Thermoelectric properties of Bi2Te3 atomic quintuple thin films

TL;DR

This study predicts a tenfold increase in thermoelectric efficiency for Bi2Te3 quintuple thin films at room temperature due to quantum confinement effects, using advanced ab initio calculations.

Contribution

It provides a theoretical prediction of enhanced thermoelectric performance in Bi2Te3 thin films based on ab initio and Landauer formalism methods.

Findings

ZT increases by a factor of 10 in thin films

ZT reaches 7.2 at room temperature

Quantum confinement alters valence band modes

Abstract

Motivated by recent experimental realizations of quintuple atomic layer films of Bi2Te3,the thermoelectric figure of merit, ZT, of the quintuple layer is calculated and found to increase by a factor of 10 (ZT = 7.2) compared to that of the bulk at room temperature. The large enhancement in ZT results from the change in the distribution of the valence band density of modes brought about by the quantum confinement in the thin film. The theoretical model uses ab initio electronic structure calculations (VASP) with full quantum-mechanical structure relaxation combined with a Landauer formalism for the linear-response transport coefficients.