Studying Effect Dimensions of Design and Simulation Silicon Nanowire Filed Effect Biosensor

2015 ◽  
Vol 754-755 ◽  
pp. 854-858 ◽  
Author(s):  
M. Wesam Al-Mufti ◽  
U. Hashim ◽  
Md. Mijanur Rahman ◽  
Tijjani Adam ◽  
Mohd Khairuddin Md Arshad ◽  
...  
Keyword(s):  
Space Charge ◽  
Surface Charge ◽  
Poisson Equation ◽  
Electrostatic Potential ◽  
Silicon Nanowire ◽  
Critical Parameters ◽  
Comsol Multiphysics ◽  
Electrode Layer ◽  
Nanowire Surface ◽  
Dna Attachment

We investigated into report a study biosensor based on silicon into an effect on the dimensions of conductance design and simulation nanowire surface with molecular DNA for sensitivity. In the design nanowire of A biosensor with 3 layers starting with polyisilicon nanowire of radius 8 NM surrounded by a 50-nm electrode layer, and the substrate by a 300nm. COMSOL Multiphysics software used to provide interaction with molecules such as DNA and the distribution of the electrostatic potential in the narrower due to the dimensions, surface nanowire charge was computed using Poisson equation with Boltzmann statistics. In the result of the effect geometry was also studied and the different dimension yield different space charge and the surface charge at interactive site were also investigated and the study demonstrate steps wise identification of all critical parameters for (DNA) attachment with surface nanowires.

An Investigation of the Distribution of Electric Potential and Space Charge in a Silicon Nanowire

2014 ◽  
Vol 69 (10-11) ◽  
pp. 597-605 ◽  
Author(s):  
A. Wesam Al-Mufti ◽  
Uda Hashim ◽  
Md. Mijanur Rahman ◽  
Tijjani Adam
Keyword(s):  
Finite Element Method ◽  
Space Charge ◽  
Electric Potential ◽  
Silicon Nanowire ◽  
Electrical Potential ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Simulation Experiments ◽  
Different Dimensions

AbstractThe distribution of electric potential and space charge in a silicon nanowire has been investigated. First, a model of the nanowire is generated taking into consideration the geometry and physics of the nanowire. The physics of the nanowire was modelled by a set of partial differential equations (PDEs) which were solved using the finite element method (FEM). Comprehensive simulation experiments were performed on the model in order to compute the distribution of potential and space charge. We also determined, through simulation, how the characteristic of the nanowire is affected by its dimensions. The characterization of the resulting nanowire, calculated by COMSOL Multiphysics, shows different dimensions and their effect on space charge and electrical potential

Investigated Effect of Points Charge of the Receptors on the Conduction of Semiconductor Nanowire

2015 ◽  
Vol 1109 ◽  
pp. 167-170
Author(s):  
M. Wesam Al-Mufti ◽  
U. Hashim ◽  
Mijanur Rahman ◽  
Tijjani Adam ◽  
A.H. Azman ◽  
...  
Keyword(s):  
Finite Element ◽  
Oxide Layer ◽  
Point Charge ◽  
Potential Distribution ◽  
Silicon Nanowire ◽  
Comsol Multiphysics ◽  
Functional Layer ◽  
Semiconductor Nanowire ◽  
Finite Element Calculations

The paper reported a study on an effect of the point charge of the bio-interface of a nanowire field biosensor on the conductance of the nanowire, through finite element calculations using COMSOL Multiphysics. A model with 5 layers starting with silicon nanowire of radius 10nm surrounded by a 2-nm oxide layer, and the oxide layer were surrounded by a 5 nm thick functional layer and 2 points charge were considered for this study and last layer is for electrolyte. The results shows that is different voltages with points change is that effected on the conductance of nanowire that is clear from different of potential distribution of point charge.

The Field Effect of Concentration DNA on Conductance of Silicon Nanowire

2015 ◽  
Vol 1109 ◽  
pp. 163-166
Author(s):  
M. Wesam Al-Mufti ◽  
U. Hashim ◽  
Mijanur Rahman ◽  
Tijjani Adam ◽  
A.S. Ibraheam ◽  
...  
Keyword(s):  
Finite Element ◽  
Surface Modification ◽  
Field Effect ◽  
Silicon Nanowire ◽  
Semiconductor Nanowires ◽  
Comsol Multiphysics ◽  
Dna Concentration ◽  
Finite Element Calculations ◽  
Potential Use

