量子限制效应对受主跃迁的影响

Effect of Quantum Confinement on Acceptor Transition inδ—doped GaAs/AlAs Multiple-quantum Wells

通过光致发光光谱,研究了量子限制效应对GaAs体材料中均匀掺杂和一系列GaAs/AlAs多量子阱(阱宽范围从30(?)到200(?))中δ-掺杂浅受主杂质铍(Be)原子带间跃迁的影响。实验中所用的样品是利用分子束外延技术生长的均匀掺Be受主的GaAs外延层和一系列在量子阱的中央进行了浅受主Be原子δ-掺杂的GaAs/AlAs多量子阱。在4.2K的低温下,测量了上述样品的光致发光谱,很清楚地观察到了受主束缚激子从基态1S_(3/2)(Γ_6)到两个激发态2S_(3/2)(Γ_6)和3S_(3/2)(Γ_6)的双空穴跃迁。研究发现,随着量子限制效应的增强,受主跃迁能量会增加。对量子限制效应调节受主杂质间跃迁能量的研究,进一步增强了对受主能态可调性的认识,为太赫兹远红外发光器或激光器的研发提供了一种新的途径。

The effect of quantum confinement on the shallow acceptor transition in 5-doped GaAs/AlAs multiple-quantum wells with a width of 30A～ 200A is studied by using photoluminescene spectra. The samples used in the experiment are the Be δ-doped GaAs epilayers grown by molecular beam epitaxy （MBE） and a series of CaAs multiple-quantum wells in the center of which shallow acceptor Be are δ- doped. The photoluminescene spectra of the samples are measured at a low temperature of 4.2K and the two-hole transition of the acceptor-bound exciton from the ground state, 1S3/2 （Г6）, to the excited states, 2S3/2 （Г6） and 3S3/2 （Г6）, are observed clearly. It is found that the transition energy of acceptors increases with the enhancement of quantum confinement. The study of the quantum confinement effect used to tune the transition energy of acceptor states has further enhanced the understanding of the acceptor states and has provided a new way to develop terahertz far infrared light emitters or lasers.