Effect of copper salt and thiourea concentrations on the formation of Cu₂ZnSnS₄ thin films by spray pyrolysis

Abstract

Abstract Thin films of Cu 2 ZnSnS 4 (CZTS), a potential candidate for absorber layer in thin film heterojunction solar cell, have been deposited by spray pyrolysis technique onto soda‐lime glass substrates held at a substrate temperature ( T s ) of 643 K. The effect of copper salt and thiourea concentrations on the formation of Cu 2 ZnSnS 4 thin films is investigated. CZTS films formed under optimized conditions are found to be polycrystalline in nature with kesterite structure. The lattice parameters are found to be a = 0.543 nm and c = 1.086 nm. The optical band gap of these films is found to be 1.43 eV. It is found to increase with decrease in copper salt concentration in the solution.