Luminescence and Structural Characterization of Gd<sub>2</sub>O<sub>2</sub>S Scintillators Doped with Tb<sup>3+</sup>, Ce<sup>3+</sup>, Pr<sup>3+</sup> and F for Imaging Applications
Alessia De Martinis,
Luigi Montalto,
Lorenzo Scalise,
Daniele Rinaldi,
Paolo Mengucci,
Christos Michail,
George Fountos,
Nicki Martini,
Vaia Koukou,
Ioannis Valais,
Athanasios Bakas,
Christine Fountzoula,
Ioannis Kandarakis,
Stratos David
Affiliations
Alessia De Martinis
Dipartimento di Ingegneria Industriale e Scienze Matematiche, Università Politecnica delle Marche, 60131 Ancona, Italy
Luigi Montalto
Dipartimento SIMAU, Università Politecnica delle Marche, 60131 Ancona, Italy
Lorenzo Scalise
Dipartimento di Ingegneria Industriale e Scienze Matematiche, Università Politecnica delle Marche, 60131 Ancona, Italy
Daniele Rinaldi
Dipartimento SIMAU, Università Politecnica delle Marche, 60131 Ancona, Italy
Paolo Mengucci
Dipartimento SIMAU, Università Politecnica delle Marche, 60131 Ancona, Italy
Christos Michail
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, University of West Attica, 60131 Athens, Greece
George Fountos
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, University of West Attica, 60131 Athens, Greece
Nicki Martini
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, University of West Attica, 60131 Athens, Greece
Vaia Koukou
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, University of West Attica, 60131 Athens, Greece
Ioannis Valais
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, University of West Attica, 60131 Athens, Greece
Athanasios Bakas
Department of Biomedical Sciences, University of West Attica, 12210 Athens, Greece
Christine Fountzoula
Department of Biomedical Sciences, University of West Attica, 12210 Athens, Greece
Ioannis Kandarakis
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, University of West Attica, 60131 Athens, Greece
Stratos David
Department of Biomedical Engineering, University of West Attica, 12210 Athens, Greece
Radiodiagnostic technologies are powerful tools for preventing diseases and monitoring the condition of patients. Medicine and sectors such as industry and research all use this inspection methodology. This field demands innovative and more sophisticated systems and materials for improving resolution and sensitivity, leading to a faster, reliable, and safe diagnosis. In this study, a large characterization of gadolinium oxysulfide (Gd2O2S) scintillator screens for imaging applications has been carried out. Seven scintillator samples were doped with praseodymium (Pr3+), terbium (Tb3+) activators and co-doped with praseodymium, cerium, and fluorine (Gd2O2S:Pr,Ce,F). The sample screens were prepared in the laboratory in the form of high packing density screens, following the methodology used in screen sample preparation in infrared spectroscopy and luminescence. Parameters such as quantum detection efficiency (QDE), energy absorption efficiency (EAE), and absolute luminescence efficiency (ALE) were evaluated. In parallel, a structural characterization was performed, via XRD and SEM analysis, for quality control purposes as well as for correlation with optical properties. Spatial resolution properties were experimentally evaluated via the Modulation Transfer Function. Results were compared with published data about Gd2O2S:Pr,Ce,F screens produced with a standard method of a sedimentation technique. In particular, the ALE rose with the X-ray tube voltage up to 100 kVp, while among the different dopants, Gd2O2S:Pr exhibited the highest ALE value. When comparing screens with different thicknesses, a linear trend for the ALE value was not observed; the highest ALE value was measured for the 0.57 mm thick Gd2O2S:Pr,Ce,F sample, while the best MTF values were found in the thinner Gd2O2S:Pr,Ce,F screen with 0.38 mm thickness.
