Organic light emitting diode device

• US 20110133226A1
• Filed: 12/02/2010
• Published: 06/09/2011
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Sung-Hun, Song, Jung-Bae
• Granted Patent: US 8,829,542 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: H10K 2101/30 Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]

Abstract

An organic light emitting diode device including an anode, a cathode facing the anode, and a light emitting member between the anode and cathode, wherein the light emitting member includes at least two light emitting units displaying the same or different color as one another, and a charge-generation layer between the at least two light emitting units, the charge-generation layer including a first charge-generation layer and a second charge-generation layer that each include an undoped material, and wherein the first charge-generation layer has an ionization energy that is about the same as or less than an electron affinity of the second charge-generation layer.

Claims

1. An organic light emitting diode device, comprising

an anode,

a cathode facing the anode, and

a light emitting member between the anode and cathode,

wherein the light emitting member includes:

at least two light emitting units displaying the same or different color as one another, and

a charge-generation layer between the at least two light emitting units, the charge-generation layer including a first charge-generation layer and a second charge-generation layer that each include an undoped material, and

wherein the first charge-generation layer has an ionization energy that is about the same as or less than an electron affinity of the second charge-generation layer.

2. The organic light emitting diode device as claimed in claim 1, wherein the first charge-generation layer has an electron transport property and the second charge-generation layer has a hole transport property.

3. The organic light emitting diode device as claimed in claim 2, wherein the first charge-generation layer is between the anode and the second charge-generation layer.

4. The organic light emitting diode device as claimed in claim 2, wherein the at least two light emitting units include:

a first light emitting unit between the anode and the first charge-generation layer; and

a second light emitting unit between the cathode and the second charge-generation layer.

5. The organic light emitting diode device as claimed in claim 2, wherein the first charge-generation layer and the second charge-generation layer include different materials from one another.

6. The organic light emitting diode device as claimed in claim 5, wherein the first charge-generation layer has an ionization energy, the ionization energy being from about the same as to about 5 eV less than an electron affinity of the second charge-generation layer.

7. The organic light emitting diode device as claimed in claim 6, wherein the ionization energy is from about 1 eV less to about 4 eV less than the electron affinity of the second charge-generation layer.

8. The organic light emitting diode device as claimed in claim 5, wherein the first charge-generation layer has an ionization energy of about 2.0 eV to about 5.0 eV and the second charge-generation layer has an electron affinity of about 4.0 eV to about 7.0 eV.

9. The organic light emitting diode device as claimed in claim 5, wherein the first charge-generation layer includes a compound including at least one of a metal-substituted tetra(hexahydro pyrimidopyrimidine), an alkali metal, and an alloy of an alkali metal.

10. The organic light emitting diode device as claimed in claim 9, wherein the first charge-generation layer includes the metal-substituted tetra(hexahydropyrimidopyrimidine), such metal-substituted tetra(hexahydropyrimidopyrimidine including at least one of ditungsten tetra(hexahydropyrimidopyrimidine) (W₂(hpp)₄) and dichromium tetra(hexahydropyrimidopyrimidine) (Cr₂(hpp)₄).

11. The organic light emitting diode device as claimed in claim 9, wherein the first charge-generation layer includes the alkali metal, such alkali metal including at least one of lithium (Li), sodium (Na), cesium (Cs), rubidium (Rb), and francium (Fr).

12. The organic light emitting diode device as claimed in claim 5, wherein the second charge-generation layer includes at least one of a hexaazatriphenylene derivative, a tetrafluoro-tetracyanoquinodimethane (F4-TCNQ) derivative, and a metal oxide.

13. The organic light emitting diode device as claimed in claim 12, wherein the second charge-generation layer includes the metal oxide, such metal oxide including at lest one of vanadium oxide (V₂O₅), tungsten oxide (WO₃), and molybdenum oxide (MoO₃).

14. The organic light emitting diode device as claimed in claim 2, wherein each light emitting unit includes:

an emission layer displaying color; and

an auxiliary layer disposed on at least one of an upper side and a lower side of the emission layer.

15. The organic light emitting diode device as claimed in claim 2, wherein the light emitting member includes at least one of a red light emitting unit, a green light emitting unit, a blue light emitting unit, an orange light emitting unit, and a white light emitting unit.

16. The organic light emitting diode device as claimed in claim 15, wherein the light emitting member includes the orange light emitting unit, such orange light emitting unit including a red emission layer and a green emission layer.

17. The organic light emitting diode device as claimed in claim 15, wherein the light emitting member includes the orange light emitting unit, such orange light emitting unit including a host doped with red light emitting material and green light emitting material.

18. The organic light emitting diode device as claimed in claim 2, wherein the light emitting member is fashioned to emit white light by combining light emitted from the at least two light emitting units.

19. The organic light emitting diode device as claimed in claim 2, further comprising a first sub-pixel, a second sub-pixel, and a third sub-pixel displaying different colors from each other and a white sub-pixel,

wherein the light emitting member is commonly disposed on the first sub-pixel, the second sub-pixel, the third sub-pixel, and the white sub-pixel;

and

wherein the first sub-pixel, the second sub-pixel, and the third sub-pixel include a red color filter, a green color filter, and blue color filter, respectively, disposed on a lower side or an upper side of the light emitting member.