Journal of Computational Electronics最新文献

This study presents an SPR-based biosensor designed to effectively detect Mycobacterium tuberculosis, leveraging 2D materials and a Kretschmann configuration, with all analyses and performance evaluations conducted through comprehensive simulation studies. The biosensor utilizes a CaF₂ prism, niobium pentoxide (Nb₂O₅), silver (Ag), ferric oxide (Fe₂O₃), and black phosphorus (BP). The work concentrates on the design and optimization of the SPR structure to obtain an exceptionally high detection sensitivity for mycobacterium tuberculosis (MTB). Strong plasmonic characteristics are provided by the combination of Ag and Fe₂O₃, and sensitivity is greatly increased by the BP-tunable bandgap and improved light–matter interactions. By facilitating surface functionalization and improving chemical stability, Nb₂O₅ makes the sensor reliable for practical uses. The primary modeling approach was the transfer matrix method (TMM) and finite element method (FEM) was employed to verify the simulation results in order to further validate the design. A maximal sensitivity of 622.33 (deg./RIU) was achieved by fine adjusting the thickness of the Nb₂O₅, Ag, Fe₂O₃, and BP layers in order to optimize the sensing structure. The sensor’s impressive QF of 142.02 (RIU⁻¹), high FOM of 140.09, and narrow FWHM of 4.382 (deg.) suggest strong resolution and detection precision. Moreover, the biosensor exhibited a consistent ability to detect refractive index (RI) fluctuations within the biologically pertinent range of 1.343–1.3551. Superior angular sensitivity and improved optical performance are demonstrated by the proposed structure in comparison with existing SPR biosensor configurations. These findings suggest that the proposed SPR sensor could be an effective and rapid tool for point-of-care testing for TB.

Graphical Abstract

This work presents the numerical design and computational analysis of a biosensing platform that utilizes a two-dimensional photonic crystal structure with a silicon rods-in-air configuration, intended for the precise detection and measurement of urinary biomarkers such as glucose, urea, and albumin. The design incorporates a linear waveguide coupled to a central hexagonal ring resonator, in which changes in the refractive index of the analyte induce measurable resonant wavelength shifts that form the basis of the sensing mechanism. The photonic band structure of the sensor is computed using the plane-wave expansion method, whiles its transmission spectrum and resonant characteristics are evaluated through a finite-difference time-domain approach. Through parametric optimization of the sensing rod radius, the design achieves a high sensitivity of 900 nm/RIU and a high quality factor of 1.4267(times)10(^textrm{6}), along with a low detection limit of 1.276(times)10(^{-7}) RIU and an impressive figure of merit of 7.8372(times)10(^textrm{5}) RIU(^{-1}). The sensor demonstrates excellent linearity, with correlation coefficients of 0.99995 for glucose and 0.99957 for urea. Furthermore, the impact of fabrication-induced disorders on performance is analyzed to assess robustness. A three-dimensional simulation validates the design’s feasibility, and a feasible fabrication process is outlined for future experimental realization. With a compact footprint of 130.235 (upmu text {m}^2), the proposed design is well suited for photonic integrated circuit applications.

The small-signal intrinsic noise behavior of a GaN high electron mobility transistors (HEMTs) was modeled using the whale optimization algorithm-hybrid kernel extreme learning machine (WOA-HKELM) algorithm. This algorithm not only addresses the issues associated with extreme learning machine (ELM), such as the challenge of determining the number of hidden-layer nodes and the occurrence of overfitting, but also identifies the optimal regularization coefficient C and kernel parameters S that support the HKELM algorithm through the utilization of the WOA. To verify the superiority of the proposed WOA-HKELM algorithm, small-signal noise modeling experiments were conducted on GaN HEMT devices with different gate dimensions under various bias conditions. The modeling performance of WOA-HKELM was compared with that of the improved Sparrow Search Optimized Hybrid Kernel Extreme Learning Machine (MShOA-HKELM), HKELM, and other algorithms. Experimental demonstrate that the WOA-HKELM achieves higher accuracy and stability in modeling the intrinsic small-signal noise characteristics of GaN HEMTs.

Contact resistance has remained a major performance obstacle in organic field-effect transistors (OFETs). This article shows a simulation-based effective approach to evaluate and reduce contact resistance by modifying contact properties using a pentacene organic semiconductor buffer layer. The source and drain consist of copper contacts on a high-mobility organic semiconductor (S-DNTT10); hafnium dioxide (HfO₂) is acting as a dielectric and aluminum (Al) as gate contact in a top-contact OFET arrangement. Results show reduction in contact resistance to 64.29 Ω.cm using Cu/pentacene electrode contacts compared to 8357 Ω.cm for a Cu-only contact. The transmission line method was used to evaluate and analyze contact resistance. The extracted electrical performance parameters showed an excellent on–off current ratio of ~ 10⁹, improved threshold voltage of 1.32 V, and significant improvement in hole field-effect mobility and subthreshold swing (SS). Thus, the Cu/pentacene electrode contact is a better alternative for contact resistance reduction in OFETs for biomedical and display applications.

A rather simple compact multifilamentary circuit-level model of bipolar memristor resistive switching with controlled multilevel conductivity tuning in a metal oxide memristor is presented. The model is implemented in a SPICE code. The proposed model differs from known multifilament models by a simpler equation for total current and the presence of only one state parameter for all filaments and, accordingly, one differential equation. This leads to a decrease in the calculation and fitting time of the model. The simplifications made do not lead to a decrease in the accuracy of the model since they are compensated by using a larger number of filaments without a corresponding increase in the number of differential equations. It is shown that the model reproduces the experimental current–voltage characteristics better. This is indicated by the higher value of the determination coefficient. In addition, the model reproduces the experimental curve of spike time-dependent plasticity quite accurately. The developed model will reduce the simulation time of signal processing in large memristor arrays compared to the known compact models of multifilament memristors.

We present a theoretical investigation of photonic quasi-crystal fibers (PQFs) composed of a Stampfli-based lattice structure along with air hole arrays in left–right of PQF region creating a “Semi-Stampfli” lattice for the supercontinuum generation covering the mid-infrared regime. The designed PQF utilizesa a highly nonlinear III–V semiconductor material, aluminum gallium arsenide (AlGaAs), as background material. AlGaAs exhibits a high refractive index (>3), a strong thermo-optic effect and efficient switching ability to second harmonic generation due to its non-centrosymmetric composition, making the proposed material suitable for nonlinear applications. The designing of PQF is followed by the optimization of the structural parameter. Following the optimization study, the designed PQF exhibits a zero-dispersion wavelength (ZDW) at 3580 nm properly defining the normal and anomalous regimes. The effective mode area and nonlinearity at 3580 nm wavelength are measured as 12.8 μm² and 1370.64 W⁻¹ km⁻¹, respectively. With respect to the extracted ZDW, the central wavelength for pumping is chosen as 3500 nm (falling in the normal regime). A hyperbolic secant pulse having 50 fs width and 16 kW power is injected into the PQF core, resulting in the generation of 1.25–15.5 μm SC band covering 87% of the transparency range of the used material. The proposed PQF offers novelty in design and material composition, correspondingly generating wide-band SC. The extracted wide-band SC from the proposed PQF may be a better alternative for nonlinear applications.

Higher transistor density is made possible by the continuous scaling of CMOS technology, but it also brings with it serious drawbacks including increased power leakage and short-channel effects. In addition to these transistor-level issues, interconnect reliability and performance are crucial as integrated circuits shrink to the 5-nm node and beyond. Higher crosstalk, propagation delay, and signal degradation, particularly at high switching frequencies, are some of the increasing problems that traditional copper (Cu) interconnects encounter with modern CMOS technologies, such as FinFET-based 5-nm nodes. These problems frequently have a greater impact than the transistors themselves and can seriously impair system performance. With a CMOS FinFET 5-nm driver, we examine both functional and dynamic crosstalk in multi-coupled hybrid copper and carbon nanotube (Cu–CNT) interconnect architectures. Using PSpice simulations as a reference, we compare the accuracy of the proposed θ-method in the time domain to the traditional finite-difference time-domain (FDTD) methodology to describe these effects. The findings show that the θ-method provides much higher accuracy in capturing propagation delay and crosstalk, demonstrating a 2.45 × speedup over FDTD and up to 2.3 × higher accuracy than other time-domain techniques like MRTD.

The single-event burnout (SEB) behavior of p-GaN gate AlGaN/GaN high-electron mobility transistors (HEMTs) was systematically investigated using technology computer-aided design (TCAD) simulations. Simulation results demonstrate that the primary mechanism underlying SEB in p-GaN gate HEMTs is hole accumulation in the buffer layer, which reduces the electron barrier from the source to the buffer layer and induces a leakage current. This causes a rapid elevation of the electric field in the channel, ultimately leading the peak electric field at the drain terminal to exceed the critical electric field of GaN, thereby triggering SEB. A radiation-hardened design is proposed, in which an AlGaN PN junction layer with the same Al mole fraction as the barrier layer is epitaxially grown on the barrier layer by metal–organic chemical vapor deposition (MOCVD). Compared with the conventional gate-field-plate p-GaN gate HEMT, the PN junction-hardened structure exhibits an optimized peak electric field distribution at the drain terminal, effectively preventing the channel electric field from exceeding the breakdown electric field limit. Under normal incidence heavy-ion irradiation with a linear energy transfer (LET) of 0.6 pC/μm, the SEB threshold voltage of the C-HEMT stands at 240 V, whereas the H-HEMT exhibits a significantly higher SEB threshold voltage of 440 V.

In this work, a novel metal-doped nanocomposite layer (Cu-WO₃) based 1D photonic crystal (PhC) is proposed as back reflector to enhance the photoconversion efficiency (PCE) of DSSCs. The transfer matrix method is used in analysing the optical properties of the proposed PhC and simulation is done using MATLAB software. From the transmittance spectra, it is evident that the photonic bandgap is enhanced in the visible wavelength spectrum as the Cu-doping in the WO₃ matrix is increased. Then, a TiO₂-based DSSC is theoretically designed, and its parameters are determined with and without the Cu-WO₃/LiF PhC back reflector, and further calculated for various Cu-doping. The enhanced solar cell parameters such as J_SC, V_OC and PCE are 7.374 mA/cm², 0.88 V and 5.24% respectively, for the DSSC with 10% Cu-doped PhC back reflector, makes it a potential candidate for eco-friendly, cost-effective back reflector for DSSCs.