OLED anode structure and OLED micro display
By introducing a silver or silver alloy modification layer into the anode structure of the OLED microdisplay, the problem of the TiN layer reducing brightness caused by the absorption of blue light is solved, and the effect of improving brightness and reducing power consumption is achieved.
Patent Information
- Application Number
- CN202421254919.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-04
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-06-04
AI Technical Summary
In the anode structure of the existing OLED microdisplay, the TiN layer has a strong absorption capacity to blue light, resulting in a decrease in product brightness. The existing solutions remove TiN or increase through holes and increase costs, lacking simple and effective solutions.
An OLED anode structure arranged in sequence is adopted, which is arranged from a CMOS substrate, an aluminum layer, a modification layer (elemental silver layer or silver alloy layer) and a transparent metal oxide layer, and the reflectivity of the anode structure is increased by a silver or silver alloy modification layer.
It improves the anode reflectivity of OLED microdisplay, improves the brightness of the microdisplay, and reduces product power consumption.
Smart Images
Figure CN223040525U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of organic light-emitting diodes, and particularly relates to an OLED anode structure and an OLED microdisplay. Background Art
[0002] At present, the anode structures of OLED microdisplays are basically substrate / Ti / Al / TiN or substrate / Ti / Al / TiN / ITO, and there is a thin TiN layer on the surface of the metal Al or between the metal Al and the transparent metal oxide. Among them, the TiN layer can be used as a protective layer to protect the Al layer from oxidation during preparation and storage; in addition, it can also ensure good adhesion between the Al layer and the ITO layer.
[0003] However, TiN has a strong absorption capacity for blue light (450 - 500 nm), which will cause the brightness of the product to decrease. Therefore, removing TiN is an effective solution to improve the brightness of OLED microdisplays.
[0004] The existing solutions at present include: 1. Removing TiN before evaporation, but this requires adding equipment for removing TiN; 2. Using the Al / SiO2 / ITO structure, this method has a good effect and can be applied to microcavity devices, but it is necessary to add through holes in SiO2, which increases the prototype production cost. Therefore, there is an urgent need for a simple technology that can improve the brightness of OLED microdisplays. Summary of the Utility Model
[0005] The purpose of the utility model is to provide an OLED anode structure and an OLED microdisplay. The OLED anode structure provided by the utility model can improve the anode reflectivity of the OLED microdisplay, thereby enhancing the brightness of the OLED microdisplay and reducing the power consumption of the product.
[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0007] The utility model provides an OLED anode structure, which comprises a CMOS substrate, an aluminum layer, a modification layer and a transparent metal oxide layer that are sequentially stacked from bottom to top;
[0008] The modification layer comprises a single silver layer or a silver alloy layer.
[0009] Preferably, the silver alloy layer comprises a magnesium-silver alloy layer or a calcium-silver alloy layer.
[0010] Preferably, the thickness of the modification layer is more than 3 nm.
[0011] Preferably, the thickness of the aluminum layer is 90 - 150 nm.
[0012] Preferably, the transparent metal oxide layer includes an ITO layer, an AZO layer, or an IZO layer.
[0013] Preferably, the thickness of the transparent metal oxide layer is 10 - 30 nm.
[0014] The present utility model also provides an OLED microdisplay, which includes an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode that are sequentially stacked from bottom to top. The anode is the OLED anode structure described in the above technical solution.
[0015] Preferably, the material of the hole injection layer is a doped material or an undoped material; the undoped material includes dipyrromethene diimine [2,3-f:2',3'-h] quinoxaline-2,3,6,7,10,11-hexacarbonitrile; the doped material includes a host material and a dopant. The host material includes 4,4',4”-tris(carbazol-9-yl)triphenylamine or 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline], and the dopant includes NDP-9; the thickness of the hole injection layer is 5 - 20 nm;
[0016] The material of the hole transport layer includes 4,4',4”-tris(carbazol-9-yl)triphenylamine or 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline]; the thickness of the hole transport layer is 10 - 150 nm;
[0017] The material of the light-emitting layer includes a host material and a guest material. The host material is ammonium dinitramide, and the guest material is 4,4'-bis(2,2'-divinyl)-1,1'-biphenyl; the doping mass concentration of the guest material in the host material is 1 - 5%; the thickness of the light-emitting layer is 15 - 40 nm;
[0018] The material of the electron transport layer includes bis(2-hydroxyphenylpyridine)beryllium or 4,7-diphenyl-1,10-phenanthroline; the thickness of the electron transport layer is 5 - 60 nm;
[0019] The material of the electron injection layer includes a main material and a dopant. The main material includes bis(2-hydroxyphenylpyridine)beryllium or 4,7-diphenyl-1,10-phenanthroline, and the dopant includes one or more of Li, Yb, and Ag. The doping mass concentration of the dopant is 0.5 - 10 wt%; the thickness of the electron injection layer is 5 - 20 nm;
[0020] The material of the cathode includes IZO, and the thickness of the cathode is 50 - 200 nm.
[0021] Preferably, the surface of the cathode further includes a packaging layer, a light filtering layer, and a cover glass that are sequentially stacked.
[0022] The present utility model provides an OLED anode structure, which includes a CMOS substrate, an aluminum layer, a modification layer, and a transparent metal oxide layer that are sequentially stacked from bottom to top; the modification layer includes a single-element silver layer or a silver alloy layer. By using silver or a silver alloy as the modification layer in the present utility model, the reflectivity of the anode structure can be further improved. When applied to an OLED microdisplay, the brightness of the microdisplay can be further enhanced. Description of the Drawings
[0023] Figure 1 It is a schematic structural diagram of the OLED anode structure provided by the present utility model. Detailed Embodiments
[0024] The present utility model provides an OLED anode structure, which includes a CMOS substrate, an aluminum layer, a modification layer, and a transparent metal oxide layer that are sequentially stacked from bottom to top;
[0025] The modification layer includes a single-element silver layer or a silver alloy layer.
[0026] In the present utility model, unless otherwise specified, all materials are commercially available products well-known to those skilled in the art.
[0027] In the present utility model, the silver alloy layer preferably includes a magnesium-silver alloy layer or a calcium-silver alloy layer. The present utility model does not have special limitations on the proportions of the elements in the silver alloy layer, and those well-known to those skilled in the art can be used. In the present utility model, the thickness of the modification layer is preferably 3 nm or more, and more preferably 3 - 150 nm.
[0028] In the present utility model, the thickness of the aluminum layer is preferably 90 - 150 nm, and more preferably 100 - 120 nm.
[0029] In the present utility model, the transparent metal oxide layer preferably includes an ITO layer, an AZO layer, or an IZO layer; the thickness of the transparent metal oxide layer is preferably 10 - 30 nm.
[0030] The present utility model does not have special limitations on the preparation method of the OLED anode structure, and those well-known to those skilled in the art can be used. In a specific embodiment of the present utility model, the preparation of the aluminum layer, the modification layer, and the transparent metal oxide layer is preferably carried out by thermal evaporation.
[0031] The present utility model also provides an OLED microdisplay, which includes an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode that are sequentially stacked from bottom to top, and the anode is the OLED anode structure described in the above technical solution.
[0032] In the present utility model, the material of the hole injection layer is preferably a doped material or an undoped material; the undoped material preferably includes dipyranohydrazonyl[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN); the doped material preferably includes a host material and a dopant, the host material preferably includes 4,4',4”-tris(carbazol-9-yl)triphenylamine (TCTA) or 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC), the dopant preferably includes NDP-9, and the doping mass concentration of the dopant is preferably 0.5 to 10 wt%; the thickness of the hole injection layer is preferably 5 to 20 nm.
[0033] In the present utility model, the material of the hole transport layer preferably includes 4,4',4”-tris(carbazol-9-yl)triphenylamine (TCTA) or 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC); the thickness of the hole transport layer is preferably 10 to 150 nm.
[0034] In the present utility model, the material of the light-emitting layer preferably includes a host material and a guest material, the host material is preferably ammonium dinitramide (ADN), and the guest material is preferably 4,4'-bis(2,2'-divinyl)-1,1'-biphenyl (DPVBi); the doping mass concentration of the guest material in the host material is preferably 1 to 5%; the thickness of the light-emitting layer is preferably 15 to 40 nm.
[0035] In the present utility model, the material of the electron transport layer preferably includes beryllium bis(2-hydroxyphenylpyridine) (Bepp2) or 4,7-diphenyl-1,10-phenanthroline (Bphen); the thickness of the electron transport layer is preferably 5 to 60 nm.
[0036] In the present utility model, the material of the electron injection layer preferably includes a main material and a doping material, the main material preferably includes beryllium bis(2-hydroxyphenylpyridine) (Bepp2) or 4,7-diphenyl-1,10-phenanthroline (Bphen), the doping material preferably includes one or more of Li, Yb, and Ag, and the doping mass concentration of the doping material is preferably 0.5 to 10 wt%; the thickness of the electron injection layer is preferably 5 to 20 nm.
[0037] In the present utility model, the material of the cathode preferably includes IZO; the thickness of the cathode is preferably 50 to 200 nm.
[0038] The present utility model has no special limitation on the preparation method of the OLED microdisplay, and those well-known to those skilled in the art can be adopted. In the specific embodiments of the present utility model, the preparation of the hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer and cathode is preferably carried out by thermal evaporation.
[0039] In order to further illustrate the present utility model, a kind of OLED anode structure and a kind of OLED microdisplay provided by the present utility model will be described in detail below with reference to the drawings and embodiments, but they cannot be understood as limiting the protection scope of the present utility model.
[0040] Example 1
[0041] The specific structures of the anode and the OLED in this example are as follows:
[0042] CMOS / Al(90nm) / Ag(10nm) / ITO(10nm) / HAT-CN(10nm) / TCTA(80nm) / AD N:DPVBi(25nm, 2wt%) / Bepp2(20nm) / Bepp2:Yb(10nm, 1wt%) / IZO(120nm);
[0043] The specific preparation method is as follows:
[0044] Anode structure CMOS / Al(90nm) / Ag(10nm) / ITO(10nm): A 90nm-thick aluminum layer, a 10nm-thick silver layer and a 10nm-thick ITO layer are sequentially prepared on the surface of the CMOS substrate by magnetron sputtering;
[0045] On the surface of the anode structure, a 10nm-thick HAT-CN hole injection layer, an 80nm-thick TCTA hole transport layer, a 25nm-thick DPVBi-doped AND light-emitting layer, a 20nm-thick Bepp2 electron transport layer, a 10nm-thick Yb-doped Bepp2 electron injection layer and a 120nm-thick IZO cathode are sequentially prepared by thermal evaporation to obtain the final OLED microdisplay.
[0046] Example 2
[0047] The specific structures of the anode and the OLED in this example are as follows:
[0048] CMOS / Al(90nm) / Mg:Ag(10nm) / ITO(10nm) / HAT-CN(10nm) / TCTA(80nm) / ADN:DPVBi(25nm, 2wt%) / Bepp2(20nm) / Bepp2:Yb(10nm, 1wt%) / IZO(120nm);
[0049] The specific preparation method is as follows:
[0050] Anode structure: CMOS / Al(90nm) / Mg:Ag(10nm) / ITO(10nm): On the surface of the CMOS substrate, an aluminum layer with a thickness of 90nm, a magnesium-silver alloy layer with a thickness of 10nm, and an ITO layer with a thickness of 10nm are sequentially prepared by controlled sputtering;
[0051] On the surface of the anode structure, a HAT-CN hole injection layer with a thickness of 10nm, a TCTA hole transport layer with a thickness of 80nm, a DPVBi-doped AND light-emitting layer with a thickness of 25nm, a Bepp2 electron transport layer with a thickness of 20nm, a Yb-doped Bepp2 electron injection layer with a thickness of 10nm, and an IZO cathode with a thickness of 120nm are sequentially prepared by thermal evaporation to obtain the final OLED microdisplay.
[0052] Comparative Example 1
[0053] The specific structures of the anode and the OLED in this comparative example are as follows:
[0054] CMOS / Al(100nm) / TiN(5nm) / ITO(10nm) / HAT-CN(10nm) / TCTA(80nm) / ADN:DPVBi(25nm, 2wt%) / Bepp2(20nm) / Bepp2:Yb(10nm, 1wt%) / IZO(120nm);
[0055] The specific preparation method is as follows:
[0056] Anode structure: CMOS / Al(100nm) / TiN(5nm) / ITO(10nm): On the surface of the CMOS substrate, an aluminum layer with a thickness of 100nm, a TiN layer with a thickness of 5nm, and an ITO layer with a thickness of 10nm are sequentially prepared by controlled sputtering;
[0057] On the surface of the anode structure, a HAT-CN hole injection layer with a thickness of 10nm, a TCTA hole transport layer with a thickness of 80nm, a DPVBi-doped AND light-emitting layer with a thickness of 25nm, a Bepp2 electron transport layer with a thickness of 20nm, a Yb-doped Bepp2 electron injection layer with a thickness of 10nm, and an IZO cathode with a thickness of 120nm are sequentially prepared by thermal evaporation to obtain the final OLED microdisplay.
[0058] Performance test
[0059] The reflectance of the OLED microdisplays obtained in the examples and comparative examples was tested, and the reflectance test results at 550nm are shown in Table 1;
[0060] Table 1 Reflectivity of the OLED microdisplay obtained in the examples and comparative examples
[0061] Example 1 Example 2 Comparative Example 1 Reflectivity / % 98.2 97.4 70 Brightness @ J10 5325 nits 5061 nits 3500 nits
[0062] As can be seen from Table 1, the OLED anode structure provided by the present invention has a high reflectivity and can effectively improve the brightness of the microdisplay. Especially when applied to a microdisplay with a strong microcavity OLED. Since the reflectivity of Al / TiN / ITO in Comparative Example 1 is about 70%, while the reflectivity of the anode structure of the present invention can reach more than 95%, the brightness of the prepared OLED microdisplay can reach 1.5 times that of the original structure.
[0063] Although the above embodiments have made a detailed description of the present invention, they are only a part of the embodiments of the present invention, not all embodiments. Other embodiments can also be obtained according to these embodiments without creative efforts, and these embodiments all fall within the protection scope of the present invention.
Claims
1. An OLED anode structure, characterized in that: It includes a CMOS substrate, an aluminum layer, a modification layer and a transparent metal oxide layer stacked in sequence from bottom to top; The modified layer comprises a single substance silver layer or a silver alloy layer; The thickness of the aluminum layer is 90 to 150 nm; the thickness of the modified layer is more than 3 nm; and the thickness of the transparent metal oxide layer is 10 to 30 nm.
2. The OLED anode structure according to claim 1, characterized in that: The silver alloy layer includes a magnesium silver alloy layer or a calcium silver alloy layer.
3. The OLED anode structure according to claim 1, characterized in that: The transparent metal oxide layer includes an ITO layer, an AZO layer or an IZO layer.
4. An OLED micro display, comprising an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer and a cathode stacked in sequence from bottom to top, characterized in that: The anode is the OLED anode structure according to any one of claims 1 to 3.
5. The OLED microdisplay according to claim 4, characterized in that: The thickness of the hole injection layer is 5 to 20 nm; The thickness of the hole transport layer is 10 to 150 nm; The thickness of the light-emitting layer is 15 to 40 nm; The thickness of the electron transport layer is 5 to 60 nm; The thickness of the electron injection layer is 5 to 20 nm; The thickness of the cathode is 50-200 nm.
6. The OLED microdisplay according to claim 4, characterized in that: The surface of the cathode also includes a packaging layer, a filter layer and a cover glass which are stacked in sequence.