Electron energy level calculations for semiconductor nanostructures
Electron energy level calculations for semiconductor nanostructures Semiconductor nanostructures have attracted tremendous interest in the past few years because of their special physical properties and their potential for applications in micro- and optoelectronic devices. In such nanostructures, the free carriers are confined to a small region of space by potential barriers, and if the size of this region is less than the electron wavelength, the electronic states become quantized at discrete energy levels. The ultimate limit of low dimensional structures is the quantum dot, in which the carriers are confined in all three directions, thus reducing the degrees of freedom to zero. We consider the problem to compute relevant energy states and corresponding wave functions of (three dimensional) semiconductor nanostructures. The governing equation characterizing the energy states E and corresponding wave functions \phi is the Schrödinger equation where the confinement potential V and the electron effective mass m are discontinous across the interface between the dot and the matrix. Assuming non-parabolicity for the electron effective mass, m depends nonlinearly on the energy state E, and the Schrödinger equation becomes a rational eigenvalue problem. Discretizing by FE or FV methods it results in a nonlinear matrix eigenvalue problem which is typically large and sparse. Iterative projection methods of Arnoldi and Jacobi-Davidson type are very efficient. One of the ongoing projects is to apply the automated multi-level substructuring to this type of problems. Weitere Informationen zu diesem Forschungsprojekt können Sie hier bekommenPublikationen
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