Thermoelectric response of Lanthanum-doped SrTiO$_{3}$ thin-films grown under various oxygen partial pressures

Doped strontium titanate is a strong candidate for the next-generation high-$Z$ bulk thermoelectric material due to both its wide tunability in transport properties and very large carrier effective mass. Thermoelectric thin-films of Sr$_{1-x}$La$_{x}$TiO$_{3-\delta }$ with various La content were grown via pulsed-laser deposition (PLD) on (001)-oriented LSAT substrates under various oxygen partial pressures. We find that electron transport is dominated by carriers from oxygen vacancies in samples grown at low $p_{O2} \quad <$ 10$^{-6}$ Torr, and that thermopower as high as 1000 \textit{$\mu $}V/K can be achieved even in heavily La-doped samples. Doping combinations that yield resistivities as low as 5 m$\Omega $-cm yield power factors @ 300K as high as 0.7 W/m-K, implying \textit{ZT} $>$ 0.1.