离子注入对InAs/GaAs量子点光学效质的影响

研究了低能质子注入诱导的界面混合和快速热退火对量子点发光效率的影响，对其光致发光 峰强进行了拟合计算.研究发现量子点的发光峰强度主要由载流子俘获时间和非辐射复合寿 命决定.由于后退火处理能够部分的消除因质子注入造成的缺陷，量子点中非辐射复合中心 浓度与注入剂量成亚线性关系；退火温度越高，非辐射复合中心被消除越多，亚线性程度越 高.界面混合导致的俘获效率的增加和注入损伤引起的非辐射复合是相互竞争过程，存在一 个临界的注入剂量N_C，当注入剂量N小于N_C，界面混合作 用较为明显，量子点 发光峰强随注入剂量增加而增强；当N大于N_C时，质子注入引起了大量的非 辐射复合 中心，主要表现为注入损伤，量子点的发光峰强随注入剂量增加而迅速减弱.退火温度越高 ，N_C越大. 关键词： 量子点 离子注入 峰强

Effect of proton implantation on photoluminescence of self-assembled InAs/GaAs quantum dots

Both the effects of the intermixing induced by the implantation dose and the annealing temperature on the light-emission efficiency of the quantum dots are studied. The intensities of photoluminesce (PL) are determined by the carriers c apture time and non-radiative center lifetime.Annealing can partly eliminate the non-radiative center (NRC), so the NRC generation rate is a sublinear function of the proton dose (N). The carrier capture efficiency enhancement is induce d by intermixing and degradation by the implantation damage which mutually compe te, so there exists a critical implantation dose (N_C). When N is less than N_C, the intermixing is the main effect and the PL intensity increases with the implantation dose. On the other hand, when N is larger than N _C, the implantation damge is so large that the intensity decreases wi th the do se. The higher the annealing temperature, the larger the N_C becom es.