News Article
R&D
Researchers from Munich-based universities and from German chemical company
Covion have developed a class of electroluminescent (EL) polymers that can
be patterned in a way similar to standard lithography photoresists (Nature,
February 20, 2003).
Researchers from Munich-based universities and from German chemical company
Covion have developed a class of electroluminescent (EL) polymers that can
be patterned in a way similar to standard lithography photoresists (Nature,
February 20, 2003). In other words, the polymer is spin coated onto a
substrate and then photographically patterned and processed.
The scientists say that the resolution of the process is sufficient for
making pixellated matrix displays. The resulting devices had RGB colours
with efficiencies comparable to - but, except for the blue polymer, not yet
achieving - state-of-the-are organic light emitting diodes with a slightly
reduced onset voltage.
The device structure was of the form of a 20nm indium tin
oxide/poly(3,4-ethylenedioxy-thiophene) (ITO/PEDOT) layer, an 80nm EL
polymer layer, a 20nm calcium layer and finally a 200nm silver layer. The
PEDOT material is a polymer commonly used for hole injection.
The paper points out that the alternative deposition methods such as vacuum
deposition, screen printing and ink jet printing each have their
disadvantages.
Covion have developed a class of electroluminescent (EL) polymers that can
be patterned in a way similar to standard lithography photoresists (Nature,
February 20, 2003). In other words, the polymer is spin coated onto a
substrate and then photographically patterned and processed.
The scientists say that the resolution of the process is sufficient for
making pixellated matrix displays. The resulting devices had RGB colours
with efficiencies comparable to - but, except for the blue polymer, not yet
achieving - state-of-the-are organic light emitting diodes with a slightly
reduced onset voltage.
The device structure was of the form of a 20nm indium tin
oxide/poly(3,4-ethylenedioxy-thiophene) (ITO/PEDOT) layer, an 80nm EL
polymer layer, a 20nm calcium layer and finally a 200nm silver layer. The
PEDOT material is a polymer commonly used for hole injection.
The paper points out that the alternative deposition methods such as vacuum
deposition, screen printing and ink jet printing each have their
disadvantages.