Luminescence investigation of Lu2MgAl4SiO12:Ce3+ and Ca2+ substituted Lu2MgAl4SiO12:Ce3+ phosphors

Abstract

Inorganic phosphors with the broad excitation bands and efficient visible emission are important to fabricate lighting emitting diodes. Herein, we fabricated the Lu2MgAl4SiO12:Ce3+ and Ca substituted Lu2MgAl4SiO12:Ce3+ phosphors by a sol-gel approach. Their characteristics were investigated by X-ray diffraction, scanning electron microscopy and fluorescence spectrophotometer. The thermal stabilities of Lu1.95Ce0.05MgAl4SiO12 and Lu1.95Ce0.05Mg0.25Ca0.75Al4SiO12 were evaluated in the temperature rage of 30–230 °C. In addition, the mechanisms of concentration quenching and thermal stability were discussed. Upon the excitation at 435 nm, Lu2−xCexMgAl4SiO12 and Lu1.95Ce0.05Mg1−yCayAl4SiO12 phosphors show emission bands with changing peak wavelength by reason of the changing crystal field splitting with the changing Ce3+ and Ca2+ concentrations. Meanwhile, the substitution of Ca2+ to Mg2+ leads to the enhancements of thermal stability of luminescence.