title: Electrical Conductance Tuning and Bistable Switching in Poly(N-vinylcarbazole)-Carbon Nanotube Composite Films.
abstract: By varying the carbon nanotube (CNT) content in poly(N-vinylcarbazole) (PVK) composite thin films, the electrical conductance behavior of an indium-tin oxide/PVK-CNT/aluminum (ITO/PVK-CNT/Al) sandwich structure can be tuned in a controlled manner. Distinctly different electrical conductance behaviors, such as (i) insulator behavior, (ii) bistable electrical conductance switching effects (write-once read-many-times (WORM) memory effect and rewritable memory effect), and (iii) conductor behavior, are discernible from the current density-voltage characteristics of the composite films. The turn-on voltage of the two bistable conductance switching devices decreases and the ON/OFF state current ratio of the WORM device increases with the increase in CNT content of the composite film. Both the WORM and rewritable devices are stable under a constant voltage stress or a continuous pulse voltage stress, with an ON/OFF state current ratio in excess of 10(3). The conductance switching effects of the composite films have been attributed to electron trapping in the CNTs of the electron-donating/hole-transporting PVK matrix.
authors.affiliation: Department of Chemical & Biomolecular Engineering.
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Qi-Dan
authors.initials: QD
authors.lastname: Ling
authors.forename: Eric Yeow Hwee
authors.initials: EY
authors.lastname: Teo
authors.forename: Chun-Xiang
authors.initials: CX
authors.lastname: Zhu
authors.forename: D Siu-Hung
authors.initials: DS
authors.lastname: Chan
authors.forename: Koon-Gee
authors.initials: KG
authors.lastname: Neoh
authors.forename: En-Tang
authors.initials: ET
authors.lastname: Kang