Flexible Cu(In,Ga)Se<sub>2</sub> photovoltaics for bending applications: advances from materials to panels

Abstract

Recent efforts to achieve effective and sustainable power generation in urban environments have increasingly focused on flexible thin-film photovoltaics, owing to their versatile applications in building-integrated and mobile devices. However, addressing this challenge requires a deeper understanding of bending-induced properties and the development of sustainable device structures. Decades of extensive research on chalcopyrite [Cu(In,Ga)Se2 (CIGS)]-based photovoltaics have led to substantial advances in the development of highly reliable and efficient solar energy generation systems. Furthermore, improvements in the well-controlled and scalable manufacturing processes of flexible CIGS solar cells have brought them closer to commercialization. This review discusses key strategies for substrate selection, artificial doping, and module fabrication, focusing on the progress achieved in the transition from laboratory research to practical commercial applications. Additionally, the review provides a detailed explanation of the evaluation methods for mechanical flexibility and durability, as well as an investigation into bending-induced phenomena. The review also examines future perspectives in the development of tandem solar cells incorporating flexible frameworks.