Liquid-Phase Synthesis of Doped Nanoparticles:  Colloids of Luminescing LaPO₄:Eu and CePO₄:Tb Particles with a Narrow Particle Size Distribution

Abstract

Nanocrystals of LaPO 4:Eu and CePO 4:Tb with a mean particle size of 5 nm and a narrow size distribution have been prepared by reacting the corresponding metal chlorides, phosphoric acid, and a base at 200 °C in tris(ethylhexyl) phosphate. Highly crystalline material was obtained as confirmed by X-ray powder diffraction measurements and high-resolution transmission electron microscopy. Successful doping with europium was evident from the splitting and the intensity pattern of the luminescence lines. Luminescence lifetime measurements were used to confirm doping and energy transfer in both materials. Colloidal solutions of CePO 4:Tb exhibit an overall luminescence quantum yield of 16%.