Journal Home > Volume 14 , Issue 11
Nano Research 2021, 14(11): 4125-4131 https://doi.org/10.1007/s12274-021-3352-9
Research Article | Issue | Published: 24 February 2021

High performance inkjet-printed QLEDs with 18.3% EQE: Improving interfacial contact by novel halogen-free binary solvent system

Show Author's Information Ming Chen1,§,  Liming Xie1,§,  Changting Wei1,  Yuan-Qiu-Qiang Yi1,  Xiaolian Chen1,  Jian Yang1,  Jinyong Zhuang2,  Fushan Li3,  Wenming Su1( ),  Zheng Cui1
Printable Electronics Research Center Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of SciencesSuzhou 215123 China
Guangdong Juhua Printed Display Technol Company Ltd.Guangzhou 510700 China
Institute of Optoelectronic Technology Fuzhou UniversityFuzhou 350002 China

§Ming Chen and Liming Xie contributed equally to this work.

Keywords:
quantum dots, inkjet printing, contact interface, quantum dots light-emitting diodes (QLEDs), halogen-free inks
Topics:
Nanodots
Cite this article:
Chen M, Xie L, Wei C, et al. High performance inkjet-printed QLEDs with 18.3% EQE: Improving interfacial contact by novel halogen-free binary solvent system. Nano Research, 2021, 14(11): 4125-4131. https://doi.org/10.1007/s12274-021-3352-9
Download citation
EndNote(RIS)
BibTeX

654

Views

51

Downloads

Citations

43

Crossref

35

WoS

38

Scopus

3

CSCD

Abstract Full text Electronic supplementary material About this article

Poly[(9, 9-dioctylfluorenyl-2, 7-diyl)-alt(4, 4'-(N-(4-butylphenyl))] (TFB), one of the most popular and widely used hole-transport layer (HTL) materials, has been successfully applied in high performance spin-coated quantum dots-based light-emitting diodes (QLEDs) due to its suitable energy level and high mobility. However, there are still many challenging issues in inkjet-printed QLED devices when using TFB as HTL. TFB normally suffers from the interlayer mixing and erosion, and low surface energy against the good film formation. Here, a novel environment-friendly binary solvent system was established for formulating quantum dot (QD) inks, which is based on mixing halogen-free alkane solvents of decalin and n-tridecane. The optimum volume ratio for the mixture of decalin and n-tridecane was found to be 7:3, at which a stable ink jetting flow and coffee-ring free QD films could be formed. To research the influence of substrate surface on the formation of inkjet-printed QD films, TFB was annealed at different temperatures, and the optimum annealing temperature was found to enable high quality inkjet-printed QD film. Inkjet-printed red QLED was ultimately manufactured. A maximum 18.3% of external quantum efficiency (EQE) was achieved, reaching 93% of the spin-coated QLED, which is the best reported high efficiency inkjet-printed red QLEDs to date. In addition, the inkjet-printed QLED achieved similar T75 operational lifetime (27 h) as compared to the spin-coated reference QLED (28 h) at 2, 000 cd·m−2. This work demonstrated that the novel orthogonal halogen-free alkane co-solvents can improve the interfacial contact and facilitate high-performance inkjet printing QLEDs with high EQE and stability.


menu
Abstract
Full text
Outline
Electronic supplementary material
About this article

High performance inkjet-printed QLEDs with 18.3% EQE: Improving interfacial contact by novel halogen-free binary solvent system

Show Author's information Ming Chen1,§, Liming Xie1,§, Changting Wei1, Yuan-Qiu-Qiang Yi1, Xiaolian Chen1, Jian Yang1, Jinyong Zhuang2, Fushan Li3, Wenming Su1( ), Zheng Cui1
Printable Electronics Research Center Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of SciencesSuzhou 215123 China
Guangdong Juhua Printed Display Technol Company Ltd.Guangzhou 510700 China
Institute of Optoelectronic Technology Fuzhou UniversityFuzhou 350002 China

§Ming Chen and Liming Xie contributed equally to this work.

