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; and

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

wherein the organic layer comprises at least one heterocyclic compound represented by Formula 1:

wherein, in Formula 1,

Y 1 is N or P,

Y 2 is B(R 1 ), P(═O)(R 1 ), or P(═S)(R 1 ),

X 1 and X 2 are each independently 0, S, C(R 2 )(R 3 ), or Si(R 2 )(R 3 ),

m1 and m2 are each independently 0, 1, or 2, wherein m1+m2>0,

when Y 2 is B(R 1 ) and m1 and m2 are each 1, at least one selected from X 1 and X 2 is C(R 2 )(R 3 ), or Si(R 2 )(R 3 ),

when Y 2 is P(═O)(R 1 ) or P(═S)(R 1 ), X 1 and X 2 are each independently S or C(R 2 )(R 3 ),

A 1 to A 3 are each independently a substituted or unsubstituted C 5 -C 60 aromatic carbocyclic group or a substituted or unsubstituted C 3 -C 60 aromatic heterocyclic group,

a10, a20, and a30 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, and 8,

R 1 to R 3 , R 10 , R 20 , and R 30 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 hydrazono 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 1 )(Q 2 )(Q 3 ), —B(Q 1 )(Q 2 ), —C(═O)(Q 1 ), —N(Q 1 )(Q 2 ), and —P(═O)(Q 1 )(Q 2 ), —S(═O) 2 (Q 1 )(Q 2 ), or

R 2 and R 3 are optionally linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, with the proviso that when m1 or m2 is 0, R 2 and R 3 of C(R 2 )(R 3 ) are not linked to form a substituted fluorene group, two or more of R 10 are optionally linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, two or more of R 20 are optionally linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, two or more of R 30 are optionally linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, R 1 and R 10 are not linked to form a ring, R 1 and R 30 are not linked to form a ring, R 2 or R 3 and R 10 are optionally linked to form a substituted or unsubstituted C 1 -C 60 heterocyclic group, R 2 or R 3 and R 20 are optionally linked to form a substituted or unsubstituted C 1 -C 60 heterocyclic group, and R 2 or R 3 and R 30 are optionally linked to form a substituted or unsubstituted C 1 -C 60 heterocyclic group,

when Y 2 is B(R 1 ), at least one of m1 or m2 is 1, and at least one of X 1 or X 2 is O, R 1 is selected from hydrogen, deuterium, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono 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 1 )(Q 2 )(Q 3 ), —B(Q 1 )(Q 2 ), —C(═O)(Q 1 ), —N(Q 1 )(Q 2 ), —P(═O)(Q 1 )(Q 2 ), and —S(═O) 2 (Q 1 )(Q 2 ),

at least one substituent of the substituted C 5 -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 hydrazono 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 hydrazono 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, and a monovalent non-aromatic condensed heteropolycyclic 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, 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 hydrazono 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, —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 ), and

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 hydrazono 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 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.

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 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 the at least one of the heterocyclic compound represented by Formula 1.

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

the emission layer consists of the at least one of the heterocyclic compound represented by Formula 1; or

the emission layer further comprises a host, and an amount of the at least one of the heterocyclic compound represented by Formula 1 is in a range about 0.1 parts by weight to about 50 parts by weight based on 100 parts by weight of the emission layer.

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

the at least one of the heterocyclic compound represented by Formula 1 comprised in the emission layer is a thermally activated delayed fluorescence (TADF) emitter, and

the emission layer emits delayed fluorescence.

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

the emission layer does not comprise an organometallic compound.

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

the emission layer emits blue light having a maximum emission wavelength of 430 nm or more and 480 nm or less.

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

the hole transport region comprises a p-dopant, and

the p-dopant has a lowest unoccupied molecular orbital (LUMO) energy level of −3.5 eV or less.

9 . A heterocyclic compound represented by Formula 1:

wherein, in Formula 1,

Y 1 is N or P,

Y 2 is B(R 1 ), P(═O)(R 1 ), or P(═S)(R 1 ),

X 1 and X 2 are each independently O, S, C(R 2 )(R 3 ), or Si(R 2 )(R 3 ),

m1 and m2 are each independently 0, 1, or 2, wherein m1+m2>0,

when Y 2 is B(R 1 ) and m1 and m2 are each 1, at least one selected from X 1 and X 2 is C(R 2 )(R 3 ), or Si(R 2 )(R 3 ),

when Y 2 is P(═O)(R 1 ) or P(═S)(R 1 ), X 1 and X 2 are each independently S or C(R 2 )(R 3 ),

A 1 to A 3 are each independently a substituted or unsubstituted C 5 -C 60 aromatic carbocyclic group or a substituted or unsubstituted C 3 -C 60 aromatic heterocyclic group,

a10, a20, and a30 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, and 8,

R 1 to R 3 , R 10 , R 20 , and R 30 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 hydrazono 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 1 )(Q 2 )(Q 3 ), —B(Q 1 )(Q 2 ), —C(═O)(Q 1 ), —N(Q 1 )(Q 2 ), —P(═O)(Q 1 )(Q 2 ), and —S(═O) 2 (Q 1 )(Q 2 ), or

R 2 and R 3 are optionally linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, with the proviso that when m1 or m2 is 0, R 2 and R 3 of C(R 2 )(R 3 ) are not linked to form a substituted fluorene group, two or more of R 10 are optionally linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, two or more of R 20 are optionally linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, two or more of R 30 are optionally linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, R 1 and R 10 are not linked to form a ring, R 1 and R 30 are not linked to form a ring, R 2 or R 3 and R 10 are optionally linked to form a substituted or unsubstituted C 1 -C 60 heterocyclic group, R 2 or R 3 and R 20 are optionally linked to form a substituted or unsubstituted C 1 -C 60 heterocyclic group, and R 2 or R 3 and R 30 are optionally linked to form a substituted or unsubstituted C 1 -C 60 heterocyclic group,

when Y 2 is B(R 1 ), at least one of m1 or m2 is 1, and at least one of X 1 or X 2 is 0, R 1 is selected from hydrogen, deuterium, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono 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 1 )(Q 2 )(Q 3 ), —B(Q 1 )(Q 2 ), —C(═O)(Q 1 ), —N(Q 1 )(Q 2 ), —P(═O)(Q 1 )(Q 2 ), and —S(═O) 2 (Q 1 )(Q 2 ),

at least one substituent of the substituted C 5 -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 hydrazono 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 hydrazono 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, and a monovalent non-aromatic condensed heteropolycyclic 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, 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 hydrazono 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, —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 ), and

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 hydrazono 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 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.

10 . The heterocyclic compound of claim 9 , wherein:

m1 is 1, and

m2 is 0 or 1.

11 . The heterocyclic compound of claim 9 , wherein:

A 1 and A 2 are each independently selected from a benzene group, a naphthalene group, a phenanthrene group, an anthracene group, a triphenylene group, a pyrene group, a chrysene group, a pyridine group, a pyrazine group, a pyrimidine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a 2,6-naphthyridine group, a 1,8-naphthyridine group, a 1,5-naphthyridine group, a 1,6-naphthyridine group, a 1,7-naphthyridine group, a 2,7-naphthyridine group, a quinoxaline group, a quinazoline group, a phenanthridine group, and a phenanthroline group.

12 . The heterocyclic compound of claim 9 , wherein:

A 3 is selected from a benzene group, a naphthalene group, a phenanthrene group, an anthracene group, a triphenylene group, a pyrene group, a chrysene group, a pyridine group, a pyrazine group, a pyrimidine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a 2,6-naphthyridine group, a 1,8-naphthyridine group, a 1,5-naphthyridine group, a 1,6-naphthyridine group, a 1,7-naphthyridine group, a 2,7-naphthyridine group, a quinoxaline group, a quinazoline group, a phenanthridine group, a phenanthroline group, a benzofuran group, a benzothiophene group, an indene group, an indole group, a furopyridine group, a thienopyridine group, a cyclopentapyridine group, a pyrrolopyridine group, a dibenzofuran group, a dibenzothiophene group, a fluorene group, a carbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzofluorene group, a benzocarbazole group, a dinaphthofuran group, a dinaphthothiophene group, a dibenzofluorene group, a dibenzocarbazole group, a benzoxazole group, a benzothiazole group, a benzimidazole group, a naphthofuran, a naphthothiophene, a spiro-bifluorene group, and a spiro-fluorene-indene group.

