Hydrothermal synthesis and vacuum ultraviolet-excited luminescence properties of novel Dy3+-doped LaPO4 white light phosphors

Novel LaPO4:Dy3+ white light phosphors with monoclinic system were successfully synthesized by hydrothermal method at 240 °C. 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 Dy3+ ion. The f–d transition of Dy3+ ion was observed locating at 182 nm. Under 147 nm excitation, La1−xPO4:xDy3+ phosphor exhibited two emission bands locating at 571 nm (yellow) and 478 nm (blue) which corresponded to the hypersensitive transitions 4F9/2–6H13/2 and 4F9/2–6H15/2. It was the two emission bands that lead to the white light.