A5074635112- Molecular Junctions and Nanostructures
- Thermal Radiation and Cooling Technologies
- Advanced Thermodynamics and Statistical Mechanics
- Thermal properties of materials
- Quantum Electrodynamics and Casimir Effect
- Plasmonic and Surface Plasmon Research
- Gold and Silver Nanoparticles Synthesis and Applications
- Graphene research and applications
- Nanowire Synthesis and Applications
- Quantum and electron transport phenomena
- Advanced Thermoelectric Materials and Devices
- Optical properties and cooling technologies in crystalline materials
- Metamaterials and Metasurfaces Applications
- Organic Electronics and Photovoltaics
- Surface and Thin Film Phenomena
- Fuel Cells and Related Materials
- Urban Heat Island Mitigation
- Calibration and Measurement Techniques
- Metal-Organic Frameworks: Synthesis and Applications
- Electrocatalysts for Energy Conversion
- Thermography and Photoacoustic Techniques
- Advanced Wireless Communication Techniques
- Nonlinear Optical Materials Studies
- Advanced Sensor Technologies Research
- Advanced battery technologies research
University of Colorado Boulder
2020-2025
University of Colorado System
2025
Fuzhou University
2024
Rice University
2019-2021
University of Michigan–Ann Arbor
2015-2019
Beihang University
2012-2014
PLA Army Engineering University
2002
Thermal transport in individual atomic junctions and chains is of great fundamental interest because the distinctive quantum effects expected to arise them. By using novel, custom-fabricated, picowatt-resolution calorimetric scanning probes, we measured thermal conductance gold platinum metallic wires down single-atom junctions. Our work reveals that quantized at room temperature shows Wiedemann-Franz law relating electrical satisfied even contacts. Furthermore, quantitatively explain our...
With the advent of molecular electronics, tremendous attention has been paid towards understanding structure-function relationship junctions. Understanding how heat is transported, dissipated, and converted into electricity in junctions great importance for designing thermally robust circuits high-performance energy conversion devices. Further, study thermal thermoelectric phenomena provides novel insights limits applicability classical laws. Here, we present a review computational...
Abstract Radiative heat transfer in Ångström- and nanometre-sized gaps is of great interest because both its technological importance open questions regarding the physics energy this regime. Here we report studies radiative few Å to 5 nm gap sizes, performed under ultrahigh vacuum conditions between a Au-coated probe featuring embedded nanoscale thermocouples heated planar Au substrate that were subjected various surface-cleaning procedures. By drawing on apparent tunnelling barrier height...
Molecular junctions offer unique opportunities for controlling charge transport on the atomic scale and studying energy conversion. For example, quantum interference effects in molecular have been proposed as an avenue highly efficient thermoelectric power conversion at room temperature. Toward this goal, we investigated effect of properties junctions. Specifically, employed oligo(phenylene ethynylene) (OPE) derivatives with a para-connected central phenyl ring (para-OPE3) meta-connected...
This review highlights molecular and nanoscale engineering of electrically insulating semiconducting polymers for improved heat transport thermoelectricity.
Graphene provides an ideal platform for active modulation of near-field radiative heat transfer. While much research here focuses on tuning the chemical potential by doping or gating, this work proposes using a magnetic field to control flux between graphene sheets. The authors predict giant thermal magnetoresistance and negative different Fermi energies, Shubnikov-de-Haas-like oscillations in spectral flux. In static field, coupling excited magnetoplasmon-polariton modes boosts transfer...
Above-threshold light emission from plasmonic tunnel junctions, when emitted photons have energies significantly higher than the energy scale of incident electrons, has attracted much recent interest in nano-optics, while underlying physics remains elusive. We examine above-threshold electromigrated junctions. Our measurements over a large ensemble devices demonstrate giant (∼104) material-dependent photon yield (emitted per electrons). This dramatic effect cannot be explained only by...
Atomic-sized plasmonic tunnel junctions are of fundamental interest, with great promise as the smallest on-chip light sources in various optoelectronic applications. Several mechanisms emission electrically driven have been proposed, from single-electron or higher-order multielectron inelastic tunneling to recombination a steady-state population hot carriers. By progressively altering conductance an aluminum junction, we tune dominant mechanism through these possibilities for first time,...
Understanding the energy transport properties of hot carriers is great importance for a diverse range topics from nanoelectronics and photochemistry to discovery quantum materials. While much progress has been made in study carrier dynamics using ultrafast far-field time-resolved spectroscopies, it remains challenge understand interaction at nanoscale. Existing theoretical models yield only qualitative predictions that are difficult validate against experiments. Here we present framework...
We propose a mechanism of active near-field heat transfer modulation relying on externally tunable metamaterials. A large effect is observed and can be explained by the coupling surface modes, which dramatically varied in presence controllable magnetoelectric finally discuss how practical picosecond-scale thermal modulator made. This allows manipulating nanoscale flux an ultrafast noncontact (by optical means) manner.
Molecular-scale junctions (MSJs) have been considered the ideal testbed for probing physical and chemical processes at molecular scale. Due to nanometric confinement, charge energy transport in MSJs are governed by quantum mechanically dictated profiles, which can be tuned chemically or physically with atomic precision, offering rich possibilities beyond conventional semiconductor devices. While has extensively studied over past two decades, understanding conversion only become...
We investigate the near-field radiative heat transfer between two dispersive and lossy chiral metamaterials. Our theory takes into account magnetoelectric coupling effect compared with existing theories. It is shown that contribution of surface modes to strongly modulated by effect. predict in presence strong effect, resonant tunneling small parallel wavenumbers activate a novel energy channel. also find dissipation material, which characterized scattering rate, significantly influences on...
Surface plasmon enhanced processes and hot-carrier dynamics in plasmonic nanostructures are of great fundamental interest to reveal light–matter interactions at the nanoscale. Using tunnel junctions as a platform supporting both electrically optically excited localized surface plasmons, we report much greater (over 1000× ) light emission upconverted photon energies under combined electro-optical excitation, compared with electrical or optical excitation separately. Two mechanisms compatible...
Understanding the origin of above-threshold photons emitted from electrically driven tunnel junctions (ℏω>eVb with Vb being applied voltage bias) is current interest in nano-optics and holds great promise to create novel on-chip optoelectronic energy conversion technologies. Here, we report experimental observation theoretical analysis light emission electromigrated Au junctions. We compare our proposed hot-carrier enhanced theory existing models, including blackbody thermal...
Adding an infrared transparent spacer to far-field thermophotovoltaic (TPV) devices boosts power density. This scalable zero-gap design surpasses vacuum blackbody limit and achieves performance comparable near-field TPV with nanoscale gaps.