Energy Transfer Processes in NASICON-Type Phosphates under Synchrotron Radiation Excitation

The luminescence properties of NASICON-type Na3.6M1.8(PO4)3 (M = Y, Lu) and Na3Sc2(PO4)3 phosphates, undoped rare earth-doped (RE Tb3+, Dy3+, Eu3+, Ce3+), were studied using synchrotron radiation in a wide energy region 4.5–45 eV. Intrinsic emission originating from self-trapped excitons with electron component localized at the 3d Sc states was detected both doped while only defect-related registered Na3.6M1.8(PO4)3. Emission RE ions substituting three-valent cations low-symmetry sites all phosphates. efficiency pass ways transfer host to centres analysed based on excitation spectra. It is shown that most efficient realized Tb3+-doped phosphors, it poor for other ions. differences efficiencies are explained by different position f crystal electronic band structure influencing charge carrier trapping substance. Based spectra analysis, bandgap values estimated ~8 eV