Display panel and display device

Abstract

The application discloses a display panel and a display device; in the light emitting device layer, the n-type charge generation layer comprises an electron transport material and an n-type doped material; the p-type charge generation layer comprises a hole transport material and a p-type doped material; wherein, the light emitting device layer has a first working voltage under a preset current density, the light emitting device layer has a second working voltage after working for a preset time under the preset current density and a first preset temperature, the absolute value of the difference between the first working voltage and the second working voltage is a1, a1 is less than or equal to 1V, and the first preset temperature is greater than or equal to 50 DEG C; the application can improve the high-temperature stability of the light emitting device layer, and improve the display stability and display effect of the display panel.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more particularly to a display panel and display device. Background Technology

[0002] Organic semiconductor materials have lower manufacturing costs, better controllability, and superior photoelectric properties compared to inorganic semiconductor materials. Organic light-emitting diodes (OLEDs) have great potential for application in optoelectronic devices such as displays and lighting.

[0003] With the development of flat panel display technology, customers' requirements for display stability are gradually increasing. In recent years, OLED displays have developed rapidly worldwide, and OLED display technology has become increasingly sophisticated. With the improvement of OLED technology capabilities and processes, the application fields of OLED displays are gradually expanding to medium and large sizes. In the field of medium and large-size OLED displays, the stability requirements of the displays are even higher, especially in terms of lifespan and temperature stability.

[0004] Although OLED devices have significant advantages in terms of efficiency and lifespan, the high heat generation of medium and large-sized products and the large heat dissipation problems in the module form of compressed product stacking space can easily cause unstable display and poor display effect if the high temperature stability of OLED devices is insufficient. Summary of the Invention

[0005] This invention provides a display panel and display device that can improve the high-temperature stability of the light-emitting device layer and enhance the display stability and display effect of the display panel.

[0006] This invention provides a display panel, the display panel including a light-emitting device layer, the light-emitting device layer including:

[0007] anode;

[0008] A first light-emitting layer is disposed on one side of the anode;

[0009] An n-type charge generation layer is disposed on the side of the first light-emitting layer away from the anode, and the n-type charge generation layer comprises: an electron transport material and an n-type doped material;

[0010] A p-type charge generation layer is disposed on the side of the n-type charge generation layer away from the first light-emitting layer. The p-type charge generation layer includes a hole transport material and a p-type doped material.

[0011] The second light-emitting layer is disposed on the side of the p-type charge generation layer away from the n-type charge generation layer;

[0012] The cathode is disposed on the side of the second light-emitting layer away from the p-type charge generation layer;

[0013] Wherein, the light-emitting device layer has a first operating voltage at a preset current density, and the light-emitting device layer has a second operating voltage after operating for a preset time at the preset current density and at a first preset temperature. The absolute value of the difference between the first operating voltage and the second operating voltage is a1, a1 is less than or equal to 1V, and the first preset temperature is greater than or equal to 50℃.

[0014] In one embodiment of the present invention, the light-emitting device layer has a third operating voltage after operating for a preset time at the preset current density and the second preset temperature, wherein the absolute value of the difference between the first operating voltage and the third operating voltage is a2, a2 ​​is less than a1, and the second preset temperature is less than 50°C.

[0015] In one embodiment of the present invention, the second operating voltage is greater than the first operating voltage, and the third operating voltage is greater than the first operating voltage.

[0016] In one embodiment of the present invention, the preset time is greater than 0 and less than or equal to 120 hours, and the preset current density is greater than or equal to 5 mA / cm². 2 .

[0017] In one embodiment of the present invention, the absolute value of the difference between the second operating voltage and the first operating voltage is less than or equal to 0.5V.

[0018] In one embodiment of the present invention, the absolute value of the difference between the second operating voltage and the first operating voltage decreases as the doping concentration of the p-type doped material in the p-type charge generation layer decreases.

[0019] In one embodiment of the present invention, the light-emitting device layer further includes a hole injection layer disposed between the anode and the first light-emitting layer, wherein a first doping material is distributed in the hole injection layer, and the first doping material is different from the p-type doping material.

[0020] In one embodiment of the present invention, the light-emitting device layer further includes a hole injection layer disposed between the anode and the first light-emitting layer. A first doping material is distributed in the hole injection layer. The first doping material is the same as the p-type doping material. The doping concentration of the first doping material in the hole injection layer is different from the doping concentration of the p-type doping material in the p-type charge generation layer.

[0021] In one embodiment of the present invention, the p-type doped material in the p-type charge generation layer has a mass percentage content greater than or equal to 0.1% and less than or equal to 20%.

[0022] In one embodiment of the present invention, the light-emitting device layer further includes a first hole transport layer disposed between the p-type charge generation layer and the second light-emitting layer, wherein the lowest unoccupied orbital energy level of the p-type doped material is > -5.5 eV, and the highest occupied orbital energy level of the material of the first hole transport layer is >

[0023] -6.5eV.

[0024] In one embodiment of the present invention, the difference between the lowest unoccupied orbital energy level of the p-type doped material and the highest occupied orbital energy level of the material of the first hole transport layer is less than 1 eV.

[0025] In one embodiment of the present invention, the wavelength of the reddest absorption peak of the p-type doped material is greater than 400 nm, and the wavelength of the fluorescence emission peak of the p-type doped material is greater than 500 nm.

[0026] In one embodiment of the present invention, the light-emitting device layer further includes a buffer layer disposed between the n-type charge generation layer and the p-type charge generation layer, and the material of the buffer layer includes at least one of organic materials and metallic materials.

[0027] According to the above-mentioned objectives of the present invention, embodiments of the present invention also provide a display device, the display device including the display panel.

