Display panel and display device

Abstract

Provided are a display panel and a display device. In the display panel, first sub-pixels are configured to emit light of a first color, second sub-pixels are configured to emit light of a second color, and third sub-pixels are configured to emit light of a third color. The first sub-pixels, the second sub-pixels, and the third sub-pixels at least satisfy one of the following relationships: relationship I: the difference between the color gamut x-coordinate of the light of the second color and the color gamut x-coordinate of the light of the third color is within the range of ±0.02 of the color gamut y-coordinate of the light of the third color, and the color gamut y-coordinate of the light of the first color is not greater than the color gamut x-coordinate and / or the color gamut y-coordinate of a white point formed by synthesizing the light of the first color, the light of the second color, and the light of the third color; and relationship II: the difference between the maximum value and the minimum value of the half-peak widths of the electroluminescence spectra of the first sub-pixels, the second sub-pixels, and the third sub-pixels is less than or equal to 11 nm, and the difference between the half-peak widths of the electroluminescence spectrum and photoluminescence spectrum of each sub-pixel is less than or equal to 16 nm.

Description

Display panel and display device Technical Field

[0001] Embodiments of this disclosure relate to a display panel and a display device. Background Technology

[0002] Organic light-emitting diode (OLED) displays have secured a place in the display field due to their self-emissive nature, high contrast ratio, and high response rate. With the development of display technology, OLED displays are finding increasingly wider applications, leading to higher demands on display performance. The emergence of high dynamic range display standards has placed even greater emphasis on display devices in terms of high contrast, wide color gamut, and high resolution.

[0003] Summary of the Invention

[0004] At least one embodiment of this disclosure relates to a display panel and display device for improving color gamut and light emission efficiency.

[0005] At least one embodiment of this disclosure provides a display panel including a plurality of sub-pixels, wherein the plurality of sub-pixels includes a plurality of first sub-pixels, a plurality of second sub-pixels, and a plurality of third sub-pixels. The first sub-pixels are configured to emit a first color light, the second sub-pixels are configured to emit a second color light, and the third sub-pixels are configured to emit a third color light. The first sub-pixels, the second sub-pixels, and the third sub-pixels satisfy at least one of the following relationships: Relationship 1: The difference between the abscissa of the color gamut of the second color light and the abscissa of the color gamut of the third color light is within ±0.02 of the ordinate of the color gamut of the third color light, and the ordinate of the color gamut of the first color light is not greater than the abscissa and / or ordinate of the color gamut of the white point synthesized by the first color light, the second color light, and the third color light; Relationship 2: The difference between the maximum and minimum values ​​of the full width at half maximum (FWHM) of the electroluminescence spectra of the first sub-pixels, the second sub-pixels, and the third sub-pixels is less than or equal to 11 nm, and the difference between the FWHM of the electroluminescence spectrum and the photoluminescence spectrum of each of the first sub-pixels, the second sub-pixels, and the third sub-pixels is less than or equal to 16 nm.

[0006] For example, the sub-pixel includes two tandemly connected light-emitting units, each of which includes a light-emitting layer.

[0007] For example, the light-emitting layer of the first sub-pixel includes a phosphorescent material, the light-emitting layer of the second sub-pixel includes a sensitized fluorescent material, and the light-emitting layer of the third sub-pixel includes a fluorescent material.

[0008] For example, in the first sub-pixel, the second sub-pixel, and the third sub-pixel, the light-emitting layer of at least one light-emitting unit of a sub-pixel includes at least three material components, the at least three material components including a material containing boron and / or a delayed fluorescence material.

[0009] For example, the doping ratio of the boron-containing material is less than 5%.

[0010] For example, the doping ratio of the boron-containing material is less than 3%.

[0011] For example, the doping ratio of the delayed fluorescence material is less than 49%.

[0012] For example, in the first sub-pixel, the second sub-pixel, and the third sub-pixel, the light-emitting layer of at least one light-emitting unit of a sub-pixel includes two material components, and the doping material of one of the material components contains a metal element.

[0013] For example, the metal element is a transition metal element.

[0014] For example, the transition metal elements include Ir, Pt, Os, and Ru.

[0015] For example, the metallic elements include rare earth metallic elements.

[0016] For example, the rare earth metal elements include La, Ce, Eu, and Tb.

[0017] For example, the doping ratio of the doped material is less than 10%.

[0018] For example, the doping ratio of the doped material is less than 5%.

[0019] For example, the light-emitting layers of different light-emitting units in the same sub-pixel are the same.

[0020] For example, the light-emitting layers of different light-emitting units in the same sub-pixel are different.

[0021] For example, the wavelength of the first color light is greater than the wavelength of the second color light, and the wavelength of the second color light is greater than the wavelength of the third color light.

[0022] For example, the first color light is red light, the second color light is green light, and the third color light is blue light.

[0023] For example, the sub-pixel includes a first electrode and a second electrode, the light-emitting unit is located between the first electrode and the second electrode, and the light-emitting unit of at least one of the first sub-pixel and the second sub-pixel further includes a color adjustment layer, in the same light-emitting unit, the color adjustment layer is located on the side of the light-emitting layer closer to the first electrode.

[0024] For example, the light-emitting unit further includes a color adjustment auxiliary layer, which is located on the side of the color adjustment layer away from the light-emitting layer.

[0025] At least one embodiment of this disclosure also provides a display device including any of the above-described display panels. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0027] Figure 1 is a schematic diagram of a display panel.

[0028] Figure 2 is a schematic diagram of a light-emitting device in a display panel provided in an embodiment of this disclosure.

[0029] Figure 3 is a schematic diagram of a light-emitting device in a display panel provided in another embodiment of this disclosure.

[0030] Figure 4 is a color gamut coordinate diagram of the display panel provided in Embodiments 1 to 5 of this disclosure.

[0031] Figure 5 is a color gamut coordinate diagram of the display panel provided in Comparative Example 1, Comparative Example 2, Embodiment 2 of this disclosure, and Embodiments 6 to 8. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0033] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0034] For display devices, looking to the future, technical solutions that balance the high color gamut and high efficiency of BT2020 will gradually become the focus of competition in display technology.

[0035] Embodiments of this disclosure provide a display panel to maximize the color gamut range of the device and obtain a high color gamut display panel.

[0036] In embodiments of this disclosure, color gamut can be represented using color coordinates, where CIEx and CIEy represent color coordinates, with CIEx being the horizontal axis and CIEy being the vertical axis. For example, in the CIE1931 color space, the coordinates of white light are approximately (0.3, 0.3).

[0037] Figure 1 is a schematic diagram of a display panel. As shown in Figure 1, the display panel includes a plurality of sub-pixels 100 located on a substrate BS, and the plurality of sub-pixels 100 are arranged in an array. As shown in Figure 1, the plurality of sub-pixels 100 are arranged in an array along a first direction X and a second direction Y.

[0038] For example, as shown in Figure 1, sub-pixels in the same column emit the same color of light, and multiple pixels PX are arranged sequentially in the same row. This embodiment uses the second direction Y as the column direction and the first direction X as the row direction for illustration. In other embodiments, the second direction Y can be the row direction, and the first direction X can be the column direction.

