A5041539253- Thermal properties of materials
- Photonic and Optical Devices
- Thermal Radiation and Cooling Technologies
- Semiconductor Lasers and Optical Devices
- Graphene research and applications
- Advanced Thermoelectric Materials and Devices
- Photonic Crystals and Applications
- Semiconductor Quantum Structures and Devices
- Advanced Fiber Laser Technologies
- Optical Coatings and Gratings
- Advanced Fiber Optic Sensors
- Advanced Thermodynamics and Statistical Mechanics
- Metamaterials and Metasurfaces Applications
- Silicon Nanostructures and Photoluminescence
- Nanofluid Flow and Heat Transfer
- Fern and Epiphyte Biology
- Nanowire Synthesis and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- nanoparticles nucleation surface interactions
- Acoustic Wave Phenomena Research
- Semiconductor materials and devices
- Mechanical and Optical Resonators
- Solid State Laser Technologies
- Heat Transfer and Optimization
- Plasmonic and Surface Plasmon Research
Eramet (France)
2023
Sichuan University
2021
Centre National de la Recherche Scientifique
2014-2020
Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion
2014-2020
Saint-Gobain Recherche Paris
2017-2018
Saint-Gobain (France)
2017-2018
Southwest Jiaotong University
2017
The University of Tokyo
2017
Tokyo University of Science
2017
Soochow University
2017
Understanding the design rules to obtain materials that enable a tight control of phonon transport over broad range frequencies would aid major developments in thermoelectric energy harvesting, heat management microelectronics, and information communication technology. Using atomistic simulations we show metamaterials approach relying on localized resonances is very promising engineer at nanoscale. Combining designed resonant structures alloying can lead extremely low thermal conductivity...
Abstract The high thermal conductivity of graphene and few-layer undergoes severe degradations through contact with the substrate. Here we show experimentally that management a micro heater is substantially improved by introducing alternative heat-escaping channels into graphene-based film bonded to functionalized oxide amino-silane molecules. Using resistance temperature probe for in situ monitoring demonstrate hotspot was lowered ∼28 °C chip operating at 1,300 W cm −2 . Thermal probed...
It is demonstrated that a graphene‐based film (GBF) functionalized with silane molecules strongly enhances thermal performance. The resistance temperature detector results show the inclusion of doubles heat spreading ability. Furthermore, molecular dynamics simulations conductivity ( κ ) GBF increased by 15%–56% respect to number density compared nonfunctionalized graphene substrate. This increase in attributed enhanced in‐plane conduction GBF, resulting from simultaneous between and...
The integration of three-dimensional microelectronics is hampered by overheating issues inherent to state-of-the-art integrated circuits. Fundamental understanding heat transfer across soft-solid interfaces important for developing efficient dissipation capabilities. At the microscopic scale, formation a dense liquid layer at solid-liquid interface decreases interfacial resistance. We show through molecular dynamics simulations n-perfluorohexane on generic wettable surface that enhancement...
We introduce and model a three-dimensional (3D) atomic-scale phononic metamaterial producing two-path phonon interference antiresonances to control the heat flux spectrum. show that crystal plane partially embedded with defect-atom arrays can completely reflect phonons at frequency prescribed by masses interaction forces. emphasize predominant role of second path destructive in origin total reflection thermal conductance reduction comparison Fano-resonance concept. The random defect...
We introduce a novel ultracompact nanocapacitor of coherent phonons formed by high-finesse interference mirrors based on atomic-scale semiconductor metamaterials. Our molecular dynamics simulations show that the stores monochromatic terahertz lattice waves, which can be used for phonon lasing-the emission phonons. Either one- or two-color realized depending geometry nanodevice. The regime originates from different incidence-angle dependence transmission longitudinal and transverse at...
The large thermal resistance across the carbon nanotube (CNT)–polymer matrix interface is a limiting factor for achieving polymer composites with high conductivities. Using equilibrium molecular dynamics simulations we show that an azide-terminated aromatic HLK5 (C22H25O3N3) functionalized onto CNT sidewall can efficiently decrease between and different types of matrices (polystyrene, epoxy, polyethylene). functionalization also significantly CNT–CNT junction resistance. Compared hydroxyl...
We study the role of solid-liquid interface thermal resistance (Kapitza resistance) on evaporation rate droplets a heated surface by using multiscale combination molecular dynamics (MD) simulations and analytical continuum theory. parametrize nonbonded interaction potential between perfluorohexane (C6F14) face-centered-cubic solid to reproduce experimental wetting behavior C6F14 black chromium through work adhesion (quantity directly related angle). The conductances (100) (111) substrates...
