Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

High efficiency warm-white light-emitting diodes based on copper–iodide clusters


Solution-processed light-emitting diodes (LEDs) based on copper–iodide clusters are promising candidates for solid state lightings due to their abundance, environmental friendliness and high luminescent efficiency. However, the development of this class of LEDs is hampered by the instability of the clusters, poor solution compatibility and low film quality, resulting in poor device performances. Here we report a new type of copper–iodide cluster hybrids with functional groups that facilitate both solubility and stability of the clusters. The hybrid clusters exhibit high structural stability in solvents, enabling smooth solution-processed thin films with low surface roughness of 0.22 nm and high photoluminescence quantum yields of over 70%. We employ the high-quality thin film as an emissive layer in warm-white LEDs, showing a maximum external quantum efficiency of 19.1%, maximum high brightness of over 40,000 cd m2 and a good operational lifetime of 232 h (T50 at an initial luminance of 100 cd m2). We also demonstrate a large-area LED with brightnesses of up to ~60,000 cd m2 through blade-coating and a series of colour-tunable LEDs based on ligand modifications. Our results suggest great potential of copper–iodide cluster-based LEDs for practical applications in panel display and solid-state lighting.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Fabrication process and characteristics of the CuI-Pyrphos LED.
Fig. 2: Solubility and stability of CuI-Pyrphos in DMF.
Fig. 3: Characterizations of CuI-Pyrphos thin film and large-area solution-processed CuI-Pyrphos LED.
Fig. 4: The extended colour tunable CuI-ligand thin film and devices.

Similar content being viewed by others

Data availability

The data that support the findings of this study are available from the corresponding author on reasonable request. The X-ray crystallography data for CuI-Pyrphos structure have been deposited in Cambridge Crystallographic Data Centre (CCDC) under accession no. CCDC-2266353. The data can be obtained free of charge from the CCDC via


  1. Han, T.-H. et al. A roadmap for the commercialization of perovskite light emitters. Nat. Rev. Mater. 7, 757–777 (2022).

    Article  ADS  Google Scholar 

  2. Woo, J. Y. et al. Advances in solution-processed OLEDs and their prospects for use in displays. Adv. Mater. 35, 2207454 (2023).

  3. Jang, E. & Jang, H. Review: quantum dot light-emitting diodes. Chem. Rev. 123, 4663–4692 (2023).

    Article  CAS  PubMed  Google Scholar 

  4. Liu, X.-K. et al. Metal halide perovskites for light-emitting diodes. Nat. Mater. 20, 10–21 (2020).

    Article  ADS  PubMed  Google Scholar 

  5. Wang, S., Zhang, H., Zhang, B., Xie, Z. & Wong, W.-Y. Towards high-power-efficiency solution-processed OLEDs: material and device perspectives. Mater. Sci. Eng. R Rep. 140, 100547 (2020).

    Article  Google Scholar 

  6. Deng, Y. et al. Solution-processed green and blue quantum-dot light-emitting diodes with eliminated charge leakage. Nat. Photon. 16, 505–511 (2022).

    Article  ADS  CAS  Google Scholar 

  7. Min, H. et al. Additive treatment yields high-performance lead-free perovskite light-emitting diodes. Nat. Photon. 17, 755–760 (2023).

  8. Hahm, D. et al. Direct patterning of colloidal quantum dots with adaptable dual-ligand surface. Nat. Nanotechnol. 17, 952–958 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  9. Li, N. et al. Versatile host materials for both D-A-type and multi-resonance TADF emitters toward solution-processed OLEDs with nearly 30% EQE. Adv. Mater. 35, 2300510 (2023).

    Article  CAS  Google Scholar 

  10. Sun, D. et al. Thermally activated delayed fluorescent dendrimers that underpin high-efficiency host-free solution-processed organic light-emitting diodes. Adv. Mater. 34, 2110344 (2022).

    Article  CAS  Google Scholar 

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

    Article  ADS  CAS  PubMed  Google Scholar 

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

    Article  ADS  CAS  PubMed  Google Scholar 

  13. Liu, W. et al. A family of highly efficient CuI-based lighting phosphors prepared by a systematic, bottom-up synthetic approach. J. Am. Chem. Soc. 137, 9400–9408 (2015).

    Article  CAS  PubMed  Google Scholar 

  14. Zhang, X. et al. Systematic approach in designing rare-earth-free hybrid semiconductor phosphors for general lighting applications. J. Am. Chem. Soc. 136, 14230–14236 (2014).

    Article  CAS  PubMed  Google Scholar 

  15. Troyano, J., Zamora, F. & Delgado, S. Copper(I)-iodide cluster structures as functional and processable platform materials. Chem. Soc. Rev. 50, 4606–4628 (2021).

