Titel
Thermoelectric properties of chalcogenide based Cu2+xZnSn1−xSe4
Autor*in
Ch. Raju
Department of Physics, Indian Institute of Science
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Abstract
Quaternary chalcogenide compounds Cu2+xZnSn1−xSe4 (0 ≤ x ≤ 0.15) were prepared by solid state synthesis. Rietveld powder X-ray diffraction (XRD) refinements combined with Electron Probe Micro Analyses (EPMA, WDS-Wavelength Dispersive Spectroscopy) and Raman spectra of all samples confirmed the stannite structure (Cu2FeSnS4-type) as the main phase. In addition to the main phase, small amounts of secondary phases like ZnSe, CuSe and SnSe were observed. Transport properties of all samples were measured as a function of temperature in the range from 300 K to 720 K. The electrical resistivity of all samples decreases with an increase in Cu content except for Cu2.1ZnSn0.9Se4, most likely due to a higher content of the ZnSe. All samples showed positive Seebeck coefficients indicating that holes are the majority charge carriers. The thermal conductivity of doped samples was high compared to Cu2ZnSnSe4 and this may be due to the larger electronic contribution and the presence of the ZnSe phase in the doped samples. The maximum zT = 0.3 at 720 K occurs for Cu2.05ZnSn0.95Se4 for which a high-pressure torsion treatment resulted in an enhancement of zT by 30% at 625 K.
Stichwort
CopperThermal conductivityElectrical resistivityThermoelectric effectsCrystal structure
Objekt-Typ
Sprache
Englisch [eng]
Persistent identifier
Erschienen in
Titel
AIP Advances
Band
3
Ausgabe
3
Seitenanfang
032106
Publication
AIP Publishing
Erscheinungsdatum
2013
Zugänglichkeit
Rechte
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