Scientists from Czech and Japanese institutions have discovered a way to make a material that converts heat into electricity work much more efficiently. Their breakthrough focuses on thin layers of scandium nitride (ScN), sputtered on magnesium oxide (MgO) substrates. This material is especially valuable at high operating temperatures – where the new method delivers up to two-and-a-half times higher efficiency than previously known, almost defect-free versions. The basic core lies in twin domains, which are special structures that form in the material during preparation.
The scandium nitride layers were prepared by deposition onto magnesium oxide substrates using reactive magnetron sputtering. “Our colleagues then carried out detailed analyses of the resulting micro-layers using various laboratory techniques (X-ray diffraction, microscopy, spectroscopy), and we compared the findings with supercomputer calculations at IT4Innovations,” explains Dominik Legut from IT4Innovations.
It turned out that the results are influenced by the arrangement of atoms in the crystal lattice. This can be compared to laying parquet flooring: if all the planks point in one direction, the result is a ‘perfect’ layer. But as soon as some planks are mirrored, a twin domain forms – and this is exactly what benefits the material.
“The results showed that layers with twin domains exhibit enhanced thermoelectric properties at high temperatures as compared to those measured for almost defect- and domain-free layers. The ScN layers with twin domains show about 30% higher Seebeck coefficient and lower thermal conductivity than the domain-free system, which makes this compound a promising material for thermoelectric application,” summarises Urszula Wdowik of IT4Innovations.
The research involved experts from the Czech Academy of Sciences, IT4Innovations at VSB – Technical University of Ostrava, the University of West Bohemia, Charles University, and two Japanese institutions – the National Institute for Materials Science and the University of Tsukuba. The calculations and simulations essential for understanding the behaviour of the material were carried out on IT4Innovations supercomputers.
The study was published in Applied Surface Science Advances and supported by the Czech Science Foundation (project 23-07228S), with Dominik Legut as the principal investigator on behalf of IT4Innovations.
Research article:
Enhancing thermoelectric properties of ScN films through twin domains
https://doi.org/10.1016/j.apsadv.2024.100674
Illustrative image adapted from: JMore-Chevalier, J., et al. (2025). Enhancing thermoelectric properties of ScN films through twin domains. Applied Surface Science Advances, 25, 100674. https://doi.org/10.1016/j.apsadv.2024.100674, Fig. 2, image cropped.