Low temperature synthesis, characterization and photoluminescence study of plate-like ZnS

• ZnS was prepared at low temperature using chemical precipitation method.
• UV–vis spectrum of ZnS shows absorption at 349 nm with a band gap of 3.55 eV.
• The blue emission of ZnS is due to surface defect states.
• The method is applicable for making a large amount of ZnS.

The plate-like ZnS microstucture has been prepared at low temperature in high yield via catalyst-free chemical precipitation method without using any surfactant, organic solvent or capping agent. The method is a highly reproducible route which could be applicable for preparation of other semiconductors. The as-synthesized ZnS belongs to cubic structure. The formation of plate-like microstructure, with the grain size of about 80–200 nm (from SEM), is possibly due to assembling of many crytallites (crystallite size of 2.7–3.4 nm, from XRD). FT-IR spectrum indicates stability of ZnS without oxidizing to ZnO during the preparation process. The blue emission in photoluminescence (PL) spectrum is quite broad over the range of 420–500 nm. This may originate from the radiative combination due to surface defect states in the ZnS microstructure.