CN108598110B

CN108598110B - OLED device

Info

Publication number: CN108598110B
Application number: CN201810368599.2A
Authority: CN
Inventors: 邴一飞
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2018-04-23
Filing date: 2018-04-23
Publication date: 2020-11-24
Anticipated expiration: 2038-04-23
Also published as: WO2019205752A1; CN108598110A

Abstract

The invention provides an OLED device, which comprises a substrate, an anode layer, a pixel defining layer and an organic functional layer, wherein the pixel defining layer consists of a hydrophobic dam layer and a hydrophilic dam layer, a plurality of stepped platforms are arranged on the hydrophobic dam layer, the hydrophobic dam layer defines a pixel opening area with a wide top and a narrow bottom above the anode layer through the stepped platforms, and the hydrophilic dam layer is arranged on the upper surface of each stepped platform, so that when the organic functional layer is manufactured by adopting an ink-jet printing process, the film surface of an ink material forming the organic functional layer in the pixel opening area can be flat, the organic functional layer can be uniformly formed in the pixel opening area, the light-emitting uniformity of the OLED device is effectively improved, and the microcavity effect of a top-emission type OLED device can be accurately controlled.

Description

OLED device

Technical Field

The invention relates to the technical field of display, in particular to an OLED device with an organic functional layer uniformly formed into a film.

Background

Organic Light Emitting Diodes (OLEDs) belong to a novel current type semiconductor Light Emitting device, and belong to an autonomous Light Emitting technology by controlling injection of current carriers of the device and compositely exciting Light Emitting display of Organic materials. Compared with a passive light emitting Liquid Crystal Display (LCD), the OLED Display capable of emitting light autonomously has the advantages of fast response speed, high contrast, wide viewing angle, and the like, is easy to realize flexible Display, is generally seen in the industry, and is considered in the industry to be a mainstream product of the next generation Display technology.

The OLED has an anode, an organic functional layer, and a cathode sequentially formed on a substrate. The organic functional Layer generally includes a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an emission Layer (EML), an Electron Injection Layer (EIL), and an Electron Transport Layer (ETL). At present, each functional material layer and the cathode metal layer film of the OLED are all prepared by a vacuum thermal evaporation process, that is, an organic small molecular material is heated in a vacuum cavity to be sublimated or melted and gasified into material vapor, and the material vapor is deposited on a glass substrate through an opening of a metal mask. But the preparation cost is high due to vacuum thermal evaporation, which limits the wide-range commercialization of the OLED display.

The Ink-jet Printing (IJP) has the advantages of high material utilization rate and the like, is a key technology for solving the problem of cost of a large-size OLED display, and compared with the traditional vacuum evaporation process, the IJP technology has the advantages of material saving, mild process conditions, more uniform film forming and the like in the preparation of a light-emitting layer of an OLED device, so that the IJP technology has higher application potential. The method is to drop a functional material ink into a predetermined pixel region using a plurality of nozzles, and then obtain a desired pattern film by drying.

On a substrate applied to the IJP film forming process, a groove is usually formed to confine ink, so that ink droplets dissolved with the OLED material can flow into the groove, and after drying and baking, the ink shrinks to form a thin film within the range limited by the groove. Referring to fig. 1, the groove 450 is defined by Bank layers 400 on both sides of the anode layer 210 on the glass substrate 100 and the anode layer 210, and the organic functional layer 220 is defined by the Bank layers 400 on the anode layer 210.

However, since the hydrophilicity of different inks is different, as shown in fig. 2, for the ink with good hydrophilicity, the slope of the inner surface of the bank layer 400 is higher, and a concave film layer 220' is formed. As shown in fig. 3, for the ink having poor hydrophilicity, the convex film layer 220 ″ may be formed in the groove 450 of the dam layer 400. The unevenness of the organic functional layer not only affects the uniformity of light emission of the OLED device, but also severely affects the microcavity effect of the Top emission (Top emission) type OLED device, so that the quality of the OLED device is reduced.

