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arXiv · 2501.04891

Energy filtering-induced ultrahigh thermoelectric power factors in Ni$_3$Ge

Fabian Garmroudi·Simone Di Cataldo·Michael Parzer·Jennifer Coulter·Yutaka Iwasaki·Matthias Grasser·Simon Stockinger·Stephan Pázmán·Sandra Witzmann·Alexander Riss·Herwig Michor·Raimund Podloucky·Sergii Khmelevskyi·Antoine Georges·Karsten Held·Takao Mori·Ernst Bauer·Andrej Pustogow
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Abstract

Traditional thermoelectric materials rely on low thermal conductivity to enhance their efficiency but suffer from inherently limited power factors. Novel pathways to optimize electronic transport are thus crucial. Here, we achieve ultrahigh power factors in Ni$_3$Ge through a new materials design principle. When overlapping flat and dispersive bands are engineered to the Fermi level, charge carriers can undergo intense interband scattering, yielding an energy filtering effect similar to what has long been predicted in certain nanostructured materials. Via a multi-step DFT-based screening method developed herein, we discover a new family of L1$_2$-ordered binary compounds with ultrahigh power factors up to 11 mW m$^{-1}$ K$^{-2}$ near room temperature, which are driven by an intrinsic phonon-mediated energy filtering mechanism. Our comprehensive experimental and theoretical study of these new intriguing materials paves the way for understanding and designing high-performance scattering-tuned metallic thermoelectrics.

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Fabian Garmroudi, Simone Di Cataldo, Michael Parzer, Jennifer Coulter, Yutaka Iwasaki, Matthias Grasser, Simon Stockinger, Stephan Pázmán, Sandra Witzmann, Alexander Riss, Herwig Michor, Raimund Podloucky, Sergii Khmelevskyi, Antoine Georges, Karsten Held, Takao Mori, Ernst Bauer, Andrej Pustogow. 2025-01-09. Energy filtering-induced ultrahigh thermoelectric power factors in Ni$_3$Ge. https://arxiv.org/abs/2501.04891

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