Optical properties of transition metal doped ZnS nanoparticles in PVK based nanocomposite films

Abstract

In the present work, the optical properties of transition metal (Mn, Fe, Cu and Ag) doped ZnS nanoparticles in PVK polymer composites have been studied. The pure and transition metal (TM) doped ZnS nanoparticles were prepared by co-precipitation method and PVK/ZnS(TM) nanocomposites were synthesized by spin coating technique. The nanocomposites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), optical absorption, energy and time-resolved photoluminescence spectroscopic techniques. The XRD patterns suggest the formation of the cubic phase of ZnS nanoparticles while FTIR spectroscopy reveals the incorporation of transition metal dopants in ZnS nanoparticles. The wide variation in surface morphology for differently doped nanoparticles in PVK based composites has been observed from FESEM technique. The optical gap has been found to increase with nanoparticle incorporation while the increased luminescence quenching is observed for PVK/ZnS:Mn nanocomposites. The time-resolved photoluminescence reveals a change in the lifetime of charge carriers for these composites. These results are important for designing new organic/inorganic nanocomposites for emerging technologies.