Eu 3+ Single-Doped Phosphor with Antithermal Quenching Behavior and Multicolor-Tunable Properties for Luminescence Thermometry.

To date, non-contact luminescence thermometry methods based on fluorescence intensity ratio (FIR) technology have been studied extensively. However, designing phosphors with high relative sensitivity () has become a research hotspot. In this work, Eu single-doped CaSbO:Eu phosphors with a high value for dual-emitting-center luminescence thermometry are developed and proposed. The anti-thermal quenching behavior of Eu originating from the energy transfer (ET) of host → Eu is found and proved in the designed phosphors. Interestingly, adjustable color emission from blue to orange can be achieved. Surprisingly, the degree of the anti-thermal quenching behavior of Eu gradually reduces from 240 to 127% as the Eu doping content increases from 0.005 to 0.05 mol, attributed to most Eu being located in the low symmetrical [Ca1O] dodecahedral site. According to the differentiable responses of the host and Eu to temperature, the maximal value reaches 3.369% K (383 K). Moreover, the ambient temperature can be intuitively predicted by observing the emitting color. Owing to the excellent performance in optical thermometry, color-tunable properties, and outstanding acid and alkali resistance for polydimethylsiloxane (PDMS) films, the developed Eu single-doped CaSbO:Eu phosphors are expected to be prospective candidates in luminescence thermometers and LED devices in various conditions.