without porous silicon layer were measured and compared. A remarkable increment of short-circuit current density and the efficiency by 48 percent and 20 percent, respectively, have been achieved for PS/(n + - pSi) solar cell comparing to (n + - p)Si solar cell without PS layer

  16. N-type solar cells: advantages, issues, and current scenarios

    Science.gov (United States)

    Singha, Bandana; Solanki, Chetan S.

    2017-07-01

    Crystalline silicon, including p-type czochralski (CZ) mono-crystalline and multi-crystalline (mc) silicon, has been the workhorse for solar cell production for decades. In recent years, there has been many developments in n-type c-Si solar cells basically due to the advantages of n-type c-Si wafers over p-type wafers. However, there are some limitations in making n-type solar cells considering the technologies involved to fabricate p-type cells. In this paper, different advantages of n-types wafers, their limitations in solar cell production, and an analysis of total market coverage are discussed.

  17. Neuronal Cell Fate Specification by the Convergence of Different Spatiotemporal Cues on a Common Terminal Selector Cascade.

    Directory of Open Access Journals (Sweden)

    Hugo Gabilondo

    2016-05-01

    Full Text Available Specification of the myriad of unique neuronal subtypes found in the nervous system depends upon spatiotemporal cues and terminal selector gene cascades, often acting in sequential combinatorial codes to determine final cell fate. However, a specific neuronal cell subtype can often be generated in different parts of the nervous system and at different stages, indicating that different spatiotemporal cues can converge on the same terminal selectors to thereby generate a similar cell fate. However, the regulatory mechanisms underlying such convergence are poorly understood. The Nplp1 neuropeptide neurons in the Drosophila ventral nerve cord can be subdivided into the thoracic-ventral Tv1 neurons and the dorsal-medial dAp neurons. The activation of Nplp1 in Tv1 and dAp neurons depends upon the same terminal selector cascade: col>ap/eya>dimm>Nplp1. However, Tv1 and dAp neurons are generated by different neural progenitors (neuroblasts with different spatiotemporal appearance. Here, we find that the same terminal selector cascade is triggered by Kr/pdm>grn in dAp neurons, but by Antp/hth/exd/lbe/cas in Tv1 neurons. Hence, two different spatiotemporal combinations can funnel into a common downstream terminal selector cascade to determine a highly related cell fate.

  18. Industrialization of polymer solar cells - phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Lauritzen, H.; Krebs, F.C. [Technical Univ. of Denmark. DTU Energy Conversion, DTU Risoe Campus, Roskilde (Denmark); Andersen, Rasmus B. [Mekoprint A/S, Stoevrimg (Denmark); Bork, J.; Bentzen, B.

    2012-03-15

    A three-phased project with the objective to industrialize DTU's basic polymer solar cell technology was started in the summer of 2009. The technology comprises a specific design of the polymer solar cell and a corresponding roll-to-roll manufacturing process. This basic technology is referred to as ProcessOne in the open literature. The present report relates to the project's phase 1.The key tasks in phase 1 are to stream-line DTU's tech-nology for the industrial utilization, to demonstrate production according to this stream-lined technology at Mekoprint A/S and finally to fertilize the market for polymer solar cells by demonstrating their use in appli-cations that harmonize with their present maturity level. The main focus in the stream-lining of DTU's technology has been to demonstrate a convincing rate of reduction for the production cost, and thereby make a competitive price plausible. This has been materialized as a learning curve showing that the polymer technology presently develops considerably faster than the silicon technology. The polymer solar cells will, under the assumption that both technologies follow a projection of the learning curve, gain a cost-leading position within a reasonable time. A production cost of 5 Euro/Wp has already been demonstrated in DTU's pilot plant, and a road map for the further decrease to 1 Euro/Wp is drawn. This target is expected to be reached in 2013 in the ongoing phase 2 of the project. Another activity essential for the industrialization has been the launch of specialized materials, equipment and services required for the processing of DTU's polymer solar cells. Relevant products and services are made available for sale on DTU's homepage, www.energyconversion.dtu.dk. A production line for polymer solar cells has been established at Mekoprint. For this a retrofit solution was chosen where the core of an existing screen-printing line was dismantled and fitted to a slot-die printing head manufactured in DTU's workshop

  19. Impact of Switching Harmonics on Capacitor Cells Balancing in Phase-Shifted PWM-Based Cascaded H-Bridge STATCOM

    DEFF Research Database (Denmark)

    Behrouzian, Ehsan; Bongiorno, Massimo; Teodorescu, Remus

    2017-01-01

    The purpose of this paper is to investigate the impact of switching harmonics on the instantaneous power distribution in the cells of a cascaded H-bridge-based STATCOM when using phase-shifted pulse width modulation. The case of high- and low-switching frequency for the converter cells is investi......The purpose of this paper is to investigate the impact of switching harmonics on the instantaneous power distribution in the cells of a cascaded H-bridge-based STATCOM when using phase-shifted pulse width modulation. The case of high- and low-switching frequency for the converter cells...... is investigated and the interaction between voltage and current harmonics is analyzed. It is shown that in both cases, this interaction results in an uneven power distribution among the cells in the same phase leg, leading to drifting of the dc-capacitor voltages and thereby the need for proper stabilization...

  20. Investigation of Indoor Stability Testing of Polymer Solar Cell

    Directory of Open Access Journals (Sweden)

    Pelin Kavak

    2016-01-01

    Full Text Available We have fabricated organic solar cell of a new low bandgap polymer poly[4,4-bis(2-ethylhexyl-4H-cyclopenta[2,1-b:3,4-b′]dithiophene-2,6-diyl-alt-4,7-bis(2-thienyl-2,1,3-benzothiadiazole-5′,5′′-diyl] (PCPDTTBTT. We have investigated for the first time the stability tests, ISOS-L-1 and ISOS-D-3, of PCPDTTBTT solar cells. Thermal annealing of PCPDTTBTT solar cells at 80°C brought about an improvement of photocurrent generation, stability, and efficiency of the solar cells. T80 value of PCPDTTBTT solar cell is about 150 hours which is close to P3HT (235 h. PCPDTTBTT is very promising polymer for both polymer solar cell efficiency and stability.

  1. Advantages of thin silicon solar cells for use in space

    Science.gov (United States)

    Denman, O. S.

    1978-01-01

    A system definition study on the Solar Power Satellite System showed that a thin, 50 micrometers, silicon solar cell has significant advantages. The advantages include a significantly lower performance degradation in a radiation environment and high power-to-mass ratios. The advantages of such cells for an employment in space is further investigated. Basic questions concerning the operation of solar cells are considered along with aspects of radiation induced performance degradation. The question arose in this connection how thin a silicon solar cell had to be to achieve resistance to radiation degradation and still have good initial performance. It was found that single-crystal silicon solar cells could be as thin as 50 micrometers and still develop high conversion efficiencies. It is concluded that the use of 50 micrometer silicon solar cells in space-based photovoltaic power systems would be advantageous.

  2. Applications of Fluorogens with Rotor Structures in Solar Cells

    Directory of Open Access Journals (Sweden)

    Kok-Haw Ong

    2017-05-01

    Full Text Available Solar cells are devices that convert light energy into electricity. To drive greater adoption of solar cell technologies, higher cell efficiencies and reductions in manufacturing cost are necessary. Fluorogens containing rotor structures may be helpful in addressing some of these challenges due to their unique twisted structures and photophysics. In this review, we discuss the applications of rotor-containing molecules as dyes for luminescent down-shifting layers and luminescent solar concentrators, where their aggregation-induced emission properties and large Stokes shifts are highly desirable. We also discuss the applications of molecules containing rotors in third-generation solar cell technologies, namely dye-sensitized solar cells and organic photovoltaics, where the twisted 3-dimensional rotor structures are used primarily for aggregation control. Finally, we discuss perspectives on the future role of molecules containing rotor structures in solar cell technologies.

  3. Applications of Fluorogens with Rotor Structures in Solar Cells.

    Science.gov (United States)

    Ong, Kok-Haw; Liu, Bin

    2017-05-29

    Solar cells are devices that convert light energy into electricity. To drive greater adoption of solar cell technologies, higher cell efficiencies and reductions in manufacturing cost are necessary. Fluorogens containing rotor structures may be helpful in addressing some of these challenges due to their unique twisted structures and photophysics. In this review, we discuss the applications of rotor-containing molecules as dyes for luminescent down-shifting layers and luminescent solar concentrators, where their aggregation-induced emission properties and large Stokes shifts are highly desirable. We also discuss the applications of molecules containing rotors in third-generation solar cell technologies, namely dye-sensitized solar cells and organic photovoltaics, where the twisted 3-dimensional rotor structures are used primarily for aggregation control. Finally, we discuss perspectives on the future role of molecules containing rotor structures in solar cell technologies.

  4. Solar Cell Nanotechnology Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Das, Biswajit [Univ. of Nevada, Las Vegas, NV (United States)

    2014-05-07

    The objective of this project is to develop a low cost nonlithographic nanofabrication technology for the fabrication of thin film porous templates as well as uniform arrays of semiconductor nanostructures for the implementation of high efficiency solar cells. Solar cells based on semiconductor nanostructures are expected to have very high energy conversion efficiencies due to the increased absorption coefficients of semiconductor nanostructures. In addition, the thin film porous template can be used for optimum surface texturing of solar cells leading to additional enhancement in energy conversion efficiency. An important requirement for these applications is the ability to synthesize nanostructure arrays of different dimensions with good size control. This project employed nanoporous alumina templates created by the anodization of aluminum thin films deposited on glass substrates for the fabrication of the nanostructures and optimized the process parameters to obtain uniform pore diameters. An additional requirement is uniformity or regularity of the nanostructure arrays. While constant current anodization was observed to provide controlled pore diameters, constant voltage anodization was needed for regularity of the nanostructure arrays. Thus a two-step anodization process was investigated and developed in this project for improving the pore size distribution and pore periodicity of the nanoporous alumina templates. CdTe was selected to be the active material for the nanowires, and the process for the successful synthesis of CdTe nanowires was developed in this project. Two different synthesis approaches were investigated in this project, electrochemical and electrophoretic deposition. While electrochemical synthesis was successfully employed for the synthesis of nanowires inside the pores of the alumina templates, the technique was determined to be non-optimum due to the need of elevated temperature that is detrimental to the structural integrity of the

  5. Hybrid Solar Cells: Materials, Interfaces, and Devices

    Science.gov (United States)

    Mariani, Giacomo; Wang, Yue; Kaner, Richard B.; Huffaker, Diana L.

    Photovoltaic technologies could play a pivotal role in tackling future fossil fuel energy shortages, while significantly reducing our carbon dioxide footprint. Crystalline silicon is pervasively used in single junction solar cells, taking up 80 % of the photovoltaic market. Semiconductor-based inorganic solar cells deliver relatively high conversion efficiencies at the price of high material and manufacturing costs. A great amount of research has been conducted to develop low-cost photovoltaic solutions by incorporating organic materials. Organic semiconductors are conjugated hydrocarbon-based materials that are advantageous because of their low material and processing costs and a nearly unlimited supply. Their mechanical flexibility and tunable electronic properties are among other attractions that their inorganic counterparts lack. Recently, collaborations in nanotechnology research have combined inorganic with organic semiconductors in a "hybrid" effort to provide high conversion efficiencies at low cost. Successful integration of these two classes of materials requires a profound understanding of the material properties and an exquisite control of the morphology, surface properties, ligands, and passivation techniques to ensure an optimal charge carrier generation across the hybrid device. In this chapter, we provide background information of this novel, emerging field, detailing the various approaches for obtaining inorganic nanostructures and organic polymers, introducing a multitude of methods for combining the two components to achieve the desired morphologies, and emphasizing the importance of surface manipulation. We highlight several studies that have fueled new directions for hybrid solar cell research, including approaches for maximizing efficiencies by controlling the morphologies of the inorganic component, and in situ molecular engineering via electrochemical polymerization of a polymer directly onto the inorganic nanowire surfaces. In the end, we

  6. Elongated nanostructures for radial junction solar cells.

    Science.gov (United States)

    Kuang, Yinghuan; Vece, Marcel Di; Rath, Jatindra K; Dijk, Lourens van; Schropp, Ruud E I

    2013-10-01

    In solar cell technology, the current trend is to thin down the active absorber layer. The main advantage of a thinner absorber is primarily the reduced consumption of material and energy during production. For thin film silicon (Si) technology, thinning down the absorber layer is of particular interest since both the device throughput of vacuum deposition systems and the stability of the devices are significantly enhanced. These features lead to lower cost per installed watt peak for solar cells, provided that the (stabilized) efficiency is the same as for thicker devices. However, merely thinning down inevitably leads to a reduced light absorption. Therefore, advanced light trapping schemes are crucial to increase the light path length. The use of elongated nanostructures is a promising method for advanced light trapping. The enhanced optical performance originates from orthogonalization of the light's travel path with respect to the direction of carrier collection due to the radial junction, an improved anti-reflection effect thanks to the three-dimensional geometric configuration and the multiple scattering between individual nanostructures. These advantages potentially allow for high efficiency at a significantly reduced quantity and even at a reduced material quality, of the semiconductor material. In this article, several types of elongated nanostructures with the high potential to improve the device performance are reviewed. First, we briefly introduce the conventional solar cells with emphasis on thin film technology, following the most commonly used fabrication techniques for creating nanostructures with a high aspect ratio. Subsequently, several representative applications of elongated nanostructures, such as Si nanowires in realistic photovoltaic (PV) devices, are reviewed. Finally, the scientific challenges and an outlook for nanostructured PV devices are presented.

  7. Nanoscale dimples for improved absorption in organic solar cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    Organic solar cells (OSC’s) have attracted much attention in the past years due to their potential low-cost, light-weight and mechanical flexibility. A method for improving the power conversion efficiencies of the devices is by incorporating structured electrodes in the solar cell architecture, a...... ordered and discorded dimple arrangement and their contribution to light management is presented. Such dimples can later be employed to fabricate nanostructured electrodes in P3HT/PCBM organic solar cells....

  8. On transport mechanisms in solar cells involving organic semiconductors

    OpenAIRE

    Nolasco Montaño, Jairo César

    2011-01-01

    The knowledge of transport mechanisms in solar cells is useful to determine electrical losses. In my doctoral thesis we studied the transport mechanisms in solar cells involving organic semiconductors. We show that models which have been used to study amorphous inorganic solar cells can be applied on organic ones. We conclude that: multitunelling capture emission and tunelling-enhanced interface recombination mechanisms contribute to the dark current characteristics in P3HT/Si, Pc/C60 and P3H...

  9. Temperature optimization of high concentrated active cooled solar cells

    OpenAIRE

    Sabry, M.

    2016-01-01

    Active cooling is essential for solar cells operating under high optical concentration ratios. A system comprises four solar cells that are in thermal contact on top of a copper tube is proposed. Water is flowing inside the tube in order to reduce solar cells temperature for increasing their performance. Computational Fluid Dynamics (CFD) simulation of such system has been performed in order to investigate the effect of water flow rate, tube internal diameter, and convective heat transfer coe...

  10. Method of fabricating bifacial tandem solar cells

    Science.gov (United States)

    Wojtczuk, Steven J; Chiu, Philip T; Zhang, Xuebing; Gagnon, Edward; Timmons, Michael

    2014-10-07

    A method of fabricating on a semiconductor substrate bifacial tandem solar cells with semiconductor subcells having a lower bandgap than the substrate bandgap on one side of the substrate and with subcells having a higher bandgap than the substrate on the other including, first, growing a lower bandgap subcell on one substrate side that uses only the same periodic table group V material in the dislocation-reducing grading layers and bottom subcells as is present in the substrate and after the initial growth is complete and then flipping the substrate and growing the higher bandgap subcells on the opposite substrate side which can be of different group V material.

  11. Dye solar cell research: EU delegation presentation

    CSIR Research Space (South Africa)

    Cummings, F

    2009-11-09

    Full Text Available Franscious Cummings Energy and Processes Materials Science and Manufacturing Council for Scientific and Industrial Research P.O. Box 395 Pretoria 0001, South Africa 13 November 2009 © CSIR 2007 www.csir.co.za CONTENT head2right...Background head2rightCSIR Dye Solar Cell Research head2rightCollaborations and Links head2rightAcknowledgements © CSIR 2007 www.csir.co.za BACKGROUND head2rightSA is dry: Annual rainfall average of 450 mm compared with a world average...

  12. Cold crucible Czochralski for solar cells

    Science.gov (United States)

    Trumble, T. M.

    1982-01-01

    The efficiency and radiation resistance of present silicon solar cells are a function of the oxygen and carbon impurities and the boron doping used to provide the proper resistivity material. The standard Czochralski process used grow single crystal silicon contaminates the silicon stock material due to the use of a quartz crucible and graphite components. The use of a process which replaces these elements with a water cooled copper to crucible has provided a major step in providing gallium doped (100) crystal orientation, low oxygen, low carbon, silicon. A discussion of the Cold Crucible Czochralski process and recent float Zone developments is provided.

  13. Solar-Hydrogen Fuel-Cell Vehicles

    OpenAIRE

    DeLuchi, Mark A.; Ogden, Joan M.

    1993-01-01

    Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional or global pollution. Hydrogen FCEVs would combine the best features of battery-powere...

  14. Hydrogen passivation of silicon sheet solar cells

    International Nuclear Information System (INIS)

    Tsuo, Y.S.; Milstein, J.B.

    1984-01-01

    Significant improvements in the efficiencies of dendritic web and edge-supported-pulling silicon sheet solar cells have been obtained after hydrogen ion beam passivation for a period of ten minutes or less. We have studied the effects of the hydrogen ion beam treatment with respect to silicon material damage, silicon sputter rate, introduction of impurities, and changes in reflectance. The silicon sputter rate for constant ion beam flux of 0.60 +- 0.05 mA/cm 2 exhibits a maximum at approximately 1400-eV ion beam energy

  15. The Photophysics of Perovskite Solar Cells

    Science.gov (United States)

    Sum, Tze-Chien

    2015-03-01

    Solution processed organic-inorganic lead halide perovskite solar cells, with power conversion efficiencies approaching 20%, are presently the forerunner amongst the next generation photovoltaic technologies. These remarkable performances can be attributed to their large absorption coefficients, long charge carrier diffusion lengths and low non-radiative recombination rates. In addition, these materials also possess excellent light emission and optical gain properties. In this talk, I will review the developmental milestones in this field and distil the recent findings on the photophysical mechanisms of this remarkable material. I will also highlight some of our latest charge dynamics studies and other investigations on the novel properties of this amazing material system.

  16. Intermediate Bandgap Solar Cells From Nanostructured Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Black, Marcie [Bandgap Engineering, Lincoln, MA (United States)

    2014-10-30

    This project aimed to demonstrate increased electronic coupling in silicon nanostructures relative to bulk silicon for the purpose of making high efficiency intermediate bandgap solar cells using silicon. To this end, we formed nanowires with controlled crystallographic orientation, small diameter, <111> sidewall faceting, and passivated surfaces to modify the electronic band structure in silicon by breaking down the symmetry of the crystal lattice. We grew and tested these silicon nanowires with <110>-growth axes, which is an orientation that should produce the coupling enhancement.

  17. Progress in batteries and solar cells. Volume 5

    International Nuclear Information System (INIS)

    Shimotake, H.

    1984-01-01

    The 89 articles in this book are on research in batteries, solar cells and fuel cells. Topics include uses of batteries in electric powered vehicles, load management in power plants, batteries for miniature electronic devices, electrochemical processes, and various electrode and electrolyte materials, including organic compounds. Types of batteries discussed are lithium, lead-acid, manganese dioxide, Silver cells, Air cells, Nickel cells and solar cells. Problems of recharging and life cycle are also discussed

  18. Performance improvement of silicon solar cells by nanoporous silicon coating

    Directory of Open Access Journals (Sweden)

    Dzhafarov T. D.

    2012-04-01

    Full Text Available In the present paper the method is shown to improve the photovoltaic parameters of screen-printed silicon solar cells by nanoporous silicon film formation on the frontal surface of the cell using the electrochemical etching. The possible mechanisms responsible for observed improvement of silicon solar cell performance are discussed.

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

    Indian Academy of Sciences (India)

    sensitized solar cells. The aim of this study was to search how a thin sub-layer of the hydrothermally grown TiO2 NCs in the photoanodes could improve the efficiency of TiO2 P25-based solar cells. The highest efficiency of 6.5% was achieved for a cell ...

  20. Photon recycling in the graded bandgap solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Rafat, N.H. [Cairo Univ., Dept. of Mathematics and Engineering Physics, Giza (Egypt); Haleem, A.M. Abdel [Cairo Univ., Dept. of Mathematics and Engineering Physics, EIFayoum (Egypt); Habib, S.E.D. [Cairo Univ., Electronics and Communication Dept., Giza (Egypt)

    2006-07-01

    We derived a general integral expression for the carrier radiative recombination rate in solar cells. The photon Boltzmann equation is solved taking into account the photon recycling effect inside the cell and assuming arbitrary spatial variation of the absorption coefficient. This expression can thus be used for graded bandgap solar cells. (Author)

  1. Silicon bulk growth for solar cells: Science and technology

    Science.gov (United States)

    Kakimoto, Koichi; Gao, Bing; Nakano, Satoshi; Harada, Hirofumi; Miyamura, Yoshiji

    2017-02-01

    The photovoltaic industry is in a phase of rapid expansion, growing by more than 30% per annum over the last few decades. Almost all commercial solar cells presently use single-crystalline or multicrystalline silicon wafers similar to those used in microelectronics; meanwhile, thin-film compounds and alloy solar cells are currently under development. The laboratory performance of these cells, at 26% solar energy conversion efficiency, is now approaching thermodynamic limits, with the challenge being to incorporate these improvements into low-cost commercial products. Improvements in the optical design of cells, particularly in their ability to trap weakly absorbed light, have also led to increasing interest in thin-film cells based on polycrystalline silicon; these cells have advantages over other thin-film photovoltaic candidates. This paper provides an overview of silicon-based solar cell research, especially the development of silicon wafers for solar cells, from the viewpoint of growing both single-crystalline and multicrystalline wafers.

  2. [Advances in microbial solar cells--A review].

    Science.gov (United States)

    Guo, Xiaoyun; Yu, Changping; Zheng, Tianling

    2015-08-04

    The energy crisis has become one of the major problems hindering the development of the world. The emergence of microbial fuel cells provides a new solution to the energy crisis. Microbial solar cells, integrating photosynthetic organisms such as plants and microalgae into microbial fuel cells, can convert solar energy into electrical energy. Microbial solar cell has steady electric energy, and broad application prospects in wastewater treatment, biodiesel processing and intermediate metabolites production. Here we reviewed recent progress of microbial solar cells from the perspective of the role of photosynthetic organisms in microbial fuel cells, based on a vast amount of literature, and discussed their advantages and deficiency. At last, brief analysis of the facing problems and research needs of microbial fuel cells are undertaken. This work was expected to be beneficial for the application of the microbial solar cells technology.

  3. Solar cells: photovoltaic energy; Les cellules solaires: energie photovoltaique

    Energy Technology Data Exchange (ETDEWEB)

    Braun, J.P.; Faraggi, B.; Labouret, A.; Cumunel, P.

    2001-07-01

    This book presents the principles of the photovoltaic conversion of solar energy, the characteristics of solar cells of various technologies, the related equipments (batteries, charge controllers) and all necessary knowledge for the design of solar power supplies and circuits. (J.S.)

  4. Nanostructured InGaP Solar Cells, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The operating conditions of conventional multijunction solar cells are severely limited by the current matching requirements of serially connected devices. The goal...

  5. Testing of gallium arsenide solar cells on the CRRES vehicle

    Science.gov (United States)

    Trumble, T. M.

    1985-01-01

    A flight experiment was designed to determine the optimum design for gallium arsenide (GaAs) solar cell panels in a radiation environment. Elements of the experiment design include, different coverglass material and thicknesses, welded and soldered interconnects, different solar cell efficiencies, different solar cell types, and measurement of annealing properties. This experiment is scheduled to fly on the Combined Release and Radiation Effects Satellite (CRRES). This satellite will simultaneously measure the radiation environment and provide engineering data on solar cell degradation that can be directly related to radiation damage.

  6. Testing of gallium arsenide solar cells on the CRRES vehicle

    International Nuclear Information System (INIS)

    Trumble, T.M.

    1985-01-01

    A flight experiment was designed to determine the optimum design for gallium arsenide (GaAs) solar cell panels in a radiation environment. Elements of the experiment design include, different coverglass material and thicknesses, welded and soldered interconnects, different solar cell efficiencies, different solar cell types, and measurement of annealing properties. This experiment is scheduled to fly on the Combined Release and Radiation Effects Satellite (CRRES). This satellite will simultaneously measure the radiation environment and provide engineering data on solar cell degradation that can be directly related to radiation damage

  7. Characterization of Inverted Polymer Bulk Heterojunction Solar Cells

    Science.gov (United States)

    Carney, Tyler; Tzolov, Marian

    Inverted solar cells were proven to be an improvement over polymer solar cells in terms of durability and reliability. We have fabricated the solar cells using P3HT and PCPDTBT as the active polymer with PC60BM as the electron acceptor. The materials we deposited from solution by spin coating on glass substrates with ITO film. Molybdenum oxide was thermally evaporated overtop the spin coated polymer solar cell to realize the inverted design. The devices were finalized by thermally evaporated aluminum contacts which were then mechanically reinforced with silver paste. Current voltage characteristics were performed both in dark and under illumination to characterize the inverted solar cells and to verify the inverted solar cell design. Impedance spectroscopy in dark and under illumination were used to gain more information about the photoelectric processes in the devices and to build a realistic equivalent circuit model of the inverted solar cells. The inverted solar cells were then compared against standard polymer bulk heterojunction solar cells produced with the same active materials.

  8. Study on the development and stability of perovskite solar cells

    Science.gov (United States)

    Xing, Shucheng

    2017-08-01

    Recently, the development of perovskite solar cells has aroused the concern of the majority of scholars, the current photoelectric conversion efficiency has reached 21%. So the thorough study of the principle of perovskite type solar cells will make better the use of its special performance. But so far, perovskite type solar cells still have many unstable factors. This paper first discusses the predecessor of perovskite solar cells, dye-sensitized batteries, and then study the working principle of the former, followed by the perovskite-type thermal instability and light instability to be discussed, at last talks about the current Major issues perovskite materials are facing and make a summary.

