Schottky diodes using as-grown single-walled carbon nanotube ensembles

摘要

We demonstrate rectifying Schottky diodes fabricated using as-grown single-walled carbon nanotubes (SWNT) ensembles, without removing the metallic SWNTs, for optoelectronic device applications. The SWNTs are contact by a low work-function metal through a high-bandgap charge-blocking layer (ZnO) resulting in highly-nonlinear current-voltage properties compared to control ensemble SWNT devices, fabricated without a charge-blocking layer, which show resistive behaviour. This significant improvement in diode behaviour is obtained by reducing source-drain leakage from the metallic SWNTs using the charge-blocking layer which channels charge transport via the semiconducting SWNTs. Moreover, we explore an alternative method of creating the charge barrier layer via oxidizing a thin film of Zn deposited on directly on the SWNTs which could potentially reduce cost and increasing scalability of this technique to obtain highly rectifying diodes from as-grown ensemble SWNTs.