Wachau, A.; Schulte, J.; Agoston, P.; Hübler, F.; Steigert, A.; Klenk, R.; Hergert, F.; Eschrich, H.; Probst, V.: Sputtered Zn(O,S) buffer layers for CIGS solar modules - from lab to pilot production. Progress in Photovoltaics 25 (2017), p. 696-705
10.1002/pip.2880

Abstract:
Sputtering of Zn(O,S) from ZnO/ZnS compound targets has been proven to be a promising buffer layer process for Cd-free CIGS modules due to easy in-line integration, low cost and high efficiency on lab scale. In this publication, we report on successful upscaling of the lab process to pilot production. A record aperture efficiency of 13.2% has been reached on a 50 × 120 cm2 sized module. Neither a non-doped ZnO layer nor additional annealing steps are required. Moreover, this very reproducible process yields a standard deviation comparable with that of the CdS base line. In contrast to lab exper- iments, strong performance gain after light soaking has been observed. The light-soak-induced power increase depends on the preparation of the window layer. Accelerated aging tests show high stability of module power. This is confirmed by outdoor testing for 20 months. Copyright © 2017 John Wiley & Sons, Ltd.