Theoretical investigation of charge transfer between the NV – center in diamond and substitutional N and P
The nitrogen-vacancy (NV) lattice defect in diamond, consisting of an N substitutional atom and an adjacent C vacancy, is commonly observed in two charge states, negative (NV – ) and neutral (NV 0 ). The NV – defect exhibits spin state-dependent fluorescence and is, therefore, amenable to optical methods for spin-state readout, while the NV 0 is not. Hence, the NV – defect is much more useful for quantum sensing and quantum information processing. However, only NV 0 electroluminescence has been observed, even from centers showing NV – in photoluminescence. In the present work, we use first-principles electronic structure calculations to determine adiabatic charge transition levels for the conversion of NV – to NV 0 in the presence of substitutional N or P impurities, which provide the charge of the NV center. Here, we find that the adiabatic charge transition levels in the presence of such impurities lie at energies close to or lower than the zero-phonon line of the NV – center and that these energies only decrease as the concentration of N donors increases. This work, therefore, elucidates the absence of observed electroluminescence from the NV – and proposes a path toward observation of the phenomenon.