Synthesis and study of upconversion Lu2(WO4)3: Yb3+, Tm3+ nanoparticles synthesized by modified Pechini method

Abstract

We report on Lu 2 (WO 4 ) 3 : Yb 3+ , Tm 3+ upconversion nanoparticles prepared via modified Pechini method, which is low-cost in comparison with analogs and allows achieving the homogenous rare earth ions (Yb 3+ and Tm 3+ ) dispersion in the host matrix. The Tm 3+ doping concentration effect on structural and luminescence properties has been studied in detail. The structure of the nanoparticles was characterized by XRD and Raman spectroscopy. Both analytical methods confirmed the formation of single phase Lu 2 (WO 4 ) 3 : Yb 3+ , Tm 3+ nanoparticles without any impurities. It was found that thulium ions are uniformly incorporated into the tungstate structure up to a concentration of 1%. SEM images showed that prepared samples consisted of weakly agglomerated nanoparticles with an average size of about 40–80 nm. Emission and excitation spectra of all Lu 2 (WO 4 ) 3 : xTm 3+ , 10% Yb 3+ samples contained characteristic transitions inside Tm 3+ ions. Upconversion spectra demonstrated intense infrared line ( 3 H 4 – 3 H 6 ) as well as weak blue 1 G 4 – 3 H 6 and two red ( 1 G 4 – 3 F 4 , 3 F 2,3 – 3 F 6 ) bands obtained upon 974 nm excitation. Optimal Tm 3+ doping concentration was found to be 0.3% for both 3 H 4 – 3 H 6 and 1 G 4 – 3 F 4 transitions. Change of chromaticity coordinates along with Tm 3+ amount increase was also observed. • Lu 2 (WO 4 ) 3 : Yb 3+ , Tm 3+ upconversion nanoparticles were synthesized by simple and economic modified Pechini method. • Influence of Tm 3+ doping concentration on structural and luminescent properties of Lu 2 (WO 4 ) 3 : Yb 3+ , Tm 3+ is discussed. • Results suggest the optical material based on Lu 2 (WO 4 ) 3 : Yb 3+ , Tm 3+ is promising for use in biomedical applications.