Electroluminescent device with improved light output

• US 20050206311A1
• Filed: 06/18/2003
• Published: 09/22/2005
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Glaser, Harald, Busselt, Wolfgang, Opitz, Joachim, Bertram, Dietrich, Klein, Markus Heinrich, Bechtel, Hans Helmut
• Granted Patent: US 7,262,551 B2
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

The invention relates to an electroluminescent device comprising a substrate (1) and a laminated body composed of a first electrode (3), an electroluminescent layer (4) and a second electrode (5). The light output out of the electroluminescent device is increased by arranging a colloidal layer (2) between the substrate (1) and the laminated body. By using pigments in the colloidal layer (2), the emmission color of the electroluminescent device can be changed and the daylight contrast improved.

Claims

1. An electroluminescent device comprising a substrate (1), a colloidal layer (2) and a laminated body composed of a first electrode (3), an electroluminescent layer (4) and a second electrode (5).

2. An electroluminescent device as claimed in claim 1, characterized in that the colloidal layer (2) borders on the substrate, and the laminated body borders on the colloidal layer (2).

3. An electroluminescent device as claimed in claim 1, characterized in that the laminated body borders on the substrate (1) and the colloidal layer (2) borders on the laminated body.

4. An electroluminescent device as claimed in claim 1, characterized in that the colloidal layer (2) contains a material selected from the group composed of the metal oxides, SiO₂, the inorganic pigments and a combination of these materials.

5. An electroluminescent device as claimed in claim 3, characterized in that the materials have a particle size in the range between 1 and 400 nm.

6. An electroluminescent device as claimed in claim 1, characterized in that the colloidal layer is a pixelated layer.