Fabrication of Cu(In,Ga)(S,Se)2 thin film solar cells via spray pyrolysis of thiourea and 1-methylthiourea-based aqueous precursor solution

Abstract

A detailed process of fabricating Cu(In,Ga)(S,Se)2 via the spray pyrolysis of a thiourea-based precursor solution followed by selenization is reported. The optimization of the selenization condition for the fabrication of the Cu(In,Ga)(S,Se)2 film led to a conversion efficiency of 7.8% for the Cu(In,Ga)(S,Se)2-based device. We also showed that 1-methylthiourea was a more suitable sulfur source for the spray pyrolysis technique, resulting in a conversion efficiency of 8.7% (VOC = 0.52 V, JSC = 31 mA cm−2, and FF = 0.54) without any antireflection coating.