Advanced Functional Materials, Vol.24, No.10, 1372-1381, 2014
High- Performance Ferroelectric Memory Based on Phase- Separated Films of Polymer Blends
High-performance polymer memory is fabricated using blends of ferroelectric poly(vinylidene-fluoride-trifluoroethylene) (P(VDF-TrFE)) and highly insulating poly(p-phenylene oxide) (PPO). The blend films spontaneously phase separate into amorphous PPO nanospheres embedded in a semicrystalline P(VDF-TrFE) matrix. Using low molecular weight PPO with high miscibility in a common solvent, i.e., methyl ethyl ketone, blend films are spin cast with extremely low roughness (R-rms approximate to 4.92 nm) and achieve nanoscale phase seperation (PPO domain size < 200 nm). These blend devices display highly improved ferroelectric and dielectric performance with low dielectric losses (<0.2 up to 1 MHz), enhanced thermal stability (up to approximate to 353 K), excellent fatigue endurance (80% retention after 10(6) cycles at 1 KHz) and high dielectric breakdown fields (approximate to 360 MV/m).