Methylation-Induced Reversible Metallic-Semiconducting Transition of Single-Walled Carbon Nanotube Arrays for High-Performance Field-Effect Transistors

Acquirement of aligned semiconducting single-walled carbon nanotube (s-SWNT) arrays is one of the most promising directions to break Moore's Law, thus developing the next-generation electronic devices. Despite that widespread approaches have been developed, it is still a great challenge to facilely prepare s-SWNT arrays with tunable electronic properties. Herein, a different perspective is proposed to produce s-SWNT arrays by implementing reversible methylation reactions on the as-grown aligned SWNT arrays. In this way, the metallic single-walled carbon nanotubes (m-SWNTs) are selectively and reversibly methylated to acquire semiconducting properties, to afford tunable electronic properties of the as-obtained SWNT arrays in a highly controllable and simple manner. Electrical measurements suggest a high fraction of s-SWNTs is attained (>97.5%) after methylation, facilitating its exceptional performance as a field-effect transistor (FET) with an on-off ratio of up to 17543. This method may provide a new way for the preparation of s-SWNT arrays with tunable electronic properties and impressive prospects toward the fabrication of high-performance FETs.