The Optimization of the Luminescence Intensity Ratio in the YVO4:Er3+,Nd3+ Phosphors within the First and Second Biological Windows
来源：ACS Publications
The optimization of the host materials is one of the methods that could be used to improve the relative sensitivity of luminescent thermometers. Here, we show the host optimization emission of Er3+ and Nd3+ ions in the YVO4 phosphors produced by a modified sol–gel route using glucose as a polymerizing agent. X-ray diffraction (XRD) was realized to analyze the formation of the crystalline phase. We found that the emission ratio depends on the size of the YVO4 particle. Here, we show that YVO4:Er3+,Nd3+ phosphors exhibit particle size-dependent relative sensitivity values, varying from 1.32 ± 0.02 to 1.80 ± 0.02% K–1 at 293 K, and temperature uncertainties below 0.7 K within the physiological range 293–233 K, operating entirely in the first and second biological windows. These sensitivity and temperature uncertainty values were achieved by defining two thermometric parameters as the luminescence intensity ratios, exploiting a combination of emissions from both ion species.