Tandem organic light-emitting diode, array substrate and display device

1. A tandem organic light-emitting diode comprising an anode, a hole transport layer, a first light-emitting layer, a first charge generation layer, a second charge generation layer, a third charge generation layer, a second light-emitting layer, an electron transport layer, and a cathode which are sequentially laminated,

wherein the first charge generation layer is an N-type bulk heterojunction, the second charge generation layer is a PN junction type bulk heterojunction, and the third charge generation layer is a P-type bulk heterojunction;

the first charge generation layer comprises a mixture of a first organic material and a second organic material, wherein a proportion of the first organic material in the first charge generation layer is greater than a proportion of the second organic material in the first charge generation layer, and the first organic material has an electron mobility of greater than 1×10 −7 cm 2 /V·s, a highest occupied orbital energy level of less than −5.5 eV and a lowest unoccupied orbital energy level of greater than −3.5 eV;

the second charge generation layer comprises a mixture of the second organic material and a third organic material, wherein the second organic material is an N-type organic material; the third organic material is a P-type organic material; and the second organic material has an electron mobility of greater than 1×10 −7 cm 2 /V·s and the third organic material has a hole mobility of greater than 1×10 −7 cm 2 /V·s;

the third charge generation layer comprises a mixture of the third organic material and a fourth organic material; a proportion of the third organic material in the third charge generation layer is less than a proportion of the fourth organic material in the third charge generation layer; and the forth organic material has a hole mobility of greater than 1×10 −7 cm 2 /V·s, a highest occupied orbital energy level of less than −5.0 eV and a lowest unoccupied orbital energy level of greater than −3.0 eV.

2. The tandem organic light-emitting diode according to claim 1 , wherein the first organic material comprises 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene; the second organic material comprises C 60 ; the third organic material comprises at least one selected from the group consisting of rubrene, pentacene, tetrafluorotetracyanoquinodimethane, copper phthalocyanine or other phthalocyanine derivatives; and the fourth organic material comprises 4,4′,4″-tri(carbazol-9-yl) triphenylamine.

3. The tandem organic light-emitting diode according to claim 1 , wherein the first organic material comprises 4,7-diphenyl-1,10-phenanthroline; the second organic material comprises C 60 ; the third organic material comprises at least one selected from the group consisting of rubrene, pentacene, tetrafluorotetracyanoquinodimethane, copper phthalocyanine or other phthalocyanine derivatives; and the fourth organic material comprises N,N′-di(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine.

4. The tandem organic light-emitting diode according to claim 1 , wherein the first light-emitting layer and the second light-emitting layer each independently comprise a mixture comprising at least one host organic material and at least one guest organic material.

5. The tandem organic light-emitting diode according to claim 4 , wherein the guest organic material comprises bis[2-(4,6-difluorophenyl)pyridinato-C 2 ,N](picolinato)iridium(III), the host organic material comprises 4,4′,4″-tri(carbazol-9-yl)triphenylamine and 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene, or the host organic material comprises N,N′-di(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine and 4,7-diphenyl-1,10-phenanthroline.

6. An array substrate, comprising a plurality of tandem organic light-emitting diodes according to claim 1 .

7. A display device, comprising the array substrate according to claim 6 .

8. The array substrate according to claim 6 , wherein the first organic material comprises 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene; the second organic material comprises C 60 ; the third organic material comprises at least one selected from the group consisting of rubrene, pentacene, tetrafluorotetracyanoquinodimethane, copper phthalocyanine or other phthalocyanine derivatives; and the fourth organic material comprises 4,4′,4″-tri(carbazol-9-yl) triphenylamine.

9. The array substrate according to claim 6 , wherein the first organic material comprises 4,7-diphenyl-1,10-phenanthroline; the second organic material comprises C 60 ; the third organic material comprises at least one selected from the group consisting of rubrene, pentacene, tetrafluorotetracyanoquinodimethane, copper phthalocyanine or other phthalocyanine derivatives; and the fourth organic material comprises N,N′-di(l-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine.

10. The array substrate according to claim 6 , wherein the first light-emitting layer and the second light-emitting layer each independently comprise a mixture comprising at least one host organic material and at least one guest organic material.

11. The array substrate according to claim 10 , wherein the guest organic material comprises bis[2-(4,6-difluorophenyl)pyridinato-C 2 ,N](picolinato)iridium(III), the host organic material comprises 4,4′,4″-tri(carbazol-9-yl)triphenylamine and 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene, or the host organic material comprises N,N′-di(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine and 4,7-diphenyl-1,10-phenanthroline.