CN107799673A - A kind of organic electroluminescence device and preparation method, display device - Google Patents

Abstract

The invention provides a kind of organic electroluminescence device and preparation method, display device, to suppress coffee toroidal effect, the performance using the OLED prepared by inkjet printing mode is influenceed so as to reduce due to coffee toroidal effect, a kind of preparation method of organic electroluminescence device provided by the invention, including：Anode layer is formed on underlay substrate；The anode layer is pre-processed so that be used for surface energy of the surface energy more than the external zones for surrounding the center for forming the center in the region of organic function layer in the anode layer；Organic function layer is formed on the anode layer for having been subjected to pretreatment using inkjet printing mode；Cathode layer is formed on the underlay substrate formed with the organic function layer.

Description

An organic electroluminescence device, its preparation method, and a display device

technical field

The invention relates to the field of display technology, in particular to an organic electroluminescent device, a preparation method and a display device.

Background technique

Organic electroluminescent devices (OLEDs) have the advantages of self-luminescence, high luminous efficiency, low power consumption, fast response, wide viewing angle, high brightness, bright colors, thin and light, etc., and are considered to have broad application prospects in the lighting and display device market , has been highly valued by the international optoelectronic academic and industrial circles.

At present, the film-forming methods of organic functional layers of OLED mainly include evaporation process and solution process. , low product cost, and can achieve large size, is considered to be an important way to achieve mass production of large size OLED.

However, there is a thorny problem in inkjet printing at present: after the ink droplets dry, it is easy to form an uneven film with thick edges and thin middle, that is, the coffee ring effect. The coffee ring effect affects the deposition morphology of the organic functional layer, and the deposition morphology of the organic functional layer directly affects the performance of the prepared OLED device (for example, causing uneven brightness of the OLED device).

Contents of the invention

The embodiments of the present invention provide an organic electroluminescent device, a preparation method, and a display device, which are used to suppress the coffee ring effect, thereby reducing the influence of the coffee ring effect on the performance of OLED devices prepared by inkjet printing.

A method for preparing an organic electroluminescent device provided in an embodiment of the present invention includes:

forming an anode layer on the base substrate;

Pretreating the anode layer such that the surface energy of a central region of the region for forming an organic functional layer in the anode layer is greater than the surface energy of a peripheral region surrounding the central region;

forming an organic functional layer on the pretreated anode layer by inkjet printing;

A cathode layer is formed on the base substrate on which the organic functional layer is formed.

By this method, before the organic functional layer is formed on the anode layer by inkjet printing, the anode layer is pretreated so that the surface energy of the central area of the area used to form the organic functional layer in the anode layer is greater than that surrounding the center. The surface energy of the peripheral area of the region, so that the coffee ring effect can be suppressed when the organic functional layer is formed by inkjet printing, so that the formed organic functional layer is relatively uniform, thereby reducing the influence of the coffee ring effect on the inkjet printing method. Properties of the fabricated OLED devices.

Preferably, the anode layer is pretreated so that the surface energy of the central region of the region used to form the organic functional layer in the anode layer is greater than the surface energy of the peripheral region surrounding the central region, specifically including:

dividing the region for forming the organic functional layer in the anode layer into a central region and a peripheral region surrounding the central region;

A self-assembled monolayer is formed on the surface of the anode layer in the peripheral region, and/or hydroxyl groups are formed on the surface of the anode layer in the central region, so that the surface energy of the anode layer in the central region is greater than that of the peripheral region The surface energy of the anode layer.

The method forms a self-assembled monomolecular layer on the surface of the anode layer in the peripheral region, and/or forms a hydroxyl group on the surface of the anode layer in the central region, so that the central region of the region used to form the organic functional layer in the anode layer The surface energy is greater than the surface energy of the peripheral area surrounding the central area, so that the coffee ring effect can be suppressed when the organic functional layer is formed by inkjet printing, so that the formed organic functional layer is relatively uniform, thereby reducing the impact due to the coffee ring effect Properties of OLED devices prepared by inkjet printing.

Preferably, the self-assembled monomolecular layer is formed on the surface of the anode layer in the peripheral region, specifically comprising:

coating a photoresist on the anode layer;

Using the first mask to expose the photoresist, and then develop, so that the surface of the anode layer in the peripheral region is exposed, and the surface of the anode layer in the remaining regions is covered with the photoresist;

placing the base substrate formed with the photoresist in an ultraviolet-ozone cleaning machine or an oxygen plasma cleaning machine for atmosphere cleaning, so as to form a layer of hydroxyl groups on the surface of the anode layer in the peripheral region;

The base substrate with hydroxyl groups formed on the surface of the anode layer of the peripheral region is placed in a chamber that has been evacuated and a liquid silane organic matter is placed in the chamber, and the silane organic matter is evaporated in a vacuum and then combined with the The hydroxyl groups on the surface of the anode layer in the peripheral region react chemically to form a self-assembled monolayer on the surface of the anode layer in the peripheral region;

Strip the photoresist from the surface of the anode layer covering the rest of the area.

