Peltier effect in a co-evaporated Sb sub(2)Te sub(3)(P)-Bi sub(2)Te sub(3)(N) thin film thermocouple

• Published in: Thin solid films Vol. 408; no. 1-2; pp. 270 - 274
• Main Authors: Rowe, D M, Williams, S G K, Zou, Helin
• Format: Journal Article
• Language: English
• Published: 03.04.2002
• ISSN: 0040-6090

A thin film Sb sub(2)Te sub(3)-Bi sub(2)Te sub(3) based thermocouple was fabricated by co-evaporation. The conditions for deposition have been investigated as a function of substrate temperature (T sub(s)) and flux ratio [F sub(r) = F(Te)/F(Sb,Bi)] and optimised to achieve a high thermoelectric power factor. It has been observed that the Seebeck coefficient and electrical conductivity of p-type Sb sub(2)Te sub(3) thin films ( alpha sub(p), rho sub(p)) and n-type Bi sub(2 )Te sub(3) thin films ( alpha sub(n), rho sub(n)) deposited by co-evaporation were found to be approximately 160 mu V/K, 3.12 x 10 super(-3) Omega cm and -200 mu V/K, 1.29 x 10 super(-3) Omega cm, respectively. From optimal deposition parameters, a thin film thermocouple was fabricated and operated in Peltier mode. The observed maximum value for temperature difference between hot and cold end is approximately 15.5 K for a current of 55 mA. The figure of merit and coefficient of performance of the thermocouple are estimated. copyright 2002 Elsevier Science B.V. All rights reserved.