AI Chat Paper
Note: Please note that the following content is generated by AMiner AI. SciOpen does not take any responsibility related to this content.
{{lang === 'zh_CN' ? '文章概述' : 'Summary'}}
{{lang === 'en_US' ? '中' : 'Eng'}}
Chat more with AI
Powered by AMiner. Clicking this button will take you away from SciOpen.
Home Nano Research Article
Article Link
Cite
EndNote(RIS) BibTeX
Collect
Submit Manuscript
Show Outline
Outline
Show full outline
Hide outline
Outline
Show full outline
Hide outline
Research Article

Approaching the theoretical efficiency limit of quantum-dot light-emitting diodes via synergistic optimization

Haotao Li, Fengshou Tian, Shuming Chen( )
Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Show Author Information

Graphical Abstract

By synergistically optimizing the optical and the electrical performances, quantum-dot light-emitting diodes (QLEDs) with efficiency approaching the theoretical limit of 33.2% can be realized. Moreover, with a high refractive index plastic substrate and a microlens array, the external quantum efficiency (EQE) can further be improved to a record value of 37.5%.

Abstract

The importance of optical resonance in enhancing light outcoupling efficiency (OCE) is frequently overlooked in conventional bottom-emitting quantum-dot light-emitting diodes (QLEDs) due to their weak microcavity effect. Herein, we show that by synergistically optimizing the optical and the electrical performances, QLEDs with efficiency approaching the theoretical limit can be realized. By introducing a high refractive index indium zinc oxide (IZO) electrode and optimizing its thickness, the light OCE is significantly improved and consequently the red QLEDs exhibit an external quantum efficiency (EQE) of 33.2%, which is 1.4-fold higher than that of the reference devices with conventional indium tin oxide (ITO) electrodes. Moreover, with a high refractive index plastic substrate and a microlens array, the EQE can further be improved to a record value of 37.5%. Similar results are obtained in green and blue devices, which show an EQE of 18.8% and 14.4%, respectively. We also predict that the theoretical EQE limit of red, green, and blue QLEDs can reach 35.4%–36.5%, 24.8%–34.0%, and 25.1%–35.8%, respectively, without using any light outcoupling structures. The proposed synergistic optimization strategy enables the efficiencies of red, green, and blue QLEDs to approach their theoretical limits.

Keywords

light-emitting diodesquantum dotslight outcoupling efficiencymicrocavitytheoretically maximal efficiency

Electronic Supplementary Material

Download File(s)
12274_2023_5520_MOESM1_ESM.pdf (1.7 MB)

References

[1]

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.
Crossref Google Scholar
[2]

Deng, Y. Z.; Peng, F.; Lu, Y.; Zhu, X. T.; Jin, W. X.; Qiu, J.; Dong, J. W.; Hao, Y. L.; Di, D. W.; Gao, Y. et al. Solution-processed green and blue quantum-dot light-emitting diodes with eliminated charge leakage. Nat. Photonics 2022, 16, 505–511.
Crossref Google Scholar
[3]

Su, Q.; Chen, S. M. Thermal assisted up-conversion electroluminescence in quantum dot light emitting diodes. Nat. Commun. 2022, 13, 369.
Crossref Google Scholar
[4]

Zhang, H.; Su, Q.; Chen, S. M. Quantum-dot and organic hybrid tandem light-emitting diodes with multi-functionality of full-color-tunability and white-light-emission. Nat. Commun. 2020, 11, 2826.
Crossref Google Scholar
[5]

Meng, T. T.; Zheng, Y. T.; Zhao, D. L.; Hu, H. L.; Zhu, Y. B.; Xu, Z. W.; Ju, S. M.; Jing, J. P.; Chen, X.; Gao, H. J. et al. Ultrahigh-resolution quantum-dot light-emitting diodes. Nat. Photonics 2022, 16, 297–303.
Crossref Google Scholar
[6]

