Optical and Structural Properties of Eu[sup 2+]-doped (Sr[sub 1−x]Ba[sub x])[sub 2]SiO[sub 4] phosphors

Europium ͑Eu 2+ ͒-doped alkaline earth orthosilicates ͑Sr 1-x Ba x ͒ 2 SiO 4 :Eu 2+ , are studied as a phosphor for color-tunable white-lightemitting diode.With an increase of Ba ions in ͑Sr 1-x Ba x ͒ 2 SiO 4 :Eu 2+ , the lattice constants increase, and the emission bands shift to higher energy in a systematic way.This blueshift behavior can be clarified by crystal field strength.Also, the lattice vibration energies from Raman spectra decrease with an increase of Ba ions in ͑Sr 1-x Ba x ͒ 2 SiO 4 :Eu 2+ .The emission-quenching temperature dependence of the lattice vibration frequency is investigated in terms of a well-known configurational coordinate diagram.