996 resultados para electro-thermal
Resumo:
We report the effect of topological as well as lattice vacancy defects on the electro-thermal transport properties of the metallic zigzag graphene nano ribbons at their ballistic limit. We employ the density function theory-Non equilibrium green's function combination to calculate the transmission details. We then present an elaborated study considering the variation in the electrical current and the heat current transport with the change in temperature as well as the voltage gradient across the nano ribbons. The comparative analysis shows, that in the case of topological defects, such as the Stone-Wales defect, the electrical current transport is minimum. Besides, for the voltage gradient of 0.5 Volt and the temperature gradient of 300 K, the heat current transport reduces by similar to 62 % and similar to 50% for the cases of Stones-Wales defect and lattice vacancy defect respectively, compared to that of the perfect one.
Theoretical insights on the electro-thermal transport properties of monolayer MoS2 with line defects
Resumo:
Two dimensional (2D) materials demonstrate several novel electrical, mechanical, and thermal properties which are quite distinctive to those of their bulk form. Among many others, one important potential application of the 2D material is its use in the field of energy harvesting. Owing to that, here we present a detailed study on electrical as well as thermal transport of monolayer MoS2, in quasi ballistic regime. Besides the perfect monolayer in its pristine form, we also consider various line defects which have been experimentally observed in mechanically exfoliated MoS2 samples. For calculating various parameters related to the electrical transmission, we employ the non-equilibrium Green's function-density functional theory combination. However, to obtain the phonon transmission, we take help of the parametrized Stillinger-Weber potential which can accurately delineate the inter-atomic interactions for the monolayer MoS2. Due to the presence of line defects, we observed significant reductions in both the charge carrier and the phonon transmissions through a monolayer MoS2 flake. Moreover, we also report a comparative analysis showing the temperature dependency of the thermoelectric figure of merit values, as obtained for the perfect as well as the other defective 2D samples. (C) 2016 AIP Publishing LLC.
Resumo:
This paper presents the application of advanced compact models of the IGBT and PIN diode to the full electrothermal system simulation of a hybrid electric vehicle converter using a look-up table of device losses. The Fourier-based solution model is used, which takes account of features such as local lifetime control and field-stop technology. Device and circuit parameters are extracted from experimental waveforms and device structural data. Matching of the switching waveforms and the resulting generation of the look-up table is presented. An example of the use of the look-up tables in simulation of inverter device temperatures is also given, for a hypothetical electric vehicle subjected to an urban driving cycle. © 2006 IEEE.
Resumo:
This paper provides a comprehensive analysis of thermal resistance of trench isolated bipolar transistors on SOI substrates based on 3D electro-thermal simulations calibrated to experimental data. The impact of emitter length, width, spacing and number of emitter fingers on thermal resistance is analysed in detail. The results are used to design and optimise transistors with minimum thermal resistance and minimum transistor area. (c) 2007 Elsevier Ltd. All rights reserved.
Resumo:
An analytic formulation of dynamic electro-thermally induced nonlinearity is developed for a general resistive element, yielding a self-heating circuit model based on a fractional derivative. The model explains the 10 dB/decade slope of the intermodulation products observed in two-tone testing. Two-tone testing at 400 MHz of attenuators, microwave chip terminations, and coaxial terminations is reported with tone spacing ranging from 1 to 100 Hz.
Resumo:
Improvements to the current state of the art in microfabricated cantilevers are investigated in order to realize enhanced functionality and increased versatility for use in ultrafast electrophoretic molecular sorting and delivery. Design rationale and fabrication process flow are described for six types of electro-thermal microcantilevers. Devices have been tailored for the process of separating mixtures of heterogeneous molecules into discrete detectable bands based on electrophoretic mobility, and delivering them to a conductive substrate using electric fields. Four device types include integrated heating elements capable of warming samples to catalyze reactions or cleaning the device for reuse. Similar devices have been shown to be capable of targeting temperatures between ambient conditions and the melting point of silicon, to within 0.1˚C precision or better. All microcantilevers types are equipped with a highly doped conductive silicon tip capable of interacting with a conductive substrate to deliver molecules under the presence of an electric field. Devices are equipped with additional electrodes to aid in sorting molecules on the surface of the probe end. Two designs contain two legs and one additional sorting electrode while four designs contain three legs and have two sorting electrodes. Devices having two sorting electrodes are designed to be capable of sorting three or more molecular species, a distinctive advancement in the state of the art. A detailed process flow of the fabrication process for all six electro-thermal cantilever designs are explained in detail.