Resistance Research Articles

Characterizing anomalous peaks in the resistance–temperature profile of Bi2Sr2CaCu2O8+δ flakes featuring surface degeneration

Abstract This study focuses on an observed anomalous resistance peak in the temperature-dependent resistance (RT) curves of Bi2Sr2CaCu2O8+δ (BSCCO), attributed to surface degradation and pronounced electrical resistance anisotropy. Employing a standard four-point probe technique on the ab-plane, this research circumvents conventional c-axis testing limitations, enhancing the understanding of BSCCO’s electrical behavior by avoiding contact resistance and etching issues. A comprehensive three-dimensional model, developed using the finite element method, captures the strong resistive anisotropy and correlates the depth of surface degradation with the anomalous resistance peaks, explaining this phenomenon from a quantitative perspective, providing a more specific reference for future analysis of relevant signals. The fabrication process involved pre-patterning and mechanical exfoliation techniques to minimize atmospheric exposure and ensure device integrity. Despite these efforts, surface degradation impacting the superconductivity of surface layers was inevitable. The study’s experimental results, complemented by numerical modeling, reveal the intricate relationship between surface layer thickness and the anomalous resistance peak, providing an approach to gauge the extent of degradation in BSCCO devices. Moreover, it underscores the potential necessity of employing some critical techniques to avoid degradation, such as low-temperature exfoliation in other literatures where degradation signal is notably absent from RT curves. This work advances the understanding of BSCCO’s electrical properties and highlights the critical need for precise fabrication and environmental controls in developing high-temperature superconducting technologies.

Post‐Mortem Analysis of Building‐Integrated Flexible Thin Film Modules

ABSTRACTFlexible, lightweight thin film (TF) photovoltaic (PV) modules offer a unique opportunity for integration into non‐planar surfaces unable to support heavy weights. While such applications increase the potential for PV in urban areas, the reliability implications are yet to be investigated. Here, prototypes of corrugated rooftiles with integrated Cu (In,Ga)Se2 (CIGS) modules were investigated after 3 years of outdoor operation. Their performance before and after the outdoor exposure was compared and defects were localized. An unpackaging method was developed, allowing access to the solar cells for more detailed characterization of present defects without causing additional damage or changes to existing defects. To our knowledge, this was the first time such an unpackaging method was successfully applied to flexible TF PV modules. The relative efficiency loss ranged from 17% to 43%, mostly due to short‐circuit current (ISC) loss and series resistance (RS) increase. The predominant cause of the RS increase was the delamination at the interconnects, ascribed to thermomechanical stresses caused by outdoor temperature fluctuations. The ISC loss was mainly caused by localized delamination of CIGS from the molybdenum (Mo) back‐contact. The occurrence of such delaminated areas pointed to presence of high local stresses during outdoor operation, possibly due to thermal fluctuations, applied deformation and/or mechanical impact. Two other types of delamination defects were found with no observable impact on performance. These results show the necessity for further optimization in the material choice and processing of TF flexible modules, to avoid mechanical stress related failures upon integration into curved surfaces.

Realization of diode structures on paper: An example of papertronics

A possibility of fabricating paper/Ag/CdTe/Au Schottky and paper/Ag/CdTe/CdS/In p-n junction diode structures has been demonstrated here. Ag (∼5 μm), CdTe (∼50 μm), CdS (∼45 μm), Au and In dots (∼5 μm) were deposited on the cellulose using appropriate stainless-steel masks to obtain the requisite diode structures. The band gaps of the CdTe and CdS layers were ∼1.55 eV and ∼1.45 eV, respectively. Current-voltage (I-V) characteristics of the paper/Ag/CdTe/Au Schottky and paper/Ag/CdTe/CdS/In p-n junction diodes were recorded at room temperature. Ideality factor (n), series resistance (RS) and barrier height (φb) of the respective diodes were computed. The barrier height (φb) and ideality factor (n) computed from current-voltage characteristics were found to be 0.74 eV and 1.8, respectively at room temperature. Series resistance and φb computed by using Cheung-Cheung method were ∼177 Ω and ∼0.45 eV, respectively. They are comparable to the resistance derived from a modified Norde method. The fabricated diodes were reproducible and stable for a few months. These diode structures were tested in an open environment at room temperature and showed no noticeable ageing effect.

