Nanocavity-encapsulated perovskite nanocrystals with enhanced luminescence by Mie resonance

Perovskite nanocrystals (PeNCs) have been regarded as one of the most promising candidate materials for next -generation display technology due to their remarkable optical performance. However, addressing the limitations of inherent instability and low luminescence efficiency of PeNC films is still a huge obstacle in its commer-cialization process. Herein, the low-cost and large-area perovskite nanocrystal composite films (NCFs) based on hexagonally distributed TiO2-based metasurface (inspired by the surface structure of butterfly wings) in com-bination with PeNCs encapsulated in PMMA matrix were fabricated. The photoluminescence intensity of perovskite NCFs can be enhanced by a maximum of 3.89 times based on the Purcell effect by tailoring to match the emission peaks of their PeNCs in various bands using the flexibility of metasurface design. The encapsulation of PMMA polymer and TiO2 nanocavities also effectively enhanced the stability of PeNCs. Benefiting from these favorable characteristics, perovskite NCFs are applied to liquid crystal displays (LCDs) as color conversion layers, with color gamut reaching 122% of the NTSC standard and 180% of the commercial LCD screen, respectively, demonstrating that perovskite NCFs possess enormous potential in the high-end display fields. Furthermore, this metasurface fabrication process avoids complicated, time-consuming, and expensive process flow, laying the foundation for further commercialization beyond the laboratory.