Dielectric Properties of a Printed Sol–Gel Matrix Composite

Abstract

Low temperature processable materials with high dielectric constants are required for application on flexible organic substrates, for example, in printed electronics. To date, mainly organic polymers with embedded functional particles have been investigated for this purpose. For the first time, we present a printable dielectric composite material composed of ferroelectric high permittivity particles (BaTiO3) bonded by a mainly inorganic sol–gel derived network. The exemplary optimization of the properties by varying the sol–gel precursor illustrates the potential of sol–gel chemistry for printable functional materials. An operational gravure printed capacitor including printed silver electrodes is presented. The measured dielectric constants are among the highest reported in literature for low temperature cured films with moderate dissipation factors. Besides these promising dielectric properties, this composite film shows a ferroelectric response.

Ferroelectric properties of composites containing BaTiO3nanoparticles of various sizes

“…It follows that the combinations of pulse voltage and polarization measured by the PUND method are points on a ferroelectric hysteresis loop in which the remanent polarization of the composite film is plotted versus the applied electric field. So far we have applied this measurement method to porous particle packings [39], to those with the porosity filled with a liquid [40], to composites with various polymeric matrix phases [37,40], and to those with sol-gel derived matrix phases [38]. A polymer with a high dielectric constant, as used in this paper, effectuates high electric fields in particles (see equation ( 4)) which results in larger polarization values in them.…”

Additive electronics manufacturing via droplet jetting technologies: materials, methods, applications, and opportunities

“…In some cases, the particular application drives the choice of dielectric material based on material properties such as dielectric constant, breakdown strength, thermal stability, and film microstructure. The dielectric constant, or relative permittivity, is a useful measure to help classify different printed materials, with high dielectric constant useful for capacitive coupling (transistor gates, capacitors), 131 while low dielectric constant is generally preferred for insulating characteristics. 130 A common device that relies on dielectrics is the thin-film transistor (TFT), a basic building block for more complex electronic circuits.…”

Printable and flexible electronics: from TFTs to bioelectronic devices

“…Moreover and in order to reduce leakage currents of thin dielectric films, the use of cross-linked polymer blend (CPB), fabricated both by spin coating and gravure printing, has been proposed. 103 Lehnert et al 104 reported a printable high dielectric constant material composed of ferroelectric barium titanate (BaTiO 3 ) particles. A hybrid ink consisting of BaTiO 3 and PMMA has also been employed as a gate insulator in fully printed TFTs fabricated on a flexible PET substrate.…”