Emission Enhancement and Color Tuning for GdVO4:Ln3+ (Ln = Dy, Eu) by Surface Modification at Single Wavelength Excitation

The surface modification can realize systematically the emission enhancement of GdVO4:Ln(3+) (Ln = Dy, Eu) microstructures and multicolor emission at single component. The structure, morphology, composition, and the surface ligands modification of as-prepared samples were studied in detail. It is found that the surface-modified ligands can act as sensitizer to improve the emission of the Eu3+ and Dy3+ ions via the energy transfer besides the VO43--Eu3+/Dy3+ process. More importantly, under a single wavelength excitation, the emission color can be effectively tuned by manipulating the doping ratio of the Eu3+ ions in the internal crystal lattice and the Tb3+ ions in the external surface ligands, simultaneously. And further, multicolor emissions are obtained under single wavelength excitation due to the high overlapping between the VO43- absorption and the pi-pi* electron transition of the ligands. These findings may open new avenues to design and develop new highly efficient luminescent materials.