Journal of Materials Science: Materials in Electronics最新文献

The rise in popularity of carbon-based adhesives is revolutionizing the industry, offering eco-friendly alternatives that can be recycled while protecting the environment from the harmful effects of solder metal. In this ground breaking study, we delve into the impact of different carbon-based conductive fillers on the overall performance of the adhesive. From reduced graphene oxide (rGO) to thermally and chemically expanded graphite (EG), we explore these fillers’ intricate 3D network structure and how they enhance both the final product’s electrical conductivity and mechanical strength. According to the findings of this research, the structure of 3D and interwoven EG plays the prominent role in electrical conductivity. Maintaining the 3D and stable structure after making the composite is due to the structure of EG, which prevents the graphene sheets from falling on top of each other, preventing the interaction of free electrons with vertical sheets. On the other hand, a similar structure was obtained using two separate methods of thermal and chemical expansion, which is optimal in terms of electrical conductivity. Our findings reveal that an adhesive containing 17.5 wt% of EG achieved a volume resistivity of 2.5 Ω cm, showcasing the remarkable conductivity of these materials. The unique 3D network structure improves electrical performance and aids in the curing process by reducing curing enthalpy to 147.19 J g⁻¹, resulting in superior mechanical properties and adhesion. Furthermore, by studying the effects of functional groups and surface characteristics of chemically expanded graphite (CEG), we discovered that sharp edges and wrinkled sheets significantly enhance the adhesive’s tensile strength, surpassing 10.24 ± 1.2 MPa. The Young’s modulus of 96.24 ± 6 MPa represents moderate stiffness while also allowing for flexibility. The results show carbon-based adhesives’ potential and pave the way for a more sustainable product.

A novel BiOCl/Co catalyst was constructed by in situ doping of metal Co nanoparticles on n-type BiOCl nanosheets. The percentage of metal Co incorporated in the photocatalysts was adjusted to improve the degradation performance of the new catalysts against pollutants. The optimized BiOCl/Co achieved up to 95.5% photocatalytic degradation efficiency of rhodamine B (RhB). This might be attributed to the enhanced visible light absorption ability of BiOCl/Co by plasmon resonance (SPR) as well as the effective interfacial separation and transport of carriers in BiOCl/Co. BiOCl/Co showed excellent mineralization capacity and reuse performance in the degradation of RhB. Furthermore, it was shown that photogenerated h⁺, ⋅OH and ⋅O₂⁻ were the major reactive substances for dye degradation. The photodegradation mechanism of RhB by BiOCl/Co was elucidated in this paper.

Solar cell substrates made from high-temperature polymer bases can be applied to various types of thin-film devices. Studying how different substrates impact the properties of semiconductor films is crucial. In this research, chemical spray pyrolysis (CSP) was utilized to coat thin layers of cadmium sulfide (CdS) on polyimide (PI) plastic bases. The coating process involved using distinct precursor solutions with molar concentrations of 0.1, 0.2, 0.3, and 0.4 M. X-ray diffraction (XRD) analysis was applied to assess the crystal structural characteristics. The XRD findings demonstrated the correct phase development in the CdS structure. The outcomes revealed that the crystallite size was directly related to the molarity concentration, with larger crystals forming at higher concentrations. Larger crystallites can lower grain boundary density, which can affect the film’s electrical and mechanical properties. Furthermore, a hexagonal structure was observed in the CdS layers. The optical band gap values of the CdS thin films increased from 2.16 to 2.21 eV as the molarity concentrations were elevated.

The escalating pollution of water resources by organic pollutants necessitates the development of efficient and eco-friendly treatment technologies. In this study, a WO₃–visible light–H₂O₂ (WO₃–Vis–H₂O₂) advanced oxidation system was constructed, and the difficult-to-degrade azo dye methyl orange (MO) was selected as the target of organic pollutants. Under the optimal conditions of the system, 97.9% of MO can be degraded under 100 min of visible light irradiation. The degradation process confirmed to the first-order kinetic equation, and the apparent rate constant k is 0.03909 min⁻¹. The degradation efficiency of MO by this system was 5.54 times higher than that of WO₃ photocatalytic degradation of MO. Free radical capture experiments proved that ·OH was the main active species. The system realized the effect of the iron-free heterogeneous photo-Fenton reaction, and WO₃ can be reused. This work not only presents a green and sustainable approach to the degradation of organic pollutants but also highlights the potential of visible light catalyst–visible–H₂O₂ system for broader environmental remediation applications.

