Highly stable perovskite light-emitting diodes

Perovskite light-emitting diodes (PeLEDs) show strong promise for a new generation of light sources. Significant research efforts have raised the external quantum efficiencies of PeLEDs to levels rivaling those of the more mature LED technologies. However, the poor operational stability of PeLEDs stands as the grandest challenge toward commercial applications. Breakthroughs in this direction were made recently. Near-infrared PeLEDs with ultralong lifetimes meeting the demands of practical applications and green PeLEDs with greatly enhanced stability were demonstrated. In this review, we analyze the state-of-the-art devices exhibiting high stability and clarify the origins of performance degradation. Emphases are given to the mechanisms of aging unique to PeLEDs, including ion migration, structural instability, and chemical processes. Some of the most critical challenges and future directions at this interdisciplinary research frontier are discussed. We expect this review to serve as a guide for enabling ultra-stable PeLEDs for display, lighting, and other emerging applications.