Hasil untuk "Electric apparatus and materials. Electric circuits. Electric networks"

Alwin Wüthrich, Benjamin M. Janzen, Roland Gillen et al.

ABSTRACT Gallium oxide (Ga2O3) is an ultra‐wide bandgap semiconductor with several polymorphs, among which the orthorhombic κ‐phase is particularly attractive for high‐power electronics, non‐volatile memory, and charge‐tunable devices due to its large spontaneous polarization and potential ferroelectric behavior. However, commonly grown κ‐Ga2O3 thin films contain nanoscale rotational domains, hindering the characterization of intrinsic properties and complicating device integration. In this work, we present the first combined experimental and theoretical Raman spectroscopy study of single‐domain κ‐Ga2O3 thin films grown on orthorhombic ε‐GaFeO3 substrates. Using polarization‐ and angle‐resolved Raman spectroscopy, we identify over 100 phonon modes, which correlate with 117 modes calculated via density functional perturbation theory. A systematic nomenclature is introduced based on mode symmetry and frequency to aid identification and comparison across future studies. Direct comparison with rotational‐domain samples shows that single‐domain films exhibit pronounced angle‐dependent Raman intensities consistent with theoretical selection rules, features that are obscured in multi‐domain films due to domain averaging. These findings establish polarization angle‐resolved Raman spectroscopy as an effective alternative to XRD and TEM for domain structure analysis and provide a robust framework for further studies of κ‐Ga2O3 in electronic applications.

Nao Kitajima, Seina Hori, Ai Otani et al.

For sensing applications, a complementary metal oxide semiconductor (CMOS) image sensor (CIS) with a lateral overflow integration capacitor (LOFIC) is in high demand. The LOFIC CIS can achieve high-dynamic-range (HDR) imaging by combining a low-conversion-gain (LCG) signal for large maximum signal electrons and a high-conversion-gain (HCG) signal for a low electron-referred noise floor. However, the LOFIC CIS faces challenges regarding the power consumption and circuit area when reading both HCG and LCG signals. To address these issues, this study proposes a readout circuit composed of area-efficient MOS capacitors using a folding DC operating point technique and an in-column signal selector for an on-chip HDR merger of HCG and LCG signals. A 10-bit test chip was fabricated with a <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.18</mn></mrow></semantics></math></inline-formula> µm CMOS process with MOS capacitors. The fabricated chip maintains high linearity, achieving an integral nonlinearity (INL) of +7.17/−6.93 LSB for the HCG signal and +7.95/−7.41 LSB for the LCG signal. Furthermore, the proposed design achieves a <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>14.92</mn><mo>%</mo></mrow></semantics></math></inline-formula> reduction in the average power consumption of the total readout circuit and a <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>36.5</mn><mo>%</mo></mrow></semantics></math></inline-formula> reduction in the readout circuit area.

Nagendra Kumar, Krishanu Kundu, Rajeev Kumar

Precise assessment of battery state of health (SoH) is vital for certifying consistent performance in order to enable maintenance of energy storage system. This work compares different deep learning methods to learn and predict the complex and nonlinear dynamics of battery. The models are developed and tested for predicting SoH using sequential degradation data from batteries. The effectiveness of these models is assessed using matrices such as RMSE, MAE and R2, along with qualitative analysis. The experiment results show that the BiLSTM model performs better than the others. It has the lowest RMSE (0.90), the lowest MAE (0.72), and the highest R2 (0.99), which highlights its enhanced ability to capture long-term temporal dependencies. The proposed models are validated using NASA lithium-ion battery aging dataset (B0005), which is widely used as a benchmark for battery health predictions studies. Overall, the findings indicate that bidirectional network architecture significantly improves the accuracy and consistency of SoH predictions when compared to unidirectional models.

Xianzhe Zhu, Pu Liu, Wence Ding et al.

The successful synthesis of few-layer CrI3 has opened new avenues for research in two-dimensional magnetic materials. Owing to its simple crystal structure and excellent physical properties, layered CrI3 has been extensively studied in magneto-optical effects, excitons, tunneling transport, and novel memory devices. However, the most current theoretical studies rely heavily on the first-principles calculations, and a general analytical theoretical framework, particularly for electric-field modulation and transport properties, is still lacking. In this work, using a 28-band tight-binding model combined with linear response theory, we systematically investigate the optoelectronic response for monolayer CrI3 and its nanoribbons. The results demonstrate that: (1) a vertical electric field can selectively close the band gap of one spin channel while the other remains insulating, resulting a transition to an half-metallic state; (2) the electric field dynamically shifts the optical transition peaks, providing a theoretical basis for extracting band parameters from experimental photoconductivity spectra; (3) nanoribbons with different edge morphologies exhibit distinct edge-state distributions and electronic properties, indicating that optical transition can be dynamically modualted through edge design. The theoretical model developed in this study, which can describe external electric field effect, offers an efficient and flexible approach for analytically investigating the CrI3 family and related materials. This model overcomes the limitations of first-principles methods and provides a solid foundation for designing spintronic and optoelectronic devices controlled by electric fields and edge effect.

