Mechanically flexible optically transparent porous mono-crystalline silicon substrate

KAUST Repository

Rojas, Jhonathan Prieto; Syed, Ahad A.; Hussain, Muhammad Mustafa

2012-01-01

For the first time, we present a simple process to fabricate a thin (≥5μm), mechanically flexible, optically transparent, porous mono-crystalline silicon substrate. Relying only on reactive ion etching steps, we are able to controllably peel off a thin layer of the original substrate. This scheme is cost favorable as it uses a low-cost silicon <100> wafer and furthermore it has the potential for recycling the remaining part of the wafer that otherwise would be lost and wasted during conventional back-grinding process. Due to its porosity, it shows see-through transparency and potential for flexible membrane applications, neural probing and such. Our process can offer flexible, transparent silicon from post high-thermal budget processed device wafer to retain the high performance electronics on flexible substrates. © 2012 IEEE.

Highly Conductive Transparent and Flexible Electrodes Including Double-Stacked Thin Metal Films for Transparent Flexible Electronics.

Science.gov (United States)

Han, Jun Hee; Kim, Do-Hong; Jeong, Eun Gyo; Lee, Tae-Woo; Lee, Myung Keun; Park, Jeong Woo; Lee, Hoseung; Choi, Kyung Cheol

2017-05-17

To keep pace with the era of transparent and deformable electronics, electrode functions should be improved. In this paper, an innovative structure is suggested to overcome the trade-off between optical and electrical properties that commonly arises with transparent electrodes. The structure of double-stacked metal films showed high conductivity (electronics are expected.

Highly Efficient and Reliable Transparent Electromagnetic Interference Shielding Film.

Science.gov (United States)

Jia, Li-Chuan; Yan, Ding-Xiang; Liu, Xiaofeng; Ma, Rujun; Wu, Hong-Yuan; Li, Zhong-Ming

2018-04-11

Electromagnetic protection in optoelectronic instruments such as optical windows and electronic displays is challenging because of the essential requirements of a high optical transmittance and an electromagnetic interference (EMI) shielding effectiveness (SE). Herein, we demonstrate the creation of an efficient transparent EMI shielding film that is composed of calcium alginate (CA), silver nanowires (AgNWs), and polyurethane (PU), via a facile and low-cost Mayer-rod coating method. The CA/AgNW/PU film with a high optical transmittance of 92% achieves an EMI SE of 20.7 dB, which meets the requirements for commercial shielding applications. A superior EMI SE of 31.3 dB could be achieved, whereas the transparent film still maintains a transmittance of 81%. The integrated efficient EMI SE and high transmittance are superior to those of most previously reported transparent EMI shielding materials. Moreover, our transparent films exhibit a highly reliable shielding ability in a complex service environment, with 98 and 96% EMI SE retentions even after 30 min of ultrasound treatment and 5000 bending cycles (1.5 mm radius), respectively. The comprehensive performance that is associated with the facile fabrication strategy imparts the CA/AgNW/PU film with great potential as an optimized EMI shielding material in emerging optoelectronic devices, such as flexible solar cells, displays, and touch panels.

Optically Transparent Wood from a Nanoporous Cellulosic Template: Combining Functional and Structural Performance.

Science.gov (United States)

Li, Yuanyuan; Fu, Qiliang; Yu, Shun; Yan, Min; Berglund, Lars

2016-04-11

Optically transparent wood (TW) with transmittance as high as 85% and haze of 71% was obtained using a delignified nanoporous wood template. The template was prepared by removing the light-absorbing lignin component, creating nanoporosity in the wood cell wall. Transparent wood was prepared by successful impregnation of lumen and the nanoscale cellulose fiber network in the cell wall with refractive-index-matched prepolymerized methyl methacrylate (MMA). During the process, the hierarchical wood structure was preserved. Optical properties of TW are tunable by changing the cellulose volume fraction. The synergy between wood and PMMA was observed for mechanical properties. Lightweight and strong transparent wood is a potential candidate for lightweight low-cost, light-transmitting buildings and transparent solar cell windows.

Transparent Nanopore Cavity Arrays Enable Highly Parallelized Optical Studies of Single Membrane Proteins on Chip.

Science.gov (United States)

Diederichs, Tim; Nguyen, Quoc Hung; Urban, Michael; Tampé, Robert; Tornow, Marc

2018-06-13

Membrane proteins involved in transport processes are key targets for pharmaceutical research and industry. Despite continuous improvements and new developments in the field of electrical readouts for the analysis of transport kinetics, a well-suited methodology for high-throughput characterization of single transporters with nonionic substrates and slow turnover rates is still lacking. Here, we report on a novel architecture of silicon chips with embedded nanopore microcavities, based on a silicon-on-insulator technology for high-throughput optical readouts. Arrays containing more than 14 000 inverted-pyramidal cavities of 50 femtoliter volumes and 80 nm circular pore openings were constructed via high-resolution electron-beam lithography in combination with reactive ion etching and anisotropic wet etching. These cavities feature both, an optically transparent bottom and top cap. Atomic force microscopy analysis reveals an overall extremely smooth chip surface, particularly in the vicinity of the nanopores, which exhibits well-defined edges. Our unprecedented transparent chip design provides parallel and independent fluorescent readout of both cavities and buffer reservoir for unbiased single-transporter recordings. Spreading of large unilamellar vesicles with efficiencies up to 96% created nanopore-supported lipid bilayers, which are stable for more than 1 day. A high lipid mobility in the supported membrane was determined by fluorescent recovery after photobleaching. Flux kinetics of α-hemolysin were characterized at single-pore resolution with a rate constant of 0.96 ± 0.06 × 10 -3 s -1 . Here, we deliver an ideal chip platform for pharmaceutical research, which features high parallelism and throughput, synergistically combined with single-transporter resolution.

Optically transparent, superhydrophobic methyltrimethoxysilane based silica coatings without silylating reagent

International Nuclear Information System (INIS)

Kavale, Mahendra S.; Mahadik, D.B.; Parale, V.G.; Wagh, P.B.; Gupta, Satish C.; Rao, A.Venkateswara; Barshilia, Harish C.

2011-01-01

The superhydrophobic surfaces have drawn lot of interest, in both academic and industries because of optically transparent, adherent and self-cleaning behavior. Surface chemical composition and morphology plays an important role in determining the superhydrophobic nature of coating surface. Such concert of non-wettability can be achieved, using surface modifying reagents or co-precursor method in sol-gel process. Attempts have been made to increase the hydrophobicity and optical transparency of methyltrimethoxysilane (MTMS) based silica coatings using polymethylmethacrylate (PMMA) instead of formal routes like surface modification using silylating reagents. The optically transparent, superhydrophobic uniform coatings were obtained by simple dip coating method. The molar ratio of MTMS:MeOH:H 2 O was kept constant at 1:5.63:1.58, respectively with 0.5 M NH 4 F as a catalyst and the weight percent of PMMA varied from 1 to 8. The hydrophobicity of silica coatings was analyzed by FTIR and contact angle measurements. These substrates exhibited 91% optical transmittance as compared to glass and water drop contact angle as high as 171 ± 1 deg. The effect of humidity on hydrophobic nature of coating has been studied by exposing these films at relative humidity of 90% at constant temperature of 30 deg. C for a period of 45 days. The micro-structural studies carried out by transmission electron microscopy (TEM).

High aspect ratio silver grid transparent electrodes using UV embossing process

Directory of Open Access Journals (Sweden)

Dong Jin Kim

2017-10-01

Full Text Available This study presents a UV embossing process to fabricate high aspect ratio silver grid transparent electrodes on a polymer film. Transparent electrodes with a high optical transmittance (93 % and low sheet resistance (4.6 Ω/sq were fabricated without any high temperature or vacuum processes. The strong adhesion force between the UV resin and the silver ink enables the fabrication of silver microstructures with an aspect ratio higher than 3. The high aspect ratio results in a low sheet resistance while maintaining a high optical transmittance. Multi-layer transparent electrodes were fabricated by repeating the proposed UV process. Additionally, a large-area of 8-inch touch panel was fabricated with the proposed UV process. The proposed UV process is a relatively simple and low cost process making it suitable for large-area production as well as mass production.

Highly transparent, low-haze, hybrid cellulose nanopaper as electrodes for flexible electronics

KAUST Repository

Xu, Xuezhu

2016-06-01

Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are still characterized by high diffuse transmittance and small direct transmittance, resulting in high optical haze of the substrates. In this study, we proposed a simple methodology for large-scale production of high-transparency, low-haze CNP comprising both long cellulose nanofibrils (CNFs) and short cellulose nanocrystals (CNCs). By varying the CNC/CNF ratio in the hybrid CNP, we could tailor its total transmittance, direct transmittance and diffuse transmittance. By increasing the CNC content, the optical haze of the hybrid CNP could be decreased and its transparency could be increased. The direct transmittance and optical haze of the CNP were 75.1% and 10.0%, respectively, greatly improved from the values of previously reported CNP (31.1% and 62.0%, respectively). Transparent, flexible electrodes were fabricated by coating the hybrid CNP with silver nanowires (AgNWs). The electrodes showed a low sheet resistance (minimum 1.2 Ω sq-1) and a high total transmittance (maximum of 82.5%). The electrodes were used to make a light emitting diode (LED) assembly to demonstrate their potential use in flexible displays. © 2016 The Royal Society of Chemistry.

Determining hyperfine transitions with electromagnetically induced transparency and optical pumping

International Nuclear Information System (INIS)

Lee Yi-Chi; Tsai Chin-Chun; Huang Chen-Han; Chui Hsiang-Chen; Chang Yung-Yung

2011-01-01

A system is designed to observe the phenomena of electromagnetically induced transparency and optical pumping in cesium D 1 and D 2 lines at room temperature. When a pump laser is frequency-locked on the top of a hyperfine transition and the frequency of the probe laser scans over another hyperfine transition, a spectrum of V-type electromagnetically induced transparency or an optical pumping can be observed depending on whether the two lasers share a common ground state. Therefore, these results can be used to identify the unknown hyperfine transitions of the D 1 line transitions. For educational purposes, this system is helpful for understanding the electromagnetically induced transparency and the optical pumping

Optical and electrical properties of Cu-based all oxide semi-transparent photodetector

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong-Sik; Patel, Malkeshkumar; Yadav, Pankaj; Kim, Joondong, E-mail: joonkim@inu.ac.kr, E-mail: dwkim@ewha.ac.kr [Photoelectric and Energy Device Application Lab (PEDAL) and Department of Electrical Engineering, Incheon National University, 119 Academy Rd., Yeonsu, Incheon 406772 (Korea, Republic of); Sohn, Ahrum; Kim, Dong-Wook, E-mail: joonkim@inu.ac.kr, E-mail: dwkim@ewha.ac.kr [Department of Physics, Ewha Womans University, Seoul 120750 (Korea, Republic of)

2016-09-05

Zero-bias operating Cu oxide-based photodetector was achieved by using large-scale available sputtering method. Cu oxide (Cu{sub 2}O or CuO) was used as p-type transparent layer to form a heterojunction by contacting n-type ZnO layer. All metal-oxide materials were employed to realize transparent device at room temperature and showed a high transparency (>75% at 600 nm) with excellent photoresponses. The structural, morphological, optical, and electrical properties of Cu oxides of CuO and Cu{sub 2}O are evaluated in depth by UV-visible spectrometer, X-ray diffraction, scanning electron microscopy, atomic force microscopy, Kelvin probe force microscopy, and Hall measurements. We may suggest a route of high-functional Cu oxide-based photoelectric devices for the applications in flexible and transparent electronics.

High-Sensitivity, Highly Transparent, Gel-Gated MoS2 Phototransistor on Biodegradable Nanopaper

KAUST Repository

Zhang, Qing

2016-06-21

Transition metal dichalcogenides hold great promise for a variety of novel electrical, optical and mechanical devices and applications. Among them, molybdenum disulphide (MoS2) is gaining increasing attention as the gate dielectric and semiconductive channel for high-perfomance field effect transistors. Here we report on the first MoS2 phototransistor built on flexible, transparent and biodegradable substrate with electrolyte gate dielectric. We have carried out systematic studies on its electrical and optoelectronic properties. The MoS2 phototransistor exhibited excellent photo responsivity of ~1.5 kA/W, about two times higher compared to typical back-gated devices reported in previous studies. The device is highly transparent at the same time with an average optical transmittance of 82%. Successful fabrication of phototransistors on flexible cellulose nanopaper with excellent performance and transparency suggests that it is feasible to achieve an ecofriendly, biodegradable phototransistor with great photoresponsivity, broad spectral range and durable flexibility.

High-Sensitivity, Highly Transparent, Gel-Gated MoS2 Phototransistor on Biodegradable Nanopaper

KAUST Repository

Zhang, Qing; Bao, Wenzhong; Gong, Amy; Gong, Tao; Ma, Dakang; Wan, Jiayu; Dai, Jiaqi; Munday, J; He, Jr-Hau; Hu, Liangbing; Zhang, Daihua

2016-01-01

Transition metal dichalcogenides hold great promise for a variety of novel electrical, optical and mechanical devices and applications. Among them, molybdenum disulphide (MoS2) is gaining increasing attention as the gate dielectric and semiconductive channel for high-perfomance field effect transistors. Here we report on the first MoS2 phototransistor built on flexible, transparent and biodegradable substrate with electrolyte gate dielectric. We have carried out systematic studies on its electrical and optoelectronic properties. The MoS2 phototransistor exhibited excellent photo responsivity of ~1.5 kA/W, about two times higher compared to typical back-gated devices reported in previous studies. The device is highly transparent at the same time with an average optical transmittance of 82%. Successful fabrication of phototransistors on flexible cellulose nanopaper with excellent performance and transparency suggests that it is feasible to achieve an ecofriendly, biodegradable phototransistor with great photoresponsivity, broad spectral range and durable flexibility.

Optically transparent, superhydrophobic, biocompatible thin film coatings and methods for producing same

Energy Technology Data Exchange (ETDEWEB)

Armstrong, Beth L.; Aytug, Tolga; Paranthaman, Mariappan Parans; Simpson, John T.; Hillesheim, Daniel A.; Trammell, Neil E.

2017-09-05

An optically transparent, hydrophobic coating, exhibiting an average contact angle of at least 100 degrees with a drop of water. The coating can be produced using low-cost, environmentally friendly components. Methods of preparing and using the optically transparent, hydrophobic coating.

Influence of the ``second gap'' on the optical absorption of transparent conducting oxides

Science.gov (United States)

Ha, Viet-Anh; Waroquiers, David; Rignanese, Gian-Marco; Hautier, Geoffroy

Transparent conducting oxides (TCOs) are critical to many technologies (e.g., thin-film solar cells, flat-panel displays or organic light-emitting diodes). TCOs are heavily doped (n or p-type) oxides that satisfy many design criteria such as high transparency to visible light (i.e., a band gap > 3 eV), high concentration and mobility of carriers (leading to high conductivity), ... In such (highly doped) systems, optical transitions from the conduction band minimum to higher energy bands in n-type or from lower energy bands to the valence band maximum in p-type are possible and can degrade transparency. In fact, it has been claimed that a high energy (> 3eV) for any of these transitions made possible by doping, commonly referred as a high ``second gap'', is a necessary design criterion for high performance TCOs. Here, we study the influence of this second gap on the transparency of doped TCOs by using ab initio calculations within the random phase approximation (RPA) for several well-known p-type and n-type TCOs. Our work highlights how the second gap affects the transparency of doped TCOs, shining light on more accurate design criteria for high performance TCOs.

Optically transparent super-hydrophobic thin film fabricated by reusable polyurethane-acrylate (PUA) mold

Science.gov (United States)

Park, J.-S.; Park, J.-H.; Lee, D.-W.

2018-02-01

In this paper, we describe a simple manufacturing method for producing an optically transparent super-hydrophobic polymer thin film using a reusable photo-curable polymer mold. Soluble photoresist (PR) molds were prepared with under-exposed and under-baked processes, which created unique hierarchical micro/nano structures. The reverse phase of the PR mold was replicated on the surface of polydimethylsiloxane (PDMS) substrates. The unique patterns on the replicated PDMS molds were successfully transferred back to the UV curable polyurethane-acrylate (PUA) using a laboratory-made UV exposure system. Continuous production of the super-hydrophobic PDMS thin film was demonstrated using the reusable PUA mold. In addition, hydrophobic nano-silica powder was sprayed onto the micro/nano structured PDMS surfaces to further improve hydrophobicity. The fabricated PDMS thin films with hierarchical surface texturing showed a water contact angle  ⩾150°. Excellent optical transmittance within the range of visible light of wavelengths between 400-800 nm was experimentally confirmed using a spectrophotometer. High efficiency of the super-hydrophobic PDMS film in optical transparency was also confirmed using solar panels. The fabricated PUA molds are very suitable for use in roll-to-roll or roll-to-plate systems which allow continuous production of super-hydrophobic thin films with an excellent optical transparency.

GO@CuSilicate nano-needle arrays hierarchical structure: a new route to prepare high optical transparent, excellent self-cleaning and anticorrosion superhydrophobic surface

Energy Technology Data Exchange (ETDEWEB)

Fan, Ping; Chen, Jingyi; Yang, Jintao; Chen, Feng; Zhong, Mingqiang, E-mail: zhongmingqiang@hotmail.com [Zhejiang University of Technology, College of Materials Science and Engineering (China)

2017-02-15

Transparent superhydrophobic coatings, which are highly desired for the protection of material surfaces, have been limited to particular kinds of materials, e.g. silicon dioxide. In this work, a hybrid compound of graphene oxide and copper silicate with hierarchical structure was developed and was used to fabricate coatings. Due to the high transparency of graphene oxide and the nanoscopic roughness created by nanoneedles of CuSilicate, with very low compound loading (0.052 mg/cm{sup 2}), the as-prepared coating was found not only showing superhydrophobic properties with a water contact angle (CA) of ∼152° and a near zero sliding angle (SA) of 0.5 but also showing high optical transparent (light transmittance is as high as 94.5 % at 500 nm). Furthermore, this surface also showed efficient anticorrosion properties and excellent self-cleaning ability. This study not only fabricated a new surface with transparency and surperhydrophobicity based on graphene materials, but also hopefully offers a method for the fabrication of multifunctional coatings.

Stretchable Transparent Electrode Arrays for Simultaneous Electrical and Optical Interrogation of Neural Circuits in Vivo.

Science.gov (United States)

Zhang, Jing; Liu, Xiaojun; Xu, Wenjing; Luo, Wenhan; Li, Ming; Chu, Fangbing; Xu, Lu; Cao, Anyuan; Guan, Jisong; Tang, Shiming; Duan, Xiaojie

2018-04-09

Recent developments of transparent electrode arrays provide a unique capability for simultaneous optical and electrical interrogation of neural circuits in the brain. However, none of these electrode arrays possess the stretchability highly desired for interfacing with mechanically active neural systems, such as the brain under injury, the spinal cord, and the peripheral nervous system (PNS). Here, we report a stretchable transparent electrode array from carbon nanotube (CNT) web-like thin films that retains excellent electrochemical performance and broad-band optical transparency under stretching and is highly durable under cyclic stretching deformation. We show that the CNT electrodes record well-defined neuronal response signals with negligible light-induced artifacts from cortical surfaces under optogenetic stimulation. Simultaneous two-photon calcium imaging through the transparent CNT electrodes from cortical surfaces of GCaMP-expressing mice with epilepsy shows individual activated neurons in brain regions from which the concurrent electrical recording is taken, thus providing complementary cellular information in addition to the high-temporal-resolution electrical recording. Notably, the studies on rats show that the CNT electrodes remain operational during and after brain contusion that involves the rapid deformation of both the electrode array and brain tissue. This enables real-time, continuous electrophysiological monitoring of cortical activity under traumatic brain injury. These results highlight the potential application of the stretchable transparent CNT electrode arrays in combining electrical and optical modalities to study neural circuits, especially under mechanically active conditions, which could potentially provide important new insights into the local circuit dynamics of the spinal cord and PNS as well as the mechanism underlying traumatic injuries of the nervous system.

Highly Transparent and Conductive Metallized Nanofibers by Electrospinning and Electroplating

Science.gov (United States)

Yoon, Sam S.; Yarin, Alexander L.

2017-11-01

Transparent conducting films (TCFs) and transparent heaters (THs) are of interest for a wide variety of applications, from displays to window defrosters. Here, we demonstrate production of highly flexible, conducting, and transparent copper (Cu), nickel (Ni), platinum (Pt), and silver (Ag) nanofibers suitable for use not only in TCFs and THs but also in some other engineering applications. The merging of fibers at their intersections (i.e. self-junctioning) minimizes contact resistance in these films. These metallized nanofibers exhibited a remarkably low sheet resistance at a high optical transmittance. This low sheet resistance allows them to serve as low-voltage heaters, achieving a high heating temperature at a relatively low applied voltage. These nanofibers are free-standing, flexible, stretchable, and their mechanical reliability was confirmed through various mechanical endurance tests.

Organic-inorganic hybrid optical foils with strong visible reflection, excellent near infrared-shielding ability and high transparency

Science.gov (United States)

Zhou, Yijie; Huang, Aibin; Zhou, Huaijuan; Ji, Shidong; Jin, Ping

2018-03-01

Research on functional flexible films has recently been attracting widespread attention especially with regards to foils, which can be designed artificially on the basis of the practical requirements. In this work, a foil with high visible reflection and a strong near infrared shielding efficiency was prepared by a simple wet chemical method. In the process of making this kind of optical foil, emulsion polymerization was first introduced to synthesize polymer opals, which were further compressed between two pieces of polyethylene terephthalate (PET) foil under polymer melting temperature to obtain a photonic crystal film with a strong reflection in the visible region to block blue rays. The following step was to coat a layer of the inorganic nano paint, which was synthesized by dispersing Cs-doped WO3 (CWO) nanoparticles homogenously into organic resin on the surface of the PET to achieve a high near infrared shielding ability. The final composite foil exhibited unique optical properties such as high visible reflectance (23.9%) to block blue rays, and excellent near infrared shielding efficiency (98.0%), meanwhile it still maintained a high transparency meaning that this foil could potentially be applied in energy-saving window films. To sum up, this study provides new insight into devising flexible hybrid films with novel optical properties, which could be further extended to prepare other optical films for potential use in automobile, architectural and other decorative fields.

Transparent ‘solution’ of ultrathin magnesium hydroxide nanocrystals for flexible and transparent nanocomposite films

International Nuclear Information System (INIS)

Wang, Jie-Xin; Sun, Qian; Chen, Bo; Zeng, Xiao-Fei; Zhang, Cong; Chen, Jian-Feng; Wu, Xi; Zou, Hai-Kui

2015-01-01

Transparent solutions of nanocrystals exhibit many unique properties, and are thus attractive materials for numerous applications. However, the synthesis of transparent nanocrystal solutions of magnesium hydroxide (MH) with wide applications is yet to be realized. Here, we report a facile two-step process, which includes a direct reactive precipitation in alcohol phase instead of aqueous phase combined with a successive surface modification, to prepare transparent alcohol solutions containing lamellar MH nanocrystals with an average size of 52 nm and an ultrathin thickness of 1–2 nm, which is the thinnest MH nanoplatelet reported in the literatures. Further, highly flexible and transparent nanocomposite films are fabricated with a solution mixing method by adding the transparent MH nanocrystal solutions into PVB solution. Considering the simplicity of the fabrication process, high transparency and good flexibility, this MH/polymer nanocomposite film is promising for flame-resistant applications in plastic electronics and optical devices with high transparency, such as flexible displays, optical filters, and flexible solar cells. (paper)

High mobility transparent conducting oxides for thin film solar cells

International Nuclear Information System (INIS)

Calnan, S.; Tiwari, A.N.

2010-01-01

A special class of transparent conducting oxides (TCO) with high mobility of > 65 cm 2 V -1 s -1 allows film resistivity in the low 10 -4 Ω cm range and a high transparency of > 80% over a wide spectrum, from 300 nm to beyond 1500 nm. This exceptional coincidence of desirable optical and electrical properties provides opportunities to improve the performance of opto-electronic devices and opens possibilities for new applications. Strategies to attain high mobility (HM) TCO materials as well as the current status of such materials based on indium and cadmium containing oxides are presented. Various concepts used to understand the underlying mechanisms for high mobility in HMTCO films are discussed. Examples of HMTCO layers used as transparent electrodes in thin film solar cells are used to illustrate possible improvements in solar cell performance. Finally, challenges and prospects for further development of HMTCO materials are discussed.

Transparent ceramic photo-optical semiconductor high power switches

Science.gov (United States)

Werne, Roger W.; Sullivan, James S.; Landingham, Richard L.

2016-01-19

A photoconductive semiconductor switch according to one embodiment includes a structure of sintered nanoparticles of a high band gap material exhibiting a lower electrical resistance when excited by light relative to an electrical resistance thereof when not exposed to the light. A method according to one embodiment includes creating a mixture comprising particles, at least one dopant, and at least one solvent; adding the mixture to a mold; forming a green structure in the mold; and sintering the green structure to form a transparent ceramic. Additional system, methods and products are also presented.

Physical impairment aware transparent optical networks

Science.gov (United States)

Antona, Jean-Christophe; Morea, Annalisa; Zami, Thierry; Leplingard, Florence

2009-11-01

As illustrated by optical fiber and optical amplification, optical telecommunications have appeared for the last ten years as one of the most promising candidates to increase the transmission capacities. More recently, the concept of optical transparency has been investigated and introduced: it consists of the optical routing of Wavelength Division Multiplexed (WDM) channels without systematic optoelectronic processing at nodes, as long as propagation impairments remain acceptable [1]. This allows achieving less power-consuming, more scalable and flexible networks, and today partial optical transparency has become a reality in deployed systems. However, because of the evolution of traffic features, optical networks are facing new challenges such as demand for higher transmitted capacity, further upgradeability, and more automation. Making all these evolutions compliant on the same current network infrastructure with a minimum of upgrades is one of the main issues for equipment vendors and operators. Hence, an automatic and efficient management of the network needs a control plan aware of the expected Quality of Transmission (QoT) of the connections to set-up with respect to numerous parameters such as: the services demanded by the customers in terms of protection/restoration; the modulation rate and format of the connection under test and also of its adjacent WDM channels; the engineering rules of the network elements traversed with an accurate knowledge of the associated physical impairments. Whatever the method and/or the technology used to collect this information, the issue about its accuracy is one of the main concerns of the network system vendors, because an inaccurate knowledge could yield a sub-optimal dimensioning and so additional costs when installing the network in the field. Previous studies [1], [2] illustrated the impact of this knowledge accuracy on the ability to predict the connection feasibility. After describing usual methods to build

Rapid ILs-polishing Processes Toward Flexible Nanostructured Paper with Dually High Transparency and Haze.

Science.gov (United States)

Ou, Yanghao; Chen, Jinbo; Lu, Pengbo; Cheng, Fan; Lin, Meiyan; Su, Lingfeng; Li, Jun; Liu, Detao

2017-07-31

Biodegradable highly nanostructured paper has received great interest in past years due to its excellent optical properties which facilitate its wide applications in green flexible electronics and devices. However, energy and/or time-consuming procedure during the process of fabricating most nanostructured transparent paper are presently the main obstacle to their scalable production. In this work, we demonstrated a novel nanostructured paper with dually high transparency (∼91%) and high haze (∼89%) that was directly fabricated from original paper with rapid ILs-polishing processes. The whole fabricating time only requires 10 min. Compared to the previously reported nanopaper made of the isolated cellulose nanofibers by pure mechanical and/or chemical approaches, this work presented herein is devoted to use green ILs to polish directly the micrometer-sized fibrous paper into the nanostructured paper. This new method brings a rapid fabrication of transparent nanostructured paper while also retaining dual intriguing properties both in optical transmittance and haze. This work is capable of fabricating next-generation flexible and highly transparent and haze paper by a high-speed roll-to-roll manufacturing process with a much lower cost.

Theoretical Analysis and Design of Ultrathin Broadband Optically Transparent Microwave Metamaterial Absorbers

Science.gov (United States)

Deng, Ruixiang; Li, Meiling; Muneer, Badar; Zhu, Qi; Shi, Zaiying; Song, Lixin; Zhang, Tao

2018-01-01

Optically Transparent Microwave Metamaterial Absorber (OTMMA) is of significant use in both civil and military field. In this paper, equivalent circuit model is adopted as springboard to navigate the design of OTMMA. The physical model and absorption mechanisms of ideal lightweight ultrathin OTMMA are comprehensively researched. Both the theoretical value of equivalent resistance and the quantitative relation between the equivalent inductance and equivalent capacitance are derived for design. Frequency-dependent characteristics of theoretical equivalent resistance are also investigated. Based on these theoretical works, an effective and controllable design approach is proposed. To validate the approach, a wideband OTMMA is designed, fabricated, analyzed and tested. The results reveal that high absorption more than 90% can be achieved in the whole 6~18 GHz band. The fabricated OTMMA also has an optical transparency up to 78% at 600 nm and is much thinner and lighter than its counterparts. PMID:29324686

Theoretical Analysis and Design of Ultrathin Broadband Optically Transparent Microwave Metamaterial Absorbers

Directory of Open Access Journals (Sweden)

Ruixiang Deng

2018-01-01

Full Text Available Optically Transparent Microwave Metamaterial Absorber (OTMMA is of significant use in both civil and military field. In this paper, equivalent circuit model is adopted as springboard to navigate the design of OTMMA. The physical model and absorption mechanisms of ideal lightweight ultrathin OTMMA are comprehensively researched. Both the theoretical value of equivalent resistance and the quantitative relation between the equivalent inductance and equivalent capacitance are derived for design. Frequency-dependent characteristics of theoretical equivalent resistance are also investigated. Based on these theoretical works, an effective and controllable design approach is proposed. To validate the approach, a wideband OTMMA is designed, fabricated, analyzed and tested. The results reveal that high absorption more than 90% can be achieved in the whole 6~18 GHz band. The fabricated OTMMA also has an optical transparency up to 78% at 600 nm and is much thinner and lighter than its counterparts.

Accounting for PMD Temporal Correlation During Lightpath Set Up in Transparent Optical Networks

DEFF Research Database (Denmark)

Sambo, Nicola; Secondini, Marco; Andriolli, Nicola

2010-01-01

stochastic characteristics. Moreover, PMD depends on time-variant factors, such as the temperature and the fiber stress. When implementing a dynamic GMPLS-controlled transparent optical network, the GMPLS protocol suite must take into account physical impairment information in order to establish lightpaths......In transparent optical networks, the signal transmission is degraded by optical layer physical impairments. Therefore, lightpaths may be blocked due to unacceptable quality of transmission (QoT). Among physical impairments, polarization mode dispersion (PMD) is a detrimental effect which has...... that PTC scheme significantly reduces the lightpath blocking probability with respect to the classical scheme. Moreover, PTC demonstrates that, by considering PMD temporal correlation, the transparency domain size can be increased, since paths that would be rejected by a classical model can be actually...

All-optical modulation based on electromagnetically induced transparency

International Nuclear Information System (INIS)

Fountoulakis, Antonios; Terzis, Andreas F.; Paspalakis, Emmanuel

2010-01-01

We numerically investigate the implementation of all-optical absorption modulation of electromagnetic pulses by a medium that exhibits electromagnetically induced transparency. The quantum system is modelled as a three-level Λ-type system that interacts with two electromagnetic pulses, a probe pulse and a coupling pulse. The dynamics of the system is described by the coupled Maxwell-density matrix equations, and we explore the dependence of the optical modulation efficiency on the parameters of the system.

Optical and electrical properties of CuMO2 transparent p-type conductors

Science.gov (United States)

Draeseke, A. D.; Jayaraj, M. K.; Ulbrich, T.; Kroupp, M.; Tate, J.; Nagarajan, R.; Oblezov, A.; Sleight, A. W.

2001-03-01

Wide band gap oxides of the type CuMO2 with the delafossite structure are p-type conductors and many of them are transparent. Films of these p-type oxides have been grown by sputtering and thermal evaporation, and characterized electrically and optically. We present transport and optical transmission measurements for CuY_1-xCa_xO_2, CuScO_2+x and other similar materials. Conductivities are in the range 1 200 S/cm and depend on details of film preparation. The carriers are p-type as determined by thermopower measurements, and typical Seebeck coefficients are several hundred µV/K. Optical transparency varies considerably, but is about 40% at 550 nm for the highest conductivity films. Excellent transparency can be achieved at the expense of conductivity, and optimization is being studied. Band gaps derived from optical transmission are larger than 3.1 eV. Prototype all-oxide pn diodes have been fabricated. This work was partially supported by the NSF under DMR-0071727 and by the Research Corporation under RA0291.

High Temperature Transparent Furnace Development

Science.gov (United States)

Bates, Stephen C.

1997-01-01

This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C.

Isometric multimodal photoacoustic microscopy based on optically transparent micro-ring ultrasonic detection.

Science.gov (United States)

Dong, Biqin; Li, Hao; Zhang, Zhen; Zhang, Kevin; Chen, Siyu; Sun, Cheng; Zhang, Hao F

2015-01-01

Photoacoustic microscopy (PAM) is an attractive imaging tool complementary to established optical microscopic modalities by providing additional molecular specificities through imaging optical absorption contrast. While the development of optical resolution photoacoustic microscopy (ORPAM) offers high lateral resolution, the acoustically-determined axial resolution is limited due to the constraint in ultrasonic detection bandwidth. ORPAM with isometric spatial resolution along both axial and lateral direction is yet to be developed. Although recently developed sophisticated optical illumination and reconstruction methods offer improved axial resolution in ORPAM, the image acquisition procedures are rather complicated, limiting their capabilities for high-speed imaging and being easily integrated with established optical microscopic modalities. Here we report an isometric ORPAM based on an optically transparent micro-ring resonator ultrasonic detector and a commercial inverted microscope platform. Owing to the superior spatial resolution and the ease of integrating our ORPAM with established microscopic modalities, single cell imaging with extrinsic fluorescence staining, intrinsic autofluorescence, and optical absorption can be achieved simultaneously. This technique holds promise to greatly improve the accessibility of PAM to the broader biomedical researchers.

Investigations on magnetic field induced optical transparency in magnetic nanofluids

Science.gov (United States)

Mohapatra, Dillip Kumar; Philip, John

2018-02-01

We study the magnetic field induced optical transparency and its origin in magnetic nanoemulsion of droplets of average size ∼200 nm containing superparamagnetic iron oxide nanoparticles. Beyond a certain volume fraction (Φ > 0.0021) of magnetic nanoemulsion and a critical magnetic field (Hc1), the transmitted light intensity increases drastically and reaches a maximum at another critical magnetic field (Hc2), beyond which the transmitted light intensity decreases and reaches a plateau. Interestingly, the transmitted light intensity at Hc2 is found to increase linearly with Φ and the critical magnetic fields Hc1 and Hc2 follow power law decay with Φ (i.e. Hc ∼ Φ-x), with exponents 0.48 and 0.27, respectively. The light intensity recovers to its initial value when the magnetic field is switched off, indicating the perfect reversibility of the field induced transparency process. The observed straight line scattered patterns above Hc2, on a screen placed perpendicular to the incident beam, confirms the formation of rod like anisotropic nanostructures perpendicular to the direction of light propagation. The magneto-optical measurements in the emulsion confirm that the observed field induced transparency in magnetic emulsions for Φ > 0.0021 is due to the optical birefringence caused by the rod like nanostructures. The reduced birefringence is found to be proportional to the square of the applied magnetic field. This finding offers several possibilities in using magnetic nanofluids in tunable optical devices.

ZnO as dielectric for optically transparent non-volatile memory

International Nuclear Information System (INIS)

Salim, N. Tjitra; Aw, K.C.; Gao, W.; Wright, Bryon E.

2009-01-01

This paper discusses the application of a DC sputtered ZnO thin film as a dielectric in an optically transparent non-volatile memory. The main motivation for using ZnO as a dielectric is due to its optical transparency and mechanical flexibility. We have established the relationship between the electrical resistivity (ρ) and the activation energy (E a ) of the electron transport in the conduction band of the ZnO film. The ρ of 2 x 10 4 -5 x 10 7 Ω-cm corresponds to E a of 0.36-0.76 eV, respectively. The k-value and optical band-gap for films sputtered with Ar:O 2 ratio of 4:1 are 53 ± 3.6 and 3.23 eV, respectively. In this paper, the basic charge storage element for a non-volatile memory is a triple layer dielectric structure in which a 50 nm thick ZnO film is sandwiched between two layers of methyl silsesquioxane sol-gel dielectric of varying thickness. A pronounced clockwise capacitance-voltage (C-V) hysteresis was observed with a memory window of 6 V. The integration with a solution-processable pentacene, 13,6-N-Sulfinylacetamodipentacene resulted in an optically transparent organic field effect transistor non-volatile memory (OFET-NVM). We have demonstrated that this OFET-NVM can be electrically programmed and erased at low voltage (± 10 V) with a threshold voltage shift of 4.0 V.

Cavity electromagnetically induced transparency and all-optical switching using ion Coulomb crystals

DEFF Research Database (Denmark)

Albert, Magnus; Dantan, Aurelien Romain; Drewsen, Michael

2011-01-01

The control of one light field by another, ultimately at the single photon level1, 2, 3, 4, 5, 6, 7, is a challenging task that has numerous interesting applications within nonlinear optics4, 5 and quantum information science6, 7, 8. This type of control can only be achieved through highly...... nonlinear interactions, such as those based on electromagnetic induced transparency (EIT)2, 3, 4, 5, 6, 9, 10, 11, 12. Here, we demonstrate for the first time EIT as well as all-optical EIT-based light switching using ion Coulomb crystals situated in an optical cavity. Changes from essentially full...... milestones for future realizations of quantum information processing devices, such as high-efficiency quantum memories8, 13, 14, single-photon transistors15, 16 and single-photon gates4, 6, 9....

New Ethernet Based Optically Transparent Network for Fiber-to-the-Desk Application

NARCIS (Netherlands)

Radovanovic, Igor; van Etten, Wim

2003-01-01

We present a new optical local area network architecture based on multimode optical fibers and components, short wavelength lasers and detectors and the widely used fast Ethernet protocol. The presented optically transparent network represent a novel approach in fiber-to-the-desk applications. It is

Highly transparent and rollable PVA-co-PE nanofibers synergistically reinforced with epoxy film for flexible electronic devices.

Science.gov (United States)

Xiong, Bing; Zhong, Weibing; Zhu, Qing; Liu, Ke; Li, Mufang; Sun, Gang; Wang, Dong

2017-12-14

The development of electronics towards a more functions-integrated, flexible and stretchable direction requires mechanically flexible substrates with high thermal and dimensional stability and optical transparency. Herein, rolls of an optically transparent PVA-co-PE nanofibrous membrane/epoxy composite with synergistically enhanced thermal stability, very low CTE, and outstanding mechanical properties are reported. The nanoscale size, the unique inter-stack structure, and the strong interfacial interactions between the PVA-co-PE nanofibers and the epoxy contribute to the synergistic effects. Because of the match between the refractive index (RI) of the PVA-co-PE nanofibers and the epoxy matrix, the visible light transmittance of nanocomposite film could be as high as 85% and the composite film was still optically transparent with a nanofiber loading content of up to 61.7 wt%. The break strength and compliance matrix of the composite film with a high fiber loading of 61.7 wt% increased by 2.3 times of that of the neat epoxy film and exceeded 3000 m 2 N -1 , respectively. PVA-co-PE nanofibers have a very low CTE value (3.634 × 10 -6 K -1 ) and could be applicable as a reinforcement to reduce the thermal expansion of epoxy. Furthermore, we developed a flexible alternating current electroluminescent (ACEL) device based on the transparent composite film and the experimental results showed that the transparent composite film could serve as substrate for flexible electronic devices. In addition, their electrical and optical properties were evaluated.

Electrical and optical properties of Zn–In–Sn–O transparent conducting thin films

International Nuclear Information System (INIS)

Carreras, Paz; Antony, Aldrin; Rojas, Fredy; Bertomeu, Joan

2011-01-01

Indium tin oxide (ITO) is one of the widely used transparent conductive oxides (TCO) for application as transparent electrode in thin film silicon solar cells or thin film transistors owing to its low resistivity and high transparency. Nevertheless, indium is a scarce and expensive element and ITO films require high deposition temperature to achieve good electrical and optical properties. On the other hand, although not competing as ITO, doped Zinc Oxide (ZnO) is a promising and cheaper alternative. Therefore, our strategy has been to deposit ITO and ZnO multicomponent thin films at room temperature by radiofrequency (RF) magnetron co-sputtering in order to achieve TCOs with reduced indium content. Thin films of the quaternary system Zn–In–Sn–O (ZITO) with improved electrical and optical properties have been achieved. The samples were deposited by applying different RF powers to ZnO target while keeping a constant RF power to ITO target. This led to ZITO films with zinc content ratio varying between 0 and 67%. The optical, electrical and morphological properties have been thoroughly studied. The film composition was analysed by X-ray Photoelectron Spectroscopy. The films with 17% zinc content ratio showed the lowest resistivity (6.6 × 10 −4 Ω cm) and the highest transmittance (above 80% in the visible range). Though X-ray Diffraction studies showed amorphous nature for the films, using High Resolution Transmission Electron Microscopy we found that the microstructure of the films consisted of nanometric crystals embedded in a compact amorphous matrix. The effect of post deposition annealing on the films in both reducing and oxidizing atmospheres were studied. The changes were found to strongly depend on the zinc content ratio in the films.

Flexible semi-transparent silicon (100) fabric with high-k/metal gate devices

KAUST Repository

Rojas, Jhonathan Prieto; Hussain, Muhammad Mustafa

2013-01-01

(100) wafers and then released as continuous, mechanically flexible, optically semi-transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree

Carbon Nanotube Networks Reinforced by Silver Nanowires with Improved Optical Transparency and Conductivity

Science.gov (United States)

Martine, Patricia; Fakhimi, Azin; Lin, Ling; Jurewicz, Izabela; Dalton, Alan; Zakhidov, Anvar A.; Baughman, Ray H.

2015-03-01

We have fabricated highly transparent and conductive free-standing nanocomposite thin film electrodes by adding silver nanowires (AgNWs) to dry-spun Multiwall Carbon Nanotube (MWNT) aerogels. This nanocomposite exhibits desirable properties such as high optical transmittance, excellent flexibility and enhanced electrical conductivity. The incorporation of the AgNWs to the MWNT aerogels was accomplished by using a spray coating method. The optical transparency and sheet resistance of the nanocomposite was tuned by adjusting the concentration of AgNWs, back pressure and nozzle distance of the spray gun to the MWNT aerogel during deposition. As the solvent evaporated, the aerogel MWNT bundles densified via surface tension which caused the MWNT bundles to collapse. This adjustable process was responsible in forming well defined apertures that increased the nanocomposite's transmittance up to 90 percent. Via AgNWs percolation and random interconnections between separate MWNT bundles in the aerogel matrix, the sheet resistance decreased from 1 K ohm/sq to less than 100 ohm/sq. Alan G. MacDiarmid NanoTech Institute

High-Quality AZO/Au/AZO Sandwich Film with Ultralow Optical Loss and Resistivity for Transparent Flexible Electrodes.

Science.gov (United States)

Zhou, Hua; Xie, Jing; Mai, Manfang; Wang, Jing; Shen, Xiangqian; Wang, Shuying; Zhang, Lihua; Kisslinger, Kim; Wang, Hui-Qiong; Zhang, Jinxing; Li, Yu; Deng, Junhong; Ke, Shanming; Zeng, Xierong

2018-05-09

Transparent flexible electrodes are in ever-growing demand for modern stretchable optoelectronic devices, such as display technologies, solar cells, and smart windows. Such sandwich-film-electrodes deposited on polymer substrates are unattainable because of the low quality of the films, inducing a relatively large optical loss and resistivity as well as a difficulty in elucidating the interference behavior of light. In this article, we report a high-quality AZO/Au/AZO sandwich film with excellent optoelectronic performance, e.g., an average transmittance of about 81.7% (including the substrate contribution) over the visible range, a sheet resistance of 5 Ω/sq, and a figure-of-merit (FoM) factor of ∼55.1. These values are well ahead of those previously reported for sandwich-film-electrodes. Additionally, the interference behaviors of light modulated by the coat and metal layers have been explored with the employment of transmittance spectra and numerical simulations. In particular, a heater device based on an AZO/Au/AZO sandwich film exhibits high performance such as short response time (∼5 s) and uniform temperature field. This work provides a deep insight into the improvement of the film quality of the sandwich electrodes and the design of high-performance transparent flexible devices by the application of a flexible substrate with an atomically smooth surface.

Optical properties of graphene-based materials in transparent polymer matrices

Energy Technology Data Exchange (ETDEWEB)

Bayrak, Osman; Demirci, Emrah, E-mail: E.Demirci@lboro.ac.uk; Silberschmidt, Vadim V. [Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU (United Kingdom); Ionita, Mariana [Advanced Polymer Materials Group, University Politehnica of Bucharest, 132 Calea Grivitei, 010737 Bucharest (Romania)

2016-08-22

Different aspects of graphene-based materials (GBMs) and GBM-nanocomposites have been investigated due to their intriguing features; one of these features is their transparency. Transparency of GBMs has been of an interest to scientists and engineers mainly with regard to electronic devices. In this study, optical transmittance of structural, purpose-made nanocomposites reinforced with GBMs was analyzed to lay a foundation for optical microstructural characterization of nanocomposites in future studies. Two main types of GBM reinforcements were studied, graphene oxide (GO) and graphite nanoplates (GNPs). The nanocomposites investigated are GO/poly(vinyl alcohol), GO/sodium alginate, and GNP/epoxy with different volume fractions of GBMs. Together with UV-visible spectrophotometry, image-processing-assisted micro and macro photography were used to assess the transparency of GBMs embedded in the matrices. The micro and macro photography methods developed were proven to be an alternative way of measuring light transmittance of semi-transparent materials. It was found that there existed a linear relationship between light absorbance and a volume fraction of GBMs embedded in the same type of polymer matrices, provided that the nanocomposites of interest had the same thicknesses. This suggests that the GBM dispersion characteristics in the same type of polymer are similar and any possible change in crystal structure of polymer due to different volumetric contents of GBM does not have an effect on light transmittance of the matrices. The study also showed that the same types of GBMs could display different optical properties in different matrix materials. The results of this study will help to develop practical microstructural characterization techniques for GBM-based nanocomposites.

Bit-rate-transparent optical RZ-to-NRZ format conversion based on linear spectral phase filtering

DEFF Research Database (Denmark)

Maram, Reza; Da Ros, Francesco; Guan, Pengyu

2017-01-01

We propose a novel and strikingly simple design for all-optical bit-rate-transparent RZ-to-NRZ conversion based on optical phase filtering. The proposed concept is experimentally validated through format conversion of a 640 Gbit/s coherent RZ signal to NRZ signal.......We propose a novel and strikingly simple design for all-optical bit-rate-transparent RZ-to-NRZ conversion based on optical phase filtering. The proposed concept is experimentally validated through format conversion of a 640 Gbit/s coherent RZ signal to NRZ signal....

Optical transparency and electrical conductivity of nonstoichiometric ultrathin InxOy films

International Nuclear Information System (INIS)

Joseph, Shay; Berger, Shlomo

2011-01-01

The effect of thickness and composition on the electrical conductivity and optical transparency, mainly in the infrared, of ultrathin In x O y films was studied. In x O y films 35-470 A thick with oxygen atomic fractions of ∼0.3 and ∼0.5 were prepared via dc magnetron sputtering. All films were polycrystalline, consisting of only the cubic bixbiyte phase of In 2 O 3 . The average grain size of the films increased from 30 to 95 nm as the film thickness increased. The weak dependence of the electrical conductivity on the frequency and the low activation energies for conduction, a few hundredths of an eV, provided an indication that free band conduction was the primary electrical conduction mechanism in the case of all ultrathin In x O y films. It was found that introducing a high degree of nonstoichiometry in the form of oxygen deficiency did not help improve the electrical conductivity, since not all vacancies contributed two free electrons for conduction and due to impurity scattering. The optical nature of these films, studied mainly by ellipsometry, was found to be dependent on the film's composition and thickness. In the infrared, the dielectric function of all In x O y films was consistent with the Drude model, inferring that the transparency loss in this region was a result of free charge carriers. In the visible however, In x O y films under 170 A, which had an oxygen atomic fraction of ∼0.5, were modeled by extending the Drude model to the shorter wavelengths. Films over 170 A, with the same composition, were modeled using the Cauchy dispersion model, meaning that no absorption was measured. These results indicate that, optically, under specific compositions, ultrathin In x O y films undergo a transition from metalliclike behavior to dielectric behavior with increasing film thickness. Using a figure of merit approach, it was determined that a nonstoichiometric 230 A thick In x O y film, with an oxygen atomic fraction of ∼0.3, had the best combination

Optical and electrical properties of structured multilayer with tunable transparency rate

International Nuclear Information System (INIS)

Bou, Adrien; Torchio, Philippe; Barakel, Damien; Guillou, Aurélie; Thoulon, Pierre-Yves; Ricci, Marc; Ayachi, Boubakeur

2015-01-01

An experimental study has been carried out on structured multilayer with tunable transparency rate. In this paper, we present the optical and electrical characterization of an oxide | metal | oxide structured electrode manufactured by e-beam deposition and patterned by a lift-off process. The obtained samples are made of grids with different geometrical parameters that lead to varying surface coverage rate on glass. The electrical and optical parameters of SnO x |Ag|SnO x grids are investigated to determine the efficiency, sustainability and limitations of such structures. A linear relationship between the transmittance of the electrodes and the increase of the surface coverage rate is obtained. Coupled to an optimization process, we are able to define a high transparency in a chosen spectral range. Electrical results show a relative stability of the resistivity from 2.9   ×   10   −  4  Ω.cm for an as-grown electrode to 5.6   ×   10   −  4  Ω.cm for a structured electrode with a surface coverage rate of 59%. (paper)

Optically transparent multiple access networks employing incoherent spectral codes

NARCIS (Netherlands)

Huiszoon, B.

2008-01-01

This Ph.D. thesis is divided into 7 chapters to provide the reader an overview of the main results achieved in di®erent sub-topics of the study towards optically transparent multiple access networks employing incoherent spectral codes taking into account wireless transmission aspects. The work

An optically transparent and flexible memory with embedded gold nanoparticles in a polymethylsilsesquioxane dielectric

International Nuclear Information System (INIS)

Ooi, P.C.; Aw, K.C.; Gao, W.; Razak, K.A.

2013-01-01

In this work, we demonstrated a simple fabrication route towards an optically transparent and flexible memory device. The device is simple and consists of a metal/insulator/semiconductor structure; namely MIS. The preliminary MIS study with gold nanoparticles embedded between the polymethylsilsesquioxane layers was fabricated on p-Si substrate and the capacitance versus voltage measurements confirmed the charge trapped capability of the fabricated MIS memory device. Subsequently, an optically transparent and flexible MIS memory device made from indium–tin-oxide coated polyethylene terephthalate substrate and pentacene was used to replace the opaque p-Si substrate as the active layer. Current versus voltage (I–V) plot of the transparent and flexible device shows the presence of hysteresis. In an I–V plot, three distinct regions have been identified and the transport mechanisms are explained. The fabricated optically transparent and mechanically flexible MIS memory device can be programmed and erased multiple times, similar to a flash memory. Mechanical characterization to determine the robustness of the flexible memory device was also conducted but failed to establish any relationship in this preliminary work as the effect was random. Hence, more work is needed to understand the reliability of this device, especially when they are subjected to mechanical stress. - Highlights: ► An optically transparent and mechanically flexible memory is presented. ► Electrical characteristics show reprogrammable memory similar to flash memory. ► Transport mechanisms are proposed and explained. ► Mechanical bending tests are conducted

An optically transparent and flexible memory with embedded gold nanoparticles in a polymethylsilsesquioxane dielectric

Energy Technology Data Exchange (ETDEWEB)

Ooi, P.C. [Mechanical Engineering, The University of Auckland (New Zealand); Aw, K.C., E-mail: k.aw@auckland.ac.nz [Mechanical Engineering, The University of Auckland (New Zealand); Gao, W. [Chemical and Materials Engineering, The University of Auckland (New Zealand); Razak, K.A. [School of Materials and Mineral Resources Engineering, Universiti Sains (Malaysia); NanoBiotechnology Research and Innovation, INFORMM, Universiti Sains (Malaysia)

2013-10-01

In this work, we demonstrated a simple fabrication route towards an optically transparent and flexible memory device. The device is simple and consists of a metal/insulator/semiconductor structure; namely MIS. The preliminary MIS study with gold nanoparticles embedded between the polymethylsilsesquioxane layers was fabricated on p-Si substrate and the capacitance versus voltage measurements confirmed the charge trapped capability of the fabricated MIS memory device. Subsequently, an optically transparent and flexible MIS memory device made from indium–tin-oxide coated polyethylene terephthalate substrate and pentacene was used to replace the opaque p-Si substrate as the active layer. Current versus voltage (I–V) plot of the transparent and flexible device shows the presence of hysteresis. In an I–V plot, three distinct regions have been identified and the transport mechanisms are explained. The fabricated optically transparent and mechanically flexible MIS memory device can be programmed and erased multiple times, similar to a flash memory. Mechanical characterization to determine the robustness of the flexible memory device was also conducted but failed to establish any relationship in this preliminary work as the effect was random. Hence, more work is needed to understand the reliability of this device, especially when they are subjected to mechanical stress. - Highlights: ► An optically transparent and mechanically flexible memory is presented. ► Electrical characteristics show reprogrammable memory similar to flash memory. ► Transport mechanisms are proposed and explained. ► Mechanical bending tests are conducted.

Positron annihilation in transparent ceramics

Science.gov (United States)

Husband, P.; Bartošová, I.; Slugeň, V.; Selim, F. A.

2016-01-01

Transparent ceramics are emerging as excellent candidates for many photonic applications including laser, scintillation and illumination. However achieving perfect transparency is essential in these applications and requires high technology processing and complete understanding for the ceramic microstructure and its effect on the optical properties. Positron annihilation spectroscopy (PAS) is the perfect tool to study porosity and defects. It has been applied to investigate many ceramic structures; and transparent ceramics field may be greatly advanced by applying PAS. In this work positron lifetime (PLT) measurements were carried out in parallel with optical studies on yttrium aluminum garnet transparent ceramics in order to gain an understanding for their structure at the atomic level and its effect on the transparency and light scattering. The study confirmed that PAS can provide useful information on their microstructure and guide the technology of manufacturing and advancing transparent ceramics.