Abstract

Poly[(9, 9-dioctylfluorenyl-2, 7-diyl)-alt(4, 4'-(N-(4-butylphenyl))] (TFB), one of the most popular and widely used hole-transport layer (HTL) materials, has been successfully applied in high performance spin-coated quantum dots-based light-emitting diodes (QLEDs) due to its suitable energy level and high mobility. However, there are still many challenging issues in inkjet-printed QLED devices when using TFB as HTL. TFB normally suffers from the interlayer mixing and erosion, and low surface energy against the good film formation. Here, a novel environment-friendly binary solvent system was established for formulating quantum dot (QD) inks, which is based on mixing halogen-free alkane solvents of decalin and n-tridecane. The optimum volume ratio for the mixture of decalin and n-tridecane was found to be 7:3, at which a stable ink jetting flow and coffee-ring free QD films could be formed. To research the influence of substrate surface on the formation of inkjet-printed QD films, TFB was annealed at different temperatures, and the optimum annealing temperature was found to enable high quality inkjet-printed QD film. Inkjet-printed red QLED was ultimately manufactured. A maximum 18.3% of external quantum efficiency (EQE) was achieved, reaching 93% of the spin-coated QLED, which is the best reported high efficiency inkjet-printed red QLEDs to date. In addition, the inkjet-printed QLED achieved similar T75 operational lifetime (27 h) as compared to the spin-coated reference QLED (28 h) at 2, 000 cd·m−2. This work demonstrated that the novel orthogonal halogen-free alkane co-solvents can improve the interfacial contact and facilitate high-performance inkjet printing QLEDs with high EQE and stability.

Keywords: quantum dots, inkjet printing, contact interface, quantum dots light-emitting diodes (QLEDs), halogen-free inks

References(38)

1

Alivisatos, A. P. Semiconductor clusters, nanocrystals, and quantum dots. Science 1996, 271, 933–937.
DOI Google Scholar
2

Sun, Q. J.; Wang, Y. A.; Li, L. S.; Wang, D. Y.; Zhu, T.; Xu, J.; Yang, C. H.; Li, Y. F. Bright, multicoloured light-emitting diodes based on quantum dots. Nat. Photonics 2007, 1, 717–722.
DOI Google Scholar
3

Bae, W. K.; Kwak, J.; Lim, J.; Lee, D.; Nam, M. K.; Char, K.; Lee, C.; Lee, S. Multicolored light-emitting diodes based on all-quantum-dot multilayer films using layer-by-layer assembly method. Nano Lett. 2010, 10, 2368–2373.
DOI Google Scholar
4

Dai, X. L.; Zhang, Z. X.; Jin, Y. Z.; Niu, Y.; Cao, H. J.; Liang, X. Y.; Chen, L. W.; Wang, J. P.; Peng, X. G. Solution-processed, high- performance light-emitting diodes based on quantum dots. Nature 2014, 515, 96–99.
DOI Google Scholar
5

Bae, W. K.; Lim, J.; Lee, D.; Park, M.; Lee, H.; Kwak, J.; Char, K.; Lee, C.; Lee, S. R/G/B/natural white light thin colloidal quantum dot-based light-emitting devices. Adv. Mater. 2014, 26, 6387–6393.
DOI Google Scholar
6

Chen, Z. N.; Su, Q.; Qin, Z. Y.; Chen, S. M. Effect and mechanism of encapsulation on aging characteristics of quantum-dot light-emitting diodes. Nano Res. 2021, 14, 320–327.
DOI Google Scholar
7

Kim, S.; Kim, J.; Kim, D.; Kim, B.; Chae, H.; Yi, H.; Hwang, B. High-performance transparent quantum dot light-emitting diode with patchable transparent electrodes. ACS Appl. Mater. Interfaces 2019, 11, 26333–26338.
DOI Google Scholar
8

Dai, X. L.; Deng, Y. Z.; Peng, X. G.; Jin, Y. Z. Quantum-dot light- emitting diodes for large-area displays: Towards the dawn of commercialization. Adv. Mater. 2017, 29, 1607022.
DOI Google Scholar
9

Cao, F.; Zhao, D. W.; Shen, P. Y.; Wu, J. L.; Wang, H. R.; Wu, Q. Q.; Wang, F. J.; Yang, X. Y. High-efficiency, solution-processed white quantum dot light-emitting diodes with serially stacked red/green/blue units. Adv. Opt. Mater. 2018, 6, 1800652.
DOI Google Scholar
10

Shen, P. Y.; Cao, F.; Wang, H. R.; Wei, B.; Wang, F. J.; Sun, X. W.; Yang, X. Y. Solution-processed double-junction quantum-dot light-emitting diodes with an EQE of over 40%. ACS Appl. Mater. Interfaces 2019, 11, 1065–1070.
DOI Google Scholar
11

Yang, Y. X.; Zheng, Y.; Cao, W. R.; Titov, A.; Hyvonen, J.; Manders, J. R.; Xue, J. G.; Holloway, P. H.; Qian, L. High-efficiency light- emitting devices based on quantum dots with tailored nanostructures. Nat. Photonics 2015, 9, 259–266.
DOI Google Scholar
12

Shen, H. B.; Gao, Q.; Zhang, Y. B.; Lin, Y.; Lin, Q. L.; Li, Z. H.; Chen, L.; Zeng, Z. P.; Li, X. J.; Jia, Y. et al. Visible quantum dot light- emitting diodes with simultaneous high brightness and efficiency. Nat. Photonics 2019, 13, 192–197.
DOI Google Scholar
13