[0039] The embodiments disclosed herein are illustrated using a plurality of sub-pixels 100 arranged in an array as shown in FIG1. ​​However, the setting position and arrangement of the plurality of sub-pixels 100 are not limited to those shown in FIG1, and can be determined as needed.

[0040] As shown in Figure 1, the display panel includes multiple pixels PX, and each pixel PX includes several sub-pixels 100. As shown in Figure 1, the multiple sub-pixels 100 include a first sub-pixel 101, a second sub-pixel 102, and a third sub-pixel 103. The first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 103 emit different colors.

[0041] The embodiments disclosed herein are illustrated using the example of a first sub-pixel 101 being a red sub-pixel, a second sub-pixel 102 being a green sub-pixel, and a third sub-pixel 103 being a blue sub-pixel. However, the emission colors of the first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 103 are not limited to red, green, and blue, respectively, and can be determined as needed.

[0042] As shown in Figure 1, the substrate BS includes a display area 601 and a peripheral area 602 located on at least one side of the display area 601. Figure 1 illustrates the example of the peripheral area 602 surrounding the display area 601. The display area 601 is the area for displaying images, and the peripheral area 602 is a non-light-emitting area.

[0043] As shown in Figure 1, an embodiment of this disclosure provides a display panel including a plurality of sub-pixels 100. The plurality of sub-pixels 100 includes a plurality of first sub-pixels 101, a plurality of second sub-pixels 102, and a plurality of third sub-pixels 103. The first sub-pixels 101 are configured to emit a first color light, the second sub-pixels 102 are configured to emit a second color light, and the third sub-pixels 103 are configured to emit a third color light. The first sub-pixels 101, the second sub-pixels 102, and the third sub-pixels 103 satisfy at least one of the following relationships.

[0044] Relationship 1: The difference between the x-coordinate of the color gamut of the second color light and the x-coordinate of the color gamut of the third color light is within ±0.02 of the y-coordinate of the color gamut of the third color light, and the y-coordinate of the color gamut of the first color light is not greater than the x-coordinate and / or y-coordinate of the color gamut of the white point synthesized by the first color light, the second color light and the third color light.

[0045] Relationship 2: The difference between the maximum and minimum full width at half maximum (FWHM) of the electroluminescence spectra of the first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 103 is less than or equal to 11 nm, and the difference between the FWHM of the electroluminescence spectrum and the photoluminescence spectrum of each of the first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 103 is less than or equal to 16 nm.

[0046] For example, Gaussian software can be used to simulate material properties, and simulation software such as Setfos can be used to simulate device performance. Combined with experimental results, the above relationship 2 can be obtained, that is, the difference between the maximum and minimum values ​​of the half-width of the electroluminescence spectrum in the luminescent region is less than or equal to 11 nm, and the difference between the half-width of the electroluminescence spectrum and the photoluminescence spectrum is less than or equal to 16 nm.

[0047] The emission wavelength of the first sub-pixel 101 is λ1, the emission wavelength of the second sub-pixel 102 is λ2, and the emission wavelength of the third sub-pixel 103 is λ3, where λ1>λ2>λ3. The horizontal coordinate of the color gamut is represented by CIEx, and the vertical coordinate by CIEy. Therefore, the horizontal coordinates of the color gamut of the first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 103 can be represented by CIEx(λ1), CIEx(λ2), and CIEx(λ3), respectively, and their vertical coordinates can be represented by CIEy(λ1), CIEy(λ2), and CIEy(λ3), respectively.

[0048] Relationship 1 can be expressed as follows: the difference between CIEx(λ2) and CIEx(λ3) is within the range of CIEy(λ3)±0.02, and CIEy(λ1) is not greater than CIEx and / or CIEy of the white point synthesized by the three luminous regions (the luminous regions of the first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 103).

[0049] The electroluminescence spectrum mentioned in Relationship 2 refers to the spectrum of light emitted by a sub-pixel when a voltage is applied.

[0050] For example, electroluminescence spectra can be obtained by measuring the device with a photometer or photodetector when the device is powered on by an applied voltage.

[0051] The photoluminescence spectrum mentioned in Relation 2 refers to the spectrum of light emitted by a sub-pixel under illumination. The illumination light is short-wavelength. The wavelength of the short-wavelength is not limited here; as long as the wavelength of the illumination light is shorter than the wavelength of the light emitted by the sub-pixel, the luminescent area will emit light.

[0052] The full width at half maximum (FWHM) of a luminescence spectrum refers to the peak width at half the height of the chromatographic peak.

[0053] For example, photoluminescence spectra can be obtained by measuring them with a fluorescence spectrometer under illumination by a light source.

[0054] The display panel provided in the embodiments of this disclosure, when satisfying relation one, has a difference between CIEx(λ2) and CIEx(λ3) within the range of CIEy(λ3) ± 0.02, and CIEy(λ1) is not greater than CIEx and / or CIEy of the white point synthesized from the three light-emitting regions. This is beneficial for maximizing the color gamut of the light synthesized from the three colors of the first sub-pixel, the second sub-pixel, and the third sub-pixel (R, G, B), achieving a display range closest to the BT2020 color gamut. In the display panel provided in the embodiments of this disclosure, CIEx(λ2) is greater than CIEx(λ3).

[0055] The display panel provided in the embodiments of this disclosure, when satisfying relation two, has a small difference between the maximum and minimum values ​​of the full width at half maximum (FWHM) of the electroluminescence spectrum of the three sub-pixels (first sub-pixel 101, second sub-pixel 102, and third sub-pixel 103), and a small difference between the FWHM of the electroluminescence spectrum and the photoluminescence spectrum of each sub-pixel (each of the first sub-pixel 101, second sub-pixel 102, and third sub-pixel 103). This is beneficial for achieving maximum light extraction efficiency while satisfying the maximum color gamut range, realizing high device performance, obtaining optimal brightness and color changes at different viewing angles, and reducing color shift.

[0056] For example, as shown in Figure 1, sub-pixel 100 includes a light-emitting area 001. The light-emitting area 001 can refer to the effective light-emitting area of ​​sub-pixel 100. The light emission status of a sub-pixel can refer to the light emission status of the light-emitting area 001 of that sub-pixel 100.

[0057] Figure 2 is a schematic diagram of a light-emitting device in a display panel according to an embodiment of the present disclosure. Figure 3 is a schematic diagram of a light-emitting device in a display panel according to another embodiment of the present disclosure.

[0058] As shown in Figures 2 and 3, each sub-pixel (light-emitting area 001) contains at least two light-emitting units, forming a tandem device structure. Figures 2 and 3 illustrate light-emitting units M1 and M2. For the first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 101, each sub-pixel 100 (each sub-pixel 100's light-emitting area 001) includes two tandem light-emitting units: light-emitting unit M1 and light-emitting unit M2. As shown in Figures 2 and 3, the light-emitting devices in the display panel are of a tandem device structure.

[0059] For example, as shown in Figures 2 and 3, sub-pixel 100 includes two light-emitting units connected in series: light-emitting unit M1 and light-emitting unit M2, each light-emitting unit including a light-emitting layer.

