Preparation, energy transfer and tunable emission properties of Ca0.2Zr0.8O1.8:Eu3+ phosphor

Novel Ca0.2Zr0.8O1.8:Eu3+ phosphor is synthesized by high-temperature solid-state reaction method in air. Host Ca0.2Zr0.8O1.8 with excitation 310 nm shows deep-blue broadband emission within the range 340-500 nm owing to the Zr4+ → O2− transition in [ZrO8] group. Ca0.2Zr0.8O1.8:Eu3+ phosphor with excitation 263 and 394 nm emits reddish-orange light owing to the 5D0 → 7FJ (J = 1, 2, 3, and 4) transitions of Eu3+ ion, and that with excitation 310 nm shows a systematically varied hue from deep-blue to reddish-orange by changing Eu3+ ion concentration. Tunable emission and energy transfer are confirmed via spectral properties. The optimal Eu3+ concentration is ∼5 mol% in Ca0.2Zr0.8O1.8:Eu3+ phosphor and the corresponding fluorescence lifetime is ∼1.994 ms. The luminous mechanism is analyzed and explained by the simplified energy level diagrams of [ZrO8] group and Eu3+ ion in Ca0.2Zr0.8O1.8:Eu3+ phosphor.