Organic light-emitting display panel and display device

Abstract

SOLUTION: An organic light-emitting display panel includes: an anode 10; a cathode 30; a plurality of quantum well units 20 stacked between the anode and the cathode; and a charge generation layer 40. Therein, each of the quantum well units includes a light-emitting layer 21 and barrier layers 22 provided on both sides of the light-emitting layer. The charge generation layer is provided between two adjacent quantum well units among the plurality of quantum well units, and is used for injecting electrons into the light-emitting layers of at least some of the quantum well units located on one side of the charge generation layer, and for injecting holes into the light-emitting layers of at least some of the quantum well units located on the other side of the charge generation layer.EFFECT: Since the holes and electrons in an anode and a cathode do not need to be transported to a light-emitting layer of each quantum well unit, the difficulty of trapping and transporting holes and electrons is reduced, the driving current of the device is reduced, which is favorable for maintaining the carrier balance, and the efficiency of the device is improved, and the service life of the organic light-emitting display panel is extended.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the technical field of displays, and in particular to organic light-emitting display panels and display devices. [Background technology]

[0002] In the quantum dot light emitting diode in the organic light emitting display panel, holes and electrons are injected and transported from the anode and cathode, respectively, and reach the light emitting layer through the hole transport layer and the electron transport layer to emit combined light. In the related art, holes and electrons are completely confined within the light emitting layer by providing multiple quantum well units stacked together, but as the number of quantum well units increases, the transport barrier of the device increases, and holes and electrons are gradually trapped and become more and more difficult to transport, resulting in carrier imbalance and reducing the efficiency of the device.

[0003] Therefore, there is an urgent need to provide an organic light-emitting display panel and a display device that can solve the above technical problems. Summary of the Invention

[0004] The present invention provides an organic light emitting display panel and a display device to solve the technical problem of carrier imbalance caused by an increase in the number of quantum well units in the conventional organic light emitting display panel and display device.

[0005] In order to solve the above problems, the technical solutions provided in the present invention are as follows:

[0006] The present invention relates to An anode; a cathode disposed opposite the anode; a plurality of quantum well units stacked between the anode and the cathode, each of the quantum well units including a light emitting layer and a barrier layer provided on both sides of the light emitting layer; and a charge generation layer provided between two adjacent quantum well units among the plurality of quantum well units, the charge generation layer being used for injecting electrons into the light-emitting layer of at least some of the quantum well units located on one side of the charge generation layer, and for injecting holes into the light-emitting layer of at least some of the quantum well units located on the other side of the charge generation layer.

[0007] In the organic light-emitting display panel provided by the present invention, the barrier layer in one of the quantum well units adjacent to the charge generation layer and close to the anode includes a first electron transport layer, and the barrier layer in one of the quantum well units adjacent to the charge generation layer and close to the cathode includes a first hole transport layer.

[0008] In the organic light-emitting display panel provided by the present invention, the charge generation layer includes an n-type charge generation layer and a p-type charge generation layer that are stacked together, The n-type charge generation layer is disposed between the first electron transport layer and the p-type charge generation layer, and the p-type charge generation layer is disposed between the n-type charge generation layer and the first hole transport layer.

[0009] According to the organic light-emitting display panel provided by the present invention, the energy level difference between the triplet state energy level of the host material in the barrier layer and the triplet state energy level of the host material in the light-emitting layer is greater than 0.2 eV, and The energy level difference between the singlet state energy level of the host material in the barrier layer and the singlet state energy level of the host material in the light-emitting layer is greater than 0.2 eV.

[0010] According to the organic light-emitting display panel provided by the present invention, the energy level difference between the highest occupied molecular orbital energy level of the host material in the barrier layer and the highest occupied molecular orbital energy level of the host material in the light-emitting layer is greater than 0.2 eV, and The energy level difference between the lowest occupied molecular orbital energy level of the host material in the barrier layer and the lowest occupied molecular orbital energy level of the host material in the light-emitting layer is greater than 0.2 eV.

[0011] According to the organic light-emitting display panel provided by the present invention, the triplet state energy level range of the host material in the barrier layer is 2.5 eV to 6.0 eV, and the triplet state energy level range of the host material in the light-emitting layer is 2.0 eV to 5.0 eV; The singlet state energy level range of the host material in the barrier layers is from 2.5 eV to 6.0 eV, and the energy level range between the singlet state energy levels of the host material in the light-emitting layer is from 2.0 eV to 5.0 eV.