  9. Organic solar cells theory, experiment, and device simulation

    CERN Document Server

    Tress, Wolfgang

    2014-01-01

    This book covers in a textbook-like fashion the basics or organic solar cells, addressing the limits of photovoltaic energy conversion and giving a well-illustrated introduction to molecular electronics with focus on the working principle and characterization of organic solar cells. Further chapters based on the author's dissertation focus on the electrical processes in organic solar cells by presenting a detailed drift-diffusion approach to describe exciton separation and charge-carrier transport and extraction. The results, although elaborated on small-molecule solar cells and with focus on

  10. Effects of radiation on solar cells as photovoltaic generators

    Directory of Open Access Journals (Sweden)

    Radosavljević Radovan Lj.

    2012-01-01

    Full Text Available The growing need for obtaining electrical energy through renewable energy sources such as solar energy have lead to significant technological developments in the production of the basic element of PV conversion, the solar cell. Basically, a solar cell is a p-n junction whose characteristics have a great influence on its output parameters, primarily efficiency. Defects and impurities in the basic material, especially if located within the energy gap, may be activated during its lifetime, becoming traps for optically produced electron-hole pairs and, thus, decreasing the output power of the cell. All of the said effects could be induced in many ways over a lifetime of a solar cell and are consistent with the effects that radiation produces in semiconductor devices. The aim of this paper is to investigate changes in the main characteristics of solar cells, such as efficiency, output current and power, due to the exposure of solar systems to different (hostile radiation environments.

  11. Photosensitizers from Spirulina for Solar Cell

    Directory of Open Access Journals (Sweden)

    Liqiu Wang

    2014-01-01

    Full Text Available Spirulina is a kind of blue-green algae with good photosynthetic efficiency and might be used for photovoltaic power generation. So this paper used living spirulina as novel photosensitizer to construct spirulina biosolar cell. The results showed that spirulina had the photoelectric conversion effect, and could let the spirulina biosolar cell have 70 μA photocurrent. Meanwhile, adding glucose sucrose or chitosan in the spirulina anode chamber, they could make the maxima current density of the cell greatly increased by 80 μA, 100 μA, and 84 μA, respectively, and the sucrose could improve the maximum power density of the cell to 63 mW/m−2. Phycobiliprotein played an important role in the photosynthesis of spirulina. So in this paper phycobiliprotein was extracted from spirulina to composite with squaraine dye to sensitize nanocrystalline TiO2 photoanode for building dye sensitized solar cell, and the photoelectric properties of the cell also were investigated.

  12. Processes for chalcopyrite-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lux-Steiner, M.C.; Ennaoui, A.; Fischer, C.-H.; Jaeger-Waldau, A.; Klaer, J.; Klenk, R.; Koenenkamp, R.; Matthes, T.; Scheer, R.; Siebentritt, S.; Weidinger, A. [Hahn-Meitner-Institut Berlin GmbH (Germany)

    2000-02-21

    This contribution deals with the investigations of chalcopyrite solar cells. Main attention is paid to absorber materials with band gaps larger than 1.5 eV. Besides the different efforts to modify and optimise stoichiometric CuInS{sub 2} films, novel deposition technologies for CuGaSe{sub 2} films and buffer layers as well as alternative buffer layers were studied and compared. With ZnSe as alternative buffer layer on Cu(InGa)(S,Se){sub 2} absorbers developed by SSI Camarillo and Siemens Solar, Munich, total area efficiencies up to 13.7% and active area efficiencies up to 15.7% could be reached, respectively. For CuInS{sub 2} two important results were achieved. The efficiency of Cu-poor CuInS{sub 2} cells could be increased to 8.3%. Standard Cu-rich prepared devices led to a new record efficiency of 12.5%. (orig.)

  13. Nanobump assembly for plasmonic organic solar cells

    Science.gov (United States)

    Song, Hyung-Jun; Jung, Kinam; Lee, Gunhee; Ko, Youngjun; Lee, Jong-Kwon; Choi, Mansoo; Lee, Changhee

    2014-10-01

    We demonstrate novel plasmonic organic solar cells (OSCs) by embedding an easy processible nanobump assembly (NBA) for harnessing more light. The NBA is consisted of precisely size-controlled Ag nanoparticles (NPs) generated by an aerosol process at atmospheric pressure and thermally deposited molybdenum oxide (MoO3) layer which follows the underlying nano structure of NPs. The active layer, spin-casted polymer blend solution, has an undulated structure conformably covering the NBA structure. To find the optimal condition of the NBA structure for enhancing light harvest as well as carrier transfer, we systematically investigate the effect of the size of Ag NPs and the MoO3 coverage on the device performance. It is observed that the photocurrent of device increases as the size of Ag NP increases owing to enhanced plasmonic and scattering effect. In addition, the increased light absorption is effectively transferred to the photocurrent with small carrier losses, when the Ag NPs are fully covered by the MoO3 layer. As a result, the NBA structure consisted of 40 nm Ag NPs enclosed by 20 nm MoO3 layer leads to 18% improvement in the power conversion efficiency compared to the device without the NBA structure. Therefore, the NBA plasmonic structure provides a reliable and efficient light harvesting in a broad range of wavelength, which consequently enhances the performance of organic solar cells.

  14. Hybrid Perovskite/Perovskite Heterojunction Solar Cells.

    Science.gov (United States)

    Hu, Yinghong; Schlipf, Johannes; Wussler, Michael; Petrus, Michiel L; Jaegermann, Wolfram; Bein, Thomas; Müller-Buschbaum, Peter; Docampo, Pablo

    2016-06-28

    Recently developed organic-inorganic hybrid perovskite solar cells combine low-cost fabrication and high power conversion efficiency. Advances in perovskite film optimization have led to an outstanding power conversion efficiency of more than 20%. Looking forward, shifting the focus toward new device architectures holds great potential to induce the next leap in device performance. Here, we demonstrate a perovskite/perovskite heterojunction solar cell. We developed a facile solution-based cation infiltration process to deposit layered perovskite (LPK) structures onto methylammonium lead iodide (MAPI) films. Grazing-incidence wide-angle X-ray scattering experiments were performed to gain insights into the crystallite orientation and the formation process of the perovskite bilayer. Our results show that the self-assembly of the LPK layer on top of an intact MAPI layer is accompanied by a reorganization of the perovskite interface. This leads to an enhancement of the open-circuit voltage and power conversion efficiency due to reduced recombination losses, as well as improved moisture stability in the resulting photovoltaic devices.

  15. Solar Cell Capacitance Determination Based on an RLC Resonant Circuit

    Directory of Open Access Journals (Sweden)

    Petru Adrian Cotfas

    2018-03-01

    Full Text Available The capacitance is one of the key dynamic parameters of solar cells, which can provide essential information regarding the quality and health state of the cell. However, the measurement of this parameter is not a trivial task, as it typically requires high accuracy instruments using, e.g., electrical impedance spectroscopy (IS. This paper introduces a simple and effective method to determine the electric capacitance of the solar cells. An RLC (Resistor Inductance Capacitor circuit is formed by using an inductor as a load for the solar cell. The capacitance of the solar cell is found by measuring the frequency of the damped oscillation that occurs at the moment of connecting the inductor to the solar cell. The study is performed through simulation based on National Instruments (NI Multisim application as SPICE simulation software and through experimental capacitance measurements of a monocrystalline silicon commercial solar cell and a photovoltaic panel using the proposed method. The results were validated using impedance spectroscopy. The differences between the capacitance values obtained by the two methods are of 1% for the solar cells and of 9.6% for the PV panel. The irradiance level effect upon the solar cell capacitance was studied obtaining an increase in the capacitance in function of the irradiance. By connecting different inductors to the solar cell, the frequency effect upon the solar cell capacitance was studied noticing a very small decrease in the capacitance with the frequency. Additionally, the temperature effect over the solar cell capacitance was studied achieving an increase in capacitance with temperature.

  16. Scalable fabrication of perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhen; Klein, Talysa R.; Kim, Dong Hoe; Yang, Mengjin; Berry, Joseph J.; van Hest, Maikel F. A. M.; Zhu, Kai

    2018-03-27

    Perovskite materials use earth-abundant elements, have low formation energies for deposition and are compatible with roll-to-roll and other high-volume manufacturing techniques. These features make perovskite solar cells (PSCs) suitable for terawatt-scale energy production with low production costs and low capital expenditure. Demonstrations of performance comparable to that of other thin-film photovoltaics (PVs) and improvements in laboratory-scale cell stability have recently made scale up of this PV technology an intense area of research focus. Here, we review recent progress and challenges in scaling up PSCs and related efforts to enable the terawatt-scale manufacturing and deployment of this PV technology. We discuss common device and module architectures, scalable deposition methods and progress in the scalable deposition of perovskite and charge-transport layers. We also provide an overview of device and module stability, module-level characterization techniques and techno-economic analyses of perovskite PV modules.

  17. TEMPERATUREEFFECT OFELECTRICALPROPERTIES OF CIGS SOLAR CELL

    Directory of Open Access Journals (Sweden)

    A. M. Ferouani

    2015-07-01

    Full Text Available In this paper we are interested in studying the copper–indium–gallium–selenium (CIGS solar cells sandwiched between cadmium sulfide (CdS and ZnO as buffer layers, and Molybdenum (Mo. Thus, we report our simulation results using the capacitance simulator (SCAPS in terms of layer thickness, absorber layer band gap and operating temperature to find out the optimum choice. An efficiency of 20.61% (with Voc of 635.2mV, Jsc of 44.08 mA/cm2 and fill factor of 0.73 has been achieved with CdS used as buffer layer as the reference case. It is also found that the high efficiency CIGS cells with the low temperature were a very high efficiency conversion.

  18. Hypothesis for thermal activation of the caspase cascade in apoptotic cell death at elevated temperatures

    Science.gov (United States)

    Pearce, John A.

    2013-02-01

    Apoptosis is an especially important process affecting disease states from HIV-AIDS to auto-immune disease to cancer. A cascade of initiator and executioner capsase functional proteins is the hallmark of apoptosis. When activated the various caspases activate other caspases or cleave structural proteins of the cytoskeleton, resulting in "blebbing" of the plasma membrane forming apoptotic bodies that completely enclose the disassembled cellular components. Containment of the cytosolic components within the apoptotic bodies differentiates apoptosis from necroptosis and necrosis, both of which release fragmented cytosol and other cellular constituents into the intracellular space. Biochemical models of caspase activation reveal the extensive feedback loops characteristic of apoptosis. They clearly explain the failure of Arrhenius models to give accurate predictions of cell survival curves in hyperthermic heating protocols. Nevertheless, each of the individual reaction velocities can reasonably be assumed to follow Arrhenius kinetics. If so, the thermal sensitivity of the reaction velocity to temperature elevation is: ∂k/∂T = Ea [k/RT2]. Particular reaction steps described by higher activation energies, Ea, are likely more thermally-sensitive than lower energy reactions and may initiate apoptosis in the absence of other stress signals. Additionally, while the classical irreversible Arrhenius formulation fails to accurately represent many cell survival and/or dye uptake curves - those that display an early stage shoulder region - an expanded reversible model of the law of mass action equation seems to prove effective and is directly based on a firm theoretical thermodynamic foundation.

  19. Metal Matrix Composite Solar Cell Metallization

    Directory of Open Access Journals (Sweden)

    Wilt David M.

    2017-01-01

    Full Text Available Advanced solar cells are moving to ever thinner formats in order to save mass and in some cases improve performance. As cells are thinned, the possibility that they may fracture or cleave due to mechanical stresses is increased. Fractures of the cell can degrade the overall device performance if the fracture propagates through the contact metallization, which frequently occurs. To address this problem, a novel semiconductor metallization system based on multi-walled carbon nanotube (CNT reinforcement, termed metal matrix composite (MMC metallization is under investigation. Electro-mechanical characterization of MMC films demonstrate their ability to provide electrical conductivity over >40 micron wide cracks in the underlying semiconductor, with the carbon nanotubes bridging the gap. In addition, these materials show a “self-healing” behaviour, electrically reconnecting at ~30 microns when strained past failure. Triple junction (TJ space cells with MMC metallization demonstrated no loss in Jsc after intentional fracture, whereas TJ cells with conventional metallization suffer up to 50% Jsc loss.

  20. Experiment Based Teaching of Solar Cell Operation and Characterization Using the SolarLab Platform

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Sera, Dezso; Kerekes, Tamas

    2014-01-01

    Experiment based teaching methods are a great way to get students involved and interested in almost any topic. This paper presents such a hands-on approach for teaching solar cell operation principles along with characterization and modelling methods. This is achieved with the SolarLab platform...... which is a laboratory teaching tool developed at Transylvania University of Brasov. Using this platform, solar cells can be characterized under various illumination, temperature and angle of light incidence. Additionally, the SolarLab platform includes guided exercises and intuitive graphical user...... interfaces for exploring different solar cell principles and topics. The exercises presented in the current paper have been adapted from the original exercises developed for the SolarLab platform and are currently included in the Photovoltaic Power Systems courses (MSc and PhD level) taught at the Department...

  1. Mevalonate cascade regulation of airway mesenchymal cell autophagy and apoptosis: a dual role for p53.

    Directory of Open Access Journals (Sweden)

    Saeid Ghavami

    2011-01-01

    Full Text Available Statins inhibit the proximal steps of cholesterol biosynthesis, and are linked to health benefits in various conditions, including cancer and lung disease. We have previously investigated apoptotic pathways triggered by statins in airway mesenchymal cells, and identified reduced prenylation of small GTPases as a primary effector mechanism leading to p53-mediated cell death. Here, we extend our studies of statin-induced cell death by assessing endpoints of both apoptosis and autophagy, and investigating their interplay and coincident regulation. Using primary cultured human airway smooth muscle (HASM and human airway fibroblasts (HAF, autophagy, and autophagosome formation and flux were assessed by transmission electron microscopy, cytochemistry (lysosome number and co-localization with LC3 and immunoblotting (LC3 lipidation and Atg12-5 complex formation. Chemical inhibition of autophagy increased simvastatin-induced caspase activation and cell death. Similarly, Atg5 silencing with shRNA, thus preventing Atg5-12 complex formation, increased pro-apoptotic effects of simvastatin. Simvastatin concomitantly increased p53-dependent expression of p53 up-regulated modulator of apoptosis (PUMA, NOXA, and damage-regulated autophagy modulator (DRAM. Notably both mevalonate cascade inhibition-induced autophagy and apoptosis were p53 dependent: simvastatin increased nuclear p53 accumulation, and both cyclic pifithrin-α and p53 shRNAi partially inhibited NOXA, PUMA expression and caspase-3/7 cleavage (apoptosis and DRAM expression, Atg5-12 complex formation, LC3 lipidation, and autophagosome formation (autophagy. Furthermore, the autophagy response is induced rapidly, significantly delaying apoptosis, suggesting the existence of a temporally coordinated p53 regulation network. These findings are relevant for the development of statin-based therapeutic approaches in obstructive airway disease.

  2. 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.

  3. Development of a shingle-type solar cell module

    Science.gov (United States)

    Shepard, N. F., Jr.; Sanchez, L. E.

    1978-01-01

    The development of a solar cell module, which is suitable for use in place of shingles on the sloping roofs of residental or commercial buildings, is reported. The design consists of nineteen series-connected 53 mm diameter solar cells arranged in a closely packed hexagon configuration. The shingle solar cell module consists of two basic functional parts: an exposed rigid portion which contains the solar cell assembly, and a semi-flexible portion which is overlapped by the higher courses of the roof installation. Consideration is given to the semi-flexible substrate configuration and solar cell and module-to-module interconnectors. The results of an electrical performance analysis are given and it is noted that high specific power output can be attributed to the efficient packing of the circular cells within the hexagon shape. The shingle should function for at least 15 years, with a specific power output of 98 W/sq w.

  4. Advanced laser processing for industrial solar cell manufacturing (ALPINISM)

    Energy Technology Data Exchange (ETDEWEB)

    Mason, N.B.; Fieret, J. [Exitech Ltd. (United Kingdom)

    2006-05-04

    The study was aimed at improving methods for the manufacture of high efficiency solar cells and thereby increase production rates. The project focused on the laser grooved buried contact solar cell (LGBC) which is produced by high-speed laser machining. The specific objectives were (i) to optimise the laser technology for high speed processing; (ii) to optimise the solar cell process conditions for high speed processing; (iii) to produce a prototype tool and demonstrate high throughput; and (iv) to demonstrate increased cell efficiency using laser processing of rear contact. Essentially, all the objectives were met and Exitech have already sold six production tools and one research tool developed in this study. In addition, it was found that laser processing at the rear cell surface offers the prospect of LGBC solar cells with an efficiency of 20 per cent. BP Solar Limited carried out this work under contract to the DTI.

  5. Electron Acceptor Materials Engineering in Colloidal Quantum Dot Solar Cells

    KAUST Repository

    Liu, Huan

    2011-07-15

    Lead sulfide colloidal quantum dot (CQD) solar cells with a solar power conversion efficiency of 5.6% are reported. The result is achieved through careful optimization of the titanium dioxide electrode that serves as the electron acceptor. Metal-ion-doped sol-gel-derived titanium dioxide electrodes produce a tunable-bandedge, well-passivated materials platform for CQD solar cell optimization. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Silicon Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Guy Beaucarne

    2007-01-01

    with plasma-enhanced chemical vapor deposition (PECVD. In spite of the fundamental limitation of this material due to its disorder and metastability, the technology is now gaining industrial momentum thanks to the entry of equipment manufacturers with experience with large-area PECVD. Microcrystalline Si (also called nanocrystalline Si is a material with crystallites in the nanometer range in an amorphous matrix, and which contains less defects than amorphous silicon. Its lower bandgap makes it particularly appropriate as active material for the bottom cell in tandem and triple junction devices. The combination of an amorphous silicon top cell and a microcrystalline bottom cell has yielded promising results, but much work is needed to implement it on large-area and to limit light-induced degradation. Finally thin-film polysilicon solar cells, with grain size in the micrometer range, has recently emerged as an alternative photovoltaic technology. The layers have a grain size ranging from 1 μm to several tens of microns, and are formed at a temperature ranging from 600 to more than 1000∘C. Solid Phase Crystallization has yielded the best results so far but there has recently been fast progress with seed layer approaches, particularly those using the aluminum-induced crystallization technique.

  7. Wafer and Solar Cell Characterization by GT-PVSCAN6000

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B.; Madjdpour, J.; Auriemma, C.; Mathei, K.; Nakano, K.; Mortiz, H.

    2002-08-01

    The PVSCAN is an instrument designed to characterize silicon solar cell materials and devices. It performs a host of measurements that yield spatial maps of dislocation density, grain distribution, reflectance, and photoresponses from near-junction and the bulk of a solar cell.

  8. Phenothiazine-Based Dyes in Solar Cell Technology

    Directory of Open Access Journals (Sweden)

    Andrei Bejan

    2017-12-01

    Full Text Available Phenothiazine is a fused heterocyclic ring with strong electron-donating character which makes it an important building block for designing organic materials for solar cells applications. The present paper reviews the most recent achievements of phenothiazine-based compounds as dyes in solar cells, with special emphasis on the structure – performance relationship.

  9. Solar cell is housed in light-bulb enclosure

    Science.gov (United States)

    Evans, J. C., Jr.

    1981-01-01

    Inexpensive, conventional solar-cell module uses focusing principle of electric lamp in reverse to produce electric power from sunlight. Standard outdoor light enclosure provides low-cost housing which concentrates sunlight in solar cell. Unit is capable of producing approximately 1 watt of electric power.

  10. STUDY OF PERFORMANCES OF ORGANIC SOLAR CELLS BY ...

    African Journals Online (AJOL)

    30 juin 2011 ... results of analysis of performances of organic solar cells by using what one call the datamining materials. ... Keywords: organic solar cells, gap energie, effiency, PCA. Author Correspondence .... oubli est malencontreux car le type de données disponibles influence toujours la direction de la recherche.

  11. Transparent conductive oxides for thin-film silicon solar cells

    NARCIS (Netherlands)

    Löffler, J.

    2005-01-01

    This thesis describes research on thin-film silicon solar cells with focus on the transparent conductive oxide (TCO) for such devices. In addition to the formation of a transparent and electrically conductive front electrode for the solar cell allowing photocurrent collection with low ohmic losses,

  12. Microstructure and Mechanical Aspects of Multicrystalline Silicon Solar Cells

    NARCIS (Netherlands)

    Popovich, V.A.

    2013-01-01

    Due to pressure from the photovoltaic industry to decrease the cost of solar cell production, there is a tendency to reduce the thickness of silicon wafers. Unfortunately, wafers contain defects created by the various processing steps involved in solar cell production, which significantly reduce the

  13. Stability and degradation mechanisms in organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ecker, Bernhard

    2012-04-26

    This thesis deals with stability improvements and the investigation of degradation mechanisms in organic solar cells. Organic solar cells have been in the focus of extensive academic research for over almost two decades and are currently entering the market in small scale applications. For successful large scale applications, next to the improvement of the power conversion efficiency, the stability of organic solar cells has to be increased. This thesis is dedicated to the investigation of novel materials and architectures to study stability-related issues and degradation mechanisms in order to contribute to the basic understanding of the working principles of organic solar cells. Here, impedance spectroscopy, a frequency domain technique, is used to gain information about stability and degradation mechanisms in organic solar cells. In combination with systematic variations in the preparation of solar cells, impedance spectroscopy gives the possibility to differentiate between interface and bulk dominated effects. Additionally, impedance spectroscopy gives access to the dielectric properties of the device, such as capacitance. This offers among other things the opportunity to probe the charge carrier concentration and the density of states. Another powerful way of evaluation is the combination of experimentally obtained impedance spectra with equivalent circuit modelling. The thesis presents results on novel materials and solar cell architectures for efficient hole and electron extraction. This indicates the importance of knowledge over interlayers and interfaces for improving both the efficiency and stability of organic solar cells.

  14. Topology optimization for improving the performance of solar cells

    NARCIS (Netherlands)

    Gupta, D.K.; Langelaar, M.; Keulen, F. van; Barink, M.

    2014-01-01

    This work introduces the application of Topology Optimization (TO) to design optimal front metallization patterns for solar cells and increase their power output. A challenging aspect of the solar cell electrode design problem is the strong nonlinear relation between the active layer current and the

  15. Topology optimization of front metallization patterns for solar cells

    NARCIS (Netherlands)

    Gupta, D.K.; Langelaar, M.; Barink, M.; Keulen, F. van

    2015-01-01

    This paper presents the application of topology optimization (TO) for designing the front electrode patterns for solar cells. Improving the front electrode design is one of the approaches to improve the performance of the solar cells. It serves to produce the voltage distribution for the front

  16. 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 ...

  17. Pathways to a New Efficiency Regime for Organic Solar Cells

    NARCIS (Netherlands)

    Koster, L. Jan Anton; Shaheen, Sean E.; Hummelen, Jan C.

    2012-01-01

    Three different theoretical approaches are presented to identify pathways to organic solar cells with power conversion efficiencies in excess of 20%. A radiation limit for organic solar cells is introduced that elucidates the role of charge-transfer (CT) state absorption. Provided this CT action is

  18. Superlattice Intermediate Band Solar Cell on Gallium Arsenide

    Science.gov (United States)

    2015-02-09

    AFRL-RV-PS- AFRL-RV-PS- TR-2015-0048 TR-2015-0048 SUPERLATTICE INTERMEDIATE BAND SOLAR CELL ON GALLIUM ARSENIDE Alexandre Freundlich...SUBTITLE 5a. CONTRACT NUMBER FA9453-13-1-0232 Superlattice Intermediate Band Solar Cell on Gallium Arsenide 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  19. Flexible PCPDTBT:PCBM solar cells with integrated grating structures

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Liu, Yinghui; Madsen, Morten

    2013-01-01

    spectra of the active layer. This optimized solar cell structure leads to an enhanced absorption in the active layer and thus improved short-circuit currents and power conversion efficiencies in the fabricated devices. Fabrication of the solar cells on thin polyimide substrates which are compatible...

  20. Combined Silicon and Gallium Arsenide Solar Cell UV Testing

    Science.gov (United States)

    Willowby, Douglas

    2005-01-01

    The near and long-term effect of UV on silicon solar cells is relatively understood. In an effort to learn more about the effects of UV radiation on the performance of GaAs/Ge solar cells, silicon and gallium arsenide on germanium (GaAs/Ge) solar cells were placed in a vacuum chamber and irradiated with ultraviolet light by a Spectrolab XT 10 solar simulator. Seventeen GaAs/Ge and 8 silicon solar cells were mounted on an 8 inch copper block. By having all the cells on the same test plate we were able to do direct comparison of silicon and GaAs/Ge solar cell degradation. The test article was attached to a cold plate in the vacuum chamber to maintain the cells at 25 degrees Celsius. A silicon solar cell standard was used to measure beam uniformity and any degradation of the ST-10 beam. The solar cell coverings tested included cells with AR-0213 coverglass, fused silica coverglass, BRR-0213 coverglass and cells without coverglass. Of interest in the test is the BRR-0213 coverglass material manufactured by OCLI. It has an added Infrared rejection coating to help reduce the solar cell operating temperature. This coverglass is relatively new and of interest to several current and future programs at Marshall. Due to moves of the laboratory equipment and location only 350 hours of UV degradation have been completed. During this testing a significant leveling off in the rate of degradation was reached. Data from the test and comparisons of the UV effect of the bare cells and cells with coverglass material will be presented.

  1. Monolithic Perovskite Silicon Tandem Solar Cells with Advanced Optics

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, Jan C.; Bett, Alexander J.; Bivour, Martin; Blasi, Benedikt; Eisenlohr, Johannes; Kohlstadt, Markus; Lee, Seunghun; Mastroianni, Simone; Mundt, Laura; Mundus, Markus; Ndione, Paul; Reichel, Christian; Schubert, Martin; Schulze, Patricia S.; Tucher, Nico; Veit, Clemens; Veurman, Welmoed; Wienands, Karl; Winkler, Kristina; Wurfel, Uli; Glunz, Stefan W.; Hermle, Martin

    2016-11-14

    For high efficiency monolithic perovskite silicon tandem solar cells, we develop low-temperature processes for the perovskite top cell, rear-side light trapping, optimized perovskite growth, transparent contacts and adapted characterization methods.

  2. Photoelectrochemistry of metallo-octacarboxyphthalocyanines for the development of dye solar cells

    CSIR Research Space (South Africa)

    Mphahlele, N

    2011-09-01

    Full Text Available Significant attention is being paid to dye solar cells (DSCs) as the next generation in solar cell technology for their low cost alternative as compared to solid state solar cells....

