Pulsed laser deposition of bismuth telluride thin films for microelectromechanical systems thermoelectric energy harvesters

This article reports on the development of thin films of p- and n-type bismuth telluride compounds which are suitable for microelectromechanical systems (MEMS) thermoelectric energy harvesters. Films were prepared by the pulsed laser deposition technique. It is shown that the thin films of binary Bi-Te alloys outperformed considerably their ternary counterparts. Furthermore, the highest thermoelectric figure of merit (ZT) was found to be 0.39 for the p-type Bi₃₂Te₆₈ alloy, whereas the optimal n-type alloy was Bi₂₅Te₇₅, which was characterized by a relatively low stress gradient.