Vasilopoulou, M.; Yusoff, A. R. B. M.; Daboczi, M.; Conforto, J.; Gavim, A. E. X.; Da Silva, W. J.; Macedo, A. G.; Soultati, A.; Pistolis, G.; Schneider, F. K. et al. High efficiency blue organic light-emitting diodes with below-bandgap electroluminescence. Nat. Commun. 2021, 12, 4868.
Crossref Google Scholar
[7]

Lim, H.; Cheon, H. J.; Woo, S. J.; Kwon, S. K.; Kim, Y. H.; Kim, J. J. Highly efficient deep-blue OLEDs using a TADF emitter with a narrow emission spectrum and high horizontal emitting dipole ratio. Adv. Mater. 2020, 32, 2004083.
Crossref Google Scholar
[8]

Chan, C. Y.; Tanaka, M.; Lee, Y. T.; Wong, Y. W.; Nakanotani, H.; Hatakeyama, T.; Adachi, C. Stable pure-blue hyperfluorescence organic light-emitting diodes with high-efficiency and narrow emission. Nat. Photonics 2021, 15, 203–207.
Crossref Google Scholar
[9]

Yang, X. Y.; Dev, K.; Wang, J. X.; Mutlugun, E.; Dang, C.; Zhao, Y. B.; Liu, S. W.; Tang, Y. X.; Tan, S. T.; Sun, X. W. et al. Light extraction efficiency enhancement of colloidal quantum dot light-emitting diodes using large-scale nanopillar arrays. Adv. Funct. Mater. 2014, 24, 5977–5984.
Crossref Google Scholar
[10]

Kim, J. B.; Lee, J. H.; Moon, C. K.; Kim, S. Y.; Kim, J. J. Highly enhanced light extraction from surface plasmonic loss minimized organic light-emitting diodes. Adv. Mater. 2013, 25, 3571–3577.
Crossref Google Scholar
[11]

Zhu, Y. B.; Xu, R.; Zhou, Y. G.; Xu, Z. W.; Liu, Y.; Tian, F. Q.; Zheng, X. J.; Ma, F. M.; Alsharafi, R.; Hu, H. L. et al. Ultrahighly efficient white quantum dot light-emitting diodes operating at low voltage. Adv. Opt. Mater. 2020, 8, 2001479.
Crossref Google Scholar
[12]

Su, Q.; Sun, Y. Z.; Zhang, H.; Chen, S. M. Origin of positive aging in quantum-dot light-emitting diodes. Adv. Sci. 2018, 5, 1800549.
Crossref Google Scholar
[13]

Song, J. J.; Wang, O. Y.; Shen, H. B.; Lin, Q. L.; Li, Z. H.; Wang, L.; Zhang, X. T.; Li, L. S. Over 30% external quantum efficiency light-emitting diodes by engineering quantum dot-assisted energy level match for hole transport layer. Adv. Funct. Mater. 2019, 29, 1808377.
Crossref Google Scholar
[14]

Furno, M.; Meerheim, R.; Hofmann, S.; Lüssem, B.; Leo, K. Efficiency and rate of spontaneous emission in organic electroluminescent devices. Phys. Rev. B 2012, 85, 115205.
Crossref Google Scholar
[15]

Barnes, W. L. Fluorescence near interfaces: The role of photonic mode density. J. Mod. Opt. 1998, 45, 661–699.
Crossref Google Scholar
[16]

Othman, D. M.; Weinstein, J. A.; Lyu, Q.; Hou, B. Photonics design theory enhancing light extraction efficiency in quantum dot light emitting diodes. J. Phys. Mater. 2022, 5, 044009.
Crossref Google Scholar
[17]

Shen, H. B.; Gao, Q.; Zhang, Y. B.; Lin, Y.; Lin, Q. L.; Li, Z. H.; Chen, L.; Zeng, Z. P.; Li, X. G.; Jia, Y. et al. Visible quantum dot light-emitting diodes with simultaneous high brightness and efficiency. Nat. Photonics 2019, 13, 192–197.
Crossref Google Scholar
[18]

