Formation and activation energy of Cd_x Zn_1-xTe nanostructures with different dimensions grown on ZnTe buffer layers

Atomic force microscopy (AFM) and photoluminescence (PL) measurements were carried out to investigate the formation process and the activation energy of different-dimensional Cdx Zn1-x TeZnTe nanostructures. The results of the AFM images show that Cdx Zn1-x Te quantum dots (QDs) are formed and that the dimensional transformation from Cdx Zn1-x Te QDs to Cdx Zn1-x Te 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 Cdx Zn1-x TeZnTe nanostructures shifts to lower energy with increasing thickness of the Cdx Zn1-x Te layer due to variations in the thickness and the dimension of the layer. The activation energy of the electrons confined in the Cdx Zn1-x TeZnTe nanostructures, as obtained from the temperature-dependent PL spectra, was significantly affected by the thickness and the dimension of the Cdx Zn1-x Te layer.