An organic electroluminescence device, a display device, and a lighting device

Abstract

The present application relates to a kind of organic electroluminescence device, display device and lighting device, the organic electroluminescence device described in the present application integrates the independent unit multiple luminescent layer organic electroluminescence device of organic electroluminescence element and external luminescent layer, the material of poor thermal stability or oxidation, reduction stability but high internal quantum efficiency is removed from the inside of organic electroluminescence element, is transferred to the side outside of the light emission of organic electroluminescence element, the material of external luminescent layer is excited by the emission light of organic electroluminescence element simultaneously luminescence, or only makes external luminescent layer luminescence, avoids the material of poor stability to directly contact with electric exciton, improves the luminous efficiency and life.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of display, and particularly relates to an organic electroluminescent device, a display device and an illuminating device. BACKGROUND

[0002] An organic electroluminescent element (OLED) is stacked by a cathode, an anode and an organic light-emitting material between the cathode and the anode, and converts electrical energy into light by applying a voltage across the cathode and the anode of the element, and has advantages of wide angle, high contrast and faster response time. Tang and Van Slyke of Eastman Kodak Company reported an organic electroluminescent element in 1987, an arylamine hole transport layer and a tris(8-hydroxyquinoline) aluminum layer as an electron transport layer and a light-emitting layer (Applied Physics Letters, 1987, 51(12): 913-915). After a voltage is applied across the element, green light is emitted from the element, which lays a foundation for the development of modern organic light-emitting diodes (OLEDs). OLEDs have advantages of low cost, low power consumption, high brightness, wide viewing angle and thin thickness, and have been widely applied in the fields of display and illumination after decades of development.

[0003] Generally, the organic light-emitting layer can be divided into three categories according to the light-emitting mechanism: fluorescent materials, phosphorescent materials and thermally activated delayed fluorescence (TADF) materials. Fluorescent materials are the first to be used in the preparation of OLEDs elements, and then in the late 1990s, phosphorescent materials are also successfully applied to OLEDs technology, and have better energy use efficiency than fluorescent materials. In recent years, TADF materials have attracted attention due to their efficiency comparable to phosphorescent materials.

[0004] In addition to the high preparation cost of phosphorescent materials, blue light has always been the biggest challenge for phosphorescent materials. Even after 20 years of research and development, it is still difficult to develop blue phosphorescent materials with efficiency, stability and pure color. The TADF material, which is highly expected, has a too wide spectrum and emits light with impure color. Now all OLEDs display screens still use fluorescent materials as blue light sources. In order to have sufficient brightness, the size of the blue pixel is about twice that of the red and green pixels, and the efficiency and service life are still short. There are many factors affecting the efficiency and service life of OLEDs. From the inside of the OLEDs, since electrons and holes are injected into the element under an applied driving voltage, more heat is generated, and the thermal stability and redox stability of the organic material will affect the service life of the element.

[0005] In view of the above reasons, the present application is proposed. SUMMARY

[0006] In order to solve the above problems in the prior art, the present application provides an organic electroluminescent device, a display device and an illumination device, the organic electroluminescent device of the present application integrates an independent unit multi-luminescent layer of an organic electroluminescent element and an external luminescent layer, moves a material with poor thermal stability or oxidation-reduction stability but high internal quantum efficiency out of the inside of the organic electroluminescent element and to the side outside the light emission of the organic electroluminescent element, simultaneously emits light by exciting the material of the external luminescent layer by the emission light of the organic electroluminescent element, or only makes the external luminescent layer emit light, avoids the direct contact of the material with poor stability with the electric exciton, and improves the light emission efficiency and the service life.

[0007] The first object of the present application provides an organic electroluminescent device, comprising a substrate, an organic electroluminescent element and an external electric drive, further comprising an external luminescent layer and a protective layer, the organic electroluminescent element is arranged on the substrate, the external luminescent layer is arranged above the organic electroluminescent element and on the side of the emission direction of the organic electroluminescent element, and the protective layer is arranged above the external luminescent layer.

[0008] Further, the organic electroluminescent element comprises an anode layer, a cathode layer and at least one organic layer arranged between the anode layer and the cathode layer, and the external electric drive is connected with the anode layer and the cathode layer, respectively.

[0009] Further, the external luminescent layer is connected with the organic electroluminescent element in contact, and the protective layer is connected with the external luminescent layer in contact.

[0010] Further, the external luminescent layer can be one layer or multiple layers.

[0011] Further, the organic electroluminescent element emits a first intrinsic peak wavelength, and the external luminescent layer emits a second intrinsic peak wavelength.

