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In the pursuit of enhancing the optoelectronic properties of perovskite thin films for photovoltaic applications, this study investigates the effects of Fe ion irradiation on methylammonium lead iodide bromide (MAPbI₂Br) thin films. Thin films of methylammonium lead iodide bromide, (CH3NH3PbI2Br, or MAPbI2Br) have been deposited by sol–gel dip coating technique. These films were irradiated with 300 keV Fe ions with flouncy of 2 × 1014 ions/cm2. The prepared films all show the cubic crystal structure. However, the film irradiated with Fe ions has a larger grain size, according to XRD. The optical characteristics, such as refractive index, band gap energy, and extinction coefficients, are examined by UV–Vis analysis. Although both the films showed a direct bandgap, the film irradiated with Fe ions showed a lower value for the bandgap energy (1.76 eV) and high refractive index. The device structure used was FTO/TiO2/MAPbI2Br/spiro-OMeTAD/Au. The devices made with 300 keV Fe ions irradiated film has high current density of 10.86 mA cm−2, fill factor of 0.80, an open circuit voltage of 1.06 V, and an efficiency of 9.93%. The findings emphasize the potential of Fe ion irradiation as a novel technique to improve grain structure and optoelectronic properties, advancing perovskite-based device technology for higher efficiency solar cells. [ABSTRACT FROM AUTHOR]

Sol-gel dip-coating technique has adapted a thin film of CH3NH3PbI2Br (MAPbI2Br) on a glass FTO substrate. The structure of the film shown from the X-ray diffraction is cubic, and the appearance indicates that the film is significantly crystalline. The V2+ 5%-doped film demonstrated a significant geometric increase in the crystallite size to 34.52 nm, a sharp decrease in the bandgap energy to 1.79 eV, an elevation in the refractive index to 2.41, and a decrease in the extinction coefficient to 1.66. Additionally, this material's conduction band edge complements the TiO2 electron transport layer appropriately. On the other hand, we constructed solar cells using the FTO/TiO2/MAPbI2Br/spiro-OMeTAD/Au configuration. Doping the MAPbI2Br film with 5% V2+ yielded the most remarkable results. It had a current density of 8.42 mA/cm2, an open-circuit voltage of 1.04 V, a fill factor of 0.76, and an efficiency of 6.58%. However, the electrochemical impedance spectroscopy (EIS) results for the same cell show that the device with 5% V2+ doping has a lower recombination rate than solar cells. This work has demonstrated that the doping effect of V2+ in the MAPbI2Br perovskite films, made of the 5% V-doped modification in the form of solar cells, improves performance and lays the groundwork for future advancements in provskite solar cells. [ABSTRACT FROM AUTHOR]

A new mathematical model to predict the time to the initiation of corrosion-induced cracking of reinforced concrete structures was developed. To determine the corrosion penetration in reinforcement steel, a three-dimensional finite element model was developed. Modeling was based on geometric parameters such as the free concrete covering, reinforcement bar diameter, type of concrete, and the corroded length. Using finite element and statistical analyses, mathematical expressions were calculated to obtain time-to-corrosion cracking. Calculated cracking times were compared to published experimental data. The parametric sensitivity of the model is established with reference to published experimental evidence, and the role of the important design variables in the evolution of this mechanical problem is identified and discussed. [ABSTRACT FROM AUTHOR]