  3. Neutral- and Multi-Colored Semitransparent Perovskite Solar Cells.

    Science.gov (United States)

    Lee, Kyu-Tae; Guo, L Jay; Park, Hui Joon

    2016-04-11

    In this review, we summarize recent works on perovskite solar cells with neutral- and multi-colored semitransparency for building-integrated photovoltaics and tandem solar cells. The perovskite solar cells exploiting microstructured arrays of perovskite "islands" and transparent electrodes-the latter of which include thin metallic films, metal nanowires, carbon nanotubes, graphenes, and transparent conductive oxides for achieving optical transparency-are investigated. Moreover, the perovskite solar cells with distinctive color generation, which are enabled by engineering the band gap of the perovskite light-harvesting semiconductors with chemical management and integrating with photonic nanostructures, including microcavity, are discussed. We conclude by providing future research directions toward further performance improvements of the semitransparent perovskite solar cells.

  4. Abooming area:non-fullerene acceptors for organic solar cells

    Directory of Open Access Journals (Sweden)

    QU Yangkun

    2016-12-01

    Full Text Available Organic solar cells have been extensively investigated in the last decade because they are one of the very important solutions to the global energy crisis.While predominant electron acceptor materials for organic solar cell are focused on fullerene and its derivatives,scientists are now more desperately looking for new alternative acceptor materials because fullerene acceptors face the challenges of narrow absorption spectrum,low solubility,high cost and non-environmental friendly synthesis processes.Non-fullerene electron acceptors have drawn great attention recently and have been widely used in organic solar cells because they have the great advantages of wide absorption spectrum,high solubility,precise structural controllability,and good processability.In this review paper,we summarize the most significant progresses in the area of non-fullerene organic solar cell acceptors during the last 6 years and we look forward to a bright future of non-fullerene organic solar cells.

  5. Simple processing of high efficiency silicon solar cells

    International Nuclear Information System (INIS)

    Hamammu, I.M.; Ibrahim, K.

    2006-01-01

    Cost effective photovoltaic devices have been an area research since the development of the first solar cells, as cost is the major factor in their usage. Silicon solar cells have the biggest share in the photovoltaic market, though silicon os not the optimal material for solar cells. This work introduces a simplified approach for high efficiency silicon solar cell processing, by minimizing the processing steps and thereby reducing cost. The suggested procedure might also allow for the usage of lower quality materials compared to the one used today. The main features of the present work fall into: simplifying the diffusion process, edge shunt isolation and using acidic texturing instead of the standard alkaline processing. Solar cells of 17% efficiency have been produced using this procedure. Investigations on the possibility of improving the efficiency and using less quality material are still underway

  6. Emerging Semitransparent Solar Cells: Materials and Device Design.

    Science.gov (United States)

    Tai, Qidong; Yan, Feng

    2017-09-01

    Semitransparent solar cells can provide not only efficient power-generation but also appealing images and show promising applications in building integrated photovoltaics, wearable electronics, photovoltaic vehicles and so forth in the future. Such devices have been successfully realized by incorporating transparent electrodes in new generation low-cost solar cells, including organic solar cells (OSCs), dye-sensitized solar cells (DSCs) and organometal halide perovskite solar cells (PSCs). In this review, the advances in the preparation of semitransparent OSCs, DSCs, and PSCs are summarized, focusing on the top transparent electrode materials and device designs, which are all crucial to the performance of these devices. Techniques for optimizing the efficiency, color and transparency of the devices are addressed in detail. Finally, a summary of the research field and an outlook into the future development in this area are provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Nanoparticles and nanoimaging for organic solar cells

    DEFF Research Database (Denmark)

    Pedersen, Emil Bøje Lind

    to a water based ink would provide a production environment without toxic fumes from organic solvents and the nanoparticle structure would provide additional morphological control. The first part of the dissertation maps photodegradation in active layers cast from organic solvents. Reduction in degradation...... in photoactive Landfester nanoparticles. The dispersed particles are characterized by size, internal structure and crystallinity. Crystal orientation and spatial distribution of materials are quantified for cast layers of Landfester particles. A layer of particles is also investigated in a tandem solar cell...... and compared to other layers in the structure using Tomographic 3D mapping. The fourth part presents a projection alignment algorithm for tomographic methods. It works by estimating projection movement through iterative logic using projection distance minimization. It is tested on simulated datasets...

  8. Wearable solar cells by stacking textile electrodes.

    Science.gov (United States)

    Pan, Shaowu; Yang, Zhibin; Chen, Peining; Deng, Jue; Li, Houpu; Peng, Huisheng

    2014-06-10

    A new and general method to produce flexible, wearable dye-sensitized solar cell (DSC) textiles by the stacking of two textile electrodes has been developed. A metal-textile electrode that was made from micrometer-sized metal wires was used as a working electrode, while the textile counter electrode was woven from highly aligned carbon nanotube fibers with high mechanical strengths and electrical conductivities. The resulting DSC textile exhibited a high energy conversion efficiency that was well maintained under bending. Compared with the woven DSC textiles that are based on wire-shaped devices, this stacked DSC textile unexpectedly exhibited a unique deformation from a rectangle to a parallelogram, which is highly desired in portable electronics. This lightweight and wearable stacked DSC textile is superior to conventional planar DSCs because the energy conversion efficiency of the stacked DSC textile was independent of the angle of incident light. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Excess junction current of silicon solar cells

    Science.gov (United States)

    Wang, E. Y.; Legge, R. N.; Christidis, N.

    1973-01-01

    The current-voltage characteristics of n(plus)-p silicon solar cells with 0.1, 1.0, 2.0, and 10 ohm-cm p-type base materials have been examined in detail. In addition to the usual I-V measurements, we have studied the temperature dependence of the slope of the I-V curve at the origin by the lock-in technique. The excess junction current coefficient (Iq) deduced from the slope at the origin depends on the square root of the intrinsic carrier concentration. The Iq obtained from the I-V curve fitting over the entire forward bias region at various temperatures shows the same temperature dependence. This result, in addition to the presence of an aging effect, suggest that the surface channel effect is the dominant cause of the excess junction current.

  10. Contact formation in gallium arsenide solar cells

    Science.gov (United States)

    Weizer, Victor G.; Fatemi, Navid S.

    1988-01-01

    Gold and gold-based alloys, commonly used as solar cell contact materials, are known to react readily with gallium arsenide. Experiments were performed to identify the mechanisms involved in these GaAs-metal interactions. It is shown that the reaction of GaAs with gold takes place via a dissociative diffusion process. It is shown further that the GaAs-metal reaction rate is controlled to a very great extent by the condition of the free surface of the contact metal, an interesting example of which is the previously unexplained increase in the reaction rate that has been observed for samples annealed in a vacuum environment as compared to those annealed in a gaseous ambient. A number of other hard-to-explain observations, such as the low-temperature formation of voids in the gold lattice and crystallite growth on the gold surface, are explained by invoking this mechanism.

  11. Workshop - Solar cells and daylight. Solar cell house. House building with integrated solar cell systems; Workshop - Solceller og dagslys. Solcellehus. Boligbyggeri med integrerede solcelleanlaeg

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Mio; Hansen, Ellen Kathrine

    2005-04-15

    The workshop 'Solar cells and daylight' at Aarhus School of Architecture aimed at studying and developing architectural potentials of integrating solar cell systems in building components for future house building. The aim of the process was to stress that technical conditions such as energy technological component design might work as central points of support in the future shaping and organisation of qualitative and functional design of houses. (BA)

  12. Solar cells: Operating principles, technology, and system applications

    Science.gov (United States)

    Green, M. A.

    Solar cell theory, materials, fabrication, design, modules, and systems are discussed. The solar source of light energy is described and quantified, along with a review of semiconductor properties and the generation, recombination, and the basic equations of photovoltaic device physics. Particular attention is given to p-n junction diodes, including efficiency limits, losses, and measurements. Si solar cell technology is described for the production of solar-quality crystals and wafers, and design, improvements, and device structures are examined. Consideration is given to alternate semiconductor materials and applications in concentrating systems, storage, and the design and construction of stand-alone systems and systems for residential and centralized power generation.

  13. High-Efficiency, Commercial Ready CdTe Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Sites, James R. [Colorado State Univ., Fort Collins, CO (United States)

    2015-11-19

    Colorado State’s F-PACE project explored several ways to increase the efficiency of CdTe solar cells and to better understand the device physics of those cells under study. Increases in voltage, current, and fill factor resulted in efficiencies above 17%. The three project tasks and additional studies are described in detail in the final report. Most cells studied were fabricated at Colorado State using an industry-compatible single-vacuum closed-space-sublimation (CSS) chamber for deposition of the key semiconductor layers. Additionally, some cells were supplied by First Solar for comparison purposes, and a small number of modules were supplied by Abound Solar.

  14. The limiting efficiency of band gap graded solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rafat, Nadia H. [Faculty of Engineering, Cairo University, Giza (Egypt); Habib, S.E.D. [Faculty of electronics and communication, Cairo University, Giza (Egypt)

    1998-09-04

    Two fundamental mechanisms limit the maximum attainable efficiency of solar cells, namely the radiative recombination and Auger recombination. We show in this paper that proper band gap grading of the solar cell localizes the Auger recombination around the metallurgical junction. Two beneficial effects result from this Auger recombination localization; first the cell is less sensitive to the surface conditions, and second, the previous estimates for the limiting efficiency of solar cells by Shockley, Tiedje, and Green are revised upwardly. We calculate the optimum bandgap grading profile for several real material systems, including GaInAsP lattice matched to InP, and a-SiGe on a-Si substrate

  15. Solar Cell and Array Technology Development for NASA Solar Electric Propulsion Missions

    Science.gov (United States)

    Piszczor, Michael; McNatt, Jeremiah; Mercer, Carolyn; Kerslake, Tom; Pappa, Richard

    2012-01-01

    NASA is currently developing advanced solar cell and solar array technologies to support future exploration activities. These advanced photovoltaic technology development efforts are needed to enable very large (multi-hundred kilowatt) power systems that must be compatible with solar electric propulsion (SEP) missions. The technology being developed must address a wide variety of requirements and cover the necessary advances in solar cell, blanket integration, and large solar array structures that are needed for this class of missions. Th is paper will summarize NASA's plans for high power SEP missions, initi al mission studies and power system requirements, plans for advanced photovoltaic technology development, and the status of specific cell and array technology development and testing that have already been conducted.

  16. Perovskite-Based Solar Cells: Materials, Methods, and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Di Zhou

    2018-01-01

    Full Text Available A novel all-solid-state, hybrid solar cell based on organic-inorganic metal halide perovskite (CH3NH3PbX3 materials has attracted great attention from the researchers all over the world and is considered to be one of the top 10 scientific breakthroughs in 2013. The perovskite materials can be used not only as light-absorbing layer, but also as an electron/hole transport layer due to the advantages of its high extinction coefficient, high charge mobility, long carrier lifetime, and long carrier diffusion distance. The photoelectric power conversion efficiency of the perovskite solar cells has increased from 3.8% in 2009 to 22.1% in 2016, making perovskite solar cells the best potential candidate for the new generation of solar cells to replace traditional silicon solar cells in the future. In this paper, we introduce the development and mechanism of perovskite solar cells, describe the specific function of each layer, and focus on the improvement in the function of such layers and its influence on the cell performance. Next, the synthesis methods of the perovskite light-absorbing layer and the performance characteristics are discussed. Finally, the challenges and prospects for the development of perovskite solar cells are also briefly presented.

  17. SLAM examination of solar cells and solar cell welds. [Scanning Laser Acoustic Microscope

    Science.gov (United States)

    Stella, P. M.; Vorres, C. L.; Yuhas, D. E.

    1981-01-01

    The scanning laser acoustic microscope (SLAM) has been evaluated for non-destructive examination of solar cells and interconnector bonds. Using this technique, it is possible to view through materials in order to reveal regions of discontinuity such as microcracks and voids. Of particular interest is the ability to evaluate, in a unique manner, the bonds produced by parallel gap welding. It is possible to not only determine the area and geometry of the bond between the tab and cell, but also to reveal any microcracks incurred during the welding. By correlating the SLAM results with conventional techniques of weld evaluation a more confident weld parameter optimization can be obtained.

  18. Comparative modeling of InP solar cell structures

    Science.gov (United States)

    Jain, R. K.; Weinberg, I.; Flood, D. J.

    1991-01-01

    The comparative modeling of p(+)n and n(+)p indium phosphide solar cell structures is studied using a numerical program PC-1D. The optimal design study has predicted that the p(+)n structure offers improved cell efficiencies as compared to n(+)p structure, due to higher open-circuit voltage. The various cell material and process parameters to achieve the maximum cell efficiencies are reported. The effect of some of the cell parameters on InP cell I-V characteristics was studied. The available radiation resistance data on n(+)p and p(+)p InP solar cells are also critically discussed.

  19. Spectral-splitting concentrator photovoltaic modules based on AlGaAs/GaAs/GaSb and GaInP/InGaAs(P) solar cells

    Science.gov (United States)

    Vlasov, A. S.; Khvostikov, V. P.; Karlina, L. B.; Sorokina, S. V.; Potapovich, N. S.; Shvarts, M. Z.; Timoshina, N. Kh.; Lantratov, V. M.; Mintairov, S. A.; Kalyuzhnyi, N. A.; Marukhina, E. P.; Andreev, V. M.

    2013-07-01

    A concentrator photovoltaic module with sunlight spectral splitting by Fresnel lens and dichroic filters is developed. The photoelectric conversion efficiency of such a module is estimated at a level of 49.4% when three single-junction cells are used and may reach 48.5-50.6% when a tandem two-junction cell is combined with narrow-band cells. Single-junction AlGaAs, GaAs, GaSb, and InGa(P)As solar sells are fabricated by zinc diffusion from the vapor phase into an n-type epitaxial layer. GaInP/GaAs cascade solar cells are prepared by MOS hydride epitaxy. The overall efficiency of the three single-junction solar cells developed for the spectral-splitting module is 38.1% (AM1.5D) at concentration ratio K c = 200x. The combination of the solar cells with the cascade structure demonstrates an efficiency of 37.9% at concentrations of 400-800 suns. The parameters of the spectral-splitting photovoltaic module are measured. The photovoltaic efficiency of this module reaches 24.7% in the case of three single-junction cells and 27.9% when the two-junction and single-junction cells are combined.

  20. A verified technique for calibrating space solar cells

    Science.gov (United States)

    Anspaugh, Bruce

    1987-01-01

    Solar cells have been flown on high-altitude balloons for over 24 years, to produce solar cell standards that can be used to set the intensity of solar simulators. The events of a typical balloon calibration flight are reported. These are: the preflight events, including the preflight cell measurements and the assembly of the flight cells onto the solar tracker; the activities at the National Scientific Balloon Facility in Palestine, Texas, including the preflight calibrations, the mating of the tracker and cells onto the balloon, preparations for launch, and the launch; the payload recovery, which includes tracking the balloon by aircraft, terminating the flight, and retrieving the payload. In 1985, the cells flow on the balloon were also flown on a shuttle flight and measured independently. The two measurement methods are compared and shown to agree within 1 percent.

  1. Radiation resistance of solar cells for space application, 1

    International Nuclear Information System (INIS)

    Mitsui, Hiroshi; Tanaka, Ryuichi; Sunaga, Hiromi

    1989-07-01

    A 50-μm thick ultrathin silicon solar cell and a 280-μm thick high performance AlGaAs/GaAs solar cell with high radiation resistance have been recently developed by National Space Development Agency of Japan (NASDA). In order to study the radiation resistance of these cells, a joint research was carried out between Japan Atomic Energy Research Institute (JAERI) and NASDA from 1984 through 1987. In this research, the irradiation method of electron beams, the effects of the irradiation conditions on the deterioration of solar cells by electron beams, and the annealing effects of the radiation damage in solar cells were investigated. This paper is the first one of a series of reports of the joint research. In this paper, the space radiation environment which artificial satellites will encounter, the solar cells used, and the experimental methods are described. In addition to these, the results of the study on the irradiation procedure of electron beams are reported. In the study of the irradiation method of electron beams, three methods, that is, the fixed irradiation method, the moving irradiation method, and the spot irradiation method were examined. In the fixed irradiation method and moving one, stationary solar cells and solar cells moving by conveyer were irradiated by scanning electron beams, respectively. On the other hand, in the spot irradiation method, stationary solar cells were irradiated by non-scanning steady electron beams. It was concluded that the fixed irradiation method was the most proper method. In addition to this, in this study, some pieces of information were obtained with respect to the changes in the electrical characteristics of solar cells caused by the irradiation of electron beams. (author) 52 refs

  2. Indacenodithienothiophene-Based Ternary Organic Solar Cells

    International Nuclear Information System (INIS)

    Gasparini, Nicola; García-Rodríguez, Amaranda; Prosa, Mario; Bayseç, Şebnem; Palma-Cando, Alex; Katsouras, Athanasios; Avgeropoulos, Apostolos; Pagona, Georgia; Gregoriou, Vasilis G.; Chochos, Christos L.; Allard, Sybille; Scherf, Ulrich; Brabec, Christoph J.; Ameri, Tayebeh

    2017-01-01

    One of the key aspects to achieve high efficiency in ternary bulk-hetorojunction solar cells is the physical and chemical compatibility between the donor materials. Here, we report the synthesis of a novel conjugated polymer (P1) containing alternating pyridyl[2,1,3]thiadiazole between two different donor fragments, dithienosilole and indacenodithienothiophene (IDTT), used as a sensitizer in a host system of indacenodithieno[3,2-b]thiophene,2,3-bis(3-(octyloxy)phenyl)quinoxaline (PIDTTQ) and [6,6]-phenyl C 70 butyric acid methyl ester (PC 71 BM). We found that the use of the same IDTT unit in the host and guest materials does not lead to significant changes in the morphology of the ternary blend compared to the host binary. With the complementary use of optoelectronic characterizations, we found that the ternary cells suffer from a lower mobility-lifetime (μτ) product, adversely impacting the fill factor. However, the significant light harvesting in the near infrared region improvement, compensating the transport losses, results in an overall power conversion efficiency enhancement of ~7% for ternary blends as compared to the PIDTTQ:PC 71 BM devices.

  3. Studies of bulk heterojunction solar cells

    Science.gov (United States)

    Cossel, Raquel; McIntyre, Max; Tzolov, Marian

    We are studying bulk heterojunction solar cells that were fabricated using a mixture of PCPDTBT and PCBM­C60. The impedance data of the cells in dark responded like a simple RC circuit. The value of the dielectric constant derived from these results is consistent with the values reported in the literature for these materials. We are showing that the parallel resistance in the equivalent circuit of linear lump elements can be interpreted using the DC current­voltage measurements. The impedance spectra under light illumination indicated the existence of additional polarization. This extra feature can be described by a model that includes a series RC circuit in parallel with the equivalent circuit for a device in dark. The physical interpretation of the additional polarization is based on photo­generated charges getting trapped in wells, which have a characteristic relaxation time corresponding to the observed break frequency in the impedance spectra. We have studied the influence of the anode and cathode interface on this phenomena, either by using different interface materials, or by depositing the metal electrode while the substate is heated.

  4. Through cell vias contacts for multijunction solar cells

    Science.gov (United States)

    Richard, Olivier; Volatier, Maïté; Darnon, Maxime; Jaouad, Abdelatif; Bouzazi, Boussairi; Arès, Richard; Fafard, Simon; Aimez, Vincent

    2015-09-01

    The efficiency of multijunction solar cells used in concentrated photovoltaic systems is limited by shading from the grid line top electrode and electrical losses in the top epilayers. We propose to use through cell vias contacts to suppress the top electrode. Simulations show that the combination of through cell vias contacts with thin fingers has a potential absolute efficiency gain of 2 to 3% for concentration factors between 500 and 2000x. In addition, bus bars suppression improves by more than 20% the power extracted from a 6" wafer. Such an architecture requires additional technological steps. We discuss the challenges associated with via etching and report promising etching results for III-V heterostructures and germanium.

  5. Surface Passivation Studies on n+pp+ Bifacial Solar Cell

    Directory of Open Access Journals (Sweden)

    Suhaila Sepeai

    2012-01-01

    Full Text Available Bifacial solar cell is a specially designed solar cell for the production of electricity from both sides of the solar cell. It is an active field of research to make photovoltaics (PV more competitive by increasing its efficiency and lowering its costs. We developed an n+pp+ structure for the bifacial solar cell. The fabrication used phosphorus-oxy-trichloride (POCl3 diffusion to form the emitter and Al diffusion using conventional screen printing to produce the back surface field (BSF. The n+pp+ bifacial solar cell was a sandwiched structure of antireflective coatings on both sides, Argentum (Ag as a front contact and Argentum/Aluminum (Ag/Al as a back contact. This paper reports the solar cell performance with different surface passivation or antireflecting coatings (ARC. Silicon nitride (SiN deposited by Plasma-Enhanced Chemical Vapor Deposition (PECVD, thermally grown silicon dioxide (SiO2, PECVD-SiO2, and SiO2/SiN stack were used as ARC. The efficiency obtained for the best bifacial solar cell having SiN as the ARC is 8.32% for front surface illumination and 3.21% for back surface illumination.

  6. Molecular and Nanoscale Engineering of High Efficiency Excitonic Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Jenekhe, Samson A. [Univ. of Washington, Seattle, WA (United States); Ginger, David S. [Univ. of Washington, Seattle, WA (United States); Cao, Guozhong [Univ. of Washington, Seattle, WA (United States)

    2016-01-15

    We combined the synthesis of new polymers and organic-inorganic hybrid materials with new experimental characterization tools to investigate bulk heterojunction (BHJ) polymer solar cells and hybrid organic-inorganic solar cells during the 2007-2010 period (phase I) of this project. We showed that the bulk morphology of polymer/fullerene blend solar cells could be controlled by using either self-assembled polymer semiconductor nanowires or diblock poly(3-alkylthiophenes) as the light-absorbing and hole transport component. We developed new characterization tools in-house, including photoinduced absorption (PIA) spectroscopy, time-resolved electrostatic force microscopy (TR-EFM) and conductive and photoconductive atomic force microscopy (c-AFM and pc-AFM), and used them to investigate charge transfer and recombination dynamics in polymer/fullerene BHJ solar cells, hybrid polymer-nanocrystal (PbSe) devices, and dye-sensitized solar cells (DSSCs); we thus showed in detail how the bulk photovoltaic properties are connected to the nanoscale structure of the BHJ polymer solar cells. We created various oxide semiconductor (ZnO, TiO2) nanostructures by solution processing routes, including hierarchical aggregates and nanorods/nanotubes, and showed that the nanostructured photoanodes resulted in substantially enhanced light-harvesting and charge transport, leading to enhanced power conversion efficiency of dye-sensitized solar cells.

  7. Business, market and intellectual property analysis of polymer solar cells

    DEFF Research Database (Denmark)

    Damgaard Nielsen, Torben; Cruickshank, C.; Foged, S.

    2010-01-01

    The business potential of polymer solar cells is reviewed and the market opportunities analyzed on the basis of the currently reported and projected performance and manufacturing cost of polymer solar cells. Possible new market areas are identified and described. An overview of the present patent....... This is viewed as a great advantage for the possible commercialization of polymer solar cells in a European setting as the competition for the market will be based on the manufacturing performance rather than domination by a few patent stakeholders.......The business potential of polymer solar cells is reviewed and the market opportunities analyzed on the basis of the currently reported and projected performance and manufacturing cost of polymer solar cells. Possible new market areas are identified and described. An overview of the present patent...... and intellectual property situation is also given and a patent map of polymer solar cells is drawn in a European context. It is found that the business potential of polymer solar cells is large when taking the projections for future performance into account while the currently available performance...

  8. Business, market and intellectual property analysis of polymer solar cells

    International Nuclear Information System (INIS)

    Nielsen, Torben D.; Krebs, Frederik C.; Cruickshank, Craig; Foged, Soeren; Thorsen, Jesper

    2010-01-01

    The business potential of polymer solar cells is reviewed and the market opportunities analyzed on the basis of the currently reported and projected performance and manufacturing cost of polymer solar cells. Possible new market areas are identified and described. An overview of the present patent and intellectual property situation is also given and a patent map of polymer solar cells is drawn in a European context. It is found that the business potential of polymer solar cells is large when taking the projections for future performance into account while the currently available performance and manufacturing cost leaves little room for competition on the thin film photovoltaic market. However, polymer solar cells do enable the competitive manufacture of low cost niche products and is viewed as financially viable in its currently available form in a large volume approximation. Finally, it is found that the polymer solar cell technology is very poorly protected in Europe with the central patents being valid in only France, Germany, the Netherlands and the United Kingdom. Several countries with a large potential for PV such as Portugal and Greece are completely open and have apparently no relevant patents. This is viewed as a great advantage for the possible commercialization of polymer solar cells in a European setting as the competition for the market will be based on the manufacturing performance rather than domination by a few patent stakeholders. (author)

  9. Single-Walled Carbon Nanotubes in Solar Cells.

    Science.gov (United States)

    Jeon, Il; Matsuo, Yutaka; Maruyama, Shigeo

    2018-01-22

    Photovoltaics, more generally known as solar cells, are made from semiconducting materials that convert light into electricity. Solar cells have received much attention in recent years due to their promise as clean and efficient light-harvesting devices. Single-walled carbon nanotubes (SWNTs) could play a crucial role in these devices and have been the subject of much research, which continues to this day. SWNTs are known to outperform multi-walled carbon nanotubes (MWNTs) at low densities, because of the difference in their optical transmittance for the same current density, which is the most important parameter in comparing SWNTs and MWNTs. SWNT films show semiconducting features, which make SWNTs function as active or charge-transporting materials. This chapter, consisting of two sections, focuses on the use of SWNTs in solar cells. In the first section, we discuss SWNTs as a light harvester and charge transporter in the photoactive layer, which are reviewed chronologically to show the history of the research progress. In the second section, we discuss SWNTs as a transparent conductive layer outside of the photoactive layer, which is relatively more actively researched. This section introduces SWNT applications in silicon solar cells, organic solar cells, and perovskite solar cells each, from their prototypes to recent results. As we go along, the science and prospects of the application of solar cells will be discussed.

  10. New Results in Optical Modelling of Quantum Well Solar Cells

    Directory of Open Access Journals (Sweden)

    Silvian Fara

    2012-01-01

    Full Text Available This project brought further advancements to the quantum well solar cell concept proposed by Keith Barnham. In this paper, the optical modelling of MQW solar cells was analyzed and we focussed on the following topics: (i simulation of the refraction index and the reflectance, (ii simulation of the absorption coefficient, (iii simulation of the quantum efficiency for the absorption process, (iv discussion and modelling of the quantum confinement effect, and (v evaluation of datasheet parameters of the MQW cell.

  11. Process development for high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gee, J.M.; Basore, P.A.; Buck, M.E.; Ruby, D.S.; Schubert, W.K.; Silva, B.L.; Tingley, J.W.

