Formation of Quantum Wires by Strain-Induced Lateral-Layer Ordering Process: Growth Mechanism and Device Applications

1995 ◽  
Vol 417 ◽  
Author(s):  
K. Y. Cheng ◽  
K. C. Hsieh
Keyword(s):  
Quantum Wells ◽  
Quantum Wires ◽  
Active Regions ◽  
Growth Direction ◽  
Single Step ◽  
Composition Modulation ◽  
Gaas Substrates ◽  
Straightforward Method ◽  
Device Applications ◽  
Substrate Patterning

AbstractGaxIn1−xAs and GaxIn1−xP quantum wire (QWR) arrays were grown by a single-step molecular beam epitaxy. Lateral Ga(In composition modulation perpendicular to the growth direction occurs spontaneously during the growth of (GaAs)m/(InAs)n or (GaP)m/(InP)n shortperiod superlattices on InP or GaAs substrates, respectively, by the strain-induced lateral-layer ordering (SILO) process, producing lateral quantum wells. This straightforward method employs standard on-axis (001)-oriented substrates, and requires no pre-growth substrate patterning, nor does it involve post-growth processing for the formation of QWRs. Both GaxIn1−xAs infrared (1.7 μm) lasers and GaxIn1−xP visible (0.7 μm) lasers with QWR active regions have been successfully fabricated. These lasers showed many unique features that have never been observed in quantum well lasers.

Damage, Strain and Quantum Confinement Issues in Dry Etched Semiconductor Nanostructures

1995 ◽  
Vol 405 ◽  
Author(s):  
Y. S. Tang ◽  
C. M. Sotomayor Torres
Keyword(s):  
Quantum Wells ◽  
Residual Strain ◽  
Quantum Confinement ◽  
Quantum Wires ◽  
Growth Direction ◽  
Semiconductor Nanostructures ◽  
Multiple Quantum ◽  
Strain Component ◽  
Device Applications ◽  
Electron Beam Patterning

AbstractSemiconductor quantum wires and dots have been fabricated in GaAs/AlGaAs, CdTe/CdMnTe and Si/SiGe multiple quantum wells using electron beam patterning and reactive ion etching and studied by photoreflectance, photoluminescence and Raman scattering. It was found that the smaller the lateral size of the nanostructure, the smaller the fabrication induced residual strain. In all cases, the dominant strain component is found to be parallel to the sample growth direction, i.e., along the etched sidewalls of the etched wires and dots. The lateral confining potential is found to be quasi-parabolic for polar semiconductor systems. Possible ways of using and controlling the damage and residual strain in nanostructures are discussed in the context of device applications of nanostructures.

RECENT DEVELOPMENTS ON ELECTRON-PHONON INTERACTIONS IN STRUCTURES FOR ELECTRONIC AND OPTOELECTRONIC DEVICES

1998 ◽  
Vol 09 (01) ◽  
pp. 281-312 ◽  
Author(s):  
M. DUTTA ◽  
M. A. STROSCIO ◽  
K. W. KIM
Keyword(s):  
Quantum Wells ◽  
Quantum Wires ◽  
Quantum Cascade Lasers ◽  
Optoelectronic Devices ◽  
Longitudinal Optical ◽  
Optical Phonons ◽  
Phonon Modes ◽  
Cross Sectional ◽  
Device Applications ◽  
Dielectric Continuum

As device dimensions in electronic and optoelectronic devices are reduced, the characteristics and interactions of dimensionally-confined longitudinal-optical (LO) and acoustic phonons deviate substantially from those of bulk semiconductors. Furthermore, as würtzite materials are applied increasingly in electronic and optoelectronic devices it becomes more important to understand the phonon modes in such systems. This account emphasizes the properties of bulk optical phonons in würtzite structures, the properties of LO-phonon modes and acoustic-phonon modes arising in polar-semiconductor quantum wells, superlattices, quantum wires and quantum dots, with a variety of cross sectional geometries and, lastly, the properties of optical phonons in würtzite materials as predicted by the dielectric continuum model. Emphasis is placed on the dielectric continuum and elastic continuum models of bulk, confined and interface phonons. This article emphasizes device applications of confined phonons in GaAs-based systems and provides a brief discussion of carrier-LO-phonon interactions in bulk würtzite structures. This account also includes discussions on the use of metal-semiconductor heterointerfaces to reduce scattering and on the role of phonons in Fröhlich, deformation and piezoelectric interactions in electronic and optoelectronic structures; specific device applications high-lighted here include quantum cascade lasers, mesoscopic devices, thermoelectric devices and optically-pumped resonant intersubband lasers.

scholarly journals Metamorphic Integration of GaInAsSb Material on GaAs Substrates for Light Emitting Device Applications

