Organic light-emitting element and organic light-emitting display device

An organic light emitting element having first, second, and third sub-pixels with different colors on a substrate, the organic light emitting element comprising:

• first electrodes disposed on the substrate;
• a second electrode disposed on the substrate to face the first electrodes;
• organic light emitting layers disposed between the first electrodes and the second electrode, the organic light emitting layers comprising a first organic light emitting layer disposed in the first sub-pixel, a second organic light emitting layer disposed in the second sub-pixel, and a third organic light emitting layer disposed in the third sub-pixel;
• a hole transport layer disposed between the first electrodes and the organic light emitting layers;
• and
• auxiliary light emitting layers disposed between the hole transport layer and the organic light emitting layers, the auxiliary light emitting layers comprising:
• a first auxiliary light emitting layer commonly disposed in the first sub-pixel, the second sub-pixel, and the third sub-pixel;
• a second auxiliary light emitting layer disposed in the second sub-pixel between the first auxiliary light emitting layer and the second organic light emitting layer, and a third auxiliary light emitting layer disposed in the third sub-pixel between the first auxiliary light emitting layer and the third light emitting layer,
• wherein the first sub-pixel comprises the first auxiliary light emitting layer disposed between the hole transport layer and the first organic light emitting layer,
• wherein the second sub-pixel comprises the first auxiliary light emitting layer and the second auxiliary light emitting layer between the hole transport layer and the second organic light emitting layer,
• wherein the third sub-pixel comprises the first auxiliary light emitting layer and the third auxiliary light emitting layer between the hole transport layer and the third organic light emitting layer, and
• wherein the highest occupied molecular orbital (HOMO) level of the first auxiliary light emitting layer is larger than the HOMO level of the hole transport layer, and smaller than the HOMO level of the second auxiliary light emitting layer and the third auxiliary light emitting layer,
• wherein the first auxiliary light emitting layer, the second auxiliary light emitting layer, and the third auxiliary light emitting layer are formed of a hole transporting material.