    1991-12-31

    Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of simplifying technology transfer into an industrial setting. The strategies emphasize the use of statistical experimental design for process optimization, and the use of baseline processes and cells for process monitoring and quality control. 8 refs.

  12. Low cost thin film poly-silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This report presents the results of a project to design and develop a high density plasma based thin-film poly-silicon (TFPS) deposition system based on PQL proprietary advanced plasma technology to produce semiconductor quality TFPS for fabricating a TFPS solar cell. Details are given of the TFPS deposition system, the material development programme, solar cell structure, and cell efficiencies. The reproducibility of the deposition process and prospects for commercial exploitation are discussed.

  13. Semiconductor Nanocrystals as Light Harvesters in Solar Cells

    OpenAIRE

    Etgar, Lioz

    2013-01-01

    Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG) capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based ...

  14. Polymethylmethacrylate-based luminescent solar concentrators with bottom-mounted solar cells

    International Nuclear Information System (INIS)

    Zhang, Yi; Sun, Song; Kang, Rui; Zhang, Jun; Zhang, Ningning; Yan, Wenhao; Xie, Wei; Ding, Jianjun; Bao, Jun; Gao, Chen

    2015-01-01

    Graphical abstract: - Highlights: • Bottom-mounted luminescent solar concentrators on dye-doped plates were studied. • The mechanism of transport process was proposed. • The fabricated luminescent solar concentrator achieved a gain of 1.38. • Power conversion efficiency of 5.03% was obtained with cell area coverage of 27%. • The lowest cost per watt of $1.89 was optimized with cell area coverage of 18%. - Abstract: Luminescent solar concentrators offer an attractive approach to concentrate sunlight economically without tracking, but the narrow absorption band of luminescent materials hinders their further development. This paper describes bottom-mounted luminescent solar concentrators on dye-doped polymethylmethacrylate plates that absorb not only the waveguided light but also the transmitted sunlight and partial fluorescent light in the escape cone. A series of bottom-mounted luminescent solar concentrators with size of 78 mm × 78 mm × 7 mm were fabricated and their gain and power conversion efficiency were investigated. The transport process of the waveguided light and the relationship between the bottom-mounted cells were studied to optimize the performance of the device. The bottom-mounted luminescent solar concentrator with cell area coverage of 9% displayed a cell gain of 1.38, to our best knowledge, which is the highest value for dye-doped polymethylmethacrylate plate luminescent solar concentrators. Power conversion efficiency as high as 5.03% was obtained with cell area coverage of 27%. Furthermore, the bottom-mounted luminescent solar concentrator was found to have a lowest cost per watt of $1.89 with cell area coverage of 18%. These results suggested that the fabricated bottom-mounted luminescent solar concentrator may have a potential in low-cost building integrated photovoltaic application

  15. Fundamental investigations on periodic nano- and microstructured organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Niggemann, M.

    2005-03-15

    Using organic semiconducting materials in solar cells is a new approach with promising possibilities. The great potential of low cost production combined with mechanical flexibility gives rise to new applications. Due to the relatively simple fabrication process from solution and the mechanical flexibility, the production of organic solar cells by the cost effective roll-to-roll process appears promising. However, the preconditions for commercialization are not fulfilled as yet. The demands on organic solar cells strongly depend on the type of application. The highest demands on solar cell technologies are set by the energy market. Organic solar cells are only expected to be competitive on the energy market when the requirements on efficiency, lifetime and costs are fulfilled at the same time. Regarding this as a long term goal, a less demanding but still challenging medium term goal would be the application of relatively small organic solar cell modules for i.e. portable electronic devices. The integration of Organic Field Effect Transistors (OFET) and Organic Light Emitting Diodes (OLED) to all-polymer electronic devices is still under development. Nevertheless, the integration of organic solar cells as one functional component appears promising as the production technologies are expected to be compatible. The innovative contribution of this thesis to the development of organic solar cells is as follows: Motivated by the desire to fabricate efficient and cost effective organic solar cells, the approach of developing novel solar cell architectures based on periodic nano- and microstructures is followed. At present, planar organic solar cells with indium tin oxide (ITO) as a transparent electrode are intensively studied. One decisive cost factor would, however, be the indium price, which is the key component of the ITO electrode. The planar cell architecture can be conceived as a one-dimensional photonic device, however the presented work widens the investigations

  16. Indium Phosphide Window Layers for Indium Gallium Arsenide Solar Cells

    Science.gov (United States)

    Jain, Raj K.

    2005-01-01

    Window layers help in reducing the surface recombination at the emitter surface of the solar cells resulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (In(x)Ga(1-x)As) and related materials based solar cells are quite promising for photovoltaic and thermophotovoltaic applications. The flexibility of the change in the bandgap energy and the growth of InGaAs on different substrates make this material very attractive for multi-bandgap energy, multi-junction solar cell approaches. The high efficiency and better radiation performance of the solar cell structures based on InGaAs make them suitable for space power applications. This work investigates the suitability of indium phosphide (InP) window layers for lattice-matched In(0.53)Ga(0.47)As (bandgap energy 0.74 eV) solar cells. We present the first data on the effects of the p-type InP window layer on p-on-n lattice-matched InGaAs solar cells. The modeled quantum efficiency results show a significant improvement in the blue region with the InP window. The bare InGaAs solar cell performance suffers due to high surface recombination velocity (10(exp 7) cm/s). The large band discontinuity at the InP/InGaAs heterojunction offers a great potential barrier to minority carriers. The calculated results demonstrate that the InP window layer effectively passivates the solar cell front surface, hence resulting in reduced surface recombination and therefore, significantly improving the performance of the InGaAs solar cell.

  17. Application of carbon nanotubes in perovskite solar cells: A review

    Science.gov (United States)

    Oo, Thet Tin; Debnath, Sujan

    2017-11-01

    Solar power, as alternative renewable energy source, has gained momentum in global energy generation in recent time. Solar photovoltaics (PV) systems now fulfill a significant portion of electricity demand and the capacity of solar PV capacity is growing every year. PV cells efficiency has improved significantly following decades of research, evolving into third generations of PV cells. These third generation PV cells are set out to provide low-cost and efficient PV systems, further improving the commercial competitiveness of solar energy generation. Among these latest generations of PV cells, perovskite solar cells have gained attraction due to the simple manufacturing process and the immense growth in PV efficiency in a short period of research and development. Despite these advantages, perovskite solar cells are known for the weak stability and decomposition in exposure to humidity and high temperature, hindering the possibility of commercialization. This paper will discuss the role of carbon nanotubes (CNTs) in improving the efficiency and stability of perovskite solar cells, in various components such as perovskite layer and hole transport layer, as well as the application of CNTs in unique aspects. These includes the use of CNTs fiber in making the perovskite solar cells flexible, as well as simplification of perovskite PV production by using CNT flash evaporation printing process. Despite these advances, challenges remain in incorporation CNTs into perovskite such as lower conversion efficiency compared to rare earth metals and improvements need to be made. Thus, the paper will be also highlighting the CNTs materials suggested for further research and improvement of perovskite solar cells.

  18. Modeling Emerging Solar Cell Materials and Devices

    Science.gov (United States)

    Thongprong, Non

    Organic photovoltaics (OPVs) and perovskite solar cells are emerging classes of solar cell that are promising for clean energy alternatives to fossil fuels. Understanding fundamental physics of these materials is crucial for improving their energy conversion efficiencies and promoting them to practical applications. Current density-voltage (JV) curves; which are important indicators of OPV efficiency, have direct connections to many fundamental properties of solar cells. They can be described by the Shockley diode equation, resulting in fitting parameters; series and parallel resistance (Rs and Rp), diode saturation current ( J0) and ideality factor (n). However, the Shockley equation was developed specifically for inorganic p-n junction diodes, so it lacks physical meanings when it is applied to OPVs. Hence, the puRposes of this work are to understand the fundamental physics of OPVs and to develop new diode equations in the same form as the Shockley equation that are based on OPV physics. We develop a numerical drift-diffusion simulation model to study bilayer OPVs, which will be called the drift-diffusion for bilayer interface (DD-BI) model. The model solves Poisson, drift-diffusion and current-continuity equations self-consistently for charge densities and potential profiles of a bilayer device with an organic heterojunction interface described by the GWWF model. We also derive new diode equations that have JV curves consistent with the DD-BI model and thus will be called self-consistent diode (SCD) equations. Using the DD-BI and the SCD model allows us to understand working principles of bilayer OPVs and physical definitions of the Shockley parameters. Due to low carrier mobilities in OPVs, space charge accumulation is common especially near the interface and electrodes. Hence, quasi-Fermi levels (i.e. chemical potentials), which depend on charge densities, are modified around the interface, resulting in a splitting of quasi-Fermi levels that works as a driving

  19. Effect of extra virgin olive oil components on the arachidonic acid cascade, colorectal cancer and colon cancer cell proliferation

    Directory of Open Access Journals (Sweden)

    C. E. Storniolo

    2016-12-01

    Full Text Available The mediterranean diet (MD reduced the risk of colorectal cancer (CRC, and olive oil, the primary source of fat in the MD, has also been found to have a protective effect. However, animals fed with oleic acid present a high number of intestinal tumours, suggesting that oleic acid and olive oil consumption can exert different effects on CRC. Considering that extra virgin olive oil (EVOO is a complex mix of fatty acids and minor compounds such as polyphenols, hydrocarbons, phytosterols and triterpenes; and that these compounds have antioxidant activity and consequently they can modulate the arachidonic acid (AA cascade and eicosanoid synthesis. This review analyzes the state of the art of olive oil components on the AA cascade and cellular mechanism involved in CRC such as intestinal epithelial cell growth/apoptosis, to understand the fact that the consumption of seed oils with high oleic content or EVOO will probably have different effects on CRC development.

  20. Effect of extra virgin olive oil components on the arachidonic acid cascade, colorectal cancer and colon cancer cell proliferation

    International Nuclear Information System (INIS)

    Storniolo, C.E.; Moreno, J.J.

    2016-01-01

    The mediterranean diet (MD) reduced the risk of colorectal cancer (CRC), and olive oil, the primary source of fat in the MD, has also been found to have a protective effect. However, animals fed with oleic acid present a high number of intestinal tumours, suggesting that oleic acid and olive oil consumption can exert different effects on CRC. Considering that extra virgin olive oil (EVOO) is a complex mix of fatty acids and minor compounds such as polyphenols, hydrocarbons, phytosterols and triterpenes; and that these compounds have antioxidant activity and consequently they can modulate the arachidonic acid (AA) cascade and eicosanoid synthesis. This review analyzes the state of the art of olive oil components on the AA cascade and cellular mechanism involved in CRC such as intestinal epithelial cell growth/apoptosis, to understand the fact that the consumption of seed oils with high oleic content or EVOO will probably have different effects on CRC development. [es

  1. Modification of circuit module of dye-sensitized solar cells (DSSC) for solar windows applications

    Science.gov (United States)

    Hastuti, S. D.; Nurosyid, F.; Supriyanto, A.; Suryana, R.

    2016-11-01

    This research has been conducted to obtain a modification of circuit producing the best efficiency of solar window modules as an alternative energy for daily usage. Solar window module was constructed by DSSC cells. In the previous research, solar window was created by a single cell of DSSC. Because it had small size, it could not be applied in the manufacture of solar window. Fabrication of solar window required a larger size of DSSC cell. Therefore, in the next research, a module of solar window was fabricated by connecting few cells of DSSC. It was done by using external electrical circuit method which was modified in the formation of series circuit and parallel circuit. Its fabrication used six cells of DSSC with the size of each cell was 1 cm × 9 cm. DSSC cells were sandwich structures constructed by an active layer of TiO2 as the working electrode, electrolyte solution, dye, and carbon layer. Characterization of module was started one by one, from one cell, two cells, three cells, until six cells of a module. It was conducted to recognize the increasing efficiency value as the larger surface area given. The efficiency of solar window module with series circuit was 0.06%, while using parallel circuit was 0.006%. Module with series circuit generated the higher voltage as the larger surface area. Meanwhile, module through parallel circuit tended to produce the constant voltage as the larger surface area. It was caused by the influence of resistance within the cable in each module. Module with circuit parallel used a longer cable than module with series circuit, so that its resistance increased. Therefore, module with parallel circuit generated voltage that tended to be constant and resulted small efficiency compared to the module with series circuit. It could be concluded that series external circuit was the best modification which could produce the higher efficiency.

  2. Air stable organic-inorganic nanoparticles hybrid solar cells

    Science.gov (United States)

    Qian, Lei; Yang, Jihua; Xue, Jiangeng; Holloway, Paul H.

    2015-09-29

    A solar cell includes a low work function cathode, an active layer of an organic-inorganic nanoparticle composite, a ZnO nanoparticle layer situated between and physically contacting the cathode and active layers; and a transparent high work function anode that is a bilayer electrode. The inclusion of the ZnO nanoparticle layer results in a solar cell displaying a conversion efficiency increase and reduces the device degradation rate. Embodiments of the invention are directed to novel ZnO nanoparticles that are advantageous for use as the ZnO nanoparticle layers of the novel solar cells and a method to prepare the ZnO nanoparticles.

  3. A Novel Robot of Manufacturing Space Solar Cell Arrays

    Directory of Open Access Journals (Sweden)

    Wu Yuexin

    2008-11-01

    Full Text Available This paper presents a novel robot employed to manufacture space solar cell arrays. First of all including the mechanical configuration and control system, the architecture of the robot is described. Then the flow velocity field of adhesive in the dispensing needles is acquired based on hydrodynamics. The accurate section form model of adhesive dispensed on the solar cells is obtained, which is essential for the robot to control the uniformity of dispensing adhesive. Finally the experiment validates the feasibility and reliability of the robot system. The application of robots instead of manual work in manufacturing space solar cell arrays will enhance the development of space industry.

  4. Stability and Degradation of Organic and Polymer Solar Cells

    DEFF Research Database (Denmark)

    during operation and this is a critical area of research towards the successful development and commercialization of these 3rd generation solar cells. Covering both small molecule and polymer solar cells, Stability and Degradation of Organic and Polymer Solar Cells summarizes the state of the art...... understanding of stability and provides a detailed analysis of the mechanisms by which degradation occurs. Following an introductory chapter which compares different photovoltaic technologies, the book focuses on OPV degradation, discussing the origin and characterization of the instability and describing...

  5. A Novel Robot of Manufacturing Space Solar Cell Arrays

    Directory of Open Access Journals (Sweden)

    Wu Yuexin

    2007-03-01

    Full Text Available This paper presents a novel robot employed to manufacture space solar cell arrays. First of all including the mechanical configuration and control system, the architecture of the robot is described. Then the flow velocity field of adhesive in the dispensing needles is acquired based on hydrodynamics. The accurate section form model of adhesive dispensed on the solar cells is obtained, which is essential for the robot to control the uniformity of dispensing adhesive. Finally the experiment validates the feasibility and reliability of the robot system. The application of robots instead of manual work in manufacturing space solar cell arrays will enhance the development of space industry.

  6. Applications of atomic layer deposition in solar cells

    Science.gov (United States)

    Niu, Wenbin; Li, Xianglin; Krishna Karuturi, Siva; Wenhui Fam, Derrick; Fan, Hongjin; Shrestha, Santosh; Wong, Lydia Helena; Iing Yoong Tok, Alfred

    2015-02-01

    Atomic layer deposition (ALD) provides a unique tool for the growth of thin films with excellent conformity and thickness control down to atomic levels. The application of ALD in energy research has received increasing attention in recent years. In this review, the versatility of ALD in solar cells will be discussed. This is specifically focused on the fabrication of nanostructured photoelectrodes, surface passivation, surface sensitization, and band-structure engineering of solar cell materials. Challenges and future directions of ALD in the applications of solar cells are also discussed.

  7. Status note on solar cell technology; Statusnotat om solcelleteknologi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This status note briefly describes development and perspectives for solar cell technology internationally and nationally. The note will form part of the background for a coming proposal for a national solar cell strategy. The strategy will be prepared by the Danish Energy Authority in collaboration with the Ministry of Science, Technology and Innovation, Elkraft System, Eltra, representatives from the industry and others. The proposal is expected to give an overall picture of Danish R and D niches and opportunities within solar cell technology. (BA)

  8. Highly doped layer for tunnel junctions in solar cells

    Science.gov (United States)

    Fetzer, Christopher M.

    2017-08-01

    A highly doped layer for interconnecting tunnel junctions in multijunction solar cells is presented. The highly doped layer is a delta doped layer in one or both layers of a tunnel diode junction used to connect two or more p-on-n or n-on-p solar cells in a multijunction solar cell. A delta doped layer is made by interrupting the epitaxial growth of one of the layers of the tunnel diode, depositing a delta dopant at a concentration substantially greater than the concentration used in growing the layer of the tunnel diode, and then continuing to epitaxially grow the remaining tunnel diode.

  9. High Efficiency Polymer Solar Cells with Long Operating Lifetimes

    KAUST Repository

    Peters, Craig H.

    2011-04-20

    Organic bulk-heterojunction solar cells comprising poly[N-9\\'-hepta-decanyl- 2,7-carbazole-alt-5,5-(4\\',7\\'-di-2-thienyl-2\\', 1\\',3\\'-benzothiadiazole) (PCDTBT) are systematically aged and demonstrate lifetimes approaching seven years, which is the longest reported lifetime for polymer solar cells. An experimental set-up is described that is capable of testing large numbers of solar cells, holding each device at its maximum power point while controlling and monitoring the temperature and light intensity. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. A solution process for inverted tandem solar cells

    DEFF Research Database (Denmark)

    Larsen-Olsen, Thue Trofod; Bundgaard, Eva; Sylvester-Hvid, Kristian O.

    2011-01-01

    Tandem solar cells with normal and inverted device geometries were prepared by a solution process. Both device types were based on the use of zinc(II)oxide as the electron transporting layer (ETL). The hole transporting layer (HTL) was either PEDOT:PSS for normal geometry tandem solar cells...... or vanadium(V)oxide in the case of inverted tandem cells. It was found that the inverted tandem solar cells performed comparable or better than the normal geometry devices, showing that the connection structure of vanadium(V)oxide, Ag nanoparticles and zinc(II)oxide functions both as a good recombination...... layer, ensuring serial connection, and as a solvent barrier, protecting the first photoactive layer from processing of the second layer. This successfully demonstrates a tandem solar cell fabrication process fully compatible with state-of-the-art solution based automated production procedures....

  11. Performance analysis of solar cell arrays in concentrating light intensity

    International Nuclear Information System (INIS)

    Xu Yongfeng; Li Ming; Lin Wenxian; Wang Liuling; Xiang Ming; Zhang Xinghua; Wang Yunfeng; Wei Shengxian

    2009-01-01

    Performance of concentrating photovoltaic/thermal system is researched by experiment and simulation calculation. The results show that the I-V curve of the GaAs cell array is better than that of crystal silicon solar cell arrays and the exergy produced by 9.51% electrical efficiency of the GaAs solar cell array can reach 68.93% of the photovoltaic/thermal system. So improving the efficiency of solar cell arrays can introduce more exergy and the system value can be upgraded. At the same time, affecting factors of solar cell arrays such as series resistance, temperature and solar irradiance also have been analyzed. The output performance of a solar cell array with lower series resistance is better and the working temperature has a negative impact on the voltage in concentrating light intensity. The output power has a -20 W/V coefficient and so cooling fluid must be used. Both heat energy and electrical power are then obtained with a solar trough concentrating photovoltaic/thermal system. (semiconductor devices)

  12. All-Weather Solar Cells: A Rising Photovoltaic Revolution.

    Science.gov (United States)

    Tang, Qunwei

    2017-06-16

    Solar cells have been considered as one of the foremost solutions to energy and environmental problems because of clean, high efficiency, cost-effective, and inexhaustible features. The historical development and state-of-the-art solar cells mainly focus on elevating photoelectric conversion efficiency upon direct sunlight illumination. It is still a challenging problem to realize persistent high-efficiency power generation in rainy, foggy, haze, and dark-light conditions (night). The physical proof-of-concept for all-weather solar cells opens a door for an upcoming photovoltaic revolution. Our group has been exploring constructive routes to build all-weather solar cells so that these advanced photovoltaic technologies can be an indication for global solar industry in bringing down the cost of energy harvesting. How the all-weather solar cells are built without reducing photo performances and why such architectures can realize electricity outputs with no visible-light are discussed. Potential pathways and opportunities to enrich all-weather solar cell families are envisaged. The aspects discussed here may enable researchers to develop undiscovered abilities and to explore wide applications of advanced photovoltaics. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Effect of the Phosphorus Gettering on Si Heterojunction Solar Cells

    Directory of Open Access Journals (Sweden)

    Hyomin Park

    2012-01-01

    Full Text Available To improve the efficiency of crystalline silicon solar cells, should be collected the excess carrier as much as possible. Therefore, minimizing the recombination both at the bulk and surface regions is important. Impurities make recombination sites and they are the major reason for recombination. Phosphorus (P gettering was introduced to reduce metal impurities in the bulk region of Si wafers and then to improve the efficiency of Si heterojunction solar cells fabricated on the wafers. Resistivity of wafers was measured by a four-point probe method. Fill factor of solar cells was measured by a solar simulator. Saturation current and ideality factor were calculated from a dark current density-voltage graph. External quantum efficiency was analyzed to assess the effect of P gettering on the performance of solar cells. Minority bulk lifetime measured by microwave photoconductance decay increases from 368.3 to 660.8 μs. Open-circuit voltage and short-circuit current density increase from 577 to 598 mV and 27.8 to 29.8 mA/cm2, respectively. The efficiency of solar cells increases from 11.9 to 13.4%. P gettering will be feasible to improve the efficiency of Si heterojunction solar cells fabricated on P-doped Si wafers.

  14. Reversible degradation of inverted organic solar cells by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manor, Assaf; Katz, Eugene A

    2011-01-01

    Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5–15 suns at three different stages: for a pristine...

  15. Light management in thin-film silicon solar cells

    NARCIS (Netherlands)

    Isabella, O.

    2013-01-01

    Solar energy can fulfil mankind’s energy needs and secure a more balanced distribution of primary sources of energy. Wafer-based and thin-film silicon solar cells dominate todays’ photovoltaic market because silicon is a non-toxic and abundant material and high conversion efficiencies are achieved

  16. Panel fabrication utilizing GaAs solar cells

    Science.gov (United States)

    Mardesich, N.

    1984-01-01

    The development of the GaAs solar cells for space applications is described. The activities in the fabrication of GaAs solar panels are outlined. Panels were fabricated while introducing improved quality control, soldering laydown and testing procedures. These panels include LIPS II, San Marco Satellite, and a low concentration panel for Rockwells' evaluation. The panels and their present status are discussed.

  17. Impurities in silicon and their impact on solar cell performance

    NARCIS (Netherlands)

    Coletti, Gianluca

    2011-01-01

    Photovoltaic conversion of solar energy is a rapidly growing technology. More than 80% of global solar cell production is currently based on silicon. The aim of this thesis is to understand the complex relation between impurity content of silicon starting material (“feedstock”) and the resulting

  18. ORGANIC THIN-FILM SOLAR CELLS: NEXT GENERATION LOW ...

    African Journals Online (AJOL)

    Solar energy has the potential to fulfil an important part of the sustainable energy demand for future power generations. Thereby, low-cost organic photovoltaic systems have come into the international researchfocus during thepast ... polymeric solar cells ultra-thin flexible material can be applied to large surfaces by printing ...

  19. Solar industry in Japan: With solar cells towards the Sun

    International Nuclear Information System (INIS)

    Odrich, B.

    1992-01-01

    In the area of solar energy Japan is considered to be leading with a 36% market share. Two third of the total output are used for consumer products, about 30% for business purposes and 3.4% for research and development. This article gives a survey of the activities of Japanese companies in this area. According to the companies there are obstacles not in the technical area but rather in the market introduction, an area for which at present high capital spendings are necessary. (BWI) [de

  20. Performance enhancement of polymer solar cells using copper oxide nanoparticles

    Science.gov (United States)

    Wanninayake, Aruna P.; Gunashekar, Subhashini; Li, Shengyi; Church, Benjamin C.; Abu-Zahra, Nidal

    2015-06-01

    Copper oxide (CuO) is a p-type semiconductor with a band gap energy of 1.5 eV, this is close to the ideal energy gap of 1.4 eV required for solar cells to allow good solar spectral absorption. The inherent electrical characteristics of CuO nanoparticles make them attractive candidates for improving the performance of polymer solar cells when incorporated into the active polymer layer. The UV-visible absorption spectra and external quantum efficiency of P3HT/PC70BM solar cells containing different weight percentages of CuO nanoparticles showed a clear enhancement in the photo absorption of the active layer, this increased the power conversion efficiency of the solar cells by 24% in comparison to the reference cell. The short circuit current of the reference cell was found to be 5.234 mA cm-2 and it seemed to increase to 6.484 mA cm-2 in cells containing 0.6 mg of CuO NPs; in addition, the fill factor increased from 61.15% to 68.0%, showing an enhancement of 11.2%. These observations suggest that the optimum concentration of CuO nanoparticles was 0.6 mg in the active layer. These significant findings can be applied to design high-efficiency polymer solar cells containing inorganic nanoparticles.

  1. Bias-dependent high saturation solar LBIC scanning of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Vorster, F.J.; van Dyk, E.E. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

    2007-06-15

    A light beam-induced current measurement system that uses concentrated solar radiation as a beam probe to map spatially distributed defects on a solar cell has been developed and tested [F.J. Vorster, E.E. van Dyk, Rev. Sci. Instrum., submitted for review]. The induced current response from a flat plate EFG Si solar cell was mapped as a function of surface position and cell bias by using a solar light beam induced current (S-LBIC) mapping system while at the same time dynamically biasing the whole cell with an external voltage. This paper examines the issues relating to transient capacitive effects as well as the electrical behaviour of typical solar cell defect mechanisms under spot illumination. By examining the bias dependence of the S-LBIC maps, various defect mechanisms of photovoltaic (PV) cells under concentrated solar irradiance may be identified. The techniques employed to interpret the spatially distributed IV curves as well as initial results are discussed. (author)

  2. Solar harvesting by a heterostructured cell with built-in variable width quantum wells

    Science.gov (United States)

    Brooks, W.; Wang, H.; Mil'shtein, S.

    2018-02-01

    We propose cascaded heterostructured p-i-n solar cells, where inside of the i-region is a set of Quantum Wells (QWs) with variable thicknesses to enhance absorption of different photonic energies and provide quick relaxation for high energy carriers. Our p-i-n heterostructure carries top p-type and bottom n-type 11.3 Å thick AlAs layers, which are doped by acceptors and donor densities up to 1019/cm3. The intrinsic region is divided into 10 segments where each segment carries ten QWs of the same width and the width of the QWs in each subsequent segment gradually increases. The top segment consists of 10 QWs with widths of 56.5Å, followed by a segment with 10 wider QWs with widths of 84.75Å, followed by increasing QW widths until the last segment has 10 QWs with widths of 565Å, bringing the total number of QWs to 100. The QW wall height is controlled by alternating AlAs and GaAs layers, where the AlAs layers are all 11.3Å thick, throughout the entire intrinsic region. Configuration of variable width QWs prescribes sets of energy levels which are suitable for absorption of a wide range of photon energies and will dissipate high electron-hole energies rapidly, reducing the heat load on the solar cell. We expect that the heating of the solar cell will be reduced by 8-11%, enhancing efficiency. The efficiency of the designed solar cell is 43.71%, the Fill Factor is 0.86, the density of short circuit current (ISC) will not exceed 338 A/m2 and the open circuit voltage (VOC) is 1.51V.

  3. Predicting Solar-Cell Dyes for Cosensitization

    Energy Technology Data Exchange (ETDEWEB)

    Bayliss, Sam L. [Cavendish; Cole, Jacqueline M. [Cavendish; Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States; Institute; Waddell, Paul G. [Cavendish; Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234, Australia; McKechnie, Scott [Cavendish; Liu, Xiaogang [Cavendish

    2014-06-19

    A major limitation of using organic dyes for dye-sensitized solar cells (DSCs) has been their lack of broad optical absorption. Co-sensitization, in which two complementary dyes are incorporated into a DSC, offers a route to combat this problem. Here we construct and implement a design route for materials discovery of new dyes for co-sensitization, beginning with a chemically compatible series of existing laser dyes which are without an anchor group necessary for DSC use. We determine the crystal structures for this dye series, and use their geometries to establish the DSC molecular design prerequisites aided by density-functional theory and time-dependent density-functional theory calculations. Based on insights gained from these existing dyes, modified sensitizers are computationally designed to include a suitable anchor group. A DSC co-sensitization strategy for these modified sensitizers is predicted, using the central features of highest-occupied, and lowest-unoccupied molecular orbital positioning, optical absorption properties, intramolecular charge-transfer characteristics, and steric effects as selection criteria. Through this molecular engineering of a series of existing non-DSC dyes, we predict new materials for DSC co-sensitization.

  4. Decohesion Kinetics in Polymer Organic Solar Cells

    KAUST Repository

    Bruner, Christopher

    2014-12-10

    © 2014 American Chemical Society. We investigate the role of molecular weight (MW) of the photoactive polymer poly(3-hexylthiophene) (P3HT) on the temperature-dependent decohesion kinetics of bulk heterojunction (BHJ) organic solar cells (OSCs). The MW of P3HT has been directly correlated to its carrier field effect mobilities and the ambient temperature also affects OSC in-service performance and P3HT arrangement within the BHJ layer. Under inert conditions, time-dependent decohesion readily occurs within the BHJ layer at loads well below its fracture resistance. We observe that by increasing the MW of P3HT, greater resistance to decohesion is achieved. However, failure consistently occurs within the BHJ layer representing the weakest layer within the device stack. Additionally, it was found that at temperatures below the glass transition temperature (∼41-45 °C), decohesion was characterized by brittle failure via molecular bond rupture. Above the glass transition temperature, decohesion growth occurred by a viscoelastic process in the BHJ layer, leading to a significant degree of viscoelastic deformation. We develop a viscoelastic model based on molecular relaxation to describe the resulting behavior. The study has implications for OSC long-term reliability and device performance, which are important for OSC production and implementation.

  5. Danish participation in the IEA solar cell activities

    International Nuclear Information System (INIS)

    1994-05-01

    In the 12-month period 01.05.93 - 30.04.94 the Danish activities in the IEA 'Solar Cell Agreement' consisted in: participation in the Executive Committee (ExCo) and participation in Task 1 'Exchange and Dissemination of Information on PV Power Systems'. ExCo has meetings every half-year and is a coordinating organ for the Agreement. Work on the Task 1 is organized in 4 subtasks: (1) mapping of solar cell activities in the OECD countries and preparation of an IEA handbook on solar cell technology; (2) publishing of a semiannual newsletter about the agreement; (3) an 'executive conference' on solar cell technology and its uses with participation of the decision-makers in respective power industries; (4) information dissemination whenever required. Demonstration projects, like a photovoltaic roof-integrated system connected to the grid. have been implemented. Three larger solar cell projects, subsidized by the EU means, comprehend 'real time monitoring' by a solar system, WHO project 'Solar Energy Applications for Primary Health Care Clinics for Remote Rural Areas' (SAPHIR) and a grid-connected photovoltaic system in a suburb residential settlement. (EG)

  6. Cytotoxic Effect of Nano-SiO2 in Human Breast Cancer Cells via Modulation of EGFR Signaling Cascades.

    Science.gov (United States)

    Jeon, Donghwan; Kim, Hyungjoo; Nam, Keesoo; Oh, Sunhwa; Son, Seog-Ho; Shin, Incheol

    2017-11-01

    Silica nanoparticles (nano-SiO 2 ) are widely used in many industrial areas and there is much controversy surrounding cytotoxic effects of such nanoparticles. In order to determine the toxicity and possible molecular mechanisms involved, we conducted several tests with two breast cancer cell lines, MDA-MB-231 and Hs578T. After exposure to nano-SiO 2 , growth, apoptosis, motility of breast cancer cells were monitored. In addition, modulation of signal transduction induced by nano-SiO 2 was detected through western blot analysis. Treatment of nano-SiO 2 repressed the growth of breast cancer cell lines. It also increased apoptosis and reduced cell motility. Moreover, exposure to nano-SiO 2 significantly disturbed the dimerization of epidermal growth factor receptor (EGFR), followed by down-regulation of its downstream cellular sarcoma kinase (c-SRC) and signal transducer and activator of transcription 3 (STAT3) signaling cascades. Nano-SiO 2 has a cytotoxic effect on MDA-MB-231 and Hs578T breast cancer cells via modulation of EGFR signaling cascades. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  7. Stability issues of dye solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Asghar, M.I.

    2012-11-01

    The thesis discusses dye solar cells (DSCs) which are emerging as a potential candidate for many applications. The goal of the work was to find more stable and higher performing materials for flexible DSCs, improve understanding of the effects on the DSC stability, and to develop experimental methods that give improved resolution of the degradation mechanisms. First an intensive critical literature review was done to highlight the important degradation mechanisms in DSCs. It was concluded that techniques giving chemical information are needed to understand the degradation reactions and their effect on electrical performance. It would be advantageous to have methods that enable monitoring chemical changes in operating DSCs, or periodically over their lifetime during accelerated ageing tests. Here the focus was on new and advanced in-situ methods that allow continuous study of the aging of the cells. In this regard, optical techniques such as Raman spectroscopy, newly introduced image processing method and recently introduced segmented cell method were employed to bridge the link between the chemical changes in the DSCs and the standard PV measurement methods. Here for instance the image processing was demonstrated to study the bleaching of electrolyte under ultraviolet and visible light at 85 deg C. The results obtained with the image processing method and the standard electrical measurements were in agreement and showed that the bleaching of electrolyte was initiated by TiO2 and slowed down by the presence of the dye. For the roll-to-roll production of DSCs cheap, flexible and stable substrates are required. In this work, a series of metals i.e. StS 304, StS 321, StS 316, StS 316L and Ti were successfully stabilized at the CE of a DSC by using a sputtered Pt catalyst layer that doubled also as a corrosion blocking layer. This work was an important step forward towards stable flexible DSCs. Finally, the degradation due to the manufacturing step related to the

  8. Crystalline silicon solar cells with high resistivity emitter

    Science.gov (United States)

    Panek, P.; Drabczyk, K.; Zięba, P.

    2009-06-01

    The paper presents a part of research targeted at the modification of crystalline silicon solar cell production using screen-printing technology. The proposed process is based on diffusion from POCl3 resulting in emitter with a sheet resistance on the level of 70 Ω/□ and then, shaped by high temperature passivation treatment. The study was focused on a shallow emitter of high resistivity and on its influence on output electrical parameters of a solar cell. Secondary ion mass spectrometry (SIMS) has been employed for appropriate distinguishing the total donor doped profile. The solar cell parameters were characterized by current-voltage characteristics and spectral response (SR) methods. Some aspects playing a role in suitable manufacturing process were discussed. The situation in a photovoltaic industry with emphasis on silicon supply and current prices of solar cells, modules and photovoltaic (PV) systems are described. The economic and quantitative estimation of the PV world market is shortly discussed.

  9. Multijunction Ultralight Solar Cells and Arrays, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a continuing need within NASA for solar cells and arrays with very high specific power densities (1000-5000 kW/kg) for generating power in a new generation...

  10. Window structure for passivating solar cells based on gallium arsenide

    Science.gov (United States)

    Barnett, Allen M. (Inventor)

    1985-01-01

    Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.

  11. High Efficiency Quantum Well Waveguide Solar Cells, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The long-term objective of this program is to develop flexible, lightweight, single-junction solar cells using quantum structured designs that can achieve ultra-high...

  12. Performance of planar heterojunction perovskite solar cells under light concentration

    Directory of Open Access Journals (Sweden)

    Aaesha Alnuaimi

    2016-11-01

    Full Text Available In this work, we present 2D simulation of planar heterojunction perovskite solar cells under high concentration using physics-based TCAD. The performance of planar perovskite heterojunction solar cells is examined up to 1000 suns. We analyze the effect of HTM mobility and band structure, surface recombination velocities at interfaces and the effect of series resistance under concentrated light. The simulation results revealed that the low mobility of HTM material limits the improvement in power conversation efficiency of perovskite solar cells under concentration. In addition, large band offset at perovskite/HTM interface contributes to the high series resistance. Moreover, losses due to high surface recombination at interfaces and the high series resistance deteriorate significantly the performance of perovskite solar cells under concentration.

  13. Plasmonic nano-antenna a-Si:H solar cell.

    Science.gov (United States)

    Di Vece, Marcel; Kuang, Yinghuan; van Duren, Stephan N F; Charry, Jamie M; van Dijk, Lourens; Schropp, Ruud E I

    2012-12-03

    In this work the effects of plasmonics, nano-focusing, and orthogonalization of carrier and photon pathways are simultaneously explored by measuring the photocurrents in an elongated nano-scale solar cell with a silver nanoneedle inside. The silver nanoneedles formed the support of a conformally grown hydrogenated amorphous silicon (a-Si:H) n-i-p junction around it. A spherical morphology of the solar cell functions as a nano-lens, focusing incoming light directly on the silver nanoneedle. We found that plasmonics, geometric optics, and Fresnel reflections affect the nanostructured solar cell performance, depending strongly on light incidence angle and polarization. This provides valuable insight in solar cell processes in which novel concepts such as plasmonics, elongated nanostructures, and nano-lenses are used.

  14. Black silicon solar cells with black bus-bar strings

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of black silicon texturing and blackened bus-bar strings as a potential method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon was realized by maskless reactive ion etching resulting in total, average reflectance...... below 0.5% across a 156x156 mm2 silicon wafer. Four different methods to obtain blackened bus-bar strings were compared with respect to reflectance, and two of these methods (i.e., oxidized copper and etched solder) were used to fabricate functional allblack solar 9-cell panels. The black bus-bars (e.......g., by oxidized copper) have a reflectance below 3% in the entire visible wavelength range. The combination of black silicon cells and blackened bus-bars results in aesthetic, all-black panels based on conventional, front-contacted solar cells without compromising efficiency....

  15. InN-Based Quantum Dot Solar Cells, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this STTR program is to employ nanostructured materials in advanced device designs to enhance the tolerance of solar cells to extreme conditions while...

  16. InN-Based Quantum Dot Solar Cells, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this STTR program is to employ nanostructured materials in an advanced device design to enhance the tolerance of solar cells to extreme environments...

  17. Environmental simulation testing of solar cell contamination by hydrazine

    Science.gov (United States)

    Moore, W. W., Jr.

    1972-01-01

    Test results for thermal vacuum and radiation environment simulation of hydrazine contamination are discussed. Solar cell performance degradation, measured by short circuit current, is presented in correlation with the variations used in environmental parameters.

  18. Highly efficient perovskite solar cells with tunable structural color.

    Science.gov (United States)

    Zhang, Wei; Anaya, Miguel; Lozano, Gabriel; Calvo, Mauricio E; Johnston, Michael B; Míguez, Hernán; Snaith, Henry J

    2015-03-11

    The performance of perovskite solar cells has been progressing over the past few years and efficiency is likely to continue to increase. However, a negative aspect for the integration of perovskite solar cells in the built environment is that the color gamut available in these materials is very limited and does not cover the green-to-blue region of the visible spectrum, which has been a big selling point for organic photovoltaics. Here, we integrate a porous photonic crystal (PC) scaffold within the photoactive layer of an opaque perovskite solar cell following a bottom-up approach employing inexpensive and scalable liquid processing techniques. The photovoltaic devices presented herein show high efficiency with tunable color across the visible spectrum. This now imbues the perovskite solar cells with highly desirable properties for cladding in the built environment and encourages design of sustainable colorful buildings and iridescent electric vehicles as future power generation sources.

  19. Broadband back grating design for thin film solar cells

    KAUST Repository

    Janjua, Bilal

    2013-01-01

    In this paper, design based on tapered circular grating structure was studied, to provide broadband enhancement in thin film amorphous silicon solar cells. In comparison to planar structure an absorption enhancement of ~ 7% was realized.

  20. Recent Development in ITO-free Flexible Polymer Solar Cells

    Directory of Open Access Journals (Sweden)

    Shudi Lu

    2017-12-01

    Full Text Available Polymer solar cells have shown good prospect for development due to their advantages of low-cost, light-weight, solution processable fabrication, and mechanical flexibility. Their compatibility with the industrial roll-to-roll manufacturing process makes it superior to other kind of solar cells. Normally, indium tin oxide (ITO is adopted as the transparent electrode in polymer solar cells, which combines good conductivity and transparency. However, some intrinsic weaknesses of ITO restrict its large scale applications in the future, including a high fabrication price using high temperature vacuum deposition method, scarcity of indium, brittleness and scaling up of resistance with the increase of area. Some substitutes to ITO have emerged in recent years, which can be used in flexible polymer solar cells. This article provides the review on recent progress using other transparent electrodes, including carbon nanotubes, graphene, metal nanowires and nanogrids, conductive polymer, and some other electrodes. Device stability is also discussed briefly.

  1. Fabrication of Solar Cells by Deposition of Phosphorous Vapour

    International Nuclear Information System (INIS)

    Ika Ismet; Shobih; Sagala, Pahlawan

    2002-01-01

    This paper shows the fabrication of solar cells by deposition of phosphorous vapor using 10x10 cm 2 polycrystalline silicon wafer. The diffusion process for forming p-n junction was carried out in the conveyor furnace at temperature of 860, 875, and 950 o C with belt velocities at 2, 3, 4, 5, 71/2 and 10 inches per minute (Ipm). The emphasize of the research is for understanding the characterization of the doping of phosphorous in order to obtain better performance of solar cells. At this initial research, it was found that solar cell efficiency is still around 7.5 - 8 % with short circuit current I SC in the range of 2.6 - 2.75 A. The current - voltage (I-V) measurement as well as the electrical parameters of solar cell are also discussed here. (author)

  2. Multijunction Ultralight Solar Cells and Arrays, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a continuing need within NASA for solar cells and arrays with very high specific power densities (1000-5000 kW/kg) for generating power in a new generation...

  3. Nanostructured InGaP Solar Cells, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Current matching constraints can severely limit the design and overall performance of conventional serially-connected multijunction solar cells. The goal of this...

  4. Electron migration and stability of dye solar cells

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2008-07-01

    Full Text Available Dye-sensitised photoelectrochemical solar cells with four different electrolyte combinations were assembled and characterised using current voltage measurements. The effects that the solvents (acetonitrile - ACN and propionitrile - PN) have...

  5. Acceptable contamination levels in solar grade silicon: From feedstock to solar cell

    International Nuclear Information System (INIS)

    Hofstetter, J.; Lelievre, J.F.; Canizo, C.; Luque, A. del

    2009-01-01

    Ultimately, alternative ways of silicon purification for photovoltaic applications are developed and applied. There is an ongoing debate about what are the acceptable contamination levels within the purified silicon feedstock to specify the material as solar grade silicon. Applying a simple model and making some additional assumptions, we calculate the acceptable contamination levels of different characteristic impurities for each fabrication step of a typical industrial mc-Si solar cell. The acceptable impurity concentrations within the finished solar cell are calculated for SRH recombination exclusively and under low injection conditions. It is assumed that during solar cell fabrication impurity concentrations are only altered by a gettering step. During the crystallization process, impurity segregation at the solid-liquid interface and at extended defects are taken into account. Finally, the initial contamination levels allowed within the feedstock are deduced. The acceptable concentration of iron in the finished solar cell is determined to be 9.7x10 -3 ppma whereas the concentration in the silicon feedstock can be as high as 12.5 ppma. In comparison, the titanium concentration admitted in the solar cell is calculated to be 2.7x10 -4 ppma and the allowed concentration of 2.2x10 -2 ppma in the feedstock is only two orders of magnitude higher. Finally, it is shown theoretically and experimentally that slow cooling rates can lead to a decrease of the interstitial Fe concentration and thus relax the purity requirements in the feedstock.

  6. Sun-believable solar paint. A transformative one-step approach for designing nanocrystalline solar cells.

    Science.gov (United States)

    Genovese, Matthew P; Lightcap, Ian V; Kamat, Prashant V

    2012-01-24

    A transformative approach is required to meet the demand of economically viable solar cell technology. By making use of recent advances in semiconductor nanocrystal research, we have now developed a one-coat solar paint for designing quantum dot solar cells. A binder-free paste consisting of CdS, CdSe, and TiO(2) semiconductor nanoparticles was prepared and applied to conducting glass surface and annealed at 473 K. The photoconversion behavior of these semiconductor film electrodes was evaluated in a photoelectrochemical cell consisting of graphene-Cu(2)S counter electrode and sulfide/polysulfide redox couple. Open-circuit voltage as high as 600 mV and short circuit current of 3.1 mA/cm(2) were obtained with CdS/TiO(2)-CdSe/TiO(2) electrodes. A power conversion efficiency exceeding 1% has been obtained for solar cells constructed using the simple conventional paint brush approach under ambient conditions. Whereas further improvements are necessary to develop strategies for large area, all solid state devices, this initial effort to prepare solar paint offers the advantages of simple design and economically viable next generation solar cells. © 2011 American Chemical Society

  7. Radiation resistant low bandgap InGaAsP solar cell for multi-junction solar cells

    International Nuclear Information System (INIS)

    Khan, Aurangzeb; Yamaguchi, Masafumi; Dharmaras, Nathaji; Yamada, Takashi; Tanabe, Tatsuya; Takagishi, Shigenori; Itoh, Hisayoshi; Ohshima, Takeshi

    2001-01-01

    We have explored the superior radiation tolerance of metal organic chemical vapor deposition (MOCVD) grown, low bandgap, (0.95eV) InGaAsP solar cells as compared to GaAs-on-Ge cells, after 1 MeV electron irradiation. The minority carrier injection due to forward bias and light illumination under low concentration ratio, can lead to enhanced recovery of radiation damage in InGaAsP n + -p junction solar cells. An injection anneal activation energy (0.58eV) of the defects involved in damage/recovery of the InGaAsP solar cells has been estimated from the resultant recovery of the solar cell properties following minority carrier injection. The results suggest that low bandgap radiation resistant InGaAsP (0.95eV) lattice matched to InP substrates provide an alternative to use as bottom cells in multi-junction solar cells instead of less radiation ressitant conventional GaAs based solar cells for space applications. (author)

  8. PbS/CdS-sensitized mesoscopic SnO2 solar cells for enhanced infrared light harnessing.

    Science.gov (United States)

    Hossain, Md Anower; Koh, Zhen Yu; Wang, Qing

    2012-05-28

    Metal oxide semiconductors with lower lying conduction band minimum and superior electron mobility are essential for efficient charge separation and collection in PbS-sensitized solar cells. In the present study, mesoscopic SnO(2) was investigated as an alternative photoanode to the commonly used TiO(2) and examined comprehensively in PbS-sensitized liquid junction solar cells. To exploit the capability of PbS in an optimized structure, cascaded nPbS/nCdS and alternate n(PbS/CdS) layers deposited by a successive ionic layer adsorption and reaction method were systematically scrutinized. It was observed that the surface of SnO(2) has greater affinity to the growth of PbS compared with TiO(2), giving rise to much enhanced light absorption. In addition, the deposition of a CdS buffer layer and a ZnS passivation layer before and after a PbS layer was found to be beneficial for efficient charge separation. Under optimized conditions, cascaded PbS/CdS-sensitized SnO(2) exhibited an unprecedented photocurrent density of 17.38 mA cm(-2) with pronounced infrared light harvesting extending beyond 1100 nm, and a power conversion efficiency of 2.23% under AM 1.5, 1 sun illumination. In comparison, TiO(2) cells fabricated under similar conditions showed much inferior performance owing to the less efficient light harnessing of long wavelength photons. We anticipate that the systematic study of PbS-sensitized solar cells utilizing different metal oxide semiconductors as electron transporters would provide useful insights and promote the development of semiconductor-sensitized mesoscopic solar cells employing panchromatic sensitizers.

  9. The interplay of nanostructure and efficiency of polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yin Chunhong

    2008-12-04

    The aim of this thesis is to achieve a deep understanding of the working mechanism of polymer based solar cells and to improve the device performance. Two types of the polymer based solar cells are studied here: the polymer-polymer solar cells, and the polymer-small molecule solar cell which has polymer as electron donor incorporating with organic small molecule as electron acceptor. For the polymer-polymer devices, I compared the photocurrent characteristics of bilayer and blend devices as well as the blend devices with different nano-morphology, which is fine tuned by applying solvents with different boiling points. The main conclusion based on the complementary measurements is that the performance-limiting step is the field-dependent generation of free charge carriers, while bimolecular recombination and charge extraction do not compromise device performance. Regarding polymer-small molecular hybrid solar cells I combined the hole-transporting polymer M3EH-PPV with a novel small molecule electron acceptor vinazene. This molecule can be either deposited from solution or by thermal evaporation, allowing for a large variety of layer architectures to be realized. I then demonstrated that the layer architecture has a large influence on the photovoltaic properties. Solar cells with very high fill factors of up to 57 % and an open circuit voltage of 1V without thermal treatment of the devices were achieved. In the past, fill factors of solar cells exceeding 50 % have only been observed when using fullerene-derivatives as the electron-acceptor. The finding that proper processing of polymer-vinazene devices leads to similar high values is a major step towards the design of efficient polymer-based solar cells. (orig.)

  10. Simple Photovoltaic Cells for Exploring Solar Energy Concepts

    Science.gov (United States)

    Appleyard, S. J.

    2006-01-01

    Low-efficiency solar cells for educational purposes can be simply made in school or home environments using wet-chemistry techniques and readily available chemicals of generally low toxicity. Instructions are given for making solar cells based on the heterojunctions Cu/Cu[subscript 2]O, Cu[subscript 2]O/ZnO and Cu[subscript 2]S/ZnO, together with…

  11. Indium gallium nitride multijunction solar cell simulation using silvaco atlas

    OpenAIRE

    Garcia, Baldomero

    2007-01-01

    This thesis investigates the potential use of wurtzite Indium Gallium Nitride as photovoltaic material. Silvaco Atlas was used to simulate a quad-junction solar cell. Each of the junctions was made up of Indium Gallium Nitride. The band gap of each junction was dependent on the composition percentage of Indium Nitride and Gallium Nitride within Indium Gallium Nitride. The findings of this research show that Indium Gallium Nitride is a promising semiconductor for solar cell use. United...

  12. Efficient spray-coated colloidal quantum dot solar cells

    KAUST Repository

    Kramer, Illan J.

    2014-11-10

    (Figure Presented). A colloidal quantum dot solar cell is fabricated by spray-coating under ambient conditions. By developing a room-temperature spray-coating technique and implementing a fully automated process with near monolayer control - an approach termed as sprayLD - an electronic defect is eliminated resulting in solar cell performance and statistical distribution superior to prior batch-processed methods along with a hero performance of 8.1%.

  13. Organic Solar Cell by Inkjet Printing—An Overview

    OpenAIRE

    Sharaf Sumaiya; Kamran Kardel; Adel El-Shahat

    2017-01-01

    In recent years, organic solar cells became more attractive due to their flexible power devices and the potential for low-cost manufacturing. Inkjet printing is a very potential manufacturing technique of organic solar cells because of its low material usage, flexibility, and large area formation. In this paper, we presented an overall review on the inkjet printing technology as well as advantages of inkjet-printing, comparison of inkjet printing with other printing technologies and its poten...

  14. Recombination process in solar cells: Impact on the carrier transport

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, Yuri G. [Departamento de Fisica, CINVESTAV-IPN, Av. IPN 2508, Apartado Postal 14-740, Mexico D.F. 07000 (Mexico); Velazquez-Perez, Jesus E. [Departamento Fisica Aplicada, Universidad de Salamanca, Plaza de la Merced, 37008 Salamanca (Spain)

    2012-10-15

    Thickness of Si solar cells is being reduced below 200 {mu}m to reduce costs and improve their performance. In conventional solar cells recombination of photo-generated charge carriers plays a major limiting role in the cell efficiency. High quality thin-film solar cells may overcome this limit if the minority diffusion lengths become large as compared to the cell dimensions, but, strikingly, the conventional model fails to describe the cell electric behaviour under these conditions. Moreover, it is shown that in the conventional model the reverse-saturation current diverges (tends to infinity) in thin solar cells. A new formulation of the basic equations describing charge carrier transport in the cell along with a set of boundary conditions is presented. An analytical closed-form solution is obtained under a linear approximation. In the new framework given, the calculation of the open-circuit voltage of the solar cell diode does not lead to unphysical results. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. CZTS nanoparticle absorber layer for thin film solar cells

    DEFF Research Database (Denmark)

    Symonowicz, Joanna; Jensen, Kirsten M. Ørnsbjerg; Engberg, Sara Lena Josefin

    Cu2ZnSnS4 (CZTS) thin film solar cells have the potential to revolutionize the solar energy market. They are cheap, non-toxic and present an efficiency up to 9,2% [1]. However, to commercialize CZTS nanoparticle thin films, the efficiency issues must yet be resolved. There are various fabrication...... is furthermore characterized. Photoluminescence measurements indicate which absorber layer are of higher efficiency, which allows us to study why some crystalline configurations enhance the efficiency of resulting solar cells....

