Organic light-emitting diodes formed by soft contact lamination

Organic optoelectronic materials enable new classes of devices that could be important for consumer electronics. Organic light emitting diodes (OLEDs), for example, form the basis of ultrathin and power efficient mechanically flexible display systems. Although tremendous progress has been made on the materials, with few exceptions OLEDs 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 much better performance than those constructed with standard processing sequences because it avoid various forms of disruption that can be introduced at the electrode/organic interface by metal evaporation. 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.