Electrode, light-emitting diode, light-emitting module and electronic device

Abstract

The present application provides an electrode, a light-emitting diode, a light-emitting module, and an electronic device. The electrode includes a second metal oxide layer, a first conductive buffer layer, a metal layer, and a first metal oxide layer stacked in sequence. The first conductive buffer layer is used to block the migration of atoms in the metal layer to the second metal oxide layer. Therefore, it can avoid a significant reduction in the transparency of the second metal oxide layer due to the migration of atoms in the metal layer, which can easily cause short circuits, dark spots on the display, and other problems.

Description

Technical Field

[0001] The present invention relates to an electrode, a light-emitting diode, a light-emitting module and an electronic device, belonging to the technical field of light-emitting display. Background Art

[0002] In the panel display industry, top-emitting LEDs typically use an ITO / Ag / ITO stacked structure as the device anode. The advantages of ITO are its high transparency and high work function of 4.5eV, which facilitates hole injection and improves luminous efficiency. Ag has the highest reflectivity among metals, facilitating light reflection and further increasing display brightness. Ag also has a low electrical resistance, reducing anode resistance.

[0003] However, top-emitting LEDs may have problems such as short circuits between the anode and cathode circuits, dark spots on the display, and reduced reflectivity during use. Summary of the Invention

[0004] The present invention provides an electrode, a light-emitting diode, a light-emitting module and an electronic device to solve the problems of top-emitting light-emitting diodes in the prior art, such as short circuits between the anode and cathode circuits, dark spots on the display, and reduced reflectivity during use.

[0005] The present invention provides an electrode comprising a second metal oxide layer, a first conductive buffer layer, a metal layer and a first metal oxide layer stacked in sequence; the first conductive buffer layer is used to block the migration of atoms in the metal layer to the second metal oxide layer.

[0006] For the electrode as described above, optionally, the material of the first conductive buffer layer includes a transparent material.

[0007] In the electrode described above, optionally, the material of the first conductive buffer layer includes graphene. In the electrode described above, optionally, the electrode further includes a total reflection structure; the total reflection structure is disposed between the metal layer and the second metal oxide layer, and is configured to fully reflect light emitted by the light-emitting functional layer.

[0008] As for the electrode as described above, optionally, the total reflection structure is provided on a side of the first conductive buffer layer close to the second metal oxide layer.

[0009] As for the electrode as described above, optionally, the total reflection structure includes: an optically sparse dielectric layer and an optically dense dielectric layer; the optically dense dielectric layer is arranged on a side of the optically sparse dielectric layer close to the second metal oxide.

[0010] For the electrode as described above, optionally, the refractive index of the optically dense dielectric layer is greater than 4.1 and less than 4.5; and the refractive index of the optically sparse dielectric layer is greater than 1.8 and less than 2.1.

[0011] As for the electrode as described above, optionally, the material of the optically sparse dielectric layer includes indium tin oxide; and the material of the optically dense dielectric layer includes graphene.

[0012] The electrode as described above may optionally further include a second conductive buffer layer; the second conductive buffer layer is disposed between the metal layer and the first metal oxide layer.

[0013] The present invention also provides a light emitting diode, comprising the electrode provided by any one of the above items.

[0014] The present invention also provides a light-emitting module, comprising a light-emitting diode as provided in any one of the above items.

[0015] The present invention also provides an electronic device, comprising the light-emitting module provided by any one of the above items.

[0016] The electrode provided by the present invention includes a second metal oxide layer, a metal layer, a first conductive buffer layer and a first metal oxide layer stacked in sequence. The first conductive buffer layer is used to block the migration of atoms in the metal layer to the second metal oxide layer. Therefore, it can avoid the transparency of the second metal oxide layer being greatly reduced due to the migration of atoms in the metal layer, which may easily cause short circuits, dark spots on the display and other problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present invention, and together with the description, serve to explain the principles of the present invention. In addition, these drawings and the description are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by reference to specific embodiments.

[0018] Figure 1 A schematic diagram of a portion of the structure of a light emitting diode according to an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of a portion of the structure of a light emitting diode according to another embodiment of the present invention;

[0020] Figure 3 FIG. 1 is a partial structural diagram of a light emitting diode in another embodiment of the present invention.

[0021] Description of reference numerals:

[0022] 1-electrode;

[0023] 11- first metal oxide layer;

[0024] 12-metal layer;

[0025] 13-first conductive buffer layer;

[0026] 14- second metal oxide layer;

[0027] 15-total reflection structure;

[0028] 151- optically dense dielectric layer;

[0029] 152-optically sparse dielectric layer;

[0030] 16- a second conductive buffer layer;

[0031] 2-Light-emitting functional layer. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The following embodiments and features in the embodiments can be combined with each other unless there is a conflict.

[0033] In the panel display industry, top-emitting LEDs typically use an ITO / Ag / ITO (indium tin oxide / silver / indium tin oxide) stacked structure as the device's anode. The advantages of ITO (indium tin oxide) are its high transparency and high work function of 4.5eV, which facilitates hole injection and improves luminous efficiency. Ag (silver) has the highest reflectivity among metals, facilitating light reflection and further increasing display brightness. Ag also has a low electrical resistance, reducing anode resistance.

[0034] However, in the use of top-emitting light-emitting diodes, Ag is prone to metal electromigration and diffuses into the interior of the ITO. In addition, the oxygen in the ITO easily undergoes an oxidation reaction with the Ag to form black Ag2O. As a result, the resistance of the ITO decreases, the work function decreases, and it is not conducive to the injection of holes in the device, resulting in a significant reduction in the transparency of the ITO and a reduction in the luminous efficiency of the device. Furthermore, the black color of Ag2O seriously reduces the reflectivity of Ag and affects the luminous efficiency. In addition, the large volume of Ag2O may cause the anode and cathode circuits to short-circuit, resulting in the problem of dark spots on the display.

[0035] The present invention provides an electrode, a light-emitting diode, a light-emitting module and an electronic device to solve the problems of top-emitting light-emitting diodes in the prior art, such as short circuits between the anode and cathode circuits, dark spots on the display, and reduced reflectivity during use.

[0036] Exemplary electrodes

[0037] Figure 1 This is a schematic diagram of the structure of an electrode in an embodiment of the present invention, referring to Figure 1 In the embodiment of the present invention, the electrode 1 is located on one side of the light-emitting functional layer 2, and the electrode 1 includes a second metal oxide layer 14, a first conductive buffer layer 13, a metal layer 12, and a first metal oxide layer 11 stacked in sequence in a direction away from the light-emitting functional layer 2;

[0038] The first conductive buffer layer 13 is used to prevent atoms of the metal layer 12 from migrating to the second metal oxide layer 14. Optionally, the atomic spacing of the first conductive buffer layer 13 is smaller than the atomic diameter of the metal layer 12.

[0039] In this configuration, since the first conductive buffer layer 13 can block the atoms of the metal layer 12 from migrating to the second metal oxide layer 14, it can prevent the transparency of the second metal oxide layer 14 from being reduced due to the migration of atoms of the metal layer 12 to the second metal oxide layer 14, thereby avoiding problems such as reduced luminous efficiency, short circuit between the anode and cathode circuits, and dark spots.

[0040] It should be noted that the electrode 1 in the figure can be the anode of the light-emitting diode, and the cathode of the light-emitting diode can be set on the same side of the light-emitting functional layer 2 as the anode, or the cathode of the light-emitting diode can be set on both sides of the light-emitting functional layer 2 respectively.

[0041] Furthermore, since the first conductive buffer layer 13 is disposed on the side of the metal layer 12 close to the light-emitting functional layer 2, if the transmittance of the first conductive buffer layer 13 is too low, it will affect the reflection of light by the metal layer 12 and the luminous efficiency of the device. Therefore, when selecting the material for the first conductive buffer layer 13, a material with high transmittance should be selected, so that the material of the first conductive buffer layer 13 includes a transparent material, thereby improving the transmittance of the first conductive buffer layer 13 and thereby improving the luminous efficiency of the device.

