Defects assisted structural and electrical properties of Ar ion irradiated TiO_2/SrTiO_3 bilayer

摘要

The present study focuses on the effect of 1 MeV Ar ion irradiation on pulsed laser deposited TiO2/SrTiO3 bilayer thin films on Si (100) and SrTiO3 (STO) substrates. Irradiation results in the reduction of crystallinity and the bilayer film on Si exhibits higher electrical conductivity compared to film on STO with the Seebeck coefficient-175 mV/K and the power factor-0.13 mW.m(-1)K(-2) at 420 K. The X-ray absorption spectra at Ti L and O K-edges reveal the reduction of the ion valence of Ti and the presence of oxygen vacancies. This study evidences that Ar ion irradiation enhances the electrical and thermoelectric properties in heterostructure oxides due to oxygen vacancies. (C) 2020 Elsevier B.V. All rights reserved.