UV Spectra Research Articles

Highly oxygenated dihydrostilbenoids and flavones from the aerial part of Glycyrrhiza uralensis and their antimicrobial activities

Abstract Background Multidrug-resistant bacteria (MDRB) represent a significant global challenge due to their high mortality rates, substantial economic burden, and rapid spread. Traditional triple or quadruple therapies have demonstrated limited efficacy as a result of increasing drug resistance. Thus, it is urgent to develop novel anti-MDRB drugs with high efficiency and low toxicity. Objectives To isolate and identify the dihydrostilbenoids and flavones from the aerial part of Glycyrrhiza uralensis (Fabaceae) and their antimicrobial activities were screened. Materials and methods The aerial part of G. uralensis was extracted with 75% aqueous EtOH. The crude extract was repeatedly isolated by macroporous resin, silica gel, Sephadex LH-20, C18-MPLC, and MCI-MPLC, which were then purified by semipreparative RP-HPLC to obtain monomer compounds. The structures of the isolates were assigned by a combination of optical rotations, UV spectra, nuclear magnetic resonance, and high-resolution electrospray ionization mass spectrometry, and the absolute configurations of compounds 2, 3, and 7 were further confirmed by electronic circular dichroism calculations. Subsequently, we investigated their antimicrobial activities by the broth microdilution method. Results Seventeen previously undescribed phenolic compounds (1–17) and 26 known analogs (18–43), including dihydrostilbenoids, flavones, and dihydroflavones, were identified from the aerial part of G. uralensis. In vitro, antimicrobial bioassays demonstrated that compound 31 displayed the strongest inhibitory effect against 4 drug-resistant Helicobacter pylori strains (MIC = 2–4 μg/mL), comparable to metronidazole (MIC = 1–32 μg/mL). Additionally, compounds 10, 13, and 15 demonstrated bactericidal activity against Staphylococcus aureus (MIC = 4 μg/mL), while compounds 15 and 22 exhibited inactivation effects against Mycobacterium smegmatis, Enterococcus faecium, and E. faecalis (MIC = 4–8 μg/mL). Conclusions These monomeric compounds with antimicrobial activities were isolated from the aerial parts of G. uralensis, providing valuable insights into the potential anti-MDRB properties of its nonmedicinal parts.

Effect of pH-Shift Treatment on IgE-Binding Capacity and Conformational Structures of Peanut Protein.

Hypoallergenic processing is an area worthy of continued exploration. In the treatment of the peanut protein (PP), pH shift was applied by acidic (pH 1.0-4.0) and alkaline (pH 9.0-12.0) treatment, after which the pH was adjusted to 7.0. Following pH-shift treatment, PP showed a larger particle size than in neutral solutions. SDS-PAGE, CD analysis, intrinsic fluorescence, UV spectra, and surface hydrophobicity indicated the protein conformation was unfolded with the exposure of more buried hydrophobic residues. Additionally, the IgE-binding capacity of PP decreased after pH-shift treatment on both sides. Label-free LC-MS/MS results demonstrated that the pH-shift treatment induced the structural changes on allergens, which altered the abundance of peptides after tryptic digestion. Less linear IgE-binding epitopes were detected in PP with pH-shift treatment. Our results suggested the pH-shift treatment is a promising alternative approach in the peanut hypoallergenic processing. This study also provides a theoretical basis for the development of hypoallergenic food processing.

Coupling solid phase microextraction to integrated optical sensors with microfluidic open interface

Increasing number of regulations today is very demanding, so many fields need to rely to screening techniques to separate samples whose content need to be confirmed with that field's gold standard approach. Therefore, the development of simple and fast approaches is very much needed. This manuscript presents the development of a microfluidic open interface integrated with ultraviolet-visible (UV–Vis) absorption detection for rapid screening applications. The system was designed as a rapid sensor readout for compounds enriched by solid-phase microextraction devices. Two azo dyes from a liquid water enhancer solution served as model analytes. These two dyes were extracted with the solid phase microextraction fiber and introduced to the system for analysis. Experimental results demonstrated that the system could effectively detect dyes with absorbance at 403 nm, indicating its potential for quantitating analytes with UV–Vis chromophores. Although this sensing method exhibits limited selectivity, it offers a cost-effective, straightforward approach to rapid screening that can be conveniently miniaturized for on-site applications. Further advances could focus on integrating low-cost sensors with specific responses in place of the UV–Vis unit, as well as simplification and miniaturization of the system to improve on-site analysis. Additionally, incorporating autosampler systems could enable high-throughput determinations, broadening the method's applicability. The developed solid phase microextraction method reliably samples and enriches small molecules from complex systems, delivering clean extracts to the selective sensor for readout without interference from the investigated sample matrix.

