Organometallic compound and organic light-emitting device including the same

1. An organometallic compound represented by Formula 1:

wherein, in Formulae 1, 2, and 3,

M is selected from a Period 1 transition metal, a Period 2 transition metal, and a Period 3 transition metal;

L 1 is a first ligand represented by Formula 2;

L 2 is a second ligand represented by Formula 3;

L 3 is selected from a monovalent organic ligand, a divalent organic ligand, and a trivalent organic ligand;

n1 and n2 are each independently an integer of 1 to 3, wherein when n1 is 2 or more, groups L 1 are identical or different, and when n2 is 2 or more, groups L 2 are identical or different;

n3 is an integer of 0 to 4, wherein when n3 is 2 or more, groups L 3 are identical or different;

A 21 and A 32 are each independently selected from a C 1 -C 10 heterocycloalkane, a C 1 -C 10 heterocycloalkene, a C 1 -C 10 heteroarene, and a non-aromatic condensed heteropolycycle;

A 22 and A 33 are each independently selected from a C 3 -C 10 cycloalkane, a C 1 -C 10 heterocycloalkane, a C 3 -C 10 cycloalkene, a C 1 -C 10 heterocycloalkene, a C 6 -C 10 arene, a C 1 -C 10 heteroarene, a non-aromatic condensed polycycle, and a non-aromatic condensed heteropolycycle;

A 31 is selected from a C 3 -C 20 cycloalkene and a C 1 -C 10 heterocycloalkene;

R 21 , R 22 , and R 31 to R 33 are each independently selected from a hydrogen, a deuterium, a hydroxyl group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C 1 -C 60 alkyl group, a substituted or unsubstituted C 2 -C 60 alkenyl group, a substituted or unsubstituted C 2 -C 60 alkynyl group, a substituted or unsubstituted C 1 -C 60 alkoxy group, a substituted or unsubstituted C 3 -C 10 cycloalkyl group, a substituted or unsubstituted C 1 -C 10 heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10 cycloalkenyl group, a substituted or unsubstituted C 1 -C 10 heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60 aryl group, a substituted or unsubstituted C 6 -C 60 aryloxy group, a substituted or unsubstituted C 6 -C 60 arylthio group, a substituted or unsubstituted C 1 -C 60 heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q 1 )(Q 2 ), —Si(Q 3 )(Q 4 )(Q 5 ), —B(Q 6 )(Q 7 ), and —Ge(Q 8 )(Q 9 )(Q 10 );

b21, b22, and b31 to b33 are each independently an integer of 1 to 4;

b23 and b24 are each independently an integer of 0 to 4, wherein the sum of b23 and b24 is 1 or more;

* and *′ are each independently a binding site with M in Formula 1;

at least one substituent of the substituted C 1 -C 60 alkyl group, substituted C 2 -C 60 alkenyl group, substituted C 2 -C 60 alkynyl group, substituted C 1 -C 60 alkoxy group, substituted C 3 -C 10 cycloalkyl group, substituted C 1 -C 10 heterocycloalkyl group, substituted C 3 -C 10 cycloalkenyl group, substituted C 1 -C 10 heterocycloalkenyl group, substituted C 6 -C 60 aryl group, substituted C 6 -C 60 aryloxy group, substituted C 6 -C 60 arylthio group, substituted C 1 -C 60 heteroaryl group, substituted monovalent non-aromatic condensed polycyclic group, and substituted monovalent non-aromatic condensed heteropolycyclic group is selected from

a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, and a C 1 -C 60 alkoxy group;

a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, and a C 1 -C 60 alkoxy group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 11 )(Q 12 ), —Si(Q 13 )(Q 14 )(Q 15 ), and —B(Q 16 )(Q 17 );

a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group;

a C 3 -C 10 cycloalkyl group, a C 2 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 2 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60 alkyl group, a C 1 -C 60 alkenyl group, a C 1 -C 60 alkynyl group, a C 1 -C 60 alkoxy group, a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 21 )(Q 22 ), —Si(Q 23 )(Q 24 )(Q 25 ), and —B(Q 26 )(Q 27 ); and

—N(Q 31 )(Q 32 ), —Si(Q 33 )(Q 34 )(Q 35 ), and —B(Q 36 )(Q 37 );

wherein Q 1 to Q 10 , Q 11 to Q 17 , Q 21 to Q 27 , and Q 31 to Q 37 are each independently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, a C 1 -C 60 alkoxy group, a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

2. The organometallic compound of claim 1 , wherein

M is Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb, or Tm.

