Bistability in Doped Organic Thin Film Transistors (Preprint)

摘要

Organic thin film transistors (TFTs) with the conducting polymer poly(3,4-ethylenedioxyt hiophene):poly(styrene sulfonic acid), PEDOT:PSS, as the active layer and crosslinked, layer-by-layer assembled poly(allylamine hydrochloride)/poly(acrylic acid) (PAH/PAA) multilayers as the gate dielectric layer were investigated. A combination of spectroscopic data and device performance characteristics were used to study the behavior of these TFT devices under a variety of controlled environmental test conditions. It was shown that depletion and recovery of the device can be induced to occur in a means that is consistent with the electrochemical oxidation and reduction of water contained in the film. In addition to acting as a reactant, moisture also acts as a plasticizer to control the movility of other species contained in the film and thereby permits bistable operation of these devices. Raman spectroscopy was used to show that the observed device switching behavior is due to a change in the PEDOT doping level.