Luminescence and structural properties of self-assembled Y(V,P)O ₄:Eu³⁺@amorphous-K-VO₃ core/shell nanophosphors

A Liquid-Phase Precursor method followed by a 5% KOH solution treatment was employed for the facile synthesis of Y(V,P)O₄:Eu ³⁺@amorphous-K-VO₃ core/shell nanophosphors with non-stoichiometric composition Y_x(V_0.44P _0.56)O₄:Eu_0.1 (x = 0.855, 0.875, 0.90 and 0.965). It was observed that this non-stoichiometric composition approach leads to the control of the size, shape and unit cell parameters depending upon the Y concentration. The shell layer of 2-7nm formed by alkaline solution treatment at room-temperature was observed by Transmission Electron Microscope (TEM). The particle size grew up by 20-50nm and the luminescence properties were enhanced by 9-31% after the KOH solution treatment. In contrast, the micro-sized Y(V,P)O₄:Eu³⁺ phosphors treated by the KOH solution did not show any change in their luminescence properties. This KOH solution treatment opens new possibilities to facilely synthesize Y(V,P)O ₄:Eu³⁺@amorphous-K-VO₃ core/shell nanophosphors with highly stable properties and improved luminescence.