Ab initio methods applied to carbon-containing defects in hexagonal boron nitride

The functionalities activated by defect centers in solids are constantly growing, opening new avenues for sustainable future technologies. These may extend to quantum optoelectronics if suitable defect centers are created and their properties understood. Recent progress in developing quantum emitters in hexagonal boron nitride (hBN) associated with carbon impurities enabled the realization of such concepts in atomically thin films, where the defect centers exhibit an unprecedented level of sensitivity toward the environment. The complexity of defects, together with new control knobs provided by van der Waals technology, poses a challenge for theory to accurately predict the properties of defect centers and to match them with experimental results. Here, we review the ab initio methods applied to carbon-containing defect centers in hBN, exploring the predictive capabilities of different levels of theory for their structural and optoelectronic properties.