Zareiee M.,Damghan University
Superlattices and Microstructures | Year: 2015
In this paper a novel feature of a nano-scale SOI-MOSFET is presented. The goal of the proposed Si3N4 Layer SOI-MOSFET (SL-SOI) is inserting a Si3N4 layer in the channel region. This layer in the channel region which has different band gap than silicon causes uniform electric field. So, hot carrier effect and gate current are controlled sufficiently. Moreover, Si3N4 layer in the channel is extended in the buried oxide to reduce the lattice temperature, and sub-threshold slope. The proposed structure is simulated with two-dimensional ATLAS simulator and compared with conventional SOI-MOSFET. The results show that the new device has a high performance which expands nano-scale MOSFET applications in high temperature. © 2015 Elsevier Ltd. All rights reserved.
Mehrad M.,Damghan University
Superlattices and Microstructures | Year: 2015
In this paper a new technique for controlling floating body effect and self-heating effects is proposed. The main idea in the proposed structure is using a L-shape SiGe region in the nano-scale SOI-MOSFET (LS-SOI). The L-shape SiGe region is located in the source region and is extended under channel. The difference band gap between silicon and silicon-germanium cause discontinuity in band diagram which helps to collect channel holes. Reducing the hole density in channel of the proposed LS-SOI in comparison to conventional SOI-MOSFET (C-SOI) results in suppressed floating body effect. Also, the SiGe region under the channel decreases the lattice temperature in the LS-SOI. Replacing the SiGe with higher thermal capability than buried oxide is useful to have a reliable structure. Moreover, effective mobility, off current and sub-threshold swing improves in the proposed structure. © 2015 Elsevier Ltd. All rights reserved.
Vali R.,Damghan University
Computational Materials Science | Year: 2011
The electronic band structure, dielectric function, and phonon spectra of SrMoO4 have been studied using density functional theory within the local density approximation. The origin of the peaks in the imaginary part of the dielectric function was analyzed based on the electronic structure. The calculated phonon spectra are in good agreement with available Raman experimental data and provide benchmark theoretical results for the interpretation of future infrared phonon measurements. © 2011 Elsevier B.V. All rights reserved.
Pourhassan B.,Damghan University
Physics of the Dark Universe | Year: 2016
In this paper, we investigate cosmological models of the extended Chaplygin gas in a universe governed by Horava-Lifshitz gravity. The equation of state for an extended Chaplygin gas is a (n+2)-variable equation determined by An, α, and B. In this work, we are interested to the case of second order (n=2) equation of state which recovers quadratic barotropic equation of state. In that case there are four free parameters. We solve conservation equation approximately and obtain energy density in terms of scale factor with mentioned free parameters. Under some assumptions we relate free parameters to each other to have only one free independent parameter (A2). It help us to obtain explicit expression for energy density in terms of scale factor. The allowed values of the second order extended Chaplygin gas parameter is fixed using the recent astrophysical and cosmological observational data. Thermodynamics of the model investigated based on the first and second law of thermodynamics. © 2016.
Abbasi Molai A.,Damghan University
Information Sciences | Year: 2013
In this paper, the LU-factorization is extended to the fuzzy square matrix with respect to the max-product composition operator called L°U- factorization. Equivalently, we will find two fuzzy (lower and upper) triangular matrices L and U for a fuzzy square matrix A such that A = L°U, where "°" is the max-product composition. An algorithm is presented to find the matrices L and U. Furthermore, some necessary and sufficient conditions are proposed for the existence and uniqueness of the L°U-factorization for a given fuzzy square matrix A. An algorithm is also proposed to find the solution set of a square system of Fuzzy Relation Equations (FRE) using the L°U-factorization. The algorithm finds the solution set without finding its minimal solutions and maximum solution. It is shown that the two algorithms have a polynomial-time complexity as O(n3). Since the determination of the minimal solutions is an NP-hard problem, the algorithm can be very important from the practical point of view. © 2011 Elsevier Inc. All rights reserved.