Stabilizing Ultrathin CsPbBr ₃ Nanoplatelet Films for Deterministic Strong Light-Matter Coupling

While the excitons in perovskite nanomaterials possess interesting properties central to their use in optoelectronic technologies, their instability limits real world applicability. In this study, we describe a method to stabilize the structures of cesium lead bromide (CsPbBr₃) nanoplatelets (NPLs) in spin-casted films. We apply this method to design, fabricate, and characterize exciton cavity polaritons formed from these nanomaterials. These studies show that we can form exciton cavity polaritons from CsPbBr₃ in precisely designed Fabry-Perot microresonators and suggest that the structures of these materials can be stabilized toward their use in other solution-processed optoelectronic devices.