Journal of Computational Electronics最新文献

Photovoltaic cell models involve nonlinear and complex parameters, and traditional identification methods often suffer from slow convergence and local optima issues, limiting their efficiency. Metaheuristic algorithms have been developed to enhance the accuracy and efficiency of parameter identification. This paper proposes a coati improved snow ablation optimization (CSAO) incorporating Weibull distribution and elite retention. First, a random probability mechanism combines the coati optimization algorithm with the basic snow ablation optimization, enhancing its global search capability. Second, a search mechanism based on Weibull distribution is incorporated to broaden the search range during local exploitation, helping to avoid falling into local optima. Finally, an elite retention strategy is added to accelerate convergence speed. The CSAO algorithm was evaluated using the CEC2017 benchmark function set. The CSAO algorithm was used for parameter identification of three photovoltaic models (single-diode, double-diode, and triple-diode) and three types of photovoltaic modules named Photowatt-PWP201, STM6-40/36, and STP6-120/36 respectively. Experimental results demonstrate that, compared to other algorithms, CSAO provides more accurate and stable parameter identification for photovoltaic cells and modules, along with faster convergence.

Digital gates are the basic electronic component of digital circuits. These circuits perform best when they are simplified as this directly leads to reducing the number of digital gates to implement a logical function, thereby reducing the circuit cost. To do this, Boolean expressions need to be optimally minimized. Karnaugh (K-map) and the Quine–McCluskey (Q–M) methods are well-known techniques to simplify Boolean techniques. K-map executions become complex for many valued functions. Comparatively, the Q–M method is a computer-based faster approach for logic function-based simplification. However, the Q–M method becomes intolerable for many valued logical functions along with its computational complexity and intensiveness simultaneously increasing. Hence, in this study an algebraic sum (A-sum) and cross-check sum (CCS) is proposed, primarily to aid in computationally efficient pairing of high numbered groups particularly for many valued logical functions and secondly to check the correctness of the paired groups as a manner to review the sanctity of the paired groups. In addition, broadly six postulates are proposed to forego the prime implicant chart in the Q–M method. In this study, the expounding of the prior through examples show that by reducing the number of computations from that which would be typically required of by the conventional Q–M method, the performance of the Q–M method is increased along with the reduction of the possibility of an error and an accurate minimization. The results can be expanded to an n-numbered logic function leading to more hardware efficient circuits. Moreover, the postulate approach is simpler, more efficient with less effort than with the use of the prime implicant tables. The proposed approach is a useful aid for both academics and industrialists where logic, digital and circuit design takes precedence at optimal performance.

Oxide-based complementary memristor, derived from standard bipolar device, offers a promising solution to the challenge of sneak path currents in large-scale crossbar arrays. In this work, we investigate the impact of filament regimes on resistive behavior in tantalum oxide-based complementary memristor through finite element simulations. Our results reveal that the memristor exhibits bipolar resistive switching (BRS) characteristics within a voltage range of (-1.6 V, + 1.6 V) and transitions to a complementary resistive switching (CRS) over a broader voltage range (−1.8 V, + 1.8 V). In the CRS regime, increasing the radius of conductive filament (CF) from 5 to 10 nm and decreasing the CF length from 15 to 7.5 nm can enhance the I_on/I_off ratio by 23% and 15%, respectively, due to improved thermal effects. Conversely, reducing the CF radius to 1.2 nm or extending its length to 26 nm diminishes the internal thermal effects, affecting the CF and causing the device to exhibit BRS characteristics. Moreover, decreasing the k_th of electrodes can also improve the I_on/I_off of the complementary memristor. This research advances the understanding of the interconversion between BRS and CRS and offers strategies to improve the performance of complementary memristors.

