Light-emitting structure and display panel

Abstract

A light-emitting structure and a display panel. The light-emitting structure (1) comprises at least two light-emitting units (4) arranged in series in a direction perpendicular to a substrate; at least one of the light-emitting units (4) comprises a light-emitting layer (11) and an exciton blocking layer (12) stacked in the direction perpendicular to the substrate, the exciton blocking layer (12) being located on the side of the light-emitting layer (11) close to the substrate; the light-emitting layer (11) comprises a red light-emitting layer (14), a green light-emitting layer (15) and a blue light-emitting layer (16) arranged in a direction parallel to the substrate, two of the red light-emitting layer (14), the green light-emitting layer (15) and the blue light-emitting layer (16) being arranged on the end surface of the exciton blocking layer (12) away from the substrate and being located between two ends of the exciton blocking layer (12) in the direction parallel to the substrate.

Description

Light-emitting structure and display panel Technical Field

[0001] This article relates to, but is not limited to, the field of display technology, and in particular to a light-emitting structure and a display panel. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are active-matrix display devices with advantages such as self-illumination, wide viewing angle, high contrast, low power consumption, and extremely fast response speed. With the continuous development of display technology, display devices using OLEDs as light-emitting devices and controlled by thin-film transistors (TFTs) have become the mainstream products in the display field.

[0003] Currently, the luminescent structures using sensitized fluorescence technology are quite complex, especially for tandem structures, and the manufacturing process is difficult.

[0004] Summary of the Invention

[0005] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0006] This disclosure provides a light-emitting structure, which includes at least two light-emitting units arranged in series in a direction perpendicular to the substrate.

[0007] At least one of the light-emitting units includes a light-emitting layer and an exciton blocking layer stacked in a direction perpendicular to the substrate, wherein the exciton blocking layer is located on the side of the light-emitting layer closer to the substrate;

[0008] The light-emitting layer includes a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer arranged parallel to the direction of the substrate;

[0009] Two of the red, green, and blue light-emitting layers are disposed on the end face of the exciton blocking layer away from the substrate, and are located between the two ends of the exciton blocking layer in the direction parallel to the substrate.

[0010] In some exemplary embodiments, the red light-emitting layer and the green light-emitting layer are arranged at a distance in a second direction, the red light-emitting layer and the green light-emitting layer being located between the two ends of the exciton blocking layer in the second direction, the second direction being parallel to the substrate.

[0011] In some exemplary embodiments, the light-emitting unit further includes a hole transport layer located on the side of the exciton blocking layer near the substrate, wherein the orthographic projection of the exciton blocking layer on the substrate lies within the orthographic projection of the hole transport layer on the substrate.

[0012] In some exemplary embodiments, a red electron blocking layer is also included, the red electron blocking layer being located on the side of the exciton blocking layer away from the substrate, and the red light emitting layer being disposed on the end face of the red electron blocking layer away from the exciton blocking layer;

[0013] The orthographic projections of the green luminescent layer and the blue luminescent layer onto the substrate do not overlap with the orthographic projection of the red electron blocking layer onto the substrate.

[0014] In some exemplary embodiments, the hole mobility of the exciton blocking layer is μ p1 The hole mobility of the hole transport layer is μ p2 The hole mobility of the red electron blocking layer is μ p3 ;

[0015] Among them, 10 -3 ≤μ p1 / μ p2 ≤1, 1≤μ p1 / μ p3 ≤10 3 .

[0016] In some exemplary embodiments, the energy level of the exciton blocking layer is H1, the energy level of the hole transport layer is H2, and the energy level of the red electron blocking layer is H3;

[0017] Among them, |H1-H2|≤0.15eV, |H1|≤|H3|.

[0018] In some exemplary embodiments, the hole transport layer and the exciton blocking layer are spaced apart in a direction perpendicular to the substrate, the energy level of the exciton blocking layer is H1, the energy level of the hole transport layer is H2, and |H1-H2|≥0.15eV.

[0019] In some exemplary embodiments, the material of the exciton blocking layer is a hole-type material, which includes triphenylamine, furan, carbazole, thiophene, or phenylfluorene groups.

[0020] In some exemplary embodiments, the area of ​​the luminescent region of the red luminescent layer projected onto the substrate is S1, the area of ​​the luminescent region of the green luminescent layer projected onto the substrate is S2, and the area of ​​the exciton blocking layer projected onto the substrate is T1, wherein T1 > (S1 + S2).

[0021] In some exemplary embodiments, the contact area between the exciton blocking layer and the light-emitting layer is T2, where T2 > S1 and T2 > S2.

[0022] In some exemplary embodiments, T1 ≥ T2.

[0023] In some exemplary embodiments, the orthogonal projections of two of the red, green, and blue light-emitting layers onto the substrate lie within the orthogonal projection of the exciton blocking layer onto the substrate.

[0024] In some exemplary embodiments, the orthogonal projections of the red emitting layer and the green emitting layer onto the substrate lie within the orthogonal projection of the exciton blocking layer onto the substrate.

[0025] In some exemplary embodiments, a blue electron blocking layer is also included, the blue electron blocking layer being located on the side of the blue emitting layer closer to the substrate;

[0026] The orthographic projection of the blue emitting layer on the substrate does not overlap with the orthographic projection of the exciton blocking layer on the substrate, and the orthographic projection of the blue emitting layer on the substrate is located within the orthographic projection of the blue electron blocking layer on the substrate.

[0027] In some exemplary embodiments, the green light-emitting layer includes a first sub-light-emitting layer, the material of which includes a host material, a sensitizing material, and a guest material;

[0028] The doping ratio of the sensitizing material in the first sub-emissive layer is less than the doping ratio of the host material in the first sub-emissive layer but greater than the doping ratio of the guest material in the first sub-emissive layer.

[0029] In some exemplary embodiments, the sensitizing material includes a fluorescent material, or a material having delayed fluorescence properties, or a complex material having a fast intergap crossing rate;

[0030] The complex material with a fast intergap crossing rate is a material containing transition metal elements;

[0031] The difference between the lowest singlet and lowest triplet energy levels of the material with delayed fluorescence properties is less than 0.3 eV.

[0032] In some exemplary embodiments, the doping ratio of the guest material in the green light-emitting layer is no higher than 5%.

[0033] In some exemplary embodiments, the green light-emitting layer further includes at least one auxiliary sub-light-emitting layer, wherein the at least one auxiliary sub-light-emitting layer is located between the first sub-light-emitting layer and the substrate, and the material of the auxiliary sub-light-emitting layer includes at least one of the host material, the sensitizing material and the guest material.

[0034] In some exemplary embodiments, at least one of the auxiliary sub-emitting layers includes a second sub-emitting layer, the material of which includes the main material;

[0035] Alternatively, the material of the second sub-light-emitting layer may include the host material and the guest material.

[0036] Alternatively, the material of the second sub-luminescent layer may include the host material, the sensitizing material, and the guest material;

[0037] The doping ratio of the sensitizing material in the first sub-emissive layer is a first ratio, and the doping ratio of the sensitizing material in the second sub-emissive layer is a second ratio, wherein the difference between the first ratio and the second ratio is less than 25%.

[0038] The doping ratio of the guest material in the first sub-light-emitting layer is a third ratio, and the doping ratio of the guest material in the second sub-light-emitting layer is a fourth ratio, wherein the variation between the third ratio and the fourth ratio is less than 5%.

[0039] In some exemplary embodiments, at least one of the auxiliary sub-light-emitting layers includes a second sub-light-emitting layer and a third sub-light-emitting layer, wherein the first sub-light-emitting layer, the third sub-light-emitting layer and the second sub-light-emitting layer are arranged sequentially in a direction away from the substrate;

[0040] The material of the second sub-emissive layer includes at least one of the host material, the sensitizing material, and the guest material, and the material of the third sub-emissive layer includes at least two of the host material, the sensitizing material, and the guest material.

[0041] In some exemplary embodiments, the material of the third sub-emitting layer includes the host material and the sensitizing material, the doping ratio of the sensitizing material in the first sub-emitting layer is a first ratio, the doping ratio of the sensitizing material in the third sub-emitting layer is a fifth ratio, and the difference between the first ratio and the fifth ratio is less than 20%.

[0042] Alternatively, the material of the third sub-emitting layer includes the host material, the sensitizing material, and the guest material, wherein the doping ratio of the sensitizing material in the first sub-emitting layer is a first ratio, and the doping ratio of the sensitizing material in the third sub-emitting layer is a fifth ratio, wherein the difference between the first ratio and the fifth ratio is less than 25%.

[0043] The doping ratio of the guest material in the first sub-light-emitting layer is a third ratio, and the doping ratio of the guest material in the third sub-light-emitting layer is a sixth ratio, wherein the difference between the third ratio and the sixth ratio is less than 5%.

[0044] This disclosure provides a display panel that includes the light-emitting structure described above.

