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Bismuth telluride (Bi2Te3) is a gray powder that is a compound of bismuth and tellurium also known as bismuth(III) telluride.
B 1900 (OTTO) Bismuth(III) telluride, 99.99% Cas 1304-82-1 - used in thermoelectric industry for cooling and energy generation. It increases the speed of microchips and acts as topological insulators in spintronics.