We use molecular dynamics simulations to investigate interfacial thermal transport between an ethanol suspension containing gold atomic clusters and a surface, using both realistic simplified models of nanoparticles. The conductance was determined via relaxation method for variety nanoparticle–nanoparticle nanoparticle–surface interaction strengths. Kapitza resistance is found increase due the presence nanoparticles in vicinity solid–liquid interface. heat flow from solid separated its...
In this chapter, we aim at presenting recent techniques based on an atomic-scale direct simulation, i.e., the equilibrium molecular dynamics (EMD) technique, allowing estimation of interfacial thermal resistance and phonon transmission. EMD relies "natural" fluctuations quantities computed in a system that freely evolve with given interaction potentials boundary conditions. It allows treatment small-size systems as well averaged microscopic cannot be excited macroscopically nonequilibrium...
We use multiscale modelings to investigate the heat dissipation in 2D transistors based on phosphorene and silicene. First, molecular dynamics (MD) simulations were used calculate thermal interface resistance Rint between materials (phosphorene silicene) dielectrics substrates (SiO2 TiO2). The calculated of these systems are close that graphene SiO2 insensitive temperature. MD values then served as inputs for finite-element at device scale. It is found heat-dissipation ability can be...
We report an unambiguous phonon resonance effect originating from germanium nanoparticles embedded in silicon matrix. Our approach features the combination of wave-packet method with atomistic dynamics and finite element rooted continuum theory. find that multimodal resonance, caused by destructive interference coherent lattice waves propagating through around nanoparticle, gives rise to sharp significant transmittance dips, blocking lower-end frequency range transport is hardly diminished...
Composition graded nanowires (NWs) have attracted increasing research interest in the application of optoelectronic devices, due to their bandgaps caused by changing composition. However, thermal transport property composition NWs is not clear, which critical for potential applications electronics and thermoelectrics. In this Letter taking SiGe NW as an example, we explore NWs. Molecular dynamics simulations reveal that conductivities (κ) can be reduced up 57% compared with corresponding...
The performance characteristics of InGaAs-GaAsP-InGaP strain compensated laser emitting near 1 μm are reported. ridge waveguide lasers have room temperature threshold current 18 mA and differential quantum efficiency 0.45 W/A/facet. linewidth enhancement factor is smaller gain coefficient larger for these compared to that conventional strained layer laser. This may be due higher effective compressive in the light devices which reduces mass. observed consistent with measured relaxation...
We have proposed a new method to achieve gradient refractive-index (GRIN) optics via compound liquid medium. By adjusting the composition of medium, refractive index was tuned in very broad range from 1.58 5.15. The medium also exhibited weak frequency dependence. Based on these properties, we designed GRIN planar lens and experimentally demonstrated feasibility this approach. beam deflection controlled by distribution lens. changing liquids different cells framework, spatial gradually...
The growth, processing, and optical characterization of a single Y-junction In/sub x/Ga/sub 1-x/As-Al/sub y/Ga/sub 1-y/As-GaAs strained-layer quantum-well heterostructure circular ring laser (6 mu m width, 11 approximately 251 outer radius) are described. lasers have been grown by metalorganic chemical vapor deposition, etched SiCl/sub 4/ reactive ion etching, planarized polyimide. dependences threshold current density peak emission wavelength (950 1015 nm) on radius presented. spectra show...
The processing and optical characteristics of an InGaAs-AlGaAs-GaAs strained-layer quantum-well heterostructure square ring laser (4 /spl mu/m width 50-/spl mu/m/side length) with two output waveguides narrow physical gap couplers are described. ridges the total internal reflection (TIR) mirrors lasers fabricated by photolithographic steps a single SiO/sub 2/ mask planarized polyimide such that TIR etched through active region while ridge not. Single longitudinal mode operation is observed...
We investigate the role of two-path destructive phonon interference induced by interatomic bonds beyond nearest neighbor in thermal conductance a silicon-germanium-like metasurface. Controlled ratio between second and first nearest-neighbor harmonic force constants, across germanium atomic plane silicon lattice exhibits trend switch path with direct bypassing defect atoms. show that heavy isotope impurity is crucial to realization local minimum conductance. highlight effect on distinct...
Two-dimensional rectangular lattice distributed feedback lasers in a waveguide geometry are described by coupled-mode analysis of scalar wave equation derived from vector field for TE guided modes. A detailed is provided two-dimensional grating which allows the method separation variables so that threshold conditions those two orthogonal one-dimensional gratings. We present correct definitions gain and detuning laser, also optimum design minimization gain. It found there an structural angle...
The monolithic integration of a strained layer InGaAs-GaAs-AlGaAs quantum-well laser with passive waveguide by conventional atmospheric pressure metalorganic chemical vapor growth is discussed. Growth inhibition from silicon dioxide mask the mechanism used for selective-area rate enhancement. Variation in width oxide stripe opening along length device results different thicknesses, allowing light generated one selective region to propagate without significant absorption loss an adjacent...