Synthesis, Luminescence Properties and Energy Transfer of CaZrO3:Sm3+, Bi3+ Phosphor

Novel CaZrO₃:Sm³⁺, Bi³⁺ phosphor is synthesized by a solid-state reaction method in air and the crystal structures and luminescence properties are investigated. The emission spectrum with excitation 308 nm contains emission of Sm³⁺ and Bi³⁺ ions at the same time; however, it only has an emission of Sm³⁺ ion with excitation 408 nm. Emission intensity of CaZrO₃:Sm³⁺ phosphor can be enhanced about four times owing to energy transfer from the Bi³⁺ ion to the Sm³⁺ ion and with the fluxing agent role of Bi³⁺ ion when Bi³⁺ ion is co-doped. The possible luminous mechanism is analyzed by energy level diagrams of Bi³⁺ and Sm³⁺ ions and the energy transfer process in CaZrO₃:Sm³⁺, Bi³⁺ phosphor. The experimental results indicate that, hopefully, CaZrO₃:Sm³⁺, Bi³⁺ phosphor can be used as a reddish orange phosphor candidate for white light-emitting diodes based on near an ultraviolet (~408 nm) chip.