Journal of Materials Science: Materials in Electronics最新文献

This study investigates α-Fe₂O₃ (hematite) nanoparticles (NPs), synthesized via hydrothermal method, as a potential electrode material for supercapacitors. The nanoparticles were comprehensively characterized using TG–DTA, XRD, FESEM-EDX, XPS, UV-DRS, BET, and VSM analyses. TG–DTA analysis revealed the thermal properties of the as-synthesized nanomaterial. XRD confirmed the hematite phase with a rhombohedral crystal structure, an average crystallite size of 24 nm, low dislocation density, and high crystallinity. FESEM displayed an agglomerated inhomogeneous spherical morphology, while EDAX confirmed the elemental composition. UV-DRS indicated a bandgap energy of 1.96 eV, supporting charge storage. XPS analysis identified Fe³⁺ ions, which are essential for electrochemical performance, and BET analysis revealed a specific surface area of 36.77 m²/g, beneficial for charge storage. VSM analysis showed strong ferromagnetic behavior, advantageous for supercapacitor applications. Electrochemical evaluations demonstrated pseudocapacitive behavior with specific capacitance values of 406 and 206 F g⁻¹ through CV and GCD analysis, respectively at low scan rates. EIS highlighted excellent ion transport, low resistance, high conductivity and efficient charge storage capability of the prepared material. These results highlight α-Fe₂O₃ NPs as promising candidates for next-generation supercapacitor electrodes, offering enhanced charge storage capacity and stability.

Microalloying is a critical technique for improving lead-free interconnections in electronic devices, as it selectively incorporates elements and significantly modifies the solidification structure. The current work investigates the effects of microalloying with Ni and Zn on the microstructures, thermal properties, and mechanical properties of Sn–0.7-wt% Cu solder alloy. The following experimental techniques were employed to evaluate the samples of Sn–0.7-wt% Cu alloy: scanning electron microscopy (SEM), optical microscopy (OM), X-ray diffraction (XRD), tensile tests, and differential scanning calorimetry (DSC). The experimental findings indicated that trace addition of Ni (0.05 wt%) could facilitate the formation of (Cu,Ni)₆Sn₅ IMCs in the interdendritic region, consequently refining the coarse β-Sn phase and resulting in a more refined grain structure. The addition of Zn (2.0 wt%) significantly affected the as-solidified microstructure, leading to the dissolution of Zn into Cu₆Sn₅ intermetallic compounds, characterized by both fine and coarse eutectic regions. Moreover, Cu₅Zn₈ phases were generated between the eutectic region and the refined β-Sn phase. The collaborative effect of Ni and Zn on Sn–0.7Cu alloy markedly improves its microstructure, leading to a refined, stable, and fine-grained Cu₆Sn₅ IMC. Additionally, the mechanical properties of the Sn–Cu alloy are enhanced by these structural differences. The results of tensile tests indicate that the Sn–0.7Cu–0.05Ni–2.0Zn solder alloy has superior mechanical properties in comparison to the Sn–Cu alloy. Specifically, the estimated increases in modulus of elasticity (EM), yield strength (YS), and ultimate tensile strength (UTS) are 375.47%, 19%, and 46.67%, respectively. However, this improvement in mechanical properties was accompanied by a decrease in ductility. The increased strength of Ni/Zn alloys was ascribed to the pinning action of (Cu,Ni)₆Sn₅ and Cu₅Zn₈ IMCs, which impede grain growth and the formation of interfacial IMCs. The DSC results showed slightly decrease in melting temperature values, with the additions of Ni and Zn resulting in values that were approximately 2.1 °C lower than those of the binary Sn–Cu alloys. In view of the results, this study offers important perspectives on soldering technology, which will help in the practical aspects of future soldering process strategies.

The cadmium indium oxide thin film (CdIn₂O₄) was formed onto a micro glass substrate using the nebulized spray pyrolysis process at substrate temperatures ranging from 350 to 550 °C with a 50 °C interval. The X-ray diffraction investigation revealed the polycrystalline nature of the films with a cubic structure and the preferred orientation along the (222) plane. The optical transmission and optical spectra were obtained using optical analysis and the multiple interference effect was significant in all of these films within the wavelength range of 300–1100 nm. These films were highly adhesive, homogeneous, and shining. Bandgap values ranging from 2.71 to 3.37 eV with direct allowed nature were obtained. The Urbach energy values and skin depth were observed for all the films. The surface ratio of the elements was analyzed using the EDAX spectrum. Scanning electron microscope images exhibited flower-shaped grains. Photoluminescence spectra at room temperature explain the four emission bands in all the samples, such as the sharp dominant peak at 490 nm in the UV–visible region. The electrical parameters were analyzed; the minimum resistivity was 0.51 × 102 Ω cm, and the mobility was 158 cm²/Vs for the film deposited at the substrate temperature of 500 °C.

