A5028833833- Chalcogenide Semiconductor Thin Films
- Semiconductor Quantum Structures and Devices
- Quantum Dots Synthesis And Properties
- Nonlinear Optical Materials Studies
- Laser-Matter Interactions and Applications
- ZnO doping and properties
- Gas Sensing Nanomaterials and Sensors
- Solid State Laser Technologies
- Semiconductor materials and devices
- Ga2O3 and related materials
- Advanced Semiconductor Detectors and Materials
- GaN-based semiconductor devices and materials
- Organic Electronics and Photovoltaics
- Spectroscopy and Quantum Chemical Studies
- Nonlinear Optical Materials Research
- Photorefractive and Nonlinear Optics
- Tribology and Wear Analysis
- Organic Light-Emitting Diodes Research
- Adhesion, Friction, and Surface Interactions
- Silicon and Solar Cell Technologies
- Advanced Cellulose Research Studies
- Transition Metal Oxide Nanomaterials
- Perovskite Materials and Applications
- Advanced Fiber Laser Technologies
- Artificial Intelligence in Games
Nantong University
2024
Henan University of Science and Technology
2023-2024
Hong Kong University of Science and Technology
1995-2014
University of Hong Kong
1995-2014
Three sorts of probe laser, which have pulse durations 200 fs, 35 ps, and 70 were employed in the measurement third-order nonlinear optical susceptibility x((3)) Au:SiO(2) composite films a degenerate four-wave mixing scheme. We found that at their absorption peak (~550 nm) had maximum , depends strongly on width laser. The value measured with 70-ps laser was ~30 times larger than 200-fs time-resolved measurements revealed nonlinearity femtosecond time scale is attributable mainly to...
High performance super TFTs with different channel widths and lengths, formed by a novel grain enhancement method, are reported. temperature annealing has been utilized to enhance the polysilicon improve quality of silicon crystal after low MILC treatment on amorphous silicon. With device scaling, it is possible fabricate entire transistor single grain, thus giving SOI MOSFET. The effects boundaries have studied, indicating existence extra leakage current paths caused traversing channel,...
World model based reinforcement learning (RL) has emerged as a promising approach for autonomous driving, which learns latent dynamics and uses it to train planning policy. To speed up the process, pretrain-finetune paradigm is often used, where online RL initialized by pretrained policy learned offline. However, naively performing such initialization in may result dramatic performance degradation during interactions new task. tackle this challenge, we first analyze identify two primary root...
A high-temperature (180 °C) gate recess technique featuring low damage and in-situ self-clean capability, in combination with O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> -assisted atomic-layer-deposition (ALD) of Al xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> dielectric, is developed for fabrication high performance normally-off AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs), which...
Self-powered broadband photodetectors operating in the ultraviolet–visible window are essential for optical communication, military monitoring, multispectral detection, and environmental monitoring. In this study, a new bottlebrush nanostructure based on Co3O4–ZnO PN junction is fabricated as an efficient photodetector capable of operation under zero bias conditions. This has reasonable band structure, exhibits improved efficiency light absorption, features reduced electron–hole...
The spectral and temporal characteristics optical-conversion efficiency of ∼150-fs laser pulses at 400 nm generated by second-harmonic generation (SHG) a regeneratively amplified mode-locked Ti:sapphire were investigated both theoretically experimentally. theoretical investigation was done taking into account cubic nonlinearity, pulse walk-off, group-velocity dispersion, Kerr quadratic broadening, frequency chirping the fundamental pulse, higher-order nonlinear mixing such as backconversion...
ZnS1−xTex (0≤x≤1) single-crystal alloy films were grown on GaAs and Si substrates by molecular beam epitaxy. Strong photoluminescence in the yellow to blue light region, with room-temperature external quantum efficiencies of 2%–4% at an unoptimized excitation wavelength 365 nm, was observed. The enhancement luminescence attributed presence Te isoelectronic hole traps films. bowing band-gap energy as a function composition x also observed, minimum near x=0.7. line width well Stokes shift peak...
We report the measurement of third-order optical nonlinearity (χ(3)) ZnO microcrystallite thin films near excitonic resonance at various temperatures using femtosecond degenerate four-wave-mixing technique. The measured χ(3) response times are 270, 240, and 160 fs 4.2 K, 77 room temperature, respectively. values range from 10−7 to 10−4 esu. maximum always correspond absorption peaks different temperatures. Room-temperature enhancement is also observed.
Photodetectors are indispensable optoelectronic devices crucial for various applications such as optical communication, military reconnaissance, multispectral sensing, and environmental surveillance. In this study, we present a photodetector design based on bottlebrush-like structure comprising Co3O4/ZnO/ZnO heterojunction, showcasing significant advancements in detection performance. The fabricated demonstrates rational band structure, leading to enhanced light absorption efficiency reduced...
Using pulses with tilted pulse fronts to compensate for the group-velocity mismatch in three-wave interactions, we constructed an efficient 400-nm pumped femtosecond collinear type I phase-matched β-barium borate optical parametric generator and amplifier. The signal idler outputs are tunable from 470 nm 2.7 µm have widths range of 100–170 fs at a 1-kHz repetition rate. A maximum output energy 6.5 µJ total conversion efficiency more than 15% were achieved.
The light emitting properties of ZnS/ZnSe and ZnSTe/ZnSe strained II–VI superlattices are investigated. Room-temperature stimulated emission by photopumping in the deep-blue spectral region is observed. An upper limit threshold carrier density required to achieve lasing estimated be 3×1018/cm3.The peak several tens meV red shifted from spontaneous peak, suggesting that exciton-exciton scattering involved process.
The time-integrated and time-resolved photoluminescence (PL) of Cd<SUB>0.3</SUB>Zn<SUB>0.7</SUB>S<SUB>0.06</SUB>Se<SUB>0.94</SUB>/ZnS<SUB>0.06</SUB>Se<SUB>0.94</SUB> single quantum wells (QW) have been studied at various temperatures. PL is obtained by sum frequency conversion technique with 300 fs resolution. line shape analysis based on a simple statistical model including both excitons free-carriers showed that free exciton radiative recombination dominates the emission even room...
Summary form only given.We report here the realization of large third-order nonlinear susceptibility, /spl xi//sup (3)/, from Au:dielectric (SiO/sub 2/ and TiO/sub 2/) composite films near Au percolation threshold. The were prepared by co-sputtering onto a fused silica substrate. wavelength dependence (3)/ was measured degenerate four-wave mixing (DFWM) scheme, its enhancement studied time-resolved measurements.
Summary form only given. We believe for the first time, femtosecond time-resolved reflectance difference spectroscopy (TRDS) has been applied to study dynamics and relaxation processes of semiconductor interface state. The instantaneous screening due photoexcited carriers 20- 30-ps recovery time 2.7-eV ZnSe-GaAs state associated with Zn-As bonds is observed in TRDS spectra.
The ultrafast excited state dynamics of Hexamethylsexithiophene are investigated by femtosecond time-resolved photoluminescence. spontaneous recombination lifetime the singlet is measured to be in order 400 ps. A photoluminescence (PL) risetime approximately 1 ps and temporal spectra redshift observed. These effects attributed planarization oligomer backbone via vibrational torsional relaxation which increases effective conjugation length oligomer. rapid gave rise PL risetime. change bandgap...