Younghoon Lim, Taehun Kim, Jaesik Eom et al.

Abstract Neuromorphic visual systems mimicking biological retina functionalities are emerging as next‐generation retinomorphic devices for consolidating sensing and memorizing systems. In particular, monolayer MoS2 has been proposed as a promising material for retinomorphic devices due to their unique electrical and optical properties. Despite the advantages of MoS2 material, several limitations, such as PPC (persistent photoconductivity) or additional operating voltage, restrict the optimization of neuromorphic visual systems in MoS2‐based retinomorphic devices. Herein, the two‐terminal retinomorphic devices are reported featuring a tailored gating voltage range near zero and enhanced synaptic plasticity by providing another recombination route to suppress the PPC effect. Furthermore, pattern recognition results confirm that the retinomorphic devices effectively emulate the functions of the retina with a low device‐to‐device variation. This remarkable performance of MoS2‐based retinomorphic devices utilizing a functionalized substrate presents proposes an important pathway toward designing 2D materials‐based synaptic devices.

Yuting Zhao, Tao Jiang, Simone Genovesi et al.

This paper presents a class of novel fabrication-tolerant resonator design for high-capacity chipless RFID tags. The proposed resonator is based on a high-quality-factor grounded dipole with a single etched slot of variable length. By controlling the slot length, the resonant frequency can be adjusted while exhibiting much lower sensitivity to design variables compared to conventional dipole resonators. This makes the design resilient to fabrication tolerances, a critical requirement for mm-wave frequency bands. This feature enables a two-step fabrication process: first, producing high-precision master tags (e.g., via roll-to-roll fabrication), and second, customizing them by etching slots using a flexible method like laser etching. The presence of a ground plane provides isolation from the tagged object, enabling application to diverse materials and geometries. An analytical model is derived to establish the relationship between slot length changes and resonant frequency shifts, enabling efficient design optimization. Sensitivity analysis shows the proposed resonator has a single parameter sensitivity of 0.008 (feasibility), and overall sensitivity of 0.04 (stability) under <inline-formula><tex-math notation="LaTeX">$\pm 50\;\mu\text{m}$</tex-math></inline-formula> fabrication tolerance, over two orders of magnitude and half lower than the sensitivity of 1 for conventional dipoles. The resonator design is validated through simulations and experiments, demonstrating its potential for high-capacity, fabrication-tolerant chipless RFID tags.

Jiayu Pan, Wenbin Zhao, Yukai Zhou et al.

Abstract Conformal electronics integrate mechanically compliant materials with advanced fabrication strategies, enabling devices to mount seamlessly onto non‐planar, dynamic, and even biological surfaces. In these scenarios, such systems deliver enhanced measurement accuracy, improved stability, and greater adaptability and comfort compared to rigid counterparts, thereby redefining the frontiers of wearable technology. In this review, we first focus on strategies and fabrication technologies for achieving conformability, and applications in fields such as healthcare, consumer electronics, and industry. Then we discuss current challenges, such as scalability and durability, while exploring future research directions in material innovation and process optimization. Finally, we provide a comprehensive understanding of conformal flexible thin film devices, charting a path for future advancements.

Jiaju Yang, Lujun Wei, Yanghui Li et al.

The nonlinear Hall effect (NLHE), as an important probe to reveal the symmetry breaking in topological properties of materials, opens up a new dimension for exploring the energy band structure and electron transport mechanism of quantum materials. Current studies mainly focus on the observation of material intrinsic the NLHE or inducing the NLHE response by artificially constructing corrugated/twisted twodimensionalmaterial systems. Notably, the modulation of NLHE signal strength, a core parameter of device performance, has attracted much attention, while theoretical predictions suggest that an applied electric field can achieve the NLHE enhancement through modulation of the Berry curvature dipole (BCD). Here we report effective modulation the magnitude and sign of the NLHE by applying additional constant electric fields of different directions and magnitudes in the semimetal TaIrTe4. The NLHE response strength is enhanced by 168 times compared to the intrinsic one at 4 K when the additional constant electric field of -0.5 kV/cm is applied to the b-axis of TaIrTe4 and the through a.c. current is parallel to the TaIrTe4 a-axis. Scaling law analysis suggests that the enhancement may be the result of the combined effect of the electric field on the intrinsic BCD and disorder scattering effect of TaIrTe4. This work provides a means to study the properties of TaIrTe4, as well as a valuable reference for the study of novel electronic devices.

