US-20260130092-A1 - LIGHT EMITTING ELEMENT, ELECTRONIC DEVICE INCLUDING THE SAME, AND METHOD FOR MANUFACTURING THE LIGHT EMITTING

Abstract

A light-emitting element includes a first electrode, a functional layer disposed on the first electrode, a second electrode on the functional layer, and a capping layer on the second electrode. The second electrode includes a first layer on the functional layer, a second layer disposed on the first layer and including a different material from that of the first layer, and a third layer disposed on the second layer and including a different material from that of the second layer. The second layer includes sub-layers each including silver (Ag). The sub-layers include a first sub-layer on the first layer, a second sub-layer on the first sub-layer, and a third sub-layer on the second sub-layer. A film density of the first sub-layer and a film density of the second sub-layer are different, and the film density of the second sub-layer and a film density of the third sub-layer are different.

Inventors

• Hwi Kim
• Ji-Hee Son
• Seoulki Lee
• Joongu LEE

Assignees

• SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date

20260507

Application Date

20250903

Priority Date

20241101

Claims (20)

1. 1 . A light-emitting element comprising: a first electrode; a functional layer disposed on the first electrode and comprising an emission layer; a second electrode disposed on the functional layer, the second electrode comprising: a first layer disposed on the functional layer; a second layer disposed on the first layer and comprising a different material from a material of the first layer, the second layer further comprising: a plurality of sub-layers each comprising silver (Ag), the plurality of sub-layers further comprising: a first sub-layer disposed on the first layer; a second sub-layer disposed on the first sub-layer; and a third sub-layer disposed on the second sub-layer; and a third layer disposed on the second layer and comprising a different material from a material of the second layer; and a capping layer disposed on the second electrode, wherein a film density of the first sub-layer and a film density of the second sub-layer are different, and the film density of the second sub-layer and a film density of the third sub-layer are different.
2. 2 . The light-emitting element of claim 1 , wherein the film density of the second sub-layer is lower than the film density of each of the first sub-layer and the third sub-layer, and the film density of the first sub-layer and the film density of the third sub-layer are substantially identical to each other.
3. 3 . The light-emitting element of claim 1 , wherein the film density of the second sub-layer is higher than the film density of each of the first sub-layer and the third sub-layer, and the film density of the first sub-layer and the film density of the third sub-layer are substantially identical to each other.
4. 4 . The light-emitting element of claim 1 , wherein the plurality of sub-layers further comprise: a fourth sub-layer disposed on the third sub-layer; and a fifth sub-layer disposed on the fourth sub-layer, wherein the film density of the third sub-layer and a film density of the fourth sub-layer are different, and the film density of the fourth sub-layer and a film density of the fifth sub-layer are different.
5. 5 . The light-emitting element of claim 1 , wherein the second sub-layer is directly disposed on the first sub-layer, and the third sub-layer is directly disposed on the second sub-layer.
6. 6 . The light-emitting element of claim 1 , wherein the first sub-layer, the second sub-layer, and the third sub-layer have a shape of a single body.
7. 7 . The light-emitting element of claim 1 , wherein the first layer is directly disposed on the functional layer, the second layer is directly disposed on the first layer, and the third layer is directly disposed on the second layer.
8. 8 . The light-emitting element of claim 1 , wherein the functional layer comprises: a hole transport region disposed on the first electrode; the emission layer disposed on the hole transport region; and an electron transport region disposed on the emission layer, wherein the first layer is directly disposed on the electron transport region, and the capping layer is directly disposed on the third layer.
9. 9 . The light-emitting element of claim 1 , wherein the second electrode is a cathode.
10. 10 . The light-emitting element of claim 1 , wherein the first electrode comprises at least one metal selected from metals including Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, and Zn, a compound of two or more selected from the metal, or at least one of indium tin oxide, indium zinc oxide, zinc oxide (ZnO), or indium tin zinc oxide.
11. 11 . The light-emitting element of claim 1 , wherein the first sub-layer has a thickness of about 20 angstroms to about 30 angstroms, the second sub-layer has a thickness of about 50 angstroms to about 70 angstroms, and the third sub-layer has a thickness of about 20 angstroms to about 30 angstroms.
12. 12 . The light-emitting element of claim 1 , wherein the first layer has a thickness of about 5 angstroms to about 30 angstroms, the second layer has a thickness of about 90 angstroms to about 300 angstroms, and the third layer has a thickness of about 5 angstroms to about 30 angstroms.
13. 13 . The light-emitting element of claim 1 , wherein each of the first layer and the third layer comprises a halogenated metal, a lanthanum group metal, or a co-deposition material of a halogenated metal and a lanthanum group metal.
14. 14 . The light-emitting element of claim 1 , wherein each of the first sub-layer, the second sub-layer, and the third sub-layer comprises silver (Ag).
15. 15 . An electronic device comprising: a base layer; a circuit layer disposed on the base layer; and a display element layer disposed on the circuit layer and comprising: a light-emitting element, the light-emitting element comprising: a first electrode; a functional layer disposed on the first electrode and comprising an emission layer; and a second electrode disposed on the functional layer, the second electrode comprising: a first layer disposed on the functional layer; a second layer disposed on the first layer and comprising a different material from a material of the first layer, the second layer further comprising: a plurality of sub-layers each comprising silver (Ag), the plurality of sub-layers further comprising: a first sub-layer disposed on the first layer; a second sub-layer disposed on the first sub-layer; and a third sub-layer disposed on the second sub-layer; and a third layer disposed on the second layer and comprising a different material from a material of the second layer, wherein a film density of the second sub-layer is lower than a film density of each of the first sub-layer and the third sub-layer, and wherein the film density of the first sub-layer and the film density of the third sub-layer are substantially identical to each other.
16. 16 . A method for manufacturing a light-emitting element, the method comprising: forming, on a first electrode, a functional layer including an emission layer; forming a second electrode on the functional layer; and forming a capping layer on the second electrode, wherein the forming the second electrode comprises: forming a first layer on the functional layer; forming a second layer on the first layer by a different material from a material of the first layer; and forming a third layer on the second layer by a different material from a material of the second layer, wherein the forming the second layer comprises: depositing silver (Ag) onto the first layer at a first deposition rate to form a first sub-layer; depositing silver (Ag) onto the first sub-layer at a second deposition rate to form a second sub-layer; and depositing silver (Ag) onto the second sub-layer at a third deposition rate to form a third sub-layer, wherein the first deposition rate and the second deposition rate are different, and the second deposition rate and the third deposition rate are different.
17. 17 . The method of claim 16 , wherein each of the forming the first sub-layer, the forming the second sub-layer, and the forming the third sub-layer comprises a thermal evaporation process.
18. 18 . The method of claim 16 , wherein the second deposition rate is lower than each of the first deposition rate and the third deposition rate, and the first deposition rate and the third deposition rate are substantially identical to each other.
19. 19 . The method of claim 16 , wherein the forming the second layer further comprises: depositing silver (Ag) onto the third sub-layer at a fourth deposition rate to form a fourth sub-layer; and depositing silver (Ag) onto the fourth sub-layer at a fifth deposition rate to form a fifth sub-layer, wherein the third deposition rate and the fourth deposition rate are different, and the fourth deposition rate and the fifth deposition rate are different.
20. 20 . The method of claim 16 , wherein, in the forming the second electrode, the first layer is directly formed on the functional layer, the second layer is directly formed on the first layer, and the third layer is directly formed on the second layer.

