Improved performance of Cu(In,Ga)Se2-based submodules with a stacked structure of ZnO window prepared by sputtering

In this study, performance improvement of CIGS-based submodules using a sputtered ZnO:5.7 wt% Ga2O3 (5.7GZO) as window layers is reported. Preheating treatment at 200°C for 15 min is applied to the parts before the deposition of GZO window layers. This contributes to increase the optical transparency (%T) of GZO window considering the %T of about +5% and to improve the Jsc of about +4 mA/cm2. Deposition of a high-resistivity, intrinsic ZnO (i-ZnO) thin layer on the Zn(O,S,OH)x buffer layer before 5.7GZO window deposition contributes to improve the properties of pn hetero-junction quality and increase the optical transparency, Voc and FF.