SYNTHETIC TRANSVERSETHERMOELEMENTS WITHA POROUS COMPONENT

摘要

It is possible to exploit the anisotropy of the Seebeck coefficient in a transverse thermoelementin which the flows of heat and electricity are perpendicular to one another. However, it doesnot seem that any single-phase material has properties that can be utilised effectively in thisway. On the other hand, substantial transverse thermoelectric effects can be observed in a two-phase layered material. Previous studies have been devoted to composites made from asemiconductor and either a metal or semimetal. However, we show here that transversethermoelements made from two semiconductors can have superior properties. One of therequirements is a substantial difference between the electrical and thermal conductivities ofthe two materials and it is shown that this can be achieved if one of them is porous orotherwise discontinuous. Our results should lead to transverse thermoelements with a figure ofmerit that is comparable with that of the best conventional thermocouples. Bearing in mindthat infinite multistaging can be achieved by suitable shaping of a transverse thermoelement, itseems likely that a temperature depression of more than 100° will be reached using atransverse Peltier cooler.