Ambient-Air Fabrication of Perovskite Films for Near-Infrared Light-Emitting Diodes

Perovskite light-emitting diodes (LEDs) are sensitive to the quality of the perovskite films, which typically require fabrication in inert atmospheres to avoid moisture-induced uncontrolled crystallization, thereby increasing manufacturing complexity and cost. Here, it is demonstrated that cesium iodide and zinc acetate suppress the formation of lead polyhalide intermediates and enable the rapid growth of three-dimensional perovskite in ambient air. This approach suppresses water-induced uncontrolled growth, leading to the formation of perovskite films with uniformly distributed grains and reduced trap density. With this approach, ambient-air-processed near-infrared perovskite LEDs with a peak external quantum efficiency of 20.2% and enhanced stability are demonstrated.