Perovskite nanocrystals (PeNCs) deliver size and composition-tunable luminescence of high efficiency and color purity in the visible. However, attaining efficient electroluminescence (EL) in the near-infrared (NIR) region from PeNCs is challenging, limiting their potential applications. Here we demonstrate a highly efficient NIR light emitting diode (LED) by doping ytterbium ions into the PeNCs host (Yb3+:PeNCs), extending the EL wavelengths toward 1000 nm, which is achieved through a direct sensitization of Yb3+ ions by the PeNC host. Efficient quantum cutting processes enable high photoluminescence quantum yields (PLQYs) of up to 126% from the Yb3+:PeNCs. Through halide-composition engineering and surface passivation strategy to improve both PLQY and charge transport balance, we demonstrate an efficient NIR LED with a peak EQE of 7.7% at a central wavelength of 990 nm, representing the most efficient perovskite-based LEDs with emission wavelengths beyond 850 nm.
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