Display panel and display device

Abstract

The display panel comprises a first electrode layer, a second electrode layer and a light-emitting layer, the first electrode layer comprises a reflection electrode layer, the second electrode layer and the first electrode layer are oppositely arranged, and the second electrode layer comprises a semi-transparent and semi-reflection electrode layer; the light-emitting layer is located between the first electrode layer and the second electrode layer, the light-emitting layer comprises a plurality of light-emitting parts, and the materials of the plurality of light-emitting parts comprise a main body material and a light-emitting material; the plurality of light-emitting parts comprise a plurality of red light-emitting parts, a plurality of blue light-emitting parts and a plurality of green light-emitting parts; wherein the light-emitting material of at least one of the plurality of red light-emitting parts comprises a dark red phosphorescent material, and the peak range of the photoluminescence spectrum of the dark red phosphorescent material is 630-650 nm.

Description

Display panel and display device Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a display panel and a display device. Background Art

[0002] Active-matrix organic light-emitting devices (AMOLEDs) offer advantages such as low power consumption, high contrast, and vibrant colors. As demand for higher-quality graphics in gaming, audiovisual, and desktop computers with integrated AMOLED displays increases, high-color-gamut display technologies, such as HDR (High Dynamic Range Image) and matching the BT2020 color gamut standard, have emerged.

[0003] Summary of the Invention

[0004] In one aspect, a display panel is provided, comprising: a first electrode layer, a second electrode layer, and a light-emitting layer. The first electrode layer comprises a reflective electrode layer, and the second electrode layer is disposed opposite the first electrode layer and comprises a semi-transmissive and semi-reflective electrode layer. The light-emitting layer is located between the first and second electrode layers. The light-emitting layer comprises multiple light-emitting sections, each of which comprises a host material and a light-emitting material. The multiple light-emitting sections comprise multiple red light-emitting sections, multiple blue light-emitting sections, and multiple green light-emitting sections. The light-emitting material of at least one of the multiple red light-emitting sections comprises a deep red phosphorescent material, and the peak photoluminescence spectrum of the deep red phosphorescent material ranges from 630 nm to 650 nm.

[0005] In some embodiments, the color coordinate Rx of the red light emitted by the deep red phosphorescent material ranges from 0.703 to 0.705.

[0006] In some embodiments, the deep red phosphorescent material is selected from any one of an iridium complex, a platinum complex, a zinc complex, a lithium complex, and a beryllium complex.

[0007] In some embodiments, at least one of the multiple green light-emitting portions further includes a green thermally activated delayed fluorescent material, and the luminescent material of the green light-emitting portion includes a dark green fluorescent material, and the peak range of the photoluminescence spectrum of the dark green fluorescent material is 500nm to 520nm.

[0008] In some embodiments, the color coordinate Gx of the green light emitted by the deep green fluorescent material ranges from 0.155 to 0.165.

[0009] In some embodiments, the deep green fluorescent material is selected from any one of coumarins, carbazole derivatives, diaminoanthracene derivatives, and pyrazoloquinoxaline derivatives.

[0010] In some embodiments, the display panel further includes a covering layer, wherein the covering layer is disposed on a side of the second electrode layer away from the light-emitting layer, and the thickness of the second electrode layer is in the range of The thickness of the covering layer is in the range of

[0011] In some embodiments, the display panel further includes a first encapsulation layer disposed on a side of the cover layer away from the second electrode layer. The first encapsulation layer is a multilayer structure comprising a first encapsulation sublayer, a second encapsulation sublayer, and a third encapsulation sublayer, disposed sequentially away from the cover layer. The refractive index of the cover layer is greater than that of the first encapsulation sublayer, the refractive index of the first encapsulation sublayer is less than that of the second encapsulation sublayer, and the refractive index of the second encapsulation sublayer is greater than that of the third encapsulation sublayer.

[0012] In some embodiments, the refractive index of the cover layer ranges from 1.7 to 1.8, the refractive index of the first encapsulation sublayer ranges from 1.4 to 1.52, the refractive index of the second encapsulation sublayer ranges from 1.7 to 1.8, and the refractive index of the third encapsulation sublayer ranges from 1.55 to 1.65.

[0013] In some embodiments, the display panel further includes: an optical regulation layer and a first encapsulation layer, which are arranged on a side of the cover layer away from the second electrode layer; the first encapsulation layer is a single-layer structure, which is arranged on a side of the optical regulation layer away from the cover layer.

[0014] In some embodiments, the display panel further includes: a second encapsulation layer and a third encapsulation layer, which are sequentially disposed on a side of the first encapsulation layer away from the covering layer.

[0015] In some embodiments, when the display panel includes a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer, the material of the first encapsulation layer includes silicon oxynitride, the material of the second encapsulation layer includes an inkjet-printed organic material, and the material of the third encapsulation layer includes silicon nitride.

[0016] In another aspect, a display panel is provided, comprising: a first electrode layer, a second electrode layer, and a light-emitting layer, wherein the first electrode layer comprises a reflective electrode layer, and the second electrode layer is disposed opposite the first electrode layer and comprises a semi-transmissive and semi-reflective electrode layer. The light-emitting layer is located between the first and second electrode layers; the light-emitting layer comprises a plurality of light-emitting portions, the materials of the plurality of light-emitting portions comprising: a host material and a light-emitting material; the plurality of light-emitting portions comprises a plurality of red light-emitting portions, a plurality of blue light-emitting portions, and a plurality of green light-emitting portions.

[0017] The luminescent material of the red light-emitting portion further includes a red thermally activated delayed fluorescent material and a deep red fluorescent material. The peak photoluminescence spectrum of the deep red fluorescent material is in the range of 630 nm to 650 nm. In the red light-emitting portion, the ratio of the mass of the deep red fluorescent material to the sum of the mass of the host material, the red thermally activated delayed fluorescent material, and the deep red fluorescent material is in the range of 0.4% to 0.6%.

[0018] In some embodiments, the color coordinate Rx of the red light emitted by the deep red fluorescent material ranges from 0.703 to 0.705.

[0019] In some embodiments, the deep red fluorescent material comprises any one of DCM series dopants, DCM derivative dopants, auxiliary dopants, conjugated fused rings, porphyrin macrocycles, and aromatic acids.

[0020] In some embodiments, at least one of the multiple green light-emitting portions further includes a green thermally activated delayed fluorescent material, and the luminescent material of the green light-emitting portion includes a dark green fluorescent material, and the peak range of the photoluminescence spectrum of the dark green fluorescent material is 500nm to 520nm.

[0021] In some embodiments, the color coordinate Gx of the green light emitted by the deep green fluorescent material ranges from 0.155 to 0.165.

[0022] In some embodiments, the deep green fluorescent material is selected from any one of coumarins, carbazole derivatives, diaminoanthracene derivatives, and pyrazoloquinoxaline derivatives.

[0023] In another aspect, a display panel is provided, comprising: a first electrode layer, a second electrode layer, and a light-emitting layer, wherein the first electrode layer comprises a reflective electrode layer, and the second electrode layer is disposed opposite the first electrode layer and comprises a transflective electrode layer. The light-emitting layer is located between the first and second electrode layers; the light-emitting layer comprises a plurality of light-emitting portions, the materials of the plurality of light-emitting portions comprising: a host material and a light-emitting material; the plurality of light-emitting portions comprises a plurality of red light-emitting portions, a plurality of blue light-emitting portions, and a plurality of green light-emitting portions.

