Electron Field Research Articles

Synergistic Multimodal Energy Dissipation Enhances Certified Efficiency of Flexible Organic Photovoltaics beyond 19.

All-polymer organic solar cells (OSCs) have shown unparalleled application potential in the field of flexible wearable electronics in recent years due to the excellent mechanical and photovoltaic properties. However, the small molecule acceptors after polymerization in still retain some mechanical and aggregation properties of the small molecule, falling short of the ductility requirements for flexible devices. Here, based on the multimodal energy dissipation theory, the mechanical and photovoltaic properties of flexible devices are co-enhanced by adding the thermoplastic elastomer material (polyurethane, PU) to the PM6:PBQx-TF:PY-IT-based active layer films. The construction of multi-fiber network structure and the decrease of films' residual stresses contribute to the enhancement of carrier transport properties and the decrease of defect state density. Eventually, the PCE (power conversion efficiency) of 19.40% is achieved on the flexible devices with an effective area of 0.102 cm2, and the third-party certified PCE reaches 19.07%, which is the highest PCE for flexible OSCs currently available. To further validate the potential of this strategy for large-area module applications, the 25-cm2-based flexible and super-flexible modules are prepared with the PCEs of 15.48% and 14.61%, respectively, and demonstration applications are implemented.

Advances in Magnetic Two Dimensional Materials

Since the discovery of graphene in 2004, two-dimensional (2D) van der Waals (vdW) layered materials have attracted extensive attention for their great potential for application in the electronic, optoelectronic, and electrochemical fields [...]

Review of: "They exist in various forms—made of metals, semiconductors, insulators, and organic compounds—and are used for applications in the fields of electronics, energy conversion, optics, and chemical sensing"

Review of: "They exist in various forms—made of metals, semiconductors, insulators, and organic compounds—and are used for applications in the fields of electronics, energy conversion, optics, and chemical sensing"

Planar and Curved π-Extended Porphyrins by On-Surface Cyclodehydrogenation.

Recent advancements in on-surface synthesis have enabled the reliable and predictable preparation of atomically precise low-dimensional materials with remarkable properties, which are often unattainable through traditional wet chemistry. Among these materials, porphyrins stand out as a particularly intriguing class of molecules, extensively studied both in solution and on surfaces. Their appeal lies in the ability to fine-tune their unique chemical and physical properties through central metal exchange or peripheral functionalization. However, the synthesis of π-extended porphyrins featuring unsubstituted anthracenyl groups has remained elusive. Herein, we report an in vacuo temperature-controlled cyclodehydrogenation of bis- and tetraanthracenyl Zn(II) porphyrins on a gold(111) surface. By gradually increasing the temperature, sequential dehydrogenation leads to the formation of fused anthracenyl porphyrin products. Notably, at high molecular coverage, the formation of bowl-shaped porphyrins occurs, along with transmetalation of Zn with Au. These findings open the door to a variety of π-extended anthracenyl-containing porphyrin products via cyclodehydrogenation and transmetalation, offering significant potential in the fields of molecular (photo/electro)catalysis, (opto)electronics, and spintronics.

Two-Dimensional Rare-Earth Metal Phosphides: From Weyl Semimetal to Semiconductor.

Two-dimensional (2D) nanomaterials have garnered extensive attention owing to their unique properties and versatile application. Here, a family of 2D rare-earth metal phosphides (M2P, M = Sc, Y, La) and their derivatives M2POT (T = F, OH) is developed to find their topological and electronic properties on the basis of density functional theory simulations. We show that the 2D M2P compounds are most possibly obtained from thermodynamically stable M2InP by chemical exfoliation. The In with a substantial atomic radius of 156 pm exhibits weak polarization ability, resulting in homogeneity of the electron cloud and a weakening of the M-In bond relative to the M-P bond. Upon exfoliation of the In layer, the M22+P3-:e- emerges as an electride with surface electrons, which is attributed to the larger ion radius and lower electronegativity of M2+ ions in M2P. The metallic M2P is found to be a Weyl semimetal derived from the contribution of surface electrons. Further, by leveraging the high reactivity of surface electrons, surface functionalization can produce M2POT compounds with the increased valence state of M3+, which results in their semiconducting properties characterized by high carrier mobilities and strong built-in electronic fields. These distinct topological and electronic characteristics position the 2D M2P and M2POT as promising candidates for a wide range of applications.

