ACS Photon. https://doi.org/c6th (2019)

Nanodiamonds featuring a high concentration of silicon–vacancy centres can function as a fast, ultrasensitive all-optical thermometer. Sumin Choi and co-workers from Australia, France and Russia report how analysis of the near-infrared (~740 nm) photoluminescence emitted from the nanodiamonds can enable ultrafast, low-noise thermometry. With a size of just 250 nm or smaller the nanodiamonds can be used to detect a temperature change as small as 0.4 °C in a measurement that takes on the order of 0.001 s. The nanodiamonds are grown by a high-pressure, high-temperature technique and the photoluminescence measurements performed using a confocal microscope and a 532-nm green excitation laser and an electron-multiplying CCD camera. Potential applications include temperature mapping of solid-state electronics.