Localized chemical switching of the charge state of nitrogen-vacancy   luminescence centers in diamond
  We present a beam-directed chemical technique for controlling the charge states of near-surface luminescence centers in semiconductors. Specifically, we fluorinate the surface of H-terminated diamond by electron beam irradiation in the presence of NF3 vapor. The fluorination treatment acts as a local chemical switch that alters the charge state of nitrogen-vacancy luminescence centers from the neutral to the negative state. The electron beam fluorination process is highly localized and can be used to control the emission spectrum of individual nanodiamonds and surface regions scanned by the electron beam 
Toby W. Shanley, Aiden A. Martin, Igor Aharonovich, and Milos Toth
cond-mat.mtrl-sci physics.optics