Phosphorescent OLEDs with exciton blocking layer
US7597967B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2004 |
| Grant date | Oct 6, 2009 |
| Priority date | — |
| Expiry date | Jun 22, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/917
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An electroluminescent device comprises a cathode and an anode; and, located therebetween, a light-emitting layer (LEL) comprising at least one hole transporting co-host and at least one electron transporting co-host, together with at least one phosphorescent emitter, and wherein the triplet energy of each of the co-host materials is greater than the triplet energy of the phosphorescent emitter, and further containing an exciton blocking layer comprising a hole transporting material with triplet energy greater or equal to 2.5 eV adjacent the emitting layer on the anode side. The invention provides devices that emit light with high luminous efficiency at low voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.