1.4% External Quantum Efficiency 988 nm Light Emitting Diode Based on Tin‐Lead Halide Perovskite

Abstract In recent years, metal halide perovskite‐based light‐emitting diodes (LEDs) have garnered significant attention as they display high quantum efficiency, good spectral tunability, and are expected to have low processing costs. When the peak emission wavelength is beyond 900 nm the interest is even higher because of the critical importance of this wavelength for biomedical imaging, night vision, and sensing. However, many challenges persist in fabricating these high‐performance NIR LEDs, particularly for wavelengths above 950 nm, which appear to be limited by low radiance and poor stability. In this study, 3‐(aminomethyl) piperidinium (3‐AMP) is employed as a bulk additive for a tin‐lead halide perovskite. The 3‐AMP passivated films exhibit a significantly longer carrier lifetime of over 1 µs compared to neat films (0.43 µs) or to those passivated with a perfluorinated aromatic mono‐ammonium molecule (0.41 µs). Our optimized tin‐lead halide perovskite‐based LEDs show a single emission peak at 988 nm and an external quantum efficiency (EQE) of ≈1.4%.