Heterocyclic compound and organic light-emitting device including the same

Abstract

A heterocyclic compound is represented by Formula 1. An organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer, wherein the organic light-emitting device includes at least one of the heterocyclic compound.

What is claimed is: 
     
         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 and comprising an emission layer; and   at least one heterocyclic compound represented by Formula 1:   
       
         
           
           
               
               
           
         
         wherein, in Formulae 1 and 2-1 to 2-7, 
         X 1  to X 3  are each independently N or C(R 15 ), wherein at least one selected from X 1  to X 3  is N, 
         L 1  to L 3  are each independently a substituted or unsubstituted C 3 -C 60  carbocyclic group or a substituted or unsubstituted C 1 -C 60  heterocyclic group, 
         a1 to a3 are each independently an integer from 0 to 3, 
         Ar 1  to Ar 3  are each independently a group represented by one selected from Formulae 2-1 to 2-7, 
         R 1  to R 15  are each independently selected from hydrogen, 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 2 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 2 -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 2 -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 ), 
         b3 is an integer from 0 to 3, b4 is an integer from 0 to 4, and b5 is an integer from 0 to 5, 
         of the groups included in the heterocyclic compound represented by Formula 1, at least one selected from the substituents R 1  to R 11  of the Formulae 2-1 to 2-7 is —Si(Q 1 )(Q 2 )(Q 3 ), 
         when Ar 1  is a group represented by Formula 2-7, a1 is 0, when Ar 2  is a group represented by Formula 2-7, a2 is 0, and when Ar 3  is a group represented by Formula 2-7, a3 is 0, 
         when Ar 1  is a group represented by Formula 2-7, Ar 2  and Ar 3  are not a group represented by Formula 2-1 and L 2  and L 3  are not a benzene group, when Ar 2  is a group represented by Formula 2-7, Ar 1  and Ar 3  are not a group represented by Formula 2-1 and L 1  and L 3  are not a benzene group, and when Ar 3  is a group represented by Formula 2-7, Ar 1  and Ar 2  are not a group represented by Formula 2-1 and L 1  and L 2  are not a benzene group, and 
         a case in which each of Ar 1  to Ar 3  is a group represented by Formula 2-1 is excluded, 
         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 2 -C 10  heterocycloalkyl group, the substituted C 3 -C 10  cycloalkenyl group, the substituted C 2 -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 2 -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, 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 1  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 1  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 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 1  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 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  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 
         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, 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, and —Si(R a )(R b )(R c ), 
         R a  to R c  are each independently selected from hydrogen, 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 2 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 2 -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 2 -C 60  heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and 
         * indicates a binding site to a neighboring atom. 
       
     
     
         2 . The organic light-emitting device of  claim 1 , wherein:
 the emission layer comprises a dopant and a host,   the host comprises at least one of the heterocyclic compound, and   the dopant is a phosphorescent dopant.   
     
     
         3 . The organic light-emitting device of  claim 2 , wherein:
 the dopant comprises platinum (Pt).   
     
     
         4 . The organic light-emitting device of  claim 2 , wherein:
 the dopant comprises an organometallic complex represented by Formula 401:   
       
         
           
           
               
               
           
         
         wherein, in Formulae 401 and 402, 
         M is platinum (Pt), 
         L 401  is selected from ligands represented by Formula 402, and xc1 is 1, 2, or 3, wherein, when xc1 is two or more, two or more L 401  (s) are identical to or different from each other, 
         L 402  is an organic ligand, and xc2 is an integer from 0 to 4, wherein, when xc2 is two or more, two or more L 402 (s) are identical to or different from each other, 
         X 401  to X 404  are each independently nitrogen or carbon, 
         X 401  and X 403  are linked via a single bond or a double bond, and X 402  and X 404  are linked via a single bond or a double bond, 
         A 401  and A 402  are each independently a C 5 -C 60  carbocyclic group or a C 1 -C 60  heterocyclic group, 
         X 405  is a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q 411 )-*′, *—C(Q 411 )(Q 412 )-*′, *—C(Ω 411 )═C(Q 412 )-*′, *—C(Q 411 )=*′, or *═C(Q 411 )=*′, wherein Q 411  and Q 412  are each independently hydrogen, deuterium, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, 
         X 406  is a single bond, O, or S, 
         R 401  and R 402  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 20  alkyl group, a substituted or unsubstituted C 1 -C 20  alkoxy group, a substituted or unsubstituted C 3 -C 10  cycloalkyl group, a substituted or unsubstituted C 1 -C 1  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 1 -C 1  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 401 )(Q 402 )(Q 403 ), —N(Q 401 )(Q 402 ), —B(Q 401 )(Q 402 ), —C(═O)(Q 401 ), —S(═O) 2 (Q 401 ), and —P(═O)(Q 401 )(Q 402 ), wherein Q 401  to Q 403  are each independently selected from a C 1 -C 10  alkyl group, a C 1 -C 10  alkoxy group, a C 6 -C 20  aryl group, and a C 1 -C 20  heteroaryl group, 
         xc11 and xc12 are each independently an integer from 0 to 10, and 
         * and *′ in Formula 402 each indicate a binding site to M in Formula 401. 
       
