Plasmonic multilayer nanoparticles enhanced photocurrent in thin film hydrogenated amorphous silicon solar cells

Abstract

A plasmonic-structure incorporated double layer of Au nanoparticles embedded in the transparent conducting oxide at the back-reflector of the hydrogenated amorphous silicon (a-Si:H) solar cells is demonstrated. These devices exhibit an increase of energy conversion efficiency of 18.4% and short-circuit current density of 9.8% while improving fill-factor and without sacrificing open-circuit voltage. The increase in photocurrent is correlated with the enhanced optical absorption in the cell, with improved optical-path-length by a factor of 7 at the wavelength of 800 nm, due to enhanced diffuse scattering of light through resonant plasmon excitations within Au nanoparticles. In addition to enhanced scattering, applying high-work-function Au nanoparticles can improve the work function match at TCO/a-Si:H interface.