Disclosure of Invention

The invention aims to provide an OLED device, which can realize the uniform film formation of an organic functional layer in a pixel opening area, effectively improve the light-emitting uniformity of the OLED device and accurately control the microcavity effect of a top-emitting OLED device.

In order to achieve the above object, the present invention provides an OLED device, including a substrate, an anode layer disposed on the substrate, a pixel defining layer disposed on the substrate and the anode layer, and an organic functional layer disposed on the anode layer;

the pixel defining layer comprises a hydrophobic dam layer, a plurality of step-shaped step platforms are arranged on the hydrophobic dam layer, a pixel opening area with a wide upper part and a narrow lower part is defined on the anode layer by the hydrophobic dam layer through the step-shaped step platforms, each step platform is provided with an upper surface and a side surface connected with the upper surface, and a hydrophilic dam layer is arranged on the upper surface of each step platform;

the organic functional layer is formed in the pixel opening area by means of inkjet printing.

The hydrophobic dam layer is provided with three step platforms, namely a first step platform, a second step platform and a third step platform which are arranged from bottom to top.

The organic functional layer comprises a hole injection layer, a hole transport layer and a light emitting layer which are sequentially arranged on the anode layer from bottom to top;

the first step platform, the second step platform and the third step platform are respectively arranged corresponding to the hole injection layer, the hole transmission layer and the light emitting layer.

The upper surface of the first step terrace is 1 to 20nm lower in height than the upper surface of the hole injection layer, the upper surface of the second step terrace is 1 to 20nm lower in height than the upper surface of the hole transport layer, and the upper surface of the third step terrace is 1 to 20nm lower in height than the upper surface of the light emitting layer.

The thickness of the hydrophilic dam layer is 1-50 nm.

The anode layer and the hydrophilic dam layer are both made of hydrophilic materials, and the hydrophobic dam layer is made of hydrophobic materials.

The organic functional layer is made of ink materials in an ink-jet printing mode;

the contact angle between the hydrophobic dam layer and the ink material forming the organic functional layer is 20-80 degrees;

the contact angles between the anode layer and the hydrophilic dam layer and the ink material forming the organic functional layer are 0-10 degrees.

The OLED device is a top-emission OLED device and further comprises a cathode layer arranged on the organic functional layer and the pixel defining layer.

The organic functional layer also comprises an electron transport layer and an electron injection layer which are sequentially arranged on the light-emitting layer from bottom to top.

The substrate base plate is a glass base plate.

The invention has the beneficial effects that: the invention provides an OLED device, which comprises a substrate, an anode layer, a pixel definition layer and an organic functional layer, the pixel defining layer consists of a hydrophobic dam layer and a hydrophilic dam layer, a plurality of step platforms in a step shape are arranged on the hydrophobic dam layer, the hydrophobic dam layer defines a pixel opening area with a wide upper part and a narrow lower part above the anode layer through the plurality of step platforms, the hydrophilic dam layer is arranged on the upper surface of each step platform, therefore, when the ink-jet printing process is adopted to manufacture the organic functional layer, the ink material forming the organic functional layer can better enter the pixel opening area, the film surface of the ink material in the pixel opening area is smooth, and further, the organic functional layer can be uniformly formed in the pixel opening area, the light-emitting uniformity of the OLED device is effectively improved, and the microcavity effect of the top-emitting OLED device can be accurately controlled.

For a better understanding of the nature and technical aspects of the present invention, reference should be made to the following detailed description of the invention, taken in conjunction with the accompanying drawings, which are provided for purposes of illustration and description and are not intended to limit the invention.

Drawings

The technical solution and other advantages of the present invention will become apparent from the following detailed description of specific embodiments of the present invention, which is to be read in connection with the accompanying drawings.

