Computational Study on Non-linear Optical and Absorption Properties of Benzothiazole based Dyes: Tunable Electron-Withdrawing Strength and Reverse Polarity

Various organic dyes possessing characteristic D-π-A-A configuration have been designed in this article. The analysis of the relation between polarity of charge transfer and the unsymmetrical nature of the benzothiazole group has been studied. The absorption spectra, electronic characteristic properties and non-linear optical responses were simulated using a quantum chemical approach. The results have indicated that the systems show higher polarizability (α) and hyperpolarizability (β) with commonly used polarity in comparison to the reverse polarity. A red-shifted absorption spectra were observed with systems having common polarities. This study illustrates the rule to design non-linear optical material with low energy charge transfer excited states and high value of oscillation.

Modelling Electronic Characteristic of InP/InGaAs Double Heterojunction Bipolar Transistor

In this paper, we are interested in studying InP/InGaAs heterojunction bipolar transistor NPN type. First and for most we should describe the structure of our simulation, then, we ploted at room temperature: Energy band diagram, Gummel plot, I_C-V_C characteristic and conduction bands for different values of V_BE. The simulation of this structure has demonstrated the validity of our model and the method of the simulation.

Modeling and Characteristic Study of Thin Film Based Biosensor Based on COMSOL

The model of thin film based biosensor is built based on COMSOL in order to simulate and optimize the electronic characteristic of dipolar electrodes system and tetrapolar electrodes system. Zones of negative sensitivity exist between current carrying electrodes and voltage measuring electrodes while the polarization occurs at the edges of electrodes. By changing the parameters embracing distance between electrodes, thickness of electrodes, and the width of inner electrodes (for tetrapolar electrodes system only), the polarization and zones of negative sensitivity can be receded to some extent, which improves the system’s performance. Tetrapolar electrodes system has less polarization but more negative-sensitivity zones compared to dipolar electrodes system and different setups response differently to these changing parameters.