Chen, L. N.; Qin, Z. Y.; Chen, S. M. Ultrahigh resolution pixelated top-emitting quantum-dot light-emitting diodes enabled by color-converting cavities. Small Methods 2022, 6, 2101090.
Crossref Google Scholar
[19]

Choi, M. K.; Yang, J.; Kang, K.; Kim, D. C.; Choi, C.; Park, C.; Kim, S. J.; Chae, S. I.; Kim, T. H.; Kim, J. H. et al. Wearable red-green-blue quantum dot light-emitting diode array using high-resolution intaglio transfer printing. Nat. Commun. 2015, 6, 7149.
Crossref Google Scholar
[20]

Kwak, J.; Bae, W. K.; Lee, D.; Park, I.; Lim, J.; Park, M.; Cho, H.; Woo, H.; Yoon, D. Y.; Char, K. et al. Bright and efficient full-color colloidal quantum dot light-emitting diodes using an inverted device structure. Nano Lett. 2012, 12, 2362–2366.
Crossref Google Scholar
[21]

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.
Crossref Google Scholar
[22]

Yang, J.; Choi, M. K.; Yang, U. J.; Kim, S. Y.; Kim, Y. S.; Kim, J. H.; Kim, D. H.; Hyeon, T. Toward full-color electroluminescent quantum dot displays. Nano Lett. 2021, 21, 26–33.
Crossref Google Scholar
[23]

Li, D.; Feng, J. W.; Zhu, Y. Q.; Lu, Z. G.; Pei, C.; Chen, Z.; Li, Y. Z.; Li, X. G.; Xu, X. G. Enhanced efficiency of top-emission InP-based green quantum dot light-emitting diodes with optimized angular distribution. Nano Res. 2021, 14, 4243–4249.
Crossref Google Scholar
[24]

Wang, L. S.; Lin, J.; Lv, Y.; Zou, B. S.; Zhao, J. L.; Liu, X. Y. Red, green, and blue microcavity quantum dot light-emitting devices with narrow line widths. ACS Appl. Nano Mater. 2020, 3, 5301–5310.
Crossref Google Scholar
[25]

Liu, G. H.; Zhou, X.; Chen, S. M. Very bright and efficient microcavity top-emitting quantum dot light-emitting diodes with Ag electrodes. ACS Appl. Mater. Interfaces 2016, 8, 16768–16775.
Crossref Google Scholar
[26]

Shinar, R.; Shinar, J. Light extraction from organic light emitting diodes (OLEDs). J. Phys. Photonics 2022, 4, 032002.
Crossref Google Scholar
[27]

Ma, F. Y.; Liu, X. Y. Phase shift and penetration depth of metal mirrors in a microcavity structure. Appl. Opt. 2007, 46, 6247–6250.
Crossref Google Scholar
[28]
Yuan, C. X.; Tian, F. S.; Chen, S. M. ZnSeTe blue top-emitting QLEDs with color saturation near Rec. 2020 standards and efficiency over 18.16%. Nano Res. , in press,https://doi.org.10.1007/s12274-022-5172-y.
[29]

Tian, F. S.; Yuan, C. X.; Chen, S. M. Influence of light–matter interaction on efficiency of quantum-dot light-emitting diodes. J. Phys. Chem. Lett. 2022, 13, 10312–10317.
Crossref Google Scholar
[30]

Tan, G. J.; Zhu, R. D.; Tsai, Y. S.; Lee, K. C.; Luo, Z. Y.; Lee, Y. Z.; Wu, S. T. High ambient contrast ratio OLED and QLED without a circular polarizer. J. Phys. D:Appl. Phys. 2016, 49, 315101.
Crossref Google Scholar
[31]

Tang, Z. B.; Lin, J.; Wang, L. S.; Lv, Y.; Hu, Y. S.; Fan, Y.; Guo, X. Y.; Zhao, J. L.; Wang, Y. J.; Liu, X. Y. High performance, top-emitting, quantum dot light-emitting diodes with all solution-processed functional layers. J. Mater. Chem. C 2017, 5, 9138–9145.
Crossref Google Scholar
[32]

