多层GaSb(QDs)/GaAs生长中量子点的聚集及发光特性

通过对多层GaSb量子点的生长研究,发现随着生长层数的增加,量子点尺寸逐渐变大,密度没有明显变化,并且量子点出现了聚集现象;当层数增加到一定数量、量子点聚集到一定大小时,聚集的量子点处会出现空洞。这些现象表明,各层量子点在生长过程中存在关联效应,并且GaAs层不能很好地覆盖在聚集的量子点之上,在继续生长其它量子点层时,聚集的量子点处在高温下出现GaSb的蒸发,从而出现空洞。PL谱出现了很宽的量子点发光峰,这很可能是由于多层量子点在生长时大小分布较宽而导致的结果。

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.