High-Resolution Thermal Sensing Using Temperature-Sensitive Cathodoluminescence Spectroscopy in Nitrogen-Doped Nanodiamonds

The evolution of the cathodoluminescence spectra from commercially available nanodiamonds with high density of nitrogen-vacancy defects has been studied in a large wavelength range, from 200 to 800 nm, and temperatures from 5 to 300 K, in order to achieve a temperature probe with high spatial resolution. The full width at half maximum of the peak associated to the neutral charge state of the NV center has been found to evolve with temperature in a predictable way, although its value may vary from sample to sample. We have attributed this shift to the differences in the nanodiamonds surface chemistry.