Growth and characterization of ZnS films by spray pyrolysis

ZnS films are formed by spray method using various zinc sources such as zinc acetate (Zn(CH3COO)(2)), zinc sulfate (ZnSO4), zinc nitrate (Zn(NO3)(2)), zinc iodide (ZnI2), zinc chloride (ZnCl2), zinc acetyl (Zn(acac)(2)). ZnS film using zinc iodide is sharp spectrum and zinc sulfate is broad spectrum by X-ray diffraction (XRD). The XRD spectra indicates that ZnS using zinc chloride and zinc iodide at 100 degrees C the source of zinc to zinc acetate and zinc nitrate at 200 degrees C, zinc acetyl at 300 degrees C, zinc sulfate at 400 degrees C can be confirmed. These results are consistent with the difference in the instability constants of each zinc source. The ionization of Zn becomes difficult with increasing the instability constant of zinc sources. Reaction is slow due to low ionized zinc in solution. Therefore, it is considered that ZnS films are hard to crystallize at low substrate temperature. The grain size becomes large with decreasing the instability constant. It is considered that this is proportional to the amount of zinc ions in solution.