A first principles study of n-doping of cubic boron nitride with carbon

Cubic boron nitride (cBN) is a super-hard, ultra-wide bandgap material that is being explored for extreme applications. To realize cBN-based devices, however, one needs to controllably n- and p-dope cBN, which has remained a challenge for this material. Recent progress in harnessing the full potential of cBN include: (i) an elucidation of reasons behind doping limitations in a comprehensive theoretical study [arXiv:2107.04454] and (ii) successful doping of cBN with carbon in experiment [ACS Applied Electronic Materials 3, 1359 (2021)]. However, the identity of the carbon-based shallow defect remains unknown. In the present theoretical work, we use density functional theory to investigate properties of carbon as a dopant, and the effects of different intrinsic and extrinsic defects that are often present in cBN. Our analysis reveals the possible candidate carbon-based defects with ionizable, delocalized (shallow) impurity states.