Electrical Switching and Memory Effects in Electroactive Polymers Containing Electron-Donor and -Acceptor Moieties

Abstract

Electroactive polymers have been of interest as alternatives to traditional inorganic semiconductor materials for application in electronic memory devices. In comparison to silicon-based memory devices, polymer electronic memories exhibit low-cost potential, simplicity in structure, good scalability, 3D stacking capability, and ease of processing. A series of electroactive polymers, including functional polyimides, polyfluorene copolymers, azobenzene-containing polymers and graphene oxide (GO)-polymer complexes, which contains electron-donor and -acceptor moieties within a single macromolecule, have been designed in this work. Electrical switching and memory effects of these polymers have been studied in terms of their current density-voltage (J-V) characteristics under electrical sweeps. The memory effects, including magnitudes of the ON and OFF state currents, volatility and reversibility of the ON state, and switching threshold voltages, are dependant to a large extent on the molecular structures. The effects of different functional groups (electron-donor or -acceptor moieties) on the resultant memory effects have been studied with the aid of molecular simulation and experimental characterization. The molecular structure-dependent switching and memory effects illustrate that it is possible to tune the electrical switching and memory behaviors of polymers via molecular design and synthesis.