Jiaju Yang, Lujun Wei, Yanghui Li et al.

The third-order nonlinear Hall effect (NLHE) serves as a sensitive probe of energy band geometric property, providing a new paradigm for revealing the Berry curvature distribution and topological response of quantum materials. In the Weyl semimetal TaIrTe4, we report for the first time that the sign of the third-order NLHE reverses with decreasing temperature. Through scaling law analysis, we think that the third-order NLHE at high (T > 23 K) and low (T < 23 K) temperatures is dominated by Berry-connection polarizability (BCP) and impurity scattering, respectively. The third-order NLHE response strength can be effectively modulated by an additional applied in-plane constant electric field. At the high temperature region, the BCP reduction induced by the electric field leads to a decrease in the third-order NLHE response strength, while at the low temperature region, the electric field cause both BCP and impurity scattering effects to weaken, resulting in a more significant modulation of the third-order NLHE response strength. At 4 K and an electric field strength of 0.3 kV/cm, the modulated relative response strength could reach up to 65.3%. This work provides a new means to explore the third-order NLHE and a valuable reference for the development of novel electronic devices.

Dror Liran, Ronen Rapaport, Kirk Baldwin et al.

The next generation of photonic circuits will require programmable, ultrafast, and energy-efficient components on a scalable platform for quantum and neuromorphic computing. Here, we present ultrafast electrical control of highly nonlinear light-matter hybrid quasi-particles, called waveguide exciton-dipolaritons, with extremely low power consumption. Our device performs as an optical transistor with a GHz-rate electrical modulation at a record-low total energy consumption $\sim$3 fJ/bit and a compact active area of down to 25 $μ$m$^2$. This work establishes waveguide-dipolariton platforms for scalable, electrically reconfigurable, ultra-low power photonic circuits for both classical and quantum computing and communication.

Jaewook Yoo, Hyeun Seung Jo, Seung‐Bae Jeon et al.

Abstract The amorphous In─Ga─Zn─O (a‐IGZO) thin film transistors (TFTs) have attracted attention as a cell transistor for the next generation DRAM architecture because of its low leakage current, high mobility, and the back‐end‐of‐line (BEOL) compatibility that enables monolithic 3D (M3D) integration. IGZO‐based electronic devices used in harsh environments such as radiation exposure can be vulnerable, resulting in functional failure. Here, the behavior of subgap density‐of‐states (DOS) over full subgap range according to the impactful gamma‐ray irradiation in a‐IGZO TFTs is investigated by employing DC current–voltage (I−V) data with multiple‐wavelength light sources. To understand the origins of the radiation effect, IGZO films have been also analyzed by x‐ray photoelectron spectroscopy (XPS). Considering in‐depth electrical and chemical analysis, the unexpected increase of subthreshold leakage current caused by total ionizing dose (TID) is strongly correlated with newly discovered deep‐donor states (gDDγ(E)) at the specific energy level. In particular, oxygen vacancies caused by the gamma‐ray irradiation give rise to undesirable electrical characteristics such as hysteresis effect and negative shift of threshold voltage (VT). Furthermore, the TCAD simulation results based on DOS model parameters are found to exhibit good agreement with experimental data and plausible explanation including (gDDγ(E)).

Abhijeet Prasad, Jay Min Lim, Ravi F Saraf

Abstract Large, open‐gate transistors made from metal nanoparticle arrays offer possibilities to build new electronic devices, such as sensors. A nanoparticle necklace network (N3) of Au particles from 300 K to cryogenic temperatures exhibit a nonohmic I–Vd behavior, I ≈ (Vd–VT)ζ, where VT is a conduction gap and ζ is a constant critical exponent. The conduction gap in N3, made from disordered networks of 1D chains of 10 nm diameter Au particles exhibits room temperature (RT) gating. Although the I–Vd behavior at RT is identical to Coulomb blockade, the conduction is modulated by field‐assisted tunneling exhibiting classical critical behavior. In this study, based on three results, invariance of VT on gating, invariance of VT on temperature, and zero–bias conductance, a sharp transition temperature at ≈140 K is discovered where the conduction mechanism switches from Coulomb blockade to classical critical percolation behavior. The N3 architecture allows the reconciliation of the Coulomb blockade versus activation process as a sharp thermal transition to serve as a model system to study the exotic behavior in nanogranular‐metallic materials. The novel global critical behavior to local Coulomb blockade governed transition in these N3 architectures may potentially lead to novel sensors and biosensors.

