Temperature Effects on Cu2ZnSnS4 (CZTS) Films Deposited by Spraying Method

Abstract

CZTS containing ink was prepared by a sonochemical method, and properties of CZTS thin films deposited by a spraying method were investigated. We used CuCl2, ZnCl, SnCl2 and thiourea as precursor materials, 2-methoxyethanol as a solvent, and monoethanolamine as a stabilizer. X-ray diffraction (XRD) patterns from the CZTS films mainly exhibited the (112), (200), (220), and (312) planes of a kesterite structure, and a phase transition was not observed in the range of annealing temperatures (maximum 500°C) investigated in this study. Full width at half maximum (FWHM) values of all the XRD peaks stay nearly constant up to the annealing temperature of 300°C, and suddenly decreases from 300°C to 450°C, and finally saturates above ∼450°C. The optical bandgap of CZTS films was ∼1.25 eV, and the atomic elemental ratio of Cu:Zn:Sn:S in CZTS films was approximately 2:1:0.9:3.5. These results demonstrate that the CZTS containing ink developed in this study has promising potential for the formation of high quality CZTS thin films for solar cell applications.