Single‐Photon Emitters in Thickness‐Controlled hBN Directly Grown on Silicon Platform

Hexagonal boron nitride (hBN) has emerged as a leading host for room‐temperature quantum light emission in 2D platforms, which enables facile integration with various photonic devices. However, scalable hBN growth is often restricted to ultrathin films and limited substrate choices, making transfer steps necessary for practical device integration. Here, we report catalyst‐free chemical vapor deposition of thickness‐controlled hBN films directly on CMOS‐compatible SiO 2 /Si substrates, enabling transfer‐free, large‐area growth of hBN hosting single‐photon emitters (SPEs). By systematically tuning the growth parameters, we engineered the SPE density from 2 × 10 7 to 7 × 10 7 cm −2 , and identified the optimal growth condition to yield the highest emitter density. Photophysical measurements confirm high‐purity emission with g 2 (0) down to 0.09 without background correction. Importantly, SPEs are well‐isolated in substantially thick hBN layers up to 100 nm, providing a device‐relevant thickness regime for optical mode confinement and fabrication of integrated photonic architectures. These results provide a scalable route to integrate hBN‐hosted quantum light sources on silicon platforms for large‐area quantum photonic devices.