Thermal Conductivity Of Bi/Sb Superlattice

ABSTRACTThe temperature-dependent cross-plane thermal conductivity of a 1-μm thick 50Å Bi / 50Å Sb superlattice on a (111) CdTe substrate was measured, using a differential 3-ω method. This method uses the temperature difference between the superlattice sample and a reference sample to calculate its cross-plane thermal conductivity. However, the substrate thermal conductivity is comparable to or smaller than the superlattice thermal conductivity near room temperature. This results in a very small or negative temperature difference, making the existing data reduction method inapplicable. Based on an improved model, the temperature-dependent thermal conductivity of the Bi/Sb superlattice is obtained and is about half of the literature value of Bi0.5Sb0.5 bulk alloy.