CN103633251B - Light takes out parts and applies its organic electroluminescence device and preparation method - Google Patents

Abstract

The invention provides a light extraction component and a preparation method thereof. The light extraction component comprises a high refractive index transparent substrate and a light extraction layer molded on the surface of the high refractive index transparent substrate. The refractive index of the high-refractive-index transparent substrate is fixed, which can effectively eliminate the total reflection from the organic layer to the substrate. The light extraction layer can improve the light extraction rate by changing the total reflection optical path. The structure is simple and the light extraction rate is high. The present invention also provides an organic electroluminescence device containing the light extraction component and its preparation method. The light extraction component is arranged between the substrate and the first electrode, and can extract the light beam confined inside the organic functional layer, with high efficiency The light extraction efficiency is high, and after the device is packaged, there are fewer passages for water vapor and oxygen to enter, which effectively improves the life of the device.

Description

Light extraction component, organic electroluminescence device using the same, and preparation method

technical field

The invention relates to the field of organic electroluminescent devices, in particular to a light extraction component, an organic electroluminescent device using the same and a preparation method thereof.

Background technique

OLED (English full name is Organic Light Emitting Device, which means organic electroluminescent device, referred to as OLED) is a next-generation display technology, which has the advantages of wide color gamut, fast response, wide viewing angle, no pollution, high contrast, and planarization.

A typical OLED device structure generally includes a glass substrate, a first electrode, a second electrode, and an organic light-emitting functional layer arranged between the two electrodes. Due to the reflection caused by the matching of the refractive index of each layer of material, the light emitted by the light-emitting layer is large. part is limited to the device. For example, the refractive index of air is approximately 1, the refractive index of glass is generally 1.5, and the organic functional layer is 1.7-1.8. When the light beam reaches the low refractive index material from the high refractive index material, the beam greater than the critical angle will be fully generated at the interface. Reflection, the reflected light will be reflected and refracted back and forth between the functional layers, and finally consumed inside the device and cannot be taken out for application. Studies have shown that the light output efficiency of OLEDs actually emitted into the air is only about 20%, and 80% of the light beams are confined or consumed inside the device, of which 50% are confined within the organic functional layer, and 50% are confined within the glass substrate. Accounted for 30%. How to improve the light beam confined inside OLED will be the key technology to improve the efficiency and lifetime of OLED devices.

Aiming at different light confinement mechanisms, various methods have been developed to improve the light extraction efficiency of OLEDs. In order to extract the light beam confined in the substrate: Chinese patent document CN102620235A discloses a light extraction film and a light-emitting element using it. The light extraction film is placed on the light-emitting surface of the substrate, that is, the outer surface, to extract the light beam confined in the substrate , the light extraction film includes a microlens array film and at least one optical film, the microlens array film has an opposite first surface and a second surface, and has a plurality of microlenses arranged on the first surface, and the optical film covers the first surface On the surface, and the optical film includes a plurality of optical particles and a layer of film, wherein the optical particles are arranged in the film layer, and the film layer has a refractive index smaller than the lens array film and greater than or equal to the refractive index of air, so as to reduce the light from the optical The amount of total reflection that occurs when the film enters air. Wherein, the material of the film layer of the optical film is a material with a high refractive index such as polyethylene terephthalate and polyethylene naphthalate. As we all know, a simple high-refractive index optical film layer can effectively eliminate total reflection; microlens arrays and optical particles with high refractive index can change the optical path of total reflection beams through refraction, which can effectively improve the luminous efficiency of the device. However, the refractive index of the film material depends largely on the thickness and flatness of the film. In this patent document, the optical thin film is formed on the microlens array, and the flatness is very poor, and the optical particles are doped in the film layer , so that the thickness of the optical film is uneven, and at the same time it is easy to breathe and permeate, which seriously affects the effect of the high refraction film layer and reduces the light extraction efficiency of the light extraction film; moreover, the light extraction film is a multi-layer film with a structure Complicated and cumbersome to make. In the light-emitting element disclosed in this patent document, the optical film is placed outside the substrate, and only the light beams confined in the glass substrate can be taken out, while a large number of light beams confined in the organic functional layer are reflected and refracted back and forth, and finally consumed Cannot be taken out of the application inside the device.

