Photon upconversion-based non-invasive temperature sensing using Gd1−x-yYbxEr yScO3 perovskite nanocrystals

Abstract

High thermal stability, high bandgap, and low phonon energy (452 cm−1) of GdScO3 perovskite make it ideal for optical applications, particularly for infrared (IR)-to-visible photon upconversion (UC) emission. This phase has been typically synthesized either in single crystal or in thin film forms which require high temperatures and a longer time. Thin films/single crystals of GdScO3 have limited optical application mostly as lasing material. Unexpectedly, the photon UC-based emission and correlated applications are completely ignored in this host so far. Herein, we have successfully synthesized pristine and Yb3+, Er3+ co-doped GdScO3 nanocrystals (powder) at low temperatures and further analyzed their crystal structure, phase, and optical absorption and emission properties at length. The photon-UC property in GdScO3 nanocrystal has been studied for the first time. Further, the material has been used for the non-contact luminescence-based temperature sensor application also. Our study shows that the maximum relative sensitivity (Sr) and absolute sensitivity (Sa) obtained for Yb3+, Er3+: GdScO3 nanocrystal is better than most of the reported oxide-based perovskite materials.