Photo induced ionization dynamics of the nitrogen vacancy defect in diamond investigated by single shot charge state detection

TL;DR

This study investigates the ionization dynamics of single nitrogen-vacancy centers in diamond under various illumination conditions, revealing charge state populations, absorption properties, and energy levels to deepen understanding of their photophysics.

Contribution

It introduces a direct measurement method for the charge state evolution of single NV centers and provides detailed data on their ionization behavior at room temperature.

Findings

Steady state NV- population is always below 75% for 450-610 nm excitation.

Absorption cross-section of NV- varies with wavelength from 540 to 610 nm.

NV- ground state energy is approximately 2.6 eV below the conduction band.

Abstract

The nitrogen-vacancy centre (NV) has drawn much attention for over a decade, yet detailed knowledge of the photophysics needs to be established. Under typical conditions, the NV can have two stable charge states, negative (NV-) or neutral (NV0), with photo induced interconversion of these two states. Here, we present detailed studies of the ionization dynamics of single NV centres in bulk diamond at room temperature during illumination in dependence of the excitation wavelength and power. We apply a recent method which allows us to directly measure the charge state of a single NV centre, and observe its temporal evolution. Results of this work are the steady state NV- population, which was found to be always < 75% for 450 to 610 nm excitation wavelength, the relative absorption cross-section of NV- for 540 to 610 nm, and the energy of the NV- ground state of 2.6 eV below the conduction band. These results will help to further understand the photo-physics of the NV centre.