羟氨苄青霉素引起大疱性类天疱疮样疹

ZnS nanostructures: From synthesis to applications

Solar energy represents one of the most abundant and yet least harvested sources of renewable energy. In recent years, tremendous progress has been made in developing photovoltaics that can be potentially mass deployed. Of particular interest to cost-effective solar cells is to use novel device structures and materials processing for enabling acceptable efficiencies. In this regard, here, we report the direct growth of highly regular, single-crystalline nanopillar arrays of optically active semiconductors on aluminium substrates that are then configured as solar-cell modules. As an example, we demonstrate a photovoltaic structure that incorporates three-dimensional, single-crystalline n-CdS nanopillars, embedded in polycrystalline thin films of p-CdTe, to enable high absorption of light and efficient collection of the carriers. Through experiments and modelling, we demonstrate the potency of this approach for enabling highly versatile solar modules on both rigid and flexible substrates with enhanced carrier collection efficiency arising from the geometric configuration of the nanopillars.

http://nano.eecs.berkeley.edu/publications/NatureMat_2009_SNOPcell.pdf

Three-dimensional nanopillar-array photovoltaics on low-cost and flexible substrates

Size dependence of nanostructures: Impact of bond order deficiency

Advances in physics

Intrinsic polycrystalline silicon (poly-Si) thin films have been prepared by plasma enhanced chemical vapor deposition at a very high excitation frequency (100 MHz) for the development of p–i–n junction solar cells. The correlation between poly-Si microstructure and photovoltaic performance of poly-Si solar cells has been investigated as a function of deposition parameters such as deposition pressure, SiH4 flow rate and SiH4 concentration. It is found that the poly-Si microstructure including crystalline volume fraction, Xc, and crystallographic orientation is closely related to the atomic hydrogen flux during film growth, which is evidenced by plasma diagnostics in the in situ measurement of optical emission spectroscopy. Basically, with an increase in Xc, open circuit voltage tends to decrease, while poly-Si with Xc > 50% and (220) preferential orientation is essential for high short circuit current. Based on these results, the role of poly-Si microstructure in the photovoltaic performance of poly-Si solar cells is discussed.

https://iopscience.iop.org/article/10.1143/JJAP.41.20/pdf

Correlation between Microstructure and Photovoltaic Performance of Polycrystalline Silicon Thin Film Solar Cells

Current–voltage characteristics and quantum efficiency spectra of efficient thin-film CdS/CdTe solar cells

Thin film polycrystalline silicon (poly-Si) solar cells have been fabricated by plasma enhanced chemical vapor deposition on differently textured ZnO/Ag/SnO2/glass substrates. Using a textured substrate with the root mean square (RMS) roughness (σ) of 38 nm, the conversion efficiency of 8.22% has been achieved due to improvement of long wavelength responses. Whereas using textured substrates with σ>38 nm , (2 2 0) preferential growth is deteriorated, yielding decreases in both short circuit current and open circuit voltage. The field-dependent carrier collection behaviors reveal that the carrier diffusion length in the poly-Si layer on textured substrates with σ>38 nm decreases due to the change in poly-Si microstructure.

Influence of substrate texture on microstructure and photovoltaic performances of thin film polycrystalline silicon solar cells

A series of experimental trials to realize the flat panel display devices using plasma CVD produced a-C:H has been reported. Fabrication technology and basic properties of the active material a-C:H are briefly introduced. Then, technical data both on the injection type and the intrinsic type EL devices are presented. The developed devices show a luminance of 30cd/m2 for the blue color emission, and 40cd/m2 for white light so far. Possibilities of performance improvements will be discussed comparing with our recent data on a-SiC LED.

Toshihiko Toyama

Papers

Correlation between Microstructure and Photovoltaic Performance of Polycrystalline Silicon Thin Film Solar Cells

Current–voltage characteristics and quantum efficiency spectra of efficient thin-film CdS/CdTe solar cells

Influence of substrate texture on microstructure and photovoltaic performances of thin film polycrystalline silicon solar cells

Blue light emission from a-C:H by thin film electroluminescence structure cell

Influence of CdS window layer on 2-μm thick CdS/CdTe thin film solar cells