中国物理B ›› 2017, Vol. 26 ›› Issue (4): 47302-047302.doi: 10.1088/1674-1056/26/4/047302

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

Enhancement of Förster energy transfer from thermally activated delayed fluorophores layer to ultrathin phosphor layer for high color stability in non-doped hybrid white organic light-emitting devices

Zijun Wang(王子君), Juan Zhao(赵娟), Chang Zhou(周畅), Yige Qi(祁一歌), Junsheng Yu(于军胜)   

  1. 1 State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China(UESTC), Chengdu 610054, China;
    2 School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
  • 收稿日期:2016-12-16 修回日期:2016-12-29 出版日期:2017-04-05 发布日期:2017-04-05
  • 通讯作者: Juan Zhao, Junsheng Yu E-mail:zhaoj95@mail.sysu.edu.cn;jsyu@uestc.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61675041 and 61605253), the Foundation for Innovation Research Groups of the National Natural Science Foundation of China (Grant No. 61421002), and the Science & Technology Department Program of Sichuan Province, China (Grant No. 2016HH0027).

Enhancement of Förster energy transfer from thermally activated delayed fluorophores layer to ultrathin phosphor layer for high color stability in non-doped hybrid white organic light-emitting devices

Zijun Wang(王子君)1, Juan Zhao(赵娟)2, Chang Zhou(周畅)1, Yige Qi(祁一歌)1, Junsheng Yu(于军胜)1   

  1. 1 State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China(UESTC), Chengdu 610054, China;
    2 School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
  • Received:2016-12-16 Revised:2016-12-29 Online:2017-04-05 Published:2017-04-05
  • Contact: Juan Zhao, Junsheng Yu E-mail:zhaoj95@mail.sysu.edu.cn;jsyu@uestc.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61675041 and 61605253), the Foundation for Innovation Research Groups of the National Natural Science Foundation of China (Grant No. 61421002), and the Science & Technology Department Program of Sichuan Province, China (Grant No. 2016HH0027).

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摘要： Fluorescence/phosphorescence hybrid white organic light-emitting devices (WOLEDs) based on double emitting layers (EMLs) with high color stability are fabricated. The simplified EMLs consist of a non-doped blue thermally activated delayed fluorescence (TADF) layer using 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone (DMAC-DPS) and an ultrathin non-doped yellow phosphorescence layer employing bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2'] iridium (acetylacetonate) ((tbt)2Ir(acac)). Two kinds of materials of 4,7-diphenyl-1,10-phenanthroline (Bphen) and 1,3,5-tris(2-N-phenylbenzimidazolyl) benzene (TPBi) are selected as the electron transporting layer (ETL), and the thickness of yellow EML is adjusted to optimize device performance. The device based on a 0.3-nm-thick yellow EML and Bphen exhibits high color stability with a slight Commission International de l'Eclairage (CIE) coordinates variation of (0.017, 0.009) at a luminance ranging from 52 cd/m2 to 6998 cd/m2. The TPBi-based device yields a high efficiency with a maximum external quantum efficiency (EQE), current efficiency, and power efficiency of 10%, 21.1 cd/A, and 21.3 lm/W, respectively. The ultrathin yellow EML suppresses hole trapping and short-radius Dexter energy transfer, so that Förster energy transfer (FRET) from DMAC-DPS to (tbt)2Ir(acac) is dominant, which is beneficial to keep the color stable. The employment of TPBi with higher triplet excited state effectively alleviates the triplet exciton quenching by ETL to improve device efficiency.

关键词: white organic light-emitting devices, non-doped emitting layers, thermally activated delayed fluorescence, color stability

Abstract: Fluorescence/phosphorescence hybrid white organic light-emitting devices (WOLEDs) based on double emitting layers (EMLs) with high color stability are fabricated. The simplified EMLs consist of a non-doped blue thermally activated delayed fluorescence (TADF) layer using 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone (DMAC-DPS) and an ultrathin non-doped yellow phosphorescence layer employing bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2'] iridium (acetylacetonate) ((tbt)2Ir(acac)). Two kinds of materials of 4,7-diphenyl-1,10-phenanthroline (Bphen) and 1,3,5-tris(2-N-phenylbenzimidazolyl) benzene (TPBi) are selected as the electron transporting layer (ETL), and the thickness of yellow EML is adjusted to optimize device performance. The device based on a 0.3-nm-thick yellow EML and Bphen exhibits high color stability with a slight Commission International de l'Eclairage (CIE) coordinates variation of (0.017, 0.009) at a luminance ranging from 52 cd/m2 to 6998 cd/m2. The TPBi-based device yields a high efficiency with a maximum external quantum efficiency (EQE), current efficiency, and power efficiency of 10%, 21.1 cd/A, and 21.3 lm/W, respectively. The ultrathin yellow EML suppresses hole trapping and short-radius Dexter energy transfer, so that Förster energy transfer (FRET) from DMAC-DPS to (tbt)2Ir(acac) is dominant, which is beneficial to keep the color stable. The employment of TPBi with higher triplet excited state effectively alleviates the triplet exciton quenching by ETL to improve device efficiency.

Key words: white organic light-emitting devices, non-doped emitting layers, thermally activated delayed fluorescence, color stability

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)