Structural effect on controllable resistive memory switching in donor-acceptor polymer systems

Controllable bistable electrical conductivity switching behavior and resistive memory effects have been demonstrated in Al/polymer/indium-tin oxide (ITO) sandwich structure devices, constructed from non-conjugated vinyl copolymers of PTPA(n)OXD(m) with pendant donor-acceptor chromophores. The observed electrical bistability can be attributed to the field-induced intra-and intermolecular charge transfer interaction between triphenylamine electron donor (D) and oxadiazole electron acceptor (A) entities, and is highly dependent on the chemical structure of the copolymers. The vinyl copolymers showed different memory behaviors, which depended on the loading of D/A ratios. The polymers containing only donor or acceptor moieties showed as insulators, the polymers containing both donor and acceptor moieties showed as WORM, flash and DRAM as D/A ratio increased. The structural effect on the physicochemical and electronic properties of the PTPA(n)OXD(m) copolymers, viz surface morphology, thermal stability, optical absorbance and photoluminescence, and molecular orbital energy levels, were investigated systematically to study the factors that influence the memory characteristics of the devices. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.