Conference Program - LOPE-C 2011

SCIENTIFIC CONF. | THURSDAY-JUNE 30, 2011
Track 4
Inorganic Materials (11:30 am - 01:20 pm) | LOCATION HARMONIE D / LEVEL C2
12:40 pm Transparent nanocomposites with high dielectric constant
Mr Tobias Lehnert,
INM ? Leibniz-Institut für Neue Materialien gGmbH, Germany
In general low temperature processable materials with high dielectric constant are required for applications on flexible organic substrates, for example in printed electronics.
Organic polymers which can naturally be used in printed electronics suffer from low dielectric constants, whereas ceramic capacitors are well established in conventional
electronics but they need a high temperature sintering step to develop their superior dielectric properties. To combine these exclusive properties mainly low temperature
processable polymers with embedded functional ceramic particles are investigated in the literature. The 0-3 connectivity composite approach usually fails for applications
were transparency is a second requirement next to the low temperature processability, for example in display applications. By varying the filler content in the composite we
were able to develop films with high dielectric constants in the range of ?r ? 40 which exceeds available polymer solutions by concurrently maintaining the high
transparency of the polymer matrix in the visible range. The curing temperature of these films is below 200°C which makes them appropriate for printed electronics. This
promising result was obtained by using small BaTiO3 nanoparticles as ceramic filler and providing a very good dispersion state of the particles in the polymer matrix as a
maximum agglomerate size of ~ 20 nm is required for transparency. Besides its good dielectric properties these multifunctional composites exhibit a very high refractive
index which opens possible application fields in printed optics or printed optoelectronics.
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