Thin film PV module

This paper proposes a model of PV module based on thin-film polycrystalline Si with porous silicon insertions. The application of porous silicon allows one to fabricate the PV module without assembling the separate silicon cells. The porous silicon is applied as a buffer layer between the supported substrate and deposited polycrystalline Si as vertical insulating bars between separate cells and as antireflection coating on the top of the cells. The contribution of antireflection effect of the top porous layer, light scattering, photoluminescence and absorption in porous insertions to the solar cell parameters are numerically assessed with the help of PC1D program. It is shown that the light trapping in the top porous layer, light scattering effects in the porous insulating bars and in porous buffer layer result in the increase of the individual cell output characteristics, whereas the effect of re-emission is negligible. Efficient solar cells and PV modules can be fabricated even for 5-10 mu m silicon layers. One of the main factors restricting the efficiency of the cells with porous silicon is the optical absorption loss. (C) 2000 Elsevier Science S.A. All rights reserved.