Ba<sub>2</sub>YV<sub>3</sub>O<sub>11</sub> Er<sup>3+</sup>/Yb<sup>3+</sup> Nanostructures for Temperature Sensing in the Presence of Bismuth Ions
Kamel Saidi, Ikhlas Kachou, Kevin Soler‐Carracedo, Mohamed Dammak, Inocencio R. Martín
Abstract
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 Yb 3+ /Er 3+ –Bi 3+ codoped Ba 2 YV 3 O 11 (BYVO) nanophosphors. Using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, we examined the influence of Bi 3+ ions on the phase structure and morphology of BYVO was examined. Power-dependent photoluminescence (PL) spectroscopy shows how Er 3+ and Yb 3+ 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 Er 3+ ions that was modified by the addition of Bi 3+ ions. The emission intensity of these bands is enhanced in the presence of Bi 3+ ions. The FIR method based on Er 3+ 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 Bi 3+ could improve the temperature resolution obtained when it is used as a thermometric sensor. The results obtained from the present study indicate that the Er 3+ –Yb 3+ –Bi 3+ tridoped BYVO nanophosphors may be of particular interest in developing near-infrared to visible upconverters, green display devices, and optical nanothermometry.