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.

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.…”

Inkjet printed thin and uniform dielectrics for capacitors and organic thin film transistors enabled by the coffee ring effect

“…In order to increase the k value of the dielectric it is common to add high-k materials such as barium titanate (BaTiO 3 ). This approach has been often reported in the literature [6,11,12,13], with k values of printed dielectrics reported as high as 102 [13]. However the approach has limitations [14], chiefly of which is the difficulty in obtaining a thin, defect free film with a suitable nanoparticle loading.…”

Dielectric Behavior of Thin Polymerized Composite Layers Fabricated by Inkjet-Printing

“…When printing on flexible substrates, ceramic/polymer composites can be used as a dielectric material. These composites have a good manufacturability and can have relatively high permittivities without the need for further thermal treatment [ 8 , 9 , 10 , 11 , 12 ]. For the application under ambient conditions, a temperature-independent permittivity is an important prerequisite.…”