Facile synthesis of rare earth-doped CeF3 two-dimensional nanosheets and their application in ratiometric luminescence temperature sensing

Discovery of new morphological and structural materials is significant but remains challenging. In this work, rare earth-doped CeF3 two-dimensional (2D) nanosheets were successfully synthesized using a facile and effective solvothermal method. By changing the amount of water in the solvent and the doping amount of rare earth ions, the morphology of CeF3 is significantly affected, but the hexagonal phase structure is always maintained. Under excitation at 254 nm, CeF3:20% Gd, 30% Tb 2D nanosheets emit bright green light, but the luminescence color changes to red when some of the Tb3+ ions are replaced by Eu3+ ions due to the efficient energy transfer from Tb3+ to Eu3+ ions. Moreover, the temperature-dependent luminescence properties of CeF3:20% Gd, 25% Tb, 5% Eu prove that it can be used as a ratiometric luminescent thermometer with an absolute sensitivity of 1.54% K-1 and a maximum relative sensitivity of 4.56% K-1 at 373 K. This study enriches the treasure trove of new materials and paves the way for future applications of CeF3-based luminescent materials in the field of temperature sensing.