LIGHT-EMITTING DEVICE

• US 20150084033A1
• Filed: 12/03/2014
• Published: 03/26/2015
• Est. Priority Date: 06/05/2000
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Yamazaki
• Granted Patent: US 9,362,343 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2102/00 Constructional details relating to the organic devices covered by this subclass
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• 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 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 85/30 Coordination compounds
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/346 comprising platinum
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

There is provided a light emitting device which enables a color display with good color balance. A triplet compound is used for a light emitting layer of an EL element that emits red color, and a singlet compound is used for a light emitting layer of an EL element that emits green color and a light emitting layer of an EL element that emits blue color. Thus, an operation voltage of the EL element emitting red color may be made the same as the EL element emitting green color and the EL element emitting blue color. Accordingly, the color display with good color balance can be realized.

Claims

1. (canceled)

2. A display module comprising:

a first current supply line;

a second current supply line;

a first pixel electrode;

a second pixel electrode;

a bank comprising a resin;

a first EL layer over the first pixel electrode;

a second EL layer over the second pixel electrode;

a cathode over the first EL layer and the second EL layer; and

an insulating passivation film over the cathode, wherein;

the first current supply line is electrically connected to the first pixel electrode;

the second current supply line is electrically connected to the second pixel electrode;

the first current supply line and the second current supply line have substantially the same width;

the bank covers a part of the first pixel electrode and a part of the second pixel electrode;

the bank has tapered regions which overlap with the first pixel electrode and the second pixel electrode; and

only one of the first EL layer and the second EL layer contains iridium.

3. The display module according to claim 2, wherein the other of the first EL layer and the second EL layer contains a fluorescent material as a light-emitting substance.

4. The display module according to claim 2, wherein the first EL layer and the second EL layer are configured to emit light different in color from each other.

5. The display module according to claim 2, wherein the one of the first EL layer and the second EL layer emits red light.

6. The display module according to claim 2, wherein the insulating passivation film comprises a film selected from a carbon film, a silicon nitride film, and a silicon nitride oxide film.

7. A display module comprising

a gate line;

a first current supply line;

a second current supply line;

a first transistor;

a second transistor;

a first pixel electrode;

a second pixel electrode;

a bank comprising a resin;

a first EL layer over the first pixel electrode;

a second EL layer over the second pixel electrode;

a cathode over the first EL layer and the second EL layer; and

an insulating passivation film over the cathode, wherein;

the first transistor and the second transistor are aligned in a direction parallel to the gate line;

the first current supply line is electrically connected to the first pixel electrode through the first transistor;

the second current supply line is electrically connected to the second pixel electrode through the second transistor;

the first current supply line and the second current supply line each intersect with the gate line;

the first current supply line and the second current supply line have substantially the same width;

the bank covers a part of the first pixel electrode and a part of the second pixel electrode;

the bank has tapered regions which overlap with the first pixel electrode and the second pixel electrode; and

only one of the first EL layer and the second EL layer contains iridium.

8. The display module according to claim 7, wherein the other of the first EL layer and the second EL layer contains a fluorescent material as a light-emitting substance.

9. The display module according to claim 7, wherein the first EL layer and the second EL layer are configured to emit light different in color from each other.

10. The display module according to claim 7, wherein the one of the first EL layer and the second EL layer emits red light.

11. The display module according to claim 7, wherein the insulating passivation film comprises a film selected from a carbon film, a silicon nitride film, and a silicon nitride oxide film.