Progress in Thin Film CIGS Photovoltaics – R&D, Manufacturing and Applications Authors: Thomas Feurer 1 , Patrick Reinhard 2 , Enrico Avancini 1 , Benjamin Bissig 1 , Johannes Löckinger 1 , Peter Fuchs 1 , Romain Carron 1 , Thomas Paul Weiss 1 , Julian Perrenoud 2 , Stephan Stutterheim 2 , Stephan Buecheler 1 , Ayodhya N. Tiwari 1 1 Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Swit- zerland 2 Flisom AG, Überlandstrasse 129, 8600 Dübendorf, Switzerland Abstract This review summarizes the current status of Cu(In,Ga)(S,Se) 2 (CIGS) thin film solar cell technology with a focus on recent advancements and emerging concepts intend- ed for higher efficiency and novel applications. The recent developments and trends of research in labs and industrial achievements communicated within the last years are reviewed and the major developments linked to alkali post deposition treatment and composition grading in CIGS, surface passivation, buffer and transparent contact layers are emphasized. Encouraging results have been achieved for CIGS based tandem solar cells and for improvement in low light device performance. Challenges of technology transfer of lab’s record high efficiency cells to average industrial pro- duction are obvious from the reported efficiency values. One section is dedicated to development and opportunities offered by flexible and lightweight CIGS modules. Introduction Cu(In,Ga)(S,Se) 2 (CIGS)-based thin film solar cells represent one of the most promis- ing photovoltaic technology, with steadily increasing champion cell efficiencies up to 22.6%[1] reported for laboratory scale absorbers. Efficiencies above 20% have been achieved on rigid and flexible substrates by different research institutes as well as in- dustrial companies (see overview in Table 1+2). Key advantages of CIGS compared to other conventional photovoltaic technologies include the high energy yield (kWh/KWp installed), low temperature coefficient of power loss, low sensitivity to shadowing and short energy payback time [2–4]. Cost-projections down to 0.35 Eu- ro/Wp have been announced for the current technology, with potential for further re- duction upon scale-up, allowing a significant reduction of the total system cost [5]. The possibility to grow thin films of large area absorber onto a glass as well as light- weight, flexible substrates opens up the field for low-cost manufacturing methods as This document is the accepted manuscript version of the following article: Feurer, T., Reinhard, P., Avancini, E., Bissig, B., Löckinger, J., Fuchs, P., … Tiwari, A. N. (2017). Progress in thin film CIGS photovoltaics – research and development, manufacturing, and applications. Progress in Photovoltaics, 25(7), 645-667. http://doi.org/10.1002/pip.2811