Inkjet-printed indium sulfide buffer layer for Cu(In,Ga)(S,Se)2 thin film solar cells

We report an environmentally friendly inkjet-printed indium sulfide (In2S3) buffer layer using benign chemistry and processing conditions. A pre-synthesized indium-thiourea compound is dissolved in a mixture of water ethanol, inkjet printed on Cu(In,Ga)(S,Se)2 absorber annealed air. The shows ?-In2S3 structure with few organic impurities band gap the range 2.3 eV. An ultraviolet ozone treatment applied to surface prior printing precursor used improve wettability ink therefore coverage layer. device fully covering In2S3 better open circuit voltage fill factor than partially best showed light electric power conversion efficiency similar reference cadmium device. Good conditions are essential for higher solar cells when inkjet-printed.