[0045] This disclosure provides a display panel, which includes: a first pixel group and a second pixel group, wherein the first pixel group includes a first sub-pixel and a second sub-pixel, and the second pixel group includes a third sub-pixel;

[0046] The first sub-pixel and the second sub-pixel are arranged alternately along the second direction, the second pixel group extends along the second direction, the first pixel group and the second pixel group are arranged alternately in the third direction, and the second direction is perpendicular to the third direction;

[0047] The display panel further includes an exciton blocking layer, which is shared by the first sub-pixel and the second sub-pixel.

[0048] This disclosure provides a display device, which includes a circuit board and the aforementioned display panel, wherein the circuit board is configured to be electrically connected to the display panel.

[0049] After reading and understanding the accompanying diagrams and detailed descriptions, the other aspects can be understood.

[0050] Overview of the attached figures

[0051] The accompanying drawings are provided to further illustrate the technical solutions of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure. The shape and size of one or more components in the drawings do not reflect actual proportions and are only intended to illustrate the content of this disclosure.

[0052] Figure 1 is a schematic diagram of a display device;

[0053] Figure 2 is a schematic diagram of the planar structure of a display device;

[0054] Figure 3 is a schematic cross-sectional view of a display device;

[0055] Figure 4 is a cross-sectional schematic diagram of a light-emitting structure according to an exemplary embodiment of this invention;

[0056] Figure 5 is a schematic diagram of the pixel arrangement of a display panel according to an exemplary embodiment of the present invention;

[0057] Figure 6 is a schematic diagram of the pixel arrangement of another display panel in this exemplary embodiment;

[0058] Figure 7 is a schematic diagram of a substrate projection of this exemplary embodiment;

[0059] Figure 8 is a cross-sectional schematic diagram of another light-emitting structure of this exemplary embodiment;

[0060] Figure 9 is a cross-sectional schematic diagram of another light-emitting structure of this exemplary embodiment;

[0061] Figure 10 is a schematic diagram of another substrate projection of this exemplary embodiment.

[0062] Detailed Explanation

[0063] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. The implementation can be carried out in many different forms. Those skilled in the art will readily understand that the methods and content can be transformed into other forms without departing from the spirit and scope of this disclosure. Therefore, this disclosure should not be construed as limited to the content described in the following embodiments. Unless otherwise specified, the embodiments and features in the embodiments of this disclosure can be arbitrarily combined with each other.

[0064] In the accompanying drawings, the size of one or more constituent elements, the thickness of layers, or areas are sometimes exaggerated for clarity. Therefore, this disclosure is not necessarily limited to these dimensions, and the shape and size of one or more parts in the drawings do not reflect true proportions. Furthermore, the drawings schematically illustrate ideal examples, and this disclosure is not limited to the shapes or values ​​shown in the drawings.

[0065] The ordinal numbers such as "first," "second," and "third" used in this specification are used to avoid confusion among the constituent elements, not to limit the quantity. The term "multiple" in this disclosure refers to two or more quantities.

[0066] In this specification, for convenience, terms such as "middle," "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are used to indicate orientation or positional relationships in conjunction with the accompanying drawings. This is solely for the purpose of facilitating the description and simplification, and does not imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this disclosure. The positional relationships of the constituent elements may be appropriately varied depending on the orientation of the constituent elements being described. Therefore, the use of terms not limited to those described in the specification may be appropriately replaced as needed.

[0067] In this specification, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or joint; a direct connection, an indirect connection via an intermediate component, or a connection within two components. Those skilled in the art will understand the meaning of these terms in this disclosure as appropriate.

[0068] In this specification, "electrical connection" includes the situation where components are connected together by elements that have a certain electrical function. There are no particular limitations on what constitutes an "electrical function," as long as it allows for the transmission of electrical signals between the connected components. Examples of "electrical functions" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements with various functions.

[0069] In this specification, a transistor is a device that includes at least three terminals: a gate, a drain, and a source. A transistor has a channel region between its drain (drain terminal, drain region, or drain electrode) and its source (source terminal, source region, or source electrode), and current can flow through the drain, the channel region, and the source. In this specification, the channel region refers to the region through which current primarily flows.

[0070] In this specification, the first terminal can be the drain and the second terminal can be the source, or vice versa. In cases where transistors with opposite polarities are used or where the current direction changes during circuit operation, the functions of the "source" and "drain" are sometimes interchanged. Therefore, in this specification, the "source" and "drain" can be interchanged. Additionally, the gate can also be called the control terminal.

[0071] In this specification, "parallel" refers to the state where the angle formed by two straight lines is greater than or equal to -10° and less than 10°, and therefore also includes the state where the angle is greater than or equal to -5° and less than 5°. Similarly, "perpendicular" refers to the state where the angle formed by two straight lines is greater than or equal to 80° and less than 100°, and therefore also includes the state where the angle is greater than or equal to 85° and less than 95°.