  16. Copper zinc tin sulfide-based thin film solar cells

    CERN Document Server

    Ito, Kentaro

    2014-01-01

    Beginning with an overview and historical background of Copper Zinc Tin Sulphide (CZTS) technology, subsequent chapters cover properties of CZTS thin films, different preparation methods of CZTS thin films, a comparative study of CZTS and CIGS solar cell, computational approach, and future applications of CZTS thin film solar modules to both ground-mount and rooftop installation. The semiconducting compound (CZTS) is made up earth-abundant, low-cost and non-toxic elements, which make it an ideal candidate to replace Cu(In,Ga)Se2 (CIGS) and CdTe solar cells which face material scarcity and tox

  17. Multiple Exciton Generation in Quantum Dot Solar Cells

    Science.gov (United States)

    Semonin, O. E.

    Photovoltaics are limited in their power conversion efficiency (PCE) by very rapid relaxation of energetic carriers to the band edge. Therefore, photons from the visible and ultraviolet parts of the spectrum typically are not efficiently converted into electrical energy. One approach that can address this is multiple exciton generation (MEG), where a single photon of sufficient energy can generate multiple excited electron-hole pairs. This process has been shown to be more efficient in quantum dots than bulk semiconductors, but it has never been demonstrated in the photocurrent of a solar cell. In order to demonstrate that multiple exciton generation can address fundamental limits for conventional photovoltaics, I have developed prototype devices from colloidal PbS and PbSe quantum dot inks. I have characterized both the colloidal suspensions and films of quantum dots with the goal of understanding what properties determine the efficiency of the solar cell and of the MEG process. I have found surface chemistry effects on solar cells, photoluminescence, and MEG, and I have found some chemical treatments that lead to solar cells showing MEG. These devices show external quantum efficiency (EQE) greater than 100% for certain parts of the solar spectrum, and I extract internal quantum efficiency (IQE) consistent with previous measurements of colloidal suspensions of quantum dots. These findings are a small first step toward breaking the single junction Shockley-Queisser limit of present-day first and second generation solar cells, thus moving photovoltaic cells toward a new regime of efficiency.

  18. Metamorphic III–V Solar Cells: Recent Progress and Potential

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Ivan; France, Ryan M.; Geisz, John F.; McMahon, William E.; Steiner, Myles A.; Johnston, Steve; Friedman, Daniel J.

    2016-01-01

    Inverted metamorphic multijunction solar cells have been demonstrated to be a pathway to achieve the highest photovoltaic (PV) conversion efficiencies. Attaining high-quality lattice-mismatched (metamorphic) semiconductor devices is challenging. However, recent improvements to compositionally graded buffer epitaxy and junction structures have led to the achievement of high-quality metamorphic solar cells exhibiting internal luminescence efficiencies over 90%. For this high material quality, photon recycling is significant, and therefore, the optical environment of the solar cell becomes important. In this paper, we first present recent progress and performance results for 1- and 0.7-eV GaInAs solar cells grown on GaAs substrates. Then, an electrooptical model is used to assess the potential performance improvements in current metamorphic solar cells under different realizable design scenarios. The results show that the quality of 1-eV subcells is such that further improving its electronic quality does not produce significant Voc increases in the four-junction inverted metamorphic subcells, unless a back reflector is used to enhance photon recycling, which would significantly complicate the structure. Conversely, improving the electronic quality of the 0.7-eV subcell would lead to significant Voc boosts, driving the progress of four-junction inverted metamorphic solar cells.

  19. Automatic Detection of Inactive Solar Cell Cracks in Electroluminescence Images

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso

    2017-01-01

    We propose an algorithm for automatic determination of the electroluminescence (EL) signal threshold level corresponding to inactive solar cell cracks, resulting from their disconnection from the electrical circuit of the cell. The method enables automatic quantification of the cell crack size an...

  20. Potential high efficiency solar cells: Applications from space photovoltaic research

    Science.gov (United States)

    Flood, D. J.

    1986-01-01

    NASA involvement in photovoltaic energy conversion research development and applications spans over two decades of continuous progress. Solar cell research and development programs conducted by the Lewis Research Center's Photovoltaic Branch have produced a sound technology base not only for the space program, but for terrestrial applications as well. The fundamental goals which have guided the NASA photovoltaic program are to improve the efficiency and lifetime, and to reduce the mass and cost of photovoltaic energy conversion devices and arrays for use in space. The major efforts in the current Lewis program are on high efficiency, single crystal GaAs planar and concentrator cells, radiation hard InP cells, and superlattice solar cells. A brief historical perspective of accomplishments in high efficiency space solar cells will be given, and current work in all of the above categories will be described. The applicability of space cell research and technology to terrestrial photovoltaics will be discussed.

  1. Real-Time Determination of Solar Cell Parameters

    Science.gov (United States)

    Hassan Ali, Mohamed; Rabhi, Abdelhamid; Haddad, Sofiane; El Hajjaji, Ahmed

    2017-11-01

    The extraction of solar cell parameters is a difficult task but is an important step in the assessment procedure of solar cells and panels. This work presents numerical methods for determining these parameters and compares their performances under different solar irradiances when they are implemented in an equivalent electrical circuit model with one or two diodes. To obtain a fast convergence rate in real-time applications, the fractional-order Darwinian particle swarm optimization (FODPSO) method is used through experimental data collected from a platform of photovoltaic (PV) energy installed near the modeling, information and systems laboratory at Amiens, France. The results showed that the one-diode model is less representative than the two-diode model. Furthermore, it is envisaged that the proposed FODPSO-based extraction method is more effective in modeling with two diodes. This will allow real-time determination of solar cells parameters and consequently will help to select the most suitable PV model.

  2. Thermodynamics of photon-enhanced thermionic emission solar cells

    International Nuclear Information System (INIS)

    Reck, Kasper; Hansen, Ole

    2014-01-01

    Photon-enhanced thermionic emission (PETE) cells in which direct photon energy as well as thermal energy can be harvested have recently been suggested as a new candidate for high efficiency solar cells. Here, we present an analytic thermodynamical model for evaluation of the efficiency of PETE solar cells including an analysis of the entropy production due to thermionic emission of general validity. The model is applied to find the maximum efficiency of a PETE cell for given cathode and anode work functions and temperatures

  3. Thermodynamics of photon-enhanced thermionic emission solar cells

    DEFF Research Database (Denmark)

    Reck, Kasper; Hansen, Ole

    2014-01-01

    Photon-enhanced thermionic emission (PETE) cells in which direct photon energy as well as thermal energy can be harvested have recently been suggested as a new candidate for high efficiency solar cells. Here, we present an analytic thermodynamical model for evaluation of the efficiency of PETE...... solar cells including an analysis of the entropy production due to thermionic emission of general validity. The model is applied to find the maximum efficiency of a PETE cell for given cathode and anode work functions and temperatures. ©...

  4. Symposium GC: Nanoscale Charge Transport in Excitonic Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Bommisetty, Venkat [Univ. of South Dakota, Vermillion, SD (United States)

    2011-06-23

    This paper provides a summary only and table of contents of the sessions. Excitonic solar cells, including all-organic, hybrid organic-inorganic and dye-sensitized solar cells (DSSCs), offer strong potential for inexpensive and large-area solar energy conversion. Unlike traditional inorganic semiconductor solar cells, where all the charge generation and collection processes are well understood, these excitonic solar cells contain extremely disordered structures with complex interfaces which results in large variations in nanoscale electronic properties and has a strong influence on carrier generation, transport, dissociation and collection. Detailed understanding of these processes is important for fabrication of highly efficient solar cells. Efforts to improve efficiency are underway at a large number of research groups throughout the world focused on inorganic and organic semiconductors, photonics, photophysics, charge transport, nanoscience, ultrafast spectroscopy, photonics, semiconductor processing, device physics, device structures, interface structure etc. Rapid progress in this multidisciplinary area requires strong synergetic efforts among researchers from diverse backgrounds. Such effort can lead to novel methods for development of new materials with improved photon harvesting and interfacial treatments for improved carrier transport, process optimization to yield ordered nanoscale morphologies with well defined electronic structures.

  5. Solar cell angle of incidence corrections

    Science.gov (United States)

    Burger, Dale R.; Mueller, Robert L.

    1995-01-01

    Literature on solar array angle of incidence corrections was found to be sparse and contained no tabular data for support. This lack along with recent data on 27 GaAs/Ge 4 cm by 4 cm cells initiated the analysis presented in this paper. The literature cites seven possible contributors to angle of incidence effects: cosine, optical front surface, edge, shadowing, UV degradation, particulate soiling, and background color. Only the first three are covered in this paper due to lack of sufficient data. The cosine correction is commonly used but is not sufficient when the incident angle is large. Fresnel reflection calculations require knowledge of the index of refraction of the coverglass front surface. The absolute index of refraction for the coverglass front surface was not known nor was it measured due to lack of funds. However, a value for the index of refraction was obtained by examining how the prediction errors varied with different assumed indices and selecting the best fit to the set of measured values. Corrections using front surface Fresnel reflection along with the cosine correction give very good predictive results when compared to measured data, except there is a definite trend away from predicted values at the larger incident angles. This trend could be related to edge effects and is illustrated by a use of a box plot of the errors and by plotting the deviation of the mean against incidence angle. The trend is for larger deviations at larger incidence angles and there may be a fourth order effect involved in the trend. A chi-squared test was used to determine if the measurement errors were normally distributed. At 10 degrees the chi-squared test failed, probably due to the very small numbers involved or a bias from the measurement procedure. All other angles showed a good fit to the normal distribution with increasing goodness-of-fit as the angles increased which reinforces the very small numbers hypothesis. The contributed data only went to 65 degrees

  6. Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays

    Science.gov (United States)

    Glaser, P. E.

    1974-01-01

    The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

  7. Solar cell junction temperature measurement of PV module

    KAUST Repository

    Huang, B.J.

    2011-02-01

    The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well as the cell junction in thermal equilibrium with the chamber. The open-circuit voltage of PV module Voc is then measured using a short pulse of solar irradiation provided by a solar simulator. Repeating the measurements at different environment temperature (40-80°C) and solar irradiation S (200-1000W/m2), the correlation between the open-circuit voltage Voc, the junction temperature Tj, and solar irradiation S is derived.The fundamental correlation of the PV module is utilized for on-site monitoring of solar cell junction temperature using the measured Voc and S at a short time instant with open circuit. The junction temperature Tj is then determined using the measured S and Voc through the fundamental correlation. The outdoor test results show that the junction temperature measured using the present method, Tjo, is more accurate. The maximum error using the average surface temperature Tave as the junction temperature is 4.8 °C underestimation; while the maximum error using the present method is 1.3 °C underestimation. © 2010 Elsevier Ltd.

  8. 3D-printed external light trap for solar cells.

    Science.gov (United States)

    van Dijk, Lourens; Paetzold, Ulrich W; Blab, Gerhard A; Schropp, Ruud E I; di Vece, Marcel

    2016-05-01

    We present a universally applicable 3D-printed external light trap for enhanced absorption in solar cells. The macroscopic external light trap is placed at the sun-facing surface of the solar cell and retro-reflects the light that would otherwise escape. The light trap consists of a reflective parabolic concentrator placed on top of a reflective cage. Upon placement of the light trap, an improvement of 15% of both the photocurrent and the power conversion efficiency in a thin-film nanocrystalline silicon (nc-Si:H) solar cell is measured. The trapped light traverses the solar cell several times within the reflective cage thereby increasing the total absorption in the cell. Consequently, the trap reduces optical losses and enhances the absorption over the entire spectrum. The components of the light trap are 3D printed and made of smoothened, silver-coated thermoplastic. In contrast to conventional light trapping methods, external light trapping leaves the material quality and the electrical properties of the solar cell unaffected. To explain the theoretical operation of the external light trap, we introduce a model that predicts the absorption enhancement in the solar cell by the external light trap. The corresponding calculated path length enhancement shows good agreement with the empirically derived value from the opto-electrical data of the solar cell. Moreover, we analyze the influence of the angle of incidence on the parasitic absorptance to obtain full understanding of the trap performance. © 2015 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons, Ltd.

  9. Silicon Solar Cell Process Development, Fabrication and Analysis, Phase 1

    Science.gov (United States)

    Yoo, H. I.; Iles, P. A.; Tanner, D. P.

    1979-01-01

    Solar cells from RTR ribbons, EFG (RF and RH) ribbons, dendritic webs, Silso wafers, cast silicon by HEM, silicon on ceramic, and continuous Czochralski ingots were fabricated using a standard process typical of those used currently in the silicon solar cell industry. Back surface field (BSF) processing and other process modifications were included to give preliminary indications of possible improved performance. The parameters measured included open circuit voltage, short circuit current, curve fill factor, and conversion efficiency (all taken under AM0 illumination). Also measured for typical cells were spectral response, dark I-V characteristics, minority carrier diffusion length, and photoresponse by fine light spot scanning. the results were compared to the properties of cells made from conventional single crystalline Czochralski silicon with an emphasis on statistical evaluation. Limited efforts were made to identify growth defects which will influence solar cell performance.

  10. Characterization of Thin Films for Polymer Solar Cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    of solar cells with low embedded time, material, and energy consumption as compared to silicon solar cells. Consequently, different demonstration products of small mobile gadgets based on polymer solar cells have been produced, which are fully competitive with conventional energy technologies, illustrating...... time of the cell is highly increased. An alternative approach is to increase the photo stability of the cell components, and especially the light absorbing conjugated polymer has been subject to extensive attention. The photo stability of conjugated polymers varies by orders of magnitude from type...... to type depending on the chemical structure of the material and consequently, the lifetime is highly influenced by the polymer stability. Photochemical degradation of polymers, i.e. degradation of thin films of polymer in the ambient under light exposure, is a technique normally applied to evaluate...

  11. Design approach for solar cell and battery of a persistent solar powered GPS tracker

    Science.gov (United States)

    Sahraei, Nasim; Watson, Sterling M.; Pennes, Anthony; Marius Peters, Ian; Buonassisi, Tonio

    2017-08-01

    Sensors with wireless communication can be powered by photovoltaic (PV) devices. However, using solar power requires thoughtful design of the power system, as well as a careful management of the power consumption, especially for devices with cellular communication (because of their higher power consumption). A design approach can minimize system size, weight, and/or cost, while maximizing device performance (data transmission rate and persistence). In this contribution, we describe our design approach for a small form-factor, solar-powered GPS tracker with cellular communication. We evaluate the power consumption of the device in different stages of operation. Combining measured power consumption and the calculated energy-yield of a solar cell, we estimate the battery capacity and solar cell area required for 5 years of continuous operation. We evaluate trade-offs between PV and battery size by simulating the battery state of charge. The data show a trade-off between battery capacity and solar-cell area for given target data transmission rate and persistence. We use this analysis to determine the combination of solar panel area and battery capacity for a given application and the data transmission rate that results in minimum cost or total weight of the system.

  12. Quantum-engineered interband cascade photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Razeghi, Manijeh; Tournié, Eric; Brown, Gail J.; Yang, Rui Q.; Lotfi, Hossein; Li, Lu; Hinkey, Robert T.; Ye, Hao; Klem, John F.; Lei, L.; Mishima, T. D.; Keay, J. C.; Santos, M. B.; Johnson, M. B.

    2013-12-18

    Quantum-engineered multiple stage photovoltaic (PV) devices are explored based on InAs/GaSb/AlSb interband cascade (IC) structures. These ICPV devices employ multiple discrete absorbers that are connected in series by widebandgap unipolar barriers using type-II heterostructure interfaces for facilitating carrier transport between cascade stages similar to IC lasers. The discrete architecture is beneficial for improving the collection efficiency and for spectral splitting by utilizing absorbers with different bandgaps. As such, the photo-voltages from each individual cascade stage in an ICPV device add together, creating a high overall open-circuit voltage, similar to conventional multi-junction tandem solar cells. Furthermore, photo-generated carriers can be collected with nearly 100% efficiency in each stage. This is because the carriers travel over only a single cascade stage, designed to be shorter than a typical diffusion length. The approach is of significant importance for operation at high temperatures where the diffusion length is reduced. Here, we will present our recent progress in the study of ICPV devices, which includes the demonstration of ICPV devices at room temperature and above with narrow bandgaps (e.g. 0.23 eV) and high open-circuit voltages. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  13. Accumulation of specific sterol precursors targets a MAP kinase cascade mediating cell–cell recognition and fusion

    Science.gov (United States)

    Weichert, Martin; Lichius, Alexander; Priegnitz, Bert-Ewald; Brandt, Ulrike; Gottschalk, Johannes; Nawrath, Thorben; Groenhagen, Ulrike; Read, Nick D.; Schulz, Stefan; Fleißner, André

    2016-01-01

    Sterols are vital components of eukaryotic cell membranes. Defects in sterol biosynthesis, which result in the accumulation of precursor molecules, are commonly associated with cellular disorders and disease. However, the effects of these sterol precursors on the metabolism, signaling, and behavior of cells are only poorly understood. In this study, we show that the accumulation of only ergosterol precursors with a conjugated double bond in their aliphatic side chain specifically disrupts cell–cell communication and fusion in the fungus Neurospora crassa. Genetically identical germinating spores of this fungus undergo cell–cell fusion, thereby forming a highly interconnected supracellular network during colony initiation. Before fusion, the cells use an unusual signaling mechanism that involves the coordinated and alternating switching between signal sending and receiving states of the two fusion partners. Accumulation of only ergosterol precursors with a conjugated double bond in their aliphatic side chain disrupts this coordinated cell–cell communication and suppresses cell fusion. These specific sterol precursors target a single ERK-like mitogen-activated protein (MAP) kinase (MAK-1)-signaling cascade, whereas a second MAP kinase pathway (MAK-2), which is also involved in cell fusion, is unaffected. These observations indicate that a minor specific change in sterol structure can exert a strong detrimental effect on a key signaling pathway of the cell, resulting in the absence of cell fusion. PMID:27708165

  14. Wavelet cascades

    Science.gov (United States)

    Giesemann, Jens; Greiner, Martin; Lipa, Peter

    1997-02-01

    The generators of binary multiplicative cascade models with a non-overlapping branching structure are given by the Haar wavelets. We construct specific generalizations of these models for which any given wavelet represents the generators of the local cascade branchings. Such “wavelet cascades”, for which we calculate spatial correlation functions, have spatially overlapping branches and are therefore useful for modeling recombination effects in hierarchical branching processes.

  15. Development of an electronic device quality aluminum antimonide (AlSb) semiconductor for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Sherohman, John W; Yee, Jick Hong; Combs, III, Arthur W

    2014-11-11

    Electronic device quality Aluminum Antimonide (AlSb)-based single crystals produced by controlled atmospheric annealing are utilized in various configurations for solar cell applications. Like that of a GaAs-based solar cell devices, the AlSb-based solar cell devices as disclosed herein provides direct conversion of solar energy to electrical power.

  16. Solar energy powered microbial fuel cell with a reversible bioelectrode.

    Science.gov (United States)

    Strik, David P B T B; Hamelers, Hubertus V M; Buisman, Cees J N

    2010-01-01

    The solar energy powered microbial fuel cell is an emerging technology for electricity generation via electrochemically active microorganisms fueled by solar energy via in situ photosynthesized metabolites from algae, cyanobacteria, or living higher plants. A general problem with microbial fuel cells is the pH membrane gradient which reduces cell voltage and power output. This problem is caused by acid production at the anode, alkaline production at the cathode, and the nonspecific proton exchange through the membrane. Here we report a solution for a new kind of solar energy powered microbial fuel cell via development of a reversible bioelectrode responsible for both biocatalyzed anodic and cathodic electron transfer. Anodic produced protons were used for the cathodic reduction reaction which held the formation of a pH membrane gradient. The microbial fuel cell continuously generated electricity and repeatedly reversed polarity dependent on aeration or solar energy exposure. Identified organisms within biocatalyzing biofilm of the reversible bioelectrode were algae, (cyano)bacteria and protozoa. These results encourage application of solar energy powered microbial fuel cells.

  17. Plasmonic Solar Cells: From Rational Design to Mechanism Overview.

    Science.gov (United States)

    Jang, Yoon Hee; Jang, Yu Jin; Kim, Seokhyoung; Quan, Li Na; Chung, Kyungwha; Kim, Dong Ha

    2016-12-28

    Plasmonic effects have been proposed as a solution to overcome the limited light absorption in thin-film photovoltaic devices, and various types of plasmonic solar cells have been developed. This review provides a comprehensive overview of the state-of-the-art progress on the design and fabrication of plasmonic solar cells and their enhancement mechanism. The working principle is first addressed in terms of the combined effects of plasmon decay, scattering, near-field enhancement, and plasmonic energy transfer, including direct hot electron transfer and resonant energy transfer. Then, we summarize recent developments for various types of plasmonic solar cells based on silicon, dye-sensitized, organic photovoltaic, and other types of solar cells, including quantum dot and perovskite variants. We also address several issues regarding the limitations of plasmonic nanostructures, including their electrical, chemical, and physical stability, charge recombination, narrowband absorption, and high cost. Next, we propose a few potentially useful approaches that can improve the performance of plasmonic cells, such as the inclusion of graphene plasmonics, plasmon-upconversion coupling, and coupling between fluorescence resonance energy transfer and plasmon resonance energy transfer. This review is concluded with remarks on future prospects for plasmonic solar cell use.

  18. Mannosylerythritol lipid induces characteristics of neuronal differentiation in PC12 cells through an ERK-related signal cascade.

    Science.gov (United States)

    Wakamatsu, Y; Zhao, X; Jin, C; Day, N; Shibahara, M; Nomura, N; Nakahara, T; Murata, T; Yokoyama, K K

    2001-01-01

    Rat pheochromocytoma PC12 cells undergo neuronal differentiation in response to nerve growth factor (NGF). The differentiation involves protein kinase cascades that include the kinases MEK and ERK, as well as activation of the transcription factors c-Jun and c-Fos. We show here, that exposure of PC12 cells to mannosylerythritol lipid (MEL), a yeast extracellular glycolipid, enhances the activity of acetylcholinesterase and interrupts the cell cycle at the G1 phase, with resulting outgrowth of neurites and partial cellular differentiation. Treatment with MEL stimulates the phosphorylation of ERK to a similar extent as treatment with NGF, although, the appearance of phosphorylated ERK is somewhat delayed. Both the MEL-induced outgrowth of neurites and the increase in the activity of acetylcholinesterase are prevented by PD98059, a specific inhibitor of MEK. Northern blotting analysis of c-jun transcripts and analysis of transcription in PC12 cells of a c-jun/CAT reporter construct demonstrated a significant increase in the rate of transcription of the c-jun gene upon treatment with MEL. The sequence elements required for the MEL-mediated activation of transcription of the c-jun gene are located between nucleotides -126 and -79 in the 5' flanking region. Our results suggest that MEL induces characteristics of neuronal differentiation in PC12 cells, with transactivation of the c-jun gene, via an ERK-related signal cascade that is partially overlapping the pathways activated in response to NGF. These results might provide the groundwork for the use of microbial extracellular glycolipids as novel reagents for the treatment of cancer cells.

  19. Light trapping effects in thin film silicon solar cells

    OpenAIRE

    Haug, FJ; Söderström, T; Dominé, D; Ballif, C

    2009-01-01

    We present advanced light trapping concepts for thin film silicon solar cells. When an amorphous and a microcrystalline absorber layers are combined into a micromorph tandem cell, light trapping becomes a challenge because it should combine the spectral region from 600 to 750 nm for the amorphous top cell and from 800 to 1100 for the microcrystalline bottom cell. Because light trapping is typically achieved by growing on textured substrates, the effect of interface textures on the material an...

  20. Optimized scalable stack of fluorescent solar concentrator systems with bifacial silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Martínez Díez, Ana Luisa, E-mail: a.martinez@itma.es [Fundación ITMA, Parque Empresarial Principado de Asturias, C/Calafates, Parcela L-3.4, 33417 Avilés (Spain); Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Gutmann, Johannes; Posdziech, Janina; Rist, Tim; Goldschmidt, Jan Christoph [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Plaza, David Gómez [Fundación ITMA, Parque Empresarial Principado de Asturias, C/Calafates, Parcela L-3.4, 33417 Avilés (Spain)

    2014-10-21

    In this paper, we present a concentrator system based on a stack of fluorescent concentrators (FCs) and a bifacial solar cell. Coupling bifacial solar cells to a stack of FCs increases the performance of the system and preserves its efficiency when scaled. We used an approach to optimize a fluorescent solar concentrator system design based on a stack of multiple fluorescent concentrators (FC). Seven individual fluorescent collectors (20 mm×20 mm×2 mm) were realized by in-situ polymerization and optically characterized in regard to their ability to guide light to the edges. Then, an optimization procedure based on the experimental data of the individual FCs was carried out to determine the stack configuration that maximizes the total number of photons leaving edges. Finally, two fluorescent concentrator systems were realized by attaching bifacial silicon solar cells to the optimized FC stacks: a conventional system, where FC were attached to one side of the solar cell as a reference, and the proposed bifacial configuration. It was found that for the same overall FC area, the bifacial configuration increases the short-circuit current by a factor of 2.2, which is also in agreement with theoretical considerations.

  1. Research Progress of Photoanodes for Quantum Dot Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    LI Zhi-min

    2017-08-01

    Full Text Available This paper presents the development status and tendency of quantum dot sensitized solar cells. Photoanode research progress and its related technologies are analyzed in detail from the three ways of semiconductor thin films, quantum dot co-sensitization and quantum dot doping, deriving from the approach that the conversion efficiency can be improved by photoanode modification for quantum dot sensitized solar cells. According to the key factors which restrict the cell efficiency, the promising future development of quantum dot sensitized solar cells is proposed,for example,optimizing further the compositions and structures of semiconductor thin films for the photoanodes, exploring new quantum dots with broadband absorption and developing high efficient techniques of interface modification.

  2. Brief overview of dye-sensitized solar cells.

    Science.gov (United States)

    Hagfeldt, Anders

    2012-01-01

    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.

  3. Quantum mechanical effects analysis of nanostructured solar cell models

    Directory of Open Access Journals (Sweden)

    Badea Andrei

    2016-01-01

    Full Text Available The quantum mechanical effects resulted from the inclusion of nanostructures, represented by quantum wells and quantum dots, in the i-layer of an intermediate band solar cell will be analyzed. We will discuss the role of these specific nanostructures in the increasing of the solar cells efficiency. InAs quantum wells being placed in the i-layer of a gallium arsenide (GaAs p-i-n cell, we will analyze the quantum confined regions and determine the properties of the eigenstates located therein. Also, we simulate the electroluminescence that occurs due to the nanostructured regions.

