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

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 (T₅₀) 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-FAPbI₃ 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.