Cho, K. S.; Lee, E. K.; Joo, W. J.; Jang, E.; Kim, T. H.; Lee, S. J.; Kwon, S. J.; Han, J. Y.; Kim, B. K.; Choi, B. L. et al. High- performance crosslinked colloidal quantum-dot light-emitting diodes. Nat. Photonics 2009, 3, 341–345.
DOI Google Scholar
14

Kim, T. H.; Cho, K. S.; Lee, E. K.; Lee, S. J.; Chae, J.; Kim, J. W.; Kim, D. H.; Kwon, J. Y.; Amaratunga, G.; Lee, S. Y. et al. Full-colour quantum dot displays fabricated by transfer printing. Nat. Photonics 2011, 5, 176–182.
DOI Google Scholar
15

Zou, Y. T.; Ban, M. Y.; Cui, W.; Huang, Q.; Wu, C.; Liu, J. W.; Wu, H. H.; Song, T.; Sun, B. Q. A general solvent selection strategy for solution processed quantum dots targeting high performance light- emitting diode. Adv. Funct. Mater. 2017, 27, 1603325.
DOI Google Scholar
16

Oh, N.; Kim, B. H.; Cho, S. Y.; Nam, S.; Rogers, S. P.; Jiang, Y. R.; Flanagan, J. C.; Zhai, Y.; Kim, J. H.; Lee, J. et al. Double- heterojunction nanorod light-responsive LEDs for display applications. Science 2017, 355, 616–619.
DOI Google Scholar
17

Lin, Q. L.; Wang, L.; Li, Z. H.; Shen, H. B.; Guo, L. J.; Kuang, Y. M.; Wang, H. Z.; Li, L. S. Nonblinking quantum-dot-based blue light- emitting diodes with high efficiency and a balanced charge-injection process. ACS Photonics 2018, 5, 939–946.
DOI Google Scholar
18

Cao, W. R.; Xiang, C. Y.; Yang, Y. X.; Chen, Q.; Chen, L. W.; Yan, X. L.; Qian, L. Highly stable QLEDs with improved hole injection via quantum dot structure tailoring. Nat. Commun. 2018, 9, 2608.
DOI Google Scholar
19

Chen, S.; Cao, W. R.; Liu, T. L.; Tsang, S. W.; Yang, Y. X.; Yan, X. L.; Qian, L. On the degradation mechanisms of quantum-dot light-emitting diodes. Nat. Commun. 2019, 10, 765.
DOI Google Scholar
20

Mei, W. H.; Zhang, Z. Q.; Zhang, A. D.; Li, D.; Zhang, X. Y.; Wang, H. W.; Chen, Z.; Li, Y. Z.; Li, X. G.; Xu, X. G. High-resolution, full-color quantum dot light-emitting diode display fabricated via photolithography approach. Nano Res. 2020, 13, 2485–2491.
DOI Google Scholar
21

Kim, B. H.; Onses, M. S.; Lim, J. B.; Nam, S.; Oh, N.; Kim, H.; Yu, K. J.; Lee, J. W.; Kim, J. H.; Kang, S. K. et al. High-resolution patterns of quantum dots formed by electrohydrodynamic jet printing for light-emitting diodes. Nano Lett. 2015, 15, 969–973.
DOI Google Scholar
22

Jiang, C. B.; Zhong, Z. M.; Liu, B. Q.; He, Z. W.; Zou, J. H.; Wang, L.; Wang, J.; Peng, J. B.; Cao, Y. Coffee-ring-free quantum dot thin film using inkjet printing from a mixed-solvent system on modified ZnO transport layer for light-emitting devices. ACS Appl. Mater. Interfaces 2016, 8, 26162–26168.
DOI Google Scholar
23

Liu, Y.; Li, F. S.; Xu, Z. W.; Zheng, C. X.; Guo, T. L; Xie, X. W; Qian, L.; Fu, D.; Yan, X. L. Efficient all-solution processed quantum dot light emitting diodes based on inkjet printing technique. ACS Appl. Mater. Interfaces 2017, 9, 25506–25512.
DOI Google Scholar
24

Zhou, L.; Yang, L.; Yu, M. J.; Jiang, Y.; Liu, C. F.; Lai, W. Y.; Huang, W. Inkjet-printed small-molecule organic light-emitting diodes: Halogen-free inks, printing optimization, and large-area patterning. ACS Appl. Mater. Interfaces 2017, 9, 40533–40540.
DOI Google Scholar
25

