Cooperative and collective quantum light emission from perovskite superball superstructures
- Yue Yu
- Bo Wang
- Minjun Feng
- How Jiunn Ming Kelvin
- Wai-Keong Mok
- Jia Wei Melvin Lim
- Zengshan Xing
- Huajun He
- Leong Chuan Kwek
- Tze Chien Sum
2026-08-14
Superfluorescence (SF), the coherent light burst from synchronized quantum emitters, has been demonstrated in perovskite quantum dot superlattices. However, limited control over self-assembly, heterogeneity and emitter properties has hindered systematic exploration of cooperative emission and its transition to collective emission regimes such as amplified spontaneous emission (ASE) and lasing. Here, we present emulsion-templated perovskite superballs (SBs) as a robust, tunable platform for investigating collective light-matter phenomena. This strategy enables versatile control over perovskite nanocrystal (PNC) size, packing density, ligand chemistry, optical cavity structure, etc. We identify a critical packing density (∼0.34) for triggering SF in PNC ensembles, in agreement with theoretical calculations. Larger SBs function as self-assembled microcavities, supporting low-threshold lasing with high quality factors. Tunable excitation fluence induces a crossover between the SF and lasing regimes, while high-density SB films also support ASE. These findings establish perovskite SBs as a versatile platform for studying cooperative and collective emission dynamics crucial for advancing scalable quantum photonic technologies.