Researchers led by John Morton have investigated the photophysical stability of near-surface nitrogen-vacancy (NV) centers in diamond under different environmental conditions, using Qnami Foundry products. Their study reveals that NV charge states behave differently in air and vacuum, with air exposure increasing NV⁻ contrast while vacuum conditions lead to significant degradation.
By analyzing surface chemistry with X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy, the team identified oxygen adsorption and desorption as key factors influencing NV stability. To address this, they demonstrated that a thin alumina (Al₂O₃) coating stabilizes the NV charge state, preventing degradation under illumination in both air and vacuum.
This work highlights alumina-coated diamond as a promising solution for enhancing NV sensor resilience, paving the way for more robust quantum sensing applications.
