Colloidal KLu3F10:Tb3+ persistent luminescence nanocrystal based flexible detectors for 3D X-ray imaging

Abstract

Scintillator-based X-ray detection and imaging have demonstrated significant potential in the domains of industrial safety inspection and medical diagnosis. However, developing X-ray detectors capable of effectively imaging three-dimensional objects with highly curved surfaces and irregular shapes remains a persistent challenge. In this study, we present the controllable synthesis and X-ray excited persistent luminescence properties of KLu₃F₁₀:Tb³⁺ (KLF:Tb) nanocrystals (NCs) through a hydrothermal reaction, which can serve as highly sensitive nanoscintillators for flat-panel-free, high-resolution, and three-dimensional X-ray detection and imaging technologies. The detection limit of the X-ray dose rate of the prepared KLF:Tb NCs is determined to be 0.094 μGy s⁻¹, significantly below the required dose rate for X-ray diagnostics (5.5 μGy s⁻¹). Flexible scintillator films with varying thicknesses have been fabricated using the drop-casting technique, exhibiting a high spatial resolution of 10.1 lp mm⁻¹@MTF = 0.2 at a thickness of 146.3 μm. It is demonstrated that the KLF:Tb-based scintillator screen enables high-quality X-ray imaging of diverse objects, including electronic devices and 3D curved objects. The imaging of ultra-long coils (∼20 cm) has also been successfully realized by utilizing the extended luminescence features of the KLF:Tb NCs. Overall, the high physicochemical and colloidal stability and exceptional scintillation performance of the as-synthesized KLF:Tb NCs open opportunities for flexible applications in X-ray detection and imaging as well as other daily applications.