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Lanthanide-doped inorganic nanoparticles turn molecular triplet excitons bright

Nature volume 587, pages 594–599 (2020)Cite this article

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Abstract

The generation, control and transfer of triplet excitons in molecular and hybrid systems is of great interest owing to their long lifetime and diffusion length in both solid-state and solution phase systems, and to their applications in light emission1, optoelectronics2,3, photon frequency conversion4,5 and photocatalysis6,7. Molecular triplet excitons (bound electron–hole pairs) are ‘dark states’ because of the forbidden nature of the direct optical transition between the spin-zero ground state and the spin-one triplet levels8. Hence, triplet dynamics are conventionally controlled through heavy-metal-based spin–orbit coupling9,10,11 or tuning of the singlet–triplet energy splitting12,13 via molecular design. Both these methods place constraints on the range of properties that can be modified and the molecular structures that can be used. Here we demonstrate that it is possible to control triplet dynamics by coupling organic molecules to lanthanide-doped inorganic insulating nanoparticles. This allows the classically forbidden transitions from the ground-state singlet to excited-state triplets to gain oscillator strength, enabling triplets to be directly generated on molecules via photon absorption. Photogenerated singlet excitons can be converted to triplet excitons on sub-10-picosecond timescales with unity efficiency by intersystem crossing. Triplet exciton states of the molecules can undergo energy transfer to the lanthanide ions with unity efficiency, which allows us to achieve luminescent harvesting of the dark triplet excitons. Furthermore, we demonstrate that the triplet excitons generated in the lanthanide nanoparticle–molecule hybrid systems by near-infrared photoexcitation can undergo efficient upconversion via a lanthanide–triplet excitation fusion process: this process enables endothermic upconversion and allows efficient upconversion from near-infrared to visible frequencies in the solid state. These results provide a new way to control triplet excitons, which is essential for many fields of optoelectronic and biomedical research.

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Fig. 1: Lanthanide-nanocrystal-coupled triplet excitation.
Fig. 2: Ultrafast intersystem crossing in organic molecules coupled to lanthanide-doped nanoparticles.
Fig. 3: Triplet energy transfer from molecules to nanoparticles.
Fig. 4: Lanthanide–triplet excitation fusion upconversion in nanoparticle–molecule blends.

Data availability

The data underlying all figures in the main text and Supplementary Information are publicly available from the University of Cambridge repository at https://doi.org/10.17863/CAM.59063.

References

  1. Bolton, O., Lee, K., Kim, H. J., Lin, K. Y. & Kim, J. Activating efficient phosphorescence from purely organic materials by crystal design. Nat. Chem. 3, 205–210 (2011); correction 3, 415 (2011).

    Article  CAS  Google Scholar 

  2. Baldo, M. A. et al. Highly efficient phosphorescent emission from organic electroluminescent devices. Nature 395, 151–154 (1998).

    Article  ADS  CAS  Google Scholar 

  3. Uoyama, H., Goushi, K., Shizu, K., Nomura, H. & Adachi, C. Highly efficient organic light-emitting diodes from delayed fluorescence. Nature 492, 234–238 (2012).

    Article  ADS  CAS  Google Scholar 

  4. Yanai, N. & Kimizuka, N. New triplet sensitization routes for photon upconversion: thermally activated delayed fluorescence molecules, inorganic nanocrystals, and singlet-to-triplet absorption. Acc. Chem. Res. 50, 2487–2495 (2017).

    Article  CAS  Google Scholar 

  5. Schulze, T. F. & Schmidt, T. W. Photochemical upconversion: present status and prospects for its application to solar energy conversion. Energy Environ. Sci. 8, 103–125 (2015).

    Article  CAS  Google Scholar 

  6. Ravetz, B. D. et al. Photoredox catalysis using infrared light via triplet fusion upconversion. Nature 565, 343–346 (2019); correction 570, E24 (2019).

    Article  ADS  CAS  Google Scholar 

  7. Mongin, C., Garakyaraghi, S., Razgoniaeva, N., Zamkov, M. & Castellano, F. N. Direct observation of triplet energy transfer from semiconductor nanocrystals. Science 351, 369–372 (2016).

    Article  ADS  CAS  Google Scholar 

  8. Köhler, A. & Bassler, H. Triplet states in organic semiconductors. Mater. Sci. Eng. Rep. 66, 71–109 (2009).

    Article  Google Scholar 

  9. Lamansky, S. et al. Highly phosphorescent bis-cyclometalated iridium complexes: synthesis, photophysical characterization, and use in organic light emitting diodes. J. Am. Chem. Soc. 123, 4304–4312 (2001).

    Article  CAS  Google Scholar 

  10. Bünzli, J.-C. G. On the design of highly luminescent lanthanide complexes. Coord. Chem. Rev. 293–294, 19–47 (2015).

    Article  Google Scholar 

  11. Klink, S. I., Kerizer, H. & van Veggel, F. C. J. M. Transition metal complexes as photosensitizers for near-infrared lanthanide luminescence. Angew. Chem. Int. Ed. 39, 4319–4321 (2000).

