Single-step growth of colloidal ternary ZnCdSe nanocrystals

Colloidal ternary ZnCdSe nanocrystals were synthesized via a single-step process by reacting Cd and Zn oleates in trioctylphosphine oxide (TOPO) solution with Se-TOP (trioctylphosphine) solution. Initial red shift of bandgap absorption during the early reaction stage was observed due to the growth of Cd-rich ZnCdSe nanocrystals. Significant blue shifts of photoluminescent emission peaks indicated the formation of ternary nanocrystals during reaction, and emission wavelength was dependent on reaction time and temperature. Initial red shift and subsequent blue shift of bandgap absorption in ZnCdSe nanocrystals are explained in terms of nucleation and growth processes controlled by reactivity and diffusion of precursors.