Search Results (299)

The motivation for increasing the efficiency of renewable energy sources is the basic problem of ongoing research. Currently, intensive research is underway in technology based on the use of dye-sensitized solar cells (DSSCs). The aim of this work is to investigate the effect of modifying the iodide electrolyte with liquid crystals (LCs) known for the self-organization of molecules into specific mesophases. The current–voltage (I-V) and power–voltage (P-V) characteristics were determined for the ruthenium-based dyes N3, Z907, and N719 to investigate the influence of their structure and concentration on the efficiency of DSSCs. The addition of a nematic LC of 4-n-pentyl-4-cyanobiphenyl (5CB) to the iodide electrolyte influences the I-V and P-V characteristics. A modification of the I-V characteristics was found, especially a change in the values of short circuit current (I_SC) and open circuit voltage (V_OC). The conversion efficiency for cells with modified electrolyte shows a complex dependence that first increases and then decreases with increasing LC concentration. It may be caused by the orientational interaction of LC molecules with the titanium dioxide (TiO₂) layer on the photoanode. A too high concentration of LC may lead to a reduction in total ionic conductivity due to the insulating effect of the elongated polar molecules. Full article

CdTe nanocrystals (NCs) have emerged as a promising active layer for efficient thin-film solar cells due to their outstanding optical properties and simple processing techniques. However, the low hole concentration and high resistance in the CdTe NC active layer lead to high carrier recombination in the back contact. Herein, we developed a novel 2-iodothiophene as a wet etching solution to treat the surface of CdTe NC. We found that surface treatment using 2-iodothiophene leads to reduced interface defects and improves carrier mobility simultaneously. The surface properties of CdTe NC thin films after iodide salt treatment are revealed through surface element analysis, space charge limited current (SCLC) studies, and energy level investigations. The CdTe NC solar cells with 2-iodothiophene treatment achieved power conversion efficiency (PCE) of 4.31% coupled with a higher voltage than in controlled devices (with NH₄I-treated ones, 3.08% PCE). Full article

In this study, a UVC photodetector (PD) was fabricated by incorporating CsI into a conventional double-cation perovskite (FAMAPbI₃) to enhance its stability. The device utilized a methylammonium iodide post-treatment solution to fabricate CsFAMAPbI₃ perovskite thin films, which functioned as the primary light-absorbing layer in an NIP structure composed of n-type SnO₂ and p-type spiro-OMeTAD. Perovskite films were fabricated and analyzed as a function of the Cs concentration to optimize the Cs content. The results demonstrated that Cs doping improved the crystallinity and phase stability of the films, leading to their enhanced electron mobility and photodetection performance. The UVC PD with an optimum Cs concentration exhibited a responsivity of 58.2 mA/W and a detectivity of 3.52 × 10¹⁴ Jones, representing an approximately 7% improvement over conventional structures. Full article

Perovskite solar cells (PSCs) have already been reported as a promising alternative to traditional energy sources due to their excellent power conversion efficiency, affordability, and versatility, which is particularly relevant considering the growing worldwide demand for energy and increasing scarcity of natural resources. However, operational concerns under environmental stresses hinder its economic feasibility. Through the addition of cesium (Cs), this study investigates how to optimize perovskite solar cells (PSCs) based on methylammonium lead-iodide (MAPbI₃) by creating mixed-cation compositions of MA_1−xCs_xPbI₃ (x = 0, 0.25, 0.5, 0.75, 1) for devices A to E, respectively. The impact of cesium content on the following factors, such as open-circuit voltage (V_oc), short-circuit current density (J_sc), fill factor (FF), and power conversion efficiency (PCE), was investigated using simulation software, with ITO/TiO₂/MA_1−xCs_xPbI₃/Spiro-OMeTAD/Au as a device architecture. Due to diminished defect density, the device with x = 0.5 (MA_0.5Cs_0.5PbI₃) attains a maximum power conversion efficiency of 18.53%, with a V_oc of 0.9238 V, J_sc of 24.22 mA/cm², and a fill factor of 82.81%. The optimal doping density of TiO₂ is approximately 10²⁰ cm⁻³, while the optimal thicknesses of the electron transport layer (TiO₂, 10–30 nm), the hole-transport layer (Spiro-OMeTAD, about 10–20 nm), and the perovskite absorber (750 nm) were identified to maximize efficiency. The inclusion of a small amount of Cs may improve photovoltaic responses; however, at elevated concentrations (x > 0.5), power conversion efficiency (PCE) diminished due to the presence of trap states. The results show that mixed-cation perovskite solar cells can be a great commercially viable option because they strike a good balance between efficiency and performance. Full article

