A device for generating
ultraviolet radiation by means of an
excimer discharge, which device is equipped with an at least partly UV-transparent
discharge vessel whose
discharge space is filled with a gas filling, with means for triggering and maintaining an
excimer discharge in the discharge space, and with a
luminescent material that contains a
phosphor comprising a host lattice of general formula (Y1-x-y-z,
Lux,Scy,Az)PO4 wherein 0≦x<1 and 0<y≦1 and 0≦z<0.05 and A is an activator selected from the group of
bismuth,
praseodymium and
neodymium is useful for disinfection and purification of fluids and surfaces and provides improved germicidal action. The invention also relates to a UVC-
phosphor comprising a host lattice of general formula (Y1-x-y-z,
Lux,Scy,Az)PO4 wherein 0≦x<1 and 0<y≦1 and 0≦z<0.05 and A is an activator selected from the group of
bismuth,
praseodymium and
neodymium comprising a improved
emission spectrum. Such UV-C phosphors show a high
quantum efficiency (>80%) and a strong absorption of 170 to 190 nm
radiation. These phosphors emit UV-C
radiation comprising a broadened band in the
wavelength range between 225 and 275 nm.