Light emitting device and manufacturing method thereof

• US 20040140465A1
• Filed: 01/12/2004
• Published: 07/22/2004
• Est. Priority Date: 01/29/2001
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Granted Patent: US 7,427,223 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/8052 Cathodes
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

There is provided a technique for obtaining a light emitting device in which no copy-in is caused in the case of a method of manufacturing a light emitting device having a glossy cathode. When an uneven portion is formed on the surface of a cathode which is in contact with an organic layer in a pixel portion, incident light is reflected in all directions. Further, since an insulating film having a high light absorption property is formed in a driver circuit portion, the copy-in becomes invisible to the observer.

Claims

1. A light emitting device comprising:

at least a transparent protrusion;

a pixel electrode over and along the transparent protrusion;

an organic layer over the pixel electrode and in contact with a portion of the pixel electrode; and

a cathode over and along the organic layer,

wherein a surface of the cathode in contact with the organic layer is uneven by forming the transparent protrusion.

2. A device according to claim 1, further comprising:

an insulating film in a transverse direction of the transparent protrusion,

wherein the insulating film has a high light absorption property.

3. A device according to claim 1,

wherein the transparent protrusion is a microlens.

4. A device according to claim 1,

wherein the light emitting device is combination with an electrical apparatus,

wherein the electrical apparatus is one selected from the group consisting of a personal computer, a video camera, a portable information terminal, a digital camera, a digital video disk player, a monitor for viewing the rear of a car for an automobile, a television telephone, a car navigation system, and an electronic game device.

5. A method of manufacturing a light emitting device, said method comprising the step of:

forming at least a transparent protrusion;

forming a pixel electrode to overlap the transparent protrusion;

forming an organic layer to overlap the pixel electrode;

forming a cathode over the organic layer.