WO2020029460A1

WO2020029460A1 - Transparent electrically-conductive film, display panel and display device

Info

Publication number: WO2020029460A1
Application number: PCT/CN2018/115787
Authority: WO
Inventors: 刘扬; 袁伟
Original assignee: 深圳市华星光电半导体显示技术有限公司
Priority date: 2018-08-10
Filing date: 2018-11-16
Publication date: 2020-02-13
Also published as: CN109192868B; CN109192868A

Abstract

A transparent electrically-conductive film (100), a display panel and a display device. The transparent electrically-conductive film (100) comprises a transparent electrically-conductive layer (120), a metal layer (130) and a dielectric layer (140). The dielectric layer (140) comprises an organic electron transport material layer and a metal material doped into the organic electron transport material layer. The transparent electrically-conductive layer (120), the metal layer (130) and the dielectric layer (140) are stacked to form a multi-layer structure. Since the transparent electrically-conductive film (100) comprises the metal layer (130) having flexible properties and the organic electron transport material layer doped with the metal material, the transparent electrically-conductive film (100) has enhanced flexibility when serving as an electrode in a display device, thereby further increasing flexibility of the display device.

Description

Transparent conductive film, display panel and display device

Technical field

The present application relates to the field of liquid crystal display, and in particular, to a method for manufacturing a display module.

Background technique

In the current lighting and display field, new display technologies such as organic light emitting diodes (also known as Organic Light-Emitting Diodes (OLEDs) and quantum dot light emitting diodes (QLEDs)) have self-luminous, Wide color gamut, high contrast, fast response speed, flexible display and other characteristics have been widely used in the development of lighting products and display panels to meet the requirements of low energy consumption, thinness, etc., and have become the next-generation display technology to replace liquid crystal display technology.

The flexible display technology of OLED and QLED is a kind of display technology with great potential, which conforms to the development trend of mobile communication and information display in the information age, and represents the future display form.

technical problem

Currently, a flexible display uses a flexible substrate, an electroluminescent layer and an electromagnetic are formed thereon, and then flexible packaging is performed to form a flexible display device. However, since the electrodes of the flexible display device are made of rigid materials, the flexibility of the flexible display device is limited, and it can only be bent and deformed to a certain extent, which seriously affects the bending degree of the flexible display device.

Technical solutions

An object of the present invention is to provide a transparent conductive film used as an electrode of a display panel to improve the flexible display performance of the display panel.

The invention also provides a display panel and a display device having the transparent conductive film.

The transparent conductive film of the present invention includes a transparent conductive layer, a metal layer, and a dielectric layer. The dielectric layer includes an organic electron transport material layer and a metal material doped in the organic electron transport material layer. The transparent conductive layer, The metal layer and the dielectric layer are stacked to form a multilayer structure.

The metal layer is located between the transparent conductive layer and the dielectric layer.

Wherein, the thickness of the metal layer is less than 30 nm.

Wherein, the electron mobility of the organic electron transport material layer is greater than 1.0 × 10 ^-4 cm / V · s.

The atomic percentage of the metal material in the dielectric layer is less than 10%.

Wherein, the organic electron transport material layer is made of an azole derivative, a quinoline derivative, an oxoline derivative, a diazanthrene derivative or a diphenanthrene derivative.

The display panel of the present invention includes a substrate and the transparent conductive film, and the transparent conductive film is located on a surface of the substrate. The transparent conductive film includes a transparent conductive layer, a metal layer, and a dielectric layer. The dielectric layer includes an organic layer. An electron transport material layer and a metal material doped in the organic electron transport material layer. The transparent conductive layer, the metal layer, and the dielectric layer are stacked to form a multilayer structure.

The display panel includes an encapsulation layer, and the encapsulation layer covers the transparent conductive film.

Wherein, the substrate includes an array substrate, and an electrode layer and a light-emitting functional layer sequentially stacked on a surface of the array substrate, and the transparent conductive film is located on a surface of the light-emitting functional layer facing away from the electrode layer.

Wherein, the thickness of the metal layer is less than 30 nm.

