Layered hybrid halide compounds offer promising functional properties, particularly tunable band gaps, conductivity, light harvesting thus making them prospective for applications in photovoltaics and optoelectronics. This study exemplifies an approach of predicting band gaps using machine learning models enhanced by invariant topological representations of these materials using the atom-specific persistent homology method in order to facilitate the discovery and design of new hybrid halide materials with tailored electronic properties.

The organo-inorganic coordination polymer Cu6I6(HMTA)(2) (HMTA - hexamethylenetetramine) has been explored as a scintillator for X-ray imaging applications. This material, synthesized from readily available precursors via a scalable solution-based method, exhibits high photoluminescence quantum yield (>95%) and exceptional thermal and radiation stability. Composite scintillation screens (CSS) were fabricated by embedding Cu6I6(HMTA)(2) nanoparticles into an ethylene-vinyl acetate (EVA) matrix, achieving high phosphor loading (up to 75 wt %) while maintaining mechanical flexibility. These CSS exhibited a maximum light yield of 63,500 photons/MeV and spatial resolution up to 18 lp/mm (line pairs/mm). Thin-film scintillators, produced by depositing Cu6I6(HMTA)(2) on porous membranes, achieved an even higher spatial resolution of 24.5 lp/mm but showed reduced mechanical robustness. Remarkably, Cu6I6(HMTA)(2)-based screens demonstrated superior radiation stability, retaining 95% of their initial radioluminescence intensity after exposure to high X-ray doses (similar to 100 Gy). These results highlight the potential of Cu6I6(HMTA)(2) as a high-performance scintillator for X-ray imaging applications.

The dependence of the degree of sorption of potassium dichromate by aerogels based on reduced graphite oxide and superparamagnetic iron oxide nanoparticles of the rGO⋅Fe3O4 composition on the mass of the sorbent, acidity, and temperature of the medium is studied. It is shown that in order to increase the degree of potassium dichromate sorption by the rGO⋅Fe3O4 magnetic aerogel, the process is best carried out at room temperature in media with low pH value lower than 5. The results obtained make it possible to propose aerogels rGO⋅Fe3O4 as environmentally friendly sorbents for water purification from the carcinogenic substance of potassium dichromate. The proposed materials after completion of the sorption process can be completely removed from the reaction medium using an external magnetic field, thereby preventing them from acting as pollutants. It is important to note that the described 3D structures based on GO and nanoparticles of superparamagnetic iron oxide Fe3O4 are of practical importance for the treatment of wastewater from enterprises using an oxidative method for removing phenols, cresols, and cyan-containing substances from impurities using potassium dichromate and sulfuric acid.

Perovskite solar cells (PSCs) have demonstrated substantial development over the past decade; however, this type of device still suffers from insufficient exploitation stability. In this work, a surface passivation approach with compact meldonium zwitterions is successfully applied for the first time. The chemical structure of meldonium zwitterions allows one to achieve a combined effect on perovskite materials, simultaneously improving their optoelectronic properties and stability toward various stress factors. PSCs similarly respond to meldonium passivation via the increase of both power conversion efficiency and thermo-photostability of encapsulated devices. A mechanism of hybrid perovskite passivation by meldonium zwitterions and subsequent stabilization of the light-absorbing material is suggested in this work for the first time.

We proposed a simple approach for quickly identifying the dimensionality of inorganic substructures, types of connections of lead halide polyhedra and structure types using common powder XRD data and a ML-decision tree classification model.

The effectiveness of an aerogel based on rGO@Co3O4 for purifying aqueous solutions from organic contaminants has been demonstrated. Experiments were carried out on the sorption of organic dyes (methylene blue, methyl orange) from solutions of varying acidity. The effective destruction of anticancer antibiotics (doxorubicin, mitomycin C) under the influence of UV irradiation in the presence of rGO@Co3O4 aerogel has also been shown.

For the first time, based on symmetry group–subgroup relation-ships, an approach is presented to create a clear classification of hybrid lead halides with low-dimensional vacancy-ordered perovskite-related crystal structures to facilitate the identification and prediction of hybrid lead-halide materials that have desired properties.

The synergistic effect of ionic liquid 1-(2-hydroxyethyl)-3-methyl-1H-imidazol-3-ium cinnamate and methylammonium chloride (MACl) on the functional properties of mixed hybrid perovskites was discovered for the first time, which leads to a notable improvement in the quality of perovskite films and the photothermal stability of perovskite solar cells compared to reference devices.

Hybrid copper(I) halides are nowadays the subject of intensive studies as promising materials for various optoelectronic applications. This class of materials is characterized by wide structural diversity enabled by a great variety in the size and shape of organic cations. Therefore, the search and analysis of composition-structure-property relationships is a key step for the rational design of new hybrid halide materials with desired properties. In this paper, we comprehensively studied two ACl/CuCl systems with dimethylammonium (DMA(+)) and acetamidinium (Ac+) organic cations and proved the formation of five new crystalline phases: DMACu(2)Cl(3), DMACuCl(2), DMA(4)[Cu2Cl6], DMA(3)CuCl(4), and AcCuCl2. Based on X-ray diffraction and Raman spectroscopy, the discovered phases are characterized by a reduced dimensionality of inorganic sublattice (1D or 0D) and loosely packed crystal structure. Depending on the structure, these phases demonstrate photoluminescence in the range from red to blue (at room temperature and at 77 K), and "0D" phases show a high quantum yield up to 80%. Additionally, the studied hybrid chlorocuprates with compact organic cations were found to have melt without decomposition at relatively low temperatures (from 32 to 120 degrees C), which provides prospects for potentially useful low-temperature facile processing of novel efficient light-emitting materials.

