CN214477454U

CN214477454U - OLED display structure and display screen

Info

Publication number: CN214477454U
Application number: CN202120163109.2U
Authority: CN
Inventors: 舒鹏; 陈龙
Original assignee: Shenzhen Royole Display Technology Co ltd
Current assignee: Shenzhen Royole Display Technology Co ltd
Priority date: 2021-01-21
Filing date: 2021-01-21
Publication date: 2021-10-22
Anticipated expiration: 2031-01-21

Abstract

The utility model provides an OLED display structure, which comprises a glass substrate, an indium tin oxide layer, a light emitting structure layer, an electrode layer, a metal oxide layer, a transparent conducting layer and a capping layer which are sequentially stacked; the transparent conducting layer is an indium tin oxide layer or an indium zinc oxide layer. And a metal oxide layer is formed on the surface of the electrode layer, and the metal oxide layer can ensure the light transmittance of the electrode layer and also can play a role in protecting the electrode layer. The transparent conducting layer with high light transmittance and high conductivity is arranged outside the metal oxide layer, so that the resistance in the electrode layer surface can be reduced, and the pressure drop (IR-drop) phenomenon is reduced, so that the imaging of the OLED display structure is clearer and more uniform. The utility model also provides a OLED display screen, this display screen includes above-mentioned OLED display structure.

Description

OLED display structure and display screen

Technical Field

The utility model relates to a liquid crystal display field especially indicates a OLED display structure and display screen.

Background

At present, in a top-emitting device of an OLED display screen, a cathode usually adopts a semitransparent and semi-reflective structure layer, and most of the cathode materials are made of an alloy of metal magnesium (Mg) and metal silver (Ag). In order to ensure a certain transmittance of the Cathode material, the thickness of the Cathode layer (Cathode) is extremely thin, generally 10 to 20 nm. The electrode layer is thinner, so that the in-plane resistance is larger, and the voltage drop on the circuit is reduced faster along with the increasing distance of the lap joint area, so that the in-plane brightness is not uniform, which is the common IR-drop phenomenon at ordinary times.

In the prior art, the conductivity is generally increased by increasing the thickness of the cathode or reducing the proportion of metal magnesium, but the light transmittance is reduced by increasing the thickness of the electrode layer, and the electron injection is not facilitated by reducing the proportion of metal magnesium, so that the voltage of the device is increased.

Therefore, a display structure and a display screen capable of reducing the voltage drop in the display screen while ensuring the light transmittance are urgently needed.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve is: the display structure and the display screen can reduce the pressure drop in the display screen under the condition of ensuring the light transmittance.

In order to solve the technical problem, the utility model discloses a technical scheme be: the OLED display structure comprises a glass substrate, an indium tin oxide layer, a light emitting structure layer, an electrode layer, a metal oxide layer, a transparent conductive layer and a capping layer which are sequentially stacked;

the transparent conducting layer is an indium tin oxide layer or an indium zinc oxide layer.

Further, the light emitting structure layer comprises an electron transport layer, a hole blocking layer, a light emitting layer, a hole transport layer and a hole injection layer which are sequentially stacked.

Furthermore, the electrode layer is a gold layer, a silver layer or an aluminum layer, and the metal oxide layer is formed by partially oxidizing one side of the electrode layer, which is far away from the glass substrate.

Further, the light emitting structure layer comprises a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer and an electron transport layer which are sequentially stacked.

Further, the electrode layer is an alloy layer of metal magnesium and metal silver.

Further, the metal oxide layer is a calcium oxide layer, a lithium oxide layer, or an aluminum oxide layer.

Furthermore, a polytetrafluoroethylene layer is further arranged on one side, away from the glass substrate, of the sealing layer.

Meanwhile, the utility model also provides a OLED display screen, this display screen includes above-mentioned arbitrary OLED display structure.

The beneficial effects of the utility model reside in that: and a metal oxide layer is formed on the surface of the electrode layer, and the metal oxide layer can ensure the light transmittance of the electrode layer and also can play a role in protecting the electrode layer. The transparent conducting layer with high light transmittance and high conductivity is arranged outside the metal oxide layer, so that the resistance in the electrode layer surface can be reduced, and the pressure drop (IR-drop) phenomenon is reduced, so that the imaging of the OLED display structure is clearer and more uniform.

Drawings

The specific structure of the present invention is detailed below with reference to the accompanying drawings:

FIG. 1 is a schematic cross-sectional view of a prior art OLED display structure;

fig. 2 is a schematic cross-sectional view of a first embodiment of an OLED display structure according to the present invention;

fig. 3 is a schematic cross-sectional view of a second embodiment of the OLED display structure of the present invention.

In the figure: the light-emitting diode comprises a glass substrate 1, an indium tin oxide layer 2, a light-emitting structure layer 3, an electron transport layer 31, a hole blocking layer 32, a light-emitting layer 33, a hole transport layer 34, a hole injection layer 35, an electrode layer 4, a metal oxide layer 5, a transparent conducting layer 6, a capping layer 7 and a polytetrafluoroethylene layer 8.

Detailed Description

In order to explain technical contents, structural features, and objects and effects of the present invention in detail, the following description is given in conjunction with the embodiments and the accompanying drawings.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

The utility model provides an OLED display structure, including glass substrate 1, indium tin oxide layer 2, light emitting structure layer 3, electrode layer 4, metal oxide layer 5, transparent conducting layer 6 and capping layer 7, please refer to fig. 1 to 3.

Specifically, the glass substrate 1, the indium tin oxide layer 2, the light emitting structure layer 3, the electrode layer 4, the metal oxide layer 5, the transparent conductive layer 6 and the capping layer 7 are sequentially laminated and connected together. The metal oxide layer 5 is formed by electrifying and oxidizing a metal layer or oxidizing the metal layer in a plasma state, and the metal oxide layer 5 is a dense metal oxide layer and can play a role in protecting the electrode layer 4.

Transparent conducting layer 6 has high light transmittance and high conductivity, when transparent conducting layer 6 sets up in the metal oxide layer 5 outside, still as auxiliary electrode when not influencing the light transmittance, can greatly reduce the resistance in the electrode layer 4 face, reduces pressure drop (IR-drop) phenomenon for OLED display structure formation of image is more clear even.

In the present invention, the transparent conductive layer 6 may be an indium tin oxide layer or an indium zinc oxide layer. The indium tin oxide layer 2 and the electrode layer 4 are the cathode or anode of the OLED display structure.

An OLED (organic light emitting diode) is similar to an LED in light emitting principle, but is different from an LED in that an inorganic semiconductor is used as a light emitting material, and the light emitting material is an organic material. According to the difference of organic materials, the organic materials can be further divided into small molecular organic materials and large molecular organic materials. Wherein, the macromolecular organic material is generally formed into a film by adopting an ink-jet printing mode, and the micromolecular organic material is generally deposited into a film by adopting an evaporation plating mode.

The final OLED device is formed by stacking an Anode (Anode), a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Emission Layer (EML), an Electron Transport Layer (ETL), and a Cathode (Cathode). More generally, a Hole Blocking Layer (HBL), an Electron Blocking Layer (EBL), and a Capping Layer (CPL), and the like.

The most fundamental condition for the choice of cathode layer material is the ease of electron injection. Therefore, it is desirable to select a low power material for the cathode of the OLED. The cathode is made of a material with a low work function, so that the electron injection efficiency can be improved, the Joule heat generated during the working of the OLED can be reduced, and the service life of the device is prolonged.

For the anode, it is required to have a high work function (work function) because holes need to be injected into the OLED. Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), gold (Au), platinum (Pt), and the like are generally used as the anode material.

The material of the light-emitting layer needs to have the characteristics of strong fluorescence in a solid state, good electron/hole transport performance, good thermal stability and chemical stability, high quantum efficiency and capability of vacuum evaporation. Since both electrons and holes need to be transported in the light-emitting layer, it is ensured that sufficient electrons and holes can recombine to emit light.

The requirement of the hole injection layer is to lower the barrier for electron injection from the cathode, enabling efficient electron injection from the cathode into the OLED device. The barrier for hole injection from the anode is reduced, allowing holes to be efficiently injected from the anode into the OLED device.

When electrons and holes migrate into the light-emitting layer, the electrons may continue to migrate toward the anode and the holes may continue to migrate toward the cathode due to the presence of the electric field, resulting in a decrease in electron/hole concentration and a decrease in light-emitting efficiency in the light-emitting region. The electron/hole blocking layer can form a migration barrier for electrons/holes due to the special energy level structure of the electron/hole blocking layer, and further migration of the electrons/holes is prevented.

When light waves (electromagnetic waves) are incident on a metal and dielectric interface, free electrons on the metal surface generate collective oscillation, the electromagnetic waves and the free electrons on the metal surface are coupled to form near-field electromagnetic waves which propagate along the metal surface, resonance is generated if the oscillation frequency of the electrons is consistent with the frequency of the incident light waves, and the energy of the electromagnetic fields is effectively converted into collective vibration energy of the free electrons on the metal surface in a resonance state, so that a special electromagnetic mode is formed: the electromagnetic field is confined to a small range of the metal surface and enhanced, and this phenomenon is called a surface plasmon phenomenon. When the light emitting layer emits light and propagates outwards, a surface plasmon effect exists near a metal/medium interface, the effect causes the efficiency of emergent light to be reduced, and the capping layer can suppress the effect. On the other hand, between the upper and lower metal electrodes, the OLED also forms a Fabry-Perot optical resonant cavity. The adjustment of the light-emitting efficiency and the selection of the spectrum can be achieved by adjusting the capping layer.

In some embodiments, a teflon layer 8 may be further deposited or inkjet-printed outside the capping layer, and the teflon layer 8 may protect the OLED material from being corroded by external moisture and oxygen, thereby functioning as an encapsulating material.

The utility model provides an among the OLED display structure, the surface of electrode layer forms the metal oxide layer, and the luminousness of electrode layer can be guaranteed on the metal oxide layer, can also play the effect of protection electrode layer. The transparent conducting layer with high light transmittance and high conductivity is arranged outside the metal oxide layer, so that the resistance in the electrode layer surface can be reduced, and the pressure drop (IR-drop) phenomenon is reduced, so that the imaging of the OLED display structure is clearer and more uniform.

Example one

The utility model provides an among the first OLED display structure, light emitting structure layer 3 includes electron transport layer 31, hole barrier layer 32, luminescent layer 33, hole transport layer 34 and hole injection layer 35.

Note that the light emitting structure layer 3 is stacked in an inverted form, that is, the indium tin oxide layer 2, the electron transport layer 31, the hole blocking layer 32, the light emitting layer 33, the hole transport layer 34, the hole injection layer 35, and the electrode layer 4 are sequentially stacked.

Preferably, the electrode layer 4 is a gold layer, a silver layer or an aluminum layer, and the metal oxide layer 5 can be formed by directly oxidizing the part of the electrode layer 4 away from one side of the glass substrate 1, so that the step of evaporating and plating the metal layer separately and then oxidizing can be saved, and the production cost is reduced. The metal oxide layer 5 can protect the electrode layer 4 and also has high light transmittance and electrical conductivity.

And a transparent conducting layer 6 with high light transmittance and high conductivity is arranged outside the metal oxide layer 5, so that the resistance of the electrode layer 4 in a display screen surface can be reduced, and the phenomenon of voltage drop (IR-drop) is reduced, so that the imaging of the OLED display structure is clearer and more uniform.

Example two

The utility model provides an among the second OLED display structure, light emitting structure layer 3 includes electron transport layer 31, hole barrier layer 32, luminescent layer 33, hole transport layer 34 and hole injection layer 35.

Note that the light emitting structure layer 3 is stacked in a conventional manner, that is, the indium tin oxide layer 2, the hole injection layer 35, the hole transport layer 34, the light emitting layer 33, the hole blocking layer 32, the electron transport layer 31, and the electrode layer 4 are sequentially stacked.

Preferably, the electrode layer 4 is an alloy layer of metallic magnesium and metallic silver. The alloy layer is formed by evaporating active low work function metal and stable high work function metal to improve quantum efficiency and stability of the device.

The metal oxide layer 5 is formed by oxidizing a metal layer deposited on the electrode layer 4 on a side away from the glass substrate 1, and preferably, the metal layer may be a calcium layer, a lithium layer, an aluminum layer, or the like.

EXAMPLE III

The utility model also provides a OLED display screen, this OLED display screen include foretell OLED display structure, and electrode layer 4's surface forms metal oxide layer 5, and metal oxide layer 5 can guarantee electrode layer 4's luminousness, can also play protection electrode layer 4's effect. And a transparent conducting layer 6 with high light transmittance and high conductivity is arranged outside the metal oxide layer 5, so that the resistance of the electrode layer 4 in the display screen surface can be reduced, and the voltage drop (IR-drop) phenomenon is reduced, so that the imaging of the OLED display screen is clearer and more uniform.

The above only is the embodiment of the present invention, not limiting the patent scope of the present invention, all the equivalent structures or equivalent processes that are used in the specification and the attached drawings or directly or indirectly applied to other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An OLED display structure, characterized in that: the LED display panel comprises a glass substrate, an indium tin oxide layer, a light emitting structure layer, an electrode layer, a metal oxide layer, a transparent conducting layer and a capping layer which are sequentially stacked;

2. The OLED display structure of claim 1, wherein: the light emitting structure layer comprises an electron transport layer, a hole blocking layer, a light emitting layer, a hole transport layer and a hole injection layer which are sequentially stacked.

3. The OLED display structure of claim 2, wherein: the electrode layer is a gold layer, a silver layer or an aluminum layer, and the metal oxide layer is formed by partially oxidizing one side of the electrode layer, which is far away from the glass substrate.

4. The OLED display structure of claim 1, wherein: the light emitting structure layer comprises a hole injection layer, a hole transmission layer, a light emitting layer, a hole blocking layer and an electron transmission layer which are sequentially stacked.

5. The OLED display structure of claim 4, wherein: the electrode layer is an alloy layer of metal magnesium and metal silver.

6. The OLED display structure of claim 5, wherein: the metal oxide layer is a calcium oxide layer, a lithium oxide layer or an aluminum oxide layer.

7. The OLED display structure of claim 1, wherein: and a polytetrafluoroethylene layer is further arranged on one side of the sealing cover layer, which is far away from the glass substrate.

8. An OLED display screen, its characterized in that: comprising an OLED display structure according to any one of claims 1-7.