Journal Article Perovskite metasurfaces Purcell enhancement Spin‐polarized exciton‐polaritons all-dielectric metasurfaces all‐solid‐state lithium‐sulfur batteries bound states in the continuum carbon nanocage carbon nanotube circularly polarized luminescence diamond synthesis dielectric metasurfaces directional emission electrical injection polaritons electrically‐tunable metadevices electrochemical‐mechanical failure halide perovskites hierarchical carbon nanocages high pressure and high temperature hybrid perovskite metasurfaces light emitting transistors metatransistors monolithic integration multi‐dimensional structural engineering optical Rashba effect optical bistability perovskite light-emitting transistors phase transition phase-change perovskites polarization vortices