Journal of Materials Science: Materials in Electronics最新文献

Pure zinc oxide nanoparticles (NPs) and its nanocomposite ZnO/Lu₂O₃ NPs with Zn/Lu varied weight ratios (Zn/Lu; 97:3, 94:6, and 91:9%) were produced using a precipitation process under optimal circumstances. The synthesized samples were analyzed using diffraction of X-ray, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM), and Raman spectra. The ZnO NPs as-prepared possess a highly crystalline structure of wurtzite ZnO and great phase purity. The combined Lu₂O₃ and ZnO NPs show a Lu₂O₃ zinc blend phase as well as the pure ZnO’s wurtzite phase, proving the samples’ excellent purity and crystallinity as-prepared. Increasing the Lu₂O₃ percentage to 9% resulted in a considerable drop in the surface area of ZnO samples from 29.9 to 8.4 m²/g and the volume of the pore from 0.3536 to 0.020 cm³/g, according to nitrogen adsorption–desorption studies. The study found that adding Lu₂O₃ NPs improves the photocatalytic capabilities of ZnO NPs for methylene blue degradation. Mixed 9% Lu₂O₃ and 91% ZnO NPs have much higher photocatalytic activity than pure ZnO NPs due to their high crystallinity and small energy gap.

This study synthesized high-quality single crystals of l-tartaric acid (LTA) and cerium (Ce)-doped LTA using the slow evaporation method at room temperature. X-ray powder diffraction (XRD) confirmed their monoclinic structure (space group P2₁), with crystal sizes of 57 nm for LTA and 49 and 48 nm for Ce-doped LTA, calculated using Scherrer’s equation. Energy-dispersive X-ray (EDAX) analysis validated elemental composition, and Fourier transform infrared (FTIR) spectroscopy identified functional groups. Optical transmittance spectra revealed broad transparency, allowing calculation of band gaps (5.06 eV for LTA and 4.85, 4.98 eV for 0.2 M%, 1 M% of Ce-doped LTA crystals), suitable for nonlinear optical (NLO) applications. Photoluminescence (PL) spectra indicated high crystalline quality for grown crystals. Dielectric properties were measured over a wide frequency range (50 Hz to 5 MHz) and varying temperatures. Thermal stability was assessed via TG–DTA analysis. The optical and dielectric properties confirmed the multifunctional nature of the crystals. Both LTA and Ce-doped LTA crystals exhibited superior laser damage thresholds (LDT) and higher second harmonic generation (SHG) efficiencies compared to potassium dihydrogen phosphate (KDP). Third-order NLO susceptibility, measured using the Z-scan technique, further demonstrated their potential. In conclusion, LTA and Ce-doped LTA crystals exhibit excellent properties for advanced NLO and electro-optic devices, offering significant potential for a range of photonic applications.

This study investigates the optical, dielectric, and structural properties of novel perovskite-type ferroelectric ceramics, specifically Bi-doped (Ba_0.8Sr_0.2)(Ti_0.85Zr_0.15)O₃ nanoparticles, synthesized via the solid-state method. The materials were doped with Bi at the A-site with compositions of x = 0.03 and 0.05. X-ray diffraction (XRD) analysis confirmed that all samples crystallize in a cubic structure with the space group Pm3m. Dielectric measurements revealed a decrease in permittivity with increasing frequency, with notable transitions at 180 K and 170 K for x = 0.03 and x = 0.05, respectively. These findings are indicative of potential applications in energy storage where temperature stability is critical. Raman spectroscopy at room temperature corroborated the dielectric observations, showing peak broadening and reduced intensity with increasing temperature, particularly for the x = 0.05 composition. While photoluminescence spectroscopy and quantum yield measurements were not performed, the observed optical properties at room temperature suggest potential for application in optical devices. The combination of favorable dielectric characteristics, stable performance across temperature ranges, and promising optical properties underscores the versatility and optical devices applications of these Bi-doped perovskite ceramics in energy storage systems and ferroelectric memory devices. This study highlights the significant improvements in material performance achieved through Bi doping, contributing to the advancement of materials with specialized applications.

MgO@C nanochains composite powders were prepared by the catalytic combustion synthesis method, employing C₄H₄O₄ and Mg powders as the primary raw materials, Ni (NO₃)₂·6H₂O as the catalyst. The carbon/ceramic composites were prepared by carbon-bed sintering with MgO@C nanochains composite powders as a conductive filler. The effects of the catalyst content on the phase composition and microstructure of the MgO@C nanochains composite powders, and on the degree of graphitization of the carbon in the composite powders were investigated. Furthermore, the phase composition, microstructure, apparent porosity, bulk density, and electrical resistivity of carbon/ceramic composites were also investigated. The results indicated that the yield of the composite powders is about 44 wt.%. The X-ray diffraction showed that the MgO@C nanochains composite powders consisted of C and MgO phases. Moreover, MgO@C nanochains composite powders prepared with 0.2 wt.% Ni (NO₃)₂·6H₂O addition had a higher degree of graphitization. The TEM images revealed the nanochains in the composite powders. For the carbon/ceramic composites with MgO@C nanochains composite powders, the resistivity of the carbon/ceramic composites decreased significantly as the content of composite powder increased, indicating that the MgO@C nanochains composite powders formed a conductive network in the carbon/ceramic composites, which contributed to the decrease in the resistivity of the samples. When composite powders are added at 9 wt.%, the properties of the sample are optimal. The apparent porosity was 27.17%, and the electrical resistivity of the sample was 590 Ω·cm.

The primary aim of this research is to create bio-based electromagnetic interface (EMI) materials from pearl millet cob microfiber and plant stalk derived highly porous cellulose for EMI shielding applications. Because of its superior mechanical and thermal qualities, biocompatibility, and biodegradability, cellulose is attracting a lot of interest in the development of EMI shielding materials. Further, the prepared reinforcing materials underwent silane treatment with 3-aminopropylmethoxysilane, and the composites were fabricated using manual layup technique. The prepared composites were further tested as per American Society for Testing and Materials (ASTM) standards. Further, results showed that the EMI shielding efficacy increased due to the incorporation of cellulose filler. The composite ENC2 with 4 vol.% high porous cellulosic content offers superior EMI shielding efficiency of 2.7 dB at 2 GHz to 3.9 dB at 8 GHz of absorption, 2.3 dB at 2 GHz to 4.7 dB at 8 GHz of reflection and 2.5 dB at 2 GHz to 3.7 dB at 8 GHz of total EMI shielding. Additionally, the composite ENC2 exhibits dielectric characteristics ranging from 2.8 at 2 GHz to 1.2 at 8 GHz, with a dielectric loss of 0.14 at 2 GHz to 0.21 at 8 GHz, and maximum total EMI shielding of 2.5 dB at 2 GHz to 3.7 dB at 8 GHz. Conversely, at a burning rate of 8.97 mm/min, the composite ENC2 with 4 vol.% filler exhibits good flame-retardant properties. On the other hand, the composite ENC1 with a 2 vol. % cellulose incorporation had the highest mechanical performance, with tensile and flexural strengths of 136.8 MPa and 158 MPa, respectively. Therefore, this EMI shielding effectiveness, dielectric properties, flame-retardant, and mechanical strength make the composites to be widely employed in communication and navigational device, sensor, and EMI shielding products.

The ozone treatment is proposed as a simple and versatile process that can be utilized across various fabrication stages to enhance the performance of silicon solar cells. The effectiveness of this treatment on p-type silicon surfaces was examined through the application of ozone dissolved in deionized water (DIO₃) and the ultraviolet-ozone (UVO₃) cleaning process prior to the two-step texturization procedure. It was found that the surface with the DIO₃ treatment for 10-min results in a tremendous surface quality on p-type silicon wafer. According to field emission scanning electron microscope (FESEM) micrographs and UV–Visible spectrometer (UV–Vis) measurements, the textured wafer with DIO₃ treatment improves the surface morphology and decreases the front surface reflection. Consequently, the DIO₃ treatments were determined to be optimal, yielding a reflectivity value of less than 12%. The range size and height of the pyramid formed were 1.9–2.0 µm and 0.8–1.5 µm, respectively. Results from the Atomic Force Microscope (AFM) also confirm the increase in average surface roughness from 203 to 300 nm was expected to improve the light absorption. Moreover, this methodology leads to a considerable reduction in surface damage and is applicable to the silicon texturization process utilized in solar cell manufacturing.

Perovskites show significant potential in addressing the global energy crises and assessing the long-term durability of pseudocapacitive materials is critical. So, doping has proven effective in improving materials’ cyclic stability and capacitive properties. In this study, Ce doping significantly enhanced the electrochemical characteristics of  SrTiO₃ electrode. The remarkable electrochemical properties of Ce-doped SrTiO₃ can be attributed to improved characteristics, such as its crystal structure, morphology and surface area. The specific capacitance of pure SrTiO₃ and Ce-doped SrTiO₃ was found to be 1071 F/g and 1339 F/g. The Nyquist plot found charge transfer resistance of 0.1 Ω. After 50 h of undergoing 5000th cycles, the material exhibited electrical stability, indicating that its structure remained unchanged. The Ce-doped SrTiO₃ electrode material with improved performance showed it has to be utilized for next generation energy storing technology.