The influence of the method of processing rapeseed seeds on their protein complex

Relevance. The recycling of secondary rapeseed raw materials is a perspective trend for increasing the efficiency of production of this agricultural crop.Methods. Degreasing of the rapeseed kernel fraction was carried out by hexane extraction, wateralcohol treatment of the low—fat rapeseed kernel with a mixture of water + ethanol (3:7). The fractional composition of the rapeseed protein complex was determined by sequential extraction with distilled water, 7% NaCl solution and 0.1M NaOH solution. Protein isolation: extractant — NaCl solution (70 g/l), pH — 9.0, T — 50 °С, duration — 90 min. The protein was precipitated at pH 4.8 and dried in a microwave oven at 500 W for 3–4 minutes. Absorption spectra of protein fractions of rapeseed seeds were recorded on a PE-5400 UV spectrophotometer using the SC5400 program.Results. It was shown that degreasing by hexane extraction contributed to an increase in the content of globulins (by 8.5%) with a decrease in albumins (by 3.0%) and glutelins (by 3.3%). Analysis of the UV spectra of these protein fractions showed the presence of synaptic acid in the fractions of albumins and globulins. The water-alcohol treatment of the skimmed rapeseed kernel, carried out to remove phenolic compounds, contributed to the partial removal of protein from the raw material (protein content decreased from 39.06 to 32.34%), limited protein denaturation, which leads to a decrease in protein solubility and protein yield in the extract, as indicated by a decrease in the yield of the protein product relative to the raw material from 26.4 to 15.3%, a decrease in protein yield relative to the protein contained in the raw material, from 28.9 to 20.3%.

CLASSY. X. Highlighting Differences between Partial Covering and Semianalytic Modeling in the Estimation of Galactic Outflow Properties

Feedback-driven massive outflows play a crucial role in galaxy evolution by regulating star formation and influencing the dynamics of surrounding media. Extracting outflow properties from spectral lines is a notoriously difficult process for a number of reasons, including the possibility that a substantial fraction of the outflow is carried by dense gas in a very narrow range in velocity. This gas can hide in spectra with insufficient resolution. Empirically motivated analysis based on the apparent optical depth method, commonly used in the literature, neglects the contribution of this gas, and may therefore underestimate the true gas column density. More complex semianalytical line transfer (e.g., SALT) models, on the other hand, allow for the presence of this gas by modeling the radial density and velocity of the outflows as power laws. Here we compare the two approaches to quantify the uncertainties in the inferences of outflow properties based on 1D “down-the-barrel” spectra, using the UV spectra of the CLASSY galaxy sample. We find that empirical modeling may significantly underestimate the column densities relative to SALT analysis, particularly in the optically thick regime. We use simulations to show that the main reason for this discrepancy is the presence of a large amount of dense material at low velocities, which can be hidden by the finite spectral resolution of the data. The SALT models in turn could overestimate the column densities if the assumed power laws of the density profiles are not a property of actual outflows.

The development and applications of multidimensional biomolecular spectroscopy illustrated by photosynthetic light harvesting.

The parallel and synergistic developments of atomic resolution structural information, new spectroscopic methods, their underpinning formalism, and the application of sophisticated theoretical methods have led to a step function change in our understanding of photosynthetic light harvesting, the process by which photosynthetic organisms collect solar energy and supply it to their reaction centers to initiate the chemistry of photosynthesis. The new spectroscopic methods, in particular multidimensional spectroscopies, have enabled a transition from recording rates of processes to focusing on mechanism. We discuss two ultrafast spectroscopies - two-dimensional electronic spectroscopy and two-dimensional electronic-vibrational spectroscopy - and illustrate their development through the lens of photosynthetic light harvesting. Both spectroscopies provide enhanced spectral resolution and, in different ways, reveal pathways of energy flow and coherent oscillations which relate to the quantum mechanical mixing of, for example, electronic excitations (excitons) and nuclear motions. The new types of information present in these spectra provoked the application of sophisticated quantum dynamical theories to describe the temporal evolution of the spectra and provide new questions for experimental investigation. While multidimensional spectroscopies have applications in many other areas of science, we feel that the investigation of photosynthetic light harvesting has had the largest influence on the development of spectroscopic and theoretical methods for the study of quantum dynamics in biology, hence the focus of this review. We conclude with key questions for the next decade of this review.

Modelling absorption and emission profiles from accretion disc winds with WINE

Fast and massive winds are ubiquitously observed in the UV and X-ray spectra of active galactic nuclei (AGNs) and other accretion-powered sources. Several theoretical and observational pieces of evidence suggest they are launched at accretion disc scales, carrying significant mass and angular momentum. Thanks to such high-energy output, they may play an important role in transferring the energy released by accretion to the surrounding environment. In the case of AGNs, this process can help to set the so-called co-evolution between an AGN and its host galaxy, which mutually regulates their growth across cosmic time. To precisely assess the effective role of UV and X-ray winds at accretion disc scales, it is necessary to accurately measure their properties, including mass and energy rates. However, this is a challenging task, due to both the limited signal-to-noise ratio of available observations and the limitations of the models currently used in the spectral analysis. We aim to maximise the scientific return of current and future observations by improving the theoretical modelling of these winds through our Winds in the Ionised Nuclear Environment (WINE) model. WINE is a spectroscopic model specifically designed for disc winds in AGNs and compact accreting sources, which couples photoionisation and radiative transfer with special relativistic effects and a three-dimensional model of the emission profiles. We explore with WINE the main spectral features associated with the disc winds in AGNs, with a particular emphasis on the detectability of the wind emission in the total transmitted spectrum. We explore the impact of the wind ionisation, column density, velocity field, and geometry in shaping the emission profiles. We simulated observations with the X-ray microcalorimeter Resolve on board the recently launched XRISM satellite and the X-IFU on board the future Athena mission. This allows us to assess the capabilities of these telescopes in the study of disc winds in X-ray spectra of AGNs for the typical physical properties and exposure times of the sources included in the XRISM performance verification phase. The wind kinematic and geometry (together with the ionisation and column density) deeply affect both shape and strength of the wind spectral features. Thanks to this, both Resolve and, on a longer timescale X-IFU will be able to accurately constrain the main properties of disc winds over a broad range of ionisation, column densities, and covering factors. We also investigate the impact of the spectral energy distribution (SED) on the resulting appearance of the wind. Our findings reveal a dramatic difference in the gas opacity when using a soft, Narrow Line Seyfert 1-like SED compared to a canonical powerlaw SED with a spectral index of $

Into the Groove: A Multitechnique Insight into the DNA–Vemurafenib Interaction

This study explores the interaction between Vemurafenib (VEM), a potent BRAF inhibitor, and calf thymus DNA (ctDNA) using a comprehensive array of biophysical and computational techniques. The primary objective is to understand the potential off-target effects of VEM on DNA, given its established role in melanoma therapy targeting the BRAF V600E mutation. The investigation employed methods such as ultraviolet–visible absorption spectroscopy, steady-state fluorescence, circular dichroism, isothermal titration calorimetry, and advanced molecular dynamics simulations. The results indicate that VEM interacts with DNA primarily through a minor groove-binding mechanism, causing minimal structural disruption to the DNA double helix. Viscosity measurements and melting temperature analyses further confirmed this non-intercalative mode of binding. Calorimetry data revealed an exothermic, thermodynamically favorable interaction between VEM and ctDNA, driven by both enthalpic and entropic factors. Finally, computer simulations identified the most probable binding site and mode of VEM within the minor groove of the nucleic acid, providing a molecular basis for the experimental findings.

Integrating Epoxidation, High-Resolution Mass Spectrometry and Ultraviolet Spectroscopy to Unravel the Complex Profile of Boswellic Acids and Related Compounds in the Boswellia serrata Gum Resin Extract

The chemical characterization of natural products is often a complex task that demands powerful analytical techniques. Liquid chromatography with high-resolution tandem mass spectrometry (HRMS/MS) is often employed, yet it can face hard challenges when isomeric species are present, and reference standards are lacking. In such cases, the confidence level in compound identification can be significantly improved by the collection of orthogonal information on target analytes. In this work, 23 key compounds in Boswellia serrata extract (BSE), 12 of which correspond to boswellic acids (BAs) and 11 to triterpenoidic acid isomers, were identified by combining RPLC followed by serial UV and ESI(-)-FTMS and FTMS/MS detections with the evaluation of the reactivity towards C=C bond epoxidation with meta-chloroperoxybenzoic acid (m-CPBA), proposed as a fast chemical tool to gather information about C=C bond steric hindrance, a key structural feature of BAs and related compounds. The interpretation of UV spectra acquired after chromatographic separation corroborated the identification of the substitution patterns of enonic and dienic residues in ketoboswellic and dehydroboswellic acids. Moreover, MS/MS based on higher-energy collision-induced dissociation (HCD) unveiled new fragmentation pathways, providing important structural details on target analytes. The integrated approach developed during this study might pave the way for a deeper understanding of the BSE bioactive properties. Moreover, it can be considered an example of a more general strategy for the analysis of complex mixtures of natural compounds including also isomeric species.

Phenolic Class Analysis in Honey: Comparison of Classical and Single UV Spectrum Methodologies

The analytical results from a study of 16 honey samples (extra white to dark honey color range) of phenolic compounds obtained using the single UV spectrum methodology and classical spectrophotometric methods (Folin–Ciocalteu and AlCl3 methods) are presented. The first method quantified all classes of phenolic compounds in honey’s SPE-C18 extract: the total hydroxybenzoic acid content (concentrations between 0.37 ± 0.05 and 4.46 ± 0.37 mg of gallic acid/g of honey), total hydroxycinnamic acid content (0.13 ± 0.03 and 2.76 ± 0.13 mg of ferulic acid/g of honey), and total flavonoid content (0.15 ± 0.03 and 1.63 ± 0.17 mg of quercetin/g of honey). The total phenolic contents were, on average, 1.86 ± 0.72 and 1.78 ± 0.79 times higher than the results obtained for raw honey and the SPE-C18 extract, respectively, using the classical Folin–Ciocalteu method. The total flavonoid contents, on average, were 6.02 ± 3.14 times larger and 0.66 ± 0.33 times smaller than the results obtained using the classical AlCl3 method for raw honey and SPE-C18 extract, respectively.

Using novel open-framework copper borovanadate as an effective catalyst in the conversion of cyclohexanol to cyclohexanone

A new open-framework copper borovanadate containing two oxidation states of V4+ and V5+ cations {[Cu5(1,2-dap)10][VV2VIV10B18O54(OH)6(H2O)]}·2H3BO3·9H2O (1,2-dap: 1, 2-propylene diamine) (1) using 1,2-dap as template agent has been successfully prepared. It is composed of five coordination cations [Cu(1,2-dap)2]2+and one borovanadate anion [VV2VIV10B18O54(OH)6(H2O)]10- constructed by one {B18O30(OH)6} and two {V6O18} subunits, as well as two isolated H3BO3 molecules and nine H2O molecules. The compound exhibits for the first time penta-coordinated copper cations, uncoordinated H3BO3 molecules and 1, 2-dap ligands in the series of open-framework borovanadates. Its UV diffuse-reflectance spectrum, Mott-Schottky curve, fluorescent emission, chromaticity and second-order lifetime were investigated in detail. The stable pH range (5.8–2.3) of the borovanadate anion in DMF solution was explored by means of fluorescence and UV spectra. In particular, it showed effective catalytic activity in the conversion of cyclohexanol to cyclohexanone (conversion: 86.8 %, selectivity: 97.4 %). The possible catalytic mechanism for the catalytic reaction had been also established. The studies revealed that the borovanadate could be used as a potential stable catalyst for the selective oxidation of cyclohexanol.

A novel copper(II) complex with a salicylidene carbohydrazide ligand that promotes oxidative stress and apoptosis in triple negative breast cancer cells.

