Journal of Electronic Materials最新文献

Ammonia (NH₃) is primarily produced through the traditional Haber–Bosch (H–B) technology which features high energy consumption and high pollution. As a sustainable alternative, electrocatalytic nitrogen reduction (eNRR) has attracted significant attention for its potential to replace the H–B process under ambient conditions. The key challenge lies in developing efficient catalysts to achieve high Faradaic efficiency (FE) for eNRR at normal temperature and pressure. Here, a metal-free composite catalyst composed of hexagonal boron nitride nanosheets (h-BNNs) and graphene oxide (GO) (h-BNNs/GO) was designed for ambient eNRR. A weak strain effect was induced between the layered structure of GO and h-BNNs, which contributed to an enhanced NH₃ yield rate of 25.0 μg h⁻¹ mg_cat.⁻¹) at −0.7 V versus reversible hydrogen electrode (RHE) in neutral media. Notably, the composite catalyst exhibited a remarkable 52.6% FE, a significant improvement over pure h-BNNs (4.7% FE). Furthermore, the morphology of the carbon support (e.g., GO vs. CNTs) was found to influence the strain effect, directly impacting the eNRR performance. This work provides valuable insights for strain-engineered catalyst design, advancing the development of sustainable nitrogen fixation technologies.

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Deep Potential (DP) technology integrates deep learning with quantum mechanical computations, enabling the efficient handling of complex data from density functional theory (DFT) while demonstrating excellent computational accuracy and data analysis capabilities. Rhodium (Rh), one of the rarest and most valuable platinum group metals, plays a crucial role due to its strategic importance in the automotive and electronics industries. However, the computational process for Rh is hindered by a lack of appropriate potential models, resulting in time-consuming and resource-intensive calculations that limit its research applications. To fill this gap, we developed a high-precision interatomic potential using the DP method, successfully applying it to classical molecular dynamics (MD) simulations, thereby offering a new computational tool. We systematically compared the predictions of the constructed DP potential function with results from DFT across various physical properties, including lattice parameters, stability, and defects, confirming that the constructed DP potential function exhibits excellent accuracy consistent with DFT in physical property predictions. Notably, in terms of thermal transport properties, the phonons dispersion and thermal conductivity results obtained from the developed DP model still remain in high consistency with those from the DFT method. Additionally, MD simulations based on the DP framework indicate that the crystal melts at a temperature of 2283 K, which is remarkably consistent with the experimentally measured melting point of 2237 K. With rising temperature, the transport of Rh atoms significantly enhances, with a self-diffusion coefficient of 7.54 × 10^-11 m²/s at the melting point, exhibiting diffusion behavior similar to that of typical face-centered cubic metals. This study serves as a foundational step in the application of deep learning to potential energy modeling of single-element Rh systems, ensuring the accuracy and reliability of the model. By extending this approach to multi-component systems in future work, it aims to provide theoretical support for the efficient and precise design of advanced materials.

In this work, the frequency-dependent conduction mechanism and dielectric relaxation processes in Bi₂Ca_2−xLa_xCoO_6, x = 0.00−0.15 (BCLCO), were investigated at temperatures between 100°C and 500°C. In this study, the novel BCLCO was successfully prepared by the coprecipitation process. We revealed the samples under study have a monoclinic structure by the investigation of x-ray diffraction (XRD) data. The XRD data was used to compute the crystallite size, lattice parameters, and unit cell volume. It is evident from all of the characterizations that the BCLCO was successfully prepared. Electrical and dielectric properties were examined with frequency at different temperatures. According to the analysis of electrical conductivity, the prepared samples exhibit semiconducting behavior. The dielectric constant is enhanced with temperature and decreases with frequency due to space charge polarization, which has been described by the Maxwell–Wagner relaxation model. In this investigation, the dielectric constant was examined up to a maximum value of 2.17 × 10⁶. In the studied samples, the Havriliak–Negami model was employed to calculate the spreading factor values. Jonscher’s universal power law was used to study the conduction mechanism of the synthesized samples. tan δ and dielectric constant studies confirmed the thermal hopping of charge transport in BCLCO. According to modulus spectroscopy, the examined samples indicated the existence of a temperature-dependent relaxation mechanism. The thermal conductivity (k = 0.540 W/m-K) was greatly reduced by La-doped bismuth cobaltite, which could make it appropriate for thermal barrier coating.

Graphical Abstract

In this work, we have synthesized gallium tungstate (Ga₂(WO₆)₃) integrated with reduced graphene oxide (rGO) as an electrode material via an ultrasonication-assisted hydrothermal method and investigated for high-performance supercapacitor applications. The fabricated electrode materials were characterized by x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and x-ray photoelectron spectroscopy (XPS). The results demonstrate the successful formation of a GaW/rGO nanocomposite with high crystallinity, uniform dispersion, and enhanced surface area. Electrochemical studies in a three-electrode configuration revealed significantly improved specific capacitance of 838 F g⁻¹ at 1 A g⁻¹ for Ga₂(WO₆)₃/rGO, outperforming pristine Ga₂(WO₆)₃ (629 F g⁻¹). The composite also exhibited excellent rate capability and outstanding cyclic stability, with 91.2% retention over 10,000 cycles. When assembled as an asymmetric supercapacitor device using activated carbon (AC) as the negative electrode, the Ga₂(WO₆)₃/rGO//AC cell achieved specific capacitance of 375 F g⁻¹ at 1 A g⁻¹, retained 93.2% capacitance after 5000 cycles, and delivered maximum energy density of 29 Wh kg⁻¹ at power density of 310 W kg⁻¹. The device also demonstrated practical applicability by powering a light-emitting diode (LED). The superior electrochemical performance is attributed to the synergistic effect between pseudocapacitive Ga₂(WO₆)₃ and highly conductive rGO, offering a promising route toward next-generation energy storage devices.

This study investigates the performance and simulation of a gallium arsenide (GaAs) Pocket-Hetero-Vertical-Tunnel field-effect transistor (GaAs-hetero-V-TFET) with a nanocavity for potential biosensing applications. The primary goal of this paper is comparing the various parameters for a few biomolecules including APTES (3-aminopropyltriethoxysilane), keratin, staphylococcal nuclease, and gelatin with varying dielectric constant values. The biomolecules with distinct dielectric constants are positioned inside the nanocavity near the sides of the channel of the device structure, which allows for the observation of the changes of the drain current versus gate voltage characteristic graph. Substantially improving the output characteristics of the proposed V-TFET, the dual metal work function designs improve the sensitivity of the GaAs-hetero-V-TFET biosensor. By incorporating distinct biomolecules, several electrical metrics, including drain current, electric field, threshold voltage, electron band-to-band tunneling rate, and drain current sensitivity, changed significantly. With an excellent subthreshold swing (14.45 mV/dec), the biosensor can detect a maximum ON-current of 6.64 × 10⁻⁵ A/µm and an OFF-current of 2.36 × 10⁻¹⁸ A/µm for the gelatin at κ = 12. The biosensor's sensitivity of κ = 12 has been determined by studying both neutral and charged biomolecules. The provided biosensor explored the transconductance sensitivity at 9.43 × 10⁵ and the drain current sensitivity at 2.61 × 10⁶. Finally, compared to earlier reported investigations, it has been demonstrated that the presented biosensor device produces superior sensitivity.

The scope of using cerium oxide–gold nanoparticles (CeO₂–Au NPs) as an optical sensor is studied via the fluorescence quenching technique. Under violet excitation, ceria NPs have a strong emission in the visible region (~530 nm), which clearly proves its strong fluorescent behavior. Here, Au NPs are embedded in situ with CeO₂ NPs. In addition, the second harmonic generation (SHG) of poly{1-[p-(3′-carboxy-4′-hydroxyphenylazo)benzenesulfonamido]-1,2-ethandiyl, sodium salt} (PCBS) and its fluorescence response with light emitting diode (LED) excitation at 780 nm were studied. The Stern–Volmer constant of PCBS in peroxide detection is 0.0987 M⁻¹, lower than the value of ceria, which is 0.1419 M⁻¹. Afterwards, the system is applied in the field of peroxide sensing in aqueous media. The fluorescence intensity is found to be affected by the addition of peroxides into CeO₂-Au NPs. The Stern–Volmer quenching constants were found to be 0.0987 M⁻¹ for PCBS, 0.1419 M⁻¹ for undoped ceria, and 0.1763 M⁻¹ for Au-doped ceria, indicating a 26.72% enhancement in sensitivity. The sensitivity of ceria NPs in peroxide quencher detection is found to be enhanced considerably by the addition of Au NPs. This is because of the plasmonic resonance of Au NPs as it is optically coupled with the fluorescence emission spectrum of ceria. The bandgap of ceria is also found to be decreased by the addition of Au NPs, which is due to the creation of more oxygen vacancies inside the nonstoichiometric crystalline structure of ceria. The sensitivity of the optical sensing material, ceria–gold NPs with added peroxide, is characterized by the Stern–Volmer constant and is found to be 0.1763 M⁻¹ which is higher than the case of using ceria NPs only. Ceria–gold NPs with enhanced optical sensitivity can be employed as an optical sensing host for peroxides, which plays a major role in many important applications such as biomedicine and water quality monitoring. This work introduces a novel dual-mode optical sensing platform by integrating the SHG response of PCBS thin films and the plasmon-enhanced fluorescence quenching behavior of Au-doped CeO₂ nanoparticles. The combined system demonstrates a 26.72% increase in peroxide sensitivity compared with pure ceria, making it a promising approach for efficient, low-cost detection in aqueous environments.

