Journal of Materials Science: Materials in Electronics最新文献

A reliable and high-rate cathode is needed to study rechargeable zinc-ion batteries (ZIBs). Spinel ZnMn₂O₄ (ZMO) has special benefits that make it an attractive cathode material for ZIBs, including high availability, cheap cost, and environmental friendliness. However, because of its poor electronic conductivity and significant volume change throughout the charge/discharge process, it significantly limits both rate capability and lifespan. In this article, high-performance cathodes for rechargeable ZIBs are made using a new conductive polymer that is composed of ZMO and polypyrrole (ZMOP). The ZMOP cathode performs as predicted, with a huge specific capacity (213 mA h⁻¹ at 0.1 Ag⁻¹), good rate capability (119 mAhg⁻¹ at 2 Ag⁻¹), and exceptional durability over time (93% retention and 99.4% columbic efficiency after 2000 cycles). Additionally, quasi-solid-state ZIBs are created using an energy density (206 W h kg⁻¹), and power density (0.18 kW kg⁻¹).

Wearable pressure sensors hold great application potential in electronic skin, personal health monitoring, motion detection, and artificial intelligence equipment, etc. As a wearable device, it requires not only good signal acquisition capabilities but also wearing comfort. Flexible and breathable are the two key desirable features for wearable sensors. However, presently, most of the wearable sensors made from impermeable polymers and metal electrodes lack breathability, although they can possess certain flexibility. Herein, we present a breathable and flexible pressure sensor, which is based on a multi-layer porous network structure, including a porous sensitive layer and mesh electrode layer. The porous skeleton decorated with functional nanomaterials enables the device not only flexibility but also great breathability. The fabricated pressure sensor shows a high sensitivity (2.1892 kPa⁻¹), a wide response range (30 kPa), rapid response time/recovery time (82 ms /83 ms), and excellent cycling stability (1000 cycles). Additionally, the new sensor proposed here has been applied to monitor human movements, such as finger tapping, finger bending, neck swallowing, wrist bending, and elbow bending, indicating its potential for applications in health monitoring and rehabilitation training.

Potassium sodium niobate (KNN) has attracted much interest as a promising lead-free ferroelectric candidate with its excellent physical properties for potential applications to novel nano-devices such as non-volatile ferroelectric memory. However, the use of KNN films in actual devices has been limited due to concerns in operational reliability (i.e., a polarization fatigue property). In this work, we demonstrate the enhancement of a polarization fatigue behavior in KNN thin films by doping of Mn ions. Ferroelectric fatigue is significantly suppressed in 0.4 mol% Mn-doped KNN films compared with pure KNN films. The amounts of mobile charged defects (e.g., oxygen vacancies and hole carriers produced with cation vacancies) are reduced in the presence of multivalent Mn dopants resulting in a decrease of leakage current density. The reduction of charged defect density can weaken the domain wall pinning effect enabling the polarization fatigue to be suppressed in KNN films. Our work is of practical interest for realizing lead-free ferroelectric memory devices with high performance.

Pb_1-xSr_x(Zr_0.53Ti_0.47)_0.99O₃ + 1 mol%Fe₂O₃ (PSZTF-100x) (x = 0.05–0.20) ceramics were prepared by solid state reaction method. With the increase of Sr content, the crystal structure of the ceramics changed from tetragonal phase to the coexistence of tetragonal phase and rhombohedral phase, then to pseudo-cubic phase. Associated with the crystal structure change, the phase transition temperature (T_C) decreased, the diffuseness at T_C increased and the domain pinning strength reduced. For the poled ceramics, PSZTF-10 ceramics show the best properties including large d₃₃ (310 pC/N), very low tanδ (0.29%), large Q_m (870) and nearly hysteresis-free strain, which suggest that PSZTF-10 ceramics are good candidates for high precision positioning application.

The environmentally friendly disposal of copper waste from automobile shops is crucial for preventing potential environmental hazards. This study introduces an innovative approach to repurpose retrieved copper by converting it into a nanomaterial, specifically a copper oxide-based nanoparticles (CSCNC). Using extracts derived from Curcuma amada leaves and Strychnos potatorum seeds, a green synthesis process were employed to synthesize CSCNCs. The synthesis involved dissolving the reduced copper waste, leaching copper into the solution, and precipitating nanoparticles using a pH-controlled method. The synthesized CSCNCs possess a monoclinic crystalline structure with a morphology resembling nano-leaf sheets, exhibiting an average pore diameter of 14 nm and a mesoporous structure. These CSCNCs demonstrated efficient degradation of Congo red (CR), a representative dye, under visible light irradiation, with a degradation efficiency of 91% under optimized conditions. Kinetic analysis revealed that pseudo-second-order reactions provided a better fit for the degradation process, with CSCNCs exhibiting exceptional performance. Radical trapping experiments identified hydroxyl radicals and holes as the primary species involved in the photocatalytic degradation mechanism. The development of CSCNCs represents a significant advancement in the repurposing of copper waste, contributing to environmental sustainability and protection while offering insights into potential applications in wastewater treatment.

