Earth-abundant non-toxic Cu2ZnSnS4 thin films by direct liquid coating from metal–thiourea precursor solution

A simple process for deposition of pure CZTS films from a methanolic solution of metal–thiourea complex is described. The precursor films are thermolysed at 200 °C in air for 10 min. Formation of kesterite CZTS is confirmed by X-ray diffraction (XRD). The films have grains of 100–200 nm and rms roughness of 1–2 nm. The energy band gap of CZTS films is 1.4 eV and is p-type in nature with electrical conductivity of 0.5 S/cm and thermo electric power coefficient of 86 μV/K. The films are photoconducting.