Coalescence and electron activation energy in CdTe/ZnTe nanostructures

Abstract

Atomic force microscopy (AFM) and photoluminescence (PL) measurements were carried out to investigate the coalescence and electron activation energy in CdTe/ZnTe nanostructures. The results of the AFM images show that uniform CdTe quantum dots (QDs) are formed and that the transformation from CdTe QDs to CdTe quantum wires is caused by the coalescence. The excitonic peaks corresponding to the transition from the ground electronic subband to the ground heavy-hole band in the CdTe/ZnTe QDs shifted to higher energy in comparison with those of the CdTe/ZnTe quantum wires. The activation energy of the electrons confined in the CdTe QDs, as obtained from the temperature-dependent PL spectra, was higher than those in CdTe quantum wells and quantum wires. The present results can help to improve the understanding of coalescence and electron activation energy in CdTe/ZnTe nanostructures.