Luminescence enhancement of zincblende ZnS:Cl− nanoparticles synthesized by a low temperature solid state reaction method

Cl−-doped ZnS (ZnS:Cl−) nanoparticles with strong blue emission were synthesized using a facile low temperature solid state reaction method. X-ray powder diffraction, scanning electron microscopy, UV–vis absorption, and X-ray photoelectron spectroscopy were used to characterize their crystal structures, microstructural characteristics, and chemical compositions, respectively. The ZnS:Cl− nanoparticles were quasi-spherical in shape and had a cubic zincblende crystal structure. Cl− doping was found to lead to a reduction in the crystallite size of the ZnS:Cl− nanoparticles. It showed that Cl− doping remarkably enhanced the luminescence properties of the ZnS:Cl− nanoparticles, and an optimal Cl− doping condition was determined. Post annealing was found to further improve the luminescence properties of the ZnS:Cl− nanoparticles. The effect of post annealing temperature on the luminescence properties of the ZnS:Cl− nanoparticles was systematically studied and discussed.