Effect of various surfactants on optical and electrical properties of Cu⁺²-doped ZnS semiconductor nanoparticles

In this work, Cu⁺²-doped ZnS semiconductor nanoparticles have been synthesized using co-precipitation route caped with various surfactants such as diethyl-amine (DEA), poly-vinyl alcohol (PVA), cetyl trimethylammonium bromide (CTAB), polyethylene glycol (PEG) and triethyl-amine (TEA). The structural analysis has been carried out by X-ray diffractometer (XRD) and Fourier-transform infrared spectroscopy (FTIR). Morphological and elemental analysis have been performed by scanning electron microscopy (SEM) and X-ray-dispersive X-ray spectroscopy (EDX), respectively. XRD and FTIR have revealed the cubic structure of prepared nanoparticles. The crystallite size has been calculated in the range 15–20 nm through XRD. A hexagonal peak of ZnO is also observed in XRD pattern. The optical and electrical properties have been studied through UV–Vis spectroscopy and Four-point probe technique, respectively. EDX has revealed the presence of S, Cu and Zn as major elements in prepared samples. Optical band gap energy has been estimated in the range 3.6–4.2 eV with absorption edge from 270 to 277 nm. The conductivity of prepared samples has been increased with the decrease in band gap.