  4. Fabrication and characterization of poly[diphenylsilane]-based solar cells

    Science.gov (United States)

    Iwase, M.; Oku, T.; Suzuki, A.; Akiyama, T.; Tokumitsu, K.; Yamada, M.; Nakamura, M.

    2012-03-01

    Poly[diphenylsilane] (PDPS)-based photovoltaic cells were fabricated by using mixture solution of PDPS, phosphorus and boron. An influence of phosphorus and boron doping into PDPS on the performance of the photovoltaic device was investigated. The solar cell using fluorine doped tin oxide glass plates provided short-circuit current density of 0.12 mA/cm2 and open-circuit voltage of 0.28 V under simulated sunlight. Energy levels, formation mechanism and microstructure of the solar cells were discussed.

  5. Solar cells in architecture; Solceller i arkitekturen

    Energy Technology Data Exchange (ETDEWEB)

    Wittchen, K.B.; Svensson, O.

    2002-07-01

    This book contains the results of an architectural evaluation of building examples with integrated photovoltaic. Danish Building and Urban Research and Danish Technological Institute conducted the work within the framework of Solar Energy Centre Denmark. Seven examples are selected to inspire Danish architects and building owners to use PV in the building environment. The examples come from Denmark and countries (the Netherlands and Germany) with similar building traditions, climate and solar conditions. All the examples demonstrate architectural concepts that integrate photovoltaic as a natural part of the building envelope. (BA)

  6. Cost Effective Polymer Solar Cells Research and Education

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Sam-Shajing [Norfolk State Univ, Norfolk, VA (United States)

    2015-10-13

    The technical or research objective of this project is to investigate and develop new polymers and polymer based optoelectronic devices for potentially cost effective (or cost competitive), durable, lightweight, flexible, and high efficiency solar energy conversion applications. The educational objective of this project includes training of future generation scientists, particularly young, under-represented minority scientists, working in the areas related to the emerging organic/polymer based solar energy technologies and related optoelectronic devices. Graduate and undergraduate students will be directly involved in scientific research addressing issues related to the development of polymer based solar cell technology.

  7. Design and Optimization of Copper Indium Gallium Selenide Solar Cells for Lightweight Battlefield Application

    Science.gov (United States)

    2014-06-01

    Photoelectric affect in solar cells , from [15]. ...................................................18 Figure 14. Solar spectral irradiance versus wavelength...depicted in Figure 13. Figure 13. Photoelectric affect in solar cells , from [15]. An in-depth explanation of solar cell losses is found in [20...the load. Since the window layer is on top of the solar cell , it needs to be transparent to the light spectrum that is required for photoelectric

  8. Controlled cadmium telluride thin films for solar cell applications (emerging materials systems for solar cell applications)

    Science.gov (United States)

    Vedam, K.; Das, M. B.; Krishnaswamy, S. V.

    1980-02-01

    Emphasis during the third quarter of the program was on the improvement of the quality of sputtered films, their characterization and use in the fabrication of Schottky barrier type diodes and solar cell structures. Films prepared under different conditions and on different substrates were examined showing modular growths under certain conditions. I-V, C-V, and photovoltaic characteristics were measured on numerous samples based on n- and p-type films on Ni substrates having top metallization of either evaporated Au and Al. The n-type samples showed up to 200 mV V/sub oc/and small short-circuit currents. The characteristics observed are indicative of the presence of interfacial layer and surface states. Surface state's capacitance were measured on p-type samples metalized with Au.

  9. Development of A Thin Film Crystalline Silicon Solar Cell

    International Nuclear Information System (INIS)

    Sopori, B.; Chen, W.; Zhang, Y.

    1998-01-01

    A new design for a single junction, thin film Si solar cell is presented. The cell design is compatible with low-temperature processing required for the use of a low-cost glass substrate, and includes effective light trapping and impurity gettering. Elements of essential process steps are discussed

  10. InP solar cell with window layer

    Science.gov (United States)

    Jain, Raj K. (Inventor); Landis, Geoffrey A. (Inventor)

    1994-01-01

    The invention features a thin light transmissive layer of the ternary semiconductor indium aluminum arsenide (InAlAs) as a front surface passivation or 'window' layer for p-on-n InP solar cells. The window layers of the invention effectively reduce front surface recombination of the object semiconductors thereby increasing the efficiency of the cells.

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

    Indian Academy of Sciences (India)

    TiO2 NPs. This could show an increase of about 30% in the efficiency compared to the similar cell with a photoanode made of two layers of hydrothermally grown TiO2 NCs. Keywords. Dye-sensitized solar cells; hydrothermal method; TiO2 nanocrystals; multilayer photoanodes; energy conversion efficiency. 1. Introduction.

  12. Planar-Structure Perovskite Solar Cells with Efficiency beyond 21.

    Science.gov (United States)

    Jiang, Qi; Chu, Zema; Wang, Pengyang; Yang, Xiaolei; Liu, Heng; Wang, Ye; Yin, Zhigang; Wu, Jinliang; Zhang, Xingwang; You, Jingbi

    2017-12-01

    Low temperature solution processed planar-structure perovskite solar cells gain great attention recently, while their power conversions are still lower than that of high temperature mesoporous counterpart. Previous reports are mainly focused on perovskite morphology control and interface engineering to improve performance. Here, this study systematically investigates the effect of precise stoichiometry, especially the PbI 2 contents on device performance including efficiency, hysteresis and stability. This study finds that a moderate residual of PbI 2 can deliver stable and high efficiency of solar cells without hysteresis, while too much residual PbI 2 will lead to serious hysteresis and poor transit stability. Solar cells with the efficiencies of 21.6% in small size (0.0737 cm 2 ) and 20.1% in large size (1 cm 2 ) with moderate residual PbI 2 in perovskite layer are obtained. The certificated efficiency for small size shows the efficiency of 20.9%, which is the highest efficiency ever recorded in planar-structure perovskite solar cells, showing the planar-structure perovskite solar cells are very promising. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. High-efficiency solar cell and method for fabrication

    Science.gov (United States)

    Hou, Hong Q.; Reinhardt, Kitt C.

    1999-01-01

    A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

  14. Colloidal quantum dot solar cells on curved and flexible substrates

    KAUST Repository

    Kramer, Illan J.

    2014-10-20

    © 2014 AIP Publishing LLC. Colloidal quantum dots (CQDs) are semiconductor nanocrystals synthesized with, processed in, and deposited from the solution phase, potentially enabling low-cost, facile manufacture of solar cells. Unfortunately, CQD solar cell reports, until now, have only explored batch-processing methods - such as spin-coating - that offer limited capacity for scaling. Spray-coating could offer a means of producing uniform colloidal quantum dot films that yield high-quality devices. Here, we explore the versatility of the spray-coating method by producing CQD solar cells in a variety of previously unexplored substrate arrangements. The potential transferability of the spray-coating method to a roll-to-roll manufacturing process was tested by spray-coating the CQD active layer onto six substrates mounted on a rapidly rotating drum, yielding devices with an average power conversion efficiency of 6.7%. We further tested the manufacturability of the process by endeavoring to spray onto flexible substrates, only to find that spraying while the substrate was flexed was crucial to achieving champion performance of 7.2% without compromise to open-circuit voltage. Having deposited onto a substrate with one axis of curvature, we then built our CQD solar cells onto a spherical lens substrate having two axes of curvature resulting in a 5% efficient device. These results show that CQDs deposited using our spraying method can be integrated to large-area manufacturing processes and can be used to make solar cells on unconventional shapes.

  15. Flexible organic solar cells including efficiency enhancing grating structures

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Liu, Yinghui; Madsen, Morten

    2013-01-01

    In this work, a new method for the fabrication of organic solar cells containing functional light-trapping nanostructures on flexible substrates is presented. Polyimide is spin-coated on silicon support substrates, enabling standard micro- and nanotechnology fabrication techniques, such as photol......-trapping efficiency for the selected active layer material (P3HT:PCBM), resulting in an enhancement of about 34% on the solar cell efficiency. The presented method can be applied to a large variety of flexible nanostructured devices in future applications.......In this work, a new method for the fabrication of organic solar cells containing functional light-trapping nanostructures on flexible substrates is presented. Polyimide is spin-coated on silicon support substrates, enabling standard micro- and nanotechnology fabrication techniques......, such as photolithography and electron-beam lithography, besides the steps required for the bulk-heterojunction organic solar cell fabrication. After the production steps, the solar cells on polyimide are peeled off the silicon support substrates, resulting in flexible devices containing nanostructures for light absorption...

  16. Material and Device Stability in Perovskite Solar Cells.

    Science.gov (United States)

    Kim, Hui-Seon; Seo, Ja-Young; Park, Nam-Gyu

    2016-09-22

    Organic-inorganic halide perovskite solar cells have attracted great attention because of their superb efficiency reaching 22 % and low-cost, facile fabrication processing. Nevertheless, stability issues in perovskite solar cells seem to block further advancements toward commercialization. Thus, device stability is one of the important topics in perovskite solar cell research. In the beginning, the poor moisture resistivity of the perovskite layer was considered as a main problem that hindered further development of perovskite solar cells, which encouraged engineering of the perovskite or protection of the perovskite by a buffer layer. Soon after, other parameters affecting long-term stability were sequentially found and various attempts have been made to enhance intrinsic and extrinsic stability. Here we review the recent progresses addressing stability issues in perovskite solar cells. In this report, we investigated factors affecting stability from material and device points of view. To gain a better understanding of the stability of the bulk perovskite material, decomposition mechanisms were investigated in relation to moisture, photons, and heat. Stability of full device should also be carefully examined because its stability is dependent not only on bulk perovskite but also on the interfaces and selective contacts. In addition, ion migration and current-voltage hysteresis were found to be closely related to stability. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Graphene and Graphene-like Molecules: Prospects in Solar Cells.

    Science.gov (United States)

    Loh, Kian Ping; Tong, Shi Wun; Wu, Jishan

    2016-02-03

    Graphene is constantly hyped as a game-changer for flexible transparent displays. However, to date, no solar cell fabricated on graphene electrodes has out-performed indium tin oxide in power conversion efficiency (PCE). This Perspective covers the enabling roles that graphene can play in solar cells because of its unique properties. Compared to transparent and conducting metal oxides, graphene may not have competitive advantages in terms of its electrical conductivity. The unique strength of graphene lies in its ability to perform various enabling roles in solar cell architectures, leading to overall improvement in PCE. Graphene can serve as an ultrathin and transparent diffusion barrier in solar cell contacts, as an intermediate layer in tandem solar cells, as an electron acceptor, etc. Inspired by the properties of graphene, chemists are also designing graphene-like molecules in which the topology of π-electron array, donor-acceptor structures, and conformation can be tuned to offer a new class of light-harvesting materials.

  18. Progress in nanostructured photoanodes for dye-sensitized solar cells

    Science.gov (United States)

    Liu, Xueyang; Fang, Jian; Liu, Yong; Lin, Tong

    2016-09-01

    Solar cells represent a principal energy technology to convert light into electricity. Commercial solar cells are at present predominately produced by single- or multi-crystalline silicon wafers. The main drawback to silicon-based solar cells, however, is high material and manufacturing costs. Dye-sensitized solar cells (DSSCs) have attracted much attention during recent years because of the low production cost and other advantages. The photoanode (working electrode) plays a key role in determining the performance of DSSCs. In particular, nanostructured photoanodes with a large surface area, high electron transfer efficiency, and low electron recombination facilitate to prepare DSSCs with high energy conversion efficiency. In this review article, we summarize recent progress in the development of novel photoanodes for DSSCs. Effect of semiconductor material (e.g. TiO2, ZnO, SnO2, N2O5, and nano carbon), preparation, morphology and structure (e.g. nanoparticles, nanorods, nanofibers, nanotubes, fiber/particle composites, and hierarchical structure) on photovoltaic performance of DSSCs is described. The possibility of replacing silicon-based solar cells with DSSCs is discussed.

  19. Strategies for increasing the efficiency of heterojunction organic solar cells: material selection and device architecture.

    Science.gov (United States)

    Heremans, Paul; Cheyns, David; Rand, Barry P

    2009-11-17

    Thin-film blends or bilayers of donor- and acceptor-type organic semiconductors form the core of heterojunction organic photovoltaic cells. Researchers measure the quality of photovoltaic cells based on their power conversion efficiency, the ratio of the electrical power that can be generated versus the power of incident solar radiation. The efficiency of organic solar cells has increased steadily in the last decade, currently reaching up to 6%. Understanding and combating the various loss mechanisms that occur in processes from optical excitation to charge collection should lead to efficiencies on the order of 10% in the near future. In organic heterojunction solar cells, the generation of photocurrent is a cascade of four steps: generation of excitons (electrically neutral bound electron-hole pairs) by photon absorption, diffusion of excitons to the heterojunction, dissociation of the excitons into free charge carriers, and transport of these carriers to the contacts. In this Account, we review our recent contributions to the understanding of the mechanisms that govern these steps. Starting from archetype donor-acceptor systems of planar small-molecule heterojunctions and solution-processed bulk heterojunctions, we outline our search for alternative materials and device architectures. We show that non-planar phthalocynanines have appealing absorption characteristics but also have reduced charge carrier transport. As a result, the donor layer needs to be ultrathin, and all layers of the device have to be tuned to account for optical interference effects. Using these optimization techniques, we illustrate cells with 3.1% efficiency for the non-planar chloroboron subphthalocyanine donor. Molecules offering a better compromise between absorption and carrier mobility should allow for further improvements. We also propose a method for increasing the exciton diffusion length by converting singlet excitons into long-lived triplets. By doping a polymer with a

  20. Utilizing Energy Transfer in Binary and Ternary Bulk Heterojunction Organic Solar Cells.

    Science.gov (United States)

    Feron, Krishna; Cave, James M; Thameel, Mahir N; O'Sullivan, Connor; Kroon, Renee; Andersson, Mats R; Zhou, Xiaojing; Fell, Christopher J; Belcher, Warwick J; Walker, Alison B; Dastoor, Paul C

    2016-08-17

    Energy transfer has been identified as an important process in ternary organic solar cells. Here, we develop kinetic Monte Carlo (KMC) models to assess the impact of energy transfer in ternary and binary bulk heterojunction systems. We used fluorescence and absorption spectroscopy to determine the energy disorder and Förster radii for poly(3-hexylthiophene-2,5-diyl), [6,6]-phenyl-C61-butyric acid methyl ester, 4-bis[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl]squaraine (DIBSq), and poly(2,5-thiophene-alt-4,9-bis(2-hexyldecyl)-4,9-dihydrodithieno[3,2-c:3',2'-h][1,5]naphthyridine-5,10-dione). Heterogeneous energy transfer is found to be crucial in the exciton dissociation process of both binary and ternary organic semiconductor systems. Circumstances favoring energy transfer across interfaces allow relaxation of the electronic energy level requirements, meaning that a cascade structure is not required for efficient ternary organic solar cells. We explain how energy transfer can be exploited to eliminate additional energy losses in ternary bulk heterojunction solar cells, thus increasing their open-circuit voltage without loss in short-circuit current. In particular, we show that it is important that the DIBSq is located at the electron donor-acceptor interface; otherwise charge carriers will be trapped in the DIBSq domain or excitons in the DIBSq domains will not be able to dissociate efficiently at an interface. KMC modeling shows that only small amounts of DIBSq (energy transfer.

  1. Nano-photonic Light Trapping In Thin Film Solar Cells

    Science.gov (United States)

    Callahan, Dennis M., Jr.

    Over the last several decades there have been significant advances in the study and understanding of light behavior in nanoscale geometries. Entire fields such as those based on photonic crystals, plasmonics and metamaterials have been developed, accelerating the growth of knowledge related to nanoscale light manipulation. Coupled with recent interest in cheap, reliable renewable energy, a new field has blossomed, that of nanophotonic solar cells. In this thesis, we examine important properties of thin-film solar cells from a nanophotonics perspective. We identify key differences between nanophotonic devices and traditional, thick solar cells. We propose a new way of understanding and describing limits to light trapping and show that certain nanophotonic solar cell designs can have light trapping limits above the so called ray-optic or ergodic limit. We propose that a necessary requisite to exceed the traditional light trapping limit is that the active region of the solar cell must possess a local density of optical states (LDOS) higher than that of the corresponding, bulk material. Additionally, we show that in addition to having an increased density of states, the absorber must have an appropriate incoupling mechanism to transfer light from free space into the optical modes of the device. We outline a portfolio of new solar cell designs that have potential to exceed the traditional light trapping limit and numerically validate our predictions for select cases. We emphasize the importance of thinking about light trapping in terms of maximizing the optical modes of the device and efficiently coupling light into them from free space. To further explore these two concepts, we optimize patterns of superlattices of air holes in thin slabs of Si and show that by adding a roughened incoupling layer the total absorbed current can be increased synergistically. We suggest that the addition of a random scattering surface to a periodic patterning can increase incoupling by

  2. Single crystalline silicon solar cells with rib structure

    Directory of Open Access Journals (Sweden)

    Shuhei Yoshiba

    2017-02-01

    Full Text Available To improve the conversion efficiency of Si solar cells, we have developed a thin Si wafer-based solar cell that uses a rib structure. The open-circuit voltage of a solar cell is known to increase with deceasing wafer thickness if the cell is adequately passivated. However, it is not easy to handle very thin wafers because they are brittle and are subject to warpage. We fabricated a lattice-shaped rib structure on the rear side of a thin Si wafer to improve the wafer’s strength. A silicon nitride film was deposited on the Si wafer surface and patterned to form a mask to fabricate the lattice-shaped rib, and the wafer was then etched using KOH to reduce the thickness of the active area, except for the rib region. Using this structure in a Si heterojunction cell, we demonstrated that a high open-circuit voltage (VOC could be obtained by thinning the wafer without sacrificing its strength. A wafer with thickness of 30 μm was prepared easily using this structure. We then fabricated Si heterojunction solar cells using these rib wafers, and measured their implied VOC as a function of wafer thickness. The measured values were compared with device simulation results, and we found that the measured VOC agrees well with the simulated results. To optimize the rib and cell design, we also performed device simulations using various wafer thicknesses and rib dimensions.

  3. Method of making quasi-grain boundary-free polycrystalline solar cell structure and solar cell structure obtained thereby

    Science.gov (United States)

    Gonzalez, Franklin N.; Neugroschel, Arnost

    1984-02-14

    A new solar cell structure is provided which will increase the efficiency of polycrystalline solar cells by suppressing or completely eliminating the recombination losses due to the presence of grain boundaries. This is achieved by avoiding the formation of the p-n junction (or other types of junctions) in the grain boundaries and by eliminating the grain boundaries from the active area of the cell. This basic concept can be applied to any polycrystalline material; however, it will be most beneficial for cost-effective materials having small grains, including thin film materials.

  4. Efficiency of bulk-heterojunction organic solar cells

    Science.gov (United States)

    Scharber, M.C.; Sariciftci, N.S.

    2013-01-01

    During the last years the performance of bulk heterojunction solar cells has been improved significantly. For a large-scale application of this technology further improvements are required. This article reviews the basic working principles and the state of the art device design of bulk heterojunction solar cells. The importance of high power conversion efficiencies for the commercial exploitation is outlined and different efficiency models for bulk heterojunction solar cells are discussed. Assuming state of the art materials and device architectures several models predict power conversion efficiencies in the range of 10–15%. A more general approach assuming device operation close to the Shockley–Queisser-limit leads to even higher efficiencies. Bulk heterojunction devices exhibiting only radiative recombination of charge carriers could be as efficient as ideal inorganic photovoltaic devices. PMID:24302787

  5. Peeled film GaAs solar cell development

    Science.gov (United States)

    Wilt, D. M.; Thomas, R. D.; Bailey, S. G.; Brinker, D. J.; Deangelo, F. L.

    1990-01-01

    Thin-film, single-crystal gallium arsenide (GaAs) solar cells could exhibit a specific power approaching 700 W/kg including coverglass. A simple process has been described whereby epitaxial GaAs layers are peeled from a reusable substrate. This process takes advantage of the extreme selectivity of the etching rate of aluminum arsenide (AlAs) over GaAs in dilute hydrofluoric acid. The feasibility of using the peeled film technique to fabricate high-efficiency, low-mass GaAs solar cells is presently demonstrated. A peeled film GaAs solar cell was successfully produced. The device, although fractured and missing the aluminum gallium arsenide window and antireflective coating, had a Voc of 874 mV and a fill factor of 68 percent under AM0 illumination.

  6. Role of Mn2+ in Doped Quantum Dot Solar Cell

    International Nuclear Information System (INIS)

    Santra, Pralay K.; Chen, Yong-Siou

    2014-01-01

    In recent times, Mn doped quantum dot sensitized solar cells (QDSSCs) have shown a lot of interest as it provides a different strategy to improve the photovoltaic performances. In this work, we have systematically studied the effect of Mn 2+ dopant concentration on the photovoltaic performances of CdS based QDSSCs. The open circuit potential increases systematically with increase in Mn 2+ dopant concentration. The efficiency of the solar cell increases from 1.63% to 2.53% from undoped to 7.5% doped CdS. The role of Mn 2+ in enhancing the photovoltaic performances was further probed by open circuit voltage decay and the energy levels were studied using transient absorption spectroscopy. Both spin and orbital forbidden Mn d-d transition ( 4 T 1 – 6 A 1 ) helps in reducing the recombination inside the solar cell, which improves the overall photovoltaic performances

  7. Single material solar cells: the next frontier for organic photovoltaics?

    Energy Technology Data Exchange (ETDEWEB)

    Roncali, Jean [Group Linear Conjugated Systems, CNRS, Moltech-Anjou, UMR 6200, University of Angers, 2 Bd Lavoisier 49045 Angers (France)

    2011-03-18

    An overview of various approaches for the realization of single-material organic solar cells (SMOCs) is presented. Fullerene-conjugated systems dyads, di-block copolymers, and self-organized donor-acceptor molecules all represent different possible approaches towards SMOCs. Although each of them presents specific advantages and poses specific problems of design and synthesis, these different routes have witnessed significant progress in the past few years and SMOCs with efficiencies in the range of 1.50% have been realized. These performances are already higher than those of bi-component bulk heterojunction solar cells some ten years ago, demonstrating that SMOCs can represent a credible approach towards efficient and simple organic solar cells. Possible directions for future research are discussed with the aim of stimulating further research on this exciting topic. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Protective material for solar cell; Taiyo denchiyo hyomen hogozai

    Energy Technology Data Exchange (ETDEWEB)

    Iimura, M.; Domoto, T. [Nitto Denko Corp., Osaka (Japan)

    1998-02-03

    The protective material for the solar cell of this invention consists of fluororesin containing from 1 to 20wt% titanium oxide particles with the particle size range from 1 to 1,000nm. Surface contamination of the protective material for the solar cell and deterioration of the adhesive are prevented when titanium oxide with particular particle size is contained in the fluororesin in a particular range as mentioned above. Titanium oxide has photocatalytic performance to decompose organic substances, and the surface protective material for the solar cell containing titanium oxide can decompose and remove dirt such as dust adhering the surface for preventing surface contamination. In addition, total light permeability can be maintained at high rate and the permeability of less than 350nm ultraviolet rays causing deterioration of the adhesive can be decreased if the particle size and content of titanium oxide are specified. Titanium dioxide of anatase type crystal structure is ideal as the titanium oxide. 1 tab.

  9. Nano-structured electron transporting materials for perovskite solar cells

    Science.gov (United States)

    Liu, Hefei; Huang, Ziru; Wei, Shiyuan; Zheng, Lingling; Xiao, Lixin; Gong, Qihuang

    2016-03-01

    Organic-inorganic hybrid perovskite solar cells have been developing rapidly in the past several years, and their power conversion efficiency has reached over 20%, nearing that of polycrystalline silicon solar cells. Because the diffusion length of the hole in perovskites is longer than that of the electron, the performance of the device can be improved by using an electron transporting layer, e.g., TiO2, ZnO and TiO2/Al2O3. Nano-structured electron transporting materials facilitate not only electron collection but also morphology control of the perovskites. The properties, morphology and preparation methods of perovskites are reviewed in the present article. A comprehensive understanding of the relationship between the structure and property will benefit the precise control of the electron transporting process and thus further improve the performance of perovskite solar cells.

  10. Recyclable organic solar cells on substrates comprising cellulose nanocrystals (CNC)

    Science.gov (United States)

    Kippelen, Bernard; Fuentes-Hernandez, Canek; Zhou, Yinhua; Moon, Robert; Youngblood, Jeffrey P

    2015-12-01

    Recyclable organic solar cells are disclosed herein. Systems and methods are further disclosed for producing, improving performance, and for recycling the solar cells. In certain example embodiments, the recyclable organic solar cells disclosed herein include: a first electrode; a second electrode; a photoactive layer disposed between the first electrode and the second electrode; an interlayer comprising a Lewis basic oligomer or polymer disposed between the photoactive layer and at least a portion of the first electrode or the second electrode; and a substrate disposed adjacent to the first electrode or the second electrode. The interlayer reduces the work function associated with the first or second electrode. In certain example embodiments, the substrate comprises cellulose nanocrystals that can be recycled. In certain example embodiments, one or more of the first electrode, the photoactive layer, and the second electrode may be applied by a film transfer lamination method.

  11. Peeled film GaAs solar cell development

    Science.gov (United States)

    Wilt, D. M.; Thomas, R. D.; Bailey, S. G.; Brinker, D. J.; Deangelo, F. L.

    Thin-film, single-crystal gallium arsenide (GaAs) solar cells could exhibit a specific power approaching 700 W/kg including coverglass. A simple process has been described whereby epitaxial GaAs layers are peeled from a reusable substrate. This process takes advantage of the extreme selectivity of the etching rate of aluminum arsenide (AlAs) over GaAs in dilute hydrofluoric acid. The feasibility of using the peeled film technique to fabricate high-efficiency, low-mass GaAs solar cells is presently demonstrated. A peeled film GaAs solar cell was successfully produced. The device, although fractured and missing the aluminum gallium arsenide window and antireflective coating, had a Voc of 874 mV and a fill factor of 68 percent under AM0 illumination.

  12. TCAD analysis of graphene silicon Schottky junction solar cell

    Science.gov (United States)

    Kuang, Yawei; Liu, Yushen; Ma, Yulong; Xu, Jing; Yang, Xifeng; Feng, Jinfu

    2015-08-01

    The performance of graphene based Schottky junction solar cell on silicon substrate is studied theoretically by TCAD Silvaco tools. We calculate the current-voltage curves and internal quantum efficiency of this device at different conditions using tow dimensional model. The results show that the power conversion efficiency of Schottky solar cell dependents on the work function of graphene and the physical properties of silicon such as thickness and doping concentration. At higher concentration of 1e17cm-3 for n-type silicon, the dark current got a sharp rise compared with lower doping concentration which implies a convert of electron emission mechanism. The biggest fill factor got at higher phos doping predicts a new direction for higher performance graphene Schottky solar cell design.

