Organic light-emitting display device and method of manufacturing the same

1. An organic light-emitting display device, comprising:

a substrate;

a first electrode on the substrate, the first electrode including a reflection film;

a hole injection layer on the first electrode;

a hole transport layer on the hole injection layer;

an emission layer on the hole transport layer;

an electron injection transport layer on the emission layer;

a second electrode on the electron injection transport layer, the second electrode including a semi-transmissive reflective material; and

a control layer positioned between an upper surface of the hole injection layer and a lower surface of the hole transport layer, the control layer including an organic material and having a refractive index lower than that of an adjacent layer.

2. The organic light-emitting display device as claimed in claim 1 , wherein the control layer is within the hole injection layer.

3. The organic light-emitting display device as claimed in claim 2 , wherein the hole injection layer includes a first hole injection layer and a second hole injection layer, the control layer being between the first and second hole injection layers and having a refractive index lower than that of the first and second hole injection layers.

4. The organic light-emitting display device as claimed in claim 1 , wherein the control layer is directly between the hole injection layer and the hole transport layer.

5. The organic light-emitting display device as claimed in claim 1 , wherein the control layer is within the hole transport layer.

6. The organic light-emitting display device as claimed in claim 5 , wherein the hole transport layer includes a first hole transport layer and a second hole transport layer, the control layer being between the first and second hole transport layers and having a refractive index lower than that of the first and second hole transport layers.

7. The organic light-emitting display device as claimed in claim 1 , wherein an image is displayed from the emission layer toward the second electrode.

8. A method of manufacturing an organic light-emitting display device, the method comprising:

forming a first electrode having a reflection film on a substrate;

forming a hole injection layer on the first electrode;

forming a hole transport layer on the hole injection layer;

forming an emission layer on the hole transport layer;

forming an electron injection transport layer on the emission layer;

forming a second electrode on the electron injection transport layer of a semi-transmissive reflective material; and

forming a control layer between an upper surface of the hole injection layer and a lower surface of the hole transport layer, the control layer including an organic material and having a refractive index lower than that of an adjacent layer.

9. The method as claimed in claim 8 , wherein forming the hole injection layer includes forming a first hole injection layer and a second hole injection layer, the control layer being formed between the first and second hole injection layers and having a refractive index lower than that of the first and second hole injection layers.

10. The method as claimed in claim 8 , wherein the control layer is formed directly between the hole injection layer and the hole transport layer.

11. The method as claimed in claim 8 , wherein forming the hole transport layer includes forming a first hole transport layer and a second hole transport layer, the control layer being formed between the first and second hole transport layers and having a refractive index lower than that of the first and second hole transport layers.

12. The method as claimed in claim 8 , wherein forming the control layer includes depositing an organic material for forming the control layer on a substrate, while the substrate is being inclined at an acute angle with respect to a depositing direction.

13. The method as claimed in claim 8 , wherein the control layer is formed during formation of the hole injection layer or the hole transport layer.