Iranian Journal of Materials Science and Engineering

Exploring the Role of Nanosphere Plasmonic Structures on the Efficiency Enhancement of Copper Indium Gallium Diselenide Solar Cells

Fatemeh Dabbagh Kashani

CIGS solar cells are currently very high-efficiency thin-film solar cells. With regard to higher efficiency in solar cells, research is being conducted on the influence of both light scattering and plasmonic resonances due to metallic nano-structures. This article discusses the assessment of the incorporate plasmonic nanostructures on the absorber layer of a 1000 nm CIGS solar cell, in terms of light absorption and device performance. It is noted that decisions on material, size, and surface coverage (Occupied Factor) were important considerations that affected the performance. Opto-electrical assessment was used to investigate absorption, charge-carrier generation, current density-voltage response, power-voltage properties, and total efficiency. Using simulations, we discovered the aluminum nanosphere arrays (200 nm diameter, Occupied Factor 0.64) at the top of the absorber layer yielded the maximum efficiency (26.14%). This was shown by the resonances, and near-field distribution garnered from the nanospheres boost charge carrier generation, diminished recombination losses, and increased charge separation. Collectively, these raised the performance of the CIGS solar cells in this research and suggested hope for moving CIGS and potentially other photovoltaics forward using nanoscale plasmonic resonances.

Electromagnetic Behavior of in-situ Synthesized MXene-based Ti3C2/TiO2 Composites

Majid Tavoosi

The present work, set out with the aim of studying the effect of in-situ precipitation of TiO₂ form Ti₃C₂T_x MXene phase on the electromagnetic (EM) behavior of Ti₃C₂/TiO₂ composites. In this regard, Ti₃C₂T_x MXene phase was synthesized using HF acidic etching of Ti₃AlC₂MAX phase and the in-situ precipitation of TiO₂ phase within Ti₃C₂ sheets was followed by controlled annealing in temperature range of 500-800 ^oC for 2 h. The phase and structural characteristics of prepared composites were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM) and differential thermal analysis. The electromagnetic behavior of samples was also analyzed using vector network analyzer (VNA). The results showed that by performing the controlled annealing process of Ti₃C₂T_x MXene phase, it is possible to in-situ formation of TiO₂ phase and form the Ti₃C₂/TiO₂ composites. The electromagnetic behavior of Ti₃C₂/TiO₂ composites is in direct relation with the percentage of TiO₂ phase deposited within Ti₃C₂ sheets during annealing process. The reflection loss (RL) changed from -7.98 to -21.28 dB (within frequency range of 1-18 GHz) with increasing in annealing temperature from 500 to 800 ^oC as well as increasing the size and percentage of formed TiO₂ particles.

Influence of Sn and Al Doping on ZnO thin films: A Study of Structural, Optical, and Langmuir Adsorption Properties for Photocatalytic Applications

Elhachmi Guettaf Temam

Zinc oxide (ZnO) thin films have garnered significant interest for their applications in optoelectronics and environmental remediation due to their exceptional optical, electrical, and photocatalytic properties. However, the high resistivity and rapid charge recombination of pure ZnO necessitate doping to enhance its performance. In this study, ZnO thin films doped with tin (Sn) and aluminum (Al) were synthesized via a cost-effective pneumatic spray technique. The structural, optical, and morphological properties of the films were systematically characterized using X-ray diffraction (XRD), UV-Vis spectrophotometry, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The results indicate that Sn and Al doping significantly influence ZnO’s crystallinity, bandgap energy, and surface morphology. The optimal crystallite size was obtained for 1 wt.% Sn (37.98 nm) and 5 wt.% Al (48.63 nm), while excessive doping (>3 wt.%) introduced microstrain (10.41 × 10⁻⁴ for Sn and 7.13 × 10⁻⁴ for Al), reducing crystallinity. The optical bandgap decreased from 3.254 eV (pure ZnO) to 3.142 eV (1 wt.% Sn) and 3.152 eV (5 wt.% Al), accompanied by increased Urbach energy (0.34 eV for 5 wt.% Al). The highest optical transmittance (86%) was observed for 3 wt.% Al-doped ZnO. Pure ZnO exhibited the highest photocatalytic efficiency, achieving 85% methylene blue degradation under solar irradiation. Langmuir adsorption modeling revealed that Sn-doped ZnO exhibited the highest adsorption capacity (1.422 mg/g), followed by Al-doped ZnO (0.617 mg/g) and pure ZnO (0.495 mg/g). These findings emphasize the critical role of doping concentration in optimizing ZnO thin films for advanced photocatalytic and optoelectronic applications.

