Experimental study of the effect of quantum-well structures on the thermoelectric figure of merit

Recently, it has been shown theoretically that it may be possible to increase the thermoelectric figure of merit ($Z$) of certain materials by preparing them in the form of two-dimensional quantum-well structures. Using $\mathrm{PbTe}/{\mathrm{Pb}}_{1-x}{\mathrm{Eu}}_x\mathrm{Te}$ multiple-quantum-well structures grown by molecular-beam epitaxy, we have performed thermoelectric and other transport measurements as a function of quantum-well thickness and doping. Our results are found to be consistent with theoretical predictions and indicate that an increase in $Z$ over bulk values may be possible through quantum confinement effects using quantum-well structures.