Impact of nitridation on the up-conversion luminescence property of Yb3Al5O12: Er3+ phosphors upon 980 nm excitation

In this work, the nitriding method was used to improve the up-conversion (UC) luminescence intensity and temperature sensing sensitivity of phosphor materials. Yb 3 Al 5 O 12 : Er 3+ and partially nitrided Yb 3 Al 5 O 12-1.50 x N x : Er 3+ phosphors by using AlN as nitrogen source were prepared via solid-state reaction method. The influence of nitridation on the UC luminescence and temperature sensing properties of Yb 3 Al 5 O 12 : Er 3+ phosphors upon 980 nm excitation were discussed. Almost pure red UC emission was obtained, and the intensity of the red UC emission of the samples was enhanced by 25 % after nitridation. Meanwhile, the absolute temperature sensitivity respectively derived from the intensity ratios of the green and red emissions increased by 5 % and 50 % after nitridation. Judd-Ofelt theory was utilized to analyze the change of the crystal field environment around Er 3+ and confirmed that the introduction of N 3– reduced the symmetry around Er 3+ and strengthened the covalence between Er 3+ and ligands, which may result in the enhancement of UC emission intensity and temperature sensing sensitivity. The experiment proved that Yb 3 Al 5 O 12 : Er 3+ red UC phosphors had potential application in luminescence imaging and temperature sensors.