Display device including a gap between light-emitting elements, method for manufacturing the display device, and electronic device

1 . A display device comprising a first light-emitting element; a second light-emitting element; and a gap,

wherein the first light-emitting element comprises a first light-emitting layer and a first electron-injection layer over the first light-emitting layer,

wherein the second light-emitting element comprises a second light-emitting layer and a second electron-injection layer over the second light-emitting layer,

wherein the first light-emitting element is adjacent to the second light-emitting element,

wherein the gap is placed between the first electron-injection layer and first light-emitting layer and the second electron-injection layer and second light-emitting layer,

wherein the first light-emitting layer is in contact with a first side surface of the gap,

wherein the second light-emitting layer is in contact with a second side surface of the gap,

wherein the first electron-injection layer comprises a region projecting from a side surface of the first light-emitting layer, and

wherein the second electron-injection layer comprises a region projecting from a side surface of the second light-emitting layer.

2 . The display device according to claim 1 , comprising a region in which a distance between a side surface of the first electron-injection layer and a side surface of the second electron-injection layer is less than or equal to 1 μm.

3 . The display device according to claim 2 , comprising a region in which the distance between the side surface of the first electron-injection layer and the side surface of the second electron-injection layer is less than or equal to 100 nm.

4 . The display device according to claim 1 , wherein the gap comprises a gas containing one or more of nitrogen, oxygen, carbon dioxide, and a Group 18 element.

5 . The display device according to claim 4 ,

wherein the Group 18 element includes one or more of helium, neon, argon, xenon, and krypton.

6 . The display device according to claim 1 ,

wherein a refractive index of the first light-emitting layer and a refractive index of the second light-emitting layer are higher than a refractive index of the gap.

7 . The display device according to claim 1 ,

wherein the first electron-injection layer and the second electron-injection layer comprise silver and a compound having at least one of a pyridine ring, a diazine ring (a pyrimidine ring, a pyrazine ring, or a pyridazine ring), and a triazine ring.

8 . The display device according to claim 7 ,

wherein the first electron-injection layer and the second electron-injection layer comprise NBPhen and silver.

9 . The display device according to claim 1 ,

wherein the first light-emitting element and the second light-emitting element are provided over an insulating layer,

wherein a top surface of the insulating layer comprises a region in contact with a bottom surface of the gap, and

wherein a thickness of the insulating layer in the region in which the top surface of the insulating layer is in contact with the bottom surface of the gap is smaller than a thickness of the insulating layer in a region overlapping with the first light-emitting layer and a thickness of the insulating layer in a region overlapping with the second light-emitting layer.

10 . The display device according to claim 1 ,

wherein the display device comprises a first transistor and a second transistor,

wherein the first light-emitting element comprises a first electrode under the first light-emitting layer,

wherein the second light-emitting element comprises a second electrode under the second light-emitting layer,

wherein one of a source and a drain of the first transistor is electrically connected to the first electrode,

wherein one of a source and a drain of the second transistor is electrically connected to the second electrode, and

wherein each of the first transistor and the second transistor comprises silicon in a channel formation region.

11 . The display device according to claim 1 ,

wherein the display device comprises a first transistor and a second transistor,

wherein the first light-emitting element comprises a first electrode under the first light-emitting layer,

wherein the second light-emitting element comprises a second electrode under the second light-emitting layer,

wherein one of a source and a drain of the first transistor is electrically connected to the first electrode,

wherein one of a source and a drain of the second transistor is electrically connected to the second electrode, and

wherein each of the first transistor and the second transistor comprises a metal oxide in a channel formation region.

12 . An electronic device comprising the display device according to claim 1 and a lens.

13 . The display device according to claim 1 ,

wherein the first electron-injection layer overlaps with the gap, and

wherein the second electron-injection layer overlaps with the gap.

14 . A method for manufacturing a display device, comprising:

depositing a layer to be a first light-emitting layer and a layer to be a first sacrifice layer and processing the layers by first etching to form the first light-emitting layer and the first sacrifice layer;

depositing a layer to be a second light-emitting layer and a layer to be a second sacrifice layer and processing the layers by second etching to form the second light-emitting layer and the second sacrifice layer;

removing the first sacrifice layer and the second sacrifice layer;

depositing layer to be a first electron-injection layer and a second electron-injection layer and processing the layers by third etching to form the first electron-injection layer and the second electron-injection layer; and

processing the first light-emitting layer and the second light-emitting layer by fourth etching so that the first electron-injection layer includes a region projecting a side surface of the first light-emitting layer and the second electron-injection layer includes a region projecting from a side surface of the second light-emitting layer.

15 . The method for manufacturing the display device according to claim 14 , wherein isotropy of the fourth etching is higher than isotropy of the first to the third etching.

16 . The method for manufacturing the display device according to claim 14 , wherein the first light-emitting layer and the second light-emitting layer are configured to emit light of different colors.

17 . A display device comprising a first light-emitting element; a second light-emitting element; and a gap,

wherein the first light-emitting element comprises a first light-emitting layer and a first electron-injection layer over the first light-emitting layer,

wherein the second light-emitting element comprises a second light-emitting layer and a second electron-injection layer over the second light-emitting layer,

wherein the first light-emitting element is adjacent to the second light-emitting element,

wherein the gap is placed between the first electron-injection layer and first light-emitting layer and the second electron-injection layer and second light-emitting layer,

wherein the first light-emitting layer is in contact with a first side surface of the gap,

wherein the second light-emitting layer is in contact with a second side surface of the gap,

wherein the first electron-injection layer is in contact with the first side surface of the gap,

wherein the second electron-injection layer is in contact with the second side surface of the gap,

wherein the first electron-injection layer comprises a region projecting from a side surface of the first light-emitting layer, and

wherein the second electron-injection layer comprises a region projecting from a side surface of the second light-emitting layer.

18 . The display device according to claim 17 , comprising a region in which a distance between a side surface of the first electron-injection layer and a side surface of the second electron-injection layer is less than or equal to 1 μm.

19 . The display device according to claim 18 , comprising a region in which the distance between the side surface of the first electron-injection layer and the side surface of the second electron-injection layer is less than or equal to 100 nm.

20 . The display device according to claim 17 , wherein the gap comprises a gas containing one or more of nitrogen, oxygen, carbon dioxide, and a Group 18 element.

21 . The display device according to claim 20 ,

wherein the Group 18 element includes one or more of helium, neon, argon, xenon, and krypton.

22 . The display device according to claim 17 ,

wherein the first electron-injection layer overlaps with the gap, and

wherein the second electron-injection layer overlaps with the gap.