The 3 method is a dynamic measurement technique developed for determining the thermal conductivity of thin films or semi-infinite bulk materials. A simplified model is often applied to deduce the thermal conductivity from the slope of the real part of the ac temperature amplitude as a function of the logarithm of frequency, which in-turn brings a limitation on the kind of samples under observation. In this work, we have measured the thermal conductivity of a forest of nanowires embedded in nanoporous alumina membranes using the 3 method. An analytical solution of 2D heat conduction is then used to model the multilayer system, considering the anisotropic thermal properties of the different layers, substrate thermal conductivity, and their thicknesses. Data treatment is performed by fitting the experimental results with the 2D model on two different sets of nanowires (silicon and BiSbTe) embedded in the matrix of nanoporous alumina templates, having thermal conductivities that differ by at least one order of magnitude. These experimental results show that this method extends the applicability of the 3 technique to more complex systems having anisotropic thermal properties.
This paper presents a study of the contact resistance between a metal M (M = Ni, Pt, and Au) and an array of n-type Bi2Te3−xSex thermoelectric nanowires deposited through the electrodeposition process in the alumina membrane. Contact resistances between different metals and thermoelectric nanowires have been tested and characterized after optimization of the mechanical thinning and polishing process of the top part of the membrane. A low areal contact resistance of 87 µΩ cm2 obtained with Au as the contact electrode is very encouraging for the development of thermoelectric modules based on nanowires in their membranes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.