The Experts below are selected from a list of 15708 Experts worldwide ranked by ideXlab platform
Stephen R Forrest - One of the best experts on this subject based on the ideXlab platform.
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Ultrathin Film high specific power inp solar cells on flexible plastic substrates
Applied Physics Letters, 2009Co-Authors: Kuenting Shiu, Jeramy D Zimmerman, Hongyu Wang, Stephen R ForrestAbstract:We demonstrate Ultrathin-Film, single-crystal InP Schottky-type solar cells mounted on flexible plastic substrates. The lightly p-doped InP cell is grown epitaxially on an InP substrate via gas source molecular beam epitaxy. The InP substrate is removed via selective chemical wet-etching after the epitaxial layers are cold-welded to a 25 μm thick Kapton® sheet, followed by the deposition of an indium tin oxide top contact that forms the Schottky barrier with InP. The power conversion efficiency under 1 sun is 10.2±1.0%, and its specific power is 2.0±0.2 kW/kg. The Ultrathin-Film solar cells can tolerate both tensile and compressive stress by bending over a <1 cm radius without damage.
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long range absorption enhancement in organic tandem thin Film solar cells containing silver nanoclusters
Journal of Applied Physics, 2004Co-Authors: Barry P Rand, Peter Peumans, Stephen R ForrestAbstract:We investigate the optical properties of silver nanoparticles used in tandem Ultrathin-Film organic photovoltaic cells. Experimental results indicate that the enhancement of an incident optical field persists into an organic dielectric for distances of up to 10nm from the center of an array of approximately 5-nm-diameter nanoparticles. Furthermore, this enhancement exists far from the resonant particle surface-plasmon excitation energy. We propose a model to explain this long-range enhancement and investigate the role that cluster spacing, shape, and an embedding dielectric medium with a complex dielectric constant play in determining plasmon enhancement. This effect is shown to increase the efficiency of tandem organic solar cells, and the implications for further solar cell efficiency improvements are discussed.
Jeffrey C Grossman - One of the best experts on this subject based on the ideXlab platform.
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two dimensional covalent triazine framework as an Ultrathin Film nanoporous membrane for desalination
Chemical Communications, 2015Co-Authors: Lichiang Lin, Jongwon Choi, Jeffrey C GrossmanAbstract:We computationally demonstrate that two-dimensional covalent triazine frameworks (CTFs) provide opportunities in water desalination. By varying the chemical building blocks, the pore structure, chemistry, and membrane performance can be designed, leading to two orders of magnitude higher water permeability than polyamide membranes while maintaining excellent ability to reject salts.
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atomistic understandings of reduced graphene oxide as an Ultrathin Film nanoporous membrane for separations
Nature Communications, 2015Co-Authors: Lichiang Lin, Jeffrey C GrossmanAbstract:The intrinsic defects in reduced graphene oxide (rGO) formed during reduction processes can act as nanopores, making rGO a promising Ultrathin-Film membrane candidate for separations. To assess the potential of rGO for such applications, molecular dynamics techniques are employed to understand the defect formation in rGO and their separation performance in water desalination and natural gas purification. We establish the relationship between rGO synthesis parameters and defect sizes, resulting in a potential means to control the size of nanopores in rGO. Furthermore, our results show that rGO membranes obtained under properly chosen synthesis conditions can achieve effective separations and provide significantly higher permeate fluxes than currently available membranes.
Lichiang Lin - One of the best experts on this subject based on the ideXlab platform.
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two dimensional covalent triazine framework as an Ultrathin Film nanoporous membrane for desalination
Chemical Communications, 2015Co-Authors: Lichiang Lin, Jongwon Choi, Jeffrey C GrossmanAbstract:We computationally demonstrate that two-dimensional covalent triazine frameworks (CTFs) provide opportunities in water desalination. By varying the chemical building blocks, the pore structure, chemistry, and membrane performance can be designed, leading to two orders of magnitude higher water permeability than polyamide membranes while maintaining excellent ability to reject salts.
