Synthesis of CdSe nanocrystals in a noncoordinating solvent: effect of reaction temperature on size and optical properties.

Colloidal synthesis of high quality CdSe nanocrystals with controllable size and tunable properties have been one of the most important topics of research over the last decade, in view of its huge technological potentials. CdSe is one of the most studied nanocrystals of this category because of its photoluminescence tunability across the visible spectrum. We have synthesized CdSe nanocrystals using CdO precursor in a noncoordinating solvent and studied the effect of the reaction temperature on the size and optical properties of the nanocrystals. The size of the nanocrystals could be varied systematically in the range of 3.5 to 6.6 nm diameter with a remarkably narrow size distribution by controlling only the reaction temperature, without any need for a post-synthesis processing. The band gap and the corresponding band edge emission could be tuned across the entire visible range by tuning the size of the nanocrystals. The narrow width of the photoluminescence emissions of different colours (blue to red) make these nanocrystals a potential candidate for different optical and optoelectronic devices.