Heterocyclic compound, organic light-emitting device comprising same, and composition for organic layer

A heterocyclic compound of the following Chemical Formula 1:

• in Chemical Formula 1,
• X1 to X3 are each independently N;
• or CH, and at least two thereof are N,
• L is a direct bond;
• or a substituted or unsubstituted C6 to C60 arylene group,
• m is an integer of 1 to 5, and when 2 or greater, Ls are the same as or different from each other,
• R1 and R2 are the same as or different from each other and each independently a substituted or unsubstituted C6 to C12 aryl group;
• a substituted or unsubstituted fluorenyl group;
• or a substituted or unsubstituted C2 to C60 heteroaryl group, and at least one of R1 and R2 is a substituted or unsubstituted fluorenyl group;
• represented by the following Chemical Formula A;
• or represented by the following Chemical Formula B, and
• R3 and R4 are the same as or different from each other and each independently a substituted or unsubstituted C6 to C12 aryl group;
• a substituted or unsubstituted fluorenyl group;
• or a heteroaryl group substituted or unsubstituted and including O or S, and at least one of R3 and R4 is a substituted or unsubstituted fluorenyl group;
• or represented by the following Chemical Formula C,
• in Chemical Formulae A to C,
• Y and Z are each independently O;
• or S,
• H1 is hydrogen;
• or deuterium,
• R11 to R14 are each independently hydrogen;
• deuterium;
• a substituted or unsubstituted C1 to C60 alkyl group;
• a substituted or unsubstituted C6 to C60 aryl group;
• or a substituted or unsubstituted C2 to C60 heteroaryl group,
• r11 is an integer of 0 to 6, and when 2 or greater, R11s are the same as or different from each other,
• r13 is an integer of 0 to 7, and when 2 or greater, R13s are the same as or different from each other, and
• r14 is an integer of 0 to 7, and when 2 or greater, R14s are the same as or different from each other.