超高純度かつ高結晶性半導体カーボンナノチューブの迅速分離法の開発と伝導特性評価

单壁碳纳米管（SWCNTs）在薄膜晶体管（TFT）等高性能半导体器件中具有广阔的应用前景。然而，取决于结构，SWCNT通常表现出金属和半导体性质。此外，半导体单壁碳纳米管（s-SWCNT）还具有不同的载流子迁移率，这与它们的直径成反比。因此，纯化大直径s-SWCNT是实现其高性能TFT应用所必需的。在这里，我们展示了使用温度控制的凝胶过滤和低组成梯度洗脱的组合的大直径的s-SWCNTs的纯化。通过将分离温度控制在310 K，大直径s-SWCNT被充分吸附在柱上，而大直径金属SWCNT（m-SWCNT）通过柱。随后，低组成梯度洗脱将大直径s-SWCNT与小直径s-SWCNT和m-SWCNT分离。因此，平均直径为1.9 nm的s-SWCNT已被成功分离并用于制造TFT。与由通常获得的1.5 nm直径的s-SWCNT制造的那些相比，由1.9 nm直径的s-SWCNT制造的TFT表现出高1.6倍的载流子迁移率和高1.3倍的电流密度。因此，我们不仅成功地纯化了大直径s-SWCNT，而且还证明了它们比通常纯化的小直径s-SWCNT优越的上级性能。

Single-wall carbon nanotubes (SWCNTs) are promising materials for high performance semiconductor devices application such as thin-film transistors (TFTs). However, SWCNTs are typically exhibit both metallic and semiconducting properties depend on the structure. In addition, the semiconducting SWCNTs (s-SWCNTs) also has various carrier mobility which inversely related to their diameter. Thus, purifying large diameter s-SWCNTs is necessary to realize their high performance TFTs application. Here, we demonstrate the purification of large diameter s-SWCNTs using combination of temperature-controlled gel filtration and low composition gradient elution. By controlling the separation temperature at 310K, large diameter s-SWCNTs are sufficiently adsorbed on the column while the large diameter metallic SWCNTs (m-SWCNTs) pass through the column. Subsequently, low composition gradient elution separate the large diameter s-SWCNTs from the small diameter s-SWCNTs and m-SWCNTs. Thus, s-SWCNTs with average diameter of 1.9 nm has been successfully separated and used to fabricate TFTs. Compared to those fabricated from the typically obtained 1.5-nm-diameter s-SWCNTs, the TFT fabricated from 1.9-nm-diameter s-SWCNTs exhibit 1.6 times higher carrier mobility and 1.3 times higher on current density. Therefore, we have not only succeeded in purifying large diameter s-SWCNTs, but also demonstrate their superior performance than the small diameter s-SWCNTs which are typically purified.