Xie, L. M.; Xiong, X. Y.; Chang, Q. W.; Chen, X. L; Wei, C. T.; Li, X.; Zhang, M.; Su, W. M.; Cui, Z. Inkjet-printed high-efficiency multilayer QLEDs based on a novel crosslinkable small-molecule hole transport material. Small 2019, 15, 1900111.
DOI Google Scholar
26

Xiong, X. Y.; Wei, C. T; Xie, L. M.; Chen, M.; Tang, P. Y.; Shen, W.; Deng, Z. T.; Li, X.; Duan, Y. J.; Su, W. M. et al. Realizing 17.0% external quantum efficiency in red quantum dot light-emitting diodes by pursuing the ideal inkjet-printed film and interface. Org. Electron. 2019, 73, 247–254.
DOI Google Scholar
27

Xiang, C. Y.; Wu, L. J.; Lu, Z. Z; Li, M. L; Wen, Y. W.; Yang, Y. X.; Liu, W. Y.; Zhang, T.; Cao, W. R.; Tsang, S. W. et al. High efficiency and stability of ink-jet printed quantum dot light emitting diodes. Nat. Commun. 2020, 11, 1646.
DOI Google Scholar
28

Yang, P. H.; Zhang, L.; Kang, D. J.; Strahl, R.; Kraus, T. High- resolution inkjet printing of quantum dot light-emitting microdiode arrays. Adv. Opt. Mater. 2020, 8, 1901429.
DOI Google Scholar
29

Li, D. Y.; Wang, J. J.; Li, M. Z.; Xie, G. C.; Guo, B.; Mu, L.; Li, H. Y.; Wang, J.; Yip, H. L.; Peng, J. B. Inkjet printing matrix perovskite quantum dot light-emitting devices. Adv. Mater. Technol. 2020, 5, 2000099.
DOI Google Scholar
30

Gaworski, C. L.; Haun, C. C.; MacEwen, J. D.; Vernot, E. H.; Bruner, R. H.; Amster, R. L.; Cowan, M. J. Jr. A 90-day vapor inhalation toxicity study of decalin. Fundam. Appl. Toxicol. 1985, 5, 785–793.
DOI Google Scholar
31

Jang, D.; Kim, D.; Moon, J. Influence of fluid physical properties on ink-jet printability. Langmuir 2009, 25, 2629–2635.
DOI Google Scholar
32

Hu, H.; Larson, R. G. Marangoni effect reverses coffee-ring depositions. J. Phys. Chem. B 2006, 110, 7090–7094.
DOI Google Scholar
33

Lim, J. A.; Lee, W. H.; Lee, H. S.; Lee, J. H.; Park, Y. D.; Cho, K. Self-organization of ink-jet-printed triisopropylsilylethynyl pentacene via evaporation-induced flows in a drying droplet. Adv. Funct. Mater. 2008, 18, 229–234.
DOI Google Scholar
34

Ding, Z. C.; Xing, R. B.; Fu, Q.; Ma, D. G.; Han, Y. C. Patterning of pinhole free small molecular organic light-emitting films by ink-jet printing. Org. Electron. 2011, 12, 703–709.
DOI Google Scholar
35

Liu, H. M.; Xu, W.; Tan, W. Y.; Zhu, X. H.; Wang, J.; Peng, J. B.; Cao, Y. Line printing solution-processable small molecules with uniform surface profile via ink-jet printer. J. Colloid Interface Sci. 2016, 465, 106–111.
DOI Google Scholar
36

Ma, F.; Xu, K. W. Using dangling bond density to characterize the surface energy of nanomaterials. Surf. Interface Anal. 2007, 39, 611–614.
DOI Google Scholar
37

Yang, Z. Q.; Huck, W. T. S.; Clarke, S. M.; Tajbakhsh, A. R.; Terentjev, E. M. Shape-memory nanoparticles from inherently non-spherical polymer colloids. Nat. Mater. 2005, 4, 486–490.
DOI Google Scholar
38

Han, Y. J.; An, K.; Kang, K. T.; Ju, B. K.; Cho, K. H. Optical and electrical analysis of annealing temperature of high-molecular weight hole transport layer for quantum-dot light-emitting diodes. Sci. Rep. 2019, 9, 10385.
DOI Google Scholar
File
12274_2021_3352_MOESM1_ESM.pdf (3.2 MB)
Publication history
Copyright
Acknowledgements

Publication history

Received: 19 November 2020
Revised: 27 December 2020
Accepted: 19 January 2021
Published: 24 February 2021
Issue date: November 2021

Copyright

© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2021

Acknowledgements

Acknowledgements

This work was supported by the National Key Research and Development Program of China (No. 2016YFB0401600), the National Natural Science Foundation of China (No. U1605244) and China Postdoctoral Science Foundation (No. 2020M681726).

Return