Effect of thermal annealing on the interband transitions and activation energies of CdTe/ZnTe quantum dots

The effect of rapid thermal annealing on CdTeZnTe quantum dots (QDs) was analyzed to investigate the interband transitions and the electron activation energy. The full width at half maximum of the photoluminescence (PL) peak corresponding to the interband transitions from the ground electronic subband to the ground heavy-hole band (E1 - HH1) in the CdTeZnTe QDs annealed at 330 °C decreased, and their integrated PL intensity of the E1 - HH1 transition peak significantly increased. The activation energy of electrons confined in CdTeZnTe QDs annealed at 330 °C increased as high as 77 meV, which was the highest value among the as-grown and annealed samples. These results indicate that the crystallinity of the CdTeZnTe QDs is improved by annealing, and the present results can help improve the understanding of the thermal annealing effect on the optical properties of CdTeZnTe QDs.