[0012] Further, when the external electric drive provides a working current density to the organic electroluminescent element, the organic electroluminescent element can emit a first spectrum and generate a first light emission area, the first spectrum contains the first intrinsic peak wavelength, the first spectrum excites the external luminescent layer to emit a second spectrum and generate a second light emission area, the second spectrum contains the second intrinsic peak wavelength, the ratio of the peak intensity of the first intrinsic peak wavelength and the second intrinsic peak wavelength is not higher than 1, and the first light emission area coincides with the second light emission area.

[0013] Further, the first intrinsic peak wavelength is 380-620 nm, and the second intrinsic peak wavelength is greater than 460 nm and less than or equal to 1000 nm.

[0014] Further, the second intrinsic peak wavelength is 460-800 nm.

[0015] Further, when the external electric drive provides the operating current density for the organic electroluminescent element, the organic electroluminescent element can emit a first spectrum, the first spectrum excites the external luminescent layer to emit a second spectrum, the second spectrum contains a first intrinsic peak wavelength and a second intrinsic peak wavelength, and the ratio of the peak intensity of the second intrinsic peak wavelength to the peak intensity of the first intrinsic peak wavelength is greater than 1.5.

[0016] Further, the external electric drive is a display panel backplane circuit or a lighting panel backplane circuit.

[0017] The second object of the present application provides a display device comprising the organic electroluminescent device.

[0018] The third object of the present application provides a lighting device comprising the organic electroluminescent device.

[0019] Compared with the prior art, the present application has the following advantages:

[0020] (1) The organic electroluminescent device integrates the independent unit multi-emitting layer of the organic electroluminescent element and the external luminescent layer, moves the material with poor thermal stability or oxidation, reduction stability but high internal quantum efficiency out of the organic electroluminescent element, to the side of the organic electroluminescent element light emission, uses the emission light of the organic electroluminescent element to excite the material of the external luminescent layer to emit light at the same time, or only makes the external luminescent layer emit light, avoids the direct contact of the material with poor stability with the electric exciton, and improves the light emitting efficiency and the life;

[0021] (2) The organic electroluminescent device of the present application can emit single color light under the operating current density, the device structure is refined, the process is simple, the voltage is low, no additional light emitting area is occupied, no additional circuit drive is needed, and the single crispy can be integrated in the display panel, or prepared into a lighting lamp source with great advantages. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0023] Figure 1 is the first top emitting device integrating the organic electroluminescent element and the external luminescent layer of the present application;

[0024] Figure 2FIG. 1 is a schematic diagram of a top emission device of the present application integrating an organic electroluminescent element and an external light emitting layer;

[0025] Figure 3 FIG. 2 is a schematic diagram of a bottom emission device of the present application integrating an organic electroluminescent element and an external light emitting layer;

[0026] Figure 4 FIG. 3 is a schematic diagram of an organic electroluminescent device prepared in Example 1 of the present application;

[0027] Figure 5 FIG. 4 is a schematic diagram of a top emission device of the present application integrating an organic electroluminescent element and two external light emitting layers.

[0028] Reference numerals

[0029] 101 - substrate, 102 - anode layer, 103 - hole injection layer, 104 - hole transport layer, 105 - electron blocking layer, 106 - first organic light emitting layer, 107 - hole blocking layer, 108 - electron transport layer, 109 - electron injection layer, 110 - cathode layer, 111 - external light emitting layer, 112 - protective layer, 113 - third light emitting layer. DETAILED DESCRIPTION

[0030] In order to make the objects, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of the present application.

[0031] In the present application, "top" means farthest from the substrate, and "bottom" means closest to the substrate. In the case where a first layer is described as "disposed above" a second layer, the first layer is disposed farther from the substrate. Unless it is specified that the first layer is "in contact with" the second layer, there can be other layers between the first layer and the second layer. For example, even if there are various organic layers between the cathode and the anode, the cathode can still be described as "disposed above" the anode.

[0032] As used herein, the term "OLED element" includes an anode layer, a cathode layer, and one or more organic layers disposed between the anode layer and the cathode layer. An "OLED element" can be a bottom emission, i.e., emitting light from one side of the substrate, or a top emission, i.e., emitting light from one side of the encapsulation layer, or a transparent element, i.e., emitting light from both the substrate and the encapsulation side.

