Light emitting device and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9287330-B2
Application number	US-201313975860-A
Country	US
Kind code	B2
Filing date	Aug 26, 2013
Priority date	Apr 23, 2002
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

A light-emitting device structured so as to increase the amount of light taken out in a certain direction is provided as well as a method of manufacturing this light emitting device. As a result of etching treatment, an upper edge portion of an insulator ( 19 ) is curved to have a radius of curvature, a slope is formed along the curved face while partially exposing layers ( 18 c and 18 d ) of a first electrode, and a layer ( 18 b ) of the first electrode is exposed in a region that serves as a light emitting region. Light emitted from an organic compound layer ( 20 ) is reflected by the slope of the first electrode (layers 18 c and 18 d ) to increase the total amount of light taken out in the direction indicated by the arrow in FIG. 1 A.

First claim

What is claimed is:

1. A light emitting device comprising:
a thin film transistor over a first substrate;
an insulating layer over the thin film transistor;
a first electrode electrically connected to the thin film transistor;
an insulator over the first electrode, the insulator including an opening which overlaps a first portion of the first electrode, wherein a second portion of the first electrode is covered with the insulator;
a light emitting layer comprising an organic material overlapping at least the first portion of the first electrode; and
a second electrode over the light emitting layer, wherein the light emitting layer is configured to emit light by a current flowing through the first electrode, the light emitting layer and the second electrode,
wherein the first portion of the first electrode is thinner than the second portion of the second electrode,
wherein an inner edge of the insulator is aligned with a boundary between the first portion and the second portion, and
wherein the thin film transistor comprises a channel forming region which comprises polycrystalline silicon.

2. The light emitting device according to claim 1 , wherein the first electrode is capable of reflecting light.

3. The light emitting device according to claim 1 , wherein the second electrode is capable of transmitting light.

4. The light emitting device according to claim 1 , wherein the light emitting layer is capable of emitting white light.

5. A light emitting device comprising:
a thin film transistor over a first substrate;
an insulating layer over the thin film transistor;
a first electrode electrically connected to the thin film transistor;
an insulator over the first electrode, the insulator including an opening which overlaps a first portion of the first electrode, wherein a second portion of the first electrode is covered with the insulator;
a light emitting layer comprising an organic material overlapping at least the first portion of the first electrode; and
a second electrode over the light emitting layer, wherein the light emitting layer is configured to emit light by a current flowing through the first electrode, the light emitting layer and the second electrode,
wherein the first electrode has a multi-layer structure comprising a first conductive layer and a second conductive layer over the first conductive layer,
wherein an inner edge of the insulator is aligned with a side edge of the second conductive layer, and
wherein the thin film transistor comprises a channel forming region which comprises polycrystalline silicon.

6. The light emitting device according to claim 5 , wherein the first electrode is capable of reflecting light.

7. The light emitting device according to claim 5 , wherein the second electrode is capable of transmitting light.

8. The light emitting device according to claim 5 , wherein the light emitting layer is capable of emitting white light.

9. The light emitting device according to claim 5 , wherein the first conductive layer comprises titanium nitride, tantalum nitride, molybdenum nitride, platinum, chromium, tungsten, nickel, zinc and tin.

10. The light emitting device according to claim 5 , wherein the second conductive layer comprises aluminum or silver.

11. A light emitting device comprising:
a thin film transistor over a first substrate;
an insulating layer over the thin film transistor;
a first electrode electrically connected to the thin film transistor;
an insulator over the first electrode, the insulator including an opening which overlaps a first portion of the first electrode, wherein a second portion of the first electrode is covered with the insulator;
a light emitting layer comprising an organic material overlapping at least the first portion of the first electrode; and
a second electrode over the light emitting layer, wherein the light emitting layer is configured to emit light by a current flowing through the first electrode, the light emitting layer and the second electrode,
wherein the first electrode has a multi-layer structure comprising a first conductive layer and a second conductive layer over the first conductive layer,
wherein the insulator covers the second conductive layer,
wherein the second conductive layer includes a tapered side surface so as to reflect light emitted by the light emitting layer toward the opening of the insulator, and
wherein the thin film transistor comprises a channel forming region which comprises polycrystalline silicon.

12. The light emitting device according to claim 11 , wherein the first electrode is capable of reflecting light.

13. The light emitting device according to claim 11 , wherein the second electrode is capable of transmitting light.

14. The light emitting device according to claim 11 , wherein the light emitting layer is capable of emitting white light.

15. The light emitting device according to claim 11 , wherein the first conductive layer comprises titanium nitride, tantalum nitride, molybdenum nitride, platinum, chromium, tungsten, nickel, zinc and tin.

16. The light emitting device according to claim 11 , wherein the second conductive layer comprises aluminum or silver.

Assignees

• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei
• Seo Satoshi
• Kuwabara Hideaki

Classifications

• H10K59/878

  comprising reflective means · CPC title

• H10K59/873

  Encapsulations · CPC title

• H10K59/871

  Self-supporting sealing arrangements · CPC title

• H10K59/80524

  Transparent cathodes, e.g. comprising thin metal layers · CPC title

• H10K59/80522

  combined with auxiliary electrodes · CPC title