Display panel, display module, display device, and display panel efficiency adjustment method

Abstract

Embodiments of the present application provide a display panel, a display module, a display device, and a method for adjusting the efficiency of a display panel. The display panel includes a first and a second stacked light-emitting layer, wherein the first and second light-emitting layers are both configured to emit blue light, the color light emitted by the first light-emitting layer has a first curve in the CIEy-BI coordinate system, the color light emitted by the second light-emitting layer has a second curve in the CIEy-BI coordinate system, and the difference between the chromaticity coordinate values ​​of the peaks of the first and second curves is less than or equal to 0.01; and / or the first and second light-emitting layers are both configured to emit green light, the color light emitted by the first light-emitting layer has a fifth curve in the CIEx-CE coordinate system, the second light-emitting layer has a sixth curve in the CIEx-CE coordinate system, and the difference between the chromaticity coordinate values ​​of the peaks of the fifth and sixth curves and a target CIEx value is less than or equal to 0.05. This application can improve the luminous efficiency of a display panel.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display panel, a display module, a display device, and a method for adjusting the efficiency of a display panel. Background Art

[0002] Organic Light-Emitting Diodes (OLEDs) are active light-emitting devices. Compared to traditional liquid crystal displays (LCDs), OLED display technology does not require a backlight and is self-luminous. OLEDs utilize a thin film of organic material and a glass substrate. When an electric current flows through it, the organic material emits light. Therefore, OLED display panels can significantly save energy, can be made lighter and thinner, can withstand a wider range of temperature changes than LCD display panels, and have a wider viewing angle. OLED display panels are expected to become the next generation of flat-panel display technology after LCDs and are currently one of the most popular flat-panel display technologies.

[0003] In the prior art, in order to reduce the power consumption of an OLED display panel, multiple layers of OLED devices are stacked. However, stacking multiple layers of OLED devices will affect the overall luminous efficiency of the OLED devices. Summary of the Invention

[0004] Embodiments of the present application provide a display panel, a display module, a display device, and a method for adjusting the efficiency of a display panel, aiming to improve the luminous efficiency of the display panel.

[0005] An embodiment of a first aspect of the present application provides a display panel, comprising at least a first light-emitting layer and a second light-emitting layer stacked together, wherein the first light-emitting layer and the second light-emitting layer are both configured to emit blue light, the color light emitted by the first light-emitting layer has a first curve in a CIEy-BI coordinate system, the color light emitted by the second light-emitting layer has a second curve in the CIEy-BI coordinate system, and the difference between the chromaticity coordinate values ​​of the peaks of the first curve and the second curve is less than or equal to 0.01;

[0006] And / or, the first light-emitting layer and the second light-emitting layer are used to emit green light, the color light emitted by the first light-emitting layer has a fifth curve in the CIEx-CE coordinate system, the color light emitted by the second light-emitting layer has a sixth curve in the CIEx-CE coordinate system, and the difference between the chromaticity coordinate values ​​of the peaks of the fifth curve and the sixth curve and the target CIEx value is less than or equal to 0.05.

[0007] According to an embodiment of the first aspect of the present application, the display panel further includes a first electrode and a second electrode, and the first light-emitting layer and the second light-emitting layer are both located between the first electrode and the second electrode.

[0008] According to an embodiment of the first aspect of the present application, the first electrode is an anode, and the first light-emitting layer is located on a side of the second light-emitting layer facing the first electrode.

[0009] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are adjacent light-emitting layers.

[0010] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are used to emit blue light, and the difference between the chromaticity coordinate values ​​of the peaks of the first curve and the second curve is less than or equal to 0.005.

[0011] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer has a third curve in the wavelength-spectral intensity coordinate system, and the second light-emitting layer has a fourth curve in the wavelength-spectral intensity coordinate system. At the same emission peak position, the half-peak width of the third curve is smaller than the half-peak width of the fourth curve.

[0012] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are used to emit blue light, and the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 10nm to 30nm.

[0013] According to any of the aforementioned embodiments of the first aspect of the present application, the material of the first light-emitting layer includes a boron-nitrogen material.

[0014] According to any of the aforementioned embodiments of the first aspect of the present application, the material of the second light-emitting layer includes an anthracene-containing material.

[0015] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are used to emit green light, and the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 5nm to 30nm.

[0016] According to any of the aforementioned embodiments of the first aspect of the present application, the material of the first light-emitting layer includes:

[0017]

[0018] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer has a third curve in the wavelength-spectral intensity coordinate system, the second light-emitting layer has a fourth curve in the wavelength-spectral intensity coordinate system, and the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve.

[0019] According to any of the aforementioned embodiments of the first aspect of the present application, the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is 1 nm to 10 nm.

[0020] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer both include a host material, and the molecular polarity of at least part of the host material of the first light-emitting layer is smaller than the molecular polarity of at least part of the host material of the second light-emitting layer.

[0021] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer both include guest materials, and the molecular polarity of at least part of the guest material in the first light-emitting layer is greater than the molecular polarity of at least part of the guest material in the second light-emitting layer.

[0022] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer both include guest materials, and the doping concentration of the guest material in the first light-emitting layer is greater than the doping concentration of the guest material in the second light-emitting layer.

[0023] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are used to emit blue light, and the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is 2nm to 4nm

[0024] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are used to emit blue light, and the material of the first light-emitting layer includes:

[0025]

[0026] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are used to emit green light, and the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is 1nm to 2nm.

[0027] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are used to emit green light, and the material of the first light-emitting layer includes:

[0028]

[0029] Wherein, R1 and R2 are each independently selected from one of the following groups: -H, -CH3, -OCH3, -NH2, -C(CH3)3, and R1 and R2 are not -H at the same time; and / or, R3, R4, R5 and R6 are each independently selected from one of the following groups: -H, -COOH, -X(Cl, Br, I), -NO2, -CN, and R3, R4, R5 and R6 are not -H at the same time.

[0030] According to any of the aforementioned embodiments of the first aspect of the present application, the first light-emitting layer and the second light-emitting layer are used to emit green light, and the target CIEx value is 0.23 to 0.25.

[0031] According to any of the aforementioned embodiments of the first aspect of the present application, the target CIEx value is 0.24.

[0032] According to any of the aforementioned embodiments of the first aspect of this application.

[0033] An embodiment of the second aspect of the present application further provides a display module, comprising a display panel according to any one of the above-mentioned embodiments of the first aspect.

[0034] The embodiment of the third aspect of the present application further provides a display device, comprising the display module of the embodiment of the above aspect.

[0035] An embodiment of the fourth aspect of the present application further provides a method for adjusting the luminous efficiency of a display panel, comprising:

[0036] At least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel, wherein the first light-emitting layer and the second light-emitting layer are used to emit blue light;

[0037] Obtaining a first curve of the color light emitted by the first light-emitting layer in the CIEy-BI coordinate system and a second curve of the color light emitted by the second light-emitting layer in the CIEy-BI coordinate system;

[0038] The difference between the chromaticity coordinate values ​​of the peaks of the first curve and the second curve is less than or equal to 0.01.

[0039] According to an embodiment of the fourth aspect of the present application, in the step of adjusting at least the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel:

[0040] Adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer;

[0041] Obtaining a third curve of the first light-emitting layer in the wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer in the wavelength-spectral intensity coordinate system;

[0042] The half-peak width of the third curve is made smaller than the half-peak width of the fourth curve.

[0043] According to any of the aforementioned embodiments of the fourth aspect of the present application, in the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer:

[0044] Adjusting the preparation material of the first light-emitting layer;

[0045] Preferably, the preparation material of the first light-emitting layer is adjusted so that the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 10 nm to 30 nm.

[0046] According to any of the aforementioned embodiments of the fourth aspect of the present application, in the step of adjusting the preparation material of the first light-emitting layer: the material of the first light-emitting layer includes a boron-nitrogen material.

[0047] According to any of the aforementioned embodiments of the fourth aspect of the present application, in the step of at least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel:

[0048] Adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer;

[0049] Obtaining a third curve of the first light-emitting layer in the wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer in the wavelength-spectral intensity coordinate system;

[0050] The wavelength of the peak of the third curve is smaller than the wavelength of the peak of the fourth curve.

[0051] According to any of the aforementioned embodiments of the fourth aspect of the present application, the preparation material of the first light-emitting layer is adjusted so that the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve.

[0052] According to any of the aforementioned embodiments of the fourth aspect of the present application, in the step of adjusting the preparation material of the first light-emitting layer so that the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve:

[0053] Obtaining a CIEy value corresponding to the peak of the second curve, and determining a target value CIEys corresponding to the peak of the first curve, wherein a difference between the target value CIEys and the CIEy value corresponding to the peak of the second curve is less than or equal to 0.01;

[0054] Adjust the preparation material of the first light-emitting layer according to the target value CIEys and the following formulas (1), (2), (3), and (4);

[0055]

[0056] Among them, x (λ) 、Y (λ) and Z (λ) is the X / Y / Z corresponding to the 1931 tristimulus value table when the wavelength is λ; I (λ) is the spectral intensity at wavelength λ.

[0057] According to any of the aforementioned embodiments of the fourth aspect of the present application, the first light-emitting layer and the second light-emitting layer both include a host material and a guest material, and in the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer:

[0058] The doping concentration of the guest material in the first light-emitting layer and / or the second light-emitting layer is adjusted so that the doping concentration of the guest material in the first light-emitting layer is greater than the doping concentration of the guest material in the second light-emitting layer.

