Composite Films of Oxidized Multiwall Carbon Nanotube and Poly(3,4-ethylenedioxythiophene): Polystyrene Sulfonate (PEDOT:PSS) As a Contact Electrode for Transistor and Inverter Devices

摘要

Composite films of multiwall carbon nanotube (MWNT)/poly(3,4-ethylenedioxythiophene) polymerized with poly(4-styrenesulfonate) (PEDOT;PSS) were prepared by spin-coating a mixture solution. The effect of the MWNT loading and the MWNT oxidation, with acid solution or ultraviolet (UV)'Ozone treatment, on the film properties such as surface roughness, work function, surface energy, opticaltransparency and conductivity were studied. Also pentacene thin film transistors and inverters were made with these composite films as a contact metal and the device characteristics were measured. The oxidation of MWNT reduced the conductivity of MWNT/PEDOT:PSS composite film, but increased the work function and transparency. UV-ozone treated MWNT/ PEDOT:PSS composite film showed higher conductivity (14000 Ω/□) and work function (4.9 eV) than acid-oxidized MWNT/ PEDOT:PSS composite film and showed better performance as a source/drain electrode in organic thin fibn transistor (OTFT) than other types of MWNI7PE0OT:PSS composite films. Hole injection barrier of the UV-ozone treated MWNT/ PEDOT:PSS composite film with pentacene was significantly lower than any other films because of the higher work function.