Chemical control of the charge state of nitrogen-vacancy centers in diamond

Abstract

We investigate the effect of surface termination on the charge state of\nnitrogen vacancy centers, which have been ion-implanted few nanometers below\nthe surface of diamond. We find that, when changing the surface termination\nfrom oxygen to hydrogen, previously stable NV- centers convert into NV0 and,\nsubsequently, into an unknown non-fluorescent state. This effect is found to\ndepend strongly on the implantation dose. Simulations of the electronic band\nstructure confirm the dissappearance of NV- in the vicinity of the\nhydrogen-terminated surface. The band bending, which induces a p-type surface\nconductive layer leads to a depletion of electrons in the nitrogen vacancies\nclose to the surface. Therefore, hydrogen surface termination provides a\nchemical way for the control of the charge state of nitrogen-vacancy centers in\ndiamond. Furthermore, it opens the way to an electrostatic control of the\ncharge state with the use of an external gate electrode.\n