Crystal Structure and Optical Performance of Al 3+ and Ce 3+ Codoped Ca 3 Sc 2 Si 3 O 12 Green Phosphors for White LED s

Ca 3 Sc 2 Si 3 O 12 : Ce 3+ ( CSS : Ce ) green phosphors used for white light‐emitting diodes ( LED s) are synthesized and codoped with Al 3+ via a solid‐state reaction method. The crystal structure and vibrational modes are analyzed by X‐ray diffraction, Fourier transform infrared spectroscopy, and Raman scattering spectroscopy. The energy transfer behavior and optical performance are characterized by photoluminescence and excitation spectra, quantum efficiency, and time‐resolved photoluminescence. The incorporation of Al 3+ into CSS : Ce can inhibit the formation of the impurity phases Sc 2 O 3 and CeO 2 , improve crystallinity, and enhance the photoluminescence intensity as well as quantum efficiency. The substitution of Sc 3+ with Al 3+ increased the crystal field splitting of Ce 3+ and resulted in the red shift of photoluminescence. The results show that Ca 3 Sc 2− x Al x Si 3 O 12 : Ce 3+ has high quantum efficiency, making it a promising green phosphor that can be collocated with a commercial 450 nm blue LED and a red phosphor for solid‐state lighting applications.