Ba2YV3O11 Er3+/Yb3+ Nanostructures for Temperature Sensing in the Presence of Bismuth Ions

Chemical compounds with high upconversion (UC) intensity are still needed for temperature-sensing media based on the fluorescence intensity ratio (FIR) technique of UC materials. In this work, the citrate-based sol–gel method was used to produce Yb3+/Er3+–Bi3+ codoped Ba2YV3O11 (BYVO) nanophosphors. Using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, we examined the influence of Bi3+ ions on the phase structure and morphology of BYVO was examined. Power-dependent photoluminescence (PL) spectroscopy shows how Er3+ and Yb3+ transfer energy, and the involved UC mechanism is part of the two-photon stimulation process. Moreover, the improved optical properties of BYVO phosphors were due to the local environment of Er3+ ions that was modified by the addition of Bi3+ ions. The emission intensity of these bands is enhanced in the presence of Bi3+ ions. The FIR method based on Er3+ thermal coupling level was used to investigate the temperature-sensing performance. The relative sensitivity of the tridoped nanophosphor has been determined to be 1.45% K–1 at 250 K. The incorporation of Bi3+ could improve the temperature resolution obtained when it is used as a thermometric sensor. The results obtained from the present study indicate that the Er3+–Yb3+–Bi3+ tridoped BYVO nanophosphors may be of particular interest in developing near-infrared to visible upconverters, green display devices, and optical nanothermometry.