by Keyword: Insulator
Huetter, L, Kyndiah, A, Gomila, G, (2023). Analytical Physical Model for Organic Metal-Electrolyte-Semiconductor Capacitors Advanced Theory And Simulations 6, 2200698 
This work presents the analytical physical modeling of undoped organic metal-electrolyte-semiconductor (OMES) capacitors in the framework of the Nernst-Planck-Poisson theory, including the presence of compact interfacial layers. This work derives an exact analytical solution, up to a quadrature, for the stationary electric potential and charge density distributions in both the semiconductor film and the electrolyte solution, and from them the sheet semiconductor charge and the stationary differential capacitance are obtained as a function of the applied voltage. The dependence of these magnitudes on the physical device parameters, like the ionic concentration of the electrolyte, the capacitance of the interfacial compact layers and the injected hole density is then analyzed. This work shows that ionic diffusive effects in the electrolyte can play an important role in the device response, inducing a broadening of the transition from the weak to the strong accumulation regimes. This fact can make that the strong accumulation regime is not achieved in OMES within the usual voltage operation range of these devices. The analytical solution is validated by means of finite element numerical calculations. The implications of the results obtained on the physics of electrolyte gated organic field effect transistors (EGOFETs) are discussed.
JTD Keywords: Analytical model, Equivalent-circuit model, Metal electrolyte semiconductor capacitors, Metal insulator semiconductor capacitors, Organic devices
Tahirbegi, I. B., Mir, M., (2011). Slit-wave model for band structures in solid state physics 
Modern Physics Letters B , 25, (3), 151-161
The reason behind the entire development in silicon technology was band models in solid state physics. However, the theories postulated in order to give response to this phenomenon do not explain all kinds of materials. In a bid to overcome this limitation, we approach the problem from another point of view. In this work, the wave properties of the electrons from the external orbitals of the atoms and its diffraction patterns through the lattice structure of the material have been used to explain the band structure of metals, semiconductor and insulators. In order to probe this hypothesis, a simulation has been used and according to the relation between the lattice constant and the atomic diameter, the splitting of the bands have been observed for different kind of materials, showing a strong correlation between the simulation and the experimental results.
JTD Keywords: Electrical band structure, Band gap, Fraunhofer diffraction, Semiconductor, Insulator
Zazoua, A., Kherrat, R., Caballero, D., Errachid, A., Jaffrezic-Renault, N., Bessueille, F., Leonard, D., (2009). Characterisation of a Cr(VI) sensitive polysiloxane membrane by x-ray photoelectron spectrometry and atomic force microscopy Sensor Letters 6th Maghreb-Europe Meeting on Materials and Their Applications for Devices and Physical, Chemical and Biological Sensors , AMER SCIENTIFIC PUBLISHERS (Rabat, Morocco) 7, (5), 995-1000
Cr(VI) sensitive polysiloxane membranes containing tributylphosphate (TBP) or trioctylphosphine oxide (TOPO) were characterized in this study. TBP and TOPO as carriers, have a high selectivity for Cr(VI). The Potentiometric response of EMIS (Electrolyte/Membrane/Insulator/Semiconductor) sensors presents a quasi-nernstian response for Cr2O2-7 exchange. The ion exchange is shown by X-ray photoelectron spectrometry (XPS), the binding energy of the Cr 2p1/2 peak corresponding to Cr(VI) and the atomic composition after exposure to Cr(VI) shows a factor 1.7 higher for silopreneTBP membrane. The conformational topography of both polymeric membranes was characterized by Atomic Force Microscopy (AFM), the exchange of Cr(VI) leading to a heterogeneous topographic state. Adhesion force measurements are also performed to study the properties of adhesion of both selective membranes with a non-functionalized Si AFM tip and with an OTS functionalized one to study the interactions between the tip and the membrane, in liquid before and after the exposure of the membrane to ion chromium. The presence of the ionophores does not practically change the adhesion force compared to pure polysiloxane, showing a good solubility of the ionophore and the orientation of the alkyl chains towards the polysiloxane surface. After the exchange with Cr(VI), the adhesion force decreases drastically due to the hydrophilic character of the surface, complex of Cr(VI) with the P-O groups of both ionophore being oriented towards the surface.
JTD Keywords: AFM, Electrolyte/membrane/insulator/semiconductor structures, Polysiloxane membrane, Xps