Understanding the Impact of Contact-Induced Strain on the Electrical Performance of Monolayer WS2 Transistors.

Two-dimensional (2D) electronics require low contact resistance (RC) to approach their fundamental limits. WS2 is a promising 2D semiconductor that is often paired with Ni contacts, but their operation is not well understood considering the nonideal alignment between the Ni work function and the WS2 conduction band. Here, we investigate the effects of contact size on nanoscale monolayer WS2 transistors and uncover that Ni contacts impart stress, which affects the WS2 device performance. The strain applied to the WS2 depends on contact size, where long (1 μm) contacts (RC ≈ 1.7 kΩ·μm) show a 78% reduction in RC compared to shorter (0.1 μm) contacts (RC ≈ 7.8 kΩ·μm). We also find that thermal annealing can relax the WS2 strain in long-contact devices, increasing RC to 8.5 kΩ·μm. These results reveal that thermo-mechanical phenomena can significantly influence 2D semiconductor-metal contacts, presenting opportunities to optimize device performance through nanofabrication and thermal budget.

Facile strategy for uniform gold coating on silver nanowires embedded PDMS for soft electronics

Silver nanowires-embedded polydimethylsiloxane (AgNWs/PDMS) electrodes are promising components for various soft electronics, but face energy mismatch with organic semiconductors. Attempts at galvanic replacement, involving spontaneous gold (Au) formation on the electrodes, often result in non-uniform and particulate Au coatings, compromising device performance and stability. In this study, we introduce a novel approach for achieving a uniform and complete Au coating on AgNWs/PDMS electrodes by adding NaCl to the Au complex solution. This addition slows down the galvanic replacement process and prevents precipitation, enabling a uniform and complete Au coating on the AgNWs surface. Such coating significantly reduces contact resistance (RC), thereby enhancing the electrical characteristics of p-type organic transistors. Furthermore, the development of high-performance, fully soft organic transistors was achieved incorporating an organic semiconductor-elastomer blend. Additionally, reliable, mechanically stable soft glucose sensor was developed, taking advantage of the complete Au coating, which protects against oxidation during the glucose sensing process.

The Effect of Exercise Training on Blood Lipids: A Systematic Review and Meta-analysis.

Dyslipidemia is a primary risk factor for cardiovascular disease (CVD). Exercise training (EXTr) improves some lipid markers but not others; the literature is dated and analyses may be underpowered. To clarify which lipid markers are altered with ExTr and establish if information size had yet reached futility. We conducted a systematic review/meta-analysis, with meta-regression, to establish expected effect size in lipid profile with aerobic (AT), resistance (RT) and combined (CT = AT + RT) ExTr. We conducted trial sequence analysis (TSA) to control for type I and II error and establish if information size had reached futility. We included 148 relevant randomized controlled trials (RCTs) of ExTr, with 227 intervention groups, total 8673 participants; exercise 5273, sedentary control 3400. Total cholesterol (TC) MD - 5.90mg/dL (95% confidence interval (CI) - 8.14, - 3.65), high-density lipoprotein cholesterol (HDL) 2.11 (95% CI 1.43, 2.79), low-density lipoprotein cholesterol (LDL) - 7.22 (95% CI - 9.08, - 5.35), triglycerides - 8.01 (95% CI - 10.45, - 5.58) and very low-density lipoprotein cholesterol (VLDL) - 3.85 (95% CI - 5.49, - 2.22) all showed significant but modest 3.5-11.7%, improvements following ExTr. TSA indicated all analyses exceeded minimum information size to reach futility. CT was optimal for dyslipidemia management. Meta-regression showed every extra weekly aerobic session reduced TC - 7.68mg/dL and for every extra week of training by - 0.5mg/dL. Each minute of session time produced an additional 2.11mg/dL HDL increase. TSA analysis revealed sufficient data exist to confirm ExTr will improve all five lipid outcomes. CT is optimal for lipid management. The modest effect observed may moderate dyslipidemia medication for primary prevention. Prediction intervals suggest TC, HDL, LDL and TGD are only improved in one-quarter of studies.

