The pick-up stick transistor

• Published in: Solid state communications 2005-09, Vol.135 (9), p.638-644
• Main Authors: Blanchet, Graciela B., Bo, X.-Z., Lee, C.Y., Strano, M.S., Nuckolls, C.
• Format: Article
• Language: English
• Subjects: A. Nanostructures; A. Semiconductors; D. Electronic transport
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2005.04.044

We demonstrate an alternative path for achieving high transconductance organic transistors in spite of relatively large source to drain distances. The method is based on creating sub-percolating conducting networks either as a single layer composite or a bi-layer assembly. In the single layer composite, individual single wall carbon nanotubes (SWNT) and narrow ropes are dispersed in a soluble organic semiconducting host. The improvement of the electronic characteristic of such a scheme is equivalent to a 60-fold increase in mobility of the underlying organic semiconductor without reduction of the on/off ratio. In the semiconducting bi-layers pentacene is evaporated onto arrays of carbon nanotubes (SWNT) of varying connectivity. These field-induced sub-percolating networks allow an effective 10× reduction in source to drain distance that concurrent with a significant lowering in the pentacene crystallinity yields to a modest 2–5× increase in mobility without reduction in the on/off ratio. In both geometries, the majority of current paths between source and drain follow the metallic nanotubes but require a short, switchable semiconducting link to complete the circuit.