13 . The heterocyclic compound of claim 9 , wherein:

the heterocyclic compound represented by Formula 1 is represented by one selected from Formulae 2-1 to 2-3:

wherein, in Formulae 2-1 to 2-3,

Y 1 , Y 2 , X 1 , and X 2 are each independently the same as described in claim 9 ,

Y 21 is N or P,

Y 22 is B(R 4 ), P(═O)(R 4 ), or P(═S)(R 4 ),

X 21 is O, S, N(R 5 ), C(R 5 )(R 6 ), or Si(R 5 )(R 6 ),

A 11 to A 13 and A 21 to A 23 are each independently selected from a benzene group, a naphthalene group, a phenanthrene group, an anthracene group, a triphenylene group, a pyrene group, a chrysene group, a pyridine group, a pyrazine group, a pyrimidine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a quinazoline group, a phenanthridine group, a phenanthroline group, a dibenzofuran group, a dibenzothiophene group, a fluorene group, a carbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzofluorene group, and a benzocarbazole group,

a10, a20, a30, a40, a50, and a60 are the same as defined in connection with a10, a20, a30 in claim 9 ,

R 10 , R 20 , and R 30 are each independently the same as described in claim 9 ,

R 4 is the same as defined in connection with R 1 in claim 9 ,

R 5 and R 6 are each independently the same as defined in connection with R 2 and R 3 in claim 9 , and

R 40 , R 50 , and R 60 are each independently the same as defined in connection with R 10 , R 20 , and R 30 in claim 9 .

14 . The heterocyclic compound of claim 9 , wherein:

the heterocyclic compound represented by Formula 1 is represented by one selected from Formulae 10-1 to 10-17:

wherein, in Formulae 10-1 to 10-17,

Y 1 , Y 2 , X 1 , and X 2 are each independently the same as described in claim 9 ,

R 11 to R 15 are each independently the same as defined in connection with R 10 in claim 9 ,

R 21 to R 26 are each independently the same as defined in connection with R 20 in claim 9 ,

R 31 to R 36 are each independently the same as defined in connection with R 30 in claim 9 ,

Y 21 is N or P,

Y 22 is B(R 4 ), P(═O)(R 4 ), or P(═S)(R 4 ),

X 21 is C(R 5 )(R 6 ) or Si(R 5 )(R 6 ),

R 4 is the same as defined in connection with R 1 in claim 9 ,

R 5 and R 6 are each independently the same as defined in connection with R 2 and R 3 in claim 9 ,

R 41 to R 43 are each independently the same as defined in connection with R 10 in claim 9 ,

R 51 to R 54 are each independently the same as defined in connection with R 20 in claim 9 ,

R 61 and R 62 are each independently the same as defined in connection with R 30 in claim 9 , and

two or more neighboring substituents selected from R 11 to R 15 are optionally linked to form a benzene group or a naphthalene group, two or more neighboring substituents selected from R 21 to R 26 are optionally linked to form a benzene group or a naphthalene group, two or more neighboring substituents selected from R 31 to R 36 are optionally linked to form a benzene group or a naphthalene group, two or more neighboring substituents selected from R 41 to R 43 are optionally linked to form a benzene group or a naphthalene group, two or more neighboring substituents selected from R 51 to R 54 are optionally linked to form a benzene group or a naphthalene group, and R 61 and R 62 are optionally linked to form a benzene group or a naphthalene group.

15 . The heterocyclic compound of claim 9 , wherein:

R 1 to R 3 are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a substituted or unsubstituted C 1 -C 60 alkyl group, a substituted or unsubstituted C 6 -C 60 aryl group, —Si(Q 1 )(Q 2 )(Q 3 ), and —N(Q 1 )(Q 2 ),

Q 1 to Q 3 are each independently selected from hydrogen, deuterium, a C 1 -C 60 alkyl group, a C 1 -C 60 alkoxy group, a C 6 -C 60 aryl 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, or

R 2 and R 3 are linked to form a substituted or unsubstituted C 5 -C 60 carbocyclic group or a substituted or unsubstituted C 1 -C 60 heterocyclic group, with the proviso that R 2 and R 3 of C(R 2 )(R 3 ) are not linked to form a substituted fluorene group.

