AES and EELFS Studies of Initial Stages of Growth of GaAs/InAs/GaAs Heterostructures.

ABSTRACTWe report on a systematic study of the composition and structure of GaAs/InAs/GaAs quantum wells using Auger Electron Spectroscopy (AES), Extended Energy Loss Fine Structure (EELFS), and Reflection High Energy Electron Diffraction (RHEED) techniques. Double heterostructures with InAs thickness ranging from 2 to 10 monolayers, capped by 2 to 10 monolayers of GaAs, were grown by MBE using a variety of techniques, including those employing sequential, interrupted, and delayed shutter timing sequences. AES peak ratios are compared with model calculations to monitor compositional development of the multilayers. The AES results are correlated with RHEED measurements to determine MBE growth parameters for optimal control of the stoichiometry and surface morphology. EELFS was used to monitor strain in the buried InAs layers. The AES results show departure from smooth laminar growth of layers of stoichiometric InAs on GaAs at temperatures below 420 C and above 470 C. AES results on the quantum well structures suggest floating InAs layers on top of the GaAs and/or facet formation in the GaAs layers. The EELFS results, when compared to bulk InAs, indicate the presence of strain in the buried InAs quantum well.

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MOCVD Growth and Characterization of GaInNAs/GaAs/InGaAs/GaAs Quantum Well Structures

MRS Proceedings ◽

10.1557/proc-744-m8.16 ◽

2002 ◽

Vol 744 ◽

Author(s):

Abdel-Rahman A. El-Emawy ◽

Hongjun Cao ◽

Noppadon Nuntawong ◽

Chiyu Liu ◽

Marek Osiński

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Growth Parameters ◽

Multiple Quantum Well ◽

Double Quantum ◽

Multiple Quantum ◽

Quantum Well Structures ◽

Mocvd Growth ◽

Double Quantum Well ◽

Wavelength Emission

ABSTRACTEffects of MOCVD growth parameters on structural and optical properties of double-quantum-well (DQW) structures containing uncoupled GaInNAs/GaAs and InGaAs/GaAs quantum wells have been investigated. By varying growth temperature, growth rate, V/III ratio, and DMHy flow rates, we have achieved a longer-wavelength emission from a GaInNAs well than from an InGaAs well grown in the same structure. GaInNAs/GaAs multiple-quantum-well structures grown under optimum conditions emitted at 1.25 μm.

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EuTe/PbTe Superlattices: Mbe Growth and Optical Characterization

MRS Proceedings ◽

10.1557/proc-301-353 ◽

1993 ◽

Vol 301 ◽

Cited By ~ 2

Author(s):

G. Springholz ◽

Shu Yuan ◽

G. Bauer ◽

M. Kriechbaum ◽

H. Krenn

Keyword(s):

Quantum Wells ◽

Band Gap ◽

Growth Parameters ◽

Energy Levels ◽

Wide Band ◽

Growth Conditions ◽

High Energy ◽

Layer By Layer ◽

Heteroepitaxial Growth ◽

Mbe Growth

ABSTRACTThe heteroepitaxial growth of EuTe on PbTe (111) by molecular beam epitaxy (MBE) was investigated using in situ reflection high energy electron diffraction (RHEED). As a function of substrate temperature and Te2 flux rate, the resulting EuTe (111) surfaces exhibit several different surface reconstructions corresponding to Te-stabilized or Eu-stabilized surfaces. The Eustabilized surface shows a (2√3 × 2√3)R30° surface reconstruction. Because of the strain induced tendency for 3D islanding, only in a narrow window of MBE growth parameters perfect 2D layer-by-layer heteroepitaxial growth exists. Using such optimized MBE growth conditions, we have fabricated a series of PbTe/EuTe superlattices. In such superlattices the wide band gap EuTe layers act as barriers and the narrow band gap PbTe as quantum wells. The superlattices were investigated by high resolution x-ray diffraction, showing their high structural perfection. Modulated low temperature Fourier transform infrared reflection measurements were performed in order to determine the confined energy levels in the PbTe quantum wells. The measurements indicate that mini-subbands are formed in the PbTe quantum wells with a mini-band width of 22 meV in agreement with envelope function calculations.

