VUV-UV-vis photoluminescence, X-ray radioluminescence and energy transfer dynamics of Ce 3+ and Eu 2+ in Sr 2 MgSi 2 O 7 .

Ce 3+ and Eu 2+ doped and Ce 3+ -Eu 2+ co-doped Sr 2 MgSi 2 O 7 phosphors are prepared via a high-temperature solid-state reaction technique. The synchrotron radiation vacuum ultraviolet-ultraviolet (VUV-UV) excitation and ultraviolet-visible (UV-vis) emission spectra of diluted Ce 3+ and Eu 2+ doped Sr 2 MgSi 2 O 7 samples are measured at cryogenic temperatures. The electron-vibrational interaction (EVI) between Ce 3+ and its surroundings is analyzed. The dependencies of the 4f-5d transitions of Ce 3+ on the structure of the host compounds Sr 2 MgSi 2 O 7 , Ba 2 MgSi 2 O 7 and BaMg 2 Si 2 O 7 are discussed in detail. Then the thermal quenching channel is proposed based on the measurements of temperature dependent luminescence intensities and decay times of Ce 3+ and Eu 2+ in Sr 2 MgSi 2 O 7 , and the Ce 3+ → Eu 2+ energy transfer mechanism is understood by three luminescence dynamic models. In addition, Sr 2 MgSi 2 O 7 :Ce 3+ /Eu 2+ samples are evaluated for the possibilities of X-ray detection applications using X-ray excited luminescence (XEL) spectroscopy, and it was found that they are not suitable.