[0060] Therefore, the display panel provided by the embodiments of this disclosure has a device structure compatible with existing device processes and is easy to manufacture.

[0061] As shown in Figures 2 and 3, the light-emitting unit M1 of the first sub-pixel 101 includes a light-emitting layer 9 (i.e., a light-emitting layer R-EML), and the light-emitting unit M2 of the first sub-pixel 101 includes a light-emitting layer 19 (i.e., a light-emitting layer R-EML).

[0062] As shown in Figures 2 and 3, the light-emitting unit M1 of the second sub-pixel 102 includes a light-emitting layer 8 (i.e., a light-emitting layer G-EML), and the light-emitting unit M2 of the second sub-pixel 102 includes a light-emitting layer 18 (i.e., a light-emitting layer G-EML).

[0063] As shown in Figures 2 and 3, the light-emitting unit M1 of the third sub-pixel 103 includes a light-emitting layer 7 (i.e., light-emitting layer B-EML), and the light-emitting unit M2 of the third sub-pixel 103 includes a light-emitting layer 17 (i.e., light-emitting layer B-EML).

[0064] Figures 2 and 3 illustrate this by showing that the light-emitting layers of light-emitting units M1 and M2 are made of the same material and in the same manner. Of course, the light-emitting layers of light-emitting units M1 and M2 can also be made of different materials and in different manners.

[0065] For example, the light-emitting layer of the first sub-pixel 101 (at least one of light-emitting layer 9 and light-emitting layer 19) includes a phosphorescent material, the light-emitting layer of the second sub-pixel 102 (at least one of light-emitting layer 8 and light-emitting layer 18) includes a sensitized fluorescent material, and the light-emitting layer of the third sub-pixel 103 (at least one of light-emitting layer 7 and light-emitting layer 17) includes a fluorescent material. Therefore, the display panel provided by the embodiments of this disclosure does not use phosphorescent materials in at least the light-emitting layers of the second sub-pixel 102 and the third sub-pixel 103, reducing the use of phosphorescent materials and metal complex luminescent materials, which helps to reduce costs.

[0066] The embodiments of this disclosure provide a display panel employing a tandem device structure. Its red light-emitting layer uses phosphorescence, its green light-emitting layer uses sensitized fluorescence, and its blue light-emitting layer uses fluorescence. The R, G, and B color dots are combined to maximize a high color gamut display effect. Furthermore, the common layer of this device is compatible with different R, G, and B light-emitting schemes, achieving high efficiency and low power consumption.

[0067] For example, in the first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 103, the light-emitting layer of at least one light-emitting unit of a sub-pixel includes at least three material components, which contain materials containing boron and / or delayed fluorescence materials. The display panel provided by the embodiments of this disclosure, by setting the number of material components and selecting the material components, and by selecting suitable light-emitting materials for the three regions, coordinates the three-color dots and the white light dot, thereby maximizing the improvement of the device's color gamut.

[0068] In the embodiments of this disclosure, the luminescent material includes a boron-containing material. An excessively high doping ratio of the boron-containing material can lead to luminescence quenching, reduced efficiency, and reduced lifetime.

[0069] For example, the doping ratio of boron-containing materials is less than 5%. In embodiments of this disclosure, the doping ratio or doping amount refers to the ratio of the mass of the substance to the total mass of the layer or the ratio of the volume of the substance to the total volume of the layer.

[0070] For example, the doping ratio of boron-containing materials is less than 3%.

[0071] In embodiments of this disclosure, the delayed fluorescence material serves as a sensitizer to generate excitons and transfer energy to the boron-containing luminescent material, thereby emitting light. For example, the doping ratio of the delayed fluorescence material is less than 49%.

[0072] For example, in the first sub-pixel 101, the second sub-pixel 102, and the third sub-pixel 103, the light-emitting layer of at least one light-emitting unit of a sub-pixel includes two material components, and the doping material of one of the material components contains a metal element. The display panel provided by the embodiments of this disclosure, by setting the number of material components and selecting the material components, and by selecting suitable light-emitting materials for the three regions, coordinates the three-color points and the white light point, thereby maximizing the improvement of the device's color gamut range.

[0073] The doping ratio of the doped material should not be too high, as an excessively high doping ratio will lead to luminescence quenching, reduced efficiency, and reduced lifetime.

[0074] For example, the doping ratio of the doped material is less than 10%. That is, the doping ratio of the doped material containing a metallic element is less than 10%.

[0075] For example, the doping ratio of the doped material is less than 5%. That is, the doping ratio of the doped material containing a metallic element is less than 5%.

[0076] For example, the metallic element is a transition metal. For example, transition metals include Ir, Pt, Os, and Ru.

[0077] For example, the metallic element can be a rare earth metal. Rare earth metals include La, Ce, Eu, and Tb.

[0078] The display panel provided in the embodiments of this disclosure has the same or different structures for the light-emitting layers of different light-emitting units in the light-emitting area.

[0079] For example, as shown in Figures 2 and 3, the light-emitting layers of different light-emitting units in the same sub-pixel (light-emitting area 001) are the same. Figures 2 and 3 illustrate this using the example of different light-emitting units in the same sub-pixel (light-emitting area 001) having the same light-emitting layer.

[0080] For example, the light-emitting layers of different light-emitting units in the same sub-pixel (light-emitting area 001) are different. For example, the materials of the light-emitting layers of different light-emitting units in the same sub-pixel (light-emitting area 001) are different.

[0081] For example, the wavelength of the first color light is longer than the wavelength of the second color light, and the wavelength of the second color light is longer than the wavelength of the third color light. For example, the first color light is red light, the second color light is green light, and the third color light is blue light.

[0082] For example, sub-pixel 100 includes a first electrode 1 (first electrode E1) and a second electrode 23 (second electrode E2), and a light-emitting unit is located between the first electrode E1 and the second electrode E2. The light-emitting unit of at least one of the first sub-pixel 101 and the second sub-pixel 102 also includes a color adjustment layer. In the same light-emitting unit, the color adjustment layer is located on the side of the light-emitting layer EML closer to the first electrode E1.

[0083] As shown in Figures 2 and 3, for the light-emitting unit M1, the color adjustment layer includes color adjustment layer 4 (G-EBL), color adjustment layer 5 (B-EBL), and color adjustment layer 6 (R-EBL).

[0084] As shown in Figures 2 and 3, for the light-emitting unit M2, the color adjustment layer includes color adjustment layer 14 (G-EBL), color adjustment layer 15 (B-EBL), and color adjustment layer 16 (R-EBL).

[0085] For example, the color adjustment layer in the embodiments of this disclosure may be made of an electron blocking layer material.

[0086] For example, as shown in Figure 3, the light-emitting unit also includes a color adjustment auxiliary layer (G-CCL), which is located on the side of the color adjustment layer away from the light-emitting layer. As shown in Figure 3, for the light-emitting unit M1, a color adjustment auxiliary layer 4-1 (color adjustment auxiliary layer G-CCL) is provided. As shown in Figure 3, for the light-emitting unit M2, a color adjustment auxiliary layer 14-1 (color adjustment auxiliary layer G-CCL) is provided. The color adjustment auxiliary layer is located on the side of the light-emitting layer closer to the first electrode E1.

