Organic light-emitting diode device and compound for charge generation layer included therein

1. An organic light-emitting diode device comprising:

a first electrode;

a second electrode disposed opposite to the first electrode;

m light-emitting units (where m is an integer of 2 or more) disposed between the first electrode and the second electrode, and comprising at least one light-emitting layer; and

m-1 charge generation layers each interposed between two adjacent light-emitting units of the m light-emitting units;

wherein at least one of the m-1 charge generation layers comprises a compound represented by Formula 1 below:

Y 2 Y 1 B-M(X) a   Formula 1

wherein:

M is a metal selected from the group consisting of Group 1 metals, Group 2 metals, transition metals, post-transition metals, lanthanides, and actinides, which have a work function of 4.0 eV or less;

X is a halogen element selected from the group consisting of F, Cl, Br, and I;

a is a natural number ranging from 1 to 4; and

Y 1 and Y 2 are the same or different, and are each independently one or more selected from the group consisting of a halogen, a hydroxyl group, a nitro group, a cyano group, an amine group, a C 1 -C 40 alkyl group, a C 6 -C 40 aryl group, and a 5- to 40-membered heteroaryl group, or they may be bonded to an adjacent group to form a condensed ring, provided that at least one of Y 1 and Y 2 is a C 6 -C 40 aryl group or a 5- to 40-membered heteroaryl group; and

wherein the alkyl group, the aryl group, and the heteroaryl group are each unsubstituted or substituted with one or more substituents selected from the group consisting of a halogen, a cyano group, a nitro group, a C 1 -C 40 alkyl group, a C 6 -C 40 aryl group, a 5- to 40-membered heteroaryl group, a C 6 -C 40 aryloxy group, a C 6 -C 40 arylphosphine oxide group, and a C 6 -C 40 arylamine group, and the substituents may be the same or different if they are plural in number.

2. The organic light-emitting diode device of claim 1 , wherein the compound represented by formula 1 is a charge-transfer (CT) complex comprising a boron-containing compound and a metal halide.

3. The organic light-emitting diode device of claim 2 , wherein a content ratio between the boron-containing compound and the metal halide is 0.5-50:50-95.5 by weight.

4. The organic light-emitting diode device of claim 1 , wherein the compound represented by formula 1 is bonded to adjacent compounds of formula 1 to form a cluster, and the cluster comprises at least one heterocyclic ring containing the boron and the metal (M).

5. The organic light-emitting diode device of claim 1 , wherein each of the m-1 charge generation layers comprises at least one host and at least one dopant, and one of the at least one host and at least one dopant is the compound represented by formula 1.

6. The organic light-emitting diode device of claim 1 , wherein the m light-emitting units are disposed alternately with the m-1 charge generation layers, and two light-emitting units of the m light-emitting units are disposed adjacent to the first electrode and the second electrode, respectively.

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

each of the m light-emitting units comprises a hole transport region, a light-emitting layer, and an electron transport region;

the hole transport region comprises at least one of a hole injection layer and a hole transport layer; and

the electron transport region comprises at least one of an electron transport layer and an electron transport layer.

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

each of the m-1 charge generation layers comprises an n-type charge generation layer and a p-type charge generation layer;

the n-type charge generation layer is disposed adjacent to the electron transport region of each of the m light-emitting units; and

the p-type charge generation layer is disposed adjacent to the hole transport region of each of the m light-emitting units.

9. The organic light-emitting diode device of claim 8 , wherein the n-type charge generation layer comprises a metal selected from the group consisting of Group 1 metals, Group 2 metals, lanthanides, and actinides, which have a work function of 4.0 eV or less.

10. The organic light-emitting diode device of claim 8 , wherein the p-type charge generation layer comprises a metal selected from the group consisting of transition metals and post-transition metals, which have a work function of 4.0 eV or less.

11. A compound for a charge generation layer, comprising:

at least one boron-containing compound; and

at least one metal halide containing a metal having a work function of 4.0 eV or less;

wherein the boron (B) of the boron-containing compound and the metal (M) of the metal halide are bonded to each other by a one-electron sigma bond.

12. The compound of claim 11 , wherein a bonding value between the metal (M) and the boron (B), which is measured by X-ray photoelectron spectrometry (XPS), ranges from 180 to 290 eV.

13. The compound of claim 11 , wherein the compound is represented by Formula 1 below:

Y 2 Y 1 B-M(X) a   Formula 1

wherein:

M is a metal selected from the group consisting of Group 1 metals, Group 2 metals, transition metals, post-transition metals, lanthanides, and actinides, which have a work function of 4.0 eV or less;

X is a halogen element selected from the group consisting of F, Cl, Br, and I;

a is a natural number ranging from 1 to 4; and

Y 1 and Y 2 are the same or different, and are each independently one or more selected from the group consisting of a halogen, a hydroxyl group, a nitro group, a cyano group, an amine group, a C 1 -C 40 alkyl group, a C 6 -C 40 aryl group, and a 5- to 40-membered heteroaryl group, or they may be bonded to an adjacent group to form a condensed ring, provided that at least one of Y 1 and Y 2 is a C 6 -C 40 aryl group or a 5- to 40-membered heteroaryl group; and

wherein the alkyl group, the aryl group, and the heteroaryl group are each unsubstituted or substituted with one or more substituents selected from the group consisting of a halogen, a cyano group, a nitro group, a C 1 -C 40 alkyl group, a C 6 -C 40 aryl group, a 5- to 40-membered heteroaryl group, a C 6 -C 40 aryloxy group, a C 6 -C 40 arylphosphine oxide group, and a C 6 -C 40 arylamine group, and the substituents may be the same or different if they are plural in number.

14. The compound of claim 11 , wherein the metal halide is a metal iodide.

15. The compound of claim 11 , wherein the compound is used for an n-type charge generation layer, a p-type charge generation layer, or both.

16. The compound of claim 15 , wherein the n-type charge generation layer comprises a metal selected from the group consisting of Group 1 metals, Group 2 metals, lanthanides, and actinides, which have a work function of 4.0 eV or less.

17. The compound of claim 15 , wherein the p-type charge generation layer comprises a metal selected from the group consisting of transition metals and post-transition metals, which have a work function of 4.0 eV or less.

18. The compound of claim 11 , wherein the compound is a charge-transfer (CT) complex comprising a boron-containing compound and a metal halide.

19. The compound of claim 18 , wherein a content ratio between the boron-containing compound and the metal halide is 0.5-50:50-95.5 by weight.

20. The compound of claim 13 , wherein the compound represented by formula 1 is bonded to adjacent compounds of formula 1 to form a cluster, and the cluster comprises at least one heterocyclic ring containing the boron and the metal (M).