A thin film thermoelectric device fabricated by a self-aligned shadow mask method

A planar thermoelectric device with 20 pairs of Sb2Te3 and Bi2Te3 thin-film legs was fabricated by using a facile self-aligned shadow mask method in combination with a thermal evaporation process. Effects of substrate temperature during the evaporation process on the Seebeck coefficient and electrical conductivity of the thin films have been investigated. The maximum Seebeck coefficient was found to be 158 µV K−1 for the Sb2Te3 film produced at 260 °C and −148 µV K−1 for the Bi2Te3 film produced at 230 °C. The device was fabricated on a glass substrate under the above optimal conditions. At a temperature difference of 90 K, it demonstrated an open-circuit voltage of more than 0.5 V (which was equivalent of a sensitivity of 5.40 mV K−1) and a maximum output power of 1.105 µW.