Facile hydrothermal synthesis of Tb2(MoO4)3:Eu3+ phosphors: controllable microstructures, tunable emission colors, and the energy transfer mechanism

Abstract

Microsphere-like Tb₂(MoO₄)₃ structures have been successfully synthesized by a facile hydrothermal method with the subsequent calcination treatment. The shape and size of the microstructure of Tb₂(MoO₄)₃ precursors can be tuned effectively by altering the amount of citric acid, and the possible formation mechanisms of various microstructures are also put forward, showing that citric acid plays a key role in controlling the morphologies of the precursors. By doping Eu³⁺, Tb₂(MoO₄)₃:Eu³⁺ phosphors exhibit excellent luminescence properties with tunable emission colors (green → yellow → red) resulting from the effective energy transfer from Tb³⁺ to Eu³⁺. Particularly, the energy transfer mechanism (Tb³⁺ → Eu³⁺) has also been investigated in detail, showing that the process mainly takes place via the dipole–dipole interaction based on a few theoretical simulations. Due to the facile preparation process, as well as intense tunable emission colors, these novel phosphors are expected to find a broad range of applications in future color displays and light-emitting devices.