Abstract
A new Na(3)Y(VO(4))(2):Eu(3+) (NYVO:Eu(3+)) phosphor was prepared using the sol-gel method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to evaluate phase purity and particle size, respectively. The optical properties were investigated by UV-visible absorption, PL, and PLE spectroscopies. The absorption measurements show the formation of the vanadate host by the presence of its characteristic band in the visible region related to VO(4) (3-) groups. The experimental results show that the NYVO:Eu(3+) phosphors exhibit high-brightness and thermally stable emission. Under near-ultraviolet (UV) excitation, both the broadband emission from VO(4) (3-) groups and the sharp peak emissions from Eu(3+) ions are observed. The highest luminescence intensity was achieved for an optimal europium concentration of 15 mol%. The study of the chromaticity parameters of these compounds gives a thermally stable hot emission in the red domain, with a color purity of about 85%, which qualifies the NYVO:Eu(3+) compound as a potential phosphor for light-emitting diode (LED) applications. Thermal sensing using NYVO:Eu(3+) phosphors are based on monitoring the luminescence intensity ratio between the NYVO host emission and Eu(3+) luminescence lines. Notably, the optical thermometry of NYVO:Eu(3+) was characterized based on the fluorescence intensity ratio of VO(4) (3-) and Eu(3+) emissions in the 298-440 K range, with maximum absolute and relative sensitivities of 3.4% K(-1) and 0.0032 K(-1) respectively and a temperature uncertainty of 0.01. NYVO:Eu(3+) can then be considered as a potential red phosphor for application in ultraviolet-pumped white light-emitting diodes and as a potential optical thermometer. It provides new possibilities for the design of multifunctional materials for red light-emitting diodes and for non-contact thermometry.