"Graphene-Like" Exfoliation of Atomically-Thin Bismuth Telluride Films

TL;DR

This paper demonstrates a graphene-like exfoliation method for large-area, atomically-thin bismuth telluride films, enabling new quantum and thermoelectric applications by producing ultra-thin, high-conductivity crystals.

Contribution

It introduces a novel mechanical exfoliation technique for bismuth telluride, producing atomically-thin layers and ribbons for enhanced thermoelectric performance.

Findings

Atomically-thin bismuth telluride can be exfoliated similarly to graphene.

The resulting 2D crystals exhibit high electrical conductivity.

Atomic-layer engineering may significantly improve thermoelectric efficiency.

Abstract

We report on graphene-like exfoliation of the large-area crystalline films and ribbons of bismuth telluride with the thicknesses of a few atoms. It is demonstrated that bismuth telluride, the most important material for thermoelectric industry, can be mechanically separated into its building blocks -[Te-Bi-Te-Bi-Te]- atomic five-folds with the thickness of ~1 nm and even further - to subunits with smaller thicknesses. The atomically-thin crystals can be structured into suspended crystalline ribbons providing quantum confinement in two dimensions. The quasi two-dimensional (2-D) crystals of bismuth telluride revealed high electrical conductivity. The proposed atomic-layer engineering of bismuth telluride opens up a principally new route for drastic enhancement of the thermoelectric figure of merit.