Investigation on the effect of complex formation on prominent high static/dynamic first and second hyperpolarizability of Co(II) complex including 4-chloro-Pyridine-2-Carboxylic acid

Nonlinear optical (NLO) materials with promising first- and second-order hyperpolarizabilities play a crucial role in the fields of electronics and optoelectronics. For the metal-organic coordination complexes, the logical selection of an appropriate ligand and metal ion is vital in designing such materials to enhance their NLO response. In this study, a novel Co(II) complex, including 4-Chloro-pyridine-2-carboxylic acid ligand, was synthesized. The crystal structure and spectroscopic properties were determined by XRD, FT-IR, and UV–Vis spectroscopies. B3LYP and CAM-B3LYP level calculations demonstrated that there is a strong electronic absorption band at 356 nm, originating from the metal-ligand charge transfer (MLCT) transfer in the UV–Vis spectrum. Both XRD and FT-IR data demonstrated that the Co(II) complex has a distorted octahedral coordination geometry. The calculations of static and frequency-dependent α, β, and γat frequencies of ω = 0.0856252 a.u (λ = 532 nm) and w = 0.0428126 au. (λ = 1064 nm) for 4Clpca and Co(II) complex have been also carried out using B3LYP and CAM-B3LYP levels. The dc-Kerr effect γ(-ω; ω,0,0) and SHG γ(-2ω; ω,ω,0) parameters for Co(II) complex calculated as 329.59 × 10−36 and 433.93 × 10−36 esu are found as dramatically higher those for single pca ligand (6.0267 × 10−36 and 163.70 × 10−36 esu). So, a significant increase was detected in the parameters of frequency-dependent α (-w; 0), β(-w; w,0), and γ (-w; w,0,0) with complex formation.

Linear and Nonlinear Rheological Investigations of Poly(3-hexylthiophene) H-Aggregated Gel Networks.

Owing to its facile synthesis and low cost, poly(3-hexylthiophene) (P3HT) has been extensively investigated in the field of organic electronics. Well-defined packing of P3HT chains and getting controlled morphologies, which solely depend on the polarity of the solvent, remain challenging. Herein, the aggregation behaviors of P3HT in organic solvents having different solvent polarities have been investigated to achieve different orderings of P3HT chains (H-type or J-type). The aggregation in the solution phase and the subsequent structural as well as morphological behaviors of P3HT chains have been investigated by absorption, X-ray powder diffraction, and topological studies, respectively. It has been noticed from absorption studies that P3HT forms H-type aggregates in anisole, phenetole, etc., whereas it produces J-type aggregates in toluene. More surprisingly, H-type aggregations of P3HT chains at low concentrations (CP3HT = 0.001 g/cm3) eventually lead to the formation of the gel network that ceases the flow of the solvents. Contrary to expectations, J-type aggregation in toluene does not produce the gel network at the said concentration. Further, to reveal the viscoelastic and microstructural properties, P3HT gel networks have been thoroughly investigated by small-amplitude oscillatory shear (SAOS) and large-amplitude oscillatory shear (LAOS) with varying concentrations, solvents, and molecular weights of P3HT. With quantitative analysis, the nonlinear rheological characteristics of higher harmonics, strain-stiffening ratio, shear-thinning ratio, dissipation ratio, intracycle transient moduli, and derivative of transient moduli have been evaluated for P3HT networks, which significantly provide the rheological information for the understanding of conducting polymer networks.

A novel hydrodynamic semiconductor model under Hall current effect and laser pulsed excitation

This paper presents a novel investigation into the effects of a strong external magnetic field on a hydro-poroelastic semiconductor model within the framework of photo-thermoelasticity theory in two dimensions. This study focuses on generating a Hall current and its impact on the coupled behavior of thermal, mechanical, and electronic fields in a semiconductor medium saturated with fluid. Using the normal mode analysis, we derive and analyze the wave propagation characteristics of key physical fields, including the non-dimensional temperature, displacement, mechanical stresses, carrier density, and excess pore water pressure, in response to the imposed magnetic field. Boundary conditions relevant to real-world applications are incorporated to assess the interactions between these fields. The results provide insight into the dynamic coupling of electromagnetic, thermal, and mechanical phenomena in porous semiconductor materials and offer potential applications in the design of magneto-sensitive semiconductor devices as well as in geophysical and biomedical engineering fields where such multi-field interactions are critical. The results obtained are plotted with some comparisons.

