Optical characterization and evaluation of the conduction band offset for ZnCdSe/ZnMgSe quantum wells grown on InP(001) by molecular-beam epitaxy (original) (raw)
Related papers
Growth and Characterization of ZnCdMgSe/ZnCdSe Quantum Wells on InP substrates for Visible Emitters
1999
High-quality lattice-matched quantum well (QW) structures of ZnCdSe/ZnCdMgSe were grown on InP substrates by molecular beam epitaxy. Emission energies from 2.306 to 2.960 eV were measured by low-temperature photoluminescence for samples with QW thicknesses between 5 and 80 Å. Bandgap measurements indicate that these structures could be used in entirely lattice-matched blue, green, and yellow diode laser structures. Experimental measurements indicated that these structures have very little strain; hence, these materials could possibly be less prone to degradation than the Abstract current II-VI blue-green lasers grown on GaAs substrates.
Molecular beam epitaxial growth and characterization of zinc-blende ZnMgSe on InP (001)
Applied Physics Letters, 2004
High crystalline quality zinc-blende structure Zn ͑1−x͒ Mg x Se epitaxial layers were grown on InP (001) substrates by molecular beam epitaxy. Their band gap energies were determined as a function of Mg concentration and a linear dependence was observed. The band gap of the Zn ͑1−x͒ Mg x Se closely lattice matched to InP was found to be 3.59 eV at 77 K and the extrapolated value for zinc-blende MgSe was determined to be 3.74 eV. Quantum wells of Zn ͑1−x͒ Cd x Se with Zn ͑1−x͒ Mg x Se as the barrier layer were grown which exhibit near ultraviolet emission.
Molecular beam epitaxy and optical properties of ZnCdS/ZnMgS quantum wells on GaP
Journal of Crystal Growth, 2000
We report the growth of ZnCdS/ZnMgS quantum wells (QWs) and their optical properties. The constituent alloy layers were grown by molecular beam epitaxy under a large S #ux and a high substrate temperature. The layers exhibit high quality in terms of double crystal X-ray rocking curve and optical spectra including photoluminescence (PL), PL excitation and re#ection spectra. The ZnCdS/ZnMgS QWs exhibit strong emission from the ZnCdS well(s) through photo-excitation at the ZnMgS barriers. By changing the growth condition of the QW structures, PL line width can be reduced. Such QWs show PL up to room temperature.
Band offset determination of Zn0.53Cd0.47Se/Zn0.29Cd0.24Mg0.47Se
Applied Physics Letters, 2003
The interband transitions of a single quantum well structure of Zn 0.53 Cd 0.47 Se/Zn 0.27 Cd 0.23 Mg 0.50 Se ͑lattice matched to InP͒ were evaluated using contactless electroreflectance at room temperature. From a comparison of the measured optical transitions with those calculated using the envelope function approximation we determined that the conduction band offset for this system is given by the parameter Q c ϭ⌬E c /⌬E 0 ϭ0.82Ϯ0.02, which yields ⌬E c of 590 meV. Such a large conduction band offset may be useful for the design of quantum cascade lasers and other devices based on intersubband transitions.
