Organic light-emitting display device

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

a substrate;

light-emitting elements on the substrate;

a light control layer structure between an anode of each of the light-emitting elements and the substrate, the light control layer structure comprising at least one pair of an alternately stacked low refractive index layer and high refractive index layer, a lowest high refractive index layer contacting an upper surface of the substrate; and

at least one thin film layer between the light control layer structure and the anode, the at least one thin film layer having a lower refractive index than the high refractive index layer.

2. The organic light-emitting display device of claim 1 , wherein the light control layer structure has a refractive index between a refractive index of the anode and a refractive index of the substrate.

3. The organic light-emitting display device of claim 1 , wherein the low refractive index layer has a greater thickness than a thickness of the high refractive index layer.

4. The organic light-emitting display device of claim 1 , wherein the light control layer structure comprises, sequentially disposed on the substrate:

a first high refractive index layer;

a first low refractive index layer;

a second high refractive index layer;

a second low refractive index layer; and

a third high refractive index layer.

5. The organic light-emitting display device of claim 4 , wherein the second low refractive index layer has a greater thickness than a thickness of at least one of the first to third high refractive index layers and a thickness of the first low refractive index layer.

6. The organic light-emitting display device of claim 1 , wherein the light control layer structure comprises, sequentially disposed on the substrate:

a first high refractive index layer;

a first low refractive index layer;

a second high refractive index layer;

a second low refractive index layer;

a third high refractive index layer;

a third low refractive index layer;

a fourth high refractive index layer;

a fourth low refractive index layer;

a fifth high refractive index layer; and

a fifth low refractive index layer.

7. The organic light-emitting display device of claim 6 , wherein at least one of the second and fourth low refractive index layers has a greater thickness than a thickness of at least one of the first to fifth high refractive index layers and a thickness of the first, third and fifth low refractive index layers.

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

a substrate;

light-emitting elements on the substrate;

a light control layer structure between an anode of each of the light-emitting elements and the substrate, the light control layer structure comprising at least one pair of an alternately stacked low refractive index layer and high refractive index layer, a lowest high refractive index layer contacting an upper surface of the substrate; and

a second light control layer structure on a lower surface of the substrate and comprising at least one pair of an alternately stacked lower low refractive index layer and lower high refractive index layer.

9. The organic light-emitting display device of claim 8 , wherein a lowest lower high refractive index layer contacts the lower surface of the substrate.

10. The organic light-emitting display device of claim 8 , wherein:

the second light control layer structure is between the substrate and an air layer on the lower surface of the substrate; and

the second light control layer structure has a refractive index between a refractive index of the substrate and a refractive index of the air layer.

11. The organic light-emitting display device of claim 8 , wherein the lower low refractive index layer has a greater thickness than a thickness of the lower high refractive index layer.

12. The organic light-emitting display device of claim 1 , wherein each of the light-emitting elements comprises:

the anode;

a cathode opposite the anode; and

at least one light-emitting stack between the anode and the cathode,

wherein the anode comprises a transparent conductive material, and

wherein the cathode comprises a reflective conductive material.

13. The organic light-emitting display device of claim 12 , wherein the at least one light-emitting stack comprises:

a first light-emitting stack on the anode, the first light-emitting stack comprising a blue light-emitting layer; and

a second light-emitting stack disposed between the first light-emitting stack and the cathode, the second light-emitting stack comprising a yellowish-green light-emitting layer.

14. The organic light-emitting display device of claim 1 , wherein the at least one thin film layer has a same refractive index as the low refractive index layer.

15. The organic light-emitting display device of claim 1 , further comprising:

a thin film transistor connected to each of the light-emitting elements;

a buffer film between an active layer of the thin film transistor and the light control layer structure;

an interlayer insulating film between a gate electrode and a drain electrode of the thin film transistor;

a protective film on the thin film transistor; and

a planarization film between the protective film and the anode,

wherein the at least one thin film layer comprises at least one of: the buffer film, the interlayer insulating film, the protective film, and the planarization film.