Generalized Purcell factor enhancement of perovskite nanocrystals in an open cavity at room temperature

Cavity interactions are crucial to several high-efficiency photonic devices, such as resonant cavity light-emitting diodes and vertical cavity surface emitting lasers. In particular, optical microcavities are conventionally used to achieve sufficiently bright single photon sources to be utilized in modern photonic quantum technologies. We present a study of the cavity-funneling effect of the optical emission from an ensemble of CsPbBr3 PNCs embedded in an open optical plano–convex microcavity at room temperature with two different radii of curvature of the convex mirror. A generalized Purcell factor of F*=30 is found. The increase in Purcell factor as a function of the cavity radius of curvature (RoC) is compared to the decrease in the effective mode volume with RoC, obtained via a 3D simulation of the two cavity configurations with radii of curvature of 12 and 99 μm. The effective mode volume reduction going from the 99 μm to the 12 μm RoC configuration is identified as the most plausible origin for the greater optical emission enhancement observed in the smaller RoC cavity. Other secondary factors such as an increased coupling to single transverse modes or the increase in the Q-factor are discussed and placed in context, as the basis for future designs of more effective cavity systems for perovskite nanocrystals at room temperature.