Electrical Carrier Research Articles

Multidimensional Integrated Architectonics for Hierarchical Hydrogels with Enhanced Thermal Conductivity for Effective Burn Healing.

To be the wound dressings that alleviate progressive thermal injury, hydrogels require to have high thermal conductivity, excellent mechanical properties, and outstanding biocompatibility, which are hard to achieve simultaneously. Inspired by the multiscale structure of spider silk, we developed a hierarchical hydrogel architecture. This architecture includes molecular-scale hydrogen bonds between oxygen plasma-treated graphene fibers (OPGFs) and poly(vinyl alcohol) (PVA), as well as within PVA molecular chains. It also features nanometer-scale ordered crystalline domains in the PVA matrix and micrometer-scale highly oriented OPGFs. The hydrogel was prepared using OPGFs assisted by a magnetic field, directional freezing, and salting-out treatment. This hierarchical structure reduces the interfacial thermal resistance between OPGFs and PVA, as proven by molecular dynamics. Finite element simulations show that the improvement in the hydrogel's thermal conductivity during the salting-out process is primarily due to the increase in PVA's intrinsic thermal conductivity. Additionally, the oriented OPGFs create directional thermal pathways. PVA/OPGFs hydrogels have a thermal conductivity of 1.71 W/(m·K), 322% higher than that of pristine PVA hydrogel. PVA/OPGFs hydrogels exhibit robust mechanical properties and good biocompatibility, indicating their vast potential as burn wound dressings. In vivo tests show that PVA/OPGFs hydrogels quickly reduce thermal damage in burn wounds and accelerate healing. Furthermore, the PVA/OPGFs hydrogels demonstrated good electrical conductivity and outstanding sensing capabilities, indicating that they can monitor motion under stress and serve as electrical stimulation carriers, showing great potential for integrated therapeutic monitoring in intelligent wound dressings. The strategy of constructing multiscale structures expands the potential applicability of hydrogels in biothermal management.

The effect of cobalt doping on the structure and properties of copper oxide thin films: Evolution in surface morphology, p- to n-type carrier transition and enhancement optoelectronic behavior

This paper reports the preparation of CuO and cobalt (Co)-doped CuO (Co:CuO) thin films (TFs) by a convenient spray pyrolysis reactor. Co concentration (conc.) was varied in CuO TFs from 2 to 8[Formula: see text]at.% at the step of 2[Formula: see text]at.%. In the FESEM images of undoped films, aggregations of nanoparticles were found. The surface morphology of CuO turned into porous and spongy nanostructures for 6[Formula: see text]at.% Co-doping. In XRD analysis, CuO film showed a monoclinic crystal structure with ([Formula: see text]11) peak occurrence. The crystallite size of the films was found to be between 5[Formula: see text]nm and 12[Formula: see text]nm. In UV–vis spectroscopy, the optical transmittance of Co:CuO films increased in the visible region and then saturated in the NIR light region. The highest transmittance of about 96% was found for the 6 at.% Co:CuO film. The band gap of Co:CuO increased with Co doping. Urbach energy, refractive index, dielectric constants and dispersion energy parameters were estimated. Electrical resistivity and carrier concentration were found in the order of [Formula: see text]-cm and [Formula: see text] [Formula: see text]cm[Formula: see text], respectively. CuO films showed n-type conductivity for 4, 6 and 8[Formula: see text]at.% Co-doping. The figure of merit increased significantly with Co-doping up to 6[Formula: see text]at.%, indicating the enhancement in optoelectronic behavior.

Effect of Electrical Heat Carrier Temperature on Bacterial Leakage of Endodontically Treated Teeth Using a Bioceramic Sealer.

