Rare earth activated lutetium oxysulfide phosphor for direct x-ray detection.

As a rare earth activated lutetium oxysulfide phosphor with an enhanced X-ray absorption coefficient for direct-X-rays, a scintillating phosphor according to the formula Lu2O2S : xM, wherein M is selected from the group of rare earth elements consisting of Eu, Pr and Sm and wherein x is from 0.0001 to 0.2, has been shown to be preferred as said phosphor prompt emits red light, which makes it particularly suitable for use as a scintillator material in a device for direct-radiography (DR).