Light emitting device and manufacturing method thereof

• US 7,332,857 B2
• Filed: 01/10/2002
• Issued: 02/19/2008
• Est. Priority Date: 01/18/2001
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Seo, Satoshi, Yamazaki, Shunpei
• Primary Examiner(s): Patel; Ashok
• Application Number:
  US10/043,812
• Publication Number:
  US 20020109136A1
• Time in Patent Office: 2,231 Days
• Field of Search: 313/504, 313/506, 313/503, 428/690, 428/917
• US Class Current: 313/504
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/164 using vacuum deposition
• CPC Class Codes: H10K 71/40 Thermal treatment, e.g. annealing in the presence of a solvent vapour
• CPC Class Codes: H10K 71/50 Forming devices by joining two substrates together, e.g. lamination techniques
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/341 Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/60 Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

A region in which the concentration of a first organic compound and the concentration of a second organic compound change gradually (namely, a concentration change region 204b) exists within an organic compound film, and therefore a clear organic boundary does not exist. However, a region in which the first organic compound is capable of expressing its function (a first functional region) and a region in which the second organic compound is capable of expressing its function (a second functional region) exist, and therefore the function of each material can be expressed.

Claims

1. A light emitting, device comprising an organic light emitting element comprising:

an anode;

a cathode; and

an organic compound film sandwiched between the anode and the cathode,

wherein the organic compound film comprises;

a first layer comprising a first compound;

a second layer comprising the first compound and a second compound; and

a third layer comprising the second compound,

wherein the first compound is a blocking compound capable of stopping the movement of holes or electrons, and

wherein the second compound is at least one selected compound selected from the group consisting of;

a hole injecting compound that receives holes from the anode;

a hole transporting compound that has a hole mobility that is larger than its electron mobility;

an electron transporting compound that has an electron mobility that is larger than is hole mobility; and

an electron injecting compound that receives electrons from the cathode,

wherein the blocking compound and the at least one compound selected are materials capable of undergoing vacuum evaporation, and

wherein the electric current versus electric voltage property of the organic light emitting elements show a rectification property.

2. A light emitting device according to claim 1, wherein the blocking compound and the at least one selected compound are hosts, and a guest is added to the region.

3. A light emitting device according to claim 2, wherein the guest is a light emitting compound for emitting light.

4. A light emitting device according to claim 1, wherein the light emitting device is included with electrical equipment selected from the group consisting of:

a display, a video camera, a digital camera, an image reproduction apparatus, a portable computer, a personal computer, a mobile telephone, and an acoustic equipment.

5. A light emitting device comprising an organic light emitting element comprising:

an anode;

a cathode; and

an organic compound film sandwiched between the anode and the cathode,

wherein the organic compound film comprises a hole injecting compound that receives holes from the anode and a hole transporting compound that has a hole mobility that is larger than its electron mobility;

wherein the hole injecting compound and the hole transporting compound are materials capable of undergoing vacuum evaporation,

wherein the organic compound film comprises a region in which the hole injecting compound and the hole transporting compound are mixed,

wherein the electric current versus electric voltage property of the organic light emitting elements show a rectification property, and

wherein a concentration of the hole injection compound decreases continuously from the anode to the cathode.

6. A light emitting device according to claim 5, wherein the hole injecting compound and the hole transporting compound are hosts, and a guest is added to the region.

7. A light emitting device according to claim 6, wherein the guest is a light emitting compound for emitting light.

8. A light emitting device according to claim 5, wherein the light emitting device is included with electrical equipment selected from the group consisting of:

a display, a video camera, a digital camera, so image reproduction apparatus, a portable computer, a personal computer, a mobile telephone, and an acoustic equipment.

9. A light emitting device comprising an organic light emitting element comprising:

an anode;

a cathode; and

an organic compound film sandwiched between the anode and the cathode,

wherein the organic compound film an electron transporting compound that has an electron mobility that is larger than its hole mobility and an electron injecting compound that receives electrons from the cathode,

wherein the electron transporting compound and the electron injecting compound are materials capable of undergoing vacuum evaporation,

wherein the organic compound film comprises a region in which the electron transporting compound and the electron injecting compound are mixed, and

wherein the electric current versus electric voltage property of the organic light emitting elements show a rectification property.

