Quantum Dots Accumulation Phenomenon in The Growth of Multilayer GaSb(QDs)/GaAs and Their Luminescence Property

The growth of multilayer GaSb(quantum dots)/GaAs and their luminescence property have been studied.The results show that the number of layer seems no obvious effect on the density of quantum dots.However,increasing the number of layer leads to the size of quantum dots becoming larger.Furthermore,the quantum dots accumulate as the number of QD layers reaches to a certain degree and some holes are formed in the location of the quantum dot accumulated,as the thickness of quantum dots increases there will be some holes just on the locations the quantum dots gathered.The results suggest that relatedness effect exists between each quantum layer and the GaAs covering layer can not grow well at the location of the accumulated GaSb quantum dots.As a result,the GaSb quantum dots become accumulate easier and evaporate easier in the following GaSb quantum dots grown,which will lead to the forming of the hole.The PL spectra of GaSb(quantum dots)/GaAs shows a broad photoluminescence peak of quantum dots,due to the broad distribution of the size of the quantum dots.