Organic light emitting element

An organic light emitting element, comprising:

• a first electrode;
• a second electrode;
• and
• an organic material layer positioned between the first electrode and the second electrode, wherein the organic material layer includes a compound represented by chemical formula 1 below:
• in chemical formula 1,
• either X or Y is N, and the other is S or O, wherein a is an integer from 0 to 5,
• R1 is each independently selected from the group consisting of a C1-C20 alkyl group;
• a C3-C30 cycloalkyl group;
• an aryloxy group;
• an arylthioxy group;
• a fluorenyl group;
• and a C6-C60 aryl group,
• R2 is selected from the group consisting of a C3-C30 cycloalkyl group;
• an aryloxy group;
• an arylthioxy group;
• a fluorenyl group;
• and a C6-C60 aryl group,
• R3 and R4 are each independently selected from the group consisting of i) a C1-C20 alkyl group;
• and a C6-C60 aryl group;
• or are bonded to each other to form a ring,
• b is an integer from 0 to 3,
• R5 is each independently a C6-C60 aryl group, and
• the alkyl group, cycloalkyl group, aryloxy group, arylthioxy group, fluorenyl group and aryl group each are further substituted with one or more substituents selected from the group consisting of a halogen group;
• a C1-C20 alkyl group;
• a C2-C20 alkenyl group;
• a C2-C20 alkynyl group;
• a fluorenyl group;
• a C6-C20 aryl group;
• and a C2-C20 heterocyclic group,
• wherein the organic material layer includes a light emitting layer,
• wherein the light emitting layer includes the compound,
• wherein the compound is a host compound of the light emitting layer, and
• wherein the light emitting layer further includes a host compound different from the compound.