Organic light emitting element and method of manufacturing the same

• US 7,829,907 B2
• Filed: 09/21/2006
• Issued: 11/09/2010
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Junji Kido, Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Junji Kido, Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Inventors: Ide, Nobuhiro, Kido, Junji, Komoda, Takuya
• Primary Examiner(s): PRENTY, MARK V
• Application Number:
  US12/067,718
• Publication Number:
  US 20090230415A1
• Time in Patent Office: 1,510 Days
• Field of Search: 257/98, 257/89, 257/E33.064, 313/498, 313/504, 313/506, 438/29
• US Class Current: 257/98
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 85/624 containing six or more rings
• CPC Class Codes: H10K 85/633 comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom

Abstract

The present invention relates to an organic light emitting element comprising: a first light emitting unit comprising a light emitting layer between a pair of electrodes; and a second light emitting unit comprising a light emitting layer between a pair of electrodes. In the organic light emitting element, one electrode of the two pairs of electrodes which is positioned on the outermost side has light reflective properties, and the other electrodes have light transmission properties, while a light-transmitting insulating layer is provided between the first and second light emitting units. The insulating layer is formed in a thickness to prevent light emitted by the light emitting layer of the light emitting unit without the light reflective electrode from interfering with other lights, or formed to have properties of scattering the emitted light. Thus, the interference between the lights emitted by the light emitting layers and the other lights is reduced, so that in the organic light emitting element, the angular dependence of light emission spectrum is small, making it possible to adjust color.

Claims

1. An organic light emitting element comprising a first light emitting unit having a light emitting layer between a pair of electrodes, and a second light emitting unit having a light emitting layer between a pair of electrodes, wherein:

one electrode of the four electrodes of the first and second light emitting units, which is positioned on the outermost side, has light reflective properties while the other electrodes have light transmission properties;

a light-transmitting insulating layer is provided between the first and second light emitting units; and

the insulating layer is formed in a thickness to prevent light emitted by the light emitting layer of the light emitting unit without the light reflective electrode from interfering with other lights, or formed to have properties of scattering the light emitted by the same light emitting layer.

4. The organic light emitting element according to claim 1, wherein at least one of the first and second light emitting units has a plurality of light emitting layers,

the plurality of light emitting layers being stacked via an equipotential surface forming layer or a charge generation layer.

5. The organic light emitting element according to claim 1, wherein the insulating layer is formed of a glass plate or a film.

6. A method of manufacturing the organic light emitting element according to claim 1, which includes:

a step of forming one of the first and second light emitting units in a manner that one material of a light transmitting material formed in a thickness to prevent the light emitted by the light emitting layer from interfering with the other lights, or a light transmitting material formed to have properties of scattering the light emitted by the light emitting layer, is prepared as a first substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the first substrate,

a step of forming the other of the first and second light emitting units in a manner that a light transparent material is prepared as a second substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the second substrate, and

a step of stacking the first and second light emitting units via the first substrate in a manner that the light emitting unit formed on the second substrate is stacked on the first substrate.

7. A method of manufacturing the organic light emitting element according to claim 1, which includes:

a step of forming one of the first and second light emitting units in a manner that one material of a light transmitting material formed in a thickness to prevent the light emitted by the light emitting layer from interfering with the other lights, or a light transmitting material formed to have properties of scattering the light emitted by the light emitting layer, is prepared as a substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the substrate, and

a step of forming the other of the first and second light emitting units in a manner that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the substrate without the one of the first and second light emitting units formed thereon.

2. An organic light emitting element comprising a first light emitting unit having a light emitting layer between a pair of electrodes, and a second light emitting unit having a light emitting layer between a pair of electrodes, wherein:

the four electrodes of the first and second light emitting units have light transmission properties, while a light reflective layer having light reflective properties is provided on an outer side of one of the electrodes which is positioned on the outermost side;

a light-transmitting insulating layer is provided between the first and second light emitting units; and

the insulating layer is formed in a thickness to prevent light emitted by the light emitting layer of the light emitting unit without the light reflective layer from interfering with other lights, or formed to have properties of scattering the light emitted by the same light emitting layer.

8. The organic light emitting element according to claim 2, wherein at least one of the first and second light emitting units has a plurality of light emitting layers,

the plurality of light emitting layers being stacked via an equipotential surface forming layer or a charge generation layer.

10. The organic light emitting element according to claim 2, wherein the insulating layer is formed of a glass plate or a film.

12. A method of manufacturing the organic light emitting element according to claim 2 which includes:

a step of forming one of the first and second light emitting units in a manner that one material of a light transmitting material formed in a thickness to prevent the light emitted by the light emitting layer from interfering with the other lights, or a light transmitting material formed to have properties of scattering the light emitted by the light emitting layer, is prepared as a first substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the first substrate,

a step of forming the other of the first and second light emitting units in a manner that a light transparent material is prepared as a second substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the second substrate, and

a step of stacking the first and second light emitting units via the first substrate in a manner that the light emitting unit formed on the second substrate is stacked on the first substrate.

14. A method of manufacturing the organic light emitting element according to claim 2, which includes:

a step of forming one of the first and second light emitting units in a manner that one material of a light transmitting material formed in a thickness to prevent the light emitted by the light emitting layer from interfering with the other lights, or a light transmitting material formed to have properties of scattering the light emitted by the light emitting layer, is prepared as a substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the substrate, and

a step of forming the other of the first and second light emitting units in a manner that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the substrate without the one of the first and second light emitting units formed thereon.

3. An organic light emitting element comprising a first light emitting unit having a light emitting layer between a pair of electrodes, and a second light emitting unit having a light emitting layer between a pair of electrodes, wherein:

the four electrodes of the first and second light emitting units have light transmission properties;

a light-transmitting insulating layer is provided on an outer side of one of the electrodes which is positioned on the outermost side, with a reflective layer having light reflective properties on an outer side of the insulating layer; and

the insulating layer is formed in a thickness to prevent light emitted by the light emitting layer of the light emitting unit without the light reflective layer from interfering with other lights, or formed to have properties of scattering the light emitted by the same light emitting layer.

9. The organic light emitting element according to claim 3, wherein at least one of the first and second light emitting units has a plurality of light emitting layers,

the plurality of light emitting layers being stacked via an equipotential surface forming layer or a charge generation layer.

11. The organic light emitting element according to claim 3, wherein the insulating layer is formed of a glass plate or a film.

13. A method of manufacturing the organic light emitting element according to claim 3 which includes:

a step of forming one of the first and second light emitting units in a manner that one material of a light transmitting material formed in a thickness to prevent the light emitted by the light emitting layer from interfering with the other lights, or a light transmitting material formed to have properties of scattering the light emitted by the light emitting layer, is prepared as a first substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the first substrate,

a step of forming the other of the first and second light emitting units in a manner that a light transparent material is prepared as a second substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the second substrate, and

a step of stacking the first and second light emitting units via the first substrate in a manner that the light emitting unit formed on the second substrate is stacked on the first substrate.

15. A method of manufacturing the organic light emitting element according to claim 3, which includes:

a step of forming one of the first and second light emitting units in a manner that one material of a light transmitting material formed in a thickness to prevent the light emitted by the light emitting layer from interfering with the other lights, or a light transmitting material formed to have properties of scattering the light emitted by the light emitting layer, is prepared as a substrate, and that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the substrate, and

a step of forming the other of the first and second light emitting units in a manner that an electrode, a light emitting layer and an electrode are stacked in this order on a surface of the substrate without the one of the first and second light emitting units formed thereon.