Laser-Induced Nondestructive Patterning of a Thin Ferroelectric Polymer Film with Controlled Crystals using Ge₈Sb₂Te₁₁ Alloy Layer for Nonvolatile Memory

Abstract

We present a simple but robust nondestructive process for fabricating micropatterns of thin ferroelectric polymer films with controlled crystals. Our method is based on utilization of localized heat arising from thin Ge(8)Sb(2)Te(11) (GST) alloy layer upon exposure of 650 nm laser. The heat was generated on GST layer within a few hundred of nanosecond exposure and subsequently transferred to a thin poly(vinylidene fluoride-co-trifluoroethylene) film deposited on GST layer. By controlling exposure time and power of the scanned laser, ferroelectric patterns of one or two microns in size are fabricated with various shape. In the micropatterned regions, ferroelectric polymer crystals were efficiently controlled in both degree of the crystallinity and the molecular orientations. Nonvolatile memory devices with laser scanned ferroelectric polymer layers exhibited excellent device performance of large remnant polarization, ON/OFF current ratio and data retention. The results are comparable with devices containing ferroelectric films thermally annealed at least for 2 h, making our process extremely efficient for saving time. Furthermore, our approach can be conveniently combined with a number of other functional organic materials for the future electronic applications.

Enhanced Energy Conversion Performance of a Magneto–Mechano–Electric Generator Using a Laminate Composite Made of Piezoelectric Polymer and Metallic Glass

“…[9,13] The ferroelectric polymers and their copolymers have been considered attractive piezoelectric components in MME generators due to their characteristics such as low production cost, easy fabrication process, and flexible nature compared to inorganic piezoelectric materials. [14] In order to achieve all features, there have been various attempts to form polymeric piezoelectric films onto magnetostrictive metal substrates for the purpose of achieving the low-cost, flexible, bio-eco-friendly, and light-weight MME generators. In those attempts, the inherently flexible and piezoelectric polymers, poly(vinylidene fluoride) (PVDF), was spin-casted onto metal substrate and annealed at high temperature for crystallization.…”

Poly(vinylidene fluoride)/NH2-Treated Graphene Nanodot/Reduced Graphene Oxide Nanocomposites with Enhanced Dielectric Performance for Ultrahigh Energy Density Capacitor

“…The neutralized and separated GNDs were treated with ethylenediamine (EDA) to attach the −NH 2 groups onto the GNDs, leading to the enhanced hydrogen bonding interaction with the −CF 2 − dipoles of the PVDF. 11,12 GO sheets were synthesized according to modified Hummer's method, and the RGO sheets were prepared by the chemical reduction treatment of the GO in a mixture of N,N-dimethylformamide/water (DMF/water, 95:5, v/v). 47,48,64 Under our experimental condition, the PVDF, RGO, and NH 2 -treated GNDs were primarily dispersed in the DMF, DMF/water, and water, respectively.…”

Solvent-Assisted Gel Printing for Micropatterning Thin Organic–Inorganic Hybrid Perovskite Films

“…Although conventional photolithography, followed by dry and wet etching processes, easily accessible in current semiconducting industry, is most common and powerful for micropatterning, the patterning based on photolithography requires the additional design of materials and processes not to damage the intrinsic properties of a perovskite film, in particular during rather harsh develop and etching processes. Nondestructive micropatterning techniques can be alternatives, including inkjet printing and direct laser writing, microcontact printing, , micromolding in capillaries, − and microimprinting − and so on, but still only a few can be applicable for fabrication of micropatterns of thin and uniform perovskite films without complicated additional processes such as etching and lift-off. For example, the selective growth of perovskite crystals was made on the hydrophilic regions of a prepatterned silicon substrate developed by high-cost photolithographic patterning processes. − …”