UV–VUV-excited photoluminescence of RE-activated CaLaP3O10 (RE=Eu,Tb)

Monazite-type polyphosphate CaLaP3O10 was synthesized by solid-state reaction at 1000 °C and their photoluminescence of Eu3+ and Tb3+ in CaLaP3O10 under ultraviolet (UV) and vacuum-ultraviolet (VUV) excitation were evaluated for the first time. The emission spectra of CaLaP3O10:Eu3+showed that Eu3+ are in a site with inversion symmetry because the magnetic dipole transition 5D0–7F1 was the strongest both upon 254 and 147 nm excitation. Monitored at 621 nm the excitation spectra consisted of host absorption bands, charge transfer band of Eu–O and the intraconfiguration 4f6 transition of Eu3+. Green phosphor CaLaP3O10:Tb3+exhibited better color purity when excited by 147 nm than that excited by 254 nm. With monitored at 542 nm the host absorption bands of CaLaP3O10:Tb3+ were also observed. Besides the host absorption bands there were strong f–d and weak f–f transitions of Tb3+.