Light-emitting device, screen module and electronic equipment

Abstract

The utility model provides a light-emitting device, a screen module and electronic equipment. The light emitting device includes a display body and a light extraction layer. The display main body comprises a cathode and a functional layer group, the light extraction layer is arranged on one side, back to the functional layer group, of the cathode, and the light extraction layer covers the cathode. The light extraction layer comprises a bottom layer close to the cathode, a top layer opposite to the bottom layer and at least one middle layer located between the top layer and the bottom layer, and the middle layer and the bottom layer are different in refractive index. The light rays passing through the bottom layer, the middle layer and the top layer form a first micro-cavity structure similar to a Bragg reflector and used for light ray oscillation in the light extraction layer due to different refractive indexes, so that the light rays are reinforced due to constructive interference, the light emitting intensity is improved, and the power consumption of the screen is reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic technology, and in particular to light-emitting devices, screen modules and electronic devices. Background Art

[0002] OLED (Organic Light-Emitting Diode) screens have been widely used in screen modules due to their advantages such as ultra-thinness, flexibility, and low driving voltage.

[0003] With the development of phosphorescent OLED light-emitting materials, heavy metal elements can promote spin-orbit coupling and enhance intersystem crossing efficiency. The internal quantum efficiency of OLED devices has approached 100%, but the external quantum efficiency is affected by the thin-film encapsulation, touch layer and the light transmittance of each module stacking material, resulting in a portion of the OLED device light being blocked, reducing the light intensity. Utility Model Content

[0004] The present disclosure provides a light-emitting device, a screen module and an electronic device to solve related technical problems.

[0005] According to a first aspect of the present disclosure, there is provided a light emitting device including a display body and a light extraction layer;

[0006] The display body includes a cathode and a functional layer group, the light extraction layer is arranged on a side of the cathode facing away from the functional layer group, and the light extraction layer covers the cathode;

[0007] The light extraction layer includes a bottom layer close to the cathode, a top layer opposite to the bottom layer, and at least one intermediate layer located between the top layer and the bottom layer, wherein the refractive index of at least one intermediate layer is greater than the refractive index of the top layer and the bottom layer, so that the light extraction layer forms a first microcavity for light oscillation between the top layer and the bottom layer.

[0008] Optionally, the functional layer group is provided with an anode on a side away from the cathode, the cathode includes a cathode reflective layer, the anode includes an anode reflective layer, and the display body forms a second microcavity for light oscillation between the cathode reflective layer and the anode reflective layer.

[0009] Optionally, the light emitting device further includes an encapsulation layer; the encapsulation layer covers the light extraction layer and the display body.

[0010] Optionally, the encapsulation layer includes two inorganic thin film layers and an organic thin film layer located between the two inorganic thin film layers.

[0011] Optionally, the light extraction layer includes at least 5 intermediate layers.

[0012] Optionally, the refractive index of the bottom layer and / or the top layer at a wavelength of 450 nm-650 nm is less than or equal to 1.6.

[0013] Optionally, the thickness of the bottom layer and / or the top layer is greater than or equal to 10 nm and less than or equal to 30 nm.

[0014] Optionally, at least one of the intermediate layers has a refractive index greater than 1.8 at a wavelength of 450 nm to 650 nm.

[0015] Optionally, when the refractive index of the intermediate layer at a wavelength of 450 nm-650 nm is greater than 1.8, the thickness of the intermediate layer is greater than or equal to 30 nm and less than or equal to 80 nm.

[0016] Optionally, the refractive index of at least one of the intermediate layers at a wavelength of 450 nm-650 nm is less than or equal to 1.6.

[0017] According to a second aspect of the present disclosure, a screen module is provided, comprising any light-emitting device described in the first aspect.

[0018] According to a third aspect of the present disclosure, an electronic device is provided, comprising any light-emitting device described in the first aspect; or any screen module described in the second aspect.

[0019] The technical solution provided by the present disclosure can achieve at least the following beneficial effects:

[0020] The present invention discloses a light extraction layer located on the side of the cathode facing away from the functional layer group, which is provided with a bottom layer, a top layer and at least one middle layer. The middle layer is located between the bottom layer and the top layer. The light passing through the bottom layer, the middle layer and the top layer forms a first microcavity structure for light oscillation similar to a Bragg reflector in the light extraction layer due to the different refractive indices, so that the light is strengthened due to the existence of constructive interference, thereby improving the light output intensity and reducing the power consumption of the screen.

[0021] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the specification and, together with the description, serve to explain the principles of the specification.

[0023] Figure 1 is a schematic cross-sectional structural diagram of a screen module in an exemplary embodiment of the present disclosure;

[0024] Figure 2 is a schematic cross-sectional structural diagram of a light emitting device in another exemplary embodiment of the present disclosure;

[0025] Figure 3 is a schematic structural diagram of an OLED device in an exemplary embodiment of the present disclosure;

[0026] Figure 4 is a schematic structural diagram of an OLED device in another exemplary embodiment of the present disclosure;

[0027] Figure 5 It is a schematic structural diagram of an OLED device in another exemplary embodiment of the present disclosure.

[0028] Reference numerals:

[0029] Screen module 1;

[0030] Display body 11; functional layer group 111; cathode 112; anode 113; HIL 114; HTL 115; Prime 116; EML 117; HBL 118; ETL 119;

[0031] Light extraction layer 12; bottom layer 121; top layer 122; middle layer 123;

[0032] Encapsulation layer 13; organic thin film layer 131; inorganic thin film layer 132. DETAILED DESCRIPTION

[0033] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with this specification. Rather, they are merely examples of apparatus and methods consistent with certain aspects of this specification, as detailed in the appended claims.

[0034] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. Unless otherwise defined, technical or scientific terms used in this specification should have the same ordinary meaning as those understood by persons of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and similar terms used in this specification and the claims do not denote any order, quantity, or importance, but are simply used to distinguish one component from another. Similarly, terms such as "a" or "an" do not denote a limitation of quantity, but rather indicate the presence of one. "Multiple" or "several" means two or more. Unless otherwise indicated, terms such as "front," "rear," "lower," and / or "upper" are used for convenience only and are not intended to limit the scope of the disclosure to a specific location or spatial orientation. Terms such as "include" or "comprising" mean that the elements or objects listed before "include" or "comprising" include the elements or objects listed after "include" or "comprising" and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect.

[0035] The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure. As used in this specification and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0036] OLED (Organic Light-Emitting Diode) screens have been widely used in display modules due to their ultra-thin, flexible, and low-voltage driving characteristics. With the development of phosphorescent OLED materials, heavy metal elements can promote spin-orbit coupling and enhance intersystem crossing efficiency. The internal quantum efficiency of OLED devices has approached 100%. However, the external quantum efficiency is affected by the light transmittance of thin-film encapsulation, touch layer, and various module stacking materials, resulting in light blocking of some OLED devices and reduced light output intensity.

[0037] The present disclosure provides a light emitting device. Figure 1 is a schematic cross-sectional structural diagram of a screen module in an exemplary embodiment of the present disclosure. Figure 2 is a schematic cross-sectional structural diagram of a light emitting device in another exemplary embodiment of the present disclosure, such as Figure 1 、 Figure 2As shown, the light-emitting device includes a display body 11 and a light extraction layer 12. The display body 11 includes a cathode 112 and a functional layer group 111. The light extraction layer 12 is disposed on the side of the cathode 112 facing away from the functional layer group 111, and the light extraction layer 12 covers the cathode 112. The light extraction layer 12 includes a bottom layer 121 adjacent to the cathode 112, a top layer 122 opposite the bottom layer 121, and at least one intermediate layer 123 between the top layer 122 and the bottom layer 121. The refractive index of the at least one intermediate layer 123 is greater than that of the top layer 122 and the bottom layer 121, so that the light extraction layer 12 forms a first microcavity for light oscillation between the top layer 122 and the bottom layer 121.

