CIGS Thin Film Photovoltaic—Approaches and Challenges

Abstract

After a short overview of the historical development of the Cu(In, Ga)Se2 (CIGS) thin film solar cell and its special features, we give an overview of the deposition and optimization of the p-type CIGS absorber as well as the subsequent n-type buffer layer and the molybdenum back contact. Developments to increase efficiency by optimizing the implemented bandgap grading via the local gallium content as well as the specific doping of the CIGS absorber by means of various alkali elements deepen the understanding. Finally, modern approaches to monolithic cell interconnection are discussed, e.g. via the use of modern ultra-short pulse lasers. Numerous literature references enable the reader to gain an even deeper insight if required.