Site selective doping of Zn for the p ‐type Cu(In,Ga)Se 2 thin film for solar cell application

Abstract

Selective doping of a Zn impurity at the group III site in a Cu(In, Ga)Se2 (CIGS) film was performed by the doping of Zn at the first stage of the three-stage method. The p-type CIGS:Zn film was obtained, which is in contrast to the n-type CIGS:Zn film obtained by the Zn impurity doping at the second and third-stages. Based on excitation intensity dependence of photoluminescence (PL) at low-temperature, the change in the acceptor level was observed. The enhancement of carrier concentration as a result of Zn-doping in the p-type CIGS:Zn film was observed. The CIGS:Zn solar cells exhibited η of 14.5% and Voc of 0.658 V, which are higher than that of the corresponding solar cells using the undoped CIGS films