Aishik Panja, Yupeng Wang, Xinghan Wang et al.

Atoms excited to Rydberg states have recently emerged as a valuable resource in neutral atom platforms for quantum computation, quantum simulation, and quantum information processing. Atoms in Rydberg states have large polarizabilities, making them highly sensitive to electric fields. Therefore, stray electric fields can decohere these atoms, in addition to compromising the fidelity of engineered interactions between them. It is therefore essential to cancel these stray electric fields. Here we present a novel, simple, and highly-compact electrode assembly, implemented in a glass cell-based vacuum chamber design, for stray electric field cancellation. The electrode assembly allows for full 3D control of the electric field in the vicinity of the atoms while blocking almost no optical access. We experimentally demonstrate the cancellation of stray electric fields to better than 10 mV/cm using this electrode assembly.

Benjamin Afotey, Godson Teddyson Sarpong

This paper presents estimation of Biogas Production Potential and Greenhouse Gas Emissions Reduction for sustainable energy management using intelligent computing technique. Slaughterhouse wastes present a promising opportunity to partially reduce reliance on fossil-based energy. Biogas technology is regarded as one of the methods used in Ghana and can be used to combat climate change, while meeting demand for energy in the country. The objective of the research seeks to theoretically estimate biogas production potential from livestock and slaughterhouse wastes in Ghana, in order for policymakers to consider biogas technology as a potential source of renewable energy to meet the country's energy demand, while contributing to the SDG goals. This study obtained livestock population data from the Ministry of Food &amp; Agriculture and the Ministry of Fisheries &amp; Livestock from 2010 to 2020, and estimated the livestock waste production from slaughterhouses, biogas generation capacity, electricity production potential, greenhouse gas (GHG) reduction potential and biofertilizer generation capacity of Ghana in the fiscal year 2020. The findings indicated that, in the year 2020, slaughterhouses in Ghana generated 4.205 × 1010 kg of waste which can be used to produce 6.792 × 109 m3 of biogas, electricity generation rate of 7.110 × 109 kwh/year which represents about 43.01% of the total electricity consumed in the country that year. Also, the amount of GHG (CO2) emissions by using methane from the AD is 3.631 × 109 kgCO2. The avoided GHG emissions estimated is 1.075 × 1010 kg and biofertilizer of 4.514 × 108 kg can be produced.

Anna Saro Vijendran, Kalaivani Ramasamy

In the last several years, the world of medical technology has seen a boom in multimodal picture fusion. Information is constrained since a single medical instrument can only acquire single modal pictures. Doctors often need a large number of multimodal pictures to get the complete information necessary for disease diagnosis. The burden associated with illness diagnosis will significantly rise when multimodal pictures are employed directly, and errors and interference are likely to occur. Fusion algorithms, which have been extensively employed in the medical industry, may very effectively combine a lot of information in multimodal pictures. However, the existing method has an issue with the earlier stages of brain tumor prediction in white images and inaccuracy image results. To overcome the above-mentioned problems, in this work, Adaptive Firefly Optimization based Convolutional Neural Network (AFFOCNN) and Modified Fully Connected Layer (MFCL) scheme is proposed. This work contains main steps such as noise removal, segmentation, feature extraction, image fusion, and image classification process. Initially, noise removal is done for improving the image quality by removing the noise. Then the modality MRI images are segmented and it is used for subdividing an image into its constituent regions or object. It segments the image into black and white images. After that, feature extraction is applied through the AFFOCNN algorithm which extracts the more informative image features. Image fusion of multi-modal images derived the lower-level, middle-level, and higher-level image contents. It can be viewed in multiple directions and fused in all directions. Finally, image classification is performed by using a Modified Fully Connected Layer (MFCL) which improves the training and testing features efficiently. It was determined from the results that the suggested combination of AFFOCN and MFCL algorithm performs improved than the current algorithms with the increased accuracy, precision, recall, and mean square error (MSE), as well as execution time with the values of 99.00%, 98.00%, 96.00%, 12.00% and 2.40 seconds respectively.

Filippo Giubileo, Daniele Capista, Enver Faella et al.