[0038] Since the light extraction layer 12 located on the side of the cathode 112 facing away from the functional layer group 111 is provided with a bottom layer 121, a top layer 122 and at least one intermediate layer 123, the intermediate layer 123 is located between the bottom layer 121 and the top layer 122. The light passing through the bottom layer 121, the intermediate layer 123 and the top layer 122 forms a first microcavity structure for light oscillation similar to a Bragg reflector in the light extraction layer 12 due to the different refractive indices, so that the light is strengthened due to the existence of constructive interference, which is beneficial to weakening the surface plasmon mode effect (SPP effect) on the surface of the cathode 112, thereby improving the light output intensity and reducing the power consumption of the screen.

[0039] In some embodiments, the refractive index of the bottom layer 121 and / or the top layer 122 at a wavelength of 450nm-650nm is less than or equal to 1.6. For example, when the refractive index of the bottom layer 121 at a wavelength of 460nm is less than or equal to 1.6, its low refractive index can be used to conduct the light transmitted from the cathode 112 to the light extraction layer 12. For example, when the refractive index of the top layer 122 at a wavelength of 460nm is less than or equal to 1.6, its low refractive index can be used to guide the light in the light extraction layer 12 to the outside of the screen module 1, avoiding total reflection and improving the light output efficiency and light output intensity. For example, when the refractive index of the bottom layer 121 and the top layer 122 at a wavelength of 460nm is less than or equal to 1.6, the light propagation efficiency and light output intensity can be further improved.

[0040] It should be noted that the refractive index of the bottom layer 121 and / or the top layer 122 at wavelengths between 450 nm and 650 nm may also be other values ​​greater than 1.6, so as to achieve enhanced transmission and oscillation of light transmitted from the cathode 112. This disclosure is not limited thereto. The refractive index of the bottom layer 121 and / or the top layer 122 at other wavelengths may also be less than the preset value to achieve a low-refractive-index transmission effect.

[0041] In the above embodiment, the bottom layer 121 and the top layer 122 can have the same refractive index at the same wavelength to simplify the structure of the light extraction layer 12. Alternatively, the bottom layer 121 and the top layer 122 can have different refractive indices at the same wavelength to achieve better light enhancement and light extraction efficiency by combining the top and bottom layers 122, 121 with different refractive indices with the multiple intermediate layers 123.

[0042] In addition, the material of the bottom layer 121 and the top layer 122 can be LiF, or a fluorine-containing organic small molecule material, or a fluorine-free organic small molecule material.

[0043] In some embodiments, the thickness of the bottom layer 121 and / or the top layer 122 is greater than or equal to 10 nm and less than or equal to 30 nm to ensure that the light extraction layer 12 effectively guides and guides light emitted from the cathode 112. For example, the top layer 122 and the bottom layer 121 can have the same thickness of 15 nm.

[0044] In other embodiments, the thicknesses of the top layer 122 and the bottom layer 121 may be different, and the present disclosure is not limited thereto.

[0045] In some embodiments, the refractive index of at least one intermediate layer 123 at a wavelength of 450 nm to 650 nm is greater than 1.8, so as to enhance the oscillation of light in the light extraction layer 12 by having a refractive index different from that of the top layer 122 and the bottom layer 121 .

[0046] When the refractive index of the intermediate layer 123 at a wavelength of 460 nm is greater than 1.8, the thickness of the intermediate layer 123 is greater than or equal to 30 nm and less than or equal to 80 nm, so as to achieve the desired light oscillation enhancement effect through the thickness of the intermediate layer 123. For example, the thickness of the intermediate layer 123 can be 50 nm.

[0047] In other embodiments, the refractive index of at least one intermediate layer 123 at a wavelength of 460 nm is less than or equal to 1.6, so that light can smoothly oscillate and propagate between the multiple intermediate layers 123 .

[0048] In the above embodiment, the light extraction layer 12 includes at least five intermediate layers 123 , so as to obtain constructive interference on the propagation of light through the multiple intermediate layers 123 , thereby enhancing the intensity of the extracted light and improving the propagation efficiency.

[0049] The refractive indices of two adjacent intermediate layers 123 at the same wavelength can be the same or different to achieve the desired light propagation effect. Depending on the refractive index at the same wavelength, the intermediate layer 123 with a refractive index less than a first preset value is designated as a low refractive index layer, while the intermediate layer 123 with a refractive index greater than a second preset value is designated as a high refractive index layer. The first and second preset values ​​can be set to 1.6, 1.8, 2.2, etc., as needed.