Lithium-ion batteries and supercapacitors both depend on the utilization and fabrication of nanomaterials to enhance efficacy. For energy accumulation purposes, electrode materials were developed through these endeavors. This investigation entailed the synthesis and utilization of bimetallic PANI@Sn-MOF/Ag(NPs) in supercapattery devices. In electrochemical examination, the PANI@Sn-MOF/Ag(NPs) electrode exhibited a specific capacity of 1433 C/g at a current density of 1.0 A/g. The electrochemical performance is enhanced by the substantial specific surface area of 79.9 m²/g, as evidenced by BET analysis. The supercapattery device (PANI@Sn-MOF/Ag(NPs)//AC) is constructed with PANI@Sn-MOF/Ag(NPs) and activated carbon which demonstrated a specific capacity of 126 C/g. It showcased a power density of 970 W/kg and an energy density 44.6 Wh/kg. Following 10,000 GCD cycles, the PANI@Sn-MOF/Ag(NPs) device retained up to 89% of its capacity. In a hydrogen evolution reaction, the PANI@Sn-MOF/Ag(NPs) composite exhibited the lowest over potential of 93.83 mV. The PANI@Sn-MOF/Ag(NPs) electrode exhibits significant potential for deployment in hydrogen evolution reaction applications and energy storage devices.

In this paper, the application of gel materials in triboelectric nanogenerators (TENGs) and its performance improvement strategy are reviewed. With the increase of energy demand and environmental awareness, TENGs as a new type of self-powered system has attracted wide attention. Because of its excellent flexibility, adjustability and good electrical properties, gels have become an important choice for improving the performance of TENGs. This paper first introduces the working principle of TENGs. Then, the application of gel materials in TENGs are divided by adjusting the composition and structure of gel materials. Finally, methods to improve the gel material properties, such as optimizing the conductivity of the gel, increasing the surface roughness and improving the stability, are proposed to increase the output of the TENGs. In addition, this paper also discusses the application examples of different types of gel materials and the actual performance improvement effects. Finally, the current research challenges and future research directions are summarized in order to provide guidance for the further application of gel materials in TENGs.

Nanoplasmonic surfaces built up from silver nanoparticles (NPs) and core–shell Ag@Ag₂O NPs with highly tunable optical properties are synthesized along two different reaction channels. Their structural properties are studied in detail and new in-depth physical insights into their tunable localized surface plasmon resonant absorption (LSPR) are provided. Classical electrodynamics model with size-modified complex dielectric constant data for Ag predicts narrow symmetrical LSPR band in monodisperse population of small (5–20 nm) Ag NPs with a red shift of the band maximum position (λ_m) of 5 nm upon particle size increase from 5 to 20 nm. Compared to our experimental data, the predicted λ_m is too low by 54 nm (356 vs. 410 nm). In line with our experiments, the LSPR band undergoes inhomogeneous broadening when NPs size dispersion is included, accompanied with a shift of λ_m from 356 to 371 nm (still 40 nm below the experimental value). Excellent agreement with our experiments (λ_m shift to 410 nm and inhomogeneous broadening with high-wavelength side asymmetry) is achieved applying the effective medium approach with experimentally determined size dispersion, which accounts for the influence of the glass substrate and interparticle coupling in the close-packed Ag NPs on the LSPR absorption. When the synthesis is carried out along sonochemically induced reaction channel, Ag₂O shell is formed around the Ag core, leading to the most prominent LSPR band shift (~ 90 nm), which we attribute to a change in effective refraction index from 1.5 to 2.2.

The flexible sensor exhibits high sensitivity, a wide detection range, and excellent cycle stability. However, achieving both high sensitivity and an extensive response range simultaneously in flexible strain sensors remains a significant challenge. In this study, we prepared a series of flexible strain sensors using CNTs/SEBS by varying the content of carbon nanotubes (CNTs), with SEBS serving as the flexible substrate and CNTs as the conductive material. The results indicated that both the mechanical properties and sensitivity of the sensor improved with increasing CNT content. Notably, when the CNT content was 0.10 g, the sensor demonstrated optimal overall performance. Within a strain range of 0 to 80%, its sensitivity reached 71.96; during this phase, its operational mechanism is characterized by disconnection phenomena. Conversely, within a strain range of 80 to 200%, sensitivity decreased to 34.68, at which point the working mechanism transitioned to tunneling. The sensor maintained stable operation across various degrees and rates of strain while preserving good sensing performance after undergoing 2000 cycles. Therefore, this flexible strain sensor showcases exceptional sensing characteristics along with a broad response range, indicating substantial potential for applications in human motion monitoring.

