Photodynamics of Organic Thin Film Multilayer Struvtures with Optical Functions

具有光学功能的有机薄膜多层结构的光动力学

• 批准号: 11450013
• 负责人: FUJITA Shizuo
• 金额: $ 5.89万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450013/
• 关键词: organic materials multilayer structures; HOMO energy; LUMO energy; photodynamics; radiative recombination lifetime; exciton localization; white EL; 光タイナミクス; Alq; TPD; PBD

This research was carried out aimed at developing a new material structure with novel optical functions, i.e., organic thin film multilayer structures, through critical characterization of their photodynamics. The results are summarized as follows ;1. Organic materials for electroluminescence (EL) applications were chosen as target for this reserach. Well-defined multilayer structures with aluminumquinoline (Alq3), diamine (TPD), oxadiazole (PBD), and cyclopentadiene (PPCP) were fabricated by molecular beam deposition technique with the controllability of smaller than 20Å, which was proven by x-ray diffraction and non-contact mode atomic force microscopy.2. Techniques for elucidating energy structures of organic materials were developed by using UPS, excitation PL, and photoabsorption characteristics. The results revealed type-II energy lineup with respect to HOMO and LUMO levels for Alq/TPD and Alq/PPCP and type-I for Alq/PBD.3. Photodynamics characterization conditions with time-resolved PL were established and with this technique fast (within few ps) energy transfer of photoexcited carriers to Alq followed by effective radiative recombination in type-I structures and separation of electrons and holes in different layers in type-II structures were evidenced.4. Doping of C60 into electron transport layers enhanced electron mobility and this successfully improved the efficiency of EL devices where electron mobility dominated the total efficiency.5. Based on the photodynamics revealed in this study, novel structures for EL devices were newly proposed and actually contributed to improvement of efficiency of green EL devices and visibility of white EL devices.

这项研究的目的是通过对其光动力学的关键表征来开发一种具有新颖光学功能的新材料结构，即有机薄膜多层结构。研究结果总结如下： 1．选择用于电致发光（EL）应用的有机材料作为本研究的目标。采用分子束沉积技术制备了铝喹啉（Alq3）、二胺（TPD）、恶二唑（PBD）和环戊二烯（PPCP）的清晰多层结构，其可控性小于20Å，并通过X射线衍射和非接触模式原子力显微镜证明了这一点。 2．利用 UPS、激发 PL 和光吸收特性开发了阐明有机材料能量结构的技术。结果揭示了 Alq/TPD 和 Alq/PPCP 的 HOMO 和 LUMO 能级的 II 型能量阵容以及 Alq/PBD.3 的 I 型能量阵容。建立了时间分辨PL的光动力学表征条件，并证明了利用该技术，光激发载流子快速（在几皮秒内）能量转移到Alq，随后在I型结构中进行有效的辐射复合，并证明了II型结构中不同层中电子和空穴的分离。 4．将C60掺杂到电子传输层中增强了电子迁移率，这成功地提高了电子迁移率在总效率中占主导地位的EL器件的效率。5．基于本研究揭示的光动力学，新提出了EL器件的新颖结构，并且实际上有助于提高绿色EL器件的效率和白色EL器件的可视性。

项目成果

FUJITA, Shizuo, et al.: "Comparative Study of Photoluminescence Dynamics of Tris (8-Hydroxyquinoline) Aluminum-Based Organic Multilayer Structures with Different Types of Energy Lineups"Japanese Journal of Applied Physics. Vol.39, No.9A. 5301-5309 (2000)

FUJITA、Shizuo 等人：“具有不同类型能量排列的三（8-羟基喹啉）铝基有机多层结构的光致发光动力学的比较研究”日本应用物理学杂志。

S.Fujita,T.Nakazawa,M.Asano 他: "Luminescence dynamics of Alq3-based multilayer structures in terms of HOMO and LUMO energy discontinuity"Materials Research Society Fall Meetings Proceedings. (印刷中).

S. Fujita、T. Nakazawa、M. Asano 等人：“基于 HOMO 和 LUMO 能量不连续性的 Alq3 多层结构的发光动力学”材料研究学会秋季会议论文集（正在出版）。

S.Fujita,T.Nakazawa,M.Asano 他: "Comparative Study of Photoluminescence Dynamics of Tris(8-Hydroxyquinoline) Aluminum-Based Organic Multilayer Structures with Different Types of Energy Lineups"Japanese Journal of Applied Physics. 39(9A). 5301-5309 (2000)

S. Fujita、T. Nakazawa、M. Asano 等人：“具有不同类型能量排列的三(8-羟基喹啉)铝基有机多层结构的光致发光动力学的比较研究”日本应用物理学杂志 39(9A)。 5301-5309（2000）。

S.Fujita,T.Nakazawa,M.Asano 他: "Comparative Study of Photoluminescence Dynamics of Tris (8-Hydroxyquinoline) Aluminum-Based Organic Multilayer Structures with Different Types of Energy Lineups"Japanese Journal of Applied Physics. 39(9A). 5301-5309 (2000)

S. Fujita、T. Nakazawa、M. Asano 等人：“具有不同类型能量排列的三（8-羟基喹啉）铝基有机多层结构的光致发光动力学的比较研究”日本应用物理学杂志 39(9A)。 5301-5309（2000）。