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atomistic understandings of reduced graphene oxide as an Ultrathin Film nanoporous membrane for separations
Nature Communications, 2015Co-Authors: Lichiang Lin, Jeffrey C GrossmanAbstract:The intrinsic defects in reduced graphene oxide (rGO) formed during reduction processes can act as nanopores, making rGO a promising Ultrathin-Film membrane candidate for separations. To assess the potential of rGO for such applications, molecular dynamics techniques are employed to understand the defect formation in rGO and their separation performance in water desalination and natural gas purification. We establish the relationship between rGO synthesis parameters and defect sizes, resulting in a potential means to control the size of nanopores in rGO. Furthermore, our results show that rGO membranes obtained under properly chosen synthesis conditions can achieve effective separations and provide significantly higher permeate fluxes than currently available membranes.
G Scoles - One of the best experts on this subject based on the ideXlab platform.
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pentacene Ultrathin Film formation on reduced and oxidized si surfaces
Physical Review B, 2003Co-Authors: Ricardo Ruiz, Bert Nickel, Norbert Koch, L C Feldman, R F Haglund, Antoine Kahn, G ScolesAbstract:We have compared the nucleation of pentacene on reduced and oxidized Si surfaces by a combination of x-ray reflectivity measurements and atomic force microscopy. For the reduced surface, the nucleation density is 0.007 μm - 2 . Second monolayer (ML) formation starts at a coverage of Θ=0.6 ML, and the first layer is completely closed at a total coverage of 2 ML. For the oxidized surface, the nucleation density is larger by a factor of 100 (0.7 μm - 2 ). Second ML formation also starts at Θ=0.6 ML, but the first layer closes already at 1.1 ML coverage, indicating nearly ideal layer-by-layer growth. For both terminations, the electron density obtained for the closed first monolayer is only 75% of the bulk value, indicating a reduced mass packing efficiency of the layer. Second ML islands are aligned relative to each other on an area limited by the lateral size of first ML islands, which act as templates for epitaxial growth.
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pentacene Ultrathin Film formation on reduced and oxidized si surfaces
Physical Review B, 2003Co-Authors: Ricardo Ruiz, Bert Nickel, Norbert Koch, L C Feldman, R F Haglund, Antoine Kahn, G ScolesAbstract:We have compared the nucleation of pentacene on reduced and oxidized Si surfaces by a combination of x-ray reflectivity measurements and atomic force microscopy. For the reduced surface, the nucleation density is 0.007 $\ensuremath{\mu}{\mathrm{m}}^{\ensuremath{-}2}.$ Second monolayer (ML) formation starts at a coverage of \ensuremath{\Theta}=0.6 ML, and the first layer is completely closed at a total coverage of 2 ML. For the oxidized surface, the nucleation density is larger by a factor of 100 (0.7 $\ensuremath{\mu}{\mathrm{m}}^{\ensuremath{-}2}).$ Second ML formation also starts at \ensuremath{\Theta}=0.6 ML, but the first layer closes already at 1.1 ML coverage, indicating nearly ideal layer-by-layer growth. For both terminations, the electron density obtained for the closed first monolayer is only 75% of the bulk value, indicating a reduced mass packing efficiency of the layer. Second ML islands are aligned relative to each other on an area limited by the lateral size of first ML islands, which act as templates for epitaxial growth.
Paul W Leu - One of the best experts on this subject based on the ideXlab platform.
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broadband light absorption enhancement in Ultrathin Film crystalline silicon solar cells with high index of refraction nanosphere arrays
Nano Energy, 2016Co-Authors: Baomin Wang, Tongchuan Gao, Paul W LeuAbstract:Abstract In this paper, we demonstrate that dielectric nanosphere arrays can enhance the absorption in Ultrathin Film crystalline silicon by coupling incident light to the underlying silicon layer. By introducing dielectric nanospheres on top of the crystalline silicon thin Film solar cell, the power conversion efficiency can be improved by 26.5%. The nanosphere coating increases the absorption and external quantum efficiency over a broadband wavelength range.
