CNT thin-film transistors are expected to enable the fabrication of high-performance, flexible and transparent devices using relatively simple techniques. However, as-grown CNTs usually contain both metallic and semiconducting nanotubes, which makes it difficult to realize high performance devices.
In this work, high-performance CNT films and devices were fabricated on flexible and transparent substrates using floating-catalyst chemical vapor deposition followed by a simple gas-phase filtration and transfer process. The resulting nanotube network has a well-controlled density and a unique morphology, consisting of long (-10μm) nanotubes connected by low-resistance Y-shaped junctions. The transistors showed a mobility of 35cm2 V-1 s-1 and an on/off ratio of 6×106 simultaneously. Flexible integrated circuits, including a 21-stage ring oscillator and master-slave flip-flops were fabricated to operate as sequential logic with propagation logic delay of 12μs.
This fabrication procedure should prove to be scalable, for example, by using high-throughput printing techniques under roll-to roll process.
Details were presented in Nature Nanotechnology*.