Heterocyclic compound and organic light-emitting device including the same

1. An organic light-emitting device comprising:

a first electrode;

a second electrode facing the first electrode;

an organic layer between the first electrode and the second electrode, the organic layer comprising an emission layer; and the organic layer comprising

at least one heterocyclic compound represented by Formula 1,

wherein the first electrode comprises indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2 ), zinc oxide (ZnO), magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof, and

the second electrode comprises lithium (Li), Ag, Mg, Al, Al—Li, Ca, Mg—In, Mg—Ag, ITO, IZO, ytterbium (Yb), silver-ytterbium (Ag—Yb), or any combination thereof:

(L 1 ) b1 -(Ar 1 ) c1 ,  <Formula 2>

wherein, in Formulae 1 and 2,

A 1 to A 7 are each independently selected from a C 5 -C 60 carbocyclic group and a C 1 -C 60 heterocyclic group,

A 1 and A 2 are optionally linked to each other via a first linking group,

A 4 and A 5 are optionally linked to each other via a second linking group,

X 1 and X 2 are each independently O or S,

L 1 is a substituted or unsubstituted C 3 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group,

b 1 is an integer from 0 to 3,

Ar 1 is a substituted or unsubstituted C 3 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group,

c1 is an integer from 1 to 3,

R 1 to R 7 are each independently selected from a group represented by Formula 2, hydrogen, deuterium, —F, —Cl, —Br, —I a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazino 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 alkoxy group, a substituted or unsubstituted C 3 -C 10 cycloalkyl group, a substituted or unsubstituted 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, —Si(Q 1 )(Q 2 )(Q 3 ), —N(Q 1 )(Q 2 ), —B(Q 1 )(Q 2 ), —S(═O) 2 (Q 1 ), and —P(═O)(Q 1 )(Q 2 ),

a1 to a7 are each independently an integer from 1 to 10,

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

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone 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;

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 deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone 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, —Si(Q 11 )(Q 12 )(Q 13 ), —N(Q 11 )(Q 12 ), —B(Q 11 )(Q 12 ), —C(═O)(Q 11 ), —S(═O) 2 (Q 11 ), and —P(═O)(Q 11 )(Q 12 );

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, a biphenyl group, and a terphenyl 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, a biphenyl group, and a terphenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone group, 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, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q 21 )(Q 22 )(Q 23 ), —N(Q 21 )(Q 22 ), —B(Q 21 )(Q 22 ), —C(═O)(Q 21 ), —S(═O) 2 (Q 21 ), and —P(═O)(Q 21 )(Q 22 ); and

—Si(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), —B(Q 31 )(Q 32 ), —C(═O)(Q 31 ), —S(═O) 2 (Q 31 ), and —P(═O)(Q 31 )(Q 32 ),

Q 1 to Q 3 , Q 11 to Q 13 , Q 21 to Q 23 , and Q 31 to Q 33 are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone group, 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 aryl group substituted with a C 1 -C 60 alkyl group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group, and

* indicates a binding site to a neighboring atom, and

wherein when i) X 1 and X 2 are each O, ii) A 1 to A 7 are each a benzene group, and iii) R 2 , R 3 , R 5 , R 6 , and R 7 are each hydrogen, each of R 1 in the number of a1 consists of hydrogen and each of R 4 in the number of a4 consists of hydrogen.

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

the first electrode is an anode,

the second electrode is a cathode,

the organic layer comprises the at least one heterocyclic compound,

the organic layer further comprises a hole transport region between the first electrode and the emission layer and an electron transport region between the emission layer and the second electrode,

the hole transport region comprises a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof, and

the electron transport region comprises a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

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

the emission layer comprises a dopant and a host, and

the host comprises the at least one heterocyclic compound.

4. The organic light-emitting device of claim 3 , wherein

the dopant is a fluorescent dopant or a phosphorescent dopant.

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

the emission layer comprises a dopant and a host, and

the dopant comprises the at least one heterocyclic compound.