The display device of the present invention includes a controller and the display panel. The controller is used to control the display panel to be turned on or off. The display panel includes a substrate and a transparent conductive film. The transparent conductive film is located on the substrate. Surface, where

The transparent conductive film includes a transparent conductive layer, a metal layer, and a dielectric layer. The dielectric layer includes an organic electron transport material layer and a metal material doped in the organic electron transport material layer. The transparent conductive layer, the The metal layer and the dielectric layer are stacked to form a multilayer structure.

Wherein, the thickness of the metal layer is less than 30 nm.

Beneficial effect

The transparent conductive film described in this application includes a transparent conductive layer, a metal layer, and a dielectric layer. Since the transparent conductive layer has high transmittance to visible light, and the dielectric layer including the metal layer and the organic electron transport material layer has Flexible. When the transparent conductive film is used as an electrode of a display panel, it can be used not only as a transparent conductive electrode, but also to improve the flexibility of the electrode, thereby improving the flexible display performance of the display panel.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without paying creative labor.

FIG. 1 is a schematic structural diagram of a first embodiment of a transparent conductive film according to the present invention.

FIG. 2 is a schematic structural diagram of a second embodiment of a transparent conductive film according to the present invention.

FIG. 3 is a schematic structural diagram of a third embodiment of the transparent conductive film according to the present invention.

FIG. 4 is a schematic structural diagram of a display device according to the present invention.

Embodiments of the invention

In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The invention provides a transparent conductive film, which is a thin film that can conduct electricity and has high transmittance in the visible light range, and is used as a transparent electrode of a display device. The transparent conductive film of the present invention includes a transparent conductive layer, a metal layer, and a dielectric layer. The dielectric layer includes an organic electron transport material layer and a metal material doped in the organic electron transport material layer. The transparent conductive layer, The metal layer and the dielectric layer are stacked to form a multilayer structure. In the present application, the multilayer structure means that the transparent conductive film is formed by stacking at least three layers.

The transparent conductive layer is made of transparent conductive oxide (Transparent Conductive Oxide, TCO). The transparent conductive oxide is a conductive material having high transmittance to visible light, such as made of In ₂ O ₃ , SnO ₂ , ZnO, Ce ₂ O ₃ , Ga ₂ O ₃ , MoO ₃ , MgO, WO ₃ and TiO ₂ ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), AZO (Aluminum Zinc Oxide), or IGO (Indium Gallium Oxide, Indium Gallium) oxide) and so on.

The dielectric layer is opposite to and parallel to the transparent conductive layer, and the dielectric layer includes an organic electron transport material layer and a metal material doped in the organic electron transport material layer. Specifically, the organic electron transport material layer is made of an organic electron transport material (ETM) with an electron transport function, and its electron mobility is generally greater than the hole mobility. Preferably, the organic The electron mobility of the electron transport material layer is greater than 1.0 × 10 ^-4 cm / V · s, that is, the average drift velocity of the electrons in the organic electron transport material layer under a unit electric field is 1.0 × 10 ^-4 cm / s. The organic electron-transporting material includes, but is not limited to, oxazoles, such as oxazole, triazole, triazine, imidazole, thiazole, and benzothiazole. Derivatives of compounds, or quinoline derivatives, quinoxaline derivatives, anthrazoline derivatives, and phenanthroline derivatives. The metal material is doped in the organic electron transport material layer to increase the conductivity of the dielectric layer, so that the electron mobility of the dielectric layer and the electron mobility of the metal layer or the transparent conductive layer Reach the same order of magnitude. It can be understood that the atomic percentage of the metal material in the dielectric layer is less than 10%, so as to ensure that the dielectric layer can have a high transmittance for visible light. Further, the type of the metal material doped in the organic electron transport material layer is not limited, and may be a metal or an alloy, such as Ag, an Ag-based alloy, Cu, Au, Ni, and Al At least one of.

The metal layer is located between the transparent conductive layer and the dielectric layer to ensure a high transmittance of the entire transparent conductive film to visible light. Specifically, the metal layer is made of a metal having good electrical conductivity, and may be a metal or an alloy, for example, at least one of materials such as Ag, an Ag-based alloy, Cu, Au, Ni, and Al. production. Further, the thickness of the metal layer is less than 30 nm, and preferably, the thickness of the metal layer is less than 20 nm to ensure that the metal layer can have high transmittance to visible light.

