A5103239207- GaN-based semiconductor devices and materials
- Nanowire Synthesis and Applications
- Silicon Carbide Semiconductor Technologies
- Advanced DC-DC Converters
- ZnO doping and properties
- Electromagnetic Compatibility and Noise Suppression
- Photonic Crystals and Applications
- Plasmonic and Surface Plasmon Research
- Semiconductor materials and interfaces
- Metal and Thin Film Mechanics
- Advanced Battery Technologies Research
- Microgrid Control and Optimization
- Multilevel Inverters and Converters
- Nanofabrication and Lithography Techniques
- Semiconductor Quantum Structures and Devices
- Optical Coatings and Gratings
- Silicon and Solar Cell Technologies
- Gold and Silver Nanoparticles Synthesis and Applications
- Photocathodes and Microchannel Plates
- Mechanical and Optical Resonators
- Nuclear Materials and Properties
- Ga2O3 and related materials
- Magnetic Field Sensors Techniques
- Surface Modification and Superhydrophobicity
- Fusion materials and technologies
State Grid Corporation of China (China)
2020-2021
EnerSys (United States)
2019-2020
Global Energy Interconnection Research Institute North America
2020
Peking University
2013-2018
University of Strathclyde
2017
Dongguan University of Technology
2017
University of Wisconsin–Milwaukee
2015-2016
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics
2013-2015
University of Nebraska–Lincoln
2013
Abstract An anodic aluminum oxide (AAO) patterned sapphire substrate, with the lattice constant of 520 ± 40 nm, pore dimension 375 50 nm and height 450 25 was firstly used as a nanoimprint lithography (NIL) stamp imprinted onto surface green light-emitting diode (LED). A significant light extraction efficiency (LEE) improved by 116% in comparison to that planar LED. uniform broad protrusion central area some sharp lobes were also obtained angular resolution photoluminescence (ARPL) for AAO...
InGaN/GaN nanorod light-emitting diode (LED) arrays were fabricated using nanoimprint and reactive ion etching. The diameters of the nanorods range from 120 to 300 nm. integral photoluminescence (PL) intensity for nm LED array is enhanced as 13 times compared that planar one. In angular-resolved PL (ARPL) measurements, there are some strong lobes resonant regime appeared in far-field radiation patterns small size array, which spectra sharp intense. lifetime 0.088 ns, 40 % lower than...
The metallic-structure dependent localized surface plasmons (LSPs) coupling behaviors with InGaN QWs in a green LED epitaxial wafer are investigated by optical transmission, scanning electron microscopy (SEM) and photoluminescence (PL) measurements. Ag nanoparticles (NPs) formed thermal annealing layer on the wafer. SEM images show that for higher temperature and/or thicker deposited layer, larger NPs can be produced, leading to redshift of absorption peaks transmission spectra. Time...
GaN/InGaN multi-quantum-wells (MQWs) micron light emitting diodes (µLEDs) with the size ranging from 10 to 300 µm are fabricated. Effects of strain relaxation on performance µLEDs have been investigated both experimentally and numerically. Kelvin probe force microscopy (KPFM) micro-photoluminescence (µPL) used characterize strained area pillars. Strain reducing polarization field in MQWs almost affects whole mesa for LEDs about 4% around lateral LEDs. It makes a great contribution high...
A novel method based on imprinting lithography and wet etching to fabricate a volcano-shaped patterned sapphire substrate (VPSS) is presented.
The silane-controlled 3D growth led to a high crystalline quality, much strain relaxation and specular surface for the GaN epilayers on NPSS.
Different size InGaN/GaN based micro-LEDs (μLEDs) are fabricated. An extremely high injection level above 16 kA/cm2 is achieved for 10 μm-diameter LED. The lateral current density and carrier distributions of the μLEDs simulated by APSYS software. Streak camera time resolved photoluminescence (TRPL) results show clear evidence that band-gap renormalization (BGR) effect weakened strain relaxation in smaller μLEDs. BGR affects free carriers on conduction band bottom multiple quantum wells...
In this letter, the Ag nanoparticles (NPs), which are located inside hexagonal photonic crystals (PhCs) array holes, successfully fabricated in green light-emitting diode (LED) by nanoimprint and lift-off techniques. The photoluminescence intensity of LED is increased 4.5 folds compared with that bare due to PhCs effect localized surface plasmon (LSP) multiple quantum wells coupling effect, further confirmed enhanced decay rate LSP-functioned LED. simulation 3-D finite difference time...
