Toray Boosts Carrier Mobility of Coating-type CNT-TFT

Feb 14, 2014
Tetsuo Nozawa, Nikkei Electronics
The single-wall CNT-TFT prototyped by Toray (photo courtesy of Toray)
The single-wall CNT-TFT prototyped by Toray (photo courtesy of Toray)
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Toray Industries Inc achieved a carrier mobility of 13cm2/Vs and electric current on/off ratio of 106 with a TFT made by using single-wall carbon nanotubes (CNTs) and a coating process.

This was announced Feb 12, 2014. The company aims to commercialize the TFT in about 2016.

Toray has been engaged in the development of coating-type TFTs made by combining single-wall CNTs and organic semiconductors for a project organized by Japan's New Energy and Industrial Technology Development Organization (NEDO) (See related article). Specifically, it is developing a technology of preventing condensation of single-wall CNTs and evenly dispersing single-wall CNTs in a solution.

Higher semiconductor purity of single-wall CNTs improves carrier mobility, reduces variation

This time, Toray made a TFT by using a single-wall CNT that has a very high semiconductor purity and was developed by the Technology Research Association for Single Wall Carbon Nanotubes (TASC) in addition to the combination of single-wall CNTs and organic semiconductors and the technology of evenly dispersing single-wall CNTs. As a result, the company succeeded in improving TFT carrier mobility.

Also, with the single-wall CNT, variation in properties among TFTs was reduced by 75%. In the past, metal-type single-wall CNTs, which are contained in TFT materials, short-circuited electrodes, increasing the variation. This time, the possibility of such a short circuit drastically dropped, reducing the variation.

Toray plans to announce the latest results at the 61st JSAP Spring Meeting, 2014, which will take place from March 17 to 20, 2014, in Sagamihara City, Kanagawa, Japan.