Stacked device and display apparatus

Abstract

The application discloses a laminated device and a display device. The laminated device comprises an electron blocking common layer. Compared with an electron blocking functional layer arranged in a non-common manner, the structure of the laminated device is simplified. An auxiliary doping material is added in a light-emitting unit, and the energy level of the auxiliary doping material is between the energy level of a host material and the energy level of a main doping material. When the host material, the main doping material and the auxiliary doping material in the light-emitting unit transfer energy, the energy is preferentially transferred from the host material to the auxiliary doping material, and then transferred from the auxiliary doping material to the main doping material. Therefore, the energy transfer is easier, the energy loss in the energy transfer process is reduced, the damage to the materials in the light-emitting unit is reduced, and the service life of the laminated device is prolonged.

Description

Technical Field

[0001] This application relates to the field of light source technology, and more particularly to a multilayer device and display device. Background Technology

[0002] In recent years, OLED displays have experienced rapid global development. With the continuous advancement of OLED display technology, their applications are gradually expanding to medium and large-sized displays. In the medium and large-sized display sector, higher performance requirements are placed on the displays, especially in terms of lifespan and power consumption. Against this backdrop, the demand for long-lifespan and high-efficiency stacked OLED devices is constantly increasing. Currently, stacked OLED devices are typically simplified to varying degrees; however, these simplifications may compromise lifespan. Therefore, there is an urgent need to research stacked devices that improve lifespan while simplifying the structure. Summary of the Invention

[0003] In view of this, this application provides a stacked device and a display apparatus, which aims to improve the problem that existing stacked devices cannot balance simplified structure and long lifespan performance.

[0004] In a first aspect, embodiments of this application provide a stacked device, including:

[0005] The first electrode is disposed on one side of the substrate;

[0006] Multiple light-emitting units are disposed on the side of the first electrode away from the substrate;

[0007] A charge generation layer is disposed between adjacent light-emitting units;

[0008] The second electrode is disposed on the side of the charge generation layer opposite to the first electrode;

[0009] Wherein, at least one of the light-emitting units is provided with an electron blocking common layer between it and the first electrode, and the orthogonal projection of the electron blocking common layer on the substrate at least covers the orthogonal projection of the light-emitting unit on the substrate;

[0010] At least one of the light-emitting units includes a host material, a main doping material, and an auxiliary doping material, wherein the energy level of the auxiliary doping material is between the energy level of the host material and the energy level of the main doping material.

[0011] Optionally, in some embodiments of this application, the plurality of light-emitting units include at least a first light-emitting unit and a second light-emitting unit, the first light-emitting unit being disposed between the first electrode and the second light-emitting unit, and the electron blocking common layer being disposed between the first electrode and the first light-emitting unit.

[0012] Optionally, in some embodiments of this application, the first light-emitting unit includes a first I light-emitting layer, a first II light-emitting layer, and a first III light-emitting layer with different light-emitting colors, and the orthogonal projection of the electron blocking common layer on the substrate at least covers the orthogonal projections of the first I light-emitting layer, the first II light-emitting layer, and the first III light-emitting layer on the substrate.

[0013] Optionally, in some embodiments of this application, the second light-emitting unit includes a second I light-emitting layer, a second II light-emitting layer, and a second III light-emitting layer. A first electron blocking layer corresponding to the second I light-emitting layer, a second electron blocking layer corresponding to the second II light-emitting layer, and a third electron blocking layer corresponding to the second III light-emitting layer are disposed between the second light-emitting unit and the charge generation layer. The electron blocking common layer and the third electron blocking layer are of the same layer and the same material.

[0014] Optionally, in some embodiments of this application, the first electron blocking layer is set as a red electron blocking layer, the second electron blocking layer is set as a green electron blocking layer, and the third electron blocking layer and the common electron blocking layer are both set as blue electron blocking layers.

[0015] Optionally, in some embodiments of this application, the thickness of the electron blocking common layer ranges from 5 nm to 8 nm.

[0016] Optionally, in some embodiments of this application, the LUMO energy level of the host material is greater than the LUMO energy level of the auxiliary doping material, and the LUMO energy level of the auxiliary doping material is greater than the LUMO energy level of the host doping material.

[0017] Optionally, in some embodiments of this application, the absolute value of the difference between the LUMO energy levels of the host material and the auxiliary doped material, and between the auxiliary doped material and the host doped material, is greater than 0.1 eV.

[0018] Optionally, in some embodiments of this application, the HOMO energy level of the host material is lower than the HOMO energy level of the auxiliary doping material, and the HOMO energy level of the auxiliary doping material is lower than the HOMO energy level of the host doping material.

[0019] Optionally, in some embodiments of this application, the absolute value of the difference between the HOMO energy levels of the host material and the auxiliary doping material, and between the auxiliary doping material and the host doping material, is greater than 0.1 eV.

[0020] Optionally, in some embodiments of this application, the main doping material and the auxiliary doping material include at least one of platinum-platinum, platinum-iridium, iridium-platinum, iridium-iridium, or osmium-osmium.

[0021] Optionally, in some embodiments of this application, the main doping material includes at least the following molecular structure:

[0022] .

[0023] Optionally, in some embodiments of this application, the auxiliary doping material includes at least the following molecular structure:

[0024] .

[0025] Optionally, in some embodiments of this application, the doping concentration of the host material in the light-emitting unit ranges from 80wt% to 99.8wt%, the doping concentration of the main dopant material in the light-emitting unit ranges from 0.1wt% to 10wt%, and the doping concentration of the auxiliary dopant material in the light-emitting unit ranges from 0.1wt% to 10wt%.

[0026] Secondly, embodiments of this application also provide a display device, including the aforementioned stacked device.

[0027] The stacked device provided in this application embodiment has an electron blocking common layer, which simplifies the structure of the stacked device compared to a non-common electron blocking functional layer. At the same time, an auxiliary dopant material is added in the light-emitting unit, and the energy level of the auxiliary dopant material is between the energy level of the host material and the energy level of the main dopant material. This makes energy transfer easier, reduces energy loss during energy transfer, and reduces damage to the materials in the light-emitting unit, thereby extending the life of the stacked device. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a multilayer device in the prior art;

[0030] Figure 2 This is a simplified schematic diagram of the stacked device according to this application.

[0031] Reference numerals: 10, first electrode; 20, light-emitting unit; 21, first light-emitting unit; 211, first I light-emitting layer; 212, first II light-emitting layer; 213, first III light-emitting layer; 22, second light-emitting unit; 221, second I light-emitting layer; 222, second II light-emitting layer; second III light-emitting layer; 30, charge generation layer; 40, second electrode; 50, electron blocking common layer; 60, electron blocking layer; 61, first electron blocking layer; 62, second electron blocking layer; 63, third electron blocking layer. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0035] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0036] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0037] In this application, the term "on" forming another layer on a certain layer is a broad concept. It can mean that the formed other layer is adjacent to a certain layer, or it can mean that there are other spacer structures between the other layer and the certain layer. For example, when a second electrode is formed "on" a first charge carrier functional layer, the term "on" can mean that the formed second electrode is adjacent to the first charge carrier functional layer, or it can mean that there are other spacer structures between the second electrode and the first charge carrier functional layer, such as a light-emitting layer.

[0038] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0039] refer to Figure 1 Typical multilayer devices include:

[0040] The first electrode 10 is disposed on one side of the substrate;

[0041] Multiple light-emitting units 20 are disposed on the side of the first electrode 10 away from the substrate;

[0042] A charge generation layer 30 is disposed between adjacent light-emitting units 20;

[0043] The second electrode 40 is disposed on the side of the charge generation layer 30 away from the first electrode 10;

[0044] Each light-emitting unit 20 includes a first I light-emitting layer 211, a first II light-emitting layer 212, and a first III light-emitting layer 213 with different light-emitting colors, as well as a first electron blocking layer 61, a second electron blocking layer 62, and a third electron blocking layer 63 corresponding to the first I light-emitting layer 211, the first II light-emitting layer 212, and the first III light-emitting layer 213, respectively.

[0045] With the development of simplified design of stacked devices, this application provides a stacked device and display device that not only ensures the characteristics of simple structure and lightweight, but also ensures the luminous efficiency and long life of the device.

[0046] According to a first aspect of the embodiments of this application, a stacked device is provided, comprising:

[0047] The first electrode is disposed on one side of the substrate;

[0048] Multiple light-emitting units are disposed on the side of the first electrode away from the substrate;

[0049] A charge generation layer is disposed between adjacent light-emitting units;

[0050] The second electrode is disposed on the side of the charge generation layer opposite to the first electrode;

[0051] Wherein, at least one light-emitting unit is provided with an electron blocking common layer between it and the first electrode, and the orthogonal projection of the electron blocking common layer on the substrate at least covers the orthogonal projection of the light-emitting unit on the substrate;

[0052] At least one light-emitting unit includes a host material, a main doped material, and an auxiliary doped material, wherein the energy level of the auxiliary doped material is between the energy level of the host material and the energy level of the main doped material.

