Recent Progress on Patterning Strategies for Perovskite Light-Emitting Diodes toward a Full-Color Display Prototype

Perovskite light-emitting diodes (PeLEDs) have attracted both academic and industrial interest because of their high efficiency, wide color gamut as well as low material and fabrication costs. However, most state-of-the-art PeLEDs are still fabricated with commonly used spin-coating methods, which are undesirable for large-scale commercial production. Achieving highly emissive perovskite microarrays at high spatial resolution with quick and large-scale growth is one of the critical steps to integrate state-of-the-art PeLEDs into full-color display panels. Here, the fabrication methods and crystallization processes of perovskite materials are first discussed because they are strongly relevant to the patterning process and the quality of the perovskite pixels. Then, the current strategies to realize perovskite patterns that can be likely integrated into display panels, through mask-free or mask-assisted methods, are explored. Self-emitting and down-conversion PeLED devices with a patterned perovskite matrix as the emissive layer are also reviewed. Finally, an outlook is provided on how to further improve the optical and electrical properties of the perovskite patterns and the performance of PeLEDs as well as to develop eco-friendly devices to accelerate the potential commercialization progress of this young technique.