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 journalArticlepeer-review

10 Citations (Scopus)


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 languageEnglish
Article number044703
Journaljournal of the physical society of japan
Issue number4
Publication statusPublished - 2010 Apr 1
Externally publishedYes


  • Orbital degeneracy
  • Photoemission spectroscopy
  • Pohoto-induced phase transition
  • Quantum paraelectricity

ASJC Scopus subject areas

  • General Physics and Astronomy


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