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651.  In1- x TlxSb for Long-Wavelength Infrared Photodetectors
Y.H. Choi, P.T. Staveteig, E. Bigan, and M. Razeghi
-- October 10, 1993
 
652.  Comparison of the Physical Properties of GaN Thin Films Deposited on (0112) and (0001) Sapphire Substrates
C.J. Sun and M. Razeghi
Applied Physics Letters 63 (7)-- August 16, 1993
A direct comparison of the physical properties of GaN thin films is made as a function of the choice of substrate orientations. Gallium nitride single crystals were grown on (0001) and (0112) sapphire substrates by metalorganic chemical vapor deposition. Better crystallinity with fine ridgelike facets is obtained on the (0112) sapphire. Also lower carrier concentration and higher mobilities indicate both lower nitrogen vacancies and less oxygen incorporation on the (0112) sapphire. The results of this study show better physical properties of GaN thin films achieved on (0112) sapphire. reprint
 
653.  Transport properties in n-type InSb films grown by metalorganic chemical vapor deposition
S.N. Song, J.B. Ketterson, Y.H. Choi, R. Sudharsanan, and M. Razeghi
Applied Physics Letters 63 (7)-- August 16, 1993
We have measured the temperature and magnetic field dependence of the Hall mobility and transverse magnetoresistance in n-type InSb films epitaxially grown on GaAs substrates by metalorganic chemical vapor deposition. The films show a giant magnetoresistance: e.g., at 240 K the resistivity increases over 20 times at a magnetic field of 5 T; the low field coefficient of resistivity at 77 K is as high as 47.5 μ·Ω· cm/G. The Hall mobility decreases with magnetic field and saturates at higher fields. By taking the interface carrier transport into account, the observed field dependence of the Hall mobility and magnetoresistance may be understood based on a two-layer model. reprint
 
654.  Growth of In1-xTlxSb, a New Infrared Material, by Low-Pressure Metalorganic Chemical Vapor Deposition
Y.H. Choi, R. Sudharsanan, C, Besikci, and M. Razeghi
Applied Physics Letters 63 (3)-- July 19, 1993
We report the growth of In1-xTlxSb, a new III-V alloy for long-wavelength infrared detector applications, by low-pressure metalorganic chemical vapor deposition. In1-xTlxSb with good surface morphology was obtained on both GaAs and InSb substrates at a growth temperature of 455 °C. X-ray diffraction measurements showed resolved peaks of In1-xTlxSb and InSb films. Infrared absorption spectrum of In1-xTlxSb showed a shift toward lower energies compared to InSb spectrum. Hall mobility data on In1-xTlxSb/InSb/GaAs structure showed enhanced mobility at low temperatures compared to InSb/GaAs structure. reprint
 
655.  GaInAsP/InP 1.35 μm Double Heterostructure Laser Grown on Silicon Substrate by Metalorganic Chemical Vapor Deposition
K. Mobarhan, C. Jelen, E. Kolev, and M. Razeghi
Journal of Applied Physics 74 (1)-- July 1, 1993
A 1.35 μm GaInAsP/InP double heterostructure laser has been grown on a Si substrate using low‐pressure metalorganic chemical vapor deposition. This was done without the use of a superlattice layer or a very thick InP buffer layer, which are used to prevent the dislocations from spreading into the active layer. Pulsed operation with output power of over 200 mW per facet was achieved at room temperature for broad area lasers with 20 μm width and 170 μm cavity length. The threshold current density of a 350 μm cavity length device was 9.8 kA/cm². The characteristic temperature was 66 K. reprint
 
656.  Anomalous Hall Effect in InSb Layers Grown by MOCVD on GaAs Substrates
C. Besikci, Y.H. Choi, R. Sudharsanan, and M. Razeghi
Journal of Applied Physics 73 (10)-- May 15, 1993
InSb epitaxial layers have been grown on GaAs substrates by low‐pressure metalorganic chemical vapor deposition. A 3.15 μm thick film yielded an x‐ray full width at half maximum of 171 arcsec. A Hall mobility of 76  200 cm²/V· s at 240 K and a full width at half maximum of 174 arcsec have been measured for a 4.85 μm thick epilayer. Measured Hall data have shown anomalous behavior. A decrease in Hall mobility with decreasing temperature has been observed and room‐temperature Hall mobility has increased with thickness. In order to explain the anomalous Hall data, and the thickness dependence of the measured parameters, the Hall coefficient and Hall mobility have been simulated using a three‐layer model including a surface layer, a bulklike layer, and an interface layer with a high density of defects. Theoretical analysis has shown that anomalous behavior can be attributed to donor-like defects caused by the large lattice mismatch and to a surface layer which dominates the transport in the material at low temperatures.   reprint
 
