Organic light-emitting diode and display device comprising the same

An organic light-emitting display device comprising:

• a substrate;
• and
• an organic light-emitting diode disposed on the substrate, wherein the organic light-emitting diode comprises:
• a first electrode;
• a first fluorescent light-emitting unit disposed on the first electrode and comprising a first hole transport layer, a first blue light-emitting layer, and a first electron transport layer;
• a first charge generating layer disposed on the first fluorescent light-emitting unit;
• a phosphorescent light-emitting unit disposed on the first charge generating layer and comprising a second hole transport layer, a red light-emitting layer, a first yellow-green light-emitting layer, a second yellow-green light-emitting layer, and a second electron transport layer;
• a second charge generating layer disposed on the phosphorescent light-emitting unit;
• a second fluorescent light-emitting unit disposed on the second charge generating layer and comprising a third hole transport layer, a second blue light-emitting layer, and a third electron transport layer;
• and
• a second electrode disposed on the second fluorescent light-emitting unit, wherein a dopant concentration of the first yellow-green light-emitting layer is greater than a dopant concentration of the second yellow-green light-emitting layer.