A5100451979- Thermal properties of materials
- 2D Materials and Applications
- Graphene research and applications
- Chalcogenide Semiconductor Thin Films
- Near-Field Optical Microscopy
- Thermal Radiation and Cooling Technologies
- Perovskite Materials and Applications
- Advanced Thermoelectric Materials and Devices
- Superconductivity in MgB2 and Alloys
- Quantum Dots Synthesis And Properties
- MXene and MAX Phase Materials
- Diamond and Carbon-based Materials Research
- Physics of Superconductivity and Magnetism
- Iron-based superconductors research
- Nanowire Synthesis and Applications
- Photonic and Optical Devices
- Integrated Circuits and Semiconductor Failure Analysis
- Optical Imaging and Spectroscopy Techniques
- Semiconductor materials and interfaces
- Boron and Carbon Nanomaterials Research
- Aluminum Alloys Composites Properties
- Thermography and Photoacoustic Techniques
- Photocathodes and Microchannel Plates
- Non-Invasive Vital Sign Monitoring
- Numerical methods in engineering
Sun Yat-sen University
2016-2025
Massachusetts Institute of Technology
1998-2022
Ningbo Institute of Industrial Technology
2021
Chinese Academy of Sciences
2021
Southeast University
2021
Philips (China)
2020
Nanjing University
2020
Gezhouba Group (China)
2019
University of Bath
2019
Dalian University of Technology
2018
Conventional theory predicts that ultrahigh lattice thermal conductivity can only occur in crystals composed of strongly bonded light elements, and it is limited by anharmonic three-phonon processes. We report experimental evidence departs from these long-held criteria. measured a local room-temperature exceeding 1000 watts per meter-kelvin an average bulk value reaching 900 boron arsenide (BAs) crystals, where arsenic are heavy respectively. The high values consistent with proposal for...
Materials with high thermal conductivity (κ) are of technological importance and fundamental interest. We grew cubic boron nitride (cBN) crystals controlled abundance isotopes measured κ greater than 1600 watts per meter-kelvin at room temperature in samples enriched 10B or 11B. In comparison, we found that the isotope enhancement is considerably lower for phosphide arsenide as identical isotopic mass disorder becomes increasingly invisible to phonons. The ultrahigh conjunction its wide...
Wavelike thermal transport in solids, referred to as second sound, is an exotic phenomenon previously limited a handful of materials at low temperatures. The rare occurrence this effect restricted its scientific and practical importance. We directly observed sound graphite temperatures above 100 kelvins by using time-resolved optical measurements on the micrometer-length scale. Our experimental results are qualitative agreement with ab initio calculations that predict wavelike phonon...
Semiconductors with high thermal conductivity and electron-hole mobility are of great importance for electronic photonic devices as well fundamental studies. Among the ultrahigh–thermal materials, cubic boron arsenide (c-BAs) is predicted to exhibit simultaneously electron hole mobilities >1000 centimeters squared per volt second. Using optical transient grating technique, we experimentally measured 1200 watts meter kelvin ambipolar 1600 second at same locations on c-BAs samples room...
We conduct experiments on two-dimensional packings of colloidal thermosensitive hydrogel particles whose packing fraction can be tuned above the jamming transition by varying temperature. By measuring displacement correlations between particles, we extract vibrational properties a corresponding ``shadow'' system with same configuration and interactions, but for which dynamics are undamped. The very similar to those predicted zero-temperature sphere found in atomic molecular glasses; there is...
As a foundational concept in many-body physics, electron-phonon interaction is essential to understanding and manipulating charge energy flow various electronic, photonic, conversion devices. While much progress has been made uncovering how phonons affect electron dynamics, it remains challenge directly observe the impact of electrons on phonon transport, especially at environmental temperatures. Here, we probe effect carriers heat transport room temperature, using modified transient thermal...
Abstract In two dimensional (2D) transition metal dichalcogenides, defect-related processes can significantly affect carrier dynamics and transport properties. Using femtosecond degenerate pump-probe spectroscopy, exciton capture, release by mid-gap defects have been observed in chemical vapor deposition (CVD) grown monolayer MoSe 2 . The defect state filling shows a clear saturation at high densities, from which the density is estimated to be around 0.5 × 10 12 /cm capture time extracted...
Non-layered 2D materials, such as indium sulfide (In2S3), possess distinctive properties due to their unsaturated surface bonds and atomically thin structures, rendering them highly promising for state-of-the-art optoelectronic applications. Herein, we conduct a comprehensive investigation into the optical characteristics ultrafast carrier dynamics of β-In2S3 nanoflakes. Through thickness-dependent Raman, photoluminescence (PL), absorption spectra, reveal critical role thickness in tuning...
2D materials have attracted numerous attention for their potential applications in nano-photoelectronic and valleytronic devices. Recently, a new material, MoSi2N4 monolayer, is synthesized reported, predicted to many unique properties. Here, its ultrafast photoelectron spin dynamics using femtosecond-resolved transient differential transmission Faraday rotation spectroscopies are investigated. Complex diverse of excitons observed with increasing probe wavelength from 510 640 nm, including...
