Luminescence\nThermometry of Pr<sup>3+</sup>-Doped\nSr<sub>3</sub>Y<sub>2</sub>Ge<sub>3</sub>O<sub>12</sub> and Sr<sub>3</sub>Sc<sub>2</sub>Ge<sub>3</sub>

Luminescence thermometry is a highly promising technique\nfor remotely\nmeasuring temperature. Nowadays, this method is unrivaled, considering\nits methodology and high potential for application. However, expanding\nthe operating range of luminescent thermometers is still a challenge.\nWe have successfully demonstrated that by introducing just one dopant,\nPr<sup>3+</sup>, to garnet hosts, we can create a luminescence thermometer\nthat operates in an impressive range of 13–1025 K. Our paper\nalso presents a thorough analysis of the Pr<sup>3+</sup> location\nin Sr<sub>3</sub>Y<sub>2</sub>Ge<sub>3</sub>O<sub>12</sub> and Sr<sub>3</sub>Sc<sub>2</sub>Ge<sub>3</sub>O<sub>12</sub> garnet hosts, revealing\nthree Pr sites in the former and two in the latter, which has not\nbeen previously reported in these phosphors. By using 5d →\n4f luminescence below room temperature, we obtained relative thermal\nsensitivities reaching ∼6%/K. By using the luminescence intensity\nratio of the 4f → 4f transitions, we achieved an operating\nrange of 13–1025 K with relative thermal sensitivity ranging\nfrom 0.1 to 0.8%/K. Finally, the small and uniform size of the particles,\nabout 150 nm in diameter, is attractive for high spatial resolution\napplications.