[0033] As used herein, the term "OLED light-emitting panel" includes a substrate, an anode layer, a cathode layer, one or more organic layers disposed between the anode layer and the cathode layer, an external light-emitting layer disposed outside the anode layer or the cathode layer and directly contacting the same, a protective layer, an encapsulating layer, and at least one anode contact and at least one cathode contact extending outside the encapsulating layer for external access. An "OLED light-emitting panel" has more than an "OLED element" in that it has a substrate, an external light-emitting layer, a protective layer, an encapsulating layer, and electrical contacts. An "OLED light-emitting panel" can include multiple "OLED elements" that can be individually encapsulated, can share the same encapsulating layer, can be simultaneously turned on or off, or can be selectively turned on or off by simple metal wiring and external circuit control. An "OLED light-emitting panel" can also include only one single "OLED element", for example, when an "OLED light-emitting panel" including multiple "OLED elements" is cut so that each "OLED element" is independently controllable, the "OLED light-emitting panel" then includes only one "OLED element".

[0034] As used herein, the term "flexible printed circuit" refers to any flexible substrate coated with any one or a combination of the following, including but not limited to: conductive wires, resistors, capacitors, inductors, transistors, micro-electro-mechanical systems, etc. The flexible substrate of a flexible printed circuit can be plastic, thin glass, thin metal foil plated with an insulating layer, fabric, leather, paper, etc. A flexible printed circuit board is generally less than 1 mm thick, more preferably less than 0.7 mm thick.

[0035] As used herein, the term "light extraction layer" can refer to a light diffusion film, or other microstructure with light extraction effect, or a thin film coating with light out-coupling effect. The light extraction layer can be disposed on the surface of the substrate of an OLED, or at other suitable locations, such as between the substrate and the anode, or between the organic layer and the cathode, between the cathode and the encapsulating layer, on the surface of the encapsulating layer, etc.

[0036] As used herein, the term "external electrical drive" refers to a device system that can supply power to a module, which generally includes a circuit control system and an external power source. The circuit control system can include, but is not limited to, anode and cathode electrical contacts, wires, flexible printed circuit boards, integrated circuits, transformers, etc.; the external power source can be directly various types of batteries, or can be connected to alternating current through a socket, or can be connected to a power bank and other electronic devices through a USB interface, or can be connected to a power generator through a wire, etc.

[0037] As used herein, the term "light-emitting area" refers to the part of the planar area where the anode, the organic layer, and the cathode overlap, excluding the light extraction effect. The "light-emitting area" does not include edge light emission, and does not represent a hemispherical light-emitting space in three dimensions.

[0038] As used in this article, "intrinsic peak wavelength" refers to the peak wavelength emitted by the luminescent layer material in the bottom emitting element, which includes at least a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. Under different matching material systems, the "intrinsic peak wavelength" of the same luminescent material may vary to some extent, but should all be within the range of ±10 nm.

[0039] As used in this article, "fill factor" refers to the ratio of the effective light-emitting area of ​​a pixel to its total area.

[0040] like Figures 1-5 As shown, a non-limiting example is a single-unit OLED light-emitting device comprising two light-emitting layers, such as... Figure 1 As shown, the diagram is not necessarily drawn to scale, and some layers can be omitted as needed. The OLED light-emitting device includes a substrate 101, an anode layer 102, a hole injection layer 103, a hole transport layer 104, an electron blocking layer 105, a first organic light-emitting layer 106, a hole blocking layer 107, an electron transport layer 108, an electron injection layer 109, a cathode layer 110, an external light-emitting layer 111, and a protective layer 112. The electron blocking layer 105 and the hole blocking layer 107 are optional layers. An OLED light-emitting element with multiple light-emitting layers in a single unit can further include a conditioning layer between the first organic light-emitting layer 106 and the hole blocking layer 107, typically with a thickness not exceeding 100 angstroms, preferably not exceeding 50 angstroms, and more preferably not exceeding 30 angstroms. The conditioning layer is typically a hole blocking material or an electron blocking material, limiting the number of holes or electrons in different recombination regions and controlling the emission ratio and intensity of the first organic light-emitting layer 106. However, the conditioning layer is not mandatory; for example, it can be tuned by matching the energy levels of different layer materials. In a top-emitting device, further layers, such as a light-refracting layer or a capping layer, can be disposed above the protective layer 112 to protect the outer light-emitting layer 111. An OLED light-emitting device with an independent unit multi-emitting layer can further include a third light-emitting layer 113 above the outer light-emitting layer 111, such as... Figure 5 As shown in the OLED light-emitting device, a regulating layer can also be added between the outer light-emitting layer 111 and the third light-emitting layer 113. The light-emitting material of the regulating layer can be selected according to actual needs, for example... Figure 1 The two light-emitting layers shown can be a blue first organic light-emitting layer 106 and a blue outer light-emitting layer 111, respectively. Figure 5 The three light-emitting layers shown can be a blue first organic light-emitting layer 106, a green outer light-emitting layer 111, and a red third light-emitting layer 113. When the injected current across the device increases, the exciton recombination region gradually moves from the electron transport end to the hole transport end, causing a change in the light intensity emitted by the first organic light-emitting layer 106. Figure 1For example, at low current density, the first organic light emitting layer 106 emits weak blue light, which excites the external light emitting layer 111, and the double light emitting layers emit light simultaneously, the peak intensity of the second spectrum in the element spectrum is much higher than that of the first spectrum, and the OLED light emitting device emits blue light. After the current density increases, the first organic light emitting layer 106 and the external light emitting layer 111 emit light simultaneously, the peak intensity of the first spectrum in the spectrum starts to rise and eventually exceeds the peak intensity of the second spectrum to become the dominant wavelength, and the OLED light emitting device emits blue light. When the first organic light emitting layer 106 and the external light emitting layer 111 use the same light emitting material, the same wavelength of light is emitted, which has the advantage of avoiding black spots in the OLED device and improving brightness and service life. In some embodiments, the first organic light emitting layer 106 can also be a green light emitting layer, and the external light emitting layer 106 or the third light emitting layer 113 can be a green light emitting layer or a red light emitting layer. In some embodiments, the first organic light emitting layer 106 can also be a red light emitting layer, and the external light emitting layer 111 or the third light emitting layer 113 can be a red light emitting layer or a near-infrared light emitting layer.

[0041] An organic electroluminescent device according to one embodiment of the present application comprises a substrate 101, an organic electroluminescent element, and an external electrical drive, further comprising an external light emitting layer 111 and a protective layer 112, wherein the organic electroluminescent element is disposed on the substrate, the external light emitting layer is disposed above the organic electroluminescent element and on the side of the organic electroluminescent element in the emission direction, and the protective layer is disposed above the external light emitting layer.

[0042] The organic electroluminescent element comprises an anode layer 102, a cathode layer 110, and at least one organic layer disposed between the anode layer and the cathode layer, and the external electrical drive is connected to the anode layer 102 and the cathode layer 110; the external light emitting layer is in contact with the organic electroluminescent element, and the protective layer is in contact with the external light emitting layer.

[0043] The present application will be further described in detail with reference to the following examples of an OLED element integrated with an external light emitting layer. It should be understood that the following examples are only for illustrative purposes and are not intended to limit the scope of the present application. Based on the following examples, those skilled in the art can improve them to obtain other embodiments of the present application.

[0044] Example 1

[0045] Blue light first organic light emitting layer and blue phosphor external light emitting layer device

[0046] As Figure 1As shown, to fabricate an organic electroluminescent device emitting blue light from the top, firstly, a glass substrate 101, on which a patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated with ultrapure water, and the ITO surface is treated with UV ozone and oxygen plasma. Afterward, the substrate 101 is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, aluminum is deposited sequentially on the ITO anode layer 102 via thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 100 nm, followed by the sequential deposition of molybdenum trioxide as the hole injection layer (HIL) 103 with a thickness of [missing information]. Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, The first organic light-emitting layer (EML) 106 contains a blue light-emitting host material doped with 10% blue light-emitting material. Hole blocking layer (HBL) 107, Electron transport layer (ETL) 108 contains LG2O1 doped with 60% LiQ, deposited by vapor deposition. LiF was used as the electron injection layer (EIL) 109, and 120 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. The outer light-emitting layer 111 contains a blue light-emitting host material doped with 8% blue phosphorescent material, and then a vapor-deposited layer is deposited on the outer light-emitting layer 111. After the protective layer 112 is applied, the component is finally transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The luminescent area of ​​this component is 9mm × 9mm. In this embodiment, the first intrinsic peak wavelength of the blue light-emitting first organic light-emitting layer 106 is approximately 467nm, and the second intrinsic peak wavelength of the blue phosphorescent external light-emitting layer 111 is approximately 470nm. Note that this component structure is merely an example and is not limited to the present invention.

[0047] Example 2

[0048] Taking the blue light first organic light-emitting layer and TADF blue light external light-emitting layer device as an example

[0049] like Figure 2 As shown, to fabricate an organic electroluminescent device emitting blue light from the top, firstly, a glass substrate 101, on which a patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated with ultrapure water, and the ITO surface is treated with UV ozone and oxygen plasma. Afterward, the substrate 101 is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶.-6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 100 nm, and then the following layers are deposited sequentially. Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, then The first organic light-emitting layer (EML) 106 includes a blue light-emitting host material doped with 10% blue light-emitting material, followed by vapor deposition on the first organic light-emitting layer 106. Electron transport layer (ETL) 108 contains 50% LiQ LG201, deposited by vapor deposition. LiF was used as the electron injection layer (EIL) 109, and 120 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. The outer light-emitting layer 111 comprises a blue light host material doped with 10% blue TADF light-emitting material, followed by evaporation on the outer light-emitting layer 111. Protective layer 112 is applied, and finally the component is transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The light-emitting area of ​​this component is 9mm × 9mm. The intrinsic peak wavelength of the first blue light-emitting organic layer used in this embodiment is around 458nm, and the intrinsic peak wavelength of the outer blue light-emitting layer is around 460nm. Note that this component structure is only an example and is not limited to the present invention.

[0050] Example 3

[0051] Taking the device with blue first organic light-emitting layer and orange outer light-emitting layer as an example

[0052] like Figure 2 As shown, to fabricate an organic electroluminescent device that emits white light from the top, firstly, a glass substrate 101, on which a patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated with ultrapure water, and the ITO surface is treated with UV ozone and oxygen plasma. Afterward, the substrate is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 100 nm, and then the following layers are deposited sequentially. Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, The first organic light-emitting layer (EML) 106 contains a blue light-emitting host material doped with 10% blue light-emitting material, which is then deposited on the first organic light-emitting layer 160. Electron transport layer (ETL) 108 contains 60% LiQ LG201, deposited by vapor deposition. LiF was used as the electron injection layer (EIL) 109, and 100 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. The outer light-emitting layer 111 comprises a yellow light-emitting host material doped with 3% yellow light-emitting material, which is then deposited on the outer light-emitting layer 111 by vapor deposition. After the protective layer 112 is applied, the component is finally transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The light-emitting area of ​​this component is 9mm × 9mm. In this embodiment, the intrinsic peak wavelength of the blue light-emitting first organic light-emitting layer 106 is approximately 460nm, and the intrinsic peak wavelength of the yellow light-emitting outer layer 111 is approximately 577nm. Note that this component structure is merely an example and is not limited to the present invention.

[0053] Example 4

[0054] Taking the device of blue light first organic light-emitting layer and blue phosphorescent outer light-emitting layer as an example

[0055] like Figure 3 As shown, to fabricate an organic electroluminescent device that emits blue light from the bottom, first, a glass substrate 101, on which a patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated with ultrapure water, and the ITO surface is treated with UV ozone and oxygen plasma. Afterward, the substrate 101 is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, the evaporation process... Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, then The first organic light-emitting layer (EML) 106 comprises a blue light-emitting host material doped with 10% blue light-emitting material, which is then deposited on the first organic light-emitting layer. Electron transport layer (ETL) 108, vapor-deposited LiF was used as the electron injection layer (EIL) 109, and 150 nm of aluminum was deposited as the cathode layer 110. Then the substrate was flipped over, and the deposition was continued. The outer light-emitting layer 111 comprises a blue light-emitting host material doped with 8% blue light-emitting material, and then deposited on the outer light-emitting layer 111. After the protective layer 112 is applied, the component is finally transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The light-emitting area of ​​this component is 9mm × 9mm. In this embodiment, the intrinsic peak wavelength of the first blue light-emitting organic layer 106 is approximately 468nm, and the intrinsic peak wavelength of the outer blue light-emitting layer 111 is approximately 470nm. Note that this component structure is merely an example and is not limited to the present invention.

[0056] Example 5

[0057] Taking a light-emitting device with a blue first organic light-emitting layer and a green outer light-emitting layer as an example

[0058] like Figure 2 As shown, to fabricate an organic electroluminescent device emitting green light from the top, firstly, a glass substrate 101, pre-coated with a patterned 120 nm thick indium tin oxide (ITO) anode layer 102, is cleaned with ultrapure water, and the ITO surface is treated with UV ozone and oxygen plasma. Afterward, the substrate 101 is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 100 nm, and then the following layers are deposited sequentially. Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, then The first organic light-emitting layer (EML) 106 includes a blue light-emitting host material doped with 5% blue light-emitting material, followed by vapor deposition on the first organic light-emitting layer 106. Electron transport layer 108 (ETL) 107 contains 50% LiQ LG201, deposited by vapor deposition. LiF was used as the electron injection layer (EIL) 109, and 120 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. The outer light-emitting layer 111 comprises a green light-emitting host material doped with 5% green phosphorescent light-emitting material, followed by evaporation on the outer light-emitting layer 111. After the protective layer 112 is applied, the component is finally transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The light-emitting area of ​​this component is 9mm × 9mm. In this embodiment, the intrinsic peak wavelength of the first blue light-emitting organic layer 106 is approximately 456nm, and the intrinsic peak wavelength of the outer blue light-emitting layer 111 is approximately 524nm. Note that this component structure is merely an example and is not limited to the present invention.

[0059] Example 6

[0060] Taking a light-emitting device with a blue first organic light-emitting layer and a red outer light-emitting layer as an example

[0061] like Figure 2 As shown, to fabricate an organic light-emitting device that emits red light from the top, firstly, a glass substrate 101 is cleaned with ultrapure water. A patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated on the substrate. After treating the ITO surface with UV ozone and oxygen plasma, the substrate 101 is dried in a nitrogen-filled glove box to remove moisture. It is then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 100 nm, and then the following layers are deposited sequentially. Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, then The first organic light-emitting layer (EML) 106 includes a blue light-emitting host material doped with 8% blue light-emitting material, followed by vapor deposition on the first organic light-emitting layer 106. Electron transport layer (ETL) 108 contains 50% LiQ LG201, deposited by vapor deposition. LiF was used as the electron injection layer (EIL) 109, and 120 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. The outer light-emitting layer 111 comprises a red light host material doped with 5% red phosphorescent luminescent material, followed by deposition on the outer light-emitting layer 111. After the protective layer 112 is applied, the component is finally transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The light-emitting area of ​​this component is 9mm × 9mm. In this embodiment, the intrinsic peak wavelength of the blue light-emitting first organic light-emitting layer 106 is approximately 458nm, and the intrinsic peak wavelength of the red light-emitting outer layer 111 is approximately 620nm. Note that this component structure is merely an example and is not limited to the present invention.

[0062] Example 7

[0063] Taking a red light-emitting device with a first organic light-emitting layer and a near-infrared external light-emitting layer as an example

[0064] like Figure 2As shown, to fabricate an organic light-emitting device that emits near-infrared light from the top, firstly, a glass substrate 101, on which a patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated with ultrapure water, and the ITO surface is treated with UV ozone and oxygen plasma. Afterward, the substrate 101 is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 120 nm, and then the following layers are deposited sequentially. Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, then The first organic light-emitting layer (EML) 106 includes a red light host material doped with 5% red light-emitting material, followed by vapor deposition on the first organic light-emitting layer 106. Electron transport layer (ETL) 108 contains 50% LiQ LG201, deposited by vapor deposition. LiF was used as the electron injection layer (EIL) 109, and 120 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. The outer light-emitting layer 111 comprises a red light host material doped with 8% near-infrared light-emitting material, followed by evaporation on the outer light-emitting layer 111. After protective layer 112, the component is finally transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The luminescent area of ​​this component is 9mm × 9mm. The intrinsic peak wavelength of the red light-emitting first organic luminescent layer 106 used in this embodiment is around 620nm, and the intrinsic peak wavelength of the near-infrared external luminescent layer 111 is around 705nm. Note that this component structure is only an example and is not limited to the present invention.

[0065] Example 8

[0066] Taking a green light-emitting device with a first organic light-emitting layer and a second green light-emitting layer as an example

[0067] like Figure 2 As shown, to fabricate an organic light-emitting device that emits green light from the top, firstly, a glass substrate 101, on which a patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated with ultrapure water, and the ITO surface is treated with UV ozone and oxygen plasma. Afterward, the substrate is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 120 nm, and then the following layers are deposited sequentially. Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, then The first organic light-emitting layer (EML) 106 comprises a phosphorescent host material doped with 5% green phosphorescent material, followed by vapor deposition on the first organic light-emitting layer 106. Electron transport layer (ETL) 108 contains 50% LiQ LG201, deposited by vapor deposition. LiF was used as the electron injection layer (EIL) 109, and 120 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. The outer light-emitting layer 111 comprises a phosphorescent host material doped with 5% green phosphorescent luminescent material, followed by vapor deposition on the outer light-emitting layer 111. After protective layer 112, the component is finally transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The light-emitting area of ​​this component is 9mm × 9mm. The intrinsic peak wavelength of the green first organic light-emitting layer 106 used in this embodiment is around 524nm, and the intrinsic peak wavelength of the green outer light-emitting layer 111 is also around 524nm. Note that this component structure is only an example and is not limited to the present invention.

[0068] Example 9

[0069] Taking a red light-emitting device with a first organic light-emitting layer and a red outer light-emitting layer as an example

[0070] like Figure 2 As shown, to fabricate an organic light-emitting device that emits red light from the top, firstly, a glass substrate 101 is cleaned with ultrapure water. A patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated on the substrate, and the ITO surface is treated with UV ozone and oxygen plasma. Afterward, the substrate is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 120 nm, and then the following layers are deposited sequentially. Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, then The first organic light emitting layer (EML) 106 comprises a red host material doped with 5% red light emitting material, followed by the deposition of The electron transport layer (ETL) 108 comprises LG201 doped with 50% LiQ, followed by the deposition of LiF as the electron injection layer (EIL) 109, and the deposition of 120 nm of silver as the semi-transparent cathode layer 110, followed by the deposition of The external light emitting layer 111 comprises a red host material doped with 5% red light emitting material, followed by the deposition of The protective layer 112, and finally the device is transferred from the deposition chamber back to the glove box and encapsulated with a glass cover. The light emitting area of the device is 9 mm x 9 mm. The red light first organic light emitting layer 106 used in this example has an intrinsic peak wavelength of about 620 nm, and the red light external light emitting layer 111 has an intrinsic peak wavelength of about 620 nm. Note that the device structure is only an example and is not limited to the present application.

[0071] Example 10

[0072] Example of a green light first organic light emitting layer and red light external light emitting layer light emitting device

[0073] As shown in Figure 1, a top-emitting red light organic light emitting device was prepared. First, a glass substrate 101, on which a patterned 120 nm thick indium tin oxide (ITO) anode layer 102 was previously coated, was cleaned with ultrapure water and the ITO surface was treated with UV ozone and oxygen plasma. The substrate was then dried in a nitrogen-filled glove box, mounted on a holder and loaded into a deposition chamber. Each of the layers specified below was deposited by thermal evaporation at a rate of 0.1 nm / s onto the ITO anode layer 102 at a vacuum of about 1 x 10 -6 Figure 2

[0074] Each of the layers specified below was deposited by thermal evaporation at a rate of 0.1 nm / s onto the ITO anode layer 102 at a vacuum of about 1 x 10 -6 A hole injection layer (HIL) 103, A hole transport layer (HTL) 104, An electron blocking layer (EBL) 105, followed by The first organic light emitting layer (EML) 106 comprises a green host material doped with 2% green light emitting material, followed by the deposition of The electron transport layer (ETL) 108 comprises LG201 doped with 50% LiQ, followed by the deposition of ​​LiF was used as the electron injection layer (EIL) 109, and 150 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. A red phosphorescent material is used as the outer light-emitting layer 111, and then a vapor deposition is performed on the outer light-emitting layer 111. After the protective layer 112 is applied, the component is finally transferred from the evaporation chamber back to the glove box and encapsulated with a glass cover. The light-emitting area of ​​this component is 9mm × 9mm. In this embodiment, the intrinsic peak wavelength of the green first organic light-emitting layer 106 is approximately 519nm, and the intrinsic peak wavelength of the red outer light-emitting layer 111 is approximately 620nm. Note that this component structure is merely an example and is not limited to the present invention.

[0075] Example 11

[0076] Taking a blue light-emitting device with a first organic light-emitting layer and a TADF blue light-emitting outer layer as an example

[0077] like Figure 4 As shown, to fabricate an organic light-emitting device that emits blue light from the top, firstly, a glass substrate 101, on which a patterned 120 nm thick indium tin oxide (ITO) anode layer 102 is pre-coated with ultrapure water, and the ITO surface is treated with UV ozone and oxygen plasma. Afterwards, the substrate is dried in a nitrogen-filled glove box to remove moisture, then mounted on a support and placed in a vapor deposition chamber. The layers specified below are deposited under a vacuum of approximately 1 × 10⁻⁶. -6 In the case of entrustment At a rate of / second, the ITO anode layer 102 is deposited sequentially by thermal evaporation. First, aluminum is deposited as the anode layer 102 with a thickness of 120 nm, and then the following layers are deposited sequentially. Hole injection layer (HIL) 103, Hole transport layer (HTL) 104, Electron blocking layer (EBL) 105, then The first organic light-emitting layer (EML) 106 includes a blue light-emitting host material doped with 10% blue light-emitting material, followed by vapor deposition on the first organic light-emitting layer 106. Electron transport layer (ETL) 108 contains 50% LiQ LG201, deposited by vapor deposition. LiF was used as the electron injection layer (EIL) 109, and 120 nm of silver was deposited as a semi-transparent cathode layer 110, followed by further deposition. Blue TADF luminescent material is used as the outer luminescent layer 111, and then evaporation is performed on the outer luminescent layer 111. The protective layer 112, the last element is transferred from the evaporation chamber back to the glove box, and the package is completed with a glass cover. The light emitting area of the element is 9mm x 9mm. The blue light first organic light emitting layer 106 used in this embodiment has an intrinsic peak wavelength of about 458nm, and the blue light external light emitting layer 111 has an intrinsic peak wavelength of about 458nm. Note that the element structure is only an example and is not limited to the present application.

[0078] Comparative Example 1

[0079] A top-emitting blue light organic electroluminescent device was prepared as shown in ​ The specific preparation method is the same as that of Example 1, except that the external light emitting layer 111 and the protective layer 112 are not evaporated.

[0080] Test Example 1

[0081] This test example uses a Keithley 2420 power generator connected to the cathode and anode of the OLED element itself for external electrical driving to form an organic electroluminescent device. When the power generator provides a working current density, the organic electroluminescent devices prepared in Example 1 and Comparative Example 1 emit a spectrum, and the element performance is shown in Table 1.

[0082] Table 1

[0083]

[0084] As can be seen from Table 1, the present application prepares a device with independent single unit multi-light emitting layer, integrates an organic electroluminescent element and an external light emitting layer, and achieves higher efficiency and lifetime. Compared with the single light emitting layer organic electroluminescent element of Comparative Example 1, it shows great advantages.

[0085] The present inventors also conducted the above test on other prepared organic electroluminescent devices, and the results were basically consistent. Due to limited space, they will not be listed one by one.

[0086] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An organic electroluminescent device, comprising a substrate, an organic electroluminescent element, and an external electric drive, characterized in that, It also includes an external light-emitting layer and a protective layer. The organic electroluminescent element is disposed on the substrate, the external light-emitting layer is disposed above the organic electroluminescent element and on one side of the emission direction of the organic electroluminescent element, and the protective layer is disposed above the external light-emitting layer. When the external electric drive provides the organic electroluminescent element with a working current density, the organic electroluminescent element can emit a first spectrum and generate a first luminescent region. The first spectrum includes a first intrinsic peak wavelength. The first spectrum excites the external luminescent layer to emit a second spectrum and generate a second luminescent region. The second spectrum includes a second intrinsic peak wavelength. The ratio of the peak intensity of the first intrinsic peak wavelength and the second intrinsic peak wavelength is not higher than 1. The first luminescent region coincides with the second luminescent region. The organic electroluminescent element emits a first intrinsic peak wavelength, and the external light-emitting layer emits a second intrinsic peak wavelength. When the external electric drive provides the organic electroluminescent element with a working current density, the organic electroluminescent element can emit a first spectrum, which excites the external light-emitting layer to emit a second spectrum. The second spectrum includes a first intrinsic peak wavelength and a second intrinsic peak wavelength, and the ratio of the peak intensity of the second intrinsic peak wavelength to the peak intensity of the first intrinsic peak wavelength is greater than 1.

5.

2. The organic electroluminescent device according to claim 1, characterized in that, The organic electroluminescent element includes an anode layer, a cathode layer, and at least one organic layer disposed between the anode layer and the cathode layer, and the external electric drive is connected to the anode layer and the cathode layer respectively; The external light-emitting layer is in contact with the organic electroluminescent element, and the protective layer is in contact with the external light-emitting layer. The external light-emitting layer can be one or more layers.

3. The organic electroluminescent device according to claim 1, characterized in that, The first intrinsic peak wavelength is 380~620nm, and the second intrinsic peak wavelength is greater than 460nm and less than or equal to 1000nm.

4. An organic electroluminescent device according to claim 3, characterized in that, The second intrinsic peak wavelength is 460-800nm.

5. An organic electroluminescent device according to claim 1, characterized in that, The external electric drive is either the display panel backplane circuit or the lighting panel backplane circuit.

6. A display device, characterized in that, It includes the organic electroluminescent device according to any one of claims 1-5.

7. A lighting device, characterized in that, It includes the organic electroluminescent device according to any one of claims 1-5.

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