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 reduced-dimensional 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.

Metal halide perovskite light-emitting diodes (LEDs) possess high external quantum efficiency (EQE) and color purity, indicating great promise for next-generation panel displays. In state-of-the-art perovskite LEDs, the hole transport layers and perovskite thin films are solution-processed, whereas the electron transport layers are fabricated through vacuum evaporation deposition. The latter method raises concerns about material waste and environmental pollution, as well as prolonged production duration and increased costs, thereby posing challenges for scalable and sustainable manufacturing. Here, we demonstrate a systematic solvent screening strategy for fabricating perovskite LEDs based on all-solution-processed functional layers. We use ethyl acetate to spin-coat the electron transport material onto perovskite thin films, thereby preserving the device’s structural integrity. The as-fabricated deep-red perovskite LEDs show a peak EQE of 4.04% and a maximum radiance of 8221 mW·sr⁻¹·m⁻², among the best performances of all-solution-processed perovskite LEDs. Quantitative analysis indicates that, compared to vacuum evaporation deposition, the material costs, processing duration, and equipment expenses have been reduced by 82%, 90%, and 95%, respectively. Our work establishes a promising construction strategy for solution-processed optoelectronic devices with low cost and high performance, thereby bringing them a significant step closer to their further industrialization and commercialization.