The preferred embodiments of the transparent conductive film described in this application will be further described in detail below with reference to the accompanying drawings. Before this, it needs to be explained that in order to explain the effect of the lamination order of the transparent conductive layer, the metal layer, and the dielectric layer on the performance of the transparent conductive film, the transparent conductive film is combined with a substrate, and The specific structure of the transparent conductive film will be described in detail.

Referring to FIG. 1, in a first embodiment of the transparent conductive film described in the present application, the transparent conductive film 100 has a three-layer structure in which a transparent conductive layer, a metal layer, and a dielectric layer are stacked. Specifically, the transparent conductive layer is an IZO layer 120 made of IZO, and the IZO layer 120 is deposited on the surface of the substrate 110 by a magnetron sputtering process, and has a thickness of 100 nm. The metal layer is an Al layer 130 made of metal Al. The Al layer 130 is deposited on a surface of the IZO layer 120 facing away from the substrate 110 by a vacuum evaporation process, and the thickness is 5 nm. The dielectric layer is Al made of 4,7-diphenyl-1,10-phenanthroline (Bphen, 4,7-Diphenyl-1,10-phenanthroline), an organic electron transport material doped with Al. A doped Bphen layer 140, the Al-doped Bphen layer 140 is deposited on the surface of the Al layer 130 facing away from the IZO layer 120 by a vacuum evaporation process, and the thickness thereof is 60 nm, and Al atoms are doped in the Al doped The atomic percentage in the hetero Bphen layer 140 is 3%.

Referring to FIG. 2, in the second embodiment of the transparent conductive film according to the present invention, the difference from the first embodiment is that the dielectric layer is an Ag doped made of Ag-doped Bphen. A hetero Bphen layer 220, the Ag-doped Bphen layer 220 is deposited on the surface of the substrate 210 by a vacuum evaporation process, and the thickness is 40 nm, and the atomic percentage of the Ag atoms in the Ag-doped Bphen layer 220 is 5%. The metal layer is an Ag layer 230 made of metal Ag. The Ag layer 230 is deposited on the surface of the Ag-doped Bphen layer 220 facing away from the substrate 210 by a vacuum evaporation process, and the thickness is 10 nm. The transparent conductive layer is an IZO layer 240 made of IZO. The IZO layer 240 is deposited on the surface of the Ag layer 230 away from the Ag-doped Bphen layer 220 by a magnetron sputtering process, and the thickness is 40 nm. .

Please refer to FIG. 3. In the third embodiment of the transparent conductive film according to the present invention, the difference from the above two embodiments is that the transparent conductive film 300 is composed of two transparent conductive layers and one metal layer. A five-layer structure with two dielectric layers stacked. In order to facilitate the distinction, the two transparent conductive layers are named a first transparent conductive layer and a second transparent conductive layer, respectively, and the two dielectric layers are named a first dielectric layer and a second dielectric layer, respectively. Specifically, the first transparent conductive layer is an ITO layer 320 made of ITO, and the ITO layer 320 is deposited on the surface of the substrate 310 by a magnetron sputtering process, and has a thickness of 50 nm. The first dielectric layer is an Mg-doped Bphen layer 330 made of Bphen doped with Mg. The Mg-doped Bphen layer 330 is deposited on the ITO layer 320 away from the substrate through a vacuum evaporation process. The surface of 310 has a thickness of 50 nm, and the atomic percentage of Mg ions in the Mg-doped Bphen layer 330 is 1%. The metal layer is a MgAg layer 340 made of metal MgAg, and the MgAg layer 340 is deposited on the surface of the Mg-doped Bphen layer 330 facing away from the ITO layer 320 by a vacuum evaporation process, and the thickness is 10 nm. The atomic percentage of Mg atoms in the MgAg layer 340 is 10%. The second dielectric layer is a Mg-doped Bphen layer 350 made of Mphen doped Bphen. The Mg-doped Bphen layer 350 is deposited on the MgAg layer 340 away from the Mg by a vacuum evaporation process. The surface of the doped Bphen layer 330 has a thickness of 50 nm, and the atomic percentage of Mg ions in the Mg doped Bphen layer 350 is 1%. The second transparent conductive layer is an ITO layer 360 made of ITO, and the ITO layer 360 is deposited on the surface of the Mg-doped Bphen layer 350 facing away from the MgAg layer 340 by a magnetron sputtering process, and the thickness thereof is 50nm.

