Tailoring of Deep‐Red Luminescence in Ca2SiO4:Eu2+

Abstract We report a new dicalcium silicate phosphor, Ca 2− x Eu x SiO 4 , which emits red light in response to blue‐light excitation. When excited at 450 nm, deep‐red emission at 650 nm was clearly observed in Ca 1.2 Eu 0.8 SiO 4 , the external and internal quantum efficiencies of which were 44 % and 50 %, respectively. The red emission from Ca 2− x Eu x SiO 4 was strongly related to the peculiar coordination environments of Eu 2+ in two types of Ca sites. The red‐emitting Ca 2 SiO 4 :Eu 2+ phosphors are promising materials for next‐generation, white‐light‐emitting diode applications.