High-performance near-infrared circularly polarized electroluminescence with an emission peak beyond 900 nm.

Wang, Jiaqi; Guan, Xiang; Li, Xiuling; Liu, Jinli; Zhao, Chunli; Wang, Junnan; Wu, Yourong; Wang, Chengjie et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Near-infrared spin-light-emitting diodes (NIR-Spin-LEDs), which generate circularly polarized light, offer opportunities for applications such as biomedicine. However, the longest reported emission wavelength of NIR-Spin-LEDs remains limited to 782 nm, making spin-polarized electroluminescence beyond 800 nm challenging. Here we show NIR-Spin-LEDs based on a mixed-dimensional tin-based perovskite heterostructure incorporating chiral R/S-α-methylbenzylammonium (R/S-MBA<sup>+</sup>) spacer cations. The low-dimensional phases induced by R/S-MBA<sup>+</sup> provide chiroptical activity, while three-dimensional FA<sub>0.9</sub>Cs<sub>0.1</sub>SnI<sub>3</sub> domains serve as the near-infrared emissive centers. Controlled crystallization produces a cypress-leaf-like morphology that promotes carrier confinement and improves charge-injection balance. The resulting devices exhibit electroluminescence peaking at 905 nm, with an external quantum efficiency of 7.8% and a maximum electroluminescence dissymmetry factor (g<sub>EL</sub>) of 5.5 × 10<sup>-2</sup>. This work extends spin-polarized electroluminescence into the deep near-infrared region and provides a strategy for developing lead-free NIR-Spin-LEDs.