Path integral approach to the theory of heavily doped semiconductors

This paper presents a review discussion of the density of states available to electrons in heavily doped semiconductors. The discussion is focussed on the density of states in the tail part of the band using three theoretical approaches; the semiclassical theory of Kane, the quantum mechanical theory of Halperin and Lax and the path integral approach developed by Sa-yakanit. A model for interpolation of the density of states in the main part of the band and the tail part of the band is proposed. The application of this model to the calculation of optical absorption in heavily doped GaAs is given. (author). 32 refs, 8 figs, 1 tab