World Record White OLED Performance Exceeds 100 lm/W
Universal Display Corporation (UDC) has successfully demonstrated a record-breaking white organic light-emitting diode (WOLED) with a power efficacy of 102 lm/W at 1000 cd/m2 using its proprietary, high-efficiency phosphorescent OLED technology. This achievement represents a significant milestone for OLED technology, demonstrating performance that surpasses the power efficacy of incandescent bulbs with less than 15 lm/W and fluorescent lamps at 60-90 lm/W. Funded in part by DOE, UDC's achievement is a major step toward DOE's roadmap goal of a 150 lm/W commercial OLED light source by 2015.
This WOLED light source offers a white emission with a CRI of 70 and a CCT of 3900K and highlights the potential of white OLEDs to offer significant energy savings and environmental benefits. Through the use of UDC's phosphorescent OLED technology, power-efficient white OLEDs have the potential to reduce energy consumption dramatically and to lower the amount of by-product heat, which creates additional energy and environmental burdens. Combining important "green" features with a very thin, lightweight and durable form factor, white OLEDs offer significant new lighting design opportunities.
UDC's current success incorporates progress achieved through a focus on four key elements of WOLED research that all must work together to achieve maximum power savings: internal quantum efficiency (IQE), outcoupling efficiency or external quantum efficiency (EQE), device voltage, and lifetime. UDC has achieved approximately 100 percent IQE through its breakthrough with phosphorescence and continues to make EQE improvements with the development of several novel technologies which further enhance outcoupling efficiency and significantly reduce the absorption losses incurred when light waveguides in the substrate.
Low voltage operation is obtained by incorporating highly conductive transport layers and by designing devices to improve charge injection and recombination in the emissive layer. Currently, under 3V has been demonstrated for WOLED devices operating at 1,000 cd/m2, with an eye toward operating at 2.4V to demonstrate the highest possible efficacy. Regarding extending device lifetime, the UDC team has targeted a goal of LT70 = 50,000 hours, which it is pursuing in tandem with the other key research areas.