Flexible amorphous silicon solar cells on surface-textured glass-fabric reinforced composite films

Flexible and lightweight amorphous silicon (a-Si:H) based thin-film solar cells on surface-textured glass-fabric reinforced inorganic-organic hybrid materials (hybrimer) composite films are developed in a superstrate configuration. The flexible and transparent film for the substrate was fabricated by impregnation and lamination of a woven glass-fabric with an epoxy-oligosiloxane based hybrimer on glass used as a temporary substrate. The epoxy hybrimer film showed high optical transparency of more than ~90% for wavelengths above 500nm and light scattering property. In order to improve light trapping, the surface texture of the film was replicated from a master texture of Asahi U-type glass by nanoimprint lithography. The fabricated cell was a single junction structure of ZnO:Al/p-μc-Si:H/p-a-SiC:H/i-a-Si:H/n-μc-Si:H/Al on the flexible film, and the thickness of i layer is ~300 nm. The flexible a-Si:H solar cell on surface-textured expoxy hybrimer film showed an conversion efficiency of 6.4%.