Electron transport of suspended quasi-metallic carbon nanotube transistors in split gate configuration

We investigate the electron transport of quasi-metallic carbon nanotube field-effect-transistors using split gate structures. The transistor exhibit metallic behavior at room temperature. At cryogenic temperatures, the device starts to exhibit semiconducting behavior with band-to-band tunneling. We characterize the device performance and show that the schottky contacts of quasi-metallic nanotube devices cannot be ignored. Our measurements give insights into the magnitude of the band gap of these quasi-metallic carbon nanotubes which can have potential narrow band gap device applications in the future.