Strategic Customization of Polymeric Nanocomposites Modified by 2D Titanium Oxide Nanosheet for High‐k and Flexible Gate Dielectrics. Issue 17 (14th March 2021)

• Record Type: Journal Article
• Authors: Jang, Moonjeong; Park, Se Yeon; Kim, Seong Ku; Jung, Dowon; Song, Wooseok; Myung, Sung; Lee, Sun Sook; Yoon, Dae Ho; An, Ki‐Seok
• Is Part Of: Small. Volume 17:Issue 17(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-03-14
• Subjects: dielectric composite -- flexibility -- gate dielectrics -- nanocomposite -- titanium dioxide (TiO 2) nanosheets; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202007213
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Organic polymer‐based dielectrics with intrinsic mechanical flexibility and good processability are excellent candidates for the dielectric layer of flexible electronics. These polymer films can become even more rigid and electrically robust when modified through cross‐linking processes. Moreover, the composites formed by dispersing nanoscale inorganic fillers in a polymer matrix can exhibit further improved polarization property. However, these strategies can be challenging as homogeneous dispersion of nanomaterials in the matrix is difficult to achieve; thus, degradation of electrically insulating properties of nanocomposite layers is often observed. Here, a high‐ k, pinhole‐free, and flexible poly(vinyl alcohol) (PVA)‐based nanocomposite dielectric is presented, incorporating 2D TiO2 nanosheets (NSs) for the first time. Despite the attractive dielectric constant, exceptional flexibility, and electrically insulating property of PVA‐TiO2 nanocomposites, only few studies on these materials have been reported. The organic/inorganic nanosheet hybrid layer, which reaches an unprecedentedly high dielectric constant of 43.8 (more than four times higher than that of cross‐linked PVA), also exhibits an outstanding leakage current density as low as 10 −9 A cm −2 . Furthermore, the repeated bending tests for nanocomposite capacitors reveal their capability of operating without any deterioration of their performances even after 1000 iterations of bending cycles at a bending radius of 3 mm. Abstract : A strategy for realizing a high dielectric constant (≈43.8) and outstanding insulating properties (i.e., leakage current) of the PVA matrix is demonstrated by interfacial complexation with synthesized TiO2 nanosheets. Furthermore, the performances of nanocomposite‐based flexible capacitors exhibit cycling stability without any deterioration even after 1000 iterations of bending. This work may open possibilities to replace current polymer/inorganic filler nanocomposite technologies.