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High light yield, low detection limit, large X-ray attenuation efficiency and nontoxic composition are critical features of scintillators for ionizing radiation detection. We herein demonstrated a new layered organic–inorganic hybrid cuprous iodide single crystal (C6H10N2)2Cu2I3(PO2)3 (C6H10N22+ = 1,4-phenylenediaminium) for X-ray detection and imaging. Upon UV light excitation, (C6H10N2)2Cu2I3(PO2)3 displays highly efficient yellow light emission with one dominant peak located at 578 nm, a large Stokes shift of 160 nm, and a high photoluminescence quantum yield (PLQY) of 96.4%. This crystal could also exhibit radioluminescence with a high scintillation light yield of 32 000 photons MeV−1. A detection limit of ∼39 nGyair s−1 is determined, which is far lower than the required value of 5.5 μGyair s−1 for regular medical diagnostics. Moreover, the (C6H10N2)2Cu2I3(PO2)3-based scintillation screen exhibits high-performance for X-ray imaging with a spatial resolution of 11.14 lp mm−1, indicating the great potential in X-ray radiography. In brief, combined merits of low toxicity and cost, negligible self-absorption, a low detection limit, a high light yield and a spatial resolution make (C6H10N2)2Cu2I3(PO2)3 an excellent candidate for X-ray scintillation. [ABSTRACT FROM AUTHOR]

Chiral hybrid Mn (II)‐based halides have attracted great interest in the optoelectronic field due to their low cost, non‐toxicity, abundant structural diversity, and excellent photoluminescence, chiroptical, and nonlinear optical characteristics. Here, chiral hybrids (R/S‐MBA)MnCl3·CH3OH (MBA = C6H5CH(CH3)NH3+) and (R/S‐NPA)Cl·H2O and (R, S‐NPA)Cl (NPA = C10H7CH(CH3)NH3+) single crystals are successfully obtained using methanol (CH3OH) as an induced‐crystallization reagent by slow evaporation method. Interestingly, (R/S‐MBA)MnCl3·CH3OH single crystals with obvious circular dichroism (CD) characteristics exhibit the strong red emission characteristics originating from the d‐d transition of Mn2+ cation, while (R/S‐NPA) Cl·H2O and (R, S‐NPA)Cl exhibit blue emission originating from the organic NPA group. Based on their chiral space group P21 (no.4), (R/S‐MBA)MnCl3·CH3OH single crystals show excellent circularly polarized luminescence (CPL) with a relatively high luminescence dissymmetry factor (glum) value, which is equivalent to that of reported Mn (II)‐based metal halides. Also, (R/S‐NPA)Cl·H2O and (R/S‐MBA)MnCl3·CH3OH exhibit the obvious second harmonic generation (SHG) response. This work not only deepens the understanding of the role of methanol‐induced crystallization in improving the quality and growth habits of Mn (II)‐based halide hybrid single crystals, but also provides guidance for further structural design, crystal growth, and optoelectronic applications of multi‐functional chiral hybrid Mn (II)‐based halide materials. [ABSTRACT FROM AUTHOR]

By combining stereochemically active lone-pair d10 metal Cd2+ with halogen anions was identified as an effective method to obtain enhanced nonlinear optical (NLO) materials. In this work, hybrid lead-free perovskite [Me3NCH2Cl]CdCl3 (abbreviated as (TMCM)CdCl3) bulk crystals were grown by the solution method, which demonstrates the one-dimensional chainlike perovskite structure with distorted {CdCl6} irregular octahedrons. The environmental, temperature, and atmospheric stabilities were systematically evaluated with a reversible transition and the phase decomposition point were determined at 125 and 271 °C, respectively. In addition, high environmental and high solvent atmospheric stability were also detected. A wide transparent region (200–900 nm) and wide band gap of 5.24 eV were determined with a moderate second harmonic generation (SHG) response of 0.73 times that of KH2PO4. Furthermore, theoretical calculations were performed to investigate the relationship between structure and performance, and an applicable birefringence of 0.043 was calculated at 1064 nm. All the results make (TMCM)CdCl3 a promising candidate for NLO material, which may also have potential applications in the solar-blind UV region. [ABSTRACT FROM AUTHOR]

The practical application of lead‐free double perovskite Cs2AgBiBr6 in photocatalytic H2 evolution is still restricted due to the low activity and poor stability. The rational design of lead‐free halide double perovskites heterojunctions with efficient charge transfer and effective active sites is a potential route to achieve the ideal prospect. Herein, in this work an S‐scheme heterojunction of Cs2AgBiBr6 with enriched Br‐vacancies and WO3 nanorods (VBr‐Cs2AgBiBr6/WO3) obtaining excellent visible‐light responsive photocatalytic H2 evolution performance and durable stability is reported. The S‐scheme heterojunction driven by the unaligned Fermi levels of these two semiconductors ensures the efficient charge transfer at the interface, and density functional theory calculations reveal the enriched Br vacancies on Cs2AgBiBr6 (022) surfaces introduced by atom thermal vibration provide effective active sites for hydrogen evolution. The optimized VBr‐Cs2AgBiBr6/WO3 S‐scheme photocatalyst exhibits the photocatalytic hydrogen evolution rate of 364.89 µmol g−1 h−1 which is 4.9‐fold of bare VBr‐Cs2AgBiBr6 (74.44 µmol g−1 h−1) and presents long‐term stability of 12 h continuous photocatalytic reaction. This work provides deep insights into the photocatalytic mechanism of VBr‐Cs2AgBiBr6/WO3 S‐scheme heterojunctions, which emerges a new strategy in the applications of perovskite‐based photocatalysts. [ABSTRACT FROM AUTHOR]

Organic phosphate nonlinear optical (NLO) materials, especially with the introduction of π-conjugated organic cations, have attracted attention due to their excellent performance and promising applications. Here, by combining the π-conjugated organic cationic 2-(aminomethyl)pyridine ((C6H9N2)+) with the inorganic moiety H2PO4−, a novel (C6H9N2)H2PO4 ((2-Ampy)H2PO4) crystal with a non-centrosymmetric structure has been grown by the slow evaporation method under the conditions of RT and ambient atmosphere. The data about the crystal structure, optical, thermal, photoluminescence and nonlinear optical properties were sufficiently studied. (2-Ampy)H2PO4 exhibits a high diffuse reflection with wide transparent range and appropriate thermal stability. Furthermore, an obvious photoluminescence characteristic was presented and displayed two emission peaks with positions at about 385 and 489 nm, while the average PL lifetime was 5.36 μs under the excitation of 300 nm. Importantly, SHG about 0.3× that of KDP is attributed to the hydrogen bond and π-conjugated cationic effects for (2-Ampy)H2PO4 crystal powder. By DFT calculations, the simulated band gap is about 3.84 eV, and the electronic states around the forbidden gap are largely determined by the combined effects of the (2-Ampy)+ and (H2PO4)− groups' contribution to the optical features. All the above characteristics should be beneficial to the design and application of novel organic–inorganic hybrid phosphate NLO materials. [ABSTRACT FROM AUTHOR]