Luminescence of Zn_xMg_1-xSe Layers Obtained by Thermal Diffusion of Mg into ZnSe and Zn_xMg_1-xSe Epilayers Grown by Molecular Beam Epitaxy

Abstract

This work deals with the study of photoluminescence properties of ZnxMg1-xSe epilayers grown by molecular beam epitaxy on (001) GaAs and (111) ZnTe substrates and ZnxMg1-xSe 1ayers obtained by thermal diffusion of Mg into ZnSe single crystals. Luminescence spectra of Zn x Mg1x Se layers are dominated by blue and violet emission bands with maxima positioned in the range of photon energies: 3.05-3.28 eV, 2.88-3.04 eV, 2.81 eV and 2.705 eV, depending on preparation conditions. In some samples the blue luminescence is observed up to room temperature.

Optical Properties of Zn1-xMgxSe Epilayers Studied by Spectroscopy Methods

“…Moreover, the luminescence band of higher intensity in blue emission region is assiociated with radiative recombination of free excitons. At high temperatures (above 130-150 K) the free excitons recombination is thermally quenched and the low energy emission coming from the deep levels recombination is observed [2].…”

“…The Zn1-x Mgx Se epilayers were grown on GaAs (001) and ZnTe (111) and silica glass substrates by solid source MBE in facility described elsewhere [2]. The photoluminescence and photoreflectivity spectra were measured in the temperature range from 10 to 300 K using a closed cycle cryogenic system (APD-Cryogenic Inc.).…”

Raman Analysis of Zn1-xMgxSe Layers Grown on GaAs and ZnTe Substrates

“…Mgx Se epilayers have been grown on semi-insulating (001) GaAs and (111)Zn ZnTe substrates with the Mg contents from 0 to 40% in a MBE system (home made). The growth conditions were described in detail elsewhere [4,5] Raman spectra were taken at room temperature in backscattering geometry at several exciting energies. Spectra were recorded using a double monochromator equipped with holografic grating and a S20 photomultiplier or CCD detecting system.…”

Dependence of Exciton Linewidth on the Composition of ZnxMg1-xSe Layers Grown by MBE

“…The usefulness of mixed ternary compounds of Mg halcogenides materials arises from the possibility of tuning of the band-gap energies and lattice constants by adjusting the content of the particular elements [1][2][3]. Unfortunately, there is a considerable lack of knowledge about the optical parameters of these materials grown on different substrates.…”

“…The Zn Mg1x Se layers were grown by solid source molecular beam epitaxy on GaAs and ZnTe substrates in facility described elsewhere [1]. The substrate temperature during the growth was kept in the range of 550-580 K. Growth rates of ZnSe and Zn Mg1x Se layers were in the range between 0.02 nm/s and 0.2 nm/s.…”