6. The organic light-emitting device of claim 5 , wherein

the host further comprises a compound represented by Formula 301:

[Ar 301 ] xb11 -[(L 301 ) xb1 -R 301 ] xb21 ,  <Formula 301>

wherein, in Formula 301,

Ar 301 is a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group,

xb11 is 1, 2, or 3,

L 301 is selected from a substituted or unsubstituted C 3 -C 10 cycloalkylene group, a substituted or unsubstituted C 1 -C 10 heterocycloalkylene group, a substituted or unsubstituted C 3 -C 10 cycloalkenylene group, a substituted or unsubstituted C 1 -C 10 heterocycloalkenylene group, a substituted or unsubstituted C 6 -C 60 arylene group, a substituted or unsubstituted C 1 -C 60 heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xb1 is an integer from 0 to 5,

R 301 is selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone group, 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, —Si(Q 301 )(Q 302 )(Q 303 ), —N(Q 301 )(Q 302 ), —B(Q 301 )(Q 302 ), —C(═O)(Q 301 ), —S(═O) 2 (Q 301 ), and —P(═O)(Q 301 )(Q 302 ),

xb21 is an integer from 1 to 5, and

Q 301 to Q 303 are each independently selected from a C 1 -C 10 alkyl group, a C 1 -C 10 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

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

the emission layer comprises the at least one heterocyclic compound,

the at least one heterocyclic compound is a thermally activated delayed fluorescence (TADF) emitter, and

the emission layer is to emit delayed fluorescence.

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

the emission layer is a first emission layer to emit a first color light,

the organic light-emitting device further comprises, between the first electrode and the second electrode, i) at least one second emission layer to emit a second color light or ii) at least one second emission layer to emit a second color light and at least one third emission layer to emit a third color light,

a maximum emission wavelength of the first color light, a maximum emission wavelength of the second color light, and a maximum emission wavelength of the third color light are identical to or different from each other, and

the first color light and the second color light are emitted in the form of mixed light, or the first color light, the second color light, and the third color light are emitted in the form of mixed light.

9. A heterocyclic compound represented by Formula 1:

*-(L 1 ) b1 -(Ar 1 ) c1 ,  <Formula 2>

wherein, in Formulae 1 and 2,

A 1 to A7 are each independently selected from a C 6 -C 60 carbocyclic group and a C 1 -C 60 heterocyclic group,

A 1 and A 2 are optionally linked to each other via a first linking group,

A 4 and A 5 are optionally linked to each other via a second linking group,

X 1 and X 2 are each independently O or S,

L 1 is a substituted or unsubstituted C 3 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group,

b1 is an integer from 0 to 3,

Ar 1 is a substituted or unsubstituted C 3 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group,

c1 is an integer from 1 to 3,

R 1 to R 7 are each independently selected from a group represented by Formula 2, hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazino 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, —Si(Q 1 )(Q 2 )(Q 3 ), —N(Q 1 )(Q 2 ), —B(Q 1 )(Q 2 ), —S(═O) 2 (Q 1 ), and —P(═O)(Q 1 )(Q 2 ),

a1 to a7 are each independently an integer from 1 to 10,

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

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone 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,

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 deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone 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, —Si(Q 11 )(Q 12 )(Q 13 ), —N(Q 11 )(Q 12 ), —B(Q 11 )(Q 12 ), —C(═O)(Q 11 ), —S(═O) 2 (Q 11 ), and —P(═O)(Q 11 )(Q 12 );

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, a biphenyl group, and a terphenyl 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, a biphenyl group, and a terphenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone group, 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, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q 21 )(Q 22 )(Q 23 ), —N(Q 21 )(Q 22 ), —B(Q 21 )(Q 22 ), —C(═O)(Q 21 ), —S(═O) 2 (Q 21 ), and —P(═O)(Q 21 )(Q 22 ); and

—Si(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), —B(Q 31 )(Q 32 ), —C(═O)(Q 31 ), —S(═O) 2 (Q 31 ), and —P(═O)(Q 31 )(Q 32 ),

Q 1 to Q 3 , Q 11 to Q 13 , Q 21 to Q 23 , and Q 31 to Q 33 are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone group, 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 aryl group substituted with a C 1 -C 60 alkyl group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group, and

* indicates a binding site to a neighboring atom, and

wherein when i) X 1 and X 2 are each O, ii) A 1 to A 7 are each a benzene group, and iii) R 2 , R 3 , R 5 , R 6 , and R 7 are each hydrogen, each of R 1 in the number of a1 consists of hydrogen and each of R 4 in the number of a4 consists of hydrogen.

10. The heterocyclic compound of claim 9 , wherein

A 1 to A 7 are each independently selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a thiophene group, a furan group, a silole group, a carbazole group, an indole group, an isoindole group, a benzofuran group, a benzothiophene group, a benzosilole group, a dibenzofuran group, a dibenzothiophene group, a benzocarbazole group, a dibenzocarbazole group, and a dibenzosilole group.

11. The heterocyclic compound of claim 9 , wherein

the first linking group and the second linking group are each independently selected from a single bond, *—O—*′, and *—S—*′, and

* and *′ each indicate a binding site to a neighboring atom.

