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Solution-processed green and blue quantum-dot light-emitting diodes with eliminated charge leakage

Abstract

Quantum-dot light-emitting diodes (QD-LEDs) promise a new generation of efficient, low-cost, large-area and flexible electroluminescent devices. However, the inferior performance of green and blue QD-LEDs compared with their red counterpart is hindering the commercialization of QD-LEDs in display and solid-state lighting applications. Here we demonstrate green and blue QD-LEDs with ~100% conversion of the injected charge carriers into emissive excitons. The key to success is the elimination of electron leakage at the organic/inorganic interface by using hole-transport polymers with simultaneous low electron affinity and reduced energetic disorder. Our devices exhibit high external quantum efficiencies over a wide range of luminance values (peak external quantum efficiencies of 28.7% for green and 21.9% for blue) and excellent stability (extrapolated T95 lifetime is 580,000 h for green and 4,400 h for blue QD-LEDs). We expect our work to provide a general strategy for eliminating charge leakage in solution-processed LEDs featuring organic/inorganic interfaces.

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Fig. 1: Disorder-enhanced electron leakage limits EL efficiencies of blue and green QD-LEDs.
Fig. 2: HTL design to eliminate the electron-leakage channel.
Fig. 3: High-efficiency green and blue QD-LEDs based on PF8Cz HTLs.
Fig. 4: Operational lifetimes of QD-LEDs based on PF8Cz HTLs.

Data availability

All data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.

References

  1. Colvin, V. L., Schlamp, M. C. & Alivisatos, A. P. Light-emitting diodes made from cadmium selenide nanocrystals and a semiconducting polymer. Nature 370, 354–357 (1994).

    ADS  Article  Google Scholar 

  2. Coe, S., Woo, W. K., Bawendi, M. & Bulović, V. Electroluminescence from single monolayers of nanocrystals in molecular organic devices. Nature 420, 800–803 (2002).

    ADS  Article  Google Scholar 

  3. Qian, L., Zheng, Y., Xue, J. & Holloway, P. H. Stable and efficient quantum-dot light-emitting diodes based on solution-processed multilayer structures. Nat. Photon. 5, 543–548 (2011).

    ADS  Article  Google Scholar 

  4. Kwak, J. et al. Bright and efficient full-color colloidal quantum dot light-emitting diodes using an inverted device structure. Nano Lett. 12, 2362–2366 (2012).

    ADS  Article  Google Scholar 

  5. Mashford, B. S. et al. High-efficiency quantum-dot light-emitting devices with enhanced charge injection. Nat. Photon. 7, 407–412 (2013).

    ADS  Article  Google Scholar 

  6. Dai, X. et al. Solution-processed, high-performance light-emitting diodes based on quantum dots. Nature 515, 96–99 (2014).

    ADS  Article  Google Scholar 

  7. Yang, Y. et al. High-efficiency light-emitting devices based on quantum dots with tailored nanostructures. Nat. Photon. 9, 259–266 (2015).

    ADS  Article  Google Scholar 

  8. Li, X. et al. Bright colloidal quantum dot light-emitting diodes enabled by efficient chlorination. Nat. Photon. 12, 159–164 (2018).

    ADS  Article  Google Scholar 

  9. Shen, H. et al. Visible quantum dot light-emitting diodes with simultaneous high brightness and efficiency. Nat. Photon. 13, 192–197 (2019).

    ADS  Article  Google Scholar 

  10. Won, Y.-H. et al. Highly efficient and stable InP/ZnSe/ZnS quantum dot light-emitting diodes. Nature 575, 634–638 (2019).

    ADS  Article  Google Scholar 

  11. Kim, T. et al. Efficient and stable blue quantum dot light-emitting diode. Nature 586, 385–389 (2020).

    ADS  Article  Google Scholar 

  12. Burroughes, J. H. et al. Light-emitting diodes based on conjugated polymers. Nature 347, 539–541 (1990).

    ADS  Article  Google Scholar 

  13. Friend, R. H. et al. Electroluminescence in conjugated polymers. Nature 397, 121–128 (1999).

    ADS  Article  Google Scholar 

  14. Kuik, M. et al. 25th anniversary article: charge transport and recombination in polymer light-emitting diodes. Adv. Mater. 26, 512–531 (2014).

    Article  Google Scholar 

  15. Niu, Q., Rohloff, R., Wetzelaer, G.-J. A. H., Blom, P. W. M. & Crăciun, N. I. Hole trap formation in polymer light-emitting diodes under current stress. Nat. Mater. 17, 557–562 (2018).

    ADS  Article  Google Scholar 

  16. Tan, Z.-K. et al. Bright light-emitting diodes based on organometal halide perovskite. Nat. Nanotechnol. 9, 687–692 (2014).

    ADS  Article  Google Scholar 

  17. Cho, H. et al. Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes. Science 350, 1222–1225 (2015).

    ADS  Article  Google Scholar 

  18. Yuan, M. et al. Perovskite energy funnels for efficient light-emitting diodes. Nat. Nanotechnol. 11, 872–877 (2016).

    ADS  Article  Google Scholar 

  19. Xiao, Z. et al. Efficient perovskite light-emitting diodes featuring nanometre-sized crystallites. Nat. Photon. 11, 108–115 (2017).

