Regular arrays of highly ordered ferroelectric polymer nanostructures for non-volatile low-voltage memories

Abstract

Ferroelectric nanostructures are attracting tremendous interest because they offer a promising route to novel integrated electronic devices such as non-volatile memories and probe-based mass data storage. Here, we demonstrate that high-density arrays of nanostructures of a ferroelectric polymer can be easily fabricated by a simple nano-embossing protocol, with integration densities larger than 33 Gbits inch(-2). The orientation of the polarization axis, about which the dipole moment rotates, is simultaneously aligned in plane over the whole patterned region. Internal structural defects are significantly eliminated in the nanostructures. The improved crystal orientation and quality enable well-defined uniform switching behaviour from cell to cell. Each nanocell shows a narrow and almost ideal square-shaped hysteresis curve, with low energy losses and a coercive field of approximately 10 MV m(-1), well below previously reported bulk values. These results pave the way to the fabrication of soft plastic memories compatible with all-organic electronics and low-power information technology.

Coplanar switching of polarization in thin films of vinylidene fluoride oligomers

“…IV) 28 is two to three orders of magnitude lower than the previously reported values for VDF oligomers (100-200 MV/m), 21 and at least an order of magnitude lower than the lowest coercive field reported for the PVDF-TrFE nanostructures (of order 10 MV/m). 31 The coercive field value obtained from analysis of the PFM images is in good agreement with the macroscopic currentvoltage measurements (Fig. 5) performed in the LB deposited VDF oligomer films.…”

Effect of thermal annealing on ferroelectric domain structures in poly(vinylidene-fluoride-trifluorethylene) Langmuir-Blodgett thin films

“…[4][5][6][7] The ferroelectric polymers also have the distinct advantages of light weight, easy fabrication, mechanical flexibility, and low cost, 1,2 making them a viable material candidate for applications in nonvolatile memories, sensors, and photovoltaic devices. [8][9][10][11][12][13][14] Understanding the nanoscale properties of the ferroelectric domains in polymer thin films, especially in the presence of disorder pinning potential and thermal perturbation, is thus of significant fundamental interests, and is critical for size scaling of the polymer-based ferroelectric device applications. Piezo-response force microscopy (PFM) has proven to be a powerful tool to probe the ferroelectric domain structures and polarization switching dynamics at the nanoscale in ferroelectric polymers.…”

Nanoscale domain patterns in ultrathin polymer ferroelectric films

“…In spite of a very high coercive field required for switching [3], discovery of ferroelectricity in ultrathin P(VDF-TrFE) films with demonstrated electrical switchability in the range of just several volts [4] makes integration of these films into allorganic electronic systems more feasible. Recent fabrication of highly ordered arrays of P(VDF-TrFE) nanomesas for nonvolatile memories [5] underscored the importance of improving crystallinity to attain spatially uniform switching properties for device applications.…”