Field of Expertise: Advanced Material Science
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Field of Expertise: Advanced Material Science | |
Conducting Cellulose Fiber Networks as Flexible Substrate for Optoelectronic Applications Electronics based on natural materials is becoming increasingly attractive. Paper, an omnipresent composite of pressed cellulose fibers, has been considered for flexible substrate in thin film electronics in the past. However, successful realizations for according diodes were so far only done by smoothing the natural microstructure either with a high density of fillers or by coating the surface with a plastic layer to prevent short circuits. Drawback of this approach is that light transparency is hindered and therewith any chance on optoelectronic applications. The present study instead, uses filler-free cellulose fiber networks, where each individual fiber acts as integrated carrier of the entire diode structure, consisting of anode, photoactive layer and cathode. Thus, short circuiting is prevented and the accessible photosensitive surface area is greatly increased. The "bottom" electrode is thereby established by adsorption of long silver nanowires wrapped around the cellulose fiber surface, subsequent to paper formation. The conductive cellulose fiber network shows electrical conductivities as high as common ITO substrates, even at low loads, thereby preserving adequate visible transparency. As follow-on coating photosensitive conjugated polymers are applied and finalized by top electrode electrode. Electrical and optical properties of the conductive cellulose fiber network and the diode structures based upon will be shown, along with their associated micromorphology. |