Cross-plane thermal conductivity of a PbSnSe/PbSe superlattice material

The cross-plane thermal conductivity of a PbSnSe/PbSe multi-period superlattice (SL) grown by molecular beam epitaxy is obtained from continuous wave photoluminescence (PL) measurements and finite element analysis (FEA). PL measurement and FEA for a structure consisting of a multiple quantum well light emitting layer on top of a PbSnSe/PbSe SL with three different periodicities of 2.4, 3.6, and 4.8 nm revealed a cross-plane lattice thermal conductivity of 0.8 W/mK. The 58% reduction relative to the 1.9 W/mK value for bulk PbSe is attributed to enhanced scattering and/or reflection of acoustic phonons within the short-period SL material.