The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Kuang-jung Chen - One of the best experts on this subject based on the ideXlab platform.
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Packaging designs and flexural stress estimation for Thin-Film Types of OLED devices
2012 7th International Microsystems Packaging Assembly and Circuits Technology Conference (IMPACT), 2012Co-Authors: Chih-sheng Wu, Tzai-liang Tzeng, Chia-hao Tsai, Yi-hao Peng, Kuang-jung ChenAbstract:Fatigue behavior with an extreme flexural stress loaded on OLED devices has been greatly paid attention while the packaging structure having multi-stacked Films becomes Thinner and more flexible. To reduce mechanical impact and enhance reliability for OLED and related critical Film materials, a derived mechanical model of plural layers is presented. Moreover, a nonlinear finite element analysis combined with the approach of full factorial design is performed to explore several concerned mechanical parameters wiThin a whole structure. The results reveal that the thickness of PI_substrate is the most dominant to determine the position of neutral axis and the bending stress of indium tin oxide Film, separately. It is also found that all the significances of main effects for each factor are obviously larger than the interaction effect among them. Consequently, the use of either Thinner Film or softer constitute for each layer could be able to reduce ITO stress effectively.
Daniel A Buttry - One of the best experts on this subject based on the ideXlab platform.
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transport properties of v2o5 polypyrrole nanocomposite prepared by a sol gel alkoxide route
Journal of Electroanalytical Chemistry, 2002Co-Authors: Fritz Huguenin, Emerson M Girotto, Roberto M Torresi, Daniel A ButtryAbstract:Nanocomposites of V2O5 xerogel and polypyrrole (Ppy) were prepared from a vanadyl tris(isopropoxide) precursor and pyrrole monomer by in situ oxidative polymerization of the pyrrole in the sol stage followed by gelation. Unlike previous sol-gel nanocomposite synthetic routes, the gel forms a stable solution from which Thin homogeneous Films can be cast. The nanocomposite was characterized by XRD, FTIR and electrochemical measurements. Three different Thin Film Types with different spatial arrangements were used to characterize the compensation of charge. X-ray diffraction reveals that the Ppy chains are intercalated wiThin the interlayer region of the V2O5, leading to an increase in the d-spacing from 11.85 Afor V2O5 to 13.8 Afor the nanocomposite. Electrogravimetric results showed that electroneutrality during charging and discharging is achieved predominantly by Litransport. EQCM studies of a bilayer Film arrangement with the nanocomposite cast over an electropolymerized Film of Ppy revealed that the nanocomposite is an effective barrier for anion transport. The nanocomposite showed a higher specific capacity (283 A h kg � 1 ) than that of V2O5 (236 A h kg � 1 ). This result was attributed to differences in structure between the two materials. The galvanostatic intermittent titration technique (GITT) was used to obtain the diffusion coefficients of Liin the nanocomposite and the V2O5 xerogel. These values range from 2� /10 � 11 to 3 � /10 � 13 cm 2 s � 1 , decreasing as the amount of intercalated Liis increased. For V2O5 the Lidiffusion coefficient ranged from 1� /10 � 12 to 8 � /10 � 14 cm 2 s � 1 , also decreasing as the amount of intercalated Liincreased. In situ resistance measurements revealed a very high conductivity over the potential range of 0.4 to � /0.7 V( vs. Ag/AgNO3) for the nanocomposite, more than a factor of five larger than that for V2O5. # 2002 Elsevier Science B.V. All rights reserved.
Chih-sheng Wu - One of the best experts on this subject based on the ideXlab platform.
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Packaging designs and flexural stress estimation for Thin-Film Types of OLED devices
2012 7th International Microsystems Packaging Assembly and Circuits Technology Conference (IMPACT), 2012Co-Authors: Chih-sheng Wu, Tzai-liang Tzeng, Chia-hao Tsai, Yi-hao Peng, Kuang-jung ChenAbstract:Fatigue behavior with an extreme flexural stress loaded on OLED devices has been greatly paid attention while the packaging structure having multi-stacked Films becomes Thinner and more flexible. To reduce mechanical impact and enhance reliability for OLED and related critical Film materials, a derived mechanical model of plural layers is presented. Moreover, a nonlinear finite element analysis combined with the approach of full factorial design is performed to explore several concerned mechanical parameters wiThin a whole structure. The results reveal that the thickness of PI_substrate is the most dominant to determine the position of neutral axis and the bending stress of indium tin oxide Film, separately. It is also found that all the significances of main effects for each factor are obviously larger than the interaction effect among them. Consequently, the use of either Thinner Film or softer constitute for each layer could be able to reduce ITO stress effectively.
