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.