Interfacial thermal transport in Bi₂Te₃

Highly efficient, room-temperature thermoelectrics are key to the future of environmental energy harvesting and solid-state cooling, among many other applications. To advance beyond the current state-of-the-art room-temperature thermoelectrics it is critical to understand the impact of interfaces on thermal transport in currently utilised materials, such as Bi2Te3, at an atomistic level. The importance of this understanding is highlighted even further considering the prevalence of nanostructured (often polycrystalline) materials. In this work, we employ reverse non-equilibrium molecular dynamics simulations (rNEMD) with a classical two-body interatomic potential (IP) [1], to examine the effect of specific interfacial structures on thermal transport in Bi2Te3. The interfacial thermal resistance (Kapitza resistance) and interfacial structures are compared across a number of twin boundaries. In addition, we will examine finite-length effects in rNEMD simulations of interfaces; often these are overlooked. We will also discuss the limitations of existing IPs and consider the development of machine-learned IPs for Bi2Te3.

[1] B. Huang et al. J. Phys. D Appl. Phys. 52 (42), ?425303 (2019)