Background/objectives: Hypoxia in the tumor microenvironment is linked to aggressiveness, epithelial–mesenchymal transition, metastasis, and therapy resistance. Targeting hypoxia to enhance antitumor immunity is crucial for overcoming therapeutic resistance. Here, we investigated the ability of Evofosfamide, a prodrug that gets activated under hypoxic conditions, to sensitize breast cancer cells to cell death. Evofosfamide is converted into bromo-isophosphoramide mustard, a potent DNA cross-linking agent that is expected to enhance the killing of cancer cells under hypoxic conditions, where these cells typically exhibit resistance. Methods: Representative breast cancer cell lines, MCF-7 and MDA-MB-231, were treated with Evofosfamide under normoxia and hypoxia. Changes in cell viability and the mechanism of cell death were measured using neutral red dye uptake, Annexin-FITC/propidium iodide staining, and Western blot analysis of markers—PARP1 and caspase 3/7. We tested Evofosfamide’s ability to counteract hypoxic suppression of type I Interferon signaling genes using quantitative PCR (qPCR), as well as its capacity to trigger natural killer (NK)-cell-mediated cytotoxicity. Results: Evofosfamide enhanced cell killing in both MCF-7 and MDA-MB-231 cells under hypoxic conditions compared to normoxic conditions. Cell killing was accompanied by increased cellular reactive oxygen species (ROS), diminished mitochondrial membrane potential, and induction of apoptosis, as demonstrated by the fragmentation or laddering of genomic DNA, the activation of caspase 3/7, and the cleavage of PARP. qPCR analysis revealed that Evofosfamide was capable of restoring type I interferon signaling in hypoxic breast cancer cells, leading to the subsequent cytolytic activity of NK cells against the tumor cells. Conclusions: Thus, conditioning the breast cancer cells with Evofosfamide resulted in enhanced cell killing under hypoxia, further underscoring its potential as a sensitizer to target hypoxia-driven tumors. Full article

Single-phase white-light-emitting materials, particularly 2D hybrid organic–inorganic halide perovskites, have garnered significant attention due to their strong electron–phonon interactions, which lead to broad luminescence and a notable Stokes shift resulting from self-trapped exciton recombination. However, 2D lead iodide perovskites typically display these characteristics poorly, restricting their efficiency as white-light emitters. This study presents a 2D lead iodide perovskite that incorporates a fluorinated π-conjugated aggregation-induced enhanced emission luminophore, FPCSA, as a bulky organic cation to create a quasi-2D perovskite. The FPCSA cation establishes a Type II energy level alignment with the lead iodide layer in the 2D perovskite, and a significant energy offset effectively suppresses charge transfer, enabling independent emission from both the organic and inorganic layers while facilitating self-trapped exciton formation. Under 315 nm UV excitation, this material demonstrates warm white-light emission with RGB triple-band photoluminescence stemming from the electronically decoupled FPCSA and perovskite layers. These findings provide a promising new method for designing efficient single-phase white-light-emitting materials for optoelectronic applications. Full article

Background/Objectives: Taeniasis, a zoonotic infection, is a common foodborne disease. Niclosamide and praziquantel have proven to be effective in treating it, but the use of the same drugs can lead to resistance, so alternative drugs need to be explored. This study investigated the anthelmintic potential of derived fractions from hydroethanolic extracts (HEs) of Aframomum melegueta (AM) and Xylopia aethiopica (XA), two medicinal plants known for their diverse bioactive properties. Methods: AM-HE fractions (dichloromethane fraction (DCMF), ether fraction (EF), aqueous fraction (AF)) and XA-HE fractions (chloroform fraction (CF), ether fraction (EF), and aqueous fraction (AF)) were used, and in vitro anthelmintic activity was assessed against Taenia spp. by using an adult motility assay for the worm’s paralysis time determination. The parasiticidal and parasitostatic activity was also tested on Taenia spp. adult worms. Cell viability was further evaluated using propidium iodide (PI) staining, with albendazole (20 mg/mL) as the reference drug. Results: The three fractions of each plant exhibited significant, dose-dependent anthelmintic activity, with AM-HE and XA-CF showing the greatest effects at 20 mg/mL. AM-EF demonstrated significant activity at 0.4% and 0.8%. Irreversibility tests revealed that most of the treated worms remained paralysis, except those exposed to the AF of both plants. PI staining confirmed the dose-dependent mortality of Taenia cells treated with HE, DCMF, and AF of AM. Conclusions: These results underscore the potential of AM and XA extracts and fractions as alternative treatments for helminth infections. Further, in vivo studies are warranted to confirm their safety and therapeutic efficacy. Full article

This work is devoted to the study of the effect of acid treatment on the structural and textural properties of natural zeolite and its sorption activity with respect to radioiodide. To carry out the experiments, natural zeolite was treated with nitric acid of various concentrations at 20 and 90 degrees. The following methods were used to study the samples: XRD, SEM, DTA, XRF, FTIR, BET, and CEC analyses. Experiments on the sorption and desorption of radioiodide were carried out. The obtained results indicate that acid treatment results in the gradual leaching of aluminum from the crystal lattice and a significant increase in the specific surface area and microporosity of the zeolite. At the same time, the morphology of clinoptilolite is not significantly changed. Additional studies have shown that acid treatment leads to the hydrophobization of zeolite channels and the formation of an amorphous aluminosilicate phase, which makes a significant contribution to the increase in the specific surface area and microporosity. It was found that, with an increase in the degree of dealumination of the zeolite, there is an increase in the sorption properties with respect to radioiodide. The maximum values of sorption capacity were obtained after treating the zeolite with a 1 M nitric acid solution at 90 °C. With a further increase in the concentration of acid, critical changes in the structure of the zeolite occur, leading to a sharp decrease in the sorption capacity. Iodide sorption is not associated with physical adsorption in the micropores of the zeolite and the newly formed amorphous phase. The main mechanism of the sorption appears to be the interaction with silanol and bridging hydroxyl groups on the surface of the zeolite and the amorphous aluminosilicate phase. Full article

To address freshwater lake blooms resulting from eutrophication, the application of quaternary ammonium compounds as algaecides serves as an effective emergency remediation strategy. Didecyl methylpropyl ammonium iodide (DMPAI) is a novel quaternary ammonium algaecide; however, its bacteriostatic properties may significantly disrupt the microbial activity in lakes, particularly within the lake–terrestrial ecotone. To investigate the degradation process of DMPAI in the lake–terrestrial ecotone and its impact on the microbial community, experiments were conducted using a large-scale indoor simulation device to analyze DMPAI concentrations, the composition of the lake microbial community, and associated gene functions. The results showed that (1) DMPAI was completely removed from the lake water body in approximately 36 h; (2) The addition of DMPAI altered the microbial community structure in the lake–terrestrial ecotone, as evidenced by an increase in the diversity index and the proliferation of microorganisms capable of tolerating and degrading DMPAI, such as Pseudomonas and Flavobacterium, within a short period. These changes were typically observed after 10 d and generally recovered, not persisting for extended periods. (3) Functional genes involved in carbon, nitrogen, and sulfur cycling are more significantly impaired in the lake–terrestrial ecotone with DMPAI addition. The destabilization of the microbial community may lead to a short-term increase in pathogenic bacteria during the recovery process. This phenomenon was more pronounced in environments with higher concentrations of DMPAI. Therefore, the concentration of DMPAI should be controlled within the range of 0.5 to 2.0 mg L⁻¹. Full article

Background: antimicrobial resistance represents a critical issue leading to delayed wound healing; hence, it is necessary to develop novel strategies to address this phenomenon. Objectives: this study aimed to explore the antimicrobial/anti-virulence action of Methylglyoxal-MGO alone or combined with novel technologies such as Light-Emitting Diodes-LED and Complex Magnetic Fields-CMFs against resistant clinical strains isolated from chronic wounds. Methods: characterized planktonic Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans isolates were used. Antimicrobial activity was evaluated by measuring optical density, Colony Forming Units-CFU, and synergy between MGO/LED or CMFs. Cellular membrane permeability by propidium iodide fluorescence and fluidity by Laurdan generalized polarization measurements were performed. P. aeruginosa motility was tested using the soft agar method. A docking study was performed to evaluate the possible interaction between MGO and urease in P. aeruginosa. Results: single/combined treatments showed significant antimicrobial activity. Major CFU reduction was detected after CMFs/MGO+CMFs application on C. albicans. Treatments exhibited significant changes in membrane permeability and fluidity. The treatments decreased P. aeruginosa motility with a major reduction after LED application. Docking analysis showed that MGO could bind with P. aeruginosa urease leading to defective folding and functional alterations. Conclusions: the results suggest that these treatments could represent promising and green therapeutic solutions against resistant isolates from chronic wounds. Full article

This study addresses the challenges of efficient, large-scale production of flexible transparent conducting electrodes (TCEs). We fabricate TCEs on polyethylene terephthalate (PET) substrates using a high-speed roll-to-roll (R2R) compatible method that combines gravure printing and photonic curing. The hybrid TCEs consist of Ag metal bus lines (Ag MBLs) coated with silver nanowires (AgNWs) and indium zinc oxide (IZO) layers. All materials are solutions deposited at speeds exceeding 10 m/min using gravure printing. We conduct a systematic study to optimize coating parameters and tune solvent composition to achieve a uniform AgNW network. The entire stack undergoes photonic curing, a low-energy annealing method that can be completed at high speeds and will not damage the plastic substrates. The resulting hybrid TCEs exhibit a transmittance of 92% averaged from 400 nm to 1100 nm and a sheet resistance of 11 Ω/sq. Mechanical durability is tested by bending the hybrid TCEs to a strain of 1% for 2000 cycles. The results show a minimal increase (<5%) in resistance. The high-throughput potential is established by showing that each hybrid TCE fabrication step can be completed at 30 m/min. We further fabricate methylammonium lead iodide solar cells to demonstrate the practical use of these TCEs, achieving an average power conversion efficiency (PCE) of 13%. The high-performance hybrid TCEs produced using R2R-compatible processes show potential as a viable choice for replacing vacuum-deposited indium tin oxide films on PET. Full article

Lead halide perovskite solar cells (PSCs) have shown tremendous progress in the last few years. However, highly toxic Pb and its instability have restricted their further development. On the other hand, antimony-based perovskites such as cesium antimony iodide (Cs₃Sb₂I₉) have shown high stability but low power conversion efficiency (PCE) due to the limited transfer of photocarriers and the poor quality of films. Here, we present a novel method to improve the performance of Cs₃Sb₂I₉ PSCs through a FACl-modified buried interface. FACl acts as a bi-functional additive, and FA incorporation enhances the crystallinity and light absorption of films. Furthermore, treatment with FACl optimizes the level position of Cs₃Sb₂I₉. In addition, transient photovoltage and transient photocurrent were employed to confirm the reduction of charge recombination and superior carrier transportation. By using a planar device structure, we found the PCE of a FACl–Cs₃Sb₂I₉-based device to be 1.66%. The device, stored for 2 months under N₂ conditions, showed a negligible loss in PCE. Overall, this study provides a new strategy to further enhance the performance of Sb-based PSCs. Full article

We herein report the enhanced electrical properties of self-powered perovskite-based photodetectors with high sensitivity and responsivity by applying the surface passivation strategy using C₆₀ (fullerene) as a surface passivating agent. The perovskite (CH₃NH₃PbI₃) thin film passivated with fullerene achieves a highly uniform and compact surface, showing reduced leakage current and higher photon-to-current conversion capability. As a result, the improved film quality of the perovskite layer allows excellent photon-detecting properties, including high values of external quantum efficiency (>95%), responsivity (>5 A W⁻¹), and specific detectivity (>10¹³ Jones) at zero bias voltage, which surpasses those of the pristine perovskite-based device. Furthermore, the passivated device showed fast rise (0.18 μs) and decay times (17 μs), demonstrating high performance and ultrafast light-detecting capability of the self-powered perovskite-based photodetectors. Full article

The most commonly used optical oxygen sensing materials are phosphorescent molecules and functionalized nanocrystals. Many exploration studies on oxygen sensing have been carried out using the fluorescence or phosphorescence of semiconductor nanomaterials. Lead halide perovskite nanocrystals, a new type of ionic semiconductor, have excellent optical properties, making them suitable for use in optoelectronic devices. They also show promising applications in analytical sensing and biological imaging, especially manganese-doped perovskite nanocrystals for optical oxygen sensing. As a class of materials with diverse sources, copper iodide cluster semiconductors have rich structural and excellent luminescent properties, and have attracted attention in recent years. These materials have adjustable optical properties and sensitive stimulus response properties, showing great potential for optical sensing applications. This review paper provides a brief introduction to traditional oxygen sensing using organic molecules and introduces research on oxygen sensing using novel luminescent semiconductor materials, perovskite metal halides and copper iodide hybrid materials in recent years. It focuses on the mechanism and application of these materials for oxygen sensing and evaluates the future development direction of these materials for oxygen sensing. Full article

Fabrication and characterization based on experimental results for methylammonium lead iodide (MAPbI₃) perovskite solar cells using chemical-substituted metal phthalocyanines (MPc) and naphthalocyanines (MNc) as hole-transport materials have been performed to improve conversion efficiency (η) and stability. The purpose of this study was to fabricate and characterize a MAPbI₃ perovskite solar cell using t-butyl MPc and MNc as a hole-transporting layer to improve the photovoltaic performance and stability of η. Photovoltaic characteristics, morphology, crystallinity, and electronic structures were characterized in perovskite solar cells using MPc and MNc. The photovoltaic performance of the perovskite solar cell using t-butyl nickel phthalocyanine (NiPc) reached the maximum value of η at 13.4%. Incorporation of NiPc passivated the surface morphology by increasing the crystal grain size and supporting the carrier diffusion while suppressing carrier recombination near the grain boundary in the perovskite layer. Simulation using a SCAPS-1D program predicted the photovoltaic characteristics of the perovskite solar cell using NiPc. The photovoltaic mechanism was discussed on the basis of an energy diagram of the perovskite solar cell. The insertion of NiPc optimized energy levels near the highest occupied molecular orbital of NiPc and the valence band state of MAPbI₃, supporting a charge transfer related to short-circuit current density and η. Full article