10. A light emitting device according to claim 9, wherein the electron injecting compound and the electron transporting compound are hosts, and a guest is added to the region.

11. A light emitting device according to claim 10, wherein the guest is a light emitting compound for emitting light.

12. A light emitting device according to claim 9, wherein the light emitting device is included with electrical equipment selected from the group consisting of:

a display, a video camera, a digital camera, an image reproduction apparatus, a portable computer, a personal computer, a mobile telephone, and an acoustic equipment.

13. A light emitting device comprising an organic light emitting element comprising:

an anode;

a cathode; and

an organic compound film sandwiched between the anode and the cathode,

wherein the organic compound film comprises;

a first layer comprising a first compound;

a second layer comprising the first compound and a second compound; and

a third layer comprising the second compound,

wherein first compound is a blocking compound capable of stopping the movement of holes or electrons, and

wherein the second at least one selected compound selected from the group consisting of;

a hole injecting compound that receives holes from the anode;

an electron transporting compound that has an electron mobility that is larger than its hole mobility; and

an electron injecting compound that receives electrons from the cathode,

wherein the blocking compound and the at least one selected compound are materials capable of undergoing vacuum evaporation, and

wherein a concentration change of the first and second compound in the second layer is continuous.

14. A light emitting device according to claim 13, wherein the blocking compound and the at least one selected compound are hosts, and a guest is added to the region.

15. A light emitting device according to claim 14, wherein the guest is a light emitting compound for emitting light.

16. A light emitting device according to claim 13, wherein the light emitting device is included with electrical equipment selected from the group consisting of:

a display, a video camera, a digital camera, an image reproduction apparatus, a portable computer, a personal computer, a mobile telephone, and an acoustic equipment.

17. A light emitting device comprising an organic light emitting element comprising:

an anode;

a cathode; and

an organic compound film sandwiched between the anode and the cathode,

wherein the organic compound film a hole injecting compound that receives holes from the anode and a hole transporting compound that has a hole mobility that is larger than its electron mobility,

wherein the hole injecting compound and the hole transporting compound are materials capable of undergoing vacuum evaporation,

wherein the organic compound film comprises a region in which the hole injecting compound and the hole transporting compound are mixed, and

wherein a concentration or the hole injection compound decreases continuously from the anode to the cathode.

18. A light emitting device according to claim 17, wherein the hole injecting compound and the hole transporting compound are hosts, and a guest is added to the region.

19. A light emitting device according to claim 18, wherein the guest is a light emitting compound for emitting light.

20. A light emitting device according to claim 17, wherein the light emitting device is included with electrical equipment selected from the group consisting of:

a display, a video camera, a digital camera, an image reproduction apparatus, a portable computer, a personal computer, a mobile telephone, and an acoustic equipment.

21. A light emitting device comprising an organic light emitting element comprising:

an anode;

a cathode; and

an organic compound film sandwiched between the anode and the cathode,

wherein the organic compound film an electron transporting compound that has an electron mobility that is larger than its hole mobility and an electron injecting compound that receives electrons from the cathode,

wherein the electron transporting compound and the electron injecting compound are materials capable of undergoing vacuum evaporation, and

wherein the organic compound film comprises a region in which the electron transporting compound and electron injecting compound are mixed.

22. A light emitting device according to claim 21, wherein the electron injecting compound and the electron transporting compound are hosts, and a guest is added to the region.

23. A light emitting device according to claim 22, wherein the guest is a light emitting compound for emitting light.

24. A light emitting device according to claim 21, wherein the light emitting device is included with electrical equipment selected from the group consisting of:

a display, a video camera, a digital camera, an image reproduction apparatus, a portable computer, a personal computer, a mobile telephone, and an acoustic equipment.