    Article  CAS  Google Scholar 

  12. Penfold, T. J., Gindensperger, E., Daniel, C. & Marian, C. M. Spin-vibronic mechanism for intersystem crossing. Chem. Rev. 118, 6975–7025 (2018).

    Article  CAS  Google Scholar 

  13. Smith, M. B. & Michl, J. Singlet fission. Chem. Rev. 110, 6891–6936 (2010).

    Article  CAS  Google Scholar 

  14. Wykes, M., Parambil, R., Beljonne, D. & Gierschner, J. Vibronic coupling in molecular crystals: a Franck-Condon Herzberg-Teller model of H-aggregate fluorescence based on quantum chemical cluster calculations. J. Chem. Phys. 143, 114116 (2015).

    Article  ADS  CAS  Google Scholar 

  15. Auzel, F. Upconversion and anti-Stokes processes with f and d ions in solids. Chem. Rev. 104, 139–174 (2004).

    Article  CAS  Google Scholar 

  16. Tobita, S., Arakawa, M. & Tanaka, I. The paramagnetic metal effect on the ligand localized S1→T1 intersystem crossing in the rare-earth-metal complexes with methyl salicylate. J. Phys. Chem. 89, 5649–5654 (1985).

    Article  CAS  Google Scholar 

  17. Tiberghien, A. & Delacote, G. Evaluation of the crystalline tetracene triplet Davydov splitting. Chem. Phys. Lett. 8, 88–90 (1971).

    Article  ADS  CAS  Google Scholar 

  18. Tao, S. et al. Optical pump-probe spectroscopy of photocarriers in rubrene single crystals. Phys. Rev. B 83, 075204 (2011).

    Article  ADS  Google Scholar 

  19. Thompson, N. J. et al. Energy harvesting of non-emissive triplet excitons in tetracene by emissive PbS nanocrystals. Nat. Mater. 13, 1039–1043 (2014).

    Article  ADS  CAS  Google Scholar 

  20. Tabachnyk, M. et al. Resonant energy transfer of triplet excitons from pentacene to PbSe nanocrystals. Nat. Mater. 13, 1033–1038 (2014).

    Article  ADS  CAS  Google Scholar 

  21. Wu, M. et al. Solid-state infrared-to-visible upconversion sensitized by colloidal nanocrystals. Nat. Photon. 10, 31–34 (2016).

    Article  ADS  CAS  Google Scholar 

  22. Zhao, J., Ji, S. & Guo, H. Triplet–triplet annihilation based upconversion: from triplet sensitizers and triplet acceptors to upconversion quantum yields. RSC Adv. 1, 937–950 (2011).

    Article  CAS  Google Scholar 

  23. Singh-Rachford, T. N. & Castellano, F. N. Photon upconversion based on sensitized triplet–triplet annihilation. Coord. Chem. Rev. 254, 2560–2573 (2010).

    Article  CAS  Google Scholar 

  24. Burdett, J. J., Müller, A. M., Gosztola, D. & Bardeen, C. J. Excited state dynamics in solid and monomeric tetracene: the roles of superradiance and exciton fission. J. Chem. Phys. 133, 144506 (2010).

    Article  ADS  Google Scholar 

  25. Zhao, J. et al. Single-nanocrystal sensitivity achieved by enhanced upconversion luminescence. Nat. Nanotechnol. 8, 729–734 (2013).

    Article  ADS  CAS  Google Scholar 

  26. Haase, M. & Schäfer, H. Upconverting nanoparticles. Angew. Chem. Int. Ed. 50, 5808–5829 (2011).

    Article  CAS  Google Scholar 

  27. Garfield, D. J. et al. Enrichment of molecular antenna triplets amplifies upconverting nanoparticle emission. Nat. Photon. 12, 402–407 (2018).

    Article  ADS  CAS  Google Scholar 

  28. Pollnau, M., Gamelin, D. R., Lüthi, S. R., Güdel, H. U. & Hehlen, M. P. Power dependence of upconversion luminescence in lanthanide and transition-metal-ion systems. Phys. Rev. B 61, 3337–3346 (2000).

    Article  ADS  CAS  Google Scholar 

  29. Nienhaus, L., Wu, M., Bulović, V., Baldo, M. A. & Bawendi, M. G. Using lead chalcogenide nanocrystals as spin mixers: a perspective on near-infrared-to-visible upconversion. Dalton Trans. 47, 8509–8516 (2018).

    Article  CAS  Google Scholar 

  30. Nienhaus, L. et al. Speed limit for triplet-exciton transfer in solid-state PbS nanocrystal-sensitized photon upconversion. ACS Nano 11, 7848–7857 (2017).

    Article  CAS  Google Scholar 

  31. Huang, Z. et al. Hybrid molecule−nanocrystal photon upconversion across the visible and near-infrared. Nano Lett. 15, 5552–5557 (2015).

    Article  ADS  CAS  Google Scholar 

  32. Wang, F., Deng, R. & Liu, X. Preparation of core-shell NaGdF4 nanoparticles doped with luminescent lanthanide ions to be used as upconversion-based probes. Nat. Protoc. 9, 1634–1644 (2014).