Positron annihilation in transparent ceramics

International Nuclear Information System (INIS)

Husband, P; Selim, F A; Bartošová, I; Slugeň, V

2016-01-01

Transparent ceramics are emerging as excellent candidates for many photonic applications including laser, scintillation and illumination. However achieving perfect transparency is essential in these applications and requires high technology processing and complete understanding for the ceramic microstructure and its effect on the optical properties. Positron annihilation spectroscopy (PAS) is the perfect tool to study porosity and defects. It has been applied to investigate many ceramic structures; and transparent ceramics field may be greatly advanced by applying PAS. In this work positron lifetime (PLT) measurements were carried out in parallel with optical studies on yttrium aluminum garnet transparent ceramics in order to gain an understanding for their structure at the atomic level and its effect on the transparency and light scattering. The study confirmed that PAS can provide useful information on their microstructure and guide the technology of manufacturing and advancing transparent ceramics. (paper)

Flexible transparent aerogels as window retrofitting films and optical elements with tunable birefringence

Energy Technology Data Exchange (ETDEWEB)

Liu, Qingkun; Frazier, Allister W.; Zhao, Xinpeng; De La Cruz, Joshua A.; Hess, Andrew J.; Yang, Ronggui; Smalyukh, Ivan I.

2018-06-01

Experimental realization of optically transparent, mechanically robust and flexible aerogels has been a longstanding challenge, which limits their practical applications in energy-saving devices, such as thermally insulating films for enhancing energy efficiency of windows. The poor transparency precluded even hypothetical consideration of the possibility of birefringent aerogels. We develop birefringent and optically isotropic aerogels that combine properties of thermal super-insulation, mechanical robustness and flexibility, and transparency to visible-spectrum light. This unusual combination of physical properties is achieved by combining liquid crystalline self-organization of cellulose nanofibers with polysiloxane cross-linking and control of the nanoscale porosity to form hybrid organic-inorganic mesostructured aerogels. Potential applications of these inexpensive materials range from single pane window retrofitting to smart fabrics.

Radio-frequency transparent demodulation for broadband hybrid wireless-optical links

DEFF Research Database (Denmark)

Zibar, Darko; Sambaraju, Rakesh; Alemany, Ruben

2010-01-01

A novel demodulation technique which is transparent to radio-frequency (RF) carrier frequency is presented and experimentally demonstrated for multigigabit wireless signals. The presented demodulation technique employs optical single-sideband filtering, coherent detection, and baseband digital si...

The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

International Nuclear Information System (INIS)

Lin, Tien-Chai; Huang, Wen-Chang; Tsai, Fu-Chun

2015-01-01

A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10 −3 Ω −1 with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10 −3 Ω −1 with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure

The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

Energy Technology Data Exchange (ETDEWEB)

Lin, Tien-Chai [Department of Electrical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Huang, Wen-Chang, E-mail: wchuang@mail.ksu.edu.tw [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Tsai, Fu-Chun [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China)

2015-08-31

A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure.

30-Gb/s bidirectional transparent optical transmission with an MMF access and an indoor optical wireless link

NARCIS (Netherlands)

Chen, H.; Boom, van den H.P.A.; Tangdiongga, E.; Koonen, A.M.J.

2012-01-01

This letter describes a 30-Gb/s bidirectional transparent optical transmission, over a 4.4-km multimode fiber (MMF) in combination with an indoor optical wireless (OW) link, which could provide limited mobility. Due to MMF's advantages, such as lower installation costs and easy maintenance, it is

Nanocellulose reinforcement of Transparent Composites

Science.gov (United States)

Joshua Steele; Hong Dong; James F. Snyder; Josh A. Orlicki; Richard S. Reiner; Alan W. Rudie

2012-01-01

In this work, we evaluate the impact of nanocellulose reinforcement on transparent composite properties. Due to the small diameter, high modulus, and high strength of cellulose nanocrystals, transparent composites that utilize these materials should show improvement in bulk mechanical performances without a corresponding reduction in optical properties. In this study...

Electrical and optical performance of transparent conducting oxide films deposited by electrostatic spray assisted vapour deposition.

Science.gov (United States)

Hou, Xianghui; Choy, Kwang-Leong; Liu, Jun-Peng

2011-09-01

Transparent conducting oxide (TCO) films have the remarkable combination of high electrical conductivity and optical transparency. There is always a strong motivation to produce TCO films with good performance at low cost. Electrostatic Spray Assisted Vapor Deposition (ESAVD), as a variant of chemical vapour deposition (CVD), is a non-vacuum and low-cost deposition method. Several types of TCO films have been deposited using ESAVD process, including indium tin oxide (ITO), antimony-doped tin oxide (ATO), and fluorine doped tin oxide (FTO). This paper reports the electrical and optical properties of TCO films produced by ESAVD methods, as well as the effects of post treatment by plasma hydrogenation on these TCO films. The possible mechanisms involved during plasma hydrogenation of TCO films are also discussed. Reduction and etching effect during plasma hydrogenation are the most important factors which determine the optical and electrical performance of TCO films.

Plasmonic transparent conductors

Science.gov (United States)

Liapis, Andreas C.; Sfeir, Matthew Y.; Black, Charles T.

2016-09-01

Many of today's technological applications, such as solar cells, light-emitting diodes, displays, and touch screens, require materials that are simultaneously optically transparent and electrically conducting. Here we explore transparent conductors based on the excitation of surface plasmons in nanostructured metal films. We measure both the optical and electrical properties of films perforated with nanometer-scale features and optimize the design parameters in order to maximize optical transmission without sacrificing electrical conductivity. We demonstrate that plasmonic transparent conductors can out-perform indium tin oxide in terms of both their transparency and their conductivity.

Studies on organic binders with high infrared transparency

International Nuclear Information System (INIS)

Cheng-Wu, Fu; Hao-Shen, Zhou; Ming-Qing, Chen

2009-01-01

This paper reports that two kinds of polymers with high infrared transparency and good mechanical and physical properties have been prepared. An internal standard method is used to evaluate the infrared transparency of the binders. The physical and mechanical properties of the binders are measured according to corresponding standards. The results show the absorbance of polymer A in 8–14 μm range is 26% that of the ethylene-vinyl acetate copolymer (EVA), and polymer B is 9% that of the EVA correspondingly. The film of polymer A shows good flexibility of above 1 mm, a hardness of grade 1, and adhesion of grade 2. The film of polymer B shows good flexibility of above 1 mm, a hardness of grade 1, and adhesion of grade 1. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Highly transparent conductive electrode with ultra-low HAZE by grain boundary modification of aqueous solution fabricated alumina-doped zinc oxide nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Nian, Qiong; Cheng, Gary J. [Birck Nanotechnology Center and School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Callahan, Michael; Bailey, John [Greentech Solutions, Inc., Hanson, Massachusetts 02341 (United States); Look, David [Semiconductor Research Center, Wright State University, Dayton, Ohio 45435 (United States); Efstathiadis, Harry [College of Nanoscale Science and Engineering (CNSE), University of Albany, Albany, New York 12203 (United States)

2015-06-01

Commercial production of transparent conducting oxide (TCO) polycrystalline films requires high electrical conductivity with minimal degradation in optical transparency. Aqueous solution deposited TCO films would reduce production costs of TCO films but suffer from low electrical mobility, which severely degrades both electrical conductivity and optical transparency in the visible spectrum. Here, we demonstrated that grain boundary modification by ultra-violet laser crystallization (UVLC) of solution deposited aluminium-doped zinc oxide (AZO) nanocrystals results in high Hall mobility, with a corresponding dramatic improvement in AZO electrical conductance. The AZO films after laser irradiation exhibit electrical mobility up to 18.1 cm{sup 2} V{sup −1} s{sup −1} with corresponding electrical resistivity and sheet resistances as low as 1 × 10{sup −3} Ω cm and 75 Ω/sq, respectively. The high mobility also enabled a high transmittance (T) of 88%-96% at 550 nm for the UVLC films. In addition, HAZE measurement shows AZO film scattering transmittance as low as 1.8%, which is superior over most other solution deposited transparent electrode alternatives such as silver nanowires. Thus, AZO films produced by the UVLC technique have a combined figure of merit for electrical conductivity, optical transparency, and optical HAZE higher than other solution based deposition techniques and comparable to vacuumed based deposition methods.

Dielectric strength behaviour and mechanical properties of transparent insulation materials suitable to optical monitoring of partial discharges

International Nuclear Information System (INIS)

Lothongkam, Chaiyaporn

2014-01-01

A novel optical detection method for partial discharge in HV/EHV cable terminations has been proposed. Optical sensor fibres integrated into the HV equipment provide high sensitivity as well as immunity to electromagnetic interference and enable therefore on-line monitoring in electromagnetically noisy environment. The availability of optically transparent silicone rubbers that meet strict dielectric and mechanical criteria is a crucial prerequisite for the implementation of this method. The optically transparent silicone rubbers can be applied for the fabrication of a modern rubber stress cone as well as for the development of a new optical sensing element sensitive to PD activities. In this thesis, AC dielectric strength behaviour and mechanical properties of three types of commercially available silicone rubbers were investigated. One of the characterized silicone rubbers was a translucent type whereas the two others were optically transparent types, however with different chemical curing reactions. The measurements of tensile strength and elongation at break were carried out according to the ISO 37 standard. For investigation of the dielectric strength E b behaviour of the virgin and modified silicone rubbers, a new methodology was developed. It is, at the same time, highly reliable and efficient, saves time and reduces material consumption in comparison to previously reported methodologies. The key component of this methodology is a specifically developed test facility. Furthermore, the methodology comprises determinations for easy preparation and handling of high-quality test specimens. This test method provides various advantages over other methods that have previously been used for measurement of the fundamental quantity E b value of silicone rubbers. Both technical and economic demands are satisfied. The new facility also enables cost-effective routine tests in material research laboratories. The high quality of the obtained test results was verified by

Ultra-Thin Optically Transparent Carbon Electrodes Produced from Layers of Adsorbed Proteins

Science.gov (United States)

Alharthi, Sarah A.; Benavidez, Tomas E.; Garcia, Carlos D.

2013-01-01

This work describes a simple, versatile, and inexpensive procedure to prepare optically transparent carbon electrodes, using proteins as precursors. Upon adsorption, the protein-coated substrates were pyrolyzed under reductive conditions (5% H2) to form ultra-thin, conductive electrodes. Because proteins spontaneously adsorb to interfaces forming uniform layers, the proposed method does not require a precise control of the preparation conditions, specialized instrumentation, or expensive precursors. The resulting electrodes were characterized by a combination of electrochemical, optical, and spectroscopic means. As a proof-of-concept, the optically-transparent electrodes were also used as substrate for the development of an electrochemical glucose biosensor. The proposed films represent a convenient alternative to more sophisticated, and less available, carbon-based nanomaterials. Furthermore, these films could be formed on a variety of substrates, without classical limitations of size or shape. PMID:23421732

Low Reflectivity and High Flexibility of Tin-Doped Indium Oxide Nanofiber Transparent Electrodes

KAUST Repository

Wu, Hui

2011-01-12

Tin-doped indium oxide (ITO) has found widespread use in solar cells, displays, and touch screens as a transparent electrode; however, two major problems with ITO remain: high reflectivity (up to 10%) and insufficient flexibility. Together, these problems severely limit the applications of ITO films for future optoelectronic devices. In this communication, we report the fabrication of ITO nanofiber network transparent electrodes. The nanofiber networks show optical reflectivity as low as 5% and high flexibility; the nanofiber networks can be bent to a radius of 2 mm with negligible changes in the sheet resistance. © 2010 American Chemical Society.

Optically transparent glass micro-actuator fabricated by femtosecond laser exposure and chemical etching

NARCIS (Netherlands)

Lenssen, B.L.K.; Bellouard, Y.

2012-01-01

Femtosecond laser manufacturing combined with chemical etching has recently emerged as a flexible platform for fabricating three-dimensional devices and integrated optical elements in glass substrates. Here, we demonstrate an optically transparent micro-actuator fabricated out of a single piece of

Optical pumping-assisted electromagnetically induced transparency

International Nuclear Information System (INIS)

Jiang Wei; Chen Qunfeng; Zhang Yongsheng; Guo, G.-C.

2006-01-01

In this paper we report an observation of the two-photon absorption in a four-level system in hot 87 Rb vapor based on the proposal of Harris and Yamamoto [Phys. Rev. Lett. 81, 3611 (1998)]. We show that this effect is reduced in hot atoms due to the non-Doppler-free nature of this scheme. Then we report a phenomenon that could be used in the same application of Harris and Yamamoto. The main result is a great enhancement of electromagnetically induced transparency (EIT) effect in hot 87 Rb vapor caused by optical pumping. We find that when the single photon detuning is near zero the EIT signal is dramatically enhanced by an optical pumping field. More interestingly when the single photon detuning is larger the signal can be changed from a sharp Raman peak to a sharp EIT dip. The full width at half maximum of the peak and dip are narrow and subnatural

Highly transparent ITO thin films on photosensitive glass: sol-gel synthesis, structure, morphology and optical properties

Energy Technology Data Exchange (ETDEWEB)

Koroesi, Laszlo; Papp, Szilvia; Dekany, Imre [University of Szeged, Supramolecular and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, Szeged (Hungary); Beke, Szabolcs [Italian Institute of Technology, Department of Nanophysics, Genova (Italy); Pecz, Bela; Horvath, Robert; Petrik, Peter; Agocs, Emil [Research Institute for Technical Physics and Materials Science, Budapest (Hungary)

2012-05-15

Conductive and highly transparent indium tin oxide (ITO) thin films were prepared on photosensitive glass substrates by the combination of sol-gel and spin-coating techniques. First, the substrates were coated with amorphous Sn-doped indium hydroxide, and these amorphous films were then calcined at 550 {sup circle} C to produce crystalline and electrically conductive ITO layers. The resulting thin films were characterized by means of scanning electron microscopy, UV-Vis spectroscopy, X-ray photoelectron spectroscopy and spectroscopic ellipsometry. The measurements revealed that the ITO films were composed of spherical crystallites around 20 nm in size with mainly cubic crystal structure. The ITO films acted as antireflection coatings increasing the transparency of the coated substrates compared to that of the bare supports. The developed ITO films with a thickness of {proportional_to}170-330 nm were highly transparent in the visible spectrum with sheet resistances of 4.0-13.7 k{omega}/sq. By coating photosensitive glass with ITO films, our results open up new perspectives in micro- and nano-technology, for example in fabricating conductive and highly transparent 3D microreactors. (orig.)

TRANSPARENT CONCRETE

OpenAIRE

Sandeep Sharma*, Dr. O.P. Reddy

2017-01-01

Transparent concrete is the new type of concrete introduced in todays world which carries special property of light transmitting due to presence of light Optical fibres. Which is also known as translucent concrete or light transmitting concrete, it is achieved by replacing coarse aggregates with transparent alternate materials (Optical fibres). The binding material in transparent concrete may be able to transmit light by using clear resins the concrete mix. The concrete used in industry in pr...

Optically transparent boron-doped nanocrystalline diamond films for spectroelectrochemical measurements on different substrates

International Nuclear Information System (INIS)

Sobaszek, M.; Bogdanowicz, R.; Pluciński, J.; Siuzdak, K.; Skowroński, Ł.

2016-01-01

Fabrication process of optically transparent boron nanocrystalline diamond (B- NCD) electrode on silicon and quartz substrate was shown. The B-NCD films were deposited on the substrates using Microwave Plasma Assisted Chemical Vapor Deposition (MWPACVD) at glass substrate temperature of 475 °C. A homogenous, continuous and polycrystalline surface morphology with high sp 3 content in B-NCD films and film thickness depending from substrate in the range of 60-300 nm was obtained. The high refraction index and transparency in visible (VIS) wavelength range was achieved. Moreover, cyclic voltammograms (CV) were recorded to determine reaction reversibility at the B-NCD electrode. CV measurements in aqueous media consisting of 1 mM K 3 [Fe(CN) 6 ] in 0.5 M Na 2 SO 4 demonstrated relatively fast kinetics expressed by a redox peak splitting below 503 mV for B-NCD/silicon and 110 mv for B-NCD/quartz

Experimental realization of an on-chip all-optical analogue to electromagnetically induced transparency.

Science.gov (United States)

Xu, Qianfan; Sandhu, Sunil; Povinelli, Michelle L; Shakya, Jagat; Fan, Shanhui; Lipson, Michal

2006-03-31

We provide the first experimental observation of structure tuning of the electromagnetically induced transparency-like spectrum in integrated on-chip optical resonator systems. The system consists of coupled silicon ring resonators with 10 microm diameter on silicon, where the coherent interference between the two coupled resonators is tuned. We measured a transparency-resonance mode with a quality factor of 11,800.

Lignin-Retaining Transparent Wood.

Science.gov (United States)

Li, Yuanyuan; Fu, Qiliang; Rojas, Ramiro; Yan, Min; Lawoko, Martin; Berglund, Lars

2017-09-11

Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt % of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80 wt % of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83 %, haze of 75 %, thermal conductivity of 0.23 W mK -1 , and work-tofracture of 1.2 MJ m -3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Development of high-index optical coating for security holograms

Science.gov (United States)

Ahmed, Nadir A. G.

2000-10-01

Over the past few years security holograms have grown into a complex business to prevent counterfeiting of security cards, banknotes and the like. Rapid advances in holographic technology have led to a growing requirement for optical materials and coating methods to produce such holograms at reasonable costs. These materials have specific refractive indices and are used to fabricate semi- transparent holograms. The present paper describes a coating process to deposit optical coating on flexible films inside a vacuum web metallizer for the production of high quality semi-transparent holograms.

Optically Transparent Thin-Film Electrode Chip for Spectroelectrochemical Sensing

Energy Technology Data Exchange (ETDEWEB)

Branch, Shirmir D.; Lines, Amanda M.; Lynch, John A.; Bello, Job M.; Heineman, William R.; Bryan, Samuel A.

2017-07-03

The electrochemical and spectroelectrochemical applications of an optically transparent thin film electrode chip are investigated. The working electrode is composed of indium tin oxide (ITO); the counter and quasi-reference electrodes are composed of platinum. The stability of the platinum quasi-reference electrode is modified by coating it with a planar, solid state Ag/AgCl layer. The Ag/AgCl reference is characterized with scanning electron microscopy and energy-dispersive X-ray spectroscopy. Open circuit potential measurements indicate that the potential of the planar Ag/AgCl electrode varies a maximum of 20 mV over four days. Cyclic voltammetry measurements show that the electrode chip is comparable to a standard electrochemical cell. Randles-Sevcik analysis of 10 mM K3[Fe(CN)6] in 0.1 M KCl using the electrode chip shows a diffusion coefficient of 1.59 × 10-6 cm2/s, in comparison to the standard electrochemical cell value of 2.38 × 10-6 cm2/s. By using the electrode chip in an optically transparent thin layer electrode (OTTLE), the spectroelectrochemical modulation of [Ru(bpy)3]2+ florescence was demonstrated, achieving a detection limit of 36 nM.

Diamond x-ray optics: Transparent, resilient, high-resolution, and wavefront preserving

International Nuclear Information System (INIS)

Shvyd’ko, Yuri; Blank, Vladimir; Terentyev, Sergey

2017-01-01

Diamond features a unique combination of outstanding physical properties perfect for numerous x-ray optics applications, where traditional materials such as silicon fail to perform. In the last two decades, impressive progress has been achieved in synthesizing diamond with high crystalline perfection, in manufacturing efficient, resilient, high-resolution, wavefront-preserving diamond optical components, and in implementing them in cutting-edge x-ray instruments. Diamond optics are essential for tailoring x-rays to the most challenging needs of x-ray research. Furthermore, they are becoming vital for the generation of fully coherent hard x-rays by seeded x-ray free-electron lasers. In this article, we review progress in manufacturing flawless diamond crystal components and their applications in diverse x-ray optical devices, such as x-ray monochromators, beam splitters, high-reflectance backscattering mirrors, lenses, phase plates, diffraction gratings, bent-crystal spectrographs, and windows.

Highly Stretchable and Transparent Microfluidic Strain Sensors for Monitoring Human Body Motions.

Science.gov (United States)

Yoon, Sun Geun; Koo, Hyung-Jun; Chang, Suk Tai

2015-12-16

We report a new class of simple microfluidic strain sensors with high stretchability, transparency, sensitivity, and long-term stability with no considerable hysteresis and a fast response to various deformations by combining the merits of microfluidic techniques and ionic liquids. The high optical transparency of the strain sensors was achieved by introducing refractive-index matched ionic liquids into microfluidic networks or channels embedded in an elastomeric matrix. The microfluidic strain sensors offer the outstanding sensor performance under a variety of deformations induced by stretching, bending, pressing, and twisting of the microfluidic strain sensors. The principle of our microfluidic strain sensor is explained by a theoretical model based on the elastic channel deformation. In order to demonstrate its capability of practical usage, the simple-structured microfluidic strain sensors were performed onto a finger, wrist, and arm. The highly stretchable and transparent microfluidic strain sensors were successfully applied as potential platforms for distinctively monitoring a wide range of human body motions in real time. Our novel microfluidic strain sensors show great promise for making future stretchable electronic devices.

Poisson-Spot Intensity Reduction with a Partially-Transparent Petal-Shaped Optical Mask

Science.gov (United States)

Shiri, Shahram; Wasylkiwskyj, Wasyl

2013-01-01

The presence of Poisson's spot, also known as the spot of Arago, formed along the optical axis in the geometrical shadow behind an obstruction, has been known since the 18th century. The presence of this spot can best be described as the consequence of constructive interference of light waves diffracted on the edge of the obstruction where its central position can··be determined by the symmetry of the object More recently, the elimination of this spot has received attention in the fields of particle physics, high-energy lasers, astronomy and lithography. In this paper, we introduce a novel, partially transparent petaled mask shape that suppresses the bright spot by up to 10 orders of magnitude in intensity, with powerful applications to many of the above fields. The optimization technique formulated in this design can identify mask shapes having partial transparency only near the petal tips.

Transparent silicon strip sensors for the optical alignment of particle detector systems

International Nuclear Information System (INIS)

Blum, W.; Kroha, H.; Widmann, P.

1995-05-01

Modern large-area precision tracking detectors require increasing accuracy for the alignment of their components. A novel multi-point laser alignment system has been developed for such applications. The position of detector components with respect to reference laser beams is monitored by semi-transparent optical position sensors which work on the principle of silicon strip photodiodes. Two types of custom designed transparent strip sensors, based on crystalline and on amorphous silicon as active material, have been studied. The sensors are optimised for the typical diameters of collimated laser beams of 3-5 mm over distances of 10-20 m. They provide very high position resolution, on the order of 1 μm, uniformly over a wide measurement range of several centimeters. The preparation of the sensor surfaces requires special attention in order to achieve high light transmittance and minimum distortion of the traversing laser beams. At selected wavelengths, produced by laser diodes, transmission rates above 90% have been achieved. This allows to position more than 30 sensors along one laser beam. The sensors will be equipped with custom designed integrated readout electronics. (orig.)

Manufacturing process scale-up of optical grade transparent spinel ceramic at ArmorLine Corporation

Science.gov (United States)

Spilman, Joseph; Voyles, John; Nick, Joseph; Shaffer, Lawrence

2013-06-01

While transparent Spinel ceramic's mechanical and optical characteristics are ideal for many Ultraviolet (UV), visible, Short-Wave Infrared (SWIR), Mid-Wave Infrared (MWIR), and multispectral sensor window applications, commercial adoption of the material has been hampered because the material has historically been available in relatively small sizes (one square foot per window or less), low volumes, unreliable supply, and with unreliable quality. Recent efforts, most notably by Technology Assessment and Transfer (TA and T), have scaled-up manufacturing processes and demonstrated the capability to produce larger windows on the order of two square feet, but with limited output not suitable for production type programs. ArmorLine Corporation licensed the hot-pressed Spinel manufacturing know-how of TA and T in 2009 with the goal of building the world's first dedicated full-scale Spinel production facility, enabling the supply of a reliable and sufficient volume of large Transparent Armor and Optical Grade Spinel plates. With over $20 million of private investment by J.F. Lehman and Company, ArmorLine has installed and commissioned the largest vacuum hot press in the world, the largest high-temperature/high-pressure hot isostatic press in the world, and supporting manufacturing processes within 75,000 square feet of manufacturing space. ArmorLine's equipment is capable of producing window blanks as large as 50" x 30" and the facility is capable of producing substantial volumes of material with its Lean configuration and 24/7 operation. Initial production capability was achieved in 2012. ArmorLine will discuss the challenges that were encountered during scale-up of the manufacturing processes, ArmorLine Optical Grade Spinel optical performance, and provide an overview of the facility and its capabilities.

Transparent bulk-size nanocomposites with high inorganic loading

International Nuclear Information System (INIS)

Chen, Shi; Gaume, Romain

2015-01-01

With relatively high nanoparticle loading in polymer matrices, hybrid nanocomposites made by colloidal dispersion routes suffer from severe inhomogeneous agglomeration, a phenomenon that deteriorates light transmission even when the refractive indices of the inorganic and organic phases are closely matched. The dispersion of particles in a matrix is of paramount importance to obtain composites of high optical quality. Here, we describe an innovative, yet straightforward method to fabricate monolithic transparent hybrid nanocomposites with very high particle loading and high refractive index mismatch tolerance between the inorganic and organic constituents. We demonstrate 77% transmission at 800 nm in a 2 mm-thick acrylate polymer nanocomposite containing 61 vol. % CaF 2 nanoparticles. Modeling shows that similar performance could easily be obtained with various inorganic phases relevant to a number of photonic applications

A high-response transparent heater based on a CuS nanosheet film with superior mechanical flexibility and chemical stability.

Science.gov (United States)

Xie, Shuyao; Li, Teng; Xu, Zijie; Wang, Yanan; Liu, Xiangyang; Guo, Wenxi

2018-04-05

Transparent heaters are widely used in technologies such as window defrosting/defogging, displays, gas sensing, and medical equipment. Apart from mechanical robustness and electrical and optical reliabilities, outstanding chemical stability is also critical to the application of transparent heaters. In this regard, we first present a highly flexible and large-area CuS transparent heater fabricated by a colloidal crackle pattern method with an optimized sheet resistance (Rs) as low as 21.5 Ω sq-1 at a ∼80% transmittance. The CuS transparent heater exhibits remarkable mechanical robustness during bending tests as well as high chemical stability against acid and alkali environments. In the application as a transparent heater, the CuS heater demonstrates a high thermal resistance of 197 °C W-1 cm2 with a fast switching time (solar panels. These CuS network TCEs with high flexibility, transparency, conductivity, and chemical stability could be widely used in wearable electronic products.

Copercolating Networks: An Approach for Realizing High-Performance Transparent Conductors using Multicomponent Nanostructured Networks

Directory of Open Access Journals (Sweden)

Das Suprem R.

2016-06-01

Full Text Available Although transparent conductive oxides such as indium tin oxide (ITO are widely employed as transparent conducting electrodes (TCEs for applications such as touch screens and displays, new nanostructured TCEs are of interest for future applications, including emerging transparent and flexible electronics. A number of twodimensional networks of nanostructured elements have been reported, including metallic nanowire networks consisting of silver nanowires, metallic carbon nanotubes (m-CNTs, copper nanowires or gold nanowires, and metallic mesh structures. In these single-component systems, it has generally been difficult to achieve sheet resistances that are comparable to ITO at a given broadband optical transparency. A relatively new third category of TCEs consisting of networks of 1D-1D and 1D-2D nanocomposites (such as silver nanowires and CNTs, silver nanowires and polycrystalline graphene, silver nanowires and reduced graphene oxide have demonstrated TCE performance comparable to, or better than, ITO. In such hybrid networks, copercolation between the two components can lead to relatively low sheet resistances at nanowire densities corresponding to high optical transmittance. This review provides an overview of reported hybrid networks, including a comparison of the performance regimes achievable with those of ITO and single-component nanostructured networks. The performance is compared to that expected from bulk thin films and analyzed in terms of the copercolation model. In addition, performance characteristics relevant for flexible and transparent applications are discussed. The new TCEs are promising, but significant work must be done to ensure earth abundance, stability, and reliability so that they can eventually replace traditional ITO-based transparent conductors.

Synthesis and characterization of optically transparent epoxy matrix nanocomposites

International Nuclear Information System (INIS)

Esposito Corcione, C.; Manera, M.G.; Maffezzoli, A.; Rella, R.

2009-01-01

In this work optically transparent nanocomposites were prepared and characterized from an optical and morphological point of view. An organically modified boehmite was added at different concentrations in a diglycidyl ether of bisphenol A (DGEBA) epoxy matrix, hardened with a polyether diamine. Nanocomposites were characterized structurally by X-ray diffraction (XRD), optically by UV-Vis-NIR spectrophotometry and their morphology was investigated by Atomic Force Microscopy (AFM). Morphological investigation reveals the presence of boehmite particles dispersed in the epoxy matrix in different dimensions ranging from ten to hundreds of nanometers; some aggregation in the particles is the tendency noticed in the AFM images. The acquisition of multiple AFM images in different areas of the sample was used for a statistical analysis of the volumetric distribution of boehmite aggregates. The obtained result, (3.6 ± 0.3)%vol, is well comparable to thermogravimetric analysis.

Realization of ultrathin silver layers in highly conductive and transparent zinc tin oxide/silver/zinc tin oxide multilayer electrodes deposited at room temperature for transparent organic devices

Energy Technology Data Exchange (ETDEWEB)

Winkler, Thomas; Schmidt, Hans; Fluegge, Harald; Nikolayzik, Fabian; Baumann, Ihno; Schmale, Stephan; Johannes, Hans-Hermann; Rabe, Torsten [Institut fuer Hochfrequenztechnik, Technische Universitaet Braunschweig, Schleinitzstr. 22, 38106 Braunschweig (Germany); Hamwi, Sami, E-mail: sami.hamwi@ihf.tu-bs.de [Institut fuer Hochfrequenztechnik, Technische Universitaet Braunschweig, Schleinitzstr. 22, 38106 Braunschweig (Germany); Riedl, Thomas [Institute of Electronic Devices, Bergische Universitaet Wuppertal, Rainer-Gruenter Str. 21, 42119 Wuppertal (Germany); Kowalsky, Wolfgang [Institut fuer Hochfrequenztechnik, Technische Universitaet Braunschweig, Schleinitzstr. 22, 38106 Braunschweig (Germany)

2012-05-01

We report on transparent and highly conductive multilayer electrodes prepared at room temperature by RF sputtering of zinc tin oxide (ZTO) and thermal evaporation of ultrathin silver (Ag) as top contact for transparent organic light emitting diodes (TOLED). Specifically, we study the morphological, electrical and optical properties of the multilayer structure in particular of the thin Ag film. The tendency of Ag to form agglomerates over time on top of ZTO is shown by atomic force microscopy. From the optical constants derived from ellipsometric measurements we evidenced a bulk like behavior of an Ag film with a thickness of 8 nm embedded in ZTO leading to a low sheet resistance of 9 {Omega}/sq. Furthermore we verify the optical constants by simulation of an optimized ZTO/Ag/ZTO structure. As an application we present a highly efficient TOLED providing a device transmittance of > 82% in the visible part of the spectrum. The TOLED shows no damage caused by sputtering on a lighting area of 80 mm{sup 2} and exhibits efficiencies of 43 cd/A and 36 lm/W.

A highly crystalline single Au wire network as a high temperature transparent heater

Science.gov (United States)

Rao, K. D. M.; Kulkarni, Giridhar U.

2014-05-01

A transparent conductor which can generate high temperatures finds important applications in optoelectronics. In this article, a wire network made of Au on quartz is shown to serve as an effective high temperature transparent heater. The heater has been fabricated by depositing Au onto a cracked sacrificial template. The highly interconnected Au wire network thus formed exhibited a transmittance of ~87% in a wide spectral range with a sheet resistance of 5.4 Ω □-1. By passing current through the network, it could be joule heated to ~600 °C within a few seconds. The extraordinary thermal performance and stability owe much to the seamless junctions present in the wire network. Furthermore, the wire network gets self-annealed through joule heating as seen from its increased crystallinity. Interestingly, both transmittance and sheet resistance improved following annealing to 92% and 3.2 Ω □-1, respectively. A transparent conductor which can generate high temperatures finds important applications in optoelectronics. In this article, a wire network made of Au on quartz is shown to serve as an effective high temperature transparent heater. The heater has been fabricated by depositing Au onto a cracked sacrificial template. The highly interconnected Au wire network thus formed exhibited a transmittance of ~87% in a wide spectral range with a sheet resistance of 5.4 Ω □-1. By passing current through the network, it could be joule heated to ~600 °C within a few seconds. The extraordinary thermal performance and stability owe much to the seamless junctions present in the wire network. Furthermore, the wire network gets self-annealed through joule heating as seen from its increased crystallinity. Interestingly, both transmittance and sheet resistance improved following annealing to 92% and 3.2 Ω □-1, respectively. Electronic supplementary information (ESI) available: Optical micrographs, EDAX, XRD, SEM and TEM images of Au metal wires. See DOI: 10.1039/c4nr00869c

Transparent Ferroelectric Capacitors on Glass

Directory of Open Access Journals (Sweden)

Daniele Sette

2017-10-01

Full Text Available We deposited transparent ferroelectric lead zirconate titanate thin films on fused silica and contacted them via Al-doped zinc oxide (AZO transparent electrodes with an interdigitated electrode (IDE design. These layers, together with a TiO2 buffer layer on the fused silica substrate, are highly transparent (>60% in the visible optical range. Fully crystallized Pb(Zr0.52Ti0.48O3 (PZT films are dielectrically functional and exhibit a typical ferroelectric polarization loop with a remanent polarization of 15 μC/cm2. The permittivity value of 650, obtained with IDE AZO electrodes is equivalent to the one measured with Pt electrodes patterned with the same design, which proves the high quality of the developed transparent structures.

Secured Optical Communications Using Quantum Entangled Two-Photon Transparency Modulation

Science.gov (United States)

Kojima, Jun (Inventor); Nguyen, Quang-Viet (Inventor); Lekki, John (Inventor)

2015-01-01

A system and method is disclosed wherein optical signals are coded in a transmitter by tuning or modulating the interbeam delay time (which modulates the fourth-order coherence) between pairs of entangled photons. The photon pairs are either absorbed or not absorbed (transparent) by an atomic or molecular fluorescer in a receiver, depending on the inter-beam delay that is introduced in the entangled photon pairs. Upon the absorption, corresponding fluorescent optical emissions follow at a certain wavelength, which are then detected by a photon detector. The advantage of the disclosed system is that it eliminates a need of a coincidence counter to realize the entanglement-based secure optical communications because the absorber acts as a coincidence counter for entangled photon pairs.

A Facile Way to Fabricate Transparent Superhydrophobic Surfaces.

Science.gov (United States)

Shi, Wentao; He, Ran; Yunus, Doruk E; Yang, Jie; Liu, Yaling

2018-07-01

A fast, easy, and low-cost way to fabricate transparent superhydrophobic (SHP) surfaces is developed. By simply mixing silica nanoparticles (SiNPs), polydimethylsiloxane (PDMS) and heptane to form a suspension, dip- or drop-coating the suspension onto different surfaces, transparent SHP surfaces can be obtained. By tuning the ratio of the three components above, transparency of the coating can reach more than 90% transmittance in the visible region, while static water contact angle of the coating can reach as high as 162°. Dynamic contact angle study shows the advancing contact angle and receding contact angle of water can be as high as 168° and 161°, and the resulting contact angle hysteresis can be as low as 7°. The reported facile way of fabricating transparent superhydrophobic (SHP) surfaces is potential for applications which need both optical transparency and self-cleaning capability, such as solar cells, optical equipment, and visible microfluidic chips.

Optically transparent ZnO-based n-i-p ultraviolet photodetectors

International Nuclear Information System (INIS)

Wang, Kai; Vygranenko, Yuriy; Nathan, Arokia

2007-01-01

An optically transparent tin-doped indium oxide/ZnO/NiO n-i-p heterostructure photodiode was fabricated by ion beam assisted e-beam evaporation. The diode clearly demonstrates rectifying current-voltage (J-V) characteristics with a current rectification ratio up to 10 4 at bias ± 2 V and a low reverse current of ∼ 100 nA/cm 2 at - 5 V. Analysis of J-V characteristics including time dependence of the dark current shows that the leakage current at low biases is attributed to thermal generation via defect states, and at high biases, field-enhanced carrier generation from the ZnO layer dominates. Spectral response and linearity measurements indicate that such a diode is particularly suitable for low level of ultraviolet detection

Enhancement of absorption and color contrast in ultra-thin highly absorbing optical coatings

Science.gov (United States)

Kats, Mikhail A.; Byrnes, Steven J.; Blanchard, Romain; Kolle, Mathias; Genevet, Patrice; Aizenberg, Joanna; Capasso, Federico

2013-09-01

Recently a new class of optical interference coatings was introduced which comprises ultra-thin, highly absorbing dielectric layers on metal substrates. We show that these lossy coatings can be augmented by an additional transparent subwavelength layer. We fabricated a sample comprising a gold substrate, an ultra-thin film of germanium with a thickness gradient, and several alumina films. The experimental reflectivity spectra showed that the additional alumina layer increases the color range that can be obtained, in agreement with calculations. More generally, this transparent layer can be used to enhance optical absorption, protect against erosion, or as a transparent electrode for optoelectronic devices.

Color transparency

International Nuclear Information System (INIS)

Miller, G.A.

1993-01-01

Imagine shooting a beam of protons of high momentum P through an atomic nucleus. Usually the nuclear interactions prevent the particles from emerging with momentum ∼P. Further, the angular distribution of elastically scattered protons is close to the optical diffraction pattern produced by a black disk. Thus the nucleus acts as a black disk and is not transparent. However, certain high momentum transfer reactions in which a proton is knocked out of the nucleus may be completely different. Suppose that the high momentum transfer process leads to the formation of a small-size color singlet wavepacket that is ejected from the nucleus. The effects of gluons emitted by color singlet systems of closely separated quarks and gluons tend to cancel. Thus the wavepacket-nuclear interactions are suppressed, the nucleus becomes transparant and one says that color transparency CT occurs. The observation of CT also requires that the wavepacket not expand very much while it moves through the nucleus. Simple quantum mechanical formulations can assess this expansion. The creation of a small-sized wavepacket is expected in asymptotic perturbative effects. The author reviews the few experimental attempts to observe color transparency in nuclear (e,e'p) and (p,pp) reactions and interpret the data and their implications

Synthesis and properties of regenerated cellulose-based hydrogels with high strength and transparency for potential use as an ocular bandage

International Nuclear Information System (INIS)

Patchan, M.; Graham, J.L.; Xia, Z.; Maranchi, J.P.; McCally, R.; Schein, O.; Elisseeff, J.H.; Trexler, M.M.

2013-01-01

Cellulose is a biologically derived material with excellent wound-healing properties. The high strength of cellulose fibers and the ability to synthesize gels with high optical transparency make these materials suitable for ocular applications. In this study, cellulose materials derived from wood pulp, cotton, and bacterial sources were dissolved in lithium chloride/N,N-dimethylacetamide to form regenerated cellulose hydrogels. Material properties of the resulting hydrogels, including water content, optical transparency, and tensile and tear strengths, were evaluated. Synthesis parameters, including activation time, dissolution time, relative humidity, and cellulose concentration, were found to impact the material properties of the resulting hydrogels. Overnight activation time improves the optical transparency of the hydrogels from 77% to 97% at 550 nm, whereas controlling cellulose concentration improves their tear strength by as much as 200%. On the basis of the measured transmittance and strength values of the regenerated hydrogels prepared via the optimized synthesis parameters, Avicel PH 101, Sigma-Aldrich microcrystalline cellulose 435236, and bacterial cellulose types were prioritized for future biocompatibility testing and potential clinical investigation. - Highlights: • Hydrogels were prepared (via LiCl/DMAc) from 7 different types of cellulose. • Synthesis parameters (activation, gelation, and concentration) were optimized. • Impact of synthesis parameters on transparency and strength was explored

Synthesis and properties of regenerated cellulose-based hydrogels with high strength and transparency for potential use as an ocular bandage

Energy Technology Data Exchange (ETDEWEB)

Patchan, M. [Research and Exploratory Development Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Graham, J.L. [Department of Biomedical Engineering, Johns Hopkins University, School of Medicine, 720 Rutland Avenue/Ross 720, Baltimore, MD 21205 (United States); Xia, Z.; Maranchi, J.P. [Research and Exploratory Development Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); McCally, R. [Research and Exploratory Development Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Wilmer Eye Institute, Johns Hopkins Medical Institutions, 600 N. Wolfe Street, Baltimore, MD 21287 (United States); Schein, O. [Wilmer Eye Institute, Johns Hopkins Medical Institutions, 600 N. Wolfe Street, Baltimore, MD 21287 (United States); Elisseeff, J.H. [Department of Biomedical Engineering, Johns Hopkins University, School of Medicine, 720 Rutland Avenue/Ross 720, Baltimore, MD 21205 (United States); Trexler, M.M., E-mail: morgana.trexler@jhuapl.edu [Research and Exploratory Development Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States)

2013-07-01

Cellulose is a biologically derived material with excellent wound-healing properties. The high strength of cellulose fibers and the ability to synthesize gels with high optical transparency make these materials suitable for ocular applications. In this study, cellulose materials derived from wood pulp, cotton, and bacterial sources were dissolved in lithium chloride/N,N-dimethylacetamide to form regenerated cellulose hydrogels. Material properties of the resulting hydrogels, including water content, optical transparency, and tensile and tear strengths, were evaluated. Synthesis parameters, including activation time, dissolution time, relative humidity, and cellulose concentration, were found to impact the material properties of the resulting hydrogels. Overnight activation time improves the optical transparency of the hydrogels from 77% to 97% at 550 nm, whereas controlling cellulose concentration improves their tear strength by as much as 200%. On the basis of the measured transmittance and strength values of the regenerated hydrogels prepared via the optimized synthesis parameters, Avicel PH 101, Sigma-Aldrich microcrystalline cellulose 435236, and bacterial cellulose types were prioritized for future biocompatibility testing and potential clinical investigation. - Highlights: • Hydrogels were prepared (via LiCl/DMAc) from 7 different types of cellulose. • Synthesis parameters (activation, gelation, and concentration) were optimized. • Impact of synthesis parameters on transparency and strength was explored.

Ultra-high-frequency microwave response from flexible transparent Au electromagnetic metamaterial nanopatterned antenna

Science.gov (United States)

Liu, Dingxin; Niu, Jiebin; Zhu, Haolin; Zhang, Jianyong

2018-02-01

Flexible transparent materials are a hot spot in current research but also a key technical difficulty in industry. They are playing an increasingly important role in flexible transparent display applications such as organic light-emitting diodes, transparent electrodes, and so on. On the other hand, the present research on nanopatterned antennas is mainly concentrated on the optical frequency but rarely on the microwave (such as 3G, 4G, and 5G) and terahertz frequency band communications, where nanopatterned antennas can have many novel applications. To the authors’ knowledge, this is the first paper that presents a method for preparing a flexible transparent Au electromagnetic metamaterial nanopatterned antenna. We study its free-space performance at ultra-high frequency and its application in electronic products such as smartphones, tablets, personal computers, and wearable devices (such as smart watches) which have the function of mobile communication. The experimental results showed that the transparency of the antenna designed and fabricated in this work can be as high as 94%, and its efficiency can reach 74.5%-91.9% of antennas commonly seen at present in academia and industry. By adjusting the capacitive and inductive reactance of the nanopatterned antenna’s matching circuit, combined with its measured efficiency and 3D electromagnetic simulation results, we speculate on the mechanism of the Au electromagnetic metamaterial nanopatterned antenna with good performance.

Transparent, flexible, and solid-state supercapacitors based on graphene electrodes

Science.gov (United States)

Gao, Y.; Zhou, Y. S.; Xiong, W.; Jiang, L. J.; Mahjouri-samani, M.; Thirugnanam, P.; Huang, X.; Wang, M. M.; Jiang, L.; Lu, Y. F.

2013-07-01

In this study, graphene-based supercapacitors with optical transparency and mechanical flexibility have been achieved using a combination of poly(vinyl alcohol)/phosphoric acid gel electrolyte and graphene electrodes. An optical transmittance of ˜67% in a wavelength range of 500-800 nm and a 92.4% remnant capacitance under a bending angle of 80° have been achieved for the supercapacitors. The decrease in capacitance under bending is ascribed to the buckling of the graphene electrode in compression. The supercapacitors with high optical transparency, electrochemical stability, and mechanical flexibility hold promises for transparent and flexible electronics.

Transparent, flexible, and solid-state supercapacitors based on graphene electrodes

Directory of Open Access Journals (Sweden)

Y. Gao

2013-07-01

Full Text Available In this study, graphene-based supercapacitors with optical transparency and mechanical flexibility have been achieved using a combination of poly(vinyl alcohol/phosphoric acid gel electrolyte and graphene electrodes. An optical transmittance of ∼67% in a wavelength range of 500-800 nm and a 92.4% remnant capacitance under a bending angle of 80° have been achieved for the supercapacitors. The decrease in capacitance under bending is ascribed to the buckling of the graphene electrode in compression. The supercapacitors with high optical transparency, electrochemical stability, and mechanical flexibility hold promises for transparent and flexible electronics.

Graphene Transparent Conductive Electrodes for Next- Generation Microshutter Arrays

Science.gov (United States)

Li, Mary; Sultana, Mahmooda; Hess, Larry

2012-01-01

Graphene is a single atomic layer of graphite. It is optically transparent and has high electron mobility, and thus has great potential to make transparent conductive electrodes. This invention contributes towards the development of graphene transparent conductive electrodes for next-generation microshutter arrays. The original design for the electrodes of the next generation of microshutters uses indium-tin-oxide (ITO) as the electrode material. ITO is widely used in NASA flight missions. The optical transparency of ITO is limited, and the material is brittle. Also, ITO has been getting more expensive in recent years. The objective of the invention is to develop a graphene transparent conductive electrode that will replace ITO. An exfoliation procedure was developed to make graphene out of graphite crystals. In addition, large areas of single-layer graphene were produced using low-pressure chemical vapor deposition (LPCVD) with high optical transparency. A special graphene transport procedure was developed for transferring graphene from copper substrates to arbitrary substrates. The concept is to grow large-size graphene sheets using the LPCVD system through chemical reaction, transfer the graphene film to a substrate, dope graphene to reduce the sheet resistance, and pattern the film to the dimension of the electrodes in the microshutter array. Graphene transparent conductive electrodes are expected to have a transparency of 97.7%. This covers the electromagnetic spectrum from UV to IR. In comparison, ITO electrodes currently used in microshutter arrays have 85% transparency in mid-IR, and suffer from dramatic transparency drop at a wavelength of near-IR or shorter. Thus, graphene also has potential application as transparent conductive electrodes for Schottky photodiodes in the UV region.

Optically transparent and durable Al2O3 coatings for harsh environments by ultra short pulsed laser deposition

Science.gov (United States)

Korhonen, Hannu; Syväluoto, Aki; Leskinen, Jari T. T.; Lappalainen, Reijo

2018-01-01

Nowadays, an environmental protection is needed for a number of optical applications in conditions quickly impairing the clarity of optical surfaces. Abrasion resistant optical coatings applied onto plastics are usually based on alumina or polysiloxane technology. In many applications transparent glasses and ceramics need a combination of abrasive and chemically resistant shielding or other protective solutions like coatings. In this study, we intended to test our hypothesis that clear and pore free alumina coating can be uniformly distributed on glass prisms by ultra short pulsed laser deposition (USPLD) technique to protect the sensitive surfaces against abrasives. Abrasive wear tests were carried out by the use of SiC emery paper using specified standard procedures. After the wear tests the measured transparencies of coated prisms turned out to be close those of the prisms before coating. The coating on sensitive surfaces consistently displayed enhanced wear resistance exhibiting still high quality, even after severe wear testing. Furthermore, the coating modified the surface properties towards hydrophobic nature in contrast to untreated prisms, which became very hydrophilic especially due to wear.

Flexible semi-transparent silicon (100) fabric with high-k/metal gate devices

KAUST Repository

Rojas, Jhonathan Prieto

2013-01-07

Can we build a flexible and transparent truly high performance computer? High-k/metal gate stack based metal-oxide-semiconductor capacitor devices are monolithically fabricated on industry\\'s most widely used low-cost bulk single-crystalline silicon (100) wafers and then released as continuous, mechanically flexible, optically semi-transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree of freedom to fabricate nanoelectronics devices using state-of-the-art CMOS compatible processes and then to utilize them in an unprecedented way for wide deployment over nearly any kind of shape and architecture surfaces. Electrical characterization shows uncompromising performance of post release devices. Mechanical characterization shows extra-ordinary flexibility (minimum bending radius of 1 cm) making this generic process attractive to extend the horizon of flexible electronics for truly high performance computers. Schematic and photograph of flexible high-k/metal gate MOSCAPs showing high flexibility and C-V plot showing uncompromised performance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Standard Test Method for Measuring Optical Angular Deviation of Transparent Parts

CERN Document Server

American Society for Testing and Materials. Philadelphia

1996-01-01

1.1 This test method covers measuring the angular deviation of a light ray imposed by transparent parts such as aircraft windscreens and canopies. The results are uncontaminated by the effects of lateral displacement, and the procedure may be performed in a relatively short optical path length. This is not intended as a referee standard. It is one convenient method for measuring angular deviations through transparent windows. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Interrelation between striction forces in dielectrics and optically induced forces in transparent media

International Nuclear Information System (INIS)

Torchigin, V P; Torchigin, A V

2012-01-01

Optically induced forces applied to a transparent optical medium, which is inserted in a closed plane optical resonator, are calculated by means of an analysis of the changes in the eigenfrequency and energy stored in the resonator at various positions of the medium. These forces are compared with striction forces applied to the medium considered as a dielectric placed in an alternate electrical field within the resonator. It is shown that the optically induced forces are equal to the striction forces. The results of using the classical formula for striction forces in electrostatics are considered. (paper)

Electromagnetically induced transparency line shapes for large probe fields and optically thick media

International Nuclear Information System (INIS)

Pack, M. V.; Camacho, R. M.; Howell, J. C.

2007-01-01

We calculate the line shape and linewidths for electromagnetically induced transparency (EIT) in optically thick, Doppler broadened media (buffer gasses are also considered). In generalizing the definition of the EIT linewidth to optically thick media, we find two different linewidth definitions apply depending on whether the experiment is pulsed or continuous wave (cw). Using the cw definition for the EIT line shape we derive analytic expressions describing the linewidth as a function of optical depth. We also review the EIT line shapes in optically thin media and provide physical arguments for how the line shapes change as a function of various parameters

Standard Practice for Optical Distortion and Deviation of Transparent Parts Using the Double-Exposure Method

CERN Document Server

American Society for Testing and Materials. Philadelphia

2009-01-01

1.1 This photographic practice determines the optical distortion and deviation of a line of sight through a simple transparent part, such as a commercial aircraft windshield or a cabin window. This practice applies to essentially flat or nearly flat parts and may not be suitable for highly curved materials. 1.2 Test Method F 801 addresses optical deviation (angluar deviation) and Test Method F 2156 addresses optical distortion using grid line slope. These test methods should be used instead of Practice F 733 whenever practical. 1.3 This standard does not purport to address the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Transparent Ceramic Scintillator Fabrication, Properties and Applications

International Nuclear Information System (INIS)

Cherepy, N.J.; Kuntz, J.D.; Roberts, J.J.; Hurst, T.A.; Drury, O.B.; Sanner, R.D.; Tillotson, T.M.; Payne, S.A.

2008-01-01

Transparent ceramics offer an alternative to single crystals for scintillator applications such as gamma ray spectroscopy and radiography. We have developed a versatile, scaleable fabrication method, using Flame Spray Pyrolysis (FSP) to produce feedstock which is readily converted into phase-pure transparent ceramics. We measure integral light yields in excess of 80,000 Ph/MeV with Cerium-doped Garnets, and excellent optical quality. Avalanche photodiode readout of Garnets provides resolution near 6%. For radiography applications, Lutetium Oxide offers a high performance metric and is formable by ceramics processing. Scatter in transparent ceramics due to secondary phases is the principal limitation to optical quality, and afterglow issues that affect the scintillation performance are presently being addressed

Wave-mixing-induced transparency with zero phase shift in atomic vapors

Science.gov (United States)

Zhou, F.; Zhu, C. J.; Li, Y.

2017-12-01

We present a wave-mixing induced transparency that can lead to a hyper-Raman gain-clamping effect. This new type of transparency is originated from a dynamic gain cancellation effect in a multiphoton process where a highly efficient light field of new frequency is generated and amplified. We further show that this novel dynamic gain cancellation effect not only makes the medium transparent to a probe light field at appropriate frequency but also eliminates the probe field propagation phase shift. This gain-cancellation-based induced transparency holds for many potential applications on optical communication and may lead to effective suppression of parasitic Raman/hyper-Raman noise field generated in high intensity optical fiber transmissions.

Growth of highly transparent Cd{sub x}Zn{sub 1−x}O (CZO) thin films: Structural and optical studies

Energy Technology Data Exchange (ETDEWEB)

Gautam, Naina, E-mail: nainagtm@gmail.com [Department of Electronic Science, University of Delhi South Campus, New Delhi 110023 (India); Singh, Fouran, E-mail: fouran@gmail.com [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Gautam, Subodh K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Singh, R.G. [Department of Physics, Bhagini Nivedita College, Delhi University, Delhi 110043 (India); Ojha, S. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Kapoor, A. [Department of Electronic Science, University of Delhi South Campus, New Delhi 110023 (India)

2015-11-25

The deposition of Cd{sub x}Zn{sub 1−x}O thin films with different cadmium concentrations i.e., x = 0.0, 0.05, 0.20 by sol–gel spin coating is reported. The doping fraction of Cd in ZnO films was measured by Rutherford backscattering spectrometry (RBS), while the surface morphology was studied by scanning electron microscopy (SEM). Grazing incidence X-ray diffraction (GIXRD) study was carried out for the structural investigations and reveals hexagonal wurtzite structure with polycrystalline nature. The various structural parameters are calculated including the lattice constants ‘a’ and ‘c’, stress (σ), strain (ε) and internal parameter (u). For x = 0.20 Cd content, the formation of secondary phase of the cubic CdO at 33.12° (111) and 38.41° (200) is observed and this is further confirmed by micro-Raman studies, where the TO mode emerges at ∼261.5 cm{sup −1}. The basic wurtzite structure is maintained as ‘c/a’ ratio and internal parameter ‘u’ found to be closer to the ideal values. All the films are found to be highly transparent in the visible region and a bending of the near band edge (NBE) absorption is observed with Cd doping. It is further confirmed by calculating the Urbach energy (E{sub u}), which is found to be increased from 0.14 eV (for x = 0.0) to 0.26 eV (for x = 0.20) with maximum value for the lightly doped films i.e. x = 0.05. However, the optical band gap is found to decrease from 3.26 eV (for x = 0.0) to 3.08 eV (for x = 0.20). - Highlights: • High transparent Cd{sub x}Zn{sub 1−x}O (CZO) thin films with an average transparency of ∼85% in the visible region. • Band-gap tuning is achieved by Cd doping in ZnO. • Segregation of cubic rock-salt CdO phase upon high doping as confirmed by Micro-Raman and SEM investigations.

