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

A heterocyclic compound represented by the following Chemical Formula 1:

• wherein, in Chemical Formula 1,
• X1 is O;
• S;
• or NAr1;
• R1 to R7 are the same as or different from each other, and each independently selected from the group consisting of hydrogen;
• deuterium;
• halogen;
• a cyano group;
• a substituted or unsubstituted C1 to C60 alkyl group;
• a substituted or unsubstituted C2 to C60 alkenyl group;
• a substituted or unsubstituted C2 to C60 alkynyl group;
• a substituted or unsubstituted C1 to C60 alkoxy group;
• a substituted or unsubstituted C3 to C60 cycloalkyl group;
• a substituted or unsubstituted C2 to C60 heterocycloalkyl group;
• a substituted or unsubstituted C6 to C60 aryl group;
• a substituted or unsubstituted C2 to C60 heteroaryl group;
• —P(═O)R101R102;
• —SiR101R102R103;
• and —NR101R102, or two or more groups adjacent to each other bond to each other to form a substituted or unsubstituted C6 to C60 aromatic hydrocarbon ring;
• or a substituted or unsubstituted C2 to C60 heteroring, and R101, R102 and R103 are the same as or different from each other and each independently 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;
• a1 is an integer of 0 to 4, and when a1 is 2 or greater, R1s are the same as or different from each other;
• a2 is an integer of 0 to 2, and when a2 is 2 or greater, R3s are the same as or different from each other;
• Ar1 is a substituted or unsubstituted C6 to C60 aryl group;
• or a substituted or unsubstituted C2 to C60 heteroaryl group;
• Ar2 and Ar3 are the same as or different from each other, and each independently a substituted or unsubstituted C6 to C60 aryl group;
• a substituted or unsubstituted C2 to C60 heteroaryl group;
• or —NAr4Ar5;
• Ar4 and Ar5 are the same as or different from each other, and each independently a substituted or unsubstituted C6 to C60 aryl group;
• or a substituted or unsubstituted C2 to C60 heteroaryl group;
• L1 to L3 are the same as or different from each other, and each independently a direct bond;
• a substituted or unsubstituted C6 to C60 arylene group;
• or a substituted or unsubstituted C2 to C60 heteroarylene group;
• b1 is an integer of 0 to 5, and when b1 is 2 or greater, L1s are the same as or different from each other;
• b2 is an integer of 0 to 5, and when b2 is 2 or greater, L2s are the same as or different from each other;
• and
• b3 is an integer of 0 to 5, and when b3 is 2 or greater, L3s are the same as or different from each other.