Organic light-emitting device

1. An organic light-emitting device comprising a first light-emitting region, a second light-emitting region, and a third light-emitting region, the organic light-emitting device comprising:

a substrate;

a first electrode layer on the substrate;

a hole injection layer on the first electrode layer;

a first resonance assistance layer on the hole injection layer in the first light-emitting region and a second resonance assistance layer on the hole injection layer in the second light-emitting region;

a first buffer layer formed of a first host on the first resonance assistance layer and a second buffer layer formed of a second host on the second resonance assistance layer;

a first emission layer comprising a third host and a first dopant on the first buffer layer and a second emission layer comprising a fourth host and a second dopant on the second buffer layer;

a common emission layer on the first emission layer, the second emission layer, and the hole injection layer;

an electron transport layer on the common emission layer; and

a second electrode layer on the electron transport layer.

2. The organic light-emitting device of claim 1 ,

the first host of the first buffer layer being same as the third host of the first emission layer, and

the second host of the second buffer layer being same as the fourth host of the second emission layer.

3. The organic light-emitting device of claim 1 , the first host and the second host being each independently formed of CBP, TCTA, or a mixture thereof.

4. The organic light-emitting device of claim 1 , the third host and the fourth host being each independently formed of CBP, TCTA, BCP, BPhen, Balq, TAZ, or a mixture thereof.