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采用远红外时间分辨光谱,研究了量子限制效应对δ掺杂在GaAs/AlAs多量子阱中铍(Be)受主态寿命的影响.在低温下的远红外吸收谱中,清楚地观察到了三条主要吸收线,它们分别来源于铍受主从基态到它的三个奇宇称激发态的跃迁.实验结果表明:随着量子限制效应的增强,受主激发态寿命而减少,实验测得体材料中Be受主2p激发态的寿命是350 ps,而阱宽10 nm的多量子阱中的寿命是55 ps.量子限制效应对布里渊区折叠声学声子模的影响增强了受主带内空穴与声学声子相互作用,从而加快了受主带内空穴的弛豫过程.
Using far-infrared time-resolved spectroscopy, the effect of quantum confinement on the acceptor state lifetime of δ (δ) doping in GaAs / AlAs multiple quantum wells was studied. In the far-infrared absorption spectrum at low temperature, three The main absorption lines originate from the beryllium acceptor transition from the ground state to its three odd-parity excited states, respectively.The experimental results show that with the increase of quantum confinement effect, the lifetime of acceptor excited states decreases, The lifetime of acceptor 2p excited states in Be is 350 ps and the lifetime in multi-quantum wells with well width 10 nm is 55 ps. The effect of quantum confinement on the folded acoustic phonon modes in the Brillouin zone enhances the effect of the acceptor band Holes interact with acoustic phonons, thereby accelerating the relaxation of holes in the acceptor band.