Seebeck-driven transverse thermoelectric generation in on-chip devices

Abstract

An unconventional approach to enhance the transverse thermopower by combining magnetic and thermoelectric materials, namely the Seebeck-driven transverse thermoelectric generation (STTG), has been proposed and demonstrated recently. Here, we improve on the previously used sample structure and achieve large transverse thermopower over 40 μV K−1 due to STTG in on-chip devices. We deposited polycrystalline Fe–Ga alloy films directly on n-type Si substrates, where Fe–Ga and Si serve as the magnetic and thermoelectric materials, respectively. Using microfabrication, contact holes were created through the SiO x layer at the top of Si to electrically connect the Fe–Ga film with the Si substrate. These thin devices with simple structure clearly exhibited enhancement of transverse thermopower due to STTG, and the obtained values agreed well with the estimation over a wide range of the size ratio between the Fe–Ga film and the Si substrate.