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1743
Author(s):  
Qi Lu ◽  
Andrew Marshall ◽  
Anthony Krier
Keyword(s):  
Quantum Wells ◽  
Buffer Layer ◽  
Lattice Mismatch ◽  
Cost Effective ◽  
Threading Dislocations ◽  
Cross Sectional ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Gaas Substrates ◽  
Device Applications

The GaInAsSb material has been conventionally grown on lattice-matched GaSb substrates. In this work, we transplanted this material onto the GaAs substrates in molecular beam epitaxy (MBE). The threading dislocations (TDs) originating from the large lattice mismatch were efficiently suppressed by a novel metamorphic buffer layer design, which included the interfacial misfit (IMF) arrays at the GaSb/GaAs interface and strained GaInSb/GaSb multi-quantum wells (MQWs) acting as dislocation filtering layers (DFLs). Cross-sectional transmission electron microscopy (TEM) images revealed that a large part of the dislocations was bonded on the GaAs/GaSb interface due to the IMF arrays, and the four repetitions of the DFL regions can block most of the remaining threading dislocations. Etch pit density (EPD) measurements indicated that the dislocation density in the GaInAsSb material on top of the buffer layer was reduced to the order of 106 /cm2, which was among the lowest for this compound material grown on GaAs. The light emitting diodes (LEDs) based on the GaInAsSb P-N structures on GaAs exhibited strong electro-luminescence (EL) in the 2.0–2.5 µm range. The successful metamorphic growth of GaInAsSb on GaAs with low dislocation densities paved the way for the integration of various GaInAsSb based light emitting devices on the more cost-effective GaAs platform.

Determination of Optical Properties of the Micro-Facetted InGaAs Quantum Wells and Quantum Wires Using Magnetophotoluminescence

1996 ◽  
Vol 452 ◽  
Author(s):  
Sung-Bock Kim ◽  
Jeong-Rae Ro ◽  
El-Hang Lee
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Quantum Wells ◽  
Ground State ◽  
Quantum Confinement ◽  
Quantum Wires ◽  
Chemical Beam Epitaxy ◽  
Gaas Substrates ◽  
Planar Substrates

AbstractWe report optical properties of the micro-facetted InGaAs quantum wells and quantum wires on non-planar substrates employing magnetophotoluminescence (MPL). The InGaAs/GaAs structures were grown by chemical beam epitaxy on V-groove patterned GaAs substrates. In the presence of a magnetic field of 18 T, the diamagnetic shifts of exciton ground states of the (001)-and side-QWLs are ΔE=15.6 and 10.3 meV, respectively. In MPL of the facetted microstructure, we found that the different diamagnetic shifts strongly depend on the magnitude of the effective magnetic field as well as the quantum confinement. From comparing the intensities and full widths at half maximum, we easily found that side-QWLs are of higher quality than (OOl)-QWLs. We also fabricated InGaAs/GaAs quantum wires with a size of about 200 Å × (500–600) Å. By fitting the diamagnetic shifts (ΔΕ = 9.5 meV) of the exciton ground state with the calculated results of a variational method, we estimated that the reduced mass of the exciton is approximately 0.052 me.

Strain measurement in In0.2Ga0.8As/GaAs quantum wires by convergent beam electron diffraction

1995 ◽  
Vol 53 ◽  
pp. 444-445
Author(s):  
S. Hillyard ◽  
Y.-P. Chen ◽  
J.D. Reed ◽  
W.J. Schaff ◽  
L.F. Eastman ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Semiconductor Lasers ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Convergent Beam Electron Diffraction ◽  
Zero Order ◽  
Beam Electron ◽  
Local Lattice ◽  
Device Applications ◽  
Convergent Beam

The positions of high-order Laue zone (HOLZ) lines in the zero order disc of convergent beam electron diffraction (CBED) patterns are extremely sensitive to local lattice parameters. With proper care, these can be measured to a level of one part in 104 in nanometer sized areas. Recent upgrades to the Cornell UHV STEM have made energy filtered CBED possible with a slow scan CCD, and this technique has been applied to the measurement of strain in In0.2Ga0.8 As wires.Semiconductor quantum wire structures have attracted much interest for potential device applications. For example, semiconductor lasers with quantum wires should exhibit an improvement in performance over quantum well counterparts. Strained quantum wires are expected to have even better performance. However, not much is known about the true behavior of strain in actual structures, a parameter critical to their performance.

