| 研究実績の概要 |
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.
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