RbF post deposition treatment for narrow bandgap Cu(In, Ga)Se-2 solar cells

Multi-junction solar cells are known to have a considerably increased efficiency potential over their typical single junction counterparts. In order to produce low cost and lightweight multi-junction devices, the availability of suitable narrow (< 1.1 eV) bandgap bottom cells is paramount. A possible absorber for such a bottom cell is the Cu(In, Ga)Se-2 (CIGS) compound semiconductor, one of the most efficient thin film materials to date.