Lead Halide Perovskite-Based Dynamic Metasurfaces

Lead halide perovskites CH₃NH₃PbX₃ (MAPbX₃) are known to have high refractive index and controllable bandgap, making them attractive for all-dielectric and tunable metasurfaces. Till now, perovskite metasurfaces have only been used in structural colors. More interesting meta-devices with 2π phase control are still absent. Here, MAPbX₃-perovskite-based metasurfaces are experimentally demonstrated with a complete control of phase shift in a reflection mode. By utilizing MAPbBr₃ cut-wires as meta-atoms on a ground metal film, it is found that the MAPbBr₃ perovskite metasurface can produce full phase control from 0 to 2π and high reflection efficiency simultaneously. Consequently, high-efficiency polarization conversion, anomalous reflection, and meta-holograms are successfully produced. Most interestingly, the bandgap of the MAPbX₃ perovskite can be post-synthetically and reversibly tuned via anion exchange, providing a new approach to dynamically control of the all-dielectric meta-devices with novel function such as anomalous reflection and hologram.