An analytical I-V model of SiC double-gate junctionless MOSFETs

Silicon carbide(SiC) double gate junctionless metal oxide semiconductor field-effect transistors(DG JL MOSFETs) have attracted significant attention due to their ideal high temperature characteristics and radiation resistance. Therefore, it is meaningful to exploit an I-V model for SiC DG JL MOSFETs. In this article, we make a linear approximation to describe the relationship between the surface mobile charge density and the surface electron concentration of the device. Based on this approximation and using the one-dimensional Poisson’s equation, we solve for the potential distribution of a SiC DG JL MOSFET in the subthreshold region. From this solution, we derived a functional relationship between the surface mobile charge density in the channel and the channel quasi-Fermi potential. Then we successfully developed a unified I-V model for the SiC DG JL MOSFETs. Based on the drain to source current calculation formula, the calculation expressions for the device’s transconductance and output conductance are derived. By comparing our model with the results from the two-dimensional numerical simulation software Silvaco Atlas, our model’s calculations closely match the two-dimensional numerical simulation results from the subthreshold region to the accumulation region. This model has reference significance for SiC DG JL MOSFETs in the high temperature electronic circuit application field.

“Rigid-Flexible” structured polyimine/graphite felt composites with excellent fire Resistance, electromagnetic shielding and recyclability

With the development of the electronic information, the conductive polymers with high electromagnetic interference (EMI) shielding effectiveness has become a research point. The polyimine material that forms a cross-linking network can rapidly achieve bond exchange at high temperatures, which is becoming a potential substrate for carbon loaded materials. In this work, a novel composite material is successfully prepared by incorporating cost-effective graphite felt (GF) with excellent electrical properties into a biobased polyimine network. Leveraging the exchange properties of dynamic imine bond (−C = N-), the two substrates can be separated by acidolysis, enabling a recycle of the GF efficiently. The electromagnetic shielding effectiveness (EMI SE) of the composite material in the X-band (8.2–12.4 GHz) reaches approximately 46 dB. Additionally, the introduction of highly fire-resistant graphite material significantly enhances the flame retardancy of the composite by reducing the peak heat release rate (HRR) by 47.1 %, which improves the fire safety in complex electromagnetic environments. Herein, we broaden the application of polyimine/graphite composites in the electronic information field and provide a new strategy for the preparation of environmentally friendly composite materials.

Experimental investigation of field electron emission from uncoated and coated graphite fiber tips

Abstract This study investigates the field emission characteristics of coated and uncoated graphite fiber tips under high vacuum conditions in the pressure range of 10–6 Pa. A 2 M Sodium hydroxide (NaOH) solution was used in the electrochemical etching procedure to produce an uncoated etched graphite fiber emitter with a diameter of 436.5 nm. An epoxy coating 2301 dielectric material with a thickness of 61 ± 1 nm was used to coat the fiber tip. Field-emitter emission micrographs, current stability, and current-voltage (I-V) characteristics were recorded. Murphy’s Good plots were used to examine and analyse the I-V characteristics. An orthodoxy test was performed to evaluate the Murphy Good plots. In the reported results, at low applied voltages, the uncoated graphite fiber emitter passed orthodoxy tests, and generated a steady current with 0.03 µA uncertainty. However, the coated graphite fiber emitter showed an increase in the applied voltage and threshold voltages but had no impact on the sample emission characteristics.

Magnetoelectric effects in a heterostructure of magnetostrictive fiber composite and piezopolymer film

