Microstructure Engineering of Hexagonal Boron Nitride for Single‐Photon Emitter Applications

Single‐photon emitters (SPEs) can play an important role in future quantum optics. Hexagonal boron nitride (h‐BN), a layered insulator (bandgap ≈6 eV), is a promising candidate for next‐generation SPEs because of its chemical and thermal stability and high brightness at room temperature. In this review, the microstructures (atomic defects, deformations, and cavities) of h‐BN are established and their SPE characteristics are analyzed. Recent progress in the synthesis of high‐quality bulk h‐BN, monoisotopic h‐BN, and epitaxial h‐BN films is also demonstrated. Some approaches for achieving SPE arrays are further discussed and the applications of h‐BN SPEs in the quantum field are investigated. The success in the preparation of large‐scale h‐BN and its microstructural engineering provides a promising future in low‐dimensional quantum optics. This review emphasizes the microstructures of h‐BN and their single‐photon emitters (SPEs) characteristics. And recent progress in the synthesis of h‐BN films, some approaches for achieving SPE arrays, and the applications of h‐BN SPEs are introduced. The success in the preparation of large‐scale h‐BN and its microstructural engineering provides a promising future in low‐dimensional quantum optics.