Exploring novel light-harvesting materials with excellent optoelectronic properties is crucial for photovoltaic technology. In this work, we investigate the optoelectronic properties of antimony selenides Na3SbSe4 using first-principles calculations and evaluate their photovoltaic potential by device simulations. The hybrid functionals predict a direct band gap of approximately 1.7 eV and effective masses of 0.549 m₀ for electron and 0.591 m₀ for hole. The light absorption coefficient is estimated to reach 10⁵ cm⁻¹ in the visible light range. Based on the spectroscopic limited maximum efficiency method, the power conversion efficiency is predicted to approach 19.58% with a thickness of 0.5 µm for light-harvesting material, revealing the excellent photovoltaic properties of Na₃SbSe₄. Device simulations further confirm that the solar cell with a device configuration of ZnO/Na₃SbSe₄/PEDOT:PSS can achieve an efficiency of 16.45%. Moreover, increasing the thickness of the light-absorbing layer and controlling the defect concentration can improve efficiency. These results can be significant theoretical guidance for the development of novel optoelectronic materials.

A significant photovoltaic material for greater light energy conversion is graphene, mostly due to its exciting features including greater carrier mobility. By substituting a graphene layer for the "hole transport layer" (HTL), a perovskite solar cell's efficiency can be increased. This study demonstrates how growing graphene using the plasma-enhanced chemical vapor deposition (PECVD) technique affects the device efficiency. We use SCAPS-1D to build and simulate a model of ITO/PCBM/CsPbI₃/graphene and use CsPbI₃ as absorber, PCBM as the electron transport layer (ETL) and graphene as the HTL. The efficiency of solar cell and the plasma parameters are found to be numerically related, and the efficiency of the simulated model and the numerically computed efficiency are compared. Furthermore, it is discovered that increasing the electron and ion density of the graphene sheet causes the device's efficiency to decrease due to an inverse relationship with the Debye length, whereas increasing the electron and ion temperatures causes the device's efficiency to increase due to a linear relationship with the Debye length. This indicates that by adjusting the various plasma parameters at an ideal absorber layer and HTL thickness, the device's efficiency can be increased, improving its performance and practical applications. The obtained results have been verified from the previously done researches based on solar cells.

Perovskite photodetectors have attracted great interest because of their excellent physical properties and the feasibility of low-cost manufacturing by printing processes. Among various types of photodetectors, phototransistors are usually characterized by superior gain due to their inherent amplification function. In the work, an n-SnO₂/p-CH₃NH₃PbI₃/n-CH₃NH₃PbI₃ heterojunction bipolar phototransistor is proposed and numerical analyzed with Silvaco TCAD simulator for the first time. The influence of perovskite base and collector doping concentration, base thickness, and SnO₂ emitter doping concentration are investigated to optimize the device performance. The simulation results indicate that properly reducing the perovskite base thickness and doping concentration will greatly enhance the emitter injection efficiency and spectral response. With higher collector doping concentration, the base–collector junction can form a higher electric field, which is conducive to producing a higher spectral response. Moreover, an enhanced emitter injection efficiency can be obtained with a higher SnO₂ emitter doping concentration. Under realistic conditions, the device exhibits excellent performance with a high external quantum efficiency of 1.48 × 10³% at 425 nm, a responsivity of 6.8 A/W at 650 nm and a detectivity is 1.63 × 10¹⁴ Jones at 650 nm under a low bias voltage of 0.8 V. Simulation result indicates that the proposed perovskite NPN heterojunction bipolar phototransistor is a promising architecture and will open a new path for the development of high-performance perovskite photodetector.

