Abstract

Predicting the thermoelectric performance of materials from first principles typically requires the expensive computation of electronic transport properties and scattering mechanisms. The recently proposed mechanism to reach ultrahigh power factors in Ni-based alloys, however, originates from an intrinsic energy filtering mechanism, governed by a strongly energy-dependent carrier mobility rather than traditional phonon-based scattering [1]. In a nutshell, energy filtering results from a sharp density of states (DOS) right below the Fermi energy, which is a computationally inexpensive quantity. Leveraging this insight, we developed a combined high-throughput and crystal structure prediction approach aimed at systematically identifying novel thermoelectric materials.

Our methodology consisted of a two-step screening process. In the first step, we performed a high-throughput screening of binary metallic alloys by pairing transition metals (Ni, Fe, Co), known for their extremely large densities of states, with all other elements of the periodic table in a reference structure. This initial screening identified element pairs with compatible Fermi energies and desirable density of states (DOS) features, narrowing our search to 24 promising systems. In the second step, we conducted rigorous ab initio crystal structure prediction calculations on these 24 pairs to identify thermodynamically stable ground-state structures. Subsequent DOS calculations allowed us to further select the most promising thermoelectric candidates.

This approach successfully pinpointed Ni3Ge, Ni3Sn, and Ni3In alloys as exceptional candidates, all of which demonstrate substantial thermoelectric promise due to their optimized electronic structures that feature overlapping flat and dispersive bands at the Fermi level. These predictions were experimentally validated, revealing notably high thermoelectric performance [2,3]. This study exemplifies the effectiveness of combining high-throughput methods with crystal structure prediction for discovering and optimizing thermoelectric performance in a broader class of metallic alloys.

[1] Garmroudi, Fabian, et al. “High thermoelectric performance in metallic NiAu alloys via interband scattering.” Science Advances 9.37 (2023): eadj1611. [2] Garmroudi, Fabian, et al. “Topological Flat-Band-Driven Metallic Thermoelectricity.” Physical Review X 15 .2 (2025): 021054 [3] Garmroudi, Fabian, et al. “Energy filtering-induced ultrahigh thermoelectric power factors in Ni3Ge.” arXiv preprint arXiv:2501.04891 (2025).