IMPACT OF GLASS SUBSTRATE TOPOGRAPHY ON EVA POLYCRYSTALLINE SILICON THIN-FILM SOLAR CELLS ON GLASS

摘要

Four types of glass substrate (planar and textured glass, both either bare or SiN-coated) are used for making polycrystalline silicon (poly-Si) thin-film solar cells. These photovoltaic devices are made by solid phase crystallization (SPC) of evaporated amorphous silicon (a-Si), and thus are named EVA solar cells (SPC of evaporated a-Si). The impact of the glass substrate topography on the optical, structural and electronic properties of EVA poly-Si thin-film solar cells is investigated. The optical measurements show that the textured samples absorb significantly better at long wavelengths than the planar samples. X-ray diffraction analysis reveals that the Si grains of all samples are preferentially (111) oriented. Unlike on planar glass, a SiN barrier layer significantly improves the crystalline quality of Si films grown on textured glass. A clear correlation between the glass substrate topography and the open-circuit voltage of EVA solar cells is observed.