Luminescence and temperature sensing properties of Y2-x-yTmxSmyMgTiO6 phosphors

Abstract

Double perovskite materials have become the first choice of luminescent matrix materials in recent years due to their advantages of more flexible, easy doping and stable performance. A series of Y2-x-yTmxSmyMgTiO6 (0 ≤ x ≤ 0.5, 0 ≤ y ≤ 0.2) phosphors were prepared by high temperature solid-state method using different concentrations of Tm3+ and Sm3+ as dopants. The X-ray diffraction spectrum (XRD), photoluminescence spectrum (PL), fluorescence lifetime curve and X-ray excitation luminescence spectrum (XEL) of the phosphors were measured. The measurement results show that the dopants Tm3+ and Sm3+ enter the host lattice and replace part of the position of Y3+. The Tm3+ -doped sample emits strong blue light (458 nm) under 360 nm excitation, and the Sm3+ -doped sample has obvious emission peaks at 568 nm, 605 nm, 652 nm and 715 nm under 409 nm excitation. The energy transfer behavior of Tm3+→Sm3+ exists in the double doped samples. The energy transfer mechanism is consistent with the mechanism of concentration quenching in the system. Tunable luminescence can be realized by changing the doping concentration and excitation wavelength, which has great application value in the field of LED lighting. The energy transfer process and energy transfer efficiency in the system can be determined from the fluorescence lifetime curve of the sample. The phosphor can be effectively excited by X-ray, and the sample has good heat resistance and radiation resistance, which can be applied to the field of X-ray imaging. In addition, the thermal excitation effects of temperature on the 4G5/2 → 6H5/2 (568 nm) and 4G5/2 → 6H7/2 (605 nm) characteristic transitions of Sm3+ are different. Optical temperature measurement can be realized by using the fluorescence intensity ratio of I568 nm/I605 nm. Good temperature measurement performance and temperature measurement range have obvious advantages in the field of non-contact optical temperature measurement.