Effect of Reduced Cu(InGa)(SeS)(2) Thickness Using Three-Step H2Se/Ar/H2S Reaction of Cu-In-Ga Metal Precursor

Cu(In,Ga)(Se,S)(2) (CIGSS) absorbers with thicknesses from 1.9 to 0.25 mu m have been grown using a three-step selenization/Ar-anneal/sulfization reaction of Cu-In-Ga metal precursors. Material characterization revealed changes in orientation, apparent grain size, and formation of voids at the Mo/CIGSS interface with reduced thickness. Even with absorber thickness decreased to 0.25 mu m and lateral compositional nonuniformity, V-OC and fill factor were nearly sustained, while J(SC) decreased due to incomplete absorption. With the 0.25-mu m-thick absorber layer, an efficiency of 9.1% (without AR coating) with V-OC = 612 mV, J(SC) = 21.0 mA/cm(2), and FF = 71.1% was obtained.