In order to meet the demand of high-quality microwave dielectric ceramics for the development of wireless communication, 0.84MgNb_2-x(Ti_1/2W_1/2)_xO₆-0.16CaTiO₃(x = 0, 0.03, 0.05, 0.07, 0.09, 0.11) microwave dielectric ceramics were prepared by solid-phase method. The effects of phase structure, sintering properties, microstructure, and microwave dielectric properties of 0.84MgNb₂O₆-0.16CaTiO₃ ceramics in which the Nb⁵⁺ ionic substituted with different contents of (Ti_1/2W_1/2)⁵⁺ were studied. The results indicate that the partial Nb⁵⁺ in the 0.84MgNb_2-x(Ti_1/2W_1/2)_xO₆-0.16CaTiO₃ nominal composition are replaced by the complex cations (Ti_1/2W_1/2)⁵⁺ in the crystal structure, and no new phase is produced. With the gradual increase of (Ti_1/2W_1/2)⁵⁺ addition, the bulk density of 0.84MgNb_2-x(Ti_1/2W_1/2)_xO₆-0.16CaTiO₃ ceramics increased, the sintering temperature did not significantly change, the ceramic cell volume decreased, and the material polarizability and filling rate decreased, resulting in a decrease in the ceramics’ dielectric constant ε_r, the quality factor Q × f increases, and the frequency temperature coefficient τ_f shifts to a positive value. The 0.84MgNb_1.95(Ti_1/2W_1/2)_0.05O₆-0.16CaTiO₃ ceramic with x = 0.05 composition sintered at 1250 °C for 4 h holding time has the best microwave dielectric properties: ε_r = 21.52, Q × f = 96983 GHz, and τ_f = − 3.8 × 10^–6/ °C.

Conventional wave-absorbing materials effectively absorb electromagnetic waves in specific frequency bands and however cannot cope with interference and radiation in a wide frequency range. Therefore, materials with broadband wave-absorbing properties are of great significance for electromagnetic interference and radiation, protection of equipment, and human health. In this experiment, carbon nanotubes/nickel–zinc ferrite/polyaniline complex and carbon nanotubes/barium–zinc ferrite/polyaniline polymers were prepared by solution blending and in situ polymerization, respectively. The results show that the carbon nanotube/NiZn ferrite/polyaniline complexes has a good impedance matching absorption effect with a peak of − 34.3 dB at 3.68 GHz prepared by solution reaction method and with a maximum reflection loss of − 28.95 dB at 12.44 GHz by in situ polymerization method. Carbon nanotube/barium–zinc ferrite/polyaniline complexes were prepared by solution reaction and in situ polymerization methods, and the samples prepared by in situ polymerization had better absorption properties, with an effective absorption bandwidth up to 8.9 GHz (6.5–14.6 GHz and 16.1–16.8 GHz) and a reflection loss reaching a maximum of − 37.95 dB at 12.84 GHz.

NiCuZnCo ferrites are ideal for electromagnetic interference (EMI) shielding applications due to their high permeability and low loss. These ferrites have an operating frequency of around 1 GHz due to the Snoek’s limit. To further enhance the operating frequency range of these materials, the present work reports the development of magnetic-polymer composites by embedding NiCuZnCo ferrite into a poly-dimethyl-siloxane (PDMS) polymer matrix. These composites blend the properties of ferrite and polymer, offering distinct features. The thermal stability of the PDMS-magnetic composite is observed at ~400 °C. The surface morphology of ferrite and its integration with the PDMS matrix are investigated using a field emission-scanning electron microscope (FE-SEM). The morphology of the ferrite in the composite material is nearly spherical. While the magnetic-PDMS composites exhibit lower saturation magnetization than the pure ferrite, the magnetization steadily increases with rising ferrite content in the PDMS matrix. Notably, the DC electrical resistivity of the ferrite-PDMS samples is of the order of 10¹² Ω.cm at room temperature. The samples’ electromagnetic properties, such as complex permittivity, complex permeability, and shielding effectiveness, are investigated in the frequency range of 1.0 MHz to 3.6 GHz. Interestingly, the composites showcase ferromagnetic resonance between the 1.8 and 2.6 GHz range, suggesting potential applicability in EMI shielding applications. Because of the higher ferrite concentration, the composite with 45% ferrite-loaded PDMS has a high SE_A of approximately 56 dB at a frequency of 1.7 GHz.

