SBIR Phase I: n-Type Conducting Polymers for All-Plastic Electronic Devices

This Small Business Innovation Research Phase I project will develop a new class of n-type conducting polymers and evaluate their electronic and optical properties when they are doped with various reducing agents and used under different environmental conditions. These n-doped conducting polymers will be used as a cathode material to fabricate a prototype of an allplastic organic light emitting diode (OLED). The cathodes of today's OLEDs are made of reactive metals such as calcium or magnesium. These low work function metals are, so far, unmatched in their ability to inject electrons into the device. Unfortunately, these metals quickly degrade upon exposure to oxygen or moisture. Cathode oxidation and delamination are largely responsible for the growth of non-emissive spots on the emitting device area, even when the devices are sealed against the elements. Reactive metal cathodes have been long recognized as one of the major barriers to the commercialization of OLEDs. Thus, replacing reactive metal cathodes with more stable materials is critical to the commercialization of these devices. The objective of this research is to develop new polymeric materials with suitably low work functions and good electrical conductivity that can replace the reactive metals in cathodes for OLEDs. n-Type conducting polymers have many interesting potential applications; their use has been evaluated for the development of all-plastic energy-storage devices, as anode materials for nonaqueous batteries, for the fabrication of all-plastic n-p junctions and field-effect transistors, and as a cathode-replacement for OLEDs. Other applications may include photochromic devices, photovoltaic cells, electrochemical sensors, and catalytic reducing agents.