A5013781069- Semiconductor Quantum Structures and Devices
- Advanced Semiconductor Detectors and Materials
- Semiconductor Lasers and Optical Devices
- Quantum and electron transport phenomena
- Photonic and Optical Devices
- Chalcogenide Semiconductor Thin Films
- Spectroscopy and Laser Applications
- Optical properties and cooling technologies in crystalline materials
- Acoustic Wave Resonator Technologies
- Quantum Dots Synthesis And Properties
- Metallurgical Processes and Thermodynamics
- Advanced Electron Microscopy Techniques and Applications
- Crystallography and Radiation Phenomena
- Materials Engineering and Processing
- Gas Sensing Nanomaterials and Sensors
- Integrated Circuits and Semiconductor Failure Analysis
- Electron and X-Ray Spectroscopy Techniques
- solar cell performance optimization
- CCD and CMOS Imaging Sensors
- Advanced Fiber Laser Technologies
- Semiconductor materials and interfaces
- Infrared Target Detection Methodologies
- Silicon Nanostructures and Photoluminescence
- Terahertz technology and applications
- Semiconductor materials and devices
University of Science and Technology Liaoning
2024
Arizona State University
2003-2015
University of Notre Dame
2012
Time-resolved photoluminescence measurements reveal a minority carrier lifetime of >412 ns at 77 K under low excitation for long-wavelength infrared InAs/InAs0.72Sb0.28 type-II superlattice (T2SL). This represents an order-of-magnitude increase in the over previously reported lifetimes InAs/Ga1−xInxSb T2SLs. The considerably longer is attributed to reduction non-radiative recombination centers with removal Ga from structure. improvement may enable background limited T2SL...
In order to explore the reaction mechanism of high‐manganese high‐aluminum steel and glazed MgO refractory, a series high‐temperature experiments are carried out with Fe‐30Mn‐2Al‐C three kinds refractory (the basicity ladle glaze was 4, 8, 12 respectively) as research objects. The changes in thickness composition determined corrosion behavior on is investigated. results show that lower glaze, easier falls off after reaction. [Mn] [Al] will transfer form MnO, (Mn, Mg)O·Al 2 O 3 spinel,...
Strain-balanced InAs/InAsSb superlattices offer access to the mid- long-wavelength infrared region with what is essentially a ternary material system at GaSb lattice constant. The absorption coefficients of grown by molecular beam epitaxy on (100)-oriented substrates are measured room temperature over 30 800 meV photon energy range using spectroscopic ellipsometry, and miniband structure each superlattice calculated Kronig-Penney model. conduction band offset used as fitting parameter align...
We discuss the growth by molecular-beam epitaxy, and studies of low-temperature electrical properties, undoped InAs/AlSb quantum wells. The two-dimensional electron gas realized in wells exhibits high mobility at low temperatures, an analysis its Shubnikov–de Haas oscillations suggests this is limited scattering from remotely located unintentional dopants. Spin splitting clearly resolved 4.2 K, revealing a g-factor as large −60 magnetic fields. size enhancement increases with decreasing...
The nonradiative lifetime and spontaneous emission quantum efficiency in molecular-beam epitaxy grown bulk GaAs is determined using injection level dependent photoluminescence (PL) measurements. These measurements were performed at temperatures of 300, 230, 100, 50K a HeNe pump laser with powers ranging from 0.3to40mW. inferred the power law relation linking integrated PL signal that predicted by rate equations. for to be 0.3μs, an additional temperature component attributed AlGaAs barriers...
A two-terminal multicolor photodetector that is most advantageous for greater than two bands proposed. This design particularly significant focal plane arrays as it maximizes the fill factor and simplifies readout integrated circuits. Individual color detection realized with appropriate optical biasing. concept demonstrated experimentally using a three-color biasing light emitting diodes. The measured linear dynamic range four orders of magnitude, making practical device broad applications.
Frequency-dependent complex conductivity of high-mobility GaAs and InAs two-dimensional-electron-gas (2DEG) systems is studied by terahertz time domain spectroscopy. Determining the momentum relaxation from a Drude model, authors find lower value than that dc measurements, particularly at high frequencies/low temperatures. These deviations are consistent with ratio τt∕τq, where τq full scattering time. This suggests small-angle leads to weaker heating 2DEGs low temperatures expected mobility.
We present a novel semiconductor quantum well (QW) structure consisting of alternating (In,Ga)As and Ga(P,As,Sb) layers grown pseudomorphically on GaAs substrate by all-solid-source molecular beam epitaxy. The band gap the QW is determined thickness composition both types can be varied from 1.1 to 1.55 μm. Calculations show that observed strong room-temperature photoluminescence in this wavelength range explained type-II transition QW. Structural investigations reflection high-energy...