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Light Emission Properties of GaN-Based Double Heterostructures and Quantum Wells

MRS Proceedings ◽

10.1557/proc-395-949 ◽

1995 ◽

Vol 395 ◽

Cited By ~ 2

Author(s):

D.A.S. Loeber ◽

J.M. Redwing ◽

N.G. Anderson ◽

M.A. Tischler

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Stimulated Emission ◽

Pump Light ◽

Band Edge Emission ◽

Emission Characteristics ◽

Nitrogen Laser ◽

Edge Emission ◽

Edge Luminescence ◽

Double Heterostructures

ABSTRACTEdge emission characteristics of optically pumped GaN-AlGaN double heterostructures and quantum wells are examined. The samples, which were grown by metalorganic vapor phase epitaxy, are photoexcited with light from a pulsed nitrogen laser. The pump light is focused to a narrow stripe on the sample surface, oriented perpendicular to a cleaved edge, and the edge luminescence is collected and analyzed. We first compare emission characteristics of highly excited GaN-AlGaN double heterostructures grown simultaneously on SiC and sapphire substrates. Polarization resolved spectral properties of edge luminescence from both structures is studied as a function of pump intensity and excitation stripe length. Characteristics indicative of stimulated emission are observed, particularly in the sample grown on SiC. We then present results demonstrating laser emission from a GaN-AlGaN separate-confinement quantum-well heterostructure. At high pump intensities, band edge emission from the quantum well exhibits five narrow (∼1 Å) modes which are evenly spaced by 10Å to within the resolution of the spectrometer. This represents the first demonstration of laser action in a GaN-based quantum-well structure.

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Analytical perturbation derivation of the exciton binding energy in generalized infinite quantum wells: Application to type-I and -II finite-quantum-well structures

Physical Review B ◽

10.1103/physrevb.53.3983 ◽

1996 ◽

Vol 53 (7) ◽

pp. 3983-3986 ◽

Cited By ~ 1

Author(s):

Guy Debarge ◽

Didier Erasme ◽

Angel Toledo-Alvarez

Keyword(s):

Binding Energy ◽

Quantum Well ◽

Quantum Wells ◽

Exciton Binding Energy ◽

Type I ◽

Quantum Well Structures ◽

Analytical Perturbation

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Photoluminescence Fatigue in Laterally-Ordered (GaP)2/(InP)2 Short-Period-Superlattices (SPS) Grown by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-325-131 ◽

1993 ◽

Vol 325 ◽

Author(s):

X. C. Liu ◽

S. Q. Gu ◽

E. E. Reuter ◽

S. G. Bishop ◽

A. C. Chen ◽

...

Keyword(s):

Molecular Beam Epitaxy ◽

Quantum Well ◽

Quantum Wells ◽

Lower Energy ◽

Molecular Beam ◽

Continuous Illumination ◽

Exciting Light ◽

Quantum Well Structures ◽

Short Period ◽

Short Period Superlattices

AbstractSpontaneously laterally ordered (GaP)2/(InP)2 short period superlattices (SPS) grown by Molecular Beam Epitaxy (MBE) on nominal (100) GaAs substrates have been studied by photoluminescence (PL) spectroscopy. The samples studied included SPS comprising 110 pairs of (GaP)2/(InP)2 (total thickness σ90 nm) and multiquantum well structures in which quantum wells comprising 12 pairs of (GaP)2/(InP)2 SPS layers (thickness σ10 nm) are alternated with lattice-matched GaInP random alloy barrier layers. The 5K PL spectra include a σ1760 meV nearband edge band, and a much broader, lower energy (σ1670 meV) luminescence band that exhibits an unusual fatiguing behavior; its intensity diminishes monotonically during continuous illumination by the exciting light. This fatigued PL state is metastable at low temperatures. In the quantum well structure, although the relative intensity of the lower energy band is significantly weaker in comparison to the higher one, the fatiguing behavior still exists. However the fatiguing rate is slower in quantum well structures than that observed in the thick SPS film.