     
     
         5 . The organic light-emitting device of  claim 4 , wherein:
 A 401  is C 1 -C 60  heterocyclic group containing at least one nitrogen.   
     
     
         6 . The organic light-emitting device of  claim 4 , wherein:
 X 405  and X 406  are each a single bond.   
     
     
         7 . The organic light-emitting device of  claim 4 , wherein:
 R 401  is not a hydrogen.   
     
     
         8 . A heterocyclic compound represented by Formula 1: 
       
         
           
           
               
               
           
         
         wherein, in Formulae 1 and 2-1 to 2-7, 
         X 1  to X 3  are each independently N or C(R 15 ), wherein at least one selected from X 1  to X 3  is N, 
         L 1  to L 3  are each independently a substituted or unsubstituted C 3 -C 60  carbocyclic group or a substituted or unsubstituted C 1 -C 60  heterocyclic group, 
         a1 to a3 are each independently an integer from 0 to 3, 
         Ar 1  to Ar 3  are each independently a group represented by one selected from Formulae 2-1 to 2-7, 
         R 1  to R 15  are each independently selected from hydrogen, 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 2 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 2 -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 2 -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 ), 
         b3 is an integer from 0 to 3, b4 is an integer from 0 to 4, and b5 is an integer from 0 to 5, 
         of the groups included in the heterocyclic compound represented by Formula 1, at least one selected from the substituents R 1  to R 11  of the Formulae 2-1 to 2-7 is —Si(Q 1 )(Q 2 )(Q 3 ), 
         when Ar 1  is a group represented by Formula 2-7, a1 is 0, when Ar 2  is a group represented by Formula 2-7, a2 is 0, and when Ar 3  is a group represented by Formula 2-7, a3 is 0, 
         when Ar 1  is a group represented by Formula 2-7, Ar 2  and Ar 3  are not a group represented by Formula 2-1 and L 2  and L 3  are not a benzene group, when Ar 2  is a group represented by Formula 2-7, Ar 1  and Ar 3  are not a group represented by Formula 2-1 and L 1  and L 3  are not a benzene group, and when Ar 3  is a group represented by Formula 2-7, Ar 1  and Ar 2  are not a group represented by Formula 2-1 and L 1  and L 2  are not a benzene group, and 
         a case in which each of Ar 1  to Ar 3  is a group represented by Formula 2-1 is excluded, 
         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 2 -C 10  heterocycloalkyl group, the substituted C 3 -C 10  cycloalkenyl group, the substituted C 2 -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 2 -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 1  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 1  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 1  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 1  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 1  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 1  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 hydrazono group, a C 1 -C 60  alkyl group, a C 2 -C 20  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 1  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 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 1  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 110  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 
         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 1  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 1  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, 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, and —Si(R a )(R b )(R c ), 
         R a  to R c  are each independently selected from hydrogen, 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 2 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 2 -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 2 -C 60  heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and 
         * indicates a binding site to a neighboring atom. 
       
     
     
         9 . The heterocyclic compound of  claim 8 , wherein:
 at least one selected from Ar 1  to Ar 3  is a group that is different from the others thereof.   
     
     
         10 . The heterocyclic compound of  claim 8 , wherein:
 i) Ar 1  and Ar 2  are each a group represented by Formula 2-1, and Ar 3  is a group represented by Formula 2-3;   ii) Ar 1  is a group represented by Formula 2-1, and Ar 2  and Ar 3  are each a group represented by Formula 2-3;   iii) Ar 1  is a group represented by Formula 2-1, Ar 2  is a group represented by Formula 2-3, and Ar 3  is a group represented by Formula 2-4;   iv) Ar 1  is a group represented by Formula 2-1, Ar 2  is a group represented by Formula 2-3, and Ar 3  is a group represented by Formula 2-3;   v) Ar 1  is a group represented by Formula 2-1, and Ar 2  and Ar 3  are each a group represented by Formula 2-4; or   vi) Ar 1  and Ar 2  are each a group represented by Formula 2-3, and Ar 3  is a group represented by Formula 2-6.   
     
     
         11 . The heterocyclic compound of  claim 8 , wherein:
 i) when Ar 1  is a group represented by Formula 2-1, at least one selected from R 1 (s) in the number of b5 is —Si(Q 1 )(Q 2 )(Q 3 ), and   ii) when Ar 1  and Ar 2  are each a group represented by Formula 2-3 and Ar 3  is a group represented by Formula 2-6, at least one selected from R 10 (s) in the number of b4 and R 11 (s) in the number of b3 is —Si(Q 1 )(Q 2 )(Q 3 ).   
     
     
         12 . The heterocyclic compound of  claim 11 , wherein:
 at least one of Q 1  to Q 3  comprises at least one deuterium.   
     