Preferably, the surface of the anode layer in the peripheral region can be controlled by the type of the silane organic substance and/or the processing time of the base substrate in the chamber where the liquid silane organic substance is placed.

Preferably, the organic silane is octadecyltrichlorosilane or hexamethyldisilazane.

Preferably, the compactness of the self-assembled monolayer is directly proportional to the processing time of the substrate in the chamber containing the liquid silane organic substance.

Preferably, the formation of hydroxyl groups on the surface of the anode layer in the central region specifically includes:

coating a photoresist on the anode layer;

Using a second mask to expose the photoresist, and then develop, so that the surface of the anode layer in the central region is exposed, and the surface of the anode layer in the remaining regions is covered with the photoresist;

The base substrate formed with the photoresist is placed in an ultraviolet-ozone cleaning machine or an oxygen plasma cleaning machine for atmospheric cleaning, so as to form a layer of hydroxyl groups on the surface of the anode layer in the central region.

Preferably, the compactness of the hydroxyl group is directly proportional to the processing time of the base substrate in an ultraviolet-ozone cleaning machine or an oxygen plasma cleaning machine.

An embodiment of the present invention also provides an organic electroluminescent device, which is an organic electroluminescent device prepared by using the method for preparing an organic electroluminescent device provided in any embodiment of the present invention.

Since the organic electroluminescent device provided by the embodiment of the present invention is prepared by the above method for preparing the organic electroluminescent device, and the above method for preparing the organic electroluminescent device is formed by forming a self-assembled monomolecular layer on the surface of the anode layer in the peripheral region , and/or form hydroxyl groups on the surface of the anode layer in the central region, so that the surface energy of the central region of the region used to form the organic functional layer in the anode layer is greater than the surface energy of the peripheral region surrounding the central region, so that when using The coffee ring effect can be suppressed when the organic functional layer is formed by the inkjet printing method, so that the formed organic functional layer is relatively uniform, thereby reducing the influence of the coffee ring effect on the performance of the OLED device prepared by the inkjet printing method.

An embodiment of the present invention also provides a display device, including the organic electroluminescence device provided in any embodiment of the present invention.

Since the display device provided by the embodiment of the present invention adopts the above-mentioned organic electroluminescent device, and the organic electroluminescent device is prepared by the above-mentioned preparation method of the organic electroluminescent device, and the above-mentioned preparation method of the organic electroluminescent device is obtained by The surface of the anode layer forms a self-assembled monolayer, and/or forms a hydroxyl group on the surface of the anode layer in the central region, so that the surface energy of the central region of the region used to form the organic functional layer in the anode layer is greater than that surrounding the center The surface energy of the peripheral area of the region, so that the coffee ring effect can be suppressed when the organic functional layer is formed by inkjet printing, so that the formed organic functional layer is relatively uniform, thereby reducing the influence of the coffee ring effect on the inkjet printing method. Properties of the fabricated OLED devices.

Description of drawings

FIG. 1 is a schematic flow diagram of a method for preparing an OLED device provided by an embodiment of the present invention;

FIG. 2 is a schematic structural view of a mask used when pretreating the anode layer in the method for preparing an OLED device provided by an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of another mask used in the pretreatment of the anode layer in the method for manufacturing an OLED device provided by an embodiment of the present invention.

Detailed ways

The embodiments of the present invention provide an organic electroluminescent device, a preparation method, and a display device, which are used to suppress the coffee ring effect, thereby reducing the influence of the coffee ring effect on the performance of OLED devices prepared by inkjet printing.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that the thickness and shape of each layer in the drawings of the present invention do not reflect the real scale, and the purpose is only to illustrate the contents of the present invention.

Referring to Fig. 1, a method for preparing an organic electroluminescent device provided by an embodiment of the present invention includes the following steps:

S101, forming an anode layer on the base substrate;

Wherein, the material of the anode layer may be, for example, ITO, IZO, AZO, FTO and the like.

S102. Perform pretreatment on the anode layer, so that the surface energy of the central region of the region used to form the organic functional layer in the anode layer is greater than the surface energy of the peripheral region surrounding the central region;

S103, forming an organic functional layer on the pretreated anode layer by inkjet printing;

Wherein, the organic functional layer may be, for example, an organic small molecule material.

S104, forming a cathode layer on the base substrate on which the organic functional layer is formed.

Among them, the cathode layer can be made of non-transparent metal materials, such as aluminum, nickel or gold, etc., and can also be made of transparent materials with a dielectric layer/metal layer/dielectric layer structure, such as ITO/Ag/ITO, ZnS/Ag/ZnS etc., which are not limited in this embodiment of the present invention.

In the above method, before the organic functional layer is formed on the anode layer by inkjet printing, the anode layer is pretreated so that the surface energy of the central area of the area used to form the organic functional layer in the anode layer is greater than that surrounding the central area. In this way, the coffee ring effect can be suppressed when the organic functional layer is formed by inkjet printing, so that the formed organic functional layer is relatively uniform, thereby reducing the influence of the coffee ring effect on the inkjet printing method. performance of OLED devices.

In a preferred embodiment, the anode layer is pretreated in step S102, so that the surface energy of the central region of the region used to form the organic functional layer in the anode layer is greater than the surface energy of the peripheral region surrounding the central region can, specifically include:

dividing the region for forming the organic functional layer in the anode layer into a central region and a peripheral region surrounding the central region;

A self-assembled monolayer is formed on the surface of the anode layer in the peripheral region such that the surface energy of the anode layer in the central region is greater than the surface energy of the anode layer in the peripheral region.

In a preferred embodiment, the anode layer is pretreated in step S102, so that the surface energy of the central region of the region used to form the organic functional layer in the anode layer is greater than the surface energy of the peripheral region surrounding the central region can, specifically include:

dividing the region for forming the organic functional layer in the anode layer into a central region and a peripheral region surrounding the central region;

Hydroxyl groups are formed on the surface of the anode layer in the central region such that the surface energy of the anode layer in the central region is greater than the surface energy of the anode layer in the peripheral region.

In a preferred embodiment, the anode layer is pretreated in step S102, so that the surface energy of the central region of the region used to form the organic functional layer in the anode layer is greater than the surface energy of the peripheral region surrounding the central region can, specifically include:

dividing the region for forming the organic functional layer in the anode layer into a central region and a peripheral region surrounding the central region;

forming a self-assembled monolayer on the surface of the anode layer in the peripheral region, and forming hydroxyl groups on the surface of the anode layer in the central region, such that the surface energy of the anode layer in the central region is greater than that of the anode layer in the peripheral region of surface energy.

Wherein, the structure diagram of anode layer is as shown in Fig. 2, Fig. 3, and the region 2 (as shown in Fig. 2, Fig. 3) that is used to form the organic functional layer in anode layer 1 is divided into center area A and surrounding this center. Region B is the periphery of Region A.

In a preferred embodiment, the self-assembled monomolecular layer is formed on the surface of the anode layer in the peripheral region, which may specifically include:

coating a photoresist on the anode layer;

Using the first mask to expose the photoresist, and then develop, so that the surface of the anode layer in the peripheral region is exposed, and the surface of the anode layer in the remaining regions is covered with the photoresist;

The base substrate formed with the photoresist is placed in an ultraviolet-ozone (UV/O ₃ ) cleaning machine or an oxygen plasma cleaning machine for atmosphere cleaning, so as to form a layer on the surface of the anode layer in the peripheral region Hydroxyl (-OH);

The base substrate with hydroxyl groups formed on the surface of the anode layer of the peripheral region is placed in a chamber that has been evacuated and a liquid silane organic matter is placed in the chamber, and the silane organic matter is evaporated in a vacuum and then combined with the The hydroxyl group on the surface of the anode layer in the peripheral area undergoes a chemical reaction to form a layer of self-assembled monomolecular layer (Self-assembled Momolayer, SAM) on the surface of the anode layer in the peripheral area;

Strip the photoresist from the surface of the anode layer covering the rest of the area.

Among them, the principle of forming hydroxyl groups on the surface of the anode layer is as follows:

The surface of the anode layer exposed to the air will absorb organic matter in the air, and the ultraviolet-ozone cleaning machine or oxygen plasma cleaning machine will generate active oxygen atoms O, which have strong oxidizing properties and can quickly oxidize the anode The organic matter on the surface of the anode layer generates CO ₂ , NO ₂ and other gases, and forms hydroxyl groups on the surface of the exposed anode layer.

The pattern (Pattern) of the first mask (Mask) can be shown, for example, as shown in FIG. 2 , the area corresponding to the central area A is opaque, and the area corresponding to the peripheral area B is hollowed out.

In a preferred embodiment, the surface energy of the anode layer in the peripheral region can be controlled by the type of silane organic matter, and can also be controlled by the processing time of the substrate substrate in the chamber where the liquid silane organic matter is placed, It can also be controlled by the type of the silane organic substance and the processing time of the substrate in the chamber in which the liquid silane organic substance is placed, which is not limited in this embodiment of the present invention.

In a preferred embodiment, the organic silanes mentioned above may be, for example, octadecyltrichlorosilane (OTDS), hexamethyldisilazane (HMDS) and the like.

In a preferred embodiment, the compactness of the self-assembled monolayer is directly proportional to the processing time of the substrate in the chamber containing the liquid silane organic substance. For example: the longer the processing time of the substrate in the chamber in which the liquid silane organic matter is placed, the denser the SAM layer formed, the stronger the liquid repellency, and the smaller the surface energy.

In specific implementation, the organic functional layer formed by inkjet printing can be relatively uniform by controlling the compactness of the SAM layer, thereby reducing the influence of the coffee ring effect on the performance of the OLED device prepared by inkjet printing.

In a preferred embodiment, the above-mentioned formation of hydroxyl groups on the surface of the anode layer in the central region may specifically include:

coating a photoresist on the anode layer;

Using a second mask to expose the photoresist, and then develop, so that the surface of the anode layer in the central region is exposed, and the surface of the anode layer in the remaining regions is covered with the photoresist;

The base substrate formed with the photoresist is placed in an ultraviolet-ozone cleaning machine or an oxygen plasma cleaning machine for atmospheric cleaning, so as to form a layer of hydroxyl groups on the surface of the anode layer in the central region.

Wherein, the pattern (Pattern) of the second mask can be shown in FIG. 3 , for example, the area corresponding to the central area A is hollowed out, and the area corresponding to the peripheral area B is opaque.

In a preferred embodiment, the compactness of the hydroxyl group is directly proportional to the processing time of the base substrate in an ultraviolet-ozone cleaning machine or an oxygen plasma cleaning machine. For example: the longer the processing time of the substrate substrate in the ultraviolet-ozone cleaning machine or oxygen plasma cleaning machine, the denser the hydroxyl groups formed, the stronger the lyophilicity, and the greater the surface energy.

In specific implementation, the organic functional layer formed by inkjet printing can be relatively uniform by controlling the density of hydroxyl groups, thereby reducing the impact of the coffee ring effect on the performance of OLED devices prepared by inkjet printing.

In specific implementation, the coffee ring effect can be effectively suppressed by adjusting the surface energy of the central area A and the peripheral area B, so that the formed organic functional layer is relatively uniform, thereby reducing the influence of the coffee ring effect on inkjet printing. Properties of the fabricated OLED devices.

The preparation process of the OLED device provided by the embodiment of the present invention will be described in detail below.

Step 1, forming an anode layer on the glass substrate;

Step 2, dividing the area used to form the organic functional layer in the anode layer into a central area and a peripheral area surrounding the central area;

Step 3, forming a self-assembled monolayer on the surface of the anode layer in the peripheral region;

Specifically include the following steps:

Coating photoresist on the anode layer;

Using the first mask to expose the photoresist, and then developing again, so that the surface of the anode layer in the peripheral area is exposed, and the surface of the anode layer in the remaining areas is covered with photoresist;

The glass substrate formed with the photoresist is placed in an ultraviolet-ozone cleaning machine or an oxygen plasma cleaning machine for atmosphere cleaning, so as to form a layer of hydroxyl groups on the surface of the anode layer in the peripheral area;

The glass substrate with hydroxyl groups formed on the surface of the anode layer of the peripheral area is placed in a chamber that has been evacuated and the liquid silane organic matter is placed in the chamber. The hydroxyl group of the chemical reaction occurs to form a self-assembled monolayer on the surface of the anode layer in the peripheral region;

The photoresist covering the surface of the anode layer in the remaining area is stripped.

Step 4, forming hydroxyl groups on the surface of the anode layer in the central region;

Specifically include the following steps:

Coating photoresist on the anode layer;

Use the second mask to expose the photoresist, and then develop again, so that the surface of the anode layer in the central area is exposed, and the surface of the anode layer in the remaining areas is covered with photoresist;

The glass substrate formed with the photoresist is placed in an ultraviolet-ozone cleaning machine or an oxygen plasma cleaning machine for atmosphere cleaning, so as to form a layer of hydroxyl groups on the surface of the anode layer in the central area.

Wherein, the surface energy of the anode layer in the central region is greater than the surface energy of the anode layer in the peripheral region.

Step 5, using inkjet printing to form an organic functional layer on the pretreated anode layer;

Step 6, forming a cathode layer on the glass substrate formed with the organic functional layer.

Based on the same inventive concept, an embodiment of the present invention also provides an organic electroluminescent device, which is an organic electroluminescent device prepared by using the method for preparing an organic electroluminescent device provided in any embodiment of the present invention. device.

Based on the same inventive concept, an embodiment of the present invention further provides a display device, including the above-mentioned organic electroluminescence display panel provided by the embodiment of the present invention. The display device may be any product or component with a display function such as a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, and the like.

To sum up, in the technical solution provided by the embodiment of the present invention, before the organic functional layer is formed on the anode layer by inkjet printing, the anode layer is pretreated so that the organic functional layer in the anode layer The surface energy of the central area of the region is greater than the surface energy of the peripheral area surrounding the central area, so that the coffee ring effect can be suppressed when the organic functional layer is formed by inkjet printing, so that the formed organic functional layer is relatively uniform, thereby reducing the The coffee ring effect affects the performance of OLED devices prepared by inkjet printing.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (10)

1. a kind of preparation method of organic electroluminescence device, it is characterised in that this method includes：

Anode layer is formed on underlay substrate；

The anode layer is pre-processed so that be used for the center for forming the region of organic function layer in the anode layer Surface energy is more than the surface energy for the external zones for surrounding the center；

Organic function layer is formed on the anode layer for having been subjected to pretreatment using inkjet printing mode；

Cathode layer is formed on the underlay substrate formed with the organic function layer.

2. according to the method for claim 1, it is characterised in that described that the anode layer is pre-processed so that described It is used for table of the surface energy more than the external zones for surrounding the center for forming the center in the region of organic function layer in anode layer Face energy, is specifically included：

The external zones of center and the encirclement center will be divided into the anode layer for forming the region of organic function layer；

Self assembled monolayer, and/or the anode layer in the center are formed on the surface of the anode layer of the external zones Surface forms hydroxyl so that the surface energy of the anode layer of the center is more than the surface energy of the anode layer of the external zones.

3. according to the method for claim 2, it is characterised in that the surface of the anode layer in the external zones is formed certainly Monolayer is assembled, is specifically included：

The coating photoresist on the anode layer；

The photoresist is exposed using the first mask plate, then developed again so that the table of the anode layer of the external zones Face is exposed, and the surface of the anode layer in remaining region is covered with the photoresist；

Underlay substrate formed with the photoresist is placed in ultraviolet-ozone cleaning machine or oxygen plasma cleaning machine Promoting the circulation of qi atmosphere cleans, to form one layer of hydroxyl on the surface of the anode layer of the external zones；

Underlay substrate of the surface of the anode layer of the external zones formed with hydroxyl, which is placed in, to be pumped through to put in vacuum and chamber has In the chamber of liquid silane organic matter, the silane organic matter volatilize in a vacuum after with the anode layer of the external zones The hydroxyl on surface is chemically reacted, and one layer of self assembled monolayer is formed on the surface of the anode layer of the external zones；

Peel off the photoresist on the surface of the anode layer in remaining region of covering.

4. according to the method for claim 3, it is characterised in that the surface energy of the anode layer of the external zones passes through the silicon The processing time of the species of alkane organic matter and/or the underlay substrate in storing has the chamber of liquid silane organic matter comes Control.

5. according to the method for claim 4, it is characterised in that the silane organic matter is octadecyl trichlorosilane alkane or six Methyl disilazane.

6. according to the method for claim 4, it is characterised in that the compactness of the self assembled monolayer and the substrate Substrate has the processing time in the chamber of liquid silane organic matter directly proportional in storing.

7. according to the method for claim 2, it is characterised in that the surface of the anode layer in the center forms hydroxyl Base, specifically include：

The coating photoresist on the anode layer；

The photoresist is exposed using the second mask plate, then developed again so that the table of the anode layer of the center Face is exposed, and the surface of the anode layer in remaining region is covered with the photoresist；

Underlay substrate formed with the photoresist is placed in ultraviolet-ozone cleaning machine or oxygen plasma cleaning machine Promoting the circulation of qi atmosphere cleans, to form one layer of hydroxyl on the surface of the anode layer of the center.

8. according to the method described in claim any one of 3-7, it is characterised in that the compactness of the hydroxyl and the substrate base Processing time of the plate in ultraviolet-ozone cleaning machine or oxygen plasma cleaning machine is directly proportional.

9. a kind of organic electroluminescence device, it is characterised in that the organic electroluminescence device is to be appointed using such as claim 1-8 The organic electroluminescence device that method described in one is prepared.

10. a kind of display device, it is characterised in that including organic electroluminescence device as claimed in claim 9.