WOLEDs Containing Two Broad Emitters

In 2001, lighting was estimated to consume 8.2 quads (approximately 762 TWh), or about 22% of the total electricity generated in the U.S. New, high-efficiency, solid-state light sources, such as light emitting diodes (LEDS) and organic LEDs (OLEDs), are needed to help reduce the ever increasing demand for energy. In particular, OLEDs represent a potentially inexpensive diffuse source that could compete directly with conventional incandescent light sources. However, improvements in the overall efficiency of these devices will be required before they become commercially viable. This project will develop novel, high-efficiency OLED fixtures to replace short lifetime 12 lm/W incandescent sources, and hence reduce overall energy consumption in the U.S. In Phase I, a white OLED, containing only two emitters, was demonstrated with an efficacy of 34 lm/W at a forward luminance of 800 cd/m2. The device had a CIE = (0.38, 0.37), a color rendering index (CRI) of 71, and a correlated color temperature of 3,900 K. Phase II will demonstrate white OLEDs that will have a CRI greater than75 and an efficacy of 60 lm/W at 1,000 cd/m2. Commercial Applications and Other Benefits as described by the awardee: The technology should permit OLEDs to become cost effective in general lighting applications. Today, OLED technology is the leading emerging technology for flat panel displays (FPDs), with recent product introductions in cell phones. Many of these same features should make OLED technology of great interest to the solid-state lighting community.