Intermediate stabilization enables antisolvent-free crystallization of perovskites for high-performance light-emitting diodes

Perovskites with superior optoelectronic properties are admirable candidates for high-performance light-emitting diode (LED) applications. However, the use of antisolvents during perovskite film fabrication increases process complexity and production costs, as well as raises toxicity concerns. Here, we demonstrated an antisolvent-free crystallization strategy enabled by intermediate stabilization for the fabrication of high-quality perovskite films. We prepared the reduceddimensional perovskite precursor, and used cesium bromide as the crystallization retardant to facilitate the formation of stable intermediate during spin coating. This intermediate directs more ordered crystal growth and achieves a uniform quantum well thickness distribution, thereby substantially enhancing film quality. By using this approach, we fabricated LEDs with a maximum external quantum efficiency of 29.36%. This work elucidates the crystallization mechanism of perovskites and establishes an antisolvent-free pathway for the scalable and sustainable fabrication of high-performance perovskite optoelectronic devices.