Intermediate band position modulated by Zn addition in Ti doped CuGaS2

Abstract

Many works have been done recently with the aim of obtaining intermediate band semiconductors, due to the significant importance of improving solar cell efficiency. Intermediate band materials based on CuGaS2 chalcopyrite semiconductor are one of the proposed materials and specifically Ti doped CuGaS2 is a promising structure to form the intermediate band. Here we present an ab-initio study using the density functional theory in this type of intermediate band chalcogens. Several concentrations of Ti and Zn substituting Ga atoms have been studied and their electronic densities of states were obtained. Results demonstrate a chalcopyrite semiconductor band-gap shortening and intermediate band position modulation inside this band-gap by Zn addition.