White organic light emitting device and display device using the same

A display device comprising:

• a substrate on which a cell driving unit comprising a thin film transistor is formed;
• a first electrode connected to the thin film transistor, and a second electrode opposite to the first electrode;
• a charge generation layer formed between the first electrode and the second electrode;
• a first stack disposed between the first electrode and the charge generation layer and comprising a first light emitting layer emitting blue light;
• and
• a second stack disposed between the charge generation layer and the second electrode and comprising a second light emitting layer that comprises at least one host doped with a phosphorescent dopant emitting light with a longer wavelength than blue light,
• wherein a total thickness of a structure comprising the first electrode and the layers disposed between the first electrode and the second electrode is in the range of 5000 Å to 6000 Å, and
• the structure satisfies an optical path condition represented by the following equation with respect to emissions of the first and second stacks,
• n
• a
• ⁢
• d
• a
• λ
• +
• ∑
• ⁢
• n
• w
• ⁢
• d
• w
• λ
• =
• 1.85
• ∼
• 2.15
• where λ is an emission peak wavelength of the first stack or the second stack, na and da are a refractive index and a thickness of a transparent electrode selected from the first and second electrode, and nw and dw are a refractive index and a thickness of any one of the layers disposed between the first electrode and the second electrode, respectively.

A display device comprising:

• a substrate on which a cell driving unit comprising a thin film transistor is formed;
• an optical compensation layer formed on the substrate provided with the cell driving unit;
• a first electrode connected to the thin film transistor and disposed on the optical compensation layer, and a second electrode opposite to the first electrode;
• a charge generation layer formed between the first electrode and the second electrode;
• a first stack disposed between the first electrode and the charge generation layer and comprising a first light emitting layer emitting blue light;
• and
• a second stack disposed between the charge generation layer and the second electrode and comprising a second light emitting layer that comprises at least one host doped with a phosphorescent dopant emitting light with a longer wavelength than blue light,
• wherein a total thickness of the layers between the first electrode and the second electrode is in the range of 2000 Å to 4000 Å,
• a thickness of the optical compensation layer is in the range of 1000 Å to 3000 Å, and
• the total thickness of the layers between the first electrode and the second electrode is in a compensation relationship with the thickness of the optical compensation layer.