The theoretical analysis of the thermoelectric semiconducting crystalline materials figure of merit

The thermoelectric figure of merit z is computed for bipolar semiconducting materials with a degenerate gas of current carriers and a nonparabolic band structure. The factors that affect the value of z are analyzed. It is established that the figure of merit of such materials increases monotonically with increasing band gap, in contrast with semiconductors with a parabolic band. It is shown that zT<3 is always true in crystalline thermoelectric materials.