Enhanced thermoelectric performance of (Ta _{1− x} Mo _x ) ₄ SiTe ₄ /polyvinylidene fluoride (PVDF) organic–inorganic flexible thermoelectric composite films

Recently, one-dimensional van der Waals crystalline Ta₄SiTe₄ has been reported as a promising component to form flexible organic/inorganic thermoelectric films due to their unique structure and excellent electronic transport properties. However, Ta₄SiTe₄ based flexible composite films carefully tuned by elemental doping have not been studied yet. In this study, we systematically synthesized (Ta_1-xMo_x)₄SiTe₄ whiskers, and a series of (Ta_1-xMo_x)₄SiTe₄/PVDF composite films with varying Mo doping concentrations were also prepared. Upon doping Mo at the Ta-sites, the electrical conductivity was dramatically enhanced, while the Seebeck coefficient decreased with a higher doping content. As a result, (Ta_0.995Mo_0.005)₄SiTe₄/PVDF exhibited a maximum power factor of 547.5 μW m^-1 K^-2, which is among the highest for organic-inorganic composite films and is more than double that of the undoped Ta₄SiTe₄/PVDF composite film.