ORGANIC LIGHT-EMITTING ELEMENT AND LIGHT-EMITTING DEVICE WITH THE ORGANIC LIGHT-EMITTING ELEMENT

• US 20150287952A1
• Filed: 04/30/2015
• Published: 10/08/2015
• Est. Priority Date: 12/26/2002
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Hiroko, SEO, Satoshi
• Granted Patent: US 9,385,339 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/121 for assisting energy transfer, e.g. sensitization
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/131 with spacer layers between the electroluminescent layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/16 Electron transporting layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/30 Devices specially adapted for multicolour light emission
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/633 : comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom

Abstract

The present invention provides a white organic light-emitting element high in the emission efficiency. In particular, the invention provides a white organic light-emitting element that has an emission spectrum having peaks in the respective wavelength regions of red color, green color and blue color and is high in the emission efficiency. It is preferable to use an electron transport material between a first emission region and a second emission region and more preferable to use a hole block material.

Claims

1. (canceled)

2. A display device comprising:

a display portion over a substrate, the display portion comprising a pixel, wherein the pixel comprises;

an anode;

a hole-injection layer over and in contact with the anode;

a hole-transport layer over the hole-injection layer;

a first emission layer over the hole-transport layer;

a second emission layer over the first emission layer, the second emission layer being spaced from the first emission layer;

an electron-transport layer over the second emission layer;

an electron-injection layer over the electron-transport layer; and

a cathode over and in contact with the electron-injection layer, and wherein;

the first emission layer comprises a first host material and a first dopant;

the second emission layer comprises a second host material and a second dopant;

a layer is located between the first emission layer and the second emission layer;

the second dopant is absent in the layer;

the first dopant and the second dopant each an iridium-containing material; and

the layer has a thickness ranging from 1 nm to 30 nm.

3. The display device according to claims 2,

wherein the first dopant gives two emission peaks.

4. The display device according to claim 2,

wherein the first dopant gives two emission peaks in a range from 400 nm to 560 nm.

5. The display device according to claim 2,

wherein the first dopant gives an excimer emission.

6. The display device according to claim 2,

wherein the second dopant gives one emission peak in a range from 560 nm to 700 nm.

7. A display device comprising:

a display portion over a substrate, the display portion comprising a pixel, wherein the pixel comprises;

an anode;

a hole-injection layer over and in contact with the anode;

a hole-transport layer over the hole-injection layer;

a first emission layer over the hole-transport layer;

a second emission layer over the first emission layer, the second emission layer being spaced from the first emission layer;

an electron-transport layer over the second emission layer;

an electron-injection layer over the electron-transport layer; and

a cathode over and in contact with the electron-injection layer, and wherein;

the first emission layer comprises a first host material and a first dopant;

the second emission layer comprises a second host material and a second dopant;

a layer is located between the first emission layer and the second emission layer;

the second dopant is absent in the layer;

the first dopant is a fluorescent material and the second dopant is an iridium-containing material; and

the layer has a thickness ranging from 1 nm to 30 nm.

8. The display device according to claim 7,

wherein the first dopant gives two emission peaks.

9. The display device according to claim 7,

wherein the first dopant gives two emission peaks in a range from 400 nm to 560 nm.

10. The display device according to claim 7,

wherein the first dopant gives an excimer emission.

11. The display device according to claim 7,

wherein the second dopant gives one emission peak in a range from 560 nm to 700 nm.

12. A display device comprising:

a display portion over a substrate, the display portion comprising a pixel, wherein the pixel comprises;

an anode;

a hole-injection layer over and in contact with the anode;

a hole-transport layer over the hole-injection layer;

a first emission layer over the hole-transport layer;

a second emission layer over the first emission layer, the second emission layer being spaced from the first emission layer;

an electron-transport layer over the second emission layer;

an electron-injection layer over the electron-transport layer; and

a cathode over and in contact with the electron-injection layer, and wherein;

the first emission layer comprises a first host material and a first dopant;

the second emission layer comprises a second host material and a second dopant;

a layer is located between the first emission layer and the second emission layer;

the second dopant is absent in the layer;

the first dopant is an iridium-containing material and the second dopant is a fluorescent material; and

the layer has a thickness ranging from 1 nm to 30 nm.

13. The display device according to claim 12,

wherein the first dopant gives two emission peaks.

14. The display device according to claim 12,

wherein the first dopant gives two emission peaks in a range from 400 nm to 560 nm.

15. The display device according to claim 12,

wherein the first dopant gives an excimer emission.

16. The display device according to claim 12,

wherein the second dopant gives one emission peak in a range from 560 nm to 700 nm.