Dependence of electron density on Fermi energy in N-type gallium antimonide

The majority electron density as a function of the Fermi energy is calculated in zinc blende, n-type GaSb for donor densities between 10(16) cm(-3) and 10(19) cm(-3). These calculations solve the charge neutrality equation self-consistently for a four-band model ( three conduction sub-bands at Gamma, L, and X and one equivalent valence band at Gamma) of GaSb. Our calculations assume parabolic densities of states and thus do not treat the density-of-states modifications due to high concentrations of dopants, many body effects, and non-parabolicity of the bands. Even with these assumptions, the results are important for interpreting optical measurements such as Raman measurements that are proposed as a nondestructive method for wafer acceptance tests.