Midgap radiative centers in carbon-enriched hexagonal boron nitride

Significance Well‐defined defect centers play a crucial role in condensed-matter physics. That is particularly evident in the case of semiconductors and wide‐gap insulators, where midgap levels provide a number of versatile functionalities: from lasing to pressure sensing. Individual defects may become single-photon sources—crucial for applications in quantum technology. Recently, such defects have been observed in hexagonal boron nitride (hBN). Here, a method to fabricate stable and reproducible defects in hBN is introduced. Large bandgap of boron nitride allows the use of such defects in many quantum applications. Fabrication and characterization of such defects in hBN, which has become a relevant, emerging, wide-bandgap 2D material, is an important step toward novel functionalities of van der Waals heterostructures.