Luminescence of nitrogen-vacancy centers in nanodiamonds at temperatures between 300 and 700 K: perspectives on nanothermometry.

It is shown that the intensity of photoluminescence of nitrogen-vacancy (NV) centers in nanodiamond decreases 4-fold (with a wide spread among nanocrystals) when the surrounding temperature rises from 300 to 670 K. The effect is accompanied by a 2.7-fold decrease in the luminescence lifetime but negligible changes in the shape of the emission spectra. The heating-cooling circle is reversible. The effect is suggested to be practically useful for thermometry with nanometre spatial resolution but also stimulates deeper insight into the photophysics and photochemistry of NV-centers.