Michael Lu

US Patent:

6885025, Apr 26, 2005

Filed:

Jul 10, 2003

Appl. No.:

10/618160

Inventors:

Michael Lu - Lawrenceville NJ, US
Raymond C. Kwong - Plainsboro NJ, US

Assignee:

Universal Display Corporation - Ewing NJ

International Classification:

H01L051/00

US Classification:

257 40, 257642

Abstract:

The present invention relates to organic light emitting devices (OLEDs). The devices of the present invention are efficient white or multicolored phosphorescent OLEDs which have a high color stability over a wide range of luminances. The devices of the present invention comprise an emissive region having at least two emissive layers, with each emissive layer comprising a different host and emissive dopant, wherein at least one of the emissive dopants emits by phosphorescence.

US Patent:

7045952, May 16, 2006

Filed:

Mar 4, 2004

Appl. No.:

10/793371

Inventors:

Michael Lu - Lawrenceville NJ, US

Assignee:

Universal Display Corporation - Ewing NJ

International Classification:

H01J 1/62

US Classification:

313504, 313506

Abstract:

An organic light emitting device is provided. The devices of the present invention comprise an emissive region having at least two emissive layers, with at least one layer comprising a first host and another layer comprising a first and a second host, and each layer further comprising a phosphorescent emissive material. In one embodiment, the device comprises an emissive region disposed between and electrically connected to an anode and a cathode, wherein the emissive region comprises (i) a first single-host emissive layer, comprising a first host material, and (ii) a mixed-host emissive layer in direct contact with the first single-host layer, wherein the mixed-host layer comprises the first host material, and a second host material, and wherein the first single-host layer and the mixed-host layer each further comprise a phosphorescent emissive material. In another embodiment, the device further comprises (iii) a second single-host emissive layer, comprising a second host material, and wherein the first single-host layer, the mixed-host layer, and the second single-host layer each further comprise a phosphorescent emissive material.