Highly temperature-tolerant p-type carbon nanotube transistor doped with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile

Abstract

The development of chemical doping methods for carbon nanotubes (CNTs) is essential for various electronic applications. However, typical p-doping methods for CNT thin-film transistors (TFTs), using oxygen and water from the atmosphere, are quite sensitive to changes in the surrounding environment, and thus, their poor temperature tolerance is a critical problem during device fabrication. As a p-dopant for CNT–TFTs, we used 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HATCN), which is a strong electron acceptor aromatic compound. The HATCN-doped CNT–TFTs exhibited p-type characteristics after exposure to a high-temperature environment of 200 °C, and prolonged heating did not degrade the p-doping performance of HATCN. In addition, stable p-type characteristics even under ambient conditions were obtained by encapsulating the surface of the device with a Parylene–Al2O3 bilayer.