Achieving beyond 30% efficiency for hole-transport-layer-free CsSnI3 perovskite solar cell: a comprehensive simulation study

In recent years, the growing significance of lead-free CsSnI3 perovskite can be credited to its outstanding optoelectronic properties and environmentally friendly nature. Nevertheless, the photovoltaic potential of CsSnI3 is limited due to challenges in achieving defect-free device structures. The current study thoroughly analyzed the performance of CsSnI3-based perovskite solar cells (PSCs) using the SCAPS-1D software. An in-depth investigation was performed on multiple physical parameters, including the thickness of perovskites layer, acceptor density (NA), operating temperature, defect densities, shunt resistance (RSh) and series resistance (RS). This comprehensive study aimed to identify the optimal device configuration that yields the highest power conversion efficiency (PCE) for the hole-transport-layer (HTL)-free CsSnI3-based PSCs. The obtained results confirmed that it is crucial to decrease the number of defects (Nt) at the perovskites/electron transport layer (ETL) interface to improve the efficiency of CsSnI3-based PSCs. The optimized device demonstrated exceptional performance, achieving an open-circuit voltage (VOC) of 1.12 V, a fill factor (FF) of 85.08%, a short-circuit current density (JSC) of 33.29 mA cm−2 and an efficiency of 31.87%. This high efficiency simulated result provide valuable insights into the design of high-performance CsSnI3-based PSCs, paving the way for potential breakthroughs in cost-effective and eco-friendly solar energy technologies.

Size and temperature effects on optoelectronic properties of Micro-LED arrays for display applications

In recent years, Micro-light-emitting diode (Micro-LED) has attracted much attention in the display field, because it provides the possibility of high pixel density, etc. The implementation of high pixel density is accompanied by the reduction of size, during which the performance degradation caused by sidewall defects gradually increases. At the same time, the increase in power density and difficulty in heat dissipation caused by high pixel density can also lead to poor thermal management, resulting in an increase in junction temperature, thus affecting the display effect. In this paper, we prepared seven different sizes of Micro-LED and studied the influence of size and temperature effects on the optoelectronic properties. Smaller-sized Micro-LED could withstand higher current densities because it was not affected by the current crowding effect. However, it tends to have a larger series resistance (RS) and a lower external quantum efficiency (EQE) due to sidewall defects created during etching. The luminance of the 100 μm and 7 μm Micro-LED was 340000 cd/m2 (at 83 A/cm2) and 32000 cd/m2 (at 773 A/cm2), respectively. The peak EQE of 100 μm Micro-LED was 16.87 %. On this basis, the temperature-dependence of the optoelectronic properties of 10 μm and 50 μm Micro-LED were studied. The larger the size of Micro-LED, the better the operational stability it exhibited. From the room temperature (RT) rose to 100 ℃, the EQE of the 10 μm and 50 μm Micro-LED decreased by 16 % and 13.1 %, respectively. These experimental results provide important data for the design and preparation of Micro-LED of different sizes and for exploring the operational stability at high temperatures.

Effects of aerobic, resistance, and combined exercise training on body fat and glucolipid metabolism in inactive middle-aged adults with overweight or obesity: a randomized trial

MethodTwenty inactive males (BMI 27.67 ± 0.88 kg/m2, age 49.15 ± 2.58 years) participated in an eight-week were randomly assigned to one of three intervention groups (combined (CT), resistance (RT), and aerobic (AT)) exercise modalities to assess within-subject and between group changes in glycolipid profile. Data were analyzed using repeated measures ANCOVA.ResultPre-post mean values of body fat percentage (%BF), area under the curve (AUC), low density lipoprotein (LDL), high density lipoprotein (HDL) and total cholesterol (TC) decreased in all three groups. The main effect of exercise modality on the AUC (F (2, 26) = 10.577, P = 0.001, η2 = 0.569) was significant. Post-hoc analyses revealed that the RT group (-30.653 ± 6.766, p = 0.001) with 11.53% and the CT group (M = -0.896, SE = 3.347, P = 0.015) with 3.79% exhibited significantly greater reductions in AUC compared to the AT group. LDL levels showed significant different between groups (F (2, 26) = 6.33, p = 0.009, η2 = 0.442), specially significantly 3.7% lowered in AT (MD = 4.783, SE = 1.563, P = 0.002) and 3.79% lower in CT (MD = 4.57, SE = 1.284, P = 0.008) groups compared to the RT group. AT significantly reduced TC by 17.716 ± 5.705 mg/dL (p = 0.02) compared to RT, representing a 7.97% decrease.ConclusionExercise type significantly influences lipid profiles and glycemic control. Notably, both aerobic and combined training demonstrated a superior ability to modulate the lipid profile, and resistance training and combined training were more effective in reducing the AUC.Trial registrationMay, 31st 2024. Registration no: PACTR202405463745521 “Retrospectively registered”.