The transmittance and resistance of the transparent conductive films in the above three embodiments under visible light of different wavelengths are shown in Table 1 below. It should be noted that the transmittance data measured in Table 1 refers to data measured by measuring visible light penetrating the transparent conductive film from the substrate toward the transparent conductive film. The sheet resistance is also referred to as a film resistance, which is used to characterize the resistance of the film layer, which is the resistance of the transparent conductive film in this application.

Table 1. Transmittance and square resistance of the transparent conductive film to visible light at different wavelengths in the above examples

As can be seen from Table 1, the order in which the transparent conductive layer, the metal layer, and the dielectric layer are stacked, the material of each layer, and the thickness of each layer all affect the visible light transmittance of the transparent conductive film. And the sheet resistance of the transparent conductive film. On the one hand, the transparent conductive films described in this application all have a certain transmittance of visible light, and can be used as transparent electrodes to conduct electricity while transporting light; on the other hand, compared to the transparent conductive film made of TCO in the conventional technology, Its square resistance is about 40Ω / sq ～ 50Ω / sq. The square resistance of the transparent conductive film formed by stacking the TCO, the metal layer and the dielectric layer in this application is significantly smaller. When it is used as an electrode in a display panel, Can effectively reduce the phenomenon of voltage drop.

It should be noted that the above-mentioned embodiments are only a part of the embodiments of the transparent conductive film described in this application. In other embodiments, the transparent conductive film may be a multilayer transparent conductive layer, a multilayer metal layer, and a multilayer dielectric. A multilayer structure in which layers are staggered and stacked, and the multilayer structure includes more than three layers. It can be understood that, in order to ensure that the transparent conductive film has high transmittance to visible light, since the metal layer has poor transmittance to visible light, the metal layer in the transparent conductive film is not located on the transparent conductive film. Both ends.

The present invention also provides a display panel. The display panel includes, but is not limited to, a flexible display panel such as an OLED or a QLED. Referring to FIG. 4, the display panel 10 includes a substrate 500 and any one of the foregoing transparent conductive films, and the transparent conductive film is located on a surface of the substrate 500.

The substrate 500 includes an array substrate 510, an electrode layer 520, and a light-emitting function layer 530. The array substrate 510 includes a base substrate 511 and a TFT (Thin Film Transistor) device layer 512 on the surface of the base substrate 511. The base substrate 511 is a flexible substrate made of a flexible material. The flexible material includes, but is not limited to, polyimide (PI, Polyimide). The electrode layer 520 is located on a surface of the TFT device layer 512 facing away from the base substrate 511. In this embodiment, the electrode layer 520 is a structure in which three layers of ITO, a metal layer, and ITO are stacked. The metal layer is made of Ag atoms and has a thickness of 100 nm. The light-emitting functional layer 530 is formed on a surface of the electrode layer 520 facing away from the TFT device layer 512 through a vapor deposition and / or inkjet printing process. Specifically, the light-emitting functional layer 530 includes an electron injection layer (EIL), an electron transport layer (ETL), an emission layer (EML), a material layer, and a hole transport layer (HTL, Hole Transport Layer) and Hole Injection Layer (HIL, Hole Inject Layer). The EIL is located on a surface of the electrode layer 520 facing away from the TFT device layer 512, and the EIL is made of metal Li. The ETL is located on a surface of the EIL facing away from the electrode layer 520, and the ETL is composed of 1,3,5-tris (1-phenyl-1H-benzimidazol-2-yl) benzene (TPBi, 1,3 5-Tris (1-Phenyl-1H-benzimidazol-2-yl) Benzene) material is formed by an evaporation process, or PFN is formed by an inkjet printing process. The EML is located on a surface of the ETL facing away from the EIL, and the EML may be made of an organic light emitting material or a quantum dot light emitting material. For example, the EML is formed from a tris (2-phenylpyridine) iridium (IR (PPY) 3, Tris (2-Phenylpyridine) Iridium) through an evaporation process, or a phenolic resin (PF, Phenolicresin) through inkjet The printing process is formed. The HTL is located on a surface of the EML facing away from the ETL, and the HTL consists of N, N′-bis (1-naphthyl) -N, N′-diphenyl-1,1′-biphenyl-4- 4′-diamine (NPB, N, N′-dispheny-N, N′-bis (1-Naphthyl) -1,1′-biphenyl-4-4′-diamine) is formed by an evaporation process, or, 1,2,4,5-tetrakis (trifluoromethyl) benzene (TFB, 1,2,4,5-Tetrakis (trifluoromethyl) benzene) is formed by inkjet printing process. The HIL is located on a surface of the HTL facing away from the EML, and the HIL is composed of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzene Philippine (HATCN, Dipyrazino [2,3-f: 2 ', 3'-h] quinoxaline-2,3,6,7,10,11-Hexacarbonitrile) is formed by evaporation process, or it is made of conductive polymer PEDOT : PSS (poly 3,4-ethylene dioxythiophene / polystyrene sulfonate) is formed by an inkjet printing process.

The transparent conductive film 600 is located on a surface of the light-emitting functional layer 530 facing away from the electrode layer 520. In this embodiment, the transparent conductive film 600 has a four-layer structure formed by stacking two transparent conductive layers, one metal layer and one dielectric layer. To facilitate the distinction, the two transparent conductive layers are named a first transparent conductive layer and a second transparent conductive layer, respectively. Specifically, the first transparent conductive layer is an ITO layer 610 made of ITO, and the ITO layer 610 is deposited on a surface of the light-emitting functional layer 530 facing away from the electrode layer 520 by a magnetron sputtering process, and the thickness thereof is It is 40nm. The dielectric layer is a Li-doped TPBi layer 620 made of Li-doped TPBi, and the Li-doped TPBi layer 620 is formed on the ITO layer 610 away from the light-emitting functional layer 530 by an evaporation process. The thickness of the surface is 120 nm, and the atomic percentage of Li atoms in the Li-doped TPBi layer 620 is 20%. The metal layer is a LiAl layer 630 made of LiAl, and the LiAl layer 630 is formed on a surface of the Li-doped TPBi layer 620 facing away from the ITO layer 610 by an evaporation process, and the thickness thereof is 20 nm, and Li The atomic percentage of atoms in the LiAl layer 630 is 10%. The second transparent electrode layer is an IZO layer 640 made of IZO. The IZO layer 640 is formed on a surface of the LiAl layer 630 facing away from the Li-doped TPBi layer 620 by a magnetron sputtering process, and a thickness thereof It is 40nm. It can be understood that, in the display device 10, the transparent conductive film 600 and the electrode layer 520 are both used as electrodes. When the electrode layer 520 is used as a cathode, the transparent conductive film 600 is used as an anode. On the contrary, when the electrode layer 520 is used as an anode, the transparent conductive film 600 is used as a cathode.

Further, the display device 10 further includes an encapsulation layer 700, and the encapsulation layer 700 covers the transparent conductive film 600. The encapsulation layer 700 encapsulates the display device 10 and protects the display device 10 from moisture and oxygen.

The display device described in this application uses a transparent conductive film including a transparent conductive oxide layer, a metal layer, and a metal-doped organic electron transport material layer as an electrode. Since both the metal layer and the organic electron transport material layer have flexible characteristics, correspondingly, This improves the flexibility of the display device. In addition, as compared with a display device that completely uses a transparent conductive oxide layer as an electrode, the use of the transparent conductive film as an electrode can also effectively reduce the resistance of the electrode, thereby reducing the occurrence of a voltage drop in the display device.

The present invention also provides a display device, including a controller and the display panel. The display device may be a small-sized mobile phone, a large-sized notebook computer, a tablet computer, a monitor, an LCD television, or the like. The controller may be a functional device such as a computer host or a remote controller that can control the display panel to be turned on or off.

