Results 1 - 1 of 1
Results 1 - 1 of 1. Search took: 0.014 seconds
[en] We investigated the 3P0 and 1D2 luminescence of Y4Al2O9 (YAM) crystals activated with Pr3+ ions after excitation of the 1D2 level. Under cryogenic temperature four distinct types of emission and excitation spectra are observed, which are attributed to 4f–4f transitions of four different sets of Pr3+ centers. The energy level structure of Pr3+ ions occupying four distinct, low symmetry Y3+ sites in YAM have been determined using site selective laser excitation and luminescence. To get better insight into local site occupancy, luminescence decay studies were also conducted. It was found that energy transfer between Pr3+ ions doped into four different sites is absent. Anti-Stokes, upconversion luminescence originating from the 3P0 state while exiting the 3H4→ 1D2 transition was observed. The whole orange to blue upconversion was site selective at cryogenic temperatures. The dynamical behavior of the upconverted emission arising from four sites was studied and modelled via energy transfer process. - Highlights: • YAM:Pr3+ crystals have been grown by the micro-pulling down method. • Four different states of Pr3+ centers in YAM have been determined. • Site-selective upconversion luminescence originating from the 3P0 state has been analyzed. • Correlation between experimental spectroscopic results and crystallographic Pr3+ sites was discussed.