Cu7.62Bi6Se12Cl6I: Discovery of a Low Band Gap, Low Thermal Conductivity Mixed Anion Material

Hawkins, Cara, Almoussawi, Batoul, Scheifers, Jan Phillip, Sonni, manel, Almushawwah, Aeshah, Manning, Troy, Zanella, Marco, Robertson, craig, Daniels, luke, Veal, tim, Claridge, john and Rosseinsky, matthew (2026) Cu7.62Bi6Se12Cl6I: Discovery of a Low Band Gap, Low Thermal Conductivity Mixed Anion Material. [Data Collection]

Data Catalogue DOI: 10.17638/datacat.liverpool.ac.uk/3063

Description

The exploration of higher dimensional chemical phase spaces and synthesis of novel compounds can be achieved by applying a multiple anion approach to materials discovery. The ability to combine and tune the stoichiometry of anions in a material can enable enhanced control of both the physical and electronic structure, providing a strategy for modification of the properties of new materials being developed for a variety of applications, including as solar absorbers and for thermoelectrics. Here we report the synthesis of Cu7.62Bi6Se12Cl6I, a quadruple-anion (Se2–, (Se2)2–, Cl–, I–) material within the Cu-Bi-Se-Cl-I phase space. Crystal growth reactions yield black, needle-like crystals, which exhibit a highly anisotropic and complex structure containing the four distinct anion types, solved from single crystal X-ray diffraction data. Compositional analysis confirms the complex material stoichiometry, and a low band gap of 0.94(5) eV is measured to understand potential for solar absorbing applications. Cu7.62Bi6Se12Cl6I has a low thermal conductivity of 0.24(2) W K–1 m–1 which is attributed to multiple structural features via analysis of experimental heat capacity data and is achieved through the diversity in bonding that is accessed through the combination of four different types of anion.

Keywords:

materials discovery, multiple anion, chalcohalide, crystal structure, Xray diffraction, Xray photoelectron spectroscopy, Thermal conductivity

Date Deposited:

06 Feb 2026 14:20

Last Modified:

06 Feb 2026 14:20

DOI:

10.17638/datacat.liverpool.ac.uk/3063

URI:

https://datacat.liverpool.ac.uk/id/eprint/3063