The ionic liquid choline cinnamate was applied for the first time as a defect passivator in light-absorbing layers of perovskite solar cells (PSCs). It was found that bulk passivation with an addition of 0.5% ionic liquid notably enhances the photothermal stability of PSCs, while surface passivation leads to the opposite effect with the loss of device stability, due to the complex origin of the influence of choline cinnamate on the defect structure and microstructure of hybrid halide perovskites.

In recent years, hybrid manganese(II) halides (HMHs) have attracted wide attention due to their impressive optical properties, low toxicity, and facile synthetic processibility. Being effective reab-sorption-free phosphors, these compounds demonstrate the potential to be used as low-cost solu-tion-processable scintillators. However, most of the HMHs studied to date contain bulk organic cations and, as a result, are characterized by low density and low X-ray stopping power. For this reason, we studied manganese(II) halides with compact organic cations such as formamidinium (FA+) and acetamidinium (Ac+). In particular, we synthesized four new phases, two of which are characterized by octahedral coordination of manganese ions (FAMnBr3, AcMnBr3) and red emis-sion, whereas the other two have tetrahedrally coordinated Mn2+ ions (FA3MnBr5, Ac2MnBr4) and green emission. Photoluminescence (PL) and radioluminescence measurements demonstrated high PL quantum yields and reasonable scintillation light yields of acetamidinium-based compounds. In addition, unlike most known HMH-based scintillators, the discovered materials have a relatively high density, due to the small fraction of the volume occupied by organic cations, so their X-ray attenuation coefficients are comparable to the well-known oxide scintillators.

Theoretical assessment of Cl-excessive, mixed-halide grain boundaries in hybrid perovskite thin films demonstrates that ordered 3D/2D interfaces along perovskite (100) crystallographic planes are the most energetically favored among other possible cases.

In solar cells, hybrid halide perovskites operate under constant bias, thus their stability towards electric field-induced degradation is of key importance. Here we report on evidence of previously unidentified electric field-induced transitions and degradation path of CH 3 NH 3 PbI 3 (MAPbI 3 ) using elemental and phase mapping. Thin films of MAPbI 3 were deposited onto 1–2 µm-pitch interdigitated electrodes and subjected to direct current (DC)-polarization. The MAPbI 3 layer polarized with < 0.8 V/µm DC electric field undergoes pronounced ion redistribution to methylammonium-rich MAPbI 3− y ( y < 0.6) and iodine-rich MA 1− x PbI 3 ( x < 0.3) regions. Polarization-induced loss of both methylammonium and iodine provokes degradation of MAPbI 3 . Using nanofocus grazing-incidence wide-angle X-ray scattering (GIWAXS), we unambiguously showed that the bias voltage induces the transformation of β-MAPbI 3 to metastable δ-MAPbI 3 polymorph via alignment of polar organic cation with the electric field. This transformation is partially reversible upon field removal. However, once formed, δ-MAPbI 3 disrupts the morphology of pristine film and undergoes decomposition to β-MAPbI 3 (β-MAPI) and PbI 2 . With the aforementioned compositional and phase changes, only MA-rich part serves as the charge separation layer, while the I-rich excitation is blocked with the PbI 2 barrier serving as holes trapping layer. These observations reveal the intermediate steps in electric-field-driven degradation of halide perovskites and show the role of polar cations in the process, which is instructive for further material design with higher stability metrics.

A new facile method for the synthesis of mixed-cation halide R2 = 0.9935 perovskites based on the chemical conversion of solid precursors (organic halides and lead halides) via an iodine-mediated transport reaction in inert liquid media under mild conditions is described. The equilibrium nature of the conversion provides an exact match between the stoichiometry of the resulting perovskite powder and the molar ratio of the precursors. This method can serve as a useful tool for the synthesis of complex perovskite precursors and the investigation of phase equilibria

L-Cysteine hydrochloride (CysCl) has been found to be an effective additive to hybrid halide perovskites, improving both the quality of perovskite films and the operando parameters of perovskite solar cells. The origin of the CysCl effect on the mixed-cation hybrid halide perovskite and related photovoltaic devices has been disclosed.

