Spectroscopic study of the effect of confinement on shallow acceptor states in GaAs/AlxGa1

Abstract

Transitions from the ground state to excited states of the Be acceptor confined in GaAs/ Al"Ga, "As quantum wells (QW's) have been observed via two independent spectroscopic techniques: Two-hole transitions of the acceptor bound exciton (BE) observed in selective photoluminescence and resonant Raman scattering. The effect of confinement on the observed acceptor 0 transitions has been investigated by varying the QW thicknesses in the range 50 -138 A. The results obtained are compared with recent theoretical predictions. An almost linear relationship was found between the binding energy of the acceptor BE and the observed acceptor transitions. This fact implies that a correspondence to Haynes's rule in bulk should be valid also for this QW system.

Acceptor binding energy in δ-doped GaAs/AlAs multiple-quantum wells

“…8 Subsequently, the transitions between splittings of the acceptor levels have also been investigated in detail with far-infrared transmission, 9 photoluminescence ͑PL͒, and photoluminescence excitation experiments. [10][11][12][13][14] However, for the Be ␦-doped GaAs/AlAs multiple-quantum wells ͑MQWs͒ with doping at the well center, there have been few reports of either experimental or theoretical work. However, this system is of especial interest as it represents the maximum possible confinement for the acceptor states in the valence band and thus the maximum possible tuning range for the 1s-2p transition of the acceptor.…”

Enhancement of the binding energy of charged excitons in disordered quantum wires

“…The photon resulting from the radiative recombination process of extrinsic complexes carries fundamental information on the nature of the chemical impurity and on final eigenstates associated with the optical transition 2 . For instance, it is well known that quantum confinement increases the binding energy of an exciton bound to a neutral acceptor 3 and the ionization energy of an impurity 4 . The direct observation of intrinsic excitonic complexes is, however, rendered more difficult by the inhomogeneous broadening of the optical transition in semiconductor nanostructures.…”

Effect of quantum-well confinement on acceptor state lifetime in δ -doped GaAs/AlAs multiple quantum wells

“…Its electronic structure and transitions between these states have been extensively studied theoretically and experimentally. [1][2][3][4] However, its dynamics properties are less well known, which could have an impact on the potential applications in far-infrared detectors and solid terahertz laser technology. [5][6][7] In multiple quantum wells ͑MQWs͒ or superlattice structures, an artificial period exists along the direction perpendicular to layers and breaks the translational symmetry of the crystal lattice, resulting in Brillouin-zone folding and producing additional phonon branches and gaps in the phonon spectrum.…”