Size-controlled synthesis of ZnO nanoparticles and their photoluminescence properties

Nanocrystalline ZnO powders have been synthesized by means of a novel gel-network precipitation method using gelatin as a template at lower temperature condition. The products were characterized by using TG-DTA, XRD and TEM techniques. The products appeared to be regularly spherical or elliptical and their sizes range from 20 to 40 nm. The average particle size increased with increasing calcining temperature, and decreased with increasing gelatin concentration. Furthermore, the photoluminescence (PL) spectra of the ZnO nanopowders were also investigated. The relative luminescent intensities for the ultraviolet band and green emission band showed a dependence on preparation conditions. The probable mechanism was discussed.