Characterization of GaAs/AlGaAs quantum wells and quantum wires by chemical lattice imaging

1994 ◽  
Vol 52 ◽  
pp. 736-737
Author(s):  
A. Carlsson ◽  
J.-O. Malm ◽  
A. Gustafsson
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Wires ◽  
Vapour Phase ◽  
Quantitative Information ◽  
Lattice Imaging ◽  
Vapour Phase Epitaxy ◽  
Metalorganic Vapour Phase Epitaxy ◽  
High Resolution Images

In this study a quantum well/quantum wire (QW/QWR) structure grown on a grating of V-grooves has been characterized by a technique related to chemical lattice imaging. This technique makes it possible to extract quantitative information from high resolution images.The QW/QWR structure was grown on a GaAs substrate patterned with a grating of V-grooves. The growth rate was approximately three monolayers per second without growth interruption at the interfaces. On this substrate a barrier of nominally Al0.35 Ga0.65 As was deposited to a thickness of approximately 300 nm using metalorganic vapour phase epitaxy . On top of the Al0.35Ga0.65As barrier a 3.5 nm GaAs quantum well was deposited and to conclude the structure an additional approximate 300 nm Al0.35Ga0.65 As was deposited. The GaAs QW deposited in this manner turns out to be significantly thicker at the bottom of the grooves giving a QWR running along the grooves. During the growth of the barriers an approximately 30 nm wide Ga-rich region is formed at the bottom of the grooves giving a Ga-rich stripe extending from the bottom of each groove to the surface.

45° REFLECTOMETRY OF SEMICONDUCTOR QUANTUM WELLS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 683-687
Author(s):  
A. SILVA-CASTILLO ◽  
F. PEREZ-RODRIGUEZ
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Growth Direction ◽  
Angle Of Incidence ◽  
Near Surface ◽  
New Information ◽  
Difference Formula ◽  
Exciton Polaritons ◽  
The Difference ◽  
First Time

We have applied the 45° reflectometry for the first time to study exciton-polaritons in quantum wells. The 45° reflectometry is a new polarization-modulation technique, which is based on the measurement of the difference [Formula: see text] between the p-polarization reflectivity (Rp) and the squared s-polarization reflectivity [Formula: see text] at an angle of incidence of 45°. We show that [Formula: see text] spectra may provide qualitatively new information on the exciton-polariton modes in a quantum well. These optical spectra turn out to be very sensitive to the zeros of the dielectric function along the quantum-well growth direction and, therefore, allow to identify the resonances associated with the Z exciton-polariton mode. We demonstrate that 45° reflectometry could be a powerful tool for studying Z exciton-polariton modes in near-surface quantum wells, which are difficult to observe in simple spectra of reflectivity Rp

Low-Lattice-Strain Long-Wavelength GaAsSb/GaInAs Type-II Quantum Wells Grown on GaAs Substrates

2002 ◽  
Vol 41 (Part 2, No. 10A) ◽  
pp. L1040-L1042 ◽  
Author(s):  
Makoto Kudo ◽  
Kiyoshi Ouchi ◽  
Jun-ichi Kasai ◽  
Tomoyoshi Mishima
Keyword(s):  
Quantum Wells ◽  
Lattice Strain ◽  
Type Ii ◽  
Long Wavelength ◽  
Gaas Substrates ◽  
Type Ii Quantum Wells

Ultrafast Carrier Dynamics, Optical Amplification, and Lasing in Nanocrystal Quantum Dots

MRS Bulletin ◽  
2001 ◽  
Vol 26 (12) ◽  
pp. 998-1004 ◽  
Author(s):  
Victor I. Klimov ◽  
Moungi G. Bawendi
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Quantum Wires ◽  
Electronic States ◽  
Three Dimensions ◽  
Band Edge ◽  
Lasing Threshold ◽  
Wide Energy Range ◽  
Band Edge Emission ◽  
Edge States

Semiconductor materials are widely used in both optically and electrically pumped lasers. The use of semiconductor quantum wells (QWs) as optical-gain media has resulted in important advances in laser technology. QWs have a two-dimensional, step-like density of electronic states that is nonzero at the band edge, enabling a higher concentration of carriers to contribute to the band-edge emission and leading to a reduced lasing threshold, improved temperature stability, and a narrower emission line. A further enhancement in the density of the band-edge states and an associated reduction in the lasing threshold are in principle possible using quantum wires and quantum dots (QDs), in which the confinement is in two and three dimensions, respectively. In very small dots, the spacing of the electronic states is much greater than the available thermal energy (strong confinement), inhibiting thermal depopulation of the lowest electronic states. This effect should result in a lasing threshold that is temperatureinsensitive at an excitation level of only 1 electron-hole (e-h) pair per dot on average. Additionally, QDs in the strongconfinement regime have an emission wavelength that is a pronounced function of size, adding the advantage of continuous spectral tunability over a wide energy range simply by changing the size of the dots.

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