Anisotropic Thermal Diffusivity Measurements in Nanostructured Samples Using a Photothermoelectric Technique

Knowledge of the thermal transport properties in thin films and nanostructures is critical for a wide range of applications in microelectronics, photonics, micro-electro-mechanical-systems, and thermoelectrics. The last twenty years have seen significant developments in thin-film thermal characterization techniques. Despite these advances, the characterization of the thermal transport properties in low-dimensional systems remains a challenging task. Recently, thermal properties of nanowire/nanotube nanocomposites such as thermoelectric nanowires and aligned carbon nanotubes (CNT) deposited on silicon substrates or in alumina or polymer matrix have attracted a great interest due to their possible applications in high efficiency thermoelectric energy conversion and thermal management applications. However, a major challenge for thermal characterization of nanowire/nanotube composites is their thermal anisotropy. This work presents measurements of anisotropic thermal properties using a photothermoelectric technique.