Light-emitting element for efficiently emitting light in different colors
Provided is a light-emitting element to highly efficiently emit light in different colors. The light-emitting element includes: a cathode; an anode; a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting regions respectively emitting light of different wavelengths; and an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of regions each corresponding to one of the light-emitting regions. The electron-transport layer includes a Zn 1-X Mg X O film (where X is 0≤X<1). Of the plurality of regions included in the electron-transport layer, a region, corresponding to one of the light-emitting regions that emits light of a shorter wavelength, is higher in composition ratio X of Mg and/or less in thickness of the Zn 1-X Mg X O film.
1. A light-emitting element, comprising:
a cathode;
an anode;
a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting regions, respectively, emitting light of different wavelengths; and
an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of regions, each of the plurality of regions corresponding to one of the plurality of light-emitting regions,
the electron-transport layer including a Zn 1-X Mg X O film (where 0≤X<1), and, of the plurality of regions included in the electron-transport layer, a region, corresponding to the one of the plurality of light-emitting regions that emits light of a shorter wavelength, being higher in a composition ratio X of Mg and less in a thickness of the Zn 1-X Mg X O film.
2. A light-emitting element, comprising:
a cathode;
an anode;
a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting regions, respectively, emitting light of different wavelengths; and
an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of regions, each of the plurality of regions corresponding to one of the plurality of light-emitting regions,
the electron-transport layer including a Zn 1-X Mg X O film (where 0≤X<1), and, of the plurality of regions included in the electron-transport layer, a region, corresponding to the one of the plurality of light-emitting regions that emits light of a shorter wavelength, being higher in a composition ratio X of Mg.
3. The light-emitting element according to claim 2 , wherein
the plurality of light-emitting regions includes a red light emitting region emitting red light, a green light emitting region emitting green light, and a blue light emitting region emitting blue light.
4. The light-emitting element according to claim 3 , wherein
of the plurality of regions included in the electron-transport layer, a region, corresponding to the red light emitting region, contains Mg having the composition ratio X of 0 or higher and lower than 0.05, a region, corresponding to the green light emitting region, contains Mg having the composition ratio X of 0.05 or higher and lower than 0.15, and a region, corresponding to the blue light emitting region, contains Mg having the composition ratio X of 0.15 or higher and lower than 0.25.
5. The light-emitting element according to claim 3 , wherein
of the plurality of regions included in the electron-transport layer, a region, corresponding to the red light emitting region, includes the Zn 1-X Mg X O film having a thickness of 45 nm or more and less than 55 nm, a region, corresponding to the green light emitting region, includes the Zn 1-X Mg X O film having the thickness of 35 nm or more and less than 45 nm, and a region, corresponding to the blue light emitting region, includes the Zn 1-X Mg X O film having the thickness of 25 nm or more and less than 35 nm.
6. The light-emitting element according to claim 2 , wherein
the light-emitting layer contains quantum dots.
7. The light-emitting element according to claim 2 , further comprising:
a hole-transport layer formed between the anode and the light-emitting layer, wherein
the hole-transport layer includes a single region corresponding to two or more of the plurality of light-emitting regions.
8. The light-emitting element according to claim 2 , wherein
at least one selected from the cathode and the anode is formed into a single region corresponding to all of the plurality of light-emitting regions, and is disposed on a substrate.
9. The light-emitting element according to claim 2 , wherein
both the cathode and the anode are formed into a single region corresponding to all of the plurality of light-emitting regions.
10. A light-emitting element, comprising:
a cathode;
an anode;
a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting region, respectively, emitting light of different wavelengths; and
an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of region, each of the plurality of regions corresponding to one of the plurality of light-emitting regions,
the electron-transport layer including a Zn 1-X Mg X O film (where 0≤X<1), and, of the plurality of regions included in the electron-transport layer, a region, corresponding to the one of the plurality of light-emitting regions that emits light of a shorter wavelength, being less in a thickness of the Zn 1-X Mg X O film, wherein
the light-emitting layer includes a red light emitting region emitting red light, a green light emitting region emitting green light, and a blue light emitting region emitting blue light, and
of the plurality of regions included in the electron-transport layer, a region, corresponding to the red light emitting region, contains Mg having a composition ratio X of 0 or higher and lower than 0.05, a region, corresponding to the green light emitting region, contains Mg having the composition ratio X of 0.05 or higher and lower than 0.15, and a region, corresponding to the blue light emitting region, contains Mg having the composition ratio X of 0.15 or higher and lower than 0.25.
11. The light-emitting element according to claim 10 , wherein
the light-emitting layer contains quantum dots.
12. The light-emitting element according to claim 10 , further comprising:
a hole-transport layer formed between the anode and the light-emitting layer, wherein
the hole-transport layer includes a single region corresponding to two or more of the plurality of light-emitting regions.
13. The light-emitting element according to claim 10 , wherein
at least one selected from the cathode and the anode is formed into a single region corresponding to all of the plurality of light-emitting regions, and is disposed on a substrate.
14. The light-emitting element according to claim 10 , wherein
both the cathode and the anode are formed into a single region corresponding to all of the plurality of light-emitting regions.
15. A light-emitting element, comprising:
a cathode;
an anode;
a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting regions, respectively, emitting light of different wavelengths; and
an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of regions, each of the plurality of regions corresponding to one of the plurality of light-emitting regions,
the electron-transport layer including a Zn 1-X Mg X O film (where 0≤X<1), and, of the plurality of regions included in the electron-transport layer, a region, corresponding to one of the plurality of light-emitting regions that emits light of a shorter wavelength, being less in a thickness of the Zn 1-X Mg X O film, wherein
the light-emitting layer includes a red light emitting region emitting red light, a green light emitting region emitting green light, and a blue light emitting region emitting blue light, and
of the plurality of regions included in the electron-transport layer, a region, corresponding to the red light emitting region, includes the Zn 1-X Mg X O film having the thickness of 45 nm or more and less than 55 nm, the region a region, corresponding to the green light emitting region-region, includes the Zn 1 -xMgxO film having the thickness of 35 nm or more and less than 45 nm, and a region, corresponding to the blue light emitting region, includes the Zn 1-X Mg X O film having the thickness of 25 nm or more and less than 35 nm.
16. The light-emitting element according to claim 15 , wherein
the light-emitting layer contains quantum dots.
17. The light-emitting element according to claim 15 , further comprising:
a hole-transport layer formed between the anode and the light-emitting layer, wherein
the hole-transport layer includes a single region corresponding to two or more of the plurality of light-emitting regions.
18. The light-emitting element according to claim 15 , wherein
at least one selected from the cathode and the anode is formed into a single region corresponding to all of the plurality of light-emitting regions, and is disposed on a substrate.
19. The light-emitting element according to claim 15 , wherein
both the cathode and the anode are formed into a single region corresponding to all of the plurality of light-emitting regions.