657.  Investigation of the Heteroepitaxial Interfaces in the GaInP/GaAs Superlattices by High Resolution X-Ray Diffraction and Dynamical Solutions
Xiaoguang He and Manijeh Razeghi
Journal of Applied Physics 73 (7)-- April 1, 1993
Two GaAs/GaInP superlattices grown on GaAs substrates by low‐pressure metalorganic chemical vapor deposition have been studied using high resolution x‐ray diffraction measurements and simulations by solving Tagaki–Taupin equations. The strained layers at both interfaces of the GaAs well are identified from the simulations of the measured diffraction patterns. The purging of indium at the interface of GaInP/GaAs accounts for the strained layer at the GaInP/GaAs interface while the pressure difference in the gas lines, which results in the different traveling time to the sample surface, is attributed to the indium‐poor strained layer at the GaAs/GaInP interface. It is shown that high‐resolution x‐ray diffraction measurements combined with a dynamical simulation, are sensitive tools to study the heteroepitaxial interfaces on an atomic layer scale. In addition, the influence of a miscut of the substrate on the measurement is discussed in the article. It is shown that even though the miscut is small, the diffraction geometry is already an asymmetric one. More than 10% error in the superlattice period for a 2° miscut substrate can result when the miscut substrate is considered a symmetric geometry. reprint
 
658.  Well Resolved Room Temperature Photovoltage Spectra of GaAs-GaInP Quantum Wells and Superlattices
Xiaoguang He and Manijeh Razeghi
Applied Physics Letters 62 (6)-- February 8, 1993
We report the first well resolved room‐temperature photovoltage spectra due to the sublevel transitions in the GaInP‐GaAs superlattices and multiquantum wells grown by low pressure metalorganic chemical vapor deposition. Sharp well resolved peaks attributed to exciton absorption of the electron‐to‐light hole and electron‐to‐heavy hole have been observed at room temperature. This indicates that GaAs‐GaInP is a promising material for the application of the modulators, optical switches, and optical bistable divices. Satisfactory agreements between experimental measurements and theoretical results have been obtained. These results demonstrate that photovoltage spectroscopy is a simple, but very powerful tool to study quantum confinement structures.   reprint
 
659.  Intermixing of GaInP/GaAs Multiple Quantum Wells
C. Francis, M.A. Bradley, P. Boucaud, F.H. Julien and M. Razeghi
Applied Physics Letters 62 (2)-- January 11, 1993
The intermixing of GaInP‐GaAs superlattices induced by a heat treatment is investigated as a function of the annealing temperature and duration. Photoluminescence experiments reveal a large red shift of the effective band gap of the annealed quantum wells thus indicating a dominant self‐diffusion of the group III atoms which is confirmed by secondary ion mass spectroscopic measurements. For long enough annealing durations, the red shift saturates and even decreases due to the competing slower self‐diffusion of the group V atoms. Experiments are well understood based on a simple diffusion model. reprint
 
660.  Finite-Size Scaling in the Dissipative Transport Regime Between Quantum Hall Plateaus
Razeghi M., S. Koch, R.J. Hang, K.V. Klitzing, K. Ploog
-- January 1, 1993
 
661.  Splitting of the Landau Level Coincidence: A Novel Phase Transition in Tilted Magnetic Fields
Razeghi M., S. Koch, R.J. Hang, K.V. Klitzing
-- January 1, 1993
 
662.  Growth of InSb/GaAs layers on YIG-coated GGG substrate
C. Jelen, S. Charriere, M. Razeghi, and V.J. Leppert
-- January 1, 1993
 
663.  High Power 0.98 μm GaInAs/GaAs/GaInP Multiple Quantum Well Laser
K. Mobarhan, M. Razeghi, G. Marquebielle and E. Vassilaki
Journal of Applied Physics 72 (9)-- November 1, 1992
We report the fabrication of high quality Ga0.8In0.2As/GaAs/Ga0.51In0.49P multiple quantum well laser emitting at 0.98 μm grown by low pressure metalorganic chemical vapor deposition. Continuous wave operation with output power of 500 mW per facet was achieved at room temperature for a broad area laser with 130 μm width and 300 μm cavity length. This is an unusually high value of output power for this wavelength laser in this material system. The differential quantum efficiency exceeded 75% with excellent homogeneity and uniformity. The characteristic temperature, T0 was in the range of 120–130 K. reprint
 
664.  High Quality InSb Epitaxial Film Grown by Low Pressure Metalorganic Chemical Vapor Deposition
Y.H. Choi, R. Sudharsanan, C. Besikci, E. Bigan, and M. Razeghi
-- November 1, 1992
 