[0028] The beneficial effects of the present invention are as follows: In the display panel provided by the present invention, after the light-emitting device layer operates at a high temperature of 50°C or higher and at a preset current density for a preset time, the absolute value of the difference between its second operating voltage and the first operating voltage at the preset current density is less than or equal to 1V, thereby enabling the light-emitting device layer to have better stability at high temperatures, and improving the stability and display effect of the display panel. Attached Figure Description

[0029] The technical solution and other beneficial effects of the present invention will become apparent from the following detailed description of specific embodiments of the invention, in conjunction with the accompanying drawings.

[0030] Figure 1 This is a schematic diagram of a light-emitting device layer in a display panel provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of a display panel provided in an embodiment of the present invention;

[0032] Figure 3This is another structural schematic diagram of the light-emitting device layer in the display panel provided in an embodiment of the present invention;

[0033] Figure 4 This is another structural schematic diagram of the light-emitting device layer in the display panel provided in an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the reactive device structure provided in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of another structure of the light-emitting device layer in the display panel provided in an embodiment of the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0038] Please combine Figure 1 and Figure 2 The display panel provided in this embodiment of the invention includes a light-emitting device layer 10, and the light-emitting device layer 10 includes an anode 11, a first light-emitting layer 12, an n-type charge generation layer 13, a p-type charge formation layer 14, a second light-emitting layer 15, and a cathode 16.

[0039] The first light-emitting layer 12 is disposed on one side of the anode 11; the n-type charge generation layer 13 is disposed on the side of the first light-emitting layer 12 away from the anode 11, and the n-type charge generation layer 13 includes an electron transport material and an n-type dopant material 131; the p-type charge generation layer 14 is disposed on the side of the n-type charge generation layer 13 away from the first light-emitting layer 12, and the p-type charge generation layer 14 includes a hole transport material and a p-type dopant material 141; the second light-emitting layer 15 is disposed on the side of the p-type charge generation layer 14 away from the n-type charge generation layer 13; and the cathode 16 is disposed on the side of the second light-emitting layer 15 away from the p-type charge generation layer 14.

[0040] Furthermore, the light-emitting device layer 10 has a first operating voltage at a preset current density, and the light-emitting device layer 10 has a second operating voltage after operating for a preset time at a preset current density and a first preset temperature. The absolute value of the difference between the first operating voltage and the second operating voltage is a1, a1 is less than or equal to 1V, and the first preset temperature is greater than or equal to 50℃.

[0041] During application, since the n-type charge generation layer 13 and the p-type charge generation layer 14 are adjacent, an electrochemical reaction occurs at the interface between the n-type doped material 131 in the n-type charge generation layer 13 and the p-type doped material 131 in the p-type charge generation layer 14 under high temperature conditions. This reaction damages the p-type doped material 141, causing structural defects in the p-type charge generation layer 14, which in turn causes a sharp increase in the operating voltage of the light-emitting device layer 10. In the display panel provided in this embodiment of the invention, after the light-emitting device layer 10 operates at a high temperature greater than or equal to 50°C and at a preset current density for a preset time, the absolute value of the difference between its second operating voltage and its first operating voltage at the preset current density is less than or equal to 1V. This results in better stability of the light-emitting device layer at high temperatures, effectively reducing the reactivity at the interface between the n-type charge generation layer 13 and the p-type charge generation layer 14 at high temperatures, and improving the stability and display effect of the display panel.

[0042] In one embodiment, please continue to combine Figure 1 and Figure 2 The display panel provided in this embodiment of the invention includes a substrate 20, a thin film transistor layer 30 disposed on the substrate 20, and a light-emitting device layer 10 disposed on the side of the thin film transistor layer 30 away from the substrate 20.

[0043] The thin-film transistor layer 30 contains multiple thin-film transistors, and the light-emitting device layer 10 can be connected to the thin-film transistors. The thin-film transistors can be used as switches to control the on / off state of signals input to the light-emitting device layer 10.

[0044] Specifically, the light-emitting device layer 10 includes an anode 11, a first light-emitting layer 12 disposed on one side of the anode 11, an n-type charge generating layer 13 disposed on the side of the first light-emitting layer 12 away from the anode 11, a p-type charge generating layer 14 disposed on the side of the n-type charge generating layer 13 away from the first light-emitting layer 12, a second light-emitting layer 15 disposed on the side of the p-type charge generating layer 14 away from the n-type charge generating layer 13, and a cathode 16 disposed on the side of the second light-emitting layer 15 away from the p-type charge generating layer 14.

[0045] The anode 11 is disposed on the side of the light-emitting device layer 10 close to the thin-film transistor layer 30, and the anode 11 can be connected to the thin-film transistor in the thin-film transistor layer 30 to receive signals.

[0046] In one embodiment, please combine Figure 1 and Figure 3 The light-emitting device layer 10 further includes a hole injection layer 171 disposed on the side of the anode 11 near the first light-emitting layer 12, a second hole transport layer 172 disposed between the hole injection layer 171 and the first light-emitting layer 12, a first electron transport layer 181 disposed between the first light-emitting layer 12 and the n-type charge generation layer 13, a first hole transport layer 173 disposed between the p-type charge generation layer 14 and the second light-emitting layer 15, a second electron transport layer 182 disposed on the side of the second light-emitting layer 15 near the cathode 16, and an electron injection layer 183 disposed between the second electron transport layer 182 and the cathode 16.

[0047] It should be noted that the display panel provided in the embodiments of the present invention is a stacked OLED display panel, that is, the light-emitting device layer 10 has multiple light-emitting layers. In this embodiment of the present invention, two light-emitting layers are used as an example for explanation. An n-type charge generation layer and a p-type charge generation layer are provided between two adjacent light-emitting layers.

[0048] In addition, an electron blocking layer can be provided on the side of the first light-emitting layer 12 near the anode 11, and a hole blocking layer can be provided on the side near the cathode 16. Similarly, an electron blocking layer can be provided on the side of the second light-emitting layer 15 near the anode 11, and a hole blocking layer can be provided on the side near the cathode 16.