The aim of this study is to investigate the effect of electrical heat carrier temperature on bacterial leakage of root canals obturated with the continuous wave of condensation (CWC) technique and a bioceramic sealer. This ex vivo experimental study was conducted on 92 extracted single-rooted teeth. The teeth were subjected to endodontic treatment and obturated with the Endoseal MTA bioceramic sealer by the CWC technique using two different temperature settings of the electrical heat carrier: 120°C (group G120, n = 41) and 200°C (group G200, n = 41). A positive and a negative control group were also considered (n = 5 each). Bacterial leakage was assessed over a 40-day period using a bacterial leakage model. The incidence of bacterial leakage was compared between the experimental groups using the log-rank test. The significance level was set at 0.05. The median survival rate was 39.0 (25.0) days in the G120 group and 34.0 (25.0) days in the G200 group. Despite a slightly higher survival rate in the G120 group, the difference between the two experimental groups was not statistically significant (p = 0.612). The tested temperatures of the electrical heat carrier (120°C and 200°C) did not have a significant effect on bacterial leakage of root canals obturated by the CWC technique and the Endoseal MTA bioceramic sealer.

Surface passivation strategies for CsPbBr3 quantum dots aiming at nonradiative suppression and enhancement of electroluminescent light-emitting diodes.

With many fascinating characteristics, such as color-tunability, narrow-band emission, and low-cost solution processability, all-inorganic lead halide perovskite quantum dots (QDs) have attracted keen attention for electroluminescent light-emitting diodes (QLEDs) and display applications. However, the performance of perovskite QLED devices is intrinsically limited by the inefficient electrical carrier transport capacity. Herein, one facile but effective method is proposed to enhance the perovskite QLED performance by incorporating a short carbon chain ligand of 2-phenethylammonium bromide (PEABr) to passivate the CsPbBr3 QD surface. With the PEABr ligand, the Br- vacancies are passivated, which could eliminate nonradiative recombination of perovskite QDs; thus their optical properties are enhanced. Meanwhile, PEABr can interact with perovskite QDs to adjust the perovskite film morphology, resulting in low current leakage and efficient electron injection. After the PEABr treatment, the CsPbBr3 QD film exhibits strong green emission located at 516 nm, with an average photoluminescence lifetime of 45.71 ns and a photoluminescence quantum yield of up to 78.64%. In addition, the surface roughness of the CsPbBr3 QD film is reduced from 3.61 nm to 1.38 nm, which is essential to prepare a QD film with high surface coverage. As a result, the QLED device with PEABr treated CsPbBr3 QDs exhibits a maximum current efficiency of 32.69 cd A-1 corresponding to an external quantum efficiency of 9.67%, 3.88-fold higher than that of the control device (pure QDs as an emission layer). This research provides an effective strategy for the improvement of the perovskite QLED performance and may be helpful for extending their actual applications.

Investigation of the electrical performance and carrier transport mechanism for heterostructured bilayer In2O3/InGaSnO thin-film transistors

In this study, InGaSnO (IGTO)-based bilayer In2O3/IGTO and IGTO/In2O3 thin-film transistors (TFTs) were designed, and their carrier transport mechanisms and electrical performances were investigated. Herein, the ultrathin In2O3 layer provided a higher carrier concentration (Ne), thus accumulating free carriers and enhancing the carrier mobility. The thick amorphous IGTO layer controlled the device and carrier conductance, yielding a reasonable threshold voltage (Vth). Consequently, the optimized bilayer In2O3/IGTO TFTs exhibited high field-effect mobility (μFE) of 43.6 cm2 V−1s−1 and good control with Vth of 1.2 V compared to the single layer In2O3 and IGTO TFTs. Experimental analysis indicated a decrease in the oxygen vacancy (VO) formation energy owing to the interaction between interstitial Ini and Sn. Consequently, numerous unpaired electrons were generated from VO at the hetero-interfaces. In addition, an analysis of the energy band shift indicated that the heterojunction generated parasitic channels to control the Ne, and the In2O3/IGTO TFT exhibited a smaller Rc (0.34 KΩ μm), which enhanced the μFE of TFTs. Overall, the high-performance bilayer In2O3/IGTO TFTs fabricated herein have significant potential for applications in thin-film electronics.

