Organic LEDs that emit light in the short-wavelength infrared (SWIR) region, which spans the 1–2 μm region, are attractive for applications in biosensors, biomedical imaging and spectroscopy, and surveillance. However, fabrication of such devices with high radiance has not yet been achieved owing to an intrinsic limitation imposed by the energy-gap law, which leads to extremely low emission efficiencies. Here, we report that acceptor–donor–acceptor-type molecules with high coplanarity, rigid π-conjugated backbones, an extremely small reorganization energy and an electron–phonon coupling factor are capable of simultaneously providing a strongly suppressed non-radiative recombination rate and a high operation stability at high current density. We achieve electrically driven SWIR organic LEDs with an irradiance of up to 3.9 mW cm−2 (corresponding to 7% of direct sunlight infrared irradiance). These findings should open a wide avenue to a new class of organic SWIR light sources for a broad range of applications.
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The data that support the findings of this study are available from the corresponding author upon reasonable request. Source data are provided with this paper.
Tang, C. W. & VanSlyke, S. A. Organic electroluminescent diodes. Appl. Phys. Lett. 51, 913–915 (1987).
Burroughes, J. H. et al. Light-emitting diodes based on conjugated polymers. Nature 347, 539–541 (1990).
Qian, G. et al. Simple and efficient near-infrared organic chromophores for light-emitting diodes with single electroluminescent emission above 1000 nm. Adv. Mater. 21, 111–116 (2009).
Zampetti, A., Minotto, A. & Cacialli, F. Near-infrared (NIR) organic light-emitting diodes (OLEDs): challenges and opportunities. Adv. Func. Mater. 29, 1807623 (2019).
Zheng, Y. & Zhu, X. Recent progress in emerging near-infrared emitting materials for light-emitting diode applications. Org. Mater. 2, 253–281 (2020).
Konstantatos, G. et al. Ultrasensitive solution-cast quantum dot photodetectors. Nature 442, 180–183 (2006).
Lu, H., Carroll, G. M., Neale, N. R. & Beard, M. C. Infrared quantum dots: progress, challenges, and opportunities. ACS Nano 13, 939–953 (2019).
Murphy, C. J. Optical sensing with quantum dots. Anal. Chem. 74, 520A–526A (2002).
Smith, A. M., Mancini, M. C. & Nie, S. Second window for in vivo imaging. Nat. Nanotechnol. 4, 710–711 (2009).
Wilson, R. H., Nadeau, K. P., Jaworski, F. B., Tromberg, B. J. & Durkin, A. J. Review of short-wave infrared spectroscopy and imaging methods for biological tissue characterization. J. Biomed. Opt. 20, 030901 (2015).
Diao, S. et al. Fluorescence imaging in vivo at wavelengths beyond 1,500 nm. Angew. Chem. Int. Ed. 54, 14758–14762 (2015).
Bruns, O. T. et al. Next-generation in vivo optical imaging with short-wave infrared quantum dots. Nat. Biomed. Eng. 1, 0056 (2017).
Minotto, A. et al. Towards efficient near-infrared fluorescent organic light-emitting diodes. Light Sci. Appl. 10, 18–27 (2021).
Wu, J. When group-III nitrides go infrared: new properties and perspectives. J. Appl. Phys. 106, 011101 (2009).
Krier, A., Chub, D., Krier, S. E., Hopkinson, M. & Hill, G. Light sources for wavelengths >2 μm grown by MBE on InP using a strain relaxed buffer. IEE Proc. Optoelectron. 145, 292–296 (1998).
Someya, T., Bao, Z. & Malliaras, G. The rise of plastic bioelectronics. Nature 540, 379–385 (2016).
Tessler, N., Medvedev, V., Kazes, M., Kan, S. & Banin, U. Efficient near-infrared polymer nanocrystal light-emitting diodes. Science 295, 1506–1508 (2002).
Qi, J., Qiao, W. & Wang, Z. Y. Advances in organic near-infrared materials and emerging applications. Chem. Rec. 16, 1531–1548 (2016).
