Micrometer-Resolution X-ray Imaging Enabled by a Flexible Perovskite Screen

Abstract

Spatial resolution improvement has been keenly sought recently in the perovskite-based scintillation community. Here, micrometer resolution (∼2.0 μm) was achieved by using an X-ray imaging screen of self-assembled perovskite nanosheets. The assembly behavior of nanosheets was applicable to many substrates, including glass, metal, and polymer surfaces. The use of a polymer substrate not only eliminated the parasite absorption of X-ray but also enabled a flexible screen with robust bending stability. The assembly behavior, on the other hand, provided vicinity for an efficient energy transfer between nanosheets of varied thicknesses, as evidenced by both transient absorption and photoluminescence lifetime measurements. Importantly, the ensuing large Stokes shift (∼316 meV) significantly mitigated the reabsorption issue, leading to a comparable light yield to LYSO/Ce crystals. With the aid of the synchrotronbased collimated X-ray beam, the fine structure of two-dimensional objects, such as microchips, was clearly visualized with the flexible scintillation screen. Furthermore, those challenging biological samples were also scanned by phase-contrast imaging, whereby a three-dimensional reconstruction was obtained successfully. Despite the labile nature of the perovskite screen, this work represents the state-of-the-art spatial resolution for perovskite scintillation.

Highly Efficient, Flexible, and Eco-Friendly Manganese(II) Halide Nanocrystal Membrane with Low Light Scattering for High-Resolution X-ray Imaging

“…Recently, lead halide perovskite materials have been extensively investigated as an emerging scintillator by virtue of their high Z atom existence, tunable light emission, fast decay time, and facile solution processability. − However, the overuse of toxic lead, self-absorption, and poor stability against moisture, high temperature, and electron beam may impede their practical applications. − …”

Aging Effects on the Exciton Relaxation and Diffusion Processes in CsPbBr3 Nanocrystals

“…On the contrary, no evident variations of the XRD spectra are observed after aging (see Figure S5, Supporting Information), with spectra dominated by diffraction peaks at 7.7° and 11.5°, that are signature of NCs self-assembly with an interplane spacing of 3.8° (2.2 nm), not affected by the aging, [61,62] and a broad peak at 15.6° suggesting a mixed phase of CsPbBr 3 with both cubic and orthorhombic in both samples, with a decreased content of the latter in the aged sample.…”

Are Inorganic Lead Halide Perovskite Nanocrystals Promising Scintillators?

“…Recently, a few papers have demonstrated ultrahigh-resolution X-ray imaging down to micrometer scale based on CsPbBr 3 NCs. 15,33 Solution processability of PNCs induces facile and low-cost fabrication of large-area films through blade or spray coating techniques on various substrates (Figure 2e).…”