Lattice dynamics and substrate-dependent transport properties of (In, Yb)-doped CoSb3 skutterudite thin films

Handle URI:
http://hdl.handle.net/10754/552776
Title:
Lattice dynamics and substrate-dependent transport properties of (In, Yb)-doped CoSb3 skutterudite thin films
Authors:
Sarath Kumar, S. R.; Cha, Dong Kyu; Alshareef, Husam N. ( 0000-0001-5029-2142 )
Abstract:
Lattice dynamics, low-temperature electrical transport, and high-temperature thermoelectric properties of (In, Yb)-doped CoSb3thin films on different substrates are reported. Pulsed laser deposition under optimized conditions yielded single-phase polycrystalline skutterudite films. Raman spectroscopy studies suggested that In and Yb dopants occupy the cage sites in the skutterudite lattice. Low-temperature electrical transport studies revealed the n-type semiconducting nature of the films with extrinsic and intrinsic conduction mechanisms, in sharp contrast to the degenerate nature reported for identical bulk samples. Calculations yielded a direct bandgap close to 50 meV with no evidence of an indirect gap. The carrier concentration of the films was identical to that reported for the bulk and increased with temperature beyond 250 K. The higher resistivity exhibited is attributed to the enhanced grain boundary scattering in films with a high concentration of grains. The maximum power factor of ∼0.68 W m−1 K−1 obtained at 660 K for the film on glass is found to be nearly four times smaller compared to that reported for the bulk. The observed difference in the power factors of the films on different substrates is explained on the basis of the diffusion of oxygen from the substrates and the formation of highly conducting CoSb2 phase upon the oxidation of CoSb3.
KAUST Department:
Materials Science and Engineering Program
Citation:
Lattice dynamics and substrate-dependent transport properties of (In, Yb)-doped CoSb3 skutterudite thin films 2011, 110 (8):083710 Journal of Applied Physics
Journal:
Journal of Applied Physics
Issue Date:
24-Oct-2011
DOI:
10.1063/1.3651382
Type:
Article
ISSN:
00218979
Additional Links:
http://scitation.aip.org/content/aip/journal/jap/110/8/10.1063/1.3651382
Appears in Collections:
Articles; Materials Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorSarath Kumar, S. R.en
dc.contributor.authorCha, Dong Kyuen
dc.contributor.authorAlshareef, Husam N.en
dc.date.accessioned2015-05-14T07:03:53Zen
dc.date.available2015-05-14T07:03:53Zen
dc.date.issued2011-10-24en
dc.identifier.citationLattice dynamics and substrate-dependent transport properties of (In, Yb)-doped CoSb3 skutterudite thin films 2011, 110 (8):083710 Journal of Applied Physicsen
dc.identifier.issn00218979en
dc.identifier.doi10.1063/1.3651382en
dc.identifier.urihttp://hdl.handle.net/10754/552776en
dc.description.abstractLattice dynamics, low-temperature electrical transport, and high-temperature thermoelectric properties of (In, Yb)-doped CoSb3thin films on different substrates are reported. Pulsed laser deposition under optimized conditions yielded single-phase polycrystalline skutterudite films. Raman spectroscopy studies suggested that In and Yb dopants occupy the cage sites in the skutterudite lattice. Low-temperature electrical transport studies revealed the n-type semiconducting nature of the films with extrinsic and intrinsic conduction mechanisms, in sharp contrast to the degenerate nature reported for identical bulk samples. Calculations yielded a direct bandgap close to 50 meV with no evidence of an indirect gap. The carrier concentration of the films was identical to that reported for the bulk and increased with temperature beyond 250 K. The higher resistivity exhibited is attributed to the enhanced grain boundary scattering in films with a high concentration of grains. The maximum power factor of ∼0.68 W m−1 K−1 obtained at 660 K for the film on glass is found to be nearly four times smaller compared to that reported for the bulk. The observed difference in the power factors of the films on different substrates is explained on the basis of the diffusion of oxygen from the substrates and the formation of highly conducting CoSb2 phase upon the oxidation of CoSb3.en
dc.relation.urlhttp://scitation.aip.org/content/aip/journal/jap/110/8/10.1063/1.3651382en
dc.rightsArchived with thanks to Journal of Applied Physicsen
dc.titleLattice dynamics and substrate-dependent transport properties of (In, Yb)-doped CoSb3 skutterudite thin filmsen
dc.typeArticleen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.identifier.journalJournal of Applied Physicsen
dc.eprint.versionPublisher's Version/PDFen
kaust.authorSarath Kumar, S. R.en
kaust.authorCha, Dong Kyuen
kaust.authorAlshareef, Husam N.en
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