Improvement of thermal stability and photoluminescence in Mg2Y2Al2Si2O12:Ce3+ by the cation substitution of Ca2+, Sr2+ and Ba2+ ions

The luminescence of Ce3+ in Mg2Y2Al2Si2O12 (MgYAlSiO6) can be controlled by substituting with Ca2+, Sr2+, and Ba2+ ions. The materials show blue shifts in their emission spectra that become highly evident with the increase in the ionic radius, and this phenomenon is the result of the combined action of the nephelauxetic effect and crystal field splitting. Due to the introduction of Ca2+, Sr2+, and Ba2+, the distortion of the crystal decreases and the structural rigidity and stability increase, improving the quantum efficiency and temperature stability of Mg2Y1.93Al2Si2O12:0.07Ce3+. Mg2Y1.93Al2Si2O12:0.07Ce3+,Ca2+ is more stable than Mg2Y1.93Al2Si2O12:0.07Ce3+,Sr2+/Ba2+ because the radius of Sr2+/Ba2+ is larger than that of Mg2+. The Mg1.9Y1.93Al2Si2O12:0.07Ce3+,0.1Ca2+ fluorescent powder and blue chip were packaged to obtain warm white light-emitting diodes (LEDs) with luminous efficiency of 60 lm W−1. These results show that the Mg2Y2Al2Si2O12:Ce3+ phosphor has potential application value in white LEDs.