Phase transition enhanced thermoelectric figure-of-merit in copper chalcogenides

Journal Article · Fri Nov 01 04:00:00 EDT 2013 · APL Materials

DOI:https://doi.org/10.1063/1.4827595· OSTI ID:22269586

Brown, David R.; Day, Tristan; Borup, Kasper A.; Christensen, Sebastian; Iversen, Bo B. ^[1]

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1. Department of Chemistry and iNano, Aarhus University, Aarhus 8000 (Denmark)

While thermoelectric materials can be used for solid state cooling, waste heat recovery, and solar electricity generation, low values of the thermoelectric figure of merit, zT, have led to an efficiency too low for widespread use. Thermoelectric effects are characterized by the Seebeck coefficient or thermopower, which is related to the entropy associated with charge transport. For example, coupling spin entropy with the presence of charge carriers has enabled the enhancement of zT in cobalt oxides. We demonstrate that the coupling of a continuous phase transition to carrier transport in Cu{sub 2}Se over a broad (360–410 K) temperature range results in a dramatic peak in thermopower, an increase in phonon and electron scattering, and a corresponding doubling of zT (to 0.7 at 406 K), and a similar but larger increase over a wider temperature range in the zT of Cu{sub 1.97}Ag{sub .03}Se (almost 1.0 at 400 K). The use of structural entropy for enhanced thermopower could lead to new engineering approaches for thermoelectric materials with high zT and new green applications for thermoelectrics.

• OSTI ID: 22269586
• Journal Information: APL Materials, Journal Name: APL Materials Journal Issue: 5 Vol. 1; ISSN AMPADS; ISSN 2166-532X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COBALT OXIDES
COOLING
COPPER
COPPER SELENIDES
EFFICIENCY
ENTROPY
PHASE TRANSFORMATIONS
SOLIDS
TEMPERATURE RANGE
THERMOELECTRIC MATERIALS
WASTE HEAT