It is imperative to develop high-efficiency polymer electrolytes to advance energy storage technologies. The goal of this research is to use the exceptional properties of ionic liquids such as their superior ionic conductivity, thermal stability, and adjustable physical and chemical characteristics to improve polymer electrolytes through doping. This study explores the incorporation of ionic liquids into polymer matrices to create novel ionic-liquid-doped polymer electrolytes (ILDPEs). We synthesized a ILDPEs using Poly(ethyl methacrylate) (PEMA) as the host polymer with salt sodium iodide (NaI) doped with a new ionic liquid (1-hexyl-3-methylimidazolium iodide) synthesized using solution cast technique. Impedance spectroscopy revealed that doping ionic liquid enhances the ionic conductivity of the PEMA + NaI complex. Ionic conductivity significantly increased upon the addition of the ionic liquid (IL), reaching a maximum value of 7.7 × 10^–4 S/cm at room temperature. The ionic transference number (t_ion) for the polymer electrolyte with the highest ionic conductivity was calculated using Wagner polarization method while electrochemical stability window was calculated by linear Sweep Voltammetry. The crystalline nature of the ILDPEs films was studied using Polarizing Optical Microscopy (POM). To confirm the complex formation and bonding structure, Fourier-transform infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD) were also employed. Finally, dye-synthesized solar cell (DSSC) and electric double-layer capacitor (EDLC) were fabricated using the highest ionic conducting polymer electrolytes.

The development of narrowband green phosphors with high efficiency and stability plays an important role in the designing of high-performance backlight white light-emitting diode (WLED) devices. In this work, trivalent terbium host-sensitized orthoniobate green phosphor, TbNbO₄, has been prepared using the traditional high-temperature solid-state reaction method. The phosphor has a monoclinic structure with the space group C2/c. Besides, the TbNbO₄ is revealed with a direct bandgap structure and the bandgap is determined to be 3.67 eV by first principle calculation. Under 353 nm UV excitation, TbNbO₄ phosphor shows strong and narrow-band green emission with center around 550 nm, attributed to the ⁵D₄ → ⁷F₅ transition of Tb³⁺ ions. Furthermore, the results demonstrated that the phosphor exhibits favorable thermal stability and activation energy, with a notably high activation energy value of 0.24 eV. This observation suggests that the host-sensitized TbNbO₄ phosphor holds potential as narrow-band green-emitting alternative for backlighting white light-emitting diodes (WLED) display application.

In order to better understand the memristive characteristics of Ag/1%(Co, Li)-co-doped ZnO/Pt/Si–SiO₂ devices, this work looks at possible uses of dual-doped materials-based memory for neuromorphic computing. Transmission electron microscopy (TEM) was used to study the device structure after a 70-nm thin layer of 1% (Co, Li)-co-doped ZnO was formed on a Si–SiO₂ substrate using a sputtering technique. The set and reset voltages of 1.22 V and 1.01 V, respectively, were demonstrated by the devices, which demonstrated dependable repeatable resistance switching for 80 cycles. Analyzing conductance modulation with recurrent both positive and negative pulses revealed depression and potentiation curves that were almost linear. In order to clarify the switching process, a physical model was put out that focused on the oxidation–reduction reactions that drive the production and rupture of Ag conductive filaments in the presence of an applied electric field. The device’s usefulness for neuromorphic computing systems is highlighted by its reversible transitions between high and low resistance states and its steady and symmetric I–V properties. These results imply that (Co, Li)-co-doped ZnO memristors are good options for creating dependable and effective memory technologies.

Magnetoelectric materials are considered as the most promising materials for multifunctional device application. In this study, we report a polycrystalline 0.9 PbZr_0.52Ti_0.48O₃-0.1 NiFe₂O₄ (0.9PZT-0.1NFO) particulate composite prepared via cost-effective solid-state reaction route. The detailed structural analysis is done by performing Rietveld refinement technique. Both X-ray diffraction and Scanning Electron Microscopy confirmed the presence of both ferrite and ferroelectric phases without any interdiffusion. The magnetic and AC electrical properties like conductivity, dielectric constant, dissipation factor (dielectric loss), and impedance spectroscopy analysis were studied in detail with different frequencies and temperatures. A relatively high dielectric constant at low frequencies and high temperatures was obtained. The transition temperature is found to be 440 °C, which is greater than that of pure PZT. Complex impedance spectroscopy and modulus spectroscopy showed the occurrence of relaxation phenomena due to both grain and grain boundaries. The ac conductivity was studied to understand the conduction mechanism in the prepared sample. The composite exhibits the NTCR behavior. The PE loop confirms the ferroelectric property of the prepared sample. The MH loop shows a well-saturated curve, in which the experimental value of saturation magnetization is well-matched with the value obtained from fitting of MH loop to Law of Approach to Saturation.

In this paper, a successful electric field modulation in Lateral Double-diffused Metal Oxide Semiconductor (LDMOS) transistors to enhance the electrical characteristics is presented. A β-Ga₂O₃ film in the drift region is incorporated. The β-Ga₂O₃ film leads to a more efficient electric field modulation and enhances the DC and RF capabilities. Also, a Silicon layer is embedded in the buried oxide of the proposed structure to improve self-heating effects. Overall, the proposed β-Ga₂O₃ film in SOI LDMOS (βF-LDMOS) structure offers improved performances in terms of electric field distribution, maximum available power gain, unilateral power gain, gate-drain capacitance, breakdown voltage, and maximum lattice temperature. This makes it a promising candidate for RF power applications requiring high voltage and high power handling capabilities.