3. The organometallic compound of claim 1 , wherein

n1 is 2, n2 is 1, and n3 is 0.

4. The organometallic compound of claim 1 , wherein

A 21 and A 32 each independently are a pyrrole, an imidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, an isoxazole, a triazole, a pyridine, a pyrazine, a pyrimidine, a quinoline, an isoquinoline, a benzoquinoline, a quinoxaline, a quinazoline, a naphthyridine, a benzoimidazole, a benzoxazole, an isobenzoxazole, an oxadiazole, or a triazine.

5. The organometallic compound of claim 1 , wherein

A 21 and A 32 each independently are a pyridine, a pyrazine, a pyrimidine, a quinoline, an isoquinoline, a quinoxaline, a quinazoline, or a naphthyridine.

6. The organometallic compound of claim 1 , wherein

A 22 and A 33 each independently are a benzene, a naphthalene, a fluorene, a spiro-fluorene, an indene, a furan, a thiophene, a carbazole, a benzofuran, a benzothiophene, a dibenzofuran, a dibenzothiophene, a pyrrole, an imidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, an isoxazole, a triazole, a pyridine, a pyrazine, a pyrimidine, a quinoline, an isoquinoline, a benzoquinoline, a quinoxaline, a quinazoline, a naphthyridine, a benzoimidazole, a benzoxazole, an isobenzoxazole, an oxadiazole, or a triazine.

7. The organometallic compound of claim 1 , wherein

A 22 and A 33 each independently are a benzene, a naphthalene, a fluorene, a carbazole, a dibenzofuran, or a dibenzothiophene.

8. The organometallic compound of claim 1 , wherein

A 31 is a cyclopentene, a cyclohexene, a cycloheptene, a bicycloheptene, a dihydrofuran, a dihydropyran, or an oxabicycloheptene.

9. The organometallic compound of claim 1 , wherein

A 31 is a cyclopentene, a cyclohexane, or a bicycloheptene.

10. The organometallic compound of claim 1 , wherein

R 21 , R 22 , and R 31 to R 33 are each independently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 20 alkyl group, and a C 1 -C 20 alkoxy group;

a C 1 -C 20 alkyl group and a C 1 -C 20 alkoxy group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a phenyl group, a naphthyl group, a pyridinyl group, and a pyrimidinyl group;

a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group;

a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and —Si(Q 33 )(Q 34 )(Q 35 ); and

—Si(Q 3 )(Q 4 )(Q 5 ) and —Ge(Q 8 )(Q 9 )(Q 10 );

wherein Q 3 to Q 5 , Q 8 to Q 10 , and Q 33 to Q 35 are each independently selected from a hydrogen, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group.

11. The organometallic compound of claim 1 , wherein

L 1 is a first ligand represented by one of Formulae 2-1 to 2-4:

wherein, in Formulae 2-1 to 2-4,

D is deuterium, and

descriptions of R 21 , R 22 , b21, b22, b23, b24, *, and *′ are the same as in claim 1 .

12. The organometallic compound of claim 1 , wherein

L 1 is a first ligand represented by one of Formulae 2-31 to 2-34:

wherein, in Formulae 2-31 to 2-34,

D is deuterium, and

descriptions of R 21 , R 22 , *, and *′ are the same as in claim 1 .

13. The organometallic compound of claim 1 , wherein

L 2 is a second ligand represented by one of Formulae 3-1 to 3-15:

wherein, in Formulae 3-1 to 3-15,

descriptions of A 31 , A 33 , R 31 to R 33 , b31 to b33, *and *′ are the same as in claim 1 .

