Recently, three-dimensional (3D) halide perovskites were considered as Xray detection materials because of their high mobility, carrier lifetime, and absorption of Xray radiation. However, their detection sensitivity and instability at extreme conditions and environments still require optimization. In our present research work, we report using onedimensional (1D) inorganic halide perovskite CsPbI 3 crystals for stable X-ray detection. Remarkably, an X-ray detector made of CsPbI 3 has a high sensitivity of 2.37 mC•Gy −1 • cm −2 , which is an order of magnitude greater than that of detectors using 3D halide perovskites reported previously. The high-sensitivity X-ray detection of CsPbI 3 crystals is attributed to their high resistivity of 7.4 × 10 9 Ω•cm and large carrier mobility−lifetime product of 3.63 × 10 −3 cm 2 •V −1 . Our investigation demonstrates the quite promising applications of X-ray detectors made of the low-dimensional perovskite crystals.

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Polarization change induced by directional electron transfer attracts considerable attention owing to its fast switching rate and potential light control. Here, we investigate electronic pyroelectricity in the crystal of a mononuclear complex, [Co(phendiox)(rac-cth)] (ClO 4)•0.5EtOH (1•0.5EtOH, H 2 phendiox = 9, 10-dihydroxyphenanthrene, rac-cth = racemic 5, 5, 7, 12, 12, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradecane), which undergoes a twostep valence tautomerism (VT). Correspondingly, pyroelectric current exhibits double peaks in the same temperature domain with the polarization change consistent with the change in dipole moments during the VT process. Time-resolved Infrared (IR) spectroscopy shows that the photo-induced metastable state can be generated within 150 ps at 190 K. Such state can be trapped for tens of minutes at 7 K, showing that photo-induced polarization change can be realized in this system. These results directly demonstrate that a change in the molecular dipole moments induced by intramolecular electron transfer can introduce a macroscopic polarization change in VT compounds.

Pyroelectricity plays a crucial role in modern sensors and energy conversion devices. However, obtaining materials with large and nearly constant pyroelectric coefficients over a wide temperature range for practical uses remains a formidable challenge. Attempting to discover a solution to this obstacle, we combined molecular design of labile electronic structure with the crystal engineering of the molecular orientation in lattice. This combination results in electronic pyroelectricity of purely molecular origin. Here, we report a polar crystal of an [FeCo] dinuclear complex exhibiting a peculiar pyroelectric behavior (a substantial sharp pyroelectric current peak and an unusual continuous pyroelectric current at higher temperatures) which is caused by a combination of Fe spin crossover (SCO) and electron transfer between the high-spin Fe ion and redox-active ligand, namely valence tautomerism (VT). As a result, temperature dependence of the pyroelectric behavior reported here is opposite from conventional ferroelectrics and originates from a transition between three distinct electronic structures. The obtained pyroelectric coefficient is comparable to that of polyvinylidene difluoride at room temperature.

Addition of Ru to Pd/γ-Al2O3 can improve the catalyst's activity and maintain the high selectivity for 2-ethylanthraquinone hydrogenation.

Organic-inorganic hybrid perovskite materials have attracted great attention for their great application potential in photovoltaics and optoelectronics. Among them, some 2D and 1D lead-iodide-based perovskites were found to exist room...

Molecule-based ferroelectrics are a class of highly desirable intelligent materials for their rich switchable physical properties, easy and environmentally friendly processing, especial lightweight and mechanical flexibility. In the current work, a new molecule-based ferroelectrics pyridin-4-ylmethanaminium perchlorate was discovered undergoing paraelectric–ferroelectric phase transition at T c = 258.40(8) K and ferroelectric–ferroelectric phase transition at T 1 = 255.93(2) K. It crystallizes in monoclinic crystal system with a centrosymmetric space group of C2/c at 293 K and also crystallizes in monoclinic crystal system but with a polar space group of Cc at 223 K. The spontaneous polarization can reach 1.25 μC/cm2 and the coercive field is about 2.6 kV/cm below 254 K. The paraelectric–ferroelectric phase transition belongs to displacive phase transition and the nearby ferroelectric–ferroelectric phase transition contains order–disorder features, which consistent with the dynamic process including deformations of each pyridin-4-ylmethanaminium cation and the resulting difference for −NH2 to be protonated. Because of the high pyroelectric coefficient values and small-amplitude anomalies of the ε′ values in the vicinity of T 1 temperature, pyridin-4-ylmethanaminium perchlorate shows two ultrahigh pyroelectric figures of merit (FOMs) with M 1 ≈ 0.16 cm2/μC and M 2 ≈ 0.21 cm3/2·J–1/2. The ultrahigh FOMs could make pyridin-4-ylmethanaminium perchlorate a potential element of the sensitive small-area pyroelectric detectors or pyroelectric vidicons.