[0053] It is understandable that setting a common electron blocking layer in a stacked device simplifies the structure of the stacked device compared to a non-common electron blocking functional layer. At the same time, adding auxiliary dopant materials in the light-emitting unit, with the energy level of the auxiliary dopant material being between the energy levels of the host material and the main dopant material, allows energy to be preferentially transferred from the host material to the auxiliary dopant material and then from the auxiliary dopant material to the main dopant material during energy transfer. This makes energy transfer easier and reduces energy loss during the energy transfer process, thereby enabling the fabrication of a simplified stacked device with a long lifetime.

[0054] It should be noted that the HOMO energy level of the electron blocking common layer ranges from 5.6 to 5.7 eV. The energy levels of the electron blocking layers in typical green and red pixels range from 5.5 to 5.6 eV. Therefore, compared to the electron blocking layers in red and green pixels, the energy level of the electron blocking common layer is deeper, resulting in a stronger blocking effect on holes. This leads to insufficient holes in the emitting layers of red and green pixels, affecting their lifespan.

[0055] It should be further explained that OLED light emission is generated by the energy transfer and radiation of excitons. The energy transfer of excitons is generally from the host material to the main dopant material. The T1 energy level of the main dopant material is significantly different from that of the host material, resulting in incomplete energy transfer. By adding auxiliary dopant material to the light-emitting unit, the T1 energy level of the auxiliary dopant material is between the T1 energy levels of the host material and the main dopant material. Therefore, the T1 energy level of the auxiliary dopant material is in the form of a "step" between the T1 energy levels of the host material and the main dopant material, making it easier and more complete for energy to transfer from the T1 energy level of the host material to the T1 energy level of the main dopant material. This reduces energy loss during the energy transfer process and thus improves the lifespan of the stacked device.

[0056] It should be further explained that auxiliary doping materials also help improve the dispersion of the main dopant and the host material. Without the introduction of auxiliary doping materials, the light-emitting layer contains only the main dopant. Energy is instantly transferred from the host material to the main dopant, resulting in a higher T1 exciton collision probability and greater damage to the material, leading to a shorter lifetime for the stacked device. However, with the introduction of auxiliary doping materials, some of the energy can be distributed, preventing excessive energy concentration on the main dopant, which is equivalent to improving the dispersion of the main dopant.

[0057] It should be further explained that as the dispersion of the host material and the main dopant material increases, the collision probability of triplet excitons will be greatly reduced, thereby reducing the damage to the material after exciton collisions and extending the device's lifespan; at the same time, the number of triplet excitons that emit light in a radiative manner will increase, thereby further improving the device's efficiency and lifespan.

[0058] In some embodiments of this application, the first electrode can be an anode electrode and the second electrode can be a cathode electrode.

[0059] In some embodiments of this application, the plurality of light-emitting units includes at least a first light-emitting unit and a second light-emitting unit. The first light-emitting unit is disposed between the first electrode and the second light-emitting unit, and an electron blocking common layer is disposed between the first electrode and the first light-emitting unit. The electron blocking common layer is disposed close to the first electrode, which helps to effectively block the electrons transmitted from above, thus confining the electrons within the light-emitting unit and preventing electrons from overflowing the light-emitting unit under high current density injection, thereby helping to improve the luminous efficiency of the stacked device.

[0060] In some embodiments of this application, the first light-emitting unit includes a first I light-emitting layer, a first II light-emitting layer, and a first III light-emitting layer with different light-emitting colors, and the orthogonal projection of the electron blocking common layer on the substrate at least covers the orthogonal projections of the first I light-emitting layer, the first II light-emitting layer, and the first III light-emitting layer on the substrate.

[0061] In some embodiments of this application, the second light-emitting unit includes a second I light-emitting layer, a second II light-emitting layer, and a second III light-emitting layer. A first electron blocking layer corresponding to the second I light-emitting layer, a second electron blocking layer corresponding to the second II light-emitting layer, and a third electron blocking layer corresponding to the second III light-emitting layer are disposed between the second light-emitting unit and the charge generation layer. The electron blocking common layer and the third electron blocking layer are of the same layer and the same material. The first light-emitting unit and the second light-emitting unit of this application have different structures. The electron blocking layers of the three primary colors of the second light-emitting unit correspond to the three primary color pixels of the light-emitting layer, while the electron blocking layer of the first light-emitting unit adopts an electron blocking common layer, thereby simplifying the structure.

[0062] In some embodiments of this application, the first electron blocking layer is set as a red electron blocking layer, the second electron blocking layer is set as a green electron blocking layer, and the third electron blocking layer and the common electron blocking layer are both set as blue electron blocking layers. Using a blue electron blocking layer as the common electron blocking layer can effectively prevent pixel crosstalk between red and green pixels, which helps to improve the sharpness and contrast of the stacked device.

[0063] It should be noted that the ease of electron injection is related to the depth of the LUMO level. The deeper the LUMO level, the easier it is to inject electrons, and the shallower the LUMO level, the more difficult it is to inject electrons. The ease of hole injection is related to the depth of the HOMO level. The shallower the HOMO level, the easier it is for holes to be spontaneously injected and transported, and the deeper the HOMO level, the more difficult it is for holes to be injected and transported.

[0064] In some embodiments of this application, the LUMO energy level of the host material is greater than that of the auxiliary doped material, and the LUMO energy level of the auxiliary doped material is greater than that of the host doped material.

[0065] In some embodiments of this application, the absolute value of the difference between the LUMO energy levels of the host material and the auxiliary doped material, and between the auxiliary doped material and the host doped material, is greater than 0.1 eV.

[0066] In some embodiments of this application, the HOMO energy level of the host material is lower than that of the auxiliary doping material, and the HOMO energy level of the auxiliary doping material is lower than that of the host doping material.

[0067] In some embodiments of this application, the absolute value of the difference between the HOMO energy levels of the host material and the auxiliary doped material, and between the auxiliary doped material and the host doped material, is greater than 0.1 eV.

[0068] It should be noted that in the stacked device of this application embodiment, the absolute value of the difference between the LUMO energy levels of the host material and the auxiliary doped material, and between the auxiliary doped material and the host doped material is greater than 0.1 eV, and the absolute value of the difference between the HOMO energy levels of the host material and the auxiliary doped material, and between the auxiliary doped material and the host doped material is greater than 0.1 eV. If the electron volt is too small, especially less than 0.1 eV, the effect of electron or hole injection is difficult to be reflected.

[0069] In some embodiments of this application, the thickness of the electron blocking common layer ranges from 5 nm to 8 nm. A thinner electron blocking common layer avoids the problem of uneven thickness affecting luminous efficiency.

[0070] In some embodiments of this application, the thickness of the red emitting layer ranges from 40 nm to 50 nm, the thickness of the green emitting layer ranges from 35 nm to 45 nm, and the thickness of the blue emitting layer ranges from 15 nm to 25 nm. A moderate thickness of the emitting layer is desirable; if the thickness is too large, it may lead to an increase in the driving voltage, which could reduce the stability of the device during operation.

[0071] In some embodiments of this application, the main doping material and the auxiliary doping material include at least one of platinum-platinum, platinum-iridium, iridium-platinum, iridium-iridium, or osmium-osmium.

[0072] It should be noted that the main dopant and auxiliary dopant can be chosen arbitrarily from the platinum-based and iridium-based systems. If the osmium-based system is chosen as the dopant, then both the main dopant and auxiliary dopant must be osmium-based.

[0073] In some embodiments of this application, the main material adopts the following molecular structure:

[0074] .

[0075] In some embodiments of this application, the main doping material includes at least the following molecular structure:

[0076] .

[0077] In some embodiments of this application, the auxiliary doping material includes at least the following molecular structure:

[0078] .

[0079] In some embodiments of this application, the doping concentration of the host material in the light-emitting unit ranges from 80wt% to 99.8wt%, the doping concentration of the main dopant material in the light-emitting unit ranges from 0.1wt% to 10wt%, and the doping concentration of the auxiliary dopant material in the light-emitting unit ranges from 0.1wt% to 10wt%.

[0080] In some embodiments of this application, the doping concentration of the host material in the light-emitting unit ranges from 80wt% to 99.4wt%, the doping concentration of the main dopant material in the light-emitting unit ranges from 0.1wt% to 10wt%, and the doping concentration of the auxiliary dopant material in the light-emitting unit ranges from 0.5wt% to 10wt%.

[0081] In some embodiments of this application, the doping concentration of the host material in the light-emitting unit ranges from 80wt% to 98.9wt%, the doping concentration of the main dopant material in the light-emitting unit ranges from 0.1wt% to 10wt%, and the doping concentration of the auxiliary dopant material in the light-emitting unit ranges from 1wt% to 10wt%.

[0082] refer to Figure 2 A stacked device according to an embodiment of this application includes:

[0083] The first electrode 10 is disposed on one side of the substrate;

[0084] The first light-emitting unit 21 includes a first I light-emitting layer 211, a first II light-emitting layer 212 and a first III light-emitting layer 213. The first I light-emitting layer 211, the first II light-emitting layer 212 and the first III light-emitting layer 213 are disposed on the side of the first electrode 10 away from the substrate, and the orthogonal projection of the first I light-emitting layer 211, the first II light-emitting layer 212 and the first III light-emitting layer 213 on the substrate at least covers the orthogonal projection of the first electrode 10 on the substrate.

[0085] A charge generation layer 30 is disposed on the side of the first light-emitting unit 21 opposite to the first electrode 10;

[0086] The second light-emitting unit 22 includes a second I light-emitting layer 221, a second II light-emitting layer 222, and a second III light-emitting layer 223. The second I light-emitting layer 221, the second II light-emitting layer 222, and the second III light-emitting layer 223 are disposed on the side of the charge generation layer 30 away from the first light-emitting unit 21, and the orthogonal projection of the second I light-emitting layer 221, the second II light-emitting layer 222, and the second III light-emitting layer 223 on the substrate at least covers the orthogonal projection of the charge generation layer 30 on the substrate.

[0087] The second electrode 40 is disposed on the side of the second light-emitting unit 22 away from the charge generation layer 30;

[0088] An electron blocking common layer 50 is provided between the first electrode 10 and the first light-emitting unit 21, and the orthogonal projection of the electron blocking common layer 50 on the substrate covers the orthogonal projection of the first light-emitting unit 21 on the substrate.

[0089] An electron blocking layer 60 is disposed between the charge generation layer 30 and the second light-emitting unit 22, including a first electron blocking layer 61, a second electron blocking layer 62 and a third electron blocking layer 63. The orthogonal projections of the first electron blocking layer 61, the second electron blocking layer 62 and the third electron blocking layer 63 on the substrate cover the orthogonal projection of the charge generation layer 30 on the substrate.

[0090] It is understandable that multilayer devices can also have some functional layers that are conventionally used in multilayer devices to help improve their performance, such as hole injection layers, hole transport layers, electron transport layers, electron blocking layers, hole blocking layers, electron injection layers, capping layers, etc.

[0091] It is understandable that the materials of each layer in a multilayer device can be adjusted according to the light-emitting requirements of the light-emitting device.

[0092] In some embodiments of this application, the first electrode and the second electrode are electrodes known in the art for use in light-emitting devices. For example, they may be, independently, but not limited to, doped metal oxide electrodes, composite electrodes, graphene electrodes, carbon nanotube electrodes, elemental metal electrodes, or alloy electrodes. The materials of the doped metal oxide electrodes may include, but are not limited to, one or more of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), aluminum-doped magnesium oxide (AMO), and cadmium-doped zinc oxide. Composite electrodes are electrodes formed by stacking two or more layers of conductive materials, such as AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc., where " / " indicates a stacked structure. For example, AZO / Ag / AZO represents a composite electrode consisting of sequentially stacked AZO, Ag, and AZO layers. The materials for elemental metal electrodes can be, but are not limited to, one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba. Alloy electrodes include, but are not limited to, Au:Mg alloy electrodes and Ag:Mg alloy electrodes.

[0093] In some embodiments of this application, the anode is an electrode with a relatively high work function, such as, but not limited to, a doped metal oxide electrode with a relatively high work function, a metal element electrode with a relatively high work function, and a carbon nanotube electrode. The metal element electrode with a high work function can be selected from, but is not limited to, Ni, Pt, Au, Ag, Ir, etc.

[0094] In some embodiments of this application, the cathode is an electrode with a relatively low work function, such as, but not limited to, a metallic element electrode with a relatively low work function, a composite electrode with a relatively low work function, and an alloy electrode with a relatively low work function. The metallic element electrode with a relatively low work function can be Ca, Ba, Al, Mg, etc. The composite electrode with a relatively low work function can be Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc. The alloy electrode with a relatively low work function is Au:Mg and Ag:Mg, etc.

[0095] In some embodiments of this application, the material of the light-emitting layer may include, but is not limited to, one or more of organic light-emitting materials and quantum dot light-emitting materials.

[0096] Organic light-emitting materials may include, but are not limited to, CBP:Ir(mppy)3 (4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridinium(III)), TCTX:Ir(mmpy) (4,4',4''-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridinium), diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, TADF (thermally activated delayed) materials, polymers containing BN covalent bonds, HLCT (hybridized local charge transfer excited state) materials, Exciplex (excitoplex) light-emitting materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, and polyfluorene and its derivatives, or one or more of these.

[0097] Quantum dot luminescent materials may include, but are not limited to, one or more of the following: single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials.

[0098] The materials of single-structure quantum dots, the core materials of core-shell structure quantum dots, and the shell materials of core-shell structure quantum dots can be one or more of the following: II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds, respectively. Group II-VI compounds may include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. Group IV-VI compounds may include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. Group III-V compounds may include, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. Group I-III-VI compounds may include, but are not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0099] As an example, core-shell structured quantum dots may include, but are not limited to, one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS.

[0100] Perovskite semiconductor materials can include, but are not limited to, doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors. The general structural formula for inorganic perovskite semiconductors is AMX3, where A is Cs. + Ions, where M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of the following. The general structural formula of organic-inorganic hybrid perovskite semiconductors is BMX3, where B is an organic amine cation, including CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of them.

[0101] In some embodiments of this application, the material of the hole transport layer can be a material known in the art for hole transport layers, such as, but not limited to, 4,4'-N,N'-dicarbazolyl-biphenyl (CBP), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4''-diamine (α-NPD), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)biphenylamine). (Poly-TPD), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro(spiro-TPD), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), 4,4',4'-tris(N-carbazolyl)-triphenylamine (TCTA), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m -MTDATA), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))](TFB), poly(N-vinylcarbazole)(PVK) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine (NPB), spiroNPB, poly(phenylene vinylidene)(PPV), poly[ [2-Methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene](MEH-PPV), poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene](MOMO-PPV), 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (spiro-omeTAD), 4,4'-cyclohexyl The following are listed: bis[N,N-bis(4-methylphenyl)aniline] (TAPC), 1,3-bis(carbazole-9-yl)benzene (MCP), polyaniline, polypyrrole, poly(p)phenylene vinylidene, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazole)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, C60, doped or undoped NiO, doped or undoped MoO3, doped or undoped WO3, doped or undoped V2O5, doped or undoped p-type gallium nitride, doped or undoped CrO3, and doped or undoped CuO.

[0102] In some embodiments of this application, the material of the electron transport layer is a material known in the art for use in electron transport layers, such as one or more selected from, but not limited to, inorganic and organic electron transport materials. Inorganic electron transport materials include, but are not limited to, one or more of doped metal oxide particles, undoped metal oxide particles, ceramic semiconductor materials, group IIB-VIA semiconductor materials, group IIIA-VA semiconductor materials, and group IB-IIIA-VIA semiconductor materials. The metal oxides in undoped metal oxide particles include, but are not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The doped metal oxides include, but are not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping elements in the doped metal oxides include, but are not limited to, one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, and Sn. For example, doped metal oxides can be aluminum zinc oxide (AZO), lithium-doped zinc oxide (LZO), magnesium-doped zinc oxide (MZO), tin-doped zinc oxide (Sn-ZnO), etc. Ceramic semiconductor materials include, but are not limited to, barium titanate. IIB-VIA group semiconductor materials include, but are not limited to, one or more of ZnS, ZnSe, and CdS. IIIA-VA group semiconductor materials include, but are not limited to, one or more of InP and GaP. IB-IIIA-VIA group semiconductor materials include, but are not limited to, one or more of CuInS and CuGaS.

[0103] Organic electron transport materials include, but are not limited to, one or more of the following: quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, and hydroxyquinoline compounds.

[0104] Metal oxide particles include, but are not limited to, one or more of doped and undoped metal oxide particles. Undoped metal oxide particles are made of, but are not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. Doped metal oxide particles contain, but are not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping elements in doped metal oxide particles include, but are not limited to, one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. For example, doped metal oxide particles can be made of aluminum zinc oxide (AZO), lithium-doped zinc oxide (LZO), and magnesium-doped zinc oxide (MZO).

[0105] In some embodiments of this application, the material of the hole injection layer can be a material known in the art for hole injection layers, such as, but not limited to, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene (HAT-CN), PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s-MoO3 (PEDOT:PSS:s-MoO3), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), tetracyanoquinone dimethyl ether (F4-TCQN), copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide.

[0106] In some embodiments of this application, the stacked device further includes a substrate disposed on the side of the anode electrode away from the light-emitting unit, or the substrate disposed on the side of the cathode electrode away from the light-emitting unit.

[0107] The substrate can be a rigid substrate or a flexible substrate. In some embodiments of this application, the substrate material may be one or more of glass, silicon wafer, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyethersulfone.

[0108] It is understandable that stacked devices can be either upright or inverted light-emitting devices. Stacked devices can be quantum dot light-emitting devices or organic light-emitting devices.

[0109] According to a second aspect of this application, a display device is provided, the display device including the aforementioned stacked device.

[0110] The display device can be any electronic product with a display function, including but not limited to smartphones, tablets, laptops, digital cameras, digital camcorders, smart wearable devices, smart weighing scales, in-vehicle displays, televisions, or e-book readers. Among them, smart wearable devices can be, for example, smart bracelets, smartwatches, virtual reality (VR) headsets, etc.

[0111] The present application will be specifically described below through specific embodiments. These embodiments are only some embodiments of the present application and are not intended to limit the present application. Unless otherwise specified, the raw materials used in the following embodiments are all commercially available products.

[0112] Example 1

[0113] Referring to Table 1, a multilayer device is provided, comprising:

[0114] The anode electrode is disposed on the substrate;

[0115] A hole injection layer is disposed on the side of the anode electrode away from the substrate;

[0116] A hole transport layer is disposed on the side of the hole injection layer away from the anode electrode;

[0117] Blue electron blocking layer 1 is disposed on the side of hole transport layer away from hole injection layer, and the orthogonal projection of blue electron blocking layer 1 on substrate covers the orthogonal projection of anode electrode on substrate.

[0118] The first light-emitting unit includes a red light-emitting layer 1, a green light-emitting layer 1 and a blue light-emitting layer 1. The red light-emitting layer 1, the green light-emitting layer 1 and the blue light-emitting layer 1 are arranged adjacent to each other in sequence, and the orthogonal projections of the red light-emitting layer 1, the green light-emitting layer 1 and the blue light-emitting layer 1 on the substrate cover the orthogonal projection of the blue electron blocking layer 1 on the substrate.

[0119] Hole blocking layer 1 is disposed on the side of the first light-emitting unit away from the blue electron blocking layer 1;

[0120] An electron transport layer 1 is disposed on the side of the hole blocking layer 1 opposite to the first light-emitting unit;

[0121] An n-type charge generation layer is disposed on the side of the electron transport layer 1 away from the hole blocking layer 1;

[0122] The p-type charge generation layer is disposed on the side of the n-type charge generation layer away from the electron transport layer 1;

[0123] Hole transport layer 2 is disposed on the side of the p-type charge generation layer away from the n-type charge generation layer;

[0124] An electron transport layer includes a red electron blocking layer 2, a green electron blocking layer 2, and a blue electron blocking layer 2. The red electron blocking layer 2, the green electron blocking layer 2, and the blue electron blocking layer 2 are arranged adjacent to each other in sequence, and the orthogonal projections of the red light-emitting layer 2, the green light-emitting layer 2, and the blue light-emitting layer 2 on the substrate cover the orthogonal projection of the blue electron blocking layer 2 on the substrate.

[0125] The second light-emitting unit includes a red light-emitting layer 2, a green light-emitting layer 2 and a blue light-emitting layer 2. The red light-emitting layer 2, the green light-emitting layer 2 and the blue light-emitting layer 2 are arranged adjacent to each other in sequence, and the orthogonal projections of the red light-emitting layer 2, the green light-emitting layer 2 and the blue light-emitting layer 2 on the substrate cover the orthogonal projection of the blue electron blocking layer 2 on the substrate.

[0126] Hole blocking layer 2 is disposed on the side of the second light-emitting unit away from hole transmission layer 2;

[0127] Electron transport layer 2 is disposed on the side of hole blocking layer 2 away from the second light-emitting unit;

[0128] An electron injection layer is disposed on the side of the electron transport layer 2 away from the hole blocking layer 2;

[0129] The cathode electrode is disposed on the side of the electron injection layer opposite to the electron transport layer 2;

[0130] Table 1

[0131]

[0132] Among them, the red emitting layer 1, green emitting layer 1, red emitting layer 2, and green emitting layer 2 adopt the materials and doping concentrations shown in Table 2:

[0133] Table 2

[0134]

[0135] Comparative Example 1

[0136] A stacked device differs from Example 1 in that the structure of each film layer is shown in Table 3:

[0137] Table 3

[0138]

[0139] Comparative Example 2:

[0140] A stacked device, which differs from Embodiment 1 in that no auxiliary doping material is added to the red light-emitting layer 1, green light-emitting layer 1, red light-emitting layer 2 and green light-emitting layer 2, while keeping the doping concentration of the main material unchanged and increasing the concentration of the main doping material to 10wt%.

[0141] Sample preparation and testing:

[0142] Fabrication method of stacked devices: Under high vacuum conditions, the functional layers from the hole injection layer to the cathode electrode and the capping layer of the stacked device are sequentially deposited on the TFT backplane substrate after cleaning and drying. Then, flexible packaging is performed by chemical vapor deposition and inkjet printing. After the sample is cut into units and manufactured into modules, corresponding optical tests and lifetime tests are performed.

[0143] The samples of the examples and comparative examples were lit up at the same brightness using the corresponding lighting devices. The brightness value of the white light 255 grayscale image of the samples was measured using a luminance meter, and the cathode output current value of the white light 255 grayscale image of the samples was measured using a multimeter. The luminous efficiency and power consumption of the samples in the white light 255 grayscale were calculated according to the formula.

[0144] The samples of the examples and comparative examples were lit at the same brightness using the corresponding lighting devices and kept lit for a long time. The brightness, current and other information of the samples were collected every 1 hour. The time when the brightness decayed to 95% of the initial brightness was recorded as the brightness lifetime of the sample.

[0145] The results of the optical and life tests are shown in Table 4.

[0146] Table 4

[0147]

[0148] As can be seen from Example 1, Comparative Examples 1-2, and Table 4, Comparative Example 1 is a traditional multilayer device. Compared with Comparative Example 1, the multilayer device of Example 1 of this application has an efficiency increased to 10%, power consumption reduced to 94%, and lifespan extended to 132%. Therefore, the multilayer device of Example 1 of this application simplifies the device structure while simultaneously improving luminous efficiency and lifespan. Comparative Example 2 is a multilayer device with a simplified structure; however, due to the deeper energy level of the blue electron blocking layer, its blocking effect on holes is stronger, resulting in insufficient holes in the luminescent layers of the red and green pixels, affecting lifespan. Furthermore, the sample of Example 1 of this application can reduce one mask, lowering process costs.

[0149] The stacked device and display apparatus provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A stacked device, characterized by, The application relates to an organic light-emitting diode, which comprises the following parts: a first electrode arranged on one side of a substrate; a plurality of light-emitting units arranged on the side of the first electrode away from the substrate; a charge generation layer arranged between adjacent light-emitting units; a second electrode arranged on the side of the charge generation layer away from the first electrode; wherein at least one of the light-emitting units and the first electrode is provided with an electron blocking common layer, the orthographic projection of the electron blocking common layer on the substrate at least covers the orthographic projection of the light-emitting unit on the substrate; the electron blocking common layer is arranged as a blue electron blocking layer; at least one of the light-emitting units comprises a host material, a main dopant material and an auxiliary dopant material, the energy level of the auxiliary dopant material is between the energy level of the host material and the energy level of the main dopant material; the LUMO energy level of the host material is greater than the LUMO energy level of the auxiliary dopant material, and the LUMO energy level of the auxiliary dopant material is greater than the LUMO energy level of the main dopant material; the HOMO energy level of the host material is less than the HOMO energy level of the auxiliary dopant material, and the HOMO energy level of the auxiliary dopant material is less than the HOMO energy level of the main dopant material. The plurality of light-emitting units at least comprises a first light-emitting unit and a second light-emitting unit, the first light-emitting unit is arranged between the first electrode and the second light-emitting unit, and the electron blocking common layer is arranged between the first electrode and the first light-emitting unit. The first light-emitting unit comprises first, second and third light-emitting layers with different light-emitting colors, and the orthographic projection of the electron blocking common layer on the substrate at least covers the orthographic projection of the first, second and third light-emitting layers on the substrate. The second light-emitting unit comprises second, third and fourth light-emitting layers, and the second light-emitting unit and the charge generation layer are provided with a first electron blocking layer corresponding to the second light-emitting layer, a second electron blocking layer corresponding to the third light-emitting layer and a third electron blocking layer corresponding to the fourth light-emitting layer; the electron blocking common layer and the third electron blocking layer are of the same material. The first electron blocking layer is arranged as a red electron blocking layer, the second electron blocking layer is arranged as a green electron blocking layer, and the third electron blocking layer is arranged as a blue electron blocking layer. The thickness of the electron blocking common layer ranges from 5nm to 8nm. The absolute value of the difference between the LUMO energy levels of the host material, the auxiliary dopant material and the main dopant material is greater than 0.1eV.

2. The stacked device of claim 1, wherein, The absolute value of the difference between the HOMO energy levels of the host material, the auxiliary dopant material and the main dopant material is greater than 0.1eV.

3. The stacked device of claim 2, wherein, The main dopant material and the auxiliary dopant material comprise at least one of a platinum system-platinum system, a platinum system-iridium system, an iridium system-platinum system, an iridium system-iridium system or an osmium system-osmium system.

4. The stacked device of claim 2, wherein, The main dopant material at least comprises the following molecular structure:

5. The stacked device of claim 4, wherein, The auxiliary dopant material at least comprises the following molecular structure:

6. The stacked device of claim 1, wherein, ​ 7. The stacked device of claim 1, wherein, ​ 8. The stacked device of claim 1, wherein, ​ 9. The stacked device of claim 1, wherein, ​ 10. The stacked device of claim 1, wherein, ​ 。 11. The stacked device of claim 1, wherein, ​ 。 12. The stacked device of claim 1, wherein, The doping concentration of the host material in the light-emitting unit is in the range of 80wt% to 99.8wt%, the doping concentration of the main dopant material in the light-emitting unit is in the range of 0.1wt% to 10wt%, and the doping concentration of the auxiliary dopant material in the light-emitting unit is in the range of 0.1wt% to 10wt%.

13. A display device comprising: The display device comprises the laminated device of any one of claims 1 to 12.

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