Analysis of the Influence of Annealing on Crystallite Sizes in Na-Doped Cu₂ZnSnS₄ Using X-Ray Diffraction

Abstract

This paper investigates the impact of thermally annealed and Na incorporated Cu2ZnSnS4 (CZTS) material. Particle size is an important determinant of material properties. It can be increased by thermal treatment and or by the addition of additives that promote grain size expansion in poly-crystalline materials. Sodium-induced CZTS films produced by thermal evaporation were investigated in this work. Thin samples were produced by evaporation on glass heated to 150°C then annealed at 400°C under two different atmospheres: (1) a vacuum heating atmosphere (Tvacuum) and (2) a sulfur heating atmosphere (Tsulfur). X-ray diffraction (XRD) was employed to determine structural properties like crystallite size and lattice strain using Debye-Scherrer (D-S), Williamson-Hall (W-H), Size-Strain Plot (SSP), Halder-Wagner (H-W)and strain distribution (S-D) models. Acceptable results were obtained with all of these models. The XRD intensities of two different atmospheres were then utilized to determine the degree of crystallinity and the texture coefficient In accordance with the results obtained, the largest particle size, high degree of crystallinity and texture coefficient were found in samples annealed in a vacuum atmosphere and with sodium doping, in particular with 1% doping.