[0024] At least one of the multiple green light-emitting portions further comprises a green thermally activated delayed fluorescent material, and the luminescent material of the green light-emitting portion comprises a dark green fluorescent material, the peak range of the photoluminescence spectrum of the dark green fluorescent material is 500nm to 520nm.

[0025] In some embodiments, the color coordinate Gx of the green light emitted by the deep green fluorescent material ranges from 0.155 to 0.165.

[0026] In some embodiments, the deep green fluorescent material is selected from any one of coumarins, carbazole derivatives, diaminoanthracene derivatives, and pyrazoloquinoxaline derivatives.

[0027] On the other hand, a display device is provided, comprising: a display panel as described in any of the above embodiments; and a driving chip for driving the display panel to perform display. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0029] FIG1 is a structural diagram of a display device according to some embodiments of the present disclosure;

[0030] FIG2 is a structural diagram of a display panel provided according to some embodiments of the present disclosure;

[0031] FIG3 is a spectrum diagram of different luminescent materials provided according to some embodiments of the present disclosure;

[0032] FIG4 is a diagram showing test results of the relationship between color coordinates and luminous efficiency according to some embodiments of the present disclosure;

[0033] FIG5 is a diagram showing test results of color coordinate relationships according to some embodiments of the present disclosure;

[0034] FIG6 is a diagram showing test results of the relationship between color coordinates and color gamut according to some embodiments of the present disclosure;

[0035] FIG7 is a diagram showing test results of the relationship between color coordinates and color gamut coverage according to some embodiments of the present disclosure;

[0036] FIG8 is a diagram of color coordinate test results provided according to some embodiments of the present disclosure;

[0037] FIG9 is a diagram showing the results of a white light visual color deviation test according to some embodiments of the present disclosure;

[0038] FIG10 is a graph showing the test results of a white light viewing angle brightness attenuation curve according to some embodiments of the present disclosure;

[0039] FIG11 is a diagram showing a test result of a red light viewing angle brightness attenuation curve according to some embodiments of the present disclosure;

[0040] FIG12 is a graph showing a green light viewing angle brightness attenuation curve test result according to some embodiments of the present disclosure;

[0041] FIG13 is a graph showing a test result of a blue light viewing angle brightness attenuation curve according to some embodiments of the present disclosure;

[0042] FIG14 is another color coordinate test result diagram provided according to some embodiments of the present disclosure;

[0043] FIG15 is another diagram showing the results of a white light visual color deviation test according to some embodiments of the present disclosure;

[0044] FIG16 is a structural diagram of another display panel provided according to some embodiments of the present disclosure;

[0045] FIG17 is a diagram showing another red light viewing angle brightness attenuation curve test result according to some embodiments of the present disclosure;

[0046] FIG18 is a graph showing another green light viewing angle brightness attenuation curve test result according to some embodiments of the present disclosure;

[0047] FIG19 is a graph showing another test result of a blue light viewing angle brightness attenuation curve according to some embodiments of the present disclosure;

[0048] FIG20 is a diagram showing another color coordinate test result according to some embodiments of the present disclosure;

[0049] FIG21 is a diagram showing another white light visual color deviation test result according to some embodiments of the present disclosure;

[0050] FIG22 is a diagram showing another test result of a red light viewing angle brightness attenuation curve according to some embodiments of the present disclosure;

[0051] FIG23 is a graph showing another green light viewing angle brightness attenuation curve test result according to some embodiments of the present disclosure;

[0052] FIG24 is a diagram showing another test result of a blue light viewing angle brightness attenuation curve according to some embodiments of the present disclosure;

[0053] FIG25 is a diagram showing another color coordinate test result according to some embodiments of the present disclosure;

[0054] FIG26 is a diagram showing another white light visual color deviation test result according to some embodiments of the present disclosure;

[0055] FIG27 is another test result diagram of the relationship between color coordinates and luminous efficiency according to some embodiments of the present disclosure;

[0056] FIG28 is a diagram showing another test result of a color coordinate relationship according to some embodiments of the present disclosure;

[0057] FIG29 is a diagram showing another test result of the relationship between color coordinates and color gamut according to some embodiments of the present disclosure;

[0058] FIG30 is a test result diagram of another relationship between color coordinates and color gamut coverage provided according to some embodiments of the present disclosure;

[0059] FIG31 is a diagram showing another color coordinate test result according to some embodiments of the present disclosure;

[0060] FIG32 is a diagram showing another white light visual color deviation test result according to some embodiments of the present disclosure;

[0061] FIG33 is a diagram showing another white light viewing angle brightness attenuation curve test result according to some embodiments of the present disclosure;

[0062] FIG34 is a spectrum diagram of different luminescent materials provided according to some embodiments;

[0063] FIG35 is a test result diagram showing the relationship between the doping concentration of a luminescent material and luminous efficiency and color coordinates according to some embodiments of the present disclosure;

[0064] FIG36 is a test result diagram of another relationship between color coordinates and color gamut coverage according to some embodiments of the present disclosure;

[0065] FIG37 is a diagram showing another color coordinate test result according to some embodiments of the present disclosure;

[0066] FIG38 is a diagram showing another white light visual color deviation test result according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0067] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0068] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0069] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0070] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0071] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0072] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0073] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0074] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0075] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0076] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0077] Some embodiments of the present disclosure provide a display device. The display device provided by the embodiments of the present disclosure can be any device that displays whether it is moving (e.g., video) or fixed (e.g., still image) and whether it is text or image. More specifically, it is expected that the embodiments can be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, cameras, game consoles, watches, clocks, calculators, television monitors, flat-panel displays, computer monitors, car displays (e.g., odometer displays, etc.), navigators, cockpit controls and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photos, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0078] As shown in FIG1 , the embodiment of the present disclosure uses a mobile phone 1000 as an example display device. Mobile phone 1000 includes a display panel 100, a frame, a circuit board, a driver chip, and other electronic components. Display panel 100 is disposed within the frame, and the driver chip is used to drive display panel 100 for display.

[0079] In some embodiments, as shown in FIG2 , a display panel 100 includes a light-emitting device 10. For example, the light-emitting device 10 includes an active matrix organic light-emitting device (AMOLED). The AMOLED matches the BT2020 color gamut standard, i.e., Rx is 0.708, Ry is 0.292, Gx is 0.17, Gy is 0.797, Bx is 0.131, and By is 0.046. AMOLED high color gamut technology development targets a BT2020 color gamut coverage of ≥93% @CIE1931 or ≥95% @CIE1976. Rx and Ry are the color coordinates of red, Gx and Gy are the color coordinates of green, and Bx and By are the color coordinates of blue. Conventional AMOLED can achieve a By of 0.046. The difficulty lies in achieving deep red Rx ≥ 0.705 and deep green Gx ≤ 0.17.

[0080] It should be noted that BT2020 refers to the color gamut standard. 93% BT2020 means that the color gamut coverage accounts for 93% of the BT2020 color gamut range. "@CIE1931" and "@CIE1976" refer to different color coordinate standards. For example, "93% BT2020 color gamut coverage @CIE1931" means that the color gamut coverage accounts for 93% of the BT2020 color gamut range within the 1931 standard system; "95% BT2020 color gamut coverage @CIE1976" means that the color gamut coverage accounts for 95% of the BT2020 color gamut range within the 1976 standard system.

