Study of CZTS Nano-powder Synthesis by Hot Injection Method by Variation of Cu and Zn Concentrations

Copper Zinc Tin Sulphide (CZTS) nano-powders were synthesized by solution based method in oleylamine at 215oC, 225oC and 235oC using copper pentane2, 4-dionate, zinc acetate, tin (II) chloride and elemental sulphur as precursors. The influence of initial Cu/ (Zn + Sn) concentration ratio (from 0.82 to 0.33) on the morphology, phase composition and elemental composition of nano-powders was studied. It was found that the average size of colloidal nano-particles of CZTS nano-powders increased from 20 nm to 10 μm with decreasing initial Cu/ (Zn + Sn) concentration ratio at every used synthesis temperature. The elemental composition of the formed nano-powders was compatible to near-stoichiometric CZTS if initial Cu/ (Zn + Sn) concentration ratios were 0.82 and 0.74. Higher initial zinc concentration i.e. higher chemical potential at specific temperature reduces the final tin concentration component in the colloidal nano-powders.