Ho, C. L., Li, H. & Wong, W. Y. Red to near-infrared organometallic phosphorescent dyes for OLED applications. J. Organomet. Chem. 751, 261–285 (2014).
Ai, X. et al. Efficient radical-based light-emitting diodes with doublet emission. Nature 563, 536–540 (2018).
Tao, R. et al. High-efficiency near-infrared organic light-emitting devices based on an iridium complex with negligible efficiency roll-off. J. Mater. Chem. C 1, 6446–6454 (2013).
Wei, Y. C. et al. Overcoming the energy gap law in near-infrared OLEDs by exciton–vibration decoupling. Nat. Photonics 14, 570–577 (2020).
Suzuki, H. Infrared electroluminescence from an organic ionic dye containing no rare-earth ions. Appl. Phys. Lett. 80, 3256–3258 (2002).
Chen, M. et al. 1 micron wavelength photo- and electroluminescence from a conjugated polymer. Appl. Phys. Lett. 84, 3570–3572 (2004).
Minotto, A. et al. Efficient near-infrared electroluminescence at 840 nm with “metal-free” small-molecule:polymer blends. Adv. Mater. 30, 1706584 (2018).
Qian, G. et al. Band gap tunable, donor–acceptor–donor charge-transfer heteroquinoid-based chromophores: near infrared photoluminescence and electroluminescence. Chem. Mater. 20, 6208–6216 (2008).
Yao, L. et al. Highly efficient near-infrared organic light-emitting diode based on a butterfly-shaped donor–acceptor chromophore with strong solid-state fluorescence and a large proportion of radiative excitons. Angew. Chem. Int. Ed. 53, 2119–2123 (2014).
Kim, D. H. et al. High efficiency electroluminescence and amplified spontaneous emission from a thermally activated delayed fluorescent near-infrared emitter. Nat. Photonics 12, 98–104 (2018).
Yu, Y. et al. Near-infrared electroluminescence beyond 800 nm with high efficiency and radiance from anthracene cored emitters. Angew. Chem. Int. Ed. 59, 21578–21584 (2020).
Tregnago, G., Steckler, T. T., Fenwick, O., Andersson, M. R. & Cacialli, F. Thia- and selenadiazole containing polymers for near-infrared light-emitting diodes. J. Mater. Chem. C 3, 2792–2797 (2015).
Lin, Y. et al. An electron acceptor challenging fullerenes for efficient polymer solar cells. Adv. Mater. 27, 1170–1174 (2015).
Liu, S. et al. High-efficiency organic solar cells with low non-radiative recombination loss and low energetic disorder. Nat. Photonics 14, 300–305 (2020).
Rau, U. Reciprocity relation between photovoltaic quantum efficiency and electroluminescent emission of solar cells. Phys. Rev. B 76, 085303 (2007).
Lee, J. et al. Bandgap narrowing in non-fullerene acceptors: single atom substitution leads to high optoelectronic response beyond 1000 nm. Adv. Energy Mater. 8, 1801212 (2018).
Roncali, J. Molecular engineering of the band gap of π-conjugated systems: facing technological applications. Macromol. Rapid Commun. 28, 1761–1775 (2007).
Shuai, Z. G. & Peng, Q. Organic light-emitting diodes: theoretical understanding of highly efficient materials and development of computational methodology. Natl Sci. Rev. 4, 224–239 (2017).
Benduhn, J. et al. Intrinsic non-radiative voltage losses in fullerene-based organic solar cells. Nat. Energy 2, 17053 (2017).
Perdigón-Toro, L. et al. Excitons dominate the emission from PM6:Y6 solar cells, but this does not help the open-circuit voltage of the device. ACS Energy Lett. 6, 557–564 (2021).
Jortner, J. Temperature dependent activation energy for electron transfer between biological molecules. J. Chem. Phys. 64, 4860–4867 (1976).
Gould, I. R. et al. Radiative and nonradiative electron transfer in contact radical-ion pairs. Chem. Phys. 176, 439–456 (1993).
Azzouzi, M. et al. Nonradiative energy losses in bulk-heterojunction organic photovoltaics. Phys. Rev. X 8, 031055 (2018).
