Fabrication of Gd₂O₂S:Tb fine scintillator film and evaluation of image quality for resolution improvement of X-ray imaging based on CMOS

Abstract

In this study, fine Gd2O2S:Tb powder was synthesized by using a low temperature solution-combustion method for a high-resolution digital x-ray imaging detector. From the fabricated phosphor power, the fine scintillator films was fabricated by particle sedimentation method and was investigated the luminescent property. From the experimental results of relative light output as a function of terbium concentration, the highest luminescent efficiency has at 5 wt% Tb concentation, and luminescent intensity decreased rapidly according to quenching effect about higher Tb concentration. Also, the relative light output of 270㎛ -Gd2O2S:Tb film has 2945 pC/cm 2 /mR. And light intensity was saturated at higher film thickness. Finally, to evaluate an image acquisition performance of fabricated phosphor, images were obtained by using commercial CMOS sensor and measured the MTF, NPS, and DQE. DQE(0 lp/mm) of fine phosphor film has 37%. But, DQE