Solution growth of chalcopyrite Cu(In1−xGax)Se2 single crystals for high open-circuit voltage photovoltaic device

Abstract

I–III–VI2 Chalcopyrite Cu(In1−x Gax)Se2 (CIGS) has attracted attention as absorbing layer in photovoltaic (PV) device. In this study, we investigated the fundamental properties of CIGS single crystals, and fabricated single crystal-based PV device. CIGS single crystals without secondary phase were successfully grown by In-solvent traveling heater method (THM). The conversion of conduction type from n- to p-type can be observed above 0.3 of Ga ratio x because of high acceptor defect concentration. PV device based on high-quality CIGS bulk single crystal demonstrates high open-circuit voltage of 0.765 V with the efficiency of 12.6%.

Keywords

• cu(in1−x gax)se2
• photovoltaic
• open-circuit voltage
• single crystal
• solution growth