Materials design of CuIn1−Zn0.5Sn0.5Se2 for low cost photovoltaic solar cells

Abstract Computational material design of a strategy for resource security of chalcopyrite-based photovoltaic solar cells (PVSC) is investigated. The electronic structure of CuIn 1 − x Z n 0.5 x S n 0.5 x S e 2 (CIZTS) is calculated by using the self-interaction-corrected local density approximation (SIC-LDA) and the Korringa–Kohn–Rostoker coherent potential approximation (KKR-CPA). It is shown that for any degree of substitution for In, CIZTS has a direct band gap and no impurity state is induced in the band gap. We propose a possibility of substitutional co-doping of Zn and Sn for In in CuInSe2 photovoltaic material to reduce the cost of materials for PVSC production.