[0087] The following description is based on the display panel and its light-emitting devices shown in Figures 2 and 3. Taking the first sub-pixel 101 as the red sub-pixel, the second sub-pixel 102 as the green sub-pixel, and the third sub-pixel 103 as the blue sub-pixel as an example.

[0088] As shown in Figures 2 and 3, the sub-pixel 100 of the display panel includes a first electrode 1, a second electrode 23, and a light-emitting functional layer located between the first electrode 1 and the second electrode 23. The first electrode 1 and the second electrode 23 can also be represented by E1 and E2, respectively. The light-emitting functional layer includes a common layer and a local layer. The common layer is a film layer shared by all sub-pixels. The local layer is a layer that is not shared by all sub-pixels. As shown in Figures 2 and 3, the light-emitting units M1 and M2 of each sub-pixel 100 are local layers, while the layer located between the first electrode 1 and the second electrode 23, excluding the layers of light-emitting units M1 and M2, is the common layer. As shown in Figures 2 and 3, the light-emitting unit M1 of the first sub-pixel 101 includes a color adjustment layer 6 and a light-emitting layer 9, and the light-emitting unit M2 of the first sub-pixel 101 includes a color adjustment layer 16 and a light-emitting layer 19; the light-emitting unit M1 of the second sub-pixel 102 includes a color adjustment layer 4 and a light-emitting layer 8, and the light-emitting unit M2 of the second sub-pixel 102 includes a color adjustment layer 14 and a light-emitting layer 18; the light-emitting unit M1 of the third sub-pixel 103 includes a color adjustment layer 5 and a light-emitting layer 7, and the light-emitting unit M2 of the third sub-pixel 103 includes a color adjustment layer 15 and a light-emitting layer 17. As shown in Figures 2 and 3, the hole injection layer (HIL) 2, hole transport layer (HTL) 3, hole blocking layer (HBL) 10, charge generation layer (NCGL) 11, charge generation layer (PCGL) 12, hole transport layer (HTL) 13, hole blocking layer (HBL) 20, electron transport layer (ETL) 21, and electron injection layer (EIL) 22 are all common layers. To distinguish them, Figures 2 and 3 use HTL-1 and HTL-2 to represent different hole transport layers, and HBL-1 and HBL-2 ​​to represent different hole blocking layers, respectively. Charge generation layer 11 is an N-type doped charge generation layer, and charge generation layer 12 is a P-type doped charge generation layer.

[0089] The following lists the various film layers. It should be noted that the film layer configuration of light-emitting devices can also adopt other forms as needed.

[0090] For example, the first electrode 1 is the anode, and the anode is a high work function electrode material, which can be (1) transparent oxides such as ITO and IZO, with a thickness of 80-200 nm; or it can be Ag / ITO, Al / ITO, Ag / IZO, Al / IZO, etc. to form a composite electrode, in which the metal thickness is generally 10-100 nm and the oxide layer thickness is generally 5-20 nm. If the transparent conductive material described in (1) is used as the anode, the device corresponds to a bottom emission structure; if the reflective composite electrode described in (2) is used, the device is a top emission structure.

[0091] For example, the hole injection layer (HIL)2 can be an injection material such as CuPc, HATCN, or MnO3, or it can be formed by p-type doping in a hole transport material. The p-type dopant can be an oxide-based inorganic material or an axialene-based organic material. The thickness of the hole injection layer 2 can be 1–30 nm. This layer can be formed by multi-source co-evaporation.

[0092] For example, hole transport layer 3 and hole transport layer 13 can be formed from materials with good hole transport characteristics. The thickness of each of hole transport layer 3 and hole transport layer 13 ranges from 1 to 200 nm. The material of the hole transport layer is generally selected from carbazole and its derivatives, which have high hole mobility. The materials of hole transport layer 3 and hole transport layer 13 can be the same or different. In a top-emitting device, the optical cavity length of the third sub-pixel (blue photonics sub-pixel) can be adjusted by modifying the thickness of hole transport layer 3 and hole transport layer 13. Hole transport layer 3 and hole transport layer 13 can also be referred to as the first hole transport layer HTL-1 and the second hole transport layer HTL-2, respectively.

[0093] For example, the main function of electron blocking layer 4 and electron blocking layer 14 is to transport holes and prevent excitons in the adjacent light-emitting layer from diffusing to the hole transport layer. The thickness of each of electron blocking layer 4 and electron blocking layer 14 is less than 10 nm, which is used to improve efficiency and device stability.

[0094] The electron blocking layer 4 and the electron blocking layer 14 can be made of the same or different materials. The electron blocking layer 4 and the electron blocking layer 14 can exist alone or simultaneously.

[0095] Electron blocking layer 4 and electron blocking layer 14 can be referred to as the first green electron blocking layer and the second green electron blocking layer, respectively.

[0096] For example, in some embodiments, as shown in FIG3, a color adjustment auxiliary layer (4-1 / 14-1) may be added between the electron blocking layer 4 / 14 and the adjacent layer in the anode direction. The main function of the color adjustment auxiliary layer 4-1 and the color adjustment auxiliary layer 14-1 is to transmit holes and to adjust the optical cavity length of the second sub-pixel 102 (green light) by adjusting the thickness. The material of each of the color adjustment auxiliary layers 4-1 and 14-1 may be selected from hole-type carbazole or aromatic amine derivatives.

[0097] For example, electron blocking layer 5 and electron blocking layer 15 can be referred to as the first blue light electron blocking layer and the second blue light electron blocking layer, respectively. Each of electron blocking layer 5 and electron blocking layer 15 is mainly responsible for lowering the transport barrier of holes from the adjacent hole transport layer (HTL) to the blue light emitting layer. Therefore, the highest occupied orbital energy level (HOMO) of the molecular material in this layer should numerically be between the HOMO of the adjacent hole transport layer and the HOMO of the main body of the blue light emitting layer. Simultaneously, this layer also has an exciton blocking effect, and the energy S1 of the first excited state of the singlet state of this layer material is greater than that of the blue light emitting layer material. S1 represents the energy level of the excited singlet state of the material. The material of this layer can optionally be carbazole and its derivatives. The materials of the first and second blue light electron blocking layers can be the same or different.

[0098] For example, electron blocking layer 6 and electron blocking layer 16 can be referred to as the first red electron blocking layer and the second red electron blocking layer, respectively. The main function of each of electron blocking layer 6 and electron blocking layer 16 is to reduce the transmission barrier of holes from the adjacent hole transport layer (HTL) to the red light emitting layers (light emitting layer 9 and light emitting layer 19), while ensuring that excitons in the light emitting layer do not leak out. In the top-emitting structure, electron blocking layer 6 and electron blocking layer 16 can also be used to adjust the optical cavity length. Optionally, electron blocking layer 6 and electron blocking layer 16 can be made of carbazole and its derivatives. The materials of the first red electron blocking layer and the second red electron blocking layer can be the same or different. For example, in some embodiments, each red blocking layer can also have a more subdivided layered structure, such as electron blocking layer 6 and / or electron blocking layer 16 comprising two sublayers, and the absolute HOMO value of each sublayer increases sequentially in the direction from the first electrode 1 to the second electrode 23.

[0099] For example, emitting layer 7 and emitting layer 17 can be referred to as the first blue light emitting layer and the second blue light emitting layer, respectively. The blue light emitting layer contains at least one host and one fluorescent guest. The emission spectrum of the host material and the absorption spectrum of the guest material have significant overlap; under normalized spectral conditions, the area of ​​the overlap region accounts for no less than 60% of the area of ​​the guest absorption spectrum. The host material can be selected from anthracene, fluorene, pyrene, and their derivatives. The guest material can be a pyrene-based organic compound or a boron-containing organic compound, with a doping concentration adjusted in the range of 0.5% to 5%, and the main emission peak wavelength between 450 and 470 nm. The materials of the first and second blue light emitting layers can be the same or different.

[0100] For example, emitting layer 8 and emitting layer 18 can be referred to as the first green emitting layer and the second green emitting layer, respectively. Each of emitting layer 8 and emitting layer 18 contains at least one hole-type host, a material with thermally activated delayed fluorescence (TADF) properties, and a fluorescent guest material. The hole-type host can be a carbazole-based material, the TADF material can be a polycarbazole-based material with a DLA structure, and the fluorescent guest can be a boron-containing organic compound. The material of this layer requires that the T1 (energy level of the triplet electronic excited state of the material) of the host material is higher than the T1 of the TADF material. For example, the T1 of the hole-type host is at least 0.1 eV higher than the T1 of the TADF material. The materials in the first green emitting layer and the second green emitting layer can be the same or different. The emission spectrum of the TADF material and the absorption spectrum of the guest material have a large overlap. For example, the overlap area of ​​the normalized spectrum needs to account for more than 60% of the area of ​​the guest absorption spectrum. In the top-emission scheme, when the color adjustment auxiliary layer 4-1 / 14-1 is not present, the thickness of the light-emitting layer 8 and the light-emitting layer 18 (the first green light-emitting layer and the second green light-emitting layer) can be used to adjust the length of the green light optical cavity.

[0101] In some cases, an auxiliary light-emitting layer can be disposed between the light-emitting layer 8 / 18 and the adjacent layer in the anode direction (i.e., between the light-emitting layer 8 / 18 and the anode). The auxiliary light-emitting layer can be disposed below the light-emitting layer 8 / 18, for example, between the electron blocking layer 4 / 14 and the light-emitting layer 8 / 18. For example, an auxiliary light-emitting layer can be disposed between the electron blocking layer 4 and the light-emitting layer 8, or between the electron blocking layer 14 and the light-emitting layer 18. The auxiliary light-emitting layer comprises a hole-type host material and a light-emitting material, and the two materials contained in this layer are the same as those in the light-emitting layer above it. The film thickness of this auxiliary light-emitting layer is less than the film thickness of the light-emitting layer above it.

[0102] For example, emitting layer 9 and emitting layer 19 can be referred to as the first red emitting layer and the second red emitting layer, respectively. The red emitting layer comprises at least one host material and one emitting object. The host material can be a single material, a material with TADF properties, or a host material formed by blending P-type and N-type materials. The emitting object can be a phosphorescent material or a boron-containing fluorescent material. The thickness of each of emitting layers 9 and 19 can be adjusted between 30 and 80 nm. The materials of emitting layers 9 and 19 (the first red emitting layer and the second red emitting layer) can be the same or different.

[0103] For example, hole blocking layer 10 and hole blocking layer 20 can be referred to as the first hole blocking layer and the second hole blocking layer, respectively. The thickness of each of hole blocking layer 10 and hole blocking layer 20 is 5–30 nm. The T1 energy of the material in hole blocking layer 10 / 20 must be greater than the T1 energy of the TADF-characteristic material in the connected green emitting layer, for example, the difference must be no less than 0.2 eV. The absolute HOMO value of this layer material must be greater than the absolute HOMO values ​​of all connected emitting layer materials, for example, the difference must exceed 0.2 eV. The absolute LUMO value of this layer material must be less than the absolute LUMO values ​​of all connected emitting layer materials.

[0104] For example, charge generation layer 11 and charge generation layer 12 can be charge generation layer N-CGL and charge generation layer P-CGL, respectively. N-CGL is generally formed by doping electron transport materials with low work function active metals (such as Li, Ca, Yb, etc.), while P-CGL is generally formed by doping hole transport materials with P-type dopants (such as molybdenum oxide, etc.). The proportion of P-type dopants in P-CGL is higher than that in hole injection layer, which is beneficial for charge generation.

[0105] For example, the electron transport layer 21 can be formed by vapor deposition of a material with good electron transport properties, or it can be formed by doping an electron transport material with materials such as LiQ3, Li, and Ca in a certain proportion. The absolute LUMO values ​​of all materials in this layer must be greater than the absolute LUMO values ​​of the connected hole blocking layer (HBL) material. In some possible embodiments, considering device performance, an electron transport layer can also be added between the hole blocking layer 10 and the charge generation layer 11. This electron transport layer has the same function as the electron transport layer 21, and the materials can be the same or different.

[0106] For example, the electron injection layer 22 can be formed by vapor deposition using a low work function metal such as Li, Ca, Yb, or metal salts such as LiF and LiQ3. The thickness of the electron injection layer 22 is 0.5–2 nm.

[0107] For example, the second electrode 23 is a cathode. The second electrode 23 can be made of metals with low work function, such as Al, Ag, and Mg, or formed of an alloy containing metals with low work function. If designing a bottom-emitting device, the thickness of the second electrode 23 needs to exceed 80 nm to ensure good reflectivity (e.g., >85%@550nm). >85%@550nm indicates a reflectivity of >85% at 550 nm. If designing a top-emitting device, the thickness of the second electrode 23 needs to be adjusted within the range of 10–20 nm to ensure a certain transmittance (e.g., >45%@550nm). >45%@550nm indicates a transmittance of >45% at 550 nm.

[0108] For example, the optical capping layer (CPL) 24 is used to improve optical output. For example, the optical capping layer 24 can be formed by vapor deposition of small organic molecule materials in the 50–80 nm range. For example, the material of the optical capping layer 24 has a refractive index greater than 1.8 or less than 1.5 at 460 nm.

[0109] For example, the encapsulation layer (EPS) 25 can be made using UV frame adhesive or thin film encapsulation (TFE).

[0110] When designing a top-emitting device, the optical thickness of the light-emitting functional layer between the cathode and anode must meet the optical path requirements of the optical micro-resonator to obtain the optimal emitted light intensity and desired color. Generally, the internal optical path of the top-emitting device is adjusted by changing the thickness of the hole transport layer (HTL), which has a relatively small impact on voltage.

