There are two types of Pr3+ ion in the Pr3+ doped oxyfluoride glass containing LaF3 nanocrystal: the lowest 4f5d state of Pr3+ in LaF3 nanocrystal is located energetically higher than the 1S0 state, while in glass the...There are two types of Pr3+ ion in the Pr3+ doped oxyfluoride glass containing LaF3 nanocrystal: the lowest 4f5d state of Pr3+ in LaF3 nanocrystal is located energetically higher than the 1S0 state, while in glass the lowest 4f5d state is lower than the 1S0 state. We deduce the positions of the lowest 4f5d band of these two types of Pr3+ ion by vacuum ultraviolet (VUV) and ultraviolet (UV) excitation spectra. When the sample is excited by 181 nm, the narrow band emission of 4f2→4f2 of Pr3+ ion in the nanocrystal and the broad band emission of 4f5d→4f2 in the glass appear at the same time. However, the second step of the photon cascade emission(PCE) of Pr3+ in the LaF3 nanocrystal, corresponding to the emission of 3P0→3H4, can be observed at 20 K, but not at room temperature. The reason accounting for this phenomenon was discussed in detail.展开更多
文摘There are two types of Pr3+ ion in the Pr3+ doped oxyfluoride glass containing LaF3 nanocrystal: the lowest 4f5d state of Pr3+ in LaF3 nanocrystal is located energetically higher than the 1S0 state, while in glass the lowest 4f5d state is lower than the 1S0 state. We deduce the positions of the lowest 4f5d band of these two types of Pr3+ ion by vacuum ultraviolet (VUV) and ultraviolet (UV) excitation spectra. When the sample is excited by 181 nm, the narrow band emission of 4f2→4f2 of Pr3+ ion in the nanocrystal and the broad band emission of 4f5d→4f2 in the glass appear at the same time. However, the second step of the photon cascade emission(PCE) of Pr3+ in the LaF3 nanocrystal, corresponding to the emission of 3P0→3H4, can be observed at 20 K, but not at room temperature. The reason accounting for this phenomenon was discussed in detail.
