Infoscience

Journal article

Ultrathin GaAs layers embedded in AlAs: The observation of intense short-wavelength emission

Type-II GaAs/AlAs multiple-quantum well samples groan by low-pressure metal-organic vapour-phase epitaxy have been investigated. The layered structures consist of 50 periods of either 2 monolayers (ML), 4 ML. 5 ML, 6 ML, or 7 ML GaAs embedded in 28 ML AlAs. Using (100) GaAs substrates 6 degrees misoriented towards the nearest (111)B plane monolayer steps at the AlAs/GaAs/AlAs interfaces with regular terrace widths (2.7 nm) can be seen by high-resolution transmission electron microscopy. In the photoluminescence spectra even at room temperature type-I luminescence is found to be dominant. The peak wavelength of this emission ranges from 620 to 440 nm and is governed by the GaAs layer thickness. The comparison of the measured transition energies with calculations based on an effective mass approach and an empirical tight-binding Green's function scheme shows good agreement. The perfect interface structure of our samples with regular distribution of monolayer steps prevents obviously the loss of photoexcited carriers from the GaAs layers to the surrounding, energetically resonant AlAs material allowing only low type-II luminescence intensity. Furthermore, for our well thicknesses 2D phonons have to be coupled with 3D electrons leading to low electron-phonon interaction.

    Note:

    Univ Leipzig, Fac Phys, D-04103 Leipzig, Germany. Univ Leipzig, Fac Chem, D-04103 Leipzig, Germany. PHB Ecublens, Swiss Fed Inst Technol Lausanne, Dept Phys, CH-1015 Lausanne, Switzerland. Schwabe, R, Univ Leipzig, Fac Phys, Linnestr 3-5, D-04103 Leipzig, Germany. schwabe@server1.rz.uni-leipzig.de

    ISI Document Delivery No.: YP830

    Times Cited: 1

    Cited Reference Count: 8

    Cited References:

    ANDREANI LC, 1997, P MODULATED SEMICOND

    DIVENTRA M, 1997, PHYS REV B, V55, P13148

    MADER KA, 1992, P INT M OPT EXC CONF, P341

    MADER KA, 1992, THESIS SWISS FEDERAL

    MASCHKE K, 1991, PHYS REV LETT, V67, P2646

    MEYNADIER MH, 1988, PHYS REV LETT, V60, P1338

    MOORE KJ, 1989, SPECTROSCOPY SEMICON, P293

    SCHWABE R, 1997, PHYS REV B, V56, R4329

    Reference

    Record created on 2007-08-31, modified on 2016-08-08

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