Comparative Study on the Effect of Precursors on the Morphology and Optical Properties of CuInS2 Nanoparticles

We present the effect of different combination of precursors in the synthesis of CuInS2 nano-powder via solvothermal route. We have fixed the synthesis temperature at 200 ℃ and we investigate the effect of the copper sulfate (CuSO4 5H2O) and Copper dichloride (CuCl2) as Cu-precursor, Thiourea (NH2CSNH2) and Thioacetamide (C2H5NS) as sulfur precursor. XRD measurements illustrate the good crystallinity of our powders in the chalcopyrite structure. This later disappears by combining copper sulfate and Thioacetamide in the synthesis protocol. The grain size was found to be between 20–36 ± 5 nm with a net variation of the morphology from an agglomeration situation to nano-rods by using thioacetamide as S-precursor. The optical study illustrates that all powders present the optimal value to photovoltaic application, of about 1.5 eV.