磷光客体三重态能级对基于PVK主体的电致发光器件的影响

doi:10.7517/j.issn.1674-0475.2012.06.411

影像科学与光化学 ›› 2012, Vol. 30 ›› Issue (6): 411-419.DOI: 10.7517/j.issn.1674-0475.2012.06.411

磷光客体三重态能级对基于PVK主体的电致发光器件的影响

刘红梅¹, 尹名¹, 汪鹏飞², 何鉴², 张晓宏², 张新平¹

1. 北京工业大学应用数理学院微纳信息光子技术研究所,北京 100124;
2. 中国科学院理化技术研究所纳米有机光电子实验室, 北京 100190

收稿日期:2012-04-11 修回日期:2012-06-28 出版日期:2012-11-15 发布日期:2012-11-15
通讯作者: 张晓宏, 张新平
基金资助:
国家自然科学基金(11074018,11104007).

Effects of Triplet Energy Levels of Phosphorescent Guests on Luminescent Efficiency of PVK Based Polymeric Light-Emitting Diodes

LIU Hong-mei¹, YIN Ming¹, WANG Peng-fei², HE Jian², ZHANG Xiao-hong², ZHANG Xin-ping¹

1. College of Applied Sciences, Beijing University of Technology, Beijing 100124, P. R. China;
2. Nano-Organic Photoelectronic Laboratory, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China

Received:2012-04-11 Revised:2012-06-28 Online:2012-11-15 Published:2012-11-15

摘要/Abstract

摘要： 将磷光客体掺入PVK:PBD主体材料中是获得高效率磷光电致发光器件 (PhPLED)的有效途径.然而,分别掺杂Ir(pppy)₃、Ir(F-pppy)₃和Ir(F₂-pppy)₃三种磷光客体的PhPLED器件性能件却显著不同.我们分别模拟主-客体间能量转移和客体直接捕获电子空穴对两种机制,研究了三种客体材料的磷光发射及其衰减过程.研究表明:平衡的载流子注入和客体高效率的载流子捕获是实现Ir-配合物掺杂的PhPLED器件性能优良的主要机制,PVK较低的三重态能级使其无法成为蓝光磷光电致发光器件的主体,在PVK中掺入PBD的方法,则进一步降低了主体材料的三重态能级,这是蓝光磷光电致发光器件运行效率较低的主要原因.本文的研究结果可为高分子磷光电致发光器件的制备技术和新型磷光主体的设计提供参考.

关键词: 高分子电致发光器件, 磷光电致发光, 时间分辨光谱, 主-客体能量转移, 电荷捕获

Abstract: Doping phosphorescent guests to PVK and PBD matrix is an effective method to achieve high-efficiency phosphorescent polymeric light-emitting diodes (PhPLED). However, by doping Ir(pppy)₃, Ir(F-pppy)₃and Ir(F₂-pppy)₃ to the PVK and PBD matrix, great difference of the device properties have been observed. In order to investigate the reasons for these phenomena, we use steady- and time-resolved-spectroscopy to study the effect of energy transfer from host to guest and direct electron and hole trapping mechanisms on the light-emitting properties of the active layers. The experimental results show that the balanced carrier injection and high efficient charge trapping are important mechanisms for obtaining high-efficiency PhPLEDs with PVK as the host. PVK does not fit blue PhPLED preparation because of its lower triplet energy level. Doping PBD to PVK host will further decrease the triplet energy level of the host. Our work provides important photophysical basis for the design of the phosphorescent hosts and the PhPLED device.

Key words: polymeric light-emitting diodes, electrophosphorescence, time resolved spectroscopy, energy transfer, charge trapping

中图分类号:

刘红梅, 尹名, 汪鹏飞, 何鉴, 张晓宏, 张新平. 磷光客体三重态能级对基于PVK主体的电致发光器件的影响[J]. 影像科学与光化学, 2012, 30(6): 411-419.

