Journal of Computational Electronics最新文献

The non-toxic nature, low cost, and excellent optical properties make oxide-based perovskites potential candidates for solar cell applications. The full potential linearized augmented plane wave approach is applied to explore the structural, electronic, optical, and thermoelectric properties of Ba₂XTiO₆ (X = Hf, Ce, and Te) for solar cell applications. As demonstrated by an elastic study, Ba₂HfTiO₆ is brittle, while Ba₂CeTiO₆ and Ba₂TeTiO₆ are ductile. The anisotropic values of Ba₂HfTiO₆, Ba₂CeTiO₆ and Ba₂TeTiO₆ are 1.14, 0.67 and 0.80 respectively. The electronic bandgap values of Ba₂HfTiO₆, Ba₂CeTiO₆, and Ba₂TeTiO₆ are computed as 3.44 eV, 2.96 eV, and 1.26 eV using the Tran-Blaha-modified Becke–Johnson approach. Moreover, the bandgap of Ba₂TeTiO₆ is compatible for solar cell applications. Optical investigation demonstrates that Ba₂TeTiO₆ shows maximum absorption in visible light among the studied perovskites. Lastly, the transport properties exhibit figure of merit values of 0.73, 0.77 and 0.81 for Ba₂HfTiO₆, Ba₂CeTiO₆, and Ba₂TeTiO₆ respectively. Consequently, with the bandgap falling in the visible region and high figure of merit among the studied perovskites, Ba₂TeTiO₆ emerges as the most suitable candidate for solar cell applications based on its electronic, optical, and thermoelectric properties.

This paper explores the utilization of matched coordinates for the comprehensive analysis of self-assembled cylinders, specifically focusing on a crossed grating with circular cross section within a hexagonal lattice. By incorporating the matched coordinate technique into the Fourier modal method (FMM), the paper addresses the limitations associated with staircase approximations when solving Maxwell’s equations in a curvilinear coordinate system. The study demonstrates that the proposed transformation significantly enhances the efficiency and speed of FMM, particularly in extracting optical characteristics such as reflection and transmission coefficients. Through a comparative analysis of a hexagonal lattice comprising air-suspended cylindrical resonators with a dielectric constant of 2, the proposed technique is shown to achieve comparable accuracy while utilizing only (40%) of the harmonics required by conventional methods. As a result, this approach offers substantial computational cost reductions of up to an order of magnitude.

Moore’s law, along with the International Roadmap for Devices and Systems, continues to guide the scaling of devices below 10 nm. The challenges posed by such small-dimensioned devices form the basis of the present work. A junctionless MOSFET with a triple-metal gate structure is proposed as an alternative to conventional single-gate bulk MOSFETs for future CMOS technology. The present work investigated the direct current and analog/radio frequency characteristics including the drain current (({I}_{{text{D}}})), transconductance ({(g}_{m})), transconductance generation factor (TGF), cut-off frequency ({(f}_{T})), frequency–transconductance product (FTP), transit time ((tau ),) and the total resistance of the source region, drain region, and channel ({(R}_{{text{SD}}+{text{CH}}})) for triple-metal (TM) inversion-mode (IM) and junctionless (JL) cylindrical gate-all-around (CGAA) silicon nanowire (SiNW) MOSFETs with 3-nm gate length using the Silvaco ATLAS 3D TCAD tool. The non-equilibrium Green’s function and the self-consistent solution of the Schrödinger and Poisson equations were considered. The channel was taken to be lightly doped in the case of the IM TM CGAA SiNW device. The effect of the TM gate work function engineering for a SiNW channel with a diameter of 3 nm and gate oxide (({{{text{Al}}}_{2}{text{O}}}_{3})) thickness of 0.8 nm was investigated with respect to ({I}_{D}),({ g}_{m}), TGF, ({f}_{T}), (tau), FTP, and ({R}_{{text{SD}}+{text{CH}}}), and a comparative study between the IM TM and JL TM CGAA SiNW devices was carried out with respect to these parameters. For the JL device, optimization of the doping concentration was performed to obtain the same (i) I_ON current and (ii) threshold voltage (V_TH) as the IM device. An 8.61- and 5.72-fold reduction in I_OFF was seen for the same I_ON and V_TH for the JL versus the IM device. It was found that the TM gate variation led to a reduction in drain-induced barrier lowering (DIBL) in the IM and JL devices. The JL SiNW showed much lower DIBL of ~39.49 mV/V, a near-ideal subthreshold slope (SS) of ~60 mV/dec, and higher ({{text{I}}}_{{text{ON}}}/{{text{I}}}_{{text{OFF}}}) current ratio of ~2.98 × 10¹². which is much better than the values reported in the literature for CGAA devices. Also, the JL SiNW device was found to perform better than the IM SiNW device in terms of SS, DIBL, ({{text{I}}}_{{text{ON}}}/{{text{I}}}_{{text{OFF}}}), ({g}_{m},) TGF, f_T, (tau), FTP, and ({R}_{{text{SD}}+{text{CH}}}).

