SCIENCE@home

Ultralow Thermal Conductivity in Layered CuGe2Se3.

Arnab Dutta,Achintya Lakshan,Simon Steinberg,I. Moudrakovski,J. Nuss,P. Jana

Published 2025 in Angewandte Chemie

ABSTRACT

Unraveling the relationship between thermodynamic factors, interatomic interactions, and electronic structure remains a crucial yet elusive challenge in the discovery of novel materials in solid-state (SS) chemistry. In the quest for new thermoelectric (TE) materials, we overcame that fundamental problem for the case of CuGe2Se3, whose synthesis, unique crystal structure, and transport properties are reported herein. The giant two-dimensional (2D) structure of CuGe2Se3, consisting of Se/(Cu─Ge)/Se and Se/(Ge─Ge)/Se slabs stacked along the c-axis, exhibits short Cu─Ge and Ge─Ge interactions, as evidenced by single-crystal X-ray diffraction (SCXRD) and SS NMR spectroscopic studies. These homopolar bonds might be surprising, as such interactions are rarely observed in group IV-chalcogenides. The compound is thermally stable up to ∼823 K. Transport properties measurements revealed a high Seebeck coefficient (∼373.6 µV·K-1) and ultralow thermal conductivity (∼0.35 W·m-1K-1) at 755 K, ascribed to its weak bonding interactions. We followed up with a theoretical analysis to gain insight into its structural peculiarities, focusing on vibrational properties and the nature of chemical bonding. The formation of Ge─Ge bonds is favored in light of the presence of multicenter bonds, which receive contributions from stereochemically non-active Ge lone pairs.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-100 of 123 references · Page 1 of 2

12
Next

CITED BY