We report the synthesis, characterization, anti-cancer activity and mechanism of action of a novel water-soluble Cu(II) complex with salicylidene carbohydrazide as the ligand and o-phenanthroline as the co-ligand. The synthesized complex (1) was characterized by FT-IR, EPR, and electronic spectroscopy, as well as single crystal X-ray diffraction. This compound was found to be paramagnetic from EPR spectra and X-ray crystallography revealed that the molecule crystallized in an orthorhombic crystal system. The crystal lattice was asymmetric containing two distinct binuclear copper complexes containing the Schiff base as the major ligand, o-phenanthroline as a co-ligand, two nitrate anions, and two water molecules. The Cu(II) in the first site coordinated with the enolised ligand comprising enolate O-, phenolate O-, and the imine N and N,N from o-phen. The major part of this complex exists as Cu(II) coordinated with two H2O molecules at the second site with nitrate acting as the counter anion. However, a smaller portion of the complex exists where Cu(II) is coordinated with NO3- and H2O, and the remaining water molecule acts as lattice water. It was tested for DNA binding and cleavage properties which revealed that it binds in an intercalative mode to CT-DNA with Kb value of 1.25 × 104 M-1. Furthermore, cleavage studies reveal that the complex has potential for efficient DNA cleavage under both oxidative and hydrolytic conditions. It was able to enhance the rate of cleavage by 2.8 × 108 times. The complex shows good cytotoxicity to breast cancer monolayer (2D) as well as spheroid (3D) systems. The IC50 values for MDA-MB-231 and MCF-7 monolayer culture was calculated as 1.86 ± 0.17 μM and 2.22 ± 0.08 μM, respectively, and in (3D) spheroids of MDA-MB-231 cells, the IC50 value was calculated to be 1.51 ± 0.29 μM. It was observed that the complex outperformed cisplatin in both breast cancer cell lines. The cells treated with complex 1 underwent severe DNA damage, increased oxidative stress and cell cycle arrest which finally led to programmed cell death or apoptosis in triple negative breast cancer cells through an intrinsic pathway.

Merocyanines: Electronic Structure and Spectroscopy in Solutions, Solid State, and Gas Phase.

Merocyanines, owing to their readily tunable electronic structure, are arguably the most versatile functional dyes, with ample opportunities for tailored design via variations of both the donor/acceptor (D/A) end groups and π-conjugated polymethine chain. A plethora of spectral properties, such as strong solvatochromism, high polarizability and hyperpolarizabilities, and sensitizing capacity, motivates extensive studies for their applications in light-converting materials for optoelectronics, nonlinear optics, optical storage, fluorescent probes, etc. Evidently, an understanding of the intrinsic structure-property relationships is a prerequisite for the successful design of functional dyes. For merocyanines, these regularities have been explored for over 70 years, but only in the past three decades have these studies expanded beyond the theory of their color and solvatochromism toward their electronic structure in the ground and excited states. This Review outlines the fundamental principles, essential for comprehension of the variable nature of merocyanines, with the main emphasis on understanding the impact of internal (chemical structure) and external (intermolecular interactions) factors on the electronic symmetry of the D-π-A chromophore. The research on the structure and properties of merocyanines in different media is reviewed in the context of interplay of the three virtual states: nonpolar polyene, ideal polymethine, and zwitterionic polyene.

Electronic Spectroscopy of Ovalene: Reassignment of the S2(B3u)- S0(Ag) Transition.

As part of our experiments to characterize solid para-hydrogen (para-H2) as a matrix host for electronic spectroscopy with potential applications in the ongoing quest for the carriers of the diffuse interstellar bands (DIB), we studied dispersed fluorescence and fluorescence excitation spectra of ovalene (C32H14), a planar polycyclic aromatic hydrocarbon (PAH) of D2h symmetry. Although generally in good agreement with previously reported data for jet-cooled C32H14, our results, in conjunction with quantum-chemical calculations, indicate that the observed spectral progressions are associated with the S2(B3u)-S0(Ag) electronic transition instead of the originally assigned S1-S0 transition for C32H14 in a supersonic jet, and that the previously reported origin band was misassigned and should be located at ∼21050 cm-1. The reassignment is further supported by the comparably long fluorescence lifetime of ∼1.7 μs. From an analysis of spectral features located >1600 cm-1 in the fluorescence excitation spectrum, we estimate an S2(B3u)-S3(B1g) energy gap of ∼350 cm-1.

Effect of supercritical CO2 extraction as pretreatment to obtain C-phycocyanin from spirulina (Arthrospira maxima)

C-phycocyanin (CPC) is a phycobiliprotein present in spirulina, which, due to its blue color, non-toxic nature, fluorescent and antioxidant properties, is of interest in the food and pharmaceutical industries. Different methods of extraction and stabilization are being investigated, including supercritical CO2 extraction, a method applied to obtain bioactive compounds from plant matrices. In this work, the effect of applying supercritical CO2 as pretreatment for the extraction of CPC at different parameters (pressure, temperature, use of cosolvent) was evaluated. Best pretreatment conditions to obtain the highest purity were at 17 MPa and 45 °C, considering it reagent grade. When comparing UV and FTIR spectra of the raffinates, a similarity was obtained with the analytical standard, with the presence of a band at 620 nm in UV and for FTIR a band at 1650 and 1540 cm−1 that corresponds to amide I and amide II, corroborating their presence and the structural characteristics.

Spectral broadening and vibronic dynamics of the S2 state of canthaxanthin in the orange carotenoid protein

We have performed a series of broadband multidimensional electronic spectroscopy experiments to probe the electronic and vibrational dynamics of the canthaxanthin chromophore of the Orange Carotenoid Protein (OCP) from Synechocystis sp. PCC 6803 in its photoactivated red state, OCPR. Cross-peaks observed below the diagonal of the two-dimensional electronic spectrum indicate that absorption transitions prepare the bright S2 state of the ketocarotenoid canthaxanthin near to a sequence of conical intersections, allowing passage to the dark S1 state via the Sx intermediate in <50 fs. Rapid damping of excited-state coherent wavepacket motions suggests that the branching coordinates of the conical intersections include out-of-plane deformation and C=C stretching coordinates of the π-conjugated isoprenoid backbone. The unusual proximity of the Franck–Condon S2 state structure to the conical intersections with Sx and S1 suggests that the protein surroundings of canthaxanthin prepare it to function as an excitation energy trap in the OCPR–phycobilisome complex. Numerical simulations using the multimode Brownian oscillator model demonstrate that the ground-state absorption spectrum of OCPR overlaps with the fluorescence emission spectrum of allophycocyanin due to spectral broadening derived especially from the intramolecular motions of the canthaxanthin chromophore in its binding site.

In vitro inhibitory effect of berberine against rotavirus combined with its antioxidant, anti-inflammatory, and cytotoxicity activities.

Although berberine (BBR) is well known as a traditional medicine used in treatment of gastrointestinal diseases, its potent against viral gastroenteritis has not been specifically reported. This study aims to investigate the antiviral activity of BBR against rotavirus and evaluate its cytotoxicity and pharmacological efficacies, including antioxidant and anti-inflammatory activities in vitro. Using ultraviolet-visible absorption spectroscopy, the saturation concentration of BBR was determined as 2261 µg/mL, indicating that BBR is a poor water-soluble compound. The inhibition rate of NO production of BBR solution at a concentration of 238 µg/mL was similar to that of Cardamonin 0.3 µM with a cell viability of 92,46±0.35%, revealing the anti-inflammatory activity of BBR. The cytotoxicity of BBR solution depended on its concentration, whereby the 50% cytotoxicity concentration (CC50) of BBR after 96 h exposure was 664 µg/mL. Investigation of cytopathic effects (CPE) of MA104 cells treated with BBR and BBR-incubated rotavirus indicates that BBR could effectively inhibit the replication of rotavirus. CPEs were not observed in the cells inoculated with rotavirus (100TCID50) which was pre-incubated with BBR for 96 hours at BBR concentration of 283 µg/mL. Therefore, the study provides reliable results to demonstrate the ability of BBR to inhibit the replication of rotavirus.

Analyzing the structural, optoelectronic, and thermoelectric properties of InGeX3 (X = Br) perovskites via DFT computations

The Electronic and optical properties of InGeX3(X = Cl, Br) were examined by adopting the density functional theory (DFT) approach. We applied the GGA + Trans-Blaha modified Becke–Johnson (TB-mBJ) technique to acquire the precise bandgap of 1.52 and 0.98 eV of the compounds InGeX3(X = Cl, Br) respectively which suggests the direct bandgap at (M-M). The stability of the material is confirmed by the formation energy (– 2.83 = Cl; – 2.35 = Br) and Mechanical stability. Primarily elastic constants were extracted for each of the materials under scrutiny, and these values then served to gauge all of the materials’ mechanical properties. The assessed Poisson’s and Pugh’s ratios for the materials InGeCl3 and InGeBr3 were verified to identify the degree of ductility. The quasi-harmonic Debye model additionally covers the temperature and pressure dependence on thermodynamic parameters, particularly volume, specific heat capacity (Cv) at constant volume, and the Gruneisen parameter (γ) in the range of 0–800 K and 0–5 GPa. It is anticipated that InGeCl3 and InGeBr3 will have static dielectric constants of 4.01 and 5.74, respectively. InGeX3(X = Cl, Br) also reveals significant absorption in the high UV spectrum. The thermoelectric properties have also been calculated vdata-element-id="9QNfR3VHbcMHX_W0fJCYp" data-element-type="html" style="display: initial; visibility: initial; opacity: initial; clip-path: initial; position: relative; float: left; top: 0px; left: 0px; z-index: 1 !important; pointer-events: none;" />ia boltztrap2 code using a k mesh of around 1,50,000 points.

