Journal of Computational Electronics最新文献

In this research, an efficient two-valley Monte Carlo model simulates the Schottky junction. Impurity and phonon scatterings are considered, and impact ionization is included in the scattering matrix. Non-parabolic energy bands are assumed, and tunneling and thermionic emission are the current components. By adding a thin layer, it is shown that the formation of an electric field opposite to the electron motion direction at the junction boundary increases the effective height of the Schottky barrier. By changing the impurity concentration density of this thin layer, the change in the effective height of the Schottky barrier and consequently the simulated passing current is studied. A comparison of the results obtained from the simulation with valid scientific data confirms the correctness of the presented model. The proposed model can be widely used in the analysis of Schottky-based devices.

The present work aims at developing a new design strategy based on optimizing light trapping management in the CsSnI₃ perovskite active layer using back groove engineering, to tune the broadband photoresponsivity. To do so, an extensive numerical simulations based on 2D-Finite Difference Time Domain (FDTD)-SILVACO calculations are carried out to assess the optoelectronic properties of the proposed sensor, including the impact of back grooves engineering. The effect of the groove geometry on the photosensing characteristics of the photodetector (PD) is analyzed. It is found that the depth, width and the period of the back grooves can modulate the optical behavior of the CsSnI₃ perovskite active layer, showing a great potential for improving the light harvesting capabilities over a wide spectral range. A Genetic Algorithm Optimization (GAO) technique is implemented to find out the best groove geometry and period, offering the highest photoresponse over UV to NIR spectral bands. The obtained results show the ability of the proposed strategy to improve and tune the optoelectronic properties of the device, demonstrating a high responsivity of 78 mA/W and an improved I_ON/I_OFF ratio of 61 dB. Therefore, the proposed approach can open new paths to enhance the optical and electrical performances of thin film perovskite photodetectors by optimizing the light trapping management using back groove engineering and metaheuristic calculations.

This study introduces a dual core photonic crystal fiber (DC-PCF) based biosensing approach for early detection of malaria in individuals by monitoring the variations in the red blood cells (RBCs). The proposed DC-PCF comprises four layers of a hexagonal lattice with circular air holes. In the proposed DC-PCF, we have used a central elliptical hole to infiltrate RBCs samples. The proposed study helps to detect various stages of malaria, such as infected RBCs, including the Ring stage, Trophozoite stage, and Schizont stage, by analyzing the changes in the peak wavelength. The proposed refractive index (RI) based sensor is designed to operate within an RI range of 1.33 to 1.41, enabling the detection of malaria. The numerical analysis indicate that our biosensor demonstrates significant sensitivity across different stages, such as 12,00000 nm/RIU for the ring stage, 11,15,263.15 nm/RIU for the trophozoite stage, and 11,13,793.10 nm/RIU for the schizont stage under x-polarization. Similarly, under y-polarization, the sensitivity is observed to be 10,50,000 nm/RIU for the ring stage, 10,54,736.84 nm/RIU for the trophozoite stage, and 10,32,758.62 nm/RIU for the schizont stage. The proposed DC-PCF-based biosensor is highly suitable for biological analysis and early malaria detection because it has a low detection limit and superior sensing performance.

We use an improved shift operator finite-difference time-domain (ISO-FDTD) algorithm, previously proposed by others, to further process more complex dielectric functions including critical models and several higher-order Lorentz models that we fitted ourselves. These function models have a total of 6–8 sub-terms, and each sub-term consists of two complex poles (Lorentz model). This work supports the universal applicability of the ISO-FDTD algorithm for processing higher-order complex dispersive materials. We applied this ISO-FDTD algorithm in split-field FDTD (SF-FDTD) to simulate dispersion media under oblique incidence. The simulation results agree well with the analytical solutions. Thus, this approach provides researchers with an alternative option apart from auxiliary differential equations (ADE) or piecewise linear recursive convolution (PLRC) methods when processing high-order dispersive media in SF-FDTD.

In this article, we illustrate the working principle of optoelectronic mixing for uni-traveling-carrier photodetector (UTC-PD). As a result of the combined influence of local oscillators (LO) and bias modulation signals (RF), the velocity and concentration of photogenerated electrons in the depletion region exhibit mixing components with frequencies of (|{f}_{LO}pm {f}_{RF}|). The optoelectronic mixing signal is primarily generated by these two components, and its peak value is determined by the concentration of photogenerated electron. Moreover, the cliff layer can greatly enhance the output power of the mixed frequency signal, since it allows more photogenerated electrons to be transmitted to the depletion region.

