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. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)