     
         13 . The heterocyclic compound of  claim 8 , wherein:
 Ar 1  to Ar 3  are each independently a group represented by one selected from Formulae 2-1(1) to 2-1(3), 2-2(1) to 2-2(2), 2-3(1) to 2-3(2), 2-4(1) to 2-4(2), and 2-6(1) to 2-6(4):   
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein, in Formulae 2-1(1) to 2-1(3), 2-2(1) to 2-2(2), 2-3(1) to 2-3(2), 2-4(1) to 2-4(2), and 2-6(1) to 2-6(4), 
         Z 11  to Z 15  are each independently selected from 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 cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bitluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl 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, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a dibenzosilolyl group, and —Si(Q 31 )(Q 32 )(Q 33 ), 
         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, 
         e3 is an integer from 0 to 3, 
         e4 is an integer from 0 to 4, 
         e5 is an integer from 0 to 5, 
         Ph indicates a phenyl group, and 
         * and *′ each indicate a binding site to a neighboring atom. 
       
     
     
         14 . The heterocyclic compound of  claim 13 , wherein:
 1) Ar 1  is a group represented by Formula 2-1(1), and Z 11  in Formula 2-1(1) is deuterium;   2) Ar 1  is a group represented by one selected from Formulae 2-1(2) and 2-1(3), and
 i) Z 11  in Formulae 2-1(2) and 2-1(3) is deuterium; 
 ii) Z 12  in Formulae 2-1(2) and 2-1(3) is selected from deuterium and a benzene group substituted with deuterium; 
 iii) Z 12  and Z 13  in Formulae 2-1(2) and 2-1(3) are each independently selected from deuterium and a benzene group substituted with deuterium; or 
 iv) Z 11  to Z 14  in Formulae 2-1(2) and 2-1(3) are each independently selected from deuterium and a benzene group substituted with deuterium; 
   3) Ar 2  is a group represented by Formula 2-3(1), and
 i) Z 11  in Formula 2-3(1) is deuterium; or 
 ii) Z 11  and Z 12  in Formula 2-3(1) are each deuterium; or 
   4) Ar 2  is a group represented by Formula 2-3(2), and
 i) Z 11  in Formulae 2-1(2) and 2-1(3) is deuterium; 
 ii) Z 12  in Formulae 2-1(2) and 2-1(3) is selected from deuterium and a benzene group substituted with deuterium; 
 iii) Z 12  and Z 13  in Formulae 2-1(2) and 2-1(3) are each independently selected from deuterium and a benzene group substituted with deuterium; or 
 iv) Z 11  to Z 14  in Formulae 2-1(2) and 2-1(3) are each independently selected from deuterium and a benzene group substituted with deuterium. 
   
     
     
         15 . The heterocyclic compound of  claim 13 , wherein:
 at least one selected from Ar 1  to Ar 3  is a group represented by one selected from Formulae 2-1(2), 2-1(3), 2-2(2), 2-3(2), 2-6(3), and 2-6(4).   
     
     
         16 . The heterocyclic compound of  claim 8 , wherein:
 i) X 1  to X 3  are each N;   ii) X 1  and X 2  are each N, and X 3  is C(R 15 );   iii) X 1  and X 3  are each N, and X 2  is C(R 15 );   iv) X 2  and X 3  are each N, and X 1  is C(R 15 );   v) X 1  is N, and X 2  and X 3  are each C(R 15 );   vi) X 2  is N, and X 1  and X 3  are each C(R 15 ); or   vii) X 3  is N, and X 1  and X 2  are each C(R 15 ),   and R 15  is hydrogen or deuterium.   
     
     
         17 . The heterocyclic compound of  claim 8 , wherein:
 at least one hydrogen atom in the heterocyclic compound represented by Formula 1 is substituted by a deuterium atom.   
     
     
         18 . The heterocyclic compound of  claim 8 , wherein:
 at least one of R 1  to R 15  in Formulae 2-1 to 2-7 comprises deuterium.   
     
     
         19 . The heterocyclic compound of  claim 8 , wherein:
 at least one of R 1  to R 15  is selected from:   deuterium;   a C 1 -C 60  alkyl group, and a C 6 -C 60  aryl group substituted with at least one deuterium; and   —Si(Q 1 )(Q 2 )(Q 3 ); and   wherein, Q 1  is selected from a phenyl group and a biphenyl group substituted with at least one deuterium, and Q 2  and Q 3  are each independently selected from a phenyl group; a biphenyl group; a phenyl group and a biphenyl group substituted with at least one deuterium.   
     
     
         20 . The heterocyclic compound of  claim 8 , wherein:
 i) R 1  is selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q 1 )(Q 2 )(Q 3 );   ii) R 4  and R 5  are each independently selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q 1 )(Q 2 )(Q 3 );   iii) R 6  and R 7  are each independently selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q 1 )(Q 2 )(Q 3 );   iv) R 10  and R 11  are each independently selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q 1 )(Q 2 )(Q 3 ); or   v) R 12  to R 14  are each independently selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q 1 )(Q 2 )(Q 3 );   wherein, Q 1  is selected from a phenyl group and a biphenyl group substituted with at least one deuterium, and Q 2  and Q 3  are each independently selected from a phenyl group; a biphenyl group; a phenyl group and a biphenyl group substituted with at least one deuterium.