    ADS  Article  Google Scholar 

  20. Hassan, Y. et al. Ligand-engineered bandgap stability in mixed-halide perovskite LEDs. Nature 591, 72–77 (2021).

    ADS  Article  Google Scholar 

  21. Alivisatos, A. P. Semiconductor clusters, nanocrystals, and quantum dots. Science 271, 933–937 (1996).

    ADS  Article  Google Scholar 

  22. Talapin, D. V., Lee, J.-S., Kovalenko, M. V. & Shevchenko, E. V. Prospects of colloidal nanocrystals for electronic and optoelectronic applications. Chem. Rev. 110, 389–458 (2010).

    Article  Google Scholar 

  23. Kagan, C. R., Lifshitz, E., Sargent, E. H. & Talapin, D. V. Building devices from colloidal quantum dots. Science 353, aac5523 (2016).

    Article  Google Scholar 

  24. Pu, C. et al. Synthetic control of exciton behavior in colloidal quantum dots. J. Am. Chem. Soc. 139, 3302–3311 (2017).

    Article  Google Scholar 

  25. Arquer, F. P. G. D. et al. Semiconductor quantum dots: technological progress and future challenges. Science 373, eaaz8541 (2021).

    Article  Google Scholar 

  26. Lim, J., Park, Y.-S., Wu, K., Yun, H. J. & Klimov, V. I. Droop-free colloidal quantum dot light-emitting diodes. Nano Lett. 18, 6645–6653 (2018) .

    ADS  Article  Google Scholar 

  27. Lee, T. et al. Bright and stable quantum dot light-emitting diodes. Adv. Mater. 34, 2106276 (2022).

  28. Cao, W. et al. Highly stable QLEDs with improved hole injection via quantum dot structure tailoring. Nat. Commun. 9, 2608 (2018).

    ADS  Article  Google Scholar 

  29. Pu, C. et al. Electrochemically-stable ligands bridge the photoluminescence-electroluminescence gap of quantum dots. Nat. Commun. 11, 937 (2020).

    ADS  Article  Google Scholar 

  30. Chen, D. et al. Shelf-stable quantum-dot light-emitting diodes with high operational performance. Adv. Mater. 32, 2006178 (2020).

    Article  Google Scholar 

  31. Deng, Y. et al. Deciphering exciton-generation processes in quantum-dot electroluminescence. Nat. Commun. 11, 2309 (2020).

    ADS  Article  Google Scholar 

  32. Luo, H. et al. Origin of subthreshold turn-on in quantum-dot light-emitting diodes. ACS Nano 13, 8229–8236 (2019).

    Article  Google Scholar 

  33. Su, Q. & Chen, S. Thermal assisted up-conversion electroluminescence in quantum dot light emitting diodes. Nat. Commun. 13, 369 (2022).

    ADS  Article  Google Scholar 

  34. Han, M. G. et al. InP-based quantum dot light-emitting diode with a blended emissive layer. ACS Energy Lett. 6, 1577–1585 (2021).

    Article  Google Scholar 

  35. Bässler, H. Charge transport in disordered organic photoconductors. A Monte Carlo simulation study. Phys. Status Solidi B 175, 15–56 (1993).

    ADS  Article  Google Scholar 

  36. Sirringhaus, H. Device physics of solution-processed organic field-effect transistors. Adv. Mater. 17, 2411–2425 (2005).

    Article  Google Scholar 

  37. Noriega, R. et al. A general relationship between disorder, aggregation and charge transport in conjugated polymers. Nat. Mater. 12, 1038–1044 (2013).

    ADS  Article  Google Scholar 

  38. Karki, A. et al. Unifying energetic disorder from charge transport and band bending in organic semiconductors. Adv. Funct. Mater. 29, 1901109 (2019).

    Article  Google Scholar 

  39. Troisi, A. Charge transport in high mobility molecular semiconductors: classical models and new theories. Chem. Soc. Rev. 40, 2347–2358 (2011).

    Article  Google Scholar 

  40. Wang, L., Li, Q., Shuai, Z., Chen, L. & Shi, Q. Multiscale study of charge mobility of organic semiconductor with dynamic disorders. Phys. Chem. Chem. Phys. 12, 3309–3314 (2010).

    Article  Google Scholar 

  41. Prodhan, S. et al. Design rules to maximize charge-carrier mobility along conjugated polymer chains. J. Phys. Chem. Lett. 11, 6519–6525 (2020).

    Article  Google Scholar 

  42. Qiu, J., Bai, X. & Wang, L. Crossing classified and corrected fewest switches surface hopping. J. Phys. Chem. Lett. 9, 4319–4325 (2018).

    Article  Google Scholar 

  43. Qiu, J., Bai, X. & Wang, L. Subspace surface hopping with size-independent dynamics. J. Phys. Chem. Lett. 10, 637–644 (2019).

