SrTiO3 thin films as high efficient thermoelectric materials

In his work we investigate the thermoelectric performance of SrTiO₃ thin films doped with Nb grown using pulsed laser deposition on crystalline LaAlO₃ substrates. We show that a large enhancement of the Seebeck coefficient is observed for thin films with thicknesses below 10 nm in accordance with previous publications. In addition, we investigated the thermal conductivity of the thin films using the 3ω technique between 4 and 300 K. We show that the thermal conductivity is reduced by a factor of three with respect to the bulk value. This reduction originates mostly in structural defects and oxygen vacancies within the thin films. Finally, the figure of merit of the thinnest films at 300 K resulted in ZT=0.62.