Deposition of kesterite Cu₂ZnSnS₄ (CZTS) thin films by spin coating technique for solar cell application

The thin films of Cu₂ZnSnS₄ (CZTS) have been successfully deposited on soda lime glass by spin coating technique. CZTS films were prepared by spin coating of a solution prepared by dissolving of copper (II) chloride, zinc (II) chloride, tin (IV) chloride and Thiourea in 2-Methoxyethanol. The X-ray diffraction studies showed the formation of kesterite phase with the peaks corresponding to (112), (220) and (312) planes. Raman spectrum indicated the presence of principal kesterite peak at 333 cm ^-1. SEM study showed that the surface of CZTS film was uniform. The electrical measurements showed the p-type conductivity, resistivity ~0 -cm with carrier concentration ∼7.9×10¹⁹ cm^-3and mobility ∼5.43 cm² V^-1s^-1 at room temperature. CZTS film showed optical absorbance of 10⁴ cm^-1 with optical band gap of 1.5 eV. Thus, CZTS films can be made using a simple spin coating technique, but improvement in the film properties by post deposition needs to be done for making photovoltaic quality films.