[0012] In the organic light-emitting display panel provided by the present invention, the plurality of quantum well units includes an even number of the quantum well units, and the number of the quantum well units located on the side of the charge generation layer closest to the anode is equal to the number of the quantum well units located on the side of the charge generation layer closest to the cathode.

[0013] According to the organic light-emitting display panel provided by the present invention, a second hole transport layer disposed on a side of the anode adjacent to the cathode; Among the plurality of quantum well units, the barrier layer in the quantum well unit adjacent to the anode includes a third hole transport layer, and among the plurality of quantum well units, the barrier layer in the quantum well unit adjacent to the cathode includes a second electron transport layer.

[0014] In the organic light-emitting display panel provided by the present invention, the barrier layer has a thickness of 2 nm to 20 nm.

[0015] The present invention provides a display device including the above organic light-emitting display panel.

[0016] The beneficial effects of the present invention are as follows. The organic light-emitting display panel and display device provided by the present invention includes an organic light-emitting display panel including an anode, a cathode, and a plurality of quantum well units stacked between the anode and the cathode, and each quantum well unit includes a light-emitting layer and a barrier layer on both sides of the light-emitting layer. The present invention provides a charge generation layer between two adjacent quantum well units among the plurality of quantum well units, so that the charge generation layer separates electrons and holes under the action of an applied electric field, and is used for injecting electrons into the light-emitting layer of at least some of the quantum well units located on one side of the charge generation layer, and for injecting holes into the light-emitting layer of at least some of the quantum well units located on the other side of the charge generation layer. As a result, the holes and electrons in the anode and the cathode do not need to be transported to the light-emitting layer of each quantum well unit, so that the difficulty of trapping and transporting holes and electrons is reduced, the driving current of the device is reduced, and it is favorable to maintaining the balance of carriers, so that the efficiency of the device is improved, and the service life of the organic light-emitting display panel is extended. [Brief description of the drawings]

[0017] In order to more clearly describe the technical solutions of the embodiments of the present invention, the following will briefly describe the drawings used in the description of the embodiments. Of course, the drawings described below are only a part of the embodiments of the present invention, and those skilled in the art can derive other drawings from these drawings without any creative efforts. [Figure 1] 1 is a schematic cross-sectional view of a first organic light-emitting display panel according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic cross-sectional view of a second organic light-emitting display panel provided in an embodiment of the present invention; [Diagram 3] 2 is a schematic cross-sectional view of the charge generating layer according to the embodiment of the present invention; FIG. [Figure 4] 3 is a schematic cross-sectional view of the organic light-emitting display panel of FIG. 2 including six quantum well units. [Diagram 5] FIG. 2 is a schematic cross-sectional view of a third organic light-emitting display panel according to an embodiment of the present invention; [Figure 6]6 is a schematic cross-sectional view of the organic light-emitting display panel of FIG. 5 including six quantum well units. [Figure 7] FIG. 4 is a schematic cross-sectional view of a fourth organic light-emitting display panel according to an embodiment of the present invention; [Figure 8] 8 is a first schematic cross-sectional view of the organic light-emitting display panel of FIG. 7 including six quantum well units. [Figure 9] 8 is a second schematic cross-sectional view of the organic light-emitting display panel of FIG. 7 when the panel includes six quantum well units. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention. Of course, the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. All other embodiments obtained by those skilled in the art without creative efforts based on the embodiments of the present invention shall fall within the scope of protection of the present invention. It should also be understood that the specific embodiments described herein are only for explaining and interpreting the present invention, and are not intended to limit the present invention. In the present invention, unless otherwise described, the directional terms used, such as "upper" and "lower", generally refer to the upper and lower sides of the device when actually used or in operation, specifically referring to the drawing direction in the drawings, while "inner" and "outer" are relative to the contour of the device.

[0019] Referring to FIG. 1, an embodiment of the present invention provides an organic light-emitting display panel including an anode 10, a cathode 30, and a charge generation layer 40. The cathode 30 is disposed opposite the anode 10, and the quantum well units 20 are stacked between the anode 10 and the cathode 30, and each quantum well unit 20 includes a light-emitting layer 21 and a barrier layer 22 disposed on both sides of the light-emitting layer 21. The barrier layer 22 is used to limit the movement region and energy range of carriers (electrons or holes) in the quantum well unit 20. The charge generation layer 40 is disposed between two adjacent quantum well units 20 among the quantum well units 20, and is used to inject electrons and holes into the light-emitting layer 21 of at least some of the quantum well units 20 located on one side of the charge generation layer 40, and to inject holes into the light-emitting layer 21 of at least some of the quantum well units 20 located on the other side of the charge generation layer 40.

[0020] What should be noted is that the display and light emitting mechanism of the organic light emitting display panel in the embodiment of the present invention is as follows.

[0021] A positive voltage is applied to the anode 10, a negative voltage is applied to the cathode 30, and carriers (including holes and electrons) are injected from the cathode 30 and the anode 10 by the action of the applied electric field. Specifically, holes are injected from the anode 10 and transported to the light-emitting layer 21 of a part of the quantum well unit 20, and electrons are injected from the cathode 30 and transported to the light-emitting layer 21 of a part of the quantum well unit 20, and the holes and electrons are combined in the light-emitting layer 21 to form excitons. Also, a voltage is applied to the charge generation layer 40, and the charge generation layer 40 separates holes and electrons by the action of the applied electric field, and injects the holes and electrons from the charge generation layer 40 into the light-emitting layer 21 of at least a part of the quantum well unit 20 located on both sides of the charge generation layer 40, and when the holes and electrons meet, they are combined in the light-emitting layer 21 to form excitons. The excitons formed as described above move under the action of an electric field and transfer energy to the organic light-emitting material corresponding to the light-emitting layer 21, and the organic light-emitting material generates photons, thereby realizing the display emission of the organic light-emitting display panel.

[0022] The embodiment of the present invention adopts a design in which the charge generation layer 40 is added, and the charge generation layer 40 is used to respectively inject holes and electrons into the light emitting layer 21 of at least a part of the quantum well unit 20. Based on this design, the holes and electrons injected from the anode 10 and the cathode 30 do not need to be transported to the light emitting layer 21 of each quantum well unit 20, so that the difficulty of trapping and transporting holes and electrons is reduced, the driving current of the device is reduced, and it is favorable to maintain the carrier balance in the light emitting layer 21, so that the efficiency of the device and the service life of the organic light emitting display panel are improved.

[0023] In an embodiment of the present invention, the organic light-emitting display panel may be a top-emission type display panel or a bottom-emission type display panel. When the organic light-emitting display panel is a top-emission type display panel, the anode 10 is a reflective electrode and the cathode 30 is a transparent electrode. When the organic light-emitting display panel is a bottom-emission type display panel, the anode 10 is a transparent electrode and the cathode 30 is a reflective electrode. Optionally, the reflective electrode may include a metal, which may be aluminum, gold or silver. The transparent electrode may be made of a light-transmitting metal oxide, such as ITO, IZO and ZnO, and the reflective electrode may be made of a metal, such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li and Ca.

[0024] In an embodiment of the present invention, the material of the light-emitting layer 21 includes an organic light-emitting material, and the light-emitting layer 21 may include at least one of a blue light-emitting layer, a green light-emitting layer, a red light-emitting layer, and a white light-emitting layer. The light-emitting layer 21 includes a host compound and a dopant material, and compared with the use of a combination of ordinary host materials or a single-component host material, the use of the above-mentioned combination of specific materials can obviously improve the overall performance of the organic electroluminescent device, such as spectrum, voltage, luminous efficiency, and service life. Optionally, in an embodiment of the present invention, the host compound may include a carbazole compound, and the dopant material may include a metal complex, an organic complex, or a dye, and different colors of light can be realized by adding different dopants, such as fluorescent dyes, phosphorescent materials, etc.

[0025] In the embodiment of the present invention, two adjacent quantum well units 20 share one barrier layer 22, i.e., one barrier layer 22 is provided between the light emitting layers 21 of the two adjacent quantum well units 20, which is advantageous for reducing processes. Of course, in other embodiments, two adjacent quantum well units 20 do not need to share one barrier layer 22.

[0026] In order to avoid carrier imbalance, in an embodiment of the present invention, the material of the barrier layer 22 is a neutral material, and optionally, the material of the barrier layer 22 includes mCP (methylcyclopentenolone) material, CBP (4,4-di(9-carbazole)biphenyl) material.

