Surface and optical property modifications of self-assembled CdTe/ZnTe quantum dots caused by thermal treatment

Abstract

Atomic force microscopy images showed that the size of the CdTe quantum dots (QDs) slightly increased with increasing annealing temperature up to 350 °C. Photoluminescence spectra showed that the excitonic peak corresponding to the interband transition from the ground electronic subband to the ground heavy-hole band (E1–HH1) in the CdTe/ZnTe QDs annealed at 350 °C was shifted to lower energy compared with that in as-grown CdTe/ZnTe QDs. The full width at half-maximum of the E1–HH1 transition peak in the CdTe/ZnTe QDs annealed at 350 °C decreased resulting from the improvement of the crystallinity for the annealed CdTe QDs.