Thermoelectric characteristics of n-Type Bi2Te3 and p-Type Sb2Te3 thin films prepared by Co-evaporation and annealing for thermopile sensor applications

Abstract

A thermoelectric thin-film device consisting of n-type Bi 2Te3 and p-type Sb2Te3 thin-film legs was prepared on a glass substrate by using co-evaporation and annealing process. The Seebeck coefficient and the power factor of the co-evaporated Bi2Te3 film were 30μV/K and 0.7 × 10 -4W/K2m, respectively, and became substantially improved to -160μV/K and 16 × 10-4W/K2m by annealing at 400°C for 20 min. While the Seebeck coefficient of the co-evaporated Sb 2Te3 thin film was 72μV/K, it increased significantly to 165142μV/ K by annealing at 200400°C for 20 min. A maximum power factor of 25 © 10-4W/K2m was achieved for the co-evaporated Sb2Te3 film by annealing at 400°C for 20 min. A thermopile sensor consisting of 10 pairs of n-type Bi2Te3 and p-type Sb2Te3 thin-film legs exhibited a sensitivity of 2.7mV/K. © 2013 The Japan Institute of Metals.