    Article  Google Scholar 

  44. Wang, L., Qiu, J., Bai, X. & Xu, J. Surface hopping methods for nonadiabatic dynamics in extended systems. WIREs Comput. Mol. Sci. 10, e1435 (2020).

    Google Scholar 

  45. Sancho-García, J. C. et al. Joint theoretical and experimental characterization of the structural and electronic properties of poly(dioctylfluorene-alt-N-butylphenyl diphenylamine). J. Phys. Chem. B 108, 5594–5599 (2004).

    Article  Google Scholar 

  46. Boudreault, P.-L. T., Beaupré, S. & Leclerc, M. Polycarbazoles for plastic electronics. Polym. Chem. 1, 127–136 (2010).

    Article  Google Scholar 

  47. Kim, J., Kwon, Y. S., Shin, W. S., Moon, S.-J. & Park, T. Carbazole-based copolymers: effects of conjugation breaks and steric hindrance. Macromolecules 44, 1909–1919 (2011).

    ADS  Article  Google Scholar 

  48. Rivnay, J., Mannsfeld, S. C. B., Miller, C. E., Salleo, A. & Toney, M. F. Quantitative determination of organic semiconductor microstructure from the molecular to device scale. Chem. Rev. 112, 5488–5519 (2012).

    Article  Google Scholar 

  49. Hwang, J., Wan, A. & Kahn, A. Energetics of metal–organic interfaces: new experiments and assessment of the field. Mater. Sci. Eng. R Rep. 64, 1–31 (2009).

    Article  Google Scholar 

  50. Lange, I. et al. Band bending in conjugated polymer layers. Phys. Rev. Lett. 106, 216402 (2011).

    ADS  Article  Google Scholar 

  51. Blakesley, J. C. & Greenham, N. C. Charge transfer at polymer-electrode interfaces: the effect of energetic disorder and thermal injection on band bending and open-circuit voltage. J. Appl. Phys. 106, 034507 (2009).

    ADS  Article  Google Scholar 

  52. Blouin, N. & Leclerc, M. Poly(2,7-carbazole)s: structure−property relationships. Acc. Chem. Res. 41, 1110–1119 (2008).

    Article  Google Scholar 

  53. So, F. & Kondakov, D. Degradation mechanisms in small-molecule and polymer organic light-emitting diodes. Adv. Mater. 22, 3762–3777 (2010).

    Article  Google Scholar 

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Acknowledgements

We thank X. Peng (Zhejiang University, China) for valuable advice. We also thank L. Jiang (Institute of Chemistry, Chinese Academy of Sciences) for assistance with the UPS analyses. Portion of the work is carried out at beamline 7.3.3 at the Advanced Light Source, Lawrence Berkeley National Laboratory, which was supported by the US Department of Energy, Office of Science, and Office of Basic Energy Sciences. We acknowledge financial support from the National Natural Science Foundation of China (21975220 and 91833303 (Y.J.); 21922305, 21873080 and 21703202 (L.W.)), Key Research and Development Program of Zhejiang Province (2020C01001 (Y.J.)), Guangdong Major Project of Basic and Applied Basic Research (2019B030302007 (L.Y. and F.H.)), Fundamental Research Funds for the Central Universities (2020XZZX002-06 (L.W.)) and China Postdoctoral Science Foundation (2021M702800 (Y.D.)).

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Contributions

Y.J., together with F.H. and L.W., conceived the idea and supervised the work. Y.D. fabricated the high-performance QD-LEDs, conducted the spectral and electrical characterizations, carried out the optical modelling, and analysed the results under Y.J.’s supervision. F.P. synthesized the high-quality PF8Cz and assisted in analysing the structural properties under the supervision of F.H. and L.Y. L.W. developed the charge-transfer simulation models and performed the theoretical analysis. Under the supervision of L.W., J.D. and J.Q. wrote the main codes of the SPADE software, J.Q. calculated the energy levels of QDs under the effective mass approximation, and Y.L. performed all the DFT calculations and dynamics simulations of the interfacial electron leakage. X.Z. assisted the device fabrication, conducted the optical characterizations, carried out the Kelvin probe measurements and analysed the hole-only devices under Y.J.’s supervision. W.J. assisted in the characterizations of QDs and QD-LEDs. Y.H. assisted in the fabrication of QD-LEDs. Y.G. assisted in the characterization of CdSe-based QDs. T.S. conducted the high-angle annular dark-field scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy characterizations. M.Z. and F.L. conducted the GIWAXS experiments and analysis. D.D. participated in data analysis and provided major revisions. All the authors discussed the results and commented on the manuscript.

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Correspondence to Linjun Wang, Lei Ying, Fei Huang or Yizheng Jin.

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Nature Photonics thanks Shuming Chen and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Notes 1–3, Figs. 1–17 and Tables 1 and 2.

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Deng, Y., Peng, F., Lu, Y. et al. Solution-processed green and blue quantum-dot light-emitting diodes with eliminated charge leakage. Nat. Photon. (2022). https://doi.org/10.1038/s41566-022-00999-9

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