A5048560910- Semiconductor Quantum Structures and Devices
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- GaN-based semiconductor devices and materials
- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Optical Network Technologies
- Advanced Photonic Communication Systems
- Advanced Semiconductor Detectors and Materials
- Nanowire Synthesis and Applications
- Diamond and Carbon-based Materials Research
- Ga2O3 and related materials
- Photocathodes and Microchannel Plates
- Semiconductor materials and devices
- Graphene research and applications
- Boron and Carbon Nanomaterials Research
- Thermal properties of materials
- Quantum Dots Synthesis And Properties
- Analytical Chemistry and Sensors
- Topological Materials and Phenomena
- Mechanical and Optical Resonators
- 2D Materials and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Metal and Thin Film Mechanics
- Molecular Junctions and Nanostructures
The Ohio State University
2018-2024
University of Michigan
2021
United States Air Force Research Laboratory
2021
Sandia National Laboratories
2021
University of California, Santa Barbara
2015-2019
Technical University of Munich
2009-2017
Schott (Germany)
2009-2017
University of California, Los Angeles
2013-2017
University of Surrey
2017
Benue State University
2017
Van der Waals growth of GaAs on silicon using a two‐dimensional layered material, graphene, as lattice mismatch/thermal expansion coefficient mismatch relieving buffer layer is presented. Two‐dimensional thin films graphene potential route towards heteroepitaxial integration in the developing field photonics. Hetero‐layered deposited by molecular beam epitaxy graphene/silicon at temperatures ranging from 350 °C to 600 under constant arsenic flux. Samples are characterized plan‐view scanning...
One-dimensional compound semiconductor nanolasers, especially nanowire (NW)-based nanolasers utilizing III-nitride (AlGaInN) materials system, are an emerging and promising area of research. Significant achievements have been made in developing NW lasers with emission wavelengths from the deep ultraviolet (UV) to near-infrared spectral range. The types under investigation include Fabry-Pérot, photonic crystal, plasmonic, ring resonator, microstadium, random, polariton, two-dimensional...
Similar to the area of microelectronics, InP-based photonic integrated circuits (PICs) in optical domain as a counterpart are also seeing clear exponential development. This rapid progress can be defined by number active/passive components monolithically on single chip. Given probability achieving low-cost, compact, robust, and energy-efficient complex systems, there have been significant achievements made realizing relatively InP-PICs recent years. The performance these PICs is reaching...
In this Letter, the electric-field control of ferromagnetism was demonstrated in a back-gated Mn-doped ZnO (Mn-ZnO) nanowire (NW) field-effect transistor (FET). The NWs were synthesized by thermal evaporation method, and Mn doping 1 atom % subsequently carried out MBE system using gas-phase surface diffusion process. Detailed structural analysis confirmed single crystallinity Mn-ZnO excluded presence any precipitates or secondary phases. For transistor, mobility n-type carrier concentration...
Hexagonal boron nitride (h-BN) is considered as one of the most promising materials for next-generation quantum technologies. In this paper, we report bulk-like multilayer h-BN epitaxially grown using a carbon-free precursor on c-plane sapphire with strong emphasis material characterization and analysis. particular, structural, morphological, vibrational properties, chemical bonding such van der Waals are presented. Between as-grown sapphire, compressive residual strain induced by both...
Temperature-dependent electrical characterization of Pt/n-GaN Schottky barrier diodes prepared by ultra high vacuum evaporation has been done. Analysis made to determine the origin anomalous temperature dependence height, ideality factor, and Richardson constant calculated from I-V-T characteristics. Variable-temperature Hall effect measurements have carried out understand charge transport at low temperature. The modified activation energy plot inhomogeneity model given value 32.2 A/(cm2 K2)...
Abstract GaInAsSb/GaSb based quantum well vertical cavity surface emitting lasers (VCSELs) operating in mid-infrared spectral range between 2 and 3 micrometres are of great importance for low cost gas monitoring applications. This paper discusses the efficiency temperature sensitivity VCSELs at 2.6 μm processes that must be controlled to provide stable operation. We show non-radiative Auger recombination dominates threshold current limits device performance room temperature. Critically, we...
An integrated heterodyne optical phase-locked loop was designed and demonstrated with an indium phosphide based photonic circuit commercial off-the-shelf electronic components. As input reference, a stable microresonator-based frequency comb 50-dB span of 25 nm (~3 THz) around 1550 nm, having spacing ~26 GHz, used. A widely-tunable on-chip sampled-grating distributed-Bragg-reflector laser is offset locked across multiple lines. arbitrary synthesis between the lines by tuning RF source,...
This feature issue contains a series of papers that report the most recent advances in field mid-infrared light sources used for medical applications, including tissue imaging, reconstruction, excision, and ablation.Many biomolecular compounds have strong resonances region medicine is ideally suited to exploit this.The precision, sterility, versatility opening more opportunities this captures some exciting.
In this paper, we present a device concept and results of an electrically pumped vertical-cavity surface-emitting laser in the (AlGaIn)(AsSb) material system grown on GaSb substrate. The structure consists n-doped GaSb/AlAsSb distributed Bragg reflector type-I GaInAsSb/AlGaAsSb active region, incorporates type-III p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -GaSb/n -InAsSb buried tunnel junction for current as well optical...
This work presents the selective area epitaxy of GaN nanostructures grown on Ga-polar GaN/sapphire substrates by plasma-assisted molecular beam epitaxy. We demonstrate three types nanostructures, including nanowires, nanofins, and nanorings GaN-on-sapphire templates as well investigate ways controlling their morphology, orientation sidewall plus top facets. A range growth conditions low to high Ga flux were employed during develop these with homogenous geometry near vertical smooth...
In this paper, electrically pumped GaSb-based vertical-cavity surface-emitting lasers operating continuous wave at a record long emission wavelength of ∼2.6 μm are presented. Owing to the excellent thermal heat management, devices exhibit single-mode operation up heat-sink temperature 55 °C. Lateral current confinement and index guiding in device accomplished by utilizing buried tunnel junction concept. Devices with aperture diameters 6 show maximum output powers 0.3 mW room quantum...
Vertical-cavity surface-emitting lasers (VCSELs) are perfect light sources for spectroscopic applications, where properties such as continuous-wave (cw) operation, single-mode emission, high lifetime and often low power consumption crucial. For applications tunable diode laser absorption spectroscopy (TDLAS), there is a growing interest in devices emitting the near- to mid-infrared wavelength range, many environmentally technologically important gases show strong lines. The (AlGaIn)(AsSb)...
The efficiency limiting mechanisms in type-I GaInAsSb-based quantum well (QW) lasers, emitting at 2.3 µm, 2.6 µm and 2.9 are investigated.Temperature characterization techniques measurements under hydrostatic pressure identify an Auger process as the dominant non-radiative recombination mechanism these devices.The results supplemented with from three additional GaInAsSb extending wavelength range investigation 1.85-2.90μm.Under pressure, contributions CHCC CHSH to threshold current density...
The development of electrically pumped semiconductor diode lasers emitting at the ultraviolet (UV)-B and -C spectral bands has been an active area research over past several years, motivated by a wide range emerging applications. III-Nitride materials their alloys, in particular AlGaN, are material choice for this ultrashort-wavelength laser technology. Despite significant progress AlGaN-based light-emitting diodes (LEDs), technological advancement innovation these is lagging due to...
GaInAsSb-GaSb strained quantum-well (QW) ridge waveguide diode lasers emitting in the wavelength range from 2.51 to 2.72 mum have been grown by molecular beam epitaxy. The devices show ultralow threshold current densities of 44 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ( <i xmlns:xlink="http://www.w3.org/1999/xlink">L</i> rarr infin) for a single QW device at mum, which is lowest reported value continuous-wave operation near...
The GaSb and InAs(Sb) material combination results in a type-III (broken gap) band alignment is of particular interest for use as an ohmic, low-resistive intra-cavity contact complex optoelectronic devices, such buried-tunnel-junction vertical-cavity surface-emitting lasers. In this work, we report electrical characteristics MBE-grown p+-GaSb/n+-InAs tunnel junctions. investigated structures exhibit ultra-low resistive behavior, yielding specific resistivity values below 2.8 × 10−7Ω cm2....
High-quality and defect-free GaAs were successfully grown via molecular beam epitaxy on silicon dioxide patterned Si(111) substrates by a two-step growth technique. Compared with the one-step approach, scheme has been found to be better pathway obtain superior-quality Si. Taking advantages of low energy for both surface GaAs/Si(111) interface, total ∼175 nm atop exhibits atomically smooth morphology, single crystallininty remarkably defect density. A low-temperature nucleation layer helps...