oa Synthesis and Properties of Nanocrystalline BiTe-Base Thermoelectric Materials for Energy Applications

Thermoelectric (TE) is the science associated with converting the thermal energy into electricity based on the Seebeck effect. The attractive features of thermoelectric devices are their long life, low maintenance, highly reliable and they do not produce emissions harmful to the environment. Thermoelectric generators are used to provide electrical power in medical, military, and space applications where their desirable properties outweigh their relatively high cost and low operating efficiency. However, the widespread use of thermoelectric components is presently limited by the low figure-of-merit of presently known materials. Bismuth telluride Bi2Te3 (which has a peak ZT value of 1.1) is currently regarded as the state-of-the art TE material with high efficiency and is therefore attractive for energy harvesting processes. The objective of the work is to demonstrate a new route to the realization of highly efficient bulk Bi2Te3 structures at the nanoscale. Nanostructures provide a chance to disconnect the linkage between thermal and electrical transport by introducing some new scattering mechanisms. This will help in increasing figure of merit and then the efficiency. We present in this work novel versions of both p-type and n-type Bi2Te3 alloy materials with significantly enhanced figures of merit (ZT) between 25 °C and 125 °C.