Center for Phononics and Thermal Energy Science,China-EU Joint Center for Nanophononics,School of Physics Science and Engineering,Tongji University,Shanghai 200092,China;College of Chemistry and Materials Engineering,Institute of New Materials and Industrial Technologies,Wenzhou University,Wenzhou 325035,China
Abstract:
Tellurene, probably one of the most promising two-dimensional (2D) system in the thermoelectric materials, displays ultra-low thermal conductivity. However, a linear thickness-dependent thermal conductivity of unique tellurium nanoribbons in this study reveals that unprecedently low thermal conductivity can be achieved via well-defined nanostructures of low-dimensional tellurium instead of pursuing dimension-reduced 2D tellurene. For thinnest tellurium nanoribbon with thickness of 144 nm, the thermal conductivity is only ∼1.88 ± 0.22 W·m−1·K−1 at room temperature. It’s a dramatic decrease (45%), compared with the well-annealed high-purity bulk tellurium. To be more specific, an expected thermal conductivity of tellurium nanoribbons is even lower than that of 2D tellurene, as a result of strong phonon-surface scattering. We have faith in low-dimensional tellurium in which the thermoelectric performance could realize further breakthrough.