Mechanisms of the Temperature Dependence of Luminescence Characteristics of CeF3–YF3 Nanoparticles Activated by Ion Pairs Tb3+/Eu3+

Ce0.50Y0.44–xTb0.06EuxF3 nanoparticles (x = 0, 0.015, 0.03, 0.06) of single-phase hexagonal structure (CeF3 matrix) are synthesized via co-precipitation. The average particle size is found to be 14.5 nm. Characteristic emission bands are observed upon excitation at 266 nm: Ce3+ (5d → 4f transition), Tb3+ (5D4 → 7FJ, 480–620 nm), and Eu3+ (5D0 → 7FJ, 570–700 nm). The temperature dependence of integral intensities and their ratios (Ce3+/Tb3+, Ce3+/Eu3+, Tb3+/Eu3+) are studied in the 80–320 K range of temperatures. The highest sensitivity toward temperature is obtained for ratio Ce3+/Eu3+ at Eu3+ concentration x = 0.03. Kinetic studies of Tb3+ luminescence confirm temperature-induced quenching due to enhanced phonon-assisted transfer of energy to Eu3+.