The thermoelectric power factor of a composite medium

The thermoelectric power factor P-e of a composite medium built of two serially connected planar components has been studied theoretically as a function of the volume fractions p(1),p(2) = 1 - p(1). This simplest case of composition shows that P-e(p(1)) can be enhanced to a maximum value that is greater than the power factors in both components if their thermoelectric properties satisfy certain algebraic inequalities, which are presented here. We have found that in a metal-thermoelectric composite, P-e(p(max)) is achieved at a very small thermoelectric fraction p(max) much less than 1 but at a relatively large composite figure of merit Delta(e).