ELECTRODE AND MANUFACTURING METHOD THEREOF AND ORGANIC ELECTROLUMINESCENT DEVICE

Abstract

The present disclosure provides an electrode having a first indium zinc oxide film, a metal film, and a second indium zinc oxide film which are laminated in sequence, in which the metal film is made of an Ag alloy. The first indium zinc oxide film has a thickness ranging from 5 nm to 40 nm; the metal film has a thickness ranging from 80 nm to 160 nm; and the second indium zinc oxide film has a thickness ranging from 5 nm to 40 nm. The electrode is applicable to organic light emitting diode (OLED) display technology or flexible OLED display technology.

Claims

1. An electrode for an organic electroluminescent device, wherein the organic electroluminescent device comprises an anode, an organic layer and a cathode formed on a substrate, wherein the electrode includes a first indium zinc oxide film, a metal film, and a second indium zinc oxide film which are laminated in sequence, wherein the metal film is made of an Ag alloy.

2. The electrode for an organic electroluminescent device according to claim 1, wherein the first indium zinc oxide film has a thickness ranging from 5 nm to 40 nm; the metal film has a thickness ranging from 80 nm to 160 nm; and the second indium zinc oxide film has a thickness ranging from 5 nm to 40 nm.

3. The electrode for an organic electroluminescent device according to claim 1, wherein the Ag alloy is a silver palladium copper alloy.

4. A manufacturing method of an electrode for an organic electroluminescent device, comprising steps of: providing a film formation substrate; forming a first indium zinc oxide film having a thickness ranging from 5 nm to 40 nm on the film formation substrate; forming a metal film having a thickness ranging from 80 nm to 160 nm on the first indium zinc oxide film; and forming a second indium zinc oxide film having a thickness ranging from 5 nm to 40 nm on the metal film; wherein the metal film is made of an Ag alloy.

5. The manufacturing method according to claim 4, wherein the film formation substrate is a glass substrate, a polyimide substrate, or a film substrate.

6. The manufacturing method according to claim 4, wherein the Ag alloy is a silver palladium copper alloy.

7. The manufacturing method according to claim 4, wherein the first indium zinc oxide film, the metal film, and the second indium zinc oxide film are formed by a direct current magnetron sputtering process.

8. The manufacturing method according to claim 7, wherein a direct current ranging from 2 kW to 8 kW and a sputtering pressure ranging from 0.2 Pa to 1 Pa are carried out during the direct current magnetron sputtering process.

9. An organic electroluminescent device, comprising an anode, an organic layer and a cathode formed on a substrate, wherein the anode is the electrode according to claim 1.

10. The organic electroluminescent device according to claim 9, wherein the organic layer comprises an electron injection layer, an electron transmission layer, a light emitting layer, a hole transmission layer, and a hole injection layer which are disposed in sequence.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0036] FIG. 1 is a schematic view of a current organic electroluminescent device.

[0037] FIG. 2 is a flowchart of film formation and etching process of an anode in a current organic electroluminescent device.

[0038] FIG. 3 is a schematic view of an electrode according to one embodiment of the present application.

[0039] FIG. 4 is a flowchart for manufacturing the electrode according to one embodiment of the present application.

[0040] FIG. 5 is a schematic view of an organic electroluminescent device according to the present application.

[0041] FIG. 6 is a flowchart of film formation and etching process for an electrode 3 of an organic electroluminescent device 5 in FIG. 5.

[0042] FIG. 7 is a schematic view of a display panel according to one embodiment of the present application.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0043] The technology of the present application will be described in detail below in combination with specific embodiments. It should be understood that the following specific embodiments are only used to assist those skilled in the art to understand this application and not to limit the application.

[0044] In this embodiment, an electrode 3 is provided. As shown in FIG. 3, the electrode 3 includes a first indium zinc oxide film 31, a metal film 32, and a second indium zinc oxide film 33 which are laminated in sequence.

[0045] The first indium zinc oxide film 31 has a thickness ranging from 5 nm to 40 nm; the metal film 32 has a thickness ranging from 80 nm to 160 nm; and the second indium zinc oxide film 31 has a thickness ranging from 5 nm to 40 nm. The metal film 32 is made of a silver palladium copper alloy (Ag—Pd—Cu). The silver palladium copper alloy is a well-known and commercially available material. Usually, the silver palladium copper alloy contains silver element of 90-95 wt %, palladium element of 4-8 wt %, and copper element of about 1 wt %.

[0046] As shown in FIG. 4, a manufacturing method of the abovementioned electrode 3 is provided in this embodiment, and the manufacturing method comprises following steps.

[0047] Step S1 of providing a film formation substrate. The film formation substrate is a glass substrate, a polyimide substrate, or a film substrate. It can be understood that the film formation substrate has structures formed by several previous processes thereon, for example, it is possible to include an inorganic layer, some layers of a thin film transistor, or a completed thin film transistor and traces. Specifically, the structures are determined according to the film to be formed by the corresponding process in the whole process flow.

[0048] Step S2 of placing the substrate obtained by the step S1 in a film forming chamber of a vacuum coating apparatus, and controlling a vacuum degree of the film forming chamber below 4×10.sup.−5 Pa to performing a direct current magnetron sputtering process by using an indium zinc oxide target, so as to form a first indium zinc oxide film having a thickness ranging from 5 nm to 40 nm on the film formation substrate.

[0049] Step S3 of using a silver palladium copper alloy target to perform a direct current magnetron sputtering process under same vacuum degree of the step S2, so as to form a metal film having a thickness ranging from 80 nm to 160 nm on the film formation substrate, wherein the Zn content of the indium zinc oxide target is 1-10 wt %.

[0050] Step S4 of using an indium zinc oxide target to perform a direct current magnetron sputtering process under same vacuum degree of the step S2, so as to form a second indium zinc oxide film having a thickness ranging from 5 nm to 40 nm on the metal film.

[0051] In the direct current magnetron sputtering process, a direct current ranging from 2 kW to 8 kW, a sputtering gas is argon, and a sputtering pressure ranging from 0.2 Pa to 1 Pa are carried out.

[0052] The vacuum coating apparatus can be, but not limited to, a monomer coating equipment, a continuous coating equipment, or an integrated coating equipment.

[0053] In the step (S2) and the step (S4) of forming the first indium zinc oxide film and the second indium zinc oxide film, the Ar gas can be added with oxygen (O.sub.2) or hydrogen (H.sub.2), and control a volume percentage of the oxygen to be 0.1% to 5% and the flow rate of the hydrogen to be 1-10 standard ml/min (sccm).

[0054] Furthermore, this embodiment provides an organic electroluminescent device 5 as shown in FIG. 5.

[0055] As shown in FIG. 5, the organic electroluminescent device 5 has a substrate 50. The substrate 50 can be selected, according to specific applications, from a group consisting of a glass substrate, a polyimide substrate, and a film substrate. It can be understood that the film formation substrate has structures formed by several previous processes thereon, for example, it is possible to include an inorganic layer, some layers of a thin film transistor, or a completed thin film transistor and traces. Specifically, the structures are determined according to the film to be formed by the corresponding process in the whole process flow. On the substrate 50, the electrode 3 as being an anode, an organic layer 54, and a cathode 52 organic electroluminescent device are disposed in sequence.

[0056] The organic layer 54 of the electroluminescent device 5 has a structure known in the art, or further includes other accessibility layers. For example, as shown in FIG. 5, the organic layer 54 comprises an electron injection layer 541, an electron transmission layer 543, a light emitting layer 545, a hole transmission layer 547, and a hole injection layer 549.

[0057] The skilled person in the art can understand that the abovementioned layers is formed by materials known in the art, and the specific selection of these materials does not affect the implementation of the technical solutions and obtain of the technical effects in the present application.

[0058] The cathode 52 is made of metals with lower work functions, such as lithium, magnesium, calcium, strontium, aluminum, or indium, or alloys formed by the metals and copper, gold, or silver, for example but not limited to Al, Mg/Ag alloy. Alternatively, the cathode 52 can be an electrode layer formed by a metal and a metal fluoride alternately, for example but not limited to an electrode formed by lithium fluoride and aluminum layer alternately. Of course, the cathode 52 can also be made of ITO or IZO.

[0059] The electron injection layer 541 can be formed by, for example but not limited to, one of graphene, carbon nanotube, ZnO, TiO.sub.2, and Cs.sub.2CO.sub.3.

[0060] The electron transmission layer 543 can be formed by, for example but not limited to, one of 4,7-diphenyl-1,10-phenanthroline (Bphen), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi), Bathocuproine (BCP), Tris(8-hydroxyquinoline)aluminum (Alq3).

[0061] The hole transmission layer 547 can be formed by, but not limited thereto, one of aromatic diamines, aromatic triamines, carbazoles, triphenylamines, furan based compounds, spiral compounds, polymer materials.

[0062] Refer to FIG. 6, FIG. 6 is a flowchart of film formation and etching process of the electrode 3 of the organic electroluminescent device 5. Compared with FIG. 2, since the indium zinc oxide film of the electrode 3 in this embodiment is an amorphous film which can be etched fast, and the electrode 3 can be wet-etched by using only an etching solution and an apparatus of an Ag alloy, so that the etching of the electrode 3 is completed by using the same etching solution on the same etching device, thereby achieving the purpose of simplifying the OLED manufacturing process. In addition, although the indium zinc oxide film is an amorphous film, it has similar transmittance characteristics to the crystallized ITO. Therefore, no annealing treatment is required in the manufacturing process of the electrode 3, thereby avoiding the Hillock phenomenon of the Ag film caused by the high temperature reaction during the annealing treatment.

[0063] Furthermore, a display panel 7 is provided in this embodiment as referred to FIG. 7. As shown in FIG. 7, the display panel 7 comprises:

[0064] a substrate 70, wherein the substrate 70 is a glass substrate, a polyimide substrate, or film substrate;

[0065] a thin film transistor device layer 72 formed on the substrate 70 and having a drain 721; and

[0066] an organic electroluminescent device layer 74 formed on the thin film transistor device layer 72.

[0067] In this embodiment, the organic electroluminescent device layer includes the electrode 3 as being an anode, an organic layer 741, and a second electrode 742 as being a cathode. The electrode 3 contacts with the drain 721 of the thin film transistor device layer 72.

[0068] One skilled in the art can understand that the display panel 7 has an essential structure of OLDE display panel as known in the art. for example, as shown in FIG. 7, the thin film transistor device layer 72 includes: a buffer layer 722 formed on the substrate 70, an active layer 723 formed on the buffer layer 722, a gate insulating layer 724 formed on the active layer 723, a gate layer 725 formed on the gate insulating layer 724, an insulating layer 726 formed on the gate layer 725, a source and the drain 721 formed on the insulating layer 726, a planarization layer 727 formed on the source and the drain 721, and the electrode 3 formed on the planarization layer 727.

[0069] The present application has been described by the above related embodiments, but the above embodiments are merely examples for implementing the present application. It must be noted that the disclosed embodiments do not limit the scope of the present application. Rather, modifications and equivalent arrangements included in the spirit and scope of the claims are intended to be included within the scope of the present application.