Mladenovski, S.; Neyts, K.; Pavicic, D.; Werner, A.; Rothe, C. Exceptionally efficient organic light emitting devices using high refractive index substrates. Opt. Express 2009, 17, 7562–7570.
Crossref Google Scholar
[33]

Zhu, R. D.; Luo, Z. Y.; Wu, S. T. Light extraction analysis and enhancement in a quantum dot light emitting diode. Opt. Express 2014, 22, A1783–A1798.
Crossref Google Scholar
[34]

Reineke, S.; Lindner, F.; Schwartz, G.; Seidler, N.; Walzer, K.; Lüssem, B.; Leo, K. White organic light-emitting diodes with fluorescent tube efficiency. Nature 2009, 459, 234–238.
Crossref Google Scholar
[35]

Su, Q.; Zhang, H.; Chen, S. M. Flexible and tandem quantum-dot light-emitting diodes with individually addressable red/green/blue emission. npj Flex. Electron. 2021, 5, 8.
Crossref Google Scholar
[36]

Kim, J. B.; Lee, J. H.; Moon, C. K.; Kim, K. H.; Kim, J. J. Highly enhanced light extraction from organic light emitting diodes with little image blurring and good color stability. Org. Electron. 2015, 17, 115–120.
Crossref Google Scholar
[37]

Ide, N.; Yamae, K.; Kittichungchit, V.; Tsuji, H.; Ota, M.; Komoda, T. Development of extremely high efficacy white OLED with over 100 lm/W. J. Photopolym. Sci. Technol. 2014, 27, 357–361.
Crossref Google Scholar
[38]

Shi, L. L.; Chen, S. M. Over 32.5% efficient top-emitting quantum-dot LEDs with angular-independent emission. ACS Appl. Mater. Interfaces 2022, 14, 30039–30045.
Crossref Google Scholar
[39]

Koh, T. W.; Choi, J. M.; Lee, S.; Yoo, S. Optical outcoupling enhancement in organic light-emitting diodes: Highly conductive polymer as a low-index layer on microstructured ITO electrodes. Adv. Mater. 2010, 22, 1849–1853.
Crossref Google Scholar
[40]

Qu, Y.; Kim, J.; Coburn, C.; Forrest, S. R. Efficient, nonintrusive outcoupling in organic light emitting devices using embedded microlens arrays. ACS Photonics 2018, 5, 2453–2458.
Crossref Google Scholar
[41]

Thomschke, M.; Reineke, S.; Lüssem, B.; Leo, K. Highly efficient white top-emitting organic light-emitting diodes comprising laminated microlens films. Nano Lett. 2012, 12, 424–428.
Crossref Google Scholar
[42]

Wang, L. S.; Lin, J.; Hu, Y. S.; Guo, X. Y.; Lv, Y.; Tang, Z. B.; Zhao, J. L.; Fan, Y.; Zhang, N.; Wang, Y. J. et al. Blue quantum dot light-emitting diodes with high electroluminescent efficiency. ACS Appl. Mater. Interfaces 2017, 9, 38755–38760.
Crossref Google Scholar
[43]

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.
Crossref Google Scholar
Nano Research
Volume 16 Issue 7,
July 2023
Pages 10156-10163
DOI: 10.1007/s12274-023-5520-6
Cite this article:
Li H, Tian F, Chen S. Approaching the theoretical efficiency limit of quantum-dot light-emitting diodes via synergistic optimization. Nano Research, 2023, 16(7): 10156-10163. https://doi.org/10.1007/s12274-023-5520-6
Topics:
Light emitting diodes

846

Views

7

Crossref

9

Web of Science

10

Scopus

0

CSCD

Altmetrics
Received: 02 December 2022
Revised: 07 January 2023
Accepted: 18 January 2023
Published: 02 April 2023
© Tsinghua University Press 2023
Return