The method of preparation is a critical factor affecting the structure and properties of Bi₂O₃ material. In this work, Bi₂O₃ was synthesized through calcination (denoted as Bi₂O₃–C) and hydrothermal methods (denoted as Bi₂O₃–H), utilizing bismuth-based metal–organic framework (Bi–MOF) as the precursor. As an electrode material for supercapacitors, Bi₂O₃–H demonstrated outstanding rate performance (515 F g⁻¹ at 50 A g⁻¹) and remarkable cycle stability (74% retention after 4000 cycles). Subsequently, the Bi₂O₃-H underwent further processing through electron beam irradiation (EBI), resulting in a sample designated as Bi₂O₃–I. Following EBI treatment, the crystalline characteristics of Bi₂O₃–I and the concentration of oxygen vacancies (OVs) exhibited a significant improvement, thereby augmenting the material's conductivity. Because the positively charged OVs can quickly attract OH⁻ from the electrolyte to the electrode surface, thereby accelerating the REDOX reaction, the current control mechanism of Bi₂O₃–I is partially derived from a surface-controlled pseudo-capacitance process. The irradiated Bi₂O₃-I electrode demonstrated superior capacitance (990 F⁻¹ at 2 A g⁻¹), enhanced rate performance (585 F⁻¹ at 50 A g⁻¹), and remarkable cycling stability (83% retention after 4000 cycles).

The consistency of electrical properties is an important factor for the industrial applications of negative temperature coefficient (NTC) thermistors. Spinel-type NTC thermistors typically consist of several transition metal elements. However, variations in the fabrication process can compromise the uniformity of these elemental components, resulting in electrical properties. This study investigates the impact of adding dispersants on the consistency of the microstructure and electrical properties of the Mn–Fe–Co–Zn–O-based NTC thermistors. Thermistors prepared using a solid-state process exhibited a more uniform distribution of elements when two dispersants ammonium citrate and polyether P123 were incorporated during the ball milling stage. The coefficients of variation of room-temperature resistivity (ρ₂₅) and material constants (B_25/50) for samples prepared without dispersants were 17.433% and 0.667%, respectively. In contrast, samples prepared with dispersants exhibited coefficients of variation ranging from 7.763 to 11.796% for ρ25 and 0.299% to 0.392% for B_25/50. This demonstrates a more uniform distribution of ρ₂₅ and B_25/50 following the addition of dispersants. Therefore, the use of dispersants enhances material’s compositional organization, leading to improved consistency in its electrical properties. These findings have significant implications for the development and application of NTC thermistors.

In the past few years, there has been notable interest in the advancement of colored photovoltaic (PV) modules. This attention is driven by their visual attractiveness and the opportunities they offer for integrating PV technology into diverse applications. However, limited color options and low efficiency restrict the widespread application of PV modules. This research introduces a targeted micropatterning strategy aimed at improving the efficiency and visual appeal of colored photovoltaic (PV) modules. This approach entails the selective elimination of black pixels from a multicolored pattern. By doing so, the surface area of the PV module is augmented, fostering enhanced light absorption and subsequently boosting output power. This study compares the performance of a selective micropatterned-based colored PV (SMPCPV) module with a reference black PV module, multicolored PV (MCPV), and a non-selective micropatterned-based colored PV (MPCPV) module. The characterization was performed in the outdoor environment where the result shows that the photoconversion efficiency (PCE) of the SMPCPV module is 11.36%. The selective micropatterning technique improved the PCE by around 18% compared to the 9.6% of the MPCPV module reported in a previous study and very close to the reference PV module (14.5%). The enhanced efficiency and aesthetically appealing SMPCPV module achieved in this investigation are pivotal in advancing future net-zero energy buildings and fostering a more sustainable environment. Furthermore, they contribute to the ongoing narrative of resilience and the adoption of sustainable, circular economic practices.