Charge compensation and enhanced photoluminescence of Sr_2SiO_4:Eu~(3+), Li~+ phosphor

摘要

A Eu~(3+) activated strontium silicate phosphor was synthesized by solid-state reaction and Li~+ ion was added to balance the charge valence. X-ray powder diffraction analysis confirmed the formation of pure Sr_2SiO_4 phase without second phase or phases of starting materials irrespective of the adding amount of Li~+. Scanning electron microscopy showed large particle size and necking shape were obtained as the concentrations of Li~+ ions increase. In the PL studies, the excitation spectrum of Sr_2SiO_4:Eu~(3+),Li~+ phosphors exhibited a broad band in the UV region centered at about 270 nm attributed to charge transfer state (CTS) band. As the Li~+ ion concentration increased, the photoluminescence intensity of the red emission at 617 nm of Eu~(3+) ions was enhanced. The results showed that Li~+ ion is a effective charge compensators used in Sr_2SiO_4:Eu~(3+) phosphor.