Effects of annealing temperature on structure/morphology and photoluminescence properties of Mn-doped ZnS nanoparticles

Manganese doped ZnS nanoparticles were synthesized via a simple chemical reaction method at room temperature and annealed at four different temperatures. The nanostructures of the prepared Mn2+ doped ZnS nanoparticles have been analyzed using X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Fourier Transform Infra-Red Spectroscopy (FTIR) and Photoluminescence (PL) studies. The phase transformation from cubic to wurtzite structure has been studied and the size of the particles is found to increase from 14 nm to 31 nm with increasing annealing temperature whereas the strain values were found to decrease. From the room-temperature photoluminescence spectrum of as prepared samples, it is seen that Mn2+ doped ZnS emit in the yellow-orange region at 585 nm due to Mn2+4T1-(6)A(1) transition under excitation of a UV light at 345 nm. PLE intensity significantly increases with the increase of annealing temperature and shows a maximum when temperature is 600 degrees C. If temperature continued to increase, namely more than 600 degrees C, the PLE intensity would decrease. (C) 2013 Elsevier B.V. All rights reserved.