14. The organometallic compound of claim 1 , wherein

L 2 is a second ligand represented by one of Formulae 3-51 to 3-65:

wherein, in Formulae 3-51 to 3-65,

descriptions of R 31 to R 33 , b31 to b33, *, and *′ are the same as in claim 1 .

15. The organometallic compound of claim 1 , wherein

L 3 is represented by one selected from Formulae 4-1 to 4-4:

wherein, in Formulae 4-1 to 4-4,

X 41 is CR 41 or N; X 42 is CR 42 or N;

Y 41 and Y 42 each independently are C or N;

A 41 to A 43 are each independently selected from a C 3 -C 10 cycloalkane, a C 1 -C 10 heterocycloalkane, a C 3 -C 10 cycloalkene, a C 1 -C 10 heterocycloalkene, a C 6 -C 10 arene, a C 1 -C 10 heteroarene, a non-aromatic condensed polycycle, and a non-aromatic condensed heteropolycycle;

R 41 to R 44 are each independently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C 1 -C 60 alkyl group, a substituted or unsubstituted C 2 -C 60 alkenyl group, a substituted or unsubstituted C 2 -C 60 alkynyl group, a substituted or unsubstituted C 1 -C 60 alkoxy group, a substituted or unsubstituted C 3 -C 10 cycloalkyl group, a substituted or unsubstituted C 1 -C 10 heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10 cycloalkenyl group, a substituted or unsubstituted C 1 -C 10 heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60 aryl group, a substituted or unsubstituted C 6 -C 60 aryloxy group, a substituted or unsubstituted C 6 -C 60 arylthio group, a substituted or unsubstituted C 1 -C 60 heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and —Si(Q 41 )(Q 42 )(Q 43 );

b43 and b44 each independently are an integer of 1 to 5;

Q 41 to Q 43 each independently are a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, a C 1 -C 60 alkoxy group, a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group; and

* and *′ each independently are a binding site with M in Formula 1.

16. The organometallic compound of claim 1 , wherein

L 3 is represented by one selected from Formulae 5-1 to 5-119:

wherein, in Formulae 5-1 to 5-119,

R 51 to R 53 are each independently selected from a hydrogen, —F, a cyano group, a nitro group, a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an iso-heptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an iso-octyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decanyl group, an iso-decanyl group, a sec-decanyl group, a tert-decanyl group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

a methyl group, an ethyl group, a propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an iso-heptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an iso-octyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decanyl group, an iso-decanyl group, a sec-decanyl group, a tert-decanyl group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from —F, a cyano group, and a nitro group;

b51 and b54 each independently are 1 or 2;

b53 and b55 each independently are an integer of 1 to 3;

b52 is an integer of 1 to 4; and

* and *′ each independently are a binding site with M in Formula 1.

17. The organometallic compound of claim 1 , wherein

the organometallic compound is represented by Formula 1-1:

M(L 1 ) n1 (L 2 ) n2   Formula 1-1

wherein, in Formulae 1-1,

M is Os, Ir, or Pt;

L 1 is represented by one selected from Formulae 6-1 to 6-11;

D is deuterium; n1 is 2; L 2 is represented by Formulae 7-1 to 7-16;

n2 is 1.

18. The organometallic compound of claim 1 , wherein

the organometallic compound is selected from Compounds 1 to 19:

wherein, D is deuterium, and TMS in Compound 8 is —Si(CH 3 ) 3 .

19. An organic light-emitting device comprising:

a first electrode;

a second electrode; and

an organic layer disposed between the first electrode and the second electrode,

wherein the organic layer comprises an emission layer and at least one organometallic compound of claim 1 .

20. The organic light-emitting device of claim 19 , wherein

the emission layer comprises the organometallic compound of claim 1 and a host, wherein the amount of the organometallic compound of claim 1 is smaller than the amount of the host.