Transfer of CuInS2 thin film by lift-off process and application to superstrate-type thin-film solar cells

Transfer of a CuInS2 thin film grown on a Mo/soda-lime glass substrate was investigated using a lift-off process. The CuInS2 thin film was flatly exfoliated, with preferential peeling occurring in the CuInS2/MoS2 interface vicinity. This suggests that the interfacial MoS2 layer behaves as a sacrificial layer. The lift-off process was also applied to solar cell fabrication. A superstrate-type CuInS2 thin-film solar cell was fabricated and exhibited no significant degradation of conversion efficiency compared with a substrate-type CuInS2 thin-film solar cell. The lift-off process could therefore also be applied to fabricate the upper part of a tandem solar cell structure. (C) 2012 Elsevier B.V. All rights reserved.