In order to take out the light beams confined in the organic functional layer, an article "High Efficiency 200-lm/W Green Light Emitting Organic Devices Prepared on High-Index of Refraction Substrate" (translated as: high-refractive-index substrate to prepare high-efficiency 200-lm/W green organic light-emitting devices), by using high-refractive-index glass, The total reflection at the interface between the organic functional layer and the glass substrate is eliminated, and the efficiency of the OLED device is improved. Although this method has a good light extraction effect, the manufacturing technology of high refractive index glass is difficult and costly.

At the same time, the Chinese patent document CN102299266A discloses a substrate of an organic electroluminescent device and a manufacturing method. A scattering layer and a planarization layer are arranged between the transparent substrate and the first electrode of the substrate. The production process is relatively simple and can be mass-produced; The light beam confined in the organic functional layer can be effectively taken out, but the scattering layer and the planarization layer are directly formed on the substrate. When the device is packaged, the scattering layer and the planarization layer provide a channel for water vapor and oxygen to enter the interior of the device, directly making The lifetime of the device becomes worse, and it also affects the light efficiency performance.

If the light extraction film disclosed in Chinese patent document CN102620235A is changed and arranged on the substrate of the substrate to extract the light beam in the organic functional layer, then there will also be that the light extraction film is directly formed on the substrate, and water vapor and Oxygen easily enters the interior of the device through the light extraction film, and the light extraction film provides a channel for oxygen and moisture to enter the interior of the device, which directly affects the life of the device and also affects the light efficiency.

Contents of the invention

For this reason, the technical problem to be solved by the present invention is that in the prior art, the light extraction components for extracting the light beams confined in the organic light-emitting functional layer are either complex in structure and not suitable for mass production, or the light extraction components form water vapor and oxygen into the interior of the device. channel and affect the lifetime of the device. Therefore, a light extraction component with high light extraction efficiency, simple process and no influence on device life is provided, as well as an organic electroluminescence device using the light extraction component and a preparation method thereof.

In order to solve the problems of the technologies described above, the technical scheme adopted in the present invention is as follows:

A light extraction component is provided, comprising,

A light extraction component for use in an organic electroluminescent device, comprising,

A high-refractive-index transparent substrate having a refractive index higher than that of a transparent substrate in an organic electroluminescent device;

The light extraction layer formed on the surface of the high refractive index transparent substrate is used to suppress the total reflection of the light emitted from the high refractive index transparent substrate incident on the transparent substrate.

The light extraction layer is a scattering layer or a microlens array layer.

The scattering layer includes a matrix with a light transmittance greater than 80% and scattering particles with a refractive index greater than that of the organic functional layer.

The matrix is photoresist, and the scattering particles are fine particles of TiO ₂ or SiO ₂ or ZnO or ZrO ₂ .

The primary particle size of the scattering particles is 0.02-0.8 μm.

The thickness of the scattering layer is 0.3-3 μm.

A method for preparing a light extraction component used in an organic electroluminescent device, comprising the following steps:

(1) Obtain a high-refractive-index transparent substrate whose refractive index is higher than that of the transparent substrate in an organic electroluminescent device;

(2) forming a light extraction layer on the surface of the high refractive index transparent substrate, wherein the light extraction layer is used to suppress the total reflection of light emitted from the high refractive index transparent substrate incident on the transparent substrate.

The light extraction layer is a scattering layer or a microlens array layer.

