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Vicinal Substrates (vicinal + substrate)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

MBE growth and magneto-optical properties of ZnCdSe-ZnMnSe wire systems

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2009
Takashi Matsumoto
Abstract Zn0.91Cd0.09Se/Zn0.88Mn0.12Se wire array embedded in a ZnSe barrier layer has been grown on GaAs vicinal substrate by MBE under step-flow growth condition, and polarized photoluminescence (PL) and reflectance spectra have been measured in external magnetic field in the Voigt geometry with magnetic field parallel and perpendicular to the wire. The sample shows strong luminescence due to exciton recombination in the Zn0.91Cd0.09Se QWRs. Zeeman shift of the luminescence is anisotropic, that is, the energy shift depends on the direction of the magnetic field and the direction of electric field of emitted light. In reflectance spectra two dips are observed. One is active to the light polarized perpendicular to the magnetic field and the other is active to the light parallel to the magnetic field. The effect of energy separation between the two dips on the PL polarization is studied, and relative contribution of the heavy- and light-hole component to the hole states responsible for the two transitions is discussed. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Polarization properties in deep-ultraviolet AlGaN quantum wells with various substrate orientations

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 7 2010
A. Atsushi Yamaguchi
Abstract It is known that emission polarization in AlGaN quantum wells (QWs) on c-plane substrates switches from in-plane polarization to c -axis polarization with increasing Al composition. This behaviour is unfavourable for light extraction from c-plane based light emitting diodes (LEDs). Previously, we proposed theoretically that this unfavourable polarization can be changed into favourable in-plane polarization by decreasing well width and/or introduction of compressive strain in c-oriented AlGaN-QWs. In this work, we have investigated the substrate orientation dependence of polarization properties in such AlGaN QWs by numerical calculation using the 6,×,6 k·p Hamiltonian. It is shown that even small inclination of c-plane substrate makes a drastic change in the polarization characteristics and that the use of the vicinal substrates as well as semipolar and nonpolar substrates could be beneficial in improving optical device performance. [source]

Temperature dependent luminescence from quantum dot arrays: phonon-assisted line broadening versus carrier escape-induced narrowing

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2010
M. B. Smirnov
Abstract The paper presents a theoretical model describing the temperature dependence of the photoluminescence spectrum of self-ordered quantum dots arrays taking into account exciton,phonon interaction and thermal carriers transfer. This model is applied to the photoluminescence behaviour of InAs quantum dots grown on GaAs vicinal substrates. It allows distinguishing between effects caused by the different temperature-induced mechanisms and thus provides information about the physical and electronic structure of the quantum dot arrays. [source]

GaN/AlN super-lattice structures on vicinal sapphire (0001) substrates grown by rf-MBE

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2005
X.Q. Shen
Abstract GaN/AlN super-lattice structures (SLs) grown on the vicinal sapphire (0001) substrates by rf-MBE are investigated using various characterization techniques. The satellite XRD diffraction peaks originating from the SLs are clearly observed, which indicate an abrupt interface and good periodicity of the SLs. Cross-sectional TEM observations show differnet features of SLs grown on the various vicinal substrates, depending on whether macro-steps form on the surface or not. DUV-Raman measurements show unique spectra from the SLs, which are different from the usual GaN and AlN films. The usage of a proper vicinal substrate angle shows a great merit to obtain high quality GaN/AlN SLs. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]