Thermal conductivity prediction and analysis of few-quintuple Bi_2Te_3 thin films: A molecular dynamics study

摘要

In this work, we use molecular dynamics simulations to predict the thermal conductivities of perfect and nanoporous few-quintuple Bi_2Te_3 thin films. We find the dimensional crossover behavior of thermal transport and a minimum thermal conductivity at three quintuple layers at room temperature, and we attribute it to the interplay between phonon Umklapp scattering and boundary scattering. Also, nanoporous films show significantly reduced thermal conductivity compared to perfect thin films, indicating that they can be very promising thermoelectric materials.