Wilson, J. S. et al. The energy gap law for triplet states in Pt-containing conjugated polymers and monomers. J. Am. Chem. Soc. 123, 9412–9417 (2001).
Cave, R. J. & Newton, M. D. Generalization of the Mulliken–Hush treatment for the calculation of electron transfer matrix elements. Chem. Phys. Lett. 249, 15–19 (1996).
Zhu, W. et al. Crystallography, morphology, electronic structure, and transport in non-fullerene/non-Indacenodithienothiophene polymer: Y6 solar cells. J. Am. Chem. Soc. 142, 14532–14547 (2020).
Zhang, G. et al. Delocalization of exciton and electron wavefunction in non-fullerene acceptor molecules enables efficient organic solar cells. Nat. Commun. 11, 3943 (2020).
Yao, H. et al. Design, synthesis, and photovoltaic characterization of a small molecular acceptor with an ultra-narrow band gap. Angew. Chem. Int. Ed. 56, 3045–3049 (2017).
Intemann, J. J. et al. Molecular weight effect on the absorption, charge carrier mobility, and photovoltaic performance of an indacenodiselenophene-based ladder-type polymer. Chem. Mater. 25, 3188–3195 (2013).
Li, Y. et al. Universal electroluminescence at voltages below the energy gap in organic light-emitting diodes. Adv. Optical Mater. 8, 2101149 (2021).
Liu, X. K. et al. Metal halide perovskites for light-emitting diodes. Nat. Mater. 20, 10–21 (2021).
Kuik, M. et al. 25th Anniversary Article: Charge transport and recombination in polymer light-emitting diodes. Adv. Mater. 26, 512–531 (2014).
Wang, W. et al. Achieving efficient polymer solar cells based on near-infrared absorptive backbone twisted non-fullerene acceptors through a synergistic strategy of indacenodiselenophene fused-ring core and chlorinated terminal group. ACS Appl. Energy Mater. 5, 1322–1330 (2022).
Li, C. et al. Non-fullerene acceptors with branched side chains and improved molecular packing to exceed 18% efficiency in organic solar cells. Nat. Energy 6, 605–613 (2021).
Jiang, K. et al. Alkyl chain tuning of small molecule acceptors for efficient organic solar cells. Joule 3, 3020–3033 (2019).
Cui, L.-S. et al. Fast spin-flip enables efficient and stable organic electroluminescence from charge-transfer states. Nat. Photonics 14, 636–642 (2020).
Frisch, M. J. et al. Gaussian 16 revision C.01 (Gaussian, Inc., 2016).
Lu, T. & Chen, F. Multiwfn: a multifunctional wavefunction analyzer. J. Comput. Chem. 33, 580–592 (2012).
Hongbin Wu thanks the National Natural Science Foundation of China (no. 52273177, 91333206 and 51521002) for financial support. Y.X. acknowledges the National Natural Science Foundation of China (no. 52003087) for financial support. C.G. thanks the Shaanxi Key Scientific and Technological Innovation Team Project (no. 2016KCT-28) and Shaanxi Key Project in Industrial Field (no. 2017ZDXM-GY-046) for financial support. W.D. acknowledges support from the National Natural Science Foundation of China (no. 62004069). X.-K.C. acknowledges the New Faculty Start-up Grant of the City University of Hong Kong (7200709 and 9610547). We thank D. Li for assistance with the OLED operational lifetime measurements.
The authors declare no competing interests.
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Nature Photonics thanks Juan Qiao, Xiaozhang Zhu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Statistical source data for Fig. 1d and the source data of the output of Gaussian 16 (ES64L-G16RevC.01).
Statistical source data for the absorption and PL spectra of the emitters, normalized reduced emission spectra and modelled PLQYs.
Statistical source data for the measured and calculated rate constants for radiative and non-radiative recombination and the PLQY of each emitter.
Statistical source data for EL spectra, J–R–V characteristics and EQE–J curves of SWIR OLEDs.
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Xie, Y., Liu, W., Deng, W. et al. Bright short-wavelength infrared organic light-emitting devices. Nat. Photon. 16, 752–761 (2022). https://doi.org/10.1038/s41566-022-01069-w