Organic light-emitting devices

• US 20030197465A1
• Filed: 01/24/2003
• Published: 10/23/2003
• Est. Priority Date: 04/03/2002
• Status: Active Grant

• Current Assignee: Tsinghua University
• Original Assignee: Tsinghua University
• Inventors: Zhang, Deqiang, Qiu, Yong, Gao, Yudi, Wei, Peng, Wang, Liduo
• Granted Patent: US 6,806,491 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 85/1135 Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: H10K 85/146 poly N-vinylcarbazol; Derivatives thereof
• CPC Class Codes: H10K 85/30 Coordination compounds
• CPC Class Codes: H10K 85/311 Phthalocyanine
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• 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: H10K 85/649 Aromatic compounds comprising a hetero atom
• CPC Class Codes: H10K 85/6565 Oxadiazole compounds
• CPC Class Codes: Y10S 977/95 Electromagnetic energy

Abstract

An organic light-emitting device including a transparent substrate, a first electrode layer, a second electrode layer, a hole-transporting layer, and a electron-transporting layer sandwiched between the first and second electrode layers, wherein the hole-transporting layer consists of organic multiple-quantum-well structure. The multiple-quantum-well structure has a period number of alternating layers formed of a layer of organic material A with wide energy gap and a layer of organic material B with narrow energy gap. Organic material A and organic material B are selected such that the highest occupied molecular orbital (HOMO) levels of organic material A are lower than those of organic material B and the lowest unoccupied molecular orbital (LUMO) levels of organic material A are higher than those of organic material B.

Claims

1. An organic light-emitting device comprising:

a transparent substrate;

a first electrode layer;

a second electrode layer;

a hole-transporting layer; and

a electron-transporting layer sandwiched between the first electrode layer and second electrode layer;

wherein,

the hole-transporting layer includes an organic multiple-quantum-well structure, and the multiple-quantum-well structure has a period number of alternating layers formed of a layer of organic material A with wide energy gap and a layer of organic material B with narrow energy gap;

highest energy occupied molecular orbital levels of the organic material A are lower than highest energy occupied molecular orbital levels of the organic material B; and

lowest energy unoccupied molecular orbital levels of the organic material A are higher than lowest energy unoccupied molecular orbital levels of the organic material B.

2. The organic light-emitting device of claim 1, wherein the period number of multiple-quantum-well structure is an integer of 1 to 10.

3. The organic light-emitting device of claim 1, wherein the organic material A layer is in the range of about 0.5 to 30.0 nm in thickness, and the organic material B layer is in the range of about 0.5 to 10.0 nm in thickness.

4. The organic light-emitting device of claim 1, wherein the organic material B is a dye material.

5. The organic light-emitting device of claim 2, wherein the organic material B is a dye material.

6. The organic light-emitting device of claim 1, wherein:

a buffer layer is introduced between the first electrode layer and the hole-transporting layer; and

a transitional layer is introduced between the hole-transporting layer and the electron-transporting layer.

7. The organic light-emitting device of claim 6, wherein:

the buffer layer is formed by phthalocyanine copper material; and

the transitional layer is formed by N,N′

-bis-(1-naphthyl)-N,N′

-diphenyl-1,1′

biphenyl 4,4′

-diamine material.

8. The organic light-emitting device of claim 1, wherein:

the organic material A is a material selected from the group consisting of benzidine derivatives, carbazole derivatives, pyrrole derivatives and oxadiazole derivatives; and

the organic material B is a phthalocyanine complex.

9. The organic light-emitting device of claim 8, wherein:

the benzidine derivatives include;

N,N′

-bis-(1-naphthyl)-N,N′

-diphenyl-1,1′

-biphenyl-4,4′

-diamine;

N,N′

-diphenyl-N,N′

-bis(3-methylphenyl)-1,1′

-biphenyl-4,4′

-diamine; and

4,4′

,4″

-tris(3-methyl-phenyl phenylamino) triphenylamine;

the carbazole derivatives include;

poly (N-vinylcarbazole);

2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline;

4,7-diphenyl-1,10-phenanthroline;

the oxadiazole derivatives include;

2,2′

,2″

-(1,3,5-benzenetriyl)-tris-[1-phenyl-1H-benzimidazole]; and

2-(4-tert-Butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole; and

the phthalocyanine complex includes at least one of;

phthalocyanine copper;

phthalocyanine; and

phthalocyanine vanadium.

10. The organic light-emitting device of claim 8, wherein:

the organic material A is N,N′

-bis-(1-naphthyl)-N,N′

-diphenyl-1,1′

-biphenyl-4,4′

-diamine; and

the organic material B is phthalocyanine copper.

11. The organic light-emitting device of claim 1, wherein the electron-transporting layer is formed by at least one of a metal chelate complex and a oxadiazole complex.

12. The organic light-emitting device of claim 11, wherein the metal chelate complex is a material selected from the group consisting of:

tris(8-hydroxyquinoline) aluminum;

salicylidene-o-aminophenolato (8-quinolinoato) aluminum;

salicylidene-o-aminophenolato (8-quinolinoato) gallium; and

4-hydroxyl acridine zinc.

13. The organic light-emitting device of claim 4, wherein:

the organic material A is a material selected from the group consisting of benzidine derivatives, carbazole derivatives, pyrrole derivatives and oxadiazole derivatives; and

the dye material is a material selected from the group consisting of polyphenylene derivatives, coumarin derivatives and bis-pyrane derivatives.

14. The organic light-emitting device of claim 13, wherein:

the polyphenylene derivatives include;

5,6,11,12-tetraphenylnaphthacene; and

pentacene;

the coumarin derivatives include 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H, 11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one; and

the bis-pyrane derivatives include;

4-(dicyanomethylene)-2-(t-butyl)-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran; and

4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran.

15. The organic light-emitting device of claim 13, wherein:

the organic material A is N,N′

-bis-(1-naphthyl)-N,N′

-diphenyl-1,1′

-biphenyl-4,-4′

-diamine; and

the dye material is 5,6,11,12-tetraphenyl-naphthacene.