[0072] In this specification, circles, ellipses, triangles, rectangles, trapezoids, pentagons, or hexagons are not strictly defined. They can be approximate circles, ellipses, triangles, rectangles, trapezoids, pentagons, or hexagons. Small deformations due to tolerances are possible, such as chamfers, curved edges, and other variations.

[0073] In this disclosure, "approximately" and "roughly" refer to situations where the limits are not strictly defined, allowing for errors in the process and measurement. In this disclosure, "roughly the same" means that the values ​​differ by no more than 10%. In this disclosure, "symmetric" refers to situations where the limits are not strictly defined, allowing for approximately symmetry within the range of errors in the process and measurement.

[0074] Sensitized fluorescence technology utilizes the high efficiency of sensitizers and possesses the advantage of high color purity of fluorescent emitters, giving it a technological advantage in the display field compared to fluorescence and phosphorescence technologies. However, the applicant has found that the light-emitting structure using sensitized fluorescence technology is more complex than that using phosphorescence technology, especially for tandem structures. Furthermore, the light-emitting structure using sensitized fluorescence technology requires additional evaporation equipment during production compared to phosphorescence technology, significantly increasing manufacturing costs and making the fabrication process more difficult.

[0075] This embodiment provides a light-emitting structure comprising at least two light-emitting units arranged in series in a direction perpendicular to the substrate. At least one of the light-emitting units includes a light-emitting layer and an exciton-blocking layer stacked in a direction perpendicular to the substrate, with the exciton-blocking layer located on the side of the light-emitting layer closest to the substrate. The light-emitting layer includes a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer arranged parallel to the substrate, with two of the red, green, and blue light-emitting layers disposed on the end face of the exciton-blocking layer away from the substrate, and located between the two ends of the exciton-blocking layer in the direction parallel to the substrate. In some exemplary embodiments, the light-emitting structure simplifies the structure, reducing the number of evaporation chambers and fine metal masks (FMMs), which is beneficial for reducing manufacturing process difficulty and cost.

[0076] In some exemplary embodiments, the hole mobility of the exciton blocking layer described above is μ p1 The hole mobility of the aforementioned hole transport layer is μ p2 The hole mobility of the aforementioned red electron blocking layer is μ p3 , of which 10 -3 ≤μ p1 / μ p2 ≤1, 1≤μ p1 / μ p3 ≤10 3 .

[0077] In some exemplary embodiments, the energy level of the exciton blocking layer is H1, the energy level of the hole transport layer is H2, and the energy level of the red electron blocking layer is H3, wherein |H1-H2| ≤ 0.15 eV, and |H1| ≤ |H3|.

[0078] In some exemplary embodiments, the hole transport layer and the exciton blocking layer are spaced apart in a direction perpendicular to the substrate, the energy level of the exciton blocking layer is H1, and the energy level of the hole transport layer is H2, wherein |H1-H2| ≥ 0.15 eV.

[0079] In some exemplary embodiments, the material of the exciton blocking layer is a hole-type material, which includes triphenylamine, furan, carbazole, thiophene, or phenylfluorene groups.

[0080] In some exemplary embodiments, the area of ​​the luminescent region of the red luminescent layer projected onto the substrate is S1, the area of ​​the luminescent region of the green luminescent layer projected onto the substrate is S2, and the area of ​​the exciton blocking layer projected onto the substrate is T1, where T1 > (S1 + S2). The contact area between the exciton blocking layer and the luminescent layer is T2, where T2 > S1, T2 > S2, and T1 ≥ T2.

[0081] The following examples illustrate the solution of this embodiment.

