‘Ink-based’ CIGS solar cells on lightweight Titanium foil

Fabrication of Copper Indium Gallium Selenide (CIGS) solar cells on Ti foil using ISET´s ink-based process is challenging, because a high temperature annealing step in hydrogen ambient causes embrittlement of the Ti substrate. To ameliorate this situation, ISET has developed a proprietary process that encapsulates the Ti foil with a thin protective layer which enables the Ti foil to survive the ink-based cell fabrication process, without compromising its flexibility. Using this approach, ISET has achieved a champion cell efficiency of 11.7% (AM1.5). In addition, the insulating nature of this protective layer has enabled us to fabricate monolithically integrated modules on titanium substrate and potentially reduce the overall cost of manufacturing CIGS modules on flexible metal foil substrates.