Comparison of the luminescent properties of LuAG:Ce films grown by pulse laser deposition and liquid phase epitaxy methods using synchrotron radiation excitation

Abstract

The paper is dedicated to the comparative study of the luminescent properties of LuAG:Ce films, grown by pulse laser deposition (PLD) and liquid phase epitaxy (LPE) methods, using the time-resolved luminescent spectroscopy under excitation by synchrotron radiation in the fundamental absorption range and above the band gap of LuAG host. We have shown the similarities and differences in the luminescence properties of LuAG:Ce PLD and LPE grown films. Specifically, the luminescence of LuAl antisite defects is absent in the emission spectra of both films in the room temperature range. Meanwhile, the low intensive bands peaked at 350 and 400 nm, corresponding to the luminescence of excitons localized around and bound with F+ centers, respectively, are present in the emission spectra of LuAG:Ce PLD films at 12 K. The energy of formation of the excitons bound with the Ce3+ ions, being equal to 7.52 eV at 12 K, and the energy of the onset of interband transitions of LuAG host, being equal to 7.76 eV (at 300 K), have been found for LuAG:Ce LPE and PLD films, respectively. We have also found that the scintillation properties of LuAG:Ce PDL film are worse in comparison with LPE grown film analogue due to the significantly larger content of the slow emission component in the scintillation decay under high-energy excitation. Such differences between the optical and scintillation properties of PLD and LPE films are caused by the different conditions of their preparation (in vacuum and in air).