LIU Hong-mei, YIN Ming, WANG Peng-fei, HE Jian, ZHANG Xiao-hong, ZHANG Xin-ping. Effects of Triplet Energy Levels of Phosphorescent Guests on Luminescent Efficiency of PVK Based Polymeric Light-Emitting Diodes[J]. Imaging Science and Photochemistry, 2012, 30(6): 411-419.

参考文献

[1] Baldo M A, O'Brien D F, You Y, et al. Highly efficient phosphorescent emission from organic electro-luminescent devices[J]. Nature, 1998, 395:151-154.
[2] Adachi C, Baldo M A, Thompson M E, et al. Nearly 100% internal phosphorescence efficiency in an organic light-emitting device[J]. J. Appl. Phys., 2001, 90:5048-5051.
[3] Ikai M, Tokito S, Sakamoto Y, et al. Highly efficient phosphorescence from organic light-emitting devices with an exciton-block layer[J]. Appl. Phys. Lett., 2001, 79:156-158.
[4] 刘红梅,郑才俊, 何鉴, 等. 高效溶液法小分子磷光电致发光器件研究[J]. 影像科学与光化学, 2008, 26(1):8-15. Liu H M, Zheng C J, He J, et al. High efficient solution processed small molecular phosphorescent organic light-emitting diodes [J]. Imaging Science and Photochemistry, 2008, 26(1):8-15.
[5] 张建成, 王夺元. 现代光化学[M]. 北京:化学工业出版社, 2006, 21-24. Zhang J C, Wang D Y. Modern. Molecular Chemistry[M]. Beijing: Chemical Industry Press, 2006. 21-24.
[6] Noh Y Y, Lee C L, Kim J J, et al. Energy transfer and device performance in phosphorescent dye doped polymer light emitting diodes [J]. J. Chem. Phys., 2003, 118: 2853.
[7] Chen F C, He G, Yang Y. Triplet exciton confinement in phosphorescent polymer light-emitting diodes [J]. Appl. Phys. Lett., 2003, 82:1006-1008.
[8] Chen F C, Chang S. C, He G, et al. Energy transfer and triplet exciton confinement in polymeric electrophosphorescent devices[J]. J. Polym. Sci. B,2003, 41(21): 2681-2690.
[9] Simon M K, Hameed A A, Rebecca J E, et al. The influence of triplet transfer and other factors on enhancing device performance[J]. Adv. Funct. Mater., 2006, 16: 1043-1050.
[10] Yang X H and Neher D. Polymer electrophosphorescence devices with high power conversion efficiencies[J]. Appl. Phys. Lett., 2004, 84:2476.
[11] Liu H M, He J, Wang P F, et al. High-efficiency polymer electrophosphorescent diodes based on an Ir(III) complex [J]. Appl. Phys. Lett., 2005, 87: 221103.
[12] Liu H M, Chew S L, Wang P F, et al. High-efficiency endothermic energy transfer in polymeric light-emitting devices based on cyclometalated Ir complexes[J]. Appl. Phys. Lett., 2008, 92: 023301.
[13] Holmes R J, Forrest S R, Tung Y J, et al. Blue organic electrophosphorescence using exothermic host guest energy transfer[J]. Appl. Phys. Lett., 2003, 82(15): 2422-2424.
[14] Kadashchuk A, Schols S, Vakhnin A, et al. Triplet dynamics and charge carrier trapping in triplet-emitter doped conjugated polymers[J]. Chemical Physics, 2009, 358: 147-155.
[15] Llorente A G, Arredondo B, and Romero B. Energy transfer within mixed phase polyfluorene based phosphorescent electroluminescent devices[J]. J. Phys. Chem. C, 2012, 116(6): 4259-4266.
[16] Chew S L, Lee C S, Lee S T, et al. Photoluminescence and electroluminescence of a new blue-emitting homoleptic iridium complex[J]. Appl. Phys. Lett., 2006, 88: 093510.

磷光客体三重态能级对基于PVK主体的电致发光器件的影响

Effects of Triplet Energy Levels of Phosphorescent Guests on Luminescent Efficiency of PVK Based Polymeric Light-Emitting Diodes

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