Journal of Materials Science: Materials in Electronics最新文献

While rare-earth doping of SnO₂ has been widely explored for structural and optical tuning, experimental realization of stable p-type conduction remains challenging and insufficiently understood. Consequently, the present study reports the synthesis of pristine and Nd-doped SnO₂ nanoparticles [Sn_1-xNd_xO₂ NPs, where x = 0, 0.05, and 0.10] via a sol–gel route. X-ray diffraction coupled with Rietveld refinement confirms the formation of a single-phase tetragonal rutile structure with (P{4}_{/2}mnm) space group for all compositions, accompanied by a systematic reduction in crystallite size. Microstructural analysis reveals nanometric grains with decreased average size from 29 nm (x = 0) to 17 nm (x = 0.10), indicating dopant-induced suppression of grain growth. Electrical characterization shows ohmic I-V behavior with a marked reduction in resistance upon doping. Hall effect measurements provide direct evidence of a conduction-type transition from n-type to p-type, attributed to acceptor-type Nd³⁺ substitution at Sn⁴⁺ sites and associated defect compensation mechanisms. Dielectric studies further reveal enhanced permittivity and modified relaxation behavior consistent with Maxwell–Wagner interfacial polarization and Koop’s theory. Nd-doped p-type SnO₂ NPs with enhanced electrical and dielectric properties highlight the potential of these nanoparticles for optoelectronic devices, transparent conducting electrodes, and spintronic applications.

As emerging sectors like new energy and flexible electronics increasingly require high-performance flexible energy storage devices, the development of lead-free inorganic dielectric films that exhibit superior energy storage capabilities and mechanical flexibility has emerged as a key area of research. In the present study, lead-free 0.94 BaZr_0.2Ti_0.8O₃–0.06 Na_0.5Bi_0.5TiO₃ (BZT–NBT) dielectric energy storage films were successfully prepared on flexible fluorophlogopite (Mica) substrates using a sol–gel. A systematic examination was conducted on how film thickness (80, 110, 150, and 200 nm) influences microstructure, electrical characteristics, and energy storage capabilities. Among all the specimens, the 110 nm-thick film exhibits the best overall performance: it has a high breakdown strength (E_b) of 2157 kV cm⁻¹, a maximum recoverable energy storage density (W_rec) of 8.38 J cm⁻³, and an energy storage efficiency (η) of 96.61%. Moreover, this film shows remarkable stability under harsh conditions: thermal stability (25–200 °C) with variation rates of 5.15% for W_rec and 6.08% for η, fatigue resistance (10⁷ cycles) with variation rates of 2.11% for W_rec and 2.24% for η, and bending durability (10⁴ cycles) with variation rates of 4.84% for W_rec and 5.70% for η.

Applications for effective spin manipulation have recently made materials with high saturation magnetization desirable, which has improved performance and opened up new spintronics functionalities. The magnetic properties have been tailored in this work by doping the Bi₄Ti₃O₁₂ (BTO) lattice with Ni²⁺ of different contents. While pristine BTO has the orthorhombic structure according to XRD analysis, the BTO that has a higher Ni²⁺ content forms the hetero-interface with Bi₂Ti₂O₇ that is consistent with the TEM image. The TEM image of Bi₄Ti₃O₁₂-doped with 1% Ni²⁺ also reveals dumbbell morphology, with a small number of them exhibiting a deformation at one end. The presence of Ni incorporated into the Aurivillius-type Bi₄Ti₃O₁₂ lattice as Ni²⁺ ions is demonstrated by the X-ray photoelectron spectrum of 1% Ni-doped Bi₄Ti₃O₁₂. In comparison to pristine BTO, Raman measurements highlight the development of a stress-induced symmetry-breaking effect inside the 1% Ni²⁺-doped BTO symmetry, resulting in fewer modes. When the Ni²⁺ content in the Bi₄Ti₃O₁₂ lattice increases, the band gap decreases from 3.12 eV to 3.05 eV, as witnessed in the UV–Vis spectra, which also suggests that photo-absorption extends into the visible light spectrum. It’s important to note, in particular, that the BTO nano-dumbbells doped with 1% Ni exhibit strong RTFM because of their increased saturation magnetization, which also indicates their implications in the emerging field of spintronics as a result of band gap shrinkage.

