Effects of Eu~(2+), Dy~(3+) Contents and Particle Sizes on the Luminescent Properties of SrAI_2O_4 Phosphor by the Sol-gel Process

摘要

A green emitting SrAl_2O_4:Eu~(2+), Dy~(3+) phosphor with high brightness and long afterglow was synthesized by the sol-gel method. Sr Al_2O_4: Eu~(2+), Dy~(3+) phosphor exhibited broad band extending from 450 to 650 nm and maximum emission spectra peaking at 520 nm. Three excited levels existed, two shoulders were observed at 270 and 330 nm in addition to the maximum at 360 nm on the excitation spectrum. After the removal of excitation light, the excellent after-glow characteristic of the phosphorescence was obtained as a result of low decay time, although the after-glow intensities of phosphor varied exponentially with the time.