3D X-ray microscopy with a CsPbBr₃ nanowire scintillator

X-ray microscopy is an essential imaging method in many scientific fields, which can be extended to three-dimensional (3D) using tomography. Recently, metal halide perovskite (MHP) nanomaterials have become a promising candidate for X-ray scintillators, due to their high light yield, high spatial resolution, and easy fabrication. Tomography requires many projections and therefore scintillators with excellent stability. This is challenging for MHPs, which often suffer from fast degradation under X-ray irradiation and ambient conditions. Here, we demonstrate that MHP scintillators of CsPbBr₃ nanowires (diameter: 60 nm, length: 5–9 µm) grown in anodized aluminum oxide (CsPbBr₃ NW/AAO) have sufficient stability for X-ray micro-tomography. A tomogram was taken with a Cu X-ray source over 41 h (dose 4.2 Gy_air). During this period the scintillator brightness fluctuated less than 5%, which enabled a successful reconstruction. A long-term study with 2 weeks of continuous X-ray exposure (37.5 Gy_air) showed less than 14% fluctuations in brightness and no long-term degradation, despite variations in the ambient relative humidity from 7.4 %RH to 34.2 %RH. The resolution was stable at (180 ± 20) lp·mm⁻¹, i.e., about 2.8 micron. This demonstrates that CsPbBr₃ NW/AAO scintillators are promising candidates for high resolution X-ray imaging detectors.