Strong blue luminescence of O2−-doped ZnS nanoparticles synthesized by a low temperature solid state reaction method

O2−-doped ZnS(ZnS:O) nanoparticles with strong blue emission were successfully synthesized using a facile low temperature solid state reaction method. X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy were used to characterize their crystal structures, sizes, morphologies, and photoluminescence. The ZnS:O nanoparticles were quasi-spherical particles with a cubic zincblende crystal structure, and their average crystallite diameter was about 8.35–13.50 nm. Dependence of the photoluminescence properties of the ZnS:O nanoparticles on the Zn/O ratio in the source materials was studied, and an optimal O2− doping condition was found to be Zn/O=10:5.3. The ZnS:O (Zn/O=10:5.3) nanoparticles exhibited strong blue emission with an intensity 9 times higher than the undoped nanoparticles.