Organic light emitting device

1. An organic light emitting device comprising:

an anode;

a cathode;

a light emitting layer disposed between the anode and the cathode; and

an electron transport region between the cathode and the light emitting layer,

wherein the light emitting layer comprises a compound represented by Chemical Formula 1, and

the electron transport region comprises a compound represented by Chemical Formula 2:

in Chemical Formula 1,

X is O or S,

L is a bond; or a substituted or unsubstituted C 6-60 arylene,

Ar is a substituted or unsubstituted C 6-60 aryl,

R and R′ are each independently hydrogen; deuterium; halogen; nitrile; nitro; amino; a substituted or unsubstituted C 1-60 alkyl; a substituted or unsubstituted C 3-60 cycloalkyl; a substituted or unsubstituted C 2-60 alkenyl group; a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S,

n1 is an integer of 0 to 3, and

n2 is an integer of 0 to 4,

in Chemical Formula 2,

Ar 1 and Ar 2 are each independently substituted or unsubstituted phenyl, substituted or unsubstituted biphenylyl, or substituted or unsubstituted terphenylyl,

L 1 , L 2 and L 3 are each independently a substituted or unsubstituted C 6-60 arylene,

i, j, and k are each independently 0 or 1,

A is represented by Chemical Formula 3,

in Chemical Formula 3,

X′ is

Y and Z are each independently hydrogen or deuterium, or Y and Z together form a bond or —W—,

wherein W is CR 17 R 18 , SiR 19 R 20 , NR 21 , O, or S,

R 1 to R 21 are each independently hydrogen; deuterium; a substituted or unsubstituted C 1-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, or two adjacent radicals of R 1 to R 21 are linked to form a substituted or unsubstituted C 6-60 aryl, and

one of R 1 to R 16 is linked to L 3 .

2. The organic light emitting device of claim 1 , wherein

L is a bond, phenylene, biphenylene, naphthylene, or anthracenylene.

3. The organic light emitting device of claim 1 , wherein

Ar is phenyl, biphenylyl, terphenylyl, naphthyl, phenylnaphthyl, naphthylphenyl, or phenanthrenyl.

4. The organic light emitting device of claim 1 , wherein R and R′ are each independently hydrogen, deuterium, phenyl, biphenylyl, or naphthyl.

5. The organic light emitting device of claim 1 , wherein

the compound represented by the Chemical Formula 1 is any one selected from the group consisting of the following:

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

L 1 , L 2 and L 3 are each independently phenylene, naphthylene, or -(phenylene)-(naphthylene)-.

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

i and j are 0, and

k is 0 or 1.

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

A is any one selected from the group consisting of the following:

in each of Chemical Formulas,

one of R″ is linked to L 3 , and the rest are hydrogen.

9. The organic light emitting device of claim 1 , wherein

the compound represented by the Chemical Formula 2 is any one selected from the group consisting of the following:

10. The organic light emitting device of claim 1 , wherein

the electron transport region comprises an electron transport layer, and

the electron transport layer comprises the compound represented by the Chemical Formula 2.

11. The organic light emitting device of claim 1 , wherein

the electron transport region comprises an electron transport layer and a hole blocking layer, and

the hole blocking layer comprises a compound represented by the Chemical Formula 2.

12. The organic light emitting device of claim 11 , wherein

the light emitting layer and the hole blocking layer are positioned adjacent to each other.