In this paper, single crystals (SCs) of the Cs₂AgBiBr₆ double perovskite were grown using the method of crystallization from a supersaturated solution. It was shown that the natural crystal growth surface of the perovskite with perfect crystal quality is along the (111) plane by X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) analyses. The fabricated high-sensitivity X-ray detector based on the Cs₂AgBiBr₆ SCs with vertical structure achieved detection sensitivity up to 316 μCGyair⁻¹ cm⁻² under bias voltage of 18 V. Furthermore, the frequency noise characteristics of the device under different posttreatment processes were systematically analyzed, which indicated that the combination of thermal annealing and isopropanol rinsing can suppress field-driven ion migration and surface conduction channel, thereby increasing the resistivity of the perovskite material and reducing the noise current of the device. Our results revealed that the Cs₂AgBiBr₆ SCs-based X-ray detector with high sensitivity and low cost has a great potential for application in manufacturing lead-free and stable radiation detection electronics in the future.

The sensitive detection of low-dose X-ray radiation is essential to many X-ray applications. In this article, the ultrasensitive X-ray detector based on pure Cs ₂ AgBiBr ₆ all-inorganic lead-free perovskite film is successfully demonstrated and encapsulated using a metal casing with a Be window. The high-quality Cs ₂ AgBiBr ₆ films are obtained through the low-cost solution process with long electron–hole diffusion length (~700 nm) and long carrier lifetime (~750 ns). Benefiting from the excellent properties of the Cs ₂ AgBiBr ₆ film and the stable ambient provided by the packaging module, the resulting device exhibits attractive X-ray detection capabilities with a minimum detectable dose rate of 145.2 ${\mathrm {nGy}}_{air}\text{s}^{-1}$ and a detection sensitivity up to $1.8\times 10^{4}\,\,\mu {\mathrm {CGy}}_{air}{}^{-1}$ cm ⁻² , which is about a thousand times higher than the sensitivity achieved with commercial a-Se X-ray detectors. Besides, the encapsulated device maintains superior detection performance after 2 months of storage, indicating the favorable reliability of the encapsulated device. This article demonstrates a possibility to use Cs ₂ AgBiBr ₆ perovskite film and Be window for the sensitive X-ray detection, which will inspire further development of radiation electronics by utilizing all-inorganic lead-free perovskite.

The ventrolateral periaqueductal gray (VLPAG) is thought to be the main PAG column for bladder control. PAG neurons (especially VLPAG neurons) and neurons in the pontine micturition center (PMC) innervating the bladder detrusor have anatomical and functional synaptic connections. The prevailing viewpoint on neural control of the bladder is that PAG neurons receive information on the decision to void made by upstream brain regions, and consequently activate the PMC through their direct projections to initiate urination reflex. However, the exact location of the PMC-projecting VLPAG neurons, their activity in response to urination, and their whole-brain inputs remain unclear. Here, we identified the distribution of VLPAG neurons that may participate in control of the bladder or project to the PMC through retrograde neural tracing. Population Ca2⁺ signals of PMC-projecting VLPAG neurons highly correlated with bladder contractions and urination as shown by in vivo recording in freely moving animals. Using a RV-based retrograde trans-synaptic tracing strategy, morphological results showed that urination-related PMC-projecting VLPAG neurons received dense inputs from multiple urination-related higher brain areas, such as the medial preoptic area, medial prefrontal cortex, and lateral hypothalamus. Thus, our findings reveal a novel insight into the VLPAG for control of bladder function and provide a potential therapeutic midbrain node for neurogenic bladder dysfunction.

Halide perovskites have attracted worldwide attention in recent years due to their fundamental scientific importance and practical applications in energy harvesting fields. However, its toxicity and instability are hindering the commercial applications of halide perovskite-based devices. Recently discovered inorganic lead-free Cs₂AgBiBr₆ double perovskite exhibits excellent optical and electronic properties and can be considered as a candidate for photovoltaic devices. In this work, we report the photoelectric performance of the Cs₂AgBiBr₆ single crystal as a photodetector both macro- and microscopically. By utilizing a nanoscale probe as a top electrode, it is discovered that the photogenerated carriers are effectively collected, as in the case of macroscopic electrodes. More importantly, the photocurrent is enhanced as the applied nanoscale mechanical load increases, which indicates that the local bandgap of the Cs₂AgBiBr₆ single crystal decreases with the increased nanoscale stress, showing similar tendency with the first-principles calculation result. The reported finding establishes a strategy to enhance the performance of photodetectors, which will be a great help in improving the performance of future optoelectronic devices and energy harvesting devices at the nanoscale.

Randomly distributed topological defects created during the spontaneous symmetry breaking are the fingerprints to trace the evolution of symmetry, range of interaction, and order parameters in condensed matter systems. However, the effective mean to manipulate topological defects into ordered form is elusive due to the topological protection. Here, we establish a strategy to effectively align the topological domain networks in hexagonal manganites through a mechanical approach. It is found that the nanoindentation strain gives rise to a threefold Magnus-type force distribution, leading to a sixfold symmetric domain pattern by driving the vortex and antivortex in opposite directions. On the basis of this rationale, sizeable mono-chirality topological stripe is readily achieved by expanding the nanoindentation to scratch, directly transferring the randomly distributed topological defects into an ordered form. This discovery provides a mechanical strategy to manipulate topological protected domains not only on ferroelectrics but also on ferromagnets/antiferromagnets and ferroelastics.