Photo-Induced In-Gap States in SrTiO3 Probed by Photoemission Spectroscopy under Ultraviolet Illumination

被引：12

作者：

Mizokawa, Takashi ^{[1
,2
]}

Takaiwa, Norihisa ^{[1
,2
]}

Fujiwara, Yukihiro ^{[1
,2
]}

Iida, Takashi ^{[1
,2
]}

Takubo, Kou ^{[1
,2
]}

Son, Jin-Young ^{[1
,2
]}

Ishikawa, Tadahiko ^{[3
]}

Itoh, Mitsuru ^{[4
]}

Takesada, Masaki ^{[5
]}

机构：

[1] Univ Tokyo, Dept Phys, Chiba 2778561, Japan

[2] Univ Tokyo, Dept Complex Sci & Engn, Chiba 2778561, Japan

[3] Tokyo Inst Technol, Dept Chem & Mat Sci, Meguro Ku, Tokyo 1528551, Japan

[4] Tokyo Inst Technol, Mat & Struct Lab, Yokohama, Kanagawa 2268503, Japan

[5] Hokkaido Univ, Dept Phys, Sapporo, Hokkaido 0600810, Japan

来源：

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN | 2010年 / 79卷 / 04期

关键词：

photoemission spectroscopy; photo-induced phase transition; quantum paraelectricity; orbital degeneracy; STRONTIUM-TITANATE; X-RAY; ELECTRIC-FIELD; PHOTOCONDUCTIVITY; FERROELECTRICITY; PEROVSKITE;

D O I：

10.1143/JPSJ.79.044703

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We report on an electronic structure study of SrTiO3 under ultraviolet illumination. Photoemission measurements at 20 K 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.

引用

页数：4

共 24 条

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