A Randomized Controlled Trial to Determine the Impact of Resistance Training versus Aerobic Training on the Management of FGF-21 and Related Physiological Variables in Obese Men with Type 2 Diabetes Mellitus.

Fibroblast growth factor 21 (FGF-21) has been suggested as a potential therapeutic target for insulin resistance in health-related metabolic disorders such as type 2 diabetes. Despite the metabolic effects of resistance (RT) and aerobic training (AT) on diabetes symptoms, uncertainty exists regarding the superiority of effects manifested through these training approaches on FGF-21 and biochemical and physiological variables associated with metabolic disorders in men diagnosed with type 2 diabetes. This study aimed to investigate the impact of a 12-week RT and AT on FGF-21 levels and symptoms associated with metabolic disorders in male individuals diagnosed with type 2 diabetes. Thirty-six sedentary obese diabetic men (40 to 45 years old) were matched based on the level of FGF-1. They and were randomly divided into two training groups (RT, n = 12 and AT, n = 12) performing three days per week of moderate-intensity RT or AT for 12 weeks and an inactive control group (n = 12). Both training interventions significantly improved FGF-21, glucose metabolism, lipid profile, hormonal changes, strength, and aerobic capacity. Subgroup analysis revealed that RT had greater adaptive responses (p < 0.01) in fasting blood sugar (ES = -0.52), HOMA-IR (ES = -0.87), testosterone (ES = 0.52), cortisol (ES = -0.82), FGF-21 (ES = 0.61), and maximal strength (ES = 1.19) compared to AT. Conversely, AT showed greater changes (p < 0.01) in cholesterol (ES = -0.28), triglyceride (ES = -0.64), HDL (ES = 0.46), LDL (ES = -0.73), and aerobic capacity (ES = 1.18) compared to RT. Overall, both RT and AT interventions yielded significant moderate to large ES in FGF-21 levels and enhanced the management of biochemical variables. RT is an effective method for controlling FGF-21 levels and glucose balance, as well as for inducing hormonal changes. On the other hand, AT is more suitable for improving lipid profiles in overweight men with type 2 diabetes mellitus.

Numerical investigation on non-toxic double perovskites A2(BB′)X6 for all-inorganic efficient photovoltaics

Presently, the Bi-based 3D A2(BB′)X6 double perovskites (DPs) show an excellent photovoltaic (PV) performance with ambient stability compared to Pb-based counterparts. The structural, electronic, and optical properties analyses of A2BiCuX6 (A=Cs, Rb, K, X=I, Br, Cl) DPs are performed by CASTEP software, and the Cs2BiCuI6 is found to be the best suitable absorber among all of them. The density of states calculation reveals that Cu-3d and X-p orbitals are the major contributors to valence band maxima (VBM), whereas Bi-6p orbitals are responsible for the contribution to conduction band minima (CBM). Using SCAPS-1D simulation tool, the impact of variation in thickness, defect density, mobility of charge carriers, series resistance (RS), shunt resistance (RSh), and device temperature on PV performance of the device has been analysed. The optimised all inorganic FTO/WS2/Cs2BiCuI6/MXene/Pt structured device has provided an excellent PV performance i.e., PCE of 31.25 %, FF of 82.71 %, VOC of 1.24 V, and JSC of 30.40 mA/cm2 using 2D structured ETL (WS2) and HTL (MXene). This analysis provides an advanced understanding of cheap, environmentally stable, easily obtainable Bi-Cu based DP counterparts, which can be used in the fabrication of PV cells practically.

Investigation of the Structural, Optical, and Electrical Properties of ZnO/4‐Amino‐2‐Methylquinoline p–n Heterojunction by Spin‐Coating Method

A p–n heterojunction diode is fabricated using a p‐type 4‐amino‐2‐methylquinoline (C10H10N2) on an n‐type ZnO film and its structural, optical, and electrical properties are investigated. First, a ZnO thin film is prepared on an ITO substrate by spin coating. Subsequently, this ZnO film is coated with a C10H10N2 film using the same method. X‐ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–vis spectroscopy, and current–voltage measurements are carried out on the prepared films. According to the XRD result, sharp peaks at 320.081, 340.488, and 360.548 are observed in the hexagonal phase of ZnO. At these angles, grain sizes of 15.308, 15.179, and 13.715 nm are calculated. The absorption peaks of electronic transitions π→π*, n→π*, and d→d* in the ZnO/C10H10N2 heterojunction film are observed. From the IV diagram, it can be seen that the heterojunction structure has a diode characteristic. From the IV data, the rectification factor is calculated to be 6.59 and its graph is drawn. With the Cheung method, ideality factor (n) = 2.87, series resistance (RS) = 1 MΩ, and shunt resistance (RSh) = 5 kΩ are found.

Responses of Soil Enzymes Activities to Sprinkler Irrigation and Differentiated Nitrogen Fertilization in Barley Cultivation

Our study aimed to assess the impact of sprinkler irrigation on the activity of selected soil enzymes in terms of nitrogen metabolism and oxidation–reduction processes in soil with different doses of inorganic nitrogen fertilizers. An Alfisol was sampled from an experimental field of spring barley within the University Research Center in the central part of Poland, namely the village of Mochełek with a moderate transitory climate, during the growing seasons of 2015–2017. The soil resistance (RS) was derived to recognize the resistance enzymes during drought. In the maturity phase, nitrate reductase activity was 18% higher in irrigated soil and the activities of other enzymes were higher than in the non-irrigated plots by 25% for dehydrogenase, 22% for peroxidase, 33% for catalase, and 17% for urease. The development phase in the barley influenced nitrate reductase activity. Enzymatic activities changed throughout the research years. During the maturity stage, a lower ammonium nitrogen content in the soil resulted from a higher spring barley uptake due to drought stress. Irrigation probably contributed to increased leaching of nitrate in the soil. The highest index of resilience was found in the soil catalase activity.

Influence of 700 keV O3+ ion implantation on current transport properties of Cr/p-GaN SBD’s

In the present study we show a detailed investigation into the influence of 700 keV O3+ ion implantation in Cr/p-GaN SBDs on electrical characteristics / current transport properties. Also the damage events along the trajectory of the ion beam were quantitatively estimated through SRIM and TRIM simulations. The Current-voltage (I-V) characteristics were analyzed using different methods such as Cheung and Cheung's method and Norde’s method to obtain different electrical parameters. The values of n and ϕB decrease up to a fluence of 1 × 1014 ions cm−2, and show a fractional increase at a fluence of 1 × 1015 ions cm−2. Further, a drastic increase in values of series resistance (RS ) of SBDs with an increase in fluence was observed. In the forward-bias voltage regions, the Cr/p-GaN SBDs conduction mechanism shows an increasingly ohmic behavior with an increase in fluence, which may be attributed to thermally generated carriers. At low voltage, the reverse current conduction mechanism is due to Poole-Frenkel emission. For the high voltage region, Schottky emission mechanism becomes more prominent. The changes in electrical parameters are closely related to the defect and damage profiles estimated through SRIM/TRIM simulations, which are strongly dependent on the dose of the 700 keV O3+ ion implantation. Additionally, we found that at high doses, the charge transport mechanism changes, with additional defects affecting not only the thermionic emission mechanism but also various current transport mechanisms.

Low contact resistance and high breakdown voltage of AlGaN/GaN HEMT grown on silicon using both AlN/GaN superlattice and Al0.07Ga0.93N back barrier layer

In this study, the growth of a high-quality AlGaN/GaN high electron mobility transistor (HEMT) heterostructure on silicon (Si) by metal–organic chemical vapor deposition was investigated by utilizing both the AlN/GaN superlattice (SL) and Al0.07Ga0.93N back barrier (BB) techniques. An atomic force microscope and high-resolution x-ray diffractometer confirm a low surface roughness of 0.26–0.34 nm and the formation of a high-quality AlN/GaN SL and GaN channel. The AlGaN/GaN heterostructures exhibit a high electron mobility of up to 1700 cm2 V−1∙s and a high carrier concentration density of (1.02–1.06 × 1013 cm−2) for both heterostructures. The AlGaN/GaN HEMT devices demonstrate a low specific contact resistivity (ρ c) of 2.7 × 10−6 Ω·cm2 and a low contact resistance (RC ) of 0.3 Ω·mm for the heterostructure with a BB layer. Furthermore, the DC characteristics demonstrate that incorporating Al0.07Ga0.93N BB in the heterostructure results in a 19.2% increase in lateral breakdown voltage (with a 10 µm spacing) and a 27.5% increase in vertical breakdown voltage (at 1 mA cm−2) compared to heterostructures without Al0.07Ga0.93N BB within the AlN/GaN SL structure. Moreover, an improvement of 10.6% in the maximum saturation current (I DS) and 15.2% in on-resistance (R ON) has been achieved for the device fabricated on an Al0.07Ga0.93N BB structure. The insertion loss of the buffer layer improves to −1.40 dB mm−1 at 40 GHz. Consequently, the proposed heterostructure investigated in this study demonstrates suitability for electronic device applications.

