Search

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 Gyair). 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 Gyair) 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) 1pmm−1, i.e., about 2.8 micron. This demonstrates that CsPbBr3 NW/AAO scintillators are promising candidates for high resolution X-ray imaging detectors.

Vertically aligned metal halide perovskite (MHP) nanowires are promising for various optoelectronic applications, which can be further enhanced by heterostructures. However, present methods to obtain free-standing vertically aligned MHP nanowire arrays and heterostructures lack the scalability needed for applications. We use a low-temperature solution process to prepare free-standing vertically aligned green-emitting CsPbBr

Metal halide perovskites (MHPs) have been studied intensely as the active material for optoelectronic devices. Lithography methods for perovskites remain limited because of the solubility of perovskites in polar solvents. Here, we demonstrate an electron-beam-lithography process with a poly(methyl methacrylate) resist based on the nonpolar solvents

X-ray scintillation detectors based on metal halide perovskites have shown excellent light yield, but they mostly target applications with spatial resolution at the tens of micrometers level. Here, we use a one-step solution method to grow arrays of 15-μm-long single-crystalline CsPbBr3 nanowires (NWs) in an AAO (anodized aluminum oxide) membrane template, with nanowire diameters ranging from 30 to 360 nm. The CsPbBr3 nanowires in AAO (CsPbBr3 NW/AAO) show increasing X-ray scintillation efficiency with decreasing nanowire diameter, with a maximum photon yield of ∼5 300 ph/MeV at 30 nm diameter. The CsPbBr3 NW/AAO composites also display high radiation resistance, with a scintillation-intensity decrease of only ∼20–30% after 24 h of X-ray exposure (integrated dose 162 Gyair) and almost no change after ambient storage for 2 months. X-ray images can distinguish line pairs with a spacing of 2 μm for all nanowire diameters, while slanted edge measurements show a spatial resolution of ∼160 lp/mm at modulation transfer function (MTF) = 0.1. The combination of high spatial resolution, radiation stability, and easy fabrication makes these CsPbBr3 NW/AAO scintillators a promising candidate for high-resolution X-ray imaging applications.