Abstract An experimental study about field emission properties of commercially available graphene flowers cloth is reported. Material characterization by means of X‐ray diffraction, Raman spectroscopy, and X‐ray photoemission spectroscopy confirms the formation of high quality vertical few‐layers graphene nanosheets. A tip‐anode setup is exploited in which nanomanipulated tungsten tip is used as the anode at controlled distance from the emitter in order to reduce the effective emitting area below 1 µm2, giving access to local characterization. A turn‐on field as low as 0.07 V nm−1 and field enhancement factor up to 32 for very small cathode–anode separation distances is demonstrated, in the range 400–700 nm. It is also shown that the turn‐on field increases for increasing distances, while the field enhancement factor decreases. Finally, time stability of the field emission current is reported, evidencing a reduction of the fluctuations for lower current levels.

Churna Bhandari, S Satpathy

Control of magnetism by an applied electric field is a desirable technique for the functionalization of magnetic materials. Motivated by recent experiments, we study the electric field control of the interfacial magnetism of CaRuO$_3$/CaMnO$_3$ (CRO/CMO) (001), a prototype interface between a non-magnetic metal and an antiferromagnetic insulator. Even without the electric field, the interfacial CMO layer acquires a ferromagnetic moment due to a spin-canted state, caused by the Anderson-Hasegawa double exchange (DEX) between the Mn moments and the leaked electrons from the CRO side. An electric field would alter the carrier density at the interface, leading to the possibility of controlling the magnetism, since DEX is sensitive to the carrier density. We study this effect quantitatively usingdensity-functional calculations in the slab geometry. We find a text-book like dielectric screening of the electric field, which introduces polarization charges at the interfaces and the surfaces. The extra charge at the interface enhances the ferromagnetism via the DEX interaction, while away from the interface the original AFM state of the Mn layers remains unchanged. The effect could have potential application in spintronics devices.

Leila Shahkarami, Farid Charmchi

We thoroughly analyze the response of the zero-temperature N=2 super Yang-Mills theory to time-dependent electric field quenches via holography. We specially focus on transient pulse-like configurations for the electric field, characterized by some model parameters, such as the maximum value of the electric field $E_0$ and the ramping time $δ_t$ which determines the time interval for switching the electric field on and off. We also compare some of the results with those of tanh-like quenches. The term tanh-like quench is used for a quench that rises from zero to a final finite value during a finite amount of time. Our numerical solutions demonstrate that when the system is subjected to pulse-like electric field quenches, the emerged electric current as a response goes through three stages as time passes. After excitation and rapidly-damping oscillatory stages, it experiences a long-lasting periodic oscillatory region. In fact the effect of the electric pulse remains in the system much longer than the duration of the presence of the electric field itself. It is extremely interesting that, as confirmed by power spectrum diagrams, these oscillations have a unique obvious frequency which is independent of the details of the electric pulse function and its parameters. Moreover, we observe a universal behavior in the adiabatic limit, when the ramping time tends to infinity. In this limit, the early and late time dynamics of the response electric current does not depend on the time dependence of the electric field. In particular, we see that for both pulse-like and tanh-like quenches, the maximum value at the first peak of the oscillations approaches the static value of the current induced by the presence of a static electric field $E_0$. However, the fast quench behavior differs extremely for different kinds of quench functions.

A.S. Khwaja, A. Anpalagan, B. Venkatesh

Juan José Gómez Acosta, Maurício N. Frota, Carlos R. Hall Barbosa et al.

This work describes the results of sound pressure measurements carried out in the vicinity of ten high voltage electrical substations operating in areas of considerable urban density in the State of Rio de Janeiro. The work was motivated as a strategy to guide the proposition of an acoustic attenuation solution to meet the imposition of the Public Prosecutor's office, which interposed a civil action in the name of dissatisfied residents of the neighbourhood of one of the substations studied. Based on the acoustic limits imposed by the applicable environmental legislation, the study evaluated the acoustic noise level at different points in the neighbourhood of ten urban substations in the city of Rio de Janeiro, studying in depth the acoustic noise in the internal and external environments of the substation subject to the civil action brought. Although it is not possible to eliminate the acoustic noise generated by high voltage transformers since it results from the natural phenomenon of magnetostriction, which is intrinsic to the operation of any high-power electrical transformer, there are alternatives to mitigate the sound pressure level. As part of the strategy, the work recommends, as a first action, eliminating any tonal component associated with the acoustic noise, as its presence in the frequency spectrum causes discomfort to the human ear and penalizes measured levels by +5 dB. The work also shows that it is not trivial to discuss the impact of acoustic noise generated by substations installed in urban communities, whose acoustic noise commonly exceeds regulated limits. In conclusion, the work confirms that most electrical substations operate on the boundary line of the permissible noise limits.