Community DC microgrid is considered as an efficient solution for providing clean energy residential areas. Connection of the to AC utility grid would need a power electronic based rectifier. Voltage Source Rectifier (VSR) and Current (CSR) are two options such application. This study compares topologies on their density efficiency. Silicon Carbide (SiC) switches used designing rectifiers get better The close proximity rectifier area requires electromagnetic compatibility (EMC) with...
The high power GaN-based blue light emitting diode (LED) on an 80-μm-thick GaN template is proposed and even realized by several technical methods like metal organic chemical vapor deposition (MOCVD), hydride vapor-phase epitaxial (HVPE), laser lift-off (LLO). Its advantages are demonstrated from material quality chip processing. It investigated resolution X-ray diffraction (XRD), transmission electron microscope (HRTEM), Rutherford back-scattering (RBS), photoluminescence, current-voltage...
The opportunities for both power density and efficiency improvements of photovoltaic (PV) inverter have come with the development commercially available wide bandgap (WBG) devices such as Gallium Nitride (GaN), Silicon Carbide (SiC). focus this paper is to demonstrate a methodology achieving minimum volume differential common mode parts output filtering while meeting quality electromagnetic interference (EMI) specification maximizing efficiency. Temperatures are kept constant between Si SiC...
We developed a new sensitive microcantilever torque magnetometer-based magnetic field sensor that can detect changes of few nano-Tesla under ambient conditions. This consists torsion oscillator, fabricated by microelectromechanical systems (MEMS) process, and soft Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">77.5</sub> Si xmlns:xlink="http://www.w3.org/1999/xlink">7.5</sub> B xmlns:xlink="http://www.w3.org/1999/xlink">15</sub> wire. paper...
In this work, we report on the fabrication of “golftee,” “castle,” and “pillar” shaped InGaN/GaN nanorod light-emitting diode (LED) arrays with a typical rod diameter 200 nm based nanoimprint lithography, dry etching, wet etching. The photoluminescence (PL) integral intensities per active region area for samples were found to be 2.6, 1.9, 2.2 times stronger than that conventional planar LED. Additionally, far-field radiation patterns three different investigated angular resolved PL (ARPL)...
Abstract In this paper, two kinds of silicon carbide (SiC) backside metallization processes were developed, which thinning combined with laser annealing to form ohmic contact and direct rapid (RTA) contact. The specific resistivity obtained by both was 3.4E-5 Ω·cm 2 3.8E-5 . order obtain the effect process on forward conduction characteristics medium voltage devices,1200V/20A JBS diode adopted above schemes, thickness 4H-SiC substrate is 200μm. According statistical results hundreds diodes,...
Motive power battery charger needs to survive in a harsh industrial environment. A typical converter module today utilizes direct forced air cooling, which introduces corrosive damages the components. This paper presents an innovative design for SiCbased LLC resonant with all natural convection cooling operating wide voltage range application. In this design, there is no touching Therefore, modules are much more durable. Both phase shift full bridge control and half mode transition proposed...
Abstract This paper introduces the design and fabrication process of 1200V SiC trench Junction Barrier Schottky (JBS) diode, tests performance diode. The cell terminal diode structure both adopt structure, by simulation early stage, structural parameters device are determined, JBS is completed through an intact technological process. test results show that leak current under at room temperature about 0.36uA, when 20A, forward voltage drop 1.53V.
In this work, we have fabricated the different diameter micro pillar <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu$</tex> LEDs with wavelength and on substrates. The electroluminescence (EL) spectra current-voltage (I-V) curves were measured. high saturate current density was achieved as 300 kA/cm <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> for 20 UV LED GaN substrate. Efficiency droop also improved greatly EDs. Crosslight...
This paper proposes a control structure for bidirectional battery charger using three-phase PWM ac/dc converter and resonant CLLC dc/dc converter. The proposed system with staged architecture focuses on improving the power quality minimizing total harmonic distortion of system. A variable frequency hysteresis along current loop is employed fast charging phase battery. For optimal performance, designed to operate at frequency. Simulation results obtained PLECS simulation software are...
Polarization in InGaN quantum‐wells (QWs) is the key issue for GaN‐based light emitting diodes (LEDs). Kelvin probe force microscopy (KPFM) used to detect strain relaxation distribution on mesa of micro LEDs (µLEDs). The results KPFM are analyzed with help numerical calculation. effects space charge layer (SCL) and polarization band structures taken into consideration. Comparing data getting from µLEDs different diameter, smaller size have larger area affected by relaxation. This phenomenon...