Electrical conductivity in oxygen-substituted SrTiO3-δ films
|Author:||Tyunina, M.1,2; Savinov, M.2; Dejneka, A.2|
1Microelectronics Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, P. O. Box 4500, FI-90014 Oulu, Finland
2Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 18221 Prague, Czech Republic
|Online Access:||PDF Full Text (PDF, 0.2 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2022020818006
American Institute of Physics,
|Publish Date:|| 2022-02-08
Enhancement of electrical conductivity in fundamentally insulating ABO₃ perovskite oxide ferroelectrics is crucial for innovative applications in resistive switching, photovoltaics, and catalysis. One of the methods to raise conductivity in bulk crystals or ceramics relies on the possibility to remove and/or substitute oxygen atoms. Here, we explored this approach for thin films of the representative perovskite oxide SrTiO₃. Small-signal AC conductivity was investigated in epitaxial and polycrystalline films, where oxygen vacancies (Vₒ), nitrogen (N), or hydrogen (H) were introduced in situ during film growth. Hopping mechanism of conductivity was evidenced by the observed strong growth of AC conductivity with temperature, frequency, and AC voltage in all films. Small polarons were identified as charge carriers. Oxygen vacancies/substitutions were suggested to facilitate hopping probability by generating sites for carrier localization. Important ferroelectric devices were proposed to benefit from the revealed hopping conductivity owing to its unique increase with an electric field.
Applied physics letters
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
216 Materials engineering
213 Electronic, automation and communications engineering, electronics
The authors acknowledge support from the Czech Science Foundation (Grant No. 19-09671S) and the European Structural and Investment Funds and the Ministry of Education, Youth and Sports of the Czech Republic through Programme “Research, Development and Education” (Project No. SOLID21-CZ.02.1.01/0.0/0.0/16_019/0000760).
© 2021 AIP Publishing. The final authenticated version is available online at https://doi.org/10.1063/5.0072225.