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Halide perovskites exhibit remarkably high-performance as semiconductors compared to conventional materials because of an unusually favorable combination of optoelectronic properties. We demonstrate here that solution-grown single-crystals of organic–inorganic hybrid perovskite CH3NH3PbI3 (MAPbI3), implemented in a Schottky-type device design, can produce outstanding hard radiation detectors with high spectral response and low dark current for the first time. Schottky-type MAPbI3 detector achieves an excellent energy resolution of 6.8% for 57Co 122 keV gamma ray. The high detector performance is achieved due to the balanced charge collection efficiency for both electrons and holes, reflected in the high mobility-lifetime (μτ) products of both carriers (∼0.8 × 10–3 cm2/V). MAPbI3 also demonstrates remarkably long electron and hole lifetimes (τe = 10 μs and τh = 17 μs) and impressive operational stability over time. Furthermore, dual-source detection of α particle (5.5 MeV) and γ-ray (59.5 keV) from the 241Am radiation source is achieved simultaneously by Schottky-type MAPbI3 detector. These results reveal the great potential of MAPbI3 as a high-performance, low-cost radiation detection material.

A polyoxometalate supported by the metal–organic framework, NU-1000, undergoes migration from the mesopore to the micropore when heated.

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CrSBr is an air-stable two-dimensional (2D) van der Waals semiconducting magnet with great technological promise, but its atomic-scale magnetic interactions-crucial information for high-frequency switching-are poorly understood. An experimental study is presented to determine the CrSBr magnetic exchange Hamiltonian and bulk magnon spectrum. The A-type antiferromagnetic order using single crystal neutron diffraction is confirmed here. The magnon dispersions are also measured using inelastic neutron scattering and rigorously fit the excitation modes to a spin wave model. The magnon spectrum is well described by an intra-plane ferromagnetic Heisenberg exchange model with seven nearest in-plane exchanges. This fitted exchange Hamiltonian enables theoretical predictions of CrSBr behavior: as one example, the fitted Hamiltonian is used to predict the presence of chiral magnon edge modes with a spin-orbit enhanced CrSBr heterostructure.

The common approach to the synthesis of a new material involves reactions held at high temperatures under certain conditions such as heating in a robust vessel in the dark for a period until it is judged to have concluded. Analysis of the vessel contents afterward provides knowledge of the final products only. Intermediates that may form during the reaction process remain unknown. This lack of awareness of transient intermediates represents lost opportunities for discovering materials or understanding how the final products form. Here we present new results using an emerging in situ monitoring approach that shows high potential in discovering new compounds. In situ synchrotron X-ray diffraction studies were conducted in the Cs/Sn/P/Se system. Powder mixtures of CsSe, Sn, and PSe were heated to 650 °C and then cooled to room temperature while acquiring consecutive in situ synchrotron diffraction patterns from the beginning to the end of the reaction process. The diffraction data was translated into the relationship of phases present versus temperature. Seven known crystalline phases were observed to form on warming in the experiment: Sn, CsSe, CsSe, CsSe, CsSnSe, CsPSe, and CsPSe. Six unknown phases were also detected; using the in situ synchrotron data as a guide three of them were isolated and characterized ex situ. These are CsSn(PSe), α-CsSnPSe, and Cs(SnSe)[Sn(PSe)]. Cs(SnSe)[Sn(PSe)] is a two-dimensional compound that behaves as an n-type doped semiconductor below 50 K and acts more like a semimetal at higher temperatures. Because all crystalline phases are revealed during the reaction, we call this approach "panoramic synthesis".