Color-tunable luminescence for Bi3+/Ln(3+): YVO4 (Ln = Eu, Sm, Dy, Ho) nanophosphors excitable by near-ultraviolet light

Bi3+/Ln(3+): YVO4 nanocrystals with a mean size of 6 nm are prepared through a mixed solvothermal route. With Bi3+ doping, the excitation band corresponding to the Ln(3+) emission is shifted from 280 nm to 345 nm, owing to the occurrence of Bi3+ -> V5+ metal-metal charge transfer and the subsequent energy transfer to Ln(3+) ions. Under near-ultraviolet excitation, the emission color of Bi3+/Ln(3+): YVO4 nanophosphors can be easily tuned by changing the Ln(3+) ions.