Geometrical magnetothermopower in semiconductors

The geometry of a semiconductor sample can be designed to create a very large change of the thermoelectric power in a magnetic field, similar to the effects of the sample geometry on the magnetoresistance. In semiconductors in which the minority carriers have a higher mobility than the majority carriers, this geometrical magnetothermopower can freeze out the contribution of the former to the total thermopower. This opens a new route toward high-efficiency thermoelectric materials. We also examine the thermoelectric reciprocity relations for these macroscopic systems.