In this work, a batch of Tm³⁺-doped Ca₂Ga₂SiO₇ phosphors was successfully synthesized via the conventional solid-state reaction method and systematically investigated for structural and photoluminescence properties. X-ray diffraction results confirmed the formation of a single-phase tetrahedral structure of Ca₂Ga₂SiO₇ with a P421m space group and no detectable impurity phase, indicating successful incorporation of Tm³⁺ ions into the host lattice. Under near-ultraviolet excitation of 355 nm, the phosphors exhibited intense blue emission centered at 455 nm. The emission peak is attributed to the ¹D₂ → ³F₄ transition of Tm³⁺ ions. The concentration-dependent study revealed an optimal dopant level of 1.0 mol% of Tm³⁺, beyond which concentration quenching occurs. The chromaticity coordinates of the optimized phosphor fall in the ideal blue region of the CIE 1931 diagram, confirming its potential to emit white light when combined with red and green phosphors. Decay time analysis showed a reduction in lifetime with increasing dopant concentration, suggesting energy transfer between neighboring Tm³⁺ ions. The results demonstrate that Ca₂Ga₂SiO₇:Tm³⁺ is a promising candidate for next-generation solid-state lighting applications.

The advancement of ultra-thin photovoltaic devices is often constrained by limitations in conventional pulse laser processing, such as irregular ablation profiles, debris generation, and narrow process windows resulting from Gaussian beam characteristics. These challenges lead to uneven energy distribution and thermal damage, compromising device performance. In this study, we present a novel approach utilizing a 193 nm ArF excimer laser for non-thermal laser contact opening (LCO) to improve energy uniformity and minimize heat-affected zones in 100-μm-thick, 6-inch single-crystal silicon solar cells. The excimer laser enables large-area, uniform ablation with reduced substrate damage, in contrast to traditional 1064 nm picosecond lasers. Comparative analysis demonstrated that the excimer-based LCO achieved a 1.04% increase in fill factor (from 78.92% to 79.96%) and a 0.35% improvement in power conversion efficiency (from 19.79% to 20.14%), along with a reduction in series resistance by 0.00054 Ω. These improvements are attributed to enhanced LCO width uniformity and edge definition. This work highlights the significant potential of excimer lasers for precision back-contact structuring in high-efficiency, thin-film photovoltaic technologies. Future work will further refine LCO parameters and explore broader applications in next-generation solar cell designs.

The present study focuses on the synthesis and optimization of the physicochemical properties of carbon nanotube-doped lanthanum oxide (CNT–La₂O₃) quantum dot-based photoanodes by incorporating cerium and cobalt ions to enhance the efficiency of dye-sensitized solar cells (DSSCs). Three quantum dot-based photoanodes were fabricated: (i) CNT–La₂O₃, (ii) cerium-doped CNT–La₂O₃ (CNT–La_1.5Ce_0.5O₃), and (iii) cerium and cobalt co-doped CNT–La₂O₃ (CNT–La_1.0Ce_0.5Co_0.5O₃). These materials were deposited on fluorine-doped tin oxide (FTO) substrates using the chemical bath deposition method. x-Ray diffraction analysis confirmed the successful incorporation of cerium (Ce³⁺/Ce⁴⁺) and cobalt (Co²⁺/Co³⁺) ions into the CNT–La₂O₃ matrix, leading to structural distortion and enhanced crystallinity. Atomic force microscopy revealed that CNT–La₂O₃ provided a well-balanced surface morphology, ensuring consistent charge transport and improved dye adherence. The incorporation of Ce ions increased defect density and surface roughness, facilitating higher dye-loading capacity and improved light scattering. In addition, cobalt ion inclusion contributed to anisotropic features and localized electronic heterogeneity, optimizing electron pathways. Ultraviolet–visible (UV–Vis) spectroscopy revealed red shifts in absorption edges, suggesting enhanced photon harvesting in the visible spectrum. A sequential reduction in bandgap across the series further demonstrated the pivotal role of Ce and Co in modulating the electronic structure of CNT–La₂O₃. DSSCs fabricated with CNT–La_1.0Ce_0.5Co_0.5O₃ exhibited the highest photon conversion efficiency of 12.50%, outperforming other configurations. This enhanced performance is attributed to optimized bandgap engineering by cerium (4f orbital) and cobalt (3d orbital) ions in the CNT–La₂O₃ matrix, leading to improved electron transport and suppressed charge recombination. The findings highlight the potential of CNT–La_1.0Ce_0.5Co_0.5O₃ quantum dots for advanced solar cell applications.