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In this work we analyze the coupled piezoelectric and semiconductive behavior of vertically aligned ZnO nanowires under uniform compression. The screening effect on the piezoelectric field caused by the free carriers in vertically compressed zinc oxide nanowires (NWs) has been computed by means of both analytical considerations and finite element(More)
We develop a computational framework, based on the Boltzmann transport equation (BTE), with the ability to compute thermal transport in nanostructured materials of any geometry using, as the only input, the bulk cumulative thermal conductivity. The main advantage of our method is twofold. First, while the scattering times and dispersion curves are unknown(More)
In this work we compute the effective thermal conductivity of porous Si by means of the phonon Boltz-mann transport equation. Simulations of heat transport across aligned square pores reveal that the thermal conductivity can be decreased either by increasing the pore size or decreasing the pore spacing. Furthermore, by including the surface specularity(More)
Nanostructured materials exhibit low thermal conductivity because of the additional scattering due to phonon-boundary interactions. As these interactions are highly sensitive to the mean free path (MFP) of phonons, MFP distributions in nanostructures can be dramatically distorted relative to bulk. Here we calculate the MFP distribution in periodic(More)
In this work we present a multiscale method to model self-heating effects in nanostructured devices. While the heating is modeled within the drift-diffusion approximation, the heat dissipation is computed by means of a concurrent coupling between a Phonon Boltzmann Transport Equation (PBTE) based method and the Fourier model. We develop the way to connect(More)
Due to the downscaling of semiconductor device dimensions and the emergence of new devices based on nanostructures, CNTs and molecules, the classical device simulation approach based on semi-classical transport theories needs to be extended towards a quantum mechanical description. We present a simulation environment designed for multiscale and multiphysics(More)
A fully selfconsistent, coupled electro-thermo-mechanical model for nitride-based devices is presented and applied to a high-power AlGaN/GaN High Electron Mobility Transistor (HEMT). The influence of converse piezoelectric effect, thermal stress and of the selfconsistent coupling on the static device characteristics and on the stress distribution in the(More)