Achieving Phase-Matching in Nonlinear Optical Materials CsMInS (M = Cd/In, Hg/In) by the Incorporation of Unprecedented Trigonal Planar MS Motifs.

The trigonal planar unit possesses significant hyperpolarizability and polarizability anisotropy, which makes it useful for optimizing nonlinear optical (NLO) materials, however, chalcogenide with this unit has seldom been reported. In this work, a novel approach is introduced by integrating the unprecedented trigonal planar MS (M = Cd/In, Hg/In) motifs into the nearly optically isotropic tetrahedral units, resulting in two novel chalcogenides CsMInS (M = Cd/In, 1; Hg/In, 2). Notably, structures 1 and 2 feature nearly planar triangular units at the center, encircled by three trimers, further interconnecting each other to create 3D frameworks.

Salt-inclusion chalcogenides with d-orbital components: unveiling remarkable nonlinear optical properties and dual-band photoluminescence.

Metals containing d-orbitals are typically characterized by strong deformation and polarization, yet they tend to induce narrow bandgaps that render them little-appreciated by high-power nonlinear optical (NLO) crystals. Incorporating highly electropositive polycations into d-orbital-containing chalcogenides to modify them into salt-inclusion chalcogenides (SICs) that are competitive in NLO materials, is a viable solution to this predicament. In the present work, two isostructural SICs [KCl][MGaS] (M = Mn, 1; Hg, 2) are successfully synthesized by the high-temperature molten-salt growth method.

HgBr: an easily growing wide-spectrum birefringent crystal.

Birefringent materials are of great significance to the development of modern optical technology; however, research on halide birefringent crystals with a wide transparent range remains limited. In this work, mercuric bromide (HgBr) has been investigated for the first time as a promising birefringent material with a wide transparent window spanning from ultraviolet (UV) to far-infrared (far-IR) spectral regions (0.34-22.

Nonlinear Optical Phosphide CuInSiP: The Inaugural Member of Diamond-Like Family I-III-IV-V Inspired by ZnGeP.

Noncentrosymmetric phosphides have garnered significant attention as promising systems of infrared (IR) nonlinear optical (NLO) materials. Herein, a new quaternary diamond-like phosphide family I-III-IV-V and its inaugural member, namely, CuInSiP (CISP), were successfully fabricated by isovalent and aliovalent substitution based on ZnGeP. First-principles calculations revealed that CISP has a large NLO coefficient ( = 110.

Ultralow Dark Current (6 fA at 1 V) in Quasi-Two-Dimensional CsGaGeSe Single Crystals for High Signal-to-Noise Ratio Photodetectors under Strong Electron Localization.

To satisfy the demands of photodetectors for weak-light detection, materials selected for device fabrication should have an extremely low background carrier concentration to suppress the dark current of devices. In this work, a new quasi-two-dimensional CsGaGeSe single crystal with an extremely low background carrier concentration was synthesized by a co-solvent reaction based on which a photoconductive detector was prepared with an ultralow dark current density (6 fA at 1 V and ∼10 A cm) and a high response speed (∼0.74 s) was achieved, presenting a great potential of being applied to the field of weak-light detection.

Activating ryanodine receptor improves isoflurane-induced cognitive dysfunction.

Background: Postoperative cognitive dysfunction (POCD) is characterized by impaired learning and memory. 6 h duration isoflurane anesthesia is an important factor to induce POCD, and the dysfunction of ryanodine receptor (RyR) in the hippocampus may be involved in this process. We investigated the expression of RyR3 in the hippocampus of mice after 6-h duration isoflurane anesthesia, as well as the improvement of RyR receptor agonist caffeine on POCD mice, while attempting to identify the underlying molecular mechanism.

Excellent Nonlinear Optical M[M Cl][Ga S ] (M = A/Ba, A = K, Rb) Achieved by Unusual Cationic Substitution Strategy.

The typical chalcopyrite AgGaQ (Q = S, Se) are commercial infrared (IR) second-order nonlinear optical (NLO) materials; however, they suffer from unexpected laser-induced damage thresholds (LIDTs) primairy due to their narrow band gaps. Herein, what sets this apart from previously reported chemical substitutions is the utilization of an unusual cationic substitution strategy, represented by [[SZn ]S + [S Zn ]S + 11ZnS ⇒ MS + [M Cl]S + 11GaS ], in which the covalent S Zn units in the diamond-like sphalerite ZnS are synergistically replaced by cationic M Cl units, resulting in two novel salt-inclusion sulfides, M[M Cl][Ga S ] (M = A/Ba, A = K, 1; Rb, 2). As expected, the introduction of mixed cations in the GaS anionic frameworks of 1 and 2 leads to wide band gaps (3.

Cs Zn P S I : the Largest Birefringence in Chalcohalide Achieved by Highly Polarizable Nonlinear Optical Functional Motifs.

