Effects of confinement on shallow donors and acceptors in GaAs/AlGaAs quantum wells

Reeder, A.A.; Mercy, J.-M.; McCombe, B. D.

doi:10.1109/3.7099

Cited by 51 publications

(16 citation statements)

References 24 publications

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“…The transition energy increase is greater than that reported previously for Al 0.3 Ga 0.7 As/GaAs MQWs in Ref. [7] because of the greater confinement in this system. It can be seen from the theoretical curve in Fig.…”

Section: Samplescontrasting

confidence: 65%

Binding energy and dynamics of Be acceptor levels in AlAs/GaAs multiple quantum wells

Halsall

Zheng

Harrison

et al. 2004

Journal of Luminescence

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Section: Samplescontrasting

confidence: 65%

Binding energy and dynamics of Be acceptor levels in AlAs/GaAs multiple quantum wells

Halsall

Zheng

Harrison

et al. 2004

Journal of Luminescence

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“…Only one previous set of absorption data for bulk GaAs:Be is known. [16][17][18][19] The Be lines shown in the earlier spectrum are much broader and less intense than those observed in the present work.…”

Section: Introductionmentioning

confidence: 70%

Energy states of Be in GaAs

et al. 1996

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Far-infrared absorption due to Lyman transitions of the Be acceptor in GaAs has been measured in bulk molecular-beam-epitaxy-grown samples at various temperatures and under different illumination conditions. Sharp lines of energy ͑at 1.9 K͒ of 134.42Ϯ0.06, 166.76Ϯ0.05, and 182.30Ϯ0.05 cm Ϫ1 are observed, being the G, D, and C lines, respectively. Fiorentini's recent calculation ͓Phys. Rev. B 51, 10 161 ͑1995͔͒ of the acceptor energy spectrum in GaAs is in good agreement with these results. At 1.9 K the G, D, and C linewidths are 1.06Ϯ0.14, 1.16Ϯ0.04, and 1.86Ϯ0.05 cm Ϫ1 , respectively, and the integrated intensities are in the ratio 11.5Ϯ5.6:100:57.6Ϯ9.8. External illumination during cooling or measurement had no effect on the observed spectra.

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“…In the photoconductivity spectra of Ge/GeSi samples #306 and #308 broad band in between 20 and 40 cm -1 and around 60 cm -1 respectively were observed (Fig.3,4). The binding energy of shallow acceptor is known to depend on the impurity position in QW [1,2]. These spectra due to the built-in strain in the Ge/GeSi heterostructures differ significantly from the impurity photoconductivity spectrum of bulk p-Ge where the maximum is located nearby 100 cm -1 .…”

Section: Methodsmentioning

confidence: 99%

Relaxation of THz impurity photoconductivity in GaAs/InGaAsP and Ge/GeSi quantum well heterostructures

Morozov

Maremyanin

Kuritsin

et al. 2009

J. Phys.: Conf. Ser.

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Abstract. In n-GaAs/InGaAsP and p-Ge/GeSi quantum well heterostructures excited by both the picosecond broad band and the nanosecond narrow band pulses of THz radiation the relaxation times of the impurity photoconductivity were measured. In one of the sample Ge/GeSi this more narrow quantum well we observed the first time increases maximum relaxation time from 9 to 14 ns at the narrow band THZ radiation frequency decrease from 60 cm -1 down to 25 cm -1 that can be explained by a dispersion of shallow acceptor binding energies. The frequency of 60 cm -1 nearly corresponds to the binding energy of acceptors situated nearby Ge QW center while that of 25 cm -1 corresponds to ionization energy for the hole (in Ge QW) bound with a remote acceptor ion in the center of GeSi barrier. We explain the observed larger relaxation time for the acceptor with lower binding energy by an enhanced probability for the hole captured by an excited impurity state to be thermally activated again into the valence band. IntroductionNowadays there is a growing interest to the nonequilibrium phenomena and possibilities to produce the intraband population inversion in semiconductor nanostructures doped with shallow impurities. In order to design THz laser operating at the optical transitions involving shallow impurity states direct information on lifetimes of carriers both excited into conduction (valence) band and captured by excited impurity states is required. In this paper we study the relaxation of impurity photoconductivity at T = 4.2K in n-GaAs/In 0.1 Ga 0.9 As 0.8 P 0.2 and p-Ge/Ge 0.9 Si 0.1 quantum well (QW) heterostructures excited by broadband THz radiation (0.5 -3 THz) generated by optical rectification of femtosecond laser pulses and by narrow band (0.2 cm -1 ) tunable THz pulses of nanosecond duration.

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Effects of confinement on shallow donors and acceptors in GaAs/AlGaAs quantum wells

Cited by 51 publications

References 24 publications

Binding energy and dynamics of Be acceptor levels in AlAs/GaAs multiple quantum wells

Binding energy and dynamics of Be acceptor levels in AlAs/GaAs multiple quantum wells

Energy states of Be in GaAs

Relaxation of THz impurity photoconductivity in GaAs/InGaAsP and Ge/GeSi quantum well heterostructures

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