High conductivity and transparent aluminum-based multi-layer source/drain electrodes for thin film transistors

Science.gov (United States)

Yao, Rihui; Zhang, Hongke; Fang, Zhiqiang; Ning, Honglong; Zheng, Zeke; Li, Xiaoqing; Zhang, Xiaochen; Cai, Wei; Lu, Xubing; Peng, Junbiao

2018-02-01

In this study, high conductivity and transparent multi-layer (AZO/Al/AZO-/Al/AZO) source/drain (S/D) electrodes for thin film transistors were fabricated via conventional physical vapor deposition approaches, without toxic elements or further thermal annealing process. The 68 nm-thick multi-layer films with excellent optical properties (transparency: 82.64%), good electrical properties (resistivity: 6.64  ×  10-5 Ω m, work function: 3.95 eV), and superior surface roughness (R q   =  0.757 nm with scanning area of 5  ×  5 µm2) were fabricated as the S/D electrodes. Significantly, comprehensive performances of AZO films are enhanced by the insertion of ultra-thin Al layers. The optimal transparent TFT with this multi-layer S/D electrodes exhibited a decent electrical performance with a saturation mobility (µ sat) of 3.2 cm2 V-1 s-1, an I on/I off ratio of 1.59  ×  106, a subthreshold swing of 1.05 V/decade. The contact resistance of AZO/Al/AZO/Al/AZO multi-layer electrodes is as low as 0.29 MΩ. Moreover, the average visible light transmittance of the unpatterned multi-layers constituting a whole transparent TFT could reach 72.5%. The high conductivity and transparent multi-layer S/D electrodes for transparent TFTs possessed great potential for the applications of the green and transparent displays industry.

Effect of high-energy electron beam irradiation on the transmittance of ZnO thin films on transparent substrates

International Nuclear Information System (INIS)

Yun, Eui-Jung; Jung, Jin-Woo; Han, Young-Hwan; Kim, Min-Wan; Lee, Byung Cheol

2010-01-01

We investigated in this study the effects of high-energy electron beam irradiation (HEEBI) on the optical transmittance of undoped ZnO films grown on transparent substrates, such as corning glass and polyethersulfone (PES) plastic substrates, with a radio frequency (rf) magnetron sputtering technique. The ZnO thin films were treated with HEEBI in air at RT with an electron beam energy of 1 MeV and doses of 4.7 x 10 14 - 4.7 x 10 16 electrons/cm 2 . The optical transmittance of the ZnO films was measured using an ultraviolet visible near-infrared spectrophotometer. The detailed estimation process for separating the transmittance of HEEBI-treated ZnO films from the total transmittance of ZnO films on transparent substrates treated with HEEBI is given in this paper. We concluded that HEEBI causes a slight suppression in the optical transmittance of ZnO thin films. We also concluded that HEEBI treatment with a high dose shifted the optical band gap (E g ) toward the lower energy region from 3.29 to 3.28 eV whereas that with a low dose unchanged E g at 3.25 eV. This shift suggested that HEEBI at RT at a high dose acts like an annealing treatment at high temperature.

Hybrid plasmonic systems: from optical transparencies to strong coupling and entanglement

Science.gov (United States)

Gray, Stephen K.

2018-02-01

Classical electrodynamics and quantum mechanical models of quantum dots and molecules interacting with plasmonic systems are discussed. Calculations show that just one quantum dot interacting with a plasmonic system can lead to interesting optical effects, including optical transparencies and more general Fano resonance features that can be tailored with ultrafast laser pulses. Such effects can occur in the limit of moderate coupling between quantum dot and plasmonic system. The approach to the strong coupling regime is also discussed. In cases with two or more quantum dots within a plasmonic system, the possibility of quantum entanglement mediated through the dissipative plasmonic structure arises.

Reflective Optical Chopper Used in NIST High-Power Laser Measurements

Directory of Open Access Journals (Sweden)

Cromer, Chris

2008-11-01

Full Text Available For the past ten years, NIST has used high-reflectivity, optical choppers as beamsplitters and attenuators when calibrating the absolute responsivity and response linearity of detectors used with high-power CW lasers. The chopper-based technique has several advantages over the use of wedge-shaped transparent materials (usually crystals often used as beam splitters in this type of measurement system. We describe the design, operation and calibration of these choppers. A comparison between choppers and transparent wedge beampslitters is also discussed.

Two transparent optical sensors for the positioning of detectors using a reference laser beam

Energy Technology Data Exchange (ETDEWEB)

Barriere, J.Ch.; Blumenfeld, H.; Bourdinaud, M.; Cloue, O.; Guyot, C.; Molinie, F.; Ponsot, P.; Saudemont, J.C.; Schuller, J.P.; Schune, Ph.; Sube, S. [CEA Saclay, 91 - Gif sur Yvette (France). Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee

1999-07-01

We have developed two different optical systems in order to position detectors with respect to a reference laser beam. The first system, a telescope, permits the absolute positioning of an element with respect to a reference laser beam. The resolution is of the order of 10 {mu}m in translation and 50 {mu}rad in rotation. It is highly transparent (-90%) permitting several elements to be aligned. A calibration procedure has also been studied and is currently being tested in order to obtain an absolute alignment information. The second system is a highly transparent (95%) two dimensional position sensor which allows the accurate positioning (below 20 {mu}m) of several (up to ten) elements to which each sensor is attached, transversally to a laser beam used as a reference straight line. The present useful area of the first sensor is 20 x 20 mm{sup 2} and is 15 x 15 mm{sup 2} for the second. In both case it can be further increased to meet the experiment's requirement. (authors)

Two transparent optical sensors for the positioning of detectors using a reference laser beam

International Nuclear Information System (INIS)

Barriere, J.Ch.; Blumenfeld, H.; Bourdinaud, M.; Cloue, O.; Guyot, C.; Molinie, F.; Ponsot, P.; Saudemont, J.C.; Schuller, J.P.; Schune, Ph.; Sube, S.

1999-01-01

We have developed two different optical systems in order to position detectors with respect to a reference laser beam. The first system, a telescope, permits the absolute positioning of an element with respect to a reference laser beam. The resolution is of the order of 10 μm in translation and 50 μrad in rotation. It is highly transparent (-90%) permitting several elements to be aligned. A calibration procedure has also been studied and is currently being tested in order to obtain an absolute alignment information. The second system is a highly transparent (95%) two dimensional position sensor which allows the accurate positioning (below 20 μm) of several (up to ten) elements to which each sensor is attached, transversally to a laser beam used as a reference straight line. The present useful area of the first sensor is 20 x 20 mm 2 and is 15 x 15 mm 2 for the second. In both case it can be further increased to meet the experiment's requirement. (authors)

Highly conducting and transparent sprayed indium tin oxide

Energy Technology Data Exchange (ETDEWEB)

Rami, M.; Benamar, E.; Messaoudi, C.; Sayah, D.; Ennaoui, A. (Faculte des Sciences, Rabat (Morocco). Lab. de Physique des Materiaux)

1998-03-01

Indium tin oxide (ITO) has a wide range of applications in solar cells (e.g. by controlling the resistivity, we can use low conductivity ITO as buffer layer and highly conducting ITO as front contact in thin films CuInS[sub 2] and CuInSe[sub 2] based solar cells) due to its wide band gap (sufficient to be transparent) in both visible and near infrared range, and high carrier concentrations with metallic conduction. A variety of deposition techniques such as reactive electron beam evaporation, DC magnetron sputtering, evaporation, reactive thermal deposition, and spray pyrolysis have been used for the preparation of undoped and tin doped indium oxide. This latter process which makes possible the preparation of large area coatings has attracted considerable attention due to its simplicity and large scale with low cost fabrication. It has been used here to deposit highly transparent and conducting films of tin doped indium oxide onto glass substrates. The electrical, optical and structural properties have been investigated as a function of various deposition parameters namely dopant concentrations, temperature and nature of substrates. X-ray diffraction patterns have shown that deposited films are polycrystalline without second phases and have preferred orientation [400]. INdium tin oxide layers with small resistivity value around 7.10[sup -5] [omega].cm and transmission coefficient in the visible and near IR range of about 85-90% have been easily obtained. (authors) 13 refs.

On-chip plasmon-induced transparency based on plasmonic coupled nanocavities.

Science.gov (United States)

Zhu, Yu; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

2014-01-17

On-chip plasmon-induced transparency offers the possibility of realization of ultrahigh-speed information processing chips. Unfortunately, little experimental progress has been made to date because it is difficult to obtain on-chip plasmon-induced transparency using only a single meta-molecule in plasmonic circuits. Here, we report a simple and efficient strategy to realize on-chip plasmon-induced transparency in a nanoscale U-shaped plasmonic waveguide side-coupled nanocavity pair. High tunability in the transparency window is achieved by covering the pair with different organic polymer layers. It is possible to realize ultrafast all-optical tunability based on pump light-induced refractive index change of a graphene cover layer. Compared with previous reports, the overall feature size of the plasmonic nanostructure is reduced by more than three orders of magnitude, while ultrahigh tunability of the transparency window is maintained. This work also provides a superior platform for the study of the various physical effects and phenomena of nonlinear optics and quantum optics.

Aerospace Transparency Research Compendium

National Research Council Canada - National Science Library

Pinkus, Alan

2003-01-01

... (ARRL), located at Wright-Patterson AFB OH, has advanced aerospace transparency technology through the investigative research of numerous optical and visual parameters inherent in aerospace transparencies...

Surface microstructure evolution of highly transparent and conductive Al-doped ZnO thin films and its application in CIGS solar cells

Science.gov (United States)

Cheng, Ke; Liu, Jingjing; Jin, Ranran; Liu, Jingling; Liu, Xinsheng; Lu, Zhangbo; Liu, Ya; Liu, Xiaolan; Du, Zuliang

2017-07-01

Aluminum-doped zinc oxide (AZO) has attained intensive attention as being a very good transparent conducting oxide for photovoltaic applications. In this work, AZO films have been deposited on glass substrate by radio frequency (RF) magnetron sputtering. The influences of substrate temperatures on morphological, structural, optical and electrical properties of AZO films were systematically investigated. The results indicate that all AZO films have the hexagonal structure with c-axis preferred orientation. Morphological and electrical measurements have revealed that the substrate temperatures have strong influence on the microstructure, optical and electrical properties of AZO films. The AZO film is highly transparent from ultraviolet up to near infrared range with highest average transparency exceeding 83%. The minimum resistivity is as low as 6.1 × 10-4 Ω cm. The carrier concentration and mobility are as high as 3.357 × 1020 cm-3 and 30.48 cm2/Vs, respectively. Finally, the performances of the AZO film are evaluated by its practical application in Cu(In1-xGax)Se2 (CIGS) photovoltaic device as a transparent electrode. Benefited from its highly transparent and conductive feature, the most efficient device reveals an efficiency of 7.8% with a short-circuit current density of 28.99 mA/cm2, an open-circuit voltage of 430 mV, and a fill factor of 62.44 under standard conditions.

Optical haze of randomly arranged silver nanowire transparent conductive films with wide range of nanowire diameters

Directory of Open Access Journals (Sweden)

M. Marus

2018-03-01

Full Text Available The effect of the diameter of randomly arranged silver nanowires on the optical haze of silver nanowire transparent conductive films was studied. Proposed simulation model behaved similarly with the experimental results, and was used to theoretically study the optical haze of silver nanowires with diameters in the broad range from 30 nm and above. Our results show that a thickening of silver nanowires from 30 to 100 nm results in the increase of the optical haze up to 8 times, while from 100 to 500 nm the optical haze increases only up to 1.38. Moreover, silver nanowires with diameter of 500 nm possess up to 5% lower optical haze and 5% higher transmittance than 100 nm thick silver nanowires for the same 10-100 Ohm/sq sheet resistance range. Further thickening of AgNWs can match the low haze of 30 nm thick AgNWs, but at higher transmittance. The results obtained from this work allow deeper analysis of the silver nanowire transparent conductive films from the perspective of the diameter of nanowires for various optoelectronic devices.

Optically and thermally controlled terahertz metamaterial via transition between direct and indirect electromagnetically induced transparency

Directory of Open Access Journals (Sweden)

Jiawei Sui

2014-12-01

Full Text Available This passage presents a design of tunable terahertz metamaterials via transition between indirect and direct electromagnetically induced transparency (EIT effects by changing semiconductor InSb’s properties to terahertz wave under optical and thermal stimuli. Mechanical model and its electrical circuit model are utilized in analytically calculating maximum transmission of transparency window. Simulated results show consistency with the analytical expressions. The results show that the metamaterials hold 98.4% modulation depth at 189 GHz between 300 K, σInSb =256000 S/m, and 80 K, σInSb =0.0162 S/m conditions , 1360 ps recovery time of the excited electrons in InSb under optical stimulus at 300 K mainly considering the direct EIT effect, and minimum bandwidth 1 GHz.

Optical precursors with tunneling-induced transparency in asymmetric quantum wells

International Nuclear Information System (INIS)

Peng Yandong; Qi Yihong; Yao Haifeng; Niu Yueping; Gong Shangqing

2011-01-01

A scheme for separating optical precursors from a square-modulated laser pulse through an asymmetric double Al x Ga 1-x As/GaAs quantum-well structure via resonant tunneling is proposed. Destructive interference inhibits linear absorption, and a tunneling-induced transparency (TIT) window appears with normal dispersion, which delays the main pulse; then optical precursors are obtained. Due to resonant tunneling, constructive interference for nonlinear susceptibility is created. The enhanced dispersion in a narrow TIT window is about one order of magnitude larger than that of the linear case. In this case, the main pulse is much delayed and the precursor signals are easier to obtain. Moreover, the main pulse builds up due to the gain introduced by the enhanced cross-nonlinearity.

Transparent conducting oxides and production thereof

Science.gov (United States)

Gessert, Timothy A.; Yoshida, Yuki; Coutts, Timothy J.

2014-06-10

Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber. The method may also comprise depositing a metal oxide on the target in the process chamber to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

Highly tough and transparent layered composites of nanocellulose and synthetic silicate

Science.gov (United States)

Wu, Chun-Nan; Yang, Quanling; Takeuchi, Miyuki; Saito, Tsuguyuki; Isogai, Akira

2013-12-01

A highly tough and transparent film material was prepared from synthetic saponite (SPN) nanoplatelets of low aspect ratios and nanofibrillar cellulose. The nanofibrillar cellulose was chemically modified by topological surface oxidation using 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) as a catalyst. Both synthetic SPN nanoplatelets and TEMPO-oxidized cellulose nanofibrils (TOCNs) have abundant negative charges in high densities on their surfaces and are dispersed in water at the individual nanoelement level. Layered nanocomposite structures of the SPN nanoplatelets and TOCNs were formed through a simple cast-drying process of the mixed aqueous dispersions. The TOCN/SPN composites with 0-50% w/w SPN content were optically transparent. Mechanical properties of the TOCN/SPN composites varied depending on the SPN content. The composite with 10% w/w SPN content (5.6% volume fraction) exhibited characteristic mechanical properties: Young's modulus of 14 GPa, tensile strength of 420 MPa, and strain-to-failure of 10%. The work of fracture of the composites increased from 4 to 30 MJ m-3 - or by more than 700% - as the SPN content was increased from 0 to 10% w/w. This surprising improvement in toughness was interpreted based on a model for fracture of polymer composites reinforced with low-aspect-ratio platelets.A highly tough and transparent film material was prepared from synthetic saponite (SPN) nanoplatelets of low aspect ratios and nanofibrillar cellulose. The nanofibrillar cellulose was chemically modified by topological surface oxidation using 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) as a catalyst. Both synthetic SPN nanoplatelets and TEMPO-oxidized cellulose nanofibrils (TOCNs) have abundant negative charges in high densities on their surfaces and are dispersed in water at the individual nanoelement level. Layered nanocomposite structures of the SPN nanoplatelets and TOCNs were formed through a simple cast-drying process of the mixed aqueous dispersions. The

Modelling and simulation of a thermally induced optical transparency in a dual micro-ring resonator.

Science.gov (United States)

Lydiate, Joseph

2017-07-01

This paper introduces the simulation and modelling of a novel dual micro-ring resonator. The geometric configuration of the resonators, and the implementation of a simulated broadband excitation source, results in the realization of optical transparencies in the combined through port output spectrum. The 130 nm silicon on insulator rib fabrication process is adopted for the simulation of the dual-ring configuration. Two titanium nitride heaters are positioned over the coupling regions of the resonators, which can be operated independently, to control the spectral position of the optical transparency. A third heater, centrally located above the dual resonator rings, can be used to red shift the entire spectrum to a required reference resonant wavelength. The free spectral range with no heater currents applied is 4.29 nm. For a simulated heater current of 7 mA (55.7 mW heater power) applied to one of the through coupling heaters, the optical transparency exhibits a red shift of 1.79 nm from the reference resonant wavelength. The ring-to-ring separation of approximately 900 nm means that it can be assumed that there is a zero ring-to-ring coupling field in this model. This novel arrangement has potential applications as a gas mass airflow sensor or a gas species identification sensor.

Optically transparent frequency selective surfaces on flexible thin plastic substrates

Energy Technology Data Exchange (ETDEWEB)

Dewani, Aliya A., E-mail: a.ashraf@griffith.edu.au; O’Keefe, Steven G.; Thiel, David V.; Galehdar, Amir [School Of Electrical Engineering, Griffith University, Brisbane, 4111 (Australia)

2015-02-15

A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm), flexible transparent plastic substrate (relative permittivity 3.2). It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing) to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

Optically transparent frequency selective surfaces on flexible thin plastic substrates

Directory of Open Access Journals (Sweden)

Aliya A. Dewani

2015-02-01

Full Text Available A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm, flexible transparent plastic substrate (relative permittivity 3.2. It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

Optically transparent frequency selective surfaces on flexible thin plastic substrates

Science.gov (United States)

Dewani, Aliya A.; O'Keefe, Steven G.; Thiel, David V.; Galehdar, Amir

2015-02-01

A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm), flexible transparent plastic substrate (relative permittivity 3.2). It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing) to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

Transparent, flexible supercapacitors from nano-engineered carbon films

Science.gov (United States)

Jung, Hyun Young; Karimi, Majid B.; Hahm, Myung Gwan; Ajayan, Pulickel M.; Jung, Yung Joon

2012-10-01

Here we construct mechanically flexible and optically transparent thin film solid state supercapacitors by assembling nano-engineered carbon electrodes, prepared in porous templates, with morphology of interconnected arrays of complex shapes and porosity. The highly textured graphitic films act as electrode and current collector and integrated with solid polymer electrolyte, function as thin film supercapacitors. The nanostructured electrode morphology and the conformal electrolyte packaging provide enough energy and power density for the devices in addition to excellent mechanical flexibility and optical transparency, making it a unique design in various power delivery applications.

Highly transparent front electrodes with metal fingers for p-i-n thin-film silicon solar cells

Directory of Open Access Journals (Sweden)

Moulin Etienne

2015-01-01

Full Text Available The optical and electrical properties of transparent conductive oxides (TCOs, traditionally used in thin-film silicon (TF-Si solar cells as front-electrode materials, are interlinked, such that an increase in TCO transparency is generally achieved at the cost of reduced lateral conductance. Combining a highly transparent TCO front electrode of moderate conductance with metal fingers to support charge collection is a well-established technique in wafer-based technologies or for TF-Si solar cells in the substrate (n-i-p configuration. Here, we extend this concept to TF-Si solar cells in the superstrate (p-i-n configuration. The metal fingers are used in conjunction with a millimeter-scale textured foil, attached to the glass superstrate, which provides an antireflective and retroreflective effect; the latter effect mitigates the shadowing losses induced by the metal fingers. As a result, a substantial increase in power conversion efficiency, from 8.7% to 9.1%, is achieved for 1-μm-thick microcrystalline silicon solar cells deposited on a highly transparent thermally treated aluminum-doped zinc oxide layer combined with silver fingers, compared to cells deposited on a state-of-the-art zinc oxide layer.

Highly Sensitive, Transparent, and Durable Pressure Sensors Based on Sea-Urchin Shaped Metal Nanoparticles.

Science.gov (United States)

Lee, Donghwa; Lee, Hyungjin; Jeong, Youngjun; Ahn, Yumi; Nam, Geonik; Lee, Youngu

2016-11-01

Highly sensitive, transparent, and durable pressure sensors are fabricated using sea-urchin-shaped metal nanoparticles and insulating polyurethane elastomer. The pressure sensors exhibit outstanding sensitivity (2.46 kPa -1 ), superior optical transmittance (84.8% at 550 nm), fast response/relaxation time (30 ms), and excellent operational durability. In addition, the pressure sensors successfully detect minute movements of human muscles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of highly-transparent protein/starch-based bioplastics.

Science.gov (United States)

Gonzalez-Gutierrez, J; Partal, P; Garcia-Morales, M; Gallegos, C

2010-03-01

Striving to achieve cost-competitive biomass-derived materials for the plastics industry, the incorporation of starch (corn and potato) to a base formulation of albumen and glycerol was considered. To study the effects of formulation and processing, albumen/starch-based bioplastics containing 0-30 wt.% starch were prepared by thermo-plastic and thermo-mechanical processing. Transmittance measurements, DSC, DMTA and tensile tests were performed on the resulting bioplastics. Optical and tensile properties were strongly affected by starch concentration. However, DMTA at low deformation proved to be insensitive to starch addition. Thermo-mechanical processing led to transparent albumen/starch materials with values of strength at low deformation comparable to commodity plastics. Consequently, albumen biopolymers may become a biodegradable alternative to oil-derived plastics for manufacturing transparent packaging and other plastic stuffs. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Fully transparent thin-film transistor devices based on SnO2 nanowires.

Science.gov (United States)

Dattoli, Eric N; Wan, Qing; Guo, Wei; Chen, Yanbin; Pan, Xiaoqing; Lu, Wei

2007-08-01

We report on studies of field-effect transistor (FET) and transparent thin-film transistor (TFT) devices based on lightly Ta-doped SnO2 nano-wires. The nanowire-based devices exhibit uniform characteristics with average field-effect mobilities exceeding 100 cm2/V x s. Prototype nano-wire-based TFT (NW-TFT) devices on glass substrates showed excellent optical transparency and transistor performance in terms of transconductance, bias voltage range, and on/off ratio. High on-currents and field-effect mobilities were obtained from the NW-TFT devices even at low nanowire coverage. The SnO2 nanowire-based TFT approach offers a number of desirable properties such as low growth cost, high electron mobility, and optical transparency and low operation voltage, and may lead to large-scale applications of transparent electronics on diverse substrates.

Highly transparent Tb3Al5O12 magneto-optical ceramics sintered from co-precipitated powders with sintering aids

Science.gov (United States)

Dai, Jiawei; Pan, Yubai; Xie, Tengfei; Kou, Huamin; Li, Jiang

2018-04-01

Highly transparent terbium aluminum garnet (Tb3Al5O12, TAG) magneto-optical ceramics were fabricated from co-precipitated nanopowders with tetraethoxysilane (TEOS) as sintering aid by vacuum sintering combined with hot isostatic pressing (HIP) post-treatment. The ball milled TAG powder shows better dispersity than the as-synthesized powder, and its average particle size is about 80 nm. For the ceramic sample pre-sintered at 1720 °C for 20 h with HIP post-treated at 1700 °C for 3 h, the in-line transmittance exceeds 76% in the region of 400-1580nm (except the absorption band), reaching a maximum value of 81.8% at the wavelength of 1390 nm. The microstructure of the TAG ceramic is homogeneous and its average grain size is approximately 19.7 μm. The Verdet constant of the sample is calculated to be -182.7 rad·T-1·m-1 at room temperature.

Highly efficient fully transparent inverted OLEDs

Science.gov (United States)

Meyer, J.; Winkler, T.; Hamwi, S.; Schmale, S.; Kröger, M.; Görrn, P.; Johannes, H.-H.; Riedl, T.; Lang, E.; Becker, D.; Dobbertin, T.; Kowalsky, W.

2007-09-01

One of the unique selling propositions of OLEDs is their potential to realize highly transparent devices over the visible spectrum. This is because organic semiconductors provide a large Stokes-Shift and low intrinsic absorption losses. Hence, new areas of applications for displays and ambient lighting become accessible, for instance, the integration of OLEDs into the windshield or the ceiling of automobiles. The main challenge in the realization of fully transparent devices is the deposition of the top electrode. ITO is commonly used as transparent bottom anode in a conventional OLED. To obtain uniform light emission over the entire viewing angle and a low series resistance, a TCO such as ITO is desirable as top contact as well. However, sputter deposition of ITO on top of organic layers causes damage induced by high energetic particles and UV radiation. We have found an efficient process to protect the organic layers against the ITO rf magnetron deposition process of ITO for an inverted OLED (IOLED). The inverted structure allows the integration of OLEDs in more powerful n-channel transistors used in active matrix backplanes. Employing the green electrophosphorescent material Ir(ppy) 3 lead to IOLED with a current efficiency of 50 cd/A and power efficiency of 24 lm/W at 100 cd/m2. The average transmittance exceeds 80 % in the visible region. The on-set voltage for light emission is lower than 3 V. In addition, by vertical stacking we achieved a very high current efficiency of more than 70 cd/A for transparent IOLED.

Transparent EuTiO3 films: a possible two-dimensional magneto-optical device

Science.gov (United States)

Bussmann-Holder, Annette; Roleder, Krystian; Stuhlhofer, Benjamin; Logvenov, Gennady; Lazar, Iwona; Soszyński, Andrzej; Koperski, Janusz; Simon, Arndt; Köhler, Jürgen

2017-01-01

The magneto-optical activity of high quality transparent thin films of insulating EuTiO3 (ETO) deposited on a thin SrTiO3 (STO) substrate, both being non-magnetic materials, are demonstrated to be a versatile tool for light modulation. The operating temperature is close to room temperature and allows for multiple device engineering. By using small magnetic fields birefringence of the samples can be switched off and on. Similarly, rotation of the sample in the field can modify its birefringence Δn. In addition, Δn can be increased by a factor of 4 in very modest fields with simultaneously enhancing the operating temperature by almost 100 K.

Generation and control of optical frequency combs using cavity electromagnetically induced transparency

Science.gov (United States)

Li, Jiahua; Qu, Ye; Yu, Rong; Wu, Ying

2018-02-01

We explore theoretically the generation and all-optical control of optical frequency combs (OFCs) in photon transmission based on a combination of single-atom-cavity quantum electrodynamics (CQED) and electromagnetically induced transparency (EIT). Here an external control field is used to form the cavity dark mode of the CQED system. When the strengths of the applied EIT control field are appropriately tuned, enhanced comb generation can be achieved. We discuss the properties of the dark mode and clearly show that the formation of the dark mode enables the efficient generation of OFCs. In our approach, the comb spacing is determined by the beating frequency between the driving pump and seed lasers. Our demonstrated theory may pave the way towards all-optical coherent control of OFCs using a CQED architecture.

Development of highly transparent Pd-coated Ag nanowire electrode for display and catalysis applications

Energy Technology Data Exchange (ETDEWEB)

Canlier, Ali, E-mail: ali.canlier@agu.edu.tr [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Ucak, Umit Volkan, E-mail: sirvolkan@gmail.com [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Usta, Hakan, E-mail: husta38@gmail.com [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Cho, Changsoon, E-mail: cscho@kaist.ac.kr [Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Lee, Jung-Yong, E-mail: jungyong.lee@kaist.ac.kr [Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Sen, Unal, E-mail: senunal@gmail.com [Department of Mechanical Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Citir, Murat, E-mail: muratcitir@gmail.com [Department of Chemical Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey)

2015-09-30

Highlights: • Highly uniform thin-layer coating of Pd onto Ag nanowire surface was accomplished. • A transparent electrode of Pd-coated Ag nanowire was uniformly deposited on flexible substrate. • 95% of optical transmittance and 175 Ω/sq sheet resistance were obtained. • Extremely low haze of 1.9% and high oxidation stability proved an efficient transparent electrode. • This electrode can be used as Pd-catalyst for synthesis reactions and fuel cell electrode applications. - Abstract: Ag nanowire transparent electrode has excellent transmittance (90%) and sheet resistance (20 Ω/sq), yet there are slight drawbacks such as optical haze and chemical instability against aerial oxidation. Chemical stability of Ag nanowires needs to be improved in order for it to be suitable for electrode applications. In our recent article, we demonstrated that coating Ag nanowires with a thin layer of Au through galvanic exchange reactions enhances the chemical stability of Ag nanowire films highly and also helps to obtain lower haze. In this study, coating of a thin Pd layer has been applied successfully onto the surface of Ag nanowires. A mild Pd complex oxidant [Pd(en){sub 2}](NO{sub 3}){sub 2} was prepared in order to oxidize Ag atoms partially on the surface via galvanic displacement. The mild galvanic exchange allowed for a thin layer (1–2 nm) of Pd coating on the Ag nanowires with minimal truncation of the nanowire, where the average length and the diameter were 12.5 μm and 59 nm, respectively. The Pd-coated Ag nanowires were suspended in methanol and then electrostatically sprayed on flexible polycarbonate substrates. It has been revealed that average total transmittance remain around 95% within visible spectrum region (400–800 nm) whereas sheet resistance rises up to 175 Ω/sq. To the best of our knowledge, for the first time in the literature, Pd coating was employed on Ag nanowires in order to design transparent electrodes for high transparency and strong

Study on the optical and electrical properties of tetracyanoethylene doped bilayer graphene stack for transparent conducting electrodes

International Nuclear Information System (INIS)

Limbu, Tej B.; Barrionuevo, Danilo; Katiyar, Ram S.; Morell, Gerardo; Mendoza, Frank; Carpena, Jennifer; Maruyama, Benji; Weiner, Brad R.

2016-01-01

We report the optical and electrical properties of chemically-doped bilayer graphene stack by tetracyanoethylene, a strong electron acceptor. The Tetracyanoethylene doping on the bilayer graphene via charge transfer was confirmed by Raman spectroscopy and Infrared Fourier transform spectroscopy. Doped graphene shows a significant increase in the sheet carrier concentration of up to 1.520 × 10"1"3 cm"−"2 with a concomitant reduction of the sheet resistance down to 414.1 Ω/sq. The high optical transmittance (ca. 84%) in the visible region in combination with the low sheet resistance of the Tetracyanoethylene-doped bilayer graphene stack opens up the possibility of making transparent conducting electrodes for practical applications.

Data Transparent and Polarization Insensitive All-Optical Switch based on Fibers with Enhanced Nonlinearity

Directory of Open Access Journals (Sweden)

M. Komanec

2014-09-01

Full Text Available We have developed a data transparent optical packet switch prototype employing wavelength conversion based on four-wave mixing. The switch is composed of an electro-optical control unit and an all-optical switching segment. To achieve higher switching efficiencies, Ge-doped silica suspended-core and chalcogenide arsenicselenide single-mode fibers were experimentally evaluated and compared to conventional highly-nonlinear fiber. Improved connectorization technology has been developed for Ge-doped suspended-core fiber, where we achieved connection losses of 0.9 dB. For the arsenic-selenide fiber we present a novel solid joint technology, with connection losses of only 0.25 dB, which is the lowest value presented up-to-date. Conversion efficiency of -13.7 dB was obtained for the highly-nonlinear fiber, which is in perfect correlation with previously published results and thus verifies the functionality of the prototype. Conversion efficiency of -16.1 dB was obtained with arsenic-selenide fiber length reduced to five meters within simulations, based on measurement results with a 26 m long component. Employment of such a short arsenic-selenide fiber segment allows significant broadening of the wavelength conversion spectral range due to possible neglection of dispersion.

Fabrication of highly transparent diamond-like carbon anti-reflecting coating for Si solar cell application

Energy Technology Data Exchange (ETDEWEB)

Banerjee, Amit, E-mail: erdd@iacs.res.in; Das, Debajyoti, E-mail: erdd@iacs.res.in [Nano-Science Group, Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700032 (India)

2014-04-24

ARC grade highly transparent unhydrogenated diamond-like carbon (DLC) films were produced, directly from a-C target, using RF magnetron sputtering deposition technique, for optoelectronic applications. Optical band gap, transmittance, reflectance, sp{sup 3} fraction, I{sub D}/I{sub G}, density, and refractive index of the films have been estimated with the help of optical tools like Uv-vis spectrophotometer, ellipsometer and micro-Raman. Optimum ARC-qualities have been identified in low-temperature grown DLC films at an Ar pressure of 4 mTorr in the reactor, accomplishing its key requirements for use in silicon solar cells.

Magnetron sputtered Hf-B-Si-C-N films with controlled electrical conductivity and optical transparency, and with ultrahigh oxidation resistance

Czech Academy of Sciences Publication Activity Database

Šímová, V.; Vlček, J.; Zuzjaková, Š.; Houška, J.; Shen, Y.; Jiang, J. C.; Meletis, E. I.; Peřina, Vratislav

2018-01-01

Roč. 653, č. 5 (2018), s. 333-340 ISSN 0040-6090 R&D Projects: GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : Hf-B-Si-C-N films * pulsed reactive magnetron sputtering * electrical conductivitiy * optical transparency * high-temperature oxidation resistance Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.879, year: 2016

Electromagnetically induced transparency with matched pulses

International Nuclear Information System (INIS)

Harris, S.E.

1993-01-01

In the last several years there have been studies and experiments showing how, by applying an additional laser beam, optically-thick transitions may be rendered nearly transparent to probing radiation. This transparency results from a quantum interference, very much like a Fano interference, which is established by the additional laser. This talk describes the difference between the quantum interference as exhibited by an independent atom and by an optically-thick ensemble of atoms. We find that an ensemble of atoms establishes transparency through a strong nonlinear interaction which, for a lambda system, tends to generate a matching temporal envelope on the complementary transition. For a ladder system, phase conjugate pulses are generated and, after a characteristic distance, establish transparency. The transparency of an optically-thick medium is therefore not a Beer's law superposition of the independent atom response. To transmit a pulse through an otherwise opaque media, the front edge of the complementary pulse should lead, in the manner of open-quotes counter-intuitiveclose quotes adiabatic transfer, the front edge of the pulse which is to be rendered transparent. Thereafter the pulses should be matched or, for a ladder system, phase-conjugately matched

Fabrication and characterization of cellulose nanocrystal based transparent electroactive polyurethane

Science.gov (United States)

Ko, Hyun-U.; Kim, Hyun Chan; Kim, Jung Woong; Zhai, Lindong; Jayaramudu, Tippabattini; Kim, Jaehwan

2017-08-01

This paper reports cellulose nanocrystal (CNC) based transparent and electroactive polyurethane (CPPU), suitable for actively tunable optical lens. CNC is used for high dielectric filler to improve electromechanical behavior of CPPU. For high transparency and homogeneous distribution of CNC in polyurethane, CNC-poly[di(ethylene glycol) adipate] is used to play a role of polyol and isocyanate salt. The fabricated CPPU exhibits high transparency (>90%) and 10% of electromechanical strain under 3 V μm-1 electric field. Mechanical, dielectric properties as well as physical and chemical characteristics are investigated to prove the electromechanical behavior of CPPU.

High Transparent Conductive Aluminum-Doped Zinc Oxide Thin Films by Reactive Co-Sputtering (Postprint)

Science.gov (United States)

2016-03-30

30 Mar 2016. This document contains color . Journal article published in Optical Interference Coatings, 19 Jun 2016. © 2016 Optical Society of...Ahn, Mi-So Lee, Moon-Ho Ham , Woong Lee, Jae-Min Myoung, “Effects of oxygen concentration on the properties of Al-doped ZnO transparent conductive

Highly transparent and conductive Al-doped ZnO nanoparticulate thin films using direct write processing

International Nuclear Information System (INIS)

Vunnam, S; Ankireddy, K; Kellar, J; Cross, W

2014-01-01

Solution processable Al-doped ZnO (AZO) thin films are attractive candidates for low cost transparent electrodes. We demonstrate here an optimized nanoparticulate ink for the fabrication of AZO thin films using scalable, low-cost direct write processing (ultrasonic spray deposition) in air at atmospheric pressure. The thin films were made via thermal processing of as-deposited films. AZO films deposited using the proposed nanoparticulate ink with further reducing in vacuum and rf plasma of forming gas exhibited optical transparency greater than 95% across the visible spectrum, and electrical resistivity of 0.5 Ω cm and it drops down to 7.0 × 10 −2 Ω cm after illuminating with UV light, which is comparable to commercially available tin doped indium oxide colloidal coatings. Various structural analyses were performed to investigate the influence of ink chemistry, deposition parameters, and annealing temperatures on the structural, optical, and electrical characteristics of the spray deposited AZO thin films. Optical micrographs confirmed the presence of surface defects and cracks using the AZO NPs ink without any additives. After adding N-(2-Aminoethyl)-3-aminopropylmethyldimethoxy silane to the ink, AZO films exhibited an optical transparency which was virtually identical to that of the plain glass substrate. (papers)

Second-order nonlinearity induced transparency.

Science.gov (United States)

Zhou, Y H; Zhang, S S; Shen, H Z; Yi, X X

2017-04-01

In analogy to electromagnetically induced transparency, optomechanically induced transparency was proposed recently in [Science330, 1520 (2010)SCIEAS0036-807510.1126/science.1195596]. In this Letter, we demonstrate another form of induced transparency enabled by second-order nonlinearity. A practical application of the second-order nonlinearity induced transparency is to measure the second-order nonlinear coefficient. Our scheme might find applications in quantum optics and quantum information processing.

Femtosecond laser ablation of dielectric materials in the optical breakdown regime: Expansion of a transparent shell

International Nuclear Information System (INIS)

Garcia-Lechuga, M.; Siegel, J.; Hernandez-Rueda, J.; Solis, J.

2014-01-01

Phase transition pathways of matter upon ablation with ultrashort laser pulses have been considered to be understood long-since for metals and semiconductors. We provide evidence that also certain dielectrics follow the same pathway, even at high pulse energies triggering optical breakdown. Employing femtosecond microscopy, we observe a characteristic ring pattern within the ablating region that dynamically changes for increasing time delays between pump and probe pulse. These transient Newton rings are related to optical interference of the probe beam reflected at the front surface of the ablating layer with the reflection at the interface of the non-ablating substrate. Analysis of the ring structure shows that the ablation mechanism is initiated by a rarefaction wave leading within a few tens of picoseconds to the formation of a transparent thin shell of reduced density and refractive index, featuring optically sharp interfaces. The shell expands and eventually detaches from the solid material at delays of the order of 100 ps.

Femtosecond laser ablation of dielectric materials in the optical breakdown regime: Expansion of a transparent shell

Energy Technology Data Exchange (ETDEWEB)

Garcia-Lechuga, M.; Siegel, J., E-mail: j.siegel@io.cfmac.csic.es; Hernandez-Rueda, J.; Solis, J. [Laser Processing Group, Instituto de Optica, Serrano 121, 28006 Madrid (Spain)

2014-09-15

Phase transition pathways of matter upon ablation with ultrashort laser pulses have been considered to be understood long-since for metals and semiconductors. We provide evidence that also certain dielectrics follow the same pathway, even at high pulse energies triggering optical breakdown. Employing femtosecond microscopy, we observe a characteristic ring pattern within the ablating region that dynamically changes for increasing time delays between pump and probe pulse. These transient Newton rings are related to optical interference of the probe beam reflected at the front surface of the ablating layer with the reflection at the interface of the non-ablating substrate. Analysis of the ring structure shows that the ablation mechanism is initiated by a rarefaction wave leading within a few tens of picoseconds to the formation of a transparent thin shell of reduced density and refractive index, featuring optically sharp interfaces. The shell expands and eventually detaches from the solid material at delays of the order of 100 ps.

Transparent wood for functional and structural applications

Science.gov (United States)

Li, Yuanyuan; Fu, Qiliang; Yang, Xuan; Berglund, Lars

2017-12-01

Optically transparent wood combines mechanical performance with optical functionalities is an emerging candidate for applications in smart buildings and structural optics and photonics. The present review summarizes transparent wood preparation methods, optical and mechanical performance, and functionalization routes, and discusses potential applications. The various challenges are discussed for the purpose of improved performance, scaled-up production and realization of advanced applications. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

Electromagnetically induced transparency and ultraslow optical solitons in a coherent atomic gas filled in a slot waveguide.

Science.gov (United States)

Xu, Jin; Huang, Guoxiang

2013-02-25

We investigate the electromagnetically induced transparency (EIT) and nonlinear pulse propagation in a Λ-type three-level atomic gas filled in a slot waveguide, in which electric field is strongly confined inside the slot of the waveguide due to the discontinuity of dielectric constant. We find that EIT effect can be greatly enhanced due to the reduction of optical-field mode volume contributed by waveguide geometry. Comparing with the atomic gases in free space, the EIT transparency window in the slot waveguide system can be much wider and deeper, and the Kerr nonlinearity of probe laser field can be much stronger. We also prove that using slot waveguide ultraslow optical solitons can be produced efficiently with extremely low generation power.

Silver nanowire based flexible electrodes with improved properties: High conductivity, transparency, adhesion and low haze

International Nuclear Information System (INIS)

Kiran Kumar, A.B.V.; Wan Bae, Chang; Piao, Longhai; Kim, Sang-Ho

2013-01-01

Graphical abstract: This graphical abstract illustrates the schematic representation of the main drawbacks and rectifications for AgNWs based transparent electrodes. - Highlights: • Films exhibited low sheet resistance and optical properties with R s ≤ 30 Ω/□ and T ≥ 90%. • We decreased haze to 2% by controlling AgNWs length, diameter, and concentration. • We achieved good adhesion for AgNWs on PET film. • There is no significant change in resistance in the bending angle from 0° to 180°, and on twisting. - Abstract: Recent work has been focusing on solution processable transparent electrodes for various applications including solar cells and displays. As well as, the research aims majorly at silver nanowires (AgNWs) to replace ITO. We enhance the transparent electrode performance as a function of optical and mechanical properties with low sheet resistance, by controlling the AgNWs accept ratios, ink composition, and processing conditions. The nanowire network of transparent films agrees with the 2D percolation law. The film transmittance values at 550 nm are coping with a reference ITO film. Sheet resistance and haze values are suitable for flexible electronic applications. We fabricate transparent flexible film using a low-cost processing technique

Silver nanowire based flexible electrodes with improved properties: High conductivity, transparency, adhesion and low haze

Energy Technology Data Exchange (ETDEWEB)

Kiran Kumar, A.B.V.; Wan Bae, Chang; Piao, Longhai, E-mail: piaolh@kongju.ac.kr; Kim, Sang-Ho, E-mail: sangho1130@kongju.ac.kr

2013-08-01

Graphical abstract: This graphical abstract illustrates the schematic representation of the main drawbacks and rectifications for AgNWs based transparent electrodes. - Highlights: • Films exhibited low sheet resistance and optical properties with R{sub s} ≤ 30 Ω/□ and T ≥ 90%. • We decreased haze to 2% by controlling AgNWs length, diameter, and concentration. • We achieved good adhesion for AgNWs on PET film. • There is no significant change in resistance in the bending angle from 0° to 180°, and on twisting. - Abstract: Recent work has been focusing on solution processable transparent electrodes for various applications including solar cells and displays. As well as, the research aims majorly at silver nanowires (AgNWs) to replace ITO. We enhance the transparent electrode performance as a function of optical and mechanical properties with low sheet resistance, by controlling the AgNWs accept ratios, ink composition, and processing conditions. The nanowire network of transparent films agrees with the 2D percolation law. The film transmittance values at 550 nm are coping with a reference ITO film. Sheet resistance and haze values are suitable for flexible electronic applications. We fabricate transparent flexible film using a low-cost processing technique.

A transparent Pyrex μ-reactor for combined in situ optical characterization and photocatalytic reactivity measurements

International Nuclear Information System (INIS)

Dionigi, F.; Hansen, O.; Nielsen, M. G.; Chorkendorff, I.; Vesborg, P. C. K.; Pedersen, T.

2013-01-01

A new Pyrex-based μ-reactor for photocatalytic and optical characterization experiments is presented. The reactor chamber and gas channels are microfabricated in a thin poly-silicon coated Pyrex chip that is sealed with a Pyrex lid by anodic bonding. The device is transparent to light in the UV-vis-near infrared range of wavelengths (photon energies between ∼0.4 and ∼4.1 eV). The absorbance of a photocatalytic film obtained with a light transmission measurement during a photocatalytic reaction is presented as a proof of concept of a photocatalytic reactivity measurement combined with in situ optical characterization. Diffuse reflectance measurements of highly scattering photocatalytic nanopowders in a sealed Pyrex μ-reactor are also possible using an integrating sphere as shown in this work. These experiments prove that a photocatalyst can be characterized with optical techniques after a photocatalytic reaction without removing the material from the reactor. The catalyst deposited in the cylindrical reactor chamber can be illuminated from both top and bottom sides and an example of application of top and bottom illumination is presented

High-performance NiO/Ag/NiO transparent electrodes for flexible organic photovoltaic cells.

Science.gov (United States)

Xue, Zhichao; Liu, Xingyuan; Zhang, Nan; Chen, Hong; Zheng, Xuanming; Wang, Haiyu; Guo, Xiaoyang

2014-09-24

Transparent electrodes with a dielectric-metal-dielectric (DMD) structure can be implemented in a simple manufacturing process and have good optical and electrical properties. In this study, nickel oxide (NiO) is introduced into the DMD structure as a more appropriate dielectric material that has a high conduction band for electron blocking and a low valence band for efficient hole transport. The indium-free NiO/Ag/NiO (NAN) transparent electrode exhibits an adjustable high transmittance of ∼82% combined with a low sheet resistance of ∼7.6 Ω·s·q(-1) and a work function of 5.3 eV after UVO treatment. The NAN electrode shows excellent surface morphology and good thermal, humidity, and environmental stabilities. Only a small change in sheet resistance can be found after NAN electrode is preserved in air for 1 year. The power conversion efficiencies of organic photovoltaic cells with NAN electrodes deposited on glass and polyethylene terephthalate (PET) substrates are 6.07 and 5.55%, respectively, which are competitive with those of indium tin oxide (ITO)-based devices. Good photoelectric properties, the low-cost material, and the room-temperature deposition process imply that NAN electrode is a striking candidate for low-cost and flexible transparent electrode for efficient flexible optoelectronic devices.

Next generation smart window display using transparent organic display and light blocking screen.

Science.gov (United States)

Kim, Gyeong Woo; Lampande, Raju; Choe, Dong Cheol; Ko, Ik Jang; Park, Jin Hwan; Pode, Ramchandra; Kwon, Jang Hyuk

2018-04-02

Transparent organic light emitting diodes (TOLED) have widespread applications in the next-generation display devices particularly in the large size transparent window and interactive displays. Herein, we report high performance and stable attractive smart window displays using facile process. Advanced smart window display is realized by integrating the high performance light blocking screen and highly transparent white OLED panel. The full smart window display reveals a maximum transmittance as high as 64.2% at the wavelength of 600 nm and extremely good along with tunable ambient contrast ratio (171.94:1) compared to that of normal TOLED (4.54:1). Furthermore, the performance decisive light blocking screen has demonstrated an excellent optical and electrical characteristics such as i) high transmittance (85.56% at 562nm) at light-penetrating state, ii) superior absorbance (2.30 at 562nm) in light interrupting mode, iii) high optical contrast (85.50 at 562 nm), iv) high optical stability for more than 25,000 cycle of driving, v) fast switching time of 1.9 sec, and vi) low driving voltage of 1.7 V. The experimental results of smart window display are also validated using optical simulation. The proposed smart window display technology allows us to adjust the intensity of daylight entering the system quickly and conveniently.

Ultrasmooth, extremely deformable and shape recoverable Ag nanowire embedded transparent electrode.

Science.gov (United States)

Nam, Sanggil; Song, Myungkwan; Kim, Dong-Ho; Cho, Byungjin; Lee, Hye Moon; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Kwon, Se-Hun; Park, Yun Chang; Jin, Sung-Ho; Kang, Jae-Wook; Jo, Sungjin; Kim, Chang Su

2014-04-25

Transparent electrodes have been widely used in electronic devices such as solar cells, displays, and touch screens. Highly flexible transparent electrodes are especially desired for the development of next generation flexible electronic devices. Although indium tin oxide (ITO) is the most commonly used material for the fabrication of transparent electrodes, its brittleness and growing cost limit its utility for flexible electronic devices. Therefore, the need for new transparent conductive materials with superior mechanical properties is clear and urgent. Ag nanowire (AgNW) has been attracting increasing attention because of its effective combination of electrical and optical properties. However, it still suffers from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to substrates. These issues need to be addressed before wide spread use of metallic NW as transparent electrodes can be realized. In this study, we demonstrated the fabrication of a flexible transparent electrode with superior mechanical, electrical and optical properties by embedding a AgNW film into a transparent polymer matrix. This technique can produce electrodes with an ultrasmooth and extremely deformable transparent electrode that have sheet resistance and transmittance comparable to those of an ITO electrode.

Fabrication and Optimization of Stable, Optically Transparent, and Reusable pH-Responsive Silk Membranes

Directory of Open Access Journals (Sweden)

Andreas Toytziaridis

2016-11-01

Full Text Available The fabrication of silk-based membranes that are stable, optically transparent and reusable is yet to be achieved. To address this bottleneck we have developed a method to produce transparent chromogenic silk patches that are optically responsive to pH. The patches were produced by blending regenerated silk fibroin (RSF, Laponite RD (nano clay and the organic dyes neutral red and Thionine acetate. The Laponite RD played a central role in the patch mechanical integrity and prevention of dye leaching. The process was optimized using a factorial design to maximize the patch response to pH by UV absorbance and fluorescence emission. New patches of the optimized protocol, made from solutions containing 125 μM neutral red or 250 μM of Thionine and 15 mg/mL silk, were further tested for operational stability over several cycles of pH altering. Stability, performance, and reusability were achieved over the tested cycles. The approach could be extended to other reporting molecules or enzymes able to bind to Laponite.

Wearable, wireless gas sensors using highly stretchable and transparent structures of nanowires and graphene

Science.gov (United States)

Park, Jihun; Kim, Joohee; Kim, Kukjoo; Kim, So-Yun; Cheong, Woon Hyung; Park, Kyeongmin; Song, Joo Hyeb; Namgoong, Gyeongho; Kim, Jae Joon; Heo, Jaeyeong; Bien, Franklin; Park, Jang-Ung

2016-05-01

Herein, we report the fabrication of a highly stretchable, transparent gas sensor based on silver nanowire-graphene hybrid nanostructures. Due to its superb mechanical and optical characteristics, the fabricated sensor demonstrates outstanding and stable performances even under extreme mechanical deformation (stable until 20% of strain). The integration of a Bluetooth system or an inductive antenna enables the wireless operation of the sensor. In addition, the mechanical robustness of the materials allows the device to be transferred onto various nonplanar substrates, including a watch, a bicycle light, and the leaves of live plants, thereby achieving next-generation sensing electronics for the `Internet of Things' area.Herein, we report the fabrication of a highly stretchable, transparent gas sensor based on silver nanowire-graphene hybrid nanostructures. Due to its superb mechanical and optical characteristics, the fabricated sensor demonstrates outstanding and stable performances even under extreme mechanical deformation (stable until 20% of strain). The integration of a Bluetooth system or an inductive antenna enables the wireless operation of the sensor. In addition, the mechanical robustness of the materials allows the device to be transferred onto various nonplanar substrates, including a watch, a bicycle light, and the leaves of live plants, thereby achieving next-generation sensing electronics for the `Internet of Things' area. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01468b

Spectroscopic and electrochemical characterization of nanostructured optically transparent carbon electrodes.

