Enhanced Optical Properties of Bredigite‐Structure Ca_13.7Eu_0.3Mg₂[SiO₄]₈ Phosphor: Effective Eu Reduction by La Co‐Doping

Abstract

A green phosphor, La 0.4 Ca 13.3 Eu 0.3 Mg 2 Si 8 O 31.6+d N 0.4d (LaCMSN:Eu 2+ ), was prepared by a solid-state reaction and an efficient green emission was observed at 506 nm under nearultraviolet (NUV) excitation. The structural and optical properties of LaCMSN:Eu 2+ phosphors as well as their thermal quenching were investigated. The partial substitution of La 3+ and N 3in Ca 13.7 Eu 0.3 Mg 2 Si 8 O 32 led to a considerable enhancement in the peak emission intensity by as much as 194%. This demonstrates not only that the total number of Eu 2+ activators increased, but also that the probability of a nonradiative transition between Eu 2+ and Eu 3+ could be reduced as the increase in concentration of the former is at the expense of the later. The white light-emitting diode (LED) was fabricated using phosphor with a NUV LED chip. The LED showed warm white light with an excellent color rendering index of 91. The LaCMSN:Eu 2+ is thus a potential greenemitting phosphor for white LEDs.