[0059] According to any of the aforementioned embodiments of the fourth aspect of the present application, the first light-emitting layer and the second light-emitting layer both include a host material and a guest material, and in the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer:

[0060] The molecular polarity of the guest material in the first light-emitting layer and / or the second light-emitting layer is adjusted so that the molecular polarity of at least part of the guest material in the first light-emitting layer is greater than that of at least part of the guest material in the second light-emitting layer.

[0061] According to any of the aforementioned embodiments of the fourth aspect of the present application, the first light-emitting layer and the second light-emitting layer both include a host material and a guest material, and in the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer:

[0062] The molecular polarity of the host material in the first light-emitting layer and / or the second light-emitting layer is adjusted so that the molecular polarity of at least part of the host material in the first light-emitting layer is smaller than that of at least part of the host material in the second light-emitting layer.

[0063] According to any of the foregoing embodiments of the fourth aspect of the present application, in the step of making the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve:

[0064] The difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is set to 2 nm to 4 nm.

[0065] According to any of the aforementioned embodiments of the fourth aspect of the present application, the material of the first light-emitting layer includes:

[0066]

[0067] An embodiment of a fifth aspect of the present application provides a method for adjusting luminous efficiency, comprising:

[0068] At least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel; the first light-emitting layer and the second light-emitting layer are used to emit green light;

[0069] Obtaining a fifth curve of the color light emitted by the first light-emitting layer in the CIEx-CE coordinate system; and a sixth curve of the color light emitted by the second light-emitting layer in the CIEx-CE coordinate system;

[0070] The difference between the chromaticity coordinate values ​​of the peaks of the fifth curve and the sixth curve and the target CIEx is less than or equal to 0.05.

[0071] According to the implementation of the fifth aspect of the present application, the target CIEx value is 0.23 to 0.25.

[0072] According to any of the foregoing embodiments of the fifth aspect of the present application, in the step of at least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel:

[0073] Adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer;

[0074] Obtaining a third curve of the first light-emitting layer in the wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer in the wavelength-spectral intensity coordinate system;

[0075] The half-peak width of the third curve is made smaller than the half-peak width of the fourth curve.

[0076] According to any of the foregoing embodiments of the fifth aspect of the present application, in the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer:

[0077] Adjust the preparation material of the first light-emitting layer.

[0078] According to any of the aforementioned embodiments of the fifth aspect of the present application, the preparation material of the first light-emitting layer is adjusted so that the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 5nm to 30nm.

[0079] According to any of the aforementioned embodiments of the fifth aspect of the present application, in the step of adjusting the preparation material of the first light-emitting layer: the material of the first light-emitting layer includes

[0080]

[0081] According to any of the foregoing embodiments of the fifth aspect of the present application, in the step of at least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel:

[0082] Adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer;

[0083] Obtaining a third curve of the first light-emitting layer in the wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer in the wavelength-spectral intensity coordinate system;

[0084] The wavelength of the peak of the third curve is made smaller than the wavelength of the peak of the fourth curve.

[0085] According to any of the aforementioned embodiments of the fifth aspect of the present application, the preparation material of the first light-emitting layer is adjusted so that the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve.

[0086] According to any of the aforementioned embodiments of the fifth aspect of the present application, in the step of adjusting the preparation material of the first light-emitting layer so that the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve:

[0087] Obtaining the CIEx value corresponding to the peak of the sixth curve, and determining the target value CIExs corresponding to the peak of the fifth curve, wherein the difference between the target value CIExs and the CIEx value corresponding to the peak of the sixth curve is less than or equal to 0.05;

[0088] Adjust the preparation material of the first light-emitting layer according to the target value CIExs and the following formulas (5), (6), (7), and (8);

[0089]

[0090]

[0091] Among them, x (λ) 、Y (λ) and Z (λ) is the X / Y / Z corresponding to the 1931 tristimulus value table when the wavelength is λ; I (λ) is the spectral intensity at wavelength λ.

[0092] According to any of the aforementioned embodiments of the fifth aspect of the present application, the preparation material of the first light-emitting layer is adjusted so that the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is 1nm to 10nm.

[0093] According to any of the foregoing embodiments of the fifth aspect of the present application, the first light-emitting layer and the second light-emitting layer both include a host material and a guest material, and in the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer:

[0094] The doping concentration of the guest material in the first light-emitting layer and / or the second light-emitting layer is adjusted so that the doping concentration of the guest material in the first light-emitting layer is greater than the doping concentration of the guest material in the second light-emitting layer.

[0095] According to any of the foregoing embodiments of the fifth aspect of the present application, the first light-emitting layer and the second light-emitting layer both include a host material and a guest material, and in the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer:

[0096] The molecular polarity of the guest material in the first light-emitting layer and / or the second light-emitting layer is adjusted so that the molecular polarity of at least part of the guest material in the first light-emitting layer is greater than that of at least part of the guest material in the second light-emitting layer.

[0097] According to any of the foregoing embodiments of the fifth aspect of the present application, the first light-emitting layer and the second light-emitting layer both include a host material and a guest material, and in the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer:

[0098] The molecular polarity of the host material in the first light-emitting layer and / or the second light-emitting layer is adjusted so that the molecular polarity of at least part of the host material in the first light-emitting layer is smaller than that of at least part of the host material in the second light-emitting layer.

[0099] In the display panel provided in the embodiment of the present application, the display panel includes a first light-emitting layer and a second light-emitting layer stacked together. Using two or more light-emitting layers stacked together can improve the display effect of the display panel.

[0100] When the first light-emitting layer and the second light-emitting layer are used to emit blue light, the difference in chromaticity coordinate values ​​corresponding to the peak of the emitted color light of the first light-emitting layer and the second light-emitting layer in the CIEy-BI coordinate system is less than or equal to 0.01, that is, the peaks of the emitted color light of the first light-emitting layer and the second light-emitting layer in the CIEy-BI coordinate system are close, the maximum values ​​of the luminous efficiency of the first light-emitting layer and the second light-emitting layer are close, the first curve and the second curve are at mutual gain positions, which can effectively improve the total luminous efficiency of the display panel.

[0101] When the first light-emitting layer and the second light-emitting layer are used to emit green light, the difference between the chromaticity coordinate values ​​corresponding to the peaks of the first light-emitting layer and the second light-emitting layer in the CIEx-CE coordinate system and the target CIEx value is less than or equal to 0.05, that is, the chromaticity coordinate values ​​corresponding to the highest efficiency points of the first light-emitting layer and the second light-emitting layer are close to the target CIEx value. On the one hand, the efficiencies of the first light-emitting layer and the second light-emitting layer benefit each other, and on the other hand, the chromaticity coordinate values ​​at the points where the efficiency of the first light-emitting layer and the second light-emitting layer is maximum meet the requirements, which can effectively improve the luminous efficiency and display effect of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features.

[0103] Figure 1 is a structural diagram of a display panel provided in an embodiment of the present application;

[0104] Figure 2 is a graph of a light-emitting layer in a display panel in the related art in the CIEy-BI coordinate system;

[0105] Figure 3 is a graph showing an intrinsic spectrum of a luminescent material of a display panel provided in an embodiment of the present application;

[0106] Figure 4 is a graph of a first light-emitting layer and a second light-emitting layer of a display panel provided in an embodiment of the present application in a CIEy-BI coordinate system;

[0107] Figure 5 is a graph of a display panel provided in an embodiment of the present application in a CIEy-BI coordinate system;

[0108] Figure 6 This is a graph of a first light-emitting layer and a second light-emitting layer of a display panel provided in another embodiment of the present application in the CIEx-CE coordinate system;

[0109] Figure 7 is a curve diagram of a display panel provided in the CIEx-CE coordinate system according to another embodiment of the present application;

[0110] Figure 8 This is a graph of a first light-emitting layer and a second light-emitting layer of a display panel in a CIEy-BI coordinate system provided by another embodiment of the present application;

[0111] Figure 9 is a curve diagram of a display panel in a CIEy-BI coordinate system provided by another embodiment of the present application;

[0112] Figure 10 yes Figure 9 Schematic diagram of a local enlarged structure;

[0113] Figure 11 is a graph of a first light-emitting layer and a second light-emitting layer of a display panel provided in another embodiment of the present application in a CIEx-CE coordinate system;

[0114] Figure 12 is a curve diagram of a display panel in the CIEx-CE coordinate system provided by another embodiment of the present application;

[0115] Figure 13 This is a graph of a first light-emitting layer and a second light-emitting layer of a display panel provided in another embodiment of the present application in the CIEx-CE coordinate system;

[0116] Figure 14 This is a flow chart of a method for adjusting the luminous efficiency of a display panel provided in an embodiment of the present application;

[0117] Figure 15 This is a flow chart of a step in a method for adjusting the luminous efficiency of a display panel provided in an embodiment of the present application;

[0118] Figure 16 is a flowchart of a step in a method for adjusting the luminous efficiency of a display panel provided in another embodiment of the present application;

[0119] Figure 17 This is a flow chart of a method for adjusting the luminous efficiency of a display panel provided in another embodiment of the present application.

[0120] Explanation of the accompanying drawings: 10, display panel; 11, first light-emitting layer; 12, second light-emitting layer; 13, pixel electrode; 14, common electrode; 15, charge generation layer; 101, first hole injection layer; 102, first hole transport layer; 103, first electron blocking layer; 104, first hole blocking layer; 105, first electron transport layer; 106, second hole injection layer; 107, second hole transport layer; 108, second electron blocking layer; 109, second hole blocking layer; 1010, second electron transport layer; 1011, second electron injection layer. DETAILED DESCRIPTION

[0121] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In the detailed description below, many specific details are set forth in order to provide a comprehensive understanding of the present application. However, it will be apparent to those skilled in the art that the present application can be implemented without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present application by illustrating examples of the present application. In the accompanying drawings and the following description, at least some of the well-known structures and technologies are not shown in order to avoid unnecessary ambiguity in the present application; and, for clarity, the sizes of some structures may be exaggerated. In addition, the features, structures, or characteristics described below may be combined in any suitable manner in one or more embodiments.

[0122] In the description of this application, it should be noted that, unless otherwise specified, "plurality" means more than two; terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are merely for the purpose of facilitating the description of this application and simplifying the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting this application. Furthermore, terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0123] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the embodiments of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0124] In order to better understand this application, Figures 1 to 17 The display panel, display module, display device and display panel efficiency adjustment method according to the embodiments of the present application are described in detail.

[0125] Figure 1 A schematic structural diagram of a display panel 10 provided in an embodiment of the present application.

[0126] like Figure 1 As shown, an embodiment of the first aspect of the present application provides a display panel 10, which includes at least a first light-emitting layer 11 and a second light-emitting layer 12 that are stacked.

[0127] In the display panel 10 provided in the embodiment of the present application, the display panel 10 includes at least a first light-emitting layer 11 and a second light-emitting layer 12 stacked together. Using two or more stacked light-emitting layers can improve the display effect of the display panel 10 .

[0128] Optionally, the first light-emitting layer 11 and the second light-emitting layer 12 are configured to emit light of the same color to ensure the display effect of the display panel 10. The first light-emitting layer 11 and the second light-emitting layer 12 can both be configured to emit blue light, green light, or red light. In addition, the display panel 10 can also include light emitting other colors, which is not specifically limited in this application.

[0129] Optionally, the display panel 10 may be a top-emitting or bottom-emitting type display panel 10 ; preferably, it is a top-emitting type display panel 10 .

[0130] like Figure 2 As shown, Figure 2 This is a graph of the emission color of a stacked device in a display panel 10 in the related art in the CIEy-BI coordinate system. The display panel 10 includes a first light-emitting layer and a second light-emitting layer stacked and configured to emit blue light. EML1 is a graph of the emission color of the first light-emitting layer in the CIEy-BI coordinate system, and EML2 is a graph of the emission color of the second light-emitting layer in the CIEy-BI coordinate system. Figure 2 It can be seen that the chromaticity coordinate value CIEy corresponding to the peak of the first light-emitting layer is approximately 0.056, and the chromaticity coordinate value CIEy corresponding to the peak of the second light-emitting layer is approximately 0.045. The chromaticity coordinate values ​​CIEy corresponding to the peaks of the first light-emitting layer and the second light-emitting layer are quite different, so it is difficult for the stacked device formed by the first light-emitting layer and the second light-emitting layer to reach the peak efficiency.

[0131] Optionally, the display panel can be a top-emitting device. As a top-emitting device structure, the cavity length of the optical microcavity of the display panel 10 can be selected to be 3 / 4λ, 5 / 4λ, etc. In order to improve the luminous efficiency of the display panel 10, the luminous efficiency curves of the emitted color light of the first luminous layer and the second luminous layer are placed at different interference constructive positions. However, there are certain differences between different positions, which may cause different luminous behaviors of the two luminous layers. Figure 2It can be seen that the emission color of the first light-emitting layer and the second light-emitting layer has different patterns of change with the CIEy value. The emission color of the first light-emitting layer and the second light-emitting layer reaches peak values ​​at different CIEy values, which makes it difficult to coordinate the first light-emitting layer and the second light-emitting layer to achieve the highest efficiency at the same time, thereby affecting the overall efficiency of the display panel 10.

[0132] In some embodiments of the present application, both the first light-emitting layer 11 and the second light-emitting layer 12 are configured to emit blue light. The color light emitted by the first light-emitting layer 11 has a first curve in the CIEy-BI coordinate system, and the color light emitted by the second light-emitting layer 12 has a second curve in the CIEy-BI coordinate system. The difference between the chromaticity coordinate values ​​of the peaks of the first curve and the second curve is less than or equal to 0.01. For example, the difference between the chromaticity coordinate values ​​of the peaks of the first curve and the second curve is less than or equal to 0.005.

[0133] The abscissa of the CIEy-BI coordinate system represents the ordinate value CIEy in the chromaticity coordinate system of the light emitted by the first and second light-emitting layers 11, 12. The ordinate of the CIEy-BI coordinate system represents the blue light efficiency (BI) of the first and second light-emitting layers 11, 12. For blue light, BI = CE / CIEy (CE: Current Efficiency). Blue light is significantly affected by CIEy, so the ordinate CIEy in the chromaticity coordinate system better reflects the characteristics of blue light. In this embodiment, the larger the BI value, the higher the luminous efficiency of the stacked device, and the better the display quality of the display panel.

[0134] In these embodiments, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit blue light, the difference in chromaticity coordinate values ​​corresponding to the peaks of the emission color light of the first light-emitting layer 11 and the second light-emitting layer 12 in the CIEy-BI coordinate system is less than or equal to 0.005, that is, the peaks of the emission color light of the first light-emitting layer 11 and the second light-emitting layer 12 in the CIEy-BI coordinate system are close, the maximum values ​​of the luminous efficiency of the first light-emitting layer 11 and the second light-emitting layer 12 are close, the first curve and the second curve are at mutual gain positions, which can effectively improve the total luminous efficiency of the display panel 10.

[0135] In other embodiments, the first light-emitting layer 11 and the second light-emitting layer 12 are both used to emit green light. The color light emitted by the first light-emitting layer 11 has the fifth curve in the CIEx-CE coordinate system, and the color light emitted by the second light-emitting layer 12 has the sixth curve in the CIEx-CE coordinate system.

[0136] Optionally, the difference between the chromaticity coordinate values ​​of the peaks of the fifth curve and the sixth curve may also be less than or equal to 0.01, so that the peaks of the fifth curve and the sixth curve are close to each other, thereby improving the luminous efficiency of the display panel 10 .

[0137] In some other embodiments, the difference between the chromaticity coordinate values ​​of the peaks of the fifth curve and the sixth curve and the target CIEx value is less than or equal to 0.05.

[0138] The abscissa of the CIEx-CE coordinate system represents the color of the emitted light, representing the CIEx color coordinate. The ordinate of the CIEx-CE coordinate system represents the current efficiency of the first and second light-emitting layers 11, 12. When the first and second light-emitting layers 11, 12 emit green light, the CIEx color coordinate better reflects the characteristics of green light, as red light is primarily affected by the CIEx value. Furthermore, a larger CE value indicates a higher luminous efficiency of the stacked device, and thus a better display quality of the display panel.

[0139] In these embodiments, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, the inventors further discovered that when the difference between the chromaticity coordinate value corresponding to the peak of the colored light emitted by the first light-emitting layer 11 and the second light-emitting layer 12 in the CIEx-CE coordinate system and the target CIEx value is less than or equal to 0.05, that is, the chromaticity coordinate value corresponding to the highest efficiency point of the first light-emitting layer 11 and the second light-emitting layer 12 is close to the target CIEx value, on the one hand, the efficiencies of the first light-emitting layer 11 and the second light-emitting layer 12 are mutually enhanced, which can further improve the luminous efficiency of the display panel 10; on the other hand, the chromaticity coordinate value at the highest efficiency point of the first light-emitting layer 11 and the second light-emitting layer 12 meets the display requirements, which can effectively improve the luminous efficiency and display effect of the display panel 10.

[0140] There are various ways to set the target CIEx value. Depending on the display color requirements of the display panel 10, the target CIEx value can be 0.23 to 0.25. This allows the first and second light-emitting layers 11 and 12 to emit green light, and the CIEx value corresponding to the peak in the CIEx-CE coordinate system to be closer to 0.23 to 0.25. This improves the color gamut performance of the first and second light-emitting layers 11 and 12, and their luminescent colors are closer to the display requirements, thereby improving the display quality of the display panel 10. In an optional embodiment, the CIEx value can be 0.23, 0.24, or 0.25, for example.

[0141] Optionally, in the display panel 10 provided in the embodiment of the present application, only the first light-emitting layer 11 and the second light-emitting layer 12 for emitting blue light can be made to satisfy the difference between the chromaticity coordinate values ​​of the peaks of the first and second curves to be less than or equal to 0.01. Alternatively, the first light-emitting layer 11 and the second light-emitting layer 12 for emitting blue light can be made to satisfy the difference between the chromaticity coordinate values ​​of the peaks of the first and second curves to be less than or equal to 0.005, and the first light-emitting layer 11 and the second light-emitting layer 12 for emitting green light can be made to satisfy the difference between the chromaticity coordinate values ​​of the peaks of the fifth and sixth curves and the target CIEx value to be less than or equal to 0.05. Alternatively, only the first light-emitting layer 11 and the second light-emitting layer 12 for emitting green light can be made to satisfy the difference between the chromaticity coordinate values ​​of the peaks of the fifth and sixth curves and the target CIEx value to be less than or equal to 0.05.

[0142] Optionally, the display panel 10 further includes a first electrode 13 and a second electrode 14 , the first light-emitting layer 11 and the second light-emitting layer 12 are both located between the first electrode 13 and the second electrode 14 , and the first electrode 13 and the second electrode 14 are used to drive the first light-emitting layer 11 and the second light-emitting layer 12 to emit light.

[0143] Preferably, the first electrode is an anode, the second electrode 14 is a cathode, and the first light-emitting layer 11 is located on a side of the second light-emitting layer 12 facing the first electrode 13 .

[0144] Optionally, the display panel 10 further includes a charge generation layer 15, which is located between the first light-emitting layer 11 and the second light-emitting layer 12. Optionally, the display panel 10 further includes a first hole injection layer 101, a first charge transport layer 102, and a first electron blocking layer 103, which are sequentially located between the pixel electrode 13 and the first light-emitting layer 11, a first hole blocking layer 104 and a first electron transport layer 105, which are sequentially located between the first light-emitting layer 11 and the charge generation layer 15, a second hole injection layer 106, a second hole transport layer 107, and a second electron blocking layer 108, which are sequentially located between the charge generation layer 15 and the second light-emitting layer 12, and a second hole blocking layer 109, a second electron transport layer 1010, and a second electron injection layer 1011, which are sequentially located between the second light-emitting layer 12 and the common electrode 14.

[0145] Figure 1 The display panel 10 shown is a dual-layer device display panel 10, which includes a first light-emitting layer 11 and a second light-emitting layer 12 disposed adjacent to each other. In other optional embodiments, the display panel 10 may include more than three light-emitting layers, and the first light-emitting layer 11 and the second light-emitting layer 12 may be two adjacent light-emitting layers among the three or more light-emitting layers, or another light-emitting layer may be disposed between the first light-emitting layer 11 and the second light-emitting layer 12.

[0146] In some optional embodiments, the first light-emitting layer 11 has a third curve in the wavelength-spectral intensity coordinate system, that is, the third curve is the intrinsic spectrum curve of the first light-emitting layer 11, and the second light-emitting layer 12 has a fourth curve in the wavelength-spectral intensity coordinate system, that is, the fourth curve is the intrinsic spectrum curve of the second light-emitting layer 12. At the same emission peak position, the half-peak width of the third curve is smaller than the half-peak width of the fourth curve.

[0147] In these optional embodiments, when the half-width at half-maximum of the third curve is smaller than the half-width at half-maximum of the fourth curve, the peak of the third curve can approach the peak of the fourth curve, thereby placing the third and fourth curves at mutually beneficial positions. At the same peak position, the spectral intensity of the first and second light-emitting layers 11 and 12 is generally enhanced. When the first and second light-emitting layers 11 and 12 are configured to emit blue light, the overall enhancement of the spectral intensity of the first and second light-emitting layers 11 and 12 helps bring the chromaticity coordinate values ​​of the first and second curves closer, thereby improving the display quality of the display panel 10. When the first and second light-emitting layers 11 and 12 are configured to emit green light, the overall enhancement of the spectral intensity of the first and second light-emitting layers 11 and 12 helps bring the chromaticity coordinate values ​​of the fifth and sixth curves closer, thereby improving the display quality of the display panel 10.

[0148] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit blue light, the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 10nm to 30nm, so that the spectral intensity of the first light-emitting layer 11 and the second light-emitting layer 12 is generally enhanced, thereby better improving the display effect of the display panel 10.

[0149] When the first light-emitting layer 11 and the second light-emitting layer 12 are configured to emit blue light, and the difference between the half-maximum width of the third curve and the half-maximum width of the fourth curve is 10 nm to 30 nm, the material of the first light-emitting layer 11 may optionally include a boron-nitrogen material. For example, the material of the first light-emitting layer 11 may include the following materials:

[0150]

[0151] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are configured to emit blue light, and the difference between the half-maximum width of the third curve and the half-maximum width of the fourth curve is 10 nm to 30 nm, the material of the second light-emitting layer 12 may include an anthracene-containing material. For example, the material of the second light-emitting layer 12 may include the following materials:

[0152]

[0153] like Figure 3As shown, curve b is the intrinsic spectrum curve of the anthracene-containing material, and curve a is the intrinsic spectrum curve of the boron-nitrogen material. The half-peak width of the intrinsic spectrum curve of the boron-nitrogen material is smaller than the half-peak width of the intrinsic spectrum curve of the anthracene-containing material. In the embodiment of the present application, by reasonably adjusting the characteristics of the materials, the difference between the half-peak width of the third curve and the half-peak width of the fourth curve can be 10nm to 30nm.

[0154] like Figure 4 As shown, Figure 4 It is a graph of the color light emitted by the first light-emitting layer 11 and the second light-emitting layer 12 in the CIEy-BI coordinate system when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit blue light. Figure 4 In the figure, S101 and S102 represent CIEy-BI curves corresponding to different intrinsic spectra of the first light-emitting layer 11, and the half-peak width of S102 is greater than the half-peak width of S101. S103 is the CIEy-BI curve corresponding to the second light-emitting layer 12. Figure 4 It can be seen that, using the same emission peak position, when the intrinsic spectrum curve of the first light-emitting layer 11 changes from S102 to S101, the chromaticity coordinate value CIEy corresponding to the optimal efficiency position of the first light-emitting layer 11 is smaller, and the chromaticity coordinate value corresponding to the optimal efficiency position of the first light-emitting layer 11 is closer to the chromaticity coordinate value CIEy corresponding to the optimal efficiency position of the second light-emitting layer 12.

[0155] like Figure 5 As shown, Figure 5 S105 is Figure 4 The curve of the emission color of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by S102 in the CIEy-BI coordinate system. Figure 4 The curve of the emission color of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by S101 in the CIEy-BI coordinate system. Figure 5 It can be seen that when the half-width of the first light-emitting layer 11 becomes narrower, the luminous efficiency of the display panel 10 is significantly improved, and the chromaticity coordinate value CIEy corresponding to the peak moves from 0.052 to 0.048.

[0156] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 5nm to 30nm, so that the spectral intensity of the first light-emitting layer 11 and the second light-emitting layer 12 is generally enhanced, thereby better improving the display effect of the display panel 10.

[0157] When the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, and the difference between the half-maximum width of the third curve and the half-maximum width of the fourth curve is 5 nm to 30 nm, the material of the first light-emitting layer 11 includes the following materials: Where D is deuterium, an isotope of hydrogen.

[0158] like Figure 6 As shown, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, a curve diagram of the color light emitted by the first light-emitting layer 11 and the second light-emitting layer 12 in the CIEx-CE coordinate system is obtained. Figure 6 In the figure, S201 and S202 represent the CIEx-CE curves corresponding to different intrinsic spectra of the first light-emitting layer 11, and the half-peak width of S201 is greater than the half-peak width of S202. S203 is the CIEx-CE curve corresponding to the second light-emitting layer 12. Figure 6 It can be seen that, with the same emission peak position, when the intrinsic spectrum curve of the first light-emitting layer 11 changes from S201 to S202, the chromaticity coordinate value CIEx corresponding to the optimal efficiency position of the first light-emitting layer 11 is smaller.

[0159] Combine Figure 7 , Figure 7 S205 Figure 6 The curve of the emission color of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by S201 in the CIEx-CE coordinate system. Figure 6 The curve of the emission color of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by S202 in the CIEx-CE coordinate system. Figure 7 It can be seen that when the half-width of the first light-emitting layer 11 becomes narrower, the luminous efficiency of the display panel 10 is significantly improved, and the chromaticity coordinate value CIEx corresponding to the peak moves from 0.29 to around 0.24. When the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 is at 0.24, the color gamut performance of the emitted color light of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 is significantly improved.

[0160] Depend on Figure 7 It can be seen that the peak of curve S204 is greater than the peak of curve S205. Therefore, when the half-peak width of the first light-emitting layer 11 is reduced, the chromaticity coordinate value CIEx corresponding to the peak of the stacked device moves from 0.29 to 0.24, which not only makes the color gamut performance of the display panel 10 better, but also improves the luminous efficiency of the display panel 10.

[0161] In addition, the distance between the first light-emitting layer 11 and the pixel electrode 13 is closer, and the microcavity effect of the first light-emitting layer 11 is stronger. By changing the curve of the first light-emitting layer 11 in the CIEy-BI / CIEx-CE coordinate system, the luminous efficiency of the first light-emitting layer 11 can be improved, thereby more effectively improving the overall luminous efficiency of the display panel 10.

[0162] In some optional embodiments, the wavelength of the peak of the third curve is smaller than the wavelength of the peak of the fourth curve, that is, the third curve is shifted leftward toward the zero point of the coordinate system relative to the fourth curve.

[0163] Optionally, the material of the first light-emitting layer 11 may be modified with electronic groups to obtain the material of the first light-emitting layer 11 , and the peak of the third curve of the first light-emitting layer 11 is shifted to the left relative to the peak of the fourth curve.

[0164] Optionally, the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is 1nm to 10nm. When the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is within the above range, it can avoid that the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is too large, causing the third curve and the fourth curve to be in a canceling position, affecting the display effect of the display panel 10, so that the overall spectral intensity of the first light-emitting layer 11 and the second light-emitting layer 12 is enhanced, thereby better improving the display effect of the display panel 10.

[0165] Optionally, the first light-emitting layer 11 and the second light-emitting layer 12 both include a main material, and the molecular polarity of at least part of the main material of the first light-emitting layer 11 is smaller than the molecular polarity of at least part of the main material of the second light-emitting layer 12, so that the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve.

[0166] For example, the host material of the first light-emitting layer 11 includes:

[0167] The host material of the second light-emitting layer 12 includes:

[0168] Alternatively, the host material of the first light-emitting layer 11 includes:

[0169] The host material of the second light-emitting layer 12 includes:

[0170] Optionally, the first light-emitting layer 11 and the second light-emitting layer 12 both include a host material and a guest material, and the molecular polarity of at least part of the guest material of the first light-emitting layer 11 is greater than the molecular polarity of at least part of the guest material of the second light-emitting layer 12, so that the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve. As for the molecular polarity of the host material, it can remain unchanged, that is, using the existing technology, or it can be changed, and the solution described in the previous embodiment can be used.

[0171] Optionally, the first light-emitting layer 11 and the second light-emitting layer 12 both include a host material and a guest material, and the doping concentration of the guest material of the first light-emitting layer 11 is greater than the doping concentration of the guest material of the second light-emitting layer 12, so that the wavelength value of the peak of the third curve is less than the wavelength value of the peak of the fourth curve.

[0172] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit blue light, the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is 2nm to 4nm, so that the wavelength values ​​of the peaks of the first light-emitting layer 11 and the second light-emitting layer 12 used to emit blue light are closer, thereby improving the luminous effect of the blue light-emitting layer of the display panel 10.

[0173] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit blue light, and the half-peak width of the third curve is smaller than the half-peak width of the fourth curve, as described above, the material of the first light-emitting layer 11 may include a boron nitride material, that is, the material of the first light-emitting layer 11 may include:

[0174]

[0175] When the peak of the first light-emitting layer 11 is further shifted to the left, for example, the difference between the wavelength of the peak of the third curve and the wavelength of the peak of the fourth curve is set to 2 nm to 4 nm, the molecular group of the boron-nitrogen material can be changed. For example, the material of the first light-emitting layer 11 may include:

[0176]

[0177] In the embodiment of the present application, the material groups can be adjusted, for example, by adjusting the boron nitride material groups, the peak of the third curve corresponding to the first light-emitting layer 11 can be shifted to the left, and the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve.

[0178] like Figure 8As shown, when the first light-emitting layer 11 and the second light-emitting layer 12 are configured to emit blue light, curves of the emission colors of the different light-emitting layers in the CIEy-BI coordinate system are obtained. EML1, EML1-2, and EML1-4 are all curves of the emission colors of the first light-emitting layer 11 in the CIEy-BI coordinate system, and the peak of the intrinsic spectrum of EML1-2 is shifted 2nm to the left relative to EML1. That is, the difference between the wavelength of the peak of the third curve of EML1 and the wavelength of the peak of EML1-2 is 2nm, and the wavelength of the peak of the third curve of EML1 is greater than the wavelength of the peak of EML1-2. Similarly, the peak of the intrinsic spectrum of EML1-4 is shifted 4nm to the left. That is, the difference between the wavelength of the peak of the third curve of EML1 and the wavelength of the peak of EML1-4 is 4nm, and the wavelength of the peak of the third curve of EML1 is greater than the wavelength of the peak of EML1-4. EML2 is the curve of the emission color light of the second light-emitting layer 12 in the CIEy-BI coordinate system. Figure 8 It can be seen that when the third curve of the first light-emitting layer 11 changes from EML1 to EML1-2 and EML1-4, it is closer to the peak of the curve of the second light-emitting layer 12 in the CIEy-BI coordinate system.

[0179] like Figure 9 and Figure 10 As shown, Figure 9 : is a simulation diagram of the efficiency of the stacked device of the first light-emitting layer 11 and the second light-emitting layer 12, Figure 10 for Figure 9 Schematic diagram of the local enlarged structure. Among them, T-normal is Figure 8 The efficiency simulation diagram of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by EML1, T-EML1-2 is the efficiency simulation diagram of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by EML1-2, and T-EML1-4 is the efficiency simulation diagram of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by EML1-4. Figure 9 and Figure 10 It can be seen that when the intrinsic spectrum peak of the first light-emitting layer 11 shifts 2 nm or 4 nm to the left, the efficiency peak of the display panel 10 increases, and the chromaticity coordinate value CIEy corresponding to the peak also decreases, thereby increasing the color gamut and improving the display effect.

[0180] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is 1nm to 10nm. For example, the difference between the wavelength value of the peak of the third curve and the wavelength value of the peak of the fourth curve is 1nm to 2nm, so that the wavelength values ​​of the peaks of the first light-emitting layer 11 and the second light-emitting layer 12 used to emit green light are closer, thereby improving the luminous effect of the green light-emitting layer of the display panel 10.

[0181] In the above embodiment, optionally, the material molecules of the first light-emitting layer 11 include the following materials:

[0182]

[0183] Wherein, R1 and R2 are each independently selected from one of the following groups: -H, -CH3, -OCH3, -NH2, -C(CH3)3, and all of the above groups, except -H, are electron-donating groups, and R1 and R2 are not both -H. That is, one or two electron-donating groups may be introduced at the para position of the pyridine N to shift the peak of the third curve to the left. And / or, R3, R4, R5, and R6 are each independently selected from one of the following groups: -H, -COOH, -X(Cl, Br, I), -NO2, -CN, and all of the above groups, except -H, are electron-donating and electron-withdrawing groups. That is, one or four electron-withdrawing groups may be introduced at the 2, 3, 4, and 5 positions of the benzene ring adjacent to the pyridine ring to shift the wavelength of the peak of the third curve to a value less than that of the peak of the fourth curve.

[0184] like Figure 11 As shown, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, the curves of the emission color light of different light-emitting layers in the CIEx-CE coordinate system are obtained. Among them, S301, S302 and S303 are all curves of the color light emitted by the first light-emitting layer 11 in the coordinate system CIEx-CE. The peak of the intrinsic spectrum of S302 is shifted to the left by 1nm relative to S301, that is, the difference between the wavelength value of the peak of the third curve of S301 and the wavelength value of the peak of S302 is 1nm, and the wavelength value of the peak of the third curve of S301 is greater than the wavelength value of the peak of S302. The peak of the intrinsic spectrum of S303 is shifted to the left by 2nm relative to S301, that is, the difference between the wavelength value of the peak of the third curve of S301 and the wavelength value of the peak of S303 is 2nm, and the wavelength value of the peak of the third curve of S301 is greater than the wavelength value of the peak of S303. S304 is the curve of the emission color light of the second light emitting layer 12 in the coordinate system CIEx-CE. Figure 11 It can be seen that when the first light-emitting layer 11 changes from S301 to S302 or S303, at the chromaticity coordinate value of 0.24, the larger the CE value, the higher the luminous efficiency, and when the chromaticity coordinate value is 0.24, the color gamut performance is better.

[0185] like Figure 12 As shown, Figure 12 is an efficiency simulation diagram of a stacked device comprising a first light-emitting layer 11 and a second light-emitting layer 12. Figure 11The efficiency curve of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by S301, the efficiency curve of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by S302, and the efficiency curve of the stacked device formed by the first light-emitting layer 11 and the second light-emitting layer 12 represented by S307. Figure 12 It can be seen that when the intrinsic spectrum peak of the first light-emitting layer 11 shifts to the left by 1 nm or 2 nm, the luminous efficiency of the display panel 10 is increased, the target CIEx is also smaller, and the color gamut is further improved.

[0186] In addition, it is worth noting that the display panel in this embodiment also includes a red stacked device, which can be a conventional stacked device, or the light-emitting layer of the red stacked device can be improved by using the principle of the above-mentioned blue light stacked device. For example, the stacked red first light-emitting layer and the red second light-emitting layer can be specifically positioned with reference to the blue light, and the blue light can be specifically positioned with reference to the blue light. Figure 13 As shown, the light emitted by the red first luminescent layer follows the eighth curve S8 in the CIEx-CE coordinate system, while the light emitted by the red second luminescent layer follows the seventh curve S7 in the CIEx-CE coordinate system. The difference in chromaticity coordinates CIEx between the peaks of curves S8 and S7 is small, within 0.001. Therefore, if cost is a concern, these two curves can be left unmodified. If cost is not a concern, improvements can be made to the red first luminescent layer. It is worth noting that, like green, the primary influencing factor for red is CIEx, and the CE value can be used to determine the luminous efficiency of the red stacked device.

[0187] Specifically, in some optional embodiments, the red first light-emitting layer has a third curve in the wavelength-spectral intensity coordinate system, and the red second light-emitting layer has a fourth curve in the wavelength-spectral intensity coordinate system. At the same emission peak position, the half-peak width of the third curve is smaller than the half-peak width of the fourth curve.

[0188] For example, the materials of the first red light-emitting layer include:

[0189] The materials of the second red light-emitting layer include:

[0190] In some optional embodiments, the red first light-emitting layer has a third curve in the wavelength-spectral intensity coordinate system, and the red second light-emitting layer has a fourth curve in the wavelength-spectral intensity coordinate system, and the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve.

[0191] For example, the materials of the first red light-emitting layer include:

[0192] Among them, Q2, Q3 and Q4 are each independently selected from one of the following groups: -H, -X(Cl, Br, I), -CN, -F, and Q2, Q3 and Q4 are not -H at the same time. Except for -H, all of the above groups are electron-withdrawing groups, that is, in this embodiment, 1 to 3 electron-withdrawing groups are introduced at positions 2, 3, and 4 of the benzene ring.

[0193] Alternatively, the material of the first red light-emitting layer includes:

[0194] Through the above design, the luminous efficiency of the stacked device formed by the first red luminescent layer and the second red luminescent layer can be improved, thereby improving the display effect of the display panel.

[0195] The embodiment of the second aspect of the present application further provides a display module, comprising the display panel 10 of any of the above-mentioned embodiments of the first aspect. Since the display module provided by the embodiment of the second aspect of the present application comprises the display panel 10 of any of the above-mentioned embodiments of the first aspect, the display module provided by the embodiment of the second aspect of the present application has the beneficial effects of the display panel 10 of any of the above-mentioned embodiments of the first aspect, and no further details are given here.

[0196] The third aspect of the present application also provides a display device comprising the display module of any of the first aspect embodiments. Since the display device provided by the second aspect of the present application comprises the display module of any of the first aspect embodiments, the display device provided by the second aspect of the present application has the same beneficial effects as the display module of any of the first aspect embodiments, and no further details are given here.

[0197] The display device in the embodiments of the present application includes but is not limited to mobile phones, personal digital assistants (PDAs), tablet computers, e-books, televisions, access control systems, smart landline phones, consoles, and other devices with display functions.

[0198] The embodiment of the fourth aspect of the present application further provides a method for adjusting the luminous efficiency of a display panel 10 , and the adjustment method can be used to prepare the display panel 10 provided by any of the above-mentioned embodiments of the first aspect.

[0199] like Figures 1 to 14 As shown, the adjustment methods include:

[0200] Step 01: at least adjust the preparation materials of the first light-emitting layer 11 and / or the second light-emitting layer 12 stacked in the display panel 10, where the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit blue light.

[0201] Step 02: Obtain a first curve of the color light emitted by the first light-emitting layer 11 in the CIEy-BI coordinate system and a second curve of the color light emitted by the second light-emitting layer 12 in the CIEy-BI coordinate system.

[0202] Step 03: Make the difference between the chromaticity coordinate values ​​of the peaks of the first curve and the second curve less than or equal to 0.01.

[0203] Optionally, both the first light-emitting layer 11 and the second light-emitting layer 12 are configured to emit blue light.

[0204] In step 01, the materials used to prepare the first light-emitting layer 11 and / or the second light-emitting layer 12 can be repeatedly adjusted, and a first curve for the first light-emitting layer 11 and a second curve for the second light-emitting layer 12 formed with different materials can be obtained multiple times. Ultimately, by adjusting the materials, the difference in chromaticity coordinate values ​​between the peaks of the first curve and the second curve is made to be less than or equal to 0.01. For example, the difference in chromaticity coordinate values ​​between the peaks of the first curve and the second curve is made to be less than or equal to 0.005.

[0205] In the adjustment method provided in the embodiment of the present application, by adjusting the preparation materials of the first light-emitting layer 11 and / or the second light-emitting layer 12, the difference between the chromaticity coordinate values ​​CIEy of the peaks of the first curve and the second curve is less than or equal to 0.005, so that the maximum values ​​of the luminous efficiency of the first light-emitting layer 11 and the second light-emitting layer 12 are close, and the first curve and the second curve are at mutual gain positions, which can effectively improve the total luminous efficiency of the display panel 10.

[0206] In step 01, there are many ways to adjust the preparation materials of the first light-emitting layer 11 and / or the second light-emitting layer 12, for example, Figure 15 As shown, including:

[0207] Step 031: Adjust the preparation materials of the first light-emitting layer 11 and / or the second light-emitting layer 12.

[0208] Step 032: Obtain a third curve of the first light-emitting layer 11 in the wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer 12 in the wavelength-spectral intensity coordinate system.

[0209] Step 033: Make the half-peak width of the third curve smaller than the half-peak width of the fourth curve. Make the half-peak width of the third curve smaller than the half-peak width of the fourth curve.

[0210] In these optional embodiments, a third curve and a fourth curve can be obtained through step 032. The third curve and the fourth curve can reflect the relationship between the wavelengths at the positions of maximum spectral intensity. Finally, through step 033, when the half-maximum width of the third curve is smaller than the half-maximum width of the fourth curve, the peak of the third curve can be close to the peak of the fourth curve, thereby making the third curve and the fourth curve mutually gain. At the same peak position, the spectral intensity of the first light-emitting layer 11 and the second light-emitting layer 12 is generally enhanced, which not only helps to make the chromaticity coordinate values ​​of the peaks of the first curve and the second curve close to each other, but also helps to improve the display effect of the display panel 10.

[0211] In some other optional embodiments, after the third curve and the fourth curve are obtained through step 031 and step 032, the first light-emitting layer 11 and the second light-emitting layer 12 may be adjusted by other methods, for example, Figure 16 As shown, including:

[0212] Step 031: Adjust the preparation materials of the first light-emitting layer 11 and / or the second light-emitting layer 12.

[0213] Step 032: Obtain a third curve of the first light-emitting layer 11 in the wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer 12 in the wavelength-spectral intensity coordinate system.

[0214] Step 033: Make the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve.

[0215] In the embodiment of the present application, the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve, that is, when the first light-emitting layer 11 and the second light-emitting layer 12 are designed, the wavelength value corresponding to the peak of the third curve is on the left side of the wavelength value corresponding to the peak of the fourth curve. When the first light-emitting layer 11 and the second light-emitting layer 12 are driven by the pixel electrode 13 to emit light, the peak of the third curve and the peak of the fourth curve are closer, so that the spectral intensity of the first light-emitting layer 11 and the second light-emitting layer 12 is generally enhanced, thereby better improving the display effect of the display panel 10.

[0216] In this embodiment, the material of the first light-emitting layer 11 can be adjusted so that the wavelength of the peak of the third curve is smaller than the wavelength of the peak of the fourth curve.

[0217] The CIEy value corresponding to the peak of the second curve may be obtained first, and the target value CIEys corresponding to the peak of the first curve may be determined. The difference between the target value CIEys and the CIEy value corresponding to the peak of the second curve may be less than or equal to 0.01.

[0218] Then, the preparation material of the first light-emitting layer 11 is adjusted according to the target value CIEys and the following formulas (1), (2), (3), and (4):

[0219]

[0220] Among them, x (λ) 、Y (λ) and Z (λ) is the X / Y / Z corresponding to the 1931 tristimulus value table when the wavelength is λ; I (λ) is the spectral intensity at wavelength λ.

[0221] Alternatively, a trial value method can be used to input a suitable λ value into the above formulas (2), (3), and (4), and then calculate CIEy according to formula (1). When the difference between CIEy and the CIEy value corresponding to the peak of the second curve is less than or equal to 0.01 (e.g., 0.005), CIEy is determined to be the target value CIEys. The material for preparing the first light-emitting layer 11 is then adjusted based on the λ value corresponding to the target value CIEys.

[0222] Optionally, the molecular polarity of the main material in the first light-emitting layer 11 and / or the second light-emitting layer 12 can be adjusted so that the molecular polarity of at least part of the main material in the first light-emitting layer 11 is smaller than the molecular polarity of at least part of the main material in the second light-emitting layer 12, thereby making the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve.

[0223] Optionally, the first light-emitting layer 11 and the second light-emitting layer 12 both include a host material and a guest material, and the doping concentration of the guest material in the first light-emitting layer 11 and / or the second light-emitting layer 12 can be adjusted so that the doping concentration of the guest material in the first light-emitting layer 11 is greater than the doping concentration of the guest material in the second light-emitting layer 12, thereby making the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve.

[0224] Optionally, the molecular polarity of the guest material in the first light-emitting layer 11 and / or the second light-emitting layer 12 can be adjusted so that the molecular polarity of at least part of the guest material in the first light-emitting layer 11 is greater than the molecular polarity of at least part of the guest material in the second light-emitting layer 12, thereby making the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve.

[0225] In this embodiment, the difference between the wavelength values ​​of the peaks of the third curve and the fourth curve can be made 2nm to 4nm, so that the wavelength values ​​of the peaks of the first light-emitting layer 11 and the second light-emitting layer 12 for emitting blue light are closer, thereby improving the luminous effect of the blue light-emitting layer of the display panel 10.

[0226] For example, the material of the first light emitting layer 11 includes:

[0227] like Figure 17Another embodiment of the present application further provides a method for adjusting the luminous efficiency of a display panel 10 . The display panel 10 may include a first luminous layer 11 and a second luminous layer 12 . The adjustment method includes:

[0228] Step 01 ′: at least adjusting the preparation materials of the first light-emitting layer 11 and / or the second light-emitting layer 12 stacked in the display panel 10 ; the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light.

[0229] Step 02 ′: Obtain a fifth curve of the color light emitted by the first light-emitting layer 11 in the CIEx-CE coordinate system; and a sixth curve of the color light emitted by the second light-emitting layer 12 in the CIEx-CE coordinate system.

[0230] Step 03 ′: ensuring that the difference between the chromaticity coordinate values ​​of the peaks of the fifth curve and the sixth curve and the target CIEx is less than or equal to 0.05.

[0231] In the adjustment method provided in the embodiment of the present application, the fifth and sixth curves of the first light-emitting layer 11 are obtained according to step 02'. The chromaticity coordinate values ​​CIEx corresponding to the peaks are determined based on the fifth and sixth curves, that is, the chromaticity coordinate values ​​CIEx corresponding to the maximum luminous efficiency of the first and second light-emitting layers 11, 12 are determined. In step 03', the difference between the chromaticity coordinate values ​​corresponding to the peaks of the first and second light-emitting layers 11, 12 in the CIEx-BI coordinate system and the target CIEx value is ensured to be less than or equal to 0.05. In other words, the chromaticity coordinate values ​​corresponding to the highest efficiency points of the first and second light-emitting layers 11, 12 are close to the target CIEx value. This not only achieves a mutual benefit between the efficiencies of the first and second light-emitting layers 11, 12, but also improves the efficiency of the first and second light-emitting layers 11, 12. Furthermore, the chromaticity coordinate values ​​meet display requirements, effectively improving the luminous efficiency and display quality of the display panel 10.

[0232] In this embodiment, there are various ways to adjust the materials used to prepare the first light-emitting layer 11 and / or the second light-emitting layer 12 so that the difference between the chromaticity coordinate values ​​of the peaks of the fifth and sixth curves and the target CIEx value is less than or equal to 0.05. For example, as described above, a third curve and a fourth curve can be obtained through steps 031 and 032. The third and fourth curves can reflect the relationship between the wavelengths at the positions of maximum spectral intensity. When the half-maximum width of the third curve is smaller than the half-maximum width of the fourth curve through step 033, the peak of the third curve can approach the peak of the fourth curve, thereby placing the third and fourth curves at mutually beneficial positions. With the same peak position, the overall spectral intensity of the first and second light-emitting layers 11 and 12 is enhanced, which not only helps to bring the chromaticity coordinate values ​​of the peaks of the fifth and sixth curves closer together, but also helps to improve the display quality of the display panel 10.

[0233] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, in step 033, the preparation material of the first light-emitting layer 11 can be adjusted so that the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 5nm to 30nm, so that the overall spectral intensity of the first light-emitting layer 11 and the second light-emitting layer 12 is enhanced, thereby better improving the display effect of the display panel 10.

[0234] For example, the material of the first light emitting layer 11 includes:

[0235] The first light-emitting layer 11 and the second light-emitting layer 12 each include a host material and a guest material.

[0236] In other optional embodiments, after obtaining the third curve and the fourth curve through step 031 and step 032, the preparation material of the first light-emitting layer 11 can be adjusted so that the wavelength value of the peak of the third curve is smaller than the wavelength value of the peak of the fourth curve.

[0237] When the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, by adjusting the fifth curve and the sixth curve, the CIEx value corresponding to the peak of the sixth curve can be first obtained, and the target value CIExs corresponding to the peak of the fifth curve can be determined. The difference between the target value CIExs and the CIEx value corresponding to the peak of the sixth curve is less than or equal to 0.05.

[0238] Then, the preparation material of the first light-emitting layer 11 is adjusted according to the target value CIExs and the following formulas (5), (6), (7), and (8):

[0239]

[0240] Among them, x (λ) 、Y (λ) and Z (λ) is the X / Y / Z corresponding to the 1931 tristimulus value table when the wavelength is λ; I (λ) is the spectral intensity at wavelength λ.

[0241] Alternatively, a trial-and-error method can be used to input appropriate λ values ​​into the above formulas (6), (7), and (8), and then CIEx is calculated according to formula (5). When the difference between CIEx and the target CIEx value is less than or equal to 0.05, CIEx is determined to be the target value CIExs. The material for preparing the first light-emitting layer 11 is then adjusted based on the λ value corresponding to the target value CIExs.

[0242] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are configured to emit green light, in step 033 , the difference between the wavelength of the peak of the third curve and the wavelength of the peak of the fourth curve can be set to 1 nm to 10 nm.

[0243] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, the molecular polarity of the main material in the first light-emitting layer 11 and / or the second light-emitting layer 12 can be adjusted so that the molecular polarity of at least part of the main material of the first light-emitting layer 11 is smaller than the molecular polarity of at least part of the main material of the second light-emitting layer 12, thereby making the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve.

[0244] Optionally, the first light-emitting layer 11 and the second light-emitting layer 12 both include a host material and a guest material. When the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, the doping concentration of the guest material in the first light-emitting layer 11 and / or the second light-emitting layer 12 can be adjusted so that the doping concentration of the guest material in the first light-emitting layer 11 is greater than the doping concentration of the guest material in the second light-emitting layer 12, thereby making the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve.

[0245] Optionally, when the first light-emitting layer 11 and the second light-emitting layer 12 are used to emit green light, the molecular polarity of the guest material in the first light-emitting layer 11 and / or the second light-emitting layer 12 can be adjusted so that the molecular polarity of at least part of the guest material in the first light-emitting layer 11 is greater than the molecular polarity of at least part of the guest material in the second light-emitting layer 12, thereby making the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve.

[0246] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A display panel, characterized in that: At least a first light-emitting layer and a second light-emitting layer are stacked, wherein: The first light-emitting layer and the second light-emitting layer are both configured to emit blue light, the color light emitted by the first light-emitting layer has a first curve in a CIEy-BI coordinate system, the color light emitted by the second light-emitting layer has a second curve in the CIEy-BI coordinate system, the difference between the chromaticity coordinate values ​​of the peaks of the first curve and the second curve is less than or equal to 0.01, the abscissa of the CIEy-BI coordinate system is the ordinate value CIEy in the color coordinate of the light emitted by the first light-emitting layer and the second light-emitting layer, and the ordinate of the CIEy-BI coordinate system is the blue light efficiency BI of the first light-emitting layer and the second light-emitting layer; And / or, the first light-emitting layer and the second light-emitting layer are used to emit green light, the colored light emitted by the first light-emitting layer has a fifth curve in the CIEx-CE coordinate system, the colored light emitted by the second light-emitting layer has a sixth curve in the CIEx-CE coordinate system, the difference between the chromaticity coordinate values ​​of the peaks of the fifth curve and the sixth curve and the target CIEx value is less than or equal to 0.05, and the target CIEx value is 0.23 to 0.

25. The abscissa of the CIEx-CE coordinate system is the abscissa CIEx of the color of the emitted colored light in the color coordinate, and the ordinate of the CIEx-CE coordinate system is the current efficiency CE of the first light-emitting layer and the second light-emitting layer; The first light-emitting layer has a third curve in the wavelength-spectral intensity coordinate system, and the second light-emitting layer has a fourth curve in the wavelength-spectral intensity coordinate system. At the same emission peak position, the half-peak width of the third curve is smaller than the half-peak width of the fourth curve.

2. The display panel according to claim 1, wherein: The display panel further includes a first electrode and a second electrode, and the first light-emitting layer and the second light-emitting layer are both located between the first electrode and the second electrode.

3. The display panel according to claim 2, wherein: The first electrode is an anode, and the first light-emitting layer is located on a side of the second light-emitting layer facing the first electrode.

4. The display panel according to claim 1, wherein: The first light-emitting layer and the second light-emitting layer are adjacent light-emitting layers.

5. The display panel according to claim 1, wherein: The first light-emitting layer and the second light-emitting layer are configured to emit blue light, and a difference between chromaticity coordinate values ​​of peaks of the first curve and the second curve is less than or equal to 0.

005.

6. The display panel according to claim 1, wherein: The first light-emitting layer and the second light-emitting layer are used for emitting blue light, and a difference between a half-maximum width of the third curve and a half-maximum width of the fourth curve is 10 nm to 30 nm.

7. The display panel according to claim 6, wherein: The material of the first light-emitting layer includes a boron-nitrogen material; And / or, the material of the second light-emitting layer includes anthracene-containing material.

8. The display panel according to claim 1, wherein: The first light-emitting layer and the second light-emitting layer are used for emitting green light, and a difference between a half-maximum width of the third curve and a half-maximum width of the fourth curve is 5 nm to 30 nm.

9. The display panel according to claim 8, wherein: The material of the first light-emitting layer includes:

10. The display panel according to claim 1 or 2, characterized in that: The first light-emitting layer has a third curve in the wavelength-spectral intensity coordinate system, and the second light-emitting layer has a fourth curve in the wavelength-spectral intensity coordinate system. The peak wavelength of the third curve is smaller than the peak wavelength of the fourth curve.

11. The display panel according to claim 10, wherein: The difference between the wavelength of the peak of the third curve and the wavelength of the peak of the fourth curve is 1 nm to 10 nm.

12. The display panel according to claim 1, wherein The first light-emitting layer and the second light-emitting layer both include a host material, and the molecular polarity of at least part of the host material of the first light-emitting layer is smaller than the molecular polarity of at least part of the host material of the second light-emitting layer; and / or, the first light-emitting layer and the second light-emitting layer both comprise guest materials, and the molecular polarity of at least part of the guest material in the first light-emitting layer is greater than the molecular polarity of at least part of the guest material in the second light-emitting layer; And / or, both the first light-emitting layer and the second light-emitting layer include a guest material, and the doping concentration of the guest material in the first light-emitting layer is greater than the doping concentration of the guest material in the second light-emitting layer.

13. The display panel according to claim 1, wherein The first light-emitting layer and the second light-emitting layer are used for emitting blue light, and a difference between a wavelength value of a peak of the third curve and a wavelength value of a peak of the fourth curve is 2 nm to 4 nm.

14. The display panel according to claim 1, wherein The first light-emitting layer and the second light-emitting layer are used to emit blue light, and the material of the first light-emitting layer includes:

15. The display panel according to claim 1, wherein The first light-emitting layer and the second light-emitting layer are used to emit green light, and a difference between a wavelength value of a peak of the third curve and a wavelength value of a peak of the fourth curve is 1 nm to 2 nm.

16. The display panel according to claim 1, wherein The first light-emitting layer and the second light-emitting layer are used to emit green light, and the material of the first light-emitting layer includes: Wherein, R1 and R2 are each independently selected from one of the following groups: -H, -CH3, -OCH3, -NH2, -C(CH3)3, and R1 and R2 are not -H at the same time; and / or, R3, R4, R5 and R6 are each independently selected from one of the following groups: -H, -COOH, -X(Cl, Br, I), -NO2, -CN, and R3, R4, R5 and R6 are not -H at the same time.

17. The display panel according to claim 1, wherein: The target CIEx value was 0.

24.

18. A display module, characterized in that: The display panel comprises the display panel according to any one of claims 1 to 17.

19. A display device, characterized in that: Including the display module according to claim 18.

20. A method for adjusting the luminous efficiency of a display panel, characterized in that: Adjusting at least the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel, wherein the first light-emitting layer and the second light-emitting layer are configured to emit blue light; Obtain a first curve of the color light emitted by the first light-emitting layer in the CIEy-BI coordinate system and a second curve of the color light emitted by the second light-emitting layer in the CIEy-BI coordinate system, where the abscissa of the CIEy-BI coordinate system is the ordinate value CIEy of the color coordinate of the light emitted by the first light-emitting layer and / or the second light-emitting layer, and the ordinate of the CIEy-BI coordinate system is the blue light efficiency BI of the first light-emitting layer and / or the second light-emitting layer; The difference between the chromaticity coordinate values ​​of the peaks of the first curve and the second curve is less than or equal to 0.

01.

21. The adjustment method according to claim 20, characterized in that: In the step of at least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel: Adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer; Obtaining a third curve of the first light-emitting layer in a wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer in a wavelength-spectral intensity coordinate system; The half-peak width of the third curve is made smaller than the half-peak width of the fourth curve.

22. The adjustment method according to claim 21, characterized in that: In the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer: Adjust the preparation material of the first light-emitting layer.

23. The adjustment method according to claim 21, characterized in that: The preparation material of the first light-emitting layer is adjusted so that the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 10 nm to 30 nm.

24. The adjustment method according to claim 21, characterized in that: In the step of adjusting the preparation material of the first light-emitting layer: the material of the first light-emitting layer includes a boron-nitrogen material.

25. The adjustment method according to claim 20, characterized in that: In the step of at least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel: Adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer; Obtaining a third curve of the first light-emitting layer in a wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer in a wavelength-spectral intensity coordinate system; The wavelength of the peak of the third curve is smaller than the wavelength of the peak of the fourth curve.

26. The adjustment method according to claim 25, characterized in that: The material used to prepare the first light-emitting layer is adjusted so that the wavelength of the peak of the third curve is smaller than the wavelength of the peak of the fourth curve.

27. The adjustment method according to claim 26, characterized in that: In the step of adjusting the material for preparing the first light-emitting layer so that the wavelength of the peak of the third curve is smaller than the wavelength of the peak of the fourth curve: Obtaining a CIEy value corresponding to the peak of the second curve, and determining a target value CIEys corresponding to the peak of the first curve, wherein a difference between the target value CIEys and the CIEy value corresponding to the peak of the second curve is less than or equal to 0.01; Adjusting the preparation material of the first light-emitting layer according to the target value CIEys and the following formulas (1), (2), (3), and (4); Among them, x (λ) 、Y (λ) and Z (λ) is the X / Y / Z corresponding to the 1931 tristimulus value table when the wavelength is λ; I (λ) is the spectral intensity at wavelength λ.

28. The adjustment method according to claim 25, characterized in that: The first light-emitting layer and the second light-emitting layer both include a host material and a guest material. In the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer: adjusting the doping concentration of the guest material in the first light-emitting layer and / or the second light-emitting layer so that the doping concentration of the guest material in the first light-emitting layer is greater than the doping concentration of the guest material in the second light-emitting layer; and / or adjusting the molecular polarity of the guest material in the first light-emitting layer and / or the second light-emitting layer so that the molecular polarity of at least part of the guest material in the first light-emitting layer is greater than the molecular polarity of at least part of the guest material in the second light-emitting layer; And / or, adjusting the molecular polarity of the main material in the first light-emitting layer and / or the second light-emitting layer so that the molecular polarity of at least part of the main material in the first light-emitting layer is smaller than the molecular polarity of at least part of the main material in the second light-emitting layer.

29. The adjustment method according to claim 25, characterized in that: In the step of making the wavelength value of the peak of the third curve smaller than the wavelength value of the peak of the fourth curve: The difference between the wavelength of the peak of the third curve and the wavelength of the peak of the fourth curve is set to 2 nm to 4 nm.

30. The adjustment method according to claim 29, characterized in that: The material of the first light-emitting layer includes:

31. A method for adjusting the luminous efficiency of a display panel, characterized in that: include: Adjusting at least the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel; the first light-emitting layer and the second light-emitting layer are used to emit green light; Obtain a fifth curve of the color light emitted by the first light-emitting layer in the CIEx-CE coordinate system; and a sixth curve of the color light emitted by the second light-emitting layer in the CIEx-CE coordinate system, where the abscissa of the CIEx-CE coordinate system is the abscissa CIEx of the color of the emitted color light in the color coordinate, and the ordinate of the CIEx-CE coordinate system is the current efficiency of the first light-emitting layer and the second light-emitting layer; The difference between the chromaticity coordinate values ​​of the peaks of the fifth curve and the sixth curve and the target CIEx value is less than or equal to 0.05; Wherein, the target CIEx value is 0.23-0.

25.

32. The adjustment method according to claim 31, characterized in that: In the step of at least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel: Adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer; Obtaining a third curve of the first light-emitting layer in a wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer in a wavelength-spectral intensity coordinate system; The half-peak width of the third curve is smaller than the half-peak width of the fourth curve.

33. The adjustment method according to claim 32, characterized in that: In the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer: Adjust the preparation material of the first light-emitting layer.

34. The adjustment method according to claim 33, characterized in that: The preparation material of the first light-emitting layer is adjusted so that the difference between the half-peak width of the third curve and the half-peak width of the fourth curve is 5 nm to 30 nm.

35. The adjustment method according to claim 33, characterized in that: In the step of adjusting the preparation material of the first light-emitting layer: the material of the first light-emitting layer includes:

36. The adjustment method according to claim 31, characterized in that: In the step of at least adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer stacked in the display panel: Adjusting the preparation materials of the first light-emitting layer and / or the second light-emitting layer; Obtaining a third curve of the first light-emitting layer in a wavelength-spectral intensity coordinate system; and a fourth curve of the second light-emitting layer in a wavelength-spectral intensity coordinate system; The wavelength of the peak of the third curve is made smaller than the wavelength of the peak of the fourth curve.

37. The adjustment method according to claim 36, characterized in that: The material used to prepare the first light-emitting layer is adjusted so that the wavelength of the peak of the third curve is smaller than the wavelength of the peak of the fourth curve.

38. The adjustment method according to claim 37, characterized in that: In the step of adjusting the material of the first light-emitting layer so that the wavelength of the peak of the third curve is smaller than the wavelength of the peak of the fourth curve: Obtaining a CIEx value corresponding to the peak of the sixth curve, and determining a target value CIExs corresponding to the peak of the fifth curve, wherein a difference between the target value CIExs and the CIEx value corresponding to the peak of the sixth curve is less than or equal to 0.05; Adjusting the preparation material of the first light-emitting layer according to the target value CIExs and the following formulas (5), (6), (7), and (8); Among them, x (λ) 、Y (λ) and Z (λ) is the X / Y / Z corresponding to the 1931 tristimulus value table when the wavelength is λ; I (λ) is the spectral intensity at wavelength λ.

39. The adjustment method according to claim 36, characterized in that: The material for preparing the first light-emitting layer is adjusted so that the difference between the wavelength of the peak of the third curve and the wavelength of the peak of the fourth curve is 1 nm to 10 nm.

40. The adjustment method according to claim 36, characterized in that: The first light-emitting layer and the second light-emitting layer both include a host material and a guest material. In the step of adjusting the preparation material of the first light-emitting layer and / or the second light-emitting layer: adjusting the doping concentration of the guest material in the first light-emitting layer and / or the second light-emitting layer so that the doping concentration of the guest material in the first light-emitting layer is greater than the doping concentration of the guest material in the second light-emitting layer; and / or adjusting the molecular polarity of the guest material in the first light-emitting layer and / or the second light-emitting layer so that the molecular polarity of at least part of the guest material in the first light-emitting layer is greater than the molecular polarity of at least part of the guest material in the second light-emitting layer; And / or, adjusting the molecular polarity of the main material in the first light-emitting layer and / or the second light-emitting layer so that the molecular polarity of at least part of the main material in the first light-emitting layer is smaller than the molecular polarity of at least part of the main material in the second light-emitting layer.

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