Highly luminescence CdTe/ZnSe core-shell QDs; synthesis by a simple low temperature approach

Highly luminescence CdTe/ZnSe core-shell QDs were produced by growth of the ZnSe shell using a simple, rapid, and low temperature photochemical approach around microwave synthesized CdTe QDs. Synthesized QDs were characterized by means of XRD, FESEM, HRTEM, EDAX, Raman, UV-Vis, and PL analysis. XRD, Raman, EDAX, and HRTEM analyses confirmed successful formation of ZnSe shell around CdTe QDs. CdTe QDs indicated a green band edge emission with a peak at about 535 nm. PL quantum yield (QY) was increased significantly from about 20% for CdTe to about 50% for CdTe/ZnSe QDs. The shell thickness was tunable simply only by UV-illumination time in the ZnSe shell growth step which resulted in the shift of the PL peak from 535 nm (green) to about 640 nm (red).