Currently, the potential use of Semiconductor nanowires as parts of future devices has triggered an increased interest in biosensor research. The COMSOL Multiphysics is simulation used that can improve the sensitivity of Bioelectronics to extend their stability and utility. In this paper, we are investigating the effect of DNA concentration of the electrolyte effect biosensor on the conductance of the nanowire through finite element calculations. First, the distribution of the electrostatic has potential in the nanowire due to the DNA concentration. In conclusion of this paper represented DNA that conductance nanowire is affected from surface modification after DNA including on the model.

scholarly journals Highly Efficient Silicon Nanowire Surface Passivation by Bismuth Nano-Coating for Multifunctional Bi@SiNWs Heterostructures

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1434
Author(s):  
Mariem Naffeti ◽  
Pablo Aitor Postigo ◽  
Radhouane Chtourou ◽  
Mohamed Ali Zaïbi
Keyword(s):  
Silicon Nanowires ◽  
Near Infrared ◽  
Surface Passivation ◽  
Silicon Nanowire ◽  
Etching Technique ◽  
Highly Efficient ◽  
Broadband Emission ◽  
New Family ◽  
Nano Coating ◽  
Nanowire Surface

A key requirement for the development of highly efficient silicon nanowires (SiNWs) for use in various kinds of cutting-edge applications is the outstanding passivation of their surfaces. In this vein, we report on a superior passivation of a SiNWs surface by bismuth nano-coating (BiNC) for the first time. A metal-assisted chemical etching technique was used to produce the SiNW arrays, while the BiNCs were anchored on the NWs through thermal evaporation. The systematic studies by Scanning Electron Microscopy (SEM), energy dispersive X-ray spectra (EDX), and Fourier Transform Infra-Red (FTIR) spectroscopies highlight the successful decoration of SiNWs by BiNC. The photoluminescence (PL) emission properties of the samples were studied in the visible and near-infrared (NIR) spectral range. Interestingly, nine-fold visible PL enhancement and NIR broadband emission were recorded for the Bi-modified SiNWs. To our best knowledge, this is the first observation of NIR luminescence from Bi-coated SiNWs (Bi@SiNWs), and thus sheds light on a new family of Bi-doped materials operating in the NIR and covering the important telecommunication wavelengths. Excellent anti-reflectance abilities of ~10% and 8% are observed for pure SiNWs and Bi@SiNWs, respectively, as compared to the Si wafer (50–90%). A large decrease in the recombination activities is also obtained from Bi@SiNWs heterostructures. The reasons behind the superior improvement of the Bi@SiNWs performance are discussed in detail. The findings demonstrate the effectiveness of Bi as a novel surface passivation coating, where Bi@SiNWs heterostructures are very promising and multifunctional for photovoltaics, optoelectronics, and telecommunications.

Characterization of Fuel Cells and Fuel Cell Systems Using Three-Dimensional X-Ray Tomography

2006 ◽  
Vol 4 (1) ◽  
pp. 84-87 ◽  
Author(s):  
Stefan Griesser ◽  
G. Buchinger ◽  
T. Raab ◽  
D. P. Claassen ◽  
Dieter Meissner
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Ionic Conductivity ◽  
First Generation ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Gas Diffusion ◽  
Critical Parameters ◽  
Electrode Layer ◽  
X Ray

Three dimensional (3D) computer aided X-ray tomography (CT) has proven to be an extremely useful tool in developing our own as well as in examining commercially available solid oxide fuel cells. The results of 3D-CT measurements became very important for understanding the functionality of our first generation and improving the development of our second fuel cell generation. Also geometrical measurements, especially the roundness and the straightness of the tube, can be evaluated, both critical parameters when the stack is heated and mechanical stress has to be avoided. By using this technique the structure of the first generation cells proved to be of insufficient quality. Problems like the variation in thickness of the electrolyte tube as well as the homogeneity in thickness of the electrodes deposited can easily be detected by this nondestructive technique. Microscopic investigations of this problem of course provide equal results, but only after cutting the samples in many slices and many single measurements of different areas of the fuel cell. Using cells with inhomogeneous thickness of course results in drastic variations of the current densities along a single cell. Electrolyte layers that are too thick will result in power loss due to the increased resistance in the ionic conductivity of the electrolyte. If the electrolyte of an electrolyte supported cell is too thin, this can cause mechanical instability. Problems can also occur with the leak tightness of the fuel cell tube. Gas diffusion through the electrode layer can become a problem when the thickness of the electrode layer is too high. On the other hand, if the layers are too thin, the result can be a discontinuous layer, leading to a high electrical series resistance of the electrode. Besides determining the thickness variations also the porosity of the electrolyte needs careful attention. Larger cavities or shrink holes form insulating islands for the ion-stream and are therefore limiting the ionic conductivity. They are also diminishing the mechanical stability and provide problems for depositing a closed electrode film in electrode supported cells.

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