[0049] In one embodiment, the anode 11 may be made of ITO material, and the cathode 16 may be made of at least one of Mg and Ag.

[0050] Furthermore, the n-type charge generation layer 13 can be formed by doping an electron transport material with an n-type dopant 131, while the p-type charge generation layer 14 can be formed by doping a hole transport material with a p-type dopant 141. In one embodiment, the n-type dopant 131 can include active alkali metals, alkaline earth metals, and their salt compounds, such as lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium, ytterbium, lithium fluoride, sodium fluoride, lithium carbonate, cesium carbonate, lithium nitride, etc., while the p-type dopant 141 can include at least one of metallic materials and organic materials. Therefore, at least the n-type charge generation layer 13 contains an n-type dopant 131, and the p-type charge generation layer 14 contains a p-type dopant 141.

[0051] In one embodiment, the mass percentage content of p-type doped material 141 in p-type charge generation layer 14 is greater than or equal to 0.1% and less than or equal to 20%, for example, it can be 0.1%, 2%, 4%, 6%, 8%, 12%, 14%, 16%, 18%, or 20%; the mass percentage content of n-type doped material 131 in n-type charge generation layer 13 is greater than or equal to 0.1% and less than or equal to 20%, for example, it can be 0.1%, 2%, 4%, 6%, 8%, 12%, 14%, 16%, 18%, or 20%.

[0052] Furthermore, the light-emitting device layer 10 has a first operating voltage at a preset current density, and after operating at a preset current density and a first preset temperature for a preset time, the light-emitting device layer 10 has a second operating voltage, and the absolute value of the difference between the first operating voltage and the second operating voltage is a1, a1 is less than or equal to 1V, and the first preset temperature is greater than or equal to 50℃; thereby enabling the light-emitting device layer to have better stability at high temperatures, effectively reducing the reactivity of the interface between the n-type charge generation layer 13 and the p-type charge generation layer 14 at high temperatures, and improving the stability and display effect of the display panel.

[0053] In one embodiment, the light-emitting device layer 10 has a third working voltage after operating for a preset time at a preset current density and a second preset temperature. The absolute value of the difference between the first working voltage and the third working voltage is a2, where a2 is less than a1, and the second preset temperature is less than 50°C. That is, the display panel provided by the embodiment of the present invention has good stability even at non-high temperatures. At temperatures below 50°C, the reaction activity at the interface between the n-type charge generation layer 13 and the p-type charge generation layer 14 is low at high temperatures, resulting in good stability of the display panel.

[0054] It should be noted that as the temperature and operating time increase, the operating voltage of the light-emitting device layer 10 will also increase. Therefore, the second operating voltage is greater than the first operating voltage, and the third operating voltage is greater than the first operating voltage.

[0055] In one embodiment, the preset current density can be greater than or equal to 5 mA / cm². 2 The preset temperature can be greater than or equal to 50℃, and the preset energizing time can be greater than 1 and less than or equal to 120h; furthermore, the preset current density can be less than or equal to 10mA / cm². 2 For example, it can be 5mA / cm 2 6mA / cm 2 7mA / cm 2 8mA / cm 2 9mA / cm 2 Or 10mA / cm 2 The preset temperature can be greater than or equal to 110℃.

[0056] In this embodiment of the invention, the difference between the second working voltage and the first working voltage is less than or equal to 1V. That is, under the same preset current density, the difference between the working voltage of the light-emitting device layer 10 at the preset temperature and the preset energizing time and the initial working voltage needs to be less than or equal to 1V. This can prevent the working voltage of the light-emitting device layer 10 from rising sharply due to high temperature. In other words, the present invention can improve the high temperature stability of the light-emitting device layer 10 and improve the display stability and display effect of the display panel.

[0057] More preferably, the difference between the second operating voltage and the first operating voltage is less than or equal to 0.5V.

[0058] It should be noted that p-type doped material 141 is distributed within the p-type charge generation layer 14. Verification of this embodiment of the invention has shown that the difference between the second operating voltage and the first operating voltage decreases as the doping concentration of p-type doped material 141 in the p-type charge generation layer 14 decreases. In other words, this embodiment of the invention can reduce the doping concentration of p-type doped material 141 within the p-type charge generation layer 14 to reduce the reactivity between n-type doped material 131 and p-type doped material 141 at high temperatures, thereby improving the high-temperature stability of the light-emitting device layer 10 and enhancing the stability and display effect of the display panel.

[0059] In this embodiment of the invention, the hole injection layer 171 may also be obtained by doping a hole transport material with a first doping material, and the electron injection layer 183 may also be obtained by doping an electron transport material with a second doping material. The first doping material may be the same as or different from the p-type doping material 141, and the second doping material may be the same as or different from the n-type doping material 131.

[0060] When the first doped material is different from the p-type doped material 141, the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperature can be controlled by controlling the material selection of the p-type doped material 141; when the first doped material is different from the p-type doped material 141, the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperature can be controlled by controlling the doping concentration of the p-type doped material 141 in the p-type charge generation layer 14.

[0061] In one embodiment, the doping concentration of the first dopant in the hole injection layer 171 is different from the doping concentration of the p-type dopant 141 in the p-type charge generation layer 14. For example, the doping concentration of the first dopant in the hole injection layer 171 can be 3%, while the doping concentration of the p-type dopant 141 in the p-type charge generation layer 14 can be 5%.

[0062] It should be noted that, in this embodiment of the invention, the reactivity between the n-type dopant 131 and the p-type dopant 141 at high temperature can be reduced by selecting the p-type dopant 141, so that the difference between the second working voltage and the first working voltage is less than or equal to 1V.

