The nitrogen-vacancy (NV) center is a photoluminescent defect in diamond that exists in different charge states, NV− and NV0, that are sensitive to the NV's nanoscale environment. Here, we show that photoluminescence (PL) from NV centers in fluorescent nanodiamonds (FNDs) can be employed for all-optical voltage sensing based on electric field-induced NV charge state modulation. More than 95% of FNDs integrated into a capacitor device show a transient increase in NV− PL intensity of up to 31% within 0.1 ms after application of an external voltage, accompanied by a simultaneous decrease in NV0 PL. The change in NV− PL increases with increasing applied voltage from 0 to 100 V, corresponding to an electric field of 0 to 625 kV cm−1 in our devices. The electric field sensitivity of a single FND is 19 V cm−1 Hz−1/2. We investigate the NV charge state photodynamics on the millisecond timescale and find that the change in NV PL strongly depends on the rate of photoexcitation. We propose a model that qualitatively explains the observed changes in NV PL based on an electric field-induced redistribution of photoexcited electrons from substitutional nitrogen defects to NV centers, leading to a transient conversion of NV0 to NV− centers upon application of an external voltage. Our results contribute to the development of FNDs as reliable, all-optical, nanoscale electric field sensors in solid-state systems.
@article{arxiv.2505.07350,
title = {All-optical electric field sensing with nanodiamond-doped polymer thin films},
author = {Roy Styles and Mengke Han and Toon Goris and James Partridge and Brett C. Johnson and Blanca del Rosal and Amanda N. Abraham and Heike Ebendorff-Heidepriem and Brant C. Gibson and Nikolai Dontschuk and Jean-Philippe Tetienne and Philipp Reineck},
journal= {arXiv preprint arXiv:2505.07350},
year = {2025}
}