Organic electronics have been extensively studied in last few decades due to their low-cost,light-weight, versatile chemical design and synthesis, mechanical flexibility, and the suitability for the roll-to-roll and printing mass production. Currently, a large part of the work on organic electronics is addressing organic photovoltaic cells (OPV cells), organic light-emitting diodes (OLEDs), and organic thin film transistors (OTFTs). OPV cells have received much attention due to their great potentials as a low-cost, renewable energy source. OLEDs have been developed as an alternative lighting source and display, providing low power consumption and wide viewing angles.
For realizing low-cost, flexible, efficient organic devices, specific objectives are conducted: (1) the development of alternative electrodes/stretchable devices, (2) interface engineering by doping technology, and (3) the development of efficient OLEDs using light extraction systems. The specific objectives are as follows.
1. Alternative Electrodes and Stretchable Devices: Highly conductive, transparent, and flexible alternative electrodes, such as conductive polymers, carbon nanotubes, silver nanowires, graphenes, and metal grids with conductive organic thin-films, are investigated for low-cost, flexible organic devices. Various doping technologies result in highly conductive, transparent electrodes and excellent energy level alignment between electrodes and organic layers in devices. Furthermore, we develop stretchable organic devices based on high performance alternative electrodes.
2. Doped Nanoparticles: The efficiency of organic devices are greatly improved by introducing functional nanoparticles optimized by various doping technologies in organic interfacial layers. In addition, the properties of various doped nanoparticles are systematically investigated.
3. Light Extraction System: High performance light extraction systems based on artificial surface nano-structures or light scattering layers are developed for OLEDs.