Raman Scattering from GaAs Nanowires Grown by Molecular Beam Epitaxy

2007 ◽  
Vol 31 ◽  
pp. 23-26 ◽  
Author(s):  
N. Begum ◽  
A.S. Bhatti ◽  
M. Piccin ◽  
G. Bais ◽  
F. Jabeen ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Structural Defects ◽  
Structural Quality ◽  
Spintronic Devices ◽  
Gaas Nanowires ◽  
Potential Applications ◽  
Self Assembled ◽  
Substrate Temperatures

Self-assembled nanowires have attracted much attention due to their potential applications in electronics and optoelectronics. A recent interest in Mn catalyzed GaAs nanowires are due to their potential use in spintronic devices at nanoscale. High densities of Au- and Mncatalyzed self-assembled GaAs nanowires (NWs) with diameter in the range of 20 to 200 nm and length of few microns were synthesized by molecular beam epitaxy (MBE) on different substrates at varied substrate temperatures. These nanowires were investigated by means of μ-Raman spectroscopy at room temperature. The Raman spectra from NWs show an energy downshift and a broadening of the LO and TO phonon lines that differ from those of epitaxial GaAs. We suggest that those downshift and broadening are due to the relaxation of the q=0 selection rule in the presence of structural defects in the nanowires. The results indicate that the use of Mn instead of Au as growth catalyst does not affect the structural quality of the nanowires drastically.

scholarly journals Morphology and surface reconstructions of m-plane GaN

2002 ◽  
Vol 743 ◽  
Author(s):  
C. D. Lee ◽  
R. M. Feenstra ◽  
J. E. Northrup ◽  
L. Lymperakis ◽  
J. Neugebauer
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Surface Morphology ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Structural Quality ◽  
Surface Reconstructions ◽  
Gan Buffer Layer

ABSTRACTM-plane GaN(1100) is grown by plasma assisted molecular beam epitaxy on ZnO(1100) substrates. A low-temperature GaN buffer layer is found to be necessary to obtain good structural quality of the films. Well oriented (1100) GaN films are obtained, with a slate like surface morphology. On the GaN(1100) surfaces, reconstructions with symmetry of c(2×2) and approximate “4×5” are found under N- and Ga-rich conditions, respectively. We propose a model for Ga-rich conditions with the “4×5” structure consisting of ≥ 2 monolayers of Ga terminating the GaN surface.

Improved structural quality of molecular‐beam epitaxy HgCdTe films

1989 ◽  
Vol 7 (2) ◽  
pp. 517-522 ◽  
Author(s):  
R. J. Koestner ◽  
H.‐Y. Liu ◽  
H. F. Schaake ◽  
T. R. Hanlon
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Structural Quality

InAsSb Photodiodes Grown on InAs, GaAs and Si Substrates by Molecular Beam Epitaxy

1990 ◽  
Vol 216 ◽  
Author(s):  
W. Dobbelaere ◽  
J. De Boeck ◽  
W. De Raedt ◽  
J. Vanhellemont ◽  
G. Zou ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Spectral Response ◽  
Structural Quality ◽  
Rutherford Back Scattering ◽  
Si Substrates ◽  
Transmission Electron ◽  
Current Voltage ◽  
K Current

ABSTRACTInAs and InAs0.85Sb0.15p-“i”-n structures were grown on InAs, GaAs and Si substrates by Molecular Beam Epitaxy. The structural quality of the layers is discussed using Transmission Electron Microscopy and Rutherford Back Scattering. The influence of the material quality on the 77 K current-voltage measurements is explained. The spectral response of the devices was measured demonstrating peak responsivities of 2.1 A/W at 3.5μm wavelength for InAs0.85Sb0.15 detectors with a 4.3 μm cut-off wavelength.

scholarly journals Спонтанное и стимулированное излучение двухчастотного квантово-каскадного лазера

2019 ◽  
Vol 53 (3) ◽  
pp. 365
Author(s):  
А.В. Бабичев ◽  
А.Г. Гладышев ◽  
А.С. Курочкин ◽  
Е.С. Колодезный ◽  
В.Н. Неведомский ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Spontaneous Emission ◽  
Solid Solutions ◽  
Quantum Cascade Laser ◽  
Molecular Beam ◽  
Laser Generation ◽  
Structural Quality ◽  
Quantum Cascade ◽  
Inp Substrate

AbstractThe results of experiments on the fabrication (by molecular-beam epitaxy) and investigation of the heterostructures of a two-frequency quantum-cascade laser produced on the basis of a heteropair of In_0.53Ga_0.47As/Al_0.48In_0.52As solid solutions on an InP substrate are presented. The heterostructures contained quantum cascades emitting at a wavelength of 9.6 μm and cascades emitting at a wavelength of 7.6 μm. The high structural quality of the fabricated heterostructures is shown. The spontaneous emission and lasing spectra are investigated and the multimodal laser generation of stripe lasers at a wavelength of 7.6 μm is demonstrated.

Surface States at LT GaAs-n+ GaAs Interfaces

1992 ◽  
Vol 281 ◽  
Author(s):  
Ashlsh K. Verma ◽  
J. S. Smith ◽  
Eicke R. Weber
Keyword(s):  
Molecular Beam ◽  
Surface States ◽  
Electrical Measurements ◽  
Interface Quality ◽  
Channel Mobility ◽  
Gaas Mesfet ◽  
Potential Applications ◽  
Substrate Temperatures ◽  
Lt Gaas

GaAs grown using Molecular Beam Epitaxy at below normal substrate temperatures (∼ 220 °C) has found many potential applications in GaAs MESFET devices. These so-called Low Temperature (LT) layers were originally used between the MESFET substrate and active region to eliminate backgating effects.[1] More recently, LT layers have been incorporated into MESFET gate structures to improve gate breakdown characteristics.[2] [3] When used in this capacity, the quality of the LT GaAs - n+ GaAs interface becomes an important issue: a large number of traps at the interface will result in channel mobility degradation. Furthermore, it is desirable to develop a method by which the interface quality can be evaluated through simple electrical measurements.

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