William Francis Nealon

Fault-tolerant, scalable organic light-emitting device architecture

High performance organic light emitting diodes (OLEDs) become problematic as emitting area increases due to the high resistivity of the transparent electrode and the increasing probability of encountering a catastrophic short-circuit defect during fabrication. In this letter, a monolithic series-connected OLED architecture is demonstrated. It is shown that such devices exhibit the same power efficiency as traditional small area OLEDs but are, in addition, relatively insensitive to electrode resistivity and tolerant to normally catastrophic short-circuit defects. This architecture should enable applications such as lighting where scalability to large emitting area without high fabrication cost or design complexity is required.

4.1: Invited Paper: Large Area White OLEDs

A large area white OLED panel that emits 1200 lumens of illumination-quality light is described. The technical approach utilizes down-conversion from an underlying blue OLED made with a fault-tolerant monolithically series-connected architecture. The high device efficiency suggests that the singlet/triplet ratio for polymer OLEDs can be greater than 25%.

OLEDs for lighting: new approaches

OLED technology has improved to the point where it is now possible to envision developing OLEDs as a low cost solid state light source. In order to realize this, significant advances have to be made in device efficiency, lifetime at high brightness, high throughput fabrication, and the generation of illumination quality white light. In this talk, the requirements for general lighting will be reviewed and various approaches to meeting them will be outlined. Emphasis will be placed on a new monolithic series-connected OLED design architecture that promises scalability without high fabrication cost or design complexity.