Synergistic Effect of Dual Ligands on Stable Blue Quasi‐2D Perovskite Light‐Emitting Diodes

Since the emergence of inorganic–organic hybrid perovskites a few years ago, there have been many promising achievements in the field of green and red perovskite light‐emitting diodes (PeLEDs). Nevertheless, the performance of blue‐light PeLEDs faces challenges. In this work, the unique synergy obtained by introducing two different ligands to successfully form quasi‐2D perovskite films, which can exhibit stable blue‐light emission, is utilized. The fabricated PeLEDs have a maximum external quantum efficiency of 2.62% and a half lifetime (T50) of 8.8 min. Meanwhile, the electroluminescence spectrum with its peak located at 485 nm, demonstrates improved stability by applying different voltage bias. The finding in this work offers a new way to achieve steady blue PeLEDs with high performance. Utilizing synergistic effects with two different ligands, a stable blue perovskite emitter is successfully fabricated. The corresponding blue perovskite light‐emitting diode shows excellent device performance with a peak external quantum efficiency of 2.62% and a T50 lifetime of 8.8 min, demonstrating remarkable color stability under operation.