Current status of transparent conducting oxide layers with high electron mobility and their application in Cu(In,Ga)Se2 mini-modules

Abstract Transparent conducting oxide (TCO) films with high mobility and low carrier density exhibit both high conductivity and high transparency in the visible and near-infrared regions. TCO films that can be fabricated at low process temperatures provide opportunities to improve the performance of solar cells and to develop new optoelectronic applications. This paper describes the current status of ZnO- and In 2 O 3 -based TCO layers and their application in Cu(In,Ga)Se 2 mini-modules. The use of solid-phase crystallized In 2 O 3 :W,H layers instead of conventional ZnO:Al or ZnO:B layers increases both short-circuit current density and fill factor, and a high certified conversion efficiency of 20.93% has been achieved via this approach.