Synthesis, Characterization and Electrical Properties of Poly 2-Aminobenzothiazole Doped by MWCNTS

mohammed mohammed

Poly(2-aminobenzothiazole) (PAT) is a relatively new heterocyclic conducting polymer having a sulfur and nitrogen-rich chemical structure. During the past decade or so, there have been notable advances on the development of PAT. Especially, PAT and PAT-based composites have shown great potential for their applications in photovoltaic cells, solar cells and anti-corrosion organic coatings. In this study, 2-aminothiazole was successfully prepared as pure polymer and as composite materials with multi-wall carbon nanotubes (MWCNTs). FTIR, X-ray diffraction and SEM images were investigated, showing that the composite of poly 2-aminobenzothiazole: MWCNTs was successfully synthesized. The electrical features of the pure polymer and the composite thin films were examined. The findings show that the conductivity of the pure polymer and composite thin films are about 1.67x10^-6 (S/cm) and 4.1x10^-2(S/cm), respectively, exhibiting a significant enhancement by a factor of 2.5x10⁴ times as a results of doping the pure polymer by 1% wt MWCNTs.

Multifunctional Effects of Green Synthesized Silver Nanoparticles on Glioblastoma Multiform Cancer Cells

Mehdi Shakibaie

Glioblastoma multiforme is an aggressive brain tumor with limited therapeutic options. This study evaluated the multifunctional anticancer effects of curcumin-synthesized silver nanoparticles (curcumin-AgNPs) on the U-87 glioblastoma cell line. Curcumin-AgNPs were biosynthesized using curcumin as a reducing and stabilizing agent and characterized by ultraviolet–visible spectroscopy (UV–Vis), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Cytotoxicity was assessed by MTT assay. The mRNA expression of apoptosis- and epithelial–mesenchymal transition (EMT)-related genes was quantified by real-time PCR. DLS and TEM analyses revealed curcumin-AgNPs with sizes of 56.27±4.59 nm and 22±3 nm, respectively. Curcumin-AgNPs reduced U-87 MG cell viability in a dose- and time-dependent manner. Analysis of apoptosis-related genes showed an increased BAX/BCL2L1 ratio. Additionally, FN1 and VIM were downregulated to 0.48- and 0.60-fold, respectively, indicating inhibitory effects on EMT and the metastatic potential of U-87 MG cells. These findings indicated that curcumin-AgNPs exhibit cytotoxic, pro-apoptotic, and EMT-modulating effects in U-87 MG cells, highlighting their potential as a multifunctional nanoplatform for glioblastoma research. Further studies are required to elucidate their underlying mechanisms.

Micro-Scale Simulation of Microstructural Evolution in Aluminum 1050 Using Crystal Plasticity Analysis

Mohammad Sedighi

The investigation of the mechanical response and microstructural evolution of engineering materials at the micro-scale under macro-scale loading poses a significant challenge in mechanical engineering, particularly in the fields of material forming and materials science. This critical has been addressed using a computational crystal plasticity tool known as DAMASK (Düsseldorf Advanced Material Simulation Kit). DAMASK is a multi-scale computational framework developed for modeling the deformation of crystalline materials by employing the principles of continuum mechanics and crystal plasticity. This software is widely recognized within the scientific community for its high flexibility and capability to simulate complex material behavior under various loading conditions. In this study, the DAMASK code—a finite element crystal plasticity software—was employed to analyze a representative volume element (RVE) containing 1000 grains under tensile loading. By applying a random initial texture to aluminum grade 1050, the microstructural evolution of the material under the specified loading conditions was evaluated. The results indicate the formation of <111> and <100> fiber textures in the (111) crystallographic plane of the FCC-structured material, which are consistent with observations obtained from EBSD experiments.

Investigation of the Static and Dynamic Mechanical Properties of the Base Metal and Weld Zone of Haynes 25 Alloy

Yaser Vahidshad

This work presents a comprehensive investigation of the high cycle fatigue behavior of Haynes 25 cobalt-based superalloy and its welds produced by pulsed continuous-wave (CW) laser welding. The alloy, manufactured through vacuum induction melting and electroslag remelting followed by rolling and annealing, exhibited a yield strength of 650 MPa, an ultimate tensile strength of 1050 MPa, and an outstanding elongation of 57% at room temperature. The fatigue limit was determined by test method as 200 MPa for lifetimes exceeding 10⁸ cycles, highlighting its excellent resistance to cyclic loading. For the weld zone, fabricated under optimized pulsed CW laser parameters, the yield and ultimate tensile strengths were 660 MPa and 965 MPa, respectively, with a fatigue limit of 175 MPa. Advanced microstructural analyses using OM, SEM, EBSD, and XRD revealed an austenitic FCC matrix with carbide precipitates, predominantly (W, Cr)₇C₃ and M₆C, decorating both the matrix and grain boundaries. Fatigue crack initiation in the base metal was associated with carbide clusters near the surface, while in the weld zone it was strongly linked to near-surface gas porosity defects. These findings not only establish fundamental fatigue benchmarks for Haynes 25 but also provide the first direct insights into the microstructural origins of fatigue damage in its laser-welded joints, thereby addressing a critical knowledge gap for its deployment in high-temperature and cyclic-loading environments.