Unravelling Optoelectronic and Transport Properties in RuZrX (X=Si, Ge) Alloys: Insights from DFT

AbstractThe structural, mechanical, electronic, and thermoelectric properties of RuZrSi and RuZrGe half‐Heusler alloys were thoroughly examined using the full‐potential linearized augmented plane‐wave (FP‐LAPW) method within the WIEN2k code, based on Density Functional Theory (DFT). The study utilized the Perdew‐Burke‐Ernzerhof generalized gradient approximation (GGA‐PBE) and the Tran‐Blaha‐Johnson (TB‐mBJ) approximations for the exchange‐correlation potential. The findings reveal that both alloys are semiconductors with indirect band gaps, and they are ductile, anisotropic, and mechanically stable. These properties make them suitable for various practical applications. The electronic analysis confirms the semiconducting nature of RuZrSi and RuZrGe due to their indirect band gaps. Mechanically, both alloys show ductility and stability, enhancing their potential usability. Additionally, their thermoelectric properties are notable, with high Seebeck coefficients (S) and a significant figure of merit (ZT), indicating strong performance in thermoelectric devices. Optical properties, including the dielectric function and absorption coefficients, suggest these materials have considerable potential for photovoltaic and optical applications, especially in the UV and visible light spectrum. While these results are promising, experimental validation is required to confirm the theoretical predictions made in this study.

The influence of precursor solutions containing an amount of silver bismuth sulfide nanoparticles (AgBiS2 NPs) on the characteristics of CH3NH3PbI3 perovskites solar cells

The utilization of organo-metal halide perovskites as absorbers in thin-film solar cells has garnered considerable interest from the scientific community in recent times. In this study, we present the introduction of silver bismuth sulfide nanoparticles (AgBiS2 NPs) doped into perovskite thin films composed of CH3NH3PbI3 thin film. Our results demonstrate that the perovskites' morphology and structure were significantly improved. The effects of AgBiS2 NPs concentration on the optical, mechanical, and crystallographic properties of CH3NH3PbI3 perovskite thin films were investigated. The findings from the structure investigations revealed that an increase in the concentration of AgBiS2 NPs resulted in a transition from a low-crystalline to a polycrystalline structure of the perovskite thin films. An elevation in the concentration of AgBiS2 NPs from 2 to 8 mg/mL led to the development of perovskite films of superior quality, consisting entirely of PbI3 and CH3NH3. These films exhibited almost impeccable deposition, compactness, and uniformity, and their particle size reached an approximate value of 1.3 μm. Furthermore, an increase in the optical absorption coefficient (∼105 cm−1) in the visible spectrum and subsequent enhancements in photoluminescence (PL) and ultraviolet–visible (UV–Vis) absorption spectroscopy serve as further evidence of the film's enhanced quality. When AgBiS2 NPs are doped into perovskites, the films' quality is significantly improved; they acquire a uniform surface morphology, an exceptional crystal structure, and enhanced light absorption, all of which contribute to accelerated PL quenching and charge transfer. Power conversion efficiency (PCE) was enhanced across all photovoltaic parameters through the use of larger granules in bulk-heterojunction solar cells, as opposed to undoped heterojunction solar cells. The PCE of the perovskite device with CH3NH3PbI3 base is 17.04 % at the optimal concentration of 6 mg/mL AgBiS2 NPs. These findings indicate that the doping of CH3NH3PbI3 perovskite thin films with AgBiS2 NPs is essential for the achievement of high crystallinity, a large particle size, and a high absorption coefficient. These properties are advantageous for the high-power conversion efficiency of solar cell applications.