Excited state management
AssigneesThe Regents of the University of Michigan, University of Southern California
InventorsStephen R. Forrest, Michael Slootsky, Mark E. Thompson
Life of this patent
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Abstract
Arrangements and techniques for providing organic emissive layers are provided, in which the emissive layer includes a first dopant having a dissociative energy level. A second dopant in the emissive layer provides a solid state sink energy level, to which doubly excited excitons and/or polarons may transition instead of to the dissociative energy level, thereby decreasing the undesirable effects of transitions to the dissociative energy level.
Claims11
An emissive layer of an opto-electronic device, the emissive layer comprising:
- a host material;
- a first dopant;
- and
- a second dopant that has a solid state sink energy level,
- wherein the first dopant is a blue-emitting, phosphorescent dopant that has a triplet energy level T1 that is lower than the solid state sink energy level of the second dopant, wherein the solid state sink energy level is at least 0.2 eV below the multiply-excited energy level of the first dopant, and
- wherein the emissive layer is disposed between an electron-transport layer (ETL) and a hole-transport layer (HTL), and the concentration of the first dopant is graded within the host material from about 20% at the HTL/emitting layer interface to about 8% at the ETL/emitting layer interface.
An opto-electronic device that includes an emissive layer comprising:
- a host material;
- a first dopant;
- and
- a second dopant that absorbs light in the ultraviolet region of the electromagnetic spectrum, and has a solid state sink energy level,
- wherein the first dopant is a blue-emitting dopant that has a triplet energy level T1 that is lower than the solid state sink energy level of the second dopant, wherein the solid state sink energy level is at least 0.2 eV below the multiply-excited energy level of the first dopant,
- wherein the emissive layer is disposed between an electron-transport layer (ETL) and a hole-transport layer (HTL), and the concentration of the first dopant is graded within the host material from about 20% at the HTL/emitting layer interface to about 8% at the ETL/emitting layer interface, and the opto-electronic device is included in a consumer product selected from the group consisting of:
- a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior illumination and/or signaling, a flexible display, a laser printer, a telephone, a cell phone, a tablet, a personal digital assistant (PDA), a laptop computer, a digital camera, a camcorder, a viewfinder, a 3-D display, a smart watch, a vehicle, a large area wall, theater or stadium screen, and a sign.
Dependencies are inferred from the claim text.