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Article
Anomalous dispersion of microcavity trion-polaritons
A study of the strong coupling of different exciton species in two-dimensional molybdenum diselenide in a cavity uncovers the rich many-body physics and may lead to new devices.
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Article
Suppression of Lateral Diffusion and Surface Leakage Currents in nBn Photodetectors Using an Inverted Design
Surface leakage and lateral diffusion currents in InAs-based nBn photodetectors have been investigated. Devices fabricated using a shallow etch processing scheme that etches through the top contact and stops a...
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Article
Surface Leakage Mechanisms in III–V Infrared Barrier Detectors
Infrared detector epitaxial structures employing unipolar barriers exhibit greatly reduced dark currents compared to simple pn-based structures. When correctly positioned within the structure, unipolar barrier...
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Article
A study of cracking in GaN grown on silicon by molecular beam epitaxy
It is observed that GaN layers grown on silicon substrates often crack. The crack characteristics in hexagonal GaN films on Si(111) has been characterized using scanning electron microscopy and Nomarski optica...
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Article
Molecular beam epitaxial growth of BGaAs ternary compounds
BxGa1−xAs ternary compounds with boron compositions varying up to x=1% have been grown by molecular beam epitaxy. Reflection high energy electron diffraction and double crystal x-ray diffraction measurements show...
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Article
Selective area growth of GaN using gas source molecular beam epitaxy
Ammonia cracking efficiencies on various surfaces were examined. The following is an ordering of surfaces according to their ammonia cracking efficiencies: GaN (highest), Si3N4, SiO2 (lowest). Selective area grow...
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Chapter and Conference Paper
Mid-Infrared Femtosecond Spectroscopy of Intersubband Hot Hole Relaxation in Quantum Wells
The relaxation time of hot holes generated by a subpicosecond mid-infrared pulse tuned on resonance with the intersubband transition energy of InGaAs quantum wells is measured as a function of temperature, dop...
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Chapter
Temperature Dependence of The Intersubband Hole Relaxation Time in P-Type Quantum Wells
Relaxation times ranging from 1 to 10 ps have been measured with infrared bleaching techniques in n-type quantum wells (QWs) when the inter-subband transition energy is larger than the LO-phonon energy.1–3 These ...
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Chapter
Hot Carrier Thermalization Dynamics in Low-Temperature-Grown III-V Semiconductors
The presence of point defects is expected to influence the properties of free carriers in semiconductors. Low-temperature-grown (LT) GaAs is a material with a high density of point defects and a unique combina...
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Article
The Ultrafast Carrier Dynamics in Semiconductors: The Role of Defects
The presence of point defects is expected to influence the properties of free carrier in semiconductors. We have used the techniques of ultrafast laser spectroscopy to characterize the dynamics of photoinjecte...
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Chapter
Low Threshold Current Density Wavelength Shifting between N=1 and N=2 Transitions in n-Type Modulation Doped GaAs/AlGaAs Quantum Well Lasers
Quantum well lasers provide a number of options for altering the emission wavelength. The effective bandgap energy of these devices is a function of well width, well composition, and, to a lesser extent, barri...
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Article
Improvement of GaAs/AlGaAs quantum well laser diodes by rapid thermal annealing
Post-growth annealing is shown to improve the laser diode quality of GaAs/AlGaAs graded-index separate confinement heterostructure quantum well laser diode structures grown at a nonoptimal substrate temperatur...
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Article
Optical Characterization of AlInP/GaAs Heterostructures
A 45 period GaAs/Al0.54In0.46P superlattice was grown by molecular beam epitaxy using valved solid-sources to supply both the arsenic (As4) and the phosphorus (P2) group V fluxes. The room temperature optical tra...
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Article
Nonlinear Optical Properties of Ultranarrow P-Type GaAs Quantum Wells
We have performed second harmonic generation (SHG) measurements in the 3–5 μm region on p-type stepped quantum wells (QWs) using the tunable, high peak power pulses generated by a free electron laser. The samp...
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Article
Phosphorus-Vacancy-Related Deep Levels in GaInP Layers Grown by Molecular Beam Epitaxy
Deep levels in lattice matched Ga0.51In0.49P/GaAs heterostructure have been investigated by thermal-electric effect spectroscopy(TEES) and temperature dependent conductivity measurements. Four samples were grown ...
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Article
Tilted superlattice composition profile determined by photoluminescence and thermal disordering
The composition profile of an (AlAs)1/2(GaAs)1/2 tilted superlattice is characterized for the first time. The tilted superlattice sample is thermally disordered, and the energy of the direct band gap photolumines...
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Article
Use of Valved, Solid Group V Sources for the Growth of GaAs/GaInP Heterostructures by Molecular Beam Epitaxy
We report on the first growth of GaAs/Ga0.5In0.5P heterostructures by conventional molecular beam epitaxy using solid-source valved crackers to supply both the arsenic and the phosphorus fluxes. By regulating the...
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Article
GaInP and AlInP grown by elemental source molecular beam epitaxy
We report on the use of a new, valved, solid phosphorus cracker source for the growth of phosphides by molecular beam epitaxy. The source avoids the relatively high expense and high level of toxicity associate...
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Article
InP Layers Grown by Molecular Beam Epitaxy at Low Substrate Temperature
InP layers were grown on semi-insulating InP wafer by molecular beam epitaxy (MBE) at low substrate temperatures (<200° C), using solid phosphorus source. We use x-ray diffraction, double crystal x-ray rocking...
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Article
Interface Recombination and Threshold Current in Grinsch-QW ALGaAs/GaAs Laser Diodes
A series of Graded-Index Waveguide Separate-Confinement Heterostructure Quantum Well (GRINSCH-QW) laser diodes were grown by MBE at the systematically varied substrate temperatures. The threshold current of la...
