CN111710697A

CN111710697A - OLED device, preparation method thereof and double-sided display panel

Info

Publication number: CN111710697A
Application number: CN202010501395.9A
Authority: CN
Inventors: 袁伟
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2020-06-04
Filing date: 2020-06-04
Publication date: 2020-09-25

Abstract

The invention provides an OLED device, a preparation method thereof and a double-sided display panel, which comprise the following steps: the first electrode and the second electrode are transparent or semitransparent electrodes; the metal structure is arranged between the first electrode and the second electrode and covers the first electrode; and the electron injection layer is arranged between the metal structure and the second electrode and covers the metal structure. The double-sided display panel has the effects of double-sided display and high color gamut expression.

Description

OLED device, preparation method thereof and double-sided display panel

Technical Field

The application relates to the technical field of display, in particular to an OLED device, a preparation method thereof and a double-sided display panel.

Background

In the direction of a commercial display panel, double-sided display requirements are indispensable in window services of show window display, communication industry, government window, financial industry, traffic industry and the like, and double-sided display can reflect humanization of services centering on customers, protect the right of awareness of the customers, effectively improve the service efficiency of a service window, improve the service transparency and receive more and more favor of the customers.

The existing display panel is generally a single-sided display device, the structure of the single-sided display device can be a bottom emission structure or a top emission structure, and the effect of one-screen double-sided display cannot be realized. However, the double-sided Display on the market is a double-screen Liquid Crystal Display (LCD) Display, and not capable of achieving the effect of displaying on two sides of one screen, and because the LCD needs to use a backlight structure, it cannot achieve the effect of displaying on two sides of a transparent Display, that is, the effect of displaying on two sides of one screen cannot be achieved.

Disclosure of Invention

The invention aims to provide an OLED device, a preparation method thereof and a double-sided display panel, and aims to solve the technical problem that the conventional display panel cannot achieve transparent and double-sided display effects.

To achieve the above object, the present invention provides an OLED device comprising: the first electrode and the second electrode are transparent or semitransparent electrodes; the metal structure is arranged between the first electrode and the second electrode and covers the first electrode; and the electron injection layer is arranged between the metal structure and the second electrode and covers the metal structure.

Further, the metal structure is a metal nanowire with a thickness of

Further, the metal structure is a conductive metal layer and is a single-layer structure or a multi-layer structure, the single-layer structure or the multi-layer structure comprises at least one of silver, aluminum, platinum, copper, molybdenum and titanium, and the thickness of the single-layer structure or the multi-layer structure is 1.8-2.2 nm.

Further, the OLED device further includes: the quantum dot light-emitting layer is arranged on the electron injection layer; the hole transport layer is arranged on the quantum dot light-emitting layer; and a hole injection layer disposed on the hole transport layer.

Further, the thickness of the electron injection layer is 9.8-10.5 nm; the thickness of the quantum dot light-emitting layer is 38-43 nm; the thickness of the hole transport layer is 18-25 nm; the thickness of the hole injection layer is 12-18 nm.

Further, the preparation method of the OLED device comprises the following steps: forming a first electrode;

forming a metal structure on the first electrode; forming an electron injection layer on the metal structure; and forming a second electrode above the electron injection layer.

Further, in the step of forming a metal structure on the first electrode, the metal structure is formed on the first electrode by adopting an ink-jet printing mode, and the metal structure is a metal nanowire; or, forming the metal structure on the first electrode by evaporation, wherein the metal structure is a conductive metal layer and is made of at least one of silver, aluminum, platinum, copper, molybdenum and titanium.

Further, after the step of forming an electron injection layer on the metal structure, the method further includes the steps of: forming a quantum dot light-emitting layer on the electron injection layer; forming a hole transport layer on the quantum dot light emitting layer; and forming a hole injection layer on the hole transport layer; wherein the second electrode is formed on the hole injection layer.

To achieve the above object, the present invention also provides a double-sided display panel including the OLED device as described above.

Further, the double-sided display panel further includes: the array substrate comprises a plurality of thin film transistors, the thin film transistors are of top gate structures or bottom gate structures, and the OLED devices are arranged on the array substrate; and the pixel definition layer is arranged on the array substrate and is provided with a plurality of pixel units arranged at intervals, two adjacent pixel units form a groove, and the OLED device is arranged in the groove.

The invention has the technical effects that the OLED device and the preparation method thereof as well as the double-sided display panel are provided, the OLED device is of an inverted structure, light can be emitted from the bottom surface and the top surface of the panel on two sides, and the effect of one-screen double-sided display is realized. The first electrode of the QLED device is connected to a drain lead of the thin film transistor, when the current is conducted, the voltage Drop (IR Drop) generated by the first electrode resistor only affects the drain voltage Vdd, but the drain voltage Vdd is in a saturation region of the electrical property of the driving TFT (n-type); and Vds is the input voltage of the Data line (Data), usually a fixed value, and Vss is the source voltage, so that the influence of the change of Vdd on Vdd is small, namely the change of Vdd has small influence on the drain current, the brightness at different positions in the panel can be represented uniformly, and the problem of non-uniform brightness caused by the panel voltage Drop (IR Drop) can be effectively solved, so that the double-sided display panel has the effect of high color gamut.

Drawings

The technical solution and other advantages of the present application will become apparent from the detailed description of the embodiments of the present application with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of the first dual-sided display panel provided in embodiment 1.

Fig. 2 is a schematic structural diagram of the OLED device provided in embodiment 1.

Fig. 3 is a schematic structural diagram of the second dual-sided display panel provided in embodiment 2.

The components of the drawings are identified as follows:

10 an array substrate; a 20 pixel definition layer; 30 an OLED device;

40 a planar layer; 50 black matrix layers; 60 a cover plate; 70 a polarizer; 80, packaging the structure;

101 a first electrode; 102 a light-emitting functional layer; 103 a second electrode;

1021 a metal structure; 1021 an electron injection layer;

1022 quantum dot light-emitting layers; 1023 a hole transport layer; 1024 a hole injection layer;

a, a first double-sided display panel; b a second dual-sided display panel;

11 a substrate; 12 a gate layer; 13 a gate insulating layer; 14 an active layer; 15 an insulating layer; 16 source drain layers;

17 a passivation layer; 18 a light-shielding layer; 19 a buffer layer; 20 a dielectric layer;

100 thin film transistors; 201 a through hole; 202, grooves; 203 a first via; 204 second via.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

Quantum dot electroluminescent diodes (QLEDs) are a new display technology, which have physical advantages that LCD technology cannot match, and have the characteristics of active light emission, real color, infinite contrast, zero delay, transparent display, flexible display, free display form, and the like, and are a next generation display technology that can replace liquid crystal display technology. The QLED display technology does not need the support of backlight, so that the structure is simpler than that of an LCD, and the volume of a display product can be thinner, thinner and transparent. Moreover, the working conditions of the solar cell have a series of advantages of low driving voltage, low energy consumption and capability of being matched with a solar cell, an integrated circuit and the like. Because the QLED is an all-solid-state and non-vacuum device and has the characteristics of shock resistance, low temperature resistance (-40 ℃) and the like, the QLED has a very wide application range. The QLED is a self-luminous structure, so that through special structural design, two-side light emission can be realized, and further one-screen two-side display in the true sense can be realized. The invention provides a novel QLED structure suitable for a large-size panel, which has the beneficial effects of double-sided display, high color gamut expression and the like, and is detailed in the following embodiment.

Example 1

As shown in fig. 1, the present embodiment provides a first dual display panel a divided into a display area and a non-display area, which includes an array substrate 10, a pixel defining layer 20, an OLED device 30, a planarization layer 40, a black matrix layer 50, a cover plate 60, and a polarizer 70.

The array substrate 10 includes a plurality of thin film transistors 100, and the thin film transistors 100 have a bottom gate structure and a top gate structure, wherein the bottom gate structure and the top gate structure are located relative to the active layer, the bottom gate structure is a gate electrode located below the active layer, and the top gate structure is a gate electrode located above the active layer. In this embodiment, the thin film Transistor 100 (TFT) has a bottom gate structure. Specifically, the array substrate 10 includes a substrate 11, a gate electrode layer 12, a gate insulating layer 13, an active layer 14, an insulating layer 15, a source drain electrode layer 16, and a passivation layer 17. The substrate 11 may be, but is not limited to, a glass substrate, a flexible PI substrate. The gate layer 12 is disposed on the substrate 11 and is a metal layer of an aluminum molybdenum (Al/Mo) structure. A gate insulating layer 13 formed on the gate electrode layer 12 and the substrate 11 and made of silicon oxide (SiO)_X) And the gate layer 12 is protected from insulation. The active layer 14 is disposed on the gate insulating layer 13, and the position of the active layer 14 corresponds to the position of the gate layer 12, and the material of the active layer 14 includes, but is not limited to, Indium Gallium Zinc Oxide (IGZO), Low Temperature Polysilicon (LTPS), a-Si, and the like. An insulating layer 15 made of silicon oxide (SiO) is disposed on the active layer 14_X) To, forThe active layer 14 serves as an insulation protection. The source/drain layer 16 has a source, a drain, and a data line, which are disposed on both sides of the insulating layer 15 and extend from the upper surface of a portion of the insulating layer 15 to the gate insulating layer 13. The passivation layer 17 is disposed on the source/drain electrode layer 16 and the substrate 11, and plays a role of passivation protection for a film layer below the passivation layer 17, the passivation layer 17 is provided with a through hole 201 penetrating through the source/drain electrode layer 16, and specifically, the through hole 201 penetrates through the drain electrode of the source/drain electrode layer 16.

The pixel defining layer 20 is disposed on the array substrate 10, and has a plurality of pixel units disposed at intervals, two adjacent pixel units form a groove 202, and the OLED device 30 is disposed in the groove 202.

As shown in fig. 2, the present embodiment provides an OLED device 30, which is an inverted structure and sequentially includes a first electrode 101, a light-emitting functional layer 102, and a second electrode 103 from bottom to top. The light-emitting functional layer 102 sequentially includes, from bottom to top, a metal structure 1021, an electron injection layer 1021, a quantum dot light-emitting layer 1022, a hole transport layer 1023, and a hole injection layer 1024. The metal structure 1021 is disposed between the first electrode 101 and the second electrode 103, and covers the first electrode 101. The electron injection layer 1021 is disposed between the metal structure 1021 and the second electrode 103, and covers the metal structure 1021.

Specifically, the first electrode 101 is disposed at the bottom of the groove 202, covers the upper surface of the passivation layer 17, and is connected to the source/drain electrode layer 16. The metal structure 1021 is disposed on the first electrode 101, and may be a metal nanowire or a conductive metal layer. When the metal structure 1021 is a metal nanowire, the metal nanowire can be a silver nanowire or a gold nanowire with a thickness of

When the metal structure 1021 is a conductive metal layer, it is a single-layer structure or a multi-layer structure, and the single-layer structure or the multi-layer structure includes at least one of silver, aluminum, platinum, copper, molybdenum, and titanium, and the thickness thereof is 1.8-2.2 nm. In this embodiment, the thickness of the electron injection layer 1021 is 9.8-10.5nm, and the metal structure 1021 is disposed between the first electrode 101 and the electron injection layer 1021 to reduce the barrier difference between the first electrode 101 and the electron injection layer 1021 and effectively increase the electron injection effectAnd (5) fruit. The quantum dot light emitting layer 1022 is disposed on the electron injection layer 1021, and has a thickness of 38-43nm, and the quantum dots include red quantum dots, green quantum dots, and blue quantum dots for emitting red, green, and blue colors. The hole transport layer 1023 is arranged on the quantum dot light emitting layer 1022, the thickness of the hole transport layer 1023 is 18-25nm, and the hole transport layer 1023 is made of an organic hole transport material and has a hole carrier transport function. The hole injection layer 1024 is disposed on the hole transport layer 1023, and has a thickness of 12-18nm, and the hole injection layer 1024 is made of an organic hole injection material and has hole carrier transport and injection functions.

With reference to fig. 1, in the structure of the first dual-sided display panel a, the second electrode 103 is disposed on the pixel defining layer 20 and the hole transporting layer 1023. In this embodiment, the first electrode 101 and the second electrode 103 are both transparent or translucent electrodes. The first electrode 101 is preferably made of Indium Tin Oxide (ITO), and the second electrode 103 may be a single-layer structure or a multi-layer structure, and is made of Transparent Conductive Oxide (TCO), such as Indium Zinc Oxide (IZO), Indium Tin Oxide (ITO), and the like. In other embodiments, the second electrode 103 may be a full-surface thin layer of metal.

The black matrix layer 50 is disposed above the pixel defining layer 20 and includes a plurality of black matrix units, and each black matrix unit corresponds to one tft 100.

The cover plate 60 and the polarizer 70 are sequentially disposed on the black matrix layer 50.

Packaging structure 80 is located first double-sided display panel A's non-display area, locates between base plate 11 and the apron 60 to avoid water oxygen to follow non-display area invades extremely the display area improves first double-sided display panel A's packaging effect, prolongs first double-sided display panel A's life-span.

The embodiment provides a first double-sided display panel a, which includes an inverted QLED device structure, so that light can be emitted from both the bottom surface and the top surface of the panel, and a real one-screen double-sided display effect is achieved. The first electrode 101 of the QLED device 30 is connected to the drain wire of the thin film transistor, and when the current is turned on, the voltage Drop (IR Drop) generated by the resistance of the first electrode 101 only affects the drain voltage Vdd, but the drain voltage Vdd is in the saturation region of the electrical property of the driving TFT (n-type); and Vd is the input voltage of the Data line (Data), usually a fixed value, and Vss is the source voltage, so that Vdd change has little influence on the gate-source voltage, that is, Vdd change has little influence on the drain current, and at the moment, the brightness at different positions in the panel can be represented uniformly, thereby effectively solving the problem of non-uniform brightness caused by panel voltage Drop (IR Drop).

The embodiment also provides a preparation method of the first double-sided display panel, which comprises a preparation method of the OLED device.

Specifically, the method for manufacturing the first dual display panel includes the following steps S11) to S16).

S11) forming an array substrate such that the array substrate has a plurality of thin film transistors. Specifically, the array substrate preparation step specifically comprises S111) -S117).

S111) providing a substrate. The substrate may be, but is not limited to, a glass substrate, a flexible PI substrate.

S112) forming a grid layer on the substrate. Specifically, a metal layer with an aluminum-molybdenum (Al/Mo) structure is sequentially deposited on the substrate, and the metal layer is patterned by exposure, development, etching, stripping (Stripe) and other processes to form the gate layer.

S113) forming a gate insulating layer on the gate layer and the substrate. Specifically, inorganic material silicon oxide (SiO) is deposited on the upper surfaces of the grid layer and the substrate_X) And forming the gate insulating layer. The gate insulating layer plays an insulating protection role for the gate layer.

S114) forming an active layer on the gate insulating layer at a position corresponding to the gate electrode layer. Specifically, the IGZO layer is deposited on the upper surface of the gate insulating layer, but not limited thereto, and the metal layer is patterned by exposure, development, etching, stripping (Stripe), and the like to form the active layer. The material of the active layer includes, but is not limited to, Indium Gallium Zinc Oxide (IGZO), Low Temperature Polysilicon (LTPS), a-Si, etc.

S115) forming an insulation layer on the active layer. The insulating layer is made of silicon oxide (SiO)_X) And the active layer is insulated and protected. Depositing inorganic material silicon oxide on the upper surface of the active layer to form an inorganic layer, and patterning the inorganic layer through processes of exposure, development, etching, stripping (Stripe) and the like to form an IS layer of the TFT, namely an insulating layer, so as to protect the active layer.

S116) forming a source drain layer, wherein the source drain layer is arranged on two sides of the insulating layer and extends to the gate insulating layer from the upper surface of part of the insulating layer. Specifically, a metal layer of a molybdenum-aluminum-molybdenum structure (Mo/Al/Mo) is sequentially deposited on the insulating layer, and the metal layer is patterned by exposure, development, etching, stripping (Stripe) and other processes to form the source/drain electrode layer. The source drain layer is provided with a source electrode, a drain electrode and a data line.

S117) forming a passivation layer on the source drain layer and the substrate. Specifically, in the process of preparing the passivation layer, the passivation layer is subjected to hole digging, and the through hole penetrates through the drain electrode of the source drain electrode layer. In this embodiment, the passivation layer plays a passivation protection role for a film layer below the passivation layer.

S12) to form an OLED device, the OLED device preparation steps specifically including S121) -S126).

S121) forming a first electrode on the passivation layer. Specifically, as shown in fig. 3, an Indium Tin Oxide (ITO) material is deposited on the upper surface of the passivation layer to form a transparent electrode layer, the through hole is filled, and the transparent electrode layer is patterned by exposure, development, etching, stripping (Stripe) and other processes to form the first electrode, wherein the first electrode has a high transmittance characteristic.

S122) forming a light-emitting functional layer on the first electrode.

Before the preparation of the luminescent functional layer, the method further comprises the following steps: and forming a pixel defining layer on the passivation layer, wherein the pixel defining layer is provided with a plurality of pixel units arranged at intervals, and two adjacent pixel units form a groove.

The steps of preparing the light emitting function layer specifically include S1211) to S1215).

S1211) forming a metal structure on the first electrode. The metal structure may be a metal nanowire or a conductive metal layer. Forming the metal structure on the first electrode by adopting an ink-jet printing mode, wherein the metal structure is a metal nanowire with the thickness of

In other embodiments, the metal structure is formed on the first electrode by evaporation, and the metal structure is a conductive metal layer and is a single-layer structure or a multi-layer structure, and the single-layer structure or the multi-layer structure includes at least one of silver, aluminum, platinum, copper, molybdenum, and titanium, and has a thickness of 1.8-2.2 nm.

S1212) forming an electron injection layer on the metal structure. And forming the electron injection layer on the upper surface of the metal structure by adopting an ink-jet printing mode, wherein the thickness of the electron injection layer is 9.8-10.5 nm. In this embodiment, the metal structure is disposed between the first electrode and the electron injection layer to reduce a barrier difference between the first electrode and the electron injection layer, thereby effectively increasing an electron injection effect.

S1213) forming a quantum dot light emitting layer on the electron injection layer. The thickness of the quantum dot light-emitting layer is 38-43nm, and the quantum dots comprise red quantum dots, green quantum dots and blue quantum dots and are used for emitting red, green and blue colors.

S1214) forming a hole transport layer on the quantum dot light emitting layer. The thickness of the hole transport layer is 18-25nm, and the hole transport layer is made of an organic hole transport material and has a hole carrier transport function.

S1215) forming a hole injection layer on the hole transport layer. The thickness of the hole injection layer is 12-18nm, and the hole injection layer is made of an organic hole injection material and has hole carrier transmission and injection functions. In this embodiment, the luminescent functional layer is prepared by inkjet printing.

S123) forming a second electrode on the hole injection layer. Specifically, the second electrode is formed on the upper surfaces of the pixel defining layer and the hole transport layer, and the second electrode may be a single-layer structure or a multi-layer structure, and is made of a Transparent Conductive Oxide (TCO), such as Indium Zinc Oxide (IZO), Indium Tin Oxide (ITO), and the like. In other embodiments, the second electrode may be a full-surface thin layer of metal.

S13) coating Black Matrix material (Black Matrix) on a cover plate, and patterning by exposure and development to form a Black Matrix layer having multiple Black Matrix units.

S14) overturning the cover plate, and attaching the cover plate to the array substrate. Each black matrix unit of the black matrix layer corresponds to a thin film transistor.

S15) arranging a packaging structure between the substrate and the cover plate, and packaging the array substrate and the cover plate to form a first double-sided display panel. The packaging structure is an inorganic-organic combined structure, and prevents water and oxygen from invading the OLED device, so that the packaging effect of the first double-sided display panel is improved.

S16) arranging a polarizer on the upper surface of the cover plate, wherein the polarizer separates the incident linear light with polarized light components, one part of the polarized light components is used for allowing the incident linear light to pass through, and the other part of the polarized light components is used for hiding the polarized light components under the actions of absorption, reflection, scattering and the like, so that the polarized light components are used for controlling the image effect through color separation and pressure reduction.

The present embodiment provides a method for manufacturing a first dual display panel, which includes a method for manufacturing an OLED device. The OLED device is of an inverted structure, so that light can be emitted from the bottom surface and the top surface of the panel on two sides, and the real one-screen two-side display effect is realized. The first electrode of the QLED device is connected to a drain lead of the thin film transistor, when the current is conducted, the voltage Drop (IR Drop) generated by the first electrode resistor only affects the drain voltage Vdd, but the drain voltage Vdd is in a saturation region of the electrical property of the driving TFT (n-type); and Vds is the input voltage of the Data line (Data), usually a fixed value, and Vss is the source voltage, so that the influence of Vdd change on the gate-source voltage is small, namely, the influence of Vdd change on the drain current is small, the brightness at different positions in the panel can be represented uniformly, and the problem of non-uniform brightness generated by panel voltage Drop (IR Drop) can be effectively solved, so that the double-sided display panel has the effect of high color gamut.

Example 2

The present embodiment provides a second dual-sided display panel B and a method for manufacturing the same, which includes most of the technical solutions of embodiment 1, and the difference is that the array substrate has a plurality of thin film transistors, and the thin film transistors are in a top gate structure. The second double-sided display panel B and the method for manufacturing the same include the structure of the OLED device and the method for manufacturing the same of embodiment 1.

As shown in fig. 3, the second dual display panel B includes an array substrate 10, and the array substrate 10 includes a thin film transistor 200 having a bottom gate structure. The array substrate 10 includes a substrate 11, a light-shielding layer 18, a buffer layer 19, an active layer 14, a gate insulating layer 13, a gate layer 12, a dielectric layer 20, a source-drain layer 16, and a passivation layer 17.

Specifically, the light-shielding layer 18 is provided on the substrate 11, and the material of the light-shielding layer 18 is molybdenum metal. The buffer layer 19 is provided on the light-shielding layer 18 and the substrate 11. The active layer is disposed on the buffer layer 19, and the material of the active layer 14 includes, but is not limited to, Indium Gallium Zinc Oxide (IGZO), Low Temperature Polysilicon (LTPS), a-Si, and the like. The gate electrode layer 12 and the gate insulating layer 13 are sequentially disposed on the active layer 14, and the gate insulating layer 13 is used for insulating and protecting the active layer 14 and the gate electrode layer 12. The gate layer 12 is a metal layer of a molybdenum aluminum molybdenum structure (Mo/Al/Mo). The dielectric layer 20 is disposed on the buffer layer 19, the active layer 14, and the gate layer 12, the dielectric layer 20 has a first via 203 and a second via 204, the first via 203 penetrates from the dielectric layer 20 to the active layer 14, and the second via 204 penetrates from the dielectric layer 20 to the light-shielding layer 18. The source drain layer 16 fills the first via 203 and the second via 204 to form a source, a drain and a capacitor of the source drain layer 16. The passivation layer 17 is disposed on the source/drain layer 16 and the dielectric layer 20, and plays a passivation role in protecting the source/drain layer 16.

In this embodiment, the OLED device 30 is disposed on the passivation layer 17 and is disposed in a groove formed by two adjacent pixel units, wherein the first electrode 101, the light emitting function layer 102 and the second electrode 103 are sequentially disposed on the passivation layer 17, and the first electrode 101 is connected to the drain electrode of the source drain layer 16.

The present embodiment further provides a method for manufacturing a second dual-sided display panel, including the method for manufacturing the OLED device in embodiment 1, which is different from the method for manufacturing the array substrate in embodiment 1.

Specifically, the array substrate preparation step specifically comprises S211) -S220).

S211) providing a substrate. The substrate may be, but is not limited to, a glass substrate, a flexible PI substrate.

S212) forming a light shielding layer on the substrate. Specifically, a molybdenum (Mo) metal layer is sequentially deposited on the substrate, and the metal layer is patterned by exposure, development, etching, stripping (Stripe) and other processes to form the light shielding layer.

S213) forming a buffer layer on the light-shielding layer. Specifically, inorganic material silicon oxide (SiO) is deposited on the shading layer and the upper surface of the substrate_X) And forming the buffer layer.

S214) forming an active layer on the buffer layer, wherein the position of the active layer corresponds to the position of the light shielding layer. Specifically, the IGZO layer is deposited on the upper surface of the buffer layer, but not limited thereto, and the metal layer is patterned by exposure, development, etching, stripping (Stripe), and the like to form the active layer. The material of the active layer includes, but is not limited to, Indium Gallium Zinc Oxide (IGZO), Low Temperature Polysilicon (LTPS), a-Si, etc.

S215) forming a gate insulating layer on the active layer. Specifically, an inorganic material silicon oxide (SiO) is deposited on the upper surface of the active layer_X) And forming the gate insulating layer. The gate insulating layer plays an insulating protection role for the active layer.

S216) forming a gate layer on the gate insulating layer. Specifically, a metal layer with a molybdenum-aluminum-molybdenum (Mo/Al/Mo) structure is deposited on the upper surface of the gate insulating layer, and the metal layer is patterned by exposure, development, etching, stripping (Stripe) and other processes to form the gate layer.

S217) forming a dielectric layer on the gate layer, the active layer and the buffer layer. Specifically, inorganic material silicon oxide (SiO) is deposited on the upper surfaces of the gate layer, the active layer and the buffer layer_X) And forming the dielectric layer.

S218) performing hole digging treatment on the dielectric layer to form a first via hole and a second via hole, wherein the first via hole penetrates from the dielectric layer to the active layer, and the second via hole penetrates from the dielectric layer to the shading layer.

