Synthesis and luminescence properties of Er3+ doped and Er3+–Yb3+ codoped phosphovanadate YP0.5V0.5O4 phosphors

A series of Orthovanadate phosphate pure YP0.5V0.5O4, YP0.5V0.5O4 doped Er3+ and codoped Er3+/Yb3+ have been synthesized using a solid-state reaction. The samples were investigated by X-ray diffraction (XRD), infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM) for detailed structural and morphological characterizations. The photoluminescence (PL) spectra were studied as a function of Er3+ concentration. The optimal Er3+ doping concentration in YP0.5V0.5O4 host was determined to be 2 mol%. The extinction phenomenon was correlated to the dipole - dipole (D - D) interactions. In the Er/Yb codoped YP0.5V0.5O4, the Er3+ green-red emission was intensified via the two-photon absorption process. Furthermore, the fluorescence intensity ratio (FIR) method was used to evaluate the optical temperature sensing parameters of the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 thermally coupled levels (TCL) over the 100–440 K range. The maximum values of Sa absolute and Sr relative sensitivity thermometric parameters were calculated to be 4.10−3 K−1 and 6.58%·K−1 respectively. The effects of the host composition by the presence of the phosphate (PO43−) and the vanadate (VO43−) entities were investigated on the Er3+ emissions and on the Er3+/Yb3+ optical thermometric parameters. YP0.5V0.5O4: Er3+, Er3+/Yb3+ prepared phosphors could be used for display and temperature sensing applications and to optimize the host effects on the luminescence and thermometric properties.