The light extraction layer is a high refractive index scattering layer, and the step (2) specifically includes the following steps:

(21) Prepare the scattering layer solution: mix and grind the scattering particles, dispersant, and solvent, then filter and take the filtrate, and then mix the obtained filtrate with the matrix to prepare the scattering layer solution;

(22) Coating the scattering layer solution on a high refractive index transparent substrate to form a film to obtain a continuous scattering layer.

In the step (21), the light transmittance of the matrix is greater than 80%, and the refractive index of the scattering particles is greater than that of the organic functional layer.

The matrix is photoresist, and the scattering particles are fine particles of TiO ₂ or SiO ₂ or ZnO or ZrO ₂ .

The primary particle size of the scattering particles is 0.02-0.8 μm.

The thickness of the scattering layer is 0.3-3 μm.

The light extraction layer is a microlens array layer, and the step (2) specifically includes the following steps:

(31) spin-coating a photoresist layer on one side of the high refractive index transparent substrate;

(32) Using photolithography technology, the photoresist layer is made into a columnar structure substrate;

(33) Heating the substrate of the columnar structure in step (32), and the upper bottom surface of each columnar structure melted protrudes to form a micro lens.

Meanwhile, an organic electroluminescence device is provided, comprising a transparent substrate, a first transparent electrode, an organic functional layer, a second electrode, and a light extraction component arranged between the transparent substrate and the first electrode, the light The extraction component is the above-mentioned light extraction component; and the light extraction layer of the light extraction component is directly bonded to the transparent substrate, and the high refractive index transparent substrate is directly bonded to the first electrode.

At the same time, a method for preparing an organic electroluminescent device is provided, comprising the steps of:

(10) bonding the light extraction component to the transparent substrate, and after bonding, the light extraction layer of the light extraction component is directly bonded to the transparent substrate;

(11) making a first transparent electrode on the surface where the high refractive index transparent substrate of the light extraction component is located;

sequentially fabricating an organic functional layer and a second electrode on the first transparent electrode;

(13) Device packaging.

The step (10) further includes a cutting step before attaching the light extraction component to the substrate, specifically: the step of cutting the light extraction component into light extraction component units corresponding to the size of the light emitting region.

The light extracting component unit after cutting is a table shape.

The above technical solution of the present invention has the following advantages compared with the prior art:

(1) The light extraction component includes a high refractive index transparent substrate and a light extraction layer, and the light extraction layer is a high refractive index scattering layer or a microlens array layer. The refractive index of the high-refractive-index transparent substrate is fixed, which can effectively eliminate the total reflection from the organic layer to the substrate. The high-refractive index scattering layer or the microlens array layer can improve the light extraction rate by changing the total reflection optical path; the structure is simple, and the light extraction high efficiency; the organic electroluminescence device provided with a light extraction component, the light extraction component is arranged between the substrate and the first electrode, can effectively extract the light beam confined inside the organic functional layer, and has a high light extraction efficiency The light extraction layer of the light extraction component is bonded to the transparent substrate, the first transparent electrode is made on the high refractive index transparent substrate of the light extraction component, and the high refractive index transparent substrate has a high density and The surface is smooth, and when the device is packaged, even if the package cover and the high-refractive index transparent substrate are packaged together, the effect of isolating water vapor and oxygen can be achieved, effectively improving the life of the device.

(2) The light extraction layer of the light extraction component can be prepared by a spin coating process and a photolithography process, the process is simple, and it is suitable for large-scale production.

(3) The high refractive index transparent substrate is made of polyethylene terephthalate substrate, polyethylene naphthalate or polyphenylene sulfide, which not only has a high refractive index, but also has a low cost. relatively low.

(4) The particle size of the scattering particles is 0.02-0.8 μm, which is at the same level as the light wavelength, which can avoid light loss and effectively scatter visible light.

(5) The thickness of the scattering layer is slightly larger than the particle size of the scattering particles, which can ensure that all the scattering particles are located in the scattering layer, so that the surface of the obtained scattering layer is smooth.

(6) Cut the light extraction component into a light extraction component unit of the size of the light-emitting area, and then attach the film unit to the corresponding position of the light-emitting area on the transparent substrate. When packaging, the light extraction component is located in the packaging cover , to ensure a better encapsulation effect.

(7) The light extraction component unit after cutting is a table shape, which avoids the fracture of the evaporated ITO electrode layer, ensures the continuity of the ITO electrode layer, and then ensures the conductive effect.

Description of drawings

In order to make the content of the present invention more easily understood, the present invention will be described in further detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

Fig. 1 is a flow chart of a method for preparing an organic electroluminescent device containing a light extraction component according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of the OLED structure prepared in Fig. 1;

Fig. 3 is a schematic diagram of the OLED structure prepared in Example 4;

4 is a schematic structural view of the light extraction component unit described in Embodiment 4;

The reference signs in the figure are represented as: 1-transparent substrate with high refractive index, 2-light extraction layer, 3-transparent glass substrate, 4-ITO transparent anode layer, 5-organic functional layer, 6-cathode layer, 7-encapsulation Glue, 8-packaging cover, 41-small piece of PEN transparent substrate, 42-small piece of scattering layer.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the implementation manner of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The organic electroluminescent device containing light extraction components as the first embodiment of the present invention, as shown in Figure 2, includes a transparent glass substrate 3, an ITO (indium oxide) transparent anode layer 4, an organic functional layer 5, a cathode layer 6, and The light extraction component arranged between the transparent glass substrate 3 and the ITO transparent anode layer 4, wherein the ITO transparent anode layer 4 constitutes the first electrode layer in this embodiment, and the cathode layer 6 constitutes the first electrode layer in this embodiment. Two electrode layers, the light extraction component further includes a high refractive index transparent substrate 1 and a light extraction layer 2 molded on the surface of the high refractive index transparent substrate 1, in this embodiment, the high refractive index transparent substrate Sheet 1 is a PEN (English name is polyethylene naphthalate, meaning polyethylene naphthalate) transparent substrate, and the light extraction layer 2 is a scattering layer; the scattering layer is directly connected to the substrate of the transparent glass substrate 3 Bonding, the PEN transparent substrate and the ITO transparent anode layer 4 are directly bonded. The scattering layer includes a photoresist with a light transmittance greater than 80% and TiO ₂ (titanium dioxide) scattering particles with a refractive index greater than that of the organic functional layer 5, and the primary particle size of the TiO ₂ is 0.02-0.8 μm , the thickness of the prepared scattering layer is 0.3-3 μm, preferably, the thickness of the scattering layer is greater than the initial particle size of the scattering particles, which can ensure that more scattering particles are located in the scattering layer, ensuring that the The obtained flatness of the scattering layer.

In this embodiment, the refractive index of the PEN transparent substrate is fixed, which can effectively eliminate total reflection, and the scattering layer can improve the light extraction rate by changing the total reflection optical path; the structure of the entire light extraction component is simple, and the light extraction rate is high; the setting An organic electroluminescent device with a light extraction component, the light extraction component is arranged between the glass transparent substrate 3 and the ITO transparent anode layer 4, which can effectively extract the light beam confined inside the organic functional layer; the ITO transparent anode layer 4 is made On the PEN transparent substrate of the light extraction component, the PEN transparent substrate has a high density and a flat surface. When the device is packaged, the packaging cover and the high refractive index transparent substrate can also be packaged together to achieve isolation from water vapor and oxygen. As a result, the life of the device is effectively improved.

As a modification of the above embodiment, the PEN transparent substrate can be PET (English name is Polyethylene terephthalate, meaning polyethylene terephthalate) or PSS (English name is Polyphenylene sulfide, meaning polyethylene terephthalate) in the prior art. It is replaced by a polyphenylene sulfide) transparent substrate, and others are the same as the above-mentioned embodiments, which can also achieve the purpose of the present invention and belong to the protection scope of the present invention; moreover, the better the refractive index of the transparent substrate used, the better the effect of light extraction the better. Wherein, a PSS (English name is Polyphenylene sulfide, meaning polyphenylene sulfide) transparent substrate is used as the high refractive index transparent substrate to constitute the third embodiment of the present invention.

As a modification of the above embodiment, the scattering particle TiO ₂ can also be replaced by fine particles of SiO ₂ (silicon dioxide), ZnO (zinc oxide) or ZrO ₂ (zirconia), and the other is the same as the above embodiment, and can also achieve The object of the present invention belongs to the protection scope of the present invention.

As other embodiments of the present invention, the light extraction layer can be replaced by other components that can suppress the total radiation of the light emitted from the high refractive index transparent substrate incident on the transparent substrate, such as a pyramid-shaped light extraction layer Or the grating diffraction layer, wherein the pyramid-shaped light extraction layer suppresses total reflection by refraction, and the grating diffraction layer suppresses total emission by diffraction; the purpose of this invention can also be realized, and it belongs to the protection scope of the present invention.

Referring to accompanying drawing 1, the manufacturing method of the organic electroluminescence device that contains light extraction component in the above-mentioned embodiment 1 specifically comprises the following steps:

First, prepare the light extraction part:

S1, prepare the light extraction part, make a layer of high refractive index scattering layer on the PEN transparent substrate, the scattering layer is made of TiO ₂ mixed in the transparent photoresist by ordinary photolithography spin coating process, wherein, TiO ₂ and light The mass ratio of the resist is 1:4, and the thickness of the high refractive index scattering layer is 0.3-3 μm.

S2, the surface where the scattering layer of the light extraction component prepared in step S1 is directly pasted on the substrate of the glass transparent substrate 3, double-sided tape, common sticky liquid glue, etc. can be used for pasting.

S3, directly sputtering one deck of ITO transparent anode layer 4 on the surface of the unformed scattering layer of the PEN transparent substrate: the ITO transparent anode layer 4 of 150nm is prepared by DC magnetron sputtering, and the ITO target material is an indium tin alloy. Composition ratio In (indium): Sn (tin) = 90%: 10%. During the preparation process, the oxygen partial pressure is 0.4 Sccm, and the argon partial pressure is 20 Sccm; after the ITO electrode layer is prepared, the ITO transparent anode layer 4 is etched by an etching method.

S4, putting each functional layer into an evaporation chamber to evaporate each functional layer: sequentially evaporate a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. During the evaporation process, the chamber pressure is lower than 5.0×10-3Pa. First, 40nm-thick N,N-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (abbreviation: NPB) is evaporated. As a hole transport layer; 30nm-thick 9,10-di(2-naphthyl)anthracene (abbreviation: ADN) and tetra-tert-butylperylene (abbreviation: TBPe) were evaporated as the light-emitting layer by double-source co-evaporation method, The ratio of TBPe in ADN was controlled by rate to be 7%; 20nm Alq3 was evaporated as electron transport layer; 0.5nm LiF was evaporated as electron injection layer. 150nm of aluminum (chemical formula: Al) is vapor-deposited on the organic functional layer as the cathode layer 6 .

In S5, an OLED device is manufactured after being encapsulated with UV encapsulant and an encapsulation cover in a conventional encapsulation method.

The organic electroluminescence device containing the light extraction component of the second embodiment of the present invention includes a transparent glass substrate 3, an ITO transparent anode layer 4, an organic functional layer 5, and a cathode layer 6, and is arranged between the transparent glass substrate 3 and the The light extraction component between the ITO transparent anode layers 4, the light extraction component further includes a high refractive index transparent substrate 1 and a light extraction layer 2 formed on the surface of the high refractive substrate. In this embodiment, the high refractive index transparent substrate 1 is a PEN transparent substrate, and the light extraction layer 2 is a microlens array layer. Wherein, the microlens array layer is directly bonded to the glass transparent substrate 3 after bonding, and the ITO transparent anode layer 4 is fabricated on the PEN transparent substrate of the light extraction component.

In this embodiment, the microlens array layer can improve the light extraction rate by changing the total reflection optical path; the structure of the entire light extraction part is simple, can effectively eliminate total reflection, and the light extraction rate is high; In a luminescent device, the light extraction part is arranged between the glass transparent substrate 3 and the ITO transparent anode layer 4, which can effectively extract the light beam confined inside the organic functional layer; the ITO transparent anode layer 4 is made on the surface of the light extraction part On the PEN transparent substrate, the PEN transparent substrate has a high density and a flat surface. When the device is packaged, the packaging cover and the high-refractive index transparent substrate can also be packaged together to achieve the effect of isolating water vapor and oxygen, effectively improving the device performance. lifespan.

The manufacturing method of the organic electroluminescent device containing the light extraction component of the second embodiment of the present invention is as follows:

First, prepare the light extraction part:

S21, preparing the light extraction part, coating a layer of photoresist on the PEN transparent substrate with a thickness of 20 μm, using photolithography technology to make a columnar structure pattern, and then heating to the molten columnar structure photoresist due to surface tension, The edge part protrudes upwards first, and then the middle part protrudes, finally forming a protruding structure to constitute a microlens.

S22, bonding the microlens layer of the light extraction component prepared in step S21 on the glass substrate 3, double-sided adhesive tape, common sticky liquid adhesive, etc. can be used for bonding;

S23, sputter a layer of ITO electrode on the substrate bonded with the film substrate, and prepare a 150nm ITO transparent anode layer by DC magnetron sputtering method. The ITO target material is indium tin alloy, and its composition ratio is In:Sn =90%:10%. During the preparation process, the oxygen partial pressure was 0.4 Sccm, and the argon partial pressure was 20 Sccm. After the ITO electrode layer is prepared, the ITO transparent anode layer 4 is etched out by an etching method.

S24, put into the evaporation chamber to evaporate each functional layer, 5. A hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer are sequentially vapor-deposited. During the evaporation process, the chamber pressure was lower than 5.0×10 ^-3 Pa. First, 40nm thick NPB was evaporated as the hole transport layer; 30nm thick ADN and TBPe were evaporated as the light-emitting layer by dual-source co-evaporation method. The proportion of TBPe in ADN is 7%; 20nm Alq ₃ is evaporated as electron transport layer; 0.5nm LiF is evaporated as electron injection layer. 150 nm of Al was vapor-deposited on the organic functional layer as the second electrode layer.

S25, after encapsulating with UV encapsulant and encapsulation cover in a conventional encapsulation method, an OLED device is made.

As Embodiment 4 of the present invention, as shown in accompanying drawings 3-4, its structure is similar to that in Embodiment 1 to Embodiment 3, and the only difference from the above embodiment is that the light extraction components are only distributed in the light-emitting area .

The preparation method of the OLED device of the embodiment four structure of the present invention is as follows:

S41, prepare the light extraction part, make a layer of high refractive index scattering layer on the PEN transparent substrate, the scattering layer is made of TiO ₂ mixed in the transparent photoresist by ordinary photolithography spin coating process, the mixed TiO ₂ and light The mass ratio of the resist is 1:4, and the thickness is 0.3-3 μm.

S42, cutting the light extraction component prepared in step S41 into a light extraction component unit of the size of the light-emitting area, the cut light extraction component unit is a table shape, wherein the small piece of scattering layer 42 is a large-sized surface, and the small piece of PEN transparent substrate The sheet 41 is a small-sized surface, and the small-sheet scattering layer 42 is bonded to the light-emitting area of the transparent glass substrate 3. Double-sided adhesive tape, common sticky liquid adhesive, etc. can be used for bonding. The light extraction component unit after cutting is mesa-shaped, and the ITO electrode layers formed on different surfaces transition smoothly to avoid breakage, ensure the continuity of the ITO electrode layer, and then ensure the conductive effect; at the same time, the light extraction component is mesa-shaped , distributed only in the light-emitting area; after encapsulation, the light extraction component is located in the encapsulation cover, that is, the device is packaged through the encapsulation cover and the glass substrate, which can obtain a better encapsulation effect of isolating water vapor and oxygen.

S43, a layer of ITO electrode is sputtered on the substrate with a small piece of PEN transparent substrate 41, and a 150nm ITO transparent anode layer is prepared by DC magnetron sputtering. The ITO target material is indium tin alloy, and its composition ratio In:Sn=90%:10%. During the preparation process, the oxygen partial pressure was 0.4 Sccm, and the argon partial pressure was 20 Sccm. After the ITO electrode layer is prepared, the ITO transparent anode layer 4 is etched out by an etching method.

S44, putting each organic functional layer 5 into an evaporation chamber to evaporate each organic function layer 5 . A hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer are sequentially vapor-deposited. During the evaporation process, the chamber pressure was lower than 5.0×10 ^-3 Pa. First, 40nm thick NPB was evaporated as the hole transport layer; 30nm thick ADN and TBPe were evaporated as the light-emitting layer by dual-source co-evaporation method. The proportion of TBPe in ADN is 7%; 20nm Alq ₃ is evaporated as electron transport layer; 0.5nm LiF is evaporated as electron injection layer. 150 nm of Al was vapor-deposited on the organic functional layer as the second electrode layer.

S45, after encapsulating with UV encapsulating adhesive and encapsulating cover in a conventional encapsulating manner, an OLED device is made.

The light extraction component is cut into a light extraction component unit of the size of the light-emitting area, and then the unit is attached to the corresponding position of the light-emitting area on the transparent glass substrate 3. When packaging, the light extraction component is located in the packaging cover to ensure Better encapsulation effect.

As Comparative Example 1 of the present invention, refer to the structure and preparation method in Example 1. The only difference from Example 1 is that the OLED device in Comparative Example 1 does not contain light extraction components, and the others are the same as Example 1.

As Comparative Example 2 of the present invention, refer to the structure and preparation method in Example 1. The only difference from Example 1 is that the OLED device in Comparative Example 2 does not contain light extraction components, but a layer of Scattering layer, the scattering layer is made of TiO ₂ mixed in transparent photoresist by ordinary photolithography spin-coating process, wherein the mass ratio of mixed TiO ₂ and photoresist is 1:4, and the thickness is 0.3-3μm; A layer of ITO electrode was sputtered on the substrate coated with scattering layer.

To test the light extraction rate of an organic electroluminescent device containing light extraction components of the present invention, the OLEDs prepared in the first to fourth embodiments were tested for brightness, and compared with the OLED devices in Comparative Examples 1 to 2 Compare, wherein comparative example 1 is the basis of comparison, and the test results are shown in the following table:

It can be seen from the above table that the brightness of the organic electroluminescent device containing the light extraction component of the present invention is qualitatively improved compared with the brightness of Comparative Examples 1 and 2 representing the prior art, and the luminous efficiency is greatly improved.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. However, the obvious changes or changes derived therefrom still fall within the scope of protection of the present invention.

Claims (14)

1. A light extraction component used in an organic electroluminescence device, characterized in that, comprising, A high-refractive-index transparent substrate having a refractive index higher than that of a transparent substrate in an organic electroluminescent device; A light extraction layer formed on the surface of the high-refractive-index transparent substrate is used to suppress the total reflection of the light emitted from the high-refractive-index transparent substrate incident on the transparent substrate; The light extraction layer is a scattering layer, and the scattering layer includes a matrix with a light transmittance greater than 80% and scattering particles with a refractive index greater than that of the organic functional layer in the organic electroluminescent device; The preparation method of the light extraction component comprises the following steps: (1) Obtain a high-refractive-index transparent substrate whose refractive index is higher than that of the transparent substrate in the organic electroluminescent device; (2) forming a light extraction layer on the surface of the high refractive index transparent substrate, wherein the light extraction layer is used to suppress the total reflection of the light emitted from the high refractive index transparent substrate incident on the transparent substrate. 2 . The light extraction component according to claim 1 , wherein the substrate is photoresist, and the scattering particles are fine particles of TiO ₂ or SiO ₂ or ZnO or ZrO ₂ . 3. The light extraction component according to claim 2, wherein the primary particle diameter of the scattering particles is 0.02-0.8 μm. 4. The light extraction component according to claim 3, wherein the thickness of the scattering layer is 0.3-3 μm. 5. The light extraction component according to claim 1, wherein the light extraction layer is a microlens array layer. 6. A preparation method for a light extraction component in an organic electroluminescent device, characterized in that it comprises the following steps: (1) Obtain a high-refractive-index transparent substrate whose refractive index is higher than that of the transparent substrate in the organic electroluminescent device; (2) forming a light extraction layer on the surface of the high refractive index transparent substrate, wherein the light extraction layer is used to suppress the total reflection of the light emitted from the high refractive index transparent substrate incident on the transparent substrate; The light extraction layer is a high refractive index scattering layer, and the step (2) specifically includes the following steps: (21) Prepare the scattering layer solution: mix and grind the scattering particles, dispersant, and solvent, filter and take the filtrate, then mix the obtained filtrate with the matrix to prepare the scattering layer solution; the light transmittance of the matrix is greater than 80%, and the scattering The refractive index of the particles is greater than the refractive index of the organic functional layer in the organic electroluminescent device; (22) Coating the scattering layer solution on a high refractive index transparent substrate to form a film to obtain a continuous scattering layer. 7 . The preparation method according to claim 6 , wherein the substrate is photoresist, and the scattering particles are fine particles of TiO ₂ or SiO ₂ or ZnO or ZrO ₂ . 8. The preparation method according to claim 7, characterized in that, the primary particle diameter of the scattering particles is 0.02-0.8 μm. 9. The preparation method according to claim 8, characterized in that, the thickness of the scattering layer is 0.3-3 μm. 10. The preparation method according to claim 6, wherein the light extraction layer is a microlens array layer, and the step (2) specifically comprises the following steps: (31) spin-coating a photoresist layer on one side of the high refractive index transparent substrate; (32) Using photolithography technology, the photoresist layer is made into a substrate with a columnar structure; (33) The substrate of the columnar structure in step (32) is heated, and the upper bottom surface of each columnar structure melted protrudes to form a microlens. 11. An organic electroluminescent device, comprising a transparent substrate, a first transparent electrode, an organic functional layer, a second electrode, and a light extraction component arranged between the transparent substrate and the first transparent electrode, characterized in that , the light extraction component is the light extraction component described in any one of claims 1-5; and the light extraction layer of the light extraction component is directly bonded to the transparent substrate, and the high refractive index transparent substrate The sheet is directly bonded to the first transparent electrode. 12. A method for preparing an organic electroluminescent device as claimed in claim 11, comprising the steps of: (10) attaching the light extraction component to the transparent substrate, and after bonding, the light extraction layer of the light extraction component is directly attached to the transparent substrate; (11) making a first transparent electrode on the surface where the high refractive index transparent substrate of the light extraction component is located; (12) making an organic functional layer and a second electrode sequentially on the first transparent electrode; (13) Device packaging. 13. The method for preparing an organic electroluminescent device according to claim 12, characterized in that the step (10) also includes a step of cutting before attaching the light extraction component to the substrate, specifically: The step of cutting out the extraction component into a light extraction component unit corresponding to the size of the light-emitting area. 14. The method for preparing an organic electroluminescent device according to claim 13, characterized in that, the light extraction component unit after cutting is a mesa shape.