Light management in large area thin-film silicon solar modules (original) (raw)
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E3S Web of Conferences, 2018
A study on the formation of black silicon (b-Si) antireflection layers on crystalline Si wafers using SF6/O2gas mixture in a reactive ion etching method is presented. The process is low-temperature, fast and does not depend on the crystallographic orientation of the Si wafer. The b-Si layers have demonstrated average reflectance values of 4% and 5% for monoand polycrystalline Si wafers respectively, feature that is suitable for the fabrication of high efficiency solar cells. Passivation of b-Si antireflection layers by suitable different thin films can significantly reduce needle-like surface recombination losses.
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2020 47th IEEE Photovoltaic Specialists Conference (PVSC), 2020
The front surface reflection losses from solar cover glass account for over 4% of incident light, limiting module efficiency. The application of a multilayer broadband antireflection coating reduces reflection losses over the wavelength range utilised by silicon solar cells. A 6-layer anti-reflection coating comprising SiO2 and ZrO2 has been deposited on glass using high rate pulsed-DC magnetron sputtering. The reflection losses are reduced by 2.4% absolute compared to uncoated glass. The increased light reaching the solar cell leads to improvements in Isc and spectral response, increasing the efficiency from 17.1 to 17.5%, a relative increase of 2.34%. The coating is environmentally robust. The sputtering process is already used for other high throughput applications by major glass manufacturers.
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Energy conversion efficiency is a critical consideration in the application of silicon solar cells. Texturing of both the front side and the backside of silicon solar cells has been used in the past to increase the absorption of infrared sun light energy in silicon solar cells. A review is given of some of the basic concepts and then a design described for the optimal textured structure that can result in improvements in conversion efficiency of up to 20% on crystalline silicon solar cells and up to 40% on thin film silicon solar cells. Some of the practical limitations are described in realizing these structures in silicon technology.
Light Trapping and Process Scale-up for Thin-film Silicon Solar Cells
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Light trapping and photon management of silicon thin film solar cells can be improved by a separate optimization of the front and back contact textures. A separate optimization of the front and back contact textures is investigated by optical simulations taking realistic device geometries into consideration. The optical simulations are confirmed by experimentally realized 1 μm thick microcrystalline silicon solar cells. The different front and back contact textures lead to an enhancement of the short circuit current by 1.2 mA/cm(2) resulting in a total short circuit current of 23.65 mA/cm(2) and an energy conversion efficiency of 8.35%.