Luminescence properties of Br-doped ZnS nanoparticles synthesized by a low temperature solid-state reaction method

Br-doped ZnS nanoparticles were synthesized using a low temperature solid-state reaction method. Influence of Br doping concentration on the crystal structures, crystallite sizes, and luminescence properties of the Br-doped ZnS nanoparticles was investigated. The Br-doped ZnS nanoparticles had a cubic zincblende crystal structure, and had an average crystallite size of about 8.0–9.5 nm. Both the lattice constant and average crystallite size of the Br-doped ZnS nanoparticles decreased with Br doping concentration. It was found that the luminescence intensity of the Br-doped ZnS nanoparticles remarkably increased with Br doping concentration. The emission intensity of the 5% Br-doped ZnS nanoparticles was about 13 times stronger than the undoped ZnS nanoparticles. Mechanism for the enhanced luminescence of the Br-doped ZnS nanoparticles was discussed. This work suggests that the low temperature solid-state reaction method can be used to synthesize Br-doped ZnS nanoparticles with strong luminescence properties.