Impedance spectroscopy using microscopic reference electrodes to analyze different rate-determining steps in aqueous dye-sensitized solar cells using nitroxide radicals as redox mediators

For new components in dye-sensitized solar cells (DSSCs), identification and quantification of rate-limiting steps is needed to evaluate their applicability. This is particularly important if fundamental changes are studied. In this work, the use of a micro-reference electrode in DSSCs is proposed to increase the significance of electrochemical impedance spectroscopy. The recombination of charge carriers at the photoanode and the regeneration of redox mediators at the counter electrode, which typically occur on similar timescales, could be studied separately but simultaneously in cells under operating conditions. This is particularly useful in the study of water-based DSSCs. Here, cells with 2,2,6,6-Tetramethylpiperidinoxyl (TEMPO) or 4-Hydroxy-TEMPO (OH-TEMPO) as redox mediators using additives like 1-Methylbenzimidazole (MBI) are discussed. It was revealed that the charge transfer resistance (RCE) for the reduction of the oxidized redox mediator at the counter electrode (CE) limits the fill factor (FF) of such DSSCs. TEMPO/MBI electrolytes yielded low RCE and high FF, whereas OH-TEMPO in otherwise identical cells resulted in large RCE, low FF, and low conversion efficiencies. This indicates that the interface between the CE and the electrolyte significantly influences the DSSC performance of these cells and strongly depends on the electrolyte composition. Important optimization strategies could be discussed based on the present results.

Impact of Rh, Ru, and Pd Leads and Contact Topologies on Performance of WSe2 FETs: A First Comparative Ab Initio Study.

2D field-effect transistors (FETs) fabricated with transition metal dichalcogenide (TMD) materials are a potential replacement for the silicon-based CMOS. However, the lack of advancement in p-type contact is also a key factor hindering TMD-based CMOS applications. The less investigated path towards improving electrical characteristics based on contact geometries with low contact resistance (RC) has also been established. Moreover, finding contact metals to reduce the RC is indeed one of the significant challenges in achieving the above goal. Our research provides the first comparative analysis of the three contact configurations for a WSe2 monolayer with different noble metals (Rh, Ru, and Pd) by employing ab initio density functional theory (DFT) and non-equilibrium Green's function (NEGF) methods. From the perspective of the contact topologies, the RC and minimum subthreshold slope (SSMIN) of all the conventional edge contacts are outperformed by the novel non-van der Waals (vdW) sandwich contacts. These non-vdW sandwich contacts reveal that their RC values are below 50 Ω∙μm, attributed to the narrow Schottky barrier widths (SBWs) and low Schottky barrier heights (SBHs). Not only are the RC values dramatically reduced by such novel contacts, but the SSMIN values are lower than 68 mV/dec. The new proposal offers the lowest RC and SSMIN, irrespective of the contact metals. Further considering the metal leads, the WSe2/Rh FETs based on the non-vdW sandwich contacts show a meager RC value of 33 Ω∙μm and an exceptional SSMIN of 63 mV/dec. The two calculated results present the smallest-ever values reported in our study, indicating that the non-vdW sandwich contacts with Rh leads can attain the best-case scenario. In contrast, the symmetric convex edge contacts with Pd leads cause the worst-case degradation, yielding an RC value of 213 Ω∙μm and an SSMIN value of 95 mV/dec. While all the WSe2/Ru FETs exhibit medium performances, the minimal shift in the transfer curves is interestingly advantageous to the circuit operation. Conclusively, the low-RC performances and the desirable SSMIN values are a combination of the contact geometries and metal leads. This innovation, achieved through noble metal leads in conjunction with the novel contact configurations, paves the way for a TMD-based CMOS with ultra-low RC and rapid switching speeds.

