Organic light emitting device

An organic light-emitting device comprising:

• a first electrode;
• a second electrode;
• at least one organic material layer between the first and second electrodes;
• a first protective film on the second electrode;
• a second protective film on the first protective film;
• and
• a driving thin-film transistor including an active layer electrically connected to the first electrode,
• wherein:
• the active layer comprises an oxide semiconductor layer;
• and
• the organic material layer comprises a compound represented by the following Chemical Formula 1:
• wherein:
• X is O or S,
• R represents one selected from the group consisting of an aryl group having 6 to 30 carbon atoms, an amino group, a heterocyclic group having 3 to 30 carbon atoms and including at least one hetero atom selected from the group consisting of O, N and S, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, and an aryloxy group having 6 to 30 carbon atoms,
• a is an integer from 0 to 4, provided when a is 2 or greater, each R is the same as or different from each other, or adjacent R groups are bonded to each other to form a ring,
• L represents a direct bond or represents one selected from the group consisting of substituted or unsubstituted arylene having 6 to 30 carbon atoms and substituted or unsubstituted heteroarylene having 3 to 30 carbon atoms,
• b is an integer from 0 to 4, and
• each of Ar1 and Ar2 independently represents one selected from the group consisting of a substituted or unsubstituted C6 to C60 aryl group, a C3 to C30 heteroaryl group containing at least one heteroatom selected from the group consisting of O, N and S, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an alkoxyl group having 1 to 30 carbon atoms, and an aryloxy group having from 6 to 30 carbon atoms.