Photo-induced in-gap states in SrTiO3 probed by photoemission spectroscopy under ultraviolet illumination

Takashi Mizokawa; Norihisa Takaiwa; Yukihiro Fujiwara; Takashi Iida; Kou Takubo; Jin Young Son; Tadahiko Ishikawa; Mitsuru Itoh; Masaki Takesada

doi:10.1143/JPSJ.79.044703

Photo-induced in-gap states in SrTiO₃ probed by photoemission spectroscopy under ultraviolet illumination

Takashi Mizokawa^*, Norihisa Takaiwa, Yukihiro Fujiwara, Takashi Iida, Kou Takubo, Jin Young Son, Tadahiko Ishikawa, Mitsuru Itoh, Masaki Takesada

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

10 Citations (Scopus)

Abstract

We report on an electronic structure study of SrTiO₃ under ultraviolet illumination. Photoemission measurements at 20K under ultraviolet illumination show that the illumination induces electronic states within the band gap. The photo-induced in-gap states show the power-law energy distribution with exponent of 3.4- 3.7 and weakly depends on the strength of illumination. The photo-induced in-gap states indicate that most of the photo-excited electrons are trapped by local lattice distortions with various size scale. We argue that the free carriers in the Ti 3d band and the localized Ti 3d electrons and O 2p holes within the band gap contribute to the photoconductivity and the ferroelectricity under the ultraviolet illumination, respectively.

Original language	English
Article number	044703
Journal	journal of the physical society of japan
Volume	79
Issue number	4
DOIs	https://doi.org/10.1143/JPSJ.79.044703
Publication status	Published - 2010 Apr 1
Externally published	Yes

Keywords

Orbital degeneracy
Photoemission spectroscopy
Pohoto-induced phase transition
Quantum paraelectricity

ASJC Scopus subject areas

Physics and Astronomy(all)

Access to Document

10.1143/JPSJ.79.044703

Cite this

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title = "Photo-induced in-gap states in SrTiO3 probed by photoemission spectroscopy under ultraviolet illumination",

abstract = "We report on an electronic structure study of SrTiO3 under ultraviolet illumination. Photoemission measurements at 20K under ultraviolet illumination show that the illumination induces electronic states within the band gap. The photo-induced in-gap states show the power-law energy distribution with exponent of 3.4- 3.7 and weakly depends on the strength of illumination. The photo-induced in-gap states indicate that most of the photo-excited electrons are trapped by local lattice distortions with various size scale. We argue that the free carriers in the Ti 3d band and the localized Ti 3d electrons and O 2p holes within the band gap contribute to the photoconductivity and the ferroelectricity under the ultraviolet illumination, respectively.",

keywords = "Orbital degeneracy, Photoemission spectroscopy, Pohoto-induced phase transition, Quantum paraelectricity",

author = "Takashi Mizokawa and Norihisa Takaiwa and Yukihiro Fujiwara and Takashi Iida and Kou Takubo and Son, {Jin Young} and Tadahiko Ishikawa and Mitsuru Itoh and Masaki Takesada",

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T1 - Photo-induced in-gap states in SrTiO3 probed by photoemission spectroscopy under ultraviolet illumination

AU - Mizokawa, Takashi

AU - Takaiwa, Norihisa

AU - Fujiwara, Yukihiro

AU - Iida, Takashi

AU - Takubo, Kou

AU - Son, Jin Young

AU - Ishikawa, Tadahiko

AU - Itoh, Mitsuru

AU - Takesada, Masaki

PY - 2010/4/1

Y1 - 2010/4/1

N2 - We report on an electronic structure study of SrTiO3 under ultraviolet illumination. Photoemission measurements at 20K under ultraviolet illumination show that the illumination induces electronic states within the band gap. The photo-induced in-gap states show the power-law energy distribution with exponent of 3.4- 3.7 and weakly depends on the strength of illumination. The photo-induced in-gap states indicate that most of the photo-excited electrons are trapped by local lattice distortions with various size scale. We argue that the free carriers in the Ti 3d band and the localized Ti 3d electrons and O 2p holes within the band gap contribute to the photoconductivity and the ferroelectricity under the ultraviolet illumination, respectively.

AB - We report on an electronic structure study of SrTiO3 under ultraviolet illumination. Photoemission measurements at 20K under ultraviolet illumination show that the illumination induces electronic states within the band gap. The photo-induced in-gap states show the power-law energy distribution with exponent of 3.4- 3.7 and weakly depends on the strength of illumination. The photo-induced in-gap states indicate that most of the photo-excited electrons are trapped by local lattice distortions with various size scale. We argue that the free carriers in the Ti 3d band and the localized Ti 3d electrons and O 2p holes within the band gap contribute to the photoconductivity and the ferroelectricity under the ultraviolet illumination, respectively.

KW - Orbital degeneracy

KW - Photoemission spectroscopy

KW - Pohoto-induced phase transition

KW - Quantum paraelectricity

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