Effect of Electrolytic Solution on Corrosion Behavior and Mechanical Properties of a Coated AZ31 Magnesium Alloy Via Plasma Electrolytic Oxidation Process

Saeed Reza allahkaram

The present work deals with the corrosion behavior and mechanical properties of a coted AZ31 magnesium alloy through plasma electrolyte oxidation (PEO) coating process in different alkaline electrolytes based on sodium silicate (Si-coating), sodium polyphosphate (P-coating) and sodium aluminate (Al-coating). The scanning electron microscopy (SEM) equipped with the energy dispersive x-ray spectroscopy (EDX) plus x-ray diffraction were recruited to investigate the morphology, chemical composition, and phase structure of coatings, respectively. Microscopic scrutiny revealed that the coating in the phosphate electrolyte was twice as thick and the relative porosity percentage was higher than those formed in the other electrolytes. The phase analysis indicated that the MgO was present as the prevailing phase in the Al-coating and P-coating. However, the dominant phase in the Si-coating was Mg₂SiO₄. Electrochemical testing was examined in a solution containing 3.5.wt% sodium chloride, showing improvements in corrosion resistance of coated alloys. These investigations confirmed that the corrosion resistance of Si-coating was dramatically higher than others which could be attributed to the presence of the dense and stable Mg₂SiO₄ phase as well as its relatively low porosity. According to the results of tensile tests, the coated samples had lower tensile strength and elongation than the uncoated one. The tensile strength and elongation diminished upon changing the electrolyte from Al-coating to P-coating, while the yield strength was almost similar. Further analyses indicated that the drop of tensile strength and elongation could be attributed to the presence of cracks and pores in the brittle ceramic PEO coating as stress concentration regions during deformation. Those areas are created due to thermal stress during the coating process and deformation in the elastic stage.

Fatigue Behavior of 4340 Steel at Room and Elevated Temperatures: Correlating Fatigue and Tensile Testing Data

Ramin Ebrahimi

In this study, an existing approach for estimating fatigue life using tensile data was extended and applied to 4340 steel under different temperature. The S-N and strain-life curves were plotted at 25, 200, and 350 ˚C. The Basquin and Coffin-Manson equation constants were determined based on the corrected true fracture stress and strain values. Moreover, the b constants were approximated as -0.065, -0.072, and -0.073 at 25, 200, and 350 ˚C, respectively. This was achieved by setting the alternating stress equal to the fatigue limit in an infinite number of cycles when b leveled off. The transition fatigue life of 1000 cycles was considered for 4340 steel to determine the c constants, which were determined to be -0.69, -0.7, and -0.699, at 25, 200, and 350 ˚C, respectively and the strain-life curves were plotted. Comparison of S-N curves obtained from both fatigue and tensile data revealed strong agreement, indicating that the tensile test is a simple and cost-effective method capable of providing a quick estimate of high- and low-cycle fatigue behavior and serving as a suitable alternative to conventional fatigue testing.

Evaluation of Corrosion Behavior of Ni/Be-free Titanium-Based Metallic Glasses Fabricated by Vacuum Arc Melting Method

Behnam Lotfi

Bulk titanium-based metallic glass with amorphous structure has led to the creation of special properties, which can be used as a suitable alternative to metallic biomaterials with crystalline structure. In the present study, bulk titanium-based metallic glass without Ni and Be elements produced by vacuum arc melting and cast into a 4 mm diameter mold. The evaluation of the results showed that the Ti₅₀Zr₁₅Cu₂₀Mo₇Ag₄Sn₃Si₁ metallic glass has a composite structure of dispersed crystalline phases (α-Ti, β-Ti and Ti₂Cu) in a glassy field. However, the Ti₅₀Zr₂₅Cu₅Mo₁₀Ag₆Sn₃Si₁alloy has a higher glass formation ability (GFA) and the crystalline phases formed in the Ti₅₀Zr₁₅Cu₂₀Mo₇Ag₄Sn₃Si₁ alloy disappeared with increasing the amount of alloying elements Zr, Mo and Ag. The corrosion current (I_Corr) of the Ti₅₀Zr₂₅Cu₅Mo₁₀Ag₆Sn₃Si₁ alloy (43.28 nA) was lower compared to the corrosion current of the Ti50Zr15Cu20Mo7Ag4Sn3Si1 and Ti6Al4V samples (133.9 and 92.41 nA, respectively) in Hank's solution, hence the Ti₅₀Zr₂₅Cu₅Mo₁₀Ag₆Sn₃Si₁ alloy showed better corrosion resistance.

