Authors: Monika BackhausRicoult James R Rustad Deenamma Vargheese Indrajit Dutta Kim Work
Publish Date: 2012/03/16
Volume: 41, Issue: 6, Pages: 1636-1647
Abstract
While the beneficial impact of nanostructural engineering on thermoelectric performance has been demonstrated for many semiconducting materials SiGe skutterudites PbTe2 etc no significant advantages have been reported for oxide nanomaterials In this study titania is used as a model material to compare the impact of grain size doping and substitution secondphase nanodispersion and crystallographic defects on the electronic and thermal properties It is shown that the lattice thermal conductivity can be most efficiently reduced by high densities of crystallographic planar defects in the Magnéli phases while modification of grain size or introduction of second phases on length scales of 20 nm to 100 nm introduces only minor improvement For the electronic properties donor dopants such as niobium provide improvement of the power factor but are not able to compete with the enhanced carrier concentration that is reached through oxygen vacancy introduction
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