Light trapping and reflection control for silicon thin films deposited on glass substrates textured by embossing

A glass substrate texture of pyramids formed by embossing, suitable for polycrystalline silicon solar cells 5-20 /spl mu/m thick, is described. A monocrystalline silicon wafer textured with inverted pyramids was used as a die. We evaluate antireflection and light trapping properties for an undoped a-Si:H silicon film (volumetric thickness 5.6 /spl mu/m; no reflector) simultaneously deposited on this texture and sandblasted glass, using total reflectance and transmittance measurements. J/sub sc/ enhancement potential from light trapping in equally thick polycrystalline silicon films on the same substrates is estimated to be 6.7 (sandblasted), 8.7 (embossed) mA/cm/sup 2/. Light trapping characteristics obtained by spectral photoconductance measurements of the specimens are compared.