I have calculated transport properties for a bulk system. On observing seeback coefficient, I see that for n-type doping, its value is around 350 uV, and for p-type, it is 300 uV. However, The value of DOS near the valence band is larger than the conduction band.
This trend of seeback coefficient and DOS seems inconsistent due to the formula S proportional to N^2/3 where N is the density of states near the band edges.
So, is it possible that the said relationship doesn’t hold, and for what reasons?
Kindly suggest me the reason of the ambiguity.
The DOS is not the only feature that determines the Seebeck coefficient. You have to consider that whole band structure topology, number of carrier pockets near the band edge etc. For example see the following work