Nearly lattice-matched Zn1-zCdzSe/Zn1-xCdxSe/Zn1-yMgySe (z > x) quantum wells for yellow emission
Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena, 2016
The authors present the results of the modeling and epitaxial growth of a nearly lattice matched Zn 1-z Cd z Se/Zn 1-x Cd x Se/Zn 1-y Mg y Se quantum well (QW) heterostructure with yellow emission. The ZnCdSe QW is composed of regions with two different Cd content: in the center, seven monolayers of Zn 1-z Cd z Se with z Cd content are surrounded on each side by eight Zn 1-x Cd x Se monolayers with x Cd content (z > x). These last regions are lattice matched to the Zn 1-y Mg y Se barrier. The quantum well design and modeling was based on calculations employing the transfer matrix method. The ZnCdSe quantum well layers were grown in a layer-by-layer mode by submonolayer pulsed beam epitaxy within ZnMgSe barriers grown by molecular beam epitaxy. The low temperature photoluminescence spectrum presented yellow excitonic emission at 2.176 eV, which is in very good agreement with the model calculations. At room temperature, the emission shifted to 2.112 eV, a deep yellow color. V
Physica Status Solidi B-basic Solid State Physics, 2006
Quantum well infrared photodetectors (QWIPs) from wide bandgap II–VI compounds are promising as high quantum efficiency detectors in the mid-IR. A series of Cl-doped ZnxCd(1–x )Se/Znx ′Cdy ′Mg(1–x ′–y ′)Se multiple-quantum-wells (MQW) with different quantum well (QW) thicknesses have been grown by MBE lattice-matched to InP substrates. The high material quality of the samples was demonstrated by X-ray diffraction (XRD), steady-state photoluminescence (PL), and time-resolved photoluminescence (t -PL) measurements. Contactless electroreflectance (CER) measurements were performed to investigate high order transitions within the QWs. From these transitions, intersubband transition energies were predicted and compared with the theoretical calculations, a very useful result for device design. Our results indicate that this material system is very promising for intersubband device applications such as QWIPs operating in the 3–5 µm region. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
IEEE Journal of Selected Topics in Quantum Electronics, 2008
Two heavily doped n-type Zn 0 .46 Cd 0 .54 Se/Zn 0 .24 Cd 0 .25 Mg 0 .51 Se multiple quantum well (MQW) structures have been grown on InP (0 0 1) substrates by molecular beam epitaxy. Photoluminescence (PL), time-resolved PL, and Fourier transform infrared (FTIR) spectroscopy were performed to characterize their interband and intersubband (ISB) properties. These two MQW samples have similar structures except for different well widths and a different number of periods. Excitation-intensity-dependent PL shows no electronic coupling between the multiquantum wells. The integrated PL intensities and the PL decay times of the MQWs were measured as functions of temperature in the range from 77 to 290 K. Theoretical fittings of temperature dependences of integrated PL intensities and PL decay times indicate that the nonradiative recombination processes observed in our samples can be well described by hole capture by acceptor-like defect centers through multiphonon emissions. ISB absorption spectra of the samples were measured by FTIR and show peak absorption at wavelengths of 3.99 and 5.35 µm for the MQWs with well widths of 28 and 42Å, respectively. Theoretical calculations based on the envelope function approximation confirm that these peaks are due to the transitions from the ground state E 1 to the first excited state E 2 .
Optical properties of Zn0.5Cd0.5Se thin films grown on InP by molecular beam epitaxy
Solid State Communications, 2003
We report photoluminescence (PL) and reflectivity measurements of Zn 0.5 Cd 0.5 Se epilayers grown by molecular beam epitaxy on InP substrates. The low-temperature PL spectra are dominated by asymmetric lines, which can be deconvoluted into two Gaussian peaks with a separation of ,8 meV. The behavior of these peaks is studied as a function of excitation intensity and temperature, revealing that these are free exciton (FE) and bound exciton emission lines. Two lower energy emission lines are also observed and assigned to the first and second longitudinal optical phonon replicas of the FE emission. The temperature dependence of the intensity, line width, and energy of the dominant emission lines are described by an Arrhenius plot, a Bose-Einstein type relationship, Varshni's and Bose-Einstein equations, respectively.
Study of ZnCdSe/ZnSe quantum-wells grown by molecular-beam epitaxy on ZnSe substrates
Journal of Crystal Growth, 1998
ZnCdSe/ZnSe multiple quantum-well (MQW) structures were grown by MBE on ZnSe(0 0 1) substrates prepared by seeded chemical-vapour transport (SCVT) in hydrogen. Scanning force microscopy (SFM) analysis of these structures was performed. A method for the preparation of the substrate surface was found that resulted in a decrease of the root-mean-square (RMS) roughness of the MQW structure surfaces, down to 1 nm. For these structures intense cathodoluminescence (CL) from the QWs was observed. By e-beam pumping a microcavity, pulse lasing was achieved at room temperature (RT). 0 1998 Elsevier Science B.V. All rights reserved.