The exploration and advancement of zinc oxide and selenide-based materials for gas sensing have seen considerable interest in recent years. These materials offer promising potential for gas sensing; however, their widespread application has been hampered by several critical challenges, including low sensitivity, lengthy recovery times, high operating temperatures, and issues with achieving complete recovery after exposure to target gases. As a result, significant research efforts have been focused on developing and optimizing gas sensors with enhanced performance characteristics. Recently, zinc selenide nanostructures have demonstrated notable room-temperature gas sensing performance. They also offer several advantages, including lower operating temperatures, enhanced sensitivity, and improved selectivity. It is also an excellent host for the formation of doped nanocrystals. This review delves into the comprehensive studies conducted in this domain, with a particular focus on the properties of these materials. Additionally, it examines various synthesis approaches employed to create these nanostructured materials, as well as innovative strategies such as the creation of nanocomposites and designing morphologies to improve the sensitivity, response times, selectivity, and overall effectiveness of gas sensors. The review also addresses the ongoing challenges in this field, such as improving the sensitivity, stability, selectivity, and reproducibility of these sensors. Finally, we highlight potential future directions for research, suggesting ways in which these nanostructures could be further developed to become more efficient and reliable gas sensors for their applications in environmental monitoring, flexible electronics, and wearable devices.

A current approach to low-temperature assembly of microelectronics is to solder to SnAgCu bumped components with eutectic or hypoeutectic SnBi. However, while the resulting hybrid joints may be more reliable than pure SnBi, their fatigue resistance cannot compete with that of pure Sn3Ag0.5Cu (SAC305). Even if fatigue failure is still through the Bi-free region near the component, the presence of Bi elsewhere reduces the overall ductility of the joint, and this gets worse for peak temperatures below 175 ˚C. We show that the fatigue resistance of hybrid joints can be improved on by annealing them to distribute the Bi all the way to the component pad as long as concentrations there remain less than 6%. Annealing of conventional SnAgCu joints is known to reduce their fatigue resistance by coarsening the Ag₃Sn precipitates, and the same is found to be true for SAC305(Bi) joints. However, the fatigue resistance of the annealed SAC305(Bi) alloys is still found to remain greater than that of unannealed SAC305. Systematic characterization of deformation and damage properties shows that this must be true for any area array assembly under isothermal cycling conditions ranging from vibration to cyclic bending, and a forthcoming publication will show the same to be true in thermal cycling. Notably, the anneal eliminates effects of the reflow parameters on the microstructure, including the interdiffusion, allowing for peak temperatures as low as 150 °C. The only significant concern is that practical considerations limit the approach to relatively short joints. Assessments are offered of minimum annealing times required at 125 °C and 150 °C, respectively, for different SAC305 joint heights with corresponding optimized SnBi volumes.

Organometal halide perovskites (OHPs) exhibit remarkable optoelectronic properties, such as wide visible absorption, high photoluminescence quantum yield, excellent solar-light-harvesting capabilities, and a low lasing threshold. Despite these advances, the best performance in perovskite typically occurs several hours to days post-fabrication, likely due to defect dynamics. The study of defect dynamics, particularly trap deactivation, is crucial for understanding and improving the stability and efficiency of OHPs. Furthermore, the effect of photon energy on these dynamics has not been fully explored. This study examined how aging impacts trap deactivation in MAPbI₃ films under different photon energies using photoluminescence (PL). We found that aging significantly enhanced the deactivation of two types of traps, namely T_L and T_H, especially within the first 10 days. T_L and T_H ware traps in MAPbI₃ that can be deactivated by low and high photon energy thresholds, respectively. PL enhanced more than doubled during this period, attributed to a small amount of oxygen penetration in vacuum conditions aiding trap deactivation. PL increased linearly with increasing aging, and trap deactivation time increased exponentially with age for both T_L and T_H deactivation. After 27 days, blue photon illumination resulted in reversible degradation and reactivation of the previously deactivated T_L and T_H traps. However, red photon illumination remained capable of deactivating the T_L traps. This research highlights the interplay between light-induced trap dynamics and aging, which is crucial for optimizing MAPbI₃ perovskite durability and performance in optoelectronic applications.