Flexible transparent electrodes for organic light-emitting diodes

The use of flexible organic light-emitting diodes (OLEDs) for the next-generation displays and solid-state lightings has been considered, but the widely used transparent conducting electrode (TCE), indium–tin-oxide (ITO), should be replaced by flexible electrodes due to its brittleness and increasing cost. Therefore, many kinds of alternative TCEs have been increasingly studied. In this paper, the properties and applications of the candidate transparent flexible electrodes classified into four categories (conducting polymer, silver nanowire, carbon nanotube and graphene) are described. This paper finally suggests how to develop alternative TCEs for replacing the conventional ITO electrode.