Highly crystalline persistent luminescent glass-ceramic for optical anti-counterfeiting

Highly crystalline persistent luminescent glass-ceramic for optical anti-counterfeiting

Optimization of Metal Capping Layer Design for Enhanced Mobility in Indium Gallium Zinc Oxide (IGZO) Thin Film Transistors

Given the increasing demand for high frame rates and fast response times in high-end displays, various strategies have been explored to enhance the mobility of IGZO TFTs. In general, plasma treatment and elemental doping are widely utilized methods for this purpose [1], [2]. However, these approaches often encounter a trade-off between electrical properties and reliability, prompting ongoing research to overcome such challenges. Another approach to improve mobility involves increasing the electron concentration of the back channel by incorporating a metal capping layer (MCL) between the source and drain [3]. However, excessive electron concentration in the back channel can induce increased off-current and hump phenomenon, resulting in degraded electrical properties [4]. Most research on MLC has primarily focused on improving mobility by using different metals, while there has been little research on the trade-off between electrical properties and carrier concentration based on MCL design [5]. In this paper, we investigated the influence of MCL design on electrical properties and present the optimized metal capping layer design which does not degrade electrical properties. Experiment A heavily doped P++ silicon with thermally oxidized SiO2 (200 nm) was used as a substrate, onto which a 20 nm thick IGZO was deposited by RF sputtering. Subsequently, the IGZO channel was patterned using a standard photolithography process, and a Ti/Al/Ti layer was deposited via e-gun evaporation to form the source and drain (S/D) electrodes. Finally, an Al-metal capping layer was deposited in the middle of the back channel between the source and drain to form the MCL, which covers a range of 6.6% to 70.8% of the IGZO back channel. Result and Discussion Based on experimental results, IGZO TFTs with an MCL coverage of 70.8% exhibited a more than twofold increase in mobility compared to pristine samples. This enhancement is attributed to the increased electron concentration that results from the redox reaction between the MCL and IGZO. However, a specific threshold of MCL coverage can trigger the hump phenomenon. In addition, this threshold varied depending on the MCL design. This suggests that the formation of additional sub-channels and electron distributions contributing to the hump phenomenon differs with each design. Therefore, we explored various MCL designs to identify the optimal structure that enhances mobility without compromising electrical properties. These findings suggest a design strategy for high-mobility devices in high-end displays, potentially applicable to backplane technology. Reference [1] Zan, H. W., Tsai, W. W., Chen, C. H., & Tsai, C. C, Advanced Materials, 23(37), 4237-4242, 2011.[2] Kawai, H., Kataoka, J., Saito, N., Ueda, T., Ishihara, T., & Ikeda, K, MRS Bulletin, 46(11), 1044-1052, 2021.[3] Yoon, C. S., Kim, H. T., Kim, M. S., Yoo, H., Park, J. W., Choi, D. H., ... & Kim, H. J, ACS Applied Materials & Interfaces, 13(3), 4110-4116, 2021.[4] Lee, B. H., Sohn, A., Kim, S., & Lee, S. Y, Scientific reports, 9(1), 886, 2019.[5] Kim, J., Park, J. B., Zheng, D., Kim, J. S., Cheng, Y., Park, S. K., ... & Facchetti, A, Advanced Materials, 34(45), 2205871, 2022.Fig.1 The transfer characteristics of IGZO TFTs with various MCL coverage, indicating two MCL types: (a) increasing MCL width with fixed length and (b) increasing MCL length with fixed width. Figure 1

Device physics of perovskite light-emitting diodes

Perovskite light-emitting diodes (LEDs) have emerged as a potential solution-processible technology that can offer efficient light emission with high color purity. Here, we explore the device physics of perovskite LEDs using simple analytical and drift-diffusion modeling, aiming to understand how the distribution of electric field, carrier densities, and recombination in these devices differs from those assumed in other technologies such as organic LEDs. High barriers to electron and hole extraction are responsible for the efficient recombination and lead to sharp build-up of electrons and holes close to the electron- and hole-blocking barriers, respectively. Despite the strongly varying carrier distributions, bimolecular recombination is surprisingly uniform throughout the device thickness, consistent with the assumption typically made in optical models. The current density is largely determined by injection from the metal electrodes, with a balance of electron and hole injection maintained by redistribution of electric field within the device by build-up of space charge.

