Luminescent properties of single quantum well of CdTe on ZnTe grown by hot-wall epitaxy

Temperature dependencies of photoluminescence (PL) spectra were investigated on thin single quantum wells (SQWs) of CdTe embedded in ZnTe barrier layer. Four types of SQWs were prepared by hot-wall epitaxy with nominal well thickness of 2, 3, 3.5 and 4 monolayers (MLs). Atomic force microscopy (AFM) investigation on uncapped CdTe layers revealed that the surface of CdTe layers were covered with self-organized cone like shaped dots (SQDs). The PL spectra measured at 4.2 K was composed of two adjoining emission bands. It was clarified that the higher energy PL bands originated from the exciton recombinations in a CdTe wetting layer while the lower energy one originated from the recombination in the SQDs of CdTe. Two thermal activation energies in the energy-integrated PL intensity are determined.