Synthesis, structure and photoluminescence properties of Ca2LuHf2(AlO4)3:Ce3+, a novel garnet-based cyan light-emitting phosphor

Abstract

A novel garnet phosphor, Ca₂LuHf₂(AlO₄)₃:Ce³⁺ (CLHA:Ce³⁺), was successfully designed and synthesized using a solid-state method. Its crystal structure, band structure and photoluminescence properties were investigated in detail. Under n-UV excitation, CLHA:Ce³⁺ exhibited cyan to blue-green emission depending on the Ce³⁺ concentration. The QE of the optimal sample was 50.3%. The concentration quenching mechanism of the Ce³⁺ emission was dominated by dipole–dipole interactions. A novel method to obtain white light was developed by combining the CLHA:Ce³⁺ phosphor with a CaAlSiN₃:Eu²⁺ red phosphor. Both the emission intensity and thermal stability of CLHA:Ce³⁺ were found to be superior to those of the commercial (Sr,Ba)₂SiO₄:Eu²⁺ phosphor. All of the results indicate the CLHA:Ce³⁺ phosphor to be a promising candidate for application in white LEDs.