An Optical/Ferroelectric Multiplexing Multidimensional Nonvolatile Memory from Ferroelectric Polymer.

Abstract

Multiplexing physical dimensions to realize multidimensional storage in a single material has been a goal to increase storage density and data security. Multidimensional storage is only achieved in optical storage material (OSM) by far. Poly(vinylidene fluoride) (PVDF), a semicrystalline polymer, is widely studied as a candidate for ferroelectric random access (FeRAM). Herein, the atomic force microscopy (AFM)-based infrared spectroscopy techniqueis used to induce multilevel phase transformations in PVDF ultrathin film on nanometric scales and for writing/readout of IR signals. An optical/ferroelectric multiplexing PVDF memory, where information can be coded with independent four-level optical IR and bilevel ferroelectric signals, is demonstrated. High data security and a storage density up to 180 GBit in.-2 are achieved simultaneously. Owing to the different critical temperature for phase transformation (optical data, <167°C) and polarization switching (ferroelectric data, <100°C), the multiplexing memory can function both as optical read-only memory and FeRAM. This work expands material supporting physical dimensions multiplexing beyond OSM for the first time, opening up new opportunities for future high-capacity, multifunctional nano-memory. The strategy proposed here enables on-demand and tunable programming on IR waves, offering prospects for fabrication of active nano-optical devices.