Fluorine-terminated diamond (110) surfaces for nitrogen-vacancy quantum sensors

Diamond (110) surface is one of the low-index diamond faces but its effects on nitrogen-vacancy (NV) based quantum sensor remain unclear. The fluorine, hydrogen, nitrogen, and oxygen-terminated diamond (110) surfaces used for the NV centers are proposed here, and their electronic properties are investigated based on first-principles calculations. The oxygen-terminated diamond (110) surface has inter-bandgap states and surface electron spins, the nitrogen-terminated (110) surface has inter-band gap states, and the hydrogen-terminated (110) surface has negative electron affinity. Thus, these three surfaces may not be suitable for shallow NV centers. The fluorine-terminated diamond (110) surface has positive electron affinity, no surface related inter bandgap states, and no surface electron spins, so it is a promising candidate for NV-based quantum sensors. [Display omitted]