This paper investigates the performance of a low-profile 8 × 8 multi-input-multi-output (MIMO) antenna with zero ground clearance, designed using an intelligent antenna recommender system. A dissimilar antenna pair is employed to achieve multi-band resonance and enhance isolation for sub-6G mobile communication. The primary antenna is a loop antenna resonating at n77, n79, and n46 bands, designed with the aid of a model developed using a support vector machine (SVM). The auxiliary antenna is a modified monopole resonating at n78 and n79 bands to minimize the antenna footprint on mobile devices. An eight-antenna MIMO array is fabricated, and measured results demonstrate that the proposed antenna has a reflection coefficient of less than − 10 dB at 3.5, 3.7, 4.5, and 5.2 GHz, with diversity gain and isolation greater than 9 dBi and 15 dB, respectively. SAR analysis conducted on a human head model shows a maximum SAR value of less than 1.6 W/kg at all sub-6G bands, compliant with FCC standards. The proposed MIMO antenna offers a viable solution, even when integrated with a battery and display, without occupying internal space within a mobile phone.

We present the results of an investigation of the optical characteristics of pristine and CO₂-adsorbed MoSe₂ monolayers with (without) an external electric field. The optical parameters of interest are the absorption coefficient (α), reflectance (R_f), refractive index (n), and photoconductivity (σ). The impact of an external electric field (−2 × 10⁸ V/cm) on the optical behavior of the MoSe₂ monolayer is systematically investigated. The results show the peaks of the real component ((varepsilon_{1})) of the dielectric function for both pristine and CO₂-adsorbed MoSe₂ monolayers in the energy range of 2–3 eV. The imaginary part ((varepsilon_{2})) of the dielectric function exhibits a shift toward the visible region from the ultraviolet (UV) region, in which CO₂ is adsorbed, and this shift increases toward the visible region with the application of an external electric field. Analysis of the absorption index, refractive index, and reflectance reveals that the peaks are aligned in the visible range for both the pristine MoSe₂ and CO₂-adsorbed MoSe₂ monolayers, with (without) an external electric field. The shifts of these peaks follow a similar trend as the imaginary part of the dielectric constant. Lastly, this study provides additional insight into the photo-detection performance parameters (internal quantum efficiency [IQE], external quantum efficiency [EQE], light extraction efficiency [LEE], and responsivity) for both pristine and CO₂-adsorbed MoSe₂ monolayers, considering the presence or absence of an external field.

This research presents a simulating electrohydrodynamically (EHD) inkjet-printed memristors in LTspice environment, a popular tool for analog circuit simulation. EHD printing technique is used as one of low cost fabrication technique for fabricate flexible thin films and memristors with high precision and resolution in a scale of nanometers. Memristors are cutting-edge components for AI hardware, and they can be fabricated through various methods, including traditional semiconductor processes and printed electronics techniques. However, printed electronics fabrication based for memristor modeling accurately remains a challenge. This paper introduces a mathematical model specifically for (EHD) inkjet-printed memristors, employing empirical mathematics to ensure compatibility with LTspice. While the modeling of printed electronic devices still in the early stage—to the knowledge of the authors-this paper will discuss for the first time mathematical and Spice modeling for printed memristor. The model is validated against actual memristors with a sandwiched structure ((text {Ag/ZrO}_{2}/text {Ag})), showing acceptable error percentage. It involves modifying an existing memristor model by incorporating a function that reflects the characteristics of the EHD printing process. This function is designed to capture the impact of the printing technique on various device parameters, such as width and length, with a focus on accurately modeling the width in the LTspice environment. This paper presents a developed LTspice model based on the proposed empirical mathematical model. The results are based on different sizes: 40 nm, 120 nm, 680 nm, respectively.

AlGaN/GaN HEMT-based gated-anode diode (GAD) has been investigated with a physics-based TCAD simulation tool to understand its electrical transport characteristics. The simulation study predicted that the GAD exhibited low turn-on voltage ((V_{text {on}}) = + 0.77 V) over a conventional Schottky barrier diode (SBD). However, the GAD suffers from low breakdown voltage ((V_{text {BD}})) because of strong electric field crowding at the gate edge. On the other hand, a δ-doped GaN cap (δ-DGC) layer has been able to spread out the electric field along the channel. With such modification in the epi-structure, a (V_{text {BD}}) of ~ 335 V could be achieved with the gated-anode-to-cathode distance ((L_{text {gac}})) of 10 μm. TCAD-based RF simulation and small-signal S-parameter analysis were carried out to evaluate the expected RF performance of the GADs. From the transient response of the extracted small-signal equivalent circuit parameters, the cut-off frequency ((f_{text {c}})) of the GADs with δ-DGC layer was 35.6 GHz at the exact turn-on condition ((V_{text {on}})) of the device.

Capacitive pressure sensors have the advantages of high accuracy and sensitivity compared to piezoresistive pressure sensors, but have serious nonlinearity problems. Although the touch mode capacitive pressure-sensitive structure has improved this issue, it has introduced a large hysteresis. To restrain this effect, a line-touch mode capacitive MEMS pressure-sensitive structure is proposed. A recess on the lower electrode plate of this structure makes the contact between the upper and lower electrode plates appears as the line-touch, and the touched area is almost zero, which can greatly minimize the hysteresis caused by the electrode plate contact. Analysis shows that the linear response range of this pressure-sensitive structure can be expanded several times more than that of the touch mode capacitive pressure-sensitive structure, while the nonlinearity is significantly reduced.