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CC BY-NC-ND 4.0 · Organic Materials 2021; 3(04): 488-492
DOI: 10.1055/a-1711-5768
Organic Materials in Electronics
Short Communication

Sensitized Fluorescence Organic Light-Emitting Diodes with Reduced Efficiency Roll-Off

Zhiyi Li 
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Ruifang Wang
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Yangyang Zeng
c   School of Materials Design & Engineering, Beijing Institute of Fashion Technology, Beijing 100029, P. R. of China
,
Xiangyu Dong
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Guanhao Liu
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Xiaoxiao Hu
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Teng Gao
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Honglei Gao
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Yuanyuan Qin
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Xiuxian Gu
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Chun-Sing Lee 
d   Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Hong Kong SAR, P. R. of China
,
Jiguang Liu
c   School of Materials Design & Engineering, Beijing Institute of Fashion Technology, Beijing 100029, P. R. of China
,
Pengfei Wang 
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
,
Ying Wang 
a   Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU−CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. of China
b   University of Chinese Academy of Sciences, Beijing 100049, P. R. of China
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Abstract

Thermally activated delayed fluorescence (TADF)-sensitized fluorescence is a promising strategy to maintain the advantage of TADF materials and fluorescent materials. Nevertheless, the delayed lifetime of the TADF sensitizer is still relatively long, which causes heavy efficiency roll-off. Here we reported a valid tactic to construct fluorescent devices with low-efficiency roll-off by utilizing the TADF sensitizer with a reduced delayed lifetime. By the construction of the sensitization system, the energy transfer efficiency can reach up to 90%. The high-energy transfer efficiency and the TADFʼs short delayed lifetime result in high sensitization over 95% and the maximum external quantum efficiency of 16.2%. Meanwhile, the TADF-sensitized fluorescent devices exhibit reduced efficiency roll-off with an “onset” current density of 23 mA · cm−2. Our results provide an effective strategy to reduce the efficiency roll-off of the TADF sensitization system.

Key words

OLED - fluorescence - TADF

Supporting Information



Publication History

Received: 11 October 2021

Accepted: 17 November 2021

Accepted Manuscript online:
02 December 2021

Article published online:
27 December 2021

© 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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  • References and Notes

    • 1a Uoyama H, Goushi K, Shizu K, Nomura H, Adachi C. Nature 2012; 492: 234
    • 1b Jeon SO, Lee KH, Kim JS, Ihn S-G, Chung YS, Kim JW, Lee H, Kim S, Choi H, Lee JY. Nat. Photonics 2021; 15: 208
  • 2 Wang Z, Wang R, Mi Y, Lu K, Liu Y, Yang C, Zhang J, Liu X, Wang Y, Shuai Z, Wei Z. Chem. Mater. 2021; 33: 4578
  • 3 Qi S, Kim S, Nguyen V-N, Kim Y, Niu G, Kim G, Kim S-J, Park S, Yoon J. ACS Appl. Mater. Interfaces 2020; 12: 51293
  • 4 Bryden MA, Zysman-Colman E. Chem. Soc. Rev. 2021; 50: 7587
  • 5 Zhang Q, Li J, Shizu K, Huang S, Hirata S, Miyazaki H, Adachi C. J. Am. Chem. Soc. 2012; 134: 14706
    • 6a Wang H, Xie L, Peng Q, Meng L, Wang Y, Yi Y, Wang P. Adv. Mater. 2014; 26: 5198
    • 6b Cai X, Qiao Z, Li M, Wu X, He Y, Jiang X, Cao Y, Su SJ. Angew. Chem. Int. Ed. 2019; 58: 13522
    • 7a Tao Y, Yuan K, Chen T, Xu P, Li H, Chen R, Zheng C, Zhang L, Huang W. Adv. Mater. 2014; 26: 7931
    • 7b Wong MY, Zysman-Colman E. Adv. Mater. 2017; 29,: 1605444
    • 7c Wada Y, Nakagawa H, Matsumoto S, Wakisaka Y, Kaji H. Nat. Photonics 2020; 14: 643
  • 8 Li M, Li S-H, Zhang D, Cai M, Duan L, Fung M-K, Chen C-F. Angew. Chem. Int. Ed. 2018; 57: 2889
  • 9 Murawski C, Leo K, Gather MC. Adv. Mater. 2013; 25: 6801
  • 10 Reineke S, Walzer K, Leo K. Phys. Rev. B: Condens. Matter 2007; 75: 125328
  • 11 Cui L-S, Ruan S-B, Bencheikh F, Nagata R, Zhang L, Inada K, Nakanotani H, Liao L-S, Adachi C. Nat. Commun. 2017; 8: 2250
  • 12 Cui L-S, Ruan S-B, Bencheikh F, Nagata R, Zhang L, Inada K, Nakanotani H, Liao L-S, Adachi C. Nat. Commun. 2017; 8: 2250
  • 13 Byeon SY, Lee DR, Yook KS, Lee JY. Adv. Mater. 2019; 31: 1803714
  • 14 Chan C-Y, Tanaka M, Lee Y-T, Wong Y-W, Nakanotani H, Hatakeyama T, Adachi C. Nat. Photonics 2021; 15: 203
  • 15 Nakanotani H, Higuchi T, Furukawa T, Masui K, Morimoto K, Numata M, Tanaka H, Sagara Y, Yasuda T, Adachi C. Nat. Commun. 2014; 5: 4016
  • 16 Kim JH, Lee KH, Lee JY. J. Mater. Chem. C 2020; 8,: 5265
  • 17 Heimel P, Mondal A, May F, Kowalsky W, Lennartz C, Andrienko D, Lovrincic R. Nat. Commun. 2018; 9: 4990
  • 18 Zhang D, Song X, Cai M, Duan L. Adv. Mater. 2018; 30: 1705250
    • 19a Song X, Zhang D, Lu Y, Yin C, Duan L. Adv. Mater. 2019; 31: 1901923
    • 19b Kim JH, Lee KH, Lee JY. Chem. Eur. J. 2019; 25: 9060
  • 20 Li Z, Hu X, Liu G, Tian L, Gao H, Dong X, Gao T, Cao M, Lee C-S, Wang P, Wang Y. J. Phys. Chem. C 2021; 125: 1980
  • 21 Li Z, Dong X, Liu G, Tian L, Hu X, Gao T, Gao H, Qin Y, Gu X, Lee C-S, Wang P, Wang Y, Liu Y. Energy Fuels 2021; 35: 19104
  • 22 Wang R, Li Z, Hu T, Tian L, Hu X, Liu S, Cao C, Zhu Z-L, Tan J-H, Yi Y, Wang P, Lee C-S, Wang Y. ACS Appl. Mater. Interfaces 2021; 13: 49066
  • 23 Wei P, Zhang D, Duan L. Adv. Funct. Mater. 2020; 30: 1907083
  • 24 Wang H, Meng L, Shen X, Wei X, Zheng X, Lv X, Yi Y, Wang Y, Wang P. Adv. Mater. 2015; 27: 4041
  • 25 Furukawa T, Nakanotani H, Inoue M, Adachi C. Sci. Rep. 2015; 5: 8429
  • 26 Baleizão C, Berberan-Santos MN. Ann. N. Y. Acad. Sci. 2008; 1130: 224
  • OLEDs were fabricated on glass substrates precoated with 150 nm ITO. The substrates should be cleaned with detergent, ultrasonicated in water, acetone and ethyl alcohol, and subsequently dried at 75 °C (10 min) in an oven. Afterward, the substrates were exposed to oxygen plasma (10 min) in order to remove organic residues and improve the work function of ITO. Then the substrates were transferred to a thermal evaporation chamber with a pressure lower than 5 × 10−4 Pa for organic semiconductor layers and metal cathode deposition. The devices were fabricated by evaporating organic materials onto the substrate at a rate of 1 – 2 Å s−1 while LiF at a rate of 0.05 Å s−1 and Al metal through a rate of 5 Å s−1. The pixel sizes of each OLED are 0.09 cm2. The electroluminescence (EL) spectra were measured by a Spectrascan PR655 photometer. The current–voltage–brightness characteristics were measured by using a computer-controlled Keithley source measurement unit (Keithley 2400) with a Konica Minolta CS-200 luminance-meter under dark and ambient atmosphere. External quantum efficiencies (EQEs; %), current efficiencies (cd A−1) and power efficiencies (lm W−1) were calculated from the electrical and optical properties. For this calculation, we assumed Lambertian light distribution.
  • 28 Jung H, Kang S, Lee H, Yu Y-J, Jeong JH, Song J, Jeon Y, Park J. ACS Appl. Mater. Interfaces 2018; 10: 30022
  • 29 Baldo MA, Adachi C, Forrest SR. Phys. Rev. B: Condens. Matter 2000; 62: 10967