ZnTe/GaSb distributed Bragg reflectors (DBRs) are proposed and demonstrated for mid-wave infrared (2–5 μm) optoelectronic applications. The reflectance spectra of DBRs simulated using the transmission matrix method, indicating a peak higher than 99.9% DBR 10 quarter-wavelength (λ/4) pairs. A series structures have been successfully grown on GaSb (001) substrates molecular beam epitaxy. X-ray diffraction results reveal smooth interfaces, uniform thicknesses, low defect density. sample seven...
The temperature dependence of the frequencies and linewidths Raman-active longitudinal optical (LO) phonons in GaAs AlAs have been measured. low-temperature lifetime LO phonon is found to be 9.7 ps, very close corresponding value 9.5 ps. This contradicts early theoretical predictions. agreement between theory experiment can restored when accidental degeneracy frequency a feature two-phonon density states taken into account.
Ga As Sb ∕ quantum wells (QWs) with 1.3μm light emission are grown using solid-source molecular beam epitaxy. The growth temperature is optimized based on photoluminescence (PL) linewidth and intensity edge-emitting laser (EEL) threshold current density; these measurements concur that the optimal ∼490°C (∼500°C) for GaAsSb∕GaAs QWs (without) GaAsP strain compensation. High performance EELs vertical-cavity surface-emitting lasers (VCSELs) demonstrated GaAsSb∕GaAs∕GaAsP compensated active...
This paper reports the improvements and limitations of MBE grown 1.3μm GaAsSb/GaAs single QW lasers. At room temperature, devices show a low threshold current density (J<sub>th</sub>) 253 Acm<sup>-2</sup>, transparent 98 an internal quantum efficiency 71%, optical loss 18 cm<sup>-1</sup> characteristic temperature (T<sub>0</sub>) = 51K. The defect related recombination in these is negligible primary non-radiative path has stronger dependence on carrier than radiative contributing to ~84% at...
The optimized growth conditions and evidence for type-II alignment in GaAsSb/InGaAs heterostructures are reported. asymmetric bilayer quantum well grown on GaAs shows promising results device applications around the wavelength of 1.3 μm. Uncompensated GaAs/GaAsSb/GaAs quantum-well systems strain-compensated GaAsP/GaAs/GaAsSb/GaAs/GaAsP compared μm applications. Inhomogeneous photoluminescence-linewidth broadening due to lateral composition thickness variation is reduced from 74 40 meV when...
To investigate the influence of B 2 O 3 on microstructure CaO–Al –CaF slag, molecular dynamics were employed. Various performance parameters such as radial distribution functions, coordination numbers, oxygen distribution, and Q n distributions considered. The results indicate that Al 3+ predominantly adopts a [AlO 4 ] 5– tetrahedral structure within with minority existing in forms 5 7– 6 9– . primarily manifests [BO 3– planar triangular slag. slag is characterised by simple network Al–O–F....
We have compiled the optical constants database for InxGa1−xAs which covers composition range from 0.51 to 0.55 and temperature 400 525 °C. The InP substrate was monitored by diffusive reflectance spectroscopy during growth of epitaxial layer. Ellipsometry used monitor over entire database. ellipsometry is within 0.002 high resolution x-ray data with exception at °C 0.005. also demonstrated real time in situ feedback control using ellipsometry. absolute accuracy controlled experiment 0.002....
We compare different methods to measure reflection high-energy electron diffraction oscillations on rotating substrates. The best signal-to-noise ratio as well the highest accuracy is obtained by measuring full width at half maximum of specular spot perpendicular surface. method within 1% and offers a practical way accurately determine growth rates for device fabrication.
An abstract is not available for this content so a preview has been provided. As you have access to content, full PDF via the ‘Save PDF’ action button.
A near infrared (NIR) and long-wavelength (LWIR) dual-band photodetector, which can switch detection bands with light bias, is demonstrated at 77 K. The scheme consists of series connected photodetectors for different bands. basic operating principle the that without shorter wavelength detector limits total current thus device operates in NIR mode. With bias on detector, LWIR becomes limiting then Proposed design allows single indium-bump per pixel focal plane arrays, covering all tactical...
Theoretical calculations of the mode characteristics an equilateral-triangle resonator (ETR) with a 10μm cavity side length show that fundamental mode, longitudinal index 25, has wavelength 2.185μm and separation 100nm. This quality factor (∼2×105) is much larger than first (∼5×104) second (∼3×104) order modes, indicating single lasing should be accessible over broad tuning range. An electrically injected ETR based on this design fabricated from InGaAsSb∕AlGaAsSb∕GaSb, graded-index...
We investigate a series of Ga(AsSb)/GaAs/AlGaAs quantum wells, that show an additional inplane confinement. This is attributed to the formation self-organized GaAsSb quantum-islands during growth with confinement energies several hundred meV.