Abstract Magnetoelectric (ME) effects in composite heterostructures comprising ferromagnetic (FM) and piezoelectric (PE) layers realize mutual transformation of magnetic and electric fields and form the basis for the development of highly sensitive magnetic field sensors, electrically tuned electronic components, and energy harvesting devices. ME effects result from a combination of magnetostriction of the FM layer and piezoelectricity in the PE layer due to mechanical coupling between the layers. In this work ME effects are studied in a flexible heterostructure containing a magnetostrictive fiber composite (MFC) and a piezopolymer layer. MFC is a set of microwires made of amorphous FeCoSiB alloy with high magnetostriction and arranged in a plane parallel to each other in a polymer matrix. MFC exhibits strong in-plane anisotropy of magnetization and magnetostriction resulting from demagnetization effects in microwires. Anisotropy leads to the dependence of the linear and nonlinear ME effects characteristics on the orientation of dc magnetic field in the plane of the heterostructure. For the fabricated heterostructure at the resonance frequency of bending vibrations, a linear magnetoelectric coefficient of 24 V/(Oe∙cm) was obtained, and the efficiency of nonlinear generation of the second voltage harmonic reached 1.6 V/(Oe2∙cm). ME effects in MFC heterostructures can be used to create magnetic field sensors and electronics devices that are sensitive to the field orientation.electronics devices that are sensitive to the field orientation.

Evolutions and prospects in research field of molecular electronics and bioelectronics - learning from the past to create the future

Abstract It is a review of the history of the research field of molecular electronics and bioelectronics (M&BE) . And the the main targets and the world-wide research are overviewed.

Microstructure, Texture and Mechanical Properties of Magnesium Alloys Processed by Multi-Directional Forging: A Review

Magnesium (Mg) and its alloys are currently the lightest structural metals in engineering applications, widely used in aerospace, defense technology, transportation and electronic 3C fields. Plastic deformation is a commonly used method to improve the comprehensive mechanical properties of Mg alloys. Multi-directional forging (MDF), as a severe plastic deformation (SPD) method, is considered as an effective technology for manufacturing large-sized Mg alloys with high strength and toughness. This paper outlines the process principle of MDF and analyzes the microstructure evolution, texture and mechanical properties of Mg alloys processed by MDF. The effect of deformation parameters, such as deformation temperature, accumulative strain and strain rate, and alloying elements on grain refinement, second phase evolution and texture are discussed systematically. Additionally, recent research highlights the Mg alloys with high strength and toughness processed by MDF. Furthermore, the contribution of grain refinement, precipitation, solid solution and texture-strengthening mechanisms on the mechanical properties are revealed. Finally, we conclude the research progress, analyze the shortcomings in development, and recommend further prospects. We hope this review will inspire new ideas on the development of Mg alloys with a high strength and MDF process.

Effect of field emission on contact spark in the spark test apparatus

Explosion-proof electrical equipment must be tested with the spark test apparatus (STA). This discharge was important for electrical explosion-proof safety. This study aimed to investigate the effect of field emission on the contact spark of the STA. Results show that the primary discharge modes were field emission and electron impact ionization. The gap width was estimated to be 6–8 μm. The distribution of the ions and radicals were revealed under the different field emissions. The impact of radicals on ignition was also discussed.

Enhancing kesterite-based thin-film solar cells: A dual-strategy approach utilizing SnS back surface field and eco-friendly ZnSe electron transport layer

The development of kesterite-based thin-film solar cells (TFSCs) has faced significant challenges, particularly due to unstable rear contact properties and low power conversion efficiency (PCE). Despite various individual approaches aimed at addressing these issues, progress has remained limited. In this study, a dual strategy is explored to address these problems simultaneously. First, the impact of an SnS intermediate layer at the back surface field in conjunction with an FTO back contact is examined. Second, the introduction of a stable PN Mott-Schottky junction is assessed by utilizing an eco-friendly ZnSe electron transport layer (ETL) as a replacement for the conventional, yet toxic, CdS ETL. The combined application of these strategies produces a synergistic effect, leading to significant improvements in the solar cell’s microstructure and key electrical parameters, including open-circuit voltage (VOC), short-circuit current density (JSC), and overall PCE. Additionally, this approach mitigates band-tailing states and reduces deep-level defects often associated with the annealing process. As a result, the power conversion efficiency is significantly enhanced, rising from 1.31 ± 0.13 % to 7.68 ± 0.98 %. This effective dual-strategy offers new insights into overcoming the challenges of unstable rear contact properties and suboptimal device parameters, paving the way for further advancements in the performance of kesterite-based TFSCs.