12. The heterocyclic compound of claim 9 , wherein

X 1 and X 2 are identical to each other.

13. The heterocyclic compound of claim 9 , wherein

i) X 1 and X 2 are both O, A 1 and A 2 are not linked to each other, and A 4 and A 5 are not linked to each other;

ii) X 1 and X 2 are both S, A 1 and A 2 are not linked to each other, and A 4 and A 5 are not linked to each other; or

iii) X 1 and X 2 are both O, and the first linking group and the second linking group are both *—O—*′, and

* and *′ each indicate a binding site to a neighboring atom.

14. The heterocyclic compound of claim 9 , wherein

L 1 is selected from:

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; and

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, —Si(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), and —B(Q 31 )(Q 32 ), and

Q 31 to Q 33 are each independently selected from a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.

15. The heterocyclic compound of claim 9 , wherein

Ar 1 is selected from:

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group;

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, —Si(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), and —B(Q 31 )(Q 32 ), and

Q 31 to Q 33 are each independently selected from a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.

16. The heterocyclic compound of claim 9 , wherein

R 1 to R 7 are each independently selected from:

a group represented by Formula 2, hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, —Si(Q 1 )(Q 2 )(Q 3 ), —N(Q 1 )(Q 2 ), —B(Q 1 )(Q 2 ), —S(═O) 2 (Q 1 ), and —P(═O)(Q 1 )(Q 2 ); and

a C 1 -C 20 alkyl group, a carbazole group, a dibenzofuran group, and a dibenzothiophene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, and a terphenyl group, and

Q 1 to Q 3 are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazone group, 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 aryl group substituted with a C 1 -C 60 alkyl group, a C 1 -C 60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.

17. The heterocyclic compound of claim 9 , wherein

the heterocyclic compound represented by Formula 1 is selected from groups represented by Formulae 1-1 to 1-3:

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

X 1 and X 2 are each independently the same as described in connection with Formula 1,

Y 1 and Y 2 are each independently selected from a single bond, *—O—*′, and *—S—*′,

R 11 to R 32 are each independently the same as defined in connection with R 1 to R 7 in connection with Formula 1, and

* and *′ each indicate a binding site to a neighboring atom, and

in Formula 1-1, when X 1 and X 2 are each O, and R 11 , R 13 to R 15 , and R 17 to R 32 are each hydrogen, R 12 and R 16 are each consisting of hydrogen.

18. The heterocyclic compound of claim 17 , wherein

i) R 12 and R 16 are identical to each other,

ii) R 20 and R 30 are identical to each other,

iii) R 22 and R 28 are identical to each other, or

at least two of the conditions i) to iii) are satisfied at the same time.

19. The heterocyclic compound of claim 17 , wherein

i) in Formula 1-1, R 11 to R 32 are each hydrogen,

ii) in Formula 1-1, R 12 and R 16 are each independently a group represented by Formula 2, a C 1 -C 20 alkyl group, or —N(Q 1 )(Q 2 ), R 14 is hydrogen or a C 1 -C 20 alkyl group, and R 11 , R 13 , R 15 , and R 17 to R 32 are each hydrogen,

iii) in Formula 1-1, R 22 and R 28 are each independently a group represented by Formula 2, R 14 is hydrogen or a C 1 -C 20 alkyl group, and Ru to R 13 , R 15 to R 21 , R 23 to R 27 , and R 29 to R 32 are each hydrogen,

iv) in Formula 1-1, R 20 and R 30 are each independently a group represented by Formula 2, R 14 is hydrogen or a C 1 -C 20 alkyl group, and R 11 to R 13 , R 15 to R 19 , R 21 to R 29 , and R 31 to R 32 are each hydrogen,

v) in Formula 1-1, R 14 is a C 1 -C 20 alkyl group, —CF 3 , or a group represented by Formula 2, and R 11 to R 13 and R 15 to R 32 are each hydrogen,

vi) in Formula 1-3, R 14 is a C 1 -C 20 alkyl group, —CF 3 , or a group represented by Formula 2, and R 12 , R 13 , R 15 , R 16 , and R 19 to R 31 are each hydrogen, or

vii) in Formula 1-3, R 12 and R 16 are each independently a group represented by Formula 2 or —N(C 21 )(Q 2 ), R 14 is a C 1 -C 20 alkyl group, and R 13 , R 15 , and R 19 to R 31 are each hydrogen.

20. The heterocyclic compound of claim 9 , wherein

the heterocyclic compound is selected from Compounds 1, 4 to 8 and 10 to 35: