All-Polymer Bistable Resistive Memory Device Based on Nanoscale Phase-Separated PCBM-Ferroelectric Blends

All polymer nonvolatile bistable memory devices are fabricated from blends of ferroelectric poly(vinylidenefluoridetrifluoroethylene (P(VDF-TrFE)) and n-type semiconducting [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The nanoscale phase separated films consist of PCBM domains that extend from bottom to top electrode, surrounded by a ferroelectric P(VDF-TrFE) matrix. Highly conducting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) polymer electrodes are used to engineer band offsets at the interfaces. The devices display resistive switching behavior due to modulation of this injection barrier. With careful optimization of the solvent and processing conditions, it is possible to spin cast very smooth blend films (Rrms approximate to 7.94 nm) and with good reproducibility. The devices exhibit high Ion/Ioff ratios (approximate to 3 x 103), low read voltages (approximate to 5 V), excellent dielectric response at high frequencies (Er approximate to 8.3 at 1 MHz), and excellent retention characteristics up to 10 000 s.