Thermoelectric Composites from the Assembly of SWCNT-Triphenylamine and Alkylated Naphthalene Diimide

Based on naphthalene diimide (NDI), an alkylated naphthalene NDI with flexible side-chains was synthesized as a potential thermoelectric material. Then, n -type NDI/single-walled carbon nanotubes (SWCNT)-triethylamine composite films with different mass ratios of NDI to SWCNTs were prepared by drop-casting. The structures and properties of the composites were characterized by Raman spectroscopy, x-ray diffraction, ultraviolet–visible (UV–Vis) spectroscopy, scanning electron microscope, and transmission electron microscope, which indicated that strong interfacial interactions existed between NDI and SWCNTs. It was found that the NDI/SWCNT-triethylamine composite with an NDI to SWCNTs mass ratio of 1:1 exhibits a power factor of 34.9 μ Wm −1 K −2 at room temperature, and when the temperature rises to 418 K, the maximum value of the power factor reaches 64.9 μ Wm −1 K −2 . These results demonstrate an effective way to enhance thermoelectric performance by improving interactions at organic and inorganic interfaces, which can also broaden the research scope of composite thermoelectric materials.