What has been disclosed above are only the preferred embodiments of the present invention, and of course, the scope of rights of the present invention cannot be limited by this. Those of ordinary skill in the art can understand all or part of the process of implementing the above embodiments and make according to the claims of the present invention. The equivalent changes still fall within the scope of the invention.

Claims

A transparent conductive film, wherein the transparent conductive film includes a transparent conductive layer, a metal layer, and a dielectric layer. The dielectric layer includes an organic electron transport material layer and a metal material doped in the organic electron transport material layer. The transparent conductive layer, the metal layer and the dielectric layer are stacked to form a multilayer structure.
The transparent conductive film according to claim 1, wherein the metal layer is located between the transparent conductive layer and the dielectric layer.
The transparent conductive film according to claim 2, wherein a thickness of the metal layer is less than 30 nm.
The transparent conductive film according to claim 1, wherein an electron mobility of the organic electron transport material layer is greater than 1.0 × 10 -4 cm / V · s.
The transparent conductive film according to claim 4, wherein an atomic percentage of the metal material in the dielectric layer is less than 10%.
The transparent conductive film according to claim 4, wherein the organic electron transport material layer is made of an azole derivative, a quinoline derivative, an oxoline derivative, a diazanthrene derivative, or a diphenanthrene derivative.
A display panel, wherein the display panel includes a substrate and a transparent conductive film, and the transparent conductive film is located on a surface of the substrate, wherein,

The transparent conductive film includes a transparent conductive layer, a metal layer, and a dielectric layer. The dielectric layer includes an organic electron transport material layer and a metal material doped in the organic electron transport material layer. The transparent conductive layer, the The metal layer and the dielectric layer are stacked to form a multilayer structure.
The display panel according to claim 7, wherein the display panel includes an encapsulation layer, and the encapsulation layer covers the transparent conductive film.
The display panel according to claim 8, wherein the substrate comprises an array substrate and an electrode layer and a light-emitting function layer sequentially stacked on a surface of the array substrate, and the transparent conductive film is located on the light-emitting function layer away from the electrode. The surface of the layer.
The display panel of claim 7, wherein the metal layer is located between the transparent conductive layer and the dielectric layer, and a thickness of the metal layer is less than 30 nm.
The display panel according to claim 7, wherein an electron mobility of the organic electron transport material layer is greater than 1.0 × 10 -4 cm / V · s.
The display panel of claim 7, wherein an atomic percentage of the metal material in the dielectric layer is less than 10%.
The display panel according to claim 11, wherein the organic electron transport material layer is made of an azole derivative, a quinoline derivative, an oxoline derivative, a diazanthrene derivative, or a diphenanthrene derivative.
A display device, wherein the display device includes a controller and a display panel, the controller is used to control the display panel to be turned on or off, the display panel includes a substrate and a transparent conductive film, and the transparent conductive film is located at A surface of the substrate, wherein

The transparent conductive film includes a transparent conductive layer, a metal layer, and a dielectric layer. The dielectric layer includes an organic electron transport material layer and a metal material doped in the organic electron transport material layer. The transparent conductive layer, the The metal layer and the dielectric layer are stacked to form a multilayer structure.
The display device according to claim 14, wherein the display panel includes an encapsulation layer, and the encapsulation layer covers the transparent conductive film.
The display device according to claim 14, wherein the substrate comprises an array substrate, and an electrode layer and a light-emitting function layer sequentially stacked on a surface of the array substrate, and the transparent conductive film is located on the light-emitting function layer away from the electrode. The surface of the layer.
The display device according to claim 14, wherein the metal layer is located between the transparent conductive layer and the dielectric layer, and a thickness thereof is less than 30 nm.
The display device according to claim 14, wherein an electron mobility of the organic electron transport material layer is greater than 1.0 × 10 -4 cm / V · s.
The display device of claim 14, wherein an atomic percentage of the metal material in the dielectric layer is less than 10%.
The display device according to claim 14, wherein the organic electron transport material layer is made of an azole derivative, a quinoline derivative, an oxoline derivative, a diazanthrene derivative, or a diphenanthrene derivative.