Face-to-Face Annealing Process of Cu₂ZnSnS₄ Thin Films Deposited by Spray Pyrolysis Method

Abstract

Cu 2 ZnSnS 4 thin films were deposited by the spray pyrolysis method. Copper(II) acetate monohydrate, zinc(II) acetate dihydrate, tin(II) chloride dihydrate, sodium trihydrate, and pure sulfur powder were used as the starting materials of spray pyrolysis solutions, and N , N -dimethylformamide and monoethanolamine were used as the solvent and the stabilizer, respectively. The solution was coated on a Mo-coated soda lime glass substrate and after coating solutions, the films were annealed in a N 2 gas atmosphere at 360, 440, and 520 °C with or without placing two films face-to-face. It was found that the face-to-face annealing process prevented losses of S and Sn during the annealing process and the samples annealed with another precursor placed face-to-face at 440 and 520 °C showed narrow and large X-ray diffraction peaks and large grains in the surface images.