Hybrid halocuprates(i) are nowadays the subject of intensive studies as promising materials for various optoelectronic applications. This class of materials is characterized by wide structural diversity enabled by a great variety in the size and shape of organic cations. Therefore, the study of composition-structure-property relationships is a key step for the rational design of new halocuprate materials with desired properties. In this paper, we comprehensively studied MABr/CuBr and FABr/CuBr systems (MA(+) = methylammonium and FA(+) = formamidinium) and established the existence of five novel phases (namely, MACu(2)Br(3), FA(2)[Cu4Br6], MACuBr(2), FACuBr(2), and FA(3)CuBr(4)) related to four different structural types and three distinct A(+) : Cu+ stoichiometries (A(+) = MA(+)/FA(+)). The optical properties of the discovered phases are studied by absorption and low-temperature photoluminescence spectroscopy. Based on a crystal-chemical analysis, we explained a unique structural diversity of the MA- and FA-based bromocuprates, as well as revealed new structure-property relationships.

The balance between the mitochondrial respiratory chain activity and the cell's needs in ATP ensures optimal cellular function. Cytochrome c is an essential component of the electron transport chain (ETC), which regulates ETC activity, oxygen consumption, ATP synthesis and can initiate apoptosis. The impact of conformational changes in cytochrome c on its function is not understood for the lack of access to these changes in intact mitochondria. We have developed a novel sensor that uses unique properties of label-free surface-enhanced Raman spectroscopy (SERS) to identify conformational changes in heme of cytochrome c and to elucidate their role in functioning mitochondria. We have verified that molecule bond vibrations assessed by SERS are a reliable indicator of the heme conformation during changes in the inner mitochondrial membrane potential and ETC activity. We have demonstrated that cytochrome c heme reversibly switches between planar and ruffled conformations in response to the inner mitochondrial membrane potential (ΔΨ) and H+ concentration in the intermembrane space. This regulates the efficiency of the mitochondrial respiratory chain, thus, adjusting the mitochondrial respiration to the cell's consumption of ATP and the overall activity. We have found that under hypertensive conditions cytochrome c heme loses its sensitivity to ΔΨ that can affect the regulation of ETC activity. The ability of the proposed SERS-based sensor to track mitochondrial function opens broad perspectives in cell bioenergetics.

We introduce a simple and universal scalable encapsulation strategy for perovskite solar cells based on thermal vacuum evaporation of MgF2 or MoO3-x capping layer followed by sealing the device with glass and UV-curable polymer. The proposed encapsulation method is beneficial to most of the other known encapsulation approaches being fully harmless to perovskite and transporting layers and processible at room temperature. Vacuum deposition of the capping layer promotes efficient removal of water, oxygen and organic solvent residuals from the device prior to sealing and could be easily performed using standard equipment for metal electrode deposition. The proposed strategy is transferrable to any lab-scale perovskite solar cell prototypes regardless of their geometry and architecture and results in excellent stability of the devices in ambient air and long operating conditions. Upon the 1000 hours stability test at ambient air (30%-60% RH), the cells preserved 92.9% of their initial efficiency on average under 1 Sun illumination at constant maximum power point tracking (MPPT, ISOS-L-1) and over 96% under storage in the dark (ISOS-D-1), thus evidencing for the high effectiveness of the proposed encapsulation approach. (c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences.Published by ELSEVIER B.V. and Science Press. All rights reserved.

The unprecedented structural flexibility of hybrid halide perovskites is accompanied by a wide range of useful optoelectronic properties, causing a high interest in this family of materials. However, there are no systematic studies yet on the relationships between the topology of structures derived of chain 1D hybrid halide perovskites and their optoelectronic properties such as the band gap as already reported for 3D and 2D hybrid halide perovskites. In the present work, we introduce a rational classification of hybrid lead iodide 1D structures. We provide a theoretical assessment of the relationship between the topology of 1D hybrid halide perovskite-derived structures with vertex-connected octahedra and show that the distortions of geometry of the chains of PbI6 octahedra are the main parameters affecting the band gap value while the distance between the chains of vertex-connected octahedra has a minor effect on the band gap.

Surface passivation by various organic molecules is a widely used approach to compensate surface defects and to improve a stability of hybrid halide perovskites. For commonly used cationic passivators, the formation of 2D phases and related heterostructures is considered as an essential part of the passivation process. However, there is an intriguing fundamental question: is it possible to achieve effective and stable passivation by the thinnest possible layer? In this article, we applied an iodide salt of a new bulky bifunctional 11-carboxy-decylammonium cation (further AUDA+) as a passivator which can not only passivate both VI center dot and VMA ' defects but can also expectedly form on the 3D perovskite surface a dense and stable "monolayer" assembled due to the strong hydrogen bonds between the terminal carboxylic groups and, hereby, suppressing the passivator migration in the bulk of the perovskite. Applying a wide set of methods such as steady-state and time-resolved photoluminescence spectroscopy, X-ray diffraction, and scanning electron microscopy, we revealed that the passivation regime could be controlled by adjustment of two treatment parameters-the concentration of AUDA+I- and the post-annealing temperature resulting in either the formation of 2D/3D heterostructures or surface defect passivation by the "monolayer" without the formation of additional phases. The "monolayer" regime was found to provide a greater improvement of optical properties: photoluminescence intensity and average charge carrier lifetime increase by 10 and 2.5 times, respectively, and demonstrate significantly better properties after long-time light soaking. These results indicate that a fine tuning of passivation conditions provides a significant increase in photostability even without formation of a 2D capping layer, thus revealing new possibilities to enhance perovskite solar cells' lifetime.