Morphology-sensitive photoluminescent properties of YVO4:Ln3+ (Ln3+ = Eu3+, Sm3+, Dy3+, Tm3+) hierarchitectures

Abstract

Novel three-dimensional YVO4:Ln3+ (Ln3+ = 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)2N(CH2)2N(CH2COO)24−)) 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 μm. 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 Eu3+ (5D0→7F2, 618 nm), Dy3+ (4F9/2 → 6H13/2, 575 nm), Sm3+ (4G5/2 → 6H7/2, 603 nm), Tm3+ (1G4→3H6, 478 nm), and morphology-sensitive photoluminescent properties.