Nonlinear effects in 3rd and 4th-order moments of transport-hydrodynamical models in semiconductors within Extended Thermodynamics

In this paper, we treat the closure relations of hydrodynamical models in order to study electron transport in semiconductors. We adopt the Extended Thermodynamics theory in order to derive hydrodynamical equations for carrier transport and we try to close the system, i.e. to find constitutive equations for the third and fourth-order moments, by means of a generalized nonequilibrium distribution function.In this paper, we treat the closure relations of hydrodynamical models in order to study electron transport in semiconductors. We adopt the Extended Thermodynamics theory in order to derive hydrodynamical equations for carrier transport and we try to close the system, i.e. to find constitutive equations for the third and fourth-order moments, by means of a generalized nonequilibrium distribution function

Global existence for the system of the macroscopic balance equations of charge transport in semiconductors

AbstractGlobal existence of a solution to the nonlinear balance equations of charge transport in semiconductors based on the maximum entropy principle [Contin. Mech. Thermodyn. 11 (1999) 307–325; Contin. Mech. Thermodyn. 12 (2000) 31–51] is proven for a typical 1D problem under certain restrictions on the doping profile and the initial data

A hydrodynamical model for covalent semiconductors with a generalized energy dispersion relation

We present the first macroscopical model for charge transport in compound semiconductors to make use of analytic ellipsoidal approximations for the energy dispersion relationships in the neighbours of the lowest minima of the conduction bands. The model considers the main scattering mechanisms charges undergo in polar semiconductors, that is the acoustic, polar optical, intervalley non-polar optical phonon interactions and the ionized impurity scattering. Simulations are shown for the cases of bulk 4H and 6H-SiC

Coulomb Drag at the Onset of Anderson Insulators

It is shown that the Coulomb drag between two identical layers in the Anderson insulting state indicates a striking difference between the Mott and Efros-Shklovskii (ES) insulators. In the former, the trans-resistance $\rho_t$ is monotonically increasing with the localization length $\xi$; in the latter, the presence of a Coulomb gap leads to an opposite result: $\rho_t$ is enhanced with a decreasing $\xi$, with the same exponential factor as the single layer resistivity. This distinction reflects the relatively pronounced role of excited density fluctuations in the ES state, implied by the enhancement in the rate of hopping processes at low frequencies. The magnitude of drag is estimated for typical experimental parameters in the different cases. It is concluded that a measurement of drag can be used to distinguish between interacting and non-interacting insulating state.Comment: 15 pages, revte

Coupled quantum-classical transport in silicon nanowires

We present an extended hydrodynamic model describing the transport of electrons in the axial direction of a silicon nanowire. This model has been formulated by closing the moment system derived from the Boltzmann equation on the basis of the maximum entropy principle of Extended Thermodynamics, coupled to the Schr¨odinger-Poisson system. Explicit closure relations for the high-order fluxes and the production terms are obtained without any fitting procedure, including scattering of electrons with acoustic and non polar optical phonons. We derive, using this model, the electron mobility