[0111] Eight embodiments and two comparative examples are given below for illustration. It should be noted that the following embodiments are used to illustrate how the display panel provided by the embodiments of this disclosure, when satisfying Relationship 1 and / or Relationship 2, facilitates the maximization of the color gamut of light synthesized from the three colors of the first sub-pixel, the second sub-pixel, and the third sub-pixel (R, G, B). The embodiments of this disclosure are not limited to the following specific embodiments. Those skilled in the art can adjust one or more layers, or adjust the material and / or thickness of one or more layers based on this disclosure, to obtain other embodiments.

[0112] Example 1: The light-emitting device in the display panel has the device structure shown in Figure 3.

[0113] Red: Ag(100nm) / ITO(8nm) / HT:p(10nm, 3%) / HT(B color adjustment) / R-EBL(R color adjustment) / RH:RD(3%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm, 10%) / HT / R-EBL(R color adjustment) / RH:RD(3%) / HB(5nm) / ET:LiQ(35nm, 50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0114] Blue: Ag(100nm) / ITO(8nm) / HT:p(10nm, 3%) / HT(B color adjustment) / B-EBL(5nm)(B color adjustment) / BH:BD(3%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm, 10%) / HT(B color adjustment) / B-EBL(5nm) / BH:BD(3%) / HB(5nm) / ET:LiQ(35nm, 50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0115] Green: Ag(100nm) / ITO(8nm) / HT:p(10nm,3%) / HT(B color adjustment) / G-CCL(G color adjustment) / G-EBL(5nm) / GH:G-TADF:GD(69%:30%:1.0%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm,10%) / HT / G-CCL(G color adjustment) / G-EBL(5nm) / GH:G-TADF:GD(69%:30%:1.0%) / HB(5nm) / ET:LiQ(35nm,50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0116] Examples 2 to 8 are the same as Example 1, except that the color of the green light emitting area (green light sub-pixel) in Examples 2 to 5 is adjusted as shown in Table 1, and the color of the red light emitting area (red light sub-pixel) in Examples 6 to 8 is adjusted as shown in Table 1.

[0117] Comparative Example 1: The light-emitting device in the display panel is shown in Figure 3, and its structure is as follows.

[0118] Red: Ag(100nm) / ITO(8nm) / HT:p(10nm,3%) / HT(B color adjustment) / R-EBL(R color adjustment) / RH:RD-1(3%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm,10%) / HT / R-EBL(R color adjustment) / RH:RD(3%) / HB(5nm) / ET:LiQ(35nm,50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0119] Blue: Ag(100nm) / ITO(8nm) / HT:p(10nm,3%) / HT(B color adjustment) / B-EBL(5nm) / BH:BD(3%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm,10%) / HT(B color adjustment) / B-EBL(5nm) / BH:BD(3%) / HB(5nm) / ET:LiQ(35nm,50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0120] Green: Ag(100nm) / ITO(8nm) / HT:p(10nm,3%) / HT(B color adjustment) / G-CCL(G color adjustment) / G-EBL(5nm) / GH:G-TADF:GD(69%:30%:1.0%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm,10%) / HT / G-CCL(G color adjustment) / G-EBL(5nm) / GH:G-TADF:GD(69%:30%:1.0%) / HB(5nm) / ET:LiQ(35nm,50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0121] Comparative Example 2: The light-emitting device in the display panel is shown in Figure 3, and its structure is as follows.

[0122] Red: Ag(100nm) / ITO(8nm) / HT:p(10nm,3%) / HT(B color adjustment) / R-EBL(R color adjustment) / RH:RD-2(3%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm,10%) / HT / R-EBL(R color adjustment) / RH:RD(3%) / HB(5nm) / ET:LiQ(35nm,50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0123] Blue: Ag(100nm) / ITO(8nm) / HT:p(10nm,3%) / HT(B color adjustment) / B-EBL(5nm) / BH:BD(3%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm,10%) / HT(B color adjustment) / B-EBL(5nm) / BH:BD(3%) / HB(5nm) / ET:LiQ(35nm,50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0124] Green: Ag(100nm) / ITO(8nm) / HT:p(10nm,3%) / HT(B color adjustment) / G-CCL(G color adjustment) / G-EBL(5nm) / GH:G-TADF:GD(69%:30%:1.0%) / HB(5nm) / n-CG:Yb(1%) / HT:p(10nm,10%) / HT / G-CCL(G color adjustment) / G-EBL(5nm) / GH:G-TADF:GD(69%:30%:1.0%) / HB(5nm) / ET:LiQ(35nm,50%:50%) / EIL(1nm) / Mg:Ag(15nm) / CPL.

[0125] In the descriptions of Comparative Examples 1, 2, and Examples 1 to 8 above, the red sub-pixels, green sub-pixels, and blue sub-pixels are described in the order from bottom to top in Figure 3 up to the optical cover layer CPL.

[0126] In the descriptions of Comparative Examples 1, 2, and Examples 1 to 8 above, the units in parentheses represent thickness in nanometers, and the percentages represent the doping ratio. Substance X: Substance Y indicates the inclusion of Substance X and Substance Y; RH and RD represent the host material and dopant material in the red emitting layer, respectively; GH and GD represent the host material and dopant material in the green emitting layer, respectively; BH and BD represent the host material and dopant material in the blue emitting layer, respectively; HB represents a material with hole-blocking properties; HT represents a material with hole transport properties; ET represents a material with electron transport properties; CG represents a material with charge generation properties; p represents a p-type dopant material; n represents an n-type dopant material; TADF represents a material with thermally activated delayed fluorescence characteristics; LiQ represents 8-hydroxyquinoline-lithium; RD-1 uses a material with a CIEx of approximately 0.680; RD-2 uses a material with a CIEx of approximately 0.704. HT (B color adjustment) refers to the thickness of the hole transport layer HTL, adjusted to meet the blue light color coordinates.

[0127] The various embodiments are described below with reference to Figure 3.

[0128] In Comparative Examples 1, 2, and Examples 1 to 8 above, the material of the first electrode 1 includes an Ag layer and an ITO layer. The thickness of the Ag layer is 100 nm and the thickness of the ITO layer is 8 nm, which is expressed as Ag(100 nm) / ITO(8 nm).

[0129] In Comparative Examples 1, 2, and Examples 1 to 8 above, the hole injection layer 2 has a thickness of 10 nm and is a p-type doped material with hole transport characteristics, with a doping amount of 3%. The hole transport characteristics material is an axial olefin organic material, denoted as HT:p(10 nm, 3%).

[0130] In Comparative Examples 1, 2, and Examples 1 to 8 above, the hole transport layer 3 / 13 is made of a material with hole transport properties, specifically carbazole, and the thickness of the hole transport layer 3 is [missing information]. The thickness of hole transport layer 13 is Hole transport layer 3 is represented as HT (B color adjustment), and hole transport layer 13 is represented as HT.

[0131] In Comparative Examples 1, 2, and Examples 1 to 8 above, the color adjustment layer 6 / 16 is made of a material with electron-blocking properties, and the material with electron-blocking properties has a thickness of [missing information]. It is represented as R-EBL (R color adjustment).

[0132] In Examples 1 to 8 above, the light-emitting layer 9 / 19 uses a host material RH and a dopant material RD, with a doping amount of 3%, expressed as RH:RD(3%). The host material RH and the dopant material RD can be selected from common materials. The light-emitting layer 9 / 19 in each embodiment can use the same material, or different materials can be used.

