ANALYTIC REPRESENTATIONS OF THE DIELECTRIC FUNCTIONS OF MATERIALS FORDEVICE AND STRUCTURAL MODELING

Analytic representations of the dielectric function epsilon are needed for the analysis of optical data of complex materials and structures. Here, we examine various harmonic-oscillator-based representations of the dielectric functions of the silicon-related materials, crystallin e Si, amorphous Si, and silicon nitride. For crystalline semiconductor s we develop a new representation with a prefactor proportional to ome ga(-2), the expected response for materials with wavefunctions that ar e eigenfunctions of the momentum operator. (C) 1998 Elsevier Science S .A.