Impedance and Interface States Depending on Frequency Analysis of Al/(ZnFe2O4-PVA)/p-Si Structures

This study investigates the properties of a film made of zinc ferrite (ZnFe2O4) doped polyvinyl alcohol (PVA). The film is sandwiched between an aluminum (Al) and p-Si semiconductor layers, and electrical measurements are conducted on the structure in a wide scope of frequency besides voltage. The study evaluates the impacts of the ZnFe2O4-PVA interlayer on surface-states (NSS), and complex-impedance (Z* = Z' - jZ''). A remarkable impact of the values of series resistance (RS) and the interlayer on the capacitance-voltage (C-V) and conductance-voltage (G/ω-V) data has been observed at moderate and high frequencies. Hence, the C and G/ω versus V qualities were modified at high frequency to eliminate the outcome of RS. The Hill-Coleman approach was utilized to estimate the values for NSS. Experimental results confirm that both the NSS , RS and the interlayer in the metal-polymer-semiconductor (MPS) structures are critical factors that significantly alter the electrical and dielectric properties. The analysis of the results obtained from the impedance study showed divergent behavior. It was observed that the impedance values increase in the low frequency, while they diminish in the higher frequencies, as a result of the mutual effect between the interface and the dipole polarization. The study suggests that due to its high dielectric value, the ZnFe2O4-PVA interlayer may be a better alternative to conventional insulators for charge/energy storage.

Basic and acidic electrolyte mediums impact on MnO2-Mn2O3/Poly-2-methylaniline hexagonal nanocomposite pseudo-supercapacitor

A highly efficient MnO2-Mn2O3/Poly-2-methylaniline (MnO2-Mn2O3/P2MA) hexagonal nanocomposite is synthesized using a one-pot technique involving oxidation polymerization. The hexagonal morphology and crystalline nature of this nanocomposite, as evidenced by the XRD pattern, affirm its exceptional characteristics. The electrical properties are assessed through charge/discharge behavior and cyclic voltammetry curves, elucidating the storage capabilities of this pseudo supercapacitor using different electrolytes NaOH and HCl. The fabricated supercapacitor exhibits impressive efficiency values of 22 F g−1 in a basic medium and a notably higher 72 F g−1 in an acidic medium at a current density of 0.2 A/g. Similarly, the power density values are calculated at 480 and 478 W.kg−1 for the basic and acidic electrolyte, correspondingly. In the basic medium, the series resistance (RS) and charge transfer resistance (RCT) are 5.2 and 0.7 Ω, respectively. In the acidic medium, these values are notably lower, with RS at 2.82 Ω and RCT at 0.2 Ω. Remarkably, even after 500 cycles, the supercapacitor stability remains high at 95% in both media, underscoring the enduring stability attributed to the oxides and polymer materials within the supercapacitor. The combination of cost-effectiveness, ease of fabrication, and potential for mass production positions this supercapacitor as a promising candidate for industrial applications of polymer-based supercapacitors.

Illumination dependent electrical, photosensitivity and photodetectivity properties of Au/SiO2/n-Si structures: optoelectronic situations

Abstract This study aims to examine the electrical, photosensitivity (S), photo-response (R), and photo-detectivity (D*) properties of Au/SiO2/n-type Si structures under different illumination intensities. The illumination-dependent properties of the Au/SiO2/n-type Si structure with SiO2 interlayer were obtained using current–voltage (I-V) characteristics. The ideality factors (n) and barrier heights (Φbo) values of Au/SiO2/n-type Si structures were obtained and compared from forward and reverse bias current–voltage (I-V) measurements at room temperature. Also, barrier heights (Φbo) and series resistance (R S ) values obtained from Norde method were compared with the values obtained from TE theory. It was observed that ideality factor and barrier height values obtained from forward bias region are higher than the values reverse bias. This means that the linearity or rectification feature in the reverse bias region is better than the forward bias region. Furthermore, photodiode values such as photo response (R), photosensitivity (S) and photodetectivity (D*) of Au/SiO2/n type Si structures were also examined depending on the light intensity. Consequently, the experimental results showed that the increase in reverse current with increasing light indicates that the Au/SiO2/n-type Si structures can be used in semiconductor technology as a photodiode, detector or sensor.