Number of electrons in a homogeneous field using delta function normalization

Abstract The number of electrons in a homogeneous electric field is derived quantum mechanically for a certain range. Using the delta function normalization method, which is described in detail in Landau–Lifshitz’s Quantum Mechanics, the normalization coefficient of the wavefunctions with continuous energy eigenvalue spectra is obtained. Subsequently, the number of electrons in a one-dimensional homogeneous field in a certain region is derived from this normalization coefficient. We illustrate the derivation of physical quantities using normalization coefficients through selected examples. The derivation provides an interesting application of delta function normalization, and thus can serve as a good textbook example of this normalization method, which used to play a limited role in quantum mechanics.

Selectively Detachable Hydrogel Adhesion Enabled by Stimulus-Specific Cleavable Cross-Linkers.

The development of detachable hydrogel adhesion presents an advancement in the fields of soft electronics and bioengineering as it offers additional functionalities to these applications. However, conventional methods typically rely on a single detachment trigger, so it is unclear whether unintentional detachment might occur in the specific environments of other detachment systems. This makes it difficult to directly introduce two independent detachment triggers directly. In this article, we present a strategy for selective detachable adhesion based on two types of cleavable cross-linkers, N,N'-bis(acryloyl)cystamine (BAC) and N,N'-(1,2-dihydroxyethylene)bis(acrylamide) (DHEBA), each with an independent cleavage trigger. BAC can be cleaved through the reduction of disulfide bonds using reducing agents, while DHEBA can be hydrolyzed through heating. We constructed stitching polymer networks for topological adhesion using two types of cleavable cross-linkers, allowing the networks to be selectively degraded depending on which cross-linker was used. Our findings show that the use of cleavable cross-linkers achieved selectively detachable adhesion in various hydrogels, with adhesion energy that reached up to 1223 J m-2 in polyacrylamide-alginate (PAAm-alginate) tough hydrogel. This strategy also proved versatile as it led to effective adhesion with various substrates, including aluminum, copper, glass, and polyester film (PET). Furthermore, we took advantage of the high programmability of this approach to construct hydrogel-based YES and AND logic gates, whose output changed depending on the applied input triggers. In addition, we designed a selective-release capsule model capable of dual-solution release, which emphasizes the potential of our strategy in creating programmable and responsive soft materials.

Nonlinear Interaction and Modulational Instability of Dust Acoustic Disturbances in a Magnetized Cometary Plasma

ABSTRACTThe interplay of dust acoustic waves (DAWs) and it's amplitude modulation is investigated in a magnetized five‐component cometary plasma comprising positively charged hydrogen and oxygen ions, negatively charged dust grains, along with superthermal electrons (solar and cometary). The interplay dynamics of the dust acoustic waves (DAWs) is described by the Kortweg–de Vries (KdV) equation. The appearance of multi‐soliton profiles are derived using Hirota's method. The amplitude modulation of the DAWs is investigated through nonlinear Schrodinger equation. In the numerical study, it appears that the dark‐envelope soliton may exist in such cometary plasmas, but the emergence of bright‐envelope soliton is not possible at any condition. Superthermality, magnetic field strength, ion and electron concentration, and other physical factors have all been explored for their impacts. The findings of this research may contribute to our understanding of the nonlinear characteristics and wave propagation stability of electrostatic wave excitations in cometary coma environments.

Engineering Heterointerface to Synergistically Regulate Kinetics and Stress of Copper-Cobalt Selenide toward Reversible Magnesium/Lithium Hybrid Batteries.

Metal chalcogenide-based cathodes are crucial for the development of rechargeable magnesium batteries, yet the strong electrostatic interactions of Mg2+ result in slow ion transport and high polarization. The Mg2+/Li+ hybrid battery holds promise for enhancing the energy storage capability. Herein, we establish a system that utilizes (Co,Cu)Se2/CoSex heterostructure grown on carbon cloth as the cathode and APC-LiCl as a dual-salt electrolyte to achieve high reversible capacity, enhanced cyclic stability, and impressive rate performance. First-principles calculations and kinetic analyses are employed to uncover that constructing the heterointerface stimulates the formation of an intrinsic electric field and high-density electron flows, thereby accelerating charge transfer and ion diffusion processes. Finite element simulations further demonstrate that the heterostructure effectively alleviates stresses associated with magnesiation/lithiation to enhance the structural integrity of the material. Moreover, the multistep reaction unveils a stepwise structural transformation pathway. This study initiates a new chapter in designing heterointerface strategies for advanced energy storage devices.