Piezoresponse force microscopy study on ferroelectric polarization of ferroelectric polymer thin films with various structural configurations

Abstract

Ferroelectric polymer-based memory devices have attracted much attention due to their potential in low-cost flexible memories. However, bad retention property of recorded logic states limited their applications. Though mechanisms of retention degradation in ferroelectric memories are complicated and still an open question, depolarization in ferroelectric polymer layer was regarded as the main influencing factor. Here we reported our piezoresponse force microscopy (PFM) study of retention property of polarization states on various ferroelectric polymer based structures. PFM results indicated that, as for ferroelectric/semiconductor structure and ferroelectric/insulator/semiconductor structure with thin insulating layer, both positive and negative polarization states could retain for a relatively long time. Mechanisms of good retention of polarization states were discussed. The discrepancy in bad retention of logic states and good polarization retention of ferroelectric layer was also analyzed.

Morphology and Ferroelectric Properties of Semiconducting/Ferroelectric Polymer Bilayers

“…In order to use more simple preparation methods, several works have been published aiming to achieve spin-coated ultrathin PVDFbased films with good ferroelectric properties on several functional substrates. 12,13 Besides the ferroelectric functionality of the thin films of P(VDF-TrFE), to obtain full profit from the synergetic properties of the pair ferroelectric/semiconducting polymers, the semiconducting polymer layer should also preserve its functionality, that is, its transport properties. In this context, studying fundamental properties of bilayers of semiconducting/ferroelectric polymers with nanometric dimensions may contribute to better control and device performance in more complicated designs.…”

“…The seminal work by Bune et al demonstrated that, in the limit of 2D ferroelectric polymer films, ferroelectricity is preserved in 1 nm thick films prepared by the Langmuir Blodgett method (two monolayers). In order to use more simple preparation methods, several works have been published aiming to achieve spin-coated ultrathin PVDF-based films with good ferroelectric properties on several functional substrates. , Besides the ferroelectric functionality of the thin films of P­(VDF-TrFE), to obtain full profit from the synergetic properties of the pair ferroelectric/semiconducting polymers, the semiconducting polymer layer should also preserve its functionality, that is, its transport properties.…”

Controlled Molecular Orientation through Intercalation in PVDF Thin Films: Exhibiting Ultralong Retention and Improved Leakage Current

“…33 Furthermore, there are a lot of studies on memory retention in organic ferroelectrics, particularly in P(VDF-TrFE); relatively little of this study has been done in PVDF thin films. 34,35 To the best of our knowledge, such ultralong retention of 20 days in organic ferroelectric has not been reported so far. Although there has been a lot of research done on the retention issue in the inorganic ferroelectric system, such as Pb(Zr,Ti)O 3 , SrBi 2 Ta 2 O 9 , LiNbO 3 , and BiFeO 3 (BFO).…”

The Impact of Contact Position on the Retention Performance in Thin‐Film Ferroelectric Transistors

“…Experimental approaches have investigated the distribution of polarization in the ferroelectric layer and displacement transients in the gate current [22][23][24][25][26][27] These methods expose the overall states of polarization distribution or get information at the surface. However, they do not make a detailed analysis of the electric field around the electrodes.…”