Hydrothermal synthesis and vacuum ultraviolet-excited luminescence properties of novel Dy~(3+)-doped LaPO_4 white light phosphors

摘要

Novel LaPO_4:Dy~(3+) white light phosphors with monoclinic system were successfully synthesized by hydrothermal method at 240 ℃. The strong absorption at around 147 nm in excitation spectrum was assigned to the host absorption which suggested that the vacuum ultraviolet-excited energy was efficiently transferred from the host to the Dy~(3+) ion. The f-d transition of Dy~(3+) ion was observed locating at 182 nm. Under 147 nm excitation, La_(1-x)PO_4:xDy~(3+) phosphor exhibited two emission bands locating at 571 nm (yellow) and 478 nm (blue) which corresponded to the hypersensitive transitions ~4F_(9/2)-~6H_(13/2) and ~4F_(9/2)-~6H_(15/2). It was the two emission bands that lead to the white light.