Synthesis, controllable luminescence and energy transfer of GdTaO4: Dy3+, Eu3+ phosphors

Abstract

In this study, Eu³⁺ and Dy³⁺ co-doped tantalum phosphor (GdTaO₄: Eu³⁺/Dy³⁺) was prepared by the sol-gel method, achieving controllable light emission across chromatic coordinates from green to orange-red wavelengths. The wide and intense photoluminescent excitation (PLE) band in the 200 nm-470 nm range is derived from the superposition of Dy³⁺ and Eu³⁺ excitation wavelengths, which means that it can be used for ultraviolet (UV) LED devices. At 352nm excitation, the phosphors emit blue, yellow and red light at 482 nm, 578 nm and 613 nm corresponded to the characteristic emission of Dy³⁺ and Eu³⁺, further indicating that white light emission can be achieved with ultraviolet chip excitation. The luminescence color of the sample can be changed by modifying the doping ratio of Dy³⁺/Eu³⁺. The energy transfer efficiency Dy³⁺→Eu³⁺ is calculated. These results deliver critical guidelines for developing multichromatic phosphors with adjustable emission characteristics.