Nickel oxide (NiO) nanostructures were synthesized by thermally oxidizing thin nickel (Ni) films deposited on glass substrates via electron beam evaporation under a controlled vacuum environment. Thermal oxidation was performed at 400 °C, 500 °C, and 600 °C in ambient air. X-ray diffraction (XRD) confirmed mixed phases of Ni and NiO at 400 °C and 500 °C, whereas a single-phase NiO with improved crystallinity was obtained at 600 °C. XRD data were analyzed using Rietveld refinement to confirm phase composition and structural evolution. Field emission scanning electron microscopy (FESEM) revealed that higher oxidation temperatures promote grain growth and induce a porous morphology. Energy-dispersive X-ray spectroscopy (EDX) confirmed the chemical purity of the oxidized films, showing only nickel and oxygen. Optical absorption analysis demonstrated a redshift in the bandgap with increasing temperature, consistent with defect-mediated electronic transitions. X-ray photoelectron spectroscopy (XPS) of the Ni 2p core level exhibited characteristic Ni 2p₃/₂ and Ni 2p₁/₂ peaks along with satellite features, evidencing the coexistence of Ni²⁺ and Ni³⁺ oxidation states. Nonlinear optical behavior was probed using the Z-scan technique at 532 nm, yielding third order nonlinear susceptibility (χ3) values in the range of 3.64 × 10^–4–1.67 × 10^–4 esu. The films displayed strong nonlinear absorption and thermal lensing effects, with an optical limiting threshold as low as 0.26 kJ/cm². These findings highlight the potential of NiO thin films as efficient candidates for nonlinear optical limiting applications, where structural tuning via oxidation temperature plays a critical role in enhancing performance.

Conductive silver pastes dominate electrode manufacturing in silicon heterojunction (SHJ) solar cells but suffer from high and volatile material costs. While silver-coated copper particles (Cu@Ag MPs) offer a promising low-cost alternative, conventional synthesis methods struggle to achieve uniform coatings, leading to poor oxidation stability and conductivity. Herein, we introduce a novel chloride-ion-assisted chemical reduction method to synthesize high-quality Cu@Ag MPs. The introduced Cl⁻ ions act as an electrostatic dispersant, effectively suppressing copper agglomeration and enabling the formation of a uniform and dense silver shell. The optimized Cu@Ag MPs (30 wt% Ag) exhibit excellent oxidation resistance below 300 °C and a low resistivity of 1.90 mΩ. When formulated into a low-temperature curing paste for SHJ solar cells, the composite ink achieves a volume resistivity of 8.22 × 10^–6 Ω·cm after curing at 210 °C. Remarkably, the paste demonstrates outstanding environmental stability, with only 1% resistivity degradation after 30 days of ambient exposure. This work presents a viable and cost-effective solution for photovoltaic metallization, reducing silver consumption by 70% while maintaining performance parity with commercial pastes, thereby paving the way for more sustainable solar cell manufacturing.

High-quality single crystals of 2-methylimidazole (2-MI) were successfully grown from water and subjected to comprehensive characterization. Single-crystal X-ray diffraction (XRD) unveiled the orthorhombic crystal system with non-centrosymmetric space group and unit cell parameters, while FT-IR, FT-Raman, and NMR spectroscopy provided detailed insights into the molecular and spectral features. Linear optical properties were explored using UV–vis spectroscopy and unveiled the cutoff wavelength as 224 nm. The compound’s thermal stability was established through TG and DSC analyses and found to be 150 °C. Hirshfeld surface analysis highlighted the nature of intermolecular interactions within the lattice. Nonlinear optical behavior was probed via the Kurtz–Perry powder technique, confirming second harmonic generation (SHG) activity as 3 times that of the standard bench mark material Potassium Dihydrogen Phosphate (KDP). Furthermore, laser-induced surface damage threshold studies demonstrated the material’s robustness with 0.524 GW/cm² for optical applications. Third-order nonlinear optical responses and optical limiting characteristics were systematically investigated using the Z-scan method. Collectively, these results underscore the potential of 2-MI as a promising candidate for advanced photonic and optoelectronic applications.

