Realizing double graded CIGSe absorbers with the R2R Hybrid-CIGSe-process

We present an approach for industrial roll-to-roll (R2R) deposition of Cu(In,Ga)Se ₂ (CIGSe) thin films on stainless steel foil for use as absorber layers in thin film solar cells. The Hybrid-CIGSe-deposition process combines magnetron sputtering with evaporation techniques and allows the realization of a double graded CIGSe layer, reaching a conversion efficiency of currently up to 14.3 % (w/o antireflective coating). The influence of different power settings of the individual magnetrons on the gallium profile is described. For a deeper understanding of differences between a static and a R2R process, a calculated flux diagram is presented.