Dual metallic-based plasmonic back reflector to broaden the absorption spectra of a thin film amorphous silicon solar cell

Here, to obtain high efficiency in a thin film amorphous silicon solar cell, a dual metallic plasmonic back reflector was investigated. The designed dual metal plasmonic back reflector can improve the photocurrent and hence the efficiency. At first, a double layer SiO2/Si3N4 as the antireflection (AR) was analyzed. The efficiencies of 8.74%, 11.38%, 12.53%, and 13.04% are obtained for a cell without AR, with SiO2, Si3N4, and SiO2/SiN4 AR layers, respectively. A disk-ring and dual rings-based Ni and Ti-based plasmonic back reflector were designed. The study was carried out by a 3D finite difference time domain method and the optimized parameters were calculated to obtain higher efficiencies. Finally, a relatively higher photocurrent and conversion efficiency of 19.86mA/cm2 and 15.65% were achieved for the optimized structure with a dual Ni rings back reflector, respectively. Because of the importance of amorphous silicon solar cells due to the cost problem of crystalline silicon, here, the simulation steps present a valuable road map to design a novel plasmonic thin-film amorphous silicon solar cell.