Description

This application claims priority to Korean Patent Application No. 10-2024-0153314, filed on Nov. 1, 2024, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which in its entirety is herein incorporated by reference. BACKGROUND 1. Field The disclosure herein relates to a light-emitting element, an electronic device including the same, and a method for manufacturing the light-emitting element. 2. Description of the Related Art Recently, organic electroluminescence display devices are being actively developed as image display devices. The organic electroluminescence display devices are different from liquid crystal display devices and the like, and are so-called self-emissive display devices in which holes and electrons injected from first electrodes and second electrodes are recombined in emission layers so that light-emitting materials including organic compounds in the emission layers emit light to implement display. High luminous efficiency and long lifespan of the light-emitting elements are desired for application of the light-emitting elements to the display devices, and materials and structures of the light-emitting elements, which may stably achieve the desires, are continuously being developed. SUMMARY The disclosure provides a light-emitting element with improved luminous efficiency and element lifespan, and an electronic device including the light-emitting element. The disclosure also provides a method for manufacturing a light-emitting element, the method having a reduced process time and improved element reliability. An embodiment of the inventive concept provides a light-emitting element including a first electrode, a functional layer disposed on the first electrode and including an emission layer, a second electrode disposed on the functional layer, and a capping layer disposed on the second electrode. The second electrode includes a first layer disposed on the functional layer, a second layer disposed on the first layer and including a different material from that of the first layer, and a third layer disposed on the second layer and including a different material from that of the second layer. The second layer includes a plurality of sub-layers each including silver (Ag), and the plurality of sub-layers include a first sub-layer disposed on the first layer, a second sub-layer disposed on the first sub-layer, and a third sub-layer disposed on the second sub-layer. A film density of the first sub-layer and a film density of the second sub-layer are different, and the film density of the second sub-layer and a film density of the third sub-layer are different. In an embodiment, the film density of the second sub-layer may be lower than the film density of each of the first sub-layer and the third sub-layer, and the film density of the first sub-layer and the film density of the third sub-layer may be substantially the same. In an embodiment, the film density of the second sub-layer may be higher than the film density of each of the first sub-layer and the third sub-layer, and the film density of the first sub-layer and the film density of the third sub-layer may be substantially the same. In an embodiment, the plurality of sub-layers may further include a fourth sub-layer disposed on the third sub-layer, and a fifth sub-layer disposed on the fourth sub-layer. The film density of the third sub-layer and a film density of the fourth sub-layer may be different, and the film density of the fourth sub-layer and a film density of the fifth sub-layer may be different. In an embodiment, the second sub-layer may be directly disposed on the first sub-layer, and the third sub-layer may be directly disposed on the second sub-layer. In an embodiment, the first sub-layer, the second sub-layer, and the third sub-layer may have a shape of a single body. In an embodiment, the first layer may be directly disposed on the functional layer, the second layer may be directly disposed on the first layer, and the third layer may be directly disposed on the second layer. In an embodiment, the functional layer may include a hole transport region disposed on the first electrode. the emission layer disposed on the hole transport region, and an electron transport region disposed on the emission layer. The first layer may be directly disposed on the electron transport region, and the capping layer may be directly disposed on the third layer. In an embodiment, the second electrode may be a cathode. In an embodiment, the first electrode may include at least one metal selected from metals including Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, and Zn, a compound of two or more selected from the metal, or at least one of indium tin oxide (“ITO”), indium zinc oxide (“IZO”), zinc oxide (ZnO), or indium tin zinc oxide (“ITZO”). In an embodiment, the first sub-layer may have a thickness of about 20 angstroms (Å) to about 30 Å, the second sub-layer may have a thickness of about