Fabrication and photoluminescence properties of color-tunable light emitting lanthanide doped GdVO4 hierarchitectures

The flower-like GdVO4:Ln3+( Ln3+=Eu3+, Dy3+, Sm3+, Tm3+) hierarchitectures have been successfully synthesized on a glass slide substrate through a one-pot hydrothermal route assisted by disodium ethylenediaminetetraacetic acid (Na2H2L, where L4-=(CH2COO)2N(CH2)2N(CH2COO)24-). A high density and ordered flower-like GdVO4:Ln3+ hierarchitectures grew epitaxially on glass substrate. The as-prepared flower-like architectures with the size about 6 μm are constructed by the numerous radially oriented single-crystalline nanorods with the width from 20 nm to 200 nm and the length from 500 nm to 3 μm. The morphologies, the thickness, and the density of as-grown flower clusters can be readily tuned by tailoring the growth time and Na2H2L/Gd3+ molar ratio. The possible formation mechanism of flower-like GdVO4:Ln3+ hierarchitectures is discussed on the basis of the results from the controlled experiments under hydrothermal conditions. Because of an energy transfer from vanadate groups to dopants, the flower-like GdVO4:Ln3+( Ln3+=Eu3+, Dy3+, Sm3+ and Tm3+) superstructures showed strong characteristic dominant emissions of the Eu3+, Dy3+, Sm3+ and Tm3+ ions at 617 nm (5D0→7F2, strong red), 575 nm (4F9/2→6H13/2, yellow), 604 nm (4G5/2→6H7/2, orange-red) and 476 nm (1G4-3H6, blue) under ultraviolet excitation, respectively.Further, the emission color of the product can also be tuned by selecting the dopant Ln3+ with characteristic emissions and varying the concentration ratio of co-doping activators. This approach could be extended to the fabrication of hierarchical structures for other oxide micro/nanomaterials, and may provide a general way to achieve multicolor-tunable emission for many applications.