Current X-ray imaging technologies involving flat-panel detectors have difficulty in imaging three-dimensional (3D) objects because fabrication of large-area, flexible silicon-based photodetectors on highly curved surfaces remains a challenge 1-3 . Here we demonstrate ultralong-lived X-ray trapping for flat-panel-free, high-resolution 3D imaging using a series of solution-processable, lanthanide-doped nanoscintillators. Corroborated with quantum mechanical simulation, our experimental characterizations show that a thermally activated slow-hopping of trapped electrons, due to radiation-induced anionic migration in host lattices, induces more than 30 days of persistent radioluminescence. We further demonstrate X-ray luminescence extension imaging (Xr-LEI) with >20-lp/mm resolution and >15-day optical memory. These findings provide insight into mechanisms underlying X-ray energy conversion through enduring electron trapping and also offer a new paradigm to motivate future research in wearable X-ray detectors for patient-centered radiography and mammogram, imaging-guided therapeutics, high-energy physics, and deep learning in radiology.

Solution‐processed metal‐halide perovskites hold great promise in developing next‐generation low‐cost, high‐performance photodetectors. However, the weak absorption of perovskites beyond the near‐infrared spectral region posts a stringent limitation on their use for broadband photodetectors. Here, the rational design and synthesis of an upconversion nanoparticles (UCNPs)–perovskite nanotransducer are presented, namely UCNPs@mSiO2@MAPbX3 (X = Cl, Br, or I), for broadband photon detection spanning from X‐rays, UV, to NIR. It is demonstrated that, by in situ crystallization and deliberately tuning the material composition in the lanthanide core and perovskites, the nanotransducers allow for a high stability and show a wide linear response to X‐rays of various dose rates, as well as UV/NIR photons of various power densities. The findings provide an opportunity to explore the next‐generation broadband photodetectors in the field of high‐quality imaging and optoelectronic devices.

Solid-state polymer electrolytes (SPEs) have great processing flexibility and electrode–electrolyte contact and have been employed as the promising electrolytes for lithium metal batteries. Among them, poly(ethylene oxide) (PEO)-based SPEs have attracted widespread attention because of easy synthesis, low mass density, good mechanical stability, low binding energy with lithium salts, and excellent mobility of charge carriers. In order to overcome the low room-temperature ionic conductivity and the poor thermodynamic stability in high-voltage devices (>4.2 V) of the PEO materials, composition modulations by incorporating PEO with inorganic and/or organic components have been designed, which could effectively enable the applications of PEO-based SPEs with widened electro-stable voltage ranges. In this mini review, we describe recent progresses of several kinds of PEO composite structures for SPEs, and we compare the synthesis strategies and properties of these SPEs in lithium batteries. Further developments and improvements of the PEO-based materials for building better rechargeable batteries are also discussed.

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Detection of haloalkanes is of great industrial and scientific importance because some haloalkanes are found serious biological and atmospheric issues. The development of a flexible, wearable sensing device for haloalkane assays is highly desired. Here, we develop a paper-based microfluidic sensor to achieve low-cost, high-throughput, and convenient detection of haloalkanes using perovskite nanocrystals as a nanoprobe through anion exchanging. We demonstrate that the CsPbX3 (X = Cl, Br, or I) nanocrystals are selectively and sensitively in response to haloalkanes (CH2Cl2, CH2Br2), and their concentrations can be determined as a function of photoluminescence spectral shifts of perovskite nanocrystals. In particular, an addition of nucleophilic trialkyl phosphines (TOP) or a UV-photon-induced electron transfer from CsPbX3 nanocrystals is responsible for achieving fast sensing of haloalkanes. We further fabricate a paper-based multichannel microfluidic sensor to implement fast colorimetric assays of CH2Cl2 and CH2Br2. We also demonstrate a direct experimental observation on chemical kinetics of anion exchanging in lead-halide perovskite nanocrystals using a slow solvent diffusion strategy. Our studies may offer an opportunity to develop flexible, wearable microfluidic sensors for haloalkane sensing, and advance the in-depth fundamental understanding of the physical origin of anion-exchanged nanocrystals.