Organic light-emitting diodes formed by soft contact lamination

Although tremendous progress has been made in organic light-emitting diodes (OLEDs), with few exceptions they are fabricated in the standard way by sequentially depositing active layers and electrodes onto a substrate. Here we describe a different approach for building OLEDs, which is based on physical lamination of thin metal electrodes supported by an elastomeric layer against an electroluminescent organic. This method relies only on van der Waals interactions to establish spatially homogeneous, intimate contacts between the electrodes and the organic. We find that devices fabricated in this manner have better performance than those constructed with standard processing techniques. The lamination approach avoids forms of disruption that can be introduced at the electrode/organic interface by metal evaporation and has a reduced sensitivity to pinhole or partial pinhole defects. In addition, because this form of "soft" contact lamination is intrinsically compatible with the techniques of soft lithography, it is easy to build patterned OLEDs with feature sizes into the nanometer regime. This method provides a new route to OLEDs for applications ranging from high performance displays to storage and lithography systems that rely on subwavelength light sources.