[0042] In one embodiment, the material of the first metal oxide layer 11 includes indium tin oxide, the material of the metal layer includes silver, the material of the second metal oxide layer 14 includes indium tin oxide, and the material of the first conductive buffer layer 13 includes graphene.

[0043] It should be noted that graphene does not easily react chemically with indium tin oxide and silver, and the atomic distance between graphene is only 0.142nm; the atomic radius of Ag is 0.144nm. Based on this, graphene can prevent the migration of Ag atoms from affecting the transmittance and work function of ITO, thereby improving the luminous efficiency. Furthermore, graphene has excellent conductivity and can reduce the anode resistance. Graphene has good light transmittance, with a transmittance of 97.7%. Based on this, the use of graphene can avoid the decrease in luminous efficiency of the light-emitting diode caused by the provision of the first conductive buffer layer 13.

[0044] In one embodiment, referring to Figure 2In order for the electrode 1 to better reflect the light emitted by the light-emitting functional layer 2, a total reflection structure 15 can be provided between the metal layer 12 and the second metal oxide layer 14. The total reflection structure 15 is used to fully reflect the light emitted by the light-emitting functional layer 2. With this arrangement, the light emitted by the light-emitting functional layer 2 can first be fully reflected by the total reflection structure 15. The light that passes through the total reflection structure 15 is then reflected by the metal layer 12. In this way, the metal layer 12 and the total reflection structure 15 jointly reflect the light emitted by the light-emitting functional layer 2, which can improve the electrode's reflective effect on the light emitted by the light-emitting functional layer 2 and improve the luminous efficiency of the device.

[0045] Specifically, the total internal reflection structure 15 reflects light by utilizing the phenomenon of total internal reflection. Total internal reflection, also known as total internal reflection, is an optical phenomenon. When light enters a medium with a higher refractive index from a medium with a lower refractive index, if the angle of incidence is greater than the critical angle (the angle at which the light is away from the normal), the refracted light disappears, and all incident light is reflected without entering the medium with a lower refractive index.

[0046] In actual applications, the total reflection structure 15 includes: a light-sparse dielectric layer 152 and a light-dense dielectric layer 151; the light-dense dielectric layer 151 is arranged on the side of the light-sparse dielectric layer 152 close to the light-emitting functional layer 2; with this arrangement, when the "light emitted by the light-emitting functional layer 2" passes through the light-dense dielectric layer 151 toward the light-sparse dielectric layer 152 at an incident angle greater than the critical angle, total reflection will be formed at the junction of the light-sparse dielectric layer 152 and the light-dense dielectric layer 151, and this part of the light will not enter the light-sparse dielectric layer 152.

[0047] Specifically, the refractive index of the optically dense dielectric layer 151 is greater than 4.1 and less than 4.5; the refractive index of the optically sparse dielectric layer 152 is greater than 1.8 and less than 2.1.

[0048] It should be noted that when selecting materials for the optically sparse dielectric layer 152 and the optically dense dielectric layer 151, not only the refractive index but also the electrical conductivity of the material must be considered. Poor electrical conductivity can affect the electrical connection between the metal layer 12 and the first metal oxide layer 11. Therefore, materials with good electrical conductivity should be selected. Furthermore, to prevent the total internal reflection structure 15 from blocking light propagation, the transmittance of the material must also be considered when selecting materials for the optically sparse dielectric layer 152 and the optically dense dielectric layer 151.

[0049] In practical applications, the material of the optically dense dielectric layer 151 may include: graphene; the material of the optically sparse dielectric layer 152 may include: indium tin oxide. Graphene has good electrical conductivity and transmittance, and the refractive index of graphene is generally 4.39. Furthermore, indium tin oxide has good electrical conductivity and transmittance, and the refractive index of indium tin oxide is generally between 1.8 and 2.1. Based on this, graphene is used to make the optically dense dielectric layer 151, and indium tin oxide is used to make the optically sparse dielectric layer 152. At this time, the refractive index of the optically dense dielectric layer 151 is greater than the refractive index of the optically sparse dielectric layer 152, and total reflection will occur on the plane where the optically dense dielectric layer 151 and the optically sparse dielectric layer 152 are in contact, and part of the light emitted by the light-emitting functional layer 2 is totally reflected.

[0050] It should be noted that the material of the optically sparse dielectric layer 152 may include: indium tin oxide; if the optically sparse dielectric layer 152 is arranged in contact with the metal layer 12, the indium tin oxide in the optically sparse dielectric layer 152 may undergo an oxidation reaction with the metal atoms of the metal layer 12 to generate black Ag2O (silver oxide). Black silver oxide is not conducive to light reflection and will reduce the luminous efficiency of the device. Furthermore, the volume of silver oxide is large and silver oxide may damage the layer structure of the electrode, for example, causing a short circuit between the anode and the cathode, resulting in dark spots on the display.

[0051] To avoid this situation, when the material of the optically sparse dielectric layer 152 includes a material that easily reacts chemically with the metal layer 12, the total reflection structure 15 can be set between the first conductive buffer layer 13 and the second metal oxide layer 14. In this way, the first conductive buffer layer 13 will isolate the metal layer 12 and the "optically sparse dielectric layer 152 in the total reflection structure 15", avoiding atomic migration and reaction between the metal layer 12 and the "optically sparse dielectric layer 152 in the total reflection structure 15", and avoiding problems such as reduced transparency, reduced device luminous efficiency, short circuit of the anode and cathode circuits, and dark spots due to the reaction between the metal layer 12 and the "optically sparse dielectric layer 152 in the total reflection structure 15".

[0052] Furthermore, in practical applications, an oxidation reaction may also occur between the metal layer 12 and the first metal oxide layer 11, affecting the performance of the electrode. Figure 3 A second conductive buffer layer 16 may be provided between the metal layer 12 and the first metal oxide layer 11. The second conductive buffer layer 16 separates the metal layer 12 and the first metal oxide layer 11 to prevent oxidation reaction between the metal layer 12 and the first metal oxide layer 11.

[0053] Specifically, the material of the metal layer 12 may include silver; the material of the first metal oxide layer 11 may include silver tin oxide; and the material of the second conductive buffer layer 16 may include graphene.

[0054] Exemplary Light Emitting Diodes

[0055] This embodiment provides a light emitting diode, referring to Figure 1 , the light-emitting diode includes: a light-emitting functional layer 2 and an electrode 1 located on one side of the light-emitting functional layer 2, the electrode 1 including the electrode provided by any embodiment of the above-mentioned exemplary electrodes. The electrode includes a first metal oxide layer, a metal layer, a first conductive buffer layer, and a second metal oxide layer stacked in sequence in a direction away from the light-emitting functional layer; the atomic spacing of the first conductive buffer layer is smaller than the atomic diameter of the metal layer. Since the atomic spacing of the first conductive buffer layer is smaller than the atomic diameter of the metal layer, the atoms of the metal layer cannot pass through the first conductive buffer layer, thereby preventing the atoms of the metal layer from achieving metal electromigration, thereby preventing problems such as reduced transparency, reduced device luminous efficiency, short circuit of the anode and cathode circuits, and dark spots caused by the metal electromigration of the atoms of the metal layer. Specifically, the material of the first conductive buffer layer includes a transparent material. The material of the first conductive buffer layer may include graphene.

[0056] Exemplary light emitting module

[0057] The present embodiment provides a light-emitting module, which includes: a light-emitting diode provided by any of the above-mentioned exemplary light-emitting diodes. In this configuration, the light-emitting diode in the light-emitting module includes: a light-emitting functional layer and an electrode located on one side of the light-emitting functional layer, the electrode including a first metal oxide layer, a metal layer, a first conductive buffer layer, and a second metal oxide layer stacked in sequence in a direction away from the light-emitting functional layer; the atomic spacing of the first conductive buffer layer is smaller than the atomic diameter of the metal layer. Since the atomic spacing of the first conductive buffer layer is smaller than the atomic diameter of the metal layer, the atoms of the metal layer cannot pass through the first conductive buffer layer, thereby preventing the atoms of the metal layer from achieving metal electromigration, thereby preventing problems such as reduced transparency, reduced device luminous efficiency, short circuit of the anode and cathode circuits, and dark spots caused by the metal electromigration of the atoms of the metal layer. Specifically, the material of the first conductive buffer layer includes a transparent material. The material of the first conductive buffer layer may include graphene.

[0058] Exemplary electronic devices

[0059] This embodiment provides an electronic device, which includes: the electronic device provided by any embodiment of the above-mentioned exemplary light-emitting module. In this way, the light-emitting diode of the electronic device includes: a light-emitting functional layer and an electrode located on one side of the light-emitting functional layer, the electrode including a first metal oxide layer, a metal layer, a first conductive buffer layer and a second metal oxide layer stacked in sequence in a direction away from the light-emitting functional layer; the atomic spacing of the first conductive buffer layer is smaller than the atomic diameter of the metal layer. Since the atomic spacing of the first conductive buffer layer is smaller than the atomic diameter of the metal layer, the atoms of the metal layer cannot pass through the first conductive buffer layer, thereby preventing the atoms of the metal layer from achieving metal electromigration, thereby preventing problems such as reduced transparency, reduced device luminous efficiency, short circuit of the anode and cathode circuits, and dark spots caused by the metal electromigration of the atoms of the metal layer. Specifically, the material of the first conductive buffer layer includes a transparent material. The material of the first conductive buffer layer may include graphene.

[0060] Furthermore, in the present invention, unless otherwise expressly specified or limited, terms such as "connected," "connected," and "stacked" should be interpreted broadly. For example, they may refer to fixed or detachable connections, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two elements or interaction between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electrode, characterized in that The electrode comprises a second metal oxide layer, a first conductive buffer layer, a metal layer and a first metal oxide layer stacked in sequence; The first conductive buffer layer is used to prevent atoms in the metal layer from migrating to the second metal oxide layer; The atomic spacing of the first conductive buffer layer is smaller than the atomic diameter of the metal layer; The electrode also includes a total reflection structure; The total reflection structure is arranged between the metal layer and the second metal oxide layer, and is used for totally reflecting the light emitted by the light-emitting functional layer.

2. The electrode according to claim 1, characterized in that The material of the first conductive buffer layer includes a transparent material.

3. The electrode according to claim 1, characterized in that The material of the first conductive buffer layer includes graphene.

4. The electrode according to claim 1, characterized in that The total reflection structure is arranged on a side of the first conductive buffer layer close to the second metal oxide layer.

5. The electrode according to claim 4, characterized in that The total reflection structure includes: an optically sparse dielectric layer and an optically dense dielectric layer; The optically dense dielectric layer is arranged on a side of the optically sparse dielectric layer close to the second metal oxide.

6. The electrode according to claim 5, characterized in that The refractive index of the optically dense medium layer is greater than 4.1 and less than 4.5; The refractive index of the optically sparse dielectric layer is greater than 1.8 and less than 2.

1.

7. The electrode according to claim 5, characterized in that The material of the optically sparse dielectric layer includes indium tin oxide; The material of the optically dense medium layer includes graphene.

8. The electrode according to claim 1, characterized in that Also comprising a second conductive buffer layer; The second conductive buffer layer is disposed between the metal layer and the first metal oxide layer.

9. A light emitting diode, characterized in that: The electrode comprises the electrode according to any one of claims 1 to 8.

10. A light emitting module, characterized in that: Comprising the light emitting diode according to claim 9.

11. An electronic device, characterized in that: Comprising the light emitting module as claimed in claim 10.

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