Intrinsic Luminescence and Configurations of Self-Trapped Excitons in Alkali Halide Crystals.

碱金属卤化物晶体中的本征发光和自陷激子的构型。

• 批准号: 02452037
• 负责人: KAN'NO Ken-ichi
• 金额: $ 4.48万
• 依托单位: KYOTO 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: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02452037/
• 关键词: Self-Trapped Exciton; Alkali Halides; Luminescence; Electron-Lattice Interaction; Lattice Relaxation; Triplet State; Zero-Field Splitting; Off-Center Effect; オフ・センタ-効果; 緩和励起子

Radiative recombination processes of self-trapped excitons (STE) in alkali halide crystals were studied systematically in various kinds of mixed crystals. It was found that the pi emission bands in nine alkali halides, NaCl, KCl, RbCl, NaBr, KBr, RbBr, NaI, KI and RbI, should be classified into three distinct types (I, II, III). It has also been shown that the sigma emission bands which are recognized only in five crystals, NaCl, KBr, RbBr, KI and RbI, are essentially the same as the so-called "pi emission" bands in NaBr and NaI (Type I). These findings bring a pleasing orderliness to the appearance, peak energies and dipole strengths of singlet sigma and triplet pi transitions in alkali halides. In this new scheme, the sigma bands generally, and the corresponding pi bands in NaBr and NaI, are suggested to originate from an on-center STE configuration. The low energy pi bands, and the Ex band in RbI, are suggested to originate from two separate off-center STE configurations, all on the same adiabatic potential surface of the lowest energy.Thus, the present study provides an unifying recognition for the mechanism of exciton self-trapping in terms of on-center and/or off-center distortion.

系统地研究了碱金属卤化物晶体中自陷激子在各种混晶中的辐射复合过程。发现NaCl、KCl、RbCl、NaBr、KBr、RbBr、NaI、KI和RbI等9种碱金属卤化物的π发射带可分为Ⅰ、Ⅱ、Ⅲ型。实验还表明，仅在NaCl、KBr、RbBr、KI和RbI五种晶体中识别的σ发射带与NaBr和NaI（I型）中的所谓π发射带基本相同。这些发现使碱金属卤化物的单重态σ和三重态π跃迁的出现、峰能量和偶极强度呈现出令人满意的规律性。在这个新方案中，σ带一般，和相应的π带在NaBr和NaI，建议起源于一个中心STE配置。RbI的低能π带和Ex带起源于两个不同的偏离中心的STE组态，它们都位于同一个最低能量的绝热势面上，从而从中心畸变和/或偏离中心畸变的角度对激子自陷机制提供了一个统一的认识.

项目成果

T.Matsumoto,T.Kawata and K.Kan'no.: "Time-Resolved Spectroscopic Study on the Type I Self-Trapped Excitons in Alkali Halide Crystals:Part I.Emission Spectra and Decay Behavior." J.Phys.Soc.Jpn.61. 4229-4241 (1992)

T.Matsumoto、T.Kawata 和 K.Kanno.：“碱金属卤化物晶体中 I 型自陷激子的时间分辨光谱研究：第一部分：发射光谱和衰变行为。”

T.Matsumoto, T.Kawata, A.Miyamoto and K.Kan'no.: "Luminescence Decay Behavior of the On-Center Self-Trapped Excitons in Alkali Halides." Proceedings of ICDIM 92 (Int. Confe. on Defects in Insulating Materials).

T.Matsumoto、T.Kawata、A.Miyamoto 和 K.Kanno.：“碱金属卤化物中中心自陷激子的发光衰变行为”。

T.Kawata,T.Mukai,T.Matsumoto and K.Kan'no.: "Magnetic Field Effect on the Luminescence Lifetime of Triplet Self-Trapped Excitons in NaBr and NaI." Proceedings of ICDIM 92.

T.Kawata、T.Mukai、T.Matsumoto 和 K.Kanno.：“磁场对 NaBr 和 NaI 中三重态自陷激子发光寿命的影响”。

K.Kan'no,K.Tanaka and T.Hayashi.: "New Aspects of Intrinsic Luminescence in Alkali Halide Crystals." Reviews of Solid State Science.4. 383-401 (1990)

K.Kanno、K.Tanaka 和 T.Hayashi.：“碱金属卤化物晶体本征发光的新方面。”

T.Matsumot,T.Kawata,A.Miyamoto,K.Kan'no,M.Hasumoto and M.Kamata.: "A Method for Time-Resolved Measurements Applied on Intrinsic Luminescence in Alkali Halides." UVSOR Activity Report.UVSOR-19. 30-31 (1992)

T.Matsumot、T.Kawata、A.Miyamoto、K.Kanno、M.Hasumoto 和 M.Kamata：“一种应用于碱卤化物本征发光的时间分辨测量方法”。