Blue to green emission and energy transfer between Ce3+ ions in Ca15Si20O10N30

Abstract

A near-ultraviolet (near-UV) excited phosphor, Ca₁₅Si₂₀O₁₀N₃₀:Ce³⁺, was synthesized by a solid state reaction, and its crystal structure and luminescence properties were investigated in detail. Ca₁₅Si₂₀O₁₀N₃₀ crystallizes in a cubic unit cell with the space group Pa and the lattice parameters are determined to be a = b = c = 15.4195(3) Å. The maximum emission wavelength can be tuned from about 470 to 520 nm as the content of Ce³⁺ increases due to the energy transfer between various Ce³⁺ activators located in different coordination environments, which was verified by the time-resolved emission spectroscopy (TRES) and the variation in the decay rate with respect to the detection wavelength. Upon excitation at 365 nm, Ca₁₅Si₂₀O₁₀N₃₀:Ce³⁺ exhibited a relatively low thermal quenching, and the T₅₀ is measured to be 233 °C. The above results indicate that Ca₁₅Si₂₀O₁₀N₃₀:Ce³⁺ is a promising candidate for application in white light-emitting diodes (LEDs).