Growth of ultimate high-density scintillating films for high-resolution X-ray imaging at synchrotrons

• Published in: Optical materials. X Vol. 22; p. 100309
• Main Authors: Wollesen, Laura, Douissard, Paul-Antoine, Cook, Philip, Loiko, Pavel, Brasse, Gurvan, Margueritat, Jérémie, Camy, Patrice, Martin, Thierry, Dujardin, Christophe
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2024; Elsevier
• Subjects: Chemical Sciences; High-density compounds; Liquid phase epitaxy; Scintillation; Thin films; Thin films; Liquid phase epitaxy; Scintillation; High-density compounds; Crystal growth; scintillation; high-density compounds; thin films
• ISSN: 2590-1478; 2590-1478
• DOI: 10.1016/j.omx.2024.100309

Scintillators are X-ray to visible light converters applied in X-ray imaging detectors used at synchrotrons. Drastically improved performances of the 4th generation synchrotron sources enable us to perform X-ray imaging experiments at higher energies. For high spatial resolution X-ray imaging (micrometer to submicrometer), thin scintillating films are required. Consequently, especially for high X-ray energies (30keV to 100keV), the detection efficiency is limited due to the low X-ray absorption efficiency of the thin films. We have used Liquid Phase Epitaxy (LPE) to grow thin films of one of the ultimate high-density materials, Lu2Hf2O7:Eu3+, which demonstrate scintillating properties and thus combine high spatial resolution and maximized absorption efficiency. X-ray imaging experiments demonstrate that the Modulation Transfer Function (MTF) reaches 10% at 900 lp/mm, and radiographs visually confirm the promising imaging properties. We present structural, luminescent, and scintillation characterization of Lu2Hf2O7:Eu thin films grown on ZrO2:Y substrates, showing that the films crystallize in the disordered fluorite structure and the europium ions incorporate into the structure and enhance the luminescence intensity. This contribution is a first step toward developing promising ultra-dense, hafnate-based scintillating screens for high spatial resolution X-ray imaging.
•High-density Lu2Hf2O7 thin films grown by Liquid Phase Epitaxy.•Disordered fluorite structure.•Luminescent when doped with Europium.•Applicable for high-resolution X-ray imaging at synchrotrons.