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The direct band gap CsPbBr3 perovskite is regarded as a promising alternative for low-cost and high-performance X-ray radiation detectors. Despite the fact that CsPbBr3 nanocrystals have been shown to be good scintillators in the indirect conversion mode, the direct X-ray conversion with CsPbBr3 single crystals is expected to yield higher spatial resolution. Here, rubidium (Rb) doping is demonstrated to be an efficient approach to improve carrier transport and X-ray detection performance in the direct-conversion X-ray detectors based on Cs(1–x)Rb x PbBr3 single crystals. Electrical properties’ characterizations as combined with X-ray photoelectron spectroscopy (XPS) measurements have revealed that Rb doping in Cs(1–x)Rb x PbBr3 single crystals can enhance the atomic interaction and orbital coupling between Pb and Br atoms, leading to an enhancement of carrier transport and X-ray detection performance. X-ray detectors based on a small amount (0.037%) of Rb-doped Cs(1–x)Rb x PbBr3 single crystals exhibited a high X-ray sensitivity of 8097 μC Gyair –1 cm–2. This work offers a feasible strategy to improve the X-ray detection performance by chemical doping in all-inorganic perovskite X-ray detectors.

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Composition optimization, structural design, and introduction of external magnetic fields into the catalytic process can remarkably improve the oxygen evolution reaction (OER) performance of a catalyst. NiFe2O4@(Ni, Fe)S/P materials with a heterogeneous core–shell structure were prepared by the sulfide/phosphorus method based on spinel-structured NiFe2O4 nanomicrospheres. After the sulfide/phosphorus treatment, not only the intrinsic activity of the material and the active surface area were increased but also the charge transfer resistance was reduced due to the internal electric field. The overpotential of NiFe2O4@(Ni, Fe)P at 10 mA cm–2 (iR correction), Tafel slope, and charge transfer resistance were 261 mV, 42 mV dec–1, and 3.163 Ω, respectively. With an alternating magnetic field, the overpotential of NiFe2O4@(Ni, Fe)P at 10 mA cm–2 (without iR correction) declined by 45.5% from 323 mV (0 mT) to 176 mV (4.320 mT). Such enhancement of performance is primarily accounted for the enrichment of the reactive ion OH– on the electrode surface induced by the inductive electric potential derived from the Faraday induction effect of the AMF. This condition increased the electrode potential and thus the charge transfer rate on the one hand and weakened the diffusion of the active substance from the electrolyte to the electrode surface on the other hand. The OER process was dominantly controlled by the charge transfer process under low current conditions. A fast charge transfer rate boosted the OER performance of the catalyst. At high currents, diffusion exerted a significant effect on the OER process and low OH– diffusion rates would lead to a decrease in the OER performance of the catalyst.