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

Abstract

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).