生长在(311)A面GaAs衬底上的InAlAs/AlGaAsⅡ型量子点的光致发光研究

摘要

The photoluminescence (PL) spectra of self-ass embled In0.55Al0.45As/Al0.5Ga0.5As quantum dots (QD) gro wn on (311)A GaAs substrate were measured. The type-Ⅱ character of PL related to the X valley was verified by excitation power dependence of peak position a nd the PL spectra under different pressure, which was attributed to the type-Ⅱ transition from X valley in Al0.5Ga0.5As to heavy holes in In0. 55Al0.45As.The high energy Γ-related transition was also observed abov e 70K and aasigned as the transition between Γ valley and heavy holes in In 0.55Al0.45As.The X-valley split was discussed to interpret the observed second X-related peak under pressure.%测量了生长在(311)A面GaAs衬底上的In0.55Al 0.45As/Al0.5Ga0.5As自组织量子点光致发光谱,变激发功率和压力实验 证明发光峰是与X能谷相关的Ⅱ型发光峰,将它指认为从Al0.5Ga0.5As势垒X能 谷到In0.55Al0.45As重空穴的Ⅱ型跃迁.高温下观察到的高能峰随压力增大向 高能方向移动,认为它来源于量子点中Γ能谷与价带之间的跃迁.在压力下还观察到了一个新 的与X相关的发光峰,认为它与双轴应变引起的导带X能谷劈裂有关.