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Lead-free halide perovskites have been investigated as promising materials for energy harvesting and thermoelectric device applications. The current article thoroughly explains the electronic behavior, stability, optical and thermoelectric characteristics of CdKF3 and CdKCl3 halide perovskite. For structural stability, the elastic constant and phonon dispersion of both halides are investigated. Additionally, thermodynamic stability is demonstrated by the investigation of formation energy (-2.45 to −1.89 eV). The ductile nature of both halides is confirmed by calculating the Poisson ratio, and their significance for the manufacturing of devices. The direct bandgap nature (2.65 eV and 0.9 eV) of both halides is observed through electronic band structures using mBJ-GGA, which has been employed to obtain more precise results for optoelectronic applications. Both halides show remarkable optoelectronic performance, with low reflectivity, high optical absorption, and conductivity. Thermal and electrical conductivity are also used to study the thermoelectric characteristics. Both halides show the figure of merit (ZT) near unity, ZT indices highlight their importance for thermoelectric devices.

Favipiravir (FP) and ebselen (EB) belong to a diverse class of antiviral drugs known for their significant efficacy in treating various viral infections. Utilizing molecular dynamics (MD) simulations, machine learning, and van der Waals density functional theory, we accurately elucidate the binding properties of these antiviral drugs on a phosphorene single-layer. To further investigate these characteristics, this study employs four distinct machine learning models—Random Forest, Gradient Boosting, XGBoost, and CatBoost. The Hamiltonian of antiviral molecules within a monolayer of phosphorene is appropriately trained. The key aspect of utilizing machine learning (ML) in drug design revolves around training models that are efficient and precise in approximating density functional theory (DFT). Furthermore, the study employs SHAP (SHapley Additive exPlanations) to elucidate model predictions, providing insights into the contribution of each feature. To explore the interaction characteristics and thermodynamic properties of the hybrid drug, we employ molecular dynamics and DFT calculations in a vacuum interface. Our findings suggest that this functionalized 2D complex exhibits robust thermostability, indicating its potential as an effective and enabled entity. The observed variations in free energy at different surface charges and temperatures suggest the adsorption potential of FP and EB molecules from the surrounding environment.

Spinel chalcogenides have great potential for optoelectronic and thermoelectric applications and therefore received huge attention in recent years. In this regard, here we investigate the structural, optical, electronic, and thermoelectric characteristics of HgY2S4 and HgY2Se4 spinel chalcogens using a density functional theory-based WIEN2k package. Ground state optimization of crystal structure and thermodynamic stability of the material is probed from the energy volume optimization graph and computation of enthalpy of formation. The computation of Poisson's and Pugh's ratios revealed the ductile nature of these materials. Bandgap calculation is performed using TB-mBJ package, which exposed the direct band nature of these semiconducting materials with bandgap values of 1.2 eV for HgY2S4 and 0.6 eV for HgY2Se4. The evaluation of optical characteristics and transport features revealed these compositions’ potential for optoelectronic and thermoelectric applications.

Abstract Background Several species in Lactobacillaceae family were recognized as potential probiotic bacteria. In this group of lactic acid bacteria, species are taxonomically closed and usually share similar 16S rRNA gene, thus, instead of so their identification and discrimination are too difficult. Method In the present study, virtual restriction fragment length polymorphism (RFLP) is instead of was used as a tool to discriminate between the closely related species Lactiplantibacillus plantarum (L plantarum), Lactiplantibacillus paraplantarum (L paraplantarum), and Lactiplantibacillus pentosus (L pentosus); Latilactobacillus sakei (L sakei), Latilactobacillus curvatus(L curvatus), and Latilactobacillus graminis (L graminis); Lacticaseibacillus casei (L casei), Lacticaseibacillus paracasei (L paracasei), Lacticaseibacillus zeae, and Lacticaseibacillus rhamnosus; Lactobacillus gasseri (L gasseri) and Lactobacillus johnsonii (L johnsonii). In silico comparative analysis of 16S rRNA sequences digested by 280 restriction enzymes was performed in order to search the key enzymes which gives different profiles. Results Results revealed that L casei, L paracasei, L zeae, and Lb rhamnosus could be separated from each other on the basis of AlwI, BpuEI, BsgI, BsrDI, BstYI, EarI, MluCI, and NsPI RFLP. Results showed also that different RFLP patterns were obtained from L sakei, L graminis and L curvatus by using both AflI and NspI endonucleases (in separated restriction) and L plantarum, L paraplantarum, and L pentosus were distinguished each one from the other by MucI, NspI, and TspDTI PCR-RFLP. Lb gasseri and L johnsonii were also separated on the basis of Mse I, Taq I, and Dra I RFLP. Conclusion In this study, we proved that too closely related species could be separated in virtual analysis on basis of their 16S rRNA RFLP patterns using key restriction enzymes method.

Double perovskite (DP) halides are a reliable source of renewable energy that plays a vital role to fulfill the requirements of energy crunch. Therefore, the analysis of these perovskite halides have promising uses for thermoelectric and optoelectronics purposes. We investigated the thermoelectric and optoelectronics properties of Rb2KScI6 and Cs2KScI6 halides for use in renewable energy devices by using FP-LAPW + lo approach based on DFT. The calculated Goldsmith's tolerance factor and enthalpy of the formation of studied halides reveal that these are structurally and thermodynamically stable in cubic phase. Moreover, the analyzed value of Poisson and Pugh ratio reveals ductile nature of these materials. Further, we computed the bandgaps by analyzing electronic characteristics. For bandgap calculations of Rb2KScI6 (Eg = 2.75 eV) and Cs2KScI6 (Eg = 2.65 eV), we employed mBJ potentials to obtain precise values as comparison to experimental values. The complex dielectric function used to reveal the optical properties of the analyzed materials. The calculated optical results clearly show the maximum absorption of light in infrared (IR) region revealed that the analyzed materials are appropriate for optoelectronic purposes. The thermoelectric behavior was examined as to figure of merit (ZT), electrical-conductivity (EC), the Seebeck-coefficient (S) as well as thermal-conductivity. Animatedly in future, the analyzed consequences would be supportive to experimental investigation of Rb2KScI6 and Cs2KScI6 for renewable energy device applications.

First-principles simulations are conducted to explore the structural stability, electronic properties, and optical responses of pristine and boron- or nitrogen-doped monolayers graphene. The computed electronic density of states revealed that the substitutional doping of boron impurity atoms on monolayer graphene (MLG) shifts the Dirac point upward, although the substitution of nitrogen impurity atoms in graphene pushes the Dirac point downward the Fermi level. This could exhibit that upon the doping of MLG with boron or nitrogen, respectively, p-type or n-type semimetal is acquired. The overall optical spectral properties of the substituted graphene with boron or nitrogen atoms are simulated and compared with the optical spectra results of pure graphene. The optical features of pristine and doped MLG are determined by taking the interband and intra-band transitions into account ranging from the far-infrared to the ultraviolet regime of the electromagnetic radiation. A remarkable red shift in the optical spectra of the doped MLG towards the visible regime of radiation is established. An enhanced reflectivity illustrated that concentration-dependent optical properties of boron and nitrogen-doped MLG happen at lower electromagnetic radiation regimes. In addition, we explored the thermoelectric behaviors of the pristine/doped graphene monolayers with 4 × 4 supercells. We found a significant improvement in the electrical conductivity of graphene when doped with boron or nitrogen impurities. However, an increase in the electrical conductivity has textured a decrease in the Seebeck coefficients. Improvement in the electrical conductivity is attributed to an interesting effect on the graphene monolayers' power factor (PF). These findings indicate a positive impact of the dopants on the thermoelectric properties of graphene monolayers and reveal that they are potential materials for thermoelectric applications and nanodevices. [ABSTRACT FROM AUTHOR]

By incorporating 4% Nb doping and using bilayer electron transport layers (ETLs) consisting of titanium dioxide (TiO2), pure tungsten trioxide (WO3), and Nb-WO3, significant enhancements were achieved in the structural, optoelectronic, and photovoltaic properties of CsPbIBr2 perovskite films. The perovskite film was analyzed using X-ray diffraction (XRD), revealing an increase in crystal size from 26.6 nm to 71.8 nm and a decrease in lattice constant from 6.010 Å to 5.982 Å after the addition of Nb doping. These data indicate an improvement in the degree of crystalline structure of the film. The light absorption efficiency increased when the energy band gap of pure and Nb-CsPbIBr2 fell from 2.021 eV to 1.955 eV, respectively. The refractive index of pure and Nb-CsPbIBr2 increased from 2.618 to 2.640, respectively, leading to improved light trapping and absorption. The XRD analysis of the WO3 ETLs revealed a monoclinic crystal structure with a higher lattice constant, which enhances the transport of charge carriers. Raman spectroscopy verifies the structural soundness of Nb-WO3. The UV-Vis absorption spectra show that Nb-WO3 has more absorption in the visible region and a larger bandgap compared to Nb-doped CsPbIBr2. Photoluminescence spectroscopy reveals emission peaks that are indicative of flaws, which are essential for enhancing the efficiency of Nb-WO3. The J-V tests demonstrated a significant enhancement in the efficiency of perovskite solar cells when double ETLs were included. This gain was evident in the increased fill factor (FF) range of 0.839–0.865 and open-circuit voltage (Voc) range of 1.064–1.073. Consequently, the overall efficiency rose from 9.81% to 10.85%. Highlights: The research introduces dual ETL comprising TiO2 and 4% Nb-WO3, enhancing the optoelectronic and photovoltaic performance. XRD analysis demonstrates a marked increase in crystal size and a decrease in lattice constant due to Nb doping, indicating enhanced crystallinity of the perovskite films. The efficiency increase in PSCs cells from 9.81% to 10.85%, evidenced through current-voltage testing with the introduction of the double ETLs. [ABSTRACT FROM AUTHOR]

Favipiravir (FP) and Ebselen (EB) belong to a broad range of antiviral drugs that have shown active potential as medications against many viruses. Employing molecular dynamics simulations and machine learning (ML) combined with van der Waals density functional theory, we have uncovered the binding characteristics of these two antiviral drugs on a phosphorene nanocarrier. Herein, by using four different machine learning models (i.e., Bagged Trees, Gaussian Process Regression (GPR), Support Vector Regression (SVR), and Regression Trees (RT)), the Hamiltonian and the interaction energy of antiviral molecules in a phosphorene monolayer are trained in an appropriate way. However, training efficient and accurate models for approximating the density functional theory (DFT) is the final step in using ML to aid in the design of new drugs. To improve the prediction accuracy, the Bayesian optimization approach has been employed to optimize the GPR, SVR, RT, and BT models. Results revealed that the GPR model obtained superior prediction performance with an R2 of 0.9649, indicating that it can explain 96.49% of the data’s variability. Then, by means of DFT calculations, we examine the interaction characteristics and thermodynamic properties in a vacuum and a continuum solvent interface. These results illustrate that the hybrid drug is an enabled, functionalized 2D complex with vigorous thermostability. The change in Gibbs free energy at different surface charges and temperatures implies that the FP and EB molecules are allowed to adsorb from the gas phase onto the 2D monolayer at different pH conditions and high temperatures. The results reveal a valuable antiviral drug therapy loaded by 2D biomaterials that may possibly open a new way of auto-treating different diseases, such as SARS-CoV, in primary terms.

The two-dimensional (2D) layered molybdenum disulfide (MoS2) material represents a nominee potent for optoelectronic devices application. In this research work, the experimental characterizations of 2D- MoS2 thin films are reported in terms of various microscopic and spectroscopic techniques. The synthesized MoS2 thin films are grown by employing the pulsed laser deposition (PLD) procedure on SiO2/Si substrates. In order to monitor the deposition rates of ablated films, the buffer argon-gas pressures are varied during the pulsed laser deposition at substrate temperature of 700 °C. The field emission scanning electron microscopy and atomic force microscopy analyzes revealed a change in the surface morphology of MoS2 films when the buffer Ar-gas pressure is varied between 0 and 100 mTorr. For all samples, a 2H-phase is revealed from X-ray diffraction patterns, indicating a reflection (2θ) around 14.85°. By varying the deposition pressure of laser-ablated MoS2 films, the X-ray photoelectron spectroscopy divulged the chemical compositional elements and valence states of Mo and S on the surface of MS2 films with low density of defects. Analysis of the photoluminescence spectroscopy illustrated emission bands spanning from the visible (Vis) to near-infrared (NIR) regimes in the deposition pressures range ~ 0–100 mTorr. This is mainly owing to the change in the recombination of electron–hole pairs and charge transfer between the deposited MoS2 films and SiO2 substrate surface under various buffer gas pressures. Additionally, first-principles electronic structure calculations are performed to qualitatively examine the effect of native point-defect species (sulfur-monovacancy and sulfur-divacancy defects) on the electronic structure and optical properties of 2D- MoS2 sheets. It is unveiled that the variation of compositional sulfur-vacancy defect in MoS2 monolayer creates an in–gap defect levels above the valence states, leading to an acceptor character. Importantly, the enhancement in the optical absorption spectra divulged a shift in the optical gap from Vis-NIR window with the increase of sulfur vacancy contents in MoS2 single-layer. The identification of intrinsic point defects may be beneficial for photovoltaic energy conversion at higher wavelengths by designing next generation 2D-semiconductors, which could be of vital significance for growing 2D layers and multilayers into practical technologies.