Ac heating–dc detecting method for Seebeck coefficient measurement of the thermoelectric micro/nano devices

Abstract

A novel ac heating–dc detecting method is developed to measure the Seebeck coefficient of thermoelectric micro/nano devices. The suspended thermoelectric device in vacuum is heated by an ac current to generate a temperature difference composed of static and harmonic components and corresponding dc and harmonic thermoelectric voltage. The Seebeck coefficient can be extracted from the ratio of the dc thermoelectric voltage and the static temperature difference. Furthermore, it has been deduced that the dc thermoelectric voltage is proportional to the square of the heating current and the Seebeck coefficient can be directly extracted from the corresponding slope. This approach has been verified by numerical simulation on a 22.0 nm thick Au-Pt heterojunction and experiment applied on a 25.4 μm thick Chromega–Alomega thermocouple, and the measured Seebeck coefficient corresponds well with the nominal value.