INFLUENCES OF LOW TEMPERATURE POST-ANNEALING ON THE SULFURIZED Cu2ZnSnS4 THIN FILMS

In this work, after the sulfurization of Cu-Zn-Sn precursors, the sulfurized thin films were post annealed to further enhance the properties of Cu2ZnSnS4 thin films The post-annealing was performed at low temperature in a sulfur-free atmosphere to avoid the decomposition of Cu2ZnSnS4. The effect of annealing temperature was studied by XRD, Raman, SEM, and UV-vis spectrophotometer measurements. The experimental results demonstrate that the structural properties of Cu2ZnSnS4 thin films enhance after annealing at 250 and 300 degrees C as the grains of thin films enlarge with increasing annealing temperature. However, when the annealing temperature increases to 350 degrees C, the grain size and compactness of thin films reduce. Besides, the appearance of secondary phase of Cu2SnS3 indicates the decomposition of Cu2ZnSnS4. Therefore, post annealing at appropriate temperature is a useful way to improve the properties of Cu2ZnSnS4 thin films A low temperature of post annealing should be chosen to avoid the decomposition of Cu2ZnSnS4.