Vacancy and anti-site disorder scattering in AgBiSe2 thermoelectricsElectronic supplementary information (ESI) available: The crystallographic data of Ag1−xBiSe2 obtained using Rietveld refinements of X-ray Bragg scattering. See DOI: 10.1039/c7dt00381a

• Main Authors: Böcher, Felix, Culver, Sean P, Peilstöcker, Jan, Weldert, Kai S, Zeier, Wolfgang G
• Format: Journal Article
• Language: English
• Published: 21.03.2017
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt00381a

AgBiSe 2 has recently been shown to exhibit promising thermoelectric properties due to the low intrinsic thermal conductivity, stemming from a large degree of lattice anharmonicity. While samples synthesized via solid-state routes usually exhibit n-type behavior, p-type transport is seen in samples based on solution synthetic routes possibly due to Ag vacancies. Using a combined approach of synchrotron diffraction, thermoelectric transport measurements and thermal transport modeling, we show the influence of synthetically induced Ag vacancies on the structure of AgBiSe 2 and the thermoelectric transport. We identify the degree of anti-site disorder of Ag and Bi due to the occurring phase transformation and the influence of the vacancy content on metal ordering. Additionally, we show that anti-site disorder and vacancies act as scattering centers for phonons, leading to enhanced point defect scattering in this interesting thermoelectric material. Ag vacancies in AgBiSe 2 influence Ag-Bi anti-site disorder and provide point defect scattering, reducing the lattice thermal conductivity.