Surface Potential Explained: A Surfactant Adsorption Model Incorporating Realistic Layer Thickness

2020 ◽  
Vol 124 (15) ◽  
pp. 3195-3205 ◽  
Author(s):  
Mengsu Peng ◽  
Timothy T. Duignan ◽  
Xiu Song Zhao ◽  
Anh V. Nguyen
2021 ◽  
Author(s):  
GIRDHAR GOPAL ◽  
Tarun varma

Abstract The Ultrathin body double gate FE layer TFET(UTB-DG-FE-TFET) is proposed and investigated in this work. Electrical performance parameters such as surface potential ψ(x), electrical field, drain current, sub-threshold swing, threshold voltage, and I on /I off ratio are further analyzed using simulation-based analysis. Integration of Si: HFO 2 ferroelectric layer on top and bottom surfaces make the structure that provides negative capacitance, higher on current, enormous surface potential, peak electric field, and improvement in SS with degradation in off Current. The suggested design is evaluated in comparison with FE-TFET and standard TFET devices. Finally, the impact of device geometry variants like ferroelectric layer thickness (t fe ), intrinsic channel thickness t si , interfacial layer types, interfacial layer thickness (t ox ) and channel length L c on transfer characteristics are investigated through 2D TCAD Sentaurus Simulator for a clear validation of its optimization. The recommended work demonstrates that it is a suitable device enabling superior performance and helpful in ultra-low-power applications.


2020 ◽  
Vol 124 (25) ◽  
pp. 5301-5310 ◽  
Author(s):  
Mengsu Peng ◽  
Timothy T. Duignan ◽  
Anh V. Nguyen

1995 ◽  
Vol 379 ◽  
Author(s):  
Jenn-Shyong Hwang ◽  
W. Y. Chou ◽  
S. L. Tyan ◽  
Y. C. Wang ◽  
J. H. Tung

ABSTRACTWe have studied the photoreflectance spectra at 300 K from a series of strained In1−xAlxAs/InP (0.42<x<0.57) strained structures grown by molecular beam epitaxy. From the observed Franz-Keldysh Oscillation we evaluate the built-in de electric field and hence the surface potential under different strain. We found that the surface Fermi level is not pinned at midgap under different strainwhich results in contrast to AIGaAs and GaAs. In addition, from the observed dependence of the built-in electric field Fdc and surface potential barrier Vm on the top layer thickness, we conclude that the surface states are distributed over two separate regions within the energy band gap under different strain and the densities of the surface states are as low as (2,71α0.05)x 1011 cm−2 for the distribution near the conduction band and (4.29α0.05)x1011 cm-2 for the distribution near the valence band. The Fermi level is weakly pinned while the top layer thickness is within the characteristic region of each sample.


Langmuir ◽  
2012 ◽  
Vol 28 (5) ◽  
pp. 2997-3004 ◽  
Author(s):  
Jyh-Ping Hsu ◽  
Hsiao-Ting Huang ◽  
Li-Hsien Yeh ◽  
Shiojenn Tseng

2008 ◽  
Vol 95 (2) ◽  
pp. 699-709 ◽  
Author(s):  
U. Klenz ◽  
M. Saleem ◽  
M.C. Meyer ◽  
H.-J. Galla

Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.


Author(s):  
M. Pan ◽  
J.M. Cowley

Electron microdiffraction patterns, obtained when a small electron probe with diameter of 10-15 Å is directed to run parallel to and outside a flat crystal surface, are sensitive to the surface nature of the crystals. Dynamical diffraction calculations have shown that most of the experimental observations for a flat (100) face of a MgO crystal, such as the streaking of the central spot in the surface normal direction and (100)-type forbidden reflections etc., could be explained satisfactorily by assuming a modified image potential field outside the crystal surface. However the origin of this extended surface potential remains uncertain. A theoretical analysis by Howie et al suggests that the surface image potential should have a form different from above-mentioned image potential and also be smaller by several orders of magnitude. Nevertheless the surface potential distribution may in practice be modified in various ways, such as by the adsorption of a monolayer of gas molecules.


Author(s):  
H. Kung ◽  
A.J. Griffin ◽  
Y.C. Lu ◽  
K.E. Sickafus ◽  
T.E. Mitchell ◽  
...  

Materials with compositionally modulated structures have gained much attention recently due to potential improvement in electrical, magnetic and mechanical properties. Specifically, Cu-Nb laminate systems have been extensively studied mainly due to the combination of high strength, and superior thermal and electrical conductivity that can be obtained and optimized for the different applications. The effect of layer thickness on the hardness, residual stress and electrical resistivity has been investigated. In general, increases in hardness and electrical resistivity have been observed with decreasing layer thickness. In addition, reduction in structural scale has caused the formation of a metastable structure which exhibits uniquely different properties. In this study, we report the formation of b.c.c. Cu in highly textured Cu/Nb nanolayers. A series of Cu/Nb nanolayered films, with alternating Cu and Nb layers, were prepared by dc magnetron sputtering onto Si {100} wafers. The nominal total thickness of each layered film was 1 μm. The layer thickness was varied between 1 nm and 500 nm with the volume fraction of the two phases kept constant at 50%. The deposition rates and film densities were determined through a combination of profilometry and ion beam analysis techniques. Cross-sectional transmission electron microscopy (XTEM) was used to examine the structure, phase and grain size distribution of the as-sputtered films. A JEOL 3000F high resolution TEM was used to characterize the microstructure.


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