Scintillating Screens for Micro-Imaging Based on the Ce-Tb Doped LuAP Single Crystal Films

Single Crystal Film (SCF) scintillators are key-components of today´s high-resolution 2D X-ray detectors used at synchrotrons for applications such as X-ray Radiography, Computed Tomography (CT), laminography, full-field XANES, and topography. Due to its high density and effective atomic number, LuAlO₃ (LuAP) perovskite has a great potential to replace or complement the currently used Eu-doped Gd₃Ga₅O₁₂ (GGG:Eu) and Tb-doped Lu₂SiO₅ (LSO:Tb) SCFs. In this article we present the growth of LuAP single crystalline films on undoped YAlO₃ (YAP) by the vertical dipping isothermal Liquid Phase Epitaxy (LPE) growth method. For the comparison of the light output of Ce and Tb doped LuAP SCF screens both cathodoluminescence (CL) and X-ray excited luminescence (RL) measurements were used. For investigations of Ce-Tb energy transfer in the afore mentioned oxide hosts, in addition to using traditional spectroscopic methods, we made time-resolved luminescent spectroscopy of Ce-Tb doped LuAP SCFs under excitation by pulsed synchrotron radiation at the Superlumi station (HASYLAB at DESY). Recently we have demonstrated the strong quenching influence of Pb²⁺ flux related impurity on the Ce³⁺ emission in the Ce-doped LuAP SCF screens. However our present investigation shows that Tb-doped LuAP SCFs are efficient X-ray scintillators, whose light output can be significantly increased by co-doping with Ce³⁺ ions. Namely, we demonstrate the efficient Ce→ Tb energy transfer in LuAP:Tb,Ce SCFs. Finally, as-grown LuAP:Tb and LuAP:Tb,Ce films were evaluated for high-resolution X-ray imaging using a spatial resolution target at the European Synchrotron Radiation Facility (ESRF), and displayed promising results.