Luminescent properties of single-phase Ba P O :xEu ,yCe , zTb phosphors for white light-emitting diode.

A series of Ba P O :xEu ,yCe ,zTb phosphors was synthesized via a co-precipitation method, then their crystal structure, quantum efficiency and luminescent properties were analyzed by XRD and FL, respectively. The results showed that these phosphors not only presented the excitation characteristics of Ba P O :xEu ,zTb , but also exhibited that of the Ba P O :yCe ,zTb phosphor. Meanwhile, the tri-doped phosphor showed a stronger absorption around 320 nm in contrast with the Eu /Ce :Tb co-doped phosphor. Not only can energy transfer from Ce →Eu be observed; the energy transfer mechanism from Eu to Tb is discussed in the tri-doped system. Ce affects the luminescence properties of Ba P O :xEu ,yCe ,zTb phosphors just as the sensitizer whereas Eu is considered both as the sensitizer and the activator. The chromaticity coordinates of tri-doped phosphors excited at 320 nm stayed steadily in the bluish-white light region,and the emitted color and color temperature (CCT) of these phosphors could be tuned by adjusting the relative contents of Eu , Ce and Tb . Hence, the single phase Ba P O :xEu ,yCe ,zTb phosphors may be considered as potential candidates for white light-emitting diodes.