Deterministic Integration of CsPbBr ₃ Quantum Dots with Plasmonic Ring Microcavities

Perovskite quantum dots hold great promise for quantum information processing as wavelength-tunable single photon sources operable over a broad temperature range. However, their deterministic integration into nanophotonic structures remains a major challenge limited by their random spatial distribution and nondirectional emission. In this work, we employ a two-step electron beam lithography process to deterministically place CsPbBr3 quantum dots within the mode volume of plasmonic ring microcavities. Simulations predict strong field enhancement within the cavity, boosting photon emission rates via the Purcell effect and improving the quantum efficiency of the emitters. Experimentally, coupling ensembles of CsPbBr3 quantum dots to the cavities results in a 4-fold enhancement in photoluminescence intensity and a 3-fold reduction in photoluminescence lifetime at room temperature. Single-emitter coupling is further investigated at cryogenic temperatures, leading to a 2-fold reduction in photoluminescence lifetime. These results demonstrate a potentially scalable approach for the integration of perovskite quantum dots into nanophotonic cavities and quantum photonic circuits.