Al-Doped CuInSe2: An Ab Initio Study of Structural and Electronic Properties of a Photovoltaic Material

Abstract

Aluminum substitution in CuInSe2could have important implications for photovoltaic applications. To better understand the Al doping effects, we have performed density functional calculations on the CuInSe2chalcopyrite as well as on Al-doped derivative compounds with different concentrations using the generalized gradient approximation. The structural and electronic properties of the pure and Al-doped CuInSe2have been calculated. We find that the substitution of In by Al creates structural deformation, and the band gap of CuIn1-xAlxSe2broadens as Al content increases. These are further discussed with the analysis of lattice parameters, bond lengths and angles, and electronic structures changes.