In car engines, in industrial plants, in power stations—there are countless places where waste heat is produced and simply released into the environment without being used. Yet there are materials that can make use of this waste heat: so-called thermoelectrics can transform temperature differences into electrical energy. Conversely, there are many applications where insufficient heat dissipation limits performance: active cooling by means of thermoelectrics can allow computer chips to maintain significantly higher processing power (“overclocking”).

Pustogow aims to use materials long thought to be entirely unsuitable for this purpose—namely metals. In 2023, he and his team were able to show that nickel–gold alloys surprisingly achieve record-high thermoelectric performance. By 2025, the team managed to demonstrate similar performance in inexpensive materials without gold, employing the same concept. Building on these materials-science insights, Pustogow now intends to systematically search for the best metallic thermoelectrics. For this purpose, he has been awarded an ERC Consolidator Grant by the European Research Council (ERC), carried out at the Institute of Solid State Physics of TU Wien.

Energy from temperature differences

Thermoelectrics can be used wherever temperature differences occur. One connects a hot and a cold side via the material—for example, an industrial plant that produces waste heat and the cooler outside air—and the charge carriers inside the material rearrange due to the temperature difference in such a way that an electric voltage is generated. This is known as the Seebeck effect.

However, previously known thermoelectric materials have always had major drawbacks: they were expensive, brittle, difficult to process, and often simply not efficient enough. “Metals could solve all these problems,” says Pustogow. “But metals are usually also very good thermal conductors. For a long time, people assumed they were useless for this purpose because the temperatures on the hot and cold sides of the metal would equalize far too quickly.”

Artificial asymmetry

But that does not necessarily have to be the case, as Pustogow’s team has shown: “If the atoms are arranged in very specific geometric patterns, one can achieve a particularly strong asymmetry inside the material: positive and negative charge carriers then behave completely differently. In the most literal sense, we create a traffic jam for the positive charges, so that only the negative charges continue to move,” explains Pustogow. As a result, the Seebeck coefficient—which indicates how efficiently a material functions as a thermoelectric—is dramatically increased in metallic materials.

In the new ERC project, Pustogow and his team now plan to systematically scan the periodic table for promising material combinations. Computer simulations will be used to identify suitable metallic compounds and alloys, which will then be synthesized and experimentally examined.

“We aim to produce the best thermoelectrics in the world—robust, inexpensive, and scalable for industrial production—and, in the medium term, to bring them into everyday household use,” Pustogow says. “In doing so, we hope to open up entirely new fields of application, such as active cooling of microprocessors, and to take thermoelectric research in a completely new direction.”

Andrej Pustogow

Andrej Pustogow studied physics at LMU Munich and ETH Zurich, where he already focused on electronic transport and the Seebeck effect. After completing his PhD with distinction Summa Cum Laude at the University of Stuttgart, he conducted postdoctoral research at the University of Stuttgart and later at the University of California, Los Angeles, supported by a Feodor Lynen Fellowship of the Alexander von Humboldt Foundation. His research ranges from quantum magnetism and unconventional superconductivity to electronic correlations and modern thermoelectric materials.

Pustogow has received substantial international recognition, including publications in Nature, Science, and PNAS. Since 2020 he has been a professor at TU Wien, where he completed his habilitation in Experimental Physics in 2025. His research program is dedicated to developing novel pathways toward a comprehensive understanding and control of electronic properties in solid-state systems.

Contact

Prof. Andrej Pustogow
Institute for Solid State Physics
TU Wien
+43 1 58801 - 131 28
andrej.pustogow@tuwien.ac.at

Text: Florian Aigner