Effect of quantum confinement on shallow acceptor transitions in δ-doped GaAs/AlAs multiple-quantum wells

Abstract

We have investigated the effect of confinement on the shallow acceptor transitions in δ-doped GaAs/AlAs multiple-quantum wells with well widths ranging from 30 to 200 Å. A series of Be δ-doped GaAs/AlAs multiple-quantum wells with doping at the well center and a single epilayer of GaAs uniformly Be doped were grown by molecular beam epitaxy. Photoluminescence spectra were measured at 4, 20, 40, 80, 120, and 200 K, respectively. Two-hole transitions of the acceptor-bound exciton from the ground state, 1S3/2(Γ6), to the excited state, 2S3/2(Γ6), were clearly observed. It is found that the acceptor transition energy increases with a decrease in quantum well width.

Photoreflectance and surface photovoltage spectroscopy of beryllium-doped GaAs∕AlAs multiple quantum wells

“…Be acceptors confined in GaAs/ AlAs MQWs has already been investigated theoretically 9 and experimentally by farinfrared absorption 7,10 and photoluminescence 9,11 techniques. The data revealed important information about the binding energy and the carrier dynamics within the Be acceptor levels, in particular, the ability to alter the transition energy and the hole lifetime by the confinement potential of the QWs was demonstrated.…”

Experimental Study of Optical Transitions in Be-Doped GaAs/AlAs Multiple Quantum Wells

“…As impurity states have transitions within this range and their energy levels can be engineered by varying quantum wells (QW) widths [4][5][6], these structures could be used as active components of THz devices. Therefore, the understanding of the optical properties and impurity features are of particular importance for designers.…”

Raman and photoluminescence studies of transitions of quantum‐confined acceptors

“…Accordingly, it is deduced that 10–13 the 1S 3/2 ( Γ 8 ) ground state of the neutral accepter Be at the center of QWs, will be split into two doublet levels, namely 1S 3/2 ( Γ 6 ) and 1S 3/2 ( Γ 7 ), while the other higher‐energy levels also will be split. There have been many articles of PL 14–17, far‐infrared 18, and also Raman scattering measurements 19–22 on GaAs/Ga 1– x Al x As systems, which have studied the effect of the quantum confinement on shallow acceptors both in theoretical studies and experiments. However, very few articles 22 have been published on the splits of accepter levels resulting from the quantum confinement.…”