September 28, 2022

Miniaturization of a thermoelectric device capable of powering IoT products

Using semiconductor microfabrication technology, a research team consisting of the National Institute of Materials Science (NIMS), AIST and the University of Tsukuba succeeded in developing a thermoelectric device consisting of a network of π junctions each composed of two types of thermoelectric layers connected by a metal electrode layer. This device has demonstrated the ability to generate voltages greater than 0.5 V, meeting a criterion for certain IoT (Internet of Things) device operations.

Thermoelectric conversion modules designed for IoT and other electronic devices must be integrated with these devices. Most of the previously developed versions of these modules were made of massive materials, incompatible with miniaturization and integration. The output voltages of thermoelectric conversion modules and devices generally decrease as their size decreases. One approach to overcome this miniaturization problem is to create a network of π junctions in a thermoelectric device. This research team has created a thermoelectric device using semiconductor microfabrication technology that can be used to produce microscale π junctions with a high degree of precision.

This research team fabricated an in-plane thermoelectric device consisting of a dense network of π junctions, each composed of a p-type Mg2sn0.8Ge0.2 thin film with high thermoelectric generation efficiency and low electrical resistance, an n-type bismuth layer, which can be produced at room temperature. Despite its small size, this device, equipped with an array of 36 tiny π junctions, was able to generate voltages greater than 0.5 V, satisfying a criterion for certain IoT device operations.

The technique used in this research to create smaller and more compact thermoelectric devices can be used to develop new IoT and other electronic products integrated with thermoelectric devices.

– This press release was originally posted on the National Institute of Materials Science website