[0082] Figure 1 is a schematic diagram of a display device. As shown in Figure 1, the display device may include a timing controller, a data driver, a scan driver, a light-emitting driver, and a pixel array. The timing controller is connected to the data driver, the scan driver, and the light-emitting driver. The data driver is connected to multiple data signal lines (D1 to Dn), the scan driver is connected to multiple scan signal lines (S1 to Sm), and the light-emitting driver is connected to multiple light-emitting signal lines (E1 to Eo). The pixel array may include multiple sub-pixels Pxij, where i and j can be natural numbers. At least one sub-pixel Pxij may include a circuit unit and a light-emitting device connected to the circuit unit. The circuit unit may include a pixel driving circuit, which is connected to the scan signal lines, the light-emitting signal lines, and the data signal lines. In an exemplary embodiment, the timing controller can provide grayscale values ​​and control signals of specifications suitable for the data driver to the data driver, provide clock signals, scan start signals, etc. of specifications suitable for the scan driver to the scan driver, and provide clock signals, emission stop signals, etc. of specifications suitable for the light-emitting driver to the light-emitting driver. The data driver can use grayscale values ​​and control signals received from the timing controller to generate data voltages to be provided to data signal lines D1, D2, D3, ..., Dn. For example, the data driver can sample grayscale values ​​using a clock signal and apply the data voltage corresponding to the grayscale value to data signal lines D1 to Dn in unit rows, where n can be a natural number. The scan driver can receive clock signals, scan start signals, etc., from the timing controller to generate scan signals to be provided to scan signal lines S1, S2, S3, ..., Sm. For example, the scan driver can sequentially provide scan signals with on-level pulses to scan signal lines S1 to Sm. For example, the scan driver can be configured as a shift register and can generate scan signals by sequentially transmitting scan start signals in the form of on-level pulses to the next stage circuit under the control of a clock signal, where m can be a natural number. The LED driver can receive clock signals, transmit stop signals, etc., from the timing controller to generate transmit signals to LED signal lines E1, E2, E3, ..., Eo. For example, the light-emitting driver can sequentially provide transmit signals with cutoff level pulses to the light-emitting signal lines E1 to Eo. For example, the light-emitting driver can be configured as a shift register and can generate transmit signals by sequentially transmitting transmit stop signals in the form of cutoff level pulses to the next stage circuit under the control of a clock signal, where o can be a natural number. In an exemplary embodiment, a pixel array can be disposed on a display substrate. Figure 2 is a schematic diagram of a planar structure of a display substrate.As shown in Figure 2, the display substrate may include multiple pixel units P arranged in a matrix. At least one pixel unit P may include a first sub-pixel P1 emitting a first color light, a second sub-pixel P2 emitting a second color light, and a third sub-pixel P3 emitting a third color light. Each sub-pixel may include a circuit unit and a light-emitting device. The circuit unit may include at least a pixel driving circuit, which is connected to a scan signal line, a light-emitting signal line, and a data signal line, respectively. The pixel driving circuit is configured to receive the data voltage transmitted by the data signal line and output a corresponding current to the light-emitting device under the control of the scan signal line and the light-emitting signal line. The light-emitting device in each sub-pixel is connected to the pixel driving circuit of its respective sub-pixel, and the light-emitting device is configured to emit light of a corresponding brightness in response to the current output by the pixel driving circuit of its respective sub-pixel.

[0083] In an exemplary embodiment, the first sub-pixel P1 can be a red sub-pixel (R) that emits red light, the second sub-pixel P2 can be a blue sub-pixel (B) that emits blue light, and the third sub-pixel P3 can be a green sub-pixel (G) that emits green light. In an exemplary embodiment, the shape of the sub-pixels can be rectangular, rhomboid, pentagonal, or hexagonal, and the three sub-pixels can be arranged in a horizontal, vertical, or triangular manner, etc., which is not limited herein.

[0084] In an exemplary embodiment, a pixel unit may include four sub-pixels, which may be arranged in a horizontal, vertical, or square manner, etc., and this disclosure does not limit the arrangement.

[0085] Figure 3 is a schematic cross-sectional view of a display substrate. As shown in Figure 3, on a plane perpendicular to the display substrate, the display substrate may include a driving circuit layer 102 disposed on a substrate 101, a light-emitting structure layer 103 disposed on the side of the driving circuit layer 102 away from the substrate 101, and an encapsulation structure layer 104 disposed on the side of the light-emitting structure layer 103 away from the substrate 101. In some possible implementations, the display substrate may include other film layers, such as a touch structure layer, etc., which are not limited herein.

[0086] In some exemplary embodiments, substrate 101 may be a rigid substrate. The rigid substrate may be, but is not limited to, one or more of glass and quartz, while the flexible substrate may be, but is not limited to, one or more of polyethylene terephthalate, polyethylene terephthalate, polyetheretherketone, polystyrene, polycarbonate, polyarylate, polyarylate, polyimide, polyvinyl chloride, polyethylene, and textile fibers. However, it is not limited to these; for example, substrate 101 may be a flexible substrate.

[0087] In an exemplary embodiment, the light-emitting structure layer 103 may include multiple light-emitting devices. Each light-emitting device may include at least an anode, a light-emitting functional layer, and a cathode. The anode may be connected to the second electrode of a transistor via a connecting electrode. The light-emitting functional layer may be connected to the anode, the cathode may be connected to the light-emitting functional layer, and the cathode may be connected to a second power line. The light-emitting functional layer emits light under the drive of the anode and the cathode. In an exemplary embodiment, the light-emitting functional layer may include a light-emitting layer (EML) and any one or more of the following: a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL).

