Russian scientists developed contacts for a multisection thermoelement

Scientists from National Research University of Electronic Technology received new high-strength contacts that can improve the quality of thermoelectric devices used for astronautics, medicine and scientific research. The results of the study were published in the Journal of Electronic Materials.

The essence of thermoelectric energy conversion is to obtain positive and negative temperatures from electricity and generate electricity from a temperature difference.

The work of thermoelectrics is based on two scientific principles - Peltier and Seebeck effects. The first one appears when electric current is passed between two dissimilar conductors, either heat or cold will be released, depending on the current direction.

When researchers explain the second effect they say if the contact of one such conductor is heated and the other is cooled, then an electromotive force appears between them.

Equipment based on thermoelectric principles is used in a number of fundamental industries. For example, it is used to maintain low temperatures in medicine and science, to power the on-board systems of spacecraft and to power modern radios.

MIET scientists say the contacts play an important role in these spheres, since the stability of the operation of the thermoelectric converter and its mechanical strength depend on them.

“The strength of the contact on the material greatly affects the mechanical stability of devices, these contacts are used as ohmic, barrier and switching layers. The problem was that there were no junctions of sufficient thickness and low resistance for high-quality thermoelectric generators,” said Maxim Stern, Associate Professor at the Institute of Advanced Materials and Technologies of MIET. According to him, the contacts of the required strength were obtained using the method of electrochemical deposition.

Most contact layers are about 300 nanometers thick. At the same time, to prevent destruction of the contact material during use, its thickness should be more than 5 micrometers. The samples are up to 12 micrometers thick, have low resistance and can operate thermoelectric devices at temperatures up to 600K.

The development of high-strength contacts was one of the significant steps in the development of a multi-section thermoelectric element. According to the researchers, it will be able to operate in the temperature range from 300 to 1200K.

Such devices can be used in all areas of application of thermoelectrics.