Display device
A display device includes: a substrate; a display element on the substrate; a capping layer on the display element; a first auxiliary layer on the capping layer; and a thin-film encapsulation layer on the first auxiliary layer, wherein the thin-film encapsulation layer comprises a (1-1)-th inorganic encapsulation layer on the first auxiliary layer and a (1-2)-th inorganic encapsulation layer on the (1-1)-th inorganic encapsulation layer, wherein a refractive index of the first auxiliary layer is smaller than a refractive index of the capping layer and a refractive index of the (1-1)-th inorganic encapsulation layer, and a refractive index of the (1-2)-th inorganic encapsulation layer is smaller than the refractive index of the (1-1)-th inorganic encapsulation layer.
1. A display device comprising:
a substrate;
a display element on the substrate;
a capping layer on the display element;
a first auxiliary layer on the capping layer; and
a thin-film encapsulation layer on the first auxiliary layer,
wherein the thin-film encapsulation layer comprises a (1-1)-th inorganic encapsulation layer on the first auxiliary layer and a (1-2)-th inorganic encapsulation layer on the (1-1)-th inorganic encapsulation layer, wherein a refractive index of the first auxiliary layer is smaller than a refractive index of the capping layer and a refractive index of the (1-1)-th inorganic encapsulation layer, and a refractive index of the (1-2)-th inorganic encapsulation layer is smaller than the refractive index of the (1-1)-th inorganic encapsulation layer,
wherein the thin-film encapsulation layer further comprises a buffer layer on the (1-2)-th inorganic encapsulation layer, and
wherein the thin-film encapsulation layer further comprises a second auxiliary layer on the buffer layer, and a refractive index of the buffer layer is between a refractive index of the second auxiliary layer and the refractive index of the (1-2)-th inorganic encapsulation layer.
2. The display device of claim 1 , wherein the refractive index of the capping layer is in a range of 1.6 to 2.3.
3. The display device of claim 1 , wherein a thickness of the capping layer is in a range of 50 to 150 nm.
4. The display device of claim 1 , wherein the refractive index of the first auxiliary layer is in a range of 1.2 to less than 1.6.
5. The display device of claim 1 , wherein a thickness of the first auxiliary layer is in a range of 20 to 100 nm.
6. The display device of claim 1 , wherein the first auxiliary layer comprises lithium fluoride (LiF) or silicon oxynitride.
7. The display device of claim 1 , wherein the refractive index of the (1-1)-th inorganic encapsulation layer is in a range of 1.7 to 2.0.
8. The display device of claim 1 , wherein a thickness of the (1-1)-th inorganic encapsulation layer is in a range of 100 to 200 nm.
9. The display device of claim 8 , wherein the (1-1)-th inorganic encapsulation layer comprises silicon nitride or silicon oxynitride.
10. The display device of claim 1 , wherein the refractive index of the (1-2)-th inorganic encapsulation layer is in a range of 1.5 to less than 1.7.
11. The display device of claim 1 , wherein a thickness of the (1-2)-th inorganic encapsulation layer is 400 nm or more.
12. The display device of claim 1 , wherein the (1-2)-th inorganic encapsulation layer comprises silicon oxynitride.
13. The display device of claim 1 , wherein a thickness of the buffer layer is in a range of 30 to 100 nm.
14. The display device of claim 1 , wherein the refractive index (n3) of the buffer layer satisfies the following condition:
min( n 1, n 2)+| n 2- n 1|×0.25< n 3<min( n 1, n 2)+| n 2- n 1|×0.75,
where n1 is the refractive index of the (1-2)-th inorganic encapsulation layer, n2 is the refractive index of the second auxiliary layer, min(n1, n2) is a minimum value among n1 and n2, and |n2-n1| is an absolute value of a difference between n2 and n1.
15. The display device of claim 1 , wherein the thin-film encapsulation layer further comprises an organic encapsulation layer on the second auxiliary layer and a second inorganic encapsulation layer on the organic encapsulation layer.
16. A display device comprising:
a substrate;
a display element on the substrate;
a capping layer on the display element;
a first auxiliary layer on the capping layer; and
a thin-film encapsulation layer on the first auxiliary layer,
wherein the thin-film encapsulation layer comprises a first inorganic encapsulation layer, a second inorganic encapsulation layer, and an organic encapsulation layer between the first inorganic encapsulation layer and the second inorganic encapsulation layer, wherein the first inorganic encapsulation layer comprises one or more layers, and refractive indices of the capping layer, the first auxiliary layer, and the layers of the first inorganic encapsulation layer are alternately high and low,
wherein the thin-film encapsulation layer further comprises a buffer layer on the second inorganic encapsulation layer, and
wherein the thin-film encapsulation layer further comprises a second auxiliary layer on the buffer layer, and a refractive index of the buffer layer is between a refractive index of the second auxiliary layer and the refractive index of the second inorganic encapsulation layer.
17. The display device of claim 16 , wherein the first inorganic encapsulation layer comprises a (1-1)-th inorganic encapsulation layer on the first auxiliary layer and a (1-2)-th inorganic encapsulation layer on the (1-1)-th inorganic encapsulation layer, wherein a refractive index of the first auxiliary layer is smaller than a refractive index of the capping layer and a refractive index of the (1-1)-th inorganic encapsulation layer, and a refractive index of the (1-2)-th inorganic encapsulation layer is smaller than the refractive index of the (1-1)-th inorganic encapsulation layer.
18. The display device of claim 16 , wherein a coordinate value of u′ at 30° is smaller than a coordinate value of u′ at 0° on CIE1976 color coordinates (u′, v′).
19. The display device of claim 16 , wherein a coordinate value of u′ at 60° is larger than a coordinate value of u′ at 45° on the CIE1976 color coordinates (u′, v′).
20. The display device of claim 12 , wherein the thin-film encapsulation layer further comprises a second auxiliary layer on the (1-2)-th inorganic encapsulation layer.
21. The display device of claim 1 , wherein the thin-film encapsulation layer further comprises an organic encapsulation layer on the buffer layer and a second inorganic encapsulation layer on the organic encapsulation layer.
22. A display device comprising:
a substrate;
a display element on the substrate;
a capping layer on the display element;
a first auxiliary layer on the capping layer; and
a thin-film encapsulation layer on the first auxiliary layer,
wherein the thin-film encapsulation layer comprises a first inorganic encapsulation layer, a second inorganic encapsulation layer, and an organic encapsulation layer between the first inorganic encapsulation layer and the second inorganic encapsulation layer,
wherein the first inorganic encapsulation layer comprises a (1-1)-th inorganic encapsulation layer on the first auxiliary layer, and
a (1-2)-th inorganic encapsulation layer on the (1-1)-th inorganic encapsulation layer,
wherein a thickness of the first auxiliary layer is in a range of 20 to 100 nm,
wherein a thickness of the (1-1)-th inorganic encapsulation layer is in a range of 100 to 300 nm,
wherein a thickness of the (1-2)-th inorganic encapsulation layer is in a range of 400 to 2200 nm,
wherein the (1-1)-th inorganic encapsulation layer comprises silicon nitride, and
wherein (1-2)-th inorganic encapsulation layer comprises silicon oxynitride,
wherein the thin-film encapsulation layer further comprises a buffer layer on the (1-2)-th inorganic encapsulation layer, and
wherein the thin-film encapsulation layer further comprises a second auxiliary layer on the buffer layer, and a refractive index of the buffer layer is between a refractive index of the second auxiliary layer and the refractive index of the (1-2)-th inorganic encapsulation layer.
23. The display device of claim 22 , wherein the first auxiliary layer comprises lithium fluoride (LiF).
24. The display device of claim 22 , wherein the first auxiliary layer directly disposed on the capping layer, and
wherein a thickness of the capping layer is in a range of 50 to 150 nm.
25. The display device of claim 22 , wherein the thin-film encapsulation layer further comprises an inorganic insulating layer disposed between the first inorganic encapsulation layer and the organic encapsulation layer, and
wherein a thickness of the inorganic insulating layer is in a range of 30 to 100 nm.
26. The display device of claim 25 , wherein the inorganic insulating layer comprises silicon nitride.
27. The display device of claim 25 , wherein the refractive index of the inorganic insulating layer is less than the refractive index of the (1-2)-th inorganic encapsulation layer.