A5088596574- GaN-based semiconductor devices and materials
- ZnO doping and properties
- Ga2O3 and related materials
- Semiconductor Quantum Structures and Devices
- Chalcogenide Semiconductor Thin Films
- Luminescence Properties of Advanced Materials
- Perovskite Materials and Applications
- Photocathodes and Microchannel Plates
- Quantum Dots Synthesis And Properties
- Solid-state spectroscopy and crystallography
- Nanowire Synthesis and Applications
- Optical Network Technologies
- Gas Sensing Nanomaterials and Sensors
- solar cell performance optimization
- Acoustic Wave Resonator Technologies
- Metallurgical and Alloy Processes
- Advanced Fiber Laser Technologies
- Advanced Semiconductor Detectors and Materials
- Advanced Photonic Communication Systems
- Copper-based nanomaterials and applications
- Ammonia Synthesis and Nitrogen Reduction
- 2D Materials and Applications
- Polyoxometalates: Synthesis and Applications
- Thin-Film Transistor Technologies
- Environmental Policies and Emissions
Lunghwa University of Science and Technology
2023-2024
Tungnan University
2007-2022
The effect of carrier localization in InGaN/GaN multiple quantum wells (MQWs) light-emitting diodes is investigated by photoluminescence (PL) and time-resolved PL (TRPL) measurements. results show that two peaks obtained Gaussian fitting both relate to the emission from localized states. By TRPL lifetimes at various energies, depths corresponding In-rich regions quasi-MQWs are obtained. Using a model we proposed, suggest compositional fluctuations In content variation well width responsible...
Three dual-wavelength InGaN/GaN multiple quantum well (MQW) light emitting diodes (LEDs) with increasing indium content are grown by metal-organic chemical vapor deposition, which contain six periods of low-In-content MQWs and two high-In-content MQWs. For the three studied samples, their internal efficiency (IQE) shows a rising trend as emission wavelength increases from 406 nm to 430 due suppression carriers escape wells barriers. However, for MQWs, sample IQE falls rapidly further...
The optical properties of the perovskite-type synthesized from sol-gel (SG) and solid-state (SS) methods were studied by absorption photoluminescence (PL) techniques. We observed significant PL emission at room temperature SS , while was negligible SG . Variation intensity peak position with demonstrated that recombination localized exciton in regular octahedra origin luminescence Ta–O–Ta bond angle affected delocalization excitons thus, behaviors
We have studied the variations in temperature-dependent absorption edge of a bulk InSe-layered semiconductor using photoconductivity (PC) measurements. From both X-ray diffraction (XRD) and Raman experimental results, structural phase as-prepared InSe sample was confirmed to be γ-polytype. Upon heating from 15 K 300 K, PC spectra found shift significantly toward lower energy, as function temperature further analyzed by Varshni’s relationship Bose–Einstein empirical equation. The Urbach...
In this study, the excitonic luminescence behaviors of ZnO thin films in temperature range 10–300 K were investigated. The photoluminescence (PL) spectrum exhibits bound-exciton emission and donor-acceptor recombination accompanying its multiphonon replicas at low temperatures. observed features exhibit redshift with an increase temperature, dependence peak position was analyzed by Varshni empirical expression. study showed dominant presence bound transition below 160 or free higher...
A new L-band automatic-gain-controlled (AGC) erbium-doped fiber amplifier (EDFA) for dense wavelength-division-multiplexing transmission systems is presented, in which a single 1480 nm laser with an internal thermoelectric cooler used as primary pump stable amplification. All C-band amplified spontaneous emission (ASE) recycled by the secondary to enhance gain efficiency. fraction of output signal electrical feedback monitor AGC improve gain-clamped (GC) flatness. Experimental results prove...
Temperature-dependent photoluminescence (PL) and time-resolved (TRPL) are measured for the (Ga1−xZnx)(N1−xOx) solid solution with x = 0.22 to study its luminescence properties. PL result shows that material exhibits visible at around 1.87 eV (663 nm) a broad emission band even room temperature. The origin of mechanism can be attributed radiative recombination electrons bound donors holes acceptors. investigation from integrated intensity TRPL as function temperature indicates activation...
We have studied the enhancement of conversion efficiency in GaAs solar cells using silver nanoparticles with particle average sizes between 11.4 to 17.2 nm. The maximum 20.2% is achieved for where Ag been incorporated. simulations according Mie theory suggest that increased radiative scattering and due a combined effect surface plasmon resonance interband transition.
We present a series of Sm3+/Tb3+ co-doped CaMoO4 phosphors synthesized by an efficient method microwave-assisted heating. The prepared samples were characterized X-ray diffraction, photoluminescence, and Commission Internationale de l’Elcairage (CIE) chromaticity diagram. diffraction results confirmed that all are crystallized in pure tetragonal phase. photoluminescence spectra significantly show both red- green emissions the phosphors. It is obvious variations intensity ratio red/green...
We reported the photoconduction properties of tungsten disulfide (WS2) nanoflakes obtained by mechanical exfoliation method. The photocurrent measurements were carried out using a 532 nm laser source with different illumination powers. results reveal linear dependence on excitation power, and photoresponsivity shows an independent behavior at higher light intensities (400-4000 Wm-2). WS2 photodetector exhibits superior performance responsivity in range 36-73 AW-1 normalized gain 3.5-7.3 10-6...
To explore the mechanism, breakthrough current bottleneck and overcome efficiency droop from green InGaN/GaN multiple quantum wells (MQWs) light-emitting diodes (LEDs). The photoluminescence properties carrier dynamics of MQW LEDs are investigated by temperature-dependent (PL) 10 K to 300 time-resolved PL (TRPL) measurements at in our new-built lab. With increasing temperature, a blue shift behavior is attributed band-tail states formed local potential minima resembling In-rich clusters....
ZnO thin films have been successfully grown on the quartz substrate by RF magnetron sputtering technique. The effects of rapid thermal annealing (RTA) structural and optical properties has investigated means X-ray diffraction (XRD), atomic force microscopy (AFM) photoluminescence (PL) measurements. defects were reduced during RTA processes crystallinity was improved after treatments. It is also found out that treatments can remarkably improve enhance UV emission in wavelength range 335 - 450...
Abstract not Available.
We studied the Raman scattering of InN epilayers with rapid thermal annealing (RTA). The longitudianl optical (LO) phonon in spectrum shifts toward lower frequency and increases asymmetric broadening as RTA temperature is increased. suggest that formation indium-related defects, such metallic indium clusters or vacancies, are responsible for change ratio LO mode. E 2 (high) mode does not exhibit significant after since atom involve
Abstract not Available.
Abstract not Available.