In the drawings, there is shown in the drawings,

FIG. 1 is a schematic structural diagram of a conventional OLED device;

FIG. 2 is a schematic view of a hydrophilic ink forming a concave film layer in a groove;

FIG. 3 is a schematic view of a hydrophobic ink forming a convex membrane layer within a groove;

fig. 4 is a schematic structural diagram of an OLED device of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Referring to fig. 4, the present invention provides an OLED device, which includes a substrate 10, an anode layer 21 disposed on the substrate 10, a pixel defining layer 40 disposed on the substrate 10 and the anode layer 21, an organic functional layer 22 disposed on the anode layer 21, and a cathode layer (not shown) disposed on the organic functional layer 22 and the pixel defining layer 40;

the pixel defining layer 40 includes a hydrophobic dam layer 41, a plurality of step platforms 411 are disposed on the hydrophobic dam layer 41, the hydrophobic dam layer 41 defines a pixel opening area 45 with a wide top and a narrow bottom above the anode layer 21 through the step platforms 411, each step platform 411 has an upper surface and a side surface connected with the upper surface, and a hydrophilic dam layer 42 is disposed on the upper surface of each step platform 411.

The height of the hydrophobic dam layer 41 of the pixel defining layer 40 is higher than that of the organic functional layer 22, and the organic functional layer 22 is formed in the pixel opening area 45 by ink-jet printing, that is, the pixel defining layer 40 encloses the organic functional layer 22 above the anode layer 21.

The pixel defining layer 40 of the OLED device of the present invention is composed of a hydrophobic dam layer 41 and a hydrophilic dam layer 42, the hydrophobic dam layer 41 is provided with a plurality of step terraces 411 in a step shape, the hydrophobic dam layer 41 defines a pixel opening region 45 with a wide top and a narrow bottom above the anode layer 21 through the step terraces 411, the hydrophilic bank layer 42 is provided on the upper surface of each step terrace, so when the organic functional layer 22 of the OLED device is manufactured by using the inkjet printing process, the ink material used to form the organic functional layer 22 can be better allowed to enter the pixel opening areas 45, and the film surface of the ink material in the pixel opening area 45 is flat, so that the organic functional layer 22 can be uniformly formed in the pixel opening area 45, therefore, the luminous uniformity of the OLED device is effectively improved, and the microcavity effect of the top-emitting OLED device can be further accurately controlled.

Specifically, the hydrophobic embankment layer 41 has three step platforms 411, which are respectively a first step platform, a second step platform and a third step platform from bottom to top.

Specifically, the organic functional layer 22 includes a hole injection layer 221, a hole transport layer 222, a light emitting layer 223, an electron transport layer, and an electron injection layer (not shown) which are sequentially disposed on the anode layer 21 from bottom to top; the first step terrace, the second step terrace, and the third step terrace of the hydrophobic bank layer 41 are respectively disposed corresponding to the hole injection layer 221, the hole transport layer 222, and the light emitting layer 223.

Specifically, the thickness of the hydrophilic bank layer 42 is 1 to 50 nm.

Preferably, the upper surface of the first step terrace is lower than the upper surface of the hole injection layer 221 by 1nm in height, the upper surface of the second step terrace is lower than the upper surface of the hole transport layer 222 by 1nm in height, and the upper surface of the third step terrace is lower than the upper surface of the light emitting layer 223 by 1nm in height.

Specifically, the anode layer 21 and the hydrophilic bank layer 42 are both made of a hydrophilic material, and the hydrophobic bank layer 41 is made of a hydrophobic material.

Specifically, the contact angle of the hydrophobic bank layer 41 with the ink material forming the organic functional layer 22 is 20 to 80 °.

Specifically, the anode layer 21 and the hydrophilic bank layer 42 have a contact angle of 0 to 10 ° with the ink material forming the organic functional layer 22.

Specifically, the substrate 10 is a glass substrate.

Specifically, the OLED device is a top-emission type OLED device.

