Obtaining air-stable and high-performance flexible n-type single-walled carbon nanotube (SWCNT)-based thermoelectric films used in wearable electronic devices is a challenge. In this work, the microstructure and thermoelectric properties of n-type SWCNTbased films have been optimized via doping C 60 and its derivative into polyethylenimine/ single-walled carbon nanotube (PEI/SWCNT) films. The result demonstrated that the dispersity of triethylene glycol-modified C 60 (TEG-C 60 ) was better in PEI/SWCNT films than that of pure C 60 . Among the prepared composite films, TEG-C 60 -doped PEI/SWCNT (TEG-C 60 /PEI/SWCNT) films exhibited the highest TE performance, achieving a peak electrical conductivity of 923 S cm −1 with a Seebeck coefficient of −42 μV K −1 at a TEG-C 60 /SWCNT mass ratio of 1:100. Compared to that of PEI/SWCNT, the power factor was increased significantly from 40 to 162 μW m −1 K −2 after the addition of TEG-C 60 , which was higher than that of films after the addition of C 60 . In addition, the n-type doped SWCNT films had good air stability at high temperatures, and the Seebeck coefficients of C 60 /PEI/SWCNT and TEG-C 60 /PEI/SWCNT at 120 °C were still negative and remained at 92% and 85%, respectively, after 20 days. Furthermore, a flexible TE device consisting of five pairs of p−n junctions was assembled using the optimum hybrid film, which generated a maximum output power of 3.6 μW at a temperature gradient of 50.2 K. Therefore, this study provides a facile way to enhance the thermoelectric properties of n-type carbon nanotube-based materials, which have potential application in flexible power generators.

The improvement of electrical conductivity of carbon nanotubes is still a challenge via tuning the carrier concentration and mobility with organic or inorganic dopants due to low doping efficiency. In this paper, single-walled carbon nanotubes (SWCNTs) have been doped with Cu3(BTC)2‧(H2O)3 (HKUST-1) as metal organic frameworks via simple mixing and vacumm filtration method. With fine acid or base post-treatment, the crystal structure of HKUST-1 was broken into fragments with more active sites and provided plenty of carriers injecting into SWCNTs. The electrical conductivity of SWCNTs/ HKUST-1 films was increased by almost 2.5 times compared to pristine SWCNTs at room temperature. The defect tuning of dopants on SWCNTs surface is an effective carrier injection strategy, which provides a way to improve the electrical conductivity of SWCNTs.