An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Synthesis, Crystal Structure, and Transport Properties of Quaternary Tetrahedral Chalcogenides
Published
Author(s)
Yongkwan Dong, Lukasz Wojtas, Joshua B. Martin, George S. Nolas
Abstract
Quaternary chalcogenides with tetrahedral zinc-blend structure types continue to be of interest for thermoelectrics applications. We report on the synthesis, crystal structure, and high temperature transport properties of Cu2.1Fe0.9SnSe4, Cu2.2Fe0.8SnSe4 and Cu2.2Zn0.2Fe0.6SnSe4. The identity and compositions for each specimen were established using a combination of Rietveld refinement and elemental analysis and indicate that all compositions are homogeneous with the stannite crystal structure. Excess Cu reduces the electrical resistivity, ρ, by an order of magnitude compared with Cu2FeSnSe4 with no significant degradation of the Seebeck coefficient, S. The energy band gaps were estimated from the high temperature S values and indicate that Cu2.1Fe0.9SnSe4 and Cu2.2Fe0.8SnSe4 possess narrow band gaps, 0.18 eV and 0.25 eV, respectively, as compared to most other quaternary chalcogenides. The power factor (PF = S2/ρ) increases with decreasing Fe content. Although Cu2.2Fe0.8SnSe4 possesses a smaller PF than that of Cu2.2Zn0.2Fe0.6SnSe4, a ZT of 0.45 was obtained at 750 K for Cu2.2Fe0.8SnSe4 due to its low thermal conductivity.
Dong, Y.
, Wojtas, L.
, Martin, J.
and Nolas, G.
(2015),
Synthesis, Crystal Structure, and Transport Properties of Quaternary Tetrahedral Chalcogenides, Journal of Materials Chemistry, [online], https://doi.org/10.1039/C5TC01606A
(Accessed December 4, 2024)