  13. Ultrathin and lightweight organic solar cells with high flexibility

    Science.gov (United States)

    Kaltenbrunner, Martin; White, Matthew S.; Głowacki, Eric D.; Sekitani, Tsuyoshi; Someya, Takao; Sariciftci, Niyazi Serdar; Bauer, Siegfried

    2012-04-01

    Application-specific requirements for future lighting, displays and photovoltaics will include large-area, low-weight and mechanical resilience for dual-purpose uses such as electronic skin, textiles and surface conforming foils. Here we demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2 μm thick, with equal power conversion efficiency to their glass-based counterparts. They can reversibly withstand extreme mechanical deformation and have unprecedented solar cell-specific weight. Instead of a single bend, we form a random network of folds within the device area. The processing methods are standard, so the same weight and flexibility should be achievable in light emitting diodes, capacitors and transistors to fully realize ultrathin organic electronics. These ultrathin organic solar cells are over ten times thinner, lighter and more flexible than any other solar cell of any technology to date.

  14. Graphene-based transparent electrodes for hybrid solar cells

    Directory of Open Access Journals (Sweden)

    Pengfei eLi

    2014-11-01

    Full Text Available The graphene-based transparent and conductive films were demonstrated to be cost-effective electrodes working in organic-inorganic hybrid Schottky solar cells. Large area graphene films were produced by chemical vapor deposition (CVD on copper foils and transferred onto glass as transparent electrodes. The hybrid solar cell devices consist of solution processed poly (3, 4-ethlenedioxythiophene: poly (styrenesulfonate (PEDOT: PSS which is sandwiched between silicon wafer and graphene electrode. The solar cells based on graphene electrodes, especially those doped with HNO3, has comparable performance to the reference devices using commercial indium tin oxide (ITO. Our work suggests that graphene-based transparent electrode is a promising candidate to replace ITO.

  15. A polymer scaffold for self-healing perovskite solar cells

    Science.gov (United States)

    Zhao, Yicheng; Wei, Jing; Li, Heng; Yan, Yin; Zhou, Wenke; Yu, Dapeng; Zhao, Qing

    2016-01-01

    Advancing of the lead halide perovskite solar cells towards photovoltaic market demands large-scale devices of high-power conversion efficiency, high reproducibility and stability via low-cost fabrication technology, and in particular resistance to humid environment for long-time operation. Here we achieve uniform perovskite film based on a novel polymer-scaffold architecture via a mild-temperature process. These solar cells exhibit efficiency of up to ~16% with small variation. The unencapsulated devices retain high output for up to 300 h in highly humid environment (70% relative humidity). Moreover, they show strong humidity resistant and self-healing behaviour, recovering rapidly after removing from water vapour. Not only the film can self-heal in this case, but the corresponding devices can present power conversion efficiency recovery after the water vapour is removed. Our work demonstrates the value of cheap, long chain and hygroscopic polymer scaffold in perovskite solar cells towards commercialization.

  16. Light harvesting enhancement in solar cells with quasicrystalline plasmonic structures.

    Science.gov (United States)

    Bauer, Christina; Giessen, Harald

    2013-05-06

    Solar cells are important in the area of renewable energies. Since it is expensive to produce solar-grade silicon [Electrochem. Soc. Interface 17, 30 (2008)], especially thin-film solar cells are interesting. However, the efficiency of such solar cells is low. Therefore, it is important to increase the efficiency. The group of Polman has shown that a periodic arrangement of metal particles is able to enhance the absorbance of light [Nano Lett. 11, 1760 (2011)]. However, a quasicrystalline arrangement of the metal particles is expected to enhance the light absorbance independent of the incident polar and azimuthal angles due to the more isotropic photonic bandstructure. In this paper, we compare the absorption enhancement of a quasiperiodic photonic crystal to that of a periodic photonic crystal. We indeed find that the absorption enhancement for the quasicrystalline arrangement shows such an isotropic behavior. This implies that the absorption efficiency of the solar cell is relatively constant during the course of the day as well as the year. This is particularly important with respect to power distribution, power storage requirements, and the stability of the electric grid upon massive use of renewable energy.

  17. Anomalous charge storage exponents of organic bulk heterojunction solar cells.

    Science.gov (United States)

    Nair, Pradeep; Dwivedi, Raaz; Kumar, Goutam; Dept of Electrical Engineering, IIT Bombay Team

    2013-03-01

    Organic bulk heterojunction (BHJ) devices are increasingly being researched for low cost solar energy conversion. The efficiency of such solar cells is dictated by various recombination processes involved. While it is well known that the ideality factor and hence the charge storage exponents of conventional PN junction diodes are influenced by the recombination processes, the same aspects are not so well understood for organic solar cells. While dark currents of such devices typically show an ideality factor of 1 (after correcting for shunt resistance effects, if any), surprisingly, a wide range of charge storage exponents for such devices are reported in literature alluding to apparent concentration dependence for bi-molecular recombination rates. In this manuscript we critically analyze the role of bi-molecular recombination processes on charge storage exponents of organic solar cells. Our results indicate that the charge storage exponents are fundamentally influenced by the electrostatics and recombination processes and can be correlated to the dark current ideality factors. We believe that our findings are novel, and advance the state-of the art understanding on various recombination processes that dictate the performance limits of organic solar cells. The authors would like to thank the Centre of Excellence in Nanoelectronics (CEN) and the National Centre for Photovoltaic Research and Education (NCPRE), IIT Bombay for computational and financial support

  18. The effect of substrate morphological structure on photoelectrical conversion performance of silicon solar cell

    Science.gov (United States)

    Li, Yongtao; Sun, Xiaomeng; Xia, Yang

    2017-03-01

    A novel method is proposed to evaluate electrical characteristics of silicon solar cell at real operating conditions. Silicon solar cells with different substrate morphological structures have various photoelectrical performances. The effect of substrate morphological structure on photoelectrical conversation performance of silicon solar cell has been investigated by illustration analysis, mathematical model and I-V test system. Results show that the solar cell with the porous-sponge like substrate has better electrical characteristics than those with conical like substrate morphological structure. The output power of porous substrate solar cell can exceed by 11% at 40 degree incident angle of sunlight compared to conical substrate solar cell.

  19. Berkeley Lab Sheds Light on Improving Solar Cell Efficiency

    International Nuclear Information System (INIS)

    Lawrence Berkeley National Laboratory

    2007-01-01

    Typical manufacturing methods produce solar cells with an efficiency of 12-15%; and 14% efficiency is the bare minimum for achieving a profit. In work performed at the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley, CA, 5 10-486-577 1)--a US Department of Energy national laboratory that conducts unclassified scientific research and is managed by the University of California--scientist Scott McHugo has obtained keen insights into the impaired performance of solar cells manufactured from polycrystalline silicon. The solar cell market is potentially vast, according to Berkeley Lab. Lightweight solar panels are highly beneficial for providing electrical power to remote locations in developing nations, since there is no need to build transmission lines or truck-in generator fuel. Moreover, industrial nations confronted with diminishing resources have active programs aimed at producing improved, less expensive solar cells. 'In a solar cell, there is a junction between p-type silicon and an n-type layer, such as diffused-in phosphorous', explained McHugo, who is now with Berkeley Lab's Accelerator and Fusion Research Division. 'When sunlight is absorbed, it frees electrons, which start migrating in a random-walk fashion toward that junction. If the electrons make it to the junction; they contribute to the cell's output of electric current. Often, however, before they reach the junction, they recombine at specific sites in the crystal' (and, therefore, cannot contribute to current output). McHugo scrutinized a map of a silicon wafer in which sites of high recombination appeared as dark regions. Previously, researchers had shown that such phenomena occurred not primarily at grain boundaries in the polycrystalline material, as might be expected, but more often at dislocations in the crystal. However, the dislocations themselves were not the problem. Using a unique heat treatment technique, McHugo performed electrical measurements to investigate the material

  20. Metal-Insulator-Semiconductor Nanowire Network Solar Cells.

    Science.gov (United States)

    Oener, Sebastian Z; van de Groep, Jorik; Macco, Bart; Bronsveld, Paula C P; Kessels, W M M; Polman, Albert; Garnett, Erik C

    2016-06-08

    Metal-insulator-semiconductor (MIS) junctions provide the charge separating properties of Schottky junctions while circumventing the direct and detrimental contact of the metal with the semiconductor. A passivating and tunnel dielectric is used as a separation layer to reduce carrier recombination and remove Fermi level pinning. When applied to solar cells, these junctions result in two main advantages over traditional p-n-junction solar cells: a highly simplified fabrication process and excellent passivation properties and hence high open-circuit voltages. However, one major drawback of metal-insulator-semiconductor solar cells is that a continuous metal layer is needed to form a junction at the surface of the silicon, which decreases the optical transmittance and hence short-circuit current density. The decrease of transmittance with increasing metal coverage, however, can be overcome by nanoscale structures. Nanowire networks exhibit precisely the properties that are required for MIS solar cells: closely spaced and conductive metal wires to induce an inversion layer for homogeneous charge carrier extraction and simultaneously a high optical transparency. We experimentally demonstrate the nanowire MIS concept by using it to make silicon solar cells with a measured energy conversion efficiency of 7% (∼11% after correction), an effective open-circuit voltage (Voc) of 560 mV and estimated short-circuit current density (Jsc) of 33 mA/cm(2). Furthermore, we show that the metal nanowire network can serve additionally as an etch mask to pattern inverted nanopyramids, decreasing the reflectivity substantially from 36% to ∼4%. Our extensive analysis points out a path toward nanowire based MIS solar cells that exhibit both high Voc and Jsc values.

  1. Polymer Substrates For Lightweight, Thin-Film Solar Cells

    Science.gov (United States)

    Lewis, Carol R.

    1993-01-01

    Substrates survive high deposition temperatures. High-temperature-resistant polymers candidate materials for use as substrates of lightweight, flexible, radiation-resistant solar photovoltaic cells. According to proposal, thin films of copper indium diselenide or cadmium telluride deposited on substrates to serve as active semiconductor layers of cells, parts of photovoltaic power arrays having exceptionally high power-to-weight ratios. Flexibility of cells exploited to make arrays rolled up for storage.

  2. Optimized designs and materials for nanostructure based solar cells

    Science.gov (United States)

    Shao, Qinghui

    Nanostructure-based solar cells are attracting significant attention as possible candidates for drastic improvement in photovoltaic (PV) energy conversion efficiency. Although such solar cells are expected to be more expensive there is growing need for the efficient and light-weight solar cells in aero-space and related industries. In this dissertation I present results of the theoretical, computational and experimental investigation of novel designs for quantum dot superlattice (QDS) based PV elements and advanced materials for transparent solar cells. In the first part of the dissertation I describe possible implementation of the intermediate-band (IB) solar cells with QDS. The IB cells were predicted to have PV efficiency exceeding the Shockley-Queisser limit for a single junction cell. The parameters of QDS structure have to be carefully tuned to achieve the desired charge carrier dispersion required for the IB operation. The first-principles models were used to calculate the electrical properties and light absorption in QDS. This approach allowed me to determine the dimensions of QDS for inducing the mini-band which plays the role of the IB. Using the detailed balance theory it was determined that the upper-bound PV efficiency of such IB solar cells can be as high as ˜51%. The required QDS dimensions on the basis of InAsN/GaAsSb are technologically challenging but feasible: ˜2-6 nm. Using the developed simulation tools I proposed several possible designs of QDS solar cells including one, which combined the benefits of the IB concept and the advanced tandem cell design. The second part of the dissertation presents a study of graphene layers as transparent electrodes for the PV cells. The graphene layers were mechanically exfoliated from bulk graphite and characterized with micro-Raman spectroscopy. It was found that graphene electrodes have good electrical conductivity, which reveals unusual temperature dependence beneficial for the proposed application. The

  3. Optimization methods and silicon solar cell numerical models

    Science.gov (United States)

    Girardini, K.; Jacobsen, S. E.

    1986-01-01

    An optimization algorithm for use with numerical silicon solar cell models was developed. By coupling an optimization algorithm with a solar cell model, it is possible to simultaneously vary design variables such as impurity concentrations, front junction depth, back junction depth, and cell thickness to maximize the predicted cell efficiency. An optimization algorithm was developed and interfaced with the Solar Cell Analysis Program in 1 Dimension (SCAP1D). SCAP1D uses finite difference methods to solve the differential equations which, along with several relations from the physics of semiconductors, describe mathematically the performance of a solar cell. A major obstacle is that the numerical methods used in SCAP1D require a significant amount of computer time, and during an optimization the model is called iteratively until the design variables converge to the values associated with the maximum efficiency. This problem was alleviated by designing an optimization code specifically for use with numerically intensive simulations, to reduce the number of times the efficiency has to be calculated to achieve convergence to the optimal solution.

  4. Back-contacted back-junction silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mangersnes, Krister

    2010-10-15

    Conventional silicon solar cells have a front-side contacted emitter. Back-contacted back-junction (BC-BJ) silicon solar cells, on the other hand, have both the complete metallization and the active diffused regions of both polarities on the backside. World-record efficiencies have already been demonstrated for this type of cell design in production, both on cell and module level. However, the production of these cells is both complex and costly, and a further cost reduction in fabrication is needed to make electricity from BC-BJ silicon solar cells cost-competitive with electricity on the grid ('grid-parity'). During the work with this thesis, we have investigated several important issues regarding BC-BJ silicon solar cells. The aim has been to reduce production cost and complexity while at the same time maintaining, or increasing, the already high conversion efficiencies demonstrated elsewhere. This has been pursued through experimental work as well as through numerical simulations and modeling. Six papers are appended to this thesis, two of which are still under review in scientific journals. In addition, two patents have been filed based on the work presented herein. Experimentally, we have focused on investigating and optimizing single, central processing steps. A laser has been the key processing tool during most of the work. We have used the same laser both to structure the backside of the cell and to make holes in a double-layer of passivating amorphous silicon and silicon oxide, where the holes were opened with the aim of making local contact to the underlying silicon. The processes developed have the possibility of using a relatively cheap and industrially proven laser and obtain results better than most state-of-the-art laser technologies. During the work with the laser, we also developed a thermodynamic model that was able to predict the outcome from laser interaction with amorphous and crystalline silicon. Alongside the experimental work, we

  5. Process Development for High Voc CdTe Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Ferekides, C. S.; Morel, D. L.

    2011-05-01

    This is a cumulative and final report for Phases I, II and III of this NREL funded project (subcontract # XXL-5-44205-10). The main research activities of this project focused on the open-circuit voltage of the CdTe thin film solar cells. Although, thin film CdTe continues to be one of the leading materials for large-scale cost-effective production of photovoltaics, the efficiency of the CdTe solar cells have been stagnant for the last few years. This report describes and summarizes the results for this 3-year research project.

  6. Multijunction solar cells for conversion of concentrated sunlight to electricity.

    Science.gov (United States)

    Kurtz, Sarah; Geisz, John

    2010-04-26

    Solar-cell efficiencies have exceeded 40% in recent years. The keys to achieving these high efficiencies include: 1) use of multiple materials that span the solar spectrum, 2) growth of these materials with near-perfect quality by using epitaxial growth on single-crystal substrates, and 3) use of concentration. Growth of near-perfect semiconductor materials is possible when the lattice constants of the materials are matched or nearly matched to that of a single-crystal substrate. Multiple material combinations have now demonstrated efficiencies exceeding 40%, motivating incorporation of these cells into concentrator systems for electricity generation. The use of concentration confers several key advantages.

  7. Relationship between encapsulation barrier performance and organic solar cell lifetime

    Science.gov (United States)

    Cros, Stéphane; Guillerez, Stéphane; de Bettignies, Rémi; Lemaître, Noëlla; Bailly, Severine; Maisse, Pascal

    2008-08-01

    This article describes a method to have a better knowledge of barrier performances needed for encapsulating materials, particularly in the case of organic solar cells devices. We have developed a high sensitivity permeameter which enables simultaneous measurements of water and oxygen permeation. Various polymers and inorganic coatings on polymer substrates have been measured. Experimental barrier parameters have been plotted considering the steady and transient states of permeation curves and compared to theoretical values. In addition, we have performed ageing experiments on encapsulated organic solar cells to establish a barrier requirement directly related to the device. Finally, we have performed such experiments using different cathode materials and encapsulating materials.

  8. Passivation Using Molecular Halides Increases Quantum Dot Solar Cell Performance

    KAUST Repository

    Lan, Xinzheng

    2015-11-18

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Here we report a solution-based passivation scheme is developed featuring the use of molecular iodine and PbS colloidal quantum dots (CQDs). The improved passivation translates into a longer carrier diffusion length in the solid film. This allows thicker solar-cell devices to be built while preserving efficient charge collection, leading to a certified power conversion efficiency of 9.9%, which is a new record in CQD solar cells.

  9. Supramolecular Approaches to Nanoscale Morphological Control in Organic Solar Cells.

    Science.gov (United States)

    Haruk, Alexander M; Mativetsky, Jeffrey M

    2015-06-11

    Having recently surpassed 10% efficiency, solar cells based on organic molecules are poised to become a viable low-cost clean energy source with the added advantages of mechanical flexibility and light weight. The best-performing organic solar cells rely on a nanostructured active layer morphology consisting of a complex organization of electron donating and electron accepting molecules. Although much progress has been made in designing new donor and acceptor molecules, rational control over active layer morphology remains a central challenge. Long-term device stability is another important consideration that needs to be addressed. This review highlights supramolecular strategies for generating highly stable nanostructured organic photovoltaic active materials by design.

  10. Impedance spectroscopy on polymer-fullerene solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Knipper, M.; Parisi, J. [Oldenburg Univ. (Germany). Energy and Semiconductor Research Lab.; Coakley, K.; Waldauf, C.; Brabec, C.J. [Konarka Technologies Germany, Nuernberg (Germany); Dyakonov, V. [Wuerzburg Univ. (Germany). Faculty of Physics and Astronomy

    2007-09-15

    Impedance spectroscopy is used for studying the electrical transport properties of bulk heterojunction solar cells. A replacement circuit is needed to translate the frequency response of the circuit to the individual interfaces and layers of the solar cell. As a material combination and device architecture, composites of P3HT and PCBM, sandwiched between a transparent ITO front electrode and an aluminum back electrode, as well as a polymer buffer layer were investigated. By varying the film thickness we identified an equivalent circuit capable to fit our experimental data. We found a dielectric constant for the P3HT and for the P3HT:PCBM bulk. (orig.)

  11. Spectral response of a polycrystalline silicon solar cell

    International Nuclear Information System (INIS)

    Ba, B.; Kane, M.

    1994-10-01

    A theoretical study of the spectral response of a polycrystalline silicon n-p junction solar cell is presented. The case of a fibrously oriented grain structure, involving grain boundary recombination velocity and grain size effects is discussed. The contribution of the base region on the internal quantum efficiency Q int is computed for different grain sizes and grain boundary recombination velocities in order to examine their influence. Suggestions are also made for the determination of base diffusion length in polycrystalline silicon solar cells using the spectral response method. (author). 15 refs, 4 figs

  12. Simulation of perovskite solar cells with inorganic hole transporting materials

    DEFF Research Database (Denmark)

    Wang, Yan; Xia, Zhonggao; Liu, Yiming

    2015-01-01

    improvement in power conversion efficiency (PCE). Here, we investigated the effect of band offset between inorganic HTM/absorber layers. The solar cell simulation program adopted in this work is named wxAMPS, an updated version of the AMPS tool (Analysis of Microelectronic and Photonic Structure).......Device modeling organolead halide perovskite solar cells with planar architecture based on inorganic hole transporting materials (HTMs) were performed. A thorough understanding of the role of the inorganic HTMs and the effect of band offset between HTM/absorber layers is indispensable for further...

  13. Incomplete Exciton Harvesting from Fullerenes in Bulk Heterojunction Solar Cells

    KAUST Repository

    Burkhard, George F.

    2009-12-09

    We investigate the internal quantum efficiencies (IQEs) of high efficiency poly-3-hexylthiophene:[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) solar cells and find them to be lower at wavelengths where the PCBM absorbs. Because the exciton diffusion length in PCBM is too small, excitons generated in PCBM decay before reaching the donor-acceptor interface. This result has implications for most state of the art organic solar cells, since all of the most efficient devices use fullerenes as electron acceptors. © 2009 American Chemical Society.

  14. First principles modeling of panchromatic dyes for solar cells applications.

    Science.gov (United States)

    di Felice, Rosa; Calzolari, Arrigo; Dong, Rui; Buongiorno Nardelli, Marco

    2013-03-01

    The state-of-the-art dye in Grätzel solar cells, N719, exhibits a total solar-to-electric conversion efficiency of 11.2%. However, it severely lacks absorption in the red and the near infrared regions of the electromagnetic spectrum, which represent more than 70% of the solar radiation spectrum. Using calculations from first principles in the time-dependent domain, we have studied the electronic and optical response of a novel class of panchromatic sensitizers that can harvest solar energy efficiently across the visible and near infrared regions, which have been recently synthesized [A. El-Shafei, M. Hussain, A. Atiq, A. Islam, and L. Han, J. Mater. Chem. 22, 24048 (2012)]. Our calculations show that, by tuning the properties of antenna groups, one can achieve a substantial improvement of the optical properties.

  15. The Effect of Interface Cracks on the Electrical Performance of Solar Cells

    Science.gov (United States)

    Kim, Hansung; Tofail, Md. Towfiq; John, Ciby

    2018-04-01

    Among a variety of solar cell types, thin-film solar cells have been rigorously investigated as cost-effective and efficient solar cells. In many cases, flexible solar cells are also fabricated as thin films and undergo frequent stress due to the rolling and bending modes of applications. These frequent motions result in crack initiation and propagation (including delamination) in the thin-film solar cells, which cause degradation in efficiency. Reliability evaluation of solar cells is essential for developing a new type of solar cell. In this paper, we investigated the effect of layer delamination and grain boundary crack on 3D thin-film solar cells. We used finite element method simulation for modeling of both electrical performance and cracked structure of 3D solar cells. Through simulations, we quantitatively calculated the effect of delamination length on 3D copper indium gallium diselenide (CIGS) solar cell performance. Moreover, it was confirmed that the grain boundary of CIGS could improve the solar cell performance and that grain boundary cracks could decrease cell performance by altering the open circuit voltage. In this paper, the investigated material is a CIGS solar cell, but our method can be applied to general polycrystalline solar cells.

  16. Universal Features of Electron Dynamics in Solar Cells with TiO2 Contact: From Dye Solar Cells to Perovskite Solar Cells.

    Science.gov (United States)

    Todinova, Anna; Idígoras, Jesús; Salado, Manuel; Kazim, Samrana; Anta, Juan A

    2015-10-01

    The electron dynamics of solar cells with mesoporous TiO2 contact is studied by electrochemical small-perturbation techniques. The study involved dye solar cells (DSC), solid-state perovskite solar cells (SSPSC), and devices where the perovskite acts as sensitizer in a liquid-junction device. Using a transport-recombination continuity equation we found that mid-frequency time constants are proper lifetimes that determine the current-voltage curve. This is not the case for the SSPSC, where a lifetime of ∼1 μs, 1 order of magnitude longer, is required to reproduce the current-voltage curve. This mismatch is attributed to the dielectric response on the mid-frequency component. Correcting for this effect, lifetimes lie on a common exponential trend with respect to open-circuit voltage. Electron transport times share a common trend line too. This universal behavior of lifetimes and transport times suggests that the main difference between the cells is the power to populate the mesoporous TiO2 contact with electrons.

  17. High efficiency cadmium telluride and zinc telluride based thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Sudharsanan, R.; Ringel, S.A.; Chou, H.C. (Georgia Inst. of Tech., Atlanta, GA (United States))

    1992-10-01

    This report describes work to improve the basic understanding of CdTe and ZnTe alloys by growing and characterizing these films along with cell fabrication. The major objective was to develop wide-band-gap (1.6--1.8 eV) material for the top cell, along with compatible window material and transparent ohmic contacts, so that a cascade cell design can be optimized. Front-wall solar cells were fabricated with a glass/SnO{sub 2}/CdS window, where the CdS film is thin to maximize transmission and current. Wide-band-gap absorber films (E{sub g} = 1.75 eV) were grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) techniques, which provided excellent control for tailoring the film composition and properties. CdZnTe films were grown by both MBE and MOCVD. All the as-grown films were characterized by several techniques (surface photovoltage spectroscopy, Auger electron spectroscopy (AES), and x-ray photoelectron spectroscopy (XPS)) for composition, bulk uniformity, thickness, and film and interface quality. Front-wall-type solar cells were fabricated in collaboration with Ametek Materials Research Laboratory using CdTe and CdZnTe polycrystalline absorber films. The effects of processing on ternary film were studied by AES and XPS coupled with capacitance voltage and current voltage measurements as a function of temperature. Bias-dependent spectral response and electrical measurements were used to test some models in order to identify and quantify dominant loss mechanisms.

  18. Characterization of solar cells for space applications. Volume 14: Electrical characteristics of Hughes liquid phase epitaxy gallium arsenide solar cells as a function of intensity, temperature and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1981-01-01

    Electrical characteristics of liquid phase epitaxy, P/N gallium aluminum arsenide solar cells are presented in graphical and tabular format as a function of solar illumination intensity and temperature. The solar cells were exposed to 1 MeV electron fluences of, respectively, 0, one hundred trillion, one quadrillion, and ten quadrillion e/sq cm.

  19. Schottky Quantum Dot Solar Cells Stable in Air under Solar Illumination

    KAUST Repository

    Tang, Jiang

    2010-01-07

    (Figure Presented) The air stability and power conversion efficiency of solution-processed PbS quantum dot solar cells is dramatically improved by the insertion of 0.8 nm LiF between the PbS nanoparticle film and the Al contact. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.

  20. Green Nanochemistry Approach to Titanium Dioxide Nanoparticle, Dye- Sensitized Solar Cells

    Science.gov (United States)

    2012-06-01

    New research into third-generation solar cells has just begun. These technologies include polymer -based solar cells, nanocrystalline cells, and...silicon solar cells. The dyes and electrolyte solution degrade over time, which makes DSSCs less efficient than silicon solar cells. However, the...their ability to absorb light and convert it into electrons in a natural and inexpensive way (5). Anthocyanin dyes are also powerful antioxidants and