Edward H. Sargent - One of the best experts on this subject based on the ideXlab platform.
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Study of Exciton Hopping Transport in PbS Colloidal Quantum Dot Thin Films Using Frequency- and Temperature-Scanned Photocarrier Radiometry
International Journal of Thermophysics, 2016Co-Authors: Andreas Mandelis, Alexander Melnikov, Xinzheng Lan, Sjoerd Hoogland, Edward H. SargentAbstract:Solution-processed colloidal quantum dots (CQDs) are promising materials for realizing low-cost, large-area, and flexible photovoltaic devices. The study of charge carrier transport in quantum dot solids is essential for understanding energy conversion mechanisms. Recently, solution-processed two-layer oleic-acid-capped PbS CQD solar cells with one layer treated with tetrabutylammonium iodide (TBAI) serving as the main light-absorbing layer and the other treated with 1,2-ethanedithiol (EDT) acting as an electron-blocking/hole-extraction layer were reported. These solar cells demonstrated a significant improvement in power conversion efficiency of 8.55% and long-term air stability. Coupled with photocarrier radiometry measurements, this work used a new trap-state mediated exciton hopping transport model, specifically for CQD Thin Films, to unveil and quantify exciton transport mechanisms through the extraction of hopping transport parameters including exciton lifetimes, hopping diffusivity, exciton detrapping time, and trap-state density. It is shown that PbS-TBAI has higher trap-state density than PbS-EDT that results in higher PbS-EDT exciton lifetimes. Hopping diffusivities of both CQD Thin Film Types show similar temperature dependence, particularly higher temperatures yield higher hopping diffusivity. The higher diffusivity of PbS-TBAI compared with PbS-EDT indicates that PbS-TBAI is a much better photovoltaic material than PbS-EDT. Furthermore, PCR temperature spectra and deep-level photothermal spectroscopy provided additional insights to CQD surface trap states: PbS-TBAI Thin Films exhibit a single dominant trap level, while PbS-EDT Films with lower trap-state densities show multiple trap levels.
Fritz Huguenin - One of the best experts on this subject based on the ideXlab platform.
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transport properties of v2o5 polypyrrole nanocomposite prepared by a sol gel alkoxide route
Journal of Electroanalytical Chemistry, 2002Co-Authors: Fritz Huguenin, Emerson M Girotto, Roberto M Torresi, Daniel A ButtryAbstract:Nanocomposites of V2O5 xerogel and polypyrrole (Ppy) were prepared from a vanadyl tris(isopropoxide) precursor and pyrrole monomer by in situ oxidative polymerization of the pyrrole in the sol stage followed by gelation. Unlike previous sol-gel nanocomposite synthetic routes, the gel forms a stable solution from which Thin homogeneous Films can be cast. The nanocomposite was characterized by XRD, FTIR and electrochemical measurements. Three different Thin Film Types with different spatial arrangements were used to characterize the compensation of charge. X-ray diffraction reveals that the Ppy chains are intercalated wiThin the interlayer region of the V2O5, leading to an increase in the d-spacing from 11.85 Afor V2O5 to 13.8 Afor the nanocomposite. Electrogravimetric results showed that electroneutrality during charging and discharging is achieved predominantly by Litransport. EQCM studies of a bilayer Film arrangement with the nanocomposite cast over an electropolymerized Film of Ppy revealed that the nanocomposite is an effective barrier for anion transport. The nanocomposite showed a higher specific capacity (283 A h kg � 1 ) than that of V2O5 (236 A h kg � 1 ). This result was attributed to differences in structure between the two materials. The galvanostatic intermittent titration technique (GITT) was used to obtain the diffusion coefficients of Liin the nanocomposite and the V2O5 xerogel. These values range from 2� /10 � 11 to 3 � /10 � 13 cm 2 s � 1 , decreasing as the amount of intercalated Liis increased. For V2O5 the Lidiffusion coefficient ranged from 1� /10 � 12 to 8 � /10 � 14 cm 2 s � 1 , also decreasing as the amount of intercalated Liincreased. In situ resistance measurements revealed a very high conductivity over the potential range of 0.4 to � /0.7 V( vs. Ag/AgNO3) for the nanocomposite, more than a factor of five larger than that for V2O5. # 2002 Elsevier Science B.V. All rights reserved.