Enhancement of ambipolar characteristics in single-walled carbon nanotubes using C-60 and fabrication of logic gates

Abstract

We demonstrate a technique to convert p-type single-walled carbon nanotube (SWNT) network transistor into ambipolar transistor by thermally evaporating C-60 on top. The addition of C-60 was observed to have two effects in enhancing ambipolar characteristics. First, C-60 served as an encapsulating layer that enhanced the ambipolar characteristics of SWNTs. Second, C-60 itself served as an electron transporting layer that contributed to the n-type conduction. Such a dual effect enables effective conversion of p-type into ambipolar characteristics. We have fabricated inverters using our SWNT/C-60 ambipolar transistors with gain as high as 24, along with adaptive NAND and NOR logic gates. (C) 2015 AIP Publishing LLC.