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A THEORETICAL AND EXPERIMENTAL STUDY OF ELECTRONIC CONFINEMENT, COUPLING, AND TRANSLAYER INTERACTION IN NOBLE-METAL QUANTUM-WELL STRUCTURES

Modern Physics Letters B ◽

10.1142/s0217984994001084 ◽

1994 ◽

Vol 08 (18) ◽

pp. 1075-1096 ◽

Cited By ~ 3

Author(s):

W. E. MCMAHON ◽

T. MILLER ◽

T.-C. CHIANG

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Noble Metal ◽

Experimental Studies ◽

Surface States ◽

Double Quantum ◽

Multilayer Systems ◽

Quantum Well Structures ◽

Double Quantum Well ◽

Bloch Electrons

Noble-metal multilayer systems have been grown and examined with angle-resolved photoemission. Surface states, and single and double quantum wells have been studied experimentally; the results can be explained with a simple theoretical model based upon Bloch electrons. In this paper, we will present our model and then give a description of some experimental studies which utilize the model. In particular, we will consider double-quantum-well systems which can be used to examine basic aspects of electronic confinement, layer–layer coupling, and translayer interaction through a barrier.

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Optical Gain Spectra in InGaN/GaN Quantum Wells with the Compositional Fluctuations

MRS Proceedings ◽

10.1557/proc-537-g2.9 ◽

1998 ◽

Vol 537 ◽

Author(s):

Takeshi Uenoyama

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Optical Gain ◽

Inhomogeneous Broadening ◽

Localized States ◽

Quantum Well Structures ◽

Potential Fluctuation ◽

Quantum Disk ◽

Gain Spectra

The compositional fluctuations of the In content were found in InGaN/GaN quantum wells and it caused the localized states by the potential fluctuation. We have evaluated the optical gain of GaN based quantum well structures with localized states. The localized states are treated as the subband states of the quantum disk-like dots in the well. It was found that the inhomogeneous broadening played an important role in the optical gain and that it should be reduced to use the benefit of the localized states for laser oscillations.

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MBE growth optimization of InyGa1-yAs/GaAs multiple quantum well structures

Journal of Crystal Growth ◽

10.1016/0022-0248(93)90679-q ◽

1993 ◽

Vol 127 (1-4) ◽

pp. 541-545 ◽

Cited By ~ 12

Author(s):

E.C. Larkins ◽

W. Rothemund ◽

M. Maier ◽

Z.M. Wang ◽

J.D. Ralston ◽

...

Keyword(s):

Quantum Well ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Mbe Growth ◽

Quantum Well Structures ◽

Growth Optimization

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MBE Growth of III-V Nitride Films and Quantum-Well Structures Using Multiple RF Plasma Sources

MRS Proceedings ◽

10.1557/proc-449-271 ◽

1996 ◽

Vol 449 ◽

Cited By ~ 9

Author(s):

M. A. L. Johnson ◽

Zhonghai Yu ◽

C. Boney ◽

W. H. Rowland ◽

W. C. Hughes ◽

...

Keyword(s):

Quantum Well ◽

Deep Level ◽

Buffer Layers ◽

Rf Plasma ◽

Multiple Sources ◽

Single Quantum Well ◽

Active Nitrogen ◽

Mbe Growth ◽

Plasma Sources ◽

Quantum Well Structures

ABSTRACTMBE growth of III-V nitrides is being studied at NCSU using MOVPE grown GaN buffer layers on SiC as substrates. Rf plasma sources are being used for the generation of active nitrogen during MBE deposition. Through the use of multiple rf plasma sources, sufficient active nitrogen is generated in order to examine the properties of III-V nitride layers grown at higher substrate temperatures and growth rates. The resulting MBE-grown GaN films exhibit remarkably intense photoluminescence (PL) dominated by a sharp band-edge peak at 3.409 eV having a FWHM of 36 meV at 300K. No deep level emission is observed. AlGaN and InGaN films and quantum well structures have also been prepared using multiple sources. A modulated beam MBE approach is used in conjunction with the multiple rf plasma sources to grow InGaN. RHEED and TEM studies reveal flat 2D InGaN quantum well structures. Depending on the indium content, GaN/InGaN single-quantum-well structures exhibit electroluminescence at 300K peaked in the blue-violet to the green spectral region.

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