Effect Of Temperature on Ionic Conductivity and Optical Bandgap Features Of TSP-NaI-Based Biopolymer Electrolytes

Krishna Jyothi N

This research systematically examines the structural, electrical, and optical characteristics of Tamarind Seed Polysaccharide (TSP)--based biopolymer electrolytes that are doped with varying concentrations of sodium iodide (NaI). Composite films were synthesized using the solution cast technique in weight percent ratios of TSP: NaI (100:0, 90:10, 80:20, 70:30) and subsequently characterized employing X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV–Vis spectroscopy, and impedance analysis. The XRD analysis indicated that the 80:20 composition displayed the highest degree of amorphousness, which is associated with improved ionic conductivity and reduced crystallite size. The FTIR analysis corroborated the occurrence of complexation between TSP and NaI, while the temperature-dependent conductivity measurements conformed to Arrhenius behaviour, with the 80:20 film achieving the ionic conductivity (1.97x10⁻⁴S/cm) and the lowest activation energy (0.69 eV). Optical absorption investigations revealed a decrease in the bandgap from 3.92 (pure TSP) to 2.68 eV (80:20 film). Minimum optical energy bandgaps were achieved for the optimized film. Opto-dielectric investigations further demonstrated that the 80:20 formulation exhibited optimal dielectric permittivity and loss. The results underscore the potential applicability of TSP–NaI biopolymer systems as sustainable, high-performance polymer electrolytes.

Surface Characteristics of Titanium Based Coatings Obtained by Detonation Spraying Under Various Process Conditions

Sergey Savotchenko

The surface properties of metal-ceramic coatings based on titanium dioxide are described in dependence on the detonation spraying conditions. It is found that such properties as surface roughness, surface thickness and its hydrophobicity can be controlled in the production process by selecting certain values of the technological parameters of the spraying process. The optimal values of the technological parameters of detonation spraying, ensuring maximum hydrophobicity of the produced coatings are determined. The roughness of the coating surface and the coating thickness depend on the speed of the nozzle passage in accordance with the inverse power law. The roughness and the contact angle depend on spray distance in accordance with a parabolic law. New equations are obtained that can be useful for predicting the characteristics of the coating surface, as well as for determining the optimal mode of spraying the coating, ensuring its best hydrophobicity.

Dual-Functional Orthopedic Implants based on Al2O3-CuO/Ti nanocomposite: Antimicrobial and Osteogenic Properties

Mojgan Heydari

In this study, we investigated the antimicrobial, bioactivity, and in vitro cytotoxicity of a nanocomposite made of copper oxide (CuO) and aluminum oxide (Al₂O₃) with two different morphologies of copper oxide (Spherical-sCuO and Nanoplate-pCuO), which was made using the Spark Plasma Sintering (SPS) process on a titanium substrate as an orthopedic implant. Two different weight percents of copper oxide nanostructures of sCuO NP (10 wt%, 20 wt%) and pCuO NP (10 wt%, 20 wt%) have been used in this research. Synthesized nanocomposites were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscope (FESEM). Based on the obtained results, the XRD pattern and XPS confirmed that the nanocomposites were successfully synthesized without impurity. FESEM images showed that CuO nanoparticles and nanoplates were distributed on the alumina matrix homogeneously. The antibacterial activity of synthesized nanocomposites was investigated using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), gram-negative and gram-positive bacteria, respectively. Antibacterial activity results showed that CuO nanoparticles had high antibacterial activity, and the effect of CuO nanostuctures depended not only on their morphology and size, but also on the type of microorganisms. Furthermore nanocomposite with nanoplate copper oxide exhibited more bioactivity properties than the spherical shape. S. aureus showed greater resistance to CuO nanostructure, while E. coli was more susceptible to them (15%). In addition, toxicity tests showed that nanoplate copper oxide exhibited greater toxicity due to its high surface reactivity than spherical nanoparticles. This study provides new insights into the role of copper oxide nanoparticle morphology in the properties of nanocomposites for use as orthopedic implants.