Journal of Electronic Materials最新文献

This study presents a surface plasmon resonance (SPR) biosensor design that integrates graphene-coated resonators with multi-metallic layers (Au, Ag, Cu, Al) for an enhanced breast cancer biomarker detection in the terahertz frequency range. Computational modelling using COMSOL Multiphysics software demonstrates exceptional performance metrics, including sensitivity’s values reaching 500 GHz/RIU, figure-of-merit up to 5.263 RIU⁻¹, and detection accuracy of 10.526 across the operational frequency range of 0.1–0.6 THz. In addition, the biosensor’s performance is further optimized through locally weighted linear regression (LWLR) machine learning algorithms, achieving prediction accuracies with R² values ranging from 86% to 93% for various operational parameters including graphene chemical potential (0.1–0.9 eV) and incident angles (0–80°). The electromagnetic field analysis reveals maximum energy confinement at 0.25 THz, with reflectance values stabilizing between 72% and 76% under optimal conditions. This innovative approach addresses critical limitations of conventional mammography and invasive biopsy procedures, offering a noninvasive, highly sensitive platform for detecting breast cancer biomarkers (CA 15-3, HER2, circulating tumor DNA) from picomolar to femtomolar concentrations, potentially revolutionizing early-stage breast cancer screening protocols.

Two-dimensional transition metal carbides (MXenes) have shown great promise for developing flexible polymer nanocomposites with high dielectric constant. A critical challenge lies in balancing high dielectric constant with low dielectric loss, which is governed by the electrical conductivity of the nanofiller. This study investigates two-dimensional Nb₂CT_x MXene as a promising low-conductivity filler for achieving this balance. Nanocomposites of poly(vinylidene fluoride) (PVDF) containing 5–30 wt.% Nb₂CT_x were prepared and characterized by x-ray diffraction, scanning electron microscopy, and simultaneous thermal analysis (TGA-DSC). The dielectric properties were studied by impedance spectroscopy over a temperature range from −50°C to 130°C. The nanocomposite with 30 wt.% Nb₂CT_x exhibited a high dielectric constant (ε’ ≈94) with a concurrently low dielectric loss tangent (tan δ ≈0.2) at 10 kHz. While the dielectric constant values were comparable to those of nanocomposites with previously studied MXene fillers, such as Ti₃C₂T_x or V₂CT_x, the dielectric losses were significantly lower, highlighting the advantage of the two-dimensional Nb₂CT_x filler. The temperature-dependent dielectric response was primarily dominated by the PVDF matrix, regardless of filler concentration. These findings underscore the potential of two-dimensional Nb₂CT_x MXene for designing advanced flexible dielectric films with tailored dielectric properties.

Direct ink writing (DIW) is an additive manufacturing technique that enables the deposition of conductive liquid materials for electronic applications. However, achieving continuous micron-scale tracks with consistent track width and electrical properties poses a critical challenge essential for the reliability of electrical circuits. This study examines the deposition of copper-based conductive ink utilizing an in-house-developed DIW setup. The objective is to optimize process parameters to enhance track width (TW) accuracy and sheet resistance (SR). The process parameters, including stand-off distance, extrusion multiplier, nozzle diameter, and print speed, were investigated for their effect on tracks and electrical performance using response surface methodology (RSM). Multi-objective optimization was utilized to define quantitative relationships between process variables and performance metrics. The findings indicate that linear, quadratic, and interaction terms significantly affect TW and SR. The predicted TW and SR values derived from Pareto-optimized parameters strongly correlate with experimental results, indicating a high level of predictive accuracy. A functional circuit was fabricated as a case study to demonstrate the practical applicability of the deposited tracks, integrating various electronic components for DC voltage regulation. Results highlight the significance of optimizing process parameters in producing high-quality conductive tracks using DIW for advanced electronic applications.

The physical properties of perovskite manganite with hexagonal structure is of interest for its additional functionalities. However, unlike LaMnO₃ with orthorhombic and rhombohedral phases, which has been extensively studied, LaMnO₃ with hexagonal structure is not typically investigated. This work systematically investigates the structure, magnetism, and transport properties of hexagonal LaMnO₃. Magnetization measurements of the hexagonal LaMnO₃ reveal a magnetic transition with a Curie temperature (T_C) of 245 K, distinct from the Néel temperature (T_N) ≈140 K of orthorhombic LaMnO₃. Resistivity measurements indicate a metal-insulator transition near T_C. Under a 6 T field, the sample exhibits a negative magnetoresistance (−MR) of 56.11% at 242 K and maintained a significant MR effect over a wide temperature range, which was attributed to the synergistic effects of spin-polarized tunneling, sample inhomogeneity, Jahn–Teller distortion, and double exchange interaction. The electrical transport behavior at high temperatures follows the variable range hopping model. The significant MR effect over a wide temperature range appears in the hexagonal LaMnO₃, highlighting the potential for spintronics applications.

This study provides a detailed analysis of the electronic and optical characteristics of 2D TiC-based MXenes using complex density functional theory (DFT) computational techniques. The study examines the impact of surface functionalization on the performance of significant transition metal MXenes, specifically Ti₃C₂, V₂C, and Nb₂C, in energy storage applications. The results show that these materials retain metallic properties crucial for optimal electrical conductivity. Ti₃C₂, V₂C, and Nb₂C reveal significant optical activity, as evidenced by their unique refractive indices and absorption coefficients, with plasma edge values observed at 0.1 eV, 0.5 eV, and 0.3 eV, respectively. Ti₃C₂ functions with an indirect bandgap, which makes it especially well-suited for infrared photodetection and thermal imaging, according to the investigation of band structures. V₂C and Nb₂C indicate potential for supercapacitor applications, attributed to their rapid charge transfer capabilities facilitated by d-orbitals above the Fermi level. Our analysis emphasizes the materials’ applicability for solar cell technology by highlighting the critical roles of the anisotropy of the dielectric constant and the overlap between the transmittance and absorption bands. These results highlight the innovative potential of TiC-based MXenes in optoelectronic devices and next-generation energy storage solutions, opening the door for future uses in various technological fields, such as sensors, semiconductor manufacturing, and renewable energy harvesting.

Graphical Abstract

With the extensive application of third-generation semiconductor devices in the drive motors of new energy vehicles, soft magnetic composites (SMCs) have attracted much attention owing to their excellent direct current (DC) bias characteristics and high saturation magnetic induction intensity. However, SMCs still face the “permeability-loss” trade-off dilemma in high-frequency and high-power density applications. In this study, an environmentally friendly acetic acid passivation strategy was innovatively adopted to in situ generate a uniform and continuous Al₂O₃ insulating layer on the surface of flaky FeSiAl powders. By systematically regulating the acetic acid passivation time (20–100 min), FeSiAl–Al₂O₃ SMCs with different Al₂O₃ coating characteristics were prepared, and their magnetic properties were characterized in detail. The experimental results show that when the acetic acid passivation time is 60 min, the FeSiAl–Al₂O₃ SMCs achieve a synergistic breakthrough in ultra-high permeability (97.6 @2 MHz), ultra-low power loss (93.6 kW/m³ @50 mT/100 kHz), and strong DC bias stability (>70%71.98 Oe) simultaneously, showing excellent comprehensive magnetic properties. This study provides new ideas and technical support for the development of high-performance and green-manufactured SMCs, and is expected to achieve more efficient electromagnetic energy conversion in high-frequency and high-power density application scenarios.

This study highlights the coupling of photocatalytic and piezocatalytic activity, potentially improving the efficacy of synthesis under both solar and visible light conditions. The melt-quench technique was employed to synthesize a single-phase Bi₂VO_5.5 (BV) sample. The orthorhombic Bi₂VO_5.5 phase was established using Raman spectroscopy and x-ray diffraction. Analysis via scanning electron microscopy demonstrated the irregular morphology of the synthesized Bi₂VO_5.5. X-ray photoelectron spectroscopy revealed the different elemental oxidation states that were present. During the synergetic piezo-photocatalysis experiment under visible light in methylene blue dye, degradation efficiency of (sim )63% within 180 min was achieved. The kinetic rate constant was investigated in relation to the concentration of the dye. The kinetic rate constants for the BV sample under sunlight were 0.01168 min⁻¹ and 0.02183 min⁻¹ for photocatalysis in 90 min and piezo-photocatalysis in 30 min, respectively.

We report a sustainable and efficient route for the fabrication of formamidinium lead iodide (FAPbI₃) perovskite solar cells (PSCs) via a green solvent-based two-step deposition process. In this method, PbI₂ is dissolved in dimethyl sulfoxide (DMSO), a less toxic solvent than traditional dimethylformamide (DMF), and spin-coated, followed by the deposition of FAI from isopropanol (IPA). Furthermore, surface passivation using a fluorinated interlayer, 4F-phenethylammonium iodide (PEAI), improves device morphology and charge transport, resulting in a power conversion efficiency (PCE) of 19.61.%. Comprehensive structural, optical, and electrical characterizations confirm enhanced crystallinity, reduced trap density, and suppressed hysteresis in treated devices. This environmentally benign and industrially scalable process paves the way for the commercialization of high-performance, low-toxicity perovskite photovoltaics.

Graphical abstract

The structural stability of multivacancies in monolayer gallium nitride has been studied using density functional theory (DFT) with the generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof for the exchange–correlation functional. The supercell consisting of 72 atomic sites is used to model the multivacancies, with all atoms in the supercell relaxed during optimization. The multivacancies are created by removing a pair of Ga–N atoms sequentially from the center of the supercell, following the part-of-hexagonal-ring method. The multivacancies modeled are monovacancy to hexadecavacancy. The stability of multivacancies is analyzed through the formation and dissociation energies. From the calculated energies, we conclude that hexa- and decavacancies are stable multivacancies, indicating that multivacancies in monolayer GaN tend to agglomerate to hexa- and decavacancies. To show the effect of atomic relaxation, we compare our DFT results with the dangling bond counting model, which ignores atomic relaxation. The symmetry of each defective system is discussed.

Graphical Abstract

Nickel oxide and aluminum-doped zinc oxide thin films were successfully deposited using pulsed laser deposition. Two nickel oxide thin films were grown at deposition pressure of 10 mTorr (≈ 1.33 Pa) and 20 mTorr (≈ 2.66 Pa). The prepared NiO thin film was successfully characterized using x-ray diffraction, ultraviolet (UV) spectroscopy, and Hall measurement techniques. The thermoelectric measurements were carried out using an in-house-developed thermoelectric setup. The Seebeck coefficient values for the nickel oxide thin films prepared at 20 mTorr and 10 mTorr were found to be nearly the same, at approximately 0.018 mV/K. The power factors at 20 mTorr and 10 mTorr for the nickel oxide thin films were estimated to be 0.00008424 mW cm⁻¹ K⁻² and 0.0000312 mW cm⁻¹ K⁻², and the figure of merit was estimated as 0.125 and 0.046, respectively.

Graphical abstract