Related papers: Experimental study of electron and phonon dynamics…
Aluminum scandium nitride alloy (Al1-xScxN) is regarded as a promising material for high-performance acoustic devices used in wireless communication systems. Phonon scattering and heat conduction processes govern the energy dissipation in…
In ballistic transport, the movement of charged carriers is essentially unimpeded by scattering events. In this limit, microscopic parameters such as crystal momentum, spin and quantum phases are well conserved, allowing electrons to…
The investigation of thermal properties of recently emerged two-dimensional (2D) materials is a necessary step towards fulfilling their potential applications in nano-electronics devices. In this study, the thermal conductivity of novel…
Acoustic phonon transport is revealed as a potential radiation-to-conduction transition mechanism for single-digit nanometer vacuum gaps. To show this, we measure heat transfer from a feedback-controlled platinum nanoheater to a laterally…
Charge and thermal conductivities are the most important parameters of carbon nanomaterials as candidates for future electronics. In this paper we address the effects of Anderson type disorder in long semiconductor carbon nanotubes (CNTs)…
Anisotropic phonon transport along different lattice directions of two-dimensional (2D) materials has been observed, however, the effect decreases with increasing the thickness beyond a few atomic layers. Here we establish a novel mechanism…
In a typical semiconductor material, the majority of heat is carried by long wavelength, long mean-free-path phonons. Nanostructuring strategies to reduce thermal conductivity, a promising direction in the field of thermoelectrics, place…
Silicon nanoparticles have the promise to surpass the theoretical efficiency limit of single-junction silicon photovoltaics by the creation of a "phonon bottleneck", a theorized slowing of the cooling rate of hot optical phonons that in…
Ultrafast thermal transport in low-dimensional materials challenges traditional diffusive models due to reduced scattering, strong electron-phonon coupling, and pronounced non-equilibrium effects. To address these complexities, we extend…
The world communicates to our senses of vision, hearing and touch in the language of waves, as the light, sound, and even heat essentially consist of microscopic vibrations of different media. The wave nature of light and sound has been…
At micro- to nano-scales, classical size effects in heat conduction play an important role in suppressing the thermal transport process. Such effects occur when the characteristic lengths become commensurate to the mean free paths (MFPs) of…
Recent advances in synthesis and electrical characterization of nanofibers and nanotubes made out of various conjugated polymers attract attention of the research community to studies of transport properties of these materials. In this work…
Nanostructured semiconducting materials are promising candidates for thermoelectrics due to their potential to suppress phonon transport while preserving electrical properties. Modeling phonon-boundary scattering in complex geometries is…
Steady-state thermal transport in nanostructures with dimensions comparable to the phonon mean-free-path is examined. Both the case of contacts at different temperatures with no internal heat generation and contacts at the same temperature…
It has been proposed for a long time now that the reduction of the thermal conductivity by reducing the phonon mean free path is one of the best way to improve the current performance of thermoelectrics. By measuring the thermal conductance…
Heat conduction by phonons is a ubiquitous process that incorporates a wide range of physics and plays an essential role in applications ranging from space power generation to LED lighting. Heat conduction has been studied for over two…
We compute atomistically the heat conductance for ultra-thin pristine silicon nanowires (SiNWs) with diameters ranging from 1 to 5 nm. The room temperature thermal conductance is found to be highly anisotropic: wires oriented along the…
Tuning thermal transport in nanostructured materials is a powerful approach to develop high-efficiency thermoelectric materials. Using a recently developed approach based on the phonon mean free path dependent Boltzmann transport equation,…
A nanophononic metamaterial is a new type of nanostructured material that features an array, or a forest, of intrinsically distributed resonating substructures. Each substructure exhibits numerous local resonances, each of which may…
Properties of phonons - quanta of the crystal lattice vibrations - in graphene have attracted strong attention of the physics and engineering communities. Acoustic phonons are the main heat carriers in graphene near room temperature while…