Pre-annealing of precursors of Cu2ZnSnS4 thin films prepared by sol-gel sulfurizing method

Cu2ZnSnS4 (CZTS) thin films were prepared by sulfurizing pre-annealed oxyhydrate precursors deposited by the sol-gel method. The precursors were obtained by coating solutions containing copper(II) acetate monohydrate, zinc(II) acetate dihydrate, tin(II) chloride dihydrate, 2-methoxyethanol, and monoethanolamine on a soda lime glass (SLG). By pre-annealing the precursors in air at 560 degrees C, chemical composition of films was almost stoichiometric, transmittance of IR region was increased and number of void was decreased while chemical composition of CZTS films deviated considerably from stoichiometry when the precursors were annealed N-2 + H-2 (5%) atmosphere at 460 and 560 degrees C.