    Article  CAS  Google Scholar 

  33. Bogdan, N., Vetrone, F., Ozin, G. A. & Capobianco, J. A. Synthesis of ligand-free colloidally stable water dispersible brightly luminescent lanthanide-doped upconverting nanoparticles. Nano Lett. 11, 835–840 (2011).

    Article  ADS  CAS  Google Scholar 

  34. de Mello, J. C., Wittmann, H. F. & Friend, R. H. An improved experimental determination of external photoluminescence quantum efficiency. Adv. Mater. 9, 230–232 (1997).

    Article  Google Scholar 

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Acknowledgements

This project received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 758826) and from Marie Skłodowska-Curie grant agreements nos 797619 (TET-Lanthanide project), 748042 (MILORD project) and 646176 (EXTMOS project). We acknowledge support from the Engineering and Physical Sciences Research Council (EPSRC) and the Winton Programme for the Physics of Sustainability, the Singapore Ministry of Education (grant MOE2017-T2-2-110), the Singapore Agency for Science, Technology and Research (grant A1883c0011), and the National Research Foundation, Prime Minister’s Office, Singapore under the NRF Investigatorship programme (award no. NRF-NRFI05-2019-0003). R.D. acknowledges support from the National Natural Science Foundation of China (grant 51872256) and the Zhejiang Provincial Natural Science Foundation of China (grant LR19B010002). Computational resources were provided by the Consortium des Équipements de Calcul Intensif (CÉCI), funded by the Fonds de la Recherche Scientifique de Belgique (FRS-FNRS) under grant no. 2.5020.11, and by the Tier-1 supercomputer of the Fédération Wallonie-Bruxelles, which is infrastructure funded by the Walloon Region under grant agreement no. 1117545. L.N. acknowledges support from the Jardine Foundation. J.Z. thanks the China Scholarship Council for a PhD scholarship (no. 201503170255). S.A. acknowledges financial support from DST-UKIERI (DST/INT/UK/P-167/2017) and SERB-ECRA (ECR/2018/002056).

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Author notes

  1. These authors contributed equally: Sanyang Han, Renren Deng

Authors and Affiliations

  1. Cavendish Laboratory, University of Cambridge, Cambridge, UK

    Sanyang Han, Renren Deng, Qifei Gu, Limeng Ni, Uyen Huynh, Jiangbin Zhang, Baodan Zhao, Mojtaba Abdi-Jalebi, Aditya Sadhanala & Akshay Rao

  2. Institute for Composites Science Innovation, School of Materials Science and Engineering, Zhejiang University, Hangzhou, China

    Renren Deng

  3. Department of Chemistry, Imperial College London, London, UK

    Jiangbin Zhang & Artem Bakulin

  4. College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China

    Jiangbin Zhang

  5. Department of Chemistry, National University of Singapore, Singapore, Singapore

    Zhigao Yi & Xiaogang Liu

  6. State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, China

    Baodan Zhao

  7. Department of Chemical System Engineering, The University of Tokyo, Tokyo, Japan

    Hiroyuki Tamura

  8. Laboratory for Chemistry of Novel Materials, University of Mons, Mons, Belgium

    Anton Pershin & David Beljonne

  9. School of Chemistry and Material Science, Heilongjiang University, Harbin, China

    Hui Xu

  10. Department of Chemistry, University of California, Riverside, Riverside, CA, USA

    Zhiyuan Huang & Ming Lee Tang

  11. Advanced Energy Materials Group, Department of Physics, Indian Institute of Technology Jodhpur, Jodhpur, India

    Shahab Ahmad

  12. Institute for Materials Discovery, University College London, London, UK

    Mojtaba Abdi-Jalebi

  13. The N.1 Institute for Health, National University of Singapore, Singapore, Singapore

    Xiaogang Liu

  14. Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Fuzhou, China

    Xiaogang Liu

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  1. Sanyang Han
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Contributions

S.H., R.D. and A.R. designed the experiments. S.H., R.D., Z.Y. and B.Z. performed nanocrystal synthesis and film preparation. S.H., R.D., L.N., U.H., A.S. and S.A. carried out spectroscopic measurements. S.H., Q.G. and J.Z. contributed to transient absorption experiments and data analysis under the supervision of A.B. and A.R. H.T., A.P. and D.B. carried out theoretical calculations. H.X. prepared organic molecules. Z.H. prepared tetracene derivatives under the supervision of M.L.T. M.A.-J. and A.S. performed PDS measurements. S.H., R.D., X.L. and A.R. wrote the manuscript. X.L. and A.R. supervised the project. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Renren Deng, Xiaogang Liu or Akshay Rao.

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Peer review information Nature thanks Jiajia Zhou and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Information

This file contains Supplementary Figures 1-54 and Supplementary Tables 1-3.

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Han, S., Deng, R., Gu, Q. et al. Lanthanide-doped inorganic nanoparticles turn molecular triplet excitons bright. Nature 587, 594–599 (2020). https://doi.org/10.1038/s41586-020-2932-2

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