Structural Control of Carbon Nanotube Networks for High-Performance Devices

In recent years, single walled carbon nanotube (swCNT)-based network devices were extensively studied for various practical applications such as transistors, sensors, etc. However, `random' network-based devices have been suffering from various limitations such as poor on-off ratio, decreased mobility and conductivity with reduced channel width. Herein, we report a simple but efficient strategy to significantly improve the performance of network-based devices by controlling the `network structures'. In this method, self-assembly monolayer was utilized to control the structures of CNT networks with desired connectivity. For example, as the channels of swCNT-based transistors became narrower, swCNTs aligned in the channels, which resulted in the enhancement of their on--off ratios. Significantly, the aligned network channels exhibited enhanced conductivity and mobility with reduced line width, which is a completely opposite behavior to randomly oriented swCNT networks or even conventional silicon-based devices. Furthermore, we could also improve the sensitivity of swCNT network-based sensors by aligning swCNTs in the networks.