[0133] In Comparative Examples 1, 2, and Examples 1 to 8 above, the color adjustment layer 5 / 15 uses a material with electron blocking properties. This electron blocking material can be selected from common materials. The color adjustment layer 5 / 15 in Comparative Examples 1, 2, and each embodiment can use the same material; however, different materials can also be used. The thickness of the color adjustment layer 5 / 15 is... It is represented as B-EBL (B color adjustment).

[0134] In Examples 1 to 8 above, the light-emitting layer 7 / 17 uses a host material BH and a dopant material BD, with a doping amount of 3%, expressed as BH:BD(3%). The host material BH and the dopant material BD can be selected from common materials. The light-emitting layer 7 / 17 in each embodiment can use the same material, or different materials can be used.

[0135] In Comparative Examples 1, 2, and Examples 1 to 8 above, the color adjustment auxiliary layer 4-1 / 14-1 can be selected from materials with good hole transport properties. The color adjustment auxiliary layer 4-1 / 14-1 in each embodiment can use the same material, or different materials can be used. The thickness of the color adjustment auxiliary layer 4-1 / 14-1 is... This is represented as G-CCL (G Color Adjustment). For example, the color adjustment auxiliary layer 4-1 / 14-1 can use a hole-type carbazole.

[0136] In Comparative Examples 1, 2, and Examples 1 to 8 above, the color adjustment layer 4 / 14 is made of a material with electron blocking properties. This material can be a material with hole transport properties. The color adjustment layer 4 / 14 in Comparative Examples 1, 2, and each example can use the same material, or different materials can be used. The thickness of the color adjustment layer 4 / 14 is 5 nm, denoted as G-EBL (5 nm).

[0137] In Examples 1 to 8 above, the luminescent layer 8 / 18 uses a host material GH, a material with thermally activated delayed fluorescence (G-TADF), and a dopant material GD, with the proportions of GH, G-TADF, and GD being 69%, 30%, and 1.0%, respectively, expressed as GH:G-TADF:GD (69%:30%:1.0%). The host material GH, dopant material GD, and G-TADF can be selected from common materials. The luminescent layer 8 / 18 in each embodiment can use the same material, or different materials can be used. The thickness of the luminescent layer 8 / 18 is...

[0138] In Comparative Examples 1, 2, and Examples 1 to 8 above, the hole blocking layer 10 / 20 is made of a material with hole blocking properties and has a thickness of 5 nm, denoted as HB (5 nm). The hole blocking layer 10 / 20 in each embodiment can be made of the same material, or different materials can be used.

[0139] In Comparative Examples 1, 2, and Examples 1 to 8 above, the charge generation layer 11 is made of a material with charge generation properties and doped with Yb. This charge generation material can be selected from common materials and is represented as n-CG:Yb(1%). The thickness of the charge generation layer 11 is approximately 10-18 nm. The charge generation layer 11 in Comparative Examples 1, 2, and each embodiment can use the same material, or different materials can be used.

[0140] In Comparative Examples 1, 2, and Examples 1 to 8 above, the charge generation layer 12 is made of a material with charge generation properties and is p-type doped. This material with charge generation properties can be selected from common materials. The thickness of the charge generation layer 12 is 10 nm, denoted as HT:p(10 nm, 10%). The charge generation layer 12 in Comparative Examples 1, 2, and each embodiment can use the same material, or different materials can be used.

[0141] In Comparative Examples 1, 2, and Examples 1 to 8 above, the electron transport layer 21 uses a material with electron transport properties and LiQ. This material with electron transport properties can be selected from common materials. The thickness of the electron transport layer 21 is 35 nm, and the electron transport layer 21 is represented as ET:LiQ(35 nm, 50%:50%). The electron transport layer 21 in Comparative Examples 1, 2, and each embodiment can use the same material; of course, different materials can also be used.

[0142] In Comparative Examples 1, 2, and Examples 1 to 8 above, the material of the electron injection layer 22 can be selected from common materials, and the thickness is 1 nm. The electron injection layer 22 is denoted as EIL (1 nm). The electron injection layer 22 in Comparative Examples 1, 2, and each embodiment can use the same material, or different materials can be used.

[0143] In Comparative Examples 1, 2, and Examples 1 to 8 above, the second electrode 23 was made of Mg and Ag, and the thickness of the second electrode 23 was 15 nm, expressed as Mg:Ag(15 nm). The second electrode 23 of Comparative Examples 1, 2, and each example can use the same material, or of course, different materials can be used.

[0144] In Comparative Examples 1, 2, and Examples 1 to 8 above, the material of the optical cover layer (CPL) 24 can be selected from common materials, and the thickness is approximately 55-95 nm. The optical cover layer (CPL) 24 of Comparative Examples 1, 2, and each embodiment can use the same material, or different materials can be used.

[0145] In Comparative Example 1, the light-emitting layer 9 uses a host material RH and a dopant material RD-1, with a doping amount of 3%, expressed as RH:RD-1(3%). The host material RH can be selected from common materials, and the dopant material RD-1 uses a material with a CIEx of approximately 0.680.

[0146] In Comparative Example 2, the light-emitting layer 9 uses a host material RH and a dopant material RD-2, with a doping amount of 3%, expressed as RH:RD-1(3%). The host material RH can be selected from common materials, and the dopant material RD-2 is a material with a CIEx of approximately 0.704.

[0147] Table 1. Energy levels, excited-state energies, and mobility of some of the materials involved.

[0148] Table 2. Device Characteristics

[0149] Table 3. Device Characteristics

[0150] The table above provides the specific values ​​of parameters CIEx, CIEy, FWHM(EL), and FWHM(PL) in Comparative Example 1, Comparative Example 2, and Relationship 1 and Relationship 2 in each embodiment.

[0151] Those skilled in the art can adjust various parameters of the display panel, such as the film layer settings, film layer materials, and film layer thickness, based on the CIEx and CIEy specified in this disclosure.

[0152] Those skilled in the art can adjust various parameters of the display panel, such as the film layer settings, film layer materials, and film layer thickness, according to the WHM(EL) and FWHM(PL) given in this disclosure.

[0153] Those skilled in the art can adjust various parameters of the display panel, such as the film layer settings, film layer materials, and film layer thickness, based on CIEx, CIEy, FWHM(EL), and FWHM(PL) provided in this disclosure.

[0154] In the table above, CIE1931 refers to the CIE1931 color space, and CIE1976 refers to the CIE1976 color space.

[0155] In the table above, FWHM(EL) represents the full width at half maximum (FWHM) of the electroluminescence spectrum, and FWHM(PL) represents the full width at half maximum (FWHM) of the photoluminescence spectrum.

[0156] The white light color coordinates synthesized in all the above embodiments and comparative examples are (0.31, 0.32). The area ratios shown in Tables 2 and 3 refer to the ratio of the area enclosed by the R, G, and B points of the embodiments to the area of ​​the BT2020 color gamut. The color gamut standard refers to CIE1931.