Due to the growing need for higher speed data, the 5G terrestrial heterogeneous wireless network deployments are expected to happen quickly throughout the world in the next decade. In such type of networks, mm-wave small-cells overlapped the sub-6 GHz macro-cells being used to serve to population-rich areas. Subsequently, many problems appear with the antenna design technologies. The presented antenna is functioning at a frequency range from 24.8 to 31.6 GHz, with a 24% bandwidth and 8.5 dB peak gain at 27 GHz. It encompasses the complete 28 GHz frequency band utilized through 5G applications. Consequently, fifth-generation communication systems are best suited for it. The proposed Hamiltonian deep neural network optimized with pelican Optimization Algorithm-fostered Substrate-Integrated Waveguide Antenna Design for 5G (SIW-HDNN-POA-5G) is implemented, and performance of proposed technique is estimated based on several metrics, including resonant frequency (GHz), reflection coefficient (S11 in dB), mean absolute error (MAE), and root mean square error (RMSE). The proposed SIW-HDNN-POA-5G method provides 24.36%, 33.55% and 44.22% higher gain and 43.21%, 38.87% and 25.65% lesser mean absolute error comparing to the existing designs, like Design of Zero Clearance SIW End fire Antenna Array Based on Machine Learning-Assisted Optimization (SIW-MLAO-5G), SIW-Fed Wideband Filtering Antenna for Millimeter-Wave Applications (SIW-5G-MLOM), and Compact SIW Fed Dual-Port Single Element Annular Slot MIMO Antenna for 5G mm Wave Applications (SIW-FWFA-MMWA), respectively.

In this paper, the dispersion characteristics of slotted photonic crystal waveguides (SPCWs) have been estimated for any arbitrary set of structural parameters using machine learning-based artificial neural network (ANN). The machine learning-based technique yields faster solutions of the three-dimensional eigenvalue equations, which otherwise require substantial time using the conventional plane wave expansion (PWE)-based numerical simulations. Most importantly, the novel contribution of the work lies in estimating the structural parameters of the SPCWs from the given specifications of the dispersion characteristics through an inverse computation. A simple feed-forward neural network has been employed for both the forward and inverse estimations. The computation performances using both the ANN model and PWE simulations are analyzed and compared. The research offers significant implications for the field of photonics. By employing machine learning techniques, particularly ANNs, researchers and engineers can swiftly and efficiently analyze the dispersion properties of SPCWs, facilitating rapid prototyping and optimization of photonic devices. Additionally, the capability to infer structural parameters from desired dispersion characteristics streamlines the design process, potentially leading to the development of customized waveguides tailored to specific applications.

