SEMICLASSICAL ELECTRICAL-CURRENT EXPRESSIONS FOR MATERIALS WITH POSITION-DEPENDENT BAND-STRUCTURE IN THE NEAR-EQUILIBRIUM APPROXIMATION

Electrical current density expressions for electrons and holes for mat erials with position-dependent band structure are presented. This incl udes materials with nonuniform composition and devices with highly dop ed regions. Changes in the energy-band edges due to spatial variations in electron affinity and band gap, and spatial variations in the loca l kinetic energy produce terms in the current-density equations in add ition to those for the homogeneous case. These new terms are derived a nd discussed. The development proceeds from the Boltzmann transport eq uation. The focus will be on the conceptual framework and the limitati ons in the underlying theory. Errors in the literature are noted where appropriate. The results are relevant to semiconductor device physics and analysis. (C) 1997 American Institute of Physics.