Microstructural and interband transition properties in CdTe quantum dots grown on ZnTe buffer layers by using atomic layer epitaxy

The microstructural and the optical properties of CdTe/ZnTe quantum dots (QDs) grown by atomic layer epitaxy (ALE) were investigated by using atomic force microscopy (AFM), transmission electron microscopy (TEM) and photoluminescence (PL) measurements. The AFM image showed that uniform CdTe QDs are formed, and the TEM image showed that the CdTe QDs were embedded into the ZnTe buffer layers. The temperature-dependent PL spectra showed that the peak corresponding to the interband transitions from the ground electronic subband to the ground heavy-hole band of the CdTe/ZnTe QDs shifted to lower energy with increasing temperature. The full widths at half maxima of the PL peaks for CdTe/ZnTe QDs grown by ALE remained almost constant regardless of the temperature variation. These present observations can help to improve understanding for the microstructural and the optical the properties of the CdTe/ZnTe QDs grown by using the ALE method.