Diamond p-i-n Diode with Nitrogen Containing Intrinsic Region for the Study of Nitrogen-Vacancy Center Electroluminescence

The results of a study of diamond p-i-n diode with a nitrogen-doped intrinsic region on a substrate with the (001) orientation are presented. When the forward voltage is applied to the diode, a high current density of about 10(3) A cm(-2)is obtained. Two narrow lines are detected in the electroluminescence spectrum of the p-i-n diode: one at a wavelength of 575 nm corresponding to the emission of the NV center (nitrogen-vacancy color center) in a neutral charge state, and the second narrow line, which previously has not been observed in the electroluminescence spectra, at a wavelength of 533 nm. The line widths at room temperature are about 7 and 3 nm, respectively. By comparing the emission intensities of NV centers using the same optical registration system for electroluminescence and photoluminescence, the emission rate of NV centers during electroluminescence is estimated to be about 10(6)photon s(-1), which allows to consider a diode of such design as a possible candidate to create single-photon sources.