Fractional capacitors, commonly called constant-phase elements or CPEs, are used in modeling and control applications, for example, for rechargeable batteries. Unfortunately, they are not natively supported in the well-used circuit simulator SPICE. This manuscript presents and demonstrates a modeling approach that allows users to incorporate these elements in circuits and model the response in the time domain. The novelty is that we implement for the first time a particular configuration of RC elements in parallel in a Foster-type network with SPICE in order to simulate a constant-phase element across a defined frequency range. We demonstrate that the circuit produces the required impedance spectrum in the frequency domain, and shows a power-law voltage response to a step change in current in the time domain, consistent with theory, and is able to reproduce the experimental voltage response to a complicated current profile in the time domain. The error depends on the chosen frequency limits and the number of RC branches, in addition to very small SPICE numerical errors. We are able to define an optimum circuit description that minimizes error while maintaining a short computation time. The scientific value is that the work permits rapid and accurate evaluation of the response of CPEs in the time domain, faster than other methods, using open source tools.

Abstract

The unprecedented photo-electronic conversion efficiency (PCE) of organic–inorganic lead perovskite solar cells (PSCs), over 25% within a span of 10 years, makes them an optimistic solution for sustainable and renewable energy sources. However, issues associated with their toxicity and short lifetime raise public concern for their long-term utility. Therefore, resolving these two problems is urgent for developing sustainable and environmentally friendly PSCs. In this study, a novel configuration of a lead-free light absorbing layer with a rudorffite structure (Ag₂BiI₅) is simulated, using the GPVDM software with TiO₂ and Spiro-OMeTAD as traditional electron and hole transport layers (HTLs). The proposed PSC structure is compared to other published results in the literature. In the meantime, by fitting the current density-voltage characteristic curves of theoretical data and experimental results, the precise photovoltaic parameters of the Ag₂BiI₅ structure are extracted. After optimizing the thickness of the Ag₂BiI₅ and replacing TiO₂ with SnO₂ and Spiro-OMeTAD with new a HTL of AgSCN, a PSC in the form of normal a FTO/SnO₂/Ag₂BiI₅/AgSCN/Ag structure is designed. Further, the effect of the thickness of the AgSCN HTL, defect density of light absorbing layer, operating temperature and metal contacts on the photovoltaic performance of the device are thoroughly evaluated. Under the optimized AgSCN HTL thickness, the best theoretical efficiency of 3.61% is achieved for this normal configuration, which is the highest value reported among rudorffite light absorbing materials-based PSCs.

This article describes a multi-objective genetic algorithm (MOGA)-based procedure used for the size reduction of a hybrid compact branch line coupler (BLC) intended for 5G applications that meet the requirements of IoT applications. Conventional λ/4 coupler transmission lines are replaced with meandering transmission lines to provide three different, simple and elegant designs that can operate at 3.5 GHz. A MOGA process is used to simultaneously balance the different design requirements and significantly reduce the bulky conventional structure size while maintaining high performance. To implement the optimization process, the proposed BLCs are designed using an interface between MATLAB software and a VBA script in the CST Studio simulator. The simulation results demonstrate a size reduction of 73.11%, 76.2% and 80%, respectively, for the three designs compared to conventional one. Then, for the demonstration of miniature BLCs operating at 3.5 GHz are fabricated on an FR-4 substrate. The measurements show good agreement with those obtained by simulation, making these BLCs a suitable choice for modern telecommunication systems requiring high compactness.

In this work, we theoretically investigate the influence of electromagnetic radiation on the electronic and thermoelectric properties of Penta-Octa-Penta Graphene (POPGraphene) nanoribbons. Specifically, we study the effects of varying the incident angle (0–90 degrees) of radiation on the density of states, transmission function, Seebeck coefficient, and electronic figure of merit (ZT_e) of the nanoribbons. Our results demonstrate that the electronic properties are highly dependent on radiation conditions due to their influence on electron transport. We find that the density of states and transmission function exhibit distinct radiation angle-dependent behaviors that highlight the role of the radiation's electric field orientation. Importantly, the ZT_e shows significant modulation with the incident angle, achieving optimized values up to 0.275. These findings provide insights into controlling the electronic and thermoelectric properties of POPGraphene nanoribbons using electromagnetic radiation. Our work underscores opportunities for developing Graphene-based nanophotonic devices with enhanced performance through all-optical means. The demonstrated tunability via irradiation paves the way for potential applications such as optical switches, sensors, and next-generation optoelectronics using POPGraphene nanoribbons.