Time-resolved cathodoluminescence spectroscopy of YAG and YAG:Ce3+ phosphors

The phosphor powders, both undoped and Ce3+ doped with different concentration Y3Al5O12 (YAG), were synthesized by the solid-state reaction method with addition of BaF2 flux. SEM and XRD characterization of the samples were performed. The spectral and luminescence decay kinetic characteristics under the electron beam irradiation with nano- and picoseconds pulse duration and the electron energies of 250 keV and 55 keV were studied, respectively. Two bands in the cathodoluminescence spectrum of YAG:Ce3+ phosphors were observed with maxima at 2.19 ± 0.05 and 2.4 eV. The intensity ratio of these two bands depends on the electron energy and the duration of the excitation pulse. Instead, only one band at 2.12 ± 0.05 eV in the luminescence spectrum of undoped YAG phosphor. It is shown that cerium ions doping increases in the number of various hole centers.