Synthesis, energy transfer, charge compensation and luminescence properties of CaZrO₃:Eu³⁺, Bi³⁺, Li⁺ phosphor

Abstract

A series of CaZrO₃:Bi³⁺, CaZrO₃:Eu³⁺, CaZrO₃:Eu³⁺, Bi³⁺, and CaZrO₃:Eu³⁺, Bi³⁺, Li⁺ phosphors are synthesized by high-temperature solid-state reaction method in air. Their luminescence properties are researched, compared, and analyzed. CaZrO₃:Bi³⁺ phosphor under excitation at 310 nm emits deep-blue light with chromaticity coordinate (0.1612, 0.0254). CaZrO₃:Eu³⁺ phosphor under excitation at 310 and 395 nm shows red-emitting with chromaticity coordinate (0.6386, 0.3611). CaZrO₃:Eu³⁺, Bi³⁺ phosphor under excitation at 310 nm exhibits a systematically varied hue from deep-blue to red light by changing Eu³⁺ ion concentration, and that with excitation at 395 nm only emits red light with chromaticity coordinate (0.6386, 0.3611). The energy transfer process from Bi³⁺ to Eu³⁺ ions may be indicated by their spectral properties. The optimal Eu³⁺ and Bi³⁺ ions concentrations are 5 mol% and 0.9 mol%, respectively. The emission intensity CaZrO₃:Eu³⁺, Bi³⁺ phosphor may be enhanced about 1.6 times due to the co-doping Li⁺ ion as charge compensator role. The luminous mechanism of CaZrO₃:Eu³⁺, Bi³⁺ phosphor is explained by the simplified energy level diagrams of Bi³⁺ and Eu³⁺ ions.