Ce~(3+) → Eu~(2+) energy transfer mechanism in the Li_2SrSiO_4:Eu~(2+), Ce~(3+) phosphor

摘要

Ce~(3+)/Eu~(2+) co-doped Li_2SrSiO_4 phosphor yields two emission bands consisted of blue and yellow components, which shows great potential as single host white phosphor for white LEDs. Effective energy transfer occurs in Ce~(3+)/Eu~(2+) co-doped Li_2SrSiO_4 due to large spectral overlap between the emission of Ce~(3+) and excitation of Eu~(2+). Co-doping of Ce~(3+) enhances the emission intensity of Eu~(2+) greatly by transferring its excitation energy to Eu~(2+). The Ce~(3+) → Eu~(2+) energy transfer, thoroughly investigated by their absorption, excitation and photoluminescence decay behaviors, is demonstrated to be in the mechanism of electric dipole-dipole interaction.