First-principle’s calculations to investigate structural, electronic, mechanical, optical, and thermoelectric properties of halide double perovskites K2InScX6 (X = Cl, Br, and I) for thermoelectric and optoelectronic applications

First-principle’s calculations to investigate structural, electronic, mechanical, optical, and thermoelectric properties of halide double perovskites K2InScX6 (X = Cl, Br, and I) for thermoelectric and optoelectronic applications

Drain self-blocking ambipolar transistors for complementary circuit applications

The development of complementary metal-oxide-semiconductor field-effect transistor (CMOSFET) based on two-dimensional (2D) materials offers an important opportunity to reduce static power and increase the integration density of integrated circuits. One promising approach to realize these CMOSFETs is to employ ambipolar 2D materials as channel materials with designed device structure to control the carrier transport properties for CMOSFET characteristics. However, these devices always suffer from complex multi-gate electrode structure, and hence face challenges in complicated inter-connection design and excessive voltage source requirement for circuit implementation. Here, we develop a three-terminal CMOSFET using ambipolar 2D material based on the drain electric field-induced carrier injection self-blocking mechanism. The designed drain electrode can effectively suppress carrier injection from the drain to the channel material, while the gate voltage can only regulate carrier injection in the source region. As a result, we can configure the device as either N-field-effect transistors (FET) or P-FET with a high current on/off ratio of over 105 by adjusting the three voltages (gate, source, and drain). Furthermore, we utilize these devices to demonstrate multifunctional wave modulator, low-static-power logic inverter (<5 pW), and combinational logic computing in the form of a compact complementary circuit. Our work would explore an efficient approach for implementing complementary circuits using 2D materials.

Fair Energy Trading in Blockchain-Inspired Smart Grid: Technological Barriers and Future Trends in the Age of Electric Vehicles

The global electricity demand from electric vehicles (EVs) increased by 3631% over the last decade, from 2600 gigawatt hours (GWh) in 2013 to 97,000 GWh in 2023. The global electricity demand from EVs will rise to 710,000 GWh by 2030. These EVs will depend on smart grids (SGs) for their charging requirements. Like EVs, SGs are a booming market. In 2021, SG technologies were valued at USD 43.1 billion and are projected to reach USD 103.4 billion by 2026. As EVs become more prevalent, they introduce additional complexity to the SG landscape, with EVs not only consuming energy, but also potentially supplying it back to the grid through vehicle-to-grid (V2G) technologies. The entry of numerous independent sellers and buyers, including EV owners, into the market will lead to intense competition, resulting in rapid fluctuations in electricity prices and constant energy transactions to maximize profit for both buyers and sellers. Blockchain technology will play a crucial role in securing data publishing and transactions in this evolving scenario, ensuring transparent and efficient interactions between EVs and the grid. This survey paper explores key research challenges from an engineering design perspective of SG operation, such as the potential for voltage instability due to the integration of numerous EVs and distributed microgrids with fluctuating generation capacities and load demands. This paper also delves into the need for a synergistic balance to optimize the energy supply and demand equation. Additionally, it discusses policies and incentives that may be enforced by national electricity carriers to maintain grid reliability and manage the influx of EVs. Furthermore, this paper addresses emerging issues of SG technology providing primary charging infrastructure for EVs, such as incentivizing green energy, the technical difficulties in integrating diverse hetero-microgrids based on HVAC and HVDC technologies, challenges related to the speed of energy transaction processing during fluctuating prices, and vulnerabilities concerning cyber-attacks on blockchain-based SG architectures. Finally, future trends are discussed, including the impact of increased EV penetration on SGs, advancements in V2G technologies, load-shaping techniques, dynamic pricing mechanisms, and AI-based stability enhancement measures in the context of widespread SG adoption.

Research on AUV Multi-Node Networking Communication Based on Underwater Electric Field CSMA/CA Channel.

To address the issues of high attenuation, weak reception signal, and channel blockage in the current electric field communication of underwater robots, research on autonomous underwater vehicle (AUV) multi-node networking communication based on underwater electric field Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) channel was conducted. This article, first through simulation, finds that the Optimized Link State Routing (OLSR) protocol has a smaller routing packet delay time and higher reliability compared to the Ad Hoc On-Demand Distance Vector (AODV) protocol on underwater electric field CSMA/CA channels. Then, a 2FSK underwater electric field communication system was established, and dynamic communication experiments were carried out between two AUV nodes. The experimental results showed that within a range of 0 to 3.5 m, this system can achieve underwater dynamic electric field communication with a bit error rate of 0 to 0.628%. Finally, to avoid channel blockage during underwater AUV multi-node communication, this article proposes a dynamic backoff method for AUV multi-node communication based on CSMA/CA. This system can achieve dynamic multi-node communication of underwater electric fields with an error rate ranging from 0 to 0.96%. The research results have engineering application prospects for underwater cluster operations.

Electronic Barriers Behavioral Analysis of a Schottky Diode Structure Featuring Two-Dimensional MoS2

This research presents a comprehensive study of a Schottky diode fabricated using a gold wafer and a bilayer molybdenum disulfide (MoS2) film. Through detailed simulations, we investigated the electric field distribution, potential profile, carrier concentration, and current–voltage characteristics of the device. Our findings confirm the successful formation of a Schottky barrier at the Au/MoS2 interface, characterized by a distinct nonlinear I–V relationship. Comparative analysis revealed that the Au/MoS2 diode significantly outperforms a traditional W/Si structure in terms of rectification performance. The Au/MoS2 diode exhibited a current density of 1.84 × 10−9 A/cm2, substantially lower than the 3.62 × 10−5 A/cm2 in the W/Si diode. Furthermore, the simulated I–V curves of the Au/MoS2 diode closely resembled the ideal diode curve, with a Pearson correlation coefficient of approximately 0.9991, indicating an ideality factor near 1. A key factor contributing to the superior rectification performance of the Au/MoS2 diode is its higher Schottky barrier height of 0.9 eV compared to the 0.67 eV of W/Si. This increased barrier height is evident in the band diagram analysis, which further elucidates the underlying physics of Schottky barrier formation in the Au/MoS2 junction. This research provides insights into the electronic properties of Schottky contacts based on two-dimensional MoS2, particularly the relationship between electronic barriers, system dimensions, and current flow. The demonstration of high-ideality-factor Au/MoS2 diodes contributes to the design and optimization of future electronic and optoelectronic devices based on 2D materials. These findings have implications for advancements in semiconductor technology, potentially enabling the development of smaller, more efficient, and flexible devices.

Enhanced Schottky barrier engineering in silver-doped TiO2/p-Si heterojunctions: Insights into electrical behavior and charge carrier dynamics

Enhanced Schottky barrier engineering in silver-doped TiO2/p-Si heterojunctions: Insights into electrical behavior and charge carrier dynamics

Design and Development of Electrical Multi-tool Carrier and its Compatible Equipment for Protected Cultivation

Design and Development of Electrical Multi-tool Carrier and its Compatible Equipment for Protected Cultivation

Electrical Study of Changes in Impedance and Internal Parameters of Nano Structures of Molybdenum Disulfide Semiconductor Type (MoS2-2H/3R) with Changes in Temperature

MoS2 nanostructures were prepared using the hydrothermal method by reacting ammonium heptamolybdate tetrahydrate ((NH4)6Mo7O244H2O) with citric acid monohydrate (C6H8O7H2O) in distilled water with the presence of sodium sulfide (Na2S), we have found from the Arenos diagram that the value of the activation energy of (MoS2 -2H/3R) is low and equal to Ea= 0.0505 (e.V). From the atomic force microscope (AFM) images, we found that the size of the surface aggregates of the sample (table - MoS2-2H/3R) ranges between (100-150) n m. From studying the changes in the impedance with different temperatures (T = 15, 30, and 60), we found that impedance is inversely proportional to both the applied frequency and the temperature, and at the frequencies the response corresponding to the temperature reaches a value of (Z = 20 K.Ω, T = 15°C). ) and at temperature (Z = 8.02 K.Ω, T = 30 °C), and at (Z = 17.1 K.Ω, T = 60 °C), It has been shown that the number of electric charge carriers (Nd) increases with increasing temperature. On the contrary, we found a decrease in the number of electronic traps (Ns) and a decrease in the relaxation time τP with increasing temperature.

Impedance Spectroscopy Study of Charge Transfer in the Bulk and Across the Interface in Networked SnO2/Ga2O3 Core–Shell Nanobelts in Ambient Air

Metal oxide core–shell fibrous nanostructures are promising gas-sensitive materials for the detection of a wide variety of both reducing and oxidizing gases. In these structures, two dissimilar materials with different work functions are brought into contact to form a coaxial heterojunction. The influence of the shell material on the transportation of the electric charge carriers along these structures is still not very well understood. This is due to homo-, hetero- and metal/semiconductor junctions, which make it difficult to investigate the electric charge transfer using direct current methods. However, in order to improve the gas-sensing properties of these complex structures, it is necessary to first establish a good understanding of the electric charge transfer in ambient air. In this article, we present an impedance spectroscopy study of networked SnO2/Ga2O3 core–shell nanobelts in ambient air. Tin dioxide nanobelts were grown directly on interdigitated gold electrodes, using the thermal sublimation method, via the vapor–liquid–solid (VLS) mechanism. Two forms of a gallium oxide shell of varying thickness were prepared via halide vapor-phase epitaxy (HVPE), and the impedance spectra were measured at 189–768 °C. The bulk resistance of the core–shell nanobelts was found to be reduced due to the formation of an electron accumulation layer in the SnO2 core. At temperatures above 530 °C, the thermal reduction of SnO2 and the associated decrease in its work function caused electrons to flow from the accumulation layer into the Ga2O3 shell, which resulted in an increase in bulk resistance. The junction resistance of said core–shell nanostructures was comparable to that of SnO2 nanobelts, as both structures are likely connected through existing SnO2/SnO2 homojunctions comprising thin amorphous layers.

Analysis of carrier dynamics and thermal effect of the GaAs photoconductive semiconductor switch in lock-on mode

Abstract The lock-on effect of the gallium arsenide photoconductive semiconductor switch (GaAs PCSS) at repetition rate aggravates the current crowding and electric field distortion, which significantly increases the risk of switch damage or even failure. Therefore, it is of great significance to investigate the carrier transport and the heat generation mechanism for improving the performance and longevity of GaAs PCSS in lock-on mode. The internal physical process of an opposed-electrode GaAs PCSS at low optical energy and strong electric field is analysed and discussed by experiment and simulation. A device-circuit hybrid simulation is employed to investigate the transient electric field, carrier concentration, and lattice temperature distribution within the GaAs PCSS in lock-on mode. The device temperature exhibits a positive correlation with the applied bias electric field, resulting in a peak temperature of 1037.25 K at an electric field of 38 kV/cm. The temperature distribution within the GaAs PCSS indicates a greater possibility for thermal breakdown and damage near the electrodes.

The Role of Doping in Modifying Semiconductor Properties

Doping is a fundamental process employed to modify the intrinsic properties of semiconductor materials, making them adaptable for a diverse array of technological applications. By introducing specific impurities into the semiconductor crystal lattice, parameters such as electrical conductivity, bandgap energy, and carrier concentration can be precisely engineered. This paper investigates the effects of various doping methods and elements on semiconductor performance, with a particular focus on their influence in devices like transistors, diodes, and solar cells. The analysis emphasizes how doping alters the optical and electrical properties of semiconductor materials, thereby enhancing their functionality in optoelectronic and advanced electronic applications. Through this study, the critical role of doping in driving the progress of semiconductor technology is underscored, highlighting its importance for the future advancement of electronic devices.

C-SPPO: A deep reinforcement learning framework for large-scale dynamic logistics UAV routing problem

C-SPPO: A deep reinforcement learning framework for large-scale dynamic logistics UAV routing problem