[0063] Furthermore, embodiments of the present invention can also verify the energy level and other properties of the p-type doped material 141 to obtain a suitable material that meets the requirements of low high-temperature reactivity.

[0064] In one embodiment, the lowest unoccupied orbital energy level of the p-type doped material 141 is > -5.5 eV, the highest occupied orbital energy level of the material of the first hole transport layer is > -6.5 eV, and the difference between the lowest unoccupied orbital energy level of the p-type doped material 141 and the highest occupied orbital energy level of the material of the first hole transport layer is less than 1 eV, so as to facilitate charge separation.

[0065] In one embodiment, the wavelength of the reddest absorption peak of the p-type doped material 141 is greater than 400 nm, the wavelength of the fluorescence emission peak of the p-type doped material 141 is greater than 500 nm, and the refractive index of the p-type doped material 141 is greater than or equal to 1.5 and less than or equal to 1.8.

[0066] In one embodiment, the p-type doped material 141 may include a dicyanomethane compound, wherein the dicyanomethane compound contains at least one dicyanomethylene group.

[0067] Specifically, the p-type doped material 141 can be selected from at least one of compounds having the structure described in formula (1):

[0068]

[0069] Where n is an integer greater than 0, and the ring Ca can be selected from substituted or unsubstituted aryl groups containing 3 to 60 carbon atoms, substituted or unsubstituted heteroaryl groups containing 2 to 60 carbon atoms, or groups composed of multiple substituted or unsubstituted aryl groups containing 3 to 60 carbon atoms or substituted or unsubstituted heteroaryl groups containing 2 to 60 carbon atoms connected together.

[0070] Furthermore, the compound shown in formula (1) may further include the following formulas (1-1), (1-2), (1-3), and (1-4):

[0071]

[0072] Formula (1-1) may include compounds represented by formulas (1-1a) to (1-1e) as follows:

[0073]

[0074] In Equation (1-1a), X101 to X104, in Equation (1-1b), X111 to X116, in Equation (1-1c), X121 to X128, in Equation (1-1d), X131 to X136, and in Equation (1-1e), X141 to X148 can each be independently N or CRa; when X101 to X148 are each independently CRa, each CRa can be the same or different. Each CRa is independent and is arbitrarily selected from one of the following: hydrogen, deuterium, substituted or unsubstituted alkyl groups with 1 to 30 carbon atoms, substituted or unsubstituted aryl groups with 6 to 50 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups with 2 to 50 carbon atoms, substituted or unsubstituted alkylsilyl groups with 1 to 30 carbon atoms, substituted or unsubstituted arylsilyl groups with 6 to 50 carbon atoms, cyano, nitro, or halogen. Furthermore, if the substituents are in adjacent positions, for example, if X101 and X102 are both CRa, their Ra groups can be further bonded together to form a ring structure.

[0075] Formula (1-2) may include compounds represented by formulas (1-2a) to (1-2g):

[0076]

[0077]

[0078] In Equation (1-2a), X201 to X204, in Equation (1-2b), X211 to X216, in Equation (1-2c), X221 to X226, in Equation (1-2d), X231 to X238, in Equation (1-2e), X241 to X248, in Equation (1-2f), X251 to X254, and in Equation (1-2g), X261 to X264 can each be independently N or CRa; when X201 to X264 are each independently CRa, each CRa can be the same or different. Each CRa group is independent of the others and is arbitrarily selected from one of the following: hydrogen, deuterium, substituted or unsubstituted alkyl groups with 1 to 30 carbon atoms, substituted or unsubstituted aryl groups with 6 to 50 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups with 2 to 50 carbon atoms, substituted or unsubstituted alkylsilyl groups with 1 to 30 carbon atoms, substituted or unsubstituted arylsilyl groups with 6 to 50 carbon atoms, cyano, nitro, or halogen. If the substituents are in adjacent positions, their Ra groups can be further bonded together to form a ring structure.

[0079] In formulas (1-2f), Y251 and Y252, and in formula (1-2g), Y261, can be independently O, S, NRb, or CRcRd, respectively; and when they are independently NRb or CRcRd, each Rb, Rc, and Rd can be the same or different from each other. Each Rb, Rc, and Rd is independent from each other and is arbitrarily selected from hydrogen, deuterium, substituted or unsubstituted alkyl with 1 to 30 carbon atoms, substituted or unsubstituted aryl with 6 to 50 carbon atoms, substituted or unsubstituted cycloalkyl with 3 to 30 carbon atoms, substituted or unsubstituted heteroaryl with 2 to 50 carbon atoms, substituted or unsubstituted alkylsilyl with 1 to 30 carbon atoms, substituted or unsubstituted arylsilyl with 6 to 50 carbon atoms, cyano, nitro, or halogen. If the above substituents are in adjacent positions, their Rb, Rc and Rd groups, as well as the adjacent Ra group, can be further bonded together to form a cyclic structure.

[0080] Formula (1-3) may further include compounds as shown in formulas (1-3a) and (1-3b):

[0081]

[0082] In formula (1-3a), X301 to X304, and in formula (1-3b), X311 to X316, can each be independently N or CRa. When X201 to X264 are each independently CRa, each CRa can be the same or different. Each CRa is independent of the others and is arbitrarily selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups with 1 to 30 carbon atoms, substituted or unsubstituted aryl groups with 6 to 50 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups with 2 to 50 carbon atoms, substituted or unsubstituted alkylsilyl groups with 1 to 30 carbon atoms, substituted or unsubstituted arylsilyl groups with 6 to 50 carbon atoms, cyano, nitro, and halogen. If the above substituents are in adjacent positions, their Ra groups can be further bonded to each other to form a ring structure.

[0083] Formula (1-4) may further include compounds as shown in formulas (1-4a) to (1-4b):

[0084]

[0085] In formula (1-4a), X301 to X306, and in formula (1-4b), X411 to X416, can each be independently N or CRa. When X201 to X264 are each independently CRa, each CRa can be the same or different. Each CRa is independent of the others and is arbitrarily selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups with 1 to 30 carbon atoms, substituted or unsubstituted aryl groups with 6 to 50 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups with 2 to 50 carbon atoms, substituted or unsubstituted alkylsilyl groups with 1 to 30 carbon atoms, substituted or unsubstituted arylsilyl groups with 6 to 50 carbon atoms, cyano, nitro, and halogen. If the above substituents are in adjacent positions, their Ra groups can be further bonded to each other to form a ring structure.

[0086] As described above, the p-type doped material 141 provided in this embodiment of the invention can be selected from at least one of PD-01 to PD-141:

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] In one embodiment, the hole transport material in the p-type charge generation layer 14 provided by the present invention may include an aromatic amine compound and contains at least one aromatic amine group, and the hole transport material may include at least one of the compounds of the following formula (2):

[0098]

[0099] R201 to R207 are independent of each other and are each arbitrarily selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups with 1 to 30 carbon atoms, substituted or unsubstituted aryl groups with 6 to 50 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups with 2 to 50 carbon atoms, substituted or unsubstituted alkylsilyl groups with 1 to 30 carbon atoms, substituted or unsubstituted arylsilyl groups with 6 to 50 carbon atoms, cyano, nitro, and halogen. Furthermore, if the substituents are in adjacent positions, such as R203 and R204, they can be bonded together to form a ring structure.

[0100] For example, the hole transport material in the p-type charge generation layer 14 can be selected from at least one of the following compounds:

[0101]

[0102]

[0103] It is understood that, in this embodiment of the invention, the hole transport material in the first hole transport layer 173 and the second hole transport layer 172 may also be the same as the hole transport material in the P-type charge generation layer 14.

[0104] In one embodiment, both the first light-emitting layer 12 and the second light-emitting layer 15 can be formed by doping a blue light-emitting shell material into a blue light host material, wherein the blue light host material may include at least one of the following compounds:

[0105]

[0106] Blue light guest materials may include at least one of the following compounds:

[0107]

[0108] In one embodiment, the electron transport material in the first electron transport layer 181, the second electron transport layer 182, and the electron injection layer 183 may include at least one of the following compounds:

[0109]

[0110] In one embodiment, the electron transport material in the n-type charge generation layer 13 may include at least one of the following compounds:

[0111]

[0112] In another embodiment of the invention, please refer to Figure 1 and Figure 4 This embodiment and Figure 3 The difference in the illustrated embodiment is that a buffer layer 19 is provided between the n-type charge generation layer 13 and the p-type charge generation layer 14, and the material of the buffer layer 19 may include at least one of organic materials and metallic materials. In this embodiment of the invention, the buffer layer 19 can serve to separate the n-type charge generation layer 13 and the p-type charge generation layer 14, and can reduce the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperatures.

[0113] In one embodiment, the material of the buffer layer 19 may include at least one of the following: hole transport layer material, electron transport layer material, organic material used in the n-type charge generation layer 13, aluminum, silver, and zinc oxide.

[0114] In summary, in this embodiment of the invention, by controlling the difference between the second operating voltage and the first operating voltage of the light-emitting device layer 10, the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperatures can be reduced, thereby improving the high-temperature stability of the light-emitting device layer 10 and enhancing the stability and display effect of the display panel.

[0115] Furthermore, to verify the effect of the present invention in reducing the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperature, the present invention provides a reactive device to verify the operating voltage under different conditions.

[0116] It is understood that the reactive device is not a functional device in the display panel, but a device provided in this embodiment of the invention to verify high-temperature reactive activity.

[0117] Please refer to Figure 5The reactive device includes a first electron transport layer 181, an n-type charge generation layer 13, a p-type charge generation layer 14, a first hole transport layer 173, an electron injection layer 183, and a cathode 16 sequentially disposed on the anode 11. Figure 3 The light-emitting device layer 10 shown has removed the first light-emitting layer 12, the second light-emitting layer 15, the second electron transport layer 182 and the second hole transport layer 172 adjacent to the light-emitting layer, and the hole injection layer 171.

[0118] Specifically, the present invention provides Comparative Example 1, Comparative Example 2, Example 1, and Example 2.

[0119] In Comparative Example 1, the anode 11 is made of ITO material; the first electron transport layer 181 is made of Liq and ET5, with Liq accounting for 50% by mass and the thickness of the first electron transport layer 181 is 10 nm; the n-type charge generation layer 13 is made of Yb and E19, with Yb accounting for 5% by mass and the thickness of the n-type charge generation layer 13 is 10 nm; the p-type charge generation layer 14 is made of PD-a1 and TAPC, with PD-a1 accounting for 5% by mass and the thickness of the p-type charge generation layer 14 is 10 nm; the first hole transport layer 173 is made of TAPC and the thickness of the first hole transport layer 173 is 10 nm; the electron injection layer 183 is made of Yb and the thickness of the electron injection layer 183 is 1 nm; the cathode 16 is made of Mg and Ag, with Mg accounting for 10% by mass and the thickness of the cathode 16 is 20 nm.

[0120] In Comparative Reference 2, the anode 11 is made of ITO material; the first electron transport layer 181 is made of Liq and ET5, with Liq accounting for 50% by mass and the thickness of the first electron transport layer 181 is 10 nm; the n-type charge generation layer 13 is made of Yb and E19, with Yb accounting for 5% by mass and the thickness of the n-type charge generation layer 13 is 10 nm; the p-type charge generation layer 14 is made of PD-a2 and TAPC, with PD-a2 accounting for 5% by mass and the thickness of the p-type charge generation layer 14 is 10 nm; the first hole transport layer 173 is made of TAPC and the thickness of the first hole transport layer 173 is 10 nm; the electron injection layer 183 is made of Yb and the thickness of the electron injection layer 183 is 1 nm; the cathode 16 is made of Mg and Ag, with Mg accounting for 10% by mass and the thickness of the cathode 16 is 20 nm.

[0121] In Example 1, the anode 11 is made of ITO material; the first electron transport layer 181 is made of Liq and ET5, wherein Liq accounts for 50% by mass and the thickness of the first electron transport layer 181 is 10 nm; the n-type charge generation layer 13 is made of Yb and E19, wherein Yb accounts for 5% by mass and the thickness of the n-type charge generation layer 13 is 10 nm; the p-type charge generation layer 14 is made of PD-113 and TAPC, wherein PD-113 accounts for 5% by mass and the thickness of the p-type charge generation layer 14 is 10 nm; the first hole transport layer 173 is made of TAPC and the thickness of the first hole transport layer 173 is 10 nm; the electron injection layer 183 is made of Yb and the thickness of the electron injection layer 183 is 1 nm; the cathode 16 is made of Mg and Ag, wherein Mg accounts for 10% by mass and the thickness of the cathode 16 is 20 nm.

[0122] In Example 2, the anode 11 is made of ITO material; the first electron transport layer 181 is made of Liq and ET5, wherein Liq accounts for 50% by mass and the thickness of the first electron transport layer 181 is 10 nm; the n-type charge generation layer 13 is made of Yb and E19, wherein Yb accounts for 5% by mass and the thickness of the n-type charge generation layer 13 is 10 nm; the p-type charge generation layer 14 is made of PD-114 and TAPC, wherein PD-114 accounts for 5% by mass and the thickness of the p-type charge generation layer 14 is 10 nm; the first hole transport layer 173 is made of TAPC and the thickness of the first hole transport layer 173 is 10 nm; the electron injection layer 183 is made of Yb and the thickness of the electron injection layer 183 is 1 nm; the cathode 16 is made of Mg and Ag, wherein Mg accounts for 10% by mass and the thickness of the cathode 16 is 20 nm.

[0123] The structural formulas of PD-a1 and PD-a2 are shown below:

[0124]

[0125] Under high vacuum conditions, the reactive devices shown in Comparative Example 1, Comparative Example 2, Example 1, and Example 2 were formed respectively. The specific testing and verification process included:

[0126] First, under normal temperature conditions, the reactive device was subjected to an A / cm² temperature of 10 mA. 2 Its first operating voltage V1 was measured at a current density of 10 mA / cm². 2After working continuously for 120 hours at the current density, its second working voltage V2 was measured, and ΔV(V2-V1) was positively correlated with the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperature. The data are shown in Table 1 below.

[0127] Table 1 Working Voltage Data Table

[0128]

[0129] As can be seen from Table 1 above, in Examples 1 and 2, the materials PD-113 and PD114 of the p-type charge generation layer 14 provided by the present invention are used. Compared with the comparative example, ΔV is significantly reduced and is less than or equal to 3V, that is, the difference between the second working voltage and the first working voltage is reduced. This indicates that the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperature can be effectively reduced in Examples 1 and 2.

[0130] Furthermore, the embodiments of the present invention provide Comparative Example 3, Comparative Example 4, Example 3, and Example 4 to verify that when the above materials are applied... Figure 6 The effect of reducing the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperature in the light-emitting device layer shown is illustrated.

[0131] In Comparative Example 3, the anode 11 is prepared using ITO; the hole injection layer 171 is made of PD-a2 and TAPC, with PD-a2 comprising 3% by mass; and the hole injection layer 171 has a thickness of 10 nm; the second hole transport layer 172 is made of TAPC, and its thickness is 25 nm; the first electron blocking layer 184 is made of TCTA, and its thickness is 5 nm; the first light-emitting layer 12 is made of BD3 and BH16, B... The D3 mass percentage content is 2%, and the thickness of the first light-emitting layer 12 is 20 nm; the material of the first hole blocking layer 174 is ET6, and the thickness of the first hole blocking layer 174 is 5 nm; the material of the first electron transport layer 181 includes Liq and ET5, the mass percentage content of Liq is 50%, and the thickness of the first electron transport layer 181 is 20 nm; the material of the n-type charge generation layer 13 includes Yb and E19, the mass percentage content of Yb is 5%, and the thickness of the n-type charge generation layer 13 is 10 nm; p The p-type charge generation layer 14 is made of PD-a1 and TAPC, with PD-a1 having a mass percentage content of 5% and a thickness of 10 nm; the second hole transport layer 172 is made of TAPC and has a thickness of 30 nm; the second electron blocking layer 185 is made of TCTA and has a thickness of 5 nm; the second light-emitting layer 15 is made of BD3 and BH16, with BD3 having a mass percentage content of 2% and a thickness of 10 nm. The thickness of the second hole-blocking layer 175 is 20 nm; the material of the second hole-blocking layer 175 includes ET6, and the thickness of the second hole-blocking layer 175 is 5 nm; the material of the second electron transport layer 182 includes Liq and ET5, the mass percentage content of Liq is 50%, and the thickness of the second electron transport layer 182 is 30 nm; the material of the electron injection layer 183 includes Yb, and the thickness of the electron injection layer 183 is 1 nm; the material of the cathode 16 includes Mg and Ag, the mass percentage content of Mg is 10%, and the thickness of the cathode 16 is 15 nm.

[0132] In Comparative Example 4, the anode 11 is prepared using ITO; the hole injection layer 171 is made of PD-a2 and TAPC, with PD-a2 comprising 3% by mass; and the hole injection layer 171 has a thickness of 10 nm; the second hole transport layer 172 is made of TAPC, and the second hole transport layer 172 has a thickness of 25 nm; the first electron blocking layer 184 is made of TCTA, and the first electron blocking layer 184 has a thickness of 5 nm; the first light-emitting layer 12 is made of BD3 and BH16, with BD3... The mass percentage content of the first light-emitting layer 12 is 2%, and the thickness of the first light-emitting layer 12 is 20 nm; the material of the first hole blocking layer 174 is ET6, and the thickness of the first hole blocking layer 174 is 5 nm; the material of the first electron transport layer 181 includes Liq and ET5, the mass percentage content of Liq is 50%, and the thickness of the first electron transport layer 181 is 20 nm; the material of the n-type charge generation layer 13 includes Yb and E19, the mass percentage content of Yb is 5%, and the thickness of the n-type charge generation layer 13 is 10 nm; p-type The charge generation layer 14 is made of PD-a2 and TAPC, with PD-a2 having a mass percentage content of 5% and a thickness of 10 nm; the second hole transport layer 172 is made of TAPC and has a thickness of 30 nm; the second electron blocking layer 185 is made of TCTA and has a thickness of 5 nm; the second light-emitting layer 15 is made of BD3 and BH16, with BD3 having a mass percentage content of 2% and a thickness of 10 nm. The thickness of the second hole-blocking layer 175 is 20 nm; the material of the second hole-blocking layer 175 includes ET6, and the thickness of the second hole-blocking layer 175 is 5 nm; the material of the second electron transport layer 182 includes Liq and ET5, the mass percentage content of Liq is 50%, and the thickness of the second electron transport layer 182 is 30 nm; the material of the electron injection layer 183 includes Yb, and the thickness of the electron injection layer 183 is 1 nm; the material of the cathode 16 includes Mg and Ag, the mass percentage content of Mg is 10%, and the thickness of the cathode 16 is 15 nm.

[0133] In Example 3, the anode 11 is fabricated using ITO; the hole injection layer 171 is made of PD-a2 and TAPC, with PD-a2 comprising 3% by mass; and the hole injection layer 171 has a thickness of 10 nm; the second hole transport layer 172 is made of TAPC, and the second hole transport layer 172 has a thickness of 25 nm; the first electron blocking layer 184 is made of TCTA, and the first electron blocking layer 184 has a thickness of 5 nm; the first light-emitting layer 12 is made of BD3 and BH16, with BD3... The mass percentage content of the first light-emitting layer 12 is 2%, and the thickness of the first light-emitting layer 12 is 20 nm; the material of the first hole blocking layer 174 is ET6, and the thickness of the first hole blocking layer 174 is 5 nm; the material of the first electron transport layer 181 includes Liq and ET5, the mass percentage content of Liq is 50%, and the thickness of the first electron transport layer 181 is 20 nm; the material of the n-type charge generation layer 13 includes Yb and E19, the mass percentage content of Yb is 5%, and the thickness of the n-type charge generation layer 13 is 10 nm; the p-type charge generation layer 13 includes Yb and E19, the mass percentage content of Yb is 5%, and the thickness of the n-type charge generation layer 13 is 10 nm; The charge generation layer 14 is made of PD-113 and TAPC, with PD-113 comprising 5% by mass and a thickness of 10 nm. The second hole transport layer 172 is made of TAPC and has a thickness of 30 nm. The second electron blocking layer 185 is made of TCTA and has a thickness of 5 nm. The second light-emitting layer 15 is made of BD3 and BH16, with BD3 comprising 2% by mass and a thickness of 10 nm. The thickness of the second hole-blocking layer 175 is 20 nm; the material of the second hole-blocking layer 175 includes ET6, and the thickness of the second hole-blocking layer 175 is 5 nm; the material of the second electron transport layer 182 includes Liq and ET5, the mass percentage content of Liq is 50%, and the thickness of the second electron transport layer 182 is 30 nm; the material of the electron injection layer 183 includes Yb, and the thickness of the electron injection layer 183 is 1 nm; the material of the cathode 16 includes Mg and Ag, the mass percentage content of Mg is 10%, and the thickness of the cathode 16 is 15 nm.

[0134] In Example 4, the anode 11 is fabricated using ITO; the hole injection layer 171 is made of PD-a2 and TAPC, with PD-a2 comprising 3% by mass; and the hole injection layer 171 has a thickness of 10 nm; the second hole transport layer 172 is made of TAPC, and the second hole transport layer 172 has a thickness of 25 nm; the first electron blocking layer 184 is made of TCTA, and the first electron blocking layer 184 has a thickness of 5 nm; the first light-emitting layer 12 is made of BD3 and BH16, with BD3... The mass percentage content of the first light-emitting layer 12 is 2%, and the thickness of the first light-emitting layer 12 is 20 nm; the material of the first hole blocking layer 174 is ET6, and the thickness of the first hole blocking layer 174 is 5 nm; the material of the first electron transport layer 181 includes Liq and ET5, the mass percentage content of Liq is 50%, and the thickness of the first electron transport layer 181 is 20 nm; the material of the n-type charge generation layer 13 includes Yb and E19, the mass percentage content of Yb is 5%, and the thickness of the n-type charge generation layer 13 is 10 nm; the p-type charge generation layer 13 includes Yb and E19, the mass percentage content of Yb is 5%, and the thickness of the n-type charge generation layer 13 is 10 nm; The charge generation layer 14 is made of PD-114 and TAPC, with PD-114 comprising 5% by mass and a thickness of 10 nm. The second hole transport layer 172 is made of TAPC and has a thickness of 30 nm. The second electron blocking layer 185 is made of TCTA and has a thickness of 5 nm. The second light-emitting layer 15 is made of BD3 and BH16, with BD3 comprising 2% by mass and a thickness of 10 nm. The thickness of the second hole-blocking layer 175 is 20 nm; the material of the second hole-blocking layer 175 includes ET6, and the thickness of the second hole-blocking layer 175 is 5 nm; the material of the second electron transport layer 182 includes Liq and ET5, the mass percentage content of Liq is 50%, and the thickness of the second electron transport layer 182 is 30 nm; the material of the electron injection layer 183 includes Yb, and the thickness of the electron injection layer 183 is 1 nm; the material of the cathode 16 includes Mg and Ag, the mass percentage content of Mg is 10%, and the thickness of the cathode 16 is 15 nm.

[0135] Under high vacuum conditions, the reactive devices shown in Comparative Example 3, Comparative Example 4, Example 3, and Example 4 were formed respectively. The specific testing and verification process included:

[0136] First, under normal temperature conditions, the reactive device was subjected to an A / cm² temperature of 10 mA. 2 Its first operating voltage V1 was measured at a current density of 10 mA / cm². 2After working continuously for 120 hours at the current density, the second working voltage (i.e. the maximum working voltage Vmax during continuous operation) was measured. ΔV(Vmax-V1) was positively correlated with the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperature. The data are shown in Table 2 below.

[0137] Table 2 Working Voltage Data Table

[0138] Delta V (V) Comparative Example Three 5.0 Comparative Example Four 4.0 Example Three 0.3 Example Four 0.4

[0139] As can be seen from Table 1 above, in Examples 3 and 4, the materials PD-113 and PD114 of the p-type charge generation layer 14 provided by the present invention are used. Compared with the comparative example, ΔV is significantly reduced and is less than or equal to 0.5V, that is, the difference between the second working voltage and the first working voltage is reduced. This indicates that the reactivity between the n-type doped material 131 and the p-type doped material 141 at high temperature can be effectively reduced in Examples 3 and 4.

[0140] In addition, embodiments of the present invention also provide a display device, which includes the display panel described in the above embodiments.

[0141] In one embodiment, the display device may include displays such as mobile, automotive, AR / VR, notebook, monitor, and television.

[0142] It is understood that since the display device includes the display panel described in the above embodiments, the display device has the same beneficial effects as the display panel described in the above embodiments, and will not be repeated here.

[0143] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0144] The above provides a detailed description of a display panel and display device provided by the embodiments of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of the present invention. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A display panel, characterized in that, The display panel includes a light-emitting device layer, the light-emitting device layer comprising: anode; A first light-emitting layer is disposed on one side of the anode; An n-type charge generation layer is disposed on the side of the first light-emitting layer away from the anode, and the n-type charge generation layer comprises: an electron transport material and an n-type doped material; A p-type charge generation layer is disposed on the side of the n-type charge generation layer away from the first light-emitting layer. The p-type charge generation layer includes a hole transport material and a p-type doped material. The second light-emitting layer is disposed on the side of the p-type charge generation layer away from the n-type charge generation layer; The cathode is disposed on the side of the second light-emitting layer away from the p-type charge generation layer; The light-emitting device layer has a first operating voltage at a preset current density, and a second operating voltage after operating for a preset time at the preset current density and a first preset temperature. The absolute value of the difference between the first operating voltage and the second operating voltage is a1, where a1 is less than or equal to 1V. The first preset temperature is greater than or equal to 50°C. The absolute value of the difference between the second operating voltage and the first operating voltage decreases as the doping concentration of the p-type doped material in the p-type charge generation layer decreases.

2. The display panel according to claim 1, characterized in that, The light-emitting device layer has a third operating voltage after operating for a preset time at the preset current density and the second preset temperature. The absolute value of the difference between the first operating voltage and the third operating voltage is a2, a2 ​​is less than a1, and the second preset temperature is less than 50°C.

3. The display panel according to claim 2, characterized in that, The second operating voltage is greater than the first operating voltage, and the third operating voltage is greater than the first operating voltage.

4. The display panel according to claim 2, characterized in that, The preset time is greater than 0 and less than or equal to 120 hours, and the preset current density is greater than or equal to 5 mA / cm². 2 .

5. The display panel according to claim 1, characterized in that, The absolute value of the difference between the second operating voltage and the first operating voltage is less than or equal to 0.5V.

6. The display panel according to claim 1, characterized in that, The light-emitting device layer further includes a hole injection layer disposed between the anode and the first light-emitting layer, wherein a first doping material is distributed in the hole injection layer, and the first doping material is different from the p-type doping material.

7. The display panel according to claim 1, characterized in that, The light-emitting device layer further includes a hole injection layer disposed between the anode and the first light-emitting layer. A first doping material is distributed in the hole injection layer. The first doping material is the same as the p-type doping material. The doping concentration of the first doping material in the hole injection layer is different from the doping concentration of the p-type doping material in the p-type charge generation layer.

8. The display panel according to claim 1, characterized in that, The p-type doped material in the p-type charge generation layer has a mass percentage content greater than or equal to 0.1% and less than or equal to 20%.

9. The display panel according to claim 1, characterized in that, The light-emitting device layer further includes a first hole transport layer disposed between the p-type charge generation layer and the second light-emitting layer, wherein the lowest unoccupied orbital energy level of the p-type doped material is >-5.5eV, and the highest occupied orbital energy level of the material of the first hole transport layer is >-6.5eV.

10. The display panel according to claim 9, characterized in that, The difference between the lowest unoccupied orbital energy level of the p-type doped material and the highest occupied orbital energy level of the material in the first hole transport layer is less than 1 eV.

11. The display panel according to claim 1, characterized in that, The wavelength of the reddest absorption peak of the p-type doped material is greater than 400 nm, and the wavelength of the fluorescence emission peak of the p-type doped material is greater than 500 nm.

12. The display panel according to claim 1, characterized in that, The light-emitting device layer further includes a buffer layer disposed between the n-type charge generation layer and the p-type charge generation layer, and the material of the buffer layer includes at least one of organic materials and metallic materials.

13. A display device, characterized in that, The display device includes a display panel as described in any one of claims 1 to 12.

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