THERMOELECTRIC CHARACTERISTICS OF THE THERMOPILE SENSORS PROCESSED WITH THE ELECTRODEPOSITED Bi–Te AND Sb–Te THIN FILMS

Abstract

A thermopile sensor composed of 196 pairs of p–n thin film legs was processed on a glass substrate by using successive electrodeposition of the n-type Bi–Te and the p-type Sb–Te thin films. The 5.3-μm thick Bi–Te film, electrodeposited at a constant voltage of -50 mV in the 50-mM electrolyte with the Bi/(Bi + Te) mole ratio of 0.5, exhibited a Seebeck coefficient of -67 μV/K. The 5.2-μm thick Sb–Te film, electrodeposited at a constant voltage of 20 mV in the 70-mM solution with the Sb/(Sb + Te) mole ratio of 0.9, possessed a Seebeck coefficient of 63 μV/K. The thermopile sensor exhibited the sensitivities of 13.1 mV/K with temperature differences smaller than 9 K and of 27.3 mV/K with temperature differences larger than 9 K respectively, across the hot and cold ends.