[0027] It should be noted that if the barrier layer 22 is too thin, it cannot play its role of confining electrons, holes and excitons within the light emitting layer 21, and if the barrier layer 22 is too thick, its ability to transport electrons and holes to the next layer, the quantum well unit 20, is greatly reduced. Therefore, in an embodiment of the present invention, the thickness of the barrier layer 22 in the quantum well unit 20 is 2 nm or more and 20 nm or less.

[0028] In an embodiment of the present invention, the barrier layers 22 of each quantum well unit 20 have the same thickness, and the barrier layers 22 of different quantum well units 20 have the same thickness. The light emitting layers 21 of each quantum well unit 20 have the same thickness, and the light emitting layers 21 of different quantum well units 20 have the same thickness. Of course, in other embodiments, the thicknesses may be designed to be different.

[0029] In the embodiment of the present invention, the quantum well units 20 are stacked to form a stacked structure, which can effectively distribute excitons in the light emitting layer 21 to different regions in a balanced manner, and even if some carriers are not confined by one of the quantum well units 20, excess carriers can be captured and confined by the quantum well units 20 of the next layer, thereby realizing composite light emission, which is favorable to improving the light emitting efficiency of the device. The quantum well unit 20 also includes the barrier layers 22 disposed on both sides of the light emitting layer 21. In a first aspect, the barrier layers 22 can prevent energy loss due to energy diffusion from the light emitting layer 21 to adjacent layers, thereby ensuring sufficient utilization of energy. In a second aspect, the barrier layers 22 can effectively confine carriers within the light emitting layer 21, which allows the light emitting layer 21 to fully utilize the injected carriers, which is favorable to improving the utilization rate of excitons, and prevents device degradation and attenuation due to an excess of single carriers or excessive exciton concentration. In the third aspect, the barrier layer 22 can prevent leakage current from occurring, which is advantageous for improving the service life of the organic light-emitting display panel.

[0030] In an embodiment of the present invention, referring to FIG. 2, the difference between FIG. 2 and FIG. 1 is that, among the plurality of quantum well units 20, the quantum well unit 20 adjacent to the charge generation layer 40 and close to the anode 10 includes a first electron transport layer 61, and among the plurality of quantum well units 20, the quantum well unit 20 adjacent to the charge generation layer 40 and close to the cathode 30 includes a first hole transport layer 51.

[0031] It can be seen that the first hole transport layer 51 is used to transport holes generated by the charge generation layer 40, and the first electron transport layer 61 is used to transport electrons generated by the charge generation layer 40, thereby ensuring that the holes and electrons generated by the charge generation layer 40 can be quickly transported through the first hole transport layer 51 and the first electron transport layer 61, respectively, and avoiding the holes and electrons from combining in the charge generation layer 40 to form excitons, which is beneficial to improving the luminous efficiency of the device.

[0032] In addition, in the embodiment of the present invention, the first hole transport layer 51 and the first electron transport layer 61 function as the barrier layer 22, so that the first hole transport layer 51 can be the barrier layer 22 of the quantum well unit 20 adjacent to the charge generation layer 40 and close to the anode 10 among the plurality of quantum well units 20, and the first electron transport layer 61 can be the barrier layer 22 of the quantum well unit 20 adjacent to the charge generation layer 40 and close to the cathode 30 among the plurality of quantum well units 20. Here, the first hole transport layer 51 and the first electron transport layer 61 are used to prevent excitons in the light emitting layer 21 of the corresponding quantum well unit 20 from being transported to the charge generation layer 40, thereby preventing holes and electrons in the charge generation layer 40 from being quenched, which is advantageous to improving the stability of the charge generation layer 40.

[0033] In the embodiment of the present invention, the first hole transport layer 51 should use a material having a high hole mobility, and the first electron transport layer 61 should use a material having a high electron mobility.

[0034] 3, in the embodiment of the present invention, the charge generation layer 40 includes an n-type charge generation layer 41 and a p-type charge generation layer 42, which are stacked together. Here, the n-type charge generation layer 41 is disposed between the first electron transport layer 61 and the p-type charge generation layer 42, and the p-type charge generation layer 42 is disposed between the n-type charge generation layer 41 and the first hole transport layer 51. The charge generation layer 40 can be compared to a stacked structure of two single-layer devices, the n-type charge generation layer 41 and the p-type charge generation layer 42, and it can be understood that with the same brightness, the two single-layer devices each account for half of the brightness of the light emitted. Therefore, the driving current can be reduced to about half of the original, which can effectively reduce the driving current of the device, double the luminous efficiency of the device, and greatly extend the service life of the device.

[0035] It should be noted that the n-type charge generation layer 41 is an N-type doping material with an electron transport tendency, and the p-type charge generation layer 42 is a P-type doping material with a hole transport tendency. The n-type charge generation layer 41 and the p-type charge generation layer 42 together form a PN junction to generate a dipole, and under the action of an electric field, the PN junction separates the P-type transport holes and the N-type transport electrons, so that the P-type transport holes are transported to the side close to the cathode 30, and the N-type transport electrons are transported to the side close to the anode 10.

[0036] In an embodiment of the present invention, the material of the charge generation layer 40 can be a material system with high charge generation ability. Optionally, the material of the p-type charge generation layer 42 can be NPB (N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine):MoO 3 (Molybdenum trioxide), m-MTDATA (4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine):HAT-CN(11-hexacyano-1), TCTA (4,4',4''-tri(carbazol-9-yl)triphenylamine):WO 3The material of the n-type charge generation layer 41 may be one or more of the following combinations: Bepp2 (di(2-hydroxyphenylpyridine) beryllium):Yb (ytterbium), PO-T2T (2,4,6-tri[3-(diphenylphosphino)phenyl]-1,3,5-triazine):LiBphen:Yb (ytterbium), Bphen (1,10-phenanthroline):CsCO 3 (Cesium carbonate).

[0037] It should be noted that, based on the configuration of the charge generation layer 40, the embodiment of the present invention can improve the efficiency of the device by providing a large number of the quantum well units 20, and in practical operation, the optimal number of the quantum well units 20 can be determined by simulation experiments. Specifically, the optimal number of the quantum well units 20 is determined according to the current efficiency and driving voltage of the device. From the simulation results performed by the inventor, it is found that there is a parabolic relationship curve between the optimal number of the quantum well units 20 and the current efficiency of the device. The optimal number of the quantum well units 20 corresponds to the situation where the current efficiency of the device is at an optimal value and the driving voltage is not significantly increased, and is generally set so that the increase in the driving voltage does not exceed 2.5V.

[0038] In order to ensure that the light-emitting effects of the two light-emitting units are similar, in an embodiment of the present invention, the optimal number of the quantum well units 20 is set to an even number, in other words, the multiple quantum well units 20 include an even number of the quantum well units 20, where the number of the quantum well units 20 located on the side of the charge generation layer 40 close to the anode 10 is equal to the number of the quantum well units 20 located on the side of the charge generation layer 40 close to the cathode 30, thereby ensuring that the number of carriers injected from the charge generation layer 40 to both sides is the same.

[0039] Alternatively, the number of quantum wells may be 2, 4, 6, 8, etc., and should be specifically selected according to the actual situation.

[0040] For example, referring to Fig. 4, the number of the quantum well units 20 in Fig. 4 is six, that is, the organic light-emitting display panel includes six of the quantum well units 20, which are a first quantum well unit S1, a second quantum well unit S2, a third quantum well unit S3, a fourth quantum well unit S4, a fifth quantum well unit S5, and a sixth quantum well unit S6 disposed between the anode 10 and the cathode 30. The charge generation layer 40 is disposed between the third quantum well unit S3 and the fourth quantum well unit S4. The first hole transport layer 51 may be the barrier layer 22 of the third quantum well unit S3, and the first electron transport layer 61 is the barrier layer 22 of the fourth quantum well unit S4.

[0041] Furthermore, the organic light-emitting display panel generates two kinds of excitons during electroluminescence: one is triplet excitons and the other is singlet excitons. Here, the singlet excitons are in the singlet state, and the triplet excitons are in the triplet state. The barrier of the quantum well unit 20 mainly comes from the higher energy level of the barrier layer 22, and the higher barrier leads to an increase in the driving voltage of the device, so that the transport of holes and electrons is gradually trapped with the increase in the barrier, making the transport more and more difficult, and finally, as the number of quantum wells exceeds the optimal number, the balance between electrons and holes is lost. In order to ensure that electrons and holes are confined within the light-emitting layer 21, in an embodiment of the present invention, the energy level difference between the triplet state energy level of the host material in the barrier layer 22 and the triplet state energy level of the host material in the light-emitting layer 21 is greater than 0.2 eV, and the energy level difference between the singlet state energy level of the host material in the barrier layer 22 and the singlet state energy level of the host material in the light-emitting layer 21 is greater than 0.2 eV.

[0042] In other words, the triplet state energy level of the host material in the barrier layer 22 is higher than the triplet state energy level of the host material in the light-emitting layer 21, and the difference between the two energy levels is controlled within an appropriate range, so that the barrier layer 22 can confine electrons and holes within the light-emitting layer 21. Furthermore, the singlet state energy level of the host material in the barrier layer 22 is higher than the singlet state energy level of the host material in the light-emitting layer 21, and the difference between the two energy levels is controlled within an appropriate range, so that the barrier layer 22 can confine electrons and holes within the light-emitting layer 21, thereby reducing energy loss and improving the luminous efficiency of the device.

[0043] Specifically, the triplet state energy level range of the host material in the barrier layer 22 is 2.5 eV to 6.0 eV, and the energy level range between the triplet state energy levels of the host material in the light-emitting layer 21 is 2.0 eV to 5.0 eV. The singlet state energy level range of the host material in the barrier layer 22 is 2.5 eV to 6.0 eV, and the energy level range between the singlet state energy levels of the host material in the light-emitting layer 21 is 2.0 eV to 5.0 eV.

[0044] Furthermore, the energy level difference between the highest occupied molecular orbital (HOMO) energy level of the host material in the barrier layer 22 and the highest occupied molecular orbital energy level of the host material in the light-emitting layer 21 is greater than 0.2 eV, and the energy level difference between the lowest occupied molecular orbital (LUMO) energy level of the host material in the barrier layer 22 and the lowest occupied molecular orbital energy level of the host material in the light-emitting layer 21 is greater than 0.2 eV, thereby further ensuring that electrons and holes are confined within the light-emitting layer 21, reducing energy loss and favoring the improvement of the luminous efficiency of the device.

[0045] Based on the above description, in an embodiment of the present invention, the barrier layer 22 has a higher singlet state energy level, triplet state energy level, LUMO energy level, and HOMO energy level than the light-emitting layer 21, which can ensure that electrons and holes are confined within the light-emitting layer 21, thereby reducing energy loss and favoring the improvement of the luminous efficiency of the device.

[0046] Of course, the organic light emitting display panel further includes a hole injection layer (not shown) and an electron injection layer (not shown). The hole injection layer is disposed between the anode 10 and the quantum well units 20 and is used to promote hole injection. The electron injection layer is disposed between the anode 10 and the quantum well units 20 and is used to promote electron injection. As shown in FIG. 3, the hole injection layer is disposed between the anode 10 and the first quantum well unit S1, and the electron injection layer is disposed between the cathode 30 and the sixth quantum well unit S6.

[0047] The organic light-emitting display panel further includes a substrate and a driving circuit layer disposed on the substrate, the driving circuit layer is used for driving the emission of light from a display device, the driving circuit layer is located between the substrate and the anode 10, and the driving circuit layer includes an active matrix driving circuit or a passive matrix driving circuit. In addition, the organic light-emitting display panel further includes other functional structures, not shown, such as a pixel definition layer and a package layer.

[0048] Further, referring to Fig. 5, the differences between Fig. 5 and Fig. 2 are as follows: the organic light-emitting display panel includes a second hole transport layer 52 provided on a side of the anode 10 adjacent to the cathode 30. The barrier layer 22 of the quantum well unit 20 provided adjacent to the anode 10 among the plurality of quantum well units 20 includes a third hole transport layer 53, and the barrier layer 22 of the quantum well unit 20 provided adjacent to the cathode 30 among the plurality of quantum well units 20 includes a second electron transport layer 62.

[0049] The second hole transport layer 52 transports holes injected from the anode 10, and the second electron transport layer 62 transports electrons injected from the cathode 30. The third hole transport layer 53 can act as the barrier layer 22, and is used to confine excitons in the light emitting layer 21, block the energy transfer of excitons, and reduce energy loss, thereby improving the luminous efficiency of the organic light emitting device. In addition, the third hole transport layer 53 has a high LUMO energy level and hole transport properties, and can block electrons from being transported through the third hole transport layer 53. The second electron transport layer 62 has a high LUMO energy level and electron transport properties, and can block holes from being transported through the second electron transport layer 62.

[0050] 6, the third hole transport layer 53 may be the barrier layer 22 of the first quantum well unit S1, and the second electron transport layer 62 may be the barrier layer 22 of the sixth quantum well unit S6. The hole injection layer (not shown) is disposed between the anode 10 and the second hole transport layer 52, and the electron injection layer (not shown) is disposed between the cathode 30 and the second electron transport layer 62.

[0051] Further, referring to FIG. 7, the differences between FIG. 7 and FIG. 2 are as follows. The organic light-emitting display panel may further include a third electron transport layer 63 laminated with the second electron transport layer 62. Specifically, the third electron transport layer 63 is provided on the side of the second electron transport layer 62 away from the cathode 30, or between the second electron transport layer 62 and the cathode 30. Similarly to the two-layer structure formed by laminating the second hole transport layer 52 and the third hole transport layer 53, the third electron transport layer 63 and the second electron transport layer 62 are laminated to form a two-layer structure, which can prevent energy transfer of excitons to the functional layer and prevent hole transport to the second electron transport layer 62 or the third electron transport layer 63.

[0052] 8, when the third electron transport layer 63 is disposed on the side of the second electron transport layer 62 away from the cathode 30, the third electron transport layer 63 is the barrier layer 22 of the sixth quantum well unit S6. Referring to FIG. 9, when the third electron transport layer 63 is disposed between the second electron transport layer 62 and the cathode 30, the second electron transport layer 62 can be the barrier layer 22 of the sixth quantum well unit S6.

[0053] An embodiment of the present invention comprises: Step S1 of forming an anode 10; Step S2 of forming a plurality of quantum well units 20 on one side of the anode 10; Step S3 of forming a charge generation layer 40 on the quantum well unit 20; Step S4 of forming a plurality of the quantum well units 20 on the charge generation layer 40; The present invention further provides a method for manufacturing an organic light emitting display panel, the method including the step S5 of forming a cathode 30 on the quantum well unit 20.

[0054] Here, the charge generation layer 40 is formed between two adjacent quantum well units 20 among the plurality of quantum well units 20, and is used to inject electrons into the light-emitting layers 21 of at least a portion of the quantum well units 20 located on one side of the charge generation layer 40, and to inject holes into the light-emitting layers 21 of at least a portion of the quantum well units 20 located on the other side of the charge generation layer 40.

[0055] Specifically, S1 is A step S10 of providing a substrate; Step S20 of forming a driving circuit layer on the substrate; The method further includes a step S30 of forming the anode 10 on the driving circuit layer.

[0056] An embodiment of the present invention further provides a display device including a processor and the organic light-emitting display panel of the above embodiment, and the processor may include a driving chip for driving the emission of the organic light-emitting display panel, etc. The display device may be a mobile phone, a tablet computer, an electronic reader, an electronic display, a notebook computer, a mobile phone, an augmented reality (AR) / virtual reality (VR) device, a media player, a wearable device, a digital camera, a car navigation system, etc.

[0057] The beneficial effects are as follows. The organic light-emitting display panel and display device provided by the present invention includes an organic light-emitting display panel including an anode, a cathode, and a plurality of quantum well units stacked between the anode and the cathode, and each quantum well unit includes a light-emitting layer and a barrier layer on both sides of the light-emitting layer. The present invention provides a charge generation layer between two adjacent quantum well units among the plurality of quantum well units, so that the charge generation layer separates electrons and holes under the action of an applied electric field, and the separated electrons are injected into the light-emitting layer of at least some of the quantum well units located on one side of the charge generation layer, and the separated holes are injected into the light-emitting layer of at least some of the quantum well units located on the other side of the charge generation layer, and the holes and electrons are combined in the light-emitting layer to emit light. As a result, the holes and electrons in the anode and cathode do not need to be transported to the light-emitting layer of each quantum well unit, so that the difficulty of trapping and transporting holes and electrons is reduced, the driving current of the device is reduced, and it is favorable to maintaining the balance of carriers, and the efficiency and service life of the device are improved.

[0058] Above, the embodiments of the present invention have been described in detail. This specification uses specific examples to explain the principles and embodiments of the present invention. The above description of the embodiments is intended to merely help the reader understand the method of the present invention and its central concept. Furthermore, those skilled in the art can make modifications to the specific embodiments and application scope based on the idea of ​​the present invention. In short, the contents of this specification should not be understood as limiting the present invention. [Explanation of symbols]

[0059] 10 Anode 20 Quantum Well Unit 21 Light-emitting layer 22 Barrier Layer 30 Cathode 40 Charge generation layer 41 n-type charge generation layer 42 p-type charge generation layer 51 First hole transport layer 52 Second hole transport layer 53 Third hole transport layer 61 First electron transport layer 62 Second electron transport layer 63 Third electron transport layer S1 First quantum well unit S2 Second quantum well unit S3 3rd quantum well unit S4 4th quantum well unit S5 5th quantum well unit S6 6th quantum well unit

Claims

1. An anode; a cathode disposed opposite the anode; a plurality of quantum well units stacked between the anode and the cathode, each of the quantum well units including a light emitting layer and a barrier layer provided on both sides of the light emitting layer; a charge generation layer provided between two adjacent quantum well units among the plurality of quantum well units, the charge generation layer being used for injecting electrons into the light-emitting layer of at least some of the quantum well units located on one side of the charge generation layer and for injecting holes into the light-emitting layer of at least some of the quantum well units located on the other side of the charge generation layer; the energy level difference between the triplet state energy level of the host material in the barrier layer and the triplet state energy level of the host material in the light-emitting layer is greater than 0.2 eV; and an energy level difference between the singlet state energy level of the host material in the barrier layer and the singlet state energy level of the host material in the light-emitting layer is greater than 0.2 eV;

2. 2. The organic light-emitting display panel of claim 1, wherein the barrier layer in one of the quantum well units adjacent to the charge generation layer and close to the anode among the plurality of quantum well units includes a first electron transport layer, and the barrier layer in one of the quantum well units adjacent to the charge generation layer and close to the cathode among the plurality of quantum well units includes a first hole transport layer.

3. the charge generation layer includes an n-type charge generation layer and a p-type charge generation layer that are stacked together, 3. The organic light-emitting display panel of claim 2, wherein the n-type charge generation layer is provided between the first electron transport layer and the p-type charge generation layer, and the p-type charge generation layer is provided between the n-type charge generation layer and the first hole transport layer.

4. the energy level difference between the highest occupied molecular orbital energy level of the host material in the barrier layer and the highest occupied molecular orbital energy level of the host material in the light-emitting layer is greater than 0.2 eV; and 2. The organic light-emitting display panel of claim 1, wherein an energy level difference between the lowest occupied molecular orbital energy level of the host material in the barrier layer and the lowest occupied molecular orbital energy level of the host material in the light-emitting layer is greater than 0.2 eV.

5. the triplet state energy level range of the host material in the barrier layer is from 2.5 eV to 6.0 eV, and the energy level range between the triplet state energy levels of the host material in the light-emitting layer is from 2.0 eV to 5.0 eV; 2. The organic light-emitting display panel according to claim 1, wherein the singlet state energy level range of the host material in the barrier layer is 2.5 eV to 6.0 eV, and the energy level range between the singlet state energy levels of the host material in the light-emitting layer is 2.0 eV to 5.0 eV.

6. 2. The organic light-emitting display panel of claim 1, wherein the plurality of quantum well units includes an even number of the quantum well units, and the number of the quantum well units located on a side of the charge generation layer adjacent to the anode is equal to the number of the quantum well units located on a side of the charge generation layer adjacent to the cathode.

7. a second hole transport layer disposed on a side of the anode adjacent to the cathode; 2. The organic light-emitting display panel according to claim 1, wherein the barrier layer in one of the quantum well units adjacent to the anode among the plurality of quantum well units includes a third hole transport layer, and the barrier layer in one of the quantum well units adjacent to the cathode among the plurality of quantum well units includes a second electron transport layer.

8. 2. The organic light-emitting display panel according to claim 1, wherein the barrier layer has a thickness of 2 nm to 20 nm.

9. A display device comprising the organic light-emitting display panel according to claim 1 .

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