Photophysics of cavity‑coupled quantum emitters in chemical vapor deposited hexagonal boron nitride

Integration of solid‑state quantum emitters with optical cavities leads to enhanced emitter quantum efficiency and Purcell factor. Hexagonal boron nitride (hBN) hosts robust room‑temperature single‑photon emitters, yet coupling to on‑demand optical cavities remains underexplored. Here, we investigate hBN emitters in tunable gold nanocavities whose resonant wavelength is set geometrically. Using micro‑exfoliated flakes, we observe zero‑phonon‑line brightening and accelerated decay consistent with Purcell‑enhanced radiative rates, while maintaining photostability under room‑temperature excitation. We extend this platform to wafer‑scale, chemical‑vapor‑deposited (CVD) hBN using wafer‑level processing. The hBN films are uniform over large areas, enabling statistically robust comparisons across thousands of devices. Guided by insights from exfoliated films, we realize cavity‑coupled emitters in CVD‑grown hBN and quantify cavity‑driven spectral selectivity, radiative‑lifetime shortening, and enhanced photon out‑coupling. We further outline routes to deterministic emitter positioning and cavity–emitter mode matching. Together, these results establish a manufacturable pathway to cavity‑integrated hBN emitters and provide practical design protocols for coupling to integrated photonics, advancing chip‑level quantum light sources and sensing.