Photothermoelectric effect as a means for thermal characterization of nanocomposites based on intrinsically conducting polymers and carbon nanotubes

摘要

Recent advances in nanostructured materials have spurred the development of improved thermoelectric (TE) devices. Performances of these systems are strongly linked to their thermal conductivities. Accurate measurement techniques of thermal parameters are therefore required to assess the efficiency of new thermoelectric materials. In this work, thermal parameters (thermal diffusivity, thermal conductivity, and thermal effusivity) of nanostructured thermoelectric composites based on oxidised or unoxidised carbon nanotubes at 6.6 wt. % mixed with doped nanofibrous polyaniline have been measured with a novel photothermal method called photothermoelectricity. The thermal parameters are obtained from analyses of the phase and amplitude of the thermoelectric signal generated by the sample when it is periodically heated by a laser beam. Figure of merits are calculated from these results which indicate that the best nanocomposite exhibits almost four order of magnitude improvement compared with that of the pure doped matrix at room temperature.