Carbazole-based compound and organic light emitting device including the same

A carbazole-based compound represented by one of the following Formulae 1 to 3:

• wherein, in Formulae 1 to 3,
• X is an oxygen atom or a sulfur atom;
• Y1 and Y2 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C2-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C2-C10 heterocycloalkenyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted C2-C30 heteroaryl group;
• R1 to R12 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxyl group, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C1-C60 alkylthio group, a substituted or unsubstituted C3-C60 cycloalkyl group, a substituted or unsubstituted C3-C60 cycloalkylene group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arythio group, a substituted or unsubstituted C2-C60 heteroaryl group, and —N(Q1)(Q2)
• Q1 and Q2 are each independently selected from a hydrogen atom, a deuterium atom, a C1-C10 alkyl group, a C6-C30 aryl group, and a C2-C30 heteroaryl group;
• or Q1 and Q2 bind to each other to form a saturated ring or an unsaturated ring formed of nitrogen, Q1, and Q2;
• a1, a5, a8, a9, a11, and a12 are each independently integers of 0 to 4;
• a2, a3, and a6 are each independently integers of 0 to 3;
• a4 is an integer of 0 to 2;
• and
• a7 and a10 are each independently integers of 0 or 1.