    Article  CAS  PubMed  Google Scholar 

  16. Xie, M. et al. Highly efficient sky blue electroluminescence from ligand-activated copper iodide clusters: overcoming the limitations of cluster light-emitting diodes. Sci. Adv. 5, eaav9857 (2019).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  17. Wang, J. J. et al. Chiral phosphine–copper iodide hybrid cluster assemblies for circularly polarized luminescence. J. Am. Chem. Soc. 143, 10860–10864 (2021).

    Article  CAS  PubMed  Google Scholar 

  18. Zhu, K. et al. A new type of hybrid copper iodide as nontoxic and ultrastable LED emissive layer material. ACS Energy Lett. 6, 2565–2574 (2021).

    Article  CAS  Google Scholar 

  19. Zhang, N. et al. Overcoming efficiency limitation of cluster light-emitting diodes with asymmetrically functionalized biphosphine Cu4I4 cubes. J. Am. Chem. Soc. 144, 6551–6557 (2022).

    Article  CAS  PubMed  Google Scholar 

  20. Volz, D. et al. Molecular construction kit for tuning solubility, stability and luminescence properties: heteroleptic MePyrPHOS–copper iodide-complexes and their application in organic light-emitting diodes. Chem. Mater. 25, 3414–3426 (2013).

    Article  CAS  Google Scholar 

  21. Zink, D. M. et al. Heteroleptic, dinuclear copper(I) complexes for application in organic light-emitting diodes. Chem. Mater. 25, 4471–4486 (2013).

    Article  CAS  Google Scholar 

  22. Trattnig, R. et al. Bright blue solution processed triple-layer polymer light-emitting diodes realized by thermal layer stabilization and orthogonal solvents. Adv. Funct. Mater. 23, 4897–4905 (2013).

    Article  CAS  Google Scholar 

  23. Lee, Y. J., Park, S.-S., Kim, J. & Kim, H. Interface morphologies and interlayer diffusions in organic light emitting device by X-ray scattering. Appl. Phys. Lett. 94, 223305–223305 (2009).

    Article  ADS  Google Scholar 

  24. Smith, A. R. et al. Diffusion-the hidden menace in organic optoelectronic devices. Adv. Mater. 24, 822–826 (2012).

    Article  CAS  PubMed  Google Scholar 

  25. Chen, J. et al. Efficient and bright white light-emitting diodes based on single-layer heterophase halide perovskites. Nat. Photon. 15, 238–244 (2020).

    Article  ADS  Google Scholar 

  26. Chen, H. et al. Efficient and bright warm-white electroluminescence from lead-free metal halides. Nat. Commun. 12, 1421 (2021).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  27. Heo, J.-M. et al. Bright lead-free inorganic CsSnBr3 perovskite light-emitting diodes. ACS Energy Lett. 7, 2807–2815 (2022).

    Article  CAS  Google Scholar 

  28. Lu, J. et al. Dendritic CsSnI3 for efficient and flexible near-infrared perovskite light-emitting diodes. Adv. Mater. 33, e2104414 (2021).

    Article  MathSciNet  PubMed  Google Scholar 

  29. Luo, J. et al. Efficient and stable emission of warm-white light from lead-free halide double perovskites. Nature 563, 541–545 (2018).

    Article  ADS  CAS  PubMed  Google Scholar 

  30. Luo, J. et al. Efficient blue light emitting diodes based on europium halide perovskites. Adv. Mater. 33, e2101903 (2021).

    Article  PubMed  Google Scholar 

  31. Ma, Z. et al. Stable yellow light-emitting devices based on ternary copper halides with broadband emissive self-trapped excitons. ACS Nano 14, 4475–4486 (2020).

    Article  CAS  PubMed  Google Scholar 

  32. Ma, Z. et al. High color-rendering index and stable white light-emitting diodes by assembling two broadband emissive self-trapped excitons. Adv. Mater. 33, e2001367 (2021).

    Article  PubMed  Google Scholar 

  33. Ma, Z. et al. Electrically-driven violet light-emitting devices based on highly stable lead-free perovskite Cs3Sb2Br9 quantum dots. ACS Energy Lett. 5, 385–394 (2019).

    Article  Google Scholar 

  34. Seo, G. et al. Lead-free halide light-emitting diodes with external quantum efficiency exceeding 7% using host–dopant strategy. ACS Energy Lett. 6, 2584–2593 (2021).

    Article  CAS  Google Scholar 

  35. Wang, K. et al. Lead-free organic-perovskite hybrid quantum wells for highly stable light-emitting diodes. ACS Nano 15, 6316–6325 (2021).

    Article  CAS  PubMed  Google Scholar 

  36. Yuan, F. L. et al. Color-pure red light-emitting diodes based on two-dimensional lead-free perovskites. Sci. Adv. 6, eabb0253 (2020).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  37. Scholz, S., Kondakov, D., Lussem, B. & Leo, K. Degradation mechanisms and reactions in organic light-emitting devices. Chem. Rev. 115, 8449–8503 (2015).

    Article  CAS  PubMed  Google Scholar 

  38. Woo, S.-J., Kim, J. S. & Lee, T.-W. Characterization of stability and challenges to improve lifetime in perovskite LEDs. Nat. Photon. 15, 630–634 (2021).

