Influence of Y(3+), Gd(3+), and Lu(3+) co-doping on the phase and luminescence properties of monoclinic Eu:LaVO4 particles.

Nano-sized particles of monoclinic-LaVO4 were prepared in a short reaction time of 30 minutes by employing a microwave assisted hydrothermal synthesis in the presence of glycerol, which was used both as a solvent and structure-directing agent. The tetragonal-LaVO4 is known to show strong luminescence properties when doped with Ln(3+), whereas the monoclinic-LaVO4 is usually considered not suitable for luminescence and therefore luminescence properties of monoclinic-LaVO4 doped with Ln(3+) ions are seldom investigated. Due to the scarce amount of research on the topic of luminescence of Ln(3+) doped monoclinic-LaVO4 in this paper a detailed study of solid state luminescence properties, including quantum yields, of nano-sized monoclinic-LaVO4 doped with different molar percentages of Eu(3+) is presented. It was observed that the 12.5%Eu(3+) doped sample showed the strongest luminescence properties. Additionally a study of the influence of different rare-earth ions (Y(3+), Gd(3+), Lu(3+)) co-doped into the particles was performed in order to explore the potential of increasing the luminescence of these materials. Furthermore stable colloidal suspensions of the Eu(3+) doped monoclinic-LaVO4 nanoparticles showing strong red emission could be obtained.