Size-Dependent Lattice Thermal Conductivity of Nanostructured Bulk Semiconductors

Recently, nanostructuring of bulk semiconductors has emerged as an effective approach to develop high-efficiency thermoelectric materials for large-scale device applications, where the thermal conductivity reduction predominates in the enhanced figure of merit of these materials. In this work, a quantitative nanothermodynamic model was established to calculate the lattice thermal conductivity of semiconductor nanocomposites considering the interface scattering effects. It is found that the lattice thermal conductivity can be significantly reduced in nanostructured bulk semiconductors compared with their bulk counterparts. The findings in this work may provide new insights into the fundamental understanding of phonon transport in nanocomposites and also the development of high-performance thermoelectric materials.