Effect of solvents on physical properties of direct-coated Cu₂CoSnS₄ films

Abstract

Direct deposition of Cu2CoSnS4 (CCoTS) films from molecular inks synthesized with three different solvents such as methanol (ME), isopropyl alcohol (IPA) and a mixture of methanol and isopropyl alcohol (ME + IPA) have been reported. The films were first dried at 150 °C followed by heated at 200 °C in air for 30 min to obtain the pure phase. It has been found that the films with ME resulted in continuous surface with smooth morphology while IPA and ME + IPA coated films show grains with microporosity. The films were pure stannite and show photoconductivity. The optical band gap of CCoTS-ME films was found vary with film thickness. In general, structural and microstructural properties of the films were affected by the type of solvents.