[0050] Taking the first preset value as 1.6 and the second preset value as 1.8 as an example, the distribution of the multiple intermediate layers 123 can be alternating low refractive index layers and high refractive index layers, or can include the case where two adjacent intermediate layers 123 are low refractive index layers, or can include the case where two adjacent intermediate layers 123 are high refractive index layers.

[0051] It should be noted that the material of the intermediate layer 123 can be LiF, or a fluorine-containing organic small molecule material, or a fluorine-free organic small molecule material, or an inorganic silicon-containing material such as silicon nitride, silicon oxynitride, or silicon oxide film.

[0052] In some embodiments, the screen module 1 further includes an encapsulation layer 13 , which covers the light extraction layer 12 and the display body 11 to prevent water and oxygen from entering the light extraction layer 12 and the display body 11 .

[0053] Among them, the encapsulation layer 13 includes two inorganic thin film layers 132 and an organic thin film layer 131 located between the two inorganic thin film layers 132, so as to encapsulate the above-mentioned display body 11 through a thin film, simplify the encapsulation process, and make the encapsulation layer 13 suitable for various scenarios such as curved screens, flexible screens and ordinary screens, thereby reducing the thickness of the screen module 1 and improving the encapsulation reliability.

[0054] In addition, if Figure 1-Figure 5 As shown, the functional layer group 111 is provided with an anode 113 on a side away from the cathode 112. The cathode 112 includes a cathode reflective layer, and the anode 113 includes an anode reflective layer. The display body 11 forms a second microcavity between the cathode and anode reflective layers for light oscillation. This second microcavity allows light emitted from the light-emitting components of the display body 11 to reflect and oscillate between the cathode and anode reflective layers, thereby amplifying the light and improving light extraction efficiency and intensity.

[0055] The cathode reflective layer and the anode reflective layer may be metal coatings formed on the cathode 112 and the anode 113 respectively. For example, the cathode reflective layer and the anode reflective layer may be made of silver.

[0056] Functional layer group 111 may also include an anode 113. Anode 113 thin film may be fabricated using magnetron sputtering. For example, in the case of anode 113 with a stacked structure of ITO1 / Ag / ITO2, the thickness of ITO1 may be 3-12 nm, the thickness of Ag may be 80-120 nm, and the thickness of ITO2 may be 7-12 nm.

[0057] The functional layer group 111 may further include a hole injection layer (HIL). The HIL 114 is doped with host and guest materials. The guest doping concentration may be 0.2%-5.0% by mass. The thickness of the HIL 114 may be 5nm-20nm.

[0058] The functional layer group 111 may further include a hole transport layer (HTL). The HTL 115 is a single material and is the same as the main material of the HIL 114 . The thickness may be 100-12 nm.

[0059] The functional layer group 111 may further include a microcavity adjustment layer (Prime). The Prime 116 functions to transport holes and adjust the microcavity length. The thickness of the blue layer may be 5 nm, the thickness of the green layer may be 25-30 nm, and the thickness of the red layer may be 75-90 nm.

[0060] The functional layer group 111 may further include a light-emitting layer (EML). The EML 117 is a doped type of host and guest materials. The doped guest can be a fluorescent material or a phosphorescent material. The doping mass ratio can be 1%-10%. The blue thickness is 18-22nm, the green thickness is 28-40nm, and the red thickness is 38-42nm.

[0061] The functional layer group 111 may further include HBL 118 , which mainly functions to transport electrons and block holes. The film is made of a single material and may have a thickness of 4-6 nm.

[0062] The functional layer group 111 may further include an ETL 119 . The ETL 119 is formed by a mixed deposition method of two materials, one of which is Liq. The film thickness may be 30-50 nm.

[0063] The cathode 112 of the screen module 1 may be a metal cathode 112 , and the cathode 112 structure may be a Yb / Mg:Ag double-layer structure, the Yb thickness may be 1 nm, the Mg:Ag ratio may be 1:9, and the Mg:Ag thickness may be 9 nm-15 nm.

[0064] The anode 113, HIL 114, HTL 115, EML 117, HBL 118, ETL 119, cathode 112 and light extraction layer 12 are sequentially stacked to form the screen module 1. Each layer of the screen module 1 can be prepared by vacuum thermal evaporation.

[0065] The present disclosure further provides a screen module 1, which includes the above-mentioned light-emitting device.

[0066] The present disclosure further provides an electronic device, which includes the above-mentioned light-emitting device or screen module 1.

[0067] Since the light extraction layer 12 located on the side of the cathode 112 facing away from the functional layer group 111 is provided with a bottom layer 121, a top layer 122 and at least one intermediate layer 123, and the intermediate layer 123 is located between the bottom layer 121 and the top layer 122, the light passing through the bottom layer 121, the intermediate layer 123 and the top layer 122 forms a first microcavity structure for light oscillation similar to a Bragg reflector in the light extraction layer 12 due to the different refractive indices, so that the light is strengthened due to the existence of constructive interference, thereby improving the light output intensity and reducing the power consumption of the screen.

[0068] It should be noted that the above-mentioned electronic device can be one of a mobile phone, a tablet computer, a computer, a vehicle-mounted device, a medical device, a wearable device, and a robot, and the present disclosure is not limited to this.

[0069] The above description is merely a preferred embodiment of the present disclosure and does not constitute any form of limitation to the present disclosure. Although the present disclosure has been disclosed as a preferred embodiment as above, it is not intended to limit the present disclosure. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of the technical content disclosed above without departing from the scope of the technical solution of the present disclosure. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present disclosure without departing from the content of the technical solution of the present disclosure are still within the scope of the technical solution of the present disclosure.

Claims

1. A light emitting device, characterized in that: including a display body and a light extraction layer; The display body includes a cathode and a functional layer group, the light extraction layer is arranged on a side of the cathode facing away from the functional layer group, and the light extraction layer covers the cathode; The light extraction layer includes a bottom layer close to the cathode, a top layer opposite to the bottom layer, and at least one intermediate layer located between the top layer and the bottom layer, wherein the refractive index of at least one intermediate layer is greater than the refractive index of the top layer and the bottom layer, so that the light extraction layer forms a first microcavity for light oscillation between the top layer and the bottom layer.

2. The light emitting device according to claim 1, wherein The functional layer group is provided with an anode on a side away from the cathode. The cathode includes a cathode reflective layer, and the anode includes an anode reflective layer. The display body forms a second microcavity for light oscillation between the cathode reflective layer and the anode reflective layer.

3. The light emitting device according to claim 1, wherein It also includes an encapsulation layer; the encapsulation layer covers the light extraction layer and the display body.

4. The light emitting device according to claim 3, characterized in that The encapsulation layer comprises two inorganic thin film layers and an organic thin film layer located between the two inorganic thin film layers.

5. The light emitting device according to claim 1, wherein The light extraction layer includes at least five intermediate layers. The light emitting device according to claim 1 , wherein: The refractive index of the bottom layer and / or the top layer at a wavelength of 450 nm to 650 nm is less than or equal to 1.

6.

7. The light emitting device according to claim 1, characterized in that The thickness of the bottom layer and / or the top layer is greater than or equal to 10 nm and less than or equal to 30 nm.

8. The light emitting device according to claim 1, wherein At least one of the intermediate layers has a refractive index greater than 1.8 at a wavelength of 450 nm to 650 nm.

9. The light emitting device according to claim 1, wherein When the refractive index of the intermediate layer at a wavelength of 450 nm to 650 nm is greater than 1.8, the thickness of the intermediate layer is greater than or equal to 30 nm and less than or equal to 80 nm.

10. The light emitting device according to claim 1, wherein The refractive index of at least one of the intermediate layers at a wavelength of 450 nm to 650 nm is less than or equal to 1.

6.

11. A screen module, characterized in that: The light emitting device comprises the light emitting device according to any one of claims 1 to 10.

12. An electronic device, characterized in that: The light-emitting device comprises the light-emitting device according to any one of claims 1 to 10; or the screen module according to claim 11.

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