Topological materials attract enormous attention due to their unique physical properties and thermoelectric applications. ZrTe5, a semimetal material, is proposed to be a new topological material and shows interesting thickness‐dependent electrical transport properties. Here, the in‐plane thermal conductivity and power factor in exfoliated few‐layer ZrTe5 nanoribbons with different thickness measured using suspended thermal bridge method are reported. A nearly linearly thickness‐dependent thermal conductivity κ is observed where thicker nanoribbons present higher thermal conductivity in the temperature range of 100–300 K due to phonon‐boundary scattering. More interestingly, the room temperature figure of merit ZT of 140 nm‐thick ZrTe5 nanoribbon is five times higher than that in bulk ZrTe5, providing superior thermoelectric performance in thinner ZrTe5 nanoribbons and revealing the promising prospect of ZrTe5 nanoribbons as thermoelectric materials.

The two-dimensional (2D) materials represented by graphene and boron nitride provide an excellent platform for the study of thermal conduction and the interfacial thermal resistance in low-dimensional system. Recent studies recover exotic physics behind the novel thermal transport properties of 2D materials, such as length effect, dimensional effect, isotopic effect, anisotropic effect, etc. In this review, we introduce the recent progress of thermal properties in 2D materials in the last decade. The principle and development of thermal conduction measurement technologies used in 2D materials are introduced, followed by the experimental progress of thermal conduction and interfacial thermal resistance. Special attention is paid to the abnormal thermal transport and relevant physical problems. Finally, we present thermal management and heat dissipation in 2D electronic devices, summarize and point out the problems and bottlenecks, and forecast the future research directions and foregrounds.

No abstract

We investigate the electrical conductivity and thermal conductivity of polycrystalline gold nanofilms, with thicknesses ranging from 40.5 nm to 115.8 nm, and identify a thickness-dependent electrical conductivity, which can be explained via the Mayadas and Shatzkes (MS) theory. At the same time, a suppressed thermal conductivity is observed, as compared to that found in the bulk material, together with a weak thickness effect. We compare the thermal conductivity of suspended and supported gold films, finding that the supporting substrate can effectively suppress the in-plane thermal conductivity of the polycrystalline gold nanofilms. Our results indicate that grain boundary scattering and substrate scattering can affect electron and phonon transport in polycrystalline metallic systems.