Journal of Materials Science: Materials in Electronics最新文献

The Mg-doped zinc oxide thin films with different concentrations were fabricated using the nebulizer spray pyrolysis process for UV photodetector applications in metal–semiconductor–metal (MSM) configuration. All the produced thin films were found to be polycrystalline type and have a hexagonal crystal structure exhibiting a strong c-axis orientation, according to X-ray diffraction examination. The scanning electron microscopy pictures exposes that the surface covered by flakes and grains type particles and well covered without any cracks. The water contact angle measurement notices diminishing of surface roughness. The maximum optical absorption of the film is approximately ~ 3.73% in the UV region for the 3% Mg-doped ZnO film. The optical band gap decreases with lower Mg concentrations and significantly increases at higher Mg doping concentrations. The photoluminescence spectra reveal the presence of defects such as zinc interstitials, oxygen vacancies, and anti-site defects in the obtained thin films. According to Hall Effect measurements, the produced thin films exhibit n-type conductivity with low resistivity (2.10 × 10⁻² Ω cm) and higher carrier concentrations (4.34 × 10¹⁹ cm⁻³) at a 3% Mg concentration. The fabricated thin-film photodetector showed a better response to UV exposure, with photocurrent increasing up to 10.629 µA. At a 3% Mg concentration, the photo-sensing capabilities, like detectivity, EQE, and responsivity, are enhanced.

With the increasing focus on environmental issues, lead-free perovskite ceramics Ba_0.83Ca_0.105Sr_0.065TiO₃ (BCST) are promising candidates for dielectric and energy storage applications. To optimize the preparation process and enhance the performance of ceramics, a traditional high-temperature solid-state method has been used to fabricate BCST ceramics with 4 mol% LiF as a sintering aid added at three different sequences: before calcination (BLiFCST), after calcination (BCLiFST), and after sintering (BCSLiFT). The results indicated that all BCST-LiF ceramics exhibited a pure tetragonal perovskite structure, and LiF effectively reduced the sintering temperature from above 1250 ℃ (for pure BCST) to 1200 ℃. Among the three addition sequences, BCLiFST ceramics achieved the highest densification with dense grain arrangement and fewer surface pores. The BCLiFST ceramics also showed the optimal dielectric and ferroelectric properties: a high dielectric constant (ɛ_r = 18,114) and low dielectric loss (tanδ = 0.0103) at room temperature, along with thin-waisted hysteresis loops induced by [Li_Ti-F_O]²⁻ defect dipoles. For energy storage performance, BCLiFST ceramics exhibited a recoverable energy density of 0.15 J/cm³ and energy storage efficiency of 58% under an electric field of 28 kV/cm. These findings demonstrate that adding LiF after calcination is an effective strategy to lower the sintering temperature and optimize the comprehensive performance of BCST ceramics, providing a promising approach for the preparation of high-performance lead-free dielectric ceramics.

Lead-based multilayer thin film capacitors with excellent energy storage performances have great application potential. However, the effect of stacking patterns on the dielectric behaviors has not been well investigated, especially for the multilayer thin films prepared by chemical solution methods. Here, the relaxor ferroelectric (RFE) (Pb_0.92La_0.08)(Zr_0.65Ti_0.35)O₃ and antiferroelectric (AFE) (Pb_0.98La_0.02)(Zr_0.95Ti_0.05)O₃ were chosen to construct diverse multilayer thin film capacitors with different RFE/AFE stacking patterns. Based on their crystal structure, dielectric features, and energy storage behaviors, the effect of stacking orders and AFE phase thicknesses on the capacitor performances were discussed from the perspectives of the positive and negative interface contribution. A superior recoverable energy density of 26.28 J cm⁻³ was achieved at a breakdown strength of 3.19 MV cm⁻¹, accompanied with thermal stability up to 170 °C, frequency stability up to 2 kHz, and fatigue endurance after 10⁶ charging-discharging cycles. The experimental results and related discussion will support the research and the industrialization of multilayer thin film capacitors.

The optical switching behavior of sol–gel–derived silver-doped silica (Ag-SiO₂) nanocomposites is demonstrated in this study. The formation of nanocomposites with varying Ag concentrations was confirmed through structural, optical, and morphological studies. The incorporation of Ag nanoparticles generated a pronounced localized surface plasmon resonance, significantly enhancing both the nonlinear absorption and refractive nonlinearities. Z-scan measurements performed using 532 nm, 5 ns laser pulses revealed strong reverse saturable absorption with an optical limiting threshold of 4.12 J/cm², accompanied by a clear self-focusing behavior. The nanocomposites exhibited a marked increase in third-order susceptibility, reaching χ⁽³⁾ ≈ 10⁻¹³ esu, and a corresponding increase in the nonlinear refractive index. Increasing the Ag loading strengthens the local electromagnetic field confinement and promotes plasmon-assisted electronic transitions, yielding n₂ enhancement factors exceeding an order of magnitude compared with undoped silica. These findings establish Ag–SiO₂ nanocomposites as an efficient plasmonically driven platform for nanoscale photonic switching and intensity-dependent optical modulation.

This study reports the synthesis of a novel bullet-like ZnFe₂O₄ via a simple hydrothermal method followed by thermal treatment. The crystal structure and morphology of the synthesized ZnFe₂O₄ were characterized using various techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. For comparative purposes, ZnO was also produced employing the same synthesis method. The investigation revealed that the optimal working temperature for the gas sensor utilizing bullet-like ZnFe₂O₄ is 140 °C, which is 120 °C lower than that of the ZnO-based sensor (260 °C). At this optimal temperature, the ZnFe₂O₄ sensor exhibits favorable performance toward 100 ppm acetone, with a response value of 76.14, rapid response time (11 s) and recovery time (15 s), as well as good selectivity and stability. These results indicate that bullet-like ZnFe₂O₄ has potential for gas sensing applications, particularly for the selective detection of acetone gas in low-power devices, though its sensing performance may be further improved by structural modification or composite doping.

The current study focusses on a carbon–polymer primer coating on stainless steel (SS) mesh current collectors (CC) as a scalable and cost-effective interface engineering strategy. Electrodes fabricated on primed stainless steel (PSS) mesh were systematically compared with those on bare stainless steel (BSS) mesh to evaluate the influence of the primer layer which composed of carbon black (CB) and polyvinylidene fluoride (PVDF) in a ratio of 95:5. This thin layer coating forms a robust and uniform conductive network, effectively reducing the contact resistance, and enhancing ion accessibility. The as fabricated device (Mo–MnO₂//AC) revealed that, PSS electrodes were able to maintain 75% of their initial capacitance at an elevated current density of 10 A g⁻¹, compared to BSS electrodes (only 31%). Notably, even with reduced conductive additive content, the PSS electrode delivered excellent cycling stability, retaining 91.5% of its capacitance after 5000 cycles. This strategy offers a cost-effective and scalable method for improving the performance of pseudocapacitor electrodes, highlighting the potential of carbon–polymer primer coatings as a valuable tool in practical energy storage applications.

Herein, multifunctional NBR/EPDM elastomeric composites were developed by reinforcing the matrix with a Cu–Al–Zn alloy and functionalizing it using 3-(trimethoxysilyl)propyl methacrylate (TMSPM) as a coupling agent. The aim was to enhance soft magnetic behavior while maintaining balanced mechanical, thermal, dielectric, and curing performance. Composites containing 2.5–35 phr alloy (NE2, NE3, NE5, NE8) were examined using rheometry, stress relaxation, DSC, TGA, tensile testing, SEM, magnetic hysteresis, and broadband dielectric spectroscopy. TMSPM promoted strong filler–matrix adhesion, enabling uniform dispersion at moderate alloy contents. NE2–NE3 exhibited improved torque response, higher tensile strength, reduced tan δ, and lower swelling, confirming increased crosslink density and stable network formation. DSC and TGA revealed enhanced chain packing and thermal stability, while magnetic analysis verified soft magnetic behavior, with NE3 offering the optimal balance of mechanical integrity and magnetization. Dielectric measurements showed increased permittivity and conductivity with alloy addition, where NE3 displayed a thermally responsive dielectric profile and NE8 achieved the highest conductivity and strongest estimated EMI attenuation at high frequency. Excessive loading (NE8) caused agglomeration and reduced mechanical uniformity. Overall, combining Cu–Al–Zn alloy with TMSPM produced elastomeric composites with enhanced mechanical, thermal, magnetic, and dielectric properties suitable for flexible magnetic components, adaptive damping systems, and lightweight EMI-absorbing applications.

The 3C-SiC/graphene composite powder was successfully synthesized through a simple carbothermal reduction method using expanded graphite and silicon powder. The effects of catalyst content, temperature, and C/Si molar ratio on the synthesized products were systematically investigated. Results demonstrated that the complete formation temperature of 3C-SiC decreased to 1350 °C with the addition of 3wt% Fe catalyst. Preparation efficiency is enhanced, and energy consumption is reduced. Simultaneously, the Fe catalyst promoted the growth of Silicon Carbide Nanowires(SiCNWs) and enhanced electromagnetic wave absorption intensity. When the expanded graphite was appropriately excessive (C/Si molar ratio of 1.1:1), graphene was in situ formed in the products at 1350 °C. This composite powder exhibits the minimum reflection loss (RL_min) of − 27.24 dB in the high-frequency range of 14–18 GHz. The synergistic effect between graphene and 3C-SiC could enhance dielectric loss, optimize impedance matching, and broaden absorption bandwidth. The 3C-SiC/graphene composite powder shows promising potential as an excellent electromagnetic wave absorbing material.

The NiO@CuO nanocomposite (NC) was synthesized via an ionic precipitation route and systematically characterized to confirm its structural, optical, and chemical properties. XRD revealed cubic NiO and monoclinic CuO phases with an average crystallite size of 23.25 nm, while UV–Vis analysis showed an indirect band gap of 1.29 eV. XPS further verified the elemental composition and oxidation states of Ni, Cu, and O. The cross-section revealed a well-adhered NiO@CuO particles, and TEM/SAED results showed an agglomerated, polycrystalline nature. The 30 mg NiO@CuO NC exhibited efficient photocatalytic degradation of Rhodamine-B (RhB), achieving 88.72% at pH 9 ± 0.1. Radical quenching studies confirmed ^•OH as the dominant reactive species. When fabricated as a NiO@CuO/n-Si photodiode, the device demonstrated strong photoresponse under illumination, with an ideality factor (n) of 3.84, barrier height (Ф_B) of 0.73 eV, responsivity (R) of 361.52 mA/W, and detectivity (D^*) of 2.87 × 10¹¹ Jones at 100 mW/cm². These results highlight the potential of NiO@CuO NC for photocatalytic and optoelectronic applications.

Lead-free perovskite ceramics Sr_1-xNa_x(Sn_0.25Ti_0.75)_1-xNb_xO₃ (0.6 ≤ x ≤ 0.9), denoted SNSTNₓ, were synthesized by the conventional solid-state route and sintered at 1350 °C. X-ray diffraction analysis confirms the formation of a single-phase perovskite structure with tetragonal symmetry (space group P4mm) for all compositions. Dielectric measurements performed as a function of temperature and frequency reveal two distinct electrical behaviors depending on composition. Samples with x ≥ 0.8 exhibit classical ferroelectric characteristics with a well-defined, frequency-independent Curie temperature, whereas compositions with x < 0.8 show relaxor-like behavior characterized by diffuse phase transitions and strong frequency dispersion of the dielectric permittivity. The relaxor nature is further supported by deviation from the Curie–Weiss law and a diffuseness parameter γ ≈ 1.7. Ferroelectric hysteresis measurements performed for x = 0.9 confirm ferroelectricity, with a remanent polarization of 0.0125 µF mm⁻² and a coercive field of 5 V mm⁻¹. The observed evolution of dielectric behavior is attributed to structural disorder induced by simultaneous A-site (Sr²⁺/Na⁺) and B-site (Sn⁴⁺/Ti⁴⁺/Nb⁵⁺) substitutions, which modify lattice distortion and reduce the phase transition temperature. These results indicate that SNSTNₓ ceramics are promising lead-free materials for temperature-stable dielectric applications.