Femtosecond spectroscopy for the dynamics of relaxation of excitons in solids with strong electron-phonon coupling

用于强电子声子耦合固体中激子弛豫动力学的飞秒光谱

• 批准号: 04452040
• 负责人: TANIMURA Katsumi
• 金额: $ 4.42万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04452040/
• 关键词: self-trapping; excitons; femtosecond spectroscopy; lattice relaxation; F-H pair; alkali halides; fluorites; SiO2; CaF_2; SiO_2

Lattice relaxation of excitons in alkali halides, fluorites, and SiO_2 have been studies by means of time-resolved spectroscopy in femtosecond time regime. Our new findings and results obtained in this study are summarized as follows :(1)Initial formation yields of F-H pairs and triplet self-trapped excitons, STEs, in alkali halides show a clear complementary relation.(2)Optical transition energies of self-trapped holes in amorphous SiO_2 have been determined.(3)Luminescence from the singlet STE in SiO_2 have been identified for the first time.(4)Self-trapping processes of holes in KBr and KI have been resolved for the first time. In particular, holes in KI are self-trapped into the well-known V_k center via an one-center type self-trapped state.(5)Initial process of F-center formation in alkali bromides has been found to involve two different pathways ; one directly from the electron-hole pairs under relaxation and the other via the off-center instability from the on-center STEs.(6)Relaxation of electron-hole pairs in CaF_2 has been observed for the first time in femtosecond time regime. The relaxation pathways are found to be similar to those in alkali halides.

利用飞秒时间范围内的时间分辨光谱研究了碱金属卤化物、萤石和SiO_2中激子的晶格弛豫。我们的新发现和成果概括如下：(1)碱卤化物中F-H对和三重态自陷激子(STE)的初始形成产率显示出明显的互补关系。(2)确定了非晶SiO_2中自陷空穴的光学跃迁能。(3)首次确定了SiO_2中单线态STE的发光。 (4)首次解决了KBr和KI空穴的自捕获过程。特别是，KI中的空穴通过单中心型自捕获态自捕获到众所周知的V_k中心。(5)碱金属溴化物中F中心形成的初始过程被发现涉及两种不同的途径；一个直接来自弛豫下的电子空穴对，另一个则通过来自中心STE的偏心不稳定性。(6)首次在飞秒时间范围内观察到CaF_2中电子空穴对的弛豫。发现弛豫途径与碱金属卤化物中的弛豫途径相似。

项目成果

K.Kan7'no and T.Tanimura: "Exciton self-trapping and defect formation in alkali halides" Solid state physics, special issue, (Agne, Tokyou, 1993). 23-38

K.Kan7no 和 T.Tanimura：“碱金属卤化物中的激子自俘获和缺陷形成”固体物理学，特刊，（Agne，Tokyo，1993）。

K.Tanimura and N.Itoh: "Defect formation induced by electronic excitation in SiO2" Solid state physics, special issue, (Agne, Tokyo, 1993). 87-93

K.Tanimura 和 N.Itoh：“SiO2 中电子激发引起的缺陷形成”固态物理学，特刊，（Agne，东京，1993 年）。

柴田隆仁: "Femtosecond spectroscopic studies of the lattice relaxation initiated by interacting electron-hole pairs under relaxation in alkali halides" Physical Review B. 49. 13255-13258 (1994)

Takahito Shibata：“碱金属卤化物弛豫下电子-空穴对相互作用引发的晶格弛豫的飞秒光谱研究”物理评论 B. 49. 13255-13258 (1994)

T.Shibata, S.Iwai, T.Tokizaki, K.Tanimura, A.Nakamura, and N.Itoh: "Femtosecond spectroscopic studies of the lattice relaxation initiated by interacting electron-hole pairs under relaxation in alkali halides" Physical Review. B49. 13255-13258 (1994)

T.Shibata、S.Iwai、T.Tokizaki、K.Tanimura、A.Nakamura 和 N.Itoh：“碱金属卤化物弛豫下电子-空穴对相互作用引发的晶格弛豫的飞秒光谱研究”物理评论。

牧村哲也: "Femtosecond time-resolved spectroscopic studies of the dynamics of the relaxation of excitons in the lowest APES in NaCl" Jounal of Physics:Condensed Matter. (印刷中). (1994)

Tetsuya Makimura：“氯化钠中最低 APES 激子弛豫动力学的飞秒时间分辨光谱研究”《物理学杂志：凝聚态》（出版中）。