Advanced light trapping interface for a-Si:H thin film

Surface texturing of transparent conducting oxides and plasmonic interfaces are two important techniques used separately in thin film solar cells to reduce reflection and enhance light-trapping. In this study, we merge the effects of Al:ZnO surface texturing and Ag nanoparticles (AgNPs) plasmonics in a single light-trapping interface to investigate their combined light trapping efficiency on a-Si:H thin film. Light scattered by this interface is optimized by placing a thin SiO2 spacer layer between AgNPs and a-Si: H absorber layer. Our results indicate that the AgNPs embedded in SiO2 significantly enhance absorption at energies close to the band gap of a-Si: H. Surface texturing by wet etching of Al: ZnO combined with AgNP produces the highest optical extinction of a-Si:H thin film at the band edge. Furthermore, the measured photocurrent in a-Si:H shows a clear increase not only at AgNPs resonance wavelength but over the entire wavelength range. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim