Effects of low energy electron irradiation on formation of nitrogen-vacancy centers in single-crystal diamond

TL;DR

This study investigates how low energy electron irradiation can induce nitrogen-vacancy (NV) centers in diamond, revealing a non-thermal formation mechanism that enhances NV creation when combined with thermal annealing, enabling spatial control at room temperature.

Contribution

It demonstrates that low energy electron beams can induce NV centers in diamond without heat, and that subsequent thermal annealing further increases NV formation efficiency, revealing a new formation pathway.

Findings

Electron irradiation induces NV centers without thermal annealing.

Thermal annealing after irradiation increases NV formation by up to 80%.

Electron-induced NV formation is less efficient than thermal annealing alone.

Abstract

Exposure to beams of low energy electrons (2 to 30 keV) in a scanning electron microscope locally induces formation of NV-centers without thermal annealing in diamonds that have been implanted with nitrogen ions. We find that non-thermal, electron beam induced NV-formation is about four times less efficient than thermal annealing. But NV-center formation in a consecutive thermal annealing step (800C) following exposure to low energy electrons increases by a factor of up to 1.8 compared to thermal annealing alone. These observations point to reconstruction of nitrogen-vacancy complexes induced by electronic excitations from low energy electrons as an NV-center formation mechanism and identify local electronic excitations as a means for spatially controlled room-temperature NV-center formation.