Morphology-controllable synthesis and photoluminescence properties of t-LaVO4:Ln3+ nanostructures on glass substrates

Tetragonal t-LaVO4:Ln3+ (Ln3+ = Eu3+, Dy3+, Sm3+) microrod array and 3D hierarchical nanostructures with sheaf-like, flower-like, cauliflower-like, and spherical morphologies have been successfully synthesized on glass substrate through a simple hydrothermal process assisted by ethylenediaminetetraacetic acid disodium salt (Na2H2L). The morphologies of the products varied dramatically when Na2H2L/La3+ molar ratio and reaction time were changed in system. A possible crystal growth mechanism is proposed for the self-assembly of nanorods into the observed microstructures based on detailed experiments. Due to an efficient energy transfer from VO4 3− to the Ln3+ dopants, the self-assembled t-LaVO4:Ln3+ (Ln3+ = Eu3+, Dy3+, Sm3+) superstructures showed strong characteristic dominant emissions of the Eu3+, Dy3+, Sm3+ ions at 616 nm (5D0 → 7F2, strong red), 573 nm (4F9/2 → 6H13/2, yellow), 603 nm (4G5/2 → 6H7/2, orange-red) under ultraviolet excitation, respectively. This work not only gives insight into understanding the hierarchical growth behaviour of t-LaVO4:Ln3+ nanoarchitectures in a solution-phase system, but also provides a potential route to building other superstructures assembled from one-dimensional nanoparticles.