scholarly journals Ultrahigh dielectric constant of thin films obtained by electrostatic force microscopy and artificial neural networks

2012 ◽  
Vol 100 (2) ◽  
pp. 023101 ◽  
Author(s):  
E. Castellano-Hernández ◽  
G. M. Sacha
2012 ◽  
Vol 7 (1) ◽  
pp. 250 ◽  
Author(s):  
Elena Castellano-Hernández ◽  
Francisco B Rodríguez ◽  
Eduardo Serrano ◽  
Pablo Varona ◽  
Gomez Sacha

2018 ◽  
Vol 4 (2) ◽  
pp. 77-85
Author(s):  
Deepak Bhatia ◽  
Sandipta Roy ◽  
S. Nawaz ◽  
R.S. Meena ◽  
V.R. Palkar

In this paper, we report the charge trapping phenomena in zinc oxide (n-ZnO) and Bi0.7Dy0.3FeO3 (BDFO)/ZnO thin films deposited on p-type <100> conducting Si substrate. The significant change in contrast above the protrusions of ZnO verifies the possibility of heavy accumulation of injected holes in there. The ZnO and BDFO/ZnO films were characterized by the electrostatic force microscopy (EFM) to understand the phase dependence phenomenon on the bias supporting electron tunnelling. The EFM has an important role in the analysis of electrical transport mechanism characterization and electric charge distribution of local surface in nanoscale devices. It was observed that in BDFO/ZnO, the contrast of EFM images remains constant with the bias switching and that primarily indicates availability of trap sites to host electrons. The change in contrast over the protrusions of ZnO suggests that mobility of the electrical charge carriers may be through the grain boundary. The formation of these hole-trapped sites may be assumed by bond breaking phenomenon.


2019 ◽  
Vol 962 ◽  
pp. 41-48
Author(s):  
Tzong Daw Wu ◽  
Jiun Shen Chen ◽  
Ching Pei Tseng ◽  
Cheng Chang Hsieh

This study presents a real-time method for determining the thickness of each layer in multilayer thin films. Artificial neural networks (ANNs) were introduced to estimate thicknesses from a transmittance spectrum. After training via theoretical spectra which were generated by thin-film optics and modified by noise, ANNs were applied to estimate the thicknesses of four-layer nanoscale films which were TiO2, Ag, Ti, and TiO2 thin films assembled sequentially on polyethylene terephthalate (PET) substrates. The results reveal that the mean squared error of the estimation is 2.6 nm2, and is accurate enough to monitor film growth in real time.


2013 ◽  
Vol 50 (52) ◽  
pp. 63-71
Author(s):  
M. H. Allahyarzadeh ◽  
A. Ashrafi ◽  
T. Shahrabi ◽  
A. Seddighian ◽  
M. Aliofkhazraei ◽  
...  

2020 ◽  
Author(s):  
Wescley Walison Valeriano ◽  
Rodrigo Ribeiro Andrade ◽  
Juan Pablo Vasco ◽  
Angelo Malachias ◽  
Bernardo Ruegger Almeida Neves ◽  
...  

  The aim of this work is to determine the dielectric constant value of a bio-nanostructured system via Electrostatic Force Microscopy (EFM) and to show how this method is useful to study natural photonic crystals. We mapped the dielectric constant of the cross-section of the posterior wing of the damselfly Chalcopteryx rutilans with nanometric resolution and obtained not only structural information on its constitutive nanolayers but also on the absolute values of the dielectric constant variation in a nanometric scale. By relating the measured profile of the static dielectric constant to the profile of the refractive index in the visible range, combined with optical reflectance measurements and simulation, we were able to describe the origin of the strongly iridescent wing colors of this Amazonian rainforest damselfly. The method we demonstrate here should be useful for the study of other nanostructured biological systems.


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