Chalcohalides not only keep the balance between the nonlinear optical (NLO) coefficient and wide band gap, but also provide a promising solution to achieve sufficient birefringence for phase-matching ability in NLO crystals. In this study, a novel chalcohalide, Cs Zn P S I (1) is successfully synthesized, by incorporating the highly electropositive Cs and the large electronegative I element into the zinc thiophosphate. Its 3D open framework features an edge-shared by distorted [ZnS ], ethanol-like [P S ], and unusual [ZnS I ] polyhedrons, which is inconsistent with the soft-hard-acids-bases theory.

Breaking the bottleneck of simultaneously wide band gap and large nonlinear optical coefficient by a "pore reconstruction" strategy in a salt-inclusion chalcogenide.

The template-based design of the crystal structure is a direct and highly efficient method to achieve optimal nonlinear optical (NLO, meaning second-order NLO) performances. The structural flexibility of porous salt-inclusion chalcogenides (SICs) provides an alternative platform for modulating the enlargement of the band gap (that is generally positive with laser-induced damage threshold) and second harmonic generation (SHG) response simultaneously. By applying the "pore reconstruction" strategy to SIC [KCl][MnGaS] (1), a new derivative KRb[KCl][LiMnGaS] (2) is successfully isolated, which unusually features a heterologous nanopore framework with inner diameters of 8.

Nonlinear Optical Sulfides LiMGa S (M = Rb/Ba, Cs/Ba) Created by Li Driven 2D Centrosymmetric to 3D Noncentrosymmetric Transformation.

Cations that can regulate the configuration of anion group are greatly important but regularly unheeded. Herein, the structural transformation from 2D CS to 3D noncentrosymmetric (NCS, which is the prerequisite for second-order NLO effect) is rationally designed to newly afford two sulfides LiMGa S (M = Rb/Ba, 1; Cs/Ba, 2) by introducing the smallest alkali metal Li cation into the interlamination of 2D centrosymmetric (CS) RbGaS . The unusual frameworks of 1 and 2 are constructed from C -type [Ga S ] supertetrahedrons in a highly parallel arrangement.

Open honeycomb frameworks of sulphides AHgGaS (A = Rb, Cs) exhibiting infrared nonlinear optical properties.

A crystal structure with a diamond-like anionic framework belongs to a non-centrosymmetric macrostructure due to the aligned arrangement of tetrahedral units, meeting the premise of second-order nonlinear optical (NLO) materials. Herein, two new Hg-based sulphides, namely RbHgGaS (1) and CsHgGaS (2), which are isostructural and crystallise in the trigonal space group 3, are successfully isolated in sealed silica tubes by a solid-state reaction. The features of their three-dimensional open honeycomb frameworks are attributed to the parallel alignment of tetrahedral MS (M is disordered by 0.

[K PbX][Ga S ] (X = Cl, Br, I): The First Lead-Containing Cationic Moieties with Ultrahigh Second-Harmonic Generation and Band Gaps Exceeding the Criterion of 2.33 eV.

In contrast to anionic group theory of nonlinear optical (NLO) materials that second-harmonic generation (SHG) responses mainly originate from anionic groups, structural regulation on the cationic groups of salt-inclusion chalcogenides (SICs) is performed to make them also contribute to the NLO effects. Herein, the stereochemically active lone-electron-pair Pb cation is first introduced to the cationic groups of NLO SICs, and the resultant [K PbX][Ga S ] (X = Cl, Br, I) are isolated via solid-state method. The features of their three-dimensional structures comprise highly oriented [Ga S ] and [K PbX] frameworks derived from AgGaS , which display the largest phase-matching SHG intensities (2.

Photochromic Semiconductors: Bottom-Up Strategy to Construct Type II-Stacking Viologen π-Aggregates.

Semiconductor conductivities depend largely on the crystal structures and the associated electronic structures. If the electronic structures can be switched reversibly in the same crystal structure, then a drastic conductivity change may be controllable. The effect of electron transfer (ET) on semiconductor conductivity remained elusive so far.

AAgGaSe (A = Rb, Cs): second-harmonic generation responses realized through the parallel arrangement of AgSe and GaSe tetrahedrons.

Two new quaternary selenides AAgGaSe, (A = Rb, 1; Cs, 2) were synthesised solid-state reaction in sealed silica tubes. Compounds 1 and 2 crystallised in the monoclinic space group (no. 8) and their three-dimensional [AgGaSe] anionic frameworks were comprised of AgSe and GaSe tetrahedrons.

AInSCl (A = Rb and Cs) and PbSnQCl (Q = S and Se): quaternary chalcohalides with mixed anionic coordination exhibit photocurrent responses.

