Published online by Cambridge University Press: 06 March 2012
IV-VI semiconductor structures grown by molecular beam epitaxy (MBE) have been used to measure the cross-plane thermal conductivity of PbSe and PbSe/PbSnSe/PbSe multiperiod superlattice (SL) materials. Continuous wave photoluminescence (PL) measurements were used to determine epilayer temperatures localized to multiple quantum well (MQW) light emitting layers on top of various IV-VI materials structures. These data combined with finite element analysis (FEA) were used to extract cross-plane thermal conductivity values for different materials designs. Structures consisting of PbSe/PbSnSe/PbSe SL materials with multiple periodicities exhibited cross-plane lattice thermal conductivity values as low as 0.30 W/mK, a significant reduction relative to the 1.9 W/mK value for bulk PbSe. This work shows that lattice thermal conductivity reduction offers a highly viable approach for improving thermoelectric materials performance.