Controllable crystal form transformation and temperature sensing properties studies of K₃Sc_0.5Lu_0.5F₆: Ho³⁺, Yb³⁺ with cryolite structure

Abstract

In this work, a method for controllable regulation of crystal form was proposed for the first time and the effects of different crystal forms on the up-conversion luminescence properties of Ho 3+ , Yb 3+ co-doped K 3 Sc 0.5 Lu 0.5 F 6 (KSLF) phosphors was explored. KSLF:Ho 3+ , Yb 3+ phosphors were synthesized by the high temperature solid-state reaction method, and X-ray diffraction (XRD) results illustrate that the compounds can obtain monoclinic phase and cubic phase at different synthesis temperatures. In addition, according to the powerdependent up-conversion luminescence (UCL) intensity, the UCL mechanism and the electronic transition process are discussed. Simultaneously, the temperature sensing behavior of the best samples with different crystal forms at different temperatures was studied by fluorescence intensity ratio technique. All the results show that KSLF:Ho 3+ , Yb 3+ phosphors show great application potential in the field of temperature sensing, and the preparation of KSLF:Ho 3+ , Yb 3+ in different crystal forms can provide a reference value for crystal design and growth.

Upconversion Luminescence Properties and Temperature Sensing Characteristics of Tm3+, Yb3+-codoped SrAl2Si2O8 Phosphors with High Thermometric Sensitivities

“…The temperature sensing properties of Nd 3+ , Tm 3+ /Yb 3+ , 24 Pr 3+ , Er 3+ /Yb 3+ , 25 Tm 3+ /Yb 3+ , 26 Ho 3+ /Yb 3+ , 27 Tb 3+ /Eu 3+ , 28 Tm 3+ /Er 3+ /Yb 3+ , 29 Tm 3+ /Ho 3+ /Yb 3+ , 30 Er 3+ /Ho 3+ /Yb 3+31 and many other rare-Earth particle-doped phosphors have been studied. However, most rare-Earth ions (e.g., Tm 3+ , Er 3+ , Nd 3+ , and Ho 3+ ) have poor and narrow absorption cross sections in the near-infrared (NIR) region, which leads to insufficient UCL efficiency and limited practical application.…”