OLED device and electronic equipment

Abstract

The invention provides an OLED device. The OLED device comprises a substrate, multiple layers of electrodes arranged on the substrate, and light emitting layers located between the adjacent electrodes. The adjacent electrodes and the light-emitting layer clamped between the adjacent electrodes form a light-emitting unit; wherein in the multiple layers of electrodes, one of the electrode closest to the substrate and the electrode farthest away from the substrate is a transmission electrode, the other electrode is a reflection electrode, and the rest electrodes are intermediate electrodes; the working current density of each light-emitting unit is monotonically decreased in the direction from the reflection electrode to the transmission electrode.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of electronic devices, and in particular relates to an OLED device and an electronic device. Background Art

[0002] In the related technology, lighting includes OLED (Organic Light-Emitting Diode) lighting and LED (Light-Emitting Diode) lighting. Compared with LED lighting, OLED lighting is a surface light source and is gentler. Most OLED desk lamps on the market are single-color temperature and adjustable brightness products. For example, the color temperature is generally 1800K~3200K (amber) or white light around 4000K, and the color temperature cannot be infinitely adjusted. OLED products that can achieve color temperature adjustment use multiple light-emitting layers of different colors placed in parallel. Light-emitting layers of different colors cannot share the same aperture ratio, which will lead to problems such as reduced lifespan. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art and provides an OLED device and an electronic device.

[0004] The present disclosure provides an OLED device, which includes a substrate, a multilayer electrode arranged on the substrate, and a light-emitting layer located between the adjacent electrodes; the adjacent electrodes and the light-emitting layer sandwiched therebetween constitute a light-emitting unit;

[0005] wherein among the multilayer electrodes, one of the electrode closest to the substrate and the electrode farthest from the substrate is a transmissive electrode, the other is a reflective electrode, and the remaining electrodes are intermediate electrodes;

[0006] Along the direction from the reflective electrode to the transmissive electrode, the working current density of each of the light-emitting units decreases monotonically.

[0007] Among them, the intermediate electrode includes multiple layers of sub-electrodes, among which a layer of sub-electrodes closest to the reflective electrode is a first sub-electrode, a layer of sub-electrodes closest to the transmissive electrode is a second sub-electrode, and a work function of the first sub-electrode is greater than a work function of the second sub-electrode.

[0008] The difference between the work functions of the first sub-electrode and the second sub-electrode is 1.2-2.5 eV.

[0009] Wherein, the work function of the first sub-electrode is greater than 4.8 eV, and / or the work function of the second sub-electrode is less than 4.3 eV.

[0010] Wherein, the material of the first sub-electrode includes at least one of IZO and ITO; and / or

[0011] The material of the second sub-electrode includes at least one of magnesium, silver and aluminum.

[0012] The intermediate electrode further includes a third sub-electrode sandwiched between the first sub-electrode and the second sub-electrode, and a work function of the third sub-electrode is smaller than a work function of the second sub-electrode.

[0013] Wherein, the light transmittance of the intermediate electrode is not less than 40%.

[0014] Wherein, the thickness of the first sub-electrode is 100-300 nm; and / or

[0015] The thickness of the second sub-electrode is 10-15 nm.

[0016] There are multiple light-emitting layers, and at least two of the light-emitting layers emit light of different colors.

[0017] The present disclosure provides an electronic device, comprising any one of the above-mentioned OLED devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an OLED device in the related art;

[0019] Figure 2 is a schematic structural diagram of an OLED device according to an embodiment of the present disclosure;

[0020] Figure 3 This is a schematic structural diagram of a light-emitting unit of an OLED device according to an example of the present disclosure;

[0021] Figure 4 A schematic structural diagram of a light-emitting unit of an OLED device according to another example of the present disclosure;

[0022] Figure 5 for Figure 2 The equivalent circuit diagram of the OLED device shown. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] like Figure 1 As shown, in the related art, the OLED device includes a base substrate 10, a pixel defining layer 20 disposed on the base substrate 10, and two light-emitting units L; wherein the two light-emitting units L are used for emitting different light, and both include a first electrode 30, a light-emitting layer, and a second electrode 50 sequentially disposed in a direction away from the base substrate 10, and the first electrodes 30 of the two light-emitting units L are not connected to each other. The light-emitting colors of the two light-emitting units L are different, so the colors of the light-emitting layers of the two are different. The pixel defining layer 20 has a pixel opening corresponding to the light-emitting unit L, wherein the first electrode 30 of the light-emitting unit L is located on a side of the pixel defining layer 20 close to the base substrate 10, the light-emitting layer of the light-emitting unit L at least covers the pixel opening and is in contact with the first electrode 30, and the second electrode 50 covers the side of the light-emitting layer away from the first electrode 30. For each light-emitting unit L, one of the first electrode 30 and the second electrode 50 is an anode, and the other is a cathode. Figure 1 In the example, the first electrode 30 is used as an anode and the second electrode 50 is used as a cathode. In some examples, in order to facilitate voltage loading and preparation, the cathodes of the two light-emitting units L are designed as an integrated structure. One of the cathode and the anode of the OLED device is a transmissive electrode and the other is a reflective electrode. Figure 1 In the OLED device in , the cathode is a reflective electrode and the anode is a transmissive electrode as an example.

[0026] It should be noted that Figure 1In the example, an OLED device including two light-emitting units L is used. For ease of description, the two light-emitting units L are respectively referred to as a first light-emitting unit L1 and a second light-emitting unit L2. The light-emitting layer of the first light-emitting unit L1 is represented by a first light-emitting layer 41, and the light-emitting layer of the second light-emitting unit L2 is represented by a second light-emitting layer 42. In order to prevent water and oxygen from affecting the light-emitting layer of the light-emitting unit L, the encapsulation layer 60 is covered on the side of the cathode of the light-emitting unit L away from the base substrate 10.

[0027] for Figure 1 The driving of the OLED device in the embodiment can be achieved by applying a corresponding voltage to the cathode and anode of the first light-emitting unit L1 so that the first light-emitting unit L1 emits a light of the first color, and by applying a corresponding voltage to the cathode and anode of the second light-emitting unit L2 so that the second light-emitting unit L2 emits a light of the second color. At this time, the light of the first color and the light of the second color are mixed so that the OLED device emits a light of the third color. For the OLED device, the intensity of the light emitted by the first light-emitting unit L1 and the second light-emitting unit L2 can be adjusted by adjusting the voltage applied to the anode of the first light-emitting unit L1 and the anode of the second light-emitting unit L2, thereby adjusting the color temperature of the light of the third color emitted by the OLED device.

[0028] The inventors have discovered that since the light-emitting units L in the OLED device are arranged in parallel, that is, one pixel opening corresponds to only one light-emitting unit L, the pixel openings of the light-emitting units L cannot be shared. Therefore, when a problem occurs in one light-emitting unit L, the OLED device cannot achieve color temperature adjustment. At the same time, the inability of the light-emitting units L to share an opening is not conducive to improving the aperture ratio, so that the orthographic projection area of ​​the first electrode 30 and / or the second electrode 50 of each light-emitting unit L on the base substrate 10 is relatively small, resulting in a larger operating current density when achieving the same brightness, which reduces the life of the light-emitting device.

[0029] In view of the problems existing in the OLED devices in the above related technologies, the present disclosure provides a new OLED device structure.

[0030] like Figure 2 As shown, the OLED device provided by the embodiment of the present disclosure includes a substrate 10, a multilayer electrode and a light-emitting layer. The multilayer electrode is arranged on the substrate 10, and the light-emitting layer is located between adjacent electrodes; the adjacent electrodes and the light-emitting layer sandwiched therebetween constitute a light-emitting unit. Among the multilayer electrodes, one of the electrode closest to the substrate 10 and the electrode farthest from the substrate 10 is a transmissive electrode, the other is a reflective electrode, and the remaining electrodes are intermediate electrodes 70; along the direction from the reflective electrode to the transmissive electrode, the working current density of each light-emitting unit decreases monotonically.

[0031] In the embodiment of the present disclosure, the electrode sandwiched between adjacent light-emitting layers simultaneously serves as the electrode of two adjacent light-emitting units. In other words, if the number of light-emitting layers is N, that is, the number of light-emitting units is N, along the direction away from the base substrate 10, the electrode of the i-th light-emitting unit on the side away from the base substrate 10 and the electrode of the i+1-th light-emitting unit on the side close to the base substrate 10 are the same electrode, where i=1~N, and N is a positive integer.

[0032] In the embodiment of the present disclosure, each light-emitting unit is stacked, and each light-emitting unit in the stacked arrangement shares an aperture ratio. Compared with the scheme in which each light-emitting unit is arranged in parallel in the related art, the aperture ratio of each light-emitting unit in the scheme of the present disclosure is larger, which is beneficial to reduce the working current density flowing through each light-emitting unit and extend the service life of the OLED device under the condition of achieving the same luminous brightness. At the same time, in the embodiment of the present disclosure, since the working current density of each light-emitting unit decreases monotonically in the direction from the reflective electrode to the transmissive electrode, the overall working voltage drop of the OLED device can be reduced, thereby reducing the IR Drop between the middle part and the edge part of the middle electrode 70, making the luminous brightness of the light-emitting unit more uniform, and improving the luminous quality of the OLED device.

[0033] In the embodiment of the present disclosure, the electrode closest to the base substrate 10 in the multilayer electrode is a transmissive electrode, and the electrode farthest from the base substrate 10 is a reflective electrode. Of course, in other embodiments, the electrode closest to the base substrate 10 in the multilayer electrode can also be set as a reflective electrode, and the electrode farthest from the base substrate 10 is a transmissive electrode.

[0034] In the embodiment of the present disclosure, the electrode closest to the base substrate 10 in the multilayer electrode is used as the anode, and the electrode farthest from the base substrate 10 is used as the cathode. Of course, in other embodiments, the electrode closest to the base substrate 10 in the multilayer electrode can also be used as the cathode, and the electrode farthest from the base substrate 10 can be used as the anode.

[0035] Next, the OLED device in this embodiment is described in detail with reference to specific examples.

[0036] In the embodiments of the present disclosure, for the convenience of description, an OLED device including three layers of electrodes and two layers of light-emitting layers is used as an example for illustration in the following examples, but this does not constitute a limitation to the present disclosure.

[0037] like Figure 2As shown, the OLED device in this example includes a substrate 10, and a pixel defining layer 20, three electrodes and two light-emitting layers arranged on the substrate 10. Among them, the three electrodes include a first electrode 30, an intermediate electrode 70 and a second electrode 50, and the two light-emitting layers include a first light-emitting layer 41 and a second light-emitting layer 42. The pixel defining layer 20 has an opening that runs through it in the thickness direction. The first electrode 30, the first light-emitting layer 41, the intermediate electrode 70, the second light-emitting layer 42 and the second electrode 50 are arranged in sequence in a direction away from the substrate 10, and these five are arranged corresponding to the opening. The first electrode 30, the first light-emitting layer 41 and the intermediate electrode 70 constitute a first light-emitting unit, and the intermediate electrode 70, the second light-emitting layer 42 and the second electrode 50 constitute a second light-emitting unit. Among them, the second electrode 50 is a reflective electrode, and the first electrode 30 is a transmissive electrode. The working current density of the second light-emitting unit is greater than the working current density of the first light-emitting unit.

[0038] In this example, the first light-emitting unit is driven to emit light by applying a first driving voltage between the first electrode 30 and the middle electrode 70, and the second light-emitting unit is driven to emit light by applying a second driving voltage between the middle electrode 70 and the second electrode 50. By setting the operating current density of the second light-emitting unit to be greater than the operating current density of the first light-emitting unit, the overall operating voltage drop of the OLED device can be reduced, thereby reducing the IRDrop between the middle part and the edge part of the middle electrode 70, so that the light-emitting brightness of the first light-emitting unit and the second light-emitting unit is more uniform, thereby improving the light-emitting quality of the OLED device.

[0039] In this example, the first electrode can be used as the anode of the first light-emitting unit, the middle electrode can be used as both the cathode of the first light-emitting unit and the anode of the second light-emitting unit, and the second electrode can be used as the cathode of the second light-emitting unit. In other examples, the first electrode can be used as the cathode of the first light-emitting unit, the middle electrode can be used as both the anode of the first light-emitting unit and the cathode of the second light-emitting unit, and the second electrode can be used as the anode of the second light-emitting unit.

[0040] In this example, the operating current density of the second light-emitting unit can be greater than the operating current density of the first light-emitting unit by adjusting the area size and material setting of the first electrode 30 , the intermediate electrode 70 and the second electrode 50 in a direction parallel to the base substrate 10 .

[0041] In some examples, the middle electrode 70 may be designed so that the operating current density of the second light emitting unit is greater than the operating current density of the first light emitting unit.

[0042] like Figure 3As shown, in one example, the intermediate electrode layer 70 includes a second sub-electrode 72 and a first sub-electrode 71 stacked in sequence in a direction away from the base substrate 10. The work function of the first sub-electrode 71 is greater than the work function of the second sub-electrode 72. In this case, by setting the intermediate electrode 70 to include the first sub-electrode 71 and the second sub-electrode 72 with different work functions, the overall square resistance of the intermediate electrode 70 can be effectively reduced, which is beneficial to reducing the overall operating voltage drop of the OLED device, reducing the IR Drop between the middle part and the edge part of the intermediate electrode 70, making the light emitting brightness of the first light emitting unit and the second light emitting unit more uniform, and improving the light emitting quality of the OLED device. Figure 3 The arrow in the figure indicates the direction of current flow.

[0043] In this example, the first electrode 30 serves as the anode of the first light emitting unit, the second sub-electrode 72 serves as the cathode of the first light emitting unit, the first sub-electrode 71 serves as the anode of the second light emitting unit, and the second electrode 50 serves as the cathode of the second light emitting unit.

[0044] Further, the difference between the work function of the first sub-electrode 71 and the second sub-electrode 72 is 1.2 to 2.5 eV. For example, the work function of the first sub-electrode 71 is greater than 4.8 eV, and / or the work function of the second sub-electrode 72 is less than 4.3 eV. Further, the work function of the first sub-electrode 71 can be 5.5 eV, 6.2 eV, etc., and the work function of the second sub-electrode 72 can be 4.0 eV, 3.5 eV, etc., which are not specifically limited here.

[0045] Furthermore, the first sub-electrode 71 can be made of a material with good light transmittance, such as IZO (Indium Zinc Oxide), ITO (Indium Tin Oxide), etc., and the second sub-electrode 72 can be made of a material with good conductivity, such as magnesium, silver, aluminum, etc. For example, the second sub-electrode 72 can be a film layer formed by a co-evaporation film process using magnesium and silver.

[0046] like Figure 4As shown, in another example, the middle electrode 70 includes a second sub-electrode 72, a third sub-electrode 73 and a first sub-electrode 71 which are stacked in sequence in a direction away from the base substrate 10. The work function of the first sub-electrode 71 is greater than the work function of the second sub-electrode 72, and the work function of the second sub-electrode 72 is greater than the work function of the third sub-electrode 73. In this case, by arranging the third sub-electrode 73 between the first sub-electrode 71 and the second sub-electrode 72, the overall square resistance of the middle electrode 70 can be further reduced, which is conducive to further reducing the overall operating voltage drop of the OLED device, reducing the IR Drop between the middle part and the edge part of the middle electrode 70, making the light emitting brightness of the first light emitting unit and the second light emitting unit more uniform, and improving the light emitting quality of the OLED device. Figure 4 The arrow in the figure indicates the direction of current flow.

[0047] In this example, the first electrode 30 serves as the anode of the first light-emitting unit, the second sub-electrode 72 and the third sub-electrode 73 serve as the cathode of the first light-emitting unit, the first sub-electrode 71 serves as the anode of the second light-emitting unit, and the second electrode 50 serves as the cathode of the second light-emitting unit.

[0048] Furthermore, the difference in work function between the first sub-electrode 71 and the second sub-electrode 72 is 1.2-2.5 eV. The specific setting of the difference in work function between the first sub-electrode 71 and the second sub-electrode 72 can refer to the above example, and will not be repeated here.

[0049] In this example, the materials of the first sub-electrode 71 and the second sub-electrode 72 can be the same materials as mentioned above, and the material of the third sub-electrode 73 can be a material with better conductivity than the second sub-electrode 72, such as silver, but the purity of the silver selected for the third sub-electrode 73 is higher than the purity of the silver selected for the second sub-electrode 72.

[0050] In some examples, the first electrode 30 may be a single-layer structure or a composite-layer structure. The first electrode may be a transmissive electrode, the material of which may include at least one of ITO and IZO; the first electrode may also be a reflective electrode, the material of which may include aluminum, silver, etc.

[0051] In some examples, the second electrode 50 may be a single-layer structure or a composite-layer structure. The second electrode may be a reflective electrode, the material of which may include aluminum, silver, etc.; the second electrode may also be a transmissive electrode, the material of which may include at least one of ITO and IZO.

[0052] In some examples, there are two light-emitting layers, namely, a first light-emitting layer 41 and a second light-emitting layer 42. The first light-emitting layer 41 emits light of a first color, and the second light-emitting layer 42 emits light of a second color. The light of the first color and the light of the second color are mixed and then emitted. The materials of the first light-emitting layer 41 and the second light-emitting layer 42 can be organic electroluminescent materials.

[0053] In some examples, the substrate 10 can be made of a rigid or flexible light-transmitting material, such as a rigid light-transmitting material such as quartz glass, a silicon substrate, a germanium substrate, etc., and a flexible light-transmitting material such as polyimide, flexible glass, etc.

[0054] In some examples, the material of the pixel defining layer 20 may be a material with a transmittance lower than a preset threshold, such as a black rubber material, etc., wherein the size of the preset threshold can be set as needed and is not specifically limited here.

[0055] like Figure 2 As shown, the OLED device further includes an encapsulation layer 60 disposed on a side of the second electrode 50 facing away from the base substrate 10 .

[0056] In some examples, the encapsulation layer 60 may be a single-layer structure or a composite layer structure. For example, the encapsulation layer 60 may include an organic encapsulation layer, an inorganic encapsulation layer, and an organic encapsulation layer, which are stacked in sequence. The material of the organic encapsulation layer may include epoxy resin, polyimide, polyamide, etc. The material of the inorganic encapsulation layer may include plastic, ceramic, and other materials. By providing the encapsulation layer 60, water and oxygen can be blocked, thereby extending the service life of the OLED device.

[0057] like Figure 2 As shown, the multilayer electrode includes a first electrode 30, an intermediate electrode 70 and a second electrode 50, and the multilayer light-emitting layer includes a first light-emitting layer 41 and a second light-emitting layer 42. The first electrode 30, the first light-emitting layer 41 and the intermediate electrode 70 constitute a first light-emitting unit, and the intermediate electrode 70, the second light-emitting layer 42 and the second electrode 50 constitute a second light-emitting unit.

[0058] like Figure 5 As shown, it is a schematic diagram of the circuit principle for driving the first light-emitting unit and the second light-emitting unit to emit light. The first light-emitting layer 41 can be equivalent to the first diode EL1, and the second light-emitting layer 42 can be equivalent to the second diode EL2. By applying a first driving voltage V1 between the first electrode 30 and the intermediate electrode 70, the first light-emitting layer 41 (equivalent to the first diode EL1) is driven to emit light, and by applying a second driving voltage V2 between the intermediate electrode 70 and the second electrode 50, the second light-emitting layer 42 (equivalent to the second diode EL2) is driven to emit light. The first driving voltage V1 is greater than the start-up voltage of the first light-emitting layer 41, and the second driving voltage V2 is greater than the start-up voltage of the second light-emitting layer 42.

[0059] In a specific example, the first electrode 30 is used as the anode of the first light-emitting unit, the second sub-electrode 72 is used as the cathode of the first light-emitting unit, and the first driving voltage V1 applied between the first electrode 30 and the middle electrode 70 is equivalent to the first driving voltage V1 applied between the first electrode 30 and the second sub-electrode 72 to drive the first light-emitting unit to emit light; the first sub-electrode 71 is used as the anode of the second light-emitting unit, the second electrode 50 is used as the cathode of the second light-emitting unit, and the second driving voltage V2 applied between the middle electrode 70 and the second electrode 50 is equivalent to the second driving voltage V2 applied between the first sub-electrode 71 and the second electrode 50 to drive the second light-emitting unit to emit light. The voltages applied to the first electrode 30, the middle electrode 70, and the second electrode 50 can be reduced in sequence.

[0060] Among them, the working current density of the second light-emitting unit is greater than the working current density of the first light-emitting unit, that is, I EL2 >I EL1 By adjusting the first driving voltage V1, the luminous intensity of the first light-emitting unit can be adjusted, thereby adjusting the brightness of the first color. By adjusting the second driving voltage V2, the luminous intensity of the second light-emitting unit can be adjusted, thereby adjusting the brightness of the second color. By adjusting the brightness of the first color and the second color respectively, the color temperature of the output light of the OLED device can be adjusted.

[0061] The above is an introduction to an OLED device including two light-emitting units. In other examples, the OLED device may also include more light-emitting units. For example, the OLED device may include three light-emitting units. By individually adjusting the light-emitting intensity of each light-emitting unit, the color temperature of the output light of the OLED device can be adjusted, and more output light with different color temperatures can be obtained.

[0062] In some examples, the intermediate electrode may include not only the above-mentioned two or three layers of sub-electrodes, but also more layers of sub-electrodes. Among the multiple layers of sub-electrodes, the layer of sub-electrodes closest to the reflective electrode is the first sub-electrode, and the layer of sub-electrode closest to the transmissive electrode is the second sub-electrode. As long as the work function of the first sub-electrode is greater than the work function of the second sub-electrode, and the work function of other sub-electrodes sandwiched between the first sub-electrode and the second sub-electrode is less than the work function of the second sub-electrode, it can be done.

[0063] Further, the difference between the work function of the first sub-electrode and the second sub-electrode is 1.2 to 2.5 eV. For example, the work function of the first sub-electrode is greater than 4.8 eV, and / or the work function of the second sub-electrode is less than 4.3 eV. Further, the work function of the first sub-electrode can be 5.5 eV, 6.2 eV, etc., and the work function of the second sub-electrode can be 4.0 eV, 3.5 eV, etc., which are not specifically limited here.

[0064] In the embodiment of the present disclosure, the materials of the first sub-electrode and the second sub-electrode can be selected so that the difference in work function between the first sub-electrode and the second sub-electrode meets preset requirements. The specific material selection can be found in the above examples and will not be repeated here.

[0065] In some examples, the intermediate electrode can be not only a single layer but also a plurality of layers. When the intermediate electrode is a plurality of layers, the intermediate electrodes located in different layers may include the same or different layers of sub-electrodes, and the difference in work function between the first sub-electrode and the second sub-electrode may be the same or different, and no specific limitation is made here.

[0066] In some examples, the light transmittance of the intermediate electrode may be set to be not less than 40% to form a microcavity between the reflective electrode and the intermediate electrode, and between the intermediate electrodes.

[0067] In the disclosed embodiment, the transmittance of the intermediate electrode can be controlled by controlling the film structure and / or material composition of the intermediate electrode. For example, the intermediate electrode can include a two-layer structure, namely, a first sub-electrode closest to the reflective electrode and a second sub-electrode closest to the transmissive electrode, wherein the material of the first sub-electrode can be selected from IZO with good transmittance, and the material of the second sub-electrode can be selected from magnesium and silver with good conductivity, so that the intermediate electrode has a certain transmittance; further, by controlling the thickness ratio of the first sub-electrode and the second sub-electrode, the transmittance of the intermediate electrode can be controlled, for example, the thickness of the first sub-electrode can be made greater than the thickness of the second sub-electrode, or the ratio of the thickness of the first sub-electrode to the second sub-electrode can be controlled to be 6:4 or 7:3 or other different ratios to increase or decrease the transmittance of the intermediate electrode. The transmittance of the intermediate electrode can be selected from 45%, 53%, etc., for example, and is not specifically limited here.

[0068] In the embodiment of the present disclosure, by setting the transmittance of the intermediate electrode to be not less than 40%, a microcavity can be formed between the reflective electrode and the intermediate electrode, and between the intermediate electrodes, so that the light emitted by the light-emitting layer forms resonance in the microcavity through interference, thereby enhancing the propagation of light.

[0069] In some examples, when there are multiple intermediate electrodes, the multiple intermediate electrodes may have the same light transmittance or different light transmittances, which is not specifically limited here.

[0070] For the solution of stacking a plurality of light-emitting units in the embodiment of the present disclosure, the overall thickness of the OLED device can be controlled by controlling the thickness of the intermediate electrode.

[0071] In some examples, the thickness of the middle electrode is 150-300 nm, wherein the thickness of the first sub-electrode is 100-300 nm; and / or the thickness of the second sub-electrode is 10-15 nm.

[0072] In the disclosed embodiment, the thickness of the middle electrode can be 160nm, 180nm, 240nm, 290nm, etc. The middle electrode should not be too thick so that the OLED device as a whole has a small thickness. In other embodiments, the middle electrode can also have other thicknesses. The specific thickness of the middle electrode can be set as needed and is not specifically limited here.

[0073] In the embodiment of the present disclosure, the thickness of the first sub-electrode can be 120nm, 150nm, 260nm, etc., and the thickness of the second sub-electrode can be 11nm, 13nm, 14nm, etc. Compared with the second sub-electrode, the first sub-electrode has a larger work function and a larger thickness, which is beneficial to reducing the square resistance of the first sub-electrode, thereby reducing the overall square resistance of the middle electrode, reducing the IR Drop between the middle part and the edge part of the middle electrode, making the light emitting brightness of the first light emitting unit and the second light emitting unit more uniform, and improving the light emitting quality of the OLED device.

[0074] In some examples, when there are multiple intermediate electrodes, the multiple intermediate electrodes may have the same thickness or different thicknesses, which is not specifically limited here. In the intermediate electrodes of different layers, the thicknesses of the first sub-electrodes may be the same or different, the thicknesses of the second sub-electrodes may be the same or different, and the thickness ratio between the first sub-electrodes and the second sub-electrodes may be the same or different, which is not specifically limited here.

[0075] In some examples, the number of light-emitting layers may be not only two but also more, such as three, four, etc., wherein at least two light-emitting layers emit light of different colors. The material of the light-emitting layer may be an organic electroluminescent material, which may emit light through carrier injection and recombination under electric field driving.

[0076] In some examples, for each light-emitting unit, between two adjacent layers of electrodes, along the direction away from the substrate, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer and an electron injection layer may be included. That is, for each light-emitting unit, a hole injection layer, a hole transport layer, an electron transport layer and an electron injection layer may also be included to increase the injection speed and injection amount of holes and electrons, reduce the energy barrier of holes injected from the anode into the light-emitting layer and the energy barrier of electrons injected from the cathode into the light-emitting layer, thereby improving the luminescence efficiency and performance of the OLED device.

[0077] In some examples, along a direction perpendicular to the surface of the base substrate 10 and pointing to the base substrate 10, except for the electrode disposed between the pixel defining layer and the base substrate, the orthographic projection area of ​​each film layer on the base substrate 10 decreases monotonically. Figure 2 The example shown is used as an example to illustrate that the orthographic projection areas of the second electrode, the second light-emitting layer, the intermediate electrode and the first light-emitting layer on the base substrate decrease monotonically.

[0078] In other examples, the size of the orthographic projection area of ​​each film layer on the base substrate can be set as needed, which is conducive to setting up power supply circuits for each electrode to drive each light-emitting unit to emit light, and to adjust the light intensity of each light-emitting unit, thereby achieving color temperature adjustment of the emitted light.

[0079] An embodiment of the present disclosure provides an electronic device, comprising any of the above-mentioned OLED devices.

[0080] In the embodiments of the present disclosure, the electronic device may be any product or component with lighting or display functions, such as a lighting device, a mobile phone, a tablet computer, a television, a display, a laptop computer, a digital photo frame, and a navigator.

[0081] In some examples, the electronic device may further include a driving circuit for the above-mentioned OLED device.

[0082] The disclosed embodiment provides a method for manufacturing an OLED device, which includes: providing a substrate, forming an electrode on the substrate, which can be referred to as the first electrode for convenience of description; forming a pixel defining layer, the pixel defining layer including a plurality of openings, the openings exposing at least a portion of the first electrode, and then forming a plurality of alternatingly stacked light-emitting layers and electrodes in the openings; the electrode farthest from the substrate relative to the first electrode is referred to as the second electrode, the other electrodes sandwiched between the first electrode and the second electrode are referred to as the intermediate electrodes, and an encapsulation layer is formed on the side of the second electrode away from the substrate. The adjacent electrodes and the light-emitting layer therebetween constitute a light-emitting unit. In the OLED device, the light-emitting layer is at least two layers, and the intermediate electrode is at least one layer.

[0083] In one example, forming the intermediate electrode may include sequentially forming a stacked second sub-electrode and a first sub-electrode in a direction away from the substrate, wherein a work function of the first sub-electrode is greater than a work function of the second sub-electrode.

[0084] In one example, forming the intermediate electrode may include sequentially forming a second sub-electrode, a third sub-electrode and a first sub-electrode stacked in a direction away from the substrate, wherein the work functions of the first sub-electrode, the second sub-electrode and the third sub-electrode decrease in sequence.

[0085] In one example, for each light-emitting unit, among its two adjacent electrodes, the electrode close to the substrate is the anode, and the electrode far from the substrate is the cathode. A stacked hole injection layer and a hole transport layer may be formed in sequence between the anode and the light-emitting layer, and a stacked electron transport layer and an electron injection layer may be formed in sequence between the light-emitting layer and the cathode.

[0086] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An OLED device, comprising a substrate, a plurality of layers of electrodes disposed on the substrate, and a light-emitting layer located between the adjacent electrodes; the adjacent electrodes and the light-emitting layer sandwiched therebetween constitute a light-emitting unit; wherein among the multilayer electrodes, one of the electrode closest to the substrate and the electrode farthest from the substrate is a transmissive electrode, the other is a reflective electrode, and the remaining electrodes are intermediate electrodes; Along the direction from the reflective electrode to the transmissive electrode, the working current density of each of the light-emitting units decreases monotonically.

2. The OLED device according to claim 1, wherein: The intermediate electrode includes multiple layers of sub-electrodes, among which a layer of sub-electrodes closest to the reflective electrode is a first sub-electrode, a layer of sub-electrodes closest to the transmissive electrode is a second sub-electrode, and a work function of the first sub-electrode is greater than a work function of the second sub-electrode.

3. The OLED device according to claim 2, wherein: The difference between the work functions of the first sub-electrode and the second sub-electrode is 1.2-2.5 eV.

4. The OLED device according to claim 2 or 3, wherein: The work function of the first sub-electrode is greater than 4.8 eV, and / or the work function of the second sub-electrode is less than 4.3 eV.

5. The OLED device according to claim 2 or 3, wherein: The material of the first sub-electrode includes at least one of IZO and ITO; and / or The material of the second sub-electrode includes at least one of magnesium, silver and aluminum.

6. The OLED device according to claim 2 or 3, wherein: The intermediate electrode further includes a third sub-electrode sandwiched between the first sub-electrode and the second sub-electrode, and a work function of the third sub-electrode is smaller than a work function of the second sub-electrode.

7. The OLED device according to claim 1, wherein: The light transmittance of the intermediate electrode is not less than 40%.

8. The OLED device according to claim 2 or 3, wherein: The thickness of the first sub-electrode is 100-300 nm; and / or The thickness of the second sub-electrode is 10-15 nm.

9. The OLED device according to claim 1, wherein: There are multiple light-emitting layers, and at least two of the light-emitting layers emit light of different colors.

10. An electronic device comprising the OLED device according to any one of claims 1 to 9.

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