[0088] Figure 4 is a cross-sectional schematic diagram of a light-emitting structure according to an exemplary embodiment of the present invention. As shown in Figure 4, the light-emitting structure 1 may include at least two light-emitting units 4 arranged in series in a direction perpendicular to the substrate (not shown in the figure). At least one light-emitting unit 4 may include a light-emitting layer 11 and an exciton blocking layer 12 stacked in a direction perpendicular to the substrate (i.e., a first direction). The exciton blocking layer 12 may be located on the side of the light-emitting layer 11 closest to the substrate. The light-emitting layer 11 may include a red light-emitting layer 14, a green light-emitting layer 15, and a blue light-emitting layer 16 arranged in a direction parallel to the substrate. Two of the red light-emitting layer 14, green light-emitting layer 15, and blue light-emitting layer 16 are disposed on the end face of the exciton blocking layer 12 away from the substrate (not shown in the figure) and located between the two ends of the exciton blocking layer 12 in the direction parallel to the substrate.

[0089] In some exemplary embodiments, as shown in FIG4, the light-emitting structure 1 may include a first electrode 5, a second electrode 6, and at least one light-emitting unit 4. The at least one light-emitting unit 4 may be located between the first electrode 5 and the second electrode 6. The second electrode 6 may be located on the side of the at least one light-emitting unit 4 closer to the substrate in a first direction, and the first electrode 5 may be located on the other side in the first direction. In some exemplary embodiments, the first electrode 5 may be a cathode, and the second electrode 6 may be an anode, but is not limited to this. For example, the first electrode 5 may be an anode, and the second electrode 6 may be a cathode. The material of the first electrode 5 may include a low work function metal, such as aluminum (Al), silver (Ag), magnesium (Mg), etc., or an alloy containing a low work function metal material. The material of the second electrode 6 may be a high work function electrode material. The material of the second electrode 6 may include a transparent oxide, such as indium tin oxide (ITO) and indium zinc oxide (IZO). The thickness of the second electrode 6 may be the minimum dimension of the second electrode 6 in the first direction, and the thickness of the second electrode 6 may be from 80 nm to 200 nm. However, this is not the only possibility. The material of the second electrode 6 may include stacked metal layers and oxide layers, wherein the metal layers and oxide layers constitute a composite electrode, such as Ag / ITO, Al / ITO, Ag / IZO, Al / IZO, etc. The thickness of the metal layer can be from 5 nm to 20 nm, and the thickness of the oxide layer can be from 5 nm to 20 nm. The light-emitting structure 1 can be a bottom-emitting device, that is, the light-emitting structure 1 can emit light towards the side with the second electrode 6. The thickness of the first electrode 5 needs to exceed 80 nm to ensure good reflectivity, and the second electrode 6 can be a transparent electrode. Alternatively, the light-emitting structure 1 can be a top-emitting device, the thickness of the first electrode 5 needs to be adjusted within the range of 10 nm to 20 nm to ensure a certain transmittance, and the second electrode 6 can be a reflective composite electrode.

[0090] In some exemplary embodiments, as shown in FIG4, a light extraction layer 2 (CPL) and an encapsulation layer 3 are sequentially disposed on the side of the first electrode 5 away from the substrate. The light extraction layer 2 can improve the optical output of the light-emitting structure 1. The light extraction layer 2 can be formed by vapor deposition of a small organic molecule material of 50 nm to 80 nm. The refractive index of the light extraction layer 2 at 460 nm is greater than 1.8 or less than 1.5. The encapsulation layer 3 can be formed by UV sealant or by thin-film encapsulation (TFE), etc., and the encapsulation layer 3 can protect the light-emitting structure 1.

[0091] In some exemplary embodiments, as shown in FIG4, the light-emitting unit 4 can emit light when a current is provided. The light-emitting unit 4 may include a hole transport layer 13, an exciton blocking layer 12, a light-emitting layer 11, and a hole blocking layer 10 arranged sequentially in the direction away from the substrate. The light-emitting layer 11 may include a red light-emitting layer 14, a green light-emitting layer 15, and a blue light-emitting layer 16. The light-emitting unit 4 also includes a red electron blocking layer 17 and a blue electron blocking layer 18. The red light-emitting layer 14, the green light-emitting layer 15, and the blue light-emitting layer 16 are configured as the same layer, and the red electron blocking layer 17 and the blue electron blocking layer 18 are configured as the same layer. The two ends of the exciton blocking layer 12 in the direction parallel to the substrate may be a first end 24 and a second end 25. The red light-emitting layer 14 and the green light-emitting layer 15 are located between the first end 24 and the second end 25. The orthographic projections of the red light-emitting layer 14 and the green light-emitting layer 15 on the substrate are located within the orthographic projection of the exciton blocking layer 12 on the substrate. The green light-emitting layer 15 is disposed on the end face of the exciton blocking layer 12 away from the substrate.

[0092] In some exemplary embodiments, as shown in FIG4, a red electron blocking layer 17 is located between a red emitting layer 14 and an exciton blocking layer 12, and the orthogonal projection of the red emitting layer 14 onto the substrate lies within the orthogonal projection of the red electron blocking layer 17 onto the substrate. The material of the red emitting layer 14 may include a host material and a guest material. The host material of the red emitting layer 14 may be a single material, a material with thermally activated delayed fluorescence (TADF) properties, or a host material formed by blending P-type and N-type materials. The guest material of the red emitting layer 14 may be a phosphorescent material or a boron-containing fluorescent material. The thickness of the red emitting layer 14 may be 30 nm to 80 nm, and the thickness may be the minimum dimension of the red emitting layer 14 in the first direction. The red electron blocking layer 17 can transport holes and prevent excitons in the red emitting layer 14 from diffusing to the hole transport layer 13, thereby improving efficiency and device stability. Adjusting the thickness of the red electron blocking layer 17 allows for adjustment of the red light optical cavity length. The material of the red electron blocking layer 17 may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives.

[0093] In some exemplary embodiments, as shown in FIG4, the blue electron blocking layer 18 is located on the side of the blue emitting layer 16 near the substrate. The orthographic projection of the blue emitting layer 16 on the substrate does not overlap with the orthographic projection of the exciton blocking layer 12 on the substrate, and the orthographic projection of the blue emitting layer 16 on the substrate lies within the orthographic projection of the blue electron blocking layer 18 on the substrate. The material of the blue emitting layer 16 includes at least one host material and one fluorescent guest material. The emission spectrum of the host material of the blue emitting layer 16 and the absorption spectrum of the fluorescent guest material have a large overlap. Under normalized spectral conditions, the area of ​​the overlapping region accounts for not less than 60% of the area of ​​the guest absorption spectrum. The host material of the blue emitting layer 16 may be anthracene, fluorene, pyrene, or their derivatives. The fluorescent guest material of the blue emitting layer 16 may include pyrene organic compounds or boron-containing organic compounds, and the doping concentration of the boron-containing organic compounds may be 0.5% to 5%. The main emission peak wavelength of the blue emitting layer 16 is between 450 nm and 470 nm. The blue electron blocking layer 18 lowers the transport barrier for holes from the adjacent hole transport layer 13 to the blue emitting layer 16. Therefore, the highest occupied orbital (HOMO) energy level of the material in the blue electron blocking layer 18 is numerically between the HOMO of the adjacent hole transport layer 13 and the HOMO of the blue emitting layer 16. Furthermore, the blue electron blocking layer 18 also exhibits exciton blocking properties, and the first excited state energy of the singlet state of the material in the blue electron blocking layer 18 is greater than that of the material in the blue emitting layer 16. The material of the blue electron blocking layer 18 may include carbazole and its derivatives.

[0094] In some exemplary embodiments, as shown in FIG4, the green light-emitting layer 15 may be in direct contact with the exciton blocking layer 12. The green light-emitting layer 15 may include a first sub-light-emitting layer. The material of the first sub-light-emitting layer includes a host material, a sensitizing material, and a guest material. The doping ratio of the sensitizing material in the first sub-light-emitting layer is less than the doping ratio of the host material in the first sub-light-emitting layer but greater than the doping ratio of the guest material in the first sub-light-emitting layer. The host material may be a carbazole-based material. The sensitizing material may include a fluorescent material, or a material with delayed fluorescence characteristics, or a coordination material with a fast inter-gap crossing rate. Complex materials with rapid intergrowth rates can be materials containing transition metal elements such as Ir, Pt, and Os; materials with delayed fluorescence properties can be polycarbazole materials with a DLA structure. Polycarbazole materials with a DLA structure refer to a class of carbazole compounds with a donor-π-bridger-acceptor (D-π-A) structure, where carbazole acts as a π-bridger, connecting the donor and acceptor groups. The difference between the lowest singlet and lowest triplet energy levels of materials with delayed fluorescence properties is less than 0.3 eV. The guest material can be a fluorescent material, which can be a boron-containing organic compound. The doping ratio of the guest material in the first sub-emissive layer is no higher than 5%, for example, in this example, the doping ratio of the guest material in the first sub-emissive layer can be less than 3%.

[0095] In some exemplary embodiments, the green light-emitting layer 15, in addition to having a first sub-light-emitting layer, also includes at least one auxiliary sub-light-emitting layer, which is located between the first sub-light-emitting layer and the substrate. The material of the auxiliary sub-light-emitting layer includes at least one of the three materials constituting the first sub-light-emitting layer, which may be a host material, a sensitizing material, and a guest material. The materials of the blue light-emitting layer 16 and the red light-emitting layer 14 may be the same as the material of the green light-emitting layer 15.

[0096] In some exemplary embodiments, the green light-emitting layer 15 includes a first sub-light-emitting layer and an auxiliary sub-light-emitting layer, wherein the auxiliary sub-light-emitting layer may be a second sub-light-emitting layer. The material of the second sub-light-emitting layer has only one material, namely the host material constituting the first sub-light-emitting layer. However, it is not limited to this; for example, the material of the second sub-light-emitting layer has two materials, namely the host material and the guest material constituting the first sub-light-emitting layer; or, for example, the material of the second sub-light-emitting layer has three materials, namely the host material, the sensitizing material, and the guest material constituting the first sub-light-emitting layer. In some exemplary embodiments, the doping ratio of the sensitizing material in the first sub-light-emitting layer is a first ratio, and the doping ratio of the sensitizing material in the second sub-light-emitting layer is a second ratio, wherein the difference between the first ratio and the second ratio may be less than 25%. The doping ratio of the guest material in the first sub-light-emitting layer is a third ratio, and the doping ratio of the guest material in the second sub-light-emitting layer is a fourth ratio, wherein the change between the third ratio and the fourth ratio may be less than 5%.

[0097] In some exemplary embodiments, the auxiliary sub-emitting layer has two components: a second sub-emitting layer and a third sub-emitting layer. The first, third, and second sub-emitting layers are sequentially disposed in a direction away from the substrate. The material of the second sub-emitting layer includes at least one material selected from the host material, sensitizing material, and guest material constituting the first sub-emitting layer. The material of the third sub-emitting layer includes at least two materials selected from the host material, sensitizing material, and guest material constituting the first sub-emitting layer. The material of the third sub-emitting layer may include two materials: the host material constituting the first sub-emitting layer and the sensitizing material. The doping ratio of the sensitizing material in the first sub-emitting layer is a first ratio, and the doping ratio of the sensitizing material in the third sub-emitting layer is a fifth ratio. The difference between the first ratio and the fifth ratio is less than 20%. The material of the third sub-emissive layer may include three types of materials: the host material constituting the first sub-emissive layer, the sensitizing material, and the guest material. The doping ratio of the sensitizing material in the first sub-emissive layer is the first ratio, and the doping ratio of the sensitizing material in the third sub-emissive layer is the fifth ratio, with the difference between the first ratio and the fifth ratio being less than 25%. The doping ratio of the guest material in the first sub-emissive layer is the third ratio, and the doping ratio of the guest material in the third sub-emissive layer is the sixth ratio, with the difference between the third ratio and the sixth ratio being less than 5%.

[0098] In some exemplary embodiments, the second sub-emitting layer has one material constituting the first sub-emitting layer, and the third sub-emitting layer has two materials constituting the first sub-emitting layer. The doping ratio of the guest material in the first, second, and third sub-emitting layers is less than 5%, and the doping ratio of the sensitizing material in the first, second, and third sub-emitting layers is less than the doping ratio of the host material, and less than 45%.

[0099] In some exemplary embodiments, as shown in FIG4, the material of the exciton blocking layer 12 includes a hole-type material with high mobility, which includes triphenylamine, furan, carbazole, thiophene or phenylfluorene groups.

[0100] In some exemplary embodiments, as shown in FIG4, the orthogonal projection of the exciton blocking layer 12 onto the substrate lies within the orthogonal projection of the hole transport layer 13 onto the substrate. The hole transport layer 13 may be formed of a material with good hole transport characteristics, and the thickness of the hole transport layer 13 may be less than or equal to 200 nm, which may be the minimum dimension of the hole transport layer 13 in the first direction. The material of the hole transport layer 13 may include carbazole and its derivatives with high hole mobility. The light-emitting structure 1 may be a top-emitting device, and the optical cavity length of the blue light emitted by the light-emitting structure 1 can be adjusted by adjusting the thickness of the hole transport layer 13. The thickness of the hole blocking layer 10 may be from 5 nm to 30 nm, and the thickness of the hole blocking layer 10 may be the minimum dimension of the hole blocking layer 10 in