Prospects for n-type conductivity in cubic boron nitride

Cubic boron nitride is an ultra-wide-band-gap semiconductor with a range of useful properties, including high breakdown field, high thermal conductivity, and excellent chemical stability. These properties make cubic boron nitride a leading candidate for applications in power electronics, deep-ultraviolet optoelectronics, and quantum information science. Realizing these applications is predicated on the ability to achieve control over doping. By employing advanced first-principles calculations, we systematically explore group-IV (C, Si, and Ge) and group-VI (O, S, and Se) elements, as well as Li and F, as potential n-type dopants. We identify Si_B and O_N as the most promising dopants due to their low formation energy and resistance to self-compensation. However, we also find native boron vacancies, which are deep acceptors, can be a source of compensation. We examine vacancy migration and suggest that control over growth kinetics is necessary to achieve n-type conductivity in cubic boron nitride.