665.  Optical Investigations of GaAs-GaInP Quantum Wells Grown on the GaAs, InP, and Si Substrates
H. Xiaoguang, M. Razeghi
Applied Physics Letters 61 (14)-- October 5, 1992
We report the first photoluminescence investigation of GaAs‐Ga0.51In0.49P lattice matched multiquantum wells grown by the low pressure metalorganic chemical vapor deposition simultaneously in the same run on GaAs, Si, and InP substrates. The sharp photoluminescence peaks indicate the high quality of the samples on three different substrates. The temperature dependence of the photoluminescence indicates that the intrinsic excitonic transitions dominate at low temperature and free‐carrier recombinations at room temperature. The photoluminescence peaks of the samples grown on Si and InP substrates shift about 15 meV from the corresponding peaks of the sample grown on the GaAs substrate. Two possible interpretations are provided for the observed energy shift. One is the diffusion of In along the dislocation threads from GaInP to GaAs and another is the localized strain induced by defects and In segregations. reprint
 
666.  Frontiers of Monolithic Integration of Semiconductor III-V Optoelectronic Devices with Si Technology
M. Razeghi, R. Sudharsanan, and J.C.C. Fan
-- August 1, 1992
 
667.  GaInAs/GaAs/GaInP Buried Ridge Structure Single Quantum Well Laser Emitting at 0.98 μm
K. Mobarhan, M. Razeghi and R. Blondeau
-- July 30, 1992
 
668.  Evaluation of the Band Offsets of GaAs-GaInP Multilayers by Electroreflectance
Razeghi M., D. Yang, J.W. Garland, Z. Zhang, D. Xue
SPIE Proceedings, Vol. 1676, pp. 130-- January 1, 1992
We report the first band offset measurement of GaAs/Ga0.51In0.49P multiquantum wells and superlattices by electrolyte electroreflectance spectroscopy. The conduction and valence band discontinuities (Delta) Ec equals 159 ± 4 meV and (Delta) Ev equals 388 ± 6 meV have been measured. The values found for the conduction band, heavy-hole and light-hole masses in the GaInP barriers and GaAs wells and for the split-off well mass are in excellent agreement with the literature. The intraband, intersubband transition energies, which are important for III - V infrared detection devices, also were directly measured. reprint
 
669.  Caracterisation optique des semiconducteurs III-V par ellipsometrie et reflectance differentielle spectroscopique
Acher O., Omnes F., Razeghi M., Drevillion B.
-- September 1, 1991
 
670.  Incorporation of Impurities in GaAs Grown by MOCVD
Razeghi M., and M.A. di Forte-Poisson
-- September 1, 1991
 
671.  Etude du dopage de type n et p des materiaux GaAs et GaInP
Omnes F., Defour M., Razeghi M.
-- September 1, 1991
 
672.  GaAs-GaInP Multipayers for High Performance Electronic Devices
Omnes F., and Razeghi M.
-- September 1, 1991
 
673.  A Review of the Band Offsets Measurements in the GaAs/Ga0.49In0.51P System
Omnes F., and Razeghi M.
-- September 1, 1991
 
674.  Optical Investigations of GaAs-GaInP Quantum Wells and Superlattices Grown by Metalorganic Chemical Vapor Deposition
Omnes F., and Razeghi M.
Applied Physics Letters 59 (9), p. 1034-- May 28, 1991
Recent experimental results on the photoluminescence and photoluminescence excitation of GaAs‐Ga0.51In0.49P lattice‐matched quantum wells and superlattices are discussed. The full width at half maximum of a 10‐period GaAs‐GaInP superlattice with Lz=90 Å and LB=100 Å is 4 meV at 4 K. The photoluminescence excitation exhibits very sharp peaks attributed to the electron to light‐hole and electron to heavy‐hole transitions. The GaInP‐GaAs interface suffers from memory effect of In, rather than P or As elements. reprint
 
675.  Defects in Organometallic Vapor-Phase Epitaxy-Grown GaInP Layers
Feng S.L., Bourgoin J.C., Omnes F., and Razeghi M.
Applied Physics Letters 59 (8), p. 941-- May 28, 1991
Non-intentionally doped metalorganic vapor‐phase epitaxy Ga1−x InxP layers, having an alloy composition (x = 0.49) corresponding to a lattice matched to GaAs, grown by metalorganic chemical vapor deposition, have been studied by capacitance‐voltage and deep-level transient spectroscopy techniques. They are found to exhibit a free‐carrier concentration at room temperature of the order of 1015 cm−3. Two electron traps have been detected. The first one, at 75 meV below the conduction band, is in small concentration (∼1013 cm−3) while the other, at about 0.9 eV and emitting electrons above room temperature, has a concentration in the range 1014–1015 cm−3. reprint
 

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