Analytic approximations for the Fermi energy in (Al,Ga)As

Simple analytic procedures are given for finding the Fermi energy in a semiconductor with a parabolic or nonparabolic band structure, and (Al,Ga)As is treated as an example of a nonparabolic material in which each of the three conduction bands, Γ, L, and X, competes effectively for electrons. The electron and hole Fermi energies form the basis for determining the voltage and further electrical characteristics of a semiconductor device.