Two-dimensional (2D) materials used to form nanohybrids have emerged as promising components for controlling carrier confinement and transportation in resistive memory devices. To investigate the memristive properties in a metal–insulator–metal (MIM) configuration, nanohybrid of reduced graphene oxide-tin disulfide (rGO-SnS₂) was synthesized and incorporated with poly (methyl methacrylate) (PMMA) matrix to prepare the polymer nanocomposites (PNCs). The crystallinity and uniformity of the spin-coated PNCs film over the ITO substrate are enhanced through annealing at 200 °C for 4 h in order to improve the resistive switching properties in memory devices. Furthermore, the optical, structural, and morphological characteristics of the films are done using various spectroscopic and microscopic techniques, namely, UV–Visible DRS, Raman, X-ray diffraction (XRD), Atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thermogravimetric analysis (TGA) is performed to ensure the stability and structural integrity of the material. XRD analysis shows the drastic reduction in the peak intensity of the film annealed at 250 °C suggesting the deterioration of the film’s crystallinity. In contrast, the film annealed at 200 °C shows better crystallinity than the as-deposited film resulting in enhanced memory behaviour. The post-annealed thin film (200 °C)-based devices exhibit write-once-read-many (WORM) memory characteristics with lower switching voltage (< 2 V) and enhanced switching ratio ((frac{{I}_{ON}}{ {I}_{OFF}})) ~ 10⁴. For resistive switching technology, rGO-SnS₂ delivers beneficial outcomes like improved trapping mechanisms and enhanced charge transport channels. The interface at the rGO and SnS₂ in the nanohybrid plays a pivotal role in the separation of charge carriers and charge conduction process in the device. A theoretical concept is elucidated to clarify the charge transport mechanism through the devices that follows space charge limited current (SCLC) conduction and Ohm’s law in the high resistance state (HRS) and low resistance state (LRS), respectively. Moreover, the charge transport phenomenon in the device is explained using a plausible energy band diagram.

The thermoluminescence (TL) properties and precise dose distribution measurement capabilities of Cr, Si, and Mg co-doped Al₂O₃ ceramics (Al₂O₃:Cr,Si,Mg) plates were investigated under X-ray irradiation. The co-doping of Si and Mg significantly enhanced the TL sensitivity, approximately doubling it compared to conventional Al₂O₃:Cr plates, due to the creation of new trapping levels. The TL dose response was proportional in the dose range of 0.5 to 5 Gy, and off-axis ratio (OAR) measurements confirmed the high spatial resolution and accuracy of the plates to reproduce the radiation distributions. This study is the first to evaluate TL plates of this size (200 × 200 mm²) that utilize Al₂O₃ as the host material, and demonstrate their significant potential for radiotherapy dosimetry systems. This significant contribution highlights the potential of Al₂O₃:Cr,Si,Mg ceramic plates to transform dosimetry systems for radiotherapy by providing a combination of high sensitivity, spatial resolution, and robustness. The results of this study lay the groundwork for the development and practical application of large-area TL imaging devices in medical dose verification.

This investigation focuses on the study of temperature-dependent electromagnetic radiation (EMR) and energy harvesting using soft-grade (SP-5A) piezoelectric lead zirconate titanate ceramics. Four samples with different dimensional ratios (t/d²) of 0.035, 0.038, 0.059, and 0.064 were analyzed, employing EMR as a non-contact measurement technique, alongside the design of an energy harvester circuit. The results demonstrate a temperature-dependent increase in capacitance within the 40 °C to 100 °C temperature range. Samples with varying dimensional ratios showed a rising trend in the EMR voltage waveform. Notably, the EMR voltage increased proportionally with temperature across all samples, peaking at 3.5 V for a sample with a dimension ratio of 0.064 at 100 °C. The dominant frequency was identified at 152.86 kHz for the sample having dimension ratio of 0.064 at 100 °C. The engineered energy harvester circuit successfully captured EMR energy, with a clear increasing trend in energy capture as both dimension ratios and temperatures rose. At peak temperature, the maximum captured EMR energy reached 1.4 µJ, corresponding to a calculated power of 3.1 W. Additional tests evaluated the energy-storing capacity of capacitors ranging from 100 to 470 nF, revealing a positive correlation between increasing capacitor values and the capacity for EMR energy storage. The findings highlight potential applications of the captured EMR energy, including powering wireless sensors, enabling structural health monitoring, and supporting microcontroller-based device power management. This research paves the way for integrating piezoelectric ceramics into self-sustaining, low-power electronic systems.