16 . The heterocyclic compound of claim 9 , wherein:

R 1 to R 3 are each independently selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an ethenyl group, a propenyl group, a butenyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxy group, and a tert-butoxy group;

a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxy group, and a tert-butoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, a phenyl group, and a biphenyl group;

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl 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 triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, and a pentacenyl 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, 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 triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, and a pentacenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxy group, and a tert-butoxy group; and

—N(Q 1 )(Q 2 ), and

when X 1 in Formula 1 is C(R 2 )(R 3 ), or Si(R 2 )(R 3 ), R 2 and R 3 are optionally linked to form a group represented by one selected from Formulae 9-1 and 9-2:

<Formula 9-1>

wherein, in Formulae 9-1 and 9-2,

X 11 is C or Si,

when X 1 in Formula 1 is C(R 2 )(R 3 ), X 11 is C, and when X 1 in Formula 1 is Si(R 2 )(R 3 ), X 11 is Si,

X 91 and X 93 are each independently selected from a single bond, O, S, Se, N(R 94 ), B(R 94 ), P(═O)(R 94 ), P(═S)(R 94 ), C(R 94 )(R 95 ), Si(R 94 )(R 95 ), and Ge(R 94 )(R 95 ),

X 92 is selected from N, B, and P,

A 91 to A 93 are each independently selected from a C 5 -C 30 carbocyclic group and a C 1 -C 30 heterocyclic group,

R 91 to R 95 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 hydrazono 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 C 1 -C 60 heteroaryloxy group, a substituted or unsubstituted C 1 -C 60 heteroarylthio 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 ), —C(═O)(Q 1 ), —S(═O) 2 (Q 1 ), and —P(═O)(Q 1 )(Q 2 ),

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 hydrazono 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 phenyl group, a biphenyl group, a terphenyl 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 triphenylenyl group, a pyrenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, and a terphenyl group, and

b91 to b93 are each independently an integer from 1 to 10.

17 . The heterocyclic compound of claim 16 , wherein:

A 91 to A 93 are each independently selected from a benzene group, a naphthalene group, a phenanthrene group, an anthracene group, a pyridine group, a pyrazine group, a pyrimidine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a dibenzofuran group, a dibenzothiophene group, a fluorene group, and a carbazole group.

18 . The heterocyclic compound of claim 9 , wherein:

R 10 , R 20 , and R 30 are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a substituted or unsubstituted C 1 -C 60 alkyl group, a substituted or unsubstituted C 6 -C 60 aryl 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 ), and —N(Q 1 )(Q 2 ), and

Q 1 to Q 3 are each independently selected from hydrogen, deuterium, a C 1 -C 60 alkyl group, a C 1 -C 60 alkoxy group, a C 6 -C 60 aryl 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.

19 . The heterocyclic compound of claim 9 , wherein:

R 10 , R 20 , and R 30 are each independently selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an ethenyl group, a propenyl group, a butenyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxy group, and a tert-butoxy group; and

a group represented by one selected from Formulae 5-1 to 5-26 and 6-1 to 6-55:

wherein, in Formulae 5-1 to 5-26 and 6-1 to 6-55,

Y 31 and Y 32 is O, S, C(Z 34 )(Z 35 ), N(Z 34 ), or Si(Z 34 )(Z 35 ),

Z 31 , Z 32 , Z 34 and Z 35 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 hydrazono group, a C 1 -C 20 alkyl group, a C 2 -C 20 alkenyl group, a C 2 -C 20 alkynyl group, a C 1 -C 20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolyl group, and a triazinyl group,

e2 is 1 or 2,

e3 is an integer from 1 to 3,

e4 is an integer from 1 to 4,

e5 is an integer from 1 to 5,

e6 is an integer from 1 to 6,

e7 is an integer from 1 to 7,

e9 is an integer from 1 to 9, and

* indicates a binding site of R 10 , R 20 , or R 30 .

20 . A heterocyclic compound selected from Compounds 1 to 12, 14 to 78, 80 to 135, 139 to 150, and 154 to 165: