Fig. 4: Properties of the VNNB defect.

a Atomic structure in top and side views, with N atoms shown as blue and B atoms as green spheres. Also shown in the side view is the N atom out-of-plane displacement z. b GW electronic band structure computed using a 5 × 5 supercell. The wave function of the two majority-spin bands that mainly contribute to the lowest-energy exciton are plotted on the right. c Absorption spectrum and (d) radiative lifetime as a function of the out-of-plane displacement z of the central N atom.