S219) forming a source drain layer on the dielectric layer, and filling the first via hole and the second via hole to form a source, a drain, and a capacitor of the source drain layer.

S220) forming a passivation layer on the dielectric layer, wherein the passivation layer is provided with a passivation layer through hole.

After the array substrate is prepared, preparing an OLED device and a pixel defining layer on the array substrate, wherein a first electrode of the OLED device covers the passivation layer and is connected to a drain electrode of the source drain layer through the passivation layer through hole. For the preparation of the OLED device, please refer to example 1.

The embodiment provides a second double-sided display panel and a preparation method thereof, and the preparation method of the second double-sided display panel comprises a preparation method of an OLED device. The OLED device is of an inverted structure, so that light can be emitted from the bottom surface and the top surface of the panel on two sides, and the effect of displaying on two sides of one screen is achieved. The first electrode of the QLED device is connected to a drain lead of the thin film transistor, when the current is conducted, the voltage Drop (IR Drop) generated by the first electrode resistor only affects the drain voltage Vdd, but the drain voltage Vdd is in a saturation region of the electrical property of the driving TFT (n-type); and Vds is the input voltage of the Data line (Data), usually a fixed value, and Vss is the source voltage, so that the influence of Vdd change on the gate-source voltage is small, namely, the influence of Vdd change on the drain current is small, the brightness at different positions in the panel can be represented uniformly, and the problem of non-uniform brightness generated by panel voltage Drop (IR Drop) can be effectively solved, so that the double-sided display panel has the effect of high color gamut.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The OLED device, the preparation method thereof, and the double-sided display panel provided in the embodiments of the present application are described in detail above, and specific examples are applied herein to explain the principle and the implementation manner of the present application, and the description of the embodiments above is only used to help understanding the technical scheme and the core concept of the present application; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. An OLED device, comprising:

the first electrode and the second electrode are transparent or semitransparent electrodes;

the metal structure is arranged between the first electrode and the second electrode and covers the first electrode;

and the electron injection layer is arranged between the metal structure and the second electrode and covers the metal structure.

2. The OLED device of claim 1,

the metal structure is a metal nanowire with a thickness of

3. The OLED device of claim 1,

the metal structure is a conductive metal layer and is a single-layer structure or a multi-layer structure, the single-layer structure or the multi-layer structure comprises at least one of silver, aluminum, platinum, copper, molybdenum and titanium, and the thickness of the single-layer structure or the multi-layer structure is 1.8-2.2 nm.

4. The OLED device of claim 1, further comprising:

the quantum dot light-emitting layer is arranged on the electron injection layer;

the hole transport layer is arranged on the quantum dot light-emitting layer; and

and the hole injection layer is arranged on the hole transport layer.

5. The OLED device of claim 4,

the thickness of the electron injection layer is 9.8-10.5 nm;

the thickness of the quantum dot light-emitting layer is 38-43 nm;

the thickness of the hole transport layer is 18-25 nm;

the thickness of the hole injection layer is 12-18 nm.

6. The preparation method of the OLED device is characterized by comprising the following steps of:

forming a first electrode;

forming a metal structure on the first electrode;

forming an electron injection layer on the metal structure; and

and forming a second electrode above the electron injection layer.

7. The method of manufacturing an OLED device according to claim 6,

in the step of forming a metal structure on the first electrode,

forming the metal structure on the first electrode in an ink-jet printing mode, wherein the metal structure is a metal nanowire; alternatively, the first and second electrodes may be,

and forming the metal structure on the first electrode in an evaporation mode, wherein the metal structure is a conductive metal layer and is made of at least one of silver, aluminum, platinum, copper, molybdenum and titanium.

8. The method of manufacturing an OLED device according to claim 6,

after the step of forming an electron injection layer on the metal structure, the method further comprises the following steps:

forming a quantum dot light-emitting layer on the electron injection layer;

forming a hole transport layer on the quantum dot light emitting layer; and

forming a hole injection layer on the hole transport layer;

wherein the second electrode is formed on the hole injection layer.

9. A dual-sided display panel comprising the OLED device of any one of claims 1-4.

10. The dual sided display panel of claim 9, further comprising:

the array substrate comprises a plurality of thin film transistors, the thin film transistors are of top gate structures or bottom gate structures, and the OLED devices are arranged on the array substrate; and

the pixel definition layer is arranged on the array substrate and is provided with a plurality of pixel units arranged at intervals, two adjacent pixel units form a groove, and the OLED device is arranged in the groove.