Abstract Radiative cooling is a zero‐energy technology that enables subambient by emitting heat into outer space (≈3K) via the atmospheric transparent windows. However, existing designs predominantly focus only on primary window (8–13 µm) and neglect another (16–25 µm), underutilizing their potential. Moreover, widely utilized organic radiative metamaterials face significant challenges, including oxidation, degradation, delamination, which ultimately reduce operational lifespan. In this...
Abstract Benefiting from the broken symmetry, 2D 3R‐ZnIn 2 S 4 exhibits unique optoelectronic properties and has gradually attracted attention. Herein, optical ultrafast exciton dynamics in nanoflakes are systematically investigated. The thickness‐dependent Raman, absorption, photoluminescence (PL) spectra measured to reveal importance of thickness engineering tuning . Especially, characteristics self‐trapped excitons (STEs), featuring a broad PL spectrum significant Stokes shift relative...
Understanding defect effect on carrier dynamics is essential for both fundamental physics and potential applications of transition metal dichalcogenides. Here, the phenomenon oxygen impurities trapping photo-excited carriers has been studied with ultrafast pump-probe spectroscopy. Oxygen are intentionally created in exfoliated multilayer MoSe2 Ar+ plasma irradiation air exposure. After treatment, signal transient absorption first increases then decreases, which a signature capturing...
Defect-carrier interaction in transition metal dichalcogenides (TMDs) plays important roles carrier relaxation dynamics and transport, which determines the performance of electronic devices. With femtosecond laser time-resolved spectroscopy, we investigated effect grain boundary/edge defects on ultrafast photoexcited molecular beam epitaxy (MBE)-grown MoTe2 MoSe2. We found that, comparing with exfoliated samples, recombination rate MBE-grown samples accelerates by about 50 times. attribute...
Abstract Antistatic composites of poly(ethylene terephthalate) (PET) and tetrapod‐shaped ZnO whisker (ZnOw), the surface which was treated with a coupling agent, were prepared by melt‐mixing using twin screw extruder. The structure morphology blends examined FTIR SEM. performance effect ZnOw loading levels investigated. conductive mechanism PET/ZnOw is presented, can be classified into tunnel effect, discharging at pinpoint network. simple formula critical volume fraction ( v c ) for forming...
We have grown Bi2Sr2Co2Oy thin films on LaAlO3 (100) and fused silica substrates by pulsed laser deposition. The are c-axis oriented partially in-plane aligned with multiple domains, while the preferred without alignment. Seebeck coefficient resistivity of both comparable to those single crystals. An oxide p-n heterojunction was formed depositing film Nb-doped SrTiO3 crystal, which showed a rectifying behavior. These heterostructures may be used for future thermoelectric applications.
Low residual resistivity in superconducting thin films is required for their applications radio frequency (RF) cavities. Here we report on clean epitaxial MgB2 fabricated by the ex situ annealing of B films, grown chemical vapour deposition, Mg vapour. The show sharp transitions at about 40 K and a high ratio 10. result indicates that precursor film contamination-free procedure are important viable fabrication process RF cavity applications.
A novel ultrafast reflective grating-imaging technique has been developed to measure ambipolar carrier diffusion in GaAs/AlAs quantum wells and bulk GaAs. By integrating a transmission grating an imaging system into the traditional pump–probe setup, this can acquire properties conveniently accurately. The fitted results of coefficient length GaAs agree well with literature values obtained by other techniques. are found increase layer thickness, which suggests that interface roughness...
Diabetes is a public health problem characterized by hyperglycemia, high mortality, and morbidity. A simple, rapid, sensitive glucose detection method for diabetes screening self-management of patients with great significance. Therefore, an attractive urine (UG) analyzer advantages fastness, sensitivity, portability was developed. cadmium telluride quantum dots (CdTe QDs)@glucose oxidase (GOx) aerogel circular array sensor can emit visible red fluorescence when excited 365 nm ultraviolet...
The ultrahigh thermal conductivity of boron arsenide makes it a promising material for next-generation electronics and optoelectronics. In this work, we report measured optical properties cubic crystals including the complex dielectric function, refractive index, absorption coefficient in ultraviolet, visible, near-infrared wavelength range. data were collected at room temperature using spectroscopic ellipsometry as well transmission reflection spectroscopy. We further calculate response...
This study explores the dynamic behaviours of shape memory alloy (SMA)-dowelled timber connection with densified veneer wood (DVW) reinforcement, so as to provide resilience structure. The performance SMA bar under cyclic bending is firstly studied, and it found that has superior self-centring effect large ductility compared steel. By testing SMA-dowelled connections conventional steel-dowelled loading at various displacement levels, shown can better larger connection. DVW reinforcement...