Interdigitated metal–semiconductor–metal (MSM) photodetectors have received considerable attention for applications in microwave optical phoswitches. The impulse response of photoswich interdigitated fabricated metal-semiconductor- on GaAs metal non-intentional doped (NID) absorbing layer is investigated. The photodetector MSM is introduced in the microwave lines have active surfaces of 3x3 m2 and electrode spacing of 0.2, 0.3, 0.5 and 1 m.. The photocurrent response was measured after excitation and we found that the screening of the dark electric field and charge accumulation exceedingly modify the drift conditions of the photogenerated electrons and holes in active region of the MSM photoswich.

Interdigitated metal-semiconductor-metal (MSM) photodetectors based on InAlAs/InGaAs materials have attracted much attention for applications in high-speed optical-fiber communication systems which need efficient light detection in the 1.3-1.55µm range [1].The performance of thin-film inverted MSM are analyzed and compared to conventional MSM, that was modeled and simulated using Silvaco TCAD (Technology Computer Aided Design) and ATLAS software.We show how the interdigital spacing and thickness of the InGaAs layer influence the impulse response and the associated bandwidth [2].

In this paper, a comparative study of two bipolar transistors realized according to the same BICMOS-0.35 technology, but with two different architectures (self-aligned and quasi-self-aligned) is presented. In each case, the type of material forming the base and the geometric differences existing between the two considered structures are taken into account. The simulation allowed us to demonstrate the interest in introducing germanium in quasi-self-aligned bipolar transistors. In addition, it has been found that in low and medium injection, the electrical characteristics of the self-aligned bipolar transistor deviate greatly from the experimental results. With the quasi-self-aligned architecture, this gap remains moderate. In strong injection, and in both types of transistors, the electrical characteristics are very close to those obtained experimentally.

Photonic crystals are nanometric structures which are composed of periodic elements of different permittivity in two or three dimensions. The periodic variation of the refractive index prevents the propagation of electromagnetic waves of certain frequencies. This implies the existence of photonic band corresponding to the frequency band in which the radiation cannot propagate. Their guide mechanism is completely different from that existing in conventional waveguides, since it is not the total reflection due to the difference in refractive indices which ensures the guiding, but the existence of a photonic band gap. This property is based on the design and development of new components based on photonic crystals for optoelectronics applications. In this paper, the parameters of structures, and the electromagnetic field propagation analyze, are determined based on 2D photonic crystal. Several guiding structures two-dimensional photonic crystals (W1 waveguide, the photonic crystal (PhC)-based L-junction waveguide T-shaped and waveguide intersection) and their electromagnetic fields distribution are optimized, using FDTD method (Finite Difference Time Domain) method and the software RSOFT with its simulation modules BandSolve, FullWAVE.

In this paper, we propose a new design principle of two-dimensional photonic crystal refractive index sensors with high transmission and sensitivity simultaneously. The proposed sensor is made of two waveguide couplers and one microcavity which is obtained by varying the radius of one air hole in the center of PC structure. The microcavity is separated from the input and output waveguides by many holes of the PC. It is shown that by injecting an analyze such as gas or a liquid into a sensing hole, and thus changing its refractive index, a shift in the resonant wavelength may occur. The transmission spectra, quality factor and sensitivity of the sensor have been analyzed numerically by the finite difference time domain (FDTD) method. The sensitivity value of the sensor has been found to be 668 nm/(RIU with minimum detection limit of 0.002 RIU), which proves the ability of the structure to produce biosensor PhC.

The microstructural and electrical characteristics of ZnO based varistors, which are composed of ZnO-Bi 2 O 3 MnO 2 Cr 2 O 3 Sb 2 O 3 and Co 3 O 4 are studied in relation to sintering temperature, in the range of 1200°C 1250°C. Microstructure, and electrical properties were studied by scanning electron microscopy (SEM) and direct current electrical measurement. The varistor ceramics had fine microstructures, the grain size varied from 2.23 to 2.96 μm. In the examined temperature range, the breakdown field decreased from 2889.76 to 2189.76 V/cm with the increase of sintering temperature, and the nonlinear coefficient α decrease from 31.21 to 25.13. The optimal samples obtained from the varistor sintered at 1200°C have average grain size of about 2.23 μm , breakdown field 2889.76 V/cm, the average breakdown voltage per grain boundaries Vgb of 0.64 V, the leakage current JL = 0.20mA/cm 2 and the nonlinear coefficient of 31.21.

The nonlinear properties of ZBMCCS-based varistors, which are composed of ZnO–Bi2O3–MnO2–Cr2O3–Sb2O3–Co3O4 and SiO2 are studied inrelation to sintering temperature, in the range of 1280–1350[Formula: see text]C. The samples are investigated for grain morphology by using scanning electron microscope (SEM). These samples were examined by using X-ray diffraction patterns (XRD) and DC electrical measurements. X-ray diffraction analysis of the samples show the presence of ZnO, Zn2SiO4 willemite phase and Co[Formula: see text]Sb[Formula: see text]O4 spinel phases.The average grain size of ZnO increased as the sintering temperature increased from 2.57 to 6.84 [Formula: see text]m. In the examined temperature range, the breakdown field decreased from 2992 to 127[Formula: see text]V/cm with the increase of sintering temperature. This system gives a relatively high nonlinearity coefficient [Formula: see text] (at a sintering temperature of 1280[Formula: see text]C) with a low leakage current of 0.21[Formula: see text]mA/cm2.

In this work, we present the methodology of creating a simple model of a photovoltaic cell contains 4 parameters using the VHDL-AMS language. Our goal is to find a adaptable model with different photovoltaic panels from manufacturers. This model must be modeled in such a way that all parameters are easily computed by avoiding complex equations. Several electric models have been developed, the aim of which is to obtain a more efficient I-V characteristics and thus improve the efficiency.

In this paper, a new conduction model for SiGe heterojunction bipolar transistors (HBTs) is proposed. The combined effect of the granular nature of the polycrystalline emitter and the defects caused by the etching process are introduced to explain the electrical conduction properties. This model is based on solving the ambipolar transport equation while considering the quantum effects present at the grain boundaries. The simulation allowed us to obtain the two-dimensional distributions of the minority and majority carriers in the structure and showed the limiting effect of the diffusion of free carriers by grain boundaries, which is especially significant for the minority free carriers. It was observed that at low and middle injection levels, the deep level-defects caused by the etching process lead to a decrease in the current gain. However, the defects present in the grain boundaries are able to limit this reduction. At high injection levels, the electrical characteristics are very close to those obtained in the absence of defects at the interfaces. (C) 2017 The Physical Society of the Republic of China (Taiwan). Published by Elsevier B.V. All rights reserved.

A two-dimensional self-consistent time-dependent simulation technique has been used to investigate electron-hole transport processes in the active region of metal-semiconductor-metal photodiode structurcs (MSM-PD) and to analyse their high-speed response [1, 2]. Ge and SiGe are promising materials for optoelectronic devices compatible with standard and well developed Si technology [3, 4]. The sensitive volumes are 270 nm thick Ge film, grown on Si. Interdigitated Cr metal top electrodes with 1.5–5 µm spacing and identical finger width form Schottky contacts on the Ge film [2]. Monte Carlo simulation is a useful means of simulating the behavior of small semiconductor devices. Unlike conventional (Drift Diffusion) simulation methods, the Monte Carlo method provides an essentially exact solution of the Boltzmann transport equation and is prone only to statistical errors [5]. Due to the shorter carrier drift length, these devices are even faster, with a pulse response of 9.4 ps FWHM at 1550 nm, but have a lower overall quantum efficiency of 0.9% [2].

Magnetic nanoparticles (MNPs) are of particular interest for biomedical application such as single molecule detection, drug release or magnetic hyperthermia treatment. The concept of hyperthermia is to use MNPs to heat a region of the body affected by cancer to temperatures between 42°C to 48°C. At these temperatures, the cancerous cells can be destroyed. In this paper, it was modeled the heating process of a single MNP inserted in a biological tissue under an external appliedmagnetic field. Using the finite element analysis in COMSOL Multiphysics software, it was analyzed the thermal response of MNPs with different shapes: sphere, cube, rod and core-shell structure materials and/or thickness. The results demonstrate the impact of nanoparticle shape and surface coating in temperature dissipation in and around the nanoparticle.

