Hall Effect and Density of States in Germanium

The usual assumptions that underlie the analysis of Hall data to obtain activation energy and density of states are based on the simple model of the band structure. They are re-examined here in the light of the known band structure of germanium. In particular, consideration is given to the limits of validity of the assumption that carrier concentration equals 1/Re. Also, energy levels of electrons bound to donors are investigated and it is shown that the effect of excited states, particularly for Sb-doped germanium, cannot be neglected. The density-of-states mass values obtained from Hall data for p- and n-type material are considered. In the latter case, the results are shown to favor a band edge at the surface of the Brillouin zone rather than inside.