Enhancing Thermal Tolerance for Bright and Stable Near‐Infrared Perovskite LEDs

Abstract Perovskite light‐emitting diodes (PeLEDs) have emerged as a promising candidate for next‐generation display technologies, owing to their high efficiency and color purity. However, the operational instability of PeLEDs at high current densities (>100 mA cm −2 ) remains a significant challenge. Here, near‐infrared (≈797 nm) PeLEDs are reported with peak external quantum efficiencies (EQEs) of ≈24.7% and EQEs of >20% across a wide range of current densities (70–1200 mA cm −2 ), resulting in an ultra‐high peak radiance of 2270 W sr −1 m −2 . These PeLEDs exhibit outstanding operational stability with operational lifetimes ( T 50 ) of 6.6, 12.7, 19.2, 49.5, 238.6, and 350 h at current densities of 500, 400, 300, 200, 100, and 50 mA cm −2 , respectively. The high stability is enabled by a multifunctional stabilizer containing formamidine groups, which prevent phase transition and decomposition of the α‐FAPbI 3 perovskite under elevated temperatures. This work demonstrates the feasibility of achieving efficient and stable PeLEDs at high current densities, providing strategies for the development of high‐power optoelectronic devices based on halide perovskites.