Phenylcarbazole-based compounds and fluorene-based compounds and organic light emitting device and flat panel display device comprising the same

An organic light emitting device, comprising:

• a substrate;
• a first electrode;
• a second electrode;
• and
• an organic layer interposed between the first electrode and the second electrode, the organic layer comprising:
• an emission layer comprising a red emission region, a green emission region and a blue emission region;
• and
• a layer comprising at least one compound selected from the group consisting of compounds represented by Formula 1 and compounds represented by Formula 2, the layer having a first region formed under the red emission region, a second region formed under the green emission region and a third region formed under the blue emission region, the thickness of the first region being in the range of 1,600 to 2,200 Å, the thickness of the second region being in the range of 1,400 to 1,800 Å, the thickness of the third region being in the range of 1,000 to 1,400 Å:
• X being one selected from the group consisting of a substituted or unsubstituted C1-C30 alkylene group, a substituted or unsubstituted C2-C30 alkenylene group, a substituted or unsubstituted C6-C30 arylene group, a substituted or unsubstituted C2-C30 heteroarylene group, and a substituted or unsubstituted C2-C30 hetero ring,
• each R1, each R2, each R3, each R4 and each R5 independently being one selected from the group consisting of a hydrogen atom, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 aryloxy group, a substituted or unsubstituted C2-C30 hetero ring, a substituted or unsubstituted C5-C30 polycyclic condensed ring, a hydroxy group, a cyano group, and a substituted or unsubstituted amino group, wherein two or more of R1, R2, and R3 can be optionally bound with one another to form a saturated or unsaturated carbon ring, and R4 and R5 can be optionally bound with one another to form a saturated or unsaturated carbon ring, and
• each Ar, and each Ar2 independently being a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted C2-C30 heteroaryl group.