In this work we present the remote control of the tank level system. The physical system is controlled in real time using local or Internet network. The client could manage the remote experiment through a simple web browser via a graphical shared user interface. The study is based on the PID identification parameters according to Ziègler-Nichols methods. After the identification of the PID parameters the experiment is tested and the result are given.

The main purpose of this paper is to show the effect of charge accumulation and screening of the electric field on the Schottky Metal-semiconductor-Metal detector response and efficiency, which result of non-uniform distribution carriers along the absorption depth, and along the line between electrodes. The MSM (PD) with an active surface of 3×3 μm 2 and electrode spacing of 0.2, 0.3, 0.5 and 1 μm has been integrated in the central strip of coplanar lines for microwave switching application. Several ways of improving the high-speed response of the MSM-PD are analyzed and discussed.

La simulation peut jouer un rôle important dans toutes les phases de développement des systèmes de communications, depuis les premières étapes de conception, jusqu’aux dernières étapes de réalisation, de test et de mise en oeuvre du système. Dans cet article, nous avons appliqué les différentes techniques de modélisation possibles du langage VHDL-AMS pour la création des modèles opérationnels d’une fibre optique à saut d’indice. Nous avons développé une bibliothèque de modèles de fibre à saut d’indice pour les utiliser dans des systèmes modernes des énergies renouvelables.

This paper describes the different steps for the development of a remote laboratory for teaching analog electronics. The course was developed to support the face to face teaching and will upgrade the knowledge of engineers and technicians for the socioeconomic sector. In this paper, after describing the steps of design and scriptwriting of teaching materials, the operational amplifier is then studied for online lab work.

In this paper, we propose a VHDL-AMS multidisciplinary modeling of a PIN photodiode taking into account the multi-technological effects, for use it into a modern system. We have writing a practical and reusable model thus requested by designers of the optical transmission and renewable energies systems. To do this, we are obliged to study of the model robustness while ensuring a design process that minimizes the industrial risk, for this, we must to manage of configurations, abstractions.

This paper presents different VHDL-AMS modeling techniques to create and improve operational models of optoelectronic components, such as vertical cavity surface emitting lasers (VCSELs) and multimode optical fibers. Our models are designed for designers and developers of optoelectronic transmission systems and intended not to replace the models created with specialized software in the domain of optics and optoelectronics but to help system designers to model the physical level. The modeling technique used is the progressive “top-down” approach; it serves to describe lows-levels abstraction in terms of highs-levels abstraction. We have modeled one by one the physical phenomena of each system component by introducing the main disturbances such as noise in the VCSEL, and fiber attenuation effects for knowing the influence of parasites parameters and transmission limitations according to the length of each fiber type. Our objective is to construct a globally accurate model taking into account the multidisciplinary effects that make up the entire optoelectronic transmission line including electrical, thermal and optical behaviors and to find the method to integrate them into a modern design tool. The simulation results are positively compared with models results published in literature.

Interdigitated metal–semiconductor–metal (MSM) photodetectors based on InAlAs/InGaAs materials have received considerable attention for applications in high-speed optical-fiber communication systems which require efficient light detection in the 1.3-1.55 µm range. The performance of thin-film inverted MSM are analyzed and compared to conventional MSM, that was modeled and simulated using Silvaco TCAD (Technology Computer Aided Design) and ATLAS software. We show how the interdigital spacing and thickness of the InGaAs layer influence the impulse response and the associated bandwidth

In this work, the influence of poling conditions (poling field, poling temperature and poling time) on the piezoelectric properties of 0.935(Bi0.5Na0.5) TiO3-0.065BaTiO(3) (BNT6.5BT) lead-free ceramics was examined. Piezoelectric properties like piezoelectric constant (d(33)) and electromechanical factors (K-p, K-t) depend on poling field and poling temperature, whereas different poling times, in the 5-30 min range, were not observed to have significant effect on the piezoelectric properties.