Science.gov (United States)

Benavidez, Tomás E; Garcia, Carlos D

2013-07-01

The present paper describes the results related to the optical and electrochemical characterization of thin carbon films fabricated by spin coating and pyrolysis of AZ P4330-RS photoresist. The goal of this paper is to provide comprehensive information allowing for the rational selection of the conditions to fabricate optically transparent carbon electrodes (OTCE) with specific electrooptical properties. According to our results, these electrodes could be appropriate choices as electrochemical transducers to monitor electrophoretic separations. At the core of this manuscript is the development and critical evaluation of a new optical model to calculate the thickness of the OTCE by variable angle spectroscopic ellipsometry. Such data were complemented with topography and roughness (obtained by atomic force microscopy), electrochemical properties (obtained by cyclic voltammetry), electrical properties (obtained by electrochemical impedance spectroscopy), and structural composition (obtained by Raman spectroscopy). Although the described OTCE were used as substrates to investigate the effect of electrode potential on the real-time adsorption of proteins by ellipsometry, these results could enable the development of other biosensors that can be then integrated into various CE platforms. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Smooth-surface silver nanowire electrode with high conductivity and transparency on functional layer coated flexible film

Energy Technology Data Exchange (ETDEWEB)

Lee, So Hee; Lim, Sooman; Kim, Haekyoung, E-mail: hkkim@ynu.ac.kr

2015-08-31

Transparent conductive electrode (TCE) with silver nanowires has been widely studied as an alternative of indium tin oxide for flexible electronic or optical devices such as organic light-emitting diodes, and solar cells. However, it has an issue of surface roughness due to nanowire's intrinsic properties. Here, to achieve a smooth electrode with high conductivity and transmittance on polyethylene terephthalate (PET) substrates, a functional layer of poly(N-vinylpyrrolidone) (PVP) is utilized with a mechanical transfer process. The silver nanowire electrode on PVP-coated PET with low surface roughness of 9 nm exhibits the low sheet resistance of 18 Ω □{sup −1} and high transmittance of 87.6%. It is produced by transferring the silver nanowire electrode spin-coated on the glass to PVP-coated PET using a pressure of 10 MPa for 10 min. Silver nanowire electrode on PVP-coated PET demonstrates the stable sheet resistance of 18 Ω □{sup −1} after the mechanical taping test due to strong adhesion between PVP functional layer and silver nanowires. Smooth TCE with silver nanowires could be proposed as a transparent electrode for flexible electronic or optical devices, which consist of thin electrical active layers on TCE. - Highlights: • Silver nanowire (Ag NWs) transparent electrodes were fabricated on flexible film. • Flexible film was coated with poly N-vinylpyrrolidone (PVP). • PVP layer plays roles as an adhesive layer and matrix in electrode. • Ag NWs electrode exhibited with low surface roughness of 9 nm. • Ag NWs electrode has a low resistance (18 Ω ☐{sup −1}) and high transmittance (87.6%)

Smooth-surface silver nanowire electrode with high conductivity and transparency on functional layer coated flexible film

International Nuclear Information System (INIS)

Lee, So Hee; Lim, Sooman; Kim, Haekyoung

2015-01-01

Transparent conductive electrode (TCE) with silver nanowires has been widely studied as an alternative of indium tin oxide for flexible electronic or optical devices such as organic light-emitting diodes, and solar cells. However, it has an issue of surface roughness due to nanowire's intrinsic properties. Here, to achieve a smooth electrode with high conductivity and transmittance on polyethylene terephthalate (PET) substrates, a functional layer of poly(N-vinylpyrrolidone) (PVP) is utilized with a mechanical transfer process. The silver nanowire electrode on PVP-coated PET with low surface roughness of 9 nm exhibits the low sheet resistance of 18 Ω □ −1 and high transmittance of 87.6%. It is produced by transferring the silver nanowire electrode spin-coated on the glass to PVP-coated PET using a pressure of 10 MPa for 10 min. Silver nanowire electrode on PVP-coated PET demonstrates the stable sheet resistance of 18 Ω □ −1 after the mechanical taping test due to strong adhesion between PVP functional layer and silver nanowires. Smooth TCE with silver nanowires could be proposed as a transparent electrode for flexible electronic or optical devices, which consist of thin electrical active layers on TCE. - Highlights: • Silver nanowire (Ag NWs) transparent electrodes were fabricated on flexible film. • Flexible film was coated with poly N-vinylpyrrolidone (PVP). • PVP layer plays roles as an adhesive layer and matrix in electrode. • Ag NWs electrode exhibited with low surface roughness of 9 nm. • Ag NWs electrode has a low resistance (18 Ω ☐ −1 ) and high transmittance (87.6%)

Atomically Bonded Transparent Superhydrophobic Coatings

Energy Technology Data Exchange (ETDEWEB)

Aytug, Tolga [ORNL

2015-08-01

Maintaining clarity and avoiding the accumulation of water and dirt on optically transparent surfaces such as US military vehicle windshields, viewports, periscope optical head windows, and electronic equipment cover glasses are critical to providing a high level of visibility, improved survivability, and much-needed safety for warfighters in the field. Through a combination of physical vapor deposition techniques and the exploitation of metastable phase separation in low-alkali borosilicate, a novel technology was developed for the fabrication of optically transparent, porous nanostructured silica thin film coatings that are strongly bonded to glass platforms. The nanotextured films, initially structurally superhydrophilic, exhibit superior superhydrophobicity, hence antisoiling ability, following a simple but robust modification in surface chemistry. The surfaces yield water droplet contact angles as high as 172°. Moreover, the nanostructured nature of these coatings provides increased light scattering in the UV regime and reduced reflectivity (i.e., enhanced transmission) over a broad range of the visible spectrum. In addition to these functionalities, the coatings exhibit superior mechanical resistance to abrasion and are thermally stable to temperatures approaching 500°C. The overall process technology relies on industry standard equipment and inherently scalable manufacturing processes and demands only nontoxic, naturally abundant, and inexpensive base materials. Such coatings, applied to the optical components of current and future combat equipment and military vehicles will provide a significant strategic advantage for warfighters. The inherent self-cleaning properties of such superhydrophobic coatings will also mitigate biofouling of optical windows exposed to high-humidity conditions and can help decrease repair/replacement costs, reduce maintenance, and increase readiness by limiting equipment downtime.

Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

KAUST Repository

Hussain, Muhammad Mustafa

2013-05-30

Today’s information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor – heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon – industry’s darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

KAUST Repository

Hussain, Muhammad Mustafa; Rojas, Jhonathan Prieto; Sevilla, Galo T.

2013-01-01

Today’s information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor – heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon – industry’s darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Transparent ceramic lamp envelope materials

Energy Technology Data Exchange (ETDEWEB)

Wei, G C [OSRAM SYLVANIA, 71 Cherry Hill Drive, Beverly, MA 01915 (United States)

2005-09-07

Transparent ceramic materials with optical qualities comparable to single crystals of similar compositions have been developed in recent years, as a result of the improved understanding of powder-processing-fabrication- sintering-property inter-relationships. These high-temperature materials with a range of thermal and mechanical properties are candidate envelopes for focused-beam, short-arc lamps containing various fills operating at temperatures higher than quartz. This paper reviews the composition, structure and properties of transparent ceramic lamp envelope materials including sapphire, small-grained polycrystalline alumina, aluminium oxynitride, yttrium aluminate garnet, magnesium aluminate spinel and yttria-lanthana. A satisfactory thermal shock resistance is required for the ceramic tube to withstand the rapid heating and cooling cycles encountered in lamps. Thermophysical properties, along with the geometry, size and thickness of a transparent ceramic tube, are important parameters in the assessment of its resistance to fracture arising from thermal stresses in lamps during service. The corrosive nature of lamp-fill liquid and vapour at high temperatures requires that all lamp components be carefully chosen to meet the target life. The wide range of new transparent ceramics represents flexibility in pushing the limit of envelope materials for improved beamer lamps.

Transparent and conductive paper from nanocellulose fibers

KAUST Repository

Hu, Liangbing

2013-01-01

Here we report on a novel substrate, nanopaper, made of cellulose nanofibrils, an earth abundant material. Compared with regular paper substrates, nanopaper shows superior optical properties. We have carried out the first study on the optical properties of nanopaper substrates. Since the size of the nanofibrils is much less than the wavelength of visible light, nanopaper is highly transparent with large light scattering in the forward direction. Successful depositions of transparent and conductive materials including tin-doped indium oxide, carbon nanotubes and silver nanowires have been achieved on nanopaper substrates, opening up a wide range of applications in optoelectronics such as displays, touch screens and interactive paper. We have also successfully demonstrated an organic solar cell on the novel substrate. © The Royal Society of Chemistry 2013.

Optical transparency of paper as a function of moisture content with applications to moisture measurement.

Science.gov (United States)

Forughi, A F; Green, S I; Stoeber, B

2016-02-01

Accurate measurement of the moisture content of paper is essential in papermaking and is also important in some paper-based microfluidic devices. Traditional measurement techniques provide very limited spatiotemporal resolution and working range. This article presents a novel method for moisture content measurement whose operating principle is the strong correlation between the optical transparency of paper and its moisture content. Spectrographic and microscopic measurement techniques were employed to characterize the relation of moisture content and relative transparency of four types of paper: hardwood chemi-thermomechanical pulp paper, Northern bleached softwood kraft paper, unbleached softwood kraft paper, and General Electric(®) Whatman™ grade 1 chromatography paper. It was found that for all paper types, the paper transparency increased monotonically with the moisture content (as the ratio of the mass-of-water to the mass-of-dry-paper increased from 0% to 120%). This significant increase in relative transparency occurred due to the refractive index matching role of water in wet paper. It is further shown that mechanical loading of the paper has little impact on the relative transparency, for loadings that would be typical on a paper machine. The results of two transient water absorption experiments are presented that show the utility and accuracy of the technique.

ZnO-Based Transparent Conductive Thin Films: Doping, Performance, and Processing

International Nuclear Information System (INIS)

Liu, Y.; Li, Y.; Zeng, H.

2013-01-01

ZnO-based transparent conductive thin films have attracted much attention as a promising substitute material to the currently used indium-tin-oxide thin films in transparent electrode applications. However, the detailed function of the dopants, acting on the electrical and optical properties of ZnO-based transparent conductive thin films, is not clear yet, which has limited the development and practical applications of ZnO transparent conductive thin films. Growth conditions such as substrate type, growth temperature, and ambient atmosphere all play important roles in structural, electrical, and optical properties of films. This paper takes a panoramic view on properties of ZnO thin films and reviews the very recent works on new, efficient, low-temperature, and high-speed deposition technologies. In addition, we highlighted the methods of producing ZnO-based transparent conductive film on flexible substrate, one of the most promising and rapidly emerging research areas. As optimum-processing-parameter conditions are being obtained and their influencing mechanism is becoming clear, we can see that there will be a promising future for ZnO-based transparent conductive films.

Synthesis and magnetic properties of bulk transparent PMMA/Fe-oxide nanocomposites

Science.gov (United States)

Li, Shanghua; Qin, Jian; Fornara, Andrea; Toprak, Muhammet; Muhammed, Mamoun; Kim, Do Kyung

2009-05-01

PMMA/Fe-oxide nanocomposites are fabricated by a chemical method. Monodispersed Fe-oxide nanoparticles are well dispersed in the PMMA matrix by in situ polymerization, resulting in a bulk transparent polymeric nanocomposite. The magnetic behavior of the PMMA/Fe-oxide nanocomposites is investigated. The transparent PMMA/Fe-oxide nanocomposite has potentially interesting magneto-optic applications without compromising the advantages of a lightweight, noncorrosive polymeric material with very high transparency even for bulk samples.

Synthesis and magnetic properties of bulk transparent PMMA/Fe-oxide nanocomposites

International Nuclear Information System (INIS)

Li Shanghua; Qin Jian; Fornara, Andrea; Toprak, Muhammet; Muhammed, Mamoun; Kim, Do Kyung

2009-01-01

PMMA/Fe-oxide nanocomposites are fabricated by a chemical method. Monodispersed Fe-oxide nanoparticles are well dispersed in the PMMA matrix by in situ polymerization, resulting in a bulk transparent polymeric nanocomposite. The magnetic behavior of the PMMA/Fe-oxide nanocomposites is investigated. The transparent PMMA/Fe-oxide nanocomposite has potentially interesting magneto-optic applications without compromising the advantages of a lightweight, noncorrosive polymeric material with very high transparency even for bulk samples.

Three-dimensional printing of transparent fused silica glass

Science.gov (United States)

Kotz, Frederik; Arnold, Karl; Bauer, Werner; Schild, Dieter; Keller, Nico; Sachsenheimer, Kai; Nargang, Tobias M.; Richter, Christiane; Helmer, Dorothea; Rapp, Bastian E.

2017-04-01

Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties. However, glasses and especially high-purity glasses such as fused silica glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features. These drawbacks have made glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite, here we create transparent fused silica glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable silica nanocomposite that is 3D printed and converted to high-quality fused silica glass via heat treatment. The printed fused silica glass is non-porous, with the optical transparency of commercial fused silica glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused silica glass for many applications in both industry and academia.

Transparent, Flexible, Conformal Capacitive Pressure Sensors with Nanoparticles.

Science.gov (United States)

Kim, Hyeohn; Kim, Gwangmook; Kim, Taehoon; Lee, Sangwoo; Kang, Donyoung; Hwang, Min-Soo; Chae, Youngcheol; Kang, Shinill; Lee, Hyungsuk; Park, Hong-Gyu; Shim, Wooyoung

2018-02-01

The fundamental challenge in designing transparent pressure sensors is the ideal combination of high optical transparency and high pressure sensitivity. Satisfying these competing demands is commonly achieved by a compromise between the transparency and usage of a patterned dielectric surface, which increases pressure sensitivity, but decreases transparency. Herein, a design strategy for fabricating high-transparency and high-sensitivity capacitive pressure sensors is proposed, which relies on the multiple states of nanoparticle dispersity resulting in enhanced surface roughness and light transmittance. We utilize two nanoparticle dispersion states on a surface: (i) homogeneous dispersion, where each nanoparticle (≈500 nm) with a size comparable to the visible light wavelength has low light scattering; and (ii) heterogeneous dispersion, where aggregated nanoparticles form a micrometer-sized feature, increasing pressure sensitivity. This approach is experimentally verified using a nanoparticle-dispersed polymer composite, which has high pressure sensitivity (1.0 kPa -1 ), and demonstrates excellent transparency (>95%). We demonstrate that the integration of nanoparticle-dispersed capacitor elements into an array readily yields a real-time pressure monitoring application and a fully functional touch device capable of acting as a pressure sensor-based input device, thereby opening up new avenues to establish processing techniques that are effective on the nanoscale yet applicable to macroscopic processing. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Layer 2 and 3 contention resolution and radio-over-fiber in OCDMA PON for transparent optical access in personal networks

NARCIS (Netherlands)

Huiszoon, B.; Hartog, F.T.H. den; Larrodé, M.G.; Koonen, A.M.J.

2008-01-01

In this paper, we analyze, for the first time, the eminent role of optical transparent networking in personal networks. We show how an optical access network mitigates many issues with respect to connectivity and mobility management. A concrete personal network user-scenario deduces requirements for

Optical Design of Porous ZnO/TiO2 Films for Highly Transparent Glasses with Broadband Ultraviolet Protection

Directory of Open Access Journals (Sweden)

Han Sung Song

2017-01-01

Full Text Available We present a design of a bilayer porous film structure on a glass substrate for the highly efficient ultraviolet (UV protection with high visible-light transparency. To effectively block UVB (280–315 nm and UVA (315–400 nm, titanium dioxide (TiO2 and zinc oxide (ZnO are used as absorbing layers having the appropriate coverages in different UV ranges with extinction coefficients, respectively. We show the process of refractive index (RI matching by controlling porosity (Pr. Effective RIs of porous media with TiO2 and ZnO were calculated based on volume averaging theory. Transmittances of the designed films with different effective RIs were calculated using rigorous coupled-wave analysis method. Using admittance loci method, the film thickness was optimized in center wavelengths from 450 to 550 nm. The results show that the optimal design provides high UV shielding performance at both UVA and UVB with high transparency in the visible range. We also analyze electrical field distributions in each layer and angle dependency with 3D HSV color map.

Structural and Optical Properties of Spray Coated Carbon Hybrid Materials Applied to Transparent and Flexible Electrodes

Directory of Open Access Journals (Sweden)

Grzegorz Wroblewski

2017-01-01

Full Text Available Transparent and flexible electrodes were fabricated with cost-effective spray coating technique on polyethylene terephthalate foil substrates. Particularly designed paint compositions contained mixtures of multiwalled carbon nanotubes and graphene platelets to achieve their desired rheology and electrooptical layers parameters. Electrodes were prepared in standard technological conditions without the need of clean rooms or high temperature processing. The sheet resistance and optical transmittance of fabricated layers were tuned with the number of coatings; then the most suitable relation of these parameters was designated through the figure of merit. Optical measurements were performed in the range of wavelengths from 250 to 2500 nm with a spectrophotometer with the integration sphere. Spectral dependence of total and diffusive optical transmission for thin films with graphene platelet covered by multiwalled carbon nanotubes was designated which allowed determining the relative absorbance. Layer parameters such as thickness, refractive index, energy gap, and effective reflectance coefficient show the correlation of electrooptical properties with the technological conditions. Moreover the structural properties of fabricated layers were examined by means of the X-ray diffraction.

Transparency in high-energy nuclear collisions

International Nuclear Information System (INIS)

Karol, P.J.

1992-01-01

Problems associated with transparency schemes based on sharp cutoff models are discussed. The soft spheres model of hadron-nucleus and nucleus-nucleus collisions has been used to explore the influence of the realistic nuclear density geometry on transparency. An average nuclear transparency and an average reaction transparency are defined and their dependence on target and projectile dimensions and on the hadron-nucleon collision cross section are described. The results are expected to be valid for projectile energies above several hundred MeV/nucleon through the ultrarelativistic regime. For uniform (hard sphere) nuclear profiles, methods for obtaining effective total transparencies are suggested

DSP-enabled reconfigurable and transparent spectral converters for converging optical and mobile fronthaul/backhaul networks.

Science.gov (United States)

Mao, M Z; Giddings, R P; Cao, B Y; Xu, Y T; Wang, M; Tang, J M

2017-06-12

Dynamically reconfigurable and transparent signal spectral conversion is expected to play a vital role in seamlessly integrating traditional metropolitan optical networks and mobile fronthaul/backhaul networks. In this paper, a simple digital signal processing (DSP)-enabled spectral converter is proposed and extensively investigated, for the first time, which just utilizes a single standard dual-parallel Mach-Zehnder modulator (DP-MZM) driven by SDN-controllable RF signals and DC bias currents. As an important thrust of the paper, optimum operating conditions of the proposed converter are analytically identified, statistically examined and experimentally verified. Optimum operating condition-supported spectral converter performances in IMDD-based network nodes are explored both theoretically and experimentally in terms of frequency detuning range-dependent conversion efficiency, spectral conversion-induced OSNR/power penalty and transparency to input signal characteristics. The proposed spectral converter has unique advantages including low configuration complexity, strict transparency, SDN-controllable performance reconfigurability and flexibility, as well as negligible spectral conversion-induced latency.

Near-unity transparency of a continuous metal film via cooperative effects of double plasmonic arrays

International Nuclear Information System (INIS)

Liu Zhengqi; Liu Guiqiang; Liu Xiaoshan; Huang Kuan; Chen Yuanhao; Fu Guolan; Zhou Haiqing

2013-01-01

Metal structures with high optical transparency and conductivity are of great importance for practical applications in optoelectronic devices. Here we investigate the transparency response of a continuous metal film sandwiched by double plasmonic nanoparticle arrays. The upper nanoparticle array shows efficient light trapping of the incident field, acting as a light input coupler, and the lower nanoparticle array shows a light release gate opening at the other side, acting as the light output coupler. The strong near-field light–matter interactions of the nano-scale separated plasmonic nanoparticles, the excitation of surface plasmon waves of the metal film, and their cooperative coupling effects result in broadband scattering cancellation and near-unity transparency (up to 96%) in the optical regime. The transparency response in such a structure can be efficiently modified by varying the gap distance of adjacent nanoparticles, dielectric environments, and the distance between the plasmonic array and the metal film. This motif may provide a new alternative approach to obtain transparent and highly conducting metal structures with potential applications in transparent conductors, plasmonic filters, and highly integrated light input and output components. (paper)

High-Efficiency Graphene Photo Sensor Using a Transparent Electrode

Institute of Scientific and Technical Information of China (English)

LIU Tao; HUANG Zheng

2011-01-01

We report the first implementation of transparent electrodes in bottom-gate graphene transistors used for photo detection.Compared to conventional nontransparent electrodes,the transparent electrodes allow photons to transmit through to the graphene beneath,providing an enlarged absorption area and thereby giving rise to an enhancement of photocurrent generation.The devices are fabricated with an asymmetric metallization scheme and the experimental results show that the maximum photocurrent density using the transparent electrodes (ITO and Pd/ITO) is over two times higher than that using the nontransparent electrodes (Ti and Pd),indicating a significant enhancement in the performance of graphene photo sensors.Graphene,a single-atomic-layer of carbon atoms with a zero-gap band structure has received great attention recently.[1-4] One promising application of graphene is in high-speed photodetection,owing to its high Fermi velocity (～1/300 of the speed of light),high electrical mobility (200000 cm2/Vs for both electrons and holes) and zero-gap induced wide absorption spectrum (in the visible-to-infrared range).[5,6]%We report the first implementation of transparent electrodes in bottom-gate graphene transistors used for photo detection. Compared to conventional nontransparent electrodes, the transparent electrodes allow photons to transmit through to the graphene beneath, providing an enlarged absorption area and thereby giving rise to an enhancement of photocurrent generation. The devices are fabricated with an asymmetric metallization scheme and the experimental results show that the maximum photocurrent density using the transparent electrodes (ITO and Pd/ITO) is over two times higher than that using the nontransparent electrodes (Ti and Pd), indicating a significant enhancement in the performance of graphene photo sensors.

Tunable phonon-induced transparency in bilayer graphene nanoribbons.

Science.gov (United States)

Yan, Hugen; Low, Tony; Guinea, Francisco; Xia, Fengnian; Avouris, Phaedon

2014-08-13

In the phenomenon of plasmon-induced transparency, which is a classical analogue of electromagnetically induced transparency (EIT) in atomic gases, the coherent interference between two plasmon modes results in an optical transparency window in a broad absorption spectrum. With the requirement of contrasting lifetimes, typically one of the plasmon modes involved is a dark mode that has limited coupling to the electromagnetic radiation and possesses relatively longer lifetime. Plasmon-induced transparency not only leads to light transmission at otherwise opaque frequency regions but also results in the slowing of light group velocity and enhanced optical nonlinearity. In this article, we report an analogous behavior, denoted as phonon-induced transparency (PIT), in AB-stacked bilayer graphene nanoribbons. Here, light absorption due to the plasmon excitation is suppressed in a narrow window due to the coupling with the infrared active Γ-point optical phonon, whose function here is similar to that of the dark plasmon mode in the plasmon-induced transparency. We further show that PIT in bilayer graphene is actively tunable by electrostatic gating and estimate a maximum slow light factor of around 500 at the phonon frequency of 1580 cm(-1), based on the measured spectra. Our demonstration opens an avenue for the exploration of few-photon nonlinear optics and slow light in this novel two-dimensional material.

Transparent conductor based on aluminum nanomesh

International Nuclear Information System (INIS)

Kazarkin, B; Mohammed, A S; Stsiapanau, A; Zhuk, S; Satskevich, Y; Smirnov, A

2014-01-01

We report a transparent conductor based on Al nanomesh, which was fabricated through Al anodization and etching processes. The Al anodization was performed at low temperature condition to slow down the anodization rate to achieve the well-controlled thickness of an Al nanomesh. By careful controlling of the anodization process, we can fabricate Al nanomesh transparent conductors with different sheet resistance and optical transparency in the visible spectrum range. We shall show that Al nanomesh transparent conductor is a strong contender for a transparent conductor dominated by ITO

Transparent semiconducting oxides: materials and devices

Energy Technology Data Exchange (ETDEWEB)

Grundmann, Marius; Frenzel, Heiko; Lajn, Alexander; Lorenz, Michael; Schein, Friedrich; von Wenckstern, Holger [Universitaet Leipzig, Institut fuer Experimentelle Physik II, Linnestr. 5, 04103 Leipzig (Germany)

2010-06-15

Transparent conductive oxides (TCOs) are a well-known material class allowing Ohmic conduction. A large free carrier concentration in the 10{sup 21} cm{sup -3} range and high conductivity (beyond 10{sup 4} S/cm) is feasible simultaneously with high transparency. Applications are manifold and include touch screens and front contacts for displays or solar cells. Transparent semiconducting oxides (TSO) are oxides with an intermediate free carrier concentration (typically 10{sup 14}-10{sup 18} cm{sup -3}) allowing the formation of depletion layers. We review recent results on TSO-based transistors and inverters. Most work has been reported on MISFETs. We show that MESFETs exhibit high performance and low voltage operation of oxide electronics. MESFET-based inverters offer superior performance compared to results reported for TSO MISFET-based circuits. Optical image of inverter based on thin film MESFETs with Mg{sub 0.003}Zn{sub 0.997}O channels (left) and experimental inverter characteristic for supply voltage of V{sub DD} = + 2.0 V (right). (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Effect of annealing over optoelectronic properties of graphene based transparent electrodes

Energy Technology Data Exchange (ETDEWEB)

Yadav, Shriniwas, E-mail: sniwas89@gmail.com; Kaur, Inderpreet, E-mail: inderpreety@yahoo.co.in [Academy of Scientific and Innovative Research- Central Scientific Instruments Organisation (AcSIR-CSIO), Sector-30C, Chandigarh (India); Council of Scientific and Industrial Research- Central Scientific Instruments Organisation (CSIR-CSIO), Sector-30C, Chandigarh (India)

2016-04-13

Graphene, an atom–thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σ{sub dc}/σ{sub opt}) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

Effect of annealing over optoelectronic properties of graphene based transparent electrodes

Science.gov (United States)

Yadav, Shriniwas; Kaur, Inderpreet

2016-04-01

Graphene, an atom-thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σdc/σopt) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

Highly transparent films from carboxymethylated microfibrillated cellulose: The effect of multiple homogenization steps on key properties

DEFF Research Database (Denmark)

Siró, Istvan; Plackett, David; Hedenqvist, M.

2011-01-01

We produced microfibrillated cellulose by passing carboxymethylated sulfite-softwood-dissolving pulp with a relatively low hemicellulose content (4.5%) through a high-shear homogenizer. The resulting gel was subjected to as many as three additional homogenization steps and then used to prepare...... solvent-cast films. The optical, mechanical, and oxygen-barrier properties of these films were determined. A reduction in the quantity and appearance of large fiber fragments and fiber aggregates in the films as a function of increasing homogenization was illustrated with optical microscopy, atomic force...... microscopy, and scanning electron microscopy. Film opacity decreased with increasing homogenization, and the use of three additional homogenization steps after initial gel production resulted in highly transparent films. The oxygen permeability of the films was not significantly influenced by the degree...

Optical transparency and mechanical properties of semi-refined iota carrageenan film reinforced with SiO2 as food packaging material

Science.gov (United States)

Aji, Afifah Iswara; Praseptiangga, Danar; Rochima, Emma; Joni, I. Made; Panatarani, Camellia

2018-02-01

Food packaging is important for protecting food from environmental influences such as heat, light, water vapor, oxygen, dirt, dust particles, gas emissions and so on, which leads to decrease the quality of food. The most widely used type of packaging in the food industry is plastic which is made from synthetic polymers and takes hundreds of years to biodegrade. Recently, food packaging with high bio-degradability is being developed using biopolymer combined with nanoparticles as reinforcing agent (filler) to improve its properties. In this study, semi-refined iota carrageenan films were prepared by incorporating SiO2 nanoparticles as filler at different concentrations (0%, 0.5%, 1.0% and 1.5% w/w carrageenan) using solution casting method. The optical transparency and mechanical properties (tensile strength and elongation at break) of the films were analyzed. The results showed that incorporation of SiO2 nanoparticles to carrageenan matrix on optical transparency of the films. For the mechanical properties, the highest tensile strength was found for incorporation of 0.5% SiO2, while the elongation at break of the films improved with increasing SiO2 concentration.

Spectral and optical performance of electrochromic poly(3,4-ethylenedioxythiophene) (PEDOT) deposited on transparent conducting oxide coated glass and polymer substrates

International Nuclear Information System (INIS)

Sindhu, S.; Narasimha Rao, K.; Ahuja, Sharath; Kumar, Anil; Gopal, E.S.R.

2006-01-01

Electrochromic devices utilizing conjugated polymers as electrochromic layers have gained increasing attention owing to their optical properties, fast switching times and contrast ratios. Polyethylenedioxythiophene (PEDOT) is an excellent material from its electrochromic properties, high conductivity and high stability in the doped form. Aqueous dispersions of PEDOT were either spin coated or electro-polymerized on transparent conducting oxide coated glass and polyethylene tetraphthalate (PET) film substrates. The spectro- and opto-electrochemical studies of the films on transparent conducting oxide coated glass/PET substrates were performed. These films have application in the fabrication of electrochromic windows (smart windows). Smart window devices having excellent switching characteristics over wide range of temperature are used for glazing applications. The aerospace industry is interested in the development of visors and windows that can control glare for pilots and passengers, especially if the coatings can be made on curved surfaces and electrically conducting

Optical and magnetic properties of a transparent garnet film for atomic physics experiments

Directory of Open Access Journals (Sweden)

Mari Saito

2016-12-01

Full Text Available We investigated the optical and magnetic properties of a transparent magnetic garnet with a particular focus on its applications to atomic physics experiments. The garnet film used in this study was a magnetically soft material that was originally designed for a Faraday rotator at optical communication wavelengths in the near infrared region. The film had a thickness of 2.1 μm and a small optical loss at a wavelength of λ=780 nm resonant with Rb atoms. The Faraday effect was also small and, thus, barely affected the polarization of light at λ=780 nm. In contrast, large Faraday rotation angles at shorter wavelengths enabled us to visualize magnetic domains, which were perpendicularly magnetized in alternate directions with a period of 3.6 μm. We confirmed the generation of an evanescent wave on the garnet film, which can be used for the optical observation and manipulation of atoms on the surface of the film. Finally, we demonstrated a magnetic mirror for laser-cooled Rb atoms using the garnet film.

Embedded Ag Grid Electrodes as Current Collector for Ultraflexible Transparent Solid-State Supercapacitor.

Science.gov (United States)

Xu, Jian-Long; Liu, Yan-Hua; Gao, Xu; Sun, Yilin; Shen, Su; Cai, Xinlei; Chen, Linsen; Wang, Sui-Dong

2017-08-23

Flexible transparent solid-state supercapacitors have attracted immerse attention for the power supply of next-generation flexible "see-through" or "invisible" electronics. For fabrication of such devices, high-performance flexible transparent current collectors are highly desired. In this paper, the utilization of embedded Ag grid transparent conductive electrodes (TCEs) fabricated by a facile soft ultraviolet imprinting lithography method combined with scrap techniques, as the current collector for flexible transparent solid-state supercapacitors, is demonstrated. The embedded Ag grid TCEs exhibit not only excellent optoelectronic properties (R S ∼ 2.0 Ω sq -1 and T ∼ 89.74%) but also robust mechanical properties, which could meet the conductivity, transparency, and flexibility needs of current collectors for flexible transparent supercapacitors. The obtained supercapacitor exhibits large specific capacitance, long cycling life, high optical transparency (T ∼ 80.58% at 550 nm), high flexibility, and high stability. Owing to the embedded Ag grid TCE structure, the device shows a slight capacitance loss of 2.6% even after 1000 cycles of repetitive bending for a bending radius of up to 2.0 mm. This paves the way for developing high-performance current collectors and thus flexible transparent energy storage devices, and their general applicability opens up opportunities for flexible transparent electronics.

Development of Solution-Processable, Optically Transparent Polyimides with Ultra-Low Linear Coefficients of Thermal Expansion

Directory of Open Access Journals (Sweden)

Masatoshi Hasegawa

2017-10-01

Full Text Available This paper reviews the development of new high-temperature polymeric materials applicable to plastic substrates in image display devices with a focus on our previous results. Novel solution-processable colorless polyimides (PIs with ultra-low linear coefficients of thermal expansion (CTE are proposed in this paper. First, the principles of the coloration of PI films are briefly discussed, including the influence of the processing conditions on the film coloration, as well as the chemical and physical factors dominating the low CTE characteristics of the resultant PI films to clarify the challenges in simultaneously achieving excellent optical transparency, a very high Tg, a very low CTE, and excellent film toughness. A possible approach of achieving these target properties is to use semi-cycloaliphatic PI systems consisting of linear chain structures. However, semi-cycloaliphatic PIs obtained using cycloaliphatic diamines suffer various problems during precursor polymerization, cyclodehydration (imidization, and film preparation. In particular, when using trans-1,4-cyclohexanediamine (t-CHDA as the cycloaliphatic diamine, a serious problem emerges: salt formation in the initial stages of the precursor polymerization, which terminates the polymerization in some cases or significantly extends the reaction period. The system derived from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA and t-CHDA can be polymerized by a controlled heating method and leads to a PI film with relatively good properties, i.e., excellent light transmittance at 400 nm (T400 = ~80%, a high Tg (>300 °C, and a very low CTE (10 ppm·K−1. However, this PI film is somewhat brittle (the maximum elongation at break, εb max is about 10%. On the other hand, the combination of cycloaliphatic tetracarboxylic dianhydrides and aromatic diamines does not result in salt formation. The steric structures of cycloaliphatic tetracarboxylic dianhydrides significantly influence

High performance, transparent a-IGZO TFTs on a flexible thin glass substrate

International Nuclear Information System (INIS)

Lee, Gwang Jun; Jang, Jae Eun; Kim, Joonwoo; Kim, Jung-Hye; Jeong, Soon Moon; Jeong, Jaewook

2014-01-01

We investigated electrical properties of transparent amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with amorphous indium zinc oxide (a-IZO) transparent electrodes on a flexble thin glass substrate. The TFTs show a high field-effect mobility, a good subthreshold slope and a high on/off ratio owing to the high temperature thermal annealing process which cannot be applied to typical transparent polymer-based flexible substrates. Bias stress instability tests applying tensile stress concurrently with the bending radius of up to 40 mm indicated that mechanically and electrically stable a-IGZO TFTs can be fabricated on the transparent thin glass substrate. (paper)

Towards transparent all-optical label-swapped networks: 40 Gbit/s ultra-fast dynamic wavelength routing using integrated devices

DEFF Research Database (Denmark)

Seoane, Jorge; Holm-Nielsen, Pablo Villanueva; Jeppesen, Palle

2006-01-01

All-optical routing of 40 Gbit/s 1.6 ns packets is demonstrated employing integrated devices based on SOA-MZIs. The scheme allows wavelength transparent operation and sub-nanosecond dynamic wavelength selection for future packet/label switched networks....

Optical and electrical characterization at the nanoscale with a transparent probe of a scanning tunnelling microscope

International Nuclear Information System (INIS)

Sychugov, Ilya; Omi, Hiroo; Murashita, Tooru; Kobayashi, Yoshihiro

2009-01-01

A new type of scanning probe microscope, combining features of the scanning tunnelling microscope, the scanning tunnelling luminescence microscope with a transparent probe and the aperture scanning near-field optical microscope, is described. Proof-of-concept experiments were performed under ultrahigh vacuum conditions at varying temperature on GaAs/AlAs heterostructures.

Flexible transparent electrode

Science.gov (United States)

Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

2011-06-01

This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

Scalable optical packet switch architecture for low latency and high load computer communication networks

NARCIS (Netherlands)

Calabretta, N.; Di Lucente, S.; Nazarathy, Y.; Raz, O.; Dorren, H.J.S.

2011-01-01

High performance computer and data-centers require PetaFlop/s processing speed and Petabyte storage capacity with thousands of low-latency short link interconnections between computers nodes. Switch matrices that operate transparently in the optical domain are a potential way to efficiently

High optical transmittance of aluminum ultrathin film with hexagonal nanohole arrays as transparent electrode

KAUST Repository

Du, Qing Guo; Yue, Weisheng; Wang, Zhihong; Lau, Wah Tung; Ren, Hengjiang; Li, Er-Ping

2016-01-01

We fabricate samples of aluminum ultrathin films with hexagonal nanohole arrays and characterize the transmission performance. High optical transmittance larger than 60% over a broad wavelength range from 430 nm to 750 nm is attained experimentally. The Fano-type resonance of the excited surface plasmon plaritons and the directly transmitted light attribute to both of the broadband transmission enhancement and the transmission suppression dips. © 2016 Optical Society of America.

High optical transmittance of aluminum ultrathin film with hexagonal nanohole arrays as transparent electrode

KAUST Repository

Du, Qing Guo

2016-02-24

We fabricate samples of aluminum ultrathin films with hexagonal nanohole arrays and characterize the transmission performance. High optical transmittance larger than 60% over a broad wavelength range from 430 nm to 750 nm is attained experimentally. The Fano-type resonance of the excited surface plasmon plaritons and the directly transmitted light attribute to both of the broadband transmission enhancement and the transmission suppression dips. © 2016 Optical Society of America.

High Transparent and Conductive TiO2/Ag/TiO2 Multilayer Electrode Films Deposited on Sapphire Substrate

Science.gov (United States)

Loka, Chadrasekhar; Moon, Sung Whan; Choi, YiSik; Lee, Kee-Sun

2018-03-01

Transparent conducting oxides attract intense interests due to its diverse industrial applications. In this study, we report sapphire substrate-based TiO2/Ag/TiO2 (TAT) multilayer structure of indium-free transparent conductive multilayer coatings. The TAT thin films were deposited at room temperature on sapphire substrates and a rigorous analysis has been presented on the electrical and optical properties of the films as a function of Ag thickness. The optical and electrical properties were mainly controlled by the Ag mid-layer thickness of the TAT tri-layer. The TAT films showed high luminous transmittance 84% at 550 nm along with noteworthy low electrical resistance 3.65 × 10-5 Ω-cm and sheet resistance of 3.77 Ω/square, which is better are than those of amorphous ITO films and any sapphire-based dielectric/metal/dielectric multilayer stack. The carrier concentration of the films was increased with respect to Ag thickness. We obtained highest Hackke's figure of merit 43.97 × 10-3 Ω-1 from the TAT multilayer thin film with a 16 nm thick Ag mid-layer.

Large-size, high-uniformity, random silver nanowire networks as transparent electrodes for crystalline silicon wafer solar cells.

Science.gov (United States)

Xie, Shouyi; Ouyang, Zi; Jia, Baohua; Gu, Min

2013-05-06

Metal nanowire networks are emerging as next generation transparent electrodes for photovoltaic devices. We demonstrate the application of random silver nanowire networks as the top electrode on crystalline silicon wafer solar cells. The dependence of transmittance and sheet resistance on the surface coverage is measured. Superior optical and electrical properties are observed due to the large-size, highly-uniform nature of these networks. When applying the nanowire networks on the solar cells with an optimized two-step annealing process, we achieved as large as 19% enhancement on the energy conversion efficiency. The detailed analysis reveals that the enhancement is mainly caused by the improved electrical properties of the solar cells due to the silver nanowire networks. Our result reveals that this technology is a promising alternative transparent electrode technology for crystalline silicon wafer solar cells.

Electrospun Metal Nanofiber Webs as High-Performance Transparent Electrode

KAUST Repository

Wu, Hui

2010-10-13

Transparent electrodes, indespensible in displays and solar cells, are currently dominated by indium tin oxide (ITO) films although the high price of indium, brittleness of films, and high vacuum deposition are limiting their applications. Recently, solution-processed networks of nanostructures such as carbon nanotubes (CNTs), graphene, and silver nanowires have attracted great attention as replacements. A low junction resistance between nanostructures is important for decreasing the sheet resistance. However, the junction resistances between CNTs and boundry resistances between graphene nanostructures are too high. The aspect ratios of silver nanowires are limited to ∼100, and silver is relatively expensive. Here, we show high-performance transparent electrodes with copper nanofiber networks by a low-cost and scalable electrospinning process. Copper nanofibers have ultrahigh aspect ratios of up to 100000 and fused crossing points with ultralow junction resistances, which result in high transmitance at low sheet resistance, e.g., 90% at 50 Ω/sq. The copper nanofiber networks also show great flexibility and stretchabilty. Organic solar cells using copper nanowire networks as transparent electrodes have a power efficiency of 3.0%, comparable to devices made with ITO electrodes. © 2010 American Chemical Society.

Electrospun Metal Nanofiber Webs as High-Performance Transparent Electrode

KAUST Repository

Wu, Hui; Hu, Liangbing; Rowell, Michael W.; Kong, Desheng; Cha, Judy J.; McDonough, James R.; Zhu, Jia; Yang, Yuan; McGehee, Michael D.; Cui, Yi

2010-01-01

Transparent electrodes, indespensible in displays and solar cells, are currently dominated by indium tin oxide (ITO) films although the high price of indium, brittleness of films, and high vacuum deposition are limiting their applications. Recently, solution-processed networks of nanostructures such as carbon nanotubes (CNTs), graphene, and silver nanowires have attracted great attention as replacements. A low junction resistance between nanostructures is important for decreasing the sheet resistance. However, the junction resistances between CNTs and boundry resistances between graphene nanostructures are too high. The aspect ratios of silver nanowires are limited to ∼100, and silver is relatively expensive. Here, we show high-performance transparent electrodes with copper nanofiber networks by a low-cost and scalable electrospinning process. Copper nanofibers have ultrahigh aspect ratios of up to 100000 and fused crossing points with ultralow junction resistances, which result in high transmitance at low sheet resistance, e.g., 90% at 50 Ω/sq. The copper nanofiber networks also show great flexibility and stretchabilty. Organic solar cells using copper nanowire networks as transparent electrodes have a power efficiency of 3.0%, comparable to devices made with ITO electrodes. © 2010 American Chemical Society.

Highly transparent, stable, and superhydrophobic coatings based on gradient structure design and fast regeneration from physical damage

International Nuclear Information System (INIS)

Chen, Zao; Liu, Xiaojiang; Wang, Yan; Li, Jun; Guan, Zisheng

2015-01-01

Graphical abstract: - Highlights: • Highly transparent, stable, and superhydrophobic PET film was fabricated by dip-coating way. • The gradient structure is beneficial to both hydrophobicity and transparency. • The superhydrophobic PET film after physical damage can quickly regain by one-step spary. • The fabrication method is available for various substrates and large-scale production. - Abstract: Optical transparency, mechanical flexibility, and fast regeneration are important factors to expand the application of superhydrophobic surfaces. Herein, we fabricated highly transparent, stable, and superhydrophobic coatings through a novel gradient structure design by versatile dip-coating of silica colloid particles (SCPs) and diethoxydimethysiliane cross-linked silica nanoparticles (DDS-SNPs) on polyethylene terephthalate (PET) film and glass, followed by the modification of octadecyltrichlorosiliane (OTCS). When the DDS concentration reached 5 wt%, the modified SCPs/DDS-SNPs coating exhibited a water contact angle (WCA) of 153° and a sliding angle (SA) <5°. Besides, the average transmittance of this superhydrophobic coating on PET film and glass was increased by 2.7% and 1% in the visible wavelength, respectively. This superhydrophobic coating also showed good robustness and stability against water dropping impact, ultrasonic damage, and acid solution. Moreover, the superhydrophobic PET film after physical damage can quickly regain the superhydrophobicity by one-step spray regenerative solution of dodecyltrichlorosilane (DTCS) modified silica nanoparticles at room temperature. The demonstrated method for the preparation and regeneration of superhydrophobic coating is available for different substrates and large-scale production at room temperature.

Microcrystalline silicon carbide alloys prepared with HWCVD as highly transparent and conductive window layers for thin film solar cells

International Nuclear Information System (INIS)

Finger, F.; Astakhov, O.; Bronger, T.; Carius, R.; Chen, T.; Dasgupta, A.; Gordijn, A.; Houben, L.; Huang, Y.; Klein, S.; Luysberg, M.; Wang, H.; Xiao, L.

2009-01-01

Crystalline silicon carbide alloys have a very high potential as transparent conductive window layers in thin-film solar cells provided they can be prepared in thin-film form and at compatible deposition temperatures. The low-temperature deposition of such material in microcrystalline form (μc-Si:C:H) was realized by use of monomethylsilane precursor gas diluted in hydrogen with the Hot-Wire Chemical Vapor Deposition process. A wide range of deposition parameters has been investigated and the structural, electronic and optical properties of the μc-SiC:H thin films have been studied. The material, which is strongly n-type from unintentional doping, has been used as window layer in n-side illuminated microcrystalline silicon solar cells. High short-circuit current densities are obtained due to the high transparency of the material resulting in a maximum solar cell conversion efficiency of 9.2%.

Tunable high-channel-count bandpass plasmonic filters based on an analogue of electromagnetically induced transparency

International Nuclear Information System (INIS)

Lu Hua; Liu Xueming; Wang Guoxi; Mao Dong

2012-01-01

We have proposed a novel type of bandpass plasmonic filter consisting of metal–insulator–metal bus waveguides coupled with a series of side-coupled cavities and stub waveguides. The theoretical modeling demonstrates that our waveguide-resonator system performs a plasmonic analogue of electromagnetically induced transparency (EIT) in atomic systems, as is confirmed by numerical experiments. The plasmonic EIT-like response enables the realization of nanoscale bandpass filters with multiple channels. Additionally, the operating wavelengths and bandwidths of our filters can be efficiently tuned by adjusting the geometric parameters such as the lengths of stub waveguides and the coupling distances between the cavities and stub waveguides. The ultracompact configurations contribute to the achievement of wavelength division multiplexing systems for optical computing and communications in highly integrated optical circuits. (paper)

Graphene-Based Flexible and Transparent Tunable Capacitors.

Science.gov (United States)

Man, Baoyuan; Xu, Shicai; Jiang, Shouzheng; Liu, Aihua; Gao, Shoubao; Zhang, Chao; Qiu, Hengwei; Li, Zhen

2015-12-01

We report a kind of electric field tunable transparent and flexible capacitor with the structure of graphene-Bi1.5MgNb1.5O7 (BMN)-graphene. The graphene films with low sheet resistance were grown by chemical vapor deposition. The BMN thin films were fabricated on graphene by using laser molecular beam epitaxy technology. Compared to BMN films grown on Au, the samples on graphene substrates show better quality in terms of crystallinity, surface morphology, leakage current, and loss tangent. By transferring another graphene layer, we fabricated flexible and transparent capacitors with the structure of graphene-BMN-graphene. The capacitors show a large dielectric constant of 113 with high dielectric tunability of ~40.7 % at a bias field of 1.0 MV/cm. Also, the capacitor can work stably in the high bending condition with curvature radii as low as 10 mm. This flexible film capacitor has a high optical transparency of ~90 % in the visible light region, demonstrating their potential application for a wide range of flexible electronic devices.

Fabrication of ATO/Graphene Multi-layered Transparent Conducting Thin Films

Science.gov (United States)

Li, Na; Chen, Fei; Shen, Qiang; Wang, Chuanbin; Zhang, Lianmeng

2013-03-01

A novel transparent conducting oxide based on the ATO/graphene multi-layered thin films has been developed to satisfy the application of transparent conductive electrode in solar cells. The ATO thin films are prepared by pulsed laser deposition method with high quality, namely the sheet resistance of 49.5 Ω/sq and average transmittance of 81.9 %. The prepared graphene sheet is well reduced and shows atomically thin, spotty distributed appearance on the top of the ATO thin films. The XRD and optical micrographs are used to confirm the successfully preparation of the ATO/graphene multi-layered thin films. The Hall measurements and UV-Vis spectrophotometer are conducted to evaluate the sheet resistance and optical transmittance of the innovative structure. It is found that graphene can improve the electrical properties of the ATO thin films with little influence on the optical transmittance.

Fabrication of ATO/Graphene Multi-layered Transparent Conducting Thin Films

International Nuclear Information System (INIS)

Li Na; Chen Fei; Shen Qiang; Wang Chuanbin; Zhang Lianmeng

2013-01-01

A novel transparent conducting oxide based on the ATO/graphene multi-layered thin films has been developed to satisfy the application of transparent conductive electrode in solar cells. The ATO thin films are prepared by pulsed laser deposition method with high quality, namely the sheet resistance of 49.5 Ω/sq and average transmittance of 81.9 %. The prepared graphene sheet is well reduced and shows atomically thin, spotty distributed appearance on the top of the ATO thin films. The XRD and optical micrographs are used to confirm the successfully preparation of the ATO/graphene multi-layered thin films. The Hall measurements and UV-Vis spectrophotometer are conducted to evaluate the sheet resistance and optical transmittance of the innovative structure. It is found that graphene can improve the electrical properties of the ATO thin films with little influence on the optical transmittance.

Bioinspired Superhydrophobic Highly Transmissive Films for Optical Applications.

Science.gov (United States)

Vüllers, Felix; Gomard, Guillaume; Preinfalk, Jan B; Klampaftis, Efthymios; Worgull, Matthias; Richards, Bryce; Hölscher, Hendrik; Kavalenka, Maryna N

2016-11-01

Inspired by the transparent hair layer on water plants Salvinia and Pistia, superhydrophobic flexible thin films, applicable as transparent coatings for optoelectronic devices, are introduced. Thin polymeric nanofur films are fabricated using a highly scalable hot pulling technique, in which heated sandblasted steel plates are used to create a dense layer of nano- and microhairs surrounding microcavities on a polymer surface. The superhydrophobic nanofur surface exhibits water contact angles of 166 ± 6°, sliding angles below 6°, and is self-cleaning against various contaminants. Additionally, subjecting thin nanofur to argon plasma reverses its surface wettability to hydrophilic and underwater superoleophobic. Thin nanofur films are transparent and demonstrate reflection values of less than 4% for wavelengths ranging from 300 to 800 nm when attached to a polymer substrate. Moreover, used as translucent self-standing film, the nanofur exhibits transmission values above 85% and high forward scattering. The potential of thin nanofur films for extracting substrate modes from organic light emitting diodes is tested and a relative increase of the luminous efficacy of above 10% is observed. Finally, thin nanofur is optically coupled to a multicrystalline silicon solar cell, resulting in a relative gain of 5.8% in photogenerated current compared to a bare photovoltaic device. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An optically transparent metasurface for broadband microwave antireflection

Science.gov (United States)

Zhao, Jie; Zhang, Cheng; Cheng, Qiang; Yang, Jin; Cui, Tie Jun

2018-02-01

Metamaterial absorbers and diffusers provide powerful routes to decrease the backward reflection significantly with advantages of ultrathin profile and customized bandwidth. Simultaneous control of the absorption and scattering behaviors of the metamaterials which helps to improve the suppression capabilities of backward reflection, however, still remains a challenge. Aiming at this goal, we propose a metasurface constituted by two kinds of elements in a pseudorandom arrangement. By the use of indium tin oxide with moderate sheet resistance in the meta-atoms, enhanced absorption of energy can be achieved in a broad spectrum when interacted with illuminated waves. In the meanwhile, electromagnetic diffusion will be invoked from the destructive interference among the elements, giving rise to significant reduction of specular reflection as a result. Excellent agreements are observed between simulation and experiment with pronounced reflection suppression from 6.8 GHz to 19.4 GHz. In addition, the optical transparence of the patterns and substrates makes the proposed metasurface a promising candidate for future applications like photovoltaic solar cells and electromagnetic shielding glasses.

Transparent Heat-Resistant PMMA Copolymers for Packing Light-Emitting Diode Materials

Directory of Open Access Journals (Sweden)

Shu-Ling Yeh

2015-07-01

Full Text Available Transparent and heat-resistant poly(methyl methacrylate copolymers were synthesized by bulk polymerizing methyl methacrylate (MMA, isobornyl methacrylate (IBMA, and methacrylamide (MAA monomers. Copolymerization was performed using a chain transfer agent to investigate the molecular weight changes of these copolymers, which exhibited advantages including a low molecular weight distribution, excellent optical properties, high transparency, high glass transition temperature, low moisture absorption, and pellets that can be readily mass produced by using extrusion or jet injection for packing light-emitting diode materials.

Making structured metals transparent for ultrabroadband electromagnetic waves and acoustic waves

International Nuclear Information System (INIS)

Fan, Ren-Hao; Peng, Ru-Wen; Huang, Xian-Rong; Wang, Mu

2015-01-01

In this review, we present our recent work on making structured metals transparent for broadband electromagnetic waves and acoustic waves via excitation of surface waves. First, we theoretically show that one-dimensional metallic gratings can become transparent and completely antireflective for extremely broadband electromagnetic waves by relying on surface plasmons or spoof surface plasmons. Second, we experimentally demonstrate that metallic gratings with narrow slits are highly transparent for broadband terahertz waves at oblique incidence and high transmission efficiency is insensitive to the metal thickness. Further, we significantly develop oblique metal gratings transparent for broadband electromagnetic waves (including optical waves and terahertz ones) under normal incidence. In the third, we find the principles of broadband transparency for structured metals can be extended from one-dimensional metallic gratings to two-dimensional cases. Moreover, similar phenomena are found in sonic artificially metallic structures, which present the transparency for broadband acoustic waves. These investigations provide guidelines to develop many novel materials and devices, such as transparent conducting panels, antireflective solar cells, and other broadband metamaterials and stealth technologies. - Highlights: • Making structured metals transparent for ultrabroadband electromagnetic waves. • Non-resonant excitation of surface plasmons or spoof surface plasmons. • Sonic artificially metallic structures transparent for broadband acoustic waves

Making structured metals transparent for ultrabroadband electromagnetic waves and acoustic waves

Energy Technology Data Exchange (ETDEWEB)

Fan, Ren-Hao [National Laboratory of Solid State Microstructures and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Peng, Ru-Wen, E-mail: rwpeng@nju.edu.cn [National Laboratory of Solid State Microstructures and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Huang, Xian-Rong [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Wang, Mu [National Laboratory of Solid State Microstructures and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

2015-07-15

In this review, we present our recent work on making structured metals transparent for broadband electromagnetic waves and acoustic waves via excitation of surface waves. First, we theoretically show that one-dimensional metallic gratings can become transparent and completely antireflective for extremely broadband electromagnetic waves by relying on surface plasmons or spoof surface plasmons. Second, we experimentally demonstrate that metallic gratings with narrow slits are highly transparent for broadband terahertz waves at oblique incidence and high transmission efficiency is insensitive to the metal thickness. Further, we significantly develop oblique metal gratings transparent for broadband electromagnetic waves (including optical waves and terahertz ones) under normal incidence. In the third, we find the principles of broadband transparency for structured metals can be extended from one-dimensional metallic gratings to two-dimensional cases. Moreover, similar phenomena are found in sonic artificially metallic structures, which present the transparency for broadband acoustic waves. These investigations provide guidelines to develop many novel materials and devices, such as transparent conducting panels, antireflective solar cells, and other broadband metamaterials and stealth technologies. - Highlights: • Making structured metals transparent for ultrabroadband electromagnetic waves. • Non-resonant excitation of surface plasmons or spoof surface plasmons. • Sonic artificially metallic structures transparent for broadband acoustic waves.

