Synthesis and Characterization of Gd2O2 S: Tb3+ Phosphor Powder for X-ray Imaging Detectors

Gadolinium oxysulfide phosphor doped with trivalent terbium have been synthesized using urea homogenous precipitation and followed by sulfurization at 800 degrees C under argon atmosphere. Structural and morphological of synthesized phosphor powder were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FT-IR). Hexagonal structure of Gd2O2S:Tb3+ phosphor was confirmed by XRD. Compositional analysis was carried out by energy dispersive x-ray (EDX) and particle induced x-ray emission (PIXE). Photoluminescence emission spectra was measured by the fluorescent spectrometer. A sedimentation technique is used to deposit the phosphor powder directly on the glass substrate using poly vinyl alcohol as a paste. A number of phosphor layers have been synthesized with the layer thickness ranging from 150 to 268 mu m. Measurement results of x-ray conversion efficiency for layers were investigated using 300 kVp X-ray tube in which the maximum light output and contrast were observed for the layer with a thickness of 193 mu m. Oxysulfide phosphor layer was analyzed by ion beam induced luminescence (IBIL). Emitting of green light from phosphor layer confirms its luminescence property.