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

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.