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Doped polysilicon (poly-Si) passivating contacts have emerged as a key technology for the next generation of silicon solar cells in mass production, owing to their excellent performance and high compatibility with the existing passivated emitter and rear cell technology. However, the current solar cell architecture based on a rear-side electron-selective (n+) poly-Si contact is also approaching its practical limit (∼26%) in mass production. The full potential of doped poly-Si passivating contacts can only be realized through incorporation of both electron-selective and hole-selective (p+) poly-Si contacts. While studies of both p+ and n+ poly-Si contacts commenced simultaneously, significant performance differences have arisen. Phosphorus-doped poly-Si contacts consistently outperform boron-doped counterparts, displaying typically lower recombination current density (J0) values (1 – 5 fA/cm2 vs 7 – 15 fA/cm2). This discrepancy can be attributed to inadequate optimization of p+ poly-Si contacts and fundamental limitations related to boron doping. The poorer passivation of p+ poly-Si contacts can be at least partly attributed to boron segregation into the interfacial oxide layers, compromising the interfacial oxide integrity and reducing the chemical passivation effectiveness. This review critically examines the progress of p+ poly-Si contacts characterized by cell efficiency and J0 values, delves into existing challenges, identifies potential solutions, and explores some potential solar cell architectures to enhance efficiency by incorporating p+ poly-Si contacts. [ABSTRACT FROM AUTHOR]

Passivating contacts based on transition metal oxides are of great interest for applications in crystalline silicon (c-Si) solar cells due to their improved optical transparency and potential cost reduction. In this work, the contact resistivity and passivation for thermally evaporated Cu2O are investigated and optimized, with and without an Al2O3 interlayer, as a hole-selective contact to c-Si. Additionally, we implement an AlyTiOx/TiO2 stack as a novel passivating tunnel interlayer for hole-selective contacts, achieving an implied open-circuit voltage iVoc of 630 mV and a record-low J0 of 212 fA cm-2 while maintaining a contact resistivity ρc of 62mΩ cm². A record-low ρc of 8mΩ cm² for Cu2O-based contacts is also demonstrated at the expense of passivation. The addition of the interlayer resulted in a 2% absolute improvement in the efficiency of proof-of-concept c-Si cells with full-area rear Cu2O contacts, reaching 19.1%.The demonstration of this novel interlayer stack provides new avenues to improve the performance also of other hole-selective passivating contacts. [ABSTRACT FROM AUTHOR]

Nanotechnology applications have been employed to improve the stability of bioactive components and drug delivery. Natural-based extracts, especially olive leaf extracts, have been associated with the green economy not only as recycled agri-waste but also in the prevention and treatment of various non-communicable diseases (NCDs). The aim of this work was to provide a comparison between the characteristics, biological activity, and gene expression of water extract of olive leaves (OLE), green synthesized OLE silver nanoparticles (OL/Ag-NPs), and OLE whey protein capsules (OL/WPNs) of the two olive varieties, Tofahy and Shemlali. The particles were characterized by dynamic light scattering, scanning electron microscope (SEM), and Fourier transform infrared. The bioactive compounds of the preparations were evaluated for their antioxidant activity and anticancer effect on HCT-116 colorectal cells as well as for their regulatory effects on cytochrome C oxidase (Cox1) and tumor necrosis factor α (TNF-α) genes. (OL/Ag-NPs) were found to be smaller than (OL/WPNs) with sizes of (37.46±1.85 and 44.86±1.62 nm) and (227.20±2.43 and 553.02±3.60 nm) for Tofahy and Shemlali, respectively. SEM showed that Shemlali (OL/Ag-NPs) had the least aggregation due to their highest Ƹ-potential (-31.76 ± 0.87 mV). The preparations were relatively nontoxic to Vero cells (IC50 = 151.94–789.25 μg/mL), while they were cytotoxic to HCT-116 colorectal cells (IC50 = 77.54–320.64 μg/mL). Shemlali and Tofahy OLE and Tofahy OL/Ag-NPs had a higher selectivity index (2.97–7.08 μg/mL) than doxorubicin (2.36 μg/mL), indicating promising anticancer activity. Moreover, Shemlali preparations regulated the expression of Cox1 (up-regulation) and TNF-α (down-regulation) on HCT-116 cells, revealing their efficiency in suppressing the expression of genes that promote cancer cell proliferation. (OL/Ag-NPs) from Tofahy and Shemlali were found to be more stable, effective, and safe than (OL/WPNs). Consequently, OL/Ag-NPs, especially Tofahy, are the best and safest nanoscale particles that can be safely used in food and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Aflatoxin M1 (AFM1) is a significant contaminant of food, particularly dairy products and can resist various industrial processes. Several probiotic strains like Lactobacillus plantarum are known to reduce aflatoxin availability in synthetic media and some food products. The current work investigated the possible chitosan coating prophylactic efficacy of Lactobacillus plantarum RM1 nanoemulsion (CS-RM1) against AFM1-induced hepatorenal toxicity in rats. Twenty-eight male Wistar rats were divided into four groups (n = 7) as follows: group 1 received normal saline, group 2 received CS-RM1 (1mL contains 6.7 × 1010 CFU), group 3 received AFM1 (60 µg/kg bwt), and group 4 received both CS-RM1(1 mL contains 6.7 × 1010 CFU) and AFM1 (60 µg/kg bwt). All receiving materials were given to rats daily via oral gavage for 28 days. AFM1 caused a significant elevation in serum levels of ALT, AST, ALP, uric acid, urea, and creatinine with marked alterations in protein and lipid profiles. Additionally, AFM1 caused marked pathological changes in the liver and kidneys, such as cellular necrosis, vascular congestion, and interstitial inflammation. AFM1 also increased the MDA levels and decreased several enzymatic and non-enzymatic antioxidants. Liver and kidney sections of the AFM1 group displayed strong caspase-3, TNF-α, and iNOS immunopositivity. Co-treatment of CS-RM1 with AFM1 significantly lowered the investigated toxicological parameter changes and markedly improved the microscopic appearance of liver and kidneys. In conclusion, AFM1 induces hepatorenal oxidative stress damage via ROS overgeneration, which induces mitochondrial caspase-3-dependent apoptosis and inflammation. Furthermore, CS-RM1 can reduce AFM1 toxicity in both the liver and kidneys. The study recommends adding CS-RM1 to milk and milk products for AFM1-elimination. [ABSTRACT FROM AUTHOR]

The photocatalytic performances of three Fe2O3–CeO2 nanocomposites were investigated toward the sulfur removal from a petroleum heavy gas oil (HGO) sample. The three composites were prepared by three different routes namely; auto-combustion, post-precipitation and precipitation. The physio-chemical features and optical properties of the presented composites were determined via proper analytical techniques. Formation of Fe2O3–CeO2 solid solution in all the prepared composites was verified via XRD analysis. These composites were then employed in photo-desulfurization of HGO and their activities were investigated at several operating conditions. The highest photocatalytic desulfurization exploit (91.5%) could be detected for the composite which was prepared via auto-combustion technique, denoted as (Fe20Ce80)ac. This maximum percentage of sulfur removal could be obtained under visible light irradiation at the following optimum operating conditions: 15 g/L (as photocatalyst dose), time of 6 h and 2:1 of H2O2 to oil ratio. The subsequent implementation of a solvent extraction step using N-methyl pyrrolidone was needed to attain the deepest desulfurization of HGO. The efficiencies of the presented composites against the process of sulfur removal were discussed in spot of their textural and optical characteristics as well as the available oxygen vacancies through their lattices structures. [ABSTRACT FROM AUTHOR]

