Bismuth telluride

Bismuth telluride
	Single crystal of bismuth telluride
	Atomic structure: ideal (l) and with a twin defect (r)
	Electron micrograph of twinned bismuth telluride
Identifiers
CAS Number	1304-82-1 ;
3D model (JSmol)	Interactive image;
ChemSpider	11278988 ;
ECHA InfoCard	100.013.760
EC Number	215-135-2;
PubChem CID	6379155;
UNII	1818R19OHO ;
CompTox Dashboard (EPA)	DTXSID90894839 ;
	InChI InChI=1S/2Bi.3Te/q2+3;3-2 Key: AZFMNKUWQAGOBM-UHFFFAOYSA-N ; InChI=1/2Bi.3Te/q2+3;3-2 Key: AZFMNKUWQAGOBM-UHFFFAOYAF;
	SMILES [Te-2].[Te-2].[Te-2].[Bi+3].[Bi+3];
Properties
Chemical formula	Bi2Te3
Molar mass	800.76 g·mol−1
Appearance	Grey powder or metallic grey crystals
Density	7.74 g/cm3
Melting point	580 °C (1,076 °F; 853 K)
Solubility in water	insoluble
Solubility in ethanol	soluble
Structure
Crystal structure	Trigonal, hR15
Space group	R3m, No. 166
Lattice constant	a = 0.4395 nm, c = 3.044 nm
Formula units (Z)	3
Hazards
NFPA 704 (fire diamond)	2 0 0
Flash point	noncombustible
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp) (pure) ; none (doped with selenium sulfide)
REL (Recommended)	TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp) (pure) TWA 5 mg/m3 (doped with selenium sulfide)
IDLH (Immediate danger)	N.D. (pure and doped)
Safety data sheet (SDS)	Sigma-Aldrich
Related compounds
Other anions	Bismuth(III) oxide; Bismuth trisulfide; Bismuth selenide;
Other cations	Arsenic telluride; Antimony telluride
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Bismuth telluride (Bi₂Te₃) is a gray powder that is a compound of bismuth and tellurium also known as bismuth(III) telluride. It is a semiconductor, which, when alloyed with antimony or selenium, is an efficient thermoelectric material for refrigeration or portable power generation. Bi₂Te₃ is a topological insulator, and thus exhibits thickness-dependent physical properties.