中国物理B ›› 2017, Vol. 26 ›› Issue (8): 87302-087302.doi: 10.1088/1674-1056/26/8/087302

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

High-efficiency organic light-emitting diodes based on ultrathin blue phosphorescent modification layer

Yun-Ke Zhu(朱云柯), Jian Zhong(钟建), Shu-Ying Lei(雷疏影), Hui Chen(陈辉), Shuang-Shuang Shao(邵双双), Yu Lin(林宇)   

  1. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electron Science and Technology of China (UESTC), Chengdu 610054, China
  • 收稿日期:2017-02-10 修回日期:2017-04-15 出版日期:2017-08-05 发布日期:2017-08-05
  • 通讯作者: Jian Zhong E-mail:zhongjian@uestc.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 61675041 and 61605253), the Foundation for Innovation Research Groups of the NSFC (Grant No. 61421002), and the Fund from the Science & Technology Department of Sichuan Province, China (Grant No. 2016HH0027).

High-efficiency organic light-emitting diodes based on ultrathin blue phosphorescent modification layer

Yun-Ke Zhu(朱云柯), Jian Zhong(钟建), Shu-Ying Lei(雷疏影), Hui Chen(陈辉), Shuang-Shuang Shao(邵双双), Yu Lin(林宇)   

  1. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electron Science and Technology of China (UESTC), Chengdu 610054, China
  • Received:2017-02-10 Revised:2017-04-15 Online:2017-08-05 Published:2017-08-05
  • Contact: Jian Zhong E-mail:zhongjian@uestc.edu.cn
  • About author:0.1088/1674-1056/26/8/
  • Supported by:

    Project supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 61675041 and 61605253), the Foundation for Innovation Research Groups of the NSFC (Grant No. 61421002), and the Fund from the Science & Technology Department of Sichuan Province, China (Grant No. 2016HH0027).

摘要:

Yellow organic light-emitting devices (YOLEDs) with a novel structure of ITO/MoO3(5 nm)/NPB(40 nm)/TCTA(15 nm)/CBP:(tbt)2Ir(acac)(x%)(25 nm)/FIrpic(y nm)/TPBi(35 nm)/Mg:Ag are fabricated. The ultrathin blue phosphorescent bis[(4,6-difluorophenyl)-pyridi-nato-N,C2\prime ](picolinate) iridium (III) (FIrpic) layer is regarded as a high-performance modification layer. By adjusting the thickness of FIrpic and the concentration of (tbt)2Ir(acac), a YOLED achieves a high luminance of 41618 cd/m2, power efficiency of 49.7 lm/W, current efficiency of 67.3 cd/A, external quantum efficiency (EQE) of 18%, and a low efficiency roll-off at high luminance. The results show that phosphorescent material of FIrpic plays a significant role in improving YOLED performance. The ultrathin FIrpic modification layer blocks excitons in EML. In the meantime, the high triplet energy of FIrpic (2.75 eV) alleviates the exciton energy transport from EML to FIrpic.

关键词: modification layer, ultrathin, YOLEDs, phosphorescence

Abstract:

Yellow organic light-emitting devices (YOLEDs) with a novel structure of ITO/MoO3(5 nm)/NPB(40 nm)/TCTA(15 nm)/CBP:(tbt)2Ir(acac)(x%)(25 nm)/FIrpic(y nm)/TPBi(35 nm)/Mg:Ag are fabricated. The ultrathin blue phosphorescent bis[(4,6-difluorophenyl)-pyridi-nato-N,C2\prime ](picolinate) iridium (III) (FIrpic) layer is regarded as a high-performance modification layer. By adjusting the thickness of FIrpic and the concentration of (tbt)2Ir(acac), a YOLED achieves a high luminance of 41618 cd/m2, power efficiency of 49.7 lm/W, current efficiency of 67.3 cd/A, external quantum efficiency (EQE) of 18%, and a low efficiency roll-off at high luminance. The results show that phosphorescent material of FIrpic plays a significant role in improving YOLED performance. The ultrathin FIrpic modification layer blocks excitons in EML. In the meantime, the high triplet energy of FIrpic (2.75 eV) alleviates the exciton energy transport from EML to FIrpic.

Key words: modification layer, ultrathin, YOLEDs, phosphorescence

中图分类号:  (Multilayers)

  • 73.21.Ac
78.60.Fi (Electroluminescence) 85.60.Jb (Light-emitting devices) 73.61.Ph (Polymers; organic compounds)