[9p-E207-1~12] 12.3 Functional Materials and Novel Devices

3:00 PM - 3:15 PM JST(6:00 AM - 6:15 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[9p-E207-6] Synthesis of a cross-linked organic superbase with methyl(oligosiloxane) linker and its application to n-type doping of carbon nanotubes

〇(M1)Kazuki Nishimoto¹, Yasuko Koshiba^1,2, Azumi Akiyama^1,2, Masahiro Funahashi^1,2, Shohei Horike^1,2,3 (1.Kobe Univ, 2.Res. Ctr. Membr. & Film Tech., Kobe. Univ., 3.Ctr. Environ. Mgmt., Kobe Univ.)

Keywords:

thermoelectric effect,CNT,doping

Carbon nanotubes (CNTs) are promising thermoelectric materials owing to their high electrical conductivity and Seebeck coefficient, as well as their tunability between p- and n-type through doping. However, n-type CNTs readily revert to p-type upon exposure to air, heat, and humidity. Although TBD, an organic superbase, can maintain n-type characteristics for over six months at high temperatures in air, it is hygroscopic and vulnerable to humidity. In this study, we synthesized 2TBD-4SiO, a novel compound in which two TBD units are bridged by a hydrophobic oligosiloxane chain, to improve humidity resistance. A freestanding CNT film doped by immersion in a 2TBD-4SiO acetone solution showed n-type conversion, confirmed by a sign change of the Seebeck coefficient from positive to negative. Stability tests at 85°C and 85%RH demonstrated that the de-doping rate of 2TBD-4SiO-doped CNT was significantly lower than that of TBD-doped CNT, confirming improved humidity resistance.