Cu1.5SeyTe1- y (y = 0.2-0.7): A Series of Narrow Band Gap Semiconductors with Low Thermal Conductivity at Ambient Temperature

Alfred Rabenbauer; Anna Vogel; Janio Venturini; Mahboubeh Moslemi; Oliver Oeckler; Dominik Daisenberger; Tom Nilges

doi:10.1021/acs.inorgchem.3c02037

Cu_1.5Se_yTe_{1- y} (y = 0.2-0.7): A Series of Narrow Band Gap Semiconductors with Low Thermal Conductivity at Ambient Temperature

Inorg Chem. 2023 Aug 7;62(31):12600-12610. doi: 10.1021/acs.inorgchem.3c02037. Epub 2023 Jul 21.

Authors

Alfred Rabenbauer¹, Anna Vogel¹, Janio Venturini¹, Mahboubeh Moslemi², Oliver Oeckler², Dominik Daisenberger³, Tom Nilges¹

Affiliations

¹ TU Munich, School of Natural Sciences (NAT), Department of Chemistry, Professorship for Synthesis and Characterization of Innovative Materials, TU Munich, Lichtenbergstraße 4, 85748 Garching b. München, Germany.
² Faculty of Chemistry and Mineralogy, Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig, Germany.
³ Diamond Light Source, Harwell Science Campus, OX11 0DE Didcot, U.K.

PMID: 37478003
DOI: 10.1021/acs.inorgchem.3c02037

Abstract

Coinage metal chalcogenides offer ideal prerequisites for high thermoelectric performance and sensor applications, with their usually low lattice thermal and high electrical conductivity, as well as small band gaps. In the solid solution Cu_1.5Se_yTe_1-y we synthesized phase pure materials with y = 0.2-0.7 and characterized them concerning selected physical properties. X-ray crystal structure determination was performed for two representatives of the solid solution, Cu_1.5Se_0.3Te_0.7 and Cu_1.5Se_0.5Te_0.5. The entire series crystallizes cubically, in space group Pm3̅n. No structural changes are observed between room temperature and the synthesis temperature of 723 K. The conductivity measurements and Seebeck coefficients of Cu_1.5Se_0.3Te_0.7 and Cu_1.5Se_0.5Te_0.5 indicate that the two representatives are narrow band gap semiconductors (E_g 0.06-0.08 eV). Both compounds show positive Seebeck coefficients and reasonably low thermal conductivities at moderate temperatures. Cu_1.5Se_0.5Te_0.5 is characterized by a bulk modulus of 40.9 GPa.