Metal{Polymer Hybrid Materials For Flexible Transparent Conductors

Science.gov (United States)

Narayanan, Sudarshan

The field of organic electronics, till recently a mere research topic, is currently making rapid strides and tremendous progress into entering the mainstream electronics industry with several applications and products such as OLED televisions, curved displays, wearable devices, flexible solar cells, etc. already having been commercialized. A major component in these devices, especially for photovoltaic applications, is a transparent conductor used as one of the electrodes, which in most commercial applications are highly doped wide bandgap semiconducting oxides also called Transparent Conducting Oxides (TCOs). However, TCOs exhibit inherent disadvantages such as limited supply, brittle mechanical properties, expensive processing that present major barriers for the more widespread economic use in applications such as exible transparent conductors, owing to which suitable alternative materials are being sought. In this context we present two approaches in realizing alternative TCs using metal-polymer hybrid materials, with high figures of merit that are easily processable, reasonably inexpensive and mechanically robust as well. In this context, our first approach employs laminated metal-polymer photonic bandgap structures to effectively tune optical and electrical properties by an appropriate design of the material stack, factoring in the effect of the materials involved, the number of layers and layer properties. We have found that in the case of a four-bilayer Au/polystyrene (AujPS) laminate structure, an enhancement in optical transmittance of ˜ 500% in comparison to a monolithic A film of equivalent thickness, can be achieved. The high conductivity (˜ 106 O--1cm--1) of the metallic component, Au in this case, also ensures planar conductivity; metallic inclusions in the dielectric polymer layer can in principle give rise to out-of-plane conductivity as well enabling a fully functional TC. Such materials also have immense potential for several other applications

Formation of electrically conducting, transparent films using silver nanoparticles connected by carbon nanotubes

International Nuclear Information System (INIS)

Hwang, Sunna; Noh, Sun Young; Kim, Heesuk; Park, Min; Lee, Hyunjung

2014-01-01

To achieve both optical transparency and electrical conductivity simultaneously, we fabricated a single-walled carbon nanotube (SWNT)/silver fiber-based transparent conductive film using silver fibers produced by the electrospinning method. Electrospun silver fibers provided a segregated structure with the silver nanoparticles within the fibrous microstructures as a framework. Additional deposition of SWNT/poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) layers resulted in a remarkable decrease in the surface resistance from very high value (> 3000 kΩ/sq) for the films of electrospun silver fibers, without affecting the optical transmittance at 550 nm. The surface resistance of the SWNT/silver film after the deposition of three layers decreased to 17 Ω/sq with 80% transmittance. Successive depositions of SWNT/PEDOT:PSS layers reduced the surface resistance to 2 Ω/sq without severe loss in optical transmittance (ca. 65%). The transparent conductive films exhibited a performance comparable to that of commercial indium tin oxide films. The individual silver nanoparticles within the electrospun fibers on the substrate were interconnected with SWNTs, which resulted in the efficient activation of a conductive network by bridging the gaps among separate silver nanoparticles. Such a construction of microscopically conductive networks with the minimum use of electrically conductive nanomaterials produced superior electrical conductivity, while maintaining the optical transparency. - Highlights: • Silver fibrous structures were produced by electrospinning method. • SWNTs/PEDOT:PSS was deposited on silver fibrous structures. • These films exhibited a low sheet resistance (∼ 17 Ω/sq) at ∼ 80% optical transparency. • Successive depositions of SWNT/PEDOT:PSS layers reduced the surface resistance to 2 Ω/sq

Quenching of surface traps in Mn doped ZnO thin films for enhanced optical transparency

International Nuclear Information System (INIS)

Ilyas, Usman; Rawat, R.S.; Roshan, G.; Tan, T.L.; Lee, P.; Springham, S.V.; Zhang, Sam; Fengji Li; Chen, R.; Sun, H.D.

2011-01-01

The structural and photoluminescence analyses were performed on un-doped and Mn doped ZnO thin films grown on Si (1 0 0) substrate by pulsed laser deposition (PLD) and annealed at different post-deposition temperatures (500-800 deg. C). X-ray diffraction (XRD), employed to study the structural properties, showed an improved crystallinity at elevated temperatures with a consistent decrease in the lattice parameter 'c'. The peak broadening in XRD spectra and the presence of Mn 2p3/2 peak at ∼640 eV in X-ray Photoelectron Spectroscopic (XPS) spectra of the doped thin films confirmed the successful incorporation of Mn in ZnO host matrix. Extended near band edge emission (NBE) spectra indicated the reduction in the concentration of the intrinsic surface traps in comparison to the doped ones resulting in improved optical transparency. Reduced deep level emission (DLE) spectra in doped thin films with declined PL ratio validated the quenching of the intrinsic surface traps thereby improving the optical transparency and the band gap, essential for optoelectronic and spintronic applications. Furthermore, the formation and uniform distribution of nano-sized grains with improved surface features of Mn-doped ZnO thin films were observed in Field Emission Scanning Electron Microscopy (FESEM) images.

Producing high-quality negatives from ERTS black-and-white transparancies

Science.gov (United States)

Richard J. Myhre

1973-01-01

A method has been devised for producing high-quality black-and-white negatives quickly and efficiently from dense transparencies orgininating from Earth Resources Technology Satellite imagery. Transparencies are evaluated on a standard light source to determine exposure and processing information needed for making negatives. A “System ASA Rating” was developed by...

Fluoroscopic screen which is optically homogeneous

International Nuclear Information System (INIS)

1975-01-01

A high efficiency fluoroscopic screen for X-ray examination consists of an optically homogeneous crystal plate of fluorescent material such as activated cesium iodide, supported on a transparent protective plate, with the edges of the assembly beveled and optically coupled to a light absorbing compound. The product is dressed to the desired thickness and provided with an X-ray-transparent light-opaque cover. (Auth.)

Electromagnetically induced transparency in an open multilevel system

International Nuclear Information System (INIS)

Li Tian; Lu Meiju; Weinstein, Jonathan D.

2011-01-01

Electromagnetically induced transparency in a multilevel system is investigated in 173 Yb. The level structure investigated is ''open'' in that the light that gives rise to the transparency also resonantly couples the atoms to excited states which do not exhibit electromagnetically induced transparency. The resulting reduction of transparency is investigated experimentally and theoretically. It is found that, while the transparency is poor in certain regimes, it can be made to perform arbitrarily well in the limit of a large intensity imbalance between the optical fields.

Transparent conducting oxide nanotubes

Science.gov (United States)

Alivov, Yahya; Singh, Vivek; Ding, Yuchen; Nagpal, Prashant

2014-09-01

Thin film or porous membranes made of hollow, transparent, conducting oxide (TCO) nanotubes, with high chemical stability, functionalized surfaces and large surface areas, can provide an excellent platform for a wide variety of nanostructured photovoltaic, photodetector, photoelectrochemical and photocatalytic devices. While large-bandgap oxide semiconductors offer transparency for incident light (below their nominal bandgap), their low carrier concentration and poor conductivity makes them unsuitable for charge conduction. Moreover, materials with high conductivity have nominally low bandgaps and hence poor light transmittance. Here, we demonstrate thin films and membranes made from TiO2 nanotubes heavily-doped with shallow Niobium (Nb) donors (up to 10%, without phase segregation), using a modified electrochemical anodization process, to fabricate transparent conducting hollow nanotubes. Temperature dependent current-voltage characteristics revealed that TiO2 TCO nanotubes, doped with 10% Nb, show metal-like behavior with resistivity decreasing from 6.5 × 10-4 Ωcm at T = 300 K (compared to 6.5 × 10-1 Ωcm for nominally undoped nanotubes) to 2.2 × 10-4 Ωcm at T = 20 K. Optical properties, studied by reflectance measurements, showed light transmittance up to 90%, within wavelength range 400 nm-1000 nm. Nb doping also improves the field emission properties of TCO nanotubes demonstrating an order of magnitude increase in field-emitter current, compared to undoped samples.

Direct ink write fabrication of transparent ceramic gain media

Science.gov (United States)

Jones, Ivy Krystal; Seeley, Zachary M.; Cherepy, Nerine J.; Duoss, Eric B.; Payne, Stephen A.

2018-01-01

Solid-state laser gain media based on the garnet structure with two spatially distinct but optically contiguous regions have been fabricated. Transparent gain media comprised of a central core of Y2.97Nd0.03Al5.00O12.00 (Nd:YAG) and an undoped cladding region of Y3Al5O12 (YAG) were fabricated by direct ink write and transparent ceramic processing. Direct ink write (DIW) was employed to form the green body, offering a general route to preparing functionally structured solid-state laser gain media. Fully-dense transparent optical ceramics in a "top hat" geometry with YAG/Nd:YAG have been fabricated by DIW methods with optical scatter at 1064 nm of <3%/cm.

Highly conducting and transparent Ti-doped CdO films by pulsed laser deposition

International Nuclear Information System (INIS)

Gupta, R.K.; Ghosh, K.; Patel, R.; Kahol, P.K.

2009-01-01

Titanium-doped cadmium oxide thin films were deposited on quartz substrate by pulsed laser deposition technique. The effect of substrate temperature on structural, optical and electrical properties was studied. The films grown at high temperature show (2 0 0) preferred orientation, while films grown at low temperature have both (1 1 1) and (2 0 0) orientation. These films are highly transparent (63-79%) in visible region, and transmittance of the films depends on growth temperature. The band gap of the films varies from 2.70 eV to 2.84 eV for various temperatures. It is observed that resistivity increases with growth temperature after attaining minimum at 150 deg. C, while carrier concentration continuously decreases with temperature. The low resistivity, high transmittance and wide band gap titanium-doped CdO films could be an excellent candidate for future optoelectronic and photovoltaic applications.

Partially Transparent Petaled Mask/Occulter for Visible-Range Spectrum

Science.gov (United States)

Shiri, Ron Shahram; Wasylkiwskyj, Wasyl

2013-01-01

The presence of the Poisson Spot, also known as the spot of Arago, has been known since the 18th century. This spot is the consequence of constructive interference of light diffracted by the edge of the obstacle where the central position can be determined by symmetry of the object. More recently, many NASA missions require the suppression of this spot in the visible range. For instance, the exoplanetary missions involving space telescopes require telescopes to image the planetary bodies orbiting central stars. For this purpose, the starlight needs to be suppressed by several orders of magnitude in order to image the reflected light from the orbiting planet. For the Earth-like planets, this suppression needs to be at least ten orders of magnitude. One of the common methods of suppression involves sharp binary petaled occulters envisioned to be placed many thousands of miles away from the telescope blocking the starlight. The suppression of the Poisson Spot by binary sharp petal tips can be problematic when the thickness of the tips becomes smaller than the wavelength of the incident beam. First they are difficult to manufacture and also it invalidates the laws of physical optics. The proposed partially transparent petaled masks/occulters compensate for this sharpness with transparency along the surface of the petals. Depending on the geometry of the problem, this transparency can be customized such that only a small region of the petal is transparent and the remaining of the surface is opaque. This feature allows easy fabrication of this type of occultation device either as a mask or occulter. A partially transparent petaled mask/ occulter has been designed for the visible spectrum range. The mask/occulter can suppress the intensity along the optical axis up to ten orders of magnitude. The design process can tailor the mask shape, number of petals, and transparency level to the near-field and farfield diffraction region. The mask/occulter can be used in space

Highly Transparent, Visible-Light Photodetector Based on Oxide Semiconductors and Quantum Dots.

Science.gov (United States)

Shin, Seung Won; Lee, Kwang-Ho; Park, Jin-Seong; Kang, Seong Jun

2015-09-09

Highly transparent phototransistors that can detect visible light have been fabricated by combining indium-gallium-zinc oxide (IGZO) and quantum dots (QDs). A wide-band-gap IGZO film was used as a transparent semiconducting channel, while small-band-gap QDs were adopted to absorb and convert visible light to an electrical signal. Typical IGZO thin-film transistors (TFTs) did not show a photocurrent with illumination of visible light. However, IGZO TFTs decorated with QDs showed enhanced photocurrent upon exposure to visible light. The device showed a responsivity of 1.35×10(4) A/W and an external quantum efficiency of 2.59×10(4) under illumination by a 635 nm laser. The origin of the increased photocurrent in the visible light was the small band gap of the QDs combined with the transparent IGZO films. Therefore, transparent phototransistors based on IGZO and QDs were fabricated and characterized in detail. The result is relevant for the development of highly transparent photodetectors that can detect visible light.

Enhancing upconversion emission of Er, Yb co-doped highly transparent YF3 films by synergistic tuning nano-textured morphology and crystallinity

International Nuclear Information System (INIS)

Qu, Ming-Hao; Wang, Ru-Zhi; Chen, Yan; Zhang, Ying; Li, Kai-Yu; Zhou, Hua; Yan, Hui

2014-01-01

Highly transparent Er, Yb codoped YF 3 upconversion films were successfully prepared by electron beam deposition method. The effects of the substrate temperature on the morphology, crystallinity and emission characteristics of Er, Yb codoped YF 3 films were studied carefully. It was found that the morphology and crystallinity varied from smooth amorphous to root-intertwined polycrystalline structure with the substrate temperature increase. Besides, the emission characteristics of the films can be modulated by the synergy of their surface morphologies and crystallinities. Remarkably, a large enhancement of the upconversion emission, up to five decades while only an insignificant decrease of the optical transmittance (10% at most), was achieved by forming root-intertwined polycrystalline structures. These highly transparent upconversion films may have good potential for enhancing the conversion efficiency of wide band-gap solar cells. -- Highlights: • Er, Yb co-dopedYF 3 upconversion films have been successfully prepared. • The upconversion property can be modulated by morphology and crystallinity. • The upconversion transparent YF 3 films are promising for solar cells applications

Toward transparent and self-activated graphene harmonic transponder sensors

Science.gov (United States)

Huang, Haiyu Harry; Sakhdari, Maryam; Hajizadegan, Mehdi; Shahini, Ali; Akinwande, Deji; Chen, Pai-Yen

2016-04-01

We propose the concept and design of a transparent, flexible, and self-powered wireless sensor comprising a graphene-based sensor/frequency-modulator circuitry and a graphene antenna. In this all-graphene device, the multilayered-graphene antenna receives the fundamental tone at C band and retransmits the frequency-modulated sensed signal (harmonic tone) at X band. The frequency orthogonality between the received/re-transmitted signals may enable high-performance sensing in severe interference/clutter background. Here, a fully passive, quad-ring frequency multiplier is proposed using graphene field-effect transistors, of which the unique ambipolar charge transports render a frequency doubling effect with conversion gain being chemically sensitive to exposed gas/molecular/chemical/infectious agents. This transparent, light-weight, and self-powered system may potentially benefit a number of wireless sensing and diagnosis applications, particularly for smart contact lenses/glasses and microscope slides that require high optical transparency.

Pitfalls in looking for color transparency at intermediate energies

International Nuclear Information System (INIS)

Frankfurt, L.L.; Strikman, M.I.; Zhalov, M.B.

1994-01-01

The problems and uncertainties in the search for color transparency at intermediate Q 2 are considered. We show that conventional (optical) model [distorted wave impulse approximation (DWIA)] predicts a substantial change of the transparency, T, with Q 2 in the kinematics of the Ne-18 (e,e ' p) experiment, while the color transparency phenomenon may lead to nearly Q 2 independent T. In the case of A(p,2p) reaction we demonstrate that the conventional optical model describes well the 1 GeV A(p,2p) data but not the transparency observed at higher energies. We find also that DWIA (with or without color transparency) predicts strong dependence of T on the momentum of the struck nucleon which is consistent with the pattern of the Brookhaven National Laboratory A(p,2p) data at p N =6 GeV/c and 10 GeV/c

Highly transparent, low-haze, hybrid cellulose nanopaper as electrodes for flexible electronics

Science.gov (United States)

Xuezhu Xu; Jian Zhou; Long Jiang; Gilles Lubineau; Tienkhee Ng; Boon S. Ooi; Hsien-Yu Liao; Chao Shen; Long Chen; Junyong Zhu

2016-01-01

Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength....

Influence of graphite contamination on the optical properties of transparent spinel obtained by spark plasma sintering

International Nuclear Information System (INIS)

Bernard-Granger, G.; Benameur, N.; Guizard, C.; Nygren, M.

2009-01-01

The optical properties of transparent spinel sintered by spark plasma sintering have been investigated for incident electromagnetic radiations with wavelengths in the range 0.2-2 μm. It is shown that residual porosities and second-phase graphite particles have a strong influence on the in-line transmittance. Because of the graphite particles, the in-line transmittance measured does not approach that of monocrystalline spinel for wavelengths above 1 μm

Influence of annealing temperature on structural and optical properties of Lu2O3:Eu3+, Tb3+ transparent films

International Nuclear Information System (INIS)

Morales-Ramírez, Ángel de Jesús; García-Murillo, Antonieta; Carrillo-Romo, Felipe de Jesús; Garrido-Hernández, Aristeo; García-Hernández, Margarita

2015-01-01

Highlights: • Lu 2 O 3 :Eu 3+ , Tb 3+ films were synthesized by sol–gel and by dip-coating technique. • Effects of annealing treatment on structural and optical properties were studied. • Optogeometrical characteristics of synthesized films were analyzed. • X-ray diffraction results showed that Lu 2 O 3 :Eu 3+ , Tb 3+ crystallizes at 700 °C. • High reddish emission on transparent films with at least 1 μm thick was observed. - Abstract: High-optical quality Lu 2 O 3 :Eu 3+ 5 mol%, X Tb 3+ (X = 0–0.04 mol%) thin films were prepared by the sol–gel process and dip-coating technique. The procedure was as follows: lutetium, europium and terbium nitrates were used as precursors, and ethanol as a solvent. Etylenglycol (EG) was added as a sol stabilizer, and the pH was adjusted by acetic acid. After 10 dipping-cycles, followed by an annealing process (600–900 °C) for 1 h, transparent, smooth and crack-free films (ra = 8–9 nm) were formed. The X-ray diffraction (XRD) results showed crystallized films into the cubic structure at 800 °C. The ellipsometry results showed that the thickness of the films varied from 1 to 1.4 μm at 1000 and 600 °C, respectively. Finally, the films presented a typical Eu 3+ red emission at 611 nm ( 5 D 0 → 7 F 2 ); furthermore, the effect of the Tb 3+ content showed that the highest emission intensity corresponded to the lower Tb 3+ content

Highly transparent and durable superhydrophobic hybrid nanoporous coatings fabricated from polysiloxane.

Science.gov (United States)

Wang, Ding; Zhang, Zongbo; Li, Yongming; Xu, Caihong

2014-07-09

Highly transparent and durable superhydrophobic hybrid nanoporous coatings with different surface roughnesses were fabricated via a simple solidification-induced phase-separation method using a liquid polysiloxane (PSO) containing SiH and SiCH═CH2 groups as precursors and methyl-terminated poly(dimethylsiloxane)s (PDMS) as porogens. Owing to the existence of SiCHn units, the hybrid material is intrinsically hydrophobic without modification with expensive fluorinated reagents. The roughness of the coating can be easily controlled at the nanometer scale by changing the viscosity of PDMS to achieve both superhydrophobicity and high transparency. The influence of surface roughness on the transparency and hydrophobicity of the coatings was investigated. The enhancement from hydrophobic to superhydrophobic with increasing surface roughness can be explained by the transition from the Wenzel state to the Cassie state. The optimum performance coating has an average transmittance higher than 85% in the visible-light range (400-780 nm), a water contact angle of 155°, and a slide angle lower than 1°. The coatings also exhibit good thermal and mechanical stability and durable superhydrophobicity, which paves the way for real applications of highly transparent superhydrophobic coatings.

Bioinspired Transparent Laminated Composite Film for Flexible Green Optoelectronics.

Science.gov (United States)

Lee, Daewon; Lim, Young-Woo; Im, Hyeon-Gyun; Jeong, Seonju; Ji, Sangyoon; Kim, Yong Ho; Choi, Gwang-Mun; Park, Jang-Ung; Lee, Jung-Yong; Jin, Jungho; Bae, Byeong-Soo

2017-07-19

Herein, we report a new version of a bioinspired chitin nanofiber (ChNF) transparent laminated composite film (HCLaminate) made of siloxane hybrid materials (hybrimers) reinforced with ChNFs, which mimics the nanofiber-matrix structure of hierarchical biocomposites. Our HCLaminate is produced via vacuum bag compressing and subsequent UV-curing of the matrix resin-impregnated ChNF transparent paper (ChNF paper). It is worthwhile to note that this new type of ChNF-based transparent substrate film retains the strengths of the original ChNF paper and compensates for ChNF paper's drawbacks as a flexible transparent substrate. As a result, compared with high-performance synthetic plastic films, such as poly(ethylene terephthalate), poly(ether sulfone), poly(ethylene naphthalate), and polyimide, our HCLaminate is characterized to exhibit extremely smooth surface topography, outstanding optical clarity, high elastic modulus, high dimensional stability, etc. To prove our HCLaminate as a substrate film, we use it to fabricate flexible perovskite solar cells and a touch-screen panel. As far as we know, this work is the first to demonstrate flexible optoelectronics, such as flexible perovskite solar cells and a touch-screen panel, actually fabricated on a composite film made of ChNF. Given its desirable macroscopic properties, we envision our HCLaminate being utilized as a transparent substrate film for flexible green optoelectronics.

Nonlinear optical properties of an electromagnetically induced transparency medium interacting with two quantized fields

CERN Document Server

Kuang-Leman; Wu Yong Shi

2003-01-01

We study linear and nonlinear optical properties of an electromagnetically induced transparency (EIT) medium interacting with two quantized laser fields in the adiabatic EIT case. We show that the EIT medium exhibits normal dispersion. Kerr and higher-order nonlinear refractive index coefficients are also calculated in a completely analytical form. It is indicated that the EIT medium exhibits giant resonantly enhanced nonlinearities. We discuss the response of the EIT medium to nonclassical light fields and find that the polarization vanishes when the probe laser is initially in a nonclassical state of no single-photon coherence.

Hybrid sol-gel optical materials

Science.gov (United States)

Zeigler, John M.

1992-01-01

Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

Design of an Optical System for High Power CO2 Laser Cutting

DEFF Research Database (Denmark)

de Lange, D.F.; Meijer, J.; Nielsen, Jakob Skov

2003-01-01

The results of a design study for the optical system for cutting with high power CO2 lasers (6 kW and up) will be presented. As transparent materials cannot be used for these power levels, mirrors have been applied. A coaxial cutting gas supply has been designed with a laser beam entrance into th...... independent of the entering beam angle or position. manufacturing tolerances have been compensated in a one time adjustment during the assembly of the optical system. Preliminary cutting results in 13 mm thick steel in a shipyard application show a signinficant improvement in the cutting performance....

Transient dynamics in cavity electromagnetically induced transparency with ion Coulomb crystals

Science.gov (United States)

Albert, Magnus; Dantan, Aurélien; Drewsen, Michael

2018-03-01

We experimentally investigate the transient dynamics of an optical cavity field interacting with large ion Coulomb crystals in a situation of electromagnetically induced transparency (EIT). EIT is achieved by injecting a probe field at the single photon level and a more intense control field with opposite circular polarization into the same mode of an optical cavity to couple Zeeman substates of a metastable level in ? ions. The EIT interaction dynamics are investigated both in the frequency-domain - by measuring the probe field steady state reflectivity spectrum - and in the time-domain - by measuring the progressive buildup of transparency. The experimental results are observed to be in excellent agreement with theoretical predictions taking into account the inhomogeneity of the control field in the interaction volume, and confirm the high degree of control on light-matter interaction that can be achieved with ion Coulomb crystals in optical cavities.

Transparent indium-tin oxide/indium-gallium-zinc oxide Schottky diodes formed by gradient oxygen doping

Science.gov (United States)

Ho, Szuheng; Yu, Hyeonggeun; So, Franky

2017-11-01

Amorphous InGaZnO (a-IGZO) is promising for transparent electronics due to its high carrier mobility and optical transparency. However, most metal/a-IGZO junctions are ohmic due to the Fermi-level pinning at the interface, restricting their device applications. Here, we report that indium-tin oxide/a-IGZO Schottky diodes can be formed by gradient oxygen doping in the a-IGZO layer that would otherwise form an ohmic contact. Making use of back-to-back a-IGZO Schottky junctions, a transparent IGZO permeable metal-base transistor is also demonstrated with a high common-base gain.

Roll-To-Roll Printing of Meter-Scale Composite Transparent Electrodes with Optimized Mechanical and Optical Properties for Photoelectronics.

Science.gov (United States)

Meng, Xiangchuan; Hu, Xiaotian; Yang, Xia; Yin, Jingping; Wang, Qingxia; Huang, Liqiang; Yu, Zoukangning; Hu, Ting; Tan, Licheng; Zhou, Weihua; Chen, Yiwang

2018-03-14

Flexible transparent electrodes are an indispensable component for flexible optoelectronic devices. In this work, the meter-scale composite transparent electrodes (CTEs) composed of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and Ag grid/polyethylene terephthalate (PET) with optimized mechanical and optical properties are demonstrated by slot-die roll-to-roll technique with solution printing method under a low cost ($15-20 per square meter), via control of the viscosity and surface energy of PEDOT:PSS ink as well as the printing parameters. The CTEs show excellent flexibility remaining 98% of the pristine value after bending 2000 times under various bending situations, and the square resistance ( R s ) of CTEs can be reduced to 4.5-5.0 Ω/sq with an appropriate transmittance. Moreover, the optical performances, such as haze, extinction coefficient, and refractive index, are investigated, as compared with indium tin oxide/PET, which are potential for the inexpensive optoelectronic flexible devices. The CTEs could be successfully employed in polymer solar cells with different areas, showing a maximal power conversion efficiency of 8.08%.

High-dynamic-range microscope imaging based on exposure bracketing in full-field optical coherence tomography.

Science.gov (United States)

Leong-Hoi, Audrey; Montgomery, Paul C; Serio, Bruno; Twardowski, Patrice; Uhring, Wilfried

2016-04-01

By applying the proposed high-dynamic-range (HDR) technique based on exposure bracketing, we demonstrate a meaningful reduction in the spatial noise in image frames acquired with a CCD camera so as to improve the fringe contrast in full-field optical coherence tomography (FF-OCT). This new signal processing method thus allows improved probing within transparent or semitransparent samples. The proposed method is demonstrated on 3 μm thick transparent polymer films of Mylar, which, due to their transparency, produce low contrast fringe patterns in white-light interference microscopy. High-resolution tomographic analysis is performed using the technique. After performing appropriate signal processing, resulting XZ sections are observed. Submicrometer-sized defects can be lost in the noise that is present in the CCD images. With the proposed method, we show that by increasing the signal-to-noise ratio of the images, submicrometer-sized defect structures can thus be detected.

Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films.

Science.gov (United States)

Aytug, Tolga; Simpson, John T; Lupini, Andrew R; Trejo, Rosa M; Jellison, Gerald E; Ivanov, Ilia N; Pennycook, Stephen J; Hillesheim, Daniel A; Winter, Kyle O; Christen, David K; Hunter, Scott R; Haynes, J Allen

2013-08-09

We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie-Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military.

Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films

Science.gov (United States)

Aytug, Tolga; Simpson, John T.; Lupini, Andrew R.; Trejo, Rosa M.; Jellison, Gerald E.; Ivanov, Ilia N.; Pennycook, Stephen J.; Hillesheim, Daniel A.; Winter, Kyle O.; Christen, David K.; Hunter, Scott R.; Haynes, J. Allen

2013-08-01

We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie-Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military.

Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films

International Nuclear Information System (INIS)

Aytug, Tolga; Simpson, John T; Lupini, Andrew R; Trejo, Rosa M; Jellison, Gerald E; Ivanov, Ilia N; Pennycook, Stephen J; Hillesheim, Daniel A; Winter, Kyle O; Christen, David K; Hunter, Scott R; Allen Haynes, J

2013-01-01

We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie–Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military. (paper)

3-D neurohistology of transparent tongue in health and injury with optical clearing

Directory of Open Access Journals (Sweden)

Tzu-En eHua

2013-10-01

Full Text Available Tongue receives extensive innervation to perform taste, sensory, and motor functions. Details of the tongue neuroanatomy and its plasticity in response to injury offer insights to investigate tongue neurophysiology and pathophysiology. However, due to the dispersed nature of the neural network, standard histology cannot provide a global view of the innervation. We prepared transparent mouse tongue by optical clearing to reveal the spatial features of the tongue innervation and its remodeling in injury. Immunostaining of neuronal markers, including PGP9.5 (pan-neuronal marker, calcitonin gene-related peptide (sensory nerves, tyrosine hydroxylase (sympathetic nerves, and vesicular acetylcholine transporter (cholinergic parasympathetic nerves and neuromuscular junctions, was combined with vessel painting and nuclear staining to label the tissue network and architecture. The tongue specimens were immersed in the optical-clearing solution to facilitate photon penetration for 3-dimensiontal (3-D confocal microscopy. Taking advantage of the transparent tissue, we simultaneously revealed the tongue microstructure and innervation with subcellular-level resolution. 3-D projection of the papillary neurovascular complex and taste bud innervation was used to demonstrate the spatial features of tongue mucosa and the panoramic imaging approach. In the tongue injury induced by 4-nitroquinoline 1-oxide administration in the drinking water, we observed neural tissue remodeling in response to the changes of mucosal and muscular structures. Neural networks and the neuromuscular junctions were both found rearranged at the peri-lesional region, suggesting the nerve-lesion interactions in response to injury. Overall, this new tongue histological approach provides a useful tool for 3-D imaging of neural tissues to better characterize their roles with the mucosal and muscular components in health and disease.

Highly concentrated collagen solutions leading to transparent scaffolds of controlled three-dimensional organizations for corneal epithelial cell colonization.

Science.gov (United States)

Tidu, Aurélien; Ghoubay-Benallaoua, Djida; Teulon, Claire; Asnacios, Sophie; Grieve, Kate; Portier, François; Schanne-Klein, Marie-Claire; Borderie, Vincent; Mosser, Gervaise

2018-05-29

This study aimed at controlling both the organization and the transparency of dense collagen scaffolds making use of the lyotropic mesogen properties of collagen. Cholesteric or plywood-like liquid crystal phases were achieved using mixtures of acetic and hydrochloric acids as solvents. The critical pH at which the switch between the two phases occurred was around pH = 3. The use of the two acids led to fibrillated collagen I scaffolds, whose visual aspect ranged from opaque to transparent. Rheological investigations showed that viscoelastic properties of the plywood-like solutions were optimized for molding due to faster recovery. They also confirmed the correlation between the elastic modulus and the diameter of collagen fibrils obtained after fibrillogenesis under ammonia vapor. Human corneal epithelial cells, grown from donor limbal explants, were cultured both on transparent plywood-like matrices and on human amniotic membranes for 14 days. The development of corneal epithelium and the preservation of epithelial stem cells were checked by optical microscopy, colony formation assay, immuno-fluorescence and quantitative polymerase chain reaction. A higher level of amplification of limbal stem cells was obtained with collagen matrices compared with amniotic membranes, showing the high biocompatibility of our scaffolds. We therefore suggest that collagen solutions presenting both plywood-like organization and transparency might be of interest for biomedical applications in ophthalmology.

Development of high-performance X-ray transparent crystallization plates for in situ protein crystal screening and analysis

Energy Technology Data Exchange (ETDEWEB)

Soliman, Ahmed S. M.; Warkentin, Matthew [Cornell University, Ithaca, New York (United States); Apker, Benjamin [MiTeGen LLC, Ithaca, New York (United States); Thorne, Robert E., E-mail: ret6@cornell.edu [Cornell University, Ithaca, New York (United States); MiTeGen LLC, Ithaca, New York (United States)

2011-07-01

An optically, UV and X-ray transparent crystallization plate suitable for in situ analysis has been developed. The plate uses contact line pinning rather than wells to confine the liquids. X-ray transparent crystallization plates based upon a novel drop-pinning technology provide a flexible, simple and inexpensive approach to protein crystallization and screening. The plates consist of open cells sealed top and bottom by thin optically, UV and X-ray transparent films. The plates do not need wells or depressions to contain liquids. Instead, protein drops and reservoir solution are held in place by rings with micrometre dimensions that are patterned onto the bottom film. These rings strongly pin the liquid contact lines, thereby improving drop shape and position uniformity, and thus crystallization reproducibility, and simplifying automated image analysis of drop contents. The same rings effectively pin solutions containing salts, proteins, cryoprotectants, oils, alcohols and detergents. Strong pinning by rings allows the plates to be rotated without liquid mixing to 90° for X-ray data collection or to be inverted for hanging-drop crystallization. The plates have the standard SBS format and are compatible with standard liquid-handling robots.

Transparent conductors based on microscale/nanoscale materials for high performance devices

Science.gov (United States)

Gao, Tongchuan

Transparent conductors are important as the top electrode for a variety of optoelectronic devices, including solar cells, light-emitting diodes (LEDs), at panel displays, and touch screens. Doped indium tin oxide (ITO) thin films are the predominant transparent conductor material. However, ITO thin films are brittle, making them unsuitable for the emerging flexible devices, and suffer from high material and processing cost. In my thesis, we developed a variety of transparent conductors toward a performance comparable with or superior to ITO thin films, with lower cost and potential for scalable manufacturing. Metal nanomesh (NM), hierarchical graphene/metal microgrid (MG), and hierarchical metal NM/MG materials were investigated. Simulation methods were used as a powerful tool to predict the transparency and sheet resistance of the transparent conductors by solving Maxwell's equations and Poisson's equation. Affordable and scalable fabrication processes were developed thereafter. Transparent conductors with over 90% transparency and less than 10 O/square sheet resistance were successfully fabricated on both rigid and flexible substrates. Durability tests, such as bending, heating and tape tests, were carried out to evaluate the robustness of the samples. Haze factor, which characterizes how blurry a transparent conductor appears, was also studied in-depth using analytical calculation and numerical simulation. We demonstrated a tunable haze factor for metal NM transparent conductors and analyzed the principle for tuning the haze factor. Plasmonic effects, excited by some transparent conductors, can lead to enhanced performance in photovoltaic devices. We systematically studied the effect of incorporating metal NM into ultrathin film silicon solar cells using numerical simulation, with the aid of optimization algorithms to reduce the optimization time. Mechanisms contributing to the enhanced performance were then identified and analyzed. Over 72% enhancement in short

High Availability in Optical Networks

Science.gov (United States)

Grover, Wayne D.; Wosinska, Lena; Fumagalli, Andrea

2005-09-01

Call for Papers: High Availability in Optical Networks Submission Deadline: 1 January 2006 The Journal of Optical Networking (JON) is soliciting papers for a feature Issue pertaining to all aspects of reliable components and systems for optical networks and concepts, techniques, and experience leading to high availability of services provided by optical networks. Most nations now recognize that telecommunications in all its forms -- including voice, Internet, video, and so on -- are "critical infrastructure" for the society, commerce, government, and education. Yet all these services and applications are almost completely dependent on optical networks for their realization. "Always on" or apparently unbreakable communications connectivity is the expectation from most users and for some services is the actual requirement as well. Achieving the desired level of availability of services, and doing so with some elegance and efficiency, is a meritorious goal for current researchers. This requires development and use of high-reliability components and subsystems, but also concepts for active reconfiguration and capacity planning leading to high availability of service through unseen fast-acting survivability mechanisms. The feature issue is also intended to reflect some of the most important current directions and objectives in optical networking research, which include the aspects of integrated design and operation of multilevel survivability and realization of multiple Quality-of-Protection service classes. Dynamic survivable service provisioning, or batch re-provisioning is an important current theme, as well as methods that achieve high availability at far less investment in spare capacity than required by brute force service path duplication or 100% redundant rings, which is still the surprisingly prevalent practice. Papers of several types are envisioned in the feature issue, including outlook and forecasting types of treatments, optimization and analysis, new

Fabrication and physical properties of transparent poly (methyl-methacrylate)-layered silicate nanocomposites

Science.gov (United States)

Vasiliu, Elena

Transparent polymer nanocomposites have promising potential for protective coating applications with improved surface resistance, higher temperature performance and low gas permeability for containers and films. Extremely thin protective layers are required for improved performance of various electronic devices in aviation, aerospace and medical equipment as well as for lenses and fiber optics in optical communications. This research study developed a method for fabricating optically transparent nanocomposites of poly(methyl-methacrylate)(PMMA) and a commercial organically-modified layered silicate CloisiteRTM 6A (C6A). The nanocomposites were produced by dispersing C6A and PMMA separately in a common solvent xylene followed by mixing the two solutions by mechanical stirring and/or ultrasonic agitation and then removing the solvent by evaporation. Processing conditions such as the mixing methods and times and the rates of solvent removal were investigated in order to achieve a high degree of dispersion and exfoliation of C6A in the polymer matrix and produce a nanocomposite material with high optical transparency. Small-angle x-ray scattering (SAXS) was used to monitor the morphology of the C6A after each processing step. Thin films of PMMA/C6A nanocomposites were produced by casting and spraying. SAXS results suggest that C6A was partially exfoliated in the composite material with an average of 2 to 3 platelets per crystallite. Transmission electron microscopy (TEM) confirmed the existence of both exfoliated and intercalated C6A in PMMA. One mm thick discs were obtained by molding the sprayed films. The optical transmission of the nanocomposite films and discs was measured with an UV/VIS spectrometer. The spectroscopic results served to identify the best process for producing PMMA-C6A films of high optical transparency. Even the nanocomposite films containing up to 20 wt.% C6A prepared by this process exhibited optical transmittance in the range of 80 to 90

Analysis of the optical and thermal properties of transparent insulating materials containing gas bubbles

International Nuclear Information System (INIS)

Cai, Qilin; Ye, Hong; Lin, Qizhao

2016-01-01

Highlights: • Transparent insulating medium containing gas bubbles was proposed. • Radiative transfer and thermal conduction models were constructed. • Bulk transmittance increases first and then decreases with the bubble number. • Effective thermal conductivity decreases with increasing filling ratio. • High filling ratio with large bubbles is preferred for good performance. - Abstract: As a medium of low absorption and low thermal conduction, introducing gas bubbles into semitransparent mediums, such as glass and polycarbonate (PC), may simultaneously improve their light transmission and thermal insulation performances. However, gas bubbles can also enhance light scattering, which is in competition with the effect of the absorption decrease. Moreover, the balance between the visible light transmittance and the effective thermal conductivity should also be considered in the material design. Therefore, a radiative transfer model and the Maxwell–Eucken model for such material were employed to analyze the optical and thermal performances, respectively. The results demonstrate that the transmittance increases when the bubble radius (r) increases with a fixed volume fraction of the gas bubbles (f_v) due to the increased scattering intensity. In addition, the effective thermal conductivity always decreases with increasing f_v. Thus, to achieve both good optical and thermal performances, high f_v with large r is preferred. When f_v=0.5, the transmittance can be kept larger than 50% as long as r ≥ 0.7 mm. To elucidate the application performance, the heat transfer of a freezer adopting the glass or PC with gas bubbles as a cover was analyzed and the energy saving can be nearly 10%.

Slow light propagation in a thin optical fiber via electromagnetically induced transparency

International Nuclear Information System (INIS)

Patnaik, Anil K.; Liang, J.Q.; Hakuta, K.

2002-01-01

We propose a configuration that utilizes electromagnetically induced transparency (EIT) to tailor a fiber mode propagating inside a thin optical fiber and coherently control its dispersion properties to drastically reduce the group velocity of the fiber mode. The key to this proposal is that the evanescent field of the thin fiber strongly couples with the surrounding active medium, so that the EIT condition is met by the medium. We show how the properties of the fiber mode are modified due to the EIT medium, both numerically and analytically. We demonstrate that the group velocity of the modified fiber mode can be drastically reduced (≅44 m/sec) using the coherently prepared orthohydrogen doped in a matrix of parahydrogen crystal as the EIT medium

The properties of transparent TiO2 films for Schottky photodetector

Directory of Open Access Journals (Sweden)

Sung-Ho Park

2017-08-01

Full Text Available In this data, the properties of transparent TiO2 film for Schottky photodetector are presented for the research article, entitled as “High-performing transparent photodetectors based on Schottky contacts” (Patel et al., 2017 [1]. The transparent photoelectric device was demonstrated by using various Schottky metals, such as Cu, Mo and Ni. This article mainly shows the optical transmittance of the Ni-transparent Schottky photodetector, analyzed by the energy dispersive spectroscopy and interfacial TEM images for transparency to observe the interface between NiO and TiO2 film. The observation and analyses clearly show that no pinhole formation in the TiO2 film by Ni diffusion. The rapid thermal process is an effective way to form the quality TiO2 film formation without degradation, such as pinholes (Qiu et al., 2015 [2]. This thermal process may apply to form functional metal oxide layers for solar cells and photodetectors.

Monolithic Flexible Vertical GaN Light-Emitting Diodes for a Transparent Wireless Brain Optical Stimulator.

Science.gov (United States)

Lee, Han Eol; Choi, JeHyuk; Lee, Seung Hyun; Jeong, Minju; Shin, Jung Ho; Joe, Daniel J; Kim, DoHyun; Kim, Chang Wan; Park, Jung Hwan; Lee, Jae Hee; Kim, Daesoo; Shin, Chan-Soo; Lee, Keon Jae

2018-05-18

Flexible inorganic-based micro light-emitting diodes (µLEDs) are emerging as a significant technology for flexible displays, which is an important area for bilateral visual communication in the upcoming Internet of Things era. Conventional flexible lateral µLEDs have been investigated by several researchers, but still have significant issues of power consumption, thermal stability, lifetime, and light-extraction efficiency on plastics. Here, high-performance flexible vertical GaN light-emitting diodes (LEDs) are demonstrated by silver nanowire networks and monolithic fabrication. Transparent, ultrathin GaN LED arrays adhere to a human fingernail and stably glow without any mechanical deformation. Experimental studies provide outstanding characteristics of the flexible vertical μLEDs (f-VLEDs) with high optical power (30 mW mm -2 ), long lifetime (≈12 years), and good thermal/mechanical stability (100 000 bending/unbending cycles). The wireless light-emitting system on the human skin is successfully realized by transferring the electrical power f-VLED. Finally, the high-density GaN f-VLED arrays are inserted onto a living mouse cortex and operated without significant histological damage of brain. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polyurethane-Based Ionogels Exhibiting Durable Thermoresponsive Optical Behavior Under High-Temperature Conditions.

Science.gov (United States)

Sato, Tomoya; England, Matt W; Wang, Liming; Urata, Chihiro; Kakiuchida, Hiroshi; Hozumi, Atsushi

2018-01-01

Polyurethane (PU)-based transparent and flexible ionogels, showing unusual thermo-responsive optical properties, were successfully prepared by mixing PU-precursor and a hydrophobic ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMIM-TFSI). Although the initial ionogels were transparent at room temperature, significant increases in opacity were observed with increasing temperature up to 120°C, because of macroscopic phase separation of the PU-matrix and hydrophobic EMIM-TFSI. In addition, the optical transition temperature could be arbitrarily controlled simply by varying the mixing ratio of EMIM-TFSI within the PU-matrix. As confirmed by UV-Vis spectra acquired at different temperatures, this thermo-responsive optical behavior was found to be reversible, repeatable and durable even after 30 cycles of a thermal-stress testing between 30 and 100°C.

Transparent Electrodes: A Review of the Use of Carbon-Based Nanomaterials

Directory of Open Access Journals (Sweden)

Edgar J. López-Naranjo

2016-01-01

Full Text Available Transparent conducting electrodes (TCE are extensively applied in a great range of optoelectronic and photovoltaic equipment (e.g., solar cells, touch panels, and flexible devices. Carbon-based nanomaterials are considered as suitable replacements to substitute traditional materials to manufacture TCE due to their remarkable characteristics, for example, high optical transmittance and outstanding electrical properties. In comparison with traditional indium tin oxide electrodes, carbon-based electrodes show good mechanical properties, chemical stability, and low cost. Nevertheless, major issues related to the development of good quality manufacture methods to produce carbon-based nanomaterials have to be overcome to meet massive market requirements. Hence, the development of alternative TCE materials as well as appropriate large production techniques that meet the requirements of a proper sheet resistance along with a high optical transparency is a priority. Therefore, in this work, we summarize and discuss novel production and synthesis methods, chemical treatments, and hybrid materials developed to satisfy the worldwide request for carbon-based nanomaterials.

Review of flexible and transparent thin-film transistors based on zinc oxide and related materials

International Nuclear Information System (INIS)

Zhang Yong-Hui; Mei Zeng-Xia; Liang Hui-Li; Du Xiao-Long

2017-01-01

Flexible and transparent electronics enters into a new era of electronic technologies. Ubiquitous applications involve wearable electronics, biosensors, flexible transparent displays, radio-frequency identifications (RFIDs), etc. Zinc oxide (ZnO) and relevant materials are the most commonly used inorganic semiconductors in flexible and transparent devices, owing to their high electrical performances, together with low processing temperatures and good optical transparencies. In this paper, we review recent advances in flexible and transparent thin-film transistors (TFTs) based on ZnO and relevant materials. After a brief introduction, the main progress of the preparation of each component (substrate, electrodes, channel and dielectrics) is summarized and discussed. Then, the effect of mechanical bending on electrical performance is highlighted. Finally, we suggest the challenges and opportunities in future investigations. (paper)

Transparent conducting zinc oxide thin film prepared by off-axis rf ...

Indian Academy of Sciences (India)

Highly conducting and transparent ZnO : Al thin films were grown by off-axis rf magnetron sputtering on amorphous silica substrates without any post-deposition annealing. The electrical and optical properties of the films deposited at various substrate temperatures and target to substrate distances were investigated in detail ...

Simple and cost-effective fabrication of highly flexible, transparent superhydrophobic films with hierarchical surface design.

Science.gov (United States)

Kim, Tae-Hyun; Ha, Sung-Hun; Jang, Nam-Su; Kim, Jeonghyo; Kim, Ji Hoon; Park, Jong-Kweon; Lee, Deug-Woo; Lee, Jaebeom; Kim, Soo-Hyung; Kim, Jong-Man

2015-03-11

Optical transparency and mechanical flexibility are both of great importance for significantly expanding the applicability of superhydrophobic surfaces. Such features make it possible for functional surfaces to be applied to various glass-based products with different curvatures. In this work, we report on the simple and potentially cost-effective fabrication of highly flexible and transparent superhydrophobic films based on hierarchical surface design. The hierarchical surface morphology was easily fabricated by the simple transfer of a porous alumina membrane to the top surface of UV-imprinted polymeric micropillar arrays and subsequent chemical treatments. Through optimization of the hierarchical surface design, the resultant superhydrophobic films showed superior surface wetting properties (with a static contact angle of >170° and contact angle hysteresis of 82% at 550 nm wavelength). The superhydrophobic films were also experimentally found to be robust without significant degradation in the superhydrophobicity, even under repetitive bending and pressing for up to 2000 cycles. Finally, the practical usability of the proposed superhydorphobic films was clearly demonstrated by examining the antiwetting performance in real time while pouring water on the film and submerging the film in water.

Development of high-performance transparent conducting oxides and their impact on the performance of CdS/CdTe solar cells

Energy Technology Data Exchange (ETDEWEB)

Coutts, T.J.; Wu, X.; Sheldon, P.; Rose, D.H. [National Renewable Energy Lab., Golden, CO (United States)

1998-09-01

This paper begins with a review of the modeled performance of transparent conducting oxides (TCOs) as a function of their free-carrier concentration, mobility, and film thickness. It is shown that it is vital to make a film with high mobility to minimize the width and height of the free-carrier absorption band, and to optimize the optical properties. The free-carrier concentration must be kept sufficiently small that the absorption band does not extend into that part of the spectrum to which the solar cell responds. Despite this consideration, a high electrical conductivity is essential to minimize series resistance losses. Hence, a high mobility is vital for these materials. The fabrication of thin-films of cadmium stannate is then discussed, and their performance is compared with that of tin oxide, both optically and as these materials influence the performance of CdTe solar cells.

All-optical loadable and erasable memory cell design based on inversionless lasing and electromagnetically induced transparency effects

International Nuclear Information System (INIS)

Gholipour Verki, N; HajiBadali, A; Abbasian, K; Rostami, A

2011-01-01

A loadable and erasable all-optical memory cell is designed by using two coupled micro-ring resonators with electromagnetically induced transparency (EIT) and lasing without inversion (LWI). To read out stored data, an additional phase is introduced in the upper ring resonator due to EIT. To compensate the fibre loss, use is made of LWI. The EIT is induced by inserting Λ-type three level quantum dots in the right-hand half of the upper ring and LWI is implemented by inserted Y-type four level quantum dots in the left-hand half of both rings. This optical memory cell can operate at a low light power level corresponding to several photons.

Visually Imperceptible Liquid-Metal Circuits for Transparent, Stretchable Electronics with Direct Laser Writing.

Science.gov (United States)

Pan, Chengfeng; Kumar, Kitty; Li, Jianzhao; Markvicka, Eric J; Herman, Peter R; Majidi, Carmel

2018-03-01

A material architecture and laser-based microfabrication technique is introduced to produce electrically conductive films (sheet resistance = 2.95 Ω sq -1 ; resistivity = 1.77 × 10 -6 Ω m) that are soft, elastic (strain limit >100%), and optically transparent. The films are composed of a grid-like array of visually imperceptible liquid-metal (LM) lines on a clear elastomer. Unlike previous efforts in transparent LM circuitry, the current approach enables fully imperceptible electronics that have not only high optical transmittance (>85% at 550 nm) but are also invisible under typical lighting conditions and reading distances. This unique combination of properties is enabled with a laser writing technique that results in LM grid patterns with a line width and pitch as small as 4.5 and 100 µm, respectively-yielding grid-like wiring that has adequate conductivity for digital functionality but is also well below the threshold for visual perception. The electrical, mechanical, electromechanical, and optomechanical properties of the films are characterized and it is found that high conductivity and transparency are preserved at tensile strains of ≈100%. To demonstrate their effectiveness for emerging applications in transparent displays and sensing electronics, the material architecture is incorporated into a couple of illustrative use cases related to chemical hazard warning. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PowerShades II. Optimisation and validation of highly transparent photovoltaic. Final report

Energy Technology Data Exchange (ETDEWEB)

2010-07-15

The objective of the project is continued development and validation of a novel Danish photovoltaic product with the work title ''PowerShade''. The PowerShade insulating glazing unit (IGU) is a combination of a strong solar shading device and a power producing photovoltaic coating. The core technology in the PowerShade IGU is a thin film silicon photovoltaic generator applied to a micro structured substrate. The geometry of the substrate provides the unique combination of properties that characterizes the PowerShade module - strong progressive shading, high transparency, and higher electrical output than other semitransparent photovoltaic products with similar transparencies. The project activities fall in two categories, namely development of the processing/product and validation of the product properties. The development part of the project is focussed on increasing the efficiency of the photovoltaic generator by changing from a single-stack type cell to a tandem-stack type cell. The inclusion of PowerShade cells in insulating glazing (IG) units is also addressed in this project. The validation part of the project aims at validation of stability, thermal and optical properties as well as validation of the electrical yield of the product. The validation of thermal and optical properties has been done using full size modules installed in a test facility built during the 2006-08 ''PowerShades'' project. The achieved results will be vital in the coming realisation of a commercial product. Initial processing steps have been automated, and more efficient tandem-type solar cells have been developed. A damp heat test of an IGU has been carried out without any degradation of the solar cell. The PowerShade module assembly concept has been further developed and discussed with different automation equipment vendors and a pick-and-place tool developed. PowerShade's influence on the indoor climate has been modelled and verified by

Optical micro-cavities on silicon

Science.gov (United States)

Dai, Daoxin; Liu, Erhu; Tan, Ying

2018-01-01

Silicon-based optical microcavities are very popular for many applications because of the ultra-compact footprint, easy scalability, and functional versatility. In this paper we give a discussion about the challenges of the optical microcavities on silicon and also give a review of our recent work, including the following parts. First, a near-"perfect" high-order MRR optical filter with a box-like filtering response is realized by introducing bent directional couplers to have sufficient coupling between the access waveguide and the microrings. Second, an efficient thermally-tunable MRR-based optical filter with graphene transparent nano-heater is realized by introducing transparent graphene nanoheaters. Thirdly, a polarization-selective microring-based optical filter is realized to work with resonances for only one of TE and TM polarizations for the first time. Finally, a on-chip reconfigurable optical add-drop multiplexer for hybrid mode- /wavelength-division-multiplexing systems is realized for the first time by monolithically integrating a mode demultiplexer, four MRR optical switches, and a mode multiplexer.

TiO2 nanorods/PMMA copolymer-based nanocomposites: highly homogeneous linear and nonlinear optical material

International Nuclear Information System (INIS)

Sciancalepore, C; Agostiano, A; Cassano, T; Valentini, A; Curri, M L; Striccoli, M; Mecerreyes, D; Tommasi, R

2008-01-01

Original nanocomposites have been obtained by direct incorporation of pre-synthesized oleic acid capped TiO 2 nanorods into properly functionalized poly(methyl methacrylate) copolymers, carrying carboxylic acid groups on the repeating polymer unit. The presence of carboxylic groups on the alkyl chain of the host functionalized copolymer allows an highly homogeneous dispersion of the nanorods in the organic matrix. The prepared TiO 2 /PMMA-co-MA nanocomposites show high optical transparency in the visible region, even at high TiO 2 nanorod content, and tunable linear refractive index depending on the nanoparticle concentration. Finally measurements of nonlinear optical properties of TiO 2 polymer nanocomposites demonstrate a negligible two-photon absorption and a negative value of nonlinear refractive index, highlighting the potential of the nanocomposite for efficient optical devices operating in the visible region

TiO2 nanorods/PMMA copolymer-based nanocomposites: highly homogeneous linear and nonlinear optical material

Science.gov (United States)

Sciancalepore, C.; Cassano, T.; Curri, M. L.; Mecerreyes, D.; Valentini, A.; Agostiano, A.; Tommasi, R.; Striccoli, M.

2008-05-01

Original nanocomposites have been obtained by direct incorporation of pre-synthesized oleic acid capped TiO2 nanorods into properly functionalized poly(methyl methacrylate) copolymers, carrying carboxylic acid groups on the repeating polymer unit. The presence of carboxylic groups on the alkyl chain of the host functionalized copolymer allows an highly homogeneous dispersion of the nanorods in the organic matrix. The prepared TiO2/PMMA-co-MA nanocomposites show high optical transparency in the visible region, even at high TiO2 nanorod content, and tunable linear refractive index depending on the nanoparticle concentration. Finally measurements of nonlinear optical properties of TiO2 polymer nanocomposites demonstrate a negligible two-photon absorption and a negative value of nonlinear refractive index, highlighting the potential of the nanocomposite for efficient optical devices operating in the visible region.

Highly dispersive transparency in coupled metamaterials

International Nuclear Information System (INIS)

Thuy, V T T; Park, J W; Lee, Y P; Tung, N T; Lam, V D; Rhee, J Y

2010-01-01

We investigate the coupling between bright and quasi-dark eigenmodes in a planar metamaterial supporting highly dispersive transparency. The specific design of such a metamaterial consists of a cut wire (CW) and a single-gap split-ring resonator (SRR). Through the numerical simulation and the equivalent-circuit analysis, we demonstrate that the response of the SRR, which is weakly excited by external electric field, plays the role of a quasi-dark eigenmode in the presence of a strongly radiative CW. Furthermore, by extending and relating our study to the trapped mode resonances and the coupling between dark and bright modes, a more comprehensive perspective for the metamaterial realization of highly dispersive transmission and slow-light applications is provided

High transmittance optical films based on quantum dot doped nanoscale polymer dispersed liquid crystals

Science.gov (United States)

Gandhi, Sahil Sandesh; Chien, Liang-Chy

2016-04-01

We propose a simple way to fabricate highly transparent nanoscale polymer dispersed liquid crystal (nano-PDLC) films between glass substrates and investigate their incident angle dependent optical transmittance properties with both collimated and Lambertian intensity distribution light sources. We also demonstrate that doping nano-PDLC films with 0.1% InP/ZnS core/shell quantum dots (QD) results in a higher optical transmittance. This work lays the foundation for such nanostructured composites to potentially serve as roll-to-roll coatable light extraction or brightness enhancement films in emissive display applications, superior to complex nanocorrugation techniques proposed in the past.

