Showing papers by "Jean Massies published in 1988"
TL;DR: In this paper, the influence of the substrate induced strain and the partial pressures of the elements III and V on the In incorporation coefficient, αIn, in MBE grown AlInAs alloys was investigated through reflection high energy electron diffraction intensity oscillations.
27 citations
TL;DR: In this article, a study of photoluminescence and reflectivity of GaAs/Ga1−x 1−x Al ≥ 12 K to room temperature was performed.
Abstract: We report a study of photoluminescence and reflectivity of GaAs/Ga1−x
Al
x
As multiple quantum well structures from 12 K to room temperature. A direct comparison between the emission peaks of the quantum wells and of bulk GaAs, as well as between the photoluminescence and reflectance spectra, shows strong evidence of exciton features up to room temperature. By means of a line shape fit of the room temperature emission spectrum, we determine the contribution of the heavy and light hole excitons and of the continuum states. From a detailed analysis of the transition energies, a 5% increase of the confinement energy is found to occur when the temperature increases from 12 K to room temperature. This effect is shown to be due to the change in the electron and hole effective masses.
25 citations
TL;DR: In this article, the epitaxial relationships between Fe, Cr, and GaAs were determined by in situ reflection high-energy electron diffraction, which showed that no significant intermixing occurs in the investigated growth temperature range −50 to +50°C.
Abstract: Molecular beam epitaxy has been used to grow single‐crystal Fe/Cr magnetic multilayer structures on homoepitaxial (001)GaAs layers. The epitaxial relationships between Fe, Cr, and GaAs were determined by in situ reflection high‐energy electron diffraction. The sharpness of the different interfaces of the Fe/Cr multilayers is illustrated by Auger electron spectroscopy sputter depth profiling, which shows that no significant intermixing occurs in the investigated growth temperature range −50 to +50 °C.
25 citations
TL;DR: In this article, the first experimental evidence of the decrease of carbon shallow acceptor concentration when using dimer rather than tetramer arsenic was presented by selectively excited photoluminescence.
Abstract: Doubly doped (C,Be) GaAs layers grown by molecular beam epitaxy under dimer or tetramer arsenic flux are studied by selectively excited photoluminescence. Acceptor spectroscopy gives the first experimental evidence of the decrease of carbon shallow acceptor concentration when using dimer rather than tetramer arsenic.
21 citations
TL;DR: The passivating oxide layer resulting from a high-temperature (250°C in air) GaAs substrate preparation procedure has been analyzed by X-ray photoelectron spectroscopy as discussed by the authors.
Abstract: The passivating oxide layer resulting from a high-temperature (250°C in air) GaAs substrate preparation procedure has been analysed by X-ray photoelectron spectroscopy. It is shown that the protective film obtained from heating a semi-insulating substrate in clean air to 250°C is mainly gallium oxide whereas it is an arsenic-rich mixture of As and Ga oxides after the standard preparation procedure. At this temperature, the oxidation steady-state conditions are reached after 5 minutes of heating. The higher the passivating temperature, the lower the arsenic content of the oxide layer.
20 citations
TL;DR: In this paper, the ground state binding energy of a neutral acceptor involving substitutional carbon acceptor in GaAs is calculated in the spherical band approximation and a short range model potential due to the neighborhood of nitrogen isoelectronic impurity is used as a perturbation.
20 citations
TL;DR: In this paper, the luminescence properties of two-and three-dimensional electron-hole plasma obtained by simultaneous photogeneration in GaAs/AlxGa1-xAs quantum wells and in the GaAs buffer layer were investigated.
Abstract: We report a comparative study of the luminescence properties of two- and three-dimensional electron-hole plasma obtained by simultaneous photogeneration in GaAs/AlxGa1-xAs quantum wells and in the GaAs buffer layer. The dependence of the luminescence on the optical excitation rate and on the temperature are studied by means of a lineshape analysis. The plasma luminescence in the quantum well results from the superposition of an excitonic emission, which does not shift with the excitation intensity, and of a free-carrier emission which shows a red shift with increasing excitation intensity. The observed shrinkage of the gap in the quantum well is in agreement with theoretical calculations.
6 citations
01 Jan 1988
5 citations
TL;DR: In this paper, an epitaxial alloy statistical model which accounts for the elastic strain and relaxation in the local equilibrium properties of III-V alloys during molecular-beam epitaxy is proposed.
Abstract: Elastic strain and relaxation are shown to play a central role in the local equilibrium properties of III-V alloys during molecular-beam epitaxy. An epitaxial alloy statistical model which accounts for these effects is proposed. The variation with temperature of the In-incorporation coefficient in (A1,In)As/InP and (A1,In)As/GaAs, measured from reflection high-energy electron-diffraction intensity oscillations, is discussed in the framework of the proposed model.
5 citations
TL;DR: In this paper, the Stokes shift of the excitation emission line from quantum well is investigated under various excitation conditions, including nonresonant and intense excitations, and the contribution of the interband transitions.
Abstract: Measurements of photoluminescence, excitation photoluminescence and reflectance are performed at various temperatures on a series of GaAs/Ga1−xAlxAs quantum well structures grown by molecularbeam epitaxy. The selective photoluminescence data of the GaAs buffer layers are analysed in order to correlate the optical properties with the growth conditions. The Stokes shift of the excitation emission line from quantum wells is investigated under various excitation conditions. A considerable decrease of the Stokes shift is observed in the case of nonresonant and intense excitations. Also the extrinsic photoluminescence, as well as its temperature dependence, are interpreted. In addition, the temperature effects on both the bulk and quantum well spectra are shown to clarify the excitation features and the contribution of the interband transitions.
2 citations
TL;DR: In this article, the temperature dependence of the emission intensity due to conduction band-to-neutral acceptor recombination (e-A0) is investigated in a GaAs/Ga0.7Al 0.3As single quantum well.
Abstract: The temperature dependence of the emission intensity due to conduction band-to-neutral acceptor recombination (e-A0) is investigated in a GaAs/Ga0.7Al0.3As single quantum well. It is shown that the thermal quenching of the (e-A0) emission peak is not monotonous with temperature. The increase of the (e-A0) emission intensity up to about 30 K is interpreted as a consequence of the ionization of shallow donors, while the decrease in emission intensity at higher temperature is due to ionization of neutral acceptors.