A new synthesis approach for upconverting nanoparticles based on rare earth ternary vanadates
According to our knowledge, rare earth based upconverting ternary vanadates are synthesized by the hydrothermal method for the first time. This facile procedure offers an alternative approach to obtain nanomaterials with the desired crystal structure, while omitting calcination step as to prevent from particle size growth and their agglomeration. The systems discussed exhibit visible luminescence under 980 nm laser irradiation, as a result of Yb3+/Ln3+ ion pairs (Ln = Er, Ho, Tm) doping. Detailed structural analysis revealed small amounts of additional vanadate phases with no major host structure changes while dopants are introduced. The emission colour was dependent on both the selected concentrations of the dopant ions and the excitation source. The most noticeable colour tunability was observed for Yb3+/Ho3+ activated materials, ranging from yellow to orange. The presence of a strong 800 nm hypersensitive emission in Yb3+/Tm3+ doped material may be used in biological studies after cytotoxicity testing.