Crystalline silicon films by chemical vapor deposition on glass for thin film solar cells

Covering glass substrates with polycrystalline Si films having an electronic quality suitable for thin-film solar cells still presents a great challenge. In a two-step process, the authors first coat a novel high-temperature resistant glass substrate with a thin film of amorphous Si, which is then solid phase crystallized. In the second step, atmospheric pressure chemical vapor deposition serves to deposit a several micron thick light absorbing film. They obtain an area weighted average grain size of 2.5 μm in their films. Hall mobilities in their p-type Si films are 68 cm^{/Vs, the minority carrier diffusion length is 2 μm. They introduce a new pyramidal film texture and numerically calculate an efficiency potential of 12 to 15% depending on surface recombination velocity for thin film solar cells using a-Si films on glass}