In summary, the present invention provides an OLED device including a substrate, an anode layer, a pixel defining layer and an organic functional layer, the pixel defining layer consists of a hydrophobic dam layer and a hydrophilic dam layer, a plurality of step platforms in a step shape are arranged on the hydrophobic dam layer, the hydrophobic dam layer defines a pixel opening area with a wide upper part and a narrow lower part above the anode layer through the plurality of step platforms, the hydrophilic dam layer is arranged on the upper surface of each step platform, therefore, when the ink-jet printing process is adopted to manufacture the organic functional layer, the ink material forming the organic functional layer can better enter the pixel opening area, the film surface of the ink material in the pixel opening area is smooth, and further, the organic functional layer can be uniformly formed in the pixel opening area, the light-emitting uniformity of the OLED device is effectively improved, and the microcavity effect of the top-emitting OLED device can be accurately controlled.

As described above, it will be apparent to those skilled in the art that other various changes and modifications may be made based on the technical solution and concept of the present invention, and all such changes and modifications are intended to fall within the scope of the appended claims.

Claims

1. An OLED device is characterized by comprising a substrate base plate (10), an anode layer (21) arranged on the substrate base plate (10), a pixel defining layer (40) arranged on the substrate base plate (10) and the anode layer (21), and an organic functional layer (22) arranged on the anode layer (21);

the pixel defining layer (40) comprises a hydrophobic dam layer (41), a plurality of step platforms (411) in a step shape are arranged on the hydrophobic dam layer (41), the hydrophobic dam layer (41) is provided with an upper surface and a side surface connected with the upper surface, the step platforms (411) are all arranged on the side surface of the hydrophobic dam layer (41), the hydrophobic dam layer (41) defines a pixel opening area (45) with a wide upper part and a narrow lower part above the anode layer (21) through the step platforms (411), each step platform (411) is provided with an upper surface and a side surface connected with the upper surface, a hydrophilic dam layer (42) is arranged on the upper surface of each step platform (411), the side surface of each step platform (411) belongs to the hydrophobic dam layer (41) and has hydrophobicity, the hydrophilic layer (42) arranged on the upper surface of each step platform (411) is directly contacted with the organic functional layer (22), the side surface of each step platform (411) is in contact with the organic functional layer (22);

the organic functional layer (22) is formed in the pixel opening region (45) by means of ink jet printing.

2. The OLED device according to claim 1, wherein the hydrophobic dam layer (41) has three step terraces (411), a first step terrace, a second step terrace, and a third step terrace, respectively, disposed from bottom to top.

3. The OLED device according to claim 2, wherein the organic functional layer (22) includes a hole injection layer (221), a hole transport layer (222), and a light emitting layer (223) sequentially disposed from bottom to top on the anode layer (21);

the first step terrace, the second step terrace and the third step terrace are respectively arranged corresponding to the hole injection layer (221), the hole transport layer (222) and the light emitting layer (223).

4. The OLED device of claim 3, wherein the upper surface of the first step plateau is 1-20nm lower in height than the upper surface of the hole injection layer (221), the upper surface of the second step plateau is 1-20nm lower in height than the upper surface of the hole transport layer (222), and the upper surface of the third step plateau is 1-20nm lower in height than the upper surface of the light emitting layer (223).

5. The OLED device of claim 1, wherein the thickness of the hydrophilic bank layer (42) is 1-50 nm.

6. The OLED device according to claim 1, wherein the anode layer (21) and the hydrophilic dam layer (42) are both made of a hydrophilic material, and the hydrophobic dam layer (41) is made of a hydrophobic material.

7. The OLED device according to claim 1, characterized in that the organic functional layer (22) is made of an ink material by means of inkjet printing;

the contact angle between the hydrophobic dam layer (41) and an ink material forming the organic functional layer (22) is 20-80 degrees;

the anode layer (21) and the hydrophilic bank layer (42) have a contact angle of 0 to 10 DEG with an ink material forming the organic functional layer (22).

8. The OLED device of claim 1, being a top-emitting OLED device, further comprising a cathode layer disposed over the organic functional layer (22) and the pixel defining layer (40).

9. The OLED device according to claim 3, wherein the organic functional layer (22) further includes an electron transport layer and an electron injection layer provided on the light emitting layer (223) in this order from bottom to top.

10. The OLED device of claim 1, wherein the substrate base plate (10) is a glass base plate.