An optically generated kink observed in the Gummel plot of AlGaAs/GaAs single heterojunction phototransistors (sHPTs) is reported when illuminated with relatively high optical powers. The observed sudden rise in collector current and decrease in the base current, referred to as ‘optical kink effect’, is carefully studied and analyzed. The measurements are performed for incident optical power of...

We study a stationary spin-polarized drift-diffusion model for semiconductor spintronic devices. This coupled system of continuity equations and a Poisson equation with mixed boundary conditions in all equations has to be considered in heterostructures. In 3D we prove the existence and boundedness of steady states. If the Dirichlet conditions are compatible or nearly compatible with thermodynam...

This article deals with the analysis of the functional iteration, denoted Generalized Gummel Map (GGM), proposed in [11] for the decoupled solution of the Quantum Drift–Diffusion (QDD) model. The solution of the problem is characterized as being a fixed point of the GGM, which permits the establishment of a close link between the theoretical existence analysis and the implementation of a numeri...

We present a stabilized finite element method for the scalar advection-diffusion equation, which does not require tunable mesh-dependent parameters. Stabilization is achieved by using diffusive fluxes extracted from an edge element lifting of Scharfetter-Gummel edge fluxes into the elements. Although the method is formally first-order accurate, qualitative numerical studies suggest that it occu...

In February 2019 this journal published the article “An efficient numerical model for liquid water uptake in porous material and its parameter estimation”, (re)introducing Scharfetter-Gummel simulation of moisture transfer building materials, applying it inverse characterization hygric properties based on a capillary absorption experiment. This critique voices concerns defined simulations perfo...

In this article, we propose a unified framework for Quantum–Corrected Drift–Diffusion (QCDD) models in nanoscale semiconductor device simulation. QCDD models are presented as a suitable generalization of the classical Drift–Diffusion (DD) system, each particular model being identified by the constitutive relation for the quantum–correction to the electric potential. We examine two special, and ...

We consider a convective-diffusive elliptic problem with Neumann boundary conditions: the presence of the convective term entails the non-coercivity of the continuous equation and, because of the boundary conditions, the equation has a kernel. We discretize this equation with finite volume techniques and in a general framework which allows to consider several treatments of the convective term: ...

The classical drift-diffusion model employed in semi-conductor simulation is now seen as part of a hierarchy of mathematical models designed to capture the intricate patterns of current flow in solid-state devices. These models include those incorporating quantum mechanical effects. Scientific computation has vastly outpaced our mathematical understanding of these models. This article is restri...