Showing papers by "Eric Tournié published in 1997"
TL;DR: In this article, the molecular-beam epitaxy of ZnBeSe ternary alloys matched onto GaAs substrates is described and the excitonic gap is determined to be 2.863 eV at 9 K.
Abstract: We report on the molecular-beam epitaxy of ZnBeSe ternary alloys lattice matched onto GaAs substrates. We demonstrate that these alloys can be grown with a high structural perfection. X-ray linewidths down to 27 arcsec are obtained even though the growth is carried out on bare substrates. Transmission electron microscopy reveals the high quality of the interface. Photoluminescence spectra of undoped layers are dominated by free-exciton recombinations. The excitonic gap is determined to be 2.863 eV at 9 K. Finally, high carrier concentrations are obtained for both n-type and p-type doping. These results are promising in view of fabricating laser diodes with this material system.
33 citations
TL;DR: In this paper, the epitaxial growth of ZnSe on GaAs(0 0 1) is simulated by employing a hybrid approach based on molecular dynamics to describe the initial kinetic behavior of deposited adatoms and Monte Carlo displacements to account for subsequent equilibration.
27 citations
TL;DR: In this article, the influence of the (001) GaAs substrate preparation on the first stages of ZnSe heteroepitaxial growth by molecular beam epitaxy was investigated.
Abstract: We have investigated the influence of the (001) GaAs substrate preparation on the first stages of ZnSe heteroepitaxial growth by molecular beam epitaxy. We show that three different GaAs reconstructions occur depending on the ex situ substrate preparation, the Se residual pressure in the growth chamber and the temperature of heating. After deoxidation, an epiready substrate leads to a (2×1)-reconstructed surface at high temperature (∼600 °C) which turns into an unreconstructed surface when cooling down to the growth temperature (280 °C). An etched substrate, on the other hand, exhibits a (2×3) or a (4×3) reconstruction depending on the temperature reached during deoxidation. Both reconstructions are stable upon cooling down to the growth temperature. Direct nucleation of ZnSe on such deoxidized substrates leads to three-dimensional (3D), quasi two-dimensional (2D) and purely 2D growth modes on the unreconstructed, (2×3) and (4×3) reconstructed surfaces, respectively. Very pronounced oscillations of the re...
14 citations
13 citations
TL;DR: In this article, optical spectroscopy studies of homo-epitaxial ZnSe layers grown by molecular beam epitaxy on substrates prepared by solid-phase recrystallization are presented.
Abstract: We first report on optical spectroscopy studies of homo-epitaxial ZnSe layers grown by molecular beam epitaxy on substrates prepared by solid-phase recrystallization. We identify the main residual impurities to be Li diffusing from the substrate, and Ga and In coming from the sample soldering before epitaxy. We show that ZnSe homoepitaxial layers are of higher structural quality than their counterparts grown directly on GaAs substrates. Their remarkable quality indicates that an “all II–VI” way might be desirable for blue-green laser diodes. In addition, we explore the possibility of using plasma-activated arsenic as a p-type dopant of ZnSe hetero-epitaxial layers. At the present stage our results lead to the conclusion that (i) even when activated via a plasma, as is difficult to incorporate into the growing ZnSe layers, and (ii) when it is actually introduced it gives rise to deep levels.
9 citations
TL;DR: In this paper, the authors describe the nature and densities of the defects encountered in pseudomorphic ZnSe films grown by molecular beam epitaxy (MBE) on bare GaAs substrates and propose a possible mechanism for the formation of stacking faults which takes into account the presence of growth islands.
5 citations
TL;DR: In this paper, an ex situ etch based on the Br 2 :HBr:H 2 O solution provides a good quality surface and in situ heat treatment plays a key role in the ZnSe nucleation.
4 citations
TL;DR: In this article, the authors report on time-resolved optical experiments performed resonantly onto the fundamental excitonic transition on several (Zn, Cd)Se/ZnSe quantum wells, for temperatures from 10 K up to room temperature.
Abstract: We report on time-resolved optical experiments performed resonantly onto the fundamental excitonic transition on several (Zn, Cd)Se/ZnSe quantum wells, for temperatures from 10 K up to room temperature. We show that the thermal quenching of the photoluminescence intensity is due to extrinsic non-radiative channels, whose activation energy is found to be 23 meV.
1 citations