Performance of Chromium Doped Zinc Selenide Nanocrystals: Morphological and Fluorescence Characteristics

Chromium doped ZnSe nanocrystals were grown at low temperature using zinc acetate and sodium selenite. A capping agent was used to avoid agglomeration of particles. It was observed that the addition of the capping agent before or after chemical synthesis of ZnSe played a very important role in controlling the size of nanoparticles and to avoid agglomeration. Size of nanoparticles of ZnSe was as small as 10 nm for both doped and undoped material. In a few cases, in spite of preventative measures, clustering of particles produced large agglomerates at room temperature. Cr-ZnSe nano particles showed fluorescence at different wavelengths compared to Cr-doped bulk crystals. Cr-doped nanocrystals showed higher bandgap than PVT grown bulk Cr-ZnSe crystals. The fluorescence intensity for Cr-ZnSe nanoparticles was significantly higher compared to undoped ZnSe nanoparticles.