具有InAlAs浸润层的InGaAs量子点的制备和特性研究

Optical properties of InGaAs self-assembled quantum dots with InAlAs wetting layer

采用自组装方法生长了一种新型的InGaAs量子点 InAlAs浸润层结构 .通过选取合适的In组分 ,使InAlAs浸润层的能级与GaAs势垒相当 ,从而使浸润层的量子阱特征消失 .通过低温光致发光 (PL)谱的测试分析得到InGaAs量子点 InAlAs浸润层在样品中的确切位置 .变温PL谱的研究显示 ,具有这种结构的量子点发光峰的半高全宽随温度上升出现展宽 ,这明显区别于普通InGaAs量子点半高全宽变窄的行为 .这是因为采用了InAlAs浸润层后 ,不仅增强了对InGaAs量子点的限制作用 ,同时切断了载流子的转移通道 ,使得量子点更加孤立后表现出来的性质 .

A new self-assembled quantum dots system where InGaAs dots are formed on InAlAs wetting layer and embedded in GaAs matrix has been fabricated. The photoluminescence linewidth increases with increasing temperature, which is very different from normal In(Ga)As/GaAs quantum dots. The results are attributed to a higher energy of the wetting layer which breaks the carrier transfer channel between dots and keeps the dots more isolated from each other.