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 PbTe/Pb₁-ₗEuₗTe 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.