Mixed-anionic compounds have caught considerable attention due to their flexible coordination manners and abundant physical properties. Four new chalcohalides RbInSCl (1), CsInSCl (2), PbSnSCl (3) and PbSnSeCl (4) were successfully obtained by the high-temperature halide salt flux method. Compounds 1 and 2 have layered structures that consist of octahedral InS and aliovalent-anionic InSCl units.

Broad transparency and wide band gap achieved in a magnetic infrared nonlinear optical chalcogenide by suppressing d-d transitions.

Magnetic infrared (IR) nonlinear optical (NLO) materials, particularly those containing d-block metals, have attracted considerable attention due to the contributions of d-orbitals to large NLO efficiency. However, the d-d transitions from the d-block metals lead to strong optical absorption and narrow band gap, seriously hindering their practical applications. The structural flexibility of salt-inclusion systems provides a good opportunity for modulating the crystal field of magnetic ions to suppress the d-d transitions but allowing the NLO-active d-s and d-p transitions.

Photocurrent, humidity sensitivity and proton conductivity properties of a new sulfide semiconductor CsCuS.

Copper chalcogenides have drawn considerable attention due to their prominent semiconducting properties. A new Cu-containing semiconductor, namely, CsCuS (1), was obtained by a halide salt flux method. Its structure featured 1D infinite ∞1[CuS] chains, where the polysulfide anion S was relatively rare in Cu chalcogenides.

TREM2 and CD163 Ameliorate Microglia-Mediated Inflammatory Environment in the Aging Brain.

Aging decreases cognitive functions, especially learning and memory. Neuroinflammation is mediated by microglia and occurs in age-related neurodegenerative diseases. The expression profiles in a dataset of cognitively normal controls (GSE11882) were obtained from the Gene Expression Omnibus (GEO) database.

Optimizing the Nonlinear Optical Performance of an A-N-M-Q (A: Alkali Metal; N: Metal; M: Main Group Metal; Q: Chalcogen) System.

Exploring new infrared nonlinear optical (IR NLO) materials with superior overall properties is scientifically and technically important. However, large second-order harmonic generation (SHG) efficiencies and high laser-induced damage thresholds (LIDT) are incompatible, which makes realizing this goal a challenge. The IR NLO performance of an A-N-M-Q (Q: chalcogen) system was optimized by simultaneously modulating A/(M + N) and M/N ratios (A: alkali metal; N, M: tetra-coordinated metals), and SHG-LIDT balance was achieved.

Balanced infrared nonlinear optical performance achieved by modulating the covalency and ionicity distributions in the electron localization function map.

The nonlinear optical (NLO) efficiency () and laser-induced damage threshold (LIDT) of a material are mainly determined by their covalency and ionicity, respectively, the incompatibility between which makes balancing the and LIDT challenging in an IR NLO material. The topological feature (fractal dimension) of the electron localization function (ELF) map (distribution of covalency and ionicity) was evaluated for a series of NLO materials, and, phenomenologically, the fine mixing of covalency and ionicity will benefit a balanced and LIDT. Chemical bonds with different interaction strengths were introduced simultaneously to mix the covalency and iconicity finely, and three new IR NLO sulfides, ABaLiGaS (A = K, 1; Rb, 2; Cs, 3), were obtained.

2D van der Waals Layered [C(NH)]SOS Exhibits Desirable UV Nonlinear-Optical Trade-Off.

It remains a challenge to develop UV nonlinear optical (NLO) crystals that can achieve a desirable trade-off on UV absorption edge, second harmonic generation (SHG), and birefringence. Here we report a thiosulfate UV NLO crystal of a 2D van der Waals layered structure, [C(NH)]SOS. Remarkably, this thiosulfate realizes the desired trade-off, with a short absorption edge of 254 nm, a strong SHG response of approximately 2.

Uncovering a Functional Motif of Nonlinear Optical Materials by In Situ Electron Density and Wavefunction Studies Under Laser Irradiation.

Exploring nonlinear optical (NLO) functional motifs (FM, the structural origin of NLO efficiency) is vital for the rational design of NLO materials. Normal spectrum techniques applied in studying photon exciting materials are invalid for NLO materials, in which electrons are not excited substantially but only distorted under laser. A general strategy of determining NLO FM is proposed by comparative studies of experimental electron density (ED) without and under the laser.

AMnAsS (A = Cs, Rb): Phase-Matchable Infrared Nonlinear Optical Functional Motif [AsS] Obtained via Surfactant-Thermal Method.

Exploration of a new nonlinear optical (NLO)-active functional motif is important in the rational design of promising infrared (IR) NLO materials. Compared with typical tetrahedral MQ (M = IIB, III, IV metals; Q = S, Se) motifs, MQ (M = As, Sb) pyramids favor high second-harmonic generation (SHG) efficiency while frequently hindering phase matching (PM) because of excessively large optical anisotropy. The surfactant-thermal method was first adopted to achieve PM in MQ-containing systems and synthesize mixed covalent-ionic IR NLO materials.