Gemini surfactants were employed to stabilize single-walled carbon nanotubes (SWNTs) in aqueous solutions. High-quality transparent conductive films (TCFs) composed of SWNTs were fabricated via the rod-coating method, and key processing parameters such as Gemini surfactant type, SWNT concentration, and ethanol post-treatment were systematically investigated. The samples were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis) spectroscopy, and X-ray photoelectron spectroscopy (XPS). It was found that the Gemini surfactant 12–2-12 exhibited excellent dispersion performance in SWNT systems. Based on the SWNT dispersions stabilized by 12–2-12, TCFs with low sheet resistance and high optical transmittance were successfully fabricated. Notably, the dispersant on the films could be effectively removed via ethanol treatment within 30 min. The sheet resistance decreased significantly by over 99%, while the transmittance at 550 nm remained unaffected. Importantly, no environmentally polluting acidic wastewater was generated during the fabrication process, rendering this an eco-friendly method for TCF preparation.

Morphological engineering is utilized to modify the microstructure and electronic structure of bismuth oxychloride; this led to a remarkable enhancement in photocatalytic performance. In this research, H-BOC nanosheets with concave-pore defects were synthesized via a glycol-mediated solvothermal etching method. Photocatalytic activity was examined using Rhodamine B (RhB, 20 mg·L⁻¹) as the target contaminant under visible-light exposure. H-BOC displayed superior photocatalytic performance within 4 min, achieving a degradation rate of 99% and a reaction rate constant of 0.9643 min^–1, significantly higher than those of T-BOC (53% and 0.1556 min^–1). The results indicate that the incorporation of concave-pore defects not only improves visible-light absorption and reduces hole migration distance but also enhances charge separation and effectively suppresses the recombination of photogenerated electron–hole pairs. This acceleration in reaction kinetics was further confirmed by trapping experiments and EPR analyses, which reveal that superoxide (•O₂⁻) and hydroxyl radicals (•OH) were the dominant reactive species. Furthermore, high-performance liquid chromatography–mass spectrometry (HPLC–MS) and the toxicity estimation software tool (T.E.S.T) were employed to investigate the degradation mechanisms, pathways, and the toxicity of RhB and its intermediates. This study presents a novel approach for designing and developing high-performance photocatalysts.

Liquid crystals are preferred in nanotechnology research due to their tunable electro-optical and dielectric parameters. Furthermore, these tunable electro-optical and dielectric parameters can be modified by adding different dopant materials to the liquid crystals. Polymers are among the leading dopant materials and are widely used in adjusting the physical parameters of liquid crystals. Polyvinyl alcohol, a type of polymer material, is also used in many scientific studies due to its water solubility, biocompatibility, and wide operating temperature range. Considering this information, the present study reports that physical characteristics of polyvinyl alcohol doped E7 nematic liquid crystal. The effects in polyvinyl alcohol on the threshold voltage, optical band gap, response time, dielectric constants, and dielectric anisotropy of E7 have been discussed. The decrease of dielectric anisotropy and optical band gap, and the increase of threshold voltage, response time, and frequency dependent dielectric constant with polyvinyl alcohol contribution in E7 have been observed. The results indicate that polyvinyl alcohol doped E7 nematic liquid crystal composite has tunable electro-optical and dielectric properties and is a material that can be recommended for electro-optical device applications.