Abstract
Superfluorescence (SF), characterized by the collective emission of photons from a dense ensemble of excited emitters, has emerged as a promising phenomenon for quantum optics and nanophotonics applications. However, SF has historically been limited to extremely low temperatures due to thermal decoherence. Here we show room-temperature tunable SF from perovskite quantum dot (QD) superlattices. Our approach involves the mesocrystallization of CsPbBr3-based QD superlattices driven by oriented attachment, which yields pyramidal-like solids with extended atomic coherency. This level of atomic-scale to nanoscale orientational structure control cannot be realized in previous QD superlattices, and it allows for quantum coherence to persist at ambient conditions. As a result, we observe multiple narrowband coherent emissions at room temperature, which we attribute to SF. Our results establish superlattices as an emerging materials platform capable of robust quantum coherence without cryogenic constraints, opening up new possibilities for quantum optics and nanophotonics applications.