High Electron Mobility of Nb-Doped SrTiO₃ Films Stemming from Rod-Type Sr Vacancy Clusters.
Achieving high electron mobility in SrTiO3 films is of significant interest, particularly in relation to technological applications such as oxide semiconductors, field-induced superconductors, and thermoelectric generators. One route to achieving high electron mobility is growth of high quality SrTiO3 films with low defect concentrations. Another approach for mobility enhancement is applying a strain to the crystal. However, the maximum mobilities obtainable by these approaches are limited both by external and internal factors (currently available fabrication techniques, and maximum crystal strain, for example). In this paper, we demonstrate a unique crystal engineering approach to alter the strain in Nb-doped SrTiO3 films based on the deliberate introduction of Sr vacancy clusters. Nb-doped SrTiO3 films produced in this manner are found to exhibit remarkably enhanced electron mobilities (exceeding 53,000 cm(2) V(-1) s(-1)). This method of defect engineering is expected to enable tuning and enhancement of electron mobilities not only in SrTiO3 films, but also in thin films and bulk crystals of other perovskite-type materials.
Nanostructures Research Laboratory, Japan Fine Ceramics Center , Atsuta, Nagoya 456-8587, Japan.
Shunsuke
S
Kobayashi
Department of Advanced Materials Science, The University of Tokyo , Kashiwa, Chiba 277-8561, Japan.
Yuki
Y
Mizumukai
National Institute for Materials Science , Tsukuba, Ibaraki 305-0044, Japan.
Tsuyoshi
T
Ohnishi
Institute of Engineering Innovation, The University of Tokyo , Bunkyo, Tokyo 113-8656, Japan.|PRESTO, Japan Science and Technology Agency , Saitama 332-0012, Japan.
Naoya
N
Shibata
Nanostructures Research Laboratory, Japan Fine Ceramics Center , Atsuta, Nagoya 456-8587, Japan.|Institute of Engineering Innovation, The University of Tokyo , Bunkyo, Tokyo 113-8656, Japan.
Yuichi
Y
Ikuhara
Nanostructures Research Laboratory, Japan Fine Ceramics Center , Atsuta, Nagoya 456-8587, Japan.|Department of Advanced Materials Science, The University of Tokyo , Kashiwa, Chiba 277-8561, Japan.|Department of Quantum Engineering, Nagoya University , Chikusa, Nagoya 464-8603, Japan.
Takahisa
T
Yamamoto
STEM; SrTiO3; defect structure; electron mobility; pulsed laser deposition; strain