(Bi<sub>2</sub>Te<sub>3</sub>) is a gray powder that is a compound of bismuth
also known as bismuth(III) telluride. It is a semiconductor
which, when alloyed with antimony
is an efficient thermoelectric
material for refrigeration or portable power generation. Topologically protected surface states
have been observed in Bismuth telluride.
Bismuth telluride is a narrow gap layered semiconductor with a trigonal unit cell. The valence and conduction band structure can be described as a many-ellipsoidal model with 6 constant-energy ellipsoids that are centered on the reflection planes. cleaves easily along the trigonal axis due to Van der Waals bonding
between neighboring tellurium atoms. Due to this, bismuth telluride based material that is used for power generation or cooling applications must be polycrystalline. Furthermore, the Seebeck coefficient of bulk Bi<sub>2</sub>Te<sub>3</sub> becomes compensated around room temperature, forcing the materials used in power generation devices to be an alloy of bismuth, antimony, tellurium, and selenium.
Recently, researchers have attempted to improve the efficiency of Bi<sub>2</sub>Te<sub>3</sub> based materials by creating structures where one or more dimensions are reduced, such as nanowires or... Read More