WHAT IS A PHOLED?
A PHOLED phosphorescent OLED is an OLED that has up to four times higher efficiency than that of a conventional fluorescent OLED.
OLEDs are monolithic, solid-state devices that typically consist of a series of organic thin films sandwiched between two thin-film conductive electrodes. When electricity is applied to an OLED, charge carriers (holes and electrons) are injected from the electrodes into the organic thin films. Then, under the influence of an electrical field, these carriers migrate through the device, until they recombine forming excitons. Once formed, these excitons, or excited states, relax to a lower energy level by giving off light and/or heat.
With conventional fluorescent emission, only about 25% of the excitonic energy generates light, with the remaining 75% lost as heat. Through the use of certain phosphorescent materials, our university partners at Princeton University and the University of Southern California discovered in the late 1990s that up to 100% of the excitonic energy could be converted into light.
This discovery was a major breakthrough. It meant that OLEDs could be up to four times more efficient than previously through possible - enabling OLEDs to compete today with LCDs as well as incandescent and fluorescent lighting in the future.