Nondecaying long range effect of surface decoration on the charge state of NV center in diamond.

On the basis of density functional theory, stability and electronic structure of nitrogen-vacancy (NV) centers in surface modified diamond have been studied. Surface decoration is traditionally expected to only have influence on those NV centers close to the surface. However, our calculations indicate that its effect to charged NV centers is nondecaying and long-range, where the formation energy of the charged NV center converges to a value typically different for different types of surface decoration. Such a nondecaying long range effect is due to the electrostatic potential shift induced by the surface dipole layer, and it leads to the preference of NV(-) center for oxygen saturated diamond and NV(0) for hydrogenated one. Our work demonstrates that surface functionalization can be used to modify the relative stabilities of differently charged defects in nonmetallic materials.