Comparison of the luminescent properties of Y₃Al₅O₁₂:Pr crystals and films

The work is dedicated to comparative investigation of the luminescent properties of Y₃Al₅O₁₂:Pr (YAG:Pr) single crystals and single crystalline films using excitation by synchrotron radiation with an energy of 3.7-25 eV in the exciton range of YAG host. We have found that the differences in the excitation spectra and luminescence decay kinetics of YAG:Pr crystals and films are caused by involving the Y_{Al} antisite defects and oxygen vacancies in the crystals and Pb²⁺ flux related dopants in the films in the excitation processes of the Pr³⁺ luminescence. Taking into account these differences, we have determined in more detail the energy structure of the Pr³⁺ ions in YAG host and estimated the differences in the energies of creation of the excitons bound with the isolated Pr³⁺ ions in YAG:Pr films and the dipole Pr-Y_{Al} antisite defect centers in the crystal counterpart.