For innovative application in wastewater treatment techniques, MnO-Fe2O3 nanocomposites were successfully synthesized using the sol–gel auto-combustion method at different temperatures for the adsorption of 137Cs and 60Co radionuclides from aqueous solution. The characterization of these nanocomposites was carried out through FT-IR, SEM-EDX, and X-ray diffraction. These nanocomposites were employed as adsorbent materials for the removal of 137Cs and 60Co radionuclides from simulated radioactive waste solutions. The study involved a series of experiments aiming to demonstrate the MnO-Fe2O3 nanoparticles' exceptional adsorption potential concerning 137Cs and 60Co. Additionally, the investigation delved into how variations in temperature, dose amount, contact time, and pH value influence the adsorption dynamics. Due to their high specific surface area, the synthesized MnO-Fe2O3 nanoparticles had high adsorption capacity of more than 60% and 90% for 137Cs and 60Co, respectively. By investigation of kinetics and adsorption isotherms, pseudo-second-order reaction and the Langmuir model turned out to fit well for the adsorption of 137Cs and 60Co onto the MnO-Fe2O3 nanocomposites. Moreover, a thermodynamic analysis revealed that the adsorption process was spontaneous for both target metals and the adsorption of 60Co was endothermic, whereas the adsorption of 137Cs was exothermic. [ABSTRACT FROM AUTHOR]

In this work, fluorine-doped tin oxide (FTO) and graphene/fluorine-doped (G-FTO) thin films were prepared using a low-cost spray pyrolysis method at a substrate temperature of 500 °C. For the FTOs, stannous chloride was dissolved in methanol and acetic acid to form the precursor solution. A 0.05 mole (M) of hydrofluoric acid was added to the precursor as an n-type impurity. The FTO thin film has an optical transmittance of 82% and electrical sheet resistance of 15 Ω/□. By meticulously integrating graphene into the optimal precursor solution of FTO, a significant improvement in the electrical conductivity of the prepared samples was achieved, leading to a reduction in the sheet resistance to 8 Ω/□ with a suitable optical transmittance of 79%. Structural, morphological, optical, and electrical properties of the prepared sample are investigated using X-ray diffraction, scanning electron microscope, UV spectroscopy, and four-point probe technique. The best performance of the FTO thin films is achieved utilizing 2.5 µmole/L of fluorine concentration at a substrate temperature of 500°C for a spraying exposer time of 20 min. The prepared sample has an electrical sheet resistance of 15 Ω/□, optical transmittance of 82%, and figure-of-merit of 91.2×10−4 Ω−1.The addition of 0.4 µmole/L of graphene to the optimum FTO samples enhances the performance by a remarkable reduction in the electrical the sheet resistance to 8 Ω/□ and an acceptable reduction in the optical transmittance of 79%. The overall value of the figure-of-merit increased to 118.3×10−4 Ω−1. The achieved results offer a high potential for adopting the prepared films for electronic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

In this study, metal oxides nanoparticles heterogeneous photocatalysts prepared by coprecipitation and ultrasonic techniques were used for diesel desulfurization. They were characterized by scanning electron microscope, powder X-ray diffraction, energy dispersive analysis, diffused reflectance spectra, photoluminescence analysis and BET surface area. The surface area of catalyst B is larger than catalyst A confirming its higher reactivity. X-ray reflectance spectroscopy was used to analyze the sulfur contents in feed. Thiophene was used as a model fuel to evaluate the photocatalytic activity of catalysts A and B. Using the Scherrer equation, sharp and intense signals suggesting their higher degrees of crystallinity, with average crystal sizes for ZnO, Bi2O3, catalysts A and B, respectively; of 18, 14.3, 29.7, and 23.8 nm. The operational parameters of the desulfurization process were optimized and have been studied and the maximum sulfur removal was achieved via a further solvent extraction step. A diesel fuel with a 24 and 19 ppm sulfur content and hence a total sulfur removal of 94.6% and 95.7% was acquired for catalysts A and B, respectively (sulfur compounds concentration in diesel fuel feedstock was 450 ppm). These findings demonstrated that photocatalysts A and B are good and effective catalysts for desulfurization of diesel fuel. [ABSTRACT FROM AUTHOR]