Organic light emitting device

An organic light emitting device, comprising:

• an anode;
• a cathode;
• and
• a light emitting layer between the anode and the cathode,
• wherein the light emitting layer comprises a compound of the following Chemical Formula 1 and a compound of the following Chemical Formula 2:
• wherein in Chemical Formula 1,
• Y is O or S,
• X1, X2 and X3 are each independently CH or N, provided that at least one of X1, X2 and X3 is N, and
• Ar1 and Ar2 are each independently a substituted or unsubstituted C6-60 aryl, or a substituted or unsubstituted C2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S,
• R1, R2, and R3 are each independently hydrogen, deuterium, substituted or unsubstituted C6-60 aryl or substituted or unsubstituted C2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S,
• n1 is an integer of 0 to 8, and
• n2+n3 is an integer of 0 to 6;
• wherein in Chemical Formula 2,
• A is a benzene ring fused with two adjacent rings,
• Ar3 and Ar4 are each independently a substituted or unsubstituted C6-60 aryl, or a substituted or unsubstituted C2-60 heteroaryl containing at least one heteroatom selected from the group consisting of O and S, provided that at least one of Ar3 and Ar4 is substituted with at least one deuterium,
• each R4 is independently hydrogen, deuterium, substituted or unsubstituted C6-60 aryl or substituted or unsubstituted C2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, provided that at least one of R4 is deuterium, and
• n4 is an integer of 1 to 10.