Highly transparent, stable, and superhydrophobic coatings based on gradient structure design and fast regeneration from physical damage

Science.gov (United States)

Chen, Zao; Liu, Xiaojiang; Wang, Yan; Li, Jun; Guan, Zisheng

2015-12-01

Optical transparency, mechanical flexibility, and fast regeneration are important factors to expand the application of superhydrophobic surfaces. Herein, we fabricated highly transparent, stable, and superhydrophobic coatings through a novel gradient structure design by versatile dip-coating of silica colloid particles (SCPs) and diethoxydimethysiliane cross-linked silica nanoparticles (DDS-SNPs) on polyethylene terephthalate (PET) film and glass, followed by the modification of octadecyltrichlorosiliane (OTCS). When the DDS concentration reached 5 wt%, the modified SCPs/DDS-SNPs coating exhibited a water contact angle (WCA) of 153° and a sliding angle (SA) glass was increased by 2.7% and 1% in the visible wavelength, respectively. This superhydrophobic coating also showed good robustness and stability against water dropping impact, ultrasonic damage, and acid solution. Moreover, the superhydrophobic PET film after physical damage can quickly regain the superhydrophobicity by one-step spray regenerative solution of dodecyltrichlorosilane (DTCS) modified silica nanoparticles at room temperature. The demonstrated method for the preparation and regeneration of superhydrophobic coating is available for different substrates and large-scale production at room temperature.

Continuous, Highly Flexible, and Transparent Graphene Films by Chemical Vapor Deposition for Organic Photovoltaics

KAUST Repository

Gomez De Arco, Lewis; Zhang, Yi; Schlenker, Cody W.; Ryu, Koungmin; Thompson, Mark E.; Zhou, Chongwu

2010-01-01

We report the implementation of continuous, highly flexible, and transparent graphene films obtained by chemical vapor deposition (CVD) as transparent conductive electrodes (TCE) in organic photovoltaic cells. Graphene films were synthesized by CVD

Transparent soil for imaging the rhizosphere.

Directory of Open Access Journals (Sweden)

Helen Downie

Full Text Available Understanding of soil processes is essential for addressing the global issues of food security, disease transmission and climate change. However, techniques for observing soil biology are lacking. We present a heterogeneous, porous, transparent substrate for in situ 3D imaging of living plants and root-associated microorganisms using particles of the transparent polymer, Nafion, and a solution with matching optical properties. Minerals and fluorescent dyes were adsorbed onto the Nafion particles for nutrient supply and imaging of pore size and geometry. Plant growth in transparent soil was similar to that in soil. We imaged colonization of lettuce roots by the human bacterial pathogen Escherichia coli O157:H7 showing micro-colony development. Micro-colonies may contribute to bacterial survival in soil. Transparent soil has applications in root biology, crop genetics and soil microbiology.

Dye-sensitized solar cell based on optically transparent TiO{sub 2} nanocrystalline electrode prepared by atomized spray pyrolysis technique

Energy Technology Data Exchange (ETDEWEB)

Bandara, H.M.N., E-mail: hmnb@pdn.ac.l [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka); Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan); Rajapakse, R.M.G. [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka); Murakami, K. [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan); Kumara, G.R.R.A.; Anuradha Sepalage, G. [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka)

2011-10-30

Highlights: > Transparent TiO{sub 2} films were prepared by the atomized spray pyrolysis method. > These films contain 3-5 nm discrete particles, interconnected to give a crack-free thin film structure. > Dye-absorption of the TiO{sub 2} film is 2.16 times higher than those used in conventional DSCs. > Conversion efficiency of 8.2% can be achieved with 1000 W m{sup -2} irradiation. - Abstract: Preparation of crack-free thin films of interconnected and non-agglomerated TiO{sub 2} nanoparticles on electronically conducting fluorine doped tin oxide surfaces is instrumental in designing and developing transparent dye-sensitized solar cells (DSCs). A novel technique called 'Atomized Spray Pyrolysis' (ASP) has been designed and developed to achieve such perfectly transparent thin films. Optical transmittance of TiO{sub 2} films produced on FTO surface by this ASP method has been compared with those obtained by doctor-blading and by hand spray methods and found that the atomized spray pyrolysis technique give films with high transparency. Dye adsorption per gram of TiO{sub 2} is 2.16 times higher in the sample produced by the ASP method when compared to the film produced by the hand spray method and is 1.60 times higher than that produced by the doctor-blading method using a commercially available TiO{sub 2} nanocrystalline paste. SEM studies show the presence of interconnected discrete particles in the film produced by the ASP method. The fill factor (ff) remains almost constant for the cells with thickness from 6 {mu}m to 13 {mu}m but the highest photovoltage and photocurrent were found in {approx}10 {mu}m film based DSC which gave 8.2% conversion efficiency at AM 1.5 irradiation for cells of 0.25 cm{sup 2} active area.

Transparent and flexible resistive switching memory devices with a very high ON/OFF ratio using gold nanoparticles embedded in a silk protein matrix

Science.gov (United States)

Gogurla, Narendar; Mondal, Suvra P.; Sinha, Arun K.; Katiyar, Ajit K.; Banerjee, Writam; Kundu, Subhas C.; Ray, Samit K.

2013-08-01

The growing demand for biomaterials for electrical and optical devices is motivated by the need to make building blocks for the next generation of printable bio-electronic devices. In this study, transparent and flexible resistive memory devices with a very high ON/OFF ratio incorporating gold nanoparticles into the Bombyx mori silk protein fibroin biopolymer are demonstrated. The novel electronic memory effect is based on filamentary switching, which leads to the occurrence of bistable states with an ON/OFF ratio larger than six orders of magnitude. The mechanism of this process is attributed to the formation of conductive filaments through silk fibroin and gold nanoparticles in the nanocomposite. The proposed hybrid bio-inorganic devices show promise for use in future flexible and transparent nanoelectronic systems.

Transparent and flexible resistive switching memory devices with a very high ON/OFF ratio using gold nanoparticles embedded in a silk protein matrix

International Nuclear Information System (INIS)

Gogurla, Narendar; Mondal, Suvra P; Sinha, Arun K; Katiyar, Ajit K; Banerjee, Writam; Ray, Samit K; Kundu, Subhas C

2013-01-01

The growing demand for biomaterials for electrical and optical devices is motivated by the need to make building blocks for the next generation of printable bio-electronic devices. In this study, transparent and flexible resistive memory devices with a very high ON/OFF ratio incorporating gold nanoparticles into the Bombyx mori silk protein fibroin biopolymer are demonstrated. The novel electronic memory effect is based on filamentary switching, which leads to the occurrence of bistable states with an ON/OFF ratio larger than six orders of magnitude. The mechanism of this process is attributed to the formation of conductive filaments through silk fibroin and gold nanoparticles in the nanocomposite. The proposed hybrid bio-inorganic devices show promise for use in future flexible and transparent nanoelectronic systems. (paper)

An Investigation on Properties of Transparent Concretes

OpenAIRE

TOPÇU, İlker Bekir; UYGUNOĞLU, Tayfun

2016-01-01

Transparentconcrete is a cement-based building material which has optical properties dueto the embedded light transmitting elements within the composite. In thisstudy, the design of transparent concrete, its mechanical properties, lighttransmission properties of optical fibers and the use of optic fibers werediscussed. The study was performed as a literature review, and it was focusedon the light absorption of translucent concrete, transmission, the mechanismand losses in the transmission. In...

Vacuum-Assisted Low-Temperature Synthesis of Reduced Graphene Oxide Thin-Film Electrodes for High-Performance Transparent and Flexible All-Solid-State Supercapacitors.

Science.gov (United States)

Aytug, Tolga; Rager, Matthew S; Higgins, Wesley; Brown, Forrest G; Veith, Gabriel M; Rouleau, Christopher M; Wang, Hui; Hood, Zachary D; Mahurin, Shannon M; Mayes, Richard T; Joshi, Pooran C; Kuruganti, Teja

2018-04-04

Simple and easily integrated design of flexible and transparent electrode materials affixed to polymer-based substrates hold great promise to have a revolutionary impact on the functionality and performance of energy storage devices for many future consumer electronics. Among these applications are touch sensors, roll-up displays, photovoltaic cells, health monitors, wireless sensors, and wearable communication devices. Here, we report an environmentally friendly, simple, and versatile approach to produce optically transparent and mechanically flexible all-solid-state supercapacitor devices. These supercapacitors were constructed on tin-doped indium oxide coated polyethylene terephthalate substrates by intercalation of a polymer-based gel electrolyte between two reduced graphene oxide (rGO) thin-film electrodes. The rGO electrodes were fabricated simply by drop-casting of graphene oxide (GO) films, followed by a novel low-temperature (≤250 °C) vacuum-assisted annealing approach for the in situ reduction of GO to rGO. A trade-off between the optical transparency and electrochemical performance is determined by the concentration of the GO in the initial dispersion, whereby the highest capacitance (∼650 μF cm -2 ) occurs at a relatively lower optical transmittance (24%). Notably, the all-solid-state supercapacitors demonstrated excellent mechanical flexibility with a capacity retention rate above 90% under various bending angles and cycles. These attributes underscore the potential of the present approach to provide a path toward the realization of thin-film-based supercapacitors as flexible and transparent energy storage devices for a variety of practical applications.

Fatigue properties and impedance analysis of potassium sodium niobate-strontium titanate transparent ceramics

Energy Technology Data Exchange (ETDEWEB)

Liu, Zhiyong; Fan, Huiqing; Lei, Shenhui; Wang, Ju; Tian, Hailin [Northwestern Polytechnical University, State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Xi' an (China)

2016-10-15

Highly transparent ferroelectric ceramics based on 0.9K{sub 0.5}Na{sub 0.5}NbO{sub 3}-0.1SrTiO{sub 3} were prepared using a pressure-less solid-state sintering method without using hot isostatic pressing and spark plasma sintering. An independence electromechanical response of bipolar switching cycles (S{sub 33} only degraded 3.2 % up to 10{sup 7} cycles) was presented in this transparent ceramics, which indicated an extremely stable property under electric field. From impedance spectroscopy and X-ray photoelectron spectroscopy analyses, it was concluded that such optical transparency and fatigue-resistant behaviors were mainly attributed to the lower density of oxygen vacancies in the ceramics. (orig.)

Preparation and RGB upconversion optic properties of transparent anti-counterfeiting films.

Science.gov (United States)

Yao, Weijing; Tian, Qingyong; Liu, Jun; Xue, Qingwen; Li, Mengxiao; Liu, Li; Lu, Qiang; Wu, Wei

2017-10-26

Advanced anti-counterfeiting labels have aroused an intensive interest in packaging industry to avoid the serious issue of counterfeit. However, the preparation and cost of the existing labels associated with the drawbacks, including the complex and high-cost equipment, limit the protection of the authenticity of goods. Herein, we developed a series of anti-counterfeiting labels based on multicolor upconversion micro-particles (UCMPs) inks via straightforward and low-cost solutions, including spin-coating, stamping and screen printing. The UCMPs were synthesized through a facile hydrothermal process and displayed tunable red (R), green (G) and blue (B) color by doping different lanthanide ions, which are Er 3+ /Tm 3+ , Yb 3+ /Er 3+ and Yb 3+ /Tm 3+ in NaYF 4 hosts, respectively. The optimal UCMPs inks were deposited on a flexible polyethylene terephthalate (PET) substrate to obtain transparent anti-counterfeiting labels possessing higher transmittance, stronger upconversion fluorescence intensity and good photostability. Under ambient conditions, the patterns and films were transparent, but could exhibit multicolor light under 980 nm laser excitation. They can be used as anti-counterfeiting labels for die-cutting packages to further elevate the security of goods. The tunable and designable transparent anti-counterfeiting labels based on RGB UCMPs inks exhibit the merits of low-cost, easy-manufacture and versatility, underlying the practical application in the field of anti-counterfeiting.

The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO2 transparent semiconducting films prepared by spray pyrolysis technique

International Nuclear Information System (INIS)

Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

2010-01-01

The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2 :Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2 :Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO 2 transparent semiconducting films prepared by spray pyrolysis technique

Science.gov (United States)

Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

2010-10-01

The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2:Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2:Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

Diamond-shaped electromagnetic transparent devices with homogeneous material parameters

International Nuclear Information System (INIS)

Li Tinghua; Huang Ming; Yang Jingjing; Yu Jiang; Lan Yaozhong

2011-01-01

Based on the linear coordinate transformation method, two-dimensional and three-dimensional electromagnetic transparent devices with diamond shape composed of homogeneous and non-singular materials are proposed in this paper. The permittivity and permeability tensors of the transparent devices are derived. The performance and scattering properties of the transparent devices are confirmed by a full-wave simulation. It can physically protect electric devices such as an antenna and a radar station inside, without sacrificing their performance. This work represents important progress towards the practical realization of metamaterial-assisted transparent devices and expands the application of transformation optics.

Transparent and stretchable strain sensors based on metal nanowire microgrids for human motion monitoring

Science.gov (United States)

Cho, Ji Hwan; Ha, Sung-Hun; Kim, Jong-Man

2018-04-01

Optical transparency is increasingly considered as one of the most important characteristics required in advanced stretchable strain sensors for application in body-attachable systems. In this paper, we present an entirely solution-processed fabrication route to highly transparent and stretchable resistive strain sensors based on silver nanowire microgrids (AgNW-MGs). The AgNW-MG strain sensors are readily prepared by patterning the AgNWs on a stretchable substrate into a MG geometry via a mesh-template-assisted contact-transfer printing. The MG has a unique architecture comprising the AgNWs and can be stretched to ɛ = 35%, with high gauge factors of ˜6.9 for ɛ = 0%-30% and ˜41.1 for ɛ = 30%-35%. The sensor also shows a high optical transmittance of 77.1% ± 1.5% (at 550 nm) and stably maintains the remarkable optical performance even at high strains. In addition, the sensor responses are found to be highly reversible with negligible hysteresis and are reliable even under repetitive stretching-releasing cycles (1000 cycles at ɛ = 10%). The practicality of the AgNW-MG strain sensor is confirmed by successfully monitoring a wide range of human motions in real time after firmly laminating the device onto various body parts.

Rare-earth doped transparent ceramics for spectral filtering and quantum information processing

Science.gov (United States)

Kunkel, Nathalie; Ferrier, Alban; Thiel, Charles W.; Ramírez, Mariola O.; Bausá, Luisa E.; Cone, Rufus L.; Ikesue, Akio; Goldner, Philippe

2015-09-01

Homogeneous linewidths below 10 kHz are reported for the first time in high-quality Eu3+ doped Y 2O3 transparent ceramics. This result is obtained on the 7F0→5D0 transition in Eu3+ doped Y 2O3 ceramics and corresponds to an improvement of nearly one order of magnitude compared to previously reported values in transparent ceramics. Furthermore, we observed spectral hole lifetimes of ˜15 min that are long enough to enable efficient optical pumping of the nuclear hyperfine levels. Additionally, different Eu3+ concentrations (up to 1.0%) were studied, resulting in an increase of up to a factor of three in the peak absorption coefficient. These results suggest that transparent ceramics can be useful in applications where narrow and deep spectral holes can be burned into highly absorbing lines, such as quantum information processing and spectral filtering.

Single quadrature duplication and transparent taps

International Nuclear Information System (INIS)

Kim, Ajung

2004-01-01

The concept of single quadrature duplication, which is the process of producing two outputs with the same homodyne detecting statistics as an input, is addressed. This device has important potential application to optical communications as a transparent optical tap in a local area network environment. The characteristics of the device are examined, and a realization scheme employing a coupler and phase-sensitive amplifiers is proposed

Structural Engineering of Metal-Mesh Structure Applicable for Transparent Electrodes Fabricated by Self-Formable Cracked Template

Directory of Open Access Journals (Sweden)

Yeong-gyu Kim

2017-08-01

Full Text Available Flexible and transparent conducting electrodes are essential for future electronic devices. In this study, we successfully fabricated a highly-interconnected metal-mesh structure (MMS using a self-formable cracked template. The template—fabricated from colloidal silica—can be easily formed and removed, presenting a simple and cost-effective way to construct a randomly and uniformly networked MMS. The structure of the MMS can be controlled by varying the spin-coating speed during the coating of the template solution or by stacking of metal-mesh layers. Through these techniques, the optical transparency and sheet resistance of the MMS can be designed for a specific purpose. A double-layered Al MMS showed high optical transparency (~80% in the visible region, low sheet resistance (~20 Ω/sq, and good flexibility under bending test compared with a single-layered MMS, because of its highly-interconnected wire structure. Additionally, we identified the applicability of the MMS in the case of practical devices by applying it to electrodes of thin-film transistors (TFTs. The TFTs with MMS electrodes showed comparable electrical characteristics to those with conventional film-type electrodes. The cracked template can be used for the fabrication of a mesh structure consisting of any material, so it can be used for not only transparent electrodes, but also various applications such as solar cells, sensors, etc.

Ultrathin and stable Nickel films as transparent conductive electrodes

Energy Technology Data Exchange (ETDEWEB)

Grilli, M.L., E-mail: marialuisa.grilli@enea.it [ENEA, Materials Technology Unit, Via Anguillarese 301, 00123 Rome (Italy); Di Sarcina, I. [ENEA, Materials Technology Unit, Via Anguillarese 301, 00123 Rome (Italy); Bossi, S. [ENEA, Robotics Laboratory, Via Anguillarese 301, 00123 Rome (Italy); The Biorobotics Institute, Scuola Superiore Sant' Anna, Viale Rinaldo Piaggio 34, 56025 Pontedera, Pisa (Italy); Rinaldi, A.; Pilloni, L.; Piegari, A. [ENEA, Materials Technology Unit, Via Anguillarese 301, 00123 Rome (Italy)

2015-11-02

Ultrathin stable transparent conductive nickel films were deposited on quartz substrates by radio frequency sputtering at room temperature. Such films showed visible transmittance up to 80% and conductivity up to 1.8 × 10{sup 4} S/cm, further increased to 2,3 × 10{sup 5} S/cm by incorporation of a micrometric silver grid. Atomic force microscopy and scanning electron microscopy revealed quite compact, smooth and low surface roughness films. Excellent film stability, ease, fast and low cost process fabrication make these films highly competitive compared to indium tin oxide alternative transparent conductors. Films were characterized regarding their morphological, optical and electrical properties. - Highlights: • Indium-free transparent conductors are proposed. • Ultrathin Ni films are fabricated with a very fast process at room temperature. • Films have conductivity values up to 1.8 × 10{sup 4} S/cm. • Ni ultrathin films are good candidates for UV and NIR optoelectronic applications.

Fabrication of Nd:YAG transparent ceramics with both TEOS and MgO additives

International Nuclear Information System (INIS)

Yang Hao; Qin Xianpeng; Zhang Jian; Wang Shiwei; Ma Jan; Wang Lixi; Zhang Qitu

2011-01-01

Research highlights: → It is well known that the use of TEOS as sintering aid is required to reach fully dense and transparent Nd:YAG ceramics. However, it is difficult to produce high quality transparent Nd:YAG ceramics only using TEOS as sintering aid. In this present work, high quality transparent Nd:YAG ceramic was fabricated using both TEOS and MgO as sintering aids. There have been few reports that both TEOS and MgO were co-added as sintering aids in YAG or Nd:YAG transparent ceramics to date. The transmittance of Nd:YAG ceramic is 83.8% at 1064 nm. The effect of MgO on the optical properties of transparent ceramics was also studied. - Abstract: Neodymium doped YAG transparent ceramics were fabricated by vacuum reactive sintering method using commercial α-Al 2 O 3 , Y 2 O 3 and Nd 2 O 3 powders as the starting materials with both tetraethyl orthosilicate (TEOS) and MgO as sintering aids. The morphologies and microstructure of the powders and Nd:YAG transparent ceramics were investigated. Fully dense Nd:YAG ceramics with average grain size of ∼10 μm were obtained by vacuum sintering at 1780 deg. C for 8 h. No pores and grain-boundary phases were observed. The in-line transmittance of the ceramic was 83.8% at 1064 nm.

Exploiting both optical and electrical anisotropy in nanowire electrodes for higher transparency.

Science.gov (United States)

Dong, Jianjin; Goldthorpe, Irene A

2018-01-26

Transparent electrodes such as indium tin oxide and random meshes of silver nanowires (AgNWs) have isotropic in-plane properties. However, we show that imparting some alignment to AgNWs can create anisotropic transparency and electrical conductivity characteristics that may benefit many applications. For example, liquid crystal displays and the touch sensors on top of them often only need to be transparent to one type of polarized light as well as predominantly conductive in only one direction. Herein, AgNWs are slightly preferentially aligned during their deposition by rod coating. Compared to randomly oriented AgNW films, the alignment boosts the transparency to perpendicularly polarized light, as well as achieves a higher transparency for a given sheet resistance in one direction compared to randomly oriented AgNWs films. These factors together increase the transparency of a 16 Ω/sq electrode by 7.3 percentage points. The alignment technique is cheap and scalable, compatible with roll-to-roll processes, and most importantly does not require extra processing steps, as rod coating is already a standard process for AgNW electrode fabrication.

Through a glass darkly - the meaning of transparency

International Nuclear Information System (INIS)

Loy, J.

2007-01-01

The paper first discusses the word 'transparency'. It is a metaphor drawn from optics; it is a term used in social and political science; the international civil society organisation. 'Transparency International' sees it as the paradigm to fight corruption in the world. From this discussion, the paper offers a working definition applicable to a nuclear regulatory organisation. The paper describes a difference between having transparent process, which might be called passive transparency; and transparent engagement with stakeholders -- active transparency. It discusses some of the issues and problems that arise for a nuclear regulatory organisation seeking to operate transparently. Much of the difficulty with true transparency is that it reveals the 'untidiness' of life. 'We see now as through a glass darkly'. What is the general view of society and the cultural attitudes towards Government agencies revealing that they are not perfect'? Can you have a transparent nuclear regulator of a secretive industry and with other stakeholders having political agendas? How can a technical 'judgment call' ever be fully transparent? Can an active culture of transparency sometimes result in a mere public relations campaign? Can transparency in a nuclear regulatory create expectations amongst stakeholders that will prove impossible to meet? These questions are discussed with some real-life examples. The paper concludes with some suggested 'fundamentals' for transparency in nuclear regulatory organisations. (author)

Fully transparent conformal organic thin-film transistor array and its application as LED front driving.

Science.gov (United States)

Cui, Nan; Ren, Hang; Tang, Qingxin; Zhao, Xiaoli; Tong, Yanhong; Hu, Wenping; Liu, Yichun

2018-02-22

A fully transparent conformal organic thin-film field-effect transistor array is demonstrated based on a photolithography-compatible ultrathin metallic grid gate electrode and a solution-processed C 8 -BTBT film. The resulting organic field-effect transistor array exhibits a high optical transparency of >80% over the visible spectrum, mobility up to 2 cm 2 V -1 s -1 , on/off ratio of 10 5 -10 6 , switching current of >0.1 mA, and excellent light stability. The transparent conformal transistor array is demonstrated to adhere well to flat and curved LEDs as front driving. These results present promising applications of the solution-processed wide-bandgap organic semiconductor thin films in future large-scale transparent conformal active-matrix displays.

Silver Nanowire Transparent Conductive Films with High Uniformity Fabricated via a Dynamic Heating Method.

Science.gov (United States)

Jia, Yonggao; Chen, Chao; Jia, Dan; Li, Shuxin; Ji, Shulin; Ye, Changhui

2016-04-20

The uniformity of the sheet resistance of transparent conductive films is one of the most important quality factors for touch panel applications. However, the uniformity of silver nanowire transparent conductive films is far inferior to that of indium-doped tin oxide (ITO). Herein, we report a dynamic heating method using infrared light to achieve silver nanowire transparent conductive films with high uniformity. This method can overcome the coffee ring effect during the drying process and suppress the aggregation of silver nanowires in the film. A nonuniformity factor of the sheet resistance of the as-prepared silver nanowire transparent conductive films could be as low as 6.7% at an average sheet resistance of 35 Ω/sq and a light transmittance of 95% (at 550 nm), comparable to that of high-quality ITO film in the market. In addition, a mechanical study shows that the sheet resistance of the films has little change after 5000 bending cycles, and the film could be used in touch panels for human-machine interactive input. The highly uniform and mechanically stable silver nanowire transparent conductive films meet the requirement for many significant applications and could play a key role in the display market in a near future.

Electronic characteristics of p-type transparent SnO monolayer with high carrier mobility

International Nuclear Information System (INIS)

Du, Juan; Xia, Congxin; Liu, Yaming; Li, Xueping; Peng, Yuting; Wei, Shuyi

2017-01-01

Graphical abstract: SnO monolayer is a p-type transparent semiconducting oxide with high hole mobility (∼641 cm 2 V −1 s −1 ), which is much higher than that of MoS 2 monolayer, which indicate that it can be a promising candidate for high-performance nanoelectronic devices. Display Omitted - Highlights: • SnO monolayer is a p-type transparent semiconducting oxide. • The transparent properties can be still maintained under the strain 8%. • It has a high hole mobility (∼641 cm 2 V −1 s −1 ), which is higher than that of MoS 2 monolayer. - Abstract: More recently, two-dimensional (2D) SnO nanosheets are attaching great attention due to its excellent carrier mobility and transparent characteristics. Here, the stability, electronic structures and carrier mobility of SnO monolayer are investigated by using first-principles calculations. The calculations of the phonon dispersion spectra indicate that SnO monolayer is dynamically stable. Moreover, the band gap values are decreased from 3.93 eV to 2.75 eV when the tensile strain is applied from 0% to 12%. Interestingly, SnO monolayer is a p-type transparent semiconducting oxide with hole mobility of 641 cm 2 V −1 s −1 , which is much higher than that of MoS 2 monolayer. These findings make SnO monolayer becomes a promising 2D material for applications in nanoelectronic devices.

Collinear light scattering using electromagnetically induced transparency

International Nuclear Information System (INIS)

Harris, S.E.; Sokolov, A.V.; Walker, D.R.; Yavuz, D.D.; Yin, G.Y.

2001-01-01

The paper describes two types of nonlinear optical processes which are based on electromagnetically induced transparency. These are: (1) Collinear generation of FM-like Raman sidebands and (2) a type of pondermotive light scattering which is inherent to the interaction of slow light with cold atoms. Connections to other areas of EIT-based nonlinear optics are also described

Transparent high-performance CDSE thin-film solar cells

International Nuclear Information System (INIS)

Mahawela, P.; Jeedigunta, S.; Vakkalanka, S.; Ferekides, C.S.; Morel, D.L.

2005-01-01

Simulations indicate that 25-30% efficiency can be achieved with a four-terminal thin-film tandem structure. The bottom low band gap cell can be CuIn 1-x Ga x Se 2 , and CdSe is proposed as the top cell, as it has an ideal band gap of 1.7 eV. In addition to the efficiency requirements, the top cell must also be transparent to effectively transmit sub band gap light to the bottom cell. We have developed CdSe devices that meet many of the requirements of this tandem structure. High electronic quality CdSe has been deposited on SnO 2 and ZnO, which serve as the transparent n-type contact. The p-type transparent contact is ZnSe/Cu. Voc's of 475 mV have been achieved and can be further improved with better contacts. However, record Jsc's in excess of 17 mA/cm 2 have been achieved. This is close to the target 18 mA/cm 2 to meet the efficiency objectives. Transmission of 80% of the sub band gap radiation has been demonstrated for 2-no. muno. m-thick absorber layers. This is also close to the 85% target to achieve the overall tandem efficiency objectives. Improvement of the contact layers to achieve the Voc target is the final challenge

Roll-to-Roll sputtered ITO/Cu/ITO multilayer electrode for flexible, transparent thin film heaters and electrochromic applications.

Science.gov (United States)

Park, Sung-Hyun; Lee, Sang-Mok; Ko, Eun-Hye; Kim, Tae-Ho; Nah, Yoon-Chae; Lee, Sang-Jin; Lee, Jae Heung; Kim, Han-Ki

2016-09-22

We fabricate high-performance, flexible, transparent electrochromic (EC) films and thin film heaters (TFHs) on an ITO/Cu/ITO (ICI) multilayer electrode prepared by continuous roll-to-roll (RTR) sputtering of ITO and Cu targets. The RTR-sputtered ICI multilayer on a 700 mm wide PET substrate at room temperature exhibits a sheet resistance of 11.8 Ω/square and optical transmittance of 73.9%, which are acceptable for the fabrication of flexible and transparent EC films and TFHs. The effect of the Cu interlayer thickness on the electrical and optical properties of the ICI multilayer was investigated in detail. The bending and cycling fatigue tests demonstrate that the RTR-sputtered ICI multilayer was more flexible than a single ITO film because of high strain failure of the Cu interlayer. The flexible and transparent EC films and TFHs fabricated on the ICI electrode show better performances than reference EC films and TFHs with a single ITO electrode. Therefore, the RTR-sputtered ICI multilayer is the best substitute for the conventional ITO film electrode in order to realize flexible, transparent, cost-effective and large-area EC devices and TFHs that can be used as flexible and smart windows.

Studies on high electronic energy deposition in transparent conducting indium tin oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Deshpande, N G [Thin Film and Nanotechnology Laboratory, Department of Physics, Dr Babasaheb Ambedkar Marathwada University, Aurangabad-431004 (MS) (India); Gudage, Y G [Thin Film and Nanotechnology Laboratory, Department of Physics, Dr Babasaheb Ambedkar Marathwada University, Aurangabad-431004 (MS) (India); Ghosh, A [Thin Film and Nanotechnology Laboratory, Department of Physics, Dr Babasaheb Ambedkar Marathwada University, Aurangabad-431004 (MS) (India); Vyas, J C [Technical and Prototype Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai (MS) (India); Singh, F [Inter-University Accelerator Center, Aruna Asaf Ali Marg, Post Box 10502, New Delhi 110067 (India); Tripathi, A [Inter-University Accelerator Center, Aruna Asaf Ali Marg, Post Box 10502, New Delhi 110067 (India); Sharma, Ramphal [Thin Film and Nanotechnology Laboratory, Department of Physics, Dr Babasaheb Ambedkar Marathwada University, Aurangabad-431004 (MS) (India)

2008-02-07

We have examined the effect of swift heavy ions using 100 MeV Au{sup 8+} ions on the electrical properties of transparent, conducting indium tin oxide polycrystalline films with resistivity of 0.58 x 10{sup -4} {omega} cm and optical transmission greater than 78% (pristine). We report on the modifications occurring after high electronic energy deposition. With the increase in fluency, x-ray line intensity of the peaks corresponding to the planes (1 1 0), (4 0 0), (4 4 1) increased, while (3 3 1) remained constant. Surface morphological studies showed a pomegranate structure of pristine samples, which was highly disturbed with a high dose of irradiation. For the high dose, there was a formation of small spherical domes uniformly distributed over the entire surface. The transmittance was seen to be decreasing with the increase in ion fluency. At higher doses, the resistivity and photoluminescence intensity was seen to be decreased. In addition, the carrier concentration was seen to be increased, which was in accordance with the decrease in resistivity. The observed modifications after high electronic energy deposition in these films may lead to fruitful device applications.

Studies on high electronic energy deposition in transparent conducting indium tin oxide thin films

International Nuclear Information System (INIS)

Deshpande, N G; Gudage, Y G; Ghosh, A; Vyas, J C; Singh, F; Tripathi, A; Sharma, Ramphal

2008-01-01

We have examined the effect of swift heavy ions using 100 MeV Au 8+ ions on the electrical properties of transparent, conducting indium tin oxide polycrystalline films with resistivity of 0.58 x 10 -4 Ω cm and optical transmission greater than 78% (pristine). We report on the modifications occurring after high electronic energy deposition. With the increase in fluency, x-ray line intensity of the peaks corresponding to the planes (1 1 0), (4 0 0), (4 4 1) increased, while (3 3 1) remained constant. Surface morphological studies showed a pomegranate structure of pristine samples, which was highly disturbed with a high dose of irradiation. For the high dose, there was a formation of small spherical domes uniformly distributed over the entire surface. The transmittance was seen to be decreasing with the increase in ion fluency. At higher doses, the resistivity and photoluminescence intensity was seen to be decreased. In addition, the carrier concentration was seen to be increased, which was in accordance with the decrease in resistivity. The observed modifications after high electronic energy deposition in these films may lead to fruitful device applications

Comparing the fundamental physics and device performance of transparent, conductive nanostructured networks with conventional transparent conducting oxides

Energy Technology Data Exchange (ETDEWEB)

Barnes, Teresa M.; Reese, Matthew O.; Bergeson, Jeremy D.; Larsen, Brian A.; Blackburn, Jeffrey L.; Beard, Matthew C.; Bult, Justin; Van de Lagemaat, Jao [NREL, 1617 Cole Blvd., Golden, CO 80401 (United States)

2012-03-15

Networks made of single-walled carbon nanotubes (SWNTs) and metallic nanowire networks, graphene, and ultra-thin metal films have all been proposed as replacements for transparent conducting oxides (TCOs) in photovoltaic and other applications. However, only limited comparisons of nanostructured networks and TCOs are available. Several common figures of merit that are often used to compare the electrical and optical performance of the transparent contacts are evaluated here, and the merits of each method of comparison are discussed. Calculating the current loss due to absorption in the TCO is the most useful metric for evaluating new materials for use in solar cells with well-defined sheet resistance requirements and known quantum efficiencies. The 'Haacke' figure of merit, {phi}{sub H}, correlates fairly well with current loss and is a good metric for evaluating electro-optical performance for more general applications. The analyses presented here demonstrate that silver nanowire networks are much closer to achieving optimal electrical and optical properties than carbon-based networks. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Fibre and components induced limitations in high capacity optical networks

DEFF Research Database (Denmark)

Peucheret, Christophe

2003-01-01

The design of future all-optical networks relies on the knowledge of the physical layer transport properties. In this thesis, we focus on two types of system impairments: those induced by the non-ideal transfer functions of optical filters to be found in network elements such as optical add...... design in order to maximise the spectral efficiency in a four add-drop node ring network. The concept of "normalised transmission sections" is introduced in order to ease the dimensioning of transparent domains in future all-optical networks. Normalised sections based on standard single mode fibre (SMF......-drop multiplexers (OADM) and optical cross-connects (OXC), as well as those due to the interaction of group-velocity dispersion, optical fibre non-linearities and accumulation of amplifier noise in the transmission path. The dispersion of fibre optics components is shown to limit their cascadability. Dispersion...

Large-Area Cross-Aligned Silver Nanowire Electrodes for Flexible, Transparent, and Force-Sensitive Mechanochromic Touch Screens.

Science.gov (United States)

Cho, Seungse; Kang, Saewon; Pandya, Ashish; Shanker, Ravi; Khan, Ziyauddin; Lee, Youngsu; Park, Jonghwa; Craig, Stephen L; Ko, Hyunhyub

2017-04-25

Silver nanowire (AgNW) networks are considered to be promising structures for use as flexible transparent electrodes for various optoelectronic devices. One important application of AgNW transparent electrodes is the flexible touch screens. However, the performances of flexible touch screens are still limited by the large surface roughness and low electrical to optical conductivity ratio of random network AgNW electrodes. In addition, although the perception of writing force on the touch screen enables a variety of different functions, the current technology still relies on the complicated capacitive force touch sensors. This paper demonstrates a simple and high-throughput bar-coating assembly technique for the fabrication of large-area (>20 × 20 cm 2 ), highly cross-aligned AgNW networks for transparent electrodes with the sheet resistance of 21.0 Ω sq -1 at 95.0% of optical transmittance, which compares favorably with that of random AgNW networks (sheet resistance of 21.0 Ω sq -1 at 90.4% of optical transmittance). As a proof of concept demonstration, we fabricate flexible, transparent, and force-sensitive touch screens using cross-aligned AgNW electrodes integrated with mechanochromic spiropyran-polydimethylsiloxane composite film. Our force-sensitive touch screens enable the precise monitoring of dynamic writings, tracing and drawing of underneath pictures, and perception of handwriting patterns with locally different writing forces. The suggested technique provides a robust and powerful platform for the controllable assembly of nanowires beyond the scale of conventional fabrication techniques, which can find diverse applications in multifunctional flexible electronic and optoelectronic devices.

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

Josephson junction between two high Tc superconductors with arbitrary transparency of interface

Directory of Open Access Journals (Sweden)

GhR Rashedi

2010-03-01

Full Text Available In this paper, a dc Josephson junction between two singlet superconductors (d-wave and s-wave with arbitrary reflection coefficient has been investigated theoretically. For the case of high Tc superconductors, the c-axes are parallel to an interface with finite transparency and their ab-planes have a mis-orientation. The physics of potential barrier will be demonstrated by a transparency coefficient via which the tunneling will occur. We have solved the nonlocal Eilenberger equations and obtained the corresponding and suitable Green functions analytically. Then, using the obtained Green functions, the current-phase diagrams have been calculated. The effect of the potential barrier and mis-orientation on the currents is studied analytically and numerically. It is observed that, the current phase relations are totally different from the case of ideal transparent Josephson junctions between d-wave superconductors and two s-wave superconductors. This apparatus can be used to demonstrate d-wave order parameter in high Tc superconductors.

Rare-earth doped transparent ceramics for spectral filtering and quantum information processing

Energy Technology Data Exchange (ETDEWEB)

Kunkel, Nathalie, E-mail: nathalie.kunkel@chimie-paristech.fr; Goldner, Philippe, E-mail: philippe.goldner@chimie-paristech.fr [PSL Research University, Chimie ParisTech–CNRS, Institut de Recherche de Chimie Paris, 11 rue Pierre et Marie Curie, 75005 Paris (France); Ferrier, Alban [PSL Research University, Chimie ParisTech–CNRS, Institut de Recherche de Chimie Paris, 11 rue Pierre et Marie Curie, 75005 Paris (France); Sorbonnes Universités, UPMC Univ Paris 06, 75005 Paris (France); Thiel, Charles W.; Cone, Rufus L. [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States); Ramírez, Mariola O.; Bausá, Luisa E. [Departamento Física de Materiales and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Ikesue, Akio [World Laboratory, Mutsuno, Atsuta-ku, Nagoya 456-0023 (Japan)

2015-09-01

Homogeneous linewidths below 10 kHz are reported for the first time in high-quality Eu{sup 3+} doped Y {sub 2}O{sub 3} transparent ceramics. This result is obtained on the {sup 7}F{sub 0}→{sup 5}D{sub 0} transition in Eu{sup 3+} doped Y {sub 2}O{sub 3} ceramics and corresponds to an improvement of nearly one order of magnitude compared to previously reported values in transparent ceramics. Furthermore, we observed spectral hole lifetimes of ∼15 min that are long enough to enable efficient optical pumping of the nuclear hyperfine levels. Additionally, different Eu{sup 3+} concentrations (up to 1.0%) were studied, resulting in an increase of up to a factor of three in the peak absorption coefficient. These results suggest that transparent ceramics can be useful in applications where narrow and deep spectral holes can be burned into highly absorbing lines, such as quantum information processing and spectral filtering.

Electronic characteristics of p-type transparent SnO monolayer with high carrier mobility

Energy Technology Data Exchange (ETDEWEB)

Du, Juan [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Xia, Congxin, E-mail: xiacongxin@htu.edu.cn [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Liu, Yaming [Henan Institute of Science and Technology, Xinxiang 453003 (China); Li, Xueping [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Peng, Yuting [Department of Physics, University of Texas at Arlington, TX 76019 (United States); Wei, Shuyi [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China)

2017-04-15

Graphical abstract: SnO monolayer is a p-type transparent semiconducting oxide with high hole mobility (∼641 cm{sup 2} V{sup −1} s{sup −1}), which is much higher than that of MoS{sub 2} monolayer, which indicate that it can be a promising candidate for high-performance nanoelectronic devices. Display Omitted - Highlights: • SnO monolayer is a p-type transparent semiconducting oxide. • The transparent properties can be still maintained under the strain 8%. • It has a high hole mobility (∼641 cm{sup 2} V{sup −1} s{sup −1}), which is higher than that of MoS{sub 2} monolayer. - Abstract: More recently, two-dimensional (2D) SnO nanosheets are attaching great attention due to its excellent carrier mobility and transparent characteristics. Here, the stability, electronic structures and carrier mobility of SnO monolayer are investigated by using first-principles calculations. The calculations of the phonon dispersion spectra indicate that SnO monolayer is dynamically stable. Moreover, the band gap values are decreased from 3.93 eV to 2.75 eV when the tensile strain is applied from 0% to 12%. Interestingly, SnO monolayer is a p-type transparent semiconducting oxide with hole mobility of 641 cm{sup 2} V{sup −1} s{sup −1}, which is much higher than that of MoS{sub 2} monolayer. These findings make SnO monolayer becomes a promising 2D material for applications in nanoelectronic devices.

Optical probing of long-range spatial correlation and symmetry in complex biophotonic architectures on transparent insect wings

International Nuclear Information System (INIS)

Kumar, Pramod; Shamoon, Danish; Singh, Dhirendra P; Singh, Kamal P; Mandal, Sudip

2015-01-01

We experimentally probe the structural organization of complex bio-photonic architecture on transparent insect wings by a simple, non-invasive, real-time optical technique. A stable and reproducible far-field diffraction pattern in transmission was observed using collimated cw and broadband fs laser pulses. A quantitative analysis of the observed diffraction pattern unveiled long-range quasi-periodic order in the arrangement of the microstructures over mm scale. These observations agree well with the Fourier analysis of SEM images of the wing taken at various length scales. We propose a simple quantitative model based on optical diffraction by an array of non overlapping microstructures with minimal disorder which supports our experimental observations. We observed a rotation of the original diffraction profile by scanning the laser beam across the wing sample which gives direct signature of organizational symmetry in microstructure arrangements at various length scales. In addition, we report the first optical detection of reorganization in the photonic architecture on the Drosophila wings by various genetic mutations. These results have potential for the design and development of diffractive optical components for applied photonics and may open up new opportunities in biomimetic device research. (letter)

Development and applications of transparent conductive nanocellulose paper

Science.gov (United States)

Li, Shaohui; Lee, Pooi See

2017-12-01

Increasing attention has been paid to the next generation of 'green' electronic devices based on renewable nanocellulose, owing to its low roughness, good thermal stability and excellent optical properties. Various proof-of-concept transparent nanopaper-based electronic devices have been fabricated; these devices exhibit excellent flexibility, bendability and even foldability. In this review, we summarize the recent progress of transparent nanopaper that uses different types of nanocellulose, including pure nanocellulose paper and composite nanocellulose paper. The latest development of transparent and flexible nanopaper electronic devices are illustrated, such as electrochromic devices, touch sensors, solar cells and transistors. Finally, we discuss the advantages of transparent nanopaper compared to conventional flexible plastic substrate and the existing challenges to be tackled in order to realize this promising potential.

Development and applications of transparent conductive nanocellulose paper.

Science.gov (United States)

Li, Shaohui; Lee, Pooi See

2017-01-01

Increasing attention has been paid to the next generation of 'green' electronic devices based on renewable nanocellulose, owing to its low roughness, good thermal stability and excellent optical properties. Various proof-of-concept transparent nanopaper-based electronic devices have been fabricated; these devices exhibit excellent flexibility, bendability and even foldability. In this review, we summarize the recent progress of transparent nanopaper that uses different types of nanocellulose, including pure nanocellulose paper and composite nanocellulose paper. The latest development of transparent and flexible nanopaper electronic devices are illustrated, such as electrochromic devices, touch sensors, solar cells and transistors. Finally, we discuss the advantages of transparent nanopaper compared to conventional flexible plastic substrate and the existing challenges to be tackled in order to realize this promising potential.

Realistic reflectance spectrum of thin films covering a transparent optically thick substrate

Energy Technology Data Exchange (ETDEWEB)

Cesaria, M., E-mail: maura.cesaria@le.infn.it; Caricato, A. P.; Martino, M. [Department of Mathematics and Physics “Ennio De Giorgi,” University of Salento, Via Arnesano, I-73100 Lecce (Italy)

2014-07-21

A spectrophotometric strategy is presented and discussed for calculating realistically the reflectance spectrum of an absorbing film deposited over a thick transparent or semi-transparent substrate. The developed route exploits simple mathematics, has wide range of applicability (high-to-weak absorption regions and thick-to-ultrathin films), rules out numerical and curve-fitting procedures as well as model-functions, inherently accounts for the non-measurable contribution of the film-substrate interface as well as substrate backside, and describes the film reflectance spectrum as determined by the experimental situation (deposition approach and parameters). The reliability of the method is tested on films of a well-known material (indium tin oxide) by deliberately changing film thickness and structural quality through doping. Results are found consistent with usual information yielded by reflectance, its inherent relationship with scattering processes and contributions to the measured total reflectance.

P -type transparent conducting oxides

International Nuclear Information System (INIS)

Zhang, Kelvin H L; Xi, Kai; Blamire, Mark G; Egdell, Russell G

2016-01-01

Transparent conducting oxides constitute a unique class of materials combining properties of electrical conductivity and optical transparency in a single material. They are needed for a wide range of applications including solar cells, flat panel displays, touch screens, light emitting diodes and transparent electronics. Most of the commercially available TCOs are n -type, such as Sn doped In 2 O 3 , Al doped ZnO, and F doped SnO 2 . However, the development of efficient p -type TCOs remains an outstanding challenge. This challenge is thought to be due to the localized nature of the O 2 p derived valence band which leads to difficulty in introducing shallow acceptors and large hole effective masses. In 1997 Hosono and co-workers (1997 Nature 389 939) proposed the concept of ‘chemical modulation of the valence band’ to mitigate this problem using hybridization of O 2 p orbitals with close-shell Cu 3 d 10 orbitals. This work has sparked tremendous interest in designing p -TCO materials together with deep understanding the underlying materials physics. In this article, we will provide a comprehensive review on traditional and recently emergent p -TCOs, including Cu + -based delafossites, layered oxychalcogenides, nd 6 spinel oxides, Cr 3+ -based oxides (3 d 3 ) and post-transition metal oxides with lone pair state (ns 2 ). We will focus our discussions on the basic materials physics of these materials in terms of electronic structures, doping and defect properties for p -type conductivity and optical properties. Device applications based on p -TCOs for transparent p – n junctions will also be briefly discussed. (topical review)

Development and applications of transparent conductive nanocellulose paper

OpenAIRE

Li, Shaohui; Lee, Pooi See

2017-01-01

Abstract Increasing attention has been paid to the next generation of ‘green’ electronic devices based on renewable nanocellulose, owing to its low roughness, good thermal stability and excellent optical properties. Various proof-of-concept transparent nanopaper-based electronic devices have been fabricated; these devices exhibit excellent flexibility, bendability and even foldability. In this review, we summarize the recent progress of transparent nanopaper that uses different types of nanoc...

Solution processed zinc oxide nanopyramid/silver nanowire transparent network films with highly tunable light scattering properties

KAUST Repository

Mehra, Saahil

2013-01-01

Metal nanowire transparent networks are promising replacements to indium tin oxide (ITO) transparent electrodes for optoelectronic devices. While the transparency and sheet resistance are key metrics for transparent electrode performance, independent control of the film light scattering properties is important to developing multifunctional electrodes for improved photovoltaic absorption. Here we show that controlled incorporation of ZnO nanopyramids into a metal nanowire network film affords independent, highly tunable control of the scattering properties (haze) with minimal effects on the transparency and sheet resistance. Varying the zinc oxide/silver nanostructure ratios prior to spray deposition results in sheet resistances, transmission (600 nm), and haze (600 nm) of 6-30 Ω □^-1, 68-86%, and 34-66%, respectively. Incorporation of zinc oxide nanopyramid scattering agents into the conducting nanowire mesh has a negligible effect on mesh connectivity, providing a straightforward method of controlling electrode scattering properties. The decoupling of the film scattering power and electrical characteristics makes these films promising candidates for highly scattering transparent electrodes in optoelectronic devices and can be generalized to other metal nanowire films as well as carbon nanotube transparent electrodes. © 2013 The Royal Society of Chemistry.

Transparent CuInS2/PMMA nanocomposites luminescent in the visible and NIR region

International Nuclear Information System (INIS)

Gugula, Krzysztof; Bredol, Michael

2014-01-01

Nanocomposites combining functional nanoparticles and transparent polymers allow for stabilization of filler properties over long periods of time while retaining transparency of the polymer matrix. Here we employ CuInS 2 /ZnS quantum dots (QDs), ternary visible- and NIR-emitting semiconductors as wavelength-tunable luminescent fillers. Luminescence in the near infrared (NIR) is of particular interest in medicine which allows deep penetration into human tissue enabling in vivo diagnostics and treatment, while visible emitters may serve as color converters in displays or lighting. To stabilize the optical properties of QDs and prevent agglomeration, polymethyl metacrylate (PMMA) was chosen as a matrix. These novel polymer nanocomposites (PNCs) show good optical properties and stability under ambient conditions, and can be easily deposited over large areas. High-quality QDs and hydrophobic functionalization with long-chain hydrocarbons are a prerequisite for embedding into a PMMA matrix. Transparent PNC films without visible scattering losses were obtained for 1 wt-% QD loading with respect to the polymer. Partial transparency is retained up to 10 wt-% QD loading and vanishes rapidly at higher loading. Luminescence properties increase up to 5 wt-% and then decrease rapidly due to QD agglomeration and reabsorption between adjacent particles. Potential applications include converter materials for medical applications, laser layers, displays and white LEDs. (orig.)

Powder metallurgy inspired low-temperature fabrication of high-performance stereocomplexed polylactide products with good optical transparency

Science.gov (United States)

Bai, Dongyu; Liu, Huili; Bai, Hongwei; Zhang, Qin; Fu, Qiang

2016-02-01

Stereocomplexation between enantiomeric poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) provides an avenue to greatly enhance performance of eco-friendly polylactide (PLA). Unfortunately, although the manufacturing of semicrystalline polymers generally involves melt processing, it is still hugely challenging to create high-performance stereocomplexed polylactide (sc-PLA) products from melt-processed high-molecular-weight PLLA/PDLA blends due to the weak crystallization memory effect of stereocomplex (sc) crystallites after complete melting as well as the substantial degradation of PLA chains at elevated melt-processing temperatures of ca. 240-260 °C. Inspired by the concept of powder metallurgy, here we report a new facile route to address these obstacles by sintering of sc-PLA powder at temperatures as low as 180-210 °C, which is distinctly different from traditional sintering of polymer powders performed at temperatures far exceeding their melting temperatures. The enantiomeric PLA chain segments from adjacent powder particles can interdiffuse across particle interfaces and co-crystallize into new sc crystallites capable of tightly welding the interfaces during the low-temperature sintering process, and thus highly transparent sc-PLA products with outstanding heat resistance, mechanical strength, and hydrolytic stability have been successfully fabricated for the first time.

Powder metallurgy inspired low-temperature fabrication of high-performance stereocomplexed polylactide products with good optical transparency

Science.gov (United States)

Bai, Dongyu; Liu, Huili; Bai, Hongwei; Zhang, Qin; Fu, Qiang

2016-01-01

Stereocomplexation between enantiomeric poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) provides an avenue to greatly enhance performance of eco-friendly polylactide (PLA). Unfortunately, although the manufacturing of semicrystalline polymers generally involves melt processing, it is still hugely challenging to create high-performance stereocomplexed polylactide (sc-PLA) products from melt-processed high-molecular-weight PLLA/PDLA blends due to the weak crystallization memory effect of stereocomplex (sc) crystallites after complete melting as well as the substantial degradation of PLA chains at elevated melt-processing temperatures of ca. 240–260 °C. Inspired by the concept of powder metallurgy, here we report a new facile route to address these obstacles by sintering of sc-PLA powder at temperatures as low as 180–210 °C, which is distinctly different from traditional sintering of polymer powders performed at temperatures far exceeding their melting temperatures. The enantiomeric PLA chain segments from adjacent powder particles can interdiffuse across particle interfaces and co-crystallize into new sc crystallites capable of tightly welding the interfaces during the low-temperature sintering process, and thus highly transparent sc-PLA products with outstanding heat resistance, mechanical strength, and hydrolytic stability have been successfully fabricated for the first time. PMID:26837848

Powder metallurgy inspired low-temperature fabrication of high-performance stereocomplexed polylactide products with good optical transparency.

Science.gov (United States)

Bai, Dongyu; Liu, Huili; Bai, Hongwei; Zhang, Qin; Fu, Qiang

2016-02-03

Stereocomplexation between enantiomeric poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) provides an avenue to greatly enhance performance of eco-friendly polylactide (PLA). Unfortunately, although the manufacturing of semicrystalline polymers generally involves melt processing, it is still hugely challenging to create high-performance stereocomplexed polylactide (sc-PLA) products from melt-processed high-molecular-weight PLLA/PDLA blends due to the weak crystallization memory effect of stereocomplex (sc) crystallites after complete melting as well as the substantial degradation of PLA chains at elevated melt-processing temperatures of ca. 240-260 °C. Inspired by the concept of powder metallurgy, here we report a new facile route to address these obstacles by sintering of sc-PLA powder at temperatures as low as 180-210 °C, which is distinctly different from traditional sintering of polymer powders performed at temperatures far exceeding their melting temperatures. The enantiomeric PLA chain segments from adjacent powder particles can interdiffuse across particle interfaces and co-crystallize into new sc crystallites capable of tightly welding the interfaces during the low-temperature sintering process, and thus highly transparent sc-PLA products with outstanding heat resistance, mechanical strength, and hydrolytic stability have been successfully fabricated for the first time.

Tunable multiple plasmon induced transparencies in parallel graphene sheets and its applications

Science.gov (United States)

khazaee, Sara; Granpayeh, Nosrat

2018-01-01

Tunable plasmon induced transparency is achieved by using only two parallel graphene sheets beyond silicon diffractive grating in mid-infrared region. Excitation of the guided-wave resonance (GWR) in this structure is illustrated on the normal incident transmission spectra and plays the bright resonance mode role. Weak hybridization between two bright modes, creates plasmon induced transparency (PIT) optical response. The resonance frequency of transparency window can be tuned by different geometrical parameters. Also, variation of graphene Fermi energy can be used to achieve tunability of the resonance frequency of transparency window without reconstruction and re-fabrication of the structure. We demonstrate the existence of multiple PIT spectral responses resulting from a series of self-assembled GWRs to be used as the wavelength demultiplexer. This study can be used for design of the optical ultra-compact devices and photonic integrated circuits.

An Optically-Transparent Aptamer-Based Detection System for Colon Cancer Applications Using Gold Nanoparticles Electrodeposited on Indium Tin Oxide

Directory of Open Access Journals (Sweden)

Mojgan Ahmadzadeh-Raji

2016-07-01

Full Text Available In this paper, a label-free aptamer based detection system (apta-DS was investigated for detecting colon cancer cells. For this purpose, we employed an aptamer specific to colon cancer cells like HCT116 expressing carcinoembryonic antigen (CEA on their surfaces. Capture aptamers were covalently immobilized on the surface of gold nanoparticles (GNPs through self-assembly monolayer of 11-mercaptoundecanoic acid (11-MUA activated with EDC (1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide/N-hydroxysuccinimide (NHS. The cyclic voltammetry (CV and chronopotentiometry (CP methods were used for electrodeposition of GNPs on the surface of indium tin oxide (ITO. In this work, the CV method was also used to demonstrate the conjugation of GNPs and aptamers and identify the cancer cell capturing events. Additionally, Field Emission Scanning Electron Microscopy (FE-SEM confirmed the deposition of GNPs on ITO and the immobilization of aptamer on the apta-DS. The electrodeposited GNPs played the role of nanoprobes for cancer cell targeting without losing the optical transparency of the ITO substrate. A conventional optical microscope also verified the detection of captured cancer cells. Based on this study’s results relying on electrochemical and optical microscopic methods, the proposed apta-DS is reliable and high sensitive with a LOD equal to 6 cell/mL for colon cancer detection.

Transparent Cu4O3/ZnO heterojunction photoelectric devices

Science.gov (United States)

Kim, Hong-Sik; Yadav, Pankaj; Patel, Malkeshkumar; Kim, Joondong; Pandey, Kavita; Lim, Donggun; Jeong, Chaehwan

2017-12-01

The present article reports the development of flexible, self-biased, broadband, high speed and transparent heterojunction photodiode, which is essentially important for the next generation electronic devices. We grow semitransparent p-type Cu4O3 using the reactive sputtering method at room temperature. The structural and optical properties of the Cu4O3 film were investigated by using the X-ray diffraction and UV-visible spectroscopy, respectively. The p-Cu4O3/n-ZnO heterojunction diode under dark condition yields rectification behavior with an extremely low saturation current value of 1.8 × 10-10 A and a zero bias photocurrent under illumination condition. The transparent p-Cu4O3/n-ZnO heterojunction photodetector can be operated without an external bias, due to the light-induced voltage production. The metal oxide heterojunction based on Cu4O3/ZnO would provide a route for the transparent and flexible photoelectric devices, including photodetectors and photovoltaics.

Stable iodide doping induced by photonic curing for carbon nanotube transparent conductive films

Science.gov (United States)

Wachi, Atsushi; Nishikawa, Hiroyuki; Zhou, Ying; Azumi, Reiko

2018-06-01

Doping has become crucial for achieving stable and high-performance conductive transparent carbon nanotube (CNT) films. In this study, we systematically investigate the doping effects of a few materials including alkali metal iodides, nonmetal iodide, and metals. We demonstrate that photonic curing can enhance the doping effects, and correspondingly improve the conductivity of CNT films, and that such iodides have better doping effects than metals. In particular, doping with a nonmetal compound (NH4I) shows the largest potential to improve the conductivity of CNT films. Typically, doping with metal iodides reduces the sheet resistance (R S) of CNT films with 70–80% optical transmittances at λ = 550 nm from 600–2400 to 250–440 Ω/square, whereas doping with NH4I reduces R S to 57 and 84 Ω/square at 74 and 84% optical transmittances, respectively. Interestingly, such a doped CNT film exhibits only a slight increase in sheet resistance under an extreme environment of high temperature (85 °C) and high relative humidity (85%) for 350 h. The results suggest that photonic-curing-induced iodide doping is a promising approach to producing high-performance conductive transparent CNT films.

Fabrication and scintillation properties of highly transparent Pr:LuAG ceramics using Sc,La-based isovalent sintering aids

Czech Academy of Sciences Publication Activity Database

Shen, Y.; Feng, X.; Babin, Vladimir; Nikl, Martin; Vedda, A.; Moretti, F.; Dell'Orto, E.; Pan, Y.; Li, J.; Zeng, Y.

2013-01-01

Roč. 39, č. 5 (2013), s. 5985-5990 ISSN 0272-8842 R&D Projects: GA MŠk LH12185; GA AV ČR KAN300100802 Institutional support: RVO:68378271 Keywords : Pr:LuAG transparent ceramics * isovalent sintering aids * scintillation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.086, year: 2013

Corneal structure and transparency

Science.gov (United States)

Meek, Keith M.; Knupp, Carlo

2015-01-01

The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225

Optical and electrical properties of transparent conductive ITO thin films under proton radiation with 100 keV

International Nuclear Information System (INIS)

Wei, Q.; He, S.Y.; Yang, D.Z.; Liu, J.C.

2005-01-01

Under the simulation environment for the vacuum and heat sink in space, the changes in optical and electrical properties of transparent conductive indium tin oxide (ITO) thin films induced by radiation of protons with 100 keV were studied. The ITO thin films were deposited on JGS1 quartz substrate by a sol-gel method. The sheet resistance and transmittance spectra of the ITO thin films were measured using the four-point probe method and a spectrophotometer, respectively. The surface morphology was analyzed by AFM. The experimental results showed that the electrical and optical performances of the ITO thin films were closely related to the irradiation fluence. When the fluence exceeded a given value 2 x 10 16 cm -2 , the sheet resistance increased obviously and the optical transmittance decreased. The AFM analysis indicated that the grain size of the ITO thin films diminished. The studies about the radiation effect on ITO thin films will help to predict performance evolution of the second surface mirrors on satellites under space radiation environment. (orig.)

Spectroscopy of strontium Rydberg states using electromagnetically induced transparency

International Nuclear Information System (INIS)

Mauger, S; Millen, J; Jones, M P A

2007-01-01

We report on the all-optical detection of Rydberg states in an effusive atomic beam of strontium atoms using electromagnetically induced transparency (EIT). Using narrow-linewidth CW lasers we obtain an EIT linewidth of 5 MHz. To illustrate the high spectroscopic resolution offered by this method, we have measured isotope shifts of the 5s18d 1 D 2 and 5s19s 1 S 0 Rydberg states. This technique could be applied to high-resolution, non-destructive measurements of ultra-cold Rydberg gases and plasmas. (fast track communication)

Transparent 1T-MoS2 nanofilm robustly anchored on substrate by layer-by-layer self-assembly and its ultra-high cycling stability as supercapacitors

Science.gov (United States)

Li, Danqin; Zhou, Weiqiang; Zhou, Qianjie; Ye, Guo; Wang, Tongzhou; Wu, Jing; Chang, Yanan; Xu, Jingkun

2017-09-01

Two-dimensional MoS2 materials have attracted more and more interest and been applied to the field of energy storage because of its unique physical, optical, electronic and electrochemical properties. However, there are no reports on high-stable transparent MoS2 nanofilms as supercapacitors electrode. Here, we describe a transparent 1T-MoS2 nanofilm electrode with super-long stability anchored on the indium tin oxide (ITO) glass by a simple alternate layer-by-layer (LBL) self-assembly of a highly charged cationic poly(diallyldimethylammonium chloride) (PDDA) and negative single-/few-layer 1T MoS2 nanosheets. The ITO/(PDDA/MoS2)20 electrode shows a transmittance of 51.6% at 550 nm and obviously exhibits excellent transparency by naked eye observation. Ultrasonic damage test validates that the (PDDA/MoS2)20 film with the average thickness about 50 nm is robustly anchored on ITO substrate. Additionally, the electrochemical results indicate that the ITO/(PDDA/MoS2)20 film shows areal capacitance of 1.1 mF cm-2 and volumetric capacitance of 220 F cm-3 at 0.04 mA cm-2, 130.6% retention of the original capacitance value after 5000 cycles. Further experiments indicate that the formation of transparent (PDDA/MoS2) x nanofilm by LBL self-assembly can be extended to other substrates, e.g., slide glass and flexible polyethylene terephthalate (PET). Thus, the easily available (PDDA/MoS2) x nanofilm electrode has great potential for application in transparent and/or flexible optoelectronic and electronics devices.

Investigation of the photoluminescence properties of composite optical resins containing high lanthanide content

International Nuclear Information System (INIS)

Wang Dongmei; Wang Fuxiang; Peng Weixian

2012-01-01

Novel composite optical resins with high lanthanide content have been synthesized through a free radical copolymerization of methacrylic acid (MA), styrene (St) and Eu(DBM) 3 ·H 2 O nanocrystals. We characterized the structure, the thermal properties, dimensions and photoluminescence properties of Eu(DBM) 3 ·H 2 O nanocrystals. Our results indicated that the diameters of the Eu(DBM) 3 ·H 2 O nanocrystals were within the range of 30 to 300 nm. These materials exhibited characteristic europium ion luminescence. The europium-bearing nanocrystals and were then incorporated into the copolymer systems of MA/St and luminescence functional optical resins with high lanthanide content (50 wt%) were obtained. The combination of these particles and optical resins is facile because the diameter of Eu(DBM) 3 ·H 2 O is decreased. These copolymer-based optical resins not only possess good transparency and mechanical performance, but also exhibit an intense narrow band emission of lanthanide complexes and longer fluorescence lifetimes under UV excitation at room temperature. - Highlights: ► Novel composite optical resins with high lanthanide content have been synthesized. ► The Eu(DBM) 3 ·H 2 O nanocrystals were within the range of 30 to 300 nm. ► Fluorescent resins with high lanthanide content (50 wt%) were obtained. ► Resins exhibit intense emission of lanthanide and longer fluorescence lifetimes. ► Variety properties of Eu(DBM) 3 ·H 2 O nanocrystals were characterized.

Electrically modulated transparent liquid crystal-optical grating projection

DEFF Research Database (Denmark)

Buss, Thomas; Smith, Cameron; Kristensen, Anders

2013-01-01

A transparent, fully integrated electrically modulated projection technique is presented based on light guiding through a thin liquid crystal layer covering sub-wavelength gratings. The reported device operates at 10 V with response times of 4.5 ms. Analysis of the liquid crystal alignment shows...

Development and applications of transparent conductive nanocellulose paper

Science.gov (United States)

Li, Shaohui; Lee, Pooi See

2017-01-01

Abstract Increasing attention has been paid to the next generation of ‘green’ electronic devices based on renewable nanocellulose, owing to its low roughness, good thermal stability and excellent optical properties. Various proof-of-concept transparent nanopaper-based electronic devices have been fabricated; these devices exhibit excellent flexibility, bendability and even foldability. In this review, we summarize the recent progress of transparent nanopaper that uses different types of nanocellulose, including pure nanocellulose paper and composite nanocellulose paper. The latest development of transparent and flexible nanopaper electronic devices are illustrated, such as electrochromic devices, touch sensors, solar cells and transistors. Finally, we discuss the advantages of transparent nanopaper compared to conventional flexible plastic substrate and the existing challenges to be tackled in order to realize this promising potential. PMID:28970870

Fabrication and characterization of differentiated aramid nanofibers and transparent films

Science.gov (United States)

Luo, Jingjing; Zhang, Meiyun; Yang, Bin; Liu, Guodong; Song, Shunxi

2018-03-01

Aramid nanofibers (ANFs) frequently are employed as versatile building blocks for constructing high-performance nanocomposites due to its structural and performance superiority. In this paper, the different ANFs and ANF films derived from the typical aramid yarns, chopped fiber, pulp fiber and fibrid fiber, respectively, were fabricated through deprotonation with potassium hydroxide in dimethyl sulphoxide, protonation with deionized water and vacuum-assisted filtration. The physical tests such as tensile test, ultraviolet transmittance and absorbance, thermogravimetric analysis were executed to evaluate and contrast the thermodynamic and optical performances of these differentiated ANFs and ANF films. The analytical results suggested that ANFs films prepared by the different forms of aramid macrofibers presented with differentiated properties such as mechanical behaviors, transparencies and flexibilities. And also it was found that the oversized nanofiber in length led to the formation of flocculation which was adverse for ANFs films in the formation of high strength. Whereas, small diameter just facilitated for the achievement of high stiffness and transparency. By contrast, the ANFs films made from chopped nanofiber, with aspect ratio of 200-500, exhibited good transparency, thermal stability and mechanical properties with transmittance value of 83%, TG10% around 521 °C, ultimate strength (σ) of 103.41 MPa, stiffness (E) of 4.70 GPa and strain at break of 5.56%. This work offers an alternative nanoscale building block as an effective nanofiller for preparing high-performance nanocomposites with different requirements in the potential fields such as transparent coating and flexible electrode or display materials, battery separator and microporous membrane.

Highly transparent conductive AZO/Zr50Cu50/AZO films in wide range of visible and near infrared wavelength grown by pulsed laser deposition

Directory of Open Access Journals (Sweden)

Jingyun Cheng

Full Text Available Novel AZO/Zr50Cu50/AZO tri-layer transparent conductive films with excellent transmittance in both visible and near infrared region were successfully prepared by pulsed laser deposition on glass substrates. The electrical and optical properties were investigated at various Zr50Cu50 thicknesses. As the AZO thickness was fixed at 50 nm and Zr50Cu50 thickness was varied between 1 and 18 nm, it was found that AZO (50 nm/Zr50Cu50/AZO (50 nm tri-layer films exhibited good conductivity and high transmittance in both visible and near infrared wavelength. Additionally, both the electrical and optical properties of AZO (50 nm/Zr50Cu50 (2 nm/AZO (50 nm tri-layer films were found to be sensitive to the growth temperature. In this work, the lowest sheet resistance (43 Ω/□ and relatively high transmittance (∼80% in the range of 400–2000 nm were achieved while the growth temperature was 350 °C. Furthermore, the AZO (50 nm/Zr50Cu50 (2 nm/AZO (50 nm thin film deposited at 350 °C exhibits the highest figure of merit of 1.42 × 10−3 Ω−1, indicating that the multilayer is promising for coated glasses and thin film solar cells. Keywords: Transparent conductive oxide, AZO, Zr50Cu50, Electrical and optical properties, Visible and near infrared transmittance

A simple two-step method to fabricate highly transparent ITO/polymer nanocomposite films

International Nuclear Information System (INIS)

Liu, Haitao; Zeng, Xiaofei; Kong, Xiangrong; Bian, Shuguang; Chen, Jianfeng

2012-01-01

Highlights: ► A simple two-step method without further surface modification step was employed. ► ITO nanoparticles were easily to be uniformly dispersed in polymer matrix. ► ITO/polymer nanocomposite film had high transparency and UV/IR blocking properties. - Abstract: Transparent functional indium tin oxide (ITO)/polymer nanocomposite films were fabricated via a simple approach with two steps. Firstly, the functional monodisperse ITO nanoparticles were synthesized via a facile nonaqueous solvothermal method using bifunctional chemical agent (N-methyl-pyrrolidone, NMP) as the reaction solvent and surface modifier. Secondly, the ITO/acrylics polyurethane (PUA) nanocomposite films were fabricated by a simple sol-solution mixing method without any further surface modification step as often employed traditionally. Flower-like ITO nanoclusters with about 45 nm in diameter were mono-dispersed in ethyl acetate and each nanocluster was assembled by nearly spherical nanoparticles with primary size of 7–9 nm in diameter. The ITO nanoclusters exhibited an excellent dispersibility in polymer matrix of PUA, remaining their original size without any further agglomeration. When the loading content of ITO nanoclusters reached to 5 wt%, the transparent functional nanocomposite film featured a high transparency more than 85% in the visible light region (at 550 nm), meanwhile cutting off near-infrared radiation about 50% at 1500 nm and blocking UV ray about 45% at 350 nm. It could be potential for transparent functional coating materials applications.

Optical fiber pH sensors for high temperature water. Final report

International Nuclear Information System (INIS)

McCrae, D.; Saaski, E.

1994-11-01

The goal of this program was the development of an optical pH measurement system capable of operating in a high-temperature aqueous environment. This project built upon a dual-wavelength fiber optic sensing system previously developed by Research International which utilizes light-emitting diodes as light sources and provides remote absorption spectroscopy via a single bidirectional optical fiber. Suitable materials for constructing an optical pH sensing element were identified during the program. These included a sapphire/Ti/Pt/Au thin-film reflector, quartz and sapphire waveguides, a poly(benzimidazole) matrix, and an azo chromophore indicator. By a suitable combination of these design elements, it appears possible to optically measure pH in aqueous systems up to a temperature of about 150 degrees C. A pH sensing system capable of operating in high-purity, low-conductivity water was built using quasi-evanescent wave sensing techniques. The sensing element incorporated a novel, mixed cellulose/cellulose acetate waveguide to which an azo indicator was bound. Testing revealed that the system could reproducibly respond to pH changes arising from 1 ppm differences in the morpholine content of low-conductivity water without influencing the measurement. The sensing system was stable for 150 hrs at room temperature, and no loss or degradation of the pH-responsive optical indicator was seen in 160 hrs at 50 degrees C. However, the prototype polymer waveguide lost transparency at 1.7% per day during this same 50 degrees C test. Additional effort is warranted in the areas of water-compatible waveguides and evanescent-wave detection methods

Color transparency

International Nuclear Information System (INIS)

Pire, B.; Ralston, J.P.

1991-01-01

This paper reviews the physics of color transparency and the unexpected energy dependence of recent measurements of high-energy fixed-angle elastic scattering in nuclear targets. The authors point out advantages of using transparency as a tool, introducing two concepts - spin and flavor flow filtering - that may be studied with nuclear targets. The special case of electroproduction is also considered

On color transparency

International Nuclear Information System (INIS)

Jennings, B.K.; Miller, G.A.

1989-10-01

A quantum mechanical treatment of high momentum transfer nuclear processes is presented. Color transparency, the suppression of initial and final state interaction effects, is shown to arise from using the closure approximation. New conditions for the appearance of color transparency are derived

Structural, optical and electrical characterization of ITO, ITO/Ag and ITO/Ni transparent conductive electrodes

International Nuclear Information System (INIS)

Ali, Ahmad Hadi; Shuhaimi, Ahmad; Hassan, Zainuriah

2014-01-01

We report on the transparent conductive oxides (TCO) characteristics based on the indium tin oxides (ITO) and ITO/metal thin layer as an electrode for optoelectronics device applications. ITO, ITO/Ag and ITO/Ni were deposited on Si and glass substrate by thermal evaporator and radio frequency (RF) magnetron sputtering at room temperature. Post deposition annealing was performed on the samples in air at moderate temperature of 500 °C and 600 °C. The structural, optical and electrical properties of the ITO and ITO/metal were characterized using X-ray diffraction (XRD), UV–Vis spectrophotometer, Hall effect measurement system and atomic force microscope (AFM). The XRD spectrum reveals significant polycrystalline peaks of ITO (2 2 2) and Ag (1 1 1) after post annealing process. The post annealing also improves the visible light transmittance and electrical resistivity of the samples. Figure of merit (FOM) of the ITO, ITO/Ag and ITO/Ni were determined as 5.5 × 10 −3 Ω −1 , 8.4 × 10 −3 Ω −1 and 3.0 × 10 −5 Ω −1 , respectively. The results show that the post annealed ITO with Ag intermediate layer improved the efficiency of the transparent conductive electrodes (TCE) as compared to the ITO and ITO/Ni.

Infrared transparency and electrical conductivity of non-stoichiometric InxOy films

International Nuclear Information System (INIS)

Joseph, Shay; Berger, Shlomo

2010-01-01

In an effort to achieve both high infrared transparency and electrical conductivity, In x O y films having different oxygen atomic fractions, ranging from 0.27 to 0.6 were prepared. From AC electrical measurements it was determined that conductivity of In x O y films, having oxygen atomic fraction near 0.6, is governed by the hopping conduction mechanism via energy states located in the band gap. Conductivity of In x O y films having non-stoichiometric compositions was found to be governed by the free band conduction mechanism. The conduction activation energy was decreased from about 0.47 eV to about 0.02 eV as the deviation of the oxygen atomic fraction from the stoichiometric value of 0.6 was increased. The dielectric function of the films was determined by applying the Drude-Lorentz model to ellipsometric measurements in the infrared and visible wavelengths. In the visible range, the major source for optical transmission loss is interband absorption, which was modeled by the Lorentz model. In the infrared range, optical absorption was measured and attributed to the presence of free charge carriers according to the Drude model. Fitting the model to the optical measurements required a correction factor, which was correlated with the films polarizability. In order to determine the optimal tradeoff between optical transparency in the infrared and electrical conductivity, which were found to be affected mainly by the oxygen concentration in the films, a figure of merit parameter was established. It was found that by introducing non-stoichiometry in the form of oxygen deficiency, the electrical conductivity was improved by as much as two orders of magnitude while the infrared transparency was decreased by no more than 30% with respect to stoichiometric In 2 O 3 films.

Optoelectronic properties of transparent p-type semiconductor Cu{sub x}S thin films

Energy Technology Data Exchange (ETDEWEB)

Parreira, P.; Valente, J. [ICEMS, IST-UTL, Lisboa (Portugal); Lavareda, G. [Departamento de Fisica, IST-UTL, Lisboa (Portugal); Nunes, F.T. [Departamento de Ciencia dos Materiais, FCT-UNL, Caparica (Portugal); Amaral, A. [Departamento de Fisica, IST-UTL, Lisboa (Portugal); ICEMS, IST-UTL, Lisboa (Portugal); Carvalho, C.N. de [Departamento de Ciencia dos Materiais, FCT-UNL, Caparica (Portugal); ICEMS, IST-UTL, Lisboa (Portugal)

2010-07-15

Nowadays, among the available transparent semiconductors for device use, the great majority (if not all) have n-type conductivity. The fabrication of a transparent p-type semiconductor with good optoelectronic properties (comparable to those of n-type: InO{sub x}, ITO, ZnO{sub x} or FTO) would significantly broaden the application field of thin films. However, until now no material has yet presented all the required properties. Cu{sub 2}S is a p-type narrow-band-gap material with an average optical transmittance of about 60% in the visible range for 50 nm thick films. However, due to its high conductivity at room temperature, 10 nm in thickness seems to be appropriate for device use. Cu{sub 2}S thin films with 10 nm in thickness have an optical visible transmittance of about 85% rendering them as very good candidates for transparent p-type semiconductors. In this work Cu{sub x}S thin films were deposited on alkali-free (AF) glass by thermal evaporation. The objective was not only the determination of its optoelectronic properties but also the feasibility of an active layer in a p-type thin film transistor. In our Cu{sub x}S thin films, p-type high conductivity with a total visible transmittance of about 50% have been achieved. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Transparent magnesium aluminate spinel: a prospective biomaterial for esthetic orthodontic brackets.

Science.gov (United States)

Krishnan, Manu; Tiwari, Brijesh; Seema, Saraswathy; Kalra, Namitha; Biswas, Papiya; Rajeswari, Kotikalapudi; Suresh, Madireddy Buchi; Johnson, Roy; Gokhale, Nitin M; Iyer, Satish R; Londhe, Sanjay; Arora, Vimal; Tripathi, Rajendra P

2014-11-01

Adult orthodontics is recently gaining popularity due to its importance in esthetics, oral and general health. However, none of the currently available alumina or zirconia based ceramic orthodontic brackets meet the esthetic demands of adult patients. Inherent hexagonal lattice structure and associated birefringence limits the visible light transmission in polycrystalline alumina and make them appear white and non transparent. Hence focus of the present study was to assess the feasibility of using magnesium aluminate (MgAl2O4) spinel; a member of the transparent ceramic family for esthetic orthodontic brackets. Transparent spinel specimens were developed from commercially available white spinel powder through colloidal shaping followed by pressureless sintering and hot isostatic pressing at optimum conditions of temperature and pressure. Samples were characterized for chemical composition, phases, density, hardness, flexural strength, fracture toughness and optical transmission. Biocompatibility was evaluated with in-vitro cell line experiments for cytotoxicity, apoptosis and genotoxicity. Results showed that transparent spinel samples had requisite physico-chemical, mechanical, optical and excellent biocompatibility for fabricating orthodontic brackets. Transparent spinel developed through this method demonstrated its possibility as a prospective biomaterial for developing esthetic orthodontic brackets.

Electro-optical characteristics of a liquid crystal cell with graphene electrodes

Directory of Open Access Journals (Sweden)

Nune H. Hakobyan

2017-12-01

Full Text Available In liquid crystal devices (LCDs the indium tin oxide (ITO films are traditionally used as transparent and conductive electrodes. However, today, due to the development of multichannel optical communication, the need for flexible LCDs and multilayer structures has grown. For this application ITO films cannot be used in principle. For this problem, graphene (an ultrathin material with unique properties, e.g., high optical transparency, chemical inertness, excellent conductivity is an excellent candidate. In this work, the electro-optical and dynamic characteristics of a liquid crystal (LC cell with graphene and ITO transparent conducting layers are investigated. To insure uniform thickness of the LC layer, as well as the same orientation boundary conditions, a hybrid LC cell containing graphene and ITO conductive layers has been prepared. The characteristics of LC cells with both types of conducting layers were found to be similar, indicating that graphene can be successfully used as a transparent conductive layer in LC devices.

Printing polymer optical waveguides on conditioned transparent flexible foils by using the aerosol jet technology

Science.gov (United States)

Reitberger, Thomas; Hoffmann, Gerd-Albert; Wolfer, Tim; Overmeyer, Ludger; Franke, Joerg

2016-09-01

The optical data transfer is considered as the future of signal transfer due to its various advantages compared to conventional copper-based technologies. The Aerosol Jet Printing (AJP) technology offers the opportunity to print materials with high viscosities, such as liquid transparent polymer adhesives (epoxy resins), on almost any possible substrate material and even in third dimension. This paper introduces a new flexible and comparatively cost-effective way of generating polymer optical waveguides through AJP. Furthermore, the conditioning of the substrate material and the printing process of planar waveguides are presented. In the first step, two lines with hydrophobic behavior are applied on foil material (PMMA, PVC, PI) by using a flexographic printing machine. These silicone based patterns containing functional polymer form barriers for the core material due to their low surface energy after curing. In the second step, the core material (liquid polymer, varnish) is printed between the barrier lines. Because of the hydrophobic behavior of the lines, the contact angle between the substrate surface and the liquid core material is increased which yields to higher aspect ratio. The distance between the barrier lines is at least 100 μm, which defines the width of the waveguide. The minimum height of the core shall be 50 μm. After UV-curing of the core polymer, the cladding material is printed on the top. This is also applied by using the AJP technology. Various tests were performed to achieve the optimal surface properties for adequate adhesion and machine process parameters.

Injection molding of high precision optics for LED applications made of liquid silicone rubber

Energy Technology Data Exchange (ETDEWEB)

Hopmann, Christian; Röbig, Malte [Institute of Plastics Processing (IKV), RWTH Aachen University, Pontstraße 49, 52062 Aachen (Germany)

2016-03-09

Light Emitting Diodes (LED) conquer the growing global market of lighting technologies. Due to their advantages, they are increasingly used in consumer products, in lighting applications in the home and in the mobility sector as well as in industrial applications. Particularly, with regard to the increasing use of high-power LED (HP-LED) the materials in the surrounding area of the light emitting semiconductor chip are of utmost importance. While the materials behind the semiconductor chip are optimized for maximum heat dissipation, the materials currently used for the encapsulation of the semiconductor chip (primary optics) and the secondary optics encounter their limits due to the high temperatures. In addition certain amounts of blue UV radiation degrade the currently used materials such as epoxy resins or polyurethanes for primary optics. In the context of an ongoing joint research project with various partners from the industry, an innovative manufacturing method for high precision optics for LED applications made of liquid silicone rubber (LSR) is analyzed at the Institut of Plastics Processing (IKV), Aachen. The aim of this project is to utilize the material-specific advantages of high transparent LSR, especially the excellent high temperature resistance and the great freedom in design. Therefore, a high integrated injection molding process is developed. For the production of combined LED primary and secondary optics a LED board is placed in an injection mold and overmolded with LSR. Due to the integrated process and the reduction of subcomponents like the secondary optics the economics of the production process can be improved significantly. Furthermore combined LED optics offer an improved effectiveness, because there are no losses of the light power at the transition of the primary and secondary optics.

Influence of annealing temperature on structural and optical properties of Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} transparent films

Energy Technology Data Exchange (ETDEWEB)

Morales-Ramírez, Ángel de Jesús [Instituto Politécnico Nacional, CIITEC IPN, Cerrada de Cecati S/N, 02250 México D.F. (Mexico); García-Murillo, Antonieta, E-mail: angarciam@ipn.mx [Instituto Politécnico Nacional, CIITEC IPN, Cerrada de Cecati S/N, 02250 México D.F. (Mexico); Carrillo-Romo, Felipe de Jesús [Instituto Politécnico Nacional, CIITEC IPN, Cerrada de Cecati S/N, 02250 México D.F. (Mexico); Garrido-Hernández, Aristeo [Instituto Politécnico Nacional, CIITEC IPN, Cerrada de Cecati S/N, 02250 México D.F. (Mexico); Universidad Tecnológica de Tecámac, División de Nanotecnología, Carretera Federal México- Pachuca Km 37.5, Sierra Hermosa, 55740, Edo. De México (Mexico); García-Hernández, Margarita [Universidad Autónoma Metropolitana, Departamento de Ciencias Naturales, Unidad Cuajimalpa, Pedro Antonio de los Santos 84, 11850 México D.F. (Mexico)

2015-10-15

Highlights: • Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} films were synthesized by sol–gel and by dip-coating technique. • Effects of annealing treatment on structural and optical properties were studied. • Optogeometrical characteristics of synthesized films were analyzed. • X-ray diffraction results showed that Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} crystallizes at 700 °C. • High reddish emission on transparent films with at least 1 μm thick was observed. - Abstract: High-optical quality Lu{sub 2}O{sub 3}:Eu{sup 3+} 5 mol%, X Tb{sup 3+} (X = 0–0.04 mol%) thin films were prepared by the sol–gel process and dip-coating technique. The procedure was as follows: lutetium, europium and terbium nitrates were used as precursors, and ethanol as a solvent. Etylenglycol (EG) was added as a sol stabilizer, and the pH was adjusted by acetic acid. After 10 dipping-cycles, followed by an annealing process (600–900 °C) for 1 h, transparent, smooth and crack-free films (ra = 8–9 nm) were formed. The X-ray diffraction (XRD) results showed crystallized films into the cubic structure at 800 °C. The ellipsometry results showed that the thickness of the films varied from 1 to 1.4 μm at 1000 and 600 °C, respectively. Finally, the films presented a typical Eu{sup 3+} red emission at 611 nm ({sup 5}D{sub 0} → {sup 7}F{sub 2}); furthermore, the effect of the Tb{sup 3+} content showed that the highest emission intensity corresponded to the lower Tb{sup 3+} content.

High performance all-carbon composite transparent electrodes containing uniform carbon nanotube networks

Energy Technology Data Exchange (ETDEWEB)

Yun, Hyung Duk; Kwak, Jinsung; Kim, Se-Yang [School of Materials Science and Engineering & Low-Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 (Korea, Republic of); Seo, Han; Bang, In Cheol; Kim, Sung Youb [School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 (Korea, Republic of); Kang, Seoktae [Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141 (Korea, Republic of); Kwon, Soon-Yong, E-mail: sykwon@unist.ac.kr [School of Materials Science and Engineering & Low-Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 (Korea, Republic of); School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 (Korea, Republic of)

2016-08-05

Indium tin oxide-free, flexible transparent electrodes (TEs) are crucial for the future commercialization of flexible and wearable electronics. While carbon-based TEs containing carbon nanotube (CNT) networks show promise, they usually exhibit poor dispersion properties, limiting their performance and practicality. In this study, we report a highly efficient and bending durable all-carbon composite TE (ac-TE) that employs uniform CNT networks on a monolayer graphene/polyethylene terephthalate (PET) substrate via a simple air spray deposition method. The air-sprayed CNT/graphene assembly was free-standing on solution, making a polymer-free transfer of carbon composites to target substrates possible. The excellent performance of the ac-TEs was attributed to the uniformly networked CNTs on the polycrystalline graphene with a well-controlled density, effectively bridging the line defects and filling the tears/voids or folds necessarily existing in the as-processed graphene. The sheet resistance of the ac-TEs was increased only 6% from its original value at a bending radius of 2.7 mm, while that of the pristine graphene/PET assembly increased 237%. Mechanical bending of the ac-TEs worsened the electrical performance by only ∼1.7% after 2000 bending cycles at a bending radius of 2.5 mm. Degradation of the performance by the bending was the result of line defects formation in the graphene, demonstrating the potential of the uniform CNT networks to achieve more efficient and flexible carbon-based TEs. Furthermore, the chemically-doped ac-TEs showed commercially suitable electronic and optical properties with much enhanced thermal stability, closer to practical TEs in flexible devices. - Highlights: • Highly efficient and bending durable all-carbon composite transparent electrodes (TEs) are designed. • The performance was strongly dependent on morphology of CNT networks on graphene. • The mechanism relies on the defect reductions in graphene by uniform CNT coating

High performance all-carbon composite transparent electrodes containing uniform carbon nanotube networks

International Nuclear Information System (INIS)

Yun, Hyung Duk; Kwak, Jinsung; Kim, Se-Yang; Seo, Han; Bang, In Cheol; Kim, Sung Youb; Kang, Seoktae; Kwon, Soon-Yong

2016-01-01

Indium tin oxide-free, flexible transparent electrodes (TEs) are crucial for the future commercialization of flexible and wearable electronics. While carbon-based TEs containing carbon nanotube (CNT) networks show promise, they usually exhibit poor dispersion properties, limiting their performance and practicality. In this study, we report a highly efficient and bending durable all-carbon composite TE (ac-TE) that employs uniform CNT networks on a monolayer graphene/polyethylene terephthalate (PET) substrate via a simple air spray deposition method. The air-sprayed CNT/graphene assembly was free-standing on solution, making a polymer-free transfer of carbon composites to target substrates possible. The excellent performance of the ac-TEs was attributed to the uniformly networked CNTs on the polycrystalline graphene with a well-controlled density, effectively bridging the line defects and filling the tears/voids or folds necessarily existing in the as-processed graphene. The sheet resistance of the ac-TEs was increased only 6% from its original value at a bending radius of 2.7 mm, while that of the pristine graphene/PET assembly increased 237%. Mechanical bending of the ac-TEs worsened the electrical performance by only ∼1.7% after 2000 bending cycles at a bending radius of 2.5 mm. Degradation of the performance by the bending was the result of line defects formation in the graphene, demonstrating the potential of the uniform CNT networks to achieve more efficient and flexible carbon-based TEs. Furthermore, the chemically-doped ac-TEs showed commercially suitable electronic and optical properties with much enhanced thermal stability, closer to practical TEs in flexible devices. - Highlights: • Highly efficient and bending durable all-carbon composite transparent electrodes (TEs) are designed. • The performance was strongly dependent on morphology of CNT networks on graphene. • The mechanism relies on the defect reductions in graphene by uniform CNT coating

Novel transparent high-performance AgNWs/ZnO electrodes prepared on unconventional substrates with 3D structured surfaces

Science.gov (United States)

Lan, Wei; Yang, Zhiwei; Zhang, Yue; Wei, Yupeng; Wang, Pengxiang; Abas, Asim; Tang, Guomei; Zhang, Xuetao; Wang, Junya; Xie, Erqing

2018-03-01

With the development of optoelectronic devices with three-dimensional (3D) structured surfaces, transparent electrodes that can be deposited on non-plane substrates have become increasingly important. In this paper, novel transparent silver nanowire (AgNWs)/ZnO film electrodes were uniformly prepared on treated 3D glass and PET substrates with a combination of spin-coating and heat-welding. The AgNWs/ZnO films show a transmittance of ∼88% and a sheet resistance of ∼10 Ω/sq. They are comparable with commercial ITO films. Furthermore, only a small in-plane resistance variation of ∼1 Ω/sq was measured using four-point probe mapping in films with a 10 cm × 10 cm area. These results confirm that these novel film electrodes are very uniform. Both electrical resistance and optical transmittance of the films remain mostly intact after 1000 bending cycles and tape peeling-tests with 10 cycles. The films show high thermal stability for more than one month at 80 °C. The strategy provides a new route for the design and fabrication of optoelectronic devices with 3D structured surfaces.

Solution-processed assembly of ultrathin transparent conductive cellulose nanopaper embedding AgNWs

Science.gov (United States)

Song, Yuanyuan; Jiang, Yaoquan; Shi, Liyi; Cao, Shaomei; Feng, Xin; Miao, Miao; Fang, Jianhui

2015-08-01

Natural biomass based cellulose nanopaper is becoming a promising transparent substrate to supersede traditional petroleum based polymer films in realizing future flexible paper-electronics. Here, ultrathin, highly transparent, outstanding conductive hybrid nanopaper with excellent mechanical flexibility was synthesized by the assembly of nanofibrillated cellulose (NFC) and silver nanowires (AgNWs) using a pressured extrusion paper-making technique. The hybrid nanopaper with a thickness of 4.5 μm has a good combination of transparent conductive performance and mechanical stability using bamboo/hemp NFC and AgNWs cross-linked by hydroxypropylmethyl cellulose (HPMC). The heterogeneous fibrous structure of BNFC/HNFC/AgNWs endows a uniform distribution and an enhanced forward light scattering, resulting in high electrical conductivity and optical transmittance. The hybrid nanopaper with an optimal weight ratio of BNFC/HNFC to AgNWs shows outstanding synergistic properties with a transmittance of 86.41% at 550 nm and a sheet resistance of 1.90 ohm sq-1, equal to the electronic conductivity, which is about 500 S cm-1. The BNFC/HNFC/AgNW hybrid nanopaper maintains a stable electrical conductivity after the peeling test and bending at 135° for 1000 cycles, indicating remarkably strong adhesion and mechanical flexibility. Of importance here is that the high-performance and low-cost hybrid nanopaper shows promising potential for electronics application in solar cells, flexible displays and other high-technology products.Natural biomass based cellulose nanopaper is becoming a promising transparent substrate to supersede traditional petroleum based polymer films in realizing future flexible paper-electronics. Here, ultrathin, highly transparent, outstanding conductive hybrid nanopaper with excellent mechanical flexibility was synthesized by the assembly of nanofibrillated cellulose (NFC) and silver nanowires (AgNWs) using a pressured extrusion paper-making technique. The

Origin of high photoconductive gain in fully transparent heterojunction nanocrystalline oxide image sensors and interconnects.

Science.gov (United States)

Jeon, Sanghun; Song, Ihun; Lee, Sungsik; Ryu, Byungki; Ahn, Seung-Eon; Lee, Eunha; Kim, Young; Nathan, Arokia; Robertson, John; Chung, U-In

2014-11-05

A technique for invisible image capture using a photosensor array based on transparent conducting oxide semiconductor thin-film transistors and transparent interconnection technologies is presented. A transparent conducting layer is employed for the sensor electrodes as well as interconnection in the array, providing about 80% transmittance at visible-light wavelengths. The phototransistor is a Hf-In-Zn-O/In-Zn-O heterostructure yielding a high quantum-efficiency in the visible range. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Observation of convection phenomenon by high-performance transparent heater based on Pt-decorated Ni micromesh

Directory of Open Access Journals (Sweden)

Han-Jung Kim

2017-02-01

Full Text Available In this study, we report for the first time on the convection phenomenon for the consistent and sensitive detection of target materials (particulate matter (PM or gases with a high-performance transparent heater. The high-performance transparent heater, based on Pt-decorated Ni micromesh, was fabricated by a combination of transfer printing process and Pt sputtering. The resulting transparent heater exhibited excellent mechanical durability, adhesion with substrates, flexibility, and heat-generating performance. We monitored the changes in the PM concentration and temperature in an airtight chamber while operating the heater. The temperature in the chamber was increased slightly, and the PM2.5 concentration was increased by approximately 50 times relative to the initial state which PM is deposed in the chamber. We anticipate that our experimental findings will aid in the development and application of heaters for sensors and actuators as well as transparent electrodes and heating devices.

Transparent Electrodes for Efficient Optoelectronics

KAUST Repository

Morales-Masis, Monica

2017-03-30

With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

Transparent Electrodes for Efficient Optoelectronics

KAUST Repository

Morales-Masis, Monica; De Wolf, Stefaan; Woods-Robinson, Rachel; Ager, Joel W.; Ballif, Christophe

2017-01-01

With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

Nonlinear optical parameters of nanocrystalline AZO thin film measured at different substrate temperatures

Energy Technology Data Exchange (ETDEWEB)

Jilani, Asim, E-mail: asim.jilane@gmail.com [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Abdel-wahab, M.Sh [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences, Beni -Suef University, Beni-Suef (Egypt); Al-ghamdi, Attieh A. [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Dahlan, Ammar sadik [Department of architecture, faculty of environmental design, King Abdulaziz University, Jeddah (Saudi Arabia); Yahia, I.S. [Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Nano-Science & Semiconductor Labs, Department of Physics, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt)

2016-01-15

The 2.2 wt% of aluminum (Al)-doped zinc oxide (AZO) transparent and preferential c-axis oriented thin films were prepared by using radio frequency (DC/RF) magnetron sputtering at different substrate temperature ranging from room temperature to 200 °C. For structural analysis, X-ray Diffraction (XRD) and Atomic Force Electron Microscope (AFM) was used for morphological studies. The optical parameters such as, optical energy gap, refractive index, extinction coefficient, dielectric loss, tangent loss, first and third order nonlinear optical properties of transparent films were investigated. High transmittance above 90% and highly homogeneous surface were observed in all samples. The substrate temperature plays an important role to get the best transparent conductive oxide thin films. The substrate temperature at 150 °C showed the growth of highly transparent AZO thin film. Energy gap increased with the increased in substrate temperature of Al doped thin films. Dielectric constant and loss were found to be photon energy dependent with substrate temperature. The change in substrate temperature of Al doped thin films also affect the non-liner optical properties of thin films. The value of χ{sup (3)} was found to be changed with the grain size of the thin films that directly affected by the substrate temperature of the pure and Al doped ZnO thin films.

Chemically etched sharpened tip of transparent crystallized glass fibers with nonlinear optical Ba2TiSi2O8 nanocrystals

International Nuclear Information System (INIS)

Enomoto, Itaru; Benino, Yasuhiko; Komatsu, Takayuki; Fujiwara, Takumi

2007-01-01

Glass fibers with a diameter of ∼100 μm are drawn by just pulling up melts of 40BaO·20TiO 2 ·40SiO 2 glass, and transparent crystallized glass fibers consisting of nonlinear optical fresnoite Ba 2 TiSi 2 O 8 nanocrystals (particle size: ∼100-200 nm) are fabricated by crystallization of glass fibers. Precursor glass fibers and nanocrystallized glass fibers are etched chemically using a meniscus method, in which an etching solution of 0.1wt%-HF/hexane is used. Glass fibers with sharpened tips (e.g., the taper length is ∼L=200 μm and the tip angle is ∼θ=23deg) are obtained. It is found that etched nanocrystallized glass fibers also have sharpened tips (L=50 μm, θ=80deg). Compared with precursor glass fibers, nanocrystallized glass fibers show a high resistance against chemical etching in a 0.1 wt%HF solution. Although sharpened tips in nanocrystallized glass fibers do not have nanoscaled apertures, the present study suggests that nanocrystallized glass fibers showing second harmonic generations would have a potential for fiber-type light control optical devices. (author)

Fabrication of highly conductive graphene/ITO transparent bi-film through CVD and organic additives-free sol-gel techniques.

Science.gov (United States)

Hemasiri, Bastian Waduge Naveen Harindu; Kim, Jae-Kwan; Lee, Ji-Myon

2017-12-19

Indium tin oxide (ITO) still remains as the main candidate for high-performance optoelectronic devices, but there is a vital requirement in the development of sol-gel based synthesizing techniques with regards to green environment and higher conductivity. Graphene/ITO transparent bi-film was synthesized by a two-step process: 10 wt. % tin-doped ITO thin films were produced by an environmentally friendly aqueous sol-gel spin coating technique with economical salts of In(NO 3 ) 3 .H 2 O and SnCl 4 , without using organic additives, on surface free energy enhanced (from 53.826 to 97.698 mJm -2 ) glass substrate by oxygen plasma treatment, which facilitated void-free continuous ITO film due to high surface wetting. The chemical vapor deposited monolayer graphene was transferred onto the synthesized ITO to enhance its electrical properties and it was capable of reducing sheet resistance over 12% while preserving the bi-film surface smoother. The ITO films contain the In 2 O 3 phase only and exhibit the polycrystalline nature of cubic structure with 14.35 ± 0.5 nm crystallite size. The graphene/ITO bi-film exhibits reproducible optical transparency with 88.66% transmittance at 550 nm wavelength, and electrical conductivity with sheet resistance of 117 Ω/sq which is much lower than that of individual sol-gel derived ITO film.

Transparent platinum counter electrode for efficient semi-transparent dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Iefanova, Anastasiia; Nepal, Jeevan; Poudel, Prashant; Davoux, Daren; Gautam, Umesh [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Mallam, Venkataiah [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Qiao, Qiquan [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Logue, Brian [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Baroughi, Mahdi Farrokh, E-mail: m.farrokhbaroughi@sdstate.edu [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States)

2014-07-01

A method for fabrication of highly transparent platinum counter electrodes (CEs) has been developed based on spray coating of Pt nanoparticles (NPs) on hot substrates. This method leads to 86% reduction in Pt consumption reducing the Pt cost per peak watt of counter electrode from $0.79/Wp down to $0.11/Wp compared to the conventional Pt counter electrodes made by sputter deposition. The simplicity and low cost of this method provide a basis for an up-scalable fabrication process. The Pt NP layer is over 88% transparent, leading to overall transparency of 80% when incorporated with indium tin oxide/glass substrates for functional counter electrodes. This counter electrode exhibits a large surface area and high catalytic activity, comparable to that of the conventional opaque CEs. Semi-transparent dye-sensitized solar cells fabricated based on this counter electrode showed 6.17% power conversion efficiency. - Highlights: • Counter electrode (CE) prepared by spraying nanoparticle (NP) Pt on hot substrate. • Low cost and scalable fabrication process of CE. • The spray deposited CE uses 10 times less Pt compared to the sputtering method. • The CE is 80% transparent and exhibits a large surface and high catalytic activity. • A semitransparent dye-sensitized solar cell with Pt NP CE was 6.17% efficient.

Controlling the optical performance of transparent conducting oxides using direct laser interference patterning

International Nuclear Information System (INIS)

Berger, Jana; Roch, Teja; Correia, Stelio; Eberhardt, Jens; Lasagni, Andrés Fabián

2016-01-01

In this study, a laser based process called Direct Laser Interference Patterning (DLIP) was used to fabricate micro-textured boron doped zinc oxide (ZnO:B) thin films to be used as electrodes in thin-film silicon solar cells. First, the ablation thresholds of the ZnO:B film were determined using a nanosecond pulsed laser at wavelengths of 266 and 355 nm (100 mJ/cm"2 and 89 mJ/cm"2, respectively). After that, DLIP experiments were performed at 355 nm wavelength. Line-like periodic surface structures with spatial periods ranging from 0.8 to 5.0 μm were fabricated using two interfering laser beams. It was found that the structuring process of the transparent conducting oxide (TCO) is mainly based on a photo-thermal mechanism. The surface of the ZnO:B film was molten and evaporated at the interference maxima positions and the depth and width of the generated microfeatures depend on the laser parameters as well as the spatial period of the interference pattern. The optical properties of the structured TCOs were investigated as a function of the utilized laser processing parameters. Both diffuse and total transmission and the intensity of the diffraction orders were determined. These data were used to calculate the increase of the optical path of the transmitted light. - Highlights: • Direct Laser Interference Patterning (DLIP) on boron doped zinc oxide (LPCVD-ZnO:B) • No relevant decrease of total transmission • Periods of 1.5 μm provide large diffraction angle and good diffraction intensity. • Significant increase of optical path length could be reached.

Controlling the optical performance of transparent conducting oxides using direct laser interference patterning

Energy Technology Data Exchange (ETDEWEB)

Berger, Jana; Roch, Teja [Fraunhofer-Institut für Werkstoff-und Strahltechnik IWS, Winterbergstr. 28, 01277 Dresden (Germany); Technische Universität Dresden, Institute of Manufacturing Technology, George-Baehr-Str.1, 01069 Dresden (Germany); Correia, Stelio; Eberhardt, Jens [Bosch Solar Energy AG, August-Broemel-Str. 6, 99310 Arnstadt (Germany); Lasagni, Andrés Fabián, E-mail: andres_fabian.lasagni@tu-dresden.de [Fraunhofer-Institut für Werkstoff-und Strahltechnik IWS, Winterbergstr. 28, 01277 Dresden (Germany); Technische Universität Dresden, Institute of Manufacturing Technology, George-Baehr-Str.1, 01069 Dresden (Germany)

2016-08-01

In this study, a laser based process called Direct Laser Interference Patterning (DLIP) was used to fabricate micro-textured boron doped zinc oxide (ZnO:B) thin films to be used as electrodes in thin-film silicon solar cells. First, the ablation thresholds of the ZnO:B film were determined using a nanosecond pulsed laser at wavelengths of 266 and 355 nm (100 mJ/cm{sup 2} and 89 mJ/cm{sup 2}, respectively). After that, DLIP experiments were performed at 355 nm wavelength. Line-like periodic surface structures with spatial periods ranging from 0.8 to 5.0 μm were fabricated using two interfering laser beams. It was found that the structuring process of the transparent conducting oxide (TCO) is mainly based on a photo-thermal mechanism. The surface of the ZnO:B film was molten and evaporated at the interference maxima positions and the depth and width of the generated microfeatures depend on the laser parameters as well as the spatial period of the interference pattern. The optical properties of the structured TCOs were investigated as a function of the utilized laser processing parameters. Both diffuse and total transmission and the intensity of the diffraction orders were determined. These data were used to calculate the increase of the optical path of the transmitted light. - Highlights: • Direct Laser Interference Patterning (DLIP) on boron doped zinc oxide (LPCVD-ZnO:B) • No relevant decrease of total transmission • Periods of 1.5 μm provide large diffraction angle and good diffraction intensity. • Significant increase of optical path length could be reached.

Multiple transparency windows and Fano interferences induced by dipole-dipole couplings

Science.gov (United States)

Diniz, E. C.; Borges, H. S.; Villas-Boas, C. J.

2018-04-01

We investigate the optical properties of a two-level system (TLS) coupled to a one-dimensional array of N other TLSs with dipole-dipole coupling between the first neighbors. The first TLS is probed by a weak field, and we assume that it has a decay rate much greater than the decay rates of the other TLSs. For N =1 and in the limit of a Rabi frequency of a probe field much smaller than the dipole-dipole coupling, the optical response of the first TLS, i.e., its absorption and dispersion, is equivalent to that of a three-level atomic system in the configuration which allows one to observe the electromagnetically induced transparency (EIT) phenomenon. Thus, here we investigate an induced transparency phenomenon where the dipole-dipole coupling plays the same role as the control field in EIT in three-level atoms. We describe this physical phenomenon, named a dipole-induced transparency (DIT), and investigate how it scales with the number of coupled TLSs. In particular, we have shown that the number of TLSs coupled to the main TLS is exactly equal to the number of transparency windows. The ideas presented here are very general and can be implemented in different physical systems, such as an array of superconducting qubits, or an array of quantum dots, spin chains, optical lattices, etc.

High Committee for transparency and information on nuclear safety: Annual activity report (January 2010 - December 2010)

International Nuclear Information System (INIS)

2010-01-01

After a description of the operation of the French 'High Committee for transparency and information on nuclear safety' (HCTISN), of its missions, its organisation and its means, the progress report presents the High Committee activity for 2010 with summaries of its report on the transparency of nuclear material and waste management, its meetings, its work groups, its visits and participations to other events

Simultaneous observation of cavitation bubbles generated in biological tissue by high-speed optical and acoustic imaging methods

Science.gov (United States)

Suzuki, Kai; Iwasaki, Ryosuke; Takagi, Ryo; Yoshizawa, Shin; Umemura, Shin-ichiro

2017-07-01

Acoustic cavitation bubbles are useful for enhancing the heating effect in high-intensity focused ultrasound (HIFU) treatment. Many studies were conducted to investigate the behavior of such bubbles in tissue-mimicking materials, such as a transparent gel phantom; however, the detailed behavior in tissue was still unclear owing to the difficulty in optical observation. In this study, a new biological phantom was developed to observe cavitation bubbles generated in an optically shallow area of tissue. Two imaging methods, high-speed photography using light scattering and high-speed ultrasonic imaging, were used for detecting the behavior of the bubbles simultaneously. The results agreed well with each other for the area of bubble formation and the temporal change in the region of bubbles, suggesting that both methods are useful for visualizing the bubbles.

Digital Thickness Measurement of a Transparent Plastic Orthodontic Device

Science.gov (United States)

Kim, Yoon-Hwan; Rhim, Sung-Han

2018-05-01

A transparent orthodontic device is used to move the teeth to the final calibration position to form a proper set of teeth. Because the uniform thickness of the device plays an important role in tooth positioning, the accuracy of the device's thickness profile is important for effective orthodontic treatment. However, due to the complexity of the device's geometry and the transparency of the device's material, measuring the complete thickness profile has been difficult. In the present study, a new optical scanning method to measure the thickness profile of transparent plastic orthodontic devices is proposed and evaluated by using scanning electron microscopy (SEM). The error of the new measurement method is less than ±18 μm. The new method can be used to measure the thickness of non-specific, multi-curved, transparent orthodontic devices.

Structural, optical and electrical characterization of ITO, ITO/Ag and ITO/Ni transparent conductive electrodes

Energy Technology Data Exchange (ETDEWEB)

Ali, Ahmad Hadi, E-mail: ahadi@uthm.edu.my [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, Penang (Malaysia); Science Department, Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn Malaysia, Johor (Malaysia); Shuhaimi, Ahmad [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, Universiti Malaya, Kuala Lumpur (Malaysia); Hassan, Zainuriah [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, Penang (Malaysia)

2014-01-01

We report on the transparent conductive oxides (TCO) characteristics based on the indium tin oxides (ITO) and ITO/metal thin layer as an electrode for optoelectronics device applications. ITO, ITO/Ag and ITO/Ni were deposited on Si and glass substrate by thermal evaporator and radio frequency (RF) magnetron sputtering at room temperature. Post deposition annealing was performed on the samples in air at moderate temperature of 500 °C and 600 °C. The structural, optical and electrical properties of the ITO and ITO/metal were characterized using X-ray diffraction (XRD), UV–Vis spectrophotometer, Hall effect measurement system and atomic force microscope (AFM). The XRD spectrum reveals significant polycrystalline peaks of ITO (2 2 2) and Ag (1 1 1) after post annealing process. The post annealing also improves the visible light transmittance and electrical resistivity of the samples. Figure of merit (FOM) of the ITO, ITO/Ag and ITO/Ni were determined as 5.5 × 10{sup −3} Ω{sup −1}, 8.4 × 10{sup −3} Ω{sup −1} and 3.0 × 10{sup −5} Ω{sup −1}, respectively. The results show that the post annealed ITO with Ag intermediate layer improved the efficiency of the transparent conductive electrodes (TCE) as compared to the ITO and ITO/Ni.

Transparent conductive Ga-doped ZnO films fabricated by MOCVD

Energy Technology Data Exchange (ETDEWEB)

Behrends, Arne; Wagner, Alexander; Al-Suleiman, Mohamed Aid Mansur; Waag, Andreas; Bakin, Andrey [Institute of Semiconductor Technology, University of Technology Braunschweig, Hans-Sommer-Str. 66, 38106 Braunschweig (Germany); Lugauer, Hans-Juergen; Strassburg, Martin; Walter, Robert; Weimar, Andreas [OSRAM Opto Semiconductors GmbH, Leibnizstr. 4, 93055 Regensburg (Germany)

2012-04-15

Transparent conductive oxides (TCOs) are used for a variety of different applications, e.g., in solar cells and light emitting diodes (LEDs). Mostly, sputtering is used, which often results in a degradation of the underlying semiconductor material. In this work we report on a ''soft'' method for the fabrication of ZnO films as TCO layers by using metal organic chemical vapor deposition (MOCVD) at particularly low temperatures. The MOCVD approach has been studied focusing on the TCO key issues: fabrication temperature, morphology, optical, and electrical properties. Very smooth ZnO films with rms values down to 0.8 nm were fabricated at a substrate temperature of only 300 C. Ga-doping is well controllable even for high carrier concentrations up to 2 x 10{sup 20} cm{sup -3}, which is above the Mott-density leading to metallic-like behavior of the films. Furthermore all films show excellent optical transparency in the visible spectral range. As a consequence, our MOCVD approach is well suited for the soft fabrication of ZnO-based TCO layers. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Transparent Indium Tin Oxide Electrodes on Muscovite Mica for High-Temperature-Processed Flexible Optoelectronic Devices.

Science.gov (United States)

Ke, Shanming; Chen, Chang; Fu, Nianqing; Zhou, Hua; Ye, Mao; Lin, Peng; Yuan, Wenxiang; Zeng, Xierong; Chen, Lang; Huang, Haitao

2016-10-26

Sn-doped In 2 O 3 (ITO) electrodes were deposited on transparent and flexible muscovite mica. The use of mica substrate makes a high-temperature annealing process (up to 500 °C) possible. ITO/mica retains its low electric resistivity even after continuous bending of 1000 times on account of the unique layered structure of mica. When used as a transparent flexible heater, ITO/mica shows an extremely fast ramping (solar cells (PSCs) with high efficiency.

Flexible Transparent Films Based on Nanocomposite Networks of Polyaniline and Carbon Nanotubes for High-Performance Gas Sensing.

Science.gov (United States)

Wan, Pengbo; Wen, Xuemei; Sun, Chaozheng; Chandran, Bevita K; Zhang, Han; Sun, Xiaoming; Chen, Xiaodong

2015-10-28

A flexible, transparent, chemical gas sensor is assembled from a transparent conducting film of carbon nanotube (CNT) networks that are coated with hierarchically nanostructured polyaniline (PANI) nanorods. The nanocomposite film is synthesized by in-situ, chemical oxidative polymerization of aniline in a functional multiwalled CNT (FMWCNT) suspension and is simultaneously deposited onto a flexible polyethylene terephthalate (PET) substrate. An as-prepared flexible transparent chemical gas sensor exhibits excellent transparency of 85.0% at 550 nm using the PANI/FMWCNT nanocomposite film prepared over a reaction time of 8 h. The sensor also shows good flexibility, without any obvious decrease in performance after 500 bending/extending cycles, demonstrating high-performance, portable gas sensing at room temperature. This superior performance could be attributed to the improved electron transport and collection due to the CNTs, resulting in reliable and efficient sensing, as well as the high surface-to-volume ratio of the hierarchically nanostructured composites. The excellent transparency, improved sensing performance, and superior flexibility of the device, may enable the integration of this simple, low-cost, gas sensor into handheld flexible transparent electronic circuitry and optoelectronic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new architecture as transparent electrodes for solar and IR applications based on photonic structures via soft lithography

Energy Technology Data Exchange (ETDEWEB)

Kuang, Ping [Iowa State Univ., Ames, IA (United States)

2011-01-01

Transparent conducting electrodes with the combination of high optical transmission and good electrical conductivity are essential for solar energy harvesting and electric lighting devices. Currently, indium tin oxide (ITO) is used because ITO offers relatively high transparency (>80%) to visible light and low sheet resistance (R_s = 10 ohms/square (Ω /2)) for electrical conduction. However, ITO is costly due to limited indium reserves, and it is brittle. These disadvantages have motivated the search for other conducting electrodes with similar or better properties. There has been research on a variety of electrode structures involving carbon nanotube networks, graphene films, nanowire and nanopatterned meshes and grids. Due to their novel characteristics in light manipulation and collection, photonic crystal structures show promise for further improvement. Here, we report on a new architecture consisting of nanoscale high aspect ratio metallic photonic structures as transparent electrodes fabricated via a combination of processes. For (Au) and silver (Ag) structures, the visible light transmission can reach as high as 80%, and the sheet resistance of the structure can be as low as 3.2Ω /2. The optical transparency of the high aspect ratio metal structures at visible wavelength range is comparable to that of ITO glass, while their sheet resistance is more than 3 times lower, which indicates a much higher electrical conductivity of the metal structures. Furthermore, the high aspect ratio metal structures have very high infrared (IR) reflection (90%) for the transverse magnetic (TM) mode, which can lead to the development of fabrication of metallic structures as IR filters for heat control applications. Investigations of interdigitated structures based on the high aspect ratio metal electrodes are ongoing to study the feasibility in smart window applications in light transmission modulation.

Optical recording medium

International Nuclear Information System (INIS)

Andriech, A.; Bivol, V.; Tridukh, G.; Tsiuleanu, D.

2002-01-01

The invention relates of the micro- and optoelectronics, computer engineering ,in particular, to tjhe optical information media and may be used in hilography. Summary of the invention consists in that the optical image recording medium, containing a dielectric substrates, onto one surface of which there are placed in series a transparent electricity conducting layer, a photo sensitive recording layer of chalcogenic glass and a thin film electrode of aluminium, is provided with an optically transparent protective layer, applied into the thin film electrode. The result of the invention consists in excluding the dependence of chemical processes course into the medium upon environmental conditions

Transparent and conductive polyethylene oxide film by the introduction of individualized single-walled carbon nanotubes.

Science.gov (United States)

Jung, Yong Chae; Muramatsu, Hiroyuki; Park, Ki Chul; Shimamoto, Daisuke; Kim, Jin Hee; Hayashi, Takuya; Song, Sung Moo; Kim, Yoong Ahm; Endo, Morinobu; Dresselhaus, Mildred S

2009-12-16

It is demonstrated that an optically transparent and electrically conductive polyethylene oxide (PEO) film is fabricated by the introduction of individualized single-walled carbon nanotubes (SWNTs). The incorporated SWNTs in the PEO film sustain their intrinsic electronic and optical properties and, in addition, the intrinsic properties of the polymer matrix are retained. The individualized SWNTs with smaller diameter provide high transmittance as well as good electrical conductivity in PEO films. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Amorphous and crystalline In_2O_3-based transparent conducting films for photovoltaics

International Nuclear Information System (INIS)

Koida, Takashi

2017-01-01

We reported solar cells with reduced electrical and optical losses using hydrogen-doped In_2O_3 (In_2O_3:H) transparent conducting layers with low sheet resistance and high transparence characteristics. The transparent conducting oxide (TCO) films were prepared by solid-phase crystallization of amorphous (a-) In_2O_3:H films grown by magnetron sputtering. The polycrystalline (poly-) In_2O_3:H films exhibited electron mobilities (over 100 cm"2V"-"1 s"-"1) 2 and 3 times greater than those of conventional TCO films. This paper describes (i) the current status of the electrical properties of In_2O_3-based TCO; (ii) the structural and optoelectrical properties of the a-In_2O_3:H and poly-In_2O_3:H films, focusing on the inhomogeneity and stability characteristics of the films; and (iii) the electrical properties of bilayer TCO. The potential of these high mobility TCO films for solar cells was also described. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Bio-Optics and Bio-Inspired Optical Materials.

Science.gov (United States)

Tadepalli, Sirimuvva; Slocik, Joseph M; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

2017-10-25

Through the use of the limited materials palette, optimally designed micro- and nanostructures, and tightly regulated processes, nature demonstrates exquisite control of light-matter interactions at various length scales. In fact, control of light-matter interactions is an important element in the evolutionary arms race and has led to highly engineered optical materials and systems. In this review, we present a detailed summary of various optical effects found in nature with a particular emphasis on the materials and optical design aspects responsible for their optical functionality. Using several representative examples, we discuss various optical phenomena, including absorption and transparency, diffraction, interference, reflection and antireflection, scattering, light harvesting, wave guiding and lensing, camouflage, and bioluminescence, that are responsible for the unique optical properties of materials and structures found in nature and biology. Great strides in understanding the design principles adapted by nature have led to a tremendous progress in realizing biomimetic and bioinspired optical materials and photonic devices. We discuss the various micro- and nanofabrication techniques that have been employed for realizing advanced biomimetic optical structures.

A high-performance, flexible and robust metal nanotrough-embedded transparent conducting film for wearable touch screen panels

Science.gov (United States)

Im, Hyeon-Gyun; An, Byeong Wan; Jin, Jungho; Jang, Junho; Park, Young-Geun; Park, Jang-Ung; Bae, Byeong-Soo

2016-02-01

We report a high-performance, flexible and robust metal nanotrough-embedded transparent conducting hybrid film (metal nanotrough-GFRHybrimer). Using an electro-spun polymer nanofiber web as a template and vacuum-deposited gold as a conductor, a junction resistance-free continuous metal nanotrough network is formed. Subsequently, the metal nanotrough is embedded on the surface of a glass-fabric reinforced composite substrate (GFRHybrimer). The monolithic composite structure of our transparent conducting film allows simultaneously high thermal stability (24 h at 250 °C in air), a smooth surface topography (Rrms touch screen panel (TSP) is fabricated using the transparent conducting films. The flexible TSP device stably operates on the back of a human hand and on a wristband.We report a high-performance, flexible and robust metal nanotrough-embedded transparent conducting hybrid film (metal nanotrough-GFRHybrimer). Using an electro-spun polymer nanofiber web as a template and vacuum-deposited gold as a conductor, a junction resistance-free continuous metal nanotrough network is formed. Subsequently, the metal nanotrough is embedded on the surface of a glass-fabric reinforced composite substrate (GFRHybrimer). The monolithic composite structure of our transparent conducting film allows simultaneously high thermal stability (24 h at 250 °C in air), a smooth surface topography (Rrms touch screen panel (TSP) is fabricated using the transparent conducting films. The flexible TSP device stably operates on the back of a human hand and on a wristband. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07657a

Some techniques and results from high-pressure shock-wave experiments utilizing the radiation from shocked transparent materials

International Nuclear Information System (INIS)

McQueen, R.G.; Fritz, J.N.

1981-01-01

It has been known for many years that some transparent materials emit radiation when shocked to high pressures. This property was used to determine the temperature of shocked fused and crystal quartz, which in turn allowed the thermal expansion of SiO 2 at high pressure and also the specific heat to be calculated. Once the radiative energy as a function of pressure is known for one material it is shown how this can be used to determine the temperature of other transparent materials. By the nature of the experiments very accurate shock velocities can be measured and hence high quality equation of state data obtained. Some techniques and results are presented on measuring sound velocities from symmetrical impact of nontransparent materials using radiation emitting transparent analyzers, and on nonsymmetrical impact experiments on transparent materials. Because of special requirements in the later experiments, techniques were developed that lead to very high-precision shock-wave data. Preliminary results, using these techniques are presented for making estimates of the melting region and the yield strength of some metals under strong shock conditions

Continuous, Highly Flexible, and Transparent Graphene Films by Chemical Vapor Deposition for Organic Photovoltaics

KAUST Repository

Gomez De Arco, Lewis

2010-05-25

We report the implementation of continuous, highly flexible, and transparent graphene films obtained by chemical vapor deposition (CVD) as transparent conductive electrodes (TCE) in organic photovoltaic cells. Graphene films were synthesized by CVD, transferred to transparent substrates, and evaluated in organic solar cell heterojunctions (TCE/poly-3,4- ethylenedioxythiophene:poly styrenesulfonate (PEDOT:PSS)/copper phthalocyanine/fullerene/bathocuproine/aluminum). Key to our success is the continuous nature of the CVD graphene films, which led to minimal surface roughness (∼ 0.9 nm) and offered sheet resistance down to 230 Ω/sq (at 72% transparency), much lower than stacked graphene flakes at similar transparency. In addition, solar cells with CVD graphene and indium tin oxide (ITO) electrodes were fabricated side-by-side on flexible polyethylene terephthalate (PET) substrates and were confirmed to offer comparable performance, with power conversion efficiencies (η) of 1.18 and 1.27%, respectively. Furthermore, CVD graphene solar cells demonstrated outstanding capability to operate under bending conditions up to 138°, whereas the ITO-based devices displayed cracks and irreversible failure under bending of 60°. Our work indicates the great potential of CVD graphene films for flexible photovoltaic applications. © 2010 American Chemical Society.

Continuous, highly flexible, and transparent graphene films by chemical vapor deposition for organic photovoltaics.

Science.gov (United States)

Gomez De Arco, Lewis; Zhang, Yi; Schlenker, Cody W; Ryu, Koungmin; Thompson, Mark E; Zhou, Chongwu

2010-05-25

We report the implementation of continuous, highly flexible, and transparent graphene films obtained by chemical vapor deposition (CVD) as transparent conductive electrodes (TCE) in organic photovoltaic cells. Graphene films were synthesized by CVD, transferred to transparent substrates, and evaluated in organic solar cell heterojunctions (TCE/poly-3,4-ethylenedioxythiophene:poly styrenesulfonate (PEDOT:PSS)/copper phthalocyanine/fullerene/bathocuproine/aluminum). Key to our success is the continuous nature of the CVD graphene films, which led to minimal surface roughness ( approximately 0.9 nm) and offered sheet resistance down to 230 Omega/sq (at 72% transparency), much lower than stacked graphene flakes at similar transparency. In addition, solar cells with CVD graphene and indium tin oxide (ITO) electrodes were fabricated side-by-side on flexible polyethylene terephthalate (PET) substrates and were confirmed to offer comparable performance, with power conversion efficiencies (eta) of 1.18 and 1.27%, respectively. Furthermore, CVD graphene solar cells demonstrated outstanding capability to operate under bending conditions up to 138 degrees , whereas the ITO-based devices displayed cracks and irreversible failure under bending of 60 degrees . Our work indicates the great potential of CVD graphene films for flexible photovoltaic applications.

Scalable Coating and Properties of Transparent, Flexible, Silver Nanowire Electrodes

KAUST Repository

Hu, Liangbing

2010-05-25

We report a comprehensive study of transparent and conductive silver nanowire (Ag NW) electrodes, including a scalable fabrication process, morphologies, and optical, mechanical adhesion, and flexibility properties, and various routes to improve the performance. We utilized a synthesis specifically designed for long and thin wires for improved performance in terms of sheet resistance and optical transmittance. Twenty Ω/sq and ∼ 80% specular transmittance, and 8 ohms/sq and 80% diffusive transmittance in the visible range are achieved, which fall in the same range as the best indium tin oxide (ITO) samples on plastic substrates for flexible electronics and solar cells. The Ag NW electrodes show optical transparencies superior to ITO for near-infrared wavelengths (2-fold higher transmission). Owing to light scattering effects, the Ag NW network has the largest difference between diffusive transmittance and specular transmittance when compared with ITO and carbon nanotube electrodes, a property which could greatly enhance solar cell performance. A mechanical study shows that Ag NW electrodes on flexible substrates show excellent robustness when subjected to bending. We also study the electrical conductance of Ag nanowires and their junctions and report a facile electrochemical method for a Au coating to reduce the wire-to-wire junction resistance for better overall film conductance. Simple mechanical pressing was also found to increase the NW film conductance due to the reduction of junction resistance. The overall properties of transparent Ag NW electrodes meet the requirements of transparent electrodes for many applications and could be an immediate ITO replacement for flexible electronics and solar cells. © 2010 American Chemical Society.

Scalable Coating and Properties of Transparent, Flexible, Silver Nanowire Electrodes

KAUST Repository

Hu, Liangbing; Kim, Han Sun; Lee, Jung-Yong; Peumans, Peter; Cui, Yi

2010-01-01

We report a comprehensive study of transparent and conductive silver nanowire (Ag NW) electrodes, including a scalable fabrication process, morphologies, and optical, mechanical adhesion, and flexibility properties, and various routes to improve the performance. We utilized a synthesis specifically designed for long and thin wires for improved performance in terms of sheet resistance and optical transmittance. Twenty Ω/sq and ∼ 80% specular transmittance, and 8 ohms/sq and 80% diffusive transmittance in the visible range are achieved, which fall in the same range as the best indium tin oxide (ITO) samples on plastic substrates for flexible electronics and solar cells. The Ag NW electrodes show optical transparencies superior to ITO for near-infrared wavelengths (2-fold higher transmission). Owing to light scattering effects, the Ag NW network has the largest difference between diffusive transmittance and specular transmittance when compared with ITO and carbon nanotube electrodes, a property which could greatly enhance solar cell performance. A mechanical study shows that Ag NW electrodes on flexible substrates show excellent robustness when subjected to bending. We also study the electrical conductance of Ag nanowires and their junctions and report a facile electrochemical method for a Au coating to reduce the wire-to-wire junction resistance for better overall film conductance. Simple mechanical pressing was also found to increase the NW film conductance due to the reduction of junction resistance. The overall properties of transparent Ag NW electrodes meet the requirements of transparent electrodes for many applications and could be an immediate ITO replacement for flexible electronics and solar cells. © 2010 American Chemical Society.

A Co-Precursor Approach Coupled with a Supercritical Modification Method for Constructing Highly Transparent and Superhydrophobic Polymethylsilsesquioxane Aerogels.

Science.gov (United States)

Lei, Chaoshuai; Li, Junning; Sun, Chencheng; Yang, Hailong; Xia, Tao; Hu, Zijun; Zhang, Yue

2018-03-30

Polymethylsilsesquioxane (PMSQ) aerogels obtained from methyltrimethoxysilane (MTMS) are well-known high-performance porous materials. Highly transparent and hydrophobic PMSQ aerogel would play an important role in transparent vacuum insulation panels. Herein, the co-precursor approach and supercritical modification method were developed to prepare the PMSQ aerogels with high transparency and superhydrophobicity. Firstly, benefiting from the introduction of tetramethoxysilane (TMOS) in the precursor, the pore structure became more uniform and the particle size was decreased. As the TMOS content increased, the light transmittance increased gradually from 54.0% to 81.2%, whereas the contact angle of water droplet decreased from 141° to 99.9°, ascribed to the increase of hydroxyl groups on the skeleton surface. Hence, the supercritical modification method utilizing hexamethyldisilazane was also introduced to enhance the hydrophobic methyl groups on the aerogel's surface. As a result, the obtained aerogels revealed superhydrophobicity with a contact angle of 155°. Meanwhile, the developed surface modification method did not lead to any significant changes in the pore structure resulting in the superhydrophobic aerogel with a high transparency of 77.2%. The proposed co-precursor approach and supercritical modification method provide a new horizon in the fabrication of highly transparent and superhydrophobic PMSQ aerogels.

Polarization-independent transparency window induced by complementary graphene metasurfaces

International Nuclear Information System (INIS)

Lu, Wei Bing; Liu, Ji Long; Zhang, Jin; Wang, Jian; Liu, Zhen Guo

2017-01-01

A fourfold symmetric graphene-based complementary metasurface featuring a polarization-independent transparency window is proposed and numerically analysed in this paper. The unit cell of the metamaterial consists of a monolayer graphene perforated with a cross and four identical split-ring resonators deposited on a substrate. Our analysis shows that the transparency window can be interpreted as a plasmonic analogy of Autler–Townes splitting. The polarization independence is achieved due to the fourfold symmetry of graphene’s complementary structure. In addition, the frequency range of the transparency window can be dynamically tuned over a broad band by changing the chemical potential of graphene, and the width of the transparency window can also be controlled by changing the split-gap orientation. This work may lead to potential applications in many area, such as slow-light devices and optical sensing. (paper)

Highly Enhanced Electromechanical Stability of Large-Area Graphene with Increased Interfacial Adhesion Energy by Electrothermal-Direct Transfer for Transparent Electrodes.

Science.gov (United States)

Kim, Jangheon; Kim, Gi Gyu; Kim, Soohyun; Jung, Wonsuk

2016-09-07

Graphene, a two-dimensional sheet of carbon atoms in a hexagonal lattice structure, has been extensively investigated for research and industrial applications as a promising material with outstanding electrical, mechanical, and chemical properties. To fabricate graphene-based devices, graphene transfer to the target substrate with a clean and minimally defective surface is the first step. However, graphene transfer technologies require improvement in terms of uniform transfer with a clean, nonfolded and nontorn area, amount of defects, and electromechanical reliability of the transferred graphene. More specifically, uniform transfer of a large area is a key challenge when graphene is repetitively transferred onto pretransferred layers because the adhesion energy between graphene layers is too low to ensure uniform transfer, although uniform multilayers of graphene have exhibited enhanced electrical and optical properties. In this work, we developed a newly suggested electrothermal-direct (ETD) transfer method for large-area high quality monolayer graphene with less defects and an absence of folding or tearing of the area at the surface. This method delivers uniform multilayer transfer of graphene by repetitive monolayer transfer steps based on high adhesion energy between graphene layers and the target substrate. To investigate the highly enhanced electromechanical stability, we conducted mechanical elastic bending experiments and reliability tests in a highly humid environment. This ETD-transferred graphene is expected to replace commercial transparent electrodes with ETD graphene-based transparent electrodes and devices such as a touch panels with outstanding electromechanical stability.

Tungsten trioxide as high-{kappa} gate dielectric for highly transparent and temperature-stable zinc-oxide-based thin-film transistors

Energy Technology Data Exchange (ETDEWEB)

Lorenz, Michael; Wenckstern, Holger von; Grundmann, Marius [Universitaet Leipzig, Fakultaet fuer Physik und Geowissenschaften, Institut fuer Experimentelle Physik II, Linnestr. 5, 04103 Leipzig (Germany)

2012-07-01

We demonstrate metal-insulator-semiconductor field-effect transistors with high-{kappa}, room-temperature deposited, highly transparent tungsten trioxide (WO{sub 3}) as gate dielectric. The channel material consists of a zinc oxide (ZnO) thin-film. The transmittance and resistivity of WO{sub 3} films was tuned in order to obtain a highly transparent and insulating WO{sub 3} dielectric. The devices were processed by standard photolithography using lift-off technique. On top of the WO{sub 3} dielectric a highly transparent and conductive oxide consisting of ZnO: Al 3% wt. was deposited. The gate structure of the devices exhibits an average transmittance in the visible spectral range of 86%. The on/off-current ratio is larger than 10{sup 8} with off- and gate leakage-currents below 3 x 10{sup -8} A/cm{sup 2}. Due to the high relative permittivity of {epsilon}{sub r} {approx} 70, a gate voltage sweep of only 2 V is necessary to turn the transistor on and off with a minimum subthreshold swing of 80 mV/decade. The channel mobility of the transistors equals the Hall-effect mobility with a value of 5 cm{sup 2}/Vs. It is furthermore shown, that the devices are stable up to operating temperatures of at least 150 C.

Fabrication of transparent, tough, and conductive shape-memory polyurethane films by incorporating a small amount of high-quality graphene.

Science.gov (United States)

Jung, Yong Chae; Kim, Jin Hee; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Terrones, Mauricio; Dresselhaus, Mildred S

2012-04-23

We report a mechanically strong, electrically and thermally conductive, and optically transparent shape-memory polyurethane composite which was fabricated by introducing a small amount (0.1 wt%) of high-quality graphene as a filler. Geometrically large (≈4.6 μm(2)), but highly crystallized few-layer graphenes, verified by Raman spectroscopy and transmission electron microscopy, were prepared by the sonication of expandable graphite in an organic solvent. Oxygen- containing functional groups at the edge plane of graphene were crucial for an effective stress transfer from the graphene to polyurethane. Homogeneously dispersed few-layered graphene enabled polyurethane to have a high shape recovery force of 1.8 MPa cm(-3). Graphene, which is intrinsically stretchable up to 10%, will enable high-performance composites to be fabricated at relatively low cost and we thus envisage that such composites may replace carbon nanotubes for various applications in the near future. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transparent back contacts for P3HT:PCBM bulk heterojunction solar cells

International Nuclear Information System (INIS)

Sendova-Vassileva, M; Dikov, H; Popkirov, G; Lazarova, E; Vitanov, P; Gancheva, V; Grancharov, G; Tsocheva, D; Mokreva, P

2014-01-01

A new combination of layers functioning as a transparent contact is proposed and tested in real solar cells. The contacts consist of TiO 2 layers and thin metal layers (Ag, Cu) and are deposited by magnetron sputtering. The optical transmission and electrical conductivity of the transparent contact layers (TCL) are measured. The TCLs are applied as back contacts in bulk heterojunction polymer solar cells deposited on ITO covered glass and consisting of the following layers: ITO/PEDOT:PSS/P3HT:PCBM/back contact. The organic layers are deposited by spin-coating. For comparison, the same bulk heterojunction polymer solar cells are prepared with a sputtered Ag back contact. The first results show a dependence of the current-voltage parameters of the studied solar cells on the thickness of the different component layers of the transparent back contacts. There is a balance that has to be observed between the electrical characteristics of the contacts and their optical transparency. Future plans involve their inclusion as intermediate contacts in tandem organic solar cells.

High capacity hybrid optical fiber-wireless links in 75–300GHz band

DEFF Research Database (Denmark)

Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

2014-01-01

Seamless convergence of fiber-optic and the wireless networks is of great interest for enabling transparent delivery of broadband services to users in different locations, including both metropolitan and rural areas. Current demand of bandwidth by end-users, especially using mobile devices......, is seeding the need to use bands located at the millimeter-wave region (30–300 GHz), mainly because of its inherent broadband nature. In our lab, we have conducted extensive research on high-speed photonic-wireless links in the W-band (75–110GHz). In this paper, we will present our latest findings...

Structural and electrical characteristics of high-k/metal gate metal oxide semiconductor capacitors fabricated on flexible, semi-transparent silicon (100) fabric

KAUST Repository

Rojas, Jhonathan Prieto

2013-02-12

In pursuit of flexible computers with high performance devices, we demonstrate a generic process to fabricate 10 000 metal-oxide-semiconductor capacitors (MOSCAPs) with semiconductor industry\\'s most advanced high-k/metal gate stacks on widely used, inexpensive bulk silicon (100) wafers and then using a combination of iso-/anisotropic etching to release the top portion of the silicon with the already fabricated devices as a mechanically flexible (bending curvature of 133 m−1), optically semi-transparent silicon fabric (1.5 cm × 3 cm × 25 μm). The electrical characteristics show 3.7 nm effective oxide thickness, −0.2 V flat band voltage, and no hysteresis from the fabricated MOSCAPs.

Structural and electrical characteristics of high-k/metal gate metal oxide semiconductor capacitors fabricated on flexible, semi-transparent silicon (100) fabric

KAUST Repository

Rojas, Jhonathan Prieto; Hussain, Muhammad Mustafa; Sevilla, Galo T.

2013-01-01

In pursuit of flexible computers with high performance devices, we demonstrate a generic process to fabricate 10 000 metal-oxide-semiconductor capacitors (MOSCAPs) with semiconductor industry's most advanced high-k/metal gate stacks on widely used, inexpensive bulk silicon (100) wafers and then using a combination of iso-/anisotropic etching to release the top portion of the silicon with the already fabricated devices as a mechanically flexible (bending curvature of 133 m−1), optically semi-transparent silicon fabric (1.5 cm × 3 cm × 25 μm). The electrical characteristics show 3.7 nm effective oxide thickness, −0.2 V flat band voltage, and no hysteresis from the fabricated MOSCAPs.

Circularly Polarized Transparent Microstrip Patch Reflectarray Integrated with Solar Cell for Satellite Applications

OpenAIRE

Zainud-Deen, S. H.; El-Shalaby, N. A.; Gaber, S. M.; Malhat, H. A.

2016-01-01

Circularly polarized (CP) transparent microstrip reflectarray antenna is integrated with solar cell for small satellite applications at 10 GHz. The reflectarray unit cell consists of a perfect electric conductor (PEC) square patch printed on an optically transparent substrate with the PEC ground plane. A comparison between using transparent conducting polymers and using the PEC in unit-cell construction has been introduced. The waveguide simulator is used to calculate the required compensatio...

Transparent Electrodes with Nanotubes and Graphene for Printed Optoelectronic Applications

Directory of Open Access Journals (Sweden)

Marcin Słoma

2014-01-01

Full Text Available We report here on printed electroluminescent structures containing transparent electrodes made of carbon nanotubes and graphene nanoplatelets. Screen-printing and spray-coating techniques were employed. Electrodes and structures were examined towards optical parameters using spectrophotometer and irradiation meter. Electromechanical properties of transparent electrodes are exterminated with cyclical bending test. Accelerated aging process was conducted according to EN 62137 standard for reliability tests of electronics. We observed significant negative influence of mechanical bending on sheet resistivity of ITO, while resistivity of nanotube and graphene based electrodes remained stable. Aging process has also negative influence on ITO based structures resulting in delamination of printed layers, while those based on carbon nanomaterials remained intact. We observe negligible changes in irradiation for structures with carbon nanotube electrodes after accelerated aging process. Such materials demonstrate a high application potential in general purpose electroluminescent devices.

Structural study of TiO2-based transparent conducting films

International Nuclear Information System (INIS)

Hitosugi, T.; Yamada, N.; Nakao, S.; Hatabayashi, K.; Shimada, T.; Hasegawa, T.

2008-01-01

We have investigated microscopic structures of sputter and pulsed laser deposited (PLD) anatase Nb-doped TiO 2 transparent conducting films, and discuss what causes the degradation of resistivity in sputter-deposited films. Cross-sectional transmission electron microscope and polarized optical microscope images show inhomogeneous intragrain structures and small grains of ∼10 μm in sputter-deposited films. From comparison with PLD films, these results suggest that homogeneous film growth is the important factor to obtain highly conducting sputter-deposited film

High performance and transparent multilayer MoS2 transistors: Tuning Schottky barrier characteristics

Directory of Open Access Journals (Sweden)

Young Ki Hong

2016-05-01

Full Text Available Various strategies and mechanisms have been suggested for investigating a Schottky contact behavior in molybdenum disulfide (MoS2 thin-film transistor (TFT, which are still in much debate and controversy. As one of promising breakthrough for transparent electronics with a high device performance, we have realized MoS2 TFTs with source/drain electrodes consisting of transparent bi-layers of a conducting oxide over a thin film of low work function metal. Intercalation of a low work function metal layer, such as aluminum, between MoS2 and transparent source/drain electrodes makes it possible to optimize the Schottky contact characteristics, resulting in about 24-fold and 3 orders of magnitude enhancement of the field-effect mobility and on-off current ratio, respectively, as well as transmittance of 87.4 % in the visible wavelength range.

Morphology-controllable of Sn doped ZnO nanorods prepared by spray pyrolysis for transparent electrode application

Science.gov (United States)

Hameed, M. Shahul; Princice, J. Joseph; Babu, N. Ramesh; Zahirullah, S. Syed; Deshmukh, Sampat G.; Arunachalam, A.

2018-05-01

Transparent conductive Sn doped ZnO nanorods have been deposited at various doping level by spray pyrolysis technique on glass substrate. The structural, surface morphological and optical properties of these films have been investigated with the help of X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and UV-Vis spectrophotometer respectively. XRD patterns revealed a successful high quality growth of single crystal ZnO nanorods with hexagonal wurtzite structure having (002) preferred orientation. The scanning electron microscope (SEM) image of the prepared films exposed the uniform distribution of Sn doped ZnO nanorod shaped grains. All these films were highly transparent in the visible region with average transmittance of 90%.

Narrow linewidth pulsed optical parametric oscillator

Indian Academy of Sciences (India)

also because of high laser damage threshold coating on mirror as well as on crystal. Now-a-days with the development of coating technology and with the availability of good optical quality crystals having high damage threshold and deep infrared. (IR) transparency it is possible to extend the tunability of the OPO.

Tailored silver grid as transparent electrodes directly written by femtosecond laser

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yuan-Yuan; Ren, Xue-Liang [Laboratory of Organic NanoPhotonics and Laboratory of Bio-Inspired Smart Interface Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, No. 29, Zhongguancun East Road, Beijing 100190 (China); University of Chinese Academy of Sciences, No. 29, Zhongguancun East Road, Beijing 100190 (China); Zheng, Mei-Ling, E-mail: zhengmeiling@mail.ipc.ac.cn, E-mail: xmduan@mail.ipc.ac.cn; Dong, Xian-Zi; Jin, Feng; Liu, Jie; Zhao, Zhen-Sheng [Laboratory of Organic NanoPhotonics and Laboratory of Bio-Inspired Smart Interface Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, No. 29, Zhongguancun East Road, Beijing 100190 (China); Duan, Xuan-Ming, E-mail: zhengmeiling@mail.ipc.ac.cn, E-mail: xmduan@mail.ipc.ac.cn [Laboratory of Organic NanoPhotonics and Laboratory of Bio-Inspired Smart Interface Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, No. 29, Zhongguancun East Road, Beijing 100190 (China); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, No. 266 Fangzheng Ave., Shuitu Technology Development Zone, Beibei District, Chongqing 400714 (China)

2016-05-30

We present the design and realization of silver grid transparent electrodes (SGTEs) easily fabricated by femtosecond laser direct writing of silver aqueous solution. The fabricated SGTEs with a sheet resistance down to 47 Ω/□ and optical transmittance up to 93% are demonstrated. These sheet resistance and transmittance values are comparable to commercially available indium tin oxide. High uniform morphology of the directly written SGTEs results in the ultra-stable tailored performance parameter at electronic and optical fields. The sheet resistance and transmittance can be tailored precisely by manipulating the filling fraction of the uniform SGTEs. This study provides an approach for creating SGTEs in a controllable fashion, and the SGTEs exhibit high transmittance and low sheet resistance, which could open up new avenues towards widespread application in electronics, photovoltaics, and optoelectronics.

Microcavity-Free Broadband Light Outcoupling Enhancement in Flexible Organic Light-Emitting Diodes with Nanostructured Transparent Metal-Dielectric Composite Electrodes.

Science.gov (United States)

Xu, Lu-Hai; Ou, Qing-Dong; Li, Yan-Qing; Zhang, Yi-Bo; Zhao, Xin-Dong; Xiang, Heng-Yang; Chen, Jing-De; Zhou, Lei; Lee, Shuit-Tong; Tang, Jian-Xin

2016-01-26

Flexible organic light-emitting diodes (OLEDs) hold great promise for future bendable display and curved lighting applications. One key challenge of high-performance flexible OLEDs is to develop new flexible transparent conductive electrodes with superior mechanical, electrical, and optical properties. Herein, an effective nanostructured metal/dielectric composite electrode on a plastic substrate is reported by combining a quasi-random outcoupling structure for broadband and angle-independent light outcoupling of white emission with an ultrathin metal alloy film for optimum optical transparency, electrical conduction, and mechanical flexibility. The microcavity effect and surface plasmonic loss can be remarkably reduced in white flexible OLEDs, resulting in a substantial increase in the external quantum efficiency and power efficiency to 47.2% and 112.4 lm W(-1).

A graphene integrated highly transparent resistive switching memory device

Science.gov (United States)

Dugu, Sita; Pavunny, Shojan P.; Limbu, Tej B.; Weiner, Brad R.; Morell, Gerardo; Katiyar, Ram S.

2018-05-01

We demonstrate the hybrid fabrication process of a graphene integrated highly transparent resistive random-access memory (TRRAM) device. The indium tin oxide (ITO)/Al2O3/graphene nonvolatile memory device possesses a high transmittance of >82% in the visible region (370-700 nm) and exhibits stable and non-symmetrical bipolar switching characteristics with considerably low set and reset voltages (ITO/Al2O3/Pt device and studied its switching characteristics for comparison and a better understanding of the ITO/Al2O3/graphene device characteristics. The conduction mechanisms in high and low resistance states were analyzed, and the observed polarity dependent resistive switching is explained based on electro-migration of oxygen ions.

Limits of transparency of transparent conducting oxides

Science.gov (United States)

Peelaers, Hartwin

A fundamental understanding of the factors that limit transparency in transparent conducting oxides (TCOs) is essential for further progress in materials and applications. These materials have a sufficiently large band gap, so that direct optical transitions do not lead to absorption of light within the visible spectrum. Since the presence of free carriers is essential for conductivity and thus for device applications, this introduces the possibility of additional absorption processes. In particular, indirect processes are possible, and these will constitute a fundamental limit of the material. The Drude theory is widely used to describe free-carrier absorption, but it is phenomenological in nature and tends to work poorly at shorter wavelengths, where band-structure effects are important. We will present calculations of phonon- and defect-assisted free-carrier absorption in a TCO completely from first principles. We will focus in detail on SnO2, but the methodology is general and we will also compare the results obtained for other TCO materials such as In2O3. These calculations provide not just quantitative results but also deeper insights in the mechanisms that govern absorption processes, which is essential for engineering improved materials to be used in more efficient devices. This work was performed in collaboration with E. Kioupakis and C.G. Van de Walle and was supported by ARO and NSF.

Optically transparent composite diamond/Ti electrodes

Czech Academy of Sciences Publication Activity Database

Ashcheulov, Petr; Taylor, Andrew; More Chevalier, Joris; Kovalenko, A.; Remeš, Zdeněk; Drahokoupil, Jan; Hubík, Pavel; Fekete, Ladislav; Klimša, Ladislav; Kopeček, Jaromír; Remiášová, Jarmila; Kohout, Michal; Frank, Otakar; Kavan, Ladislav; Mortet, Vincent

2017-01-01

Roč. 119, Aug (2017), s. 179-189 ISSN 0008-6223 R&D Projects: GA MŠk LO1409; GA MŠk LM2015088; GA ČR GA13-31783S Grant - others:FUNBIO(XE) CZ.2.16/3.1.00/21568; AV ČR(CZ) Fellowship J. E. Purkyně; AV ČR(CZ) MSM100101602 Program:Program na podporu mezinárodní spolupráce začínajících výzkumných pracovníků Institutional support: RVO:68378271 ; RVO:61388955 Keywords : diamond * transparent film * composite electrode * conductive thin film Subject RIV: BM - Solid Matter Physics ; Magnetism; CF - Physical ; Theoretical Chemistry (UFCH-W) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.); Physical chemistry (UFCH-W) Impact factor: 6.337, year: 2016

Influence of sputtering power on the optical properties of ITO thin films

Energy Technology Data Exchange (ETDEWEB)

K, Aijo John; M, Deepak, E-mail: manju.thankamoni@gmail.com; T, Manju, E-mail: manju.thankamoni@gmail.com [Department of Physics, Sree Sankara College, Kalady P. O., Ernakulam Dist., Kerala (India); Kumar, Vineetha V. [Dept. of Physics, K. E. College, Mannanam, Kottayam Dist., Kerala (India)

2014-10-15

Tin doped indium oxide films are widely used in transparent conducting coatings such as flat panel displays, crystal displays and in optical devices such as solar cells and organic light emitting diodes due to the high electrical resistivity and optical transparency in the visible region of solar spectrum. The deposition parameters have a commendable influence on the optical and electrical properties of the thin films. In this study, ITO thin films were prepared by RF magnetron sputtering. The properties of the films prepared under varying sputtering power were compared using UV- visible spectrophotometry. Effect of sputtering power on the energy band gap, absorption coefficient and refractive index are investigated.

Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt

OpenAIRE

Bai, Yuanyuan; Chen, Baohong; Xiang, Feng; Zhou, Jinxiong; Wang, Hong; Suo, Zhigang

2014-01-01

Polyacrylamide hydrogels containing salt as electrolyte have been used as highly stretchable transparent electrodes in flexible electronics, but those hydrogels are easy to dry out due to water evaporation. Targeted, we try to enhance water retention capacity of polyacrylamide hydrogel by introducing highly hydratable salts into the hydrogel. These hydrogels show enhanced water retention capacity in different level. Specially, polyacrylamide hydrogel containing high content of lithium chlorid...

Simultaneously improving optical absorption of both transverse-electric polarized and transverse-magnetic polarized light for organic solar cells with Ag grating used as transparent electrode

Directory of Open Access Journals (Sweden)

Yongbing Long

2014-08-01

Full Text Available Theoretical simulations are performed to investigate optical performance of organic solar cells with Ag grating electrode. It is demonstrated that optical absorption for both transverse-electric (TE polarized and transverse-magnetic(TM polarized light is simultaneously improved when compared with that for the device without the Ag grating. The improvement is respectively attributed to the resonance and the surface plasmon polaritons within the device. After an additional WO3 layer is capped on the Ag grating, absorption of TE-polarized light is further improved due to resonance of double microcavities within the device, and absorption of TM-polarized light is improved by the combined effects of the microcavity resonance and the surface plasmon polaritons. Correspondingly, the short current density for randomly polarized light is improved by 18.1% from that of the device without the Ag grating. Finally, it is demonstrated that high transmission may not be an essential prerequisite for metallic gratings when they are used as transparent electrode since absorption loss caused by low transmission can be compensated by using a capping layer to optimize optical resonance of the WMC structure within the device.

Low-resistance and highly transparent Ag/IZO ohmic contact to p-type GaN

Energy Technology Data Exchange (ETDEWEB)

Kim, Han-Ki, E-mail: imdlhkkim@khu.ac.k [Department of Display Materials Engineering, Kyung Hee University, 1 Seochoen-dong, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Yi, Min-Su [Department of Materials Science and Engineering, Kyungpook National University, Sangju, Gyeongbuk, 742-711 (Korea, Republic of); Lee, Sung-Nam [Department of Engineering in Energy and Applied Chemistry, Silla University, Busan, 617-736 (Korea, Republic of)

2009-05-29

The electrical, structural, and optical characteristics of Ag/ZnO-doped In{sub 2}O{sub 3} (IZO) ohmic contacts to p-type GaN:Mg (2.5 x 10{sup 17} cm{sup -3}) were investigated. The Ag and IZO (10 nm/50 nm) layers were prepared by thermal evaporation and linear facing target sputtering, respectively. Although the as-deposited and 400 {sup o}C annealed samples showed rectifying behavior, the 500 and 600 {sup o}C annealed samples showed linear I-V characteristics indicative of the formation of an ohmic contact. The annealing of the contact at 600 {sup o}C for 3 min in a vacuum ({approx} 10{sup -3} Torr) resulted in the lowest specific contact resistivity of 1.8 x 10{sup -4} {Omega}.cm{sup 2} and high transparency of 78% at a wavelength of 470 nm. Using Auger electron spectroscopy, depth profiling and synchrotron X-ray scattering analysis, we suggested a possible mechanism to explain the annealing dependence of the electrical properties of the Ag/IZO contacts.

Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes

Science.gov (United States)

Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

2016-02-01

We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials.

High transparent shape memory gel

Science.gov (United States)

Gong, Jin; Arai, Masanori; Kabir, M. H.; Makino, Masato; Furukawa, Hidemitsu

2014-03-01

Gels are a new material having three-dimensional network structures of macromolecules. They possess excellent properties as swellability, high permeability and biocompatibility, and have been applied in various fields of daily life, food, medicine, architecture, and chemistry. In this study, we tried to prepare new multi-functional and high-strength gels by using Meso-Decoration (Meso-Deco), one new method of structure design at intermediate mesoscale. High-performance rigid-rod aromatic polymorphic crystals, and the functional groups of thermoreversible Diels-Alder reaction were introduced into soft gels as crosslinkable pendent chains. The functionalization and strengthening of gels can be realized by meso-decorating the gels' structure using high-performance polymorphic crystals and thermoreversible pendent chains. New gels with good mechanical properties, novel optical properties and thermal properties are expected to be developed.

Optics

CERN Document Server

Mathieu, Jean Paul

1975-01-01

Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

Mesh parameters influence on transparent and active antennas performance at microwaves

Directory of Open Access Journals (Sweden)

Alexis Martin

2017-08-01

Full Text Available Optically transparent and active square loop coplanar antennas operating in X-band are investigated in this letter. The frequency tunability is provided by a surface mounted beam-lead varactor with micrometric size, thereby no-visible to the naked eye. The influence of the metal mesh parameters on the sheet resistance (from 0.05 Ω/sq to 0.54 Ω/sq, the optical transparency (from 66% to 89% and the microwave performance (return loss, resonance frequency, radiation pattern and gain of such antennas is evaluated, compared with those of an opaque counterpart, and finally discussed. This study paves the way of their promising implementation on new surfaces, namely building and car windows for future wireless communications systems.

Optical properties of photodetectors based on single GaN nanowires with a transparent graphene contact

Energy Technology Data Exchange (ETDEWEB)

Babichev, A. V., E-mail: A.Babichev@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Institute (Russian Federation); Zhang, H.; Guan, N. [University Paris Saclay, Institut d’Electronique Fondamentale, UMR 8622 CNRS (France); Egorov, A. Yu. [ITMO University (Russian Federation); Julien, F. H.; Messanvi, A. [University Paris Saclay, Institut d’Electronique Fondamentale, UMR 8622 CNRS (France); Durand, C.; Eymery, J. [University Grenoble Alpes (France); Tchernycheva, M. [University Paris Saclay, Institut d’Electronique Fondamentale, UMR 8622 CNRS (France)

2016-08-15

We report the fabrication and optical and electrical characterization of photodetectors for the UV spectral range based on single p–n junction nanowires with a transparent contact of a new type. The contact is based on CVD-grown (chemical-vapor deposition) graphene. The active region of the nitride nanowires contains a set of 30 radial In{sub 0.18}Ga{sub 0.82}N/GaN quantum wells. The structure is grown by metal-organic vaporphase epitaxy. The photodetectors are fabricated using electron-beam lithography. The current–voltage characteristics exhibit a rectifying behavior. The spectral sensitivity of the photodetector is recorded starting from 3 eV and extending far in the UV range. The maximal photoresponse is observed at a wavelength of 367 nm (sensitivity 1.9 mA/W). The response switching time of the photodetector is less than 0.1 s.

Flexible and Transparent Strain Sensors with Embedded Multiwalled Carbon Nanotubes Meshes.

Science.gov (United States)

Nie, Bangbang; Li, Xiangming; Shao, Jinyou; Li, Xin; Tian, Hongmiao; Wang, Duorui; Zhang, Qiang; Lu, Bingheng

2017-11-22

Strain sensors combining high sensitivity with good transparency and flexibility would be of great usefulness in smart wearable/flexible electronics. However, the fabrication of such strain sensors is still challenging. In this study, new strain sensors with embedded multiwalled carbon nanotubes (MWCNTs) meshes in polydimethylsiloxane (PDMS) films were designed and tested. The strain sensors showed elevated optical transparency of up to 87% and high sensitivity with a gauge factor of 1140 at a small strain of 8.75%. The gauge factors of the sensors were also found relatively stable since they did not obviously change after 2000 stretching/releasing cycles. The sensors were tested to detect motion in the human body, such as wrist bending, eye blinking, mouth phonation, and pulse, and the results were shown to be satisfactory. Furthermore, the fabrication of the strain sensor consisting of mechanically blading MWCNTs aqueous dispersions into microtrenches of prestructured PDMS films was straightforward, was low cost, and resulted in high yield. All these features testify to the great potential of these sensors in future real applications.

Nonlinear optical properties of ZnO/poly (vinyl alcohol) nanocomposite films

International Nuclear Information System (INIS)

Jeeju, P. P.; Jayalekshmi, S.; Chandrasekharan, K.

2014-01-01

Extensive studies have already been reported on the optical characteristics of ZnO/polymer nanocomposite films, using a variety of polymers including transparent polymers such as polystyrene, polymethyl methacrylate etc and many interesting results have been established regarding the non linear optical characteristics of these systems. Poly (vinyl alcohol)(PVA) is a water soluble polymer. Though the structural and optical studies of ZnO/PVA nanocomposite films have already been investigated, there are no detailed reports on the nonlinear optical characteristics of ZnO/PVA nanocomposite films, irrespective of the fact that these nanocomposite films can be synthesized using quite easy and cost effective methods. The present work is an attempt to study in detail the nonlinear optical behaviour of ZnO/PVA nanocomposite films using Z-scan technique. Highly transparent ZnO/PVA nanocomposite films were prepared from the ZnO incorporated PVA solution in water using spin coating technique. The ZnO nanoparticles were synthesized by the simple chemical route at room temperature. High-resolution transmission electron microscopy studies show that the ZnO nanoparticles are of size around 10 nm. The ZnO/PVA nanocomposite films were structurally characterized by X-ray diffraction technique, from which the presence of both PVA and ZnO in the nanocomposite was established. The optical absorptive nonlinearity in the nanocomposite films was investigated using open aperture Z-scan technique. The results indicate optical limiting type nonlinearity in the films due to two photon absorption in ZnO with efficiency more than 50%. These films also show a self defocusing type negative nonlinear refraction in closed aperture Z-scan experiment. The present studies indicate that, highly transparent and homogeneous films of ZnO/PVA nanocomposite can be obtained on glass substrates using simple methods, in a highly cost effective way, since PVA is water soluble. These nanocomposite films offer

Fully solution-processing route toward highly transparent polymer solar cells.

Science.gov (United States)

Guo, Fei; Kubis, Peter; Stubhan, Tobias; Li, Ning; Baran, Derya; Przybilla, Thomas; Spiecker, Erdmann; Forberich, Karen; Brabec, Christoph J

2014-10-22

We report highly transparent polymer solar cells using metallic silver nanowires (AgNWs) as both the electron- and hole-collecting electrodes. The entire stack of the devices is processed from solution using a doctor blading technique. A thin layer of zinc oxide nanoparticles is introduced between photoactive layer and top AgNW electrode which plays decisive roles in device functionality: it serves as a mechanical foundation which allows the solution-deposition of top AgNWs, and more importantly it facilitates charge carriers extraction due to the better energy level alignment and the formation of ohmic contacts between the active layer/ZnO and ZnO/AgNWs. The resulting semitransparent polymer:fullerene solar cells showed a power conversion efficiency of 2.9%, which is 72% of the efficiency of an opaque reference device. Moreover, an average transmittance of 41% in the wavelength range of 400-800 nm is achieved, which is of particular interest for applications in transparent architectures.

Exploring Quantitative Framework to Evaluate Nuclear Transparency

International Nuclear Information System (INIS)

Ha, Jeemin; Yim, Mansung; Park, Hyeon Seok

2014-01-01

In this work, a definition of nuclear transparency is elaborated and ways to represent a country's nuclear transparency are examined. For evaluating nuclear transparency, it is necessary to define three elements first; an information seeker who wants to see, an information seek whom an information seeker wants to see, and information related to nuclear materials and activities. The States with high capacity of civilian nuclear power had a tendency to follow IAEA safeguards agreements well. And it means that their levels of the transparency are relatively high. Besides, the data of international assurances is one of the good indicators to confirm States' transparency. The current study explored the use of two measures, IAEA safeguards and voluntary reporting as a way to represent nuclear transparency. Using these measures seemed to agree with the notion that nuclear transparency is important in the success of civilian nuclear power development

A novel optically transparent RF shielding for fully integrated PET/MRI systems

Science.gov (United States)

Parl, C.; Kolb, A.; Schmid, A. M.; Wehrl, H. F.; Disselhorst, J. A.; Soubiran, P. D.; Stricker-Shaver, D.; Pichler, B. J.

2017-09-01

Preclinical imaging benefits from simultaneous acquisition of high-resolution anatomical and molecular data. Additionally, PET/MRI systems can provide functional PET and functional MRI data. To optimize PET sensitivity, we propose a system design that fully integrates the MRI coil into the PET system. This allows positioning the scintillators near the object but requires an optimized design of the MRI coil and PET detector. It further requires a new approach in realizing the radiofrequency (RF) shielding. Thus, we propose the use of an optically transparent RF shielding material between the PET scintillator and the light sensor, suppressing the interference between both systems. We evaluated two conductive foils (ITO, 9900) and a wire mesh. The PET performance was tested on a dual-layer scintillator consisting of 12  ×  12 LSO matrices, shifted by half a pitch. The pixel size was 0.9  ×  0.9 mm2 the lengths were 10.0 mm and 5.0 mm, respectively. For a light sensor, we used a 4  ×  4 SiPM array. The RF attenuation was measured from 320 kHz to 420 MHz using two pick-up coils. MRI-compatibility and shielding effect of the materials were evaluated with an MRI system. The average FWHM energy resolution at 511 keV of all 144 crystals of the layer next to the SiPM was deteriorated from 15.73  ±  0.24% to 16.32  ±  0.13%, 16.60  ±  0.25%, and 19.16  ±  0.21% by the ITO foil, 9900 foil, mesh material, respectively. The average peak-to-valley ratio of the PET detector changed from 5.77  ±  0.29 to 4.50  ±  0.39, 4.78  ±  0.48, 3.62  ±  0.16, respectively. The ITO, 9900, mesh attenuated the scintillation light by 11.3  ±  1.6%, 11.0  ±  1.8%, 54.3  ±  0.4%, respectively. To attenuate the RF from 20 MHz to 200 MHz, mesh performed better than copper. The results show that an RF shielding material that is sufficiently transparent for