Formation and activation energy of CdxZn1-xTe nanostructures with different dimensions grown on ZnTe buffer layers

Abstract

Atomic force microscopy (AFM) and photoluminescence (PL) measurements were carried out to investigate the formation process and the activation energy of different-dimensional CdxZn1-xTe/ZnTe nanostructures. The results of the AFM images show that CdxZn1-xTe quantum dots (QDs) are formed and that the dimensional transformation from CdxZn1-xTe QDs to CdxZn1-xTe quantum wires is caused by coalescence. The excitonic peak corresponding to the transition from the ground electronic subband to the ground heavy-hole transitions in CdxZn1-xTe/ZnTe nanostructures shifts to lower energy with increasing thickness of the CdxZn1-xTe layer due to variations in the thickness and the dimension of the layer. The activation energy of the electrons confined in the CdxZn1-xTe/ZnTe nanostructures, as obtained from the temperature-dependent PL spectra, was significantly affected by the thickness and the dimension of the CdxZn1-xTe layer.