Absorbers based on two-dimensional transition metal dichalcogenide (TMDC) heterostructures with direct band gap have recently attracted great research attention in optoelectronic applications. In this study, we design a multi-color absorber using a multilayer periodic arrangement of van der Waals heterostructures, including different TMDC thin layers (MoSe₂, MoS₂, WSe₂, and WS₂) on SiO₂ substrate. This newly emerging platform based on different compositions of TMDCs has been investigated to improve light absorption in the visible range. Multi-color detection can be achieved by combining distinct types of TMDCs with different layers. For instance, for two-color absorption, 3-layer-MoS₂ and 1-layer-WSe₂ have been located on the SiO₂ substrate alternatively to form a periodic heterostructure. In this case, the absorption spectrum illustrates two narrow peaks at 520 nm (green) and 700 nm (red) wavelengths. For three-color absorption, 3-layer-WSe₂ and 1-layer-WS₂ have been deposited on SiO₂ substrate alternatively, and the absorption spectrum displays three narrow peaks at 520 nm (green), 610 nm (orange), and 710 nm (red) wavelengths. Effects of the number of periods and the number of TMDC layers on the absorption spectrum have been investigated. As a result, the utilization of the periodic form of multilayer TMDCs demonstrates a high absorption peak of approximately 40% for distinct wavelengths within the visible range. This property can be employed in various optoelectronic devices and visible light communication.

Driven by their outstanding optoelectronic properties, two-dimensional (2D) materials have attracted significant attention in solar cells, LEDs, and other optoelectronic fields. Besides, the strain effect has served as a powerful approach to enhance the optoelectronic performance of 2D materials. This study employs first-principles calculations to investigate the tunable optoelectronic properties of monolayer C2/m-SnX (X = P, As) materials under uniaxial/biaxial strains ranging from -10% to 10%. The results demonstrate that under uniaxial/biaxial strains ranging from -10% to 10%, the structure of C2/m-SnX (X = P, As) maintains good stability. Their electronic and optical properties can uphold semiconductive characteristics unchanged across the entire strain conditions. Under different strains, their mechanical and optical properties are anisotropic. All of the outcomes above attest to their favorable flexibility. In addition, their mechanical, electronic, and optical properties display different and regular patterns of change under the modulation of various strains. In our opinion, this study not only validates the potential of C2/m-SnX as a strain-tunable flexible semiconductor but also furnishes a theoretical basis and directive for the future application in practice, where the application of strain can enable targeted regulation of its mechanical and optoelectronics properties, thus transforming and broadening its performance manifestations.

This study explores the electronic, optical, and electrochemical properties of novel D–π–A organic dyes with different π-bridges using DFT and TD-DFT calculations, emphasizing their potential as efficient light harvesters. Geometric analysis shows that the dyes’ bond lengths and dihedral angles support intramolecular charge transfer, light absorption, and stability. The π-bridge improves electronic coupling, promoting conjugation and electron mobility. Frontier molecular orbital analysis reveals HOMO and LUMO levels aligned with TiO₂ conduction band and the electrolyte's redox potential, ensuring efficient electron injection and dye regeneration. The dyes’ energy gaps (2.1151–2.5426 eV) enable effective visible-light absorption. Molecular orbital distribution supports charge separation for efficient donor-to-acceptor electron transfer. Global reactivity parameters indicate high stability and enhanced charge transfer capabilities. Molecular electrostatic potential and reduced density gradient analyses highlight charge distribution and non-covalent interactions that improve stability and electronic properties. UV–Vis spectra (543.021–624.762 nm) reveal enhanced light-harvesting efficiency via n → π* transitions enabled by the π-bridge. Electrochemical parameters, including oxidation potential and free energy changes, confirm their suitability for DSSCs. These dyes demonstrate significant potential for renewable energy applications, particularly in DSSCs.

Through-silicon-via (TSV) technology represents a significant advancement in the fabrication of three-dimensional (3D) integrated circuits, enabling the vertical interconnection of chips. This process results in several defects that impact the signal transmission performance of TSVs. This study establishes a unified equivalent circuit model that includes leakage defect TSV, void defect TSV, and defect-free TSV, using a distributed modelling approach. The established equivalent circuit model is then simulated, and its accuracy is confirmed by comparing the S-parameter values with those from 3D electromagnetic simulator simulations. The impact of defects on the transmission performance of TSV signals was investigated by varying the dimension of the leakage factor, the position of the leakage defects, and the voiding factor and void defect position. Additionally, the impact of the coexistence of void and leakage defects on TSV signal transmission performance is investigated.