Visible nanocrystal-based light-emitting diodes (LEDs) are about to become commercially available. However, their infrared counterparts suffer from two key limitations. First, III–V semiconductor technologies are strong competitors. Second, their potential for operation beyond 1.7 µm remains unexplored. The range from 1.5 to 4 µm corresponds to a technological gap in which the efficiency of interband quantum-well-based devices vanishes and quantum cascade lasers are not efficient enough. Powerful infrared LEDs in this range are needed for applications such as active imaging, organic molecule sensing and airfield lighting. Here we report the design of a HgTe nanocrystal-based LED with luminescence between 2 and 2.3 µm. With an external quantum efficiency of 0.3% and radiance up to 3 W Sr−1 m−2, these HgTe LEDs already present a competitive performance for emission above 2 µm.
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We thank P. Hollander and D. Henry for experimental support. The project is supported by ERC starting grant blackQD (grant no. 756225, E.L.) and Ne2Dem (grant no. 853049, S.I.). We acknowledge the use of clean-room facilities at the Centrale de Proximité Paris-Centre. This work has been supported by the Region Île-de-France in the framework of DIM Nano-K (grant dopQD, E.L.) and in the framework of the SESAME Electrophonon (grant no. 14014520, D.B.). We acknowledge financial support from the French Department of Defence (DGA) in the frame of the Oscillateur térahertz project (grant no. 2018 60 0071 00 470 75 01, D.B.), and of PALM in the framework of the TPS grant (grant no. ANR‐10‐LABX‐0039‐PALM, D.B.). This work was supported by French state funds managed by the ANR within the Investissements d’Avenir programme under reference ANR-11-IDEX-0004-02 (E.L.) and, more specifically, within the framework of the Cluster of Excellence MATISSE and also by the grant IPER-Nano2 (ANR-18CE30-0023-01, E.L.), Copin (ANR-19-CE24-0022, E.L.), Frontal (ANR-19-CE09-0017, M.G.S.), Graskop (ANR-19-CE09-0026, E.L.), TOCYDYS (ANR-19-CE30-0015-03, D.B.) and NITQuantum (ANR-20-ASTR-0008-01, E.L.), Bright (ANR-21-CE24-0012-02, E.L.) and MixDFerro (ANR-21-CE09-0029, E.L.). J.Q. thanks the Chinese Scholarship Council for PhD funding and A.C. thanks Agence Innovation Defense.
The authors declare no competing interests.
Peer review information Nature Photonics thanks Ni Zhao and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Qu, J., Weis, M., Izquierdo, E. et al. Electroluminescence from nanocrystals above 2 µm. Nat. Photon. 16, 38–44 (2022). https://doi.org/10.1038/s41566-021-00902-y