    Article  ADS  CAS  Google Scholar 

  39. Kim, J. S. et al. Ultra-bright, efficient and stable perovskite light-emitting diodes. Nature 611, 688–694 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  40. Zink, D. M. et al. Synthesis, structure, and characterization of dinuclear copper(I) halide complexes with P^N ligands featuring exciting photoluminescence properties. Inorg. Chem. 52, 2292–2305 (2013).

    Article  CAS  PubMed  Google Scholar 

  41. Wallesch, M. et al. Towards printed organic light-emitting devices: a solution-stable, highly soluble Cu(I)-NHetPHOS. Chem. Eur. J. 22, 16400–16405 (2016).

    Article  CAS  PubMed  Google Scholar 

  42. Liu, X. K. et al. Metal halide perovskites for light-emitting diodes. Nat. Mater. 20, 10–21 (2021).

    Article  ADS  CAS  PubMed  Google Scholar 

  43. Chen, X. L. et al. A strongly greenish-blue-emitting Cu4Cl4 cluster with an efficient spin-orbit coupling (SOC): fast phosphorescence versus thermally activated delayed fluorescence. Chem. Commun. 52, 6288–6291 (2016).

    Article  CAS  Google Scholar 

  44. Hofbeck, T., Monkowius, U. & Yersin, H. Highly efficient luminescence of Cu(I) compounds: thermally activated delayed fluorescence combined with short-lived phosphorescence. J. Am. Chem. Soc. 137, 399–404 (2015).

    Article  CAS  PubMed  Google Scholar 

  45. CrysAlisPro, Rigaku Oxford Diffraction, Revision (Rigaku Corporation, 2021).

  46. Sheldrick, G. M. A short history of SHELX. Acta Crystallogr. A 64, 112–122 (2008).

    Article  ADS  CAS  PubMed  Google Scholar 

  47. Sheldrick, G.M. Crystal structure refinement with SHELXL. Acta Crystallogr. C Struct. Chem. 71, 3–8 (2015).

    Article  ADS  PubMed  PubMed Central  Google Scholar 

  48. Grimme, S., Brandenburg, J. G., Bannwarth, C. & Hansen, A. Consistent structures and interactions by density functional theory with small atomic orbital basis sets. J. Chem. Phys. 143, 054107 (2015).

    Article  ADS  PubMed  Google Scholar 

  49. Neese, F. Software update: the ORCA program system—version 5.0. WIREs Comput. Mol. Sci. 12, e1606 (2022).

    Article  Google Scholar 

  50. Gaussian 09 Revision D.01 (Gaussian, Inc., 2013).

Download references


We acknowledge the financial support from the National Key Research and Development Program of China (grant no. 2022YFA1204800 to H.-B.Y.), the National Natural Science Foundation of China (grant nos. 22325505, 52073271, 22161142004 to H.-B.Y.; 62175226, 62234004 to Z.X.; and 52272167 to F.F.), the USTC Research Funds of the Double First-Class Initiative (grant no. YD2060002034 to H.-B.Y.), the Collaborative Innovation Program of Hefei Science Center, CAS (grant no. 2022HSC-CIP018 to H.-B.Y.) and Innovation Program for Quantum Science and Technology (grant no.2021ZD0301603 to F.F.). We thank J. Wang for helping us collect in situ PL/UV spectra and X. Chen for helping us test temperature dependent PLQY. We thank the support from the USTC Center for Micro and Nanoscale Research and Fabrication. We also thank the support from the USTC Supercomputing Center the computing resource and the National Synchrotron Radiation Laboratory (NSRL) in Hefei.

Author information

Authors and Affiliations



H.-B.Y. and J.-J.W. conceived the idea, designed the experiment, and analysed the data. J.-J.W. and L.-Z.F. synthesized the materials, performed characterizations and analysed the data. G.S., J.-N.Y. and Z.X. participated in the fabrication of LED devices and performed the performance tests. Y.-D.Z. and X.-S.Z. performed the XAS characterizations and analysed the data. H.X. and F.F. conducted the optical simulation for theoretical limit on outcoupling efficiency and maximum EQE. K.-H.S. and T.C. performed TEM and AFM characterizations and discussed the results. G.Z. performed DFT and TDDFT calculations and analysed the computational results. J.-J.W., L.-Z.F., G.S., J.-N.Y., G.Z. and H.-B.Y. co-wrote the manuscript. H.-B.Y. directed and supervised the project. All authors contributed to discussions and finalizing the manuscript.

Corresponding author

Correspondence to Hong-Bin Yao.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Photonics thanks Yizheng Jin, Tae-Woo Lee and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–21, Tables 1–5, references and experimental section.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, JJ., Feng, LZ., Shi, G. et al. High efficiency warm-white light-emitting diodes based on copper–iodide clusters. Nat. Photon. 18, 200–206 (2024).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing