Issue 6, 2022

On the thermoelectric properties of Nb-doped SrTiO3 epitaxial thin films

Abstract

The exploration for thermoelectric thin films of complex oxides such as SrTiO3-based oxides is driven by the need for miniaturized harvesting devices for powering the Internet of Things (IoT). However, there is still not a clear consensus in the literature for the underlying influence of film thickness on thermoelectric properties. Here, we report the fabrication of epitaxial thin films of 6% Nb-doped SrTiO3 on (001) (LaAlO3)0.3(Sr2AlTaO6)0.7 (LSAT) single crystal using pulsed laser deposition (PLD) where the film thickness was varied from 2 nm to 68 nm. The thickness dependence shows a subtle increase of tetragonality of the thin film lattice and a gradual drop of the electrical conductivity, the density of charge carriers, and the thermoelectric Seebeck coefficient as the film thickness decreases. DFT-based calculations show that ∼2.8% increase in tetragonality results in an increased splitting between t2g and eg orbitals to ∼42.3 meV. However, experimentally observed tetragonality for films between 68 to 13 nm is only 0.06%. Hence, the effect of thickness on tetragonality is neglected. We have discussed the decrease of conductivity and the Seebeck coefficient based on the decrease of carriers and change in the scattering mechanism, respectively.

Graphical abstract: On the thermoelectric properties of Nb-doped SrTiO3 epitaxial thin films

Supplementary files

Article information

Article type
Paper
Submitted
10 Aug 2021
Accepted
17 Jan 2022
First published
17 Jan 2022

Phys. Chem. Chem. Phys., 2022,24, 3741-3748

On the thermoelectric properties of Nb-doped SrTiO3 epitaxial thin films

A. Chatterjee, Z. Lan, D. V. Christensen, F. Bauitti, A. Morata, E. Chavez-Angel, S. Sanna, I. E. Castelli, Y. Chen, A. Tarancon and N. Pryds, Phys. Chem. Chem. Phys., 2022, 24, 3741 DOI: 10.1039/D1CP03679C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements