Charge generation layer, organic electroluminescent device and organic light emitting device

Abstract

The embodiment of the present disclosure provides a charge generation layer, an organic electroluminescent device and an organic light emitting device, the material of the charge generation layer comprises a first electron transport material, a second electron transport material and a first metal material doped in the first electron transport material and the second electron transport material, and the electron mobility of the first electron transport material and the electron mobility of the second electron transport material are different.

Description

Technical Field

[0001] This disclosure relates to the field of electroluminescence technology, and in particular to a charge generation layer, an organic electroluminescent device, and an organic light-emitting apparatus. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are display devices that emit light by electro-exciting organic compounds such as phosphors or phosphors. OLEDs are considered to have enormous application potential in the display field due to their numerous advantages, including self-illumination, all-solid-state operation, wide viewing angle, and fast response time.

[0003] Traditional organic light-emitting diodes (OLEDs) consist of an anode, a cathode, and a light-emitting functional layer (light-emitting unit) disposed between the anode and cathode. Driven by an external voltage, holes injected from the anode and electrons injected from the cathode recombine in the recombination region of the light-emitting unit to form excitons. These excitons then undergo radiative transitions, emitting photons and thus generating electroluminescence. However, due to the different mobilities of holes and electrons, an imbalance in the injection of holes and electrons occurs, resulting in a relatively low actual luminous efficiency of the organic OLED.

[0004] Currently, in order to improve luminous brightness and luminous efficiency, more and more research is focused on stacked devices. This structure usually uses a charge generation layer as a connecting layer to connect several light-emitting units in series. Compared with single-unit devices, stacked structure devices often have several times the current efficiency and luminous brightness. Summary of the Invention

[0005] This disclosure provides a charge generation layer, an organic electroluminescent device, and an organic light-emitting apparatus, the specific solutions of which are as follows: This disclosure provides a charge generation layer, the materials of which include a first electron transport material, a second electron transport material, and a first metal material doped in the first electron transport material and the second electron transport material, wherein the electron mobility of the first electron transport material and the electron mobility of the second electron transport material are different.

[0006] In one possible implementation, in the charge generation layer provided in the embodiments of this disclosure, the ratio between the electron mobility of the first electron transport material and the electron mobility of the second electron transport material is greater than or equal to 10 and less than or equal to 100.

[0007] In one possible implementation, the charge generation layer provided in the embodiments of this disclosure has a thickness of less than or equal to 20 nm.

[0008] In one possible implementation, the charge generation layer provided in the embodiments of this disclosure includes a first charge generation layer and a second charge generation layer stacked alternately. The material of the first charge generation layer includes the first electron transport material, the second electron transport material, and the first metal material. The material of the second charge generation layer is different from the material of the first charge generation layer, and the number of the second charge generation layers is greater than the number of the first charge generation layers.

[0009] In one possible implementation, in the charge generation layer provided in the embodiments of this disclosure, the material of the second charge generation layer includes a third electron transport material and a second metal material doped in the third electron transport material.

[0010] In one possible implementation, in the charge generation layer provided in the embodiments of this disclosure, the third electron transport material is the same as the first electron transport material, or the third electron transport material is the same as the second electron transport material, and the second metal material is the same as the first metal material.

[0011] In one possible implementation, the sum of the number of the first charge generation layer and the second charge generation layer provided in the embodiments of this disclosure is 3 to 7 layers.

[0012] In one possible implementation, in the charge generation layer provided in the embodiments of this disclosure, the number of first charge generation layers is greater than or equal to two, and the doping concentration of the first metal material in each first charge generation layer varies in a gradient along the thickness direction of the charge generation layer.

[0013] In one possible implementation, in the charge generation layer provided in the embodiments of this disclosure, the thickness of the first charge generation layer is less than or equal to 3 nm, and the thickness of the second charge generation layer is less than or equal to 3 nm.

[0014] In one possible implementation, in the charge generation layer provided in the embodiments of this disclosure, both the first metal material and the second metal material comprise lithium.

[0015] In one possible implementation, in the charge generation layer provided in the embodiments of this disclosure, the doping concentration of the first metal material and the doping concentration of the second metal material are within 1% to 5%.

[0016] In one possible implementation, in the charge generation layer provided in the embodiments of this disclosure, the first electron transport material comprises 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, and the second electron transport material comprises o-phenanthroline.

[0017] Accordingly, embodiments of this disclosure also provide an organic electroluminescent device, comprising: First electrode; The second electrode is disposed opposite to the first electrode; At least two light-emitting functional layers are stacked between the first electrode and the second electrode; A charge generation layer is located between each two adjacent light-emitting functional layers; wherein the charge generation layer is any of the charge generation layers described above according to the embodiments of this disclosure.

[0018] In one possible implementation, in the organic electroluminescent device provided in the embodiments of this disclosure, the at least two light-emitting functional layers include a first light-emitting functional layer, a second light-emitting functional layer, and a third light-emitting functional layer stacked together. The first light-emitting functional layer is close to the first electrode, and the third light-emitting functional layer is close to the second electrode. The light-emitting colors of the first light-emitting functional layer, the second light-emitting layer, and the third light-emitting functional layer are all different.

[0019] In one possible implementation, in the organic electroluminescent device provided in the embodiments of this disclosure, the first light-emitting functional layer includes a first hole injection layer, a first hole transport layer, a first light-emitting layer and a first electron transport layer stacked sequentially, with the first hole injection layer close to the first electrode.

[0020] In one possible implementation, in the organic electroluminescent device provided in the embodiments of this disclosure, the second light-emitting functional layer includes a second hole transport layer, a second light-emitting layer and a second electron transport layer stacked sequentially, with the second hole transport layer close to the first electrode.

[0021] In one possible implementation, in the organic electroluminescent device provided in the embodiments of this disclosure, the third light-emitting functional layer includes a third hole transport layer, a third light-emitting layer, a third electron transport layer and a first electron injection layer stacked sequentially, with the third hole transport layer close to the first electrode.

[0022] In one possible implementation, in the organic electroluminescent device provided in the embodiments of this disclosure, the first electrode is the anode and the second electrode is the cathode.

[0023] Accordingly, this disclosure also provides an organic light-emitting device, including the organic electroluminescent device described in any of the above embodiments of this disclosure. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the structure of a charge generation layer provided in an embodiment of the present disclosure; Figure 2 This is a schematic diagram of another charge generation layer provided in an embodiment of the present disclosure; Figure 3 This is a schematic diagram of the structure of an organic electroluminescent device provided in an embodiment of the present disclosure; Figure 4 A schematic diagram of the structure of another organic electroluminescent device provided in this disclosure embodiment; Figure 5 A schematic diagram of the structure of another organic electroluminescent device provided in this disclosure embodiment; Figure 6 A schematic diagram of the structure of another organic electroluminescent device provided in this disclosure embodiment; Figure 7A A schematic diagram of the red emission spectrum in an organic electroluminescent device provided in the prior art and embodiments of this disclosure; Figure 7B A schematic diagram of the green emission spectrum in an organic electroluminescent device provided by prior art and embodiments of this disclosure; Figure 7C A schematic diagram of the green-blue emission spectrum in an organic electroluminescent device provided in the prior art and embodiments of this disclosure; Figure 8 This is a schematic diagram of the light emission of an organic electroluminescent device provided in an embodiment of this disclosure. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Furthermore, the embodiments and features in the embodiments of this disclosure can be combined with each other without conflict. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0026] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "comprising" or "including," and similar terms as used in this disclosure, mean that an element or object preceding the term encompasses the elements or objects listed following the term and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "inner," "outer," "upper," and "lower" are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0027] It should be noted that the dimensions and shapes of the figures in the accompanying drawings do not reflect actual proportions and are intended only to illustrate the content of this disclosure. Furthermore, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0028] With the development of display technology, users demand high-resolution (PPI) displays. High-PPI displays, due to the close proximity of adjacent pixels and the fact that the charge generation layer of organic electroluminescent devices is typically a full-surface element, are prone to crosstalk between adjacent pixels due to the high lateral conductivity of the charge generation layer. This can lead to lateral leakage between adjacent pixels.

[0029] In view of this, embodiments of the present disclosure provide a charge generation layer 1, such as Figure 1 As shown, the charge generation layer 1 is made of a first electron transport material ETL1, a second electron transport material ETL2, and a first metal material M1 doped in the first electron transport material ETL1 and the second electron transport material ETL2. The electron mobility μ1 of the first electron transport material ETL1 and the electron mobility μ2 of the second electron transport material ETL2 are different.

[0030] The light-emitting functional layer of an electroluminescent device mainly includes an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, and a hole injection layer. Due to the influence of the material properties of each film layer in the light-emitting functional layer, electroluminescent devices are generally multi-electron systems, resulting in a large number of electrons transported laterally. In this embodiment, a first electron transport material and a second electron transport material with different electron mobilities are used. The first and second electron transport materials mainly provide electrons, and the difference in mobility can increase the difficulty of electron transport, thereby reducing the possibility of lateral leakage. Furthermore, through the interaction and constraint between the doped first metal material and the first and second electron transport materials, the carrier flow has a certain directionality, which can reduce the number of electrons transported laterally and increase the number of electrons transported longitudinally. Applying this charge generation layer to an organic electroluminescent device can reduce the problem of lateral leakage, improve the color gamut of the organic electroluminescent device, and thus improve the lifetime of the organic electroluminescent device.

[0031] Specifically, such as Figure 1 As shown, the electrons that are transported laterally in the charge generation layer 1 are represented by arrow L1, and the electrons that are transported vertically in the charge generation layer 1 are represented by arrow L2. Arrow L1 is thinner, indicating that there are fewer electrons transported laterally; arrow L2 is thicker, indicating that there are more electrons transported vertically.

[0032] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 1 As shown, the ratio μ1 / μ2 between the electron mobility μ1 of the first electron transport material ETL1 and the electron mobility μ2 of the second electron transport material ETL2 is greater than or equal to 10 and less than or equal to 100. This can effectively improve the lateral leakage problem of the charge generation layer in high PPI pixel design, reduce the light emission phenomenon of adjacent pixels, and improve the color gamut of electroluminescent devices by about 5%.

[0033] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 1 As shown, the thickness of charge generation layer 1 is less than or equal to 20 nm. For example, the thickness of charge generation layer 1 can be 5 nm, 10 nm, 15 nm, 20 nm, etc.

[0034] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 1 As shown, the first metallic material can be, but is not limited to, lithium. For example, it can be a doped lithium salt.

[0035] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 1As shown, the doping concentration of the first metal material M1 is within the range of 1% to 5%. Specifically, if the doping concentration of the first metal material M1 is less than 1%, the amount of charge generated by the charge generation layer 1 is small, which is not conducive to improving device efficiency; if the doping concentration of the first metal material M1 is greater than 5%, the first metal material M1 is prone to diffusion, causing device instability; therefore, in this embodiment of the present disclosure, the doping concentration of the first metal material M1 is preferably within the range of 1% to 5%.

[0036] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 1 As shown, the first electron transport material ETL1 includes, but is not limited to, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, and the second electron transport material ETL2 includes, but is not limited to, o-phenanthroline. Specifically, any two electron transport materials that satisfy the ratio μ1 / μ2 between the electron mobility μ1 of the first electron transport material ETL1 and the electron mobility μ2 of the second electron transport material ETL2 are within the scope of protection of the embodiments of this disclosure, and are not listed here.

[0037] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 2 As shown, the charge generation layer 1 includes a first charge generation layer 11 and a second charge generation layer 12 stacked alternately. The material of the first charge generation layer 11 includes the first electron transport material ETL1, the second electron transport material ETL2 and the first metal material M1 mentioned above. The material of the second charge generation layer 12 is different from that of the first charge generation layer 11, and the number of second charge generation layers 12 is greater than the number of first charge generation layers 11. Specifically, by configuring the charge generation layer 1 to include a first charge generation layer 11 and a second charge generation layer 12 stacked alternately, the material of the first charge generation layer 11 includes a first electron transport material ETL1, a second electron transport material ETL2 and a first metal material M1, and the ratio μ1 / μ2 between the electron mobility μ1 of the first electron transport material ETL1 and the electron mobility μ2 of the second electron transport material ETL2 is different (preferably μ1 / μ2 is greater than or equal to 10 and less than or equal to 100), the number of electrons transported laterally can be reduced and the number of electrons transported longitudinally can be increased. Applying this charge generation layer to an organic electroluminescent device can reduce the problem of lateral leakage current, improve the color gamut of the organic electroluminescent device, and thus improve the lifespan of the organic electroluminescent device.

[0038] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 2As shown, the material of the second charge generation layer 12 may include a third electron transport material ETL3 and a second metal material M2 doped in the third electron transport material ETL3. Specifically, the third electron transport material ETL3 may be the same as the first electron transport material ETL1, or the third electron transport material ETL3 may also be the same as the second electron transport material ETL2, and the second metal material M2 may be the same as the first metal material M1.

[0039] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 2 As shown, the first metal material M1 in the first charge generation layer 11 may include lithium, and the second metal material M2 in the second charge generation layer 12 may also include lithium. For example, it may be a doped lithium salt.

[0040] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 2 As shown, the doping concentration of the first metal material M1 in the first charge generation layer 11 is within the range of 1% to 5%, and the doping concentration of the second metal material M2 in the second charge generation layer 12 is within the range of 1% to 5%. Specifically, if the doping concentrations of both the first metal material M1 and the second metal material M2 are less than 1%, the amount of charge generated by the first charge generation layer 11 and the second charge generation layer 12 will be relatively small, which is not conducive to improving device efficiency; if the doping concentrations of both the first metal material M1 and the second metal material M2 are greater than 5%, the first metal material M1 and the second metal material M2 will easily diffuse, causing the device to be unstable; therefore, in this embodiment of the present disclosure, the doping concentration range of the first metal material M1 and the second metal material M2 is preferably within the range of 1% to 5%.

[0041] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 2 As shown, the first electron transport material ETL1 in the first charge generation layer 11 includes, but is not limited to, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, and the second electron transport material ETL2 in the first charge generation layer 11 includes, but is not limited to, o-phenanthroline; the third electron transport material ETL3 in the second charge generation layer 12 can be 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, or the third electron transport material ETL3 in the second charge generation layer 12 can be o-phenanthroline.

[0042] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 2As shown, the total number of first charge generating layers 11 and second charge generating layers 12 can be 3 to 7. For example, the total number of first charge generating layers 11 and second charge generating layers 12 can be 3 layers, where the first charge generating layer 11 is one layer, the second charge generating layer 12 is two layers, and the first charge generating layer 11 is located between two layers of second charge generating layers 12; for example, the total number of first charge generating layers 11 and second charge generating layers 12 can be 5 layers, where the first charge generating layer 11 is two layers, the second charge generating layer 12 is three layers, and there is one first charge generating layer 11 between every two adjacent layers of second charge generating layers 12; for example, the total number of first charge generating layers 11 and second charge generating layers 12 can be 7 layers, where the first charge generating layer 11 is three layers, the second charge generating layer 12 is four layers, and there is one first charge generating layer 11 between every two adjacent layers of second charge generating layers 12.

[0043] It should be noted that the embodiments of this disclosure... Figure 2 The illustration is based on the example where the sum of the number of the first charge generation layer 11 and the second charge generation layer 12 is 5.

[0044] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 2 As shown, the number of first charge generation layers 11 is greater than or equal to two (e.g., two layers). Along the thickness direction of the charge generation layer 1, the doping concentration of the first metal material M1 in each first charge generation layer 11 varies in a gradient. For example, the doping concentration of the first metal material M1 in the bottommost first charge generation layer 11 is 2%, and the doping concentration of the first metal material M1 in the topmost first charge generation layer 11 is 4%. Of course, the doping concentration of the first metal material M1 in each first charge generation layer 11 can be set according to actual needs. When the charge generation layer 1 is applied to an organic electroluminescent device, the film position of the first charge generation layer 11 with a higher doping concentration is selected as needed.

[0045] Specifically, lithium is an active metal that is prone to material changes. The doping concentration of the first metal material M1 in each of the first charge generation layers 11 varies in a gradient to balance the device requirements and reduce lithium diffusion, thereby ensuring both device stability and transmission performance.

[0046] In specific implementation, in the charge generation layer provided in the embodiments of this disclosure, such as Figure 2 As shown, the thickness of the first charge generation layer 11 can be less than or equal to 3 nm, for example, the thickness of the first charge generation layer 11 can be 1 nm, 2 nm or 3 nm; the thickness of the second charge generation layer 12 can be less than or equal to 3 nm, for example, the thickness of the second charge generation layer 12 can be 1 nm, 2 nm or 3 nm.

[0047] In summary, when the charge generation layer provided in the embodiments of this disclosure is applied to an organic electroluminescent device, it can improve the lateral leakage problem, and by reasonably setting the concentration of doped Li, it can improve the diffusion of Li concentration and enhance the stability of the device.

[0048] Based on the same inventive concept, this disclosure also provides an organic electroluminescent device, such as... Figure 3 and Figure 4 As shown, it includes: First electrode 2; The second electrode 3 is disposed opposite to the first electrode 2; At least two light-emitting functional layers (taking three as an example, denoted as 41, 42 and 43 respectively) are stacked between the first electrode 2 and the second electrode 3; A charge generation layer 1 is located between every two adjacent light-emitting functional layers; wherein, the charge generation layer 1 is the charge generation layer 1 provided according to the embodiments of this disclosure.

[0049] The organic electroluminescent device provided in this embodiment of the present disclosure, by setting a charge generation layer between each two adjacent light-emitting functional layers, and by employing a first electron transport material and a second electron transport material with different electron mobility in the charge generation layer, the first electron transport material and the second electron transport material mainly provide electrons. Through the interaction and constraint between the doped first metal material and the first electron transport material and the second electron transport material, the number of electrons transported laterally can be reduced and the number of electrons transported longitudinally can be increased. Applying this charge generation layer to the organic electroluminescent device can reduce the problem of lateral leakage current, improve the color gamut of the organic electroluminescent device, and thus improve the lifespan of the organic electroluminescent device.

[0050] It should be noted that the specific structure and materials of the charge generation layer in the organic electroluminescent device provided in this disclosure embodiment can be found in the aforementioned description of a charge generation layer. Figure 3 The structure and material of the charge generation layer shown are similar to Figure 1 The structure and material of the charge generation layer shown are the same. Figure 4 The structure and material of the charge generation layer shown are similar to Figure 2 The structure and materials of the charge generation layer shown are the same, and the problem they solve is the lateral leakage problem that high PPI display products are prone to. They will not be elaborated on here.

[0051] In specific implementations, in the organic electroluminescent devices provided in the embodiments of this disclosure, such as Figure 3 and Figure 4As shown, at least two light-emitting functional layers (41, 42, and 43) may include a first light-emitting functional layer 41, a second light-emitting functional layer 42, and a third light-emitting functional layer 43 stacked together. The first light-emitting functional layer 41 is close to the first electrode 2, and the third light-emitting functional layer 43 is close to the second electrode 3. The light-emitting colors of the first light-emitting functional layer 41, the second light-emitting functional layer 42, and the third light-emitting functional layer 43 are all different. Specifically, the light-emitting color of the first light-emitting functional layer 41 can be red, the light-emitting color of the second light-emitting functional layer 42 can be green, and the light-emitting color of the third light-emitting functional layer 43 can be blue, achieving full-color display through the three primary colors of red, green, and blue.

[0052] In specific implementations, in the organic electroluminescent devices provided in the embodiments of this disclosure, such as Figure 3 and Figure 4 As shown, the first electrode 2 can be the anode, and the second electrode 3 can be the cathode. Specifically, the materials of the anode and cathode are the same as those in the prior art, and will not be described in detail here.

[0053] In specific implementations, in the organic electroluminescent devices provided in the embodiments of this disclosure, such as Figure 5 and Figure 6 As shown, the first light-emitting functional layer 41 includes a first light-emitting layer 413 and at least one of a first hole injection layer 411, a first hole transport layer 412 and a first electron transport layer 414. Preferably, the first light-emitting functional layer 41 includes a first hole injection layer 411, a first hole transport layer 412, a first light-emitting layer 413 and a first electron transport layer 414 stacked sequentially, with the first hole injection layer 411 close to the first electrode 2.

[0054] Specifically, the materials of the first hole injection layer 411, the first hole transport layer 412, the first light-emitting layer 413, and the first electron transport layer 414 are the same as those in the prior art, and will not be described in detail here.

[0055] In specific implementations, in the organic electroluminescent devices provided in the embodiments of this disclosure, such as Figure 5 and Figure 6 As shown, the second light-emitting functional layer 42 includes a second light-emitting layer 422 and at least one of a second hole transport layer 421 and a second electron transport layer 423. Preferably, the second light-emitting functional layer 42 includes a second hole transport layer 421, a second light-emitting layer 422 and a second electron transport layer 423 stacked sequentially, with the second hole transport layer 421 close to the first electrode 2.

[0056] Specifically, the materials of the second hole transport layer 421, the second light-emitting layer 422, and the second electron transport layer 423 are the same as those in the prior art, and will not be described in detail here.

[0057] In specific implementations, in the organic electroluminescent devices provided in the embodiments of this disclosure, such as Figure 5 and Figure 6 As shown, the third light-emitting functional layer 43 includes a third light-emitting layer 432 and at least one of a third hole transport layer 431, a third electron transport layer 433 and a first electron injection layer 434. Preferably, the third light-emitting functional layer 43 includes a third hole transport layer 431, a third light-emitting layer 432, a third electron transport layer 433 and a first electron injection layer 434 stacked sequentially, with the third hole transport layer 431 close to the first electrode 2.

[0058] Specifically, the materials of the third hole transport layer 431, the third light-emitting layer 432, the third electron transport layer 433, and the first electron injection layer 434 are the same as those in the prior art, and will not be described in detail here.

[0059] In existing technologies, the charge generation layer uses only one electron transport material and lithium doping. The emission spectra of different colors of the emitting functional layers in existing organic light-emitting devices and the organic light-emitting devices provided in this disclosure embodiment were tested. Figures 7A-7C As shown, Figure 7A The images show the emission spectra of the first light-emitting functional layer (emitting red, R) in the prior art (comparative example) and the first light-emitting functional layer 41 (emitting red, R) in this embodiment. Figure 7B The images show the emission spectra of the second light-emitting functional layer (emitting green, G) in the prior art (comparative example) and the second light-emitting functional layer 42 (emitting green, G) in this embodiment. Figure 7C The images show the emission spectra of the third light-emitting functional layer (emitting blue, B) in the prior art (comparative example) and the third light-emitting functional layer 43 (emitting blue, B) in the embodiments of this disclosure. Figure 7A , Figure 7B and Figure 7C In the figure, C represents the red emission spectrum in the prior art (comparative example). Figure 7A , Figure 7B and Figure 7C In this embodiment, D represents the red emission spectrum. It can be seen that by setting the charge generation layer provided in this embodiment, the stray peaks in the red, green, and blue emission spectra can be significantly reduced compared to those in the prior art. For example... Figure 8 As shown, each pixel emits light independently, reducing crosstalk between adjacent pixels and minimizing lateral leakage.

[0060] Furthermore, the inventors of this case have discovered that, compared to the prior art which uses only one electron transport material and a lithium-doped charge generation layer, and the present invention which uses two electron transport materials with different mobilities and lithium doping, the prior art's organic electroluminescent devices can achieve an average color gamut of 90.7%, while the present invention's organic electroluminescent devices can achieve an average color gamut of 95.4%. The average color gamut of the present invention's organic electroluminescent devices can be improved by about 5% compared to the prior art.

[0061] Based on the same inventive concept, this disclosure also provides an organic light-emitting device, including the organic electroluminescent device described above. Since the principle by which this organic light-emitting device solves the problem is similar to that of the aforementioned organic electroluminescent device, the implementation of this organic light-emitting device can refer to the implementation of the aforementioned organic electroluminescent device, and repeated details will not be elaborated further. This organic light-emitting device can be any product or component with display or touch functionality, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0062] In specific implementations, the tactile feedback device provided in the embodiments of this disclosure may also include other functional structures well known to those skilled in the art, which will not be described in detail here.

[0063] This disclosure provides a charge generation layer, an organic electroluminescent device, and an organic light-emitting apparatus. By employing a first electron transport material and a second electron transport material with different electron mobilities, the first and second electron transport materials primarily provide electrons. The difference in mobility increases the difficulty of electron transport, thereby reducing the possibility of lateral leakage. Furthermore, through the interaction and constraint between the doped first metal material and the first and second electron transport materials, the carrier flow has a certain directionality, which reduces the number of electrons transported laterally and increases the number of electrons transported longitudinally. Applying this charge generation layer to an organic electroluminescent device can reduce the problem of lateral leakage, improve the color gamut of the organic electroluminescent device, and thus improve the lifetime of the organic electroluminescent device.

[0064] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.

[0065] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this disclosure without departing from the spirit and scope of the embodiments of this disclosure. Therefore, if these modifications and variations to the embodiments of this disclosure fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include these modifications and variations.

Claims

1. A charge-generating layer, wherein, The charge generation layer includes a first charge generation layer and a second charge generation layer stacked alternately. The material of the first charge generation layer includes a first electron transport material, a second electron transport material, and a first metal material doped in the first electron transport material and the second electron transport material. The electron mobility of the first electron transport material and the electron mobility of the second electron transport material are different. The material of the second charge generation layer is different from the material of the first charge generation layer, and the number of the second charge generation layers is greater than the number of the first charge generation layers.

2. The charge generation layer according to claim 1, wherein, The ratio between the electron mobility of the first electron transport material and the electron mobility of the second electron transport material is greater than or equal to 10 and less than or equal to 100.

3. The charge-generating layer according to claim 1 or 2, wherein, The thickness of the charge generation layer is less than or equal to 20 nm.

4. The charge generation layer according to claim 1, wherein, The material of the second charge generation layer includes a third electron transport material and a second metallic material doped in the third electron transport material.

5. The charge generation layer according to claim 4, wherein, The third electron transport material is the same as the first electron transport material, or the third electron transport material is the same as the second electron transport material, and the second metal material is the same as the first metal material.

6. The charge generation layer according to claim 1, wherein, The sum of the number of the first charge generation layer and the second charge generation layer is 3 to 7 layers.

7. The charge-generating layer according to claim 6, wherein, The number of the first charge generation layers is greater than or equal to two, and the doping concentration of the first metal material in each of the first charge generation layers varies in a gradient along the thickness direction of the charge generation layers.

8. The charge-generating layer according to claim 1, wherein, The thickness of the first charge generation layer is less than or equal to 3 nm, and the thickness of the second charge generation layer is less than or equal to 3 nm.

9. The charge-generating layer according to claim 4, wherein, Both the first metallic material and the second metallic material include lithium.

10. The charge-generating layer according to claim 4, wherein, The doping concentration of the first metal material and the doping concentration of the second metal material are within 1% to 5%.

11. The charge-generating layer according to claim 1, wherein, The first electron transport material comprises 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, and the second electron transport material comprises o-phenanthroline.

12. An organic electroluminescent device, wherein, include: First electrode; The second electrode is disposed opposite to the first electrode; At least two light-emitting functional layers are stacked between the first electrode and the second electrode; A charge generation layer is located between each two adjacent light-emitting functional layers; wherein the charge generation layer is the charge generation layer according to any one of claims 1-11.

13. The organic electroluminescent device according to claim 12, wherein, The at least two light-emitting functional layers include a first light-emitting functional layer, a second light-emitting functional layer, and a third light-emitting functional layer stacked together. The first light-emitting functional layer is close to the first electrode, and the third light-emitting functional layer is close to the second electrode. The first light-emitting functional layer, the second light-emitting functional layer, and the third light-emitting functional layer emit different colors.

14. The organic electroluminescent device according to claim 13, wherein, The first light-emitting functional layer includes a first hole injection layer, a first hole transport layer, a first light-emitting layer and a first electron transport layer stacked in sequence, with the first hole injection layer close to the first electrode.

15. The organic electroluminescent device according to claim 13, wherein, The second light-emitting functional layer includes a second hole transport layer, a second light-emitting layer, and a second electron transport layer stacked sequentially, with the second hole transport layer close to the first electrode.

16. The organic electroluminescent device according to claim 13, wherein, The third light-emitting functional layer includes a third hole transport layer, a third light-emitting layer, a third electron transport layer and a first electron injection layer stacked in sequence, with the third hole transport layer close to the first electrode.

17. The organic electroluminescent device according to any one of claims 13-16, wherein, The first electrode is the anode, and the second electrode is the cathode.

18. An organic light-emitting device, wherein, Including the organic electroluminescent device according to any one of claims 12-17.

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