Robust superfluorescence from perovskite nanocrystals and rare-earth ion doped nanocrystal superlattices

Developing room-temperature superfluorescent (SF) photon sources is key to realizing their applications in ultra-narrow linewidth lasers, quantum communication and quantum metrology. Ordered emitter geometry, uniform emission frequencies, and high fluorescence quantum yield, all enhance SF emission. Lead halide perovskite nanocrystals readily self-assemble into superlattices and emit photons from polaron states, allowing them to meet the above criteria. I will present theoretical results showing how the nature of exciton-phonon interactions in CsPbBr₃ and MAPbBr₃ allow for this ideal combination of properties. The theory is corrobotated by temperature-dependent photoluminescence quantum yield and anti-Stokes emission data from perovskite nanocrystals.

Despite the above favorable characteristics, SF emission from perovskite nanocrystal superlattices remains orders of magnitude weaker than the theoretical maximum. On the other hand, rare-earth ion doped solids show strong SF emission despite a lack of geometrical order. I will present results of theoretical simulations, which predict that superlattices of nanocrystals doped with rare-earth ions (e.g., Nd³⁺) can show stronger and more disorder-resistant superfluorescence than undoped nanocrystals. The theoretical modeling also reveals optimal nanocrystal sizes, geometries, and doping concentrations for superfluorescence.