Morphology-Sensitive Photoluminescent Properties Of Yvo4:Ln(3+) (Ln(3+)= Eu3+, Sm3+, Dy3+, Tm3+) Hierarchitectures

Novel three-dimensional YVO4:Ln(3+)(Ln(3+)= Eu3+, Sm3+, Dy3+, Tm3+) hierarchitectures were successfully fabricated on glass substrate by a simple, hydrothermal process by using disodium ethylenediaminetetraacetic acid (Na2H2L, where L4- = (CH2COO)(2)N(CH2)(2)N(CH2COO)(2)(4-))) as a capping agent. The shape and size of product can be tailored by controlling the reaction time and the Na2H2L/Y3+ molar ratio. As a typical morphology, YVO4:Eu3+ shows a flower-like hiearchitecture, which is composed of a primary microrod trunk and a large number of secondary nanonails. The trunk is a rectangle prism with a length of 2 mu m. The nanonail branch has a length of 400 nm and a diameter of 80 nm, and its cap has a diameter of 100 nm with a thickness of 20 nm. A possible formation mechanism of this flower-like hierarchical structure was proposed, and it is investigated in detail through time evolution experiments. Under UV radiation, the thin film samples were shown the emission characteristic of Fu(3+) (D-5(0) -> E-7(2), 618 nm), Dy3+ (F-4(9/2 )-> H-6(13/2), 575 nm), Sm3+ ((4)G(5/2) -> H-6(7/2), 603 nm), Tm3+ ((1)G(4) -> H- 3(6), 478 nm), and morphology-sensitive photoluminescent properties.