Ensuring nuclear safety has become of great significance as nuclear power is playing an increasingly important role in supplying worldwide electricity. β-ray monitoring is a crucial method, but commercial organic scintillators for β-ray detection suffer from high temperature failure and irradiation damage. Here, we report a type of β-ray scintillator with good thermotolerance and irradiation hardness based on a two-dimensional halide perovskite. Comprehensive composition engineering and doping are carried out with the rationale elaborated. Consequently, effective β-ray scintillation is obtained, the scintillator shows satisfactory thermal quenching and high decomposition temperature, no functionality decay or hysteresis is observed after an accumulated radiation dose of 10 kGy (dose rate 0.67 kGy h −1). Besides, the two-dimensional halide perovskite β-ray scintillator also overcomes the notorious intrinsic water instability, and benefits from low-cost aqueous synthesis along with superior waterproofness, thus paving the way towards practical application.
The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.201905362. Fluorescence imaging with photodetectors (PDs) toward near-infrared I (NIR-I) photons (700-900 nm), the so-called "optical window" in organisms, has provided an important path for tracing biological processes in vivo. With both excitation photons and fluorescence photons in this narrow range, a stringent requirement arises that the fluorescence signal should be efficiently differentiated for effective sensing, which cannot be fulfilled by common PDs with a broadband response such as Si-based PDs. In this work, delicate optical microcavities are designed to develop a series of bionic PDs with selective response to NIR-I photons, the merits of a narrowband response with a full width at half maximum (FWHM) of <50 nm, and tunability to cover the NIR-I range are highlighted. Inorganic halide perovskite CsPb 0.5 Sn 0.5 I 3 is chosen as the photoactive layer with comprehensive bandgap and film engineering. As a result, these bionic PDs offer a signal/ noise ratio of ≈10 6 , a large bandwidth of 543 kHz and an ultralow detection limit of 0.33 nW. Meanwhile, the peak responsivity (R) and detectivity (D*) reach up to 270 mA W −1 and 5.4 × 10 14 Jones, respectively. Finally, proof-ofconcept NIR-I imaging using the PDs is demonstrated to show great promise in real-life application.Near-infrared photodetectors (NIR PDs) toward distinct photon signal from 700-900 nm (NIR-I) have attracted much attention in the past decades due to their tremendous potential in medical instruments. [1] Benefitting from merits including low
Recently, halide perovskites represent potential materials in X‐ray detection via both direct and indirect ways. Generally, thick active materials are necessary to completely absorb X‐ray photons while inefficient carrier collection leads to low device sensitivity. Besides, though perovskite nanocrystal (NC) scintillators can be used with silicon detectors, they suffer from strong reabsorption problem and the responsivity of silicon detectors is usually low. Herein, an effective strategy based on all‐perovskite integrated device is demonstrated to greatly improve the sensitivity of X‐ray detector. On one hand, efficient ultrafast exciton routing within CsPbBr3 NCs induces a large Stokes shift, and then greatly improved photoluminescence quantum yield (> 50%) and radioluminescence efficiency (> 3‐fold) are achieved. On the other hand, perovskite photodiode (PD) with responsivity higher than 0.4 A W−1 in a wide band is fabricated. The integrated detector takes full advantages of high X‐ray to emission efficiency of engineered CsPbBr3 NCs and high responsivity of perovskite PDs, respectively, and a record high sensitivity of 54684 µC Gy−1 cm−2 at the dose rate of 8.8 µGy s−1 is achieved. This work undoubtedly opens another window for perovskite X‐ray detectors with better performances or even higher spatial resolution.
Bone-implant materials are important for bone repairing and orthopedics surgery, which include bone plates and bone nails. These materials need to be designed not only considering its biostability and biocompatibility, but also their by-products induced infection after therapy or long-time treatment in vivo. Thus, the development of novel implant materials is quite urgent. Red phosphorus has great biocompatibility and exhibits efficient photothermal ability. Herein, a red phosphorus/IR780/arginine-glycine-asparticacid-cysteine (RGDC) coating on titanium bone-implant was prepared. The temperature sensitivity of Staphylococcus aureus biofilm is enhanced in the presence of ROS produced by IR780 with 808 nm light irradiation. With keeping the cells and tissues normal, a high antibacterial performance can be realized by near-infrared (808 nm) irradiated within 10 min at 50 °C. Besides the high effective antibacterial efficacy provided by photothermal therapy (PTT) and photodynamic therapy (PDT), the RGDC decorated surface can also possess an excellent performance in osteogenesis in vivo.
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