Up-scaling ILGAR In2S3 buffer layers production for chalcopyrite solar modules

Indium sulfide buffer layers produced by the spray ion-layer-gas-reaction (ILGAR) have already been shown to be a suitable replacement for the standard CdS layer in chalcopyrite based thin film solar cells. However, to date, all of the results have been shown on small area solar cells. Here we demonstrate both the up-scaling of the spray ILGAR process for the first time and show results for mini-modules based on Cu(In,Ga)(Se,S)₂ (CIGSSe) absorbers from the AVANCIS pilot line. The mini-module efficiencies reach 12.4% and damp heat stability is comparable to CdS buffered references. Analysis of the modules by thermography shows a strong correlation between homogeneity and module performance. This preliminary up-scaled 10 × 10 cm deposition chamber paved the way for further large scale development. This includes a tape coater, built in-house, a 30 × 30 cm machine under construction with STANGL semiconductor equipment AG and a roll-to-roll ILGAR machine, which is currently part of the pilot production line operating at CIS-Solartechnik in Hamburg.