量子阱中Be受主的光致发光

报道了掺杂在GaAs体材料中和δ掺杂在一系列GaAs/AlAs多量子阱中的Be受主带间跃迁的光致发光.实验所用样品,GaAs体材料中均匀掺杂Be受主的外延单层和一系列量子阱宽度从3到20nm,并在量子阱中央进行了Be受主δ掺杂的GaAs/AlAs多量子阱样品都是通过分子束外延技术制备的.在4,20,40,80及120K不同温度下,分别对上述样品进行了光致发光谱的测量,清楚地观察到了受主束缚激子从1S3/2(Γ6)基态到同种宇称2S3/2(Γ6)激发态的两空穴跃迁,并从实验上得到了不同量子阱宽度下Be受主从1S3/2(Γ6)到2S3/2(Γ6)态的带间跃迁能量.理论上利用变分原理,在单带有效质量模型和包络函数近似下,数值计算了Be受主1S3/2(Γ6)→2S3/2(Γ6)的跃迁能量随量子阱宽度的变化关系,比较发现理论计算和实验结果符合较好.

Photoluminescence of the Beryllium Acceptor at the Centre of Quantum Wells

We report photoluminescence studies of internal transitions of shallow Be acceptors in bulk GaAs and a series of δ-doped GaAs/AtAs multiple quantum well samples with well width ranging from 3 to 20nm.A series of Be δ-doped GaAs/AlAs multiple-quantum wells with the doping at the well center and a single epilayer of GaAs uniformly Be doped were grown by molecular beam epitaxy.The photoluminescence spectra were measured at 4,20,40,80,and 120K,respectively.A two-hole transition of the acceptor-bound exciton from the ground state,1S3/2(Γ6),to the first.excited state,2S3/2(Γ6),has been clearly observed.A variational principle is presented to obtain the 2s-1s transition energies of quantum confined Be acceptors as a function of the well width under the single-band effective mass and envelop function approximations.It is found that the acceptor transition energy increases with decreasing quantum-well width,and the experimental results agree well with the theoretical calculation.