Year: 2015
Type: article
Abstract: We calculate the conduction-band structures and $n$-type thermoelectric transport properties for the ${\mathrm{TiO}}_{2}$ polymorphs rutile, anatase, and brookite from first principles within the constant-relaxation-time approximation. Although the Seebeck coefficient is nearly isotropic in all polymorphs, the power factor is anisotropic and takes its largest values along [100] in rutile and anatase and along [010] in brookite. We also identify the free-carrier concentrations and temperatures that maximize the power factor. Our results for the theoretical upper bounds of the figure of merit at high temperature show that optimized rutile exhibits thermoelectric conversion efficiency that is superior to anatase and brookite and can reach values desirable for waste-heat recovery applications.
Source: Physical Review B
Authors: Dylan Bayerl, Emmanouil Kioupakis
Institution: University of Michigan
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2338207073