Doping site dependent thermoelectric properties of epitaxial strontium titanate thin films
AuthorsAbutaha, Anas I.
Sarath Kumar, S. R.
Mehdizadeh Dehkordi, Arash
Tritt, Terry M.
Alshareef, Husam N.
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
Functional Nanomaterials and Devices Research Group
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AbstractWe demonstrate that the thermoelectric properties of epitaxial strontium titanate (STO) thin films can be improved by additional B-site doping of A-site doped ABO3 type perovskite STO. The additional B-site doping of A-site doped STO results in increased electrical conductivity, but at the expense of Seebeck coefficient. However, doping on both sites of the STO lattice significantly reduces the lattice thermal conductivity of STO by adding more densely and strategically distributed phononic scattering centers that attack wider phonon spectra. The additional B-site doping limits the trade-off relationship between the electrical conductivity and total thermal conductivity of A-site doped STO, leading to an improvement in the room-temperature thermoelectric figure of merit, ZT. The 5% Pr3+ and 20% Nb5+ double-doped STO film exhibits the best ZT of 0.016 at room temperature. This journal is
SponsorsThe authors acknowledge the financial support of the competitive Faculty Initiated Collaboration Grant from KAUST.
PublisherRoyal Society of Chemistry (RSC)
JournalJ. Mater. Chem. C