Tunable dielectric constant of polyimide–barium titanate nanocomposite materials as the gate dielectrics for organic thin film transistor applications

Abstract

We report on a systematic study of hydroxyl-containing polyimide (PI)-BaTiO 3 (BT) nanoparticle (NP) nanocomposite dielectric materials, to determine the effects of BT NPs loadings (X) for X ¼ 0, 2, 5, 8, 10, and 12 wt%, on p-type pentacene organic thin film transistors (OTFTs). A condensation reaction to produce well-dispersed BT NPs within the PI matrix was followed by spin-coating to form a dielectric thin film directly on a silicon substrate. The thermal, optical, surface, dielectric, and electrical properties of the PI-BPX hybrid dielectric composite correlated to BT content for each sample. The hybrid dielectric composites exhibit tunable insulating properties, including high dielectric constant values in the range 5.2-11.3, high capacitances from 3.1 to 27.9 nF cm À2 for a film thickness of approximately 350 nm, and low leakage current densities in the range of 1.85 Â 10 À7 to 2.76 Â 10 À6 A cm À2 at 2 MV cm À1 .Bottom-gate top-contact OTFTs fabricated using various PI-BTX hybrid dielectrics, exhibit low threshold voltages of À4.09-2.62 V, moderately high field-effect mobility rates of 3.36 Â 10 À2 $2.32 Â 10 À1 cm 2 V À1 s À1 , and high ON/OFF ratios of approximately 10 5 . This study opens a route towards transparent and highly stable hybrid dielectric materials with tunable dielectric properties, by careful selection of NPs and polymer matrix combinations.

Dielectric properties of graphene–iron oxide/polyimide films with oriented graphene

“…High‐dielectric‐constant ( k ) materials are widely used in microelectronics, including bypass capacitors, organic field‐effect transistors, organic thin‐film electroluminescent devices, electrical stress control applications, actuators, and energy‐storage devices . As one kind of high‐k materials, high‐k polymer composites have received increasing interest recently for their high k and easy processing .…”

Preparation and Application of Organic-Inorganic Nanocomposite Materials in Stretched Organic Thin Film Transistors

“…The relative parameters for thermal properties are listed in Table 1. This indicates that the thermal decomposition temperature increases with the content of TiO 2 -SiO 2 nanoparticles due to the formation of chemical bonding between polyimide and TiO 2 -SiO 2 , which can restrict the polyimide chain reaction, and the T d and thermal stability for the hybrid films thus increases as TiO 2 -SiO 2 content increases [22]. In addition, the addition of Jeffamine D2000 and polyurethane also increase the T d from 426 • C to 477 • C for B0-B40 and 405 • C to 454 • C for C0-C40.…”

“…Hybrid materials [22][23][24] are organic-inorganic polymer blends that are molecularly mixed and blended through van der Waals forces, hydrogen bonds, ionic bonds, or covalent bonds, thus overcoming…”

Modelling of Porous Piezoelectric Material and Potential Applications to Vibration Energy Harvesting

“…The porosity (P) is defined as the volume of the pores with respect to the total volume of inclusions and matrix material. Porosity in piezoelectric materials has already been highlighted as a beneficial characteristic for different applications such as hydrophone sensors [127,128], energy harvesting [71,92,129] or microelectronic devices due to their good tunable characteristics [130,131]. In reference [71], a theoretical energy harvester with a porous piezoelectric patch is modelled using the approach presented in [15].…”

“…Porosity in piezoelectric materials has already been highlighted as a beneficial characteristic for different applications such as hydrophone sensors [127,128], energy harvesting [68,71,92,125,129] or microelectronic devices due to their good tunable characteristics [130,131]. In reference [92], porous piezoelectric barium titanate (BaTiO 3 ) is sandwiched with non-porous barium titanate in order to improve the overall behaviour of the composite.…”