[0081] Based on this, as shown in Figure 2, an embodiment of the present disclosure provides a display panel 100, which includes: a first electrode layer 101 and a second electrode layer 102, the first electrode layer 101 includes a reflective electrode layer, the second electrode layer 102 is arranged opposite to the first electrode layer 101, and the second electrode layer 102 includes a semi-transmissive and semi-reflective electrode layer.

[0082] The display panel 100 further includes a light emitting layer 11 , which is located between the first electrode layer 101 and the second electrode layer 102 .

[0083] It should be noted that the first electrode layer 101, the light-emitting layer 11, and the second electrode layer 102 form the light-emitting device 10, wherein the first electrode layer 101 is the anode of the light-emitting device 10, and the second electrode layer 102 is the cathode of the light-emitting device 10; alternatively, the first electrode layer 101 is the cathode of the light-emitting device 10, and the second electrode layer 102 is the anode of the light-emitting device 10. The embodiments of the present disclosure are described by taking the first electrode layer 101 as the anode of the light-emitting device 10 and the second electrode layer 102 as the cathode of the light-emitting device 10 as an example.

[0084] Exemplarily, the first electrode layer 101 includes a reflective electrode layer, that is, the first electrode layer 101 includes a reflective electrode, which is used to reflect light incident on the first electrode layer 101. The first electrode layer 101 can have a single-layer structure or a stacked structure. The reflective electrode refers to an electrode with a reflectivity greater than 90%.

[0085] The second electrode layer 102 includes a semi-transmissive, semi-reflective electrode layer. That is, the second electrode layer 102 includes a semi-transmissive, semi-reflective electrode that is configured to reflect some of the light that strikes the second electrode layer 102 and also to transmit some of the light that strikes the second electrode layer 102. A semi-transmissive, semi-reflective electrode refers to an electrode having a reflectivity of 50% to 60%. Thus, the first electrode layer 101 and the second electrode layer 102 form a resonant cavity. The light-emitting layer 11 is located between the first electrode layer 101 and the second electrode layer 102, i.e., the light-emitting layer 11 is located within the resonant cavity. The intensity of light of a certain wavelength emitted by the light-emitting layer 11 is increased, and the spectrum of the light of a certain wavelength is narrowed. The resonant cavity allows most of the light emitted by the light-emitting layer 11 to exit the display panel 100 through the second electrode layer 102, thereby improving the luminous efficiency of the light-emitting device 10.

[0086] 2 , at least one of a hole injection layer 103, a hole transport layer 104, and an electron blocking layer 105 is further provided between the first electrode layer 101 and the light-emitting layer 11. At least one of an electron injection layer 106, an electron transport layer 107, and a hole blocking layer 108 is further provided between the second electrode layer 102 and the light-emitting layer 11.

[0087] When the light-emitting device 10 includes a hole injection layer 103, a hole transport layer 104, and an electron blocking layer 105, the hole injection layer 103, the hole transport layer 104, and the electron blocking layer 105 are sequentially stacked in a direction away from the first electrode layer 101. When the light-emitting device 10 includes an electron injection layer 106, an electron transport layer 107, and a hole blocking layer 108, the electron injection layer 106, the electron transport layer 107, and the hole blocking layer 108 are sequentially stacked in a direction away from the second electrode layer 102.

[0088] The light-emitting layer 11 includes a plurality of light-emitting sections, and the materials of the light-emitting sections include a host material and a light-emitting material. The light-emitting sections include a plurality of red light-emitting sections 12 , a plurality of blue light-emitting sections 14 , and a plurality of green light-emitting sections 13 .

[0089] It should be noted that the red light-emitting unit 12 is configured to emit red light, the blue light-emitting unit 14 is configured to emit blue light, and the green light-emitting unit 13 is configured to emit green light. The cooperation of multiple red light-emitting units 12, multiple blue light-emitting units 14, and multiple green light-emitting units 13 can achieve full-color display on the display panel 100. For example, the cooperation of multiple red light-emitting units 12, multiple blue light-emitting units 14, and multiple green light-emitting units 13 can enable the display panel 100 to display a white image.

[0090] The luminescent material of at least one of the multiple red luminescent portions 12 includes a deep red phosphorescent material, and the peak range of the photoluminescence spectrum of the deep red phosphorescent material is 630 nm to 650 nm.

[0091] It should be noted that the singlet excitons and triplet excitons generated by the phosphorescent material upon excitation can emit light when transitioning to the ground state, so that the IQE (Internal Quantum Efficiency) of the phosphorescent light emitting device 10 reaches 100%.

[0092] As shown in FIG3 and Table 1, conventional red light materials are, for example, conventional red fluorescent materials, and deep red light materials are, for example, deep red phosphorescent materials. Compared to conventional red light materials, the peak of the photoluminescence (PL) spectrum of the deep red light material is red-shifted by 10 nm to 20 nm. Since the peak of the photoluminescence spectrum of the luminescent material of the red light-emitting portion 12 is required to be greater than or equal to 630 nm, the use of a deep red phosphorescent material with a peak photoluminescence spectrum in the range of 630 nm to 650 nm can meet the requirements of high color gamut technology development.

[0093] It should be noted that after being excited, the fluorescent material will generate singlet excitons and triplet excitons in a ratio of 25:75. 25% of the singlet excitons emit fluorescence when transitioning to the ground state, and 75% of the triplet excitons do not emit light when transitioning to the ground state.

[0094] Table 1 Photoluminescence spectra of different materials

[0095] In some examples, as shown in FIG4 , the optimal color coordinate range of the luminous efficiency of the light-emitting device 10 made of conventional red light material is Rx<0.695. When the microcavity length of the light-emitting device 10 is forcibly increased to increase the color coordinate Rx in order to achieve a high color gamut, the luminous efficiency of the light-emitting device 10 is significantly reduced due to the mismatch between the microcavity gain spectrum and the electroluminescence spectrum of the light-emitting device 10. When the color coordinate Rx increases from 0.693 to 0.701, the luminous efficiency decreases by 17%.

[0096] However, the color coordinate range of the light emitting device 10 of the deep red light material with the best luminous efficiency (luminous efficiency attenuation range ≤ 10%) is 0.702≤Rx≤0.706, while meeting the high color gamut requirement.

[0097] It should be noted that the first deep red light material includes an iridium complex, and the second deep red light material includes a platinum complex.

[0098] In some examples, the color coordinate Rx of the red light emitted by the deep red phosphorescent material ranges from 0.703 to 0.705.

[0099] Illustratively, the deep red phosphorescent material is selected from any one of an iridium complex, a platinum complex, a zinc complex, a lithium complex, and a beryllium complex.

[0100] By using a deep red phosphorescent material whose color coordinate Rx of the emitted red light ranges from 0.703 to 0.705, the color shift problem of the white light viewing angle can be reduced while ensuring that the color gamut of the light emitting device 10 is increased.

[0101] It should be noted that, as shown in FIG2 , the direction perpendicular to the display panel 100 is the first direction X. Observing the display panel 100 from different viewing angles can cause color shift. Different viewing angles refer to observing the display panel 100 from the light-emitting side of the display panel 100 at a certain angle to the first direction X. For example, a 30° viewing angle means observing the display panel 100 from the first direction X at a 30° angle.

[0102] The following describes the relationship between color coordinates, color gamut, white light visual color shift, and luminous efficiency when using a deep red phosphorescent material with a color coordinate Rx value range of 0.703 to 0.705.

[0103] Figure 5 shows the corresponding relationship between Rx and Ry in the color coordinate range (Rx>0.7) of deep red phosphorescent materials. It can be seen from the figure that as Rx increases, Ry decreases at a constant rate, and the above change trends of Rx and Ry are all conducive to increasing the color gamut.

[0104] Because Rx and Ry change with equal amplitude, under the premise that the color coordinates (Gx, Gy) of the green light-emitting part 13 are fixed at (0.163, 0.761) and the color coordinates (Bx, By) of the blue light-emitting part 14 are fixed at (0.140, 0.042), as shown in Figure 6, when Rx continues to increase from 0.702 to 0.706, the color gamut continues to increase.

[0105] Figure 7 is a color coordinate diagram, in which the graph represented by BT2020 has three vertices, represented as O(0.17, 0.797), P(0.131, 0.046), and Q(0.708, 0.292). The area enclosed by the three vertices is the area with the largest color gamut.

[0106] It should be noted that chromaticity coordinates are the coordinates of color, also called colorimetric systems. The commonly used color coordinates now have the horizontal axis as X and the vertical axis as Y, with (X, Y) used to represent a color. BT2020 stipulates that the standard red color coordinates are Q (0.708, 0.292), the standard green color coordinates are O (0.17, 0.797), the standard blue color coordinates are P (0.131, 0.046), and the pure white light color coordinates are (0.33, 0.33). In the color coordinate diagram, when the value of the horizontal axis X and the value of the vertical axis Y are both around 0.3, the color displayed in the color coordinate diagram is white. When the value of the horizontal axis X is greater than 0.3 and greater than the value of the vertical axis Y, it is simply called X greater than Y, and the colors displayed in the color coordinate diagram are mostly red. When the value of the vertical axis Y is greater than 0.3 and greater than the value of the horizontal axis X, it is simply called X less than Y, and the colors displayed in the color coordinate diagram are mostly green.

[0107] As shown in Figure 7, the overlapping area of ​​the graph represented by Rx and the graph represented by BT2020 represents the size of the color gamut under the color coordinates. The larger the overlapping area, the larger the color gamut. For example, the overlapping area of ​​the graph represented by Rx0.72 and the graph represented by BT2020 represents the color gamut under the color coordinates, the overlapping area of ​​the graph represented by Rx0.74 and the graph represented by BT2020 represents the color gamut under the color coordinates, and the overlapping area of ​​the graph represented by Rx0.76 and the graph represented by BT2020 represents the color gamut under the color coordinates. Table 2 shows the optical correspondence between the red color coordinates and the white light viewing angle. Combining Figure 7 and Table 2, it can be seen that when Rx continues to increase from 0.702 to 0.706, Ry decreases from 0.298 to 0.294. Therefore, as shown in Figure 7, in the dotted box area, when Rx continues to increase from 0.702 to 0.706, Ry decreases from 0.298 to 0.294. The closer to the coordinate Q (0.708, 0.292), the color gamut continues to increase.

[0108] Table 2 Optical correspondence between red color coordinates and white light viewing angle

[0109] Figure 8 shows a graph of the color deviation trajectory for white light viewing angles. The center point H of the ellipses 3.0 JNCD (JNCD is a standard for measuring screen color accuracy), 4.5 JNCD, and 6.0 JNCD is at the coordinates (0.33, 0.33), which are the color coordinates of pure white light. The color coordinates X and Y (i.e., CIEx and CIEy) in the graph can be used to determine the color represented by the area. The color coordinates X and Y and the colors represented can be referred to in the description of the color coordinate graph above and will not be repeated here. It is understood that the inflection point G of the curve in the graph represents the color deviation value at a 30° viewing angle. The greater the distance from the center point H to the inflection point G, the greater the color deviation. Figure 9 shows a graph of the color deviation curve for white light viewing angles. As can be seen from Table 2, Figures 8, and 9, as the color gamut increases, the redness of white light at small viewing angles (≤30°) increases, and the color deviation value for viewing angles continues to deteriorate. Figure 10 shows a graph of the brightness attenuation curve. An increase in Rx has little effect on the brightness attenuation of white light viewing angles. Considering that when Rx ≥ 0.703, the BT2020 color gamut coverage is ≥ 93% @ CIE1931 and ≥ 95% @ CIE1976, in order to balance the color gamut and the color bias of white light viewing angle, the preferred range of the color coordinates of deep red light is 0.703 ≤ Rx ≤ 0.705.

[0110] As can be seen from the above description of red color coordinates and white light visual color shift, the optimal color coordinate range for deep red light, 0.703 ≤ Rx ≤ 0.705, offers a trade-off between color gamut and white light visual color shift. Within this range, Rx = 0.705 provides the best color gamut, but also the most severe red cast at low viewing angles. To maximize the color gamut while mitigating the degradation of white light visual color shift at low viewing angles, the following embodiments are provided.

[0111] As shown in FIG2 , the display panel 100 further includes a cover layer 20 , which is disposed on a side of the second electrode layer 102 away from the light emitting layer 11 . The thickness d1 of the second electrode layer 102 is in the range of The thickness d2 of the cover layer 20 is in the range of

[0112] For example, the thickness d1 of the second electrode layer 102 is or The thickness d2 of the cover layer 20 is in the range of or There is no limit here.

[0113] In the related art, the thickness d1 of the second electrode layer 102 of the display panel 100 is less than The thickness d2 of the cover layer 20 is generally In the embodiment of the present disclosure, the thickness d1 of the second electrode layer 102 is in the range of The thickness d2 of the cover layer 20 is in the range of That is to say, in the embodiment of the present disclosure, the thickness d1 of the second electrode layer 102 and the thickness d2 of the covering layer 20 are thickened, so that the red brightness at a small viewing angle (≤30°) can be independently adjusted, thereby improving the problem of increased redness of white light at a small viewing angle (≤30°).

[0114] In order to prove that increasing the thickness d1 of the second electrode layer 102 and the thickness d2 of the cover layer 20 can improve the problem of increased redness at small viewing angles (≤30°) of white light, the following data are provided.

[0115] As shown in FIG11 to FIG13, the conventional device indicates that the thickness d1 of the second electrode layer 102 and the thickness d2 of the cover layer 20 are conventional thicknesses, and no thickening is performed. In this embodiment, the thickness d1 of the second electrode layer 102 in the conventional device is The thickness d2 of the cover layer 20 is Take this as an example to illustrate.

[0116] Based on the thickness d1 of the second electrode layer 102 and the thickness d2 of the cover layer 20 of the conventional device, MgAg+10&CPL+150 means that the thickness d1 of the second electrode layer 102 is thickened. The thickness d2 of the cover layer 20 is increased That is, the thickness d2 of the cover layer 20 is The thickness d1 of the second electrode layer 102 is

[0117] CPL+50 means the thickness d2 of the cover layer 20 is increased. That is, the thickness d2 of the cover layer 20 is

[0118] It can be seen that the thickness d2 of the cover layer 20 is (Thickened ), the brightness attenuation of red light at full viewing angle is slightly accelerated, the brightness attenuation of green light at large viewing angle (≥45°) is slightly accelerated, and the brightness attenuation of blue light viewing angle has no effect. The thickness d2 of the cover layer 20 is (Thickened ) and the thickness d1 of the second electrode layer 102 is (Thickened ), the brightness attenuation of red light at all viewing angles is significantly accelerated, the brightness attenuation of green light at medium and large viewing angles (≥30°) is accelerated, and the brightness attenuation of blue light viewing angles has no effect. Compared with the cover layer 20 thicker The thickness d2 of the cover layer 20 is increased Combined with the thickness d1 of the second electrode layer 102 being thicker The technical solution provided by the embodiment significantly accelerates the attenuation of red light brightness within a small viewing angle (≤30°), and has a more significant effect on improving the redness problem of white light at a small viewing angle (≤30°).

[0119] FIG14 is a diagram of the angular deviation trajectory of white light viewing angle, and FIG15 is a diagram of the brightness attenuation of white light viewing angle. FIG14 and FIG15 further illustrate that the thickening of the cover layer 20 Combined with the second electrode layer 102 to thicken In the example, the redness problem of white light with a small viewing angle (≤30°) is significantly improved.

[0120] In some embodiments, as shown in FIG2 , the display panel 100 further includes an optical control layer 30 and an encapsulation layer 40. The optical control layer 30 is made of lithium fluoride. The encapsulation layer 40 includes a first encapsulation layer 401, a second encapsulation layer 402, and a third encapsulation layer 403, stacked sequentially away from the light-emitting device 10. For example, the first encapsulation layer 401 may be a single-layer structure.

[0121] Illustratively, the material of the first encapsulation layer 401 includes silicon oxynitride, the material of the second encapsulation layer 402 includes an inkjet-printed organic material, and the material of the third encapsulation layer 403 includes silicon nitride.

[0122] In order to further eliminate the problem of reddening of white light at small viewing angles (≤30°), the following embodiments are provided.

[0123] In some embodiments, as shown in FIG16 , the encapsulation layer 40 of the display panel 100 includes: a first encapsulation layer 401, which is disposed on a side of the cover layer 20 away from the second electrode layer 102. The first encapsulation layer 401 is a multi-layer structure, including a first encapsulation sublayer 41A, a second encapsulation sublayer 41B, and a third encapsulation sublayer 41C, and is sequentially disposed in a direction away from the cover layer 20. The refractive index n1 of the cover layer 20 is greater than the refractive index n2 of the first encapsulation sublayer 41A, the refractive index n2 of the first encapsulation sublayer 41A is less than the refractive index n3 of the second encapsulation sublayer 41B, and the refractive index n3 of the second encapsulation sublayer 41B is greater than the refractive index n4 of the third encapsulation sublayer 41C. That is, n1>n2, n2<n3,n3> n4, from the cover layer 20 to the third encapsulation sub-layer 41C, a refractive index structure of high / low / high / low is formed.

[0124] Exemplarily, the material of the first encapsulation sublayer 41A, the second encapsulation sublayer 41B, and the third encapsulation sublayer 41C includes silicon oxynitride.

[0125] In an embodiment, forming a high / low / high / low refractive index structure from the cover layer 20 to the third encapsulation sublayer 41C can eliminate the technical problem of the white light of the light-emitting device 10 being red at a small viewing angle (≤30°). As shown in Figure 16, the display panel 100 is not provided with an optical control layer 30. The refractive index of the optical control layer 30 is not sufficient to form the above-mentioned high / low / high / low structure. Therefore, in order to eliminate the technical problem of the white light of the light-emitting device 10 being red at a small viewing angle (≤30°), the first encapsulation layer 401 is configured as a multi-layer structure with a refractive index that meets the requirements.

[0126] As shown in Figures 17 to 19, the first encapsulation layer has a multi-layer structure corresponding to the display panel 100 shown in Figure 16, while the conventional device corresponds to a single-layer structure for the first encapsulation layer. As can be seen from Figure 17, compared with conventional technology, the red light full-viewing angle brightness attenuation of the display panel 100 with a first encapsulation layer having a multi-layer structure is significantly accelerated; as can be seen from Figure 18, although the green light small viewing angle (≤30°) brightness attenuation is also accelerated, the degree of acceleration is significantly less than that of red light; as can be seen from Figure 19, the blue light viewing angle brightness attenuation has no effect. By setting the first encapsulation layer to a multi-layer structure, a refractive index structure of high / low / high / low is formed from the cover layer 20 to the third encapsulation sublayer 41C, thereby accelerating the red light brightness attenuation within a small viewing angle (≤30°), effectively eliminating the problem of white light turning red at a small viewing angle (≤30°).

[0127] Figure 20 is a diagram of the chromatic aberration trajectory of white light visual angles, and Figure 21 is a diagram of the chromatic aberration curve of white light visual angles. It can be seen from Figure 20 that, compared with conventional devices, the device with a multi-layer structure as the first encapsulation layer has a color deviation trajectory that is far away from the red area (the area close to the color coordinate Q (0.708, 0.292)). It can be further seen that the redness of white light with a small viewing angle (≤30°) is eliminated. It can be seen from Figure 21 that the color deviation value of white light with a small viewing angle (≤30°) is significantly reduced.

[0128] In some embodiments, the refractive index n1 of the cover layer 20 ranges from 1.7 to 1.8, the refractive index n2 of the first encapsulation sublayer 41A ranges from 1.4 to 1.52, the refractive index n3 of the second encapsulation sublayer 41B ranges from 1.7 to 1.8, and the refractive index n4 of the third encapsulation sublayer 41C ranges from 1.55 to 1.65.

[0129] Exemplarily, the refractive index n1 of the covering layer 20 is 1.7, 1.75 or 1.8, the refractive index n2 of the first encapsulation sublayer 41A is 1.4, 1.43, 1.47, 1.5 or 1.52, the refractive index n3 of the second encapsulation sublayer 41B is 1.7, 1.75 or 1.8, and the refractive index n4 of the third encapsulation sublayer 41C is 1.55, 1.6 or 1.65.

[0130] In some embodiments, the structure of the display panel 100 can be referred to FIG. 16 , and the thickness d1 of the second electrode layer 102 of the display panel 100 is in the range of The thickness d2 of the cover layer 20 is in the range of The first encapsulation layer 401 includes a first encapsulation sublayer 41A, a second encapsulation sublayer 41B and a third encapsulation sublayer 41C, which are sequentially arranged in a direction away from the cover layer 20 , thereby achieving full-view chromatic aberration optimization of white light.

[0131] As shown in FIG22 to FIG24, the conventional device indicates that the thickness d1 of the second electrode layer 102 and the thickness d2 of the cover layer 20 are conventional thicknesses and are not thickened. That is, the thickness d1 of the second electrode layer 102 is The thickness d2 of the cover layer 20 is The first encapsulation layer 401 is a single-layer structure.

[0132] MgAg+10&CPL+150 and the first encapsulation layer 401 are multi-layer structures: the thickness d1 of the second electrode layer 102 is thickened The thickness d2 of the cover layer 20 is increased That is, the thickness d2 of the cover layer 20 is The thickness d1 of the second electrode layer 102 is The first encapsulation layer 401 includes a first encapsulation sublayer 41A, a second encapsulation sublayer 41B, and a third encapsulation sublayer 41C. From the cover layer 20 to the third encapsulation sublayer 41C, a refractive index structure of high / low / high / low is formed.

[0133] As can be seen from the figures, as shown in Figure 22, the brightness decay of red light is significantly accelerated across all viewing angles; as shown in Figure 23, the brightness decay of green light is accelerated across medium and large viewing angles (≥30°); and as shown in Figure 24, the brightness decay of blue light is unaffected by viewing angles. Therefore, within the narrow viewing angle range (≤30°), only the brightness decay of red light is significantly accelerated.

[0134] Figure 25 is a diagram of the chromatic aberration trajectory for white light viewing, and Figure 26 is a diagram of the chromatic aberration for white light viewing. As can be seen from the above description of the color coordinate diagram, the color coordinates of standard green are O (0.17, 0.797), the color coordinates of standard blue are P (0.131, 0.046), and the color coordinates of pure white light are (0.33, 0.33). In the color coordinate diagram, when the values ​​of the horizontal axis X and the vertical axis Y are both around 0.3, the color displayed on the color coordinate diagram is white. When the value of the horizontal axis X is greater than 0.3 and greater than the value of the vertical axis Y, it is simply called "X is greater than Y", and the color displayed on the color coordinate diagram is mostly red. When the value of the vertical axis Y is greater than 0.3 and greater than the value of the horizontal axis X, it is simply called "X is less than Y", and the color displayed on the color coordinate diagram is mostly green.

[0135] As shown in FIG25 and FIG26, the chromatic aberration trajectory of white light with a small viewing angle changes from red to cyan, and starts to turn green at a medium viewing angle (=45°), eliminating the technical problem of red light from the light-emitting device 10 with a small viewing angle (≤30°).

[0136] In some embodiments, as shown in Figures 2 and 16, at least one green light-emitting portion 13 of the multiple green light-emitting portions 13 also includes a green thermally activated delayed fluorescent material, and the luminescent material of the green light-emitting portion 13 includes a dark green fluorescent material, and the peak range of the photoluminescence spectrum of the dark green fluorescent material is 500nm to 520nm.

[0137] Table 3 Photoluminescence spectra of different materials

[0138] As shown in Figure 3 and Table 3, conventional green materials include conventional green fluorescent materials, and deep green materials include deep green fluorescent materials. Compared to conventional green materials, the PL spectrum peak of the deep green material is blue-shifted by 10nm to 20nm. Since the peak of the photoluminescence spectrum of the luminescent material of the green light-emitting portion 13 is required to be less than or equal to 515nm, using a deep green fluorescent material with a photoluminescence spectrum peak range of 500nm to 520nm can meet the requirements of high color gamut technology development.

[0139] Furthermore, as shown in Figure 3, Tables 3, and 4, the half-wave peak width of deep green light materials has significantly narrowed by 5 to 10 nm, requiring a half-wave peak width of less than or equal to 20 nm. Even within the half-wave peak width of less than or equal to 20 nm, the color gamut increases as the half-wave peak width narrows and Gy increases at the same Gx.

[0140] Table 4 Relationship between half-wave peak width and color coordinates of dark green light materials

[0141] The first deep green light material includes carbazole derivatives, and the second deep green light material includes diaminoanthracene derivatives.

[0142] In some examples, as shown in Figure 27, the optimal color coordinate range for luminous efficiency in a light-emitting device 10 made of conventional green light materials is Gx > 0.24. Reducing Gx to achieve deep green and significantly shorten the microcavity length leads to a mismatch between the microcavity gain spectrum and the electroluminescence spectrum, also resulting in a significant decrease in luminous efficiency. When Gx decreases from 0.25 to 0.21, the efficiency drops by 24%.

[0143] However, the color coordinate range of the light emitting device 10 of the deep green light material with the best luminous efficiency (efficiency attenuation range ≤ 10%) is 0.14≤Gx≤0.18, while taking into account the high color gamut.

[0144] Therefore, by using a deep green fluorescent material with a peak range of the photoluminescence spectrum of 500 nm to 520 nm, the luminous efficiency of the light-emitting device 10 can be taken into consideration while achieving the high color gamut green spectrum requirement of the light-emitting device 10 .

[0145] In some examples, the color coordinate Gx of the green light emitted by the dark green fluorescent material ranges from 0.155 to 0.165.

[0146] Exemplarily, the deep green fluorescent material is selected from any one of coumarins, carbazole derivatives, diaminoanthracene derivatives and pyrazoloquinoxaline derivatives.

[0147] By using a dark green fluorescent material with a color coordinate Gx value range of 0.155 to 0.165, the green light-emitting portion 13 of the light-emitting device 10 can achieve the goals of having a high color gamut and a small color deviation of the white light visual color.

[0148] Figure 28 shows the corresponding relationship between Gx and Gy in the color coordinate range of dark green light materials (Gx<0.2). It can be seen from the figure that as Gx decreases, Gy increases, and the above change trends of Gx and Gy are conducive to increasing the color gamut.

[0149] However, because the increase in Gy is significantly smaller than the decrease in Gx (affected by the half-wave peak width), under the premise that the color coordinates (Rx, Ry) of the red light-emitting unit 12 are fixed at (0.705, 0.295) and the color coordinates (Bx, By) of the blue light-emitting unit 14 are fixed at (0.140, 0.042), as shown in Figure 29, when Gx decreases from 0.18 to 0.14, the color gamut first increases and then decreases, that is, the decrease in Gx cannot continue to contribute to the color gamut, and the color gamut is maximum when Gx = 0.16. As shown in the dotted box part of Figure 30, when the graph represented by Gx takes different values ​​is closer to O (0.17, 0.797) in this area, the color gamut is larger. It can be seen that when Gx = 0.16 or so, the color gamut is maximum.

[0150] Figure 31 shows the trajectory of chromatic aberration in white light vision, and Figure 32 shows the curve of chromatic aberration in white light vision. As shown in Table 5, Figures 31 and 32, the trajectory becomes shorter as Gx decreases from 0.18 to 0.16, indicating that the greenish tint and color shift of white light decrease at wide viewing angles (≥30°). However, as Gx decreases from 0.16 to 0.14, the reddish tint and color shift of white light increase at narrow viewing angles (≤30°). The optimal chromatic aberration for white light vision is achieved at Gx = 0.16.

[0151] Table 5 Optical correspondence between green color coordinates and white light viewing angle

[0152] Figure 33 shows the brightness decay of white light viewing angles. It can be seen that decreasing Gx significantly accelerates the brightness decay of white light viewing angles. Therefore, considering the color gamut, color shift, and brightness decay of white light viewing angles, the color coordinate range of the dark green material is 0.155 ≤ Gx ≤ 0.165.

[0153] In some embodiments, the structure of the display panel 100 can be seen with reference to FIG2 . The light-emitting layer 11 of the light-emitting device 10 includes a red light-emitting portion 12, a green light-emitting portion 13, and a blue light-emitting portion 14. At least one of the multiple green light-emitting portions 13 further includes a green thermally activated delayed fluorescent material. The light-emitting material of the green light-emitting portion 13 includes a dark green fluorescent material, and the peak photoluminescence spectrum of the dark green fluorescent material is in the range of 500 nm to 520 nm. The materials of the red light-emitting portion 12 and the blue light-emitting portion 14 of the light-emitting device 10 are not limited.

[0154] For an introduction to the performance of the green light-emitting portion 13 comprising a dark green fluorescent material, please refer to the above content and will not be repeated here.

[0155] In some embodiments, the structure of the display panel 100 can refer to FIG2 , and the light-emitting layer 11 of the light-emitting device 10 includes a red light-emitting portion 12, a green light-emitting portion 13, and a blue light-emitting portion 14. The material of the red light-emitting portion 12 includes a host material and a fluorescent material.

[0156] In order to improve the luminous efficiency, the material of the red light-emitting part 12 also includes a red thermally activated delayed fluorescence (TADF, Thermally Activated Delayed Fluorescence) sensitizer, which is represented by RTADF. The reverse intergap crossing mechanism of the RTADF sensitizer is utilized to effectively utilize the triplet exciton energy and transfer it to the fluorescent material, thereby improving the luminous efficiency.

[0157] However, the doping concentration of the fluorescent material in the red light-emitting portion 12 cannot take into account both the light leakage of the RTADF sensitizer and the luminous efficiency. As shown in FIG34 , when the angle between the observer's line of sight and the first direction X (as shown in FIG2 ) is 60° (indicated as @60° viewing angle in FIG34 ), when the doping concentration of the fluorescent material is relatively low, the energy transfer from the RTADF sensitizer to the fluorescent material is incomplete, resulting in significant light leakage of the RTADF sensitizer. Since the RTADF sensitizer is orange-red light, as shown in FIG35 , light leakage of the RTADF sensitizer will significantly reduce the color coordinate Rx, resulting in the inability to achieve deep red. Increasing the doping concentration of the fluorescent material to reduce light leakage will cause a significant decrease in luminous efficiency.

[0158] Therefore, if the red fluorescent material doping concentration is inappropriate, the existing RTADF-sensitized all-fluorescent light-emitting device 10 cannot meet the requirements of high color gamut and high luminous efficiency. Reducing the red fluorescent material doping concentration will cause the RTADF orange-yellow light to leak, hindering the achievement of deep red. Increasing the red fluorescent material doping concentration will reduce the molecular distance between the RTADF and the fluorescent material, causing some triplet excitons formed on the RTADF to be transferred to the fluorescent material and annihilated before being converted into singlet excitons, significantly reducing the luminous efficiency.

[0159] Based on this, as shown in Figure 2, a display panel 100 is provided, which includes: a first electrode layer 101 and a second electrode layer 102, the first electrode layer 101 includes a reflective electrode layer, the second electrode layer 102 is arranged opposite to the first electrode layer 101, and the second electrode layer 102 includes a semi-transmissive and semi-reflective electrode layer.

[0160] For the introduction of the first electrode layer 101 and the second electrode layer 102 , reference can be made to the above content and will not be repeated here.

[0161] Display panel 100 also includes a light-emitting layer 11, which is located between first electrode layer 101 and second electrode layer 102. Light-emitting layer 11 includes multiple light-emitting sections, each made of a host material and a light-emitting material. The multiple light-emitting sections include multiple red light-emitting sections 12, multiple blue light-emitting sections 14, and multiple green light-emitting sections 13.

[0162] The luminescent materials of the red light-emitting portion 12 also include red thermally activated delayed fluorescent material and deep red fluorescent material. The peak range of the photoluminescence spectrum of the deep red fluorescent material is 630nm~650nm. In the red light-emitting portion 12, the ratio of the mass of the deep red fluorescent material to the sum of the mass of the main material, the red thermally activated delayed fluorescent material and the deep red fluorescent material is in the range of 0.4%~0.6%.

[0163] In some examples, as shown in FIG3 and Table 1, the deep red light material is, for example, a deep red fluorescent material. Compared to conventional red light materials, the peak of the photoluminescence (PL) spectrum of the deep red fluorescent material is red-shifted by 10 nm to 20 nm. Since the peak of the PL spectrum of the luminescent material of the red light-emitting portion 12 is required to be greater than or equal to 630 nm, the use of a deep red fluorescent material with a peak PL spectrum in the range of 630 nm to 650 nm can meet the requirements of high color gamut technology development.

[0164] Illustratively, the ratio of the mass of the deep red fluorescent material to the sum of the mass of the host material, the red thermally activated delayed fluorescent material and the deep red fluorescent material is 0.4%, 0.45%, 0.5% or 0.6%, etc., which is not limited here.

[0165] Setting the ratio of the mass of the deep red fluorescent material to the sum of the masses of the main material, the red thermally activated delayed fluorescent material and the deep red fluorescent material in the range of 0.4% to 0.6% can achieve higher luminous efficiency requirements while taking into account high color gamut requirements to a certain extent.

[0166] As shown in Figures 35 and 36, when the red fluorescent material doping concentration (RD%) is 0.4%, the corresponding color coordinate Rx = 0.696, and the color gamut coverage is 91% BT2020. When the red fluorescent material doping concentration is 0.6%, the corresponding color coordinate Rx = 0.700, and the color gamut coverage is 92% BT2020.

[0167] Figure 37 shows the trajectory of the color deviation of white light viewing angles, and Figure 38 shows the color deviation of white light viewing angles. As can be seen from the figures, when the red fluorescent material doping concentration is 0.4%, the white light with a small viewing angle (≤30°) has a more severe red cast and a larger color deviation. When the red fluorescent material doping concentration is 0.6%, the red cast of white light with a small viewing angle (≤30°) is improved to a certain extent, the color deviation is optimized, and the color gamut is improved, while the luminous efficiency decreases by 5%. Therefore, in this embodiment, the ratio of the mass of the deep red fluorescent material to the sum of the masses of the host material, the red thermally activated delayed fluorescent material, and the deep red fluorescent material is set within a range of 0.4% to 0.6%. This can, to a certain extent, achieve a balance between color gamut and luminous efficiency, thus optimizing the doping concentration of the deep red fluorescent material.

[0168] In some examples, the color coordinate Rx of the red light emitted by the deep red fluorescent material ranges from 0.703 to 0.705. Using a deep red fluorescent material with a color coordinate Rx of the red light emitted from the deep red fluorescent material in the range of 0.703 to 0.705 can reduce the color shift of the white light viewing angle while ensuring that the color gamut of the light emitting device 10 is increased.

[0169] Exemplarily, the deep red fluorescent material includes any one of DCM series dopants, DCM derivative dopants, auxiliary dopants, conjugated fused rings, porphyrin macrocycles, and aromatic acids.

[0170] In some embodiments, the structure of the display panel 100 is shown in reference to Figure 2 or Figure 16. The light-emitting material of the red light-emitting portion 12 of the light-emitting device 10 includes a red thermally activated delayed fluorescent material and a deep red fluorescent material. In the red light-emitting portion 12, the ratio of the mass of the deep red fluorescent material to the sum of the masses of the main material, the red thermally activated delayed fluorescent material and the deep red fluorescent material is in the range of 0.4% to 0.6%; at least one green light-emitting portion 13 of the multiple green light-emitting portions 13 of the light-emitting device 10 also includes a blue thermally activated delayed fluorescent material, and the light-emitting material of the green light-emitting portion 13 includes a deep green fluorescent material. The peak range of the photoluminescence spectrum of the deep green fluorescent material is 500nm to 520nm, and the color coordinate Gx of the green light emitted by the deep green fluorescent material is in the range of 0.155 to 0.165; the light-emitting material of at least one blue light-emitting portion 14 of the multiple blue light-emitting portions 14 of the light-emitting device 10 is a blue fluorescent light-emitting material, thereby realizing the design of the display panel 100 with full fluorescence and high color gamut.

[0171] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A display panel, comprising: A first electrode layer, including a reflective electrode layer; A second electrode layer, arranged opposite to the first electrode layer, and the second electrode layer comprises a semi-transmissive and semi-reflective electrode layer; A light-emitting layer is located between the first electrode layer and the second electrode layer; the light-emitting layer includes a plurality of light-emitting parts, and the materials of the plurality of light-emitting parts include: a main material and a light-emitting material; the plurality of light-emitting parts include a plurality of red light-emitting parts, a plurality of blue light-emitting parts and a plurality of green light-emitting parts; The light-emitting material of at least one of the multiple red light-emitting units includes a deep red phosphorescent material, and the peak range of the photoluminescence spectrum of the deep red phosphorescent material is 630nm to 650nm.

2. The display panel according to claim 1, wherein: The color coordinate Rx of the red light emitted by the deep red phosphorescent material ranges from 0.703 to 0.

705.

3. The display panel according to claim 1 or 2, wherein: The deep red phosphorescent material is selected from any one of an iridium complex, a platinum complex, a zinc complex, a lithium complex and a beryllium complex.

4. The display panel according to any one of claims 1 to 3, wherein: At least one of the plurality of green light-emitting portions further comprises a green thermally activated delayed fluorescent material, and the luminescent material of the green light-emitting portion comprises a dark green fluorescent material, and a peak range of the photoluminescence spectrum of the dark green fluorescent material is 500nm to 520nm.

5. The display panel according to claim 4, wherein: The color coordinate Gx of the green light emitted by the dark green fluorescent material ranges from 0.155 to 0.

165.

6. The display panel according to claim 4 or 5, wherein: The dark green fluorescent material is selected from any one of coumarins, carbazole derivatives, diaminoanthracene derivatives and pyrazoloquinoxaline derivatives.

7. The display panel according to any one of claims 1 to 6, further comprising: a covering layer, the covering layer being arranged on a side of the second electrode layer away from the light-emitting layer; The thickness of the second electrode layer is in the range of The thickness of the covering layer is in the range of 8. The display panel according to claim 7, further comprising: A first encapsulation layer is disposed on a side of the cover layer away from the second electrode layer; Wherein, the first encapsulation layer is a multi-layer structure, including a first encapsulation sublayer, a second encapsulation sublayer and a third encapsulation sublayer, and are sequentially arranged in a direction away from the covering layer; The refractive index of the cover layer is greater than the refractive index of the first encapsulation sublayer; The refractive index of the first encapsulation sublayer is less than the refractive index of the second encapsulation sublayer; The refractive index of the second encapsulation sublayer is greater than the refractive index of the third encapsulation sublayer.

9. The display panel according to claim 8, wherein: The refractive index of the cover layer ranges from 1.7 to 1.8; The refractive index of the first encapsulation sublayer ranges from 1.4 to 1.52; The refractive index of the second encapsulation sublayer is in the range of 1.7 to 1.8; The refractive index of the third encapsulation sublayer is in the range of 1.55 to 1.

65.

10. The display panel according to any one of claims 1 to 7, further comprising: An optical regulation layer is arranged on a side of the cover layer away from the second electrode layer; The first encapsulation layer is a single-layer structure and is disposed on a side of the optical regulation layer away from the covering layer.

11. The display panel according to any one of claims 8 to 10, further comprising: The second encapsulation layer and the third encapsulation layer are sequentially arranged on a side of the first encapsulation layer away from the covering layer.

12. The display panel according to claim 11, wherein: The material of the first encapsulation layer includes silicon oxynitride; The material of the second encapsulation layer includes an organic material; The material of the third encapsulation layer includes silicon nitride.

13. A display panel, comprising: A first electrode layer, including a reflective electrode layer; A second electrode layer, arranged opposite to the first electrode layer, and the second electrode layer comprises a semi-transmissive and semi-reflective electrode layer; A light-emitting layer is located between the first electrode layer and the second electrode layer; the light-emitting layer includes a plurality of light-emitting parts, and the materials of the plurality of light-emitting parts include: a main material and a light-emitting material; the plurality of light-emitting parts include a plurality of red light-emitting parts, a plurality of blue light-emitting parts and a plurality of green light-emitting parts; Among them, the luminescent material of the red light-emitting part also includes a red thermally activated delayed fluorescent material and a deep red fluorescent material, and the peak range of the photoluminescence spectrum of the deep red fluorescent material is 630nm~650nm; in the red light-emitting part, the ratio of the mass of the deep red fluorescent material to the sum of the mass of the main material, the red thermally activated delayed fluorescent material and the deep red fluorescent material is in the range of 0.4%~0.6%.

14. The display panel according to claim 13, wherein: The color coordinate Rx of the red light emitted by the deep red fluorescent material ranges from 0.703 to 0.

705.

15. The display panel according to claim 13 or 14, wherein: The deep red fluorescent material comprises any one of DCM series doping type, DCM derivative doping type, auxiliary doping agent type, conjugated condensed ring type, porphyrin macrocyclic type and aromatic acid.

16. The display panel according to any one of claims 13 to 15, wherein: At least one of the plurality of green light-emitting portions further comprises a green thermally activated delayed fluorescent material, and the luminescent material of the green light-emitting portion comprises a dark green fluorescent material, and a peak range of the photoluminescence spectrum of the dark green fluorescent material is 500nm to 520nm.

17. The display panel according to claim 16, wherein: The color coordinate Gx of the green light emitted by the dark green fluorescent material ranges from 0.155 to 0.

165.

18. The display panel according to claim 16 or 17, wherein: The dark green fluorescent material is selected from any one of coumarins, carbazole derivatives, diaminoanthracene derivatives and pyrazoloquinoxaline derivatives.

19. A display panel, comprising: A first electrode layer, including a reflective electrode layer; A second electrode layer, arranged opposite to the first electrode layer, and the second electrode layer comprises a semi-transmissive and semi-reflective electrode layer; A light-emitting layer is located between the first electrode layer and the second electrode layer; the light-emitting layer includes a plurality of light-emitting parts, and the materials of the plurality of light-emitting parts include: a main material and a light-emitting material; the plurality of light-emitting parts include a plurality of red light-emitting parts, a plurality of blue light-emitting parts and a plurality of green light-emitting parts; Among them, at least one of the multiple green light-emitting parts further includes a green thermally activated delayed fluorescent material, and the luminescent material of the green light-emitting part includes a dark green fluorescent material, and the peak range of the photoluminescence spectrum of the dark green fluorescent material is 500nm to 520nm.

20. The display panel according to claim 19, wherein: The color coordinate Gx of the green light emitted by the dark green fluorescent material ranges from 0.155 to 0.

165.

21. The display panel according to claim 19 or 20, wherein: The dark green fluorescent material is selected from any one of coumarins, carbazole derivatives, diaminoanthracene derivatives and pyrazoloquinoxaline derivatives.

22. A display device, comprising: The display panel according to any one of claims 1 to 21; A driving chip is used to drive the display panel to display.

Images