[0157] Figure 4 is a color gamut coordinate diagram of the display panel provided in Embodiments 1 to 5 of this disclosure. Figure 5 is a color gamut coordinate diagram of the display panel provided in Comparative Example 1, Comparative Example 2, Embodiment 2 of this disclosure, and Embodiments 6 to 8.

[0158] For Examples 1 to 5, with R and B unchanged, the color change of the green photon sub-pixel (green light-emitting area) is adjusted by G-CCL. As indicated by the arrows in Figure 4, the color gamut horizontal coordinate (G CIEx) of the green light gradually increases. At this time, the relative position of the green light color coordinate and the blue light color coordinate has the greatest impact on the entire color gamut. The larger the difference between G CIEx and the blue light color gamut horizontal coordinate (B CIEx), the smaller the color gamut area ratio, and the smaller the corresponding color gamut area covering BT2020, that is, the smaller the display color gamut range. When the difference between G CIEx and B CIEx is large, that is, when G CIEx is too small or too large, it exceeds the optimal color coordinate range of the doped material (GD) of the green light-emitting layer. Therefore, under the action of the microcavity, it will lead to a decrease in light extraction efficiency and color shift problems at different viewing angles.

[0159] Compared to Comparative Example 1, the optimal color coordinate range of the doped material (RD) in the red light emitting layer used in Examples 2, 6 to 8 is (0.700, 0.300) to (0.706, 0.294), while the optimal range of RD in Comparative Example 1 is (0.680, 0.320) to (0.690, 0.310). Since the chromaticity gamut abscissa (R CIEx) of red light is in the range of 0.680 to 0.700, changes in color coordinates have a significant impact on the gamut. Therefore, an RD with R CIEx ≥ 0.700 is required. As shown in Figure 5, the increase in R CIEx in Examples 2, 6 to 8 has a relatively small impact on the gamut.

[0160] Compared with Comparative Example 2, although the color gamut is the same, the light extraction efficiency is reduced due to the wider full width at half maximum (FWHM) of the intrinsic photoluminescence spectrum (PL) of the RD used in Comparative Example 2, which in turn reduces the white light efficiency and leads to an increase in device power consumption.

[0161] Therefore, by matching appropriate luminescent materials under the RGBW color coordinate scheme, a display effect with the closest color gamut range to BT2020 and the best viewing angle color bias can be obtained, while achieving high efficiency and low power consumption device performance.

[0162] Embodiments of this disclosure also provide a display device, including any of the above-described display panels.

[0163] For example, display devices include OLED display devices or any product or device with display functionality, such as computers, mobile phones, watches, electronic picture frames, and navigators that include such display devices.

[0164] The following points need to be explained:

[0165] (1) Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components.

[0166] (2) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.

[0167] (3) For clarity, the thickness of layers or regions is magnified in the drawings used to describe embodiments of the present disclosure. It will be understood that when an element such as a layer, film, region or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element, or there may be intermediate elements present.

[0168] (4) Where there is no conflict, the embodiments of this disclosure and the features in the embodiments can be combined with each other.

[0169] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A display panel comprising a plurality of sub-pixels, wherein, The plurality of sub-pixels includes a plurality of first sub-pixels, a plurality of second sub-pixels, and a plurality of third sub-pixels, wherein the first sub-pixels are configured to emit a first color of light, the second sub-pixels are configured to emit a second color of light, and the third sub-pixels are configured to emit a third color of light. The first sub-pixel, the second sub-pixel, and the third sub-pixel satisfy at least one of the following relationships: Relationship 1: The difference between the x-coordinate of the color gamut of the second color light and the x-coordinate of the color gamut of the third color light is within ±0.02 of the y-coordinate of the color gamut of the third color light, and the y-coordinate of the color gamut of the first color light is not greater than the x-coordinate and / or y-coordinate of the color gamut of the white point synthesized by the first color light, the second color light and the third color light. Relationship 2: The difference between the maximum and minimum values ​​of the full width at half maximum (FWHM) of the electroluminescence spectra of the first sub-pixel, the second sub-pixel, and the third sub-pixel is less than or equal to 11 nm, and the difference between the FWHM of the electroluminescence spectrum and the photoluminescence spectrum of each of the first sub-pixel, the second sub-pixel, and the third sub-pixel is less than or equal to 16 nm.

2. The display panel according to claim 1, wherein, The sub-pixel includes two tandemly connected light-emitting units, each of which includes a light-emitting layer.

3. The display panel according to claim 2, wherein, The first sub-pixel's light-emitting layer includes a phosphorescent material, the second sub-pixel's light-emitting layer includes a sensitized fluorescent material, and the third sub-pixel's light-emitting layer includes a fluorescent material.

4. The display panel according to claim 2 or 3, wherein, In the first sub-pixel, the second sub-pixel, and the third sub-pixel, the light-emitting layer of at least one light-emitting unit of a sub-pixel includes at least three material components, the at least three material components including a material containing boron and / or a delayed fluorescence material.

5. The display panel according to claim 4, wherein, The doping ratio of the boron-containing material is less than 5%.

6. The display panel according to claim 4 or 5, wherein, The doping ratio of the boron-containing material is less than 3%.

7. The display panel according to claim 4, wherein, The doping ratio of the delayed fluorescence material is less than 49%.

8. The display panel according to claim 4, wherein, In the first sub-pixel, the second sub-pixel, and the third sub-pixel, the light-emitting layer of at least one light-emitting unit of a sub-pixel comprises two material components, and the doping material of one of the material components contains a metal element.

9. The display panel according to claim 8, wherein, The metal element is a transition metal element.

10. The display panel according to claim 9, wherein, The transition metal elements include Ir, Pt, Os, and Ru.

11. The display panel according to claim 8, wherein, The metallic elements include rare earth metallic elements.

12. The display panel according to claim 11, wherein, The rare earth metal elements include La, Ce, Eu, and Tb.

13. The display panel according to any one of claims 8-12, wherein, The doping ratio of the doped material is less than 10%.

14. The display panel according to claim 13, wherein, The doping ratio of the doped material is less than 5%.

15. The display panel according to any one of claims 2-14, wherein, The light-emitting layers of different light-emitting units in the same sub-pixel are the same.

16. The display panel according to any one of claims 2-14, wherein, The light-emitting layers of different light-emitting units in the same sub-pixel are different.

17. The display panel according to any one of claims 2-16, wherein, The wavelength of the first color light is greater than the wavelength of the second color light, and the wavelength of the second color light is greater than the wavelength of the third color light.

18. The display panel according to claim 17, wherein, The first color light is red light, the second color light is green light, and the third color light is blue light.

19. The display panel according to any one of claims 1-18, wherein, The sub-pixel includes a first electrode and a second electrode, and the light-emitting unit is located between the first electrode and the second electrode. The light-emitting unit of at least one of the first sub-pixel and the second sub-pixel also includes a color adjustment layer. In the same light-emitting unit, the color adjustment layer is located on the side of the light-emitting layer closer to the first electrode.

20. The display panel according to claim 19, wherein, The light-emitting unit further includes a color adjustment auxiliary layer, which is located on the side of the color adjustment layer away from the light-emitting layer.

21. A display device comprising a display panel according to any one of claims 1-20.

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