Heterocyclic compound, organic light emitting device including the same and composition for organic layer of organic light emitting device

An organic light emitting device, comprising:

• a first electrode;
• a second electrode facing the first electrode;
• a first emitting material layer between the first and second electrodes;
• and
• a first electron blocking layer between the first emitting material layer and the first electrode,
• wherein one or more of the at least one organic material layer includes a first compound and a second compound,
• wherein the first compound is represented by Formula 1:
• wherein N-Het is substituted or unsubstituted and a monocyclic or polycyclic C2 to C60 heterocyclic group having at least one nitrogen atom,
• wherein L is a direct bond, a substituted or unsubstituted C6 to C60 arylene group or a substituted or unsubstituted C2 to C60 heteroarylene group, and a is an integer of 1 to 3, wherein when a is 2 or more, two or more L are same or different,
• wherein R1 to R12 are same or different, wherein each of R1 to R12 is 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)RR′;
• —SiRR′R″;
• and —NRR′, or adjacent two or more of R1 to R12 are bonded to each other to form a substituted or unsubstituted C6 to C60 aromatic hydrocarbon ring or a substituted or unsubstituted C2 to C60 heterocyclic ring, wherein b is an integer of 1 to 3, wherein when b is 2 or more, two or more R9 are the same as or different,
• wherein R, R′ and R″ are the same or different, wherein each of R, R′ and R″ is independently selected from the group consisting of 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 a heteroaryl group,
• wherein a deuteration ratio of the heterocyclic compound is 20% to 100%,
• wherein the second compound is represented by Formula 2:
• wherein Ra and Rb are same or different, and each of Ra and Rb is independently a substituted or unsubstituted C6 to C60 aryl group or a substituted or unsubstituted C2 to C60 heteroaryl group,
• wherein Ra1 to Ra14 are same or different, and wherein each of Ra1 to Ra14 is 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 C6 to C60 aryl group and a substituted or unsubstituted C2 to C60 heteroaryl group, or adjacent two or more of Ra1 to Ra14 are bonded to each other to form a substituted or unsubstituted C6 to C60 aromatic hydrocarbon ring or a substituted or unsubstituted C2 to C60 heterocyclic ring,
• wherein the electron blocking layer includes a first electron blocking material represented by Formula 10:
• wherein each of R51 and R52 is independently a substituted or unsubstituted C1 to C10 alkyl, or adjacent two of R51 and R52 is connected to form a ring, wherein b1 is an integer of 0 to 4, and b2 is an integer of 0 to 5,
• wherein each of R53 and R54 is independently a substituted or unsubstituted C1 to C10 alkyl, or adjacent two of R53 and R54 is connected to form a ring, wherein b3 is an integer of 0 to 4, and b4 is an integer of 0 to 5,
• wherein each of R55 and R56 is hydrogen, or adjacent two of R55 and R56 is connected to form a ring,
• wherein each of c1, c2 and c3 is independently 0 or a positive integer, and at least one of c1, c2 and c3 is the positive integer, and
• wherein Dc1, Dc2 and Dc3 refer the number of hydrogens replaced with deuterium.