A5065475133- Ga2O3 and related materials
- ZnO doping and properties
- GaN-based semiconductor devices and materials
- Semiconductor materials and devices
- Chalcogenide Semiconductor Thin Films
- Advanced Photocatalysis Techniques
- Advanced Semiconductor Detectors and Materials
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and interfaces
- Gas Sensing Nanomaterials and Sensors
- Advanced Thermoelectric Materials and Devices
- Quantum Dots Synthesis And Properties
- Silicon Carbide Semiconductor Technologies
- Photocathodes and Microchannel Plates
- Electronic and Structural Properties of Oxides
- Optical Coatings and Gratings
- Electron and X-Ray Spectroscopy Techniques
- Copper-based nanomaterials and applications
- Plasmonic and Surface Plasmon Research
- Silicon and Solar Cell Technologies
- Advancements in Semiconductor Devices and Circuit Design
- Advanced X-ray and CT Imaging
- Radiation Detection and Scintillator Technologies
- Ion-surface interactions and analysis
- Spectroscopy and Laser Applications
University of Central Florida
2016-2025
National Academies of Sciences, Engineering, and Medicine
2022
United States Naval Research Laboratory
2022
University of Florida
2018-2022
Pennsylvania State University
2022
Weizmann Institute of Science
1992-2020
Truventic (United States)
2018
Infrared Laboratories (United States)
2018
The Ohio State University
2018
University of New Mexico
2018
We report on p–n junction light-emitting diodes fabricated from MgZnO∕ZnO∕AlGaN∕GaN triple heterostructures. Energy band diagrams of the diode structure incorporating piezoelectric and spontaneous polarization fields were simulated, revealing a strong hole confinement near n-ZnO∕p-AlGaN interface with sheet density as large 1.82×1013cm−2 for strained structures. The measured current–voltage (IV) characteristics heterostructure junctions have rectifying turn-on voltage ∼3.2V....
Minority carrier diffusion length in epitaxial GaN layers was measured as a function of majority concentration and temperature. The holes n-type is found to decrease from 3.4 1.2 μm the doping range 5×1015–2×1018 cm−3. experimental results can be fitted by assuming Einstein relation dependence hole mobilities on concentration. low injection lifetime ∼15 ns, used fit, largely independent level. length, for ∼5×1015 2×1018 cm−3 dopant concentrations, shows an increase with increasing...
An electrically pumped ZnO homojunction random laser diode based on nitrogen‐doped p‐type nanowires is reported. Nitrogen‐doped are grown a thin film silicon substrate by chemical vapor deposition without using any metal catalyst. The behavior studied output characteristics and transfer characteristic of the nanowire back‐gated field‐effect transistor, as well low‐temperature photoluminescence. formation p–n junction confirmed current–voltage electron beam‐induced current. nanowire/thin‐film...
ZnO p-n homojunctions based on Sb-doped p-type nanowire array and n-type film were grown by combining chemical vapor deposition (for nanowires) with molecular-beam epitaxy film). Indium tin oxide Ti/Au used as contacts to the nanowires film, respectively. Characteristics of field-effect transistors using channels indicate conductivity nanowires. Electron beam induced current profiling confirmed existence homojunction. Rectifying I-V characteristic showed a turn-on voltage around 3 V. Very...
The influence of 1.5 MeV electron irradiation on minority transport properties Si doped β-Ga2O3 vertical Schottky rectifiers was observed for fluences up to 1.43 × 1016 cm−2. Electron Beam-Induced Current technique used determine the hole diffusion length as a function temperature each dose. This revealed activation energies related shallow donors at 40.9 meV and radiation-induced defects with 18.1 13.6 meV. Time-resolved cathodoluminescence measurements showed an ultrafast 210 ps decay...
We report on the low pressure metal organic chemical vapor deposition of single crystal, wurtzitic layers GaN and GaN/InGaN heterostructures (111) GaAs/Si composite substrates. The structural, optical, electrical properties epitaxial are evaluated using x-ray diffraction, transmission electron microscopy, photoluminescence, measurements minority carrier diffusion length. These demonstrate high quality grown substrate.
Abstract ZnO nanorods and nanowires are promising candidates as new types of high‐sensitivity ultraviolet (UV) photodetectors due to their wide bandgap large aspect ratio. In this study, single‐crystalline were grown on glass substrates by a hydrothermal method. Specific structural, morphological, electrical, optical measurements carried out. A single nanorod‐based photodetector was fabricated using the in‐situ lift‐out technique in focused ion beam (FIB/SEM) instrument characterized. With...
AlGaN/GaN high electron mobility transistors were irradiated with 60Co gamma-rays to doses up 1000 Gy, in order analyze the effects of irradiation on devices' transport properties. Temperature-dependent beam-induced current measurements, conducted devices before and after exposure gamma-irradiation, allowed for obtaining activation energies related radiation-induced defects due nitrogen vacancies. DC current-voltage measurements also assess impact gamma-irradiation transfer, gate, drain...
The surface of single-crystal (-201) oriented β-Ga2O3 was etched in BCl3/Ar inductively coupled plasmas under conditions (an excitation frequency 13.56 MHz, a source power 400 W, and dc self-bias −450 V) that produce removal rates ∼700 Å min−1. Annealing at 450 °C carried out after etching on Ni/Au Schottky diodes formed the either before or annealing step. Current–voltage (I–V) measurements were used to extract barrier height (Φ), diode ideality factor (n), reverse breakdown voltage (VRB)...
We present a review of the published experimental and simulation radiation damage results in Ga 2 O 3 . All polytypes are expected to show similar resistance as GaN SiC, considering their average bond strengths. However, this is not enough explain orders magnitude difference relative these materials compared GaAs dynamic annealing defects much more effective It important examine effect all types radiation, given that devices will potentially be deployed both space terrestrial applications....
Cu diffusion in chalcopyrite CuInSe2 was studied directly, using 64Cu as a radioactive tracer. For from thin surface layer, the coefficients at 380 and 430 °C, were found to vary 10−8 10−9 cm2/s. In case of volume source 400 value 10−10 cm2/s calculated profiles. Electromigration demonstrated, by applying strong electric field sample following redistribution 64Cu, that had been thermally diffused into sample, prior application.
We have examined the nature of V-defects and inclusions embedded within these defects by atomic force microscopy (AFM) high-resolution scanning electron (SEM)/cathodoluminescence (CL) in InGaN/GaN multiple quantum wells (MQWs). To date, indium distribution nonuniformity well or GaN barrier growth temperature been identified as main factors responsible for V-defect occurrence propagation. Further complicating matter, originating at first InGaN-to-GaN interface observed under certain...
The electrical performance of vertical geometry Ga2O3 rectifiers was measured before and after 10 MeV proton irradiation at a fixed fluence 1014 cm−2, as well subsequent annealing up to 450 °C. Point defects introduced by the damage create trap states that reduce carrier concentration in Ga2O3, with removal rate 235.7 cm−1 for protons this energy. rates under these conditions are comparable GaN-based films heterostructures. Even 300 °C produces recovery approximately half carriers while...
Gallium oxide (Ga2O3) exists in different polymorphic forms, including the trigonal (α), monoclinic (β), cubic (γ), and orthorhombic (κ) phases, each exhibiting distinct structural electronic properties. Among these, β-Ga2O3 is most thermodynamically stable widely studied for high-power electronics applications due to its ability be grown as high-quality bulk crystals. However, metastable phases such α-, γ-, κ-Ga2O3 offer unique properties, wider bandgap or strong polarization ferroelectric...
Abstract Lateral Schottky or heterojunction rectifiers were irradiated with 10 MeV protons and neutrons. For proton irradiation, the forward current of both types decreased by approximately an order magnitude, a corresponding increase in on-state resistance. The resultant on/off ratio improved after irradiation because larger decrease reverse compared to current. Both displayed shift RON curves lower voltages irradiation. This could be due defects created neutron introducing deep energy...
The diffusion length, L, of electrons in Mg-doped p-GaN grown by metal-organic chemical vapor deposition was found to increase linearly from 0.55 2.0 μm during 1500 s electron beam irradiation. Similar trends were observed for p-type GaN and AlGaN/GaN superlattices molecular-beam epitaxy. While the length p-(Al)GaN depends on irradiation time, holes n-GaN remains unchanged, with L∼0.35 μm. We attribute change an minority carrier lifetime. This is likely due beam-induced charging deep...
Carrier trapping in Li-doped ZnO was studied using Electron Beam Induced Current technique, as well cathodoluminescence spectroscopy and persistent photoconductivity measurements. Under electron beam excitation, the minority carrier diffusion length underwent a significant increase, which correlated with growing lifetime, demonstrated by irradiation-induced decay of CL intensity near-band-edge transition. Variable-temperature experiments showed evidence yielded activation energies 280 245...
Radiation effects have a critical impact on the reliability of SiC and GaN power electronics must be understood for space avionics applications involving exposure to various types ionizing non-ionizing radiation. While these semiconductors shown excellent radiation hardness total dose displacement damage effects, devices are susceptible degradation from single event (SEE) resulting high-energy, heavy-ion environment (galactic cosmic rays) that cannot shielded. This occurs at <50% rated...
Electron beam-induced current in the temperature range from 304 to 404 K was employed measure minority carrier diffusion length metal–organic chemical vapor deposition-grown p-Ga2O3 thin films with two different concentrations of majority carriers. The electrons exhibited a decrease increasing temperature. In addition, cathodoluminescence emission spectrum identified optical signatures acceptor levels associated VGa−–VO++ complex. activation energies for and quenching were ascribed thermal...