The development of industrial applications in lighting and flat color display screens based on a xenon plasma discharge, which generates VUV radiation within an energy range of approximately 8.5 to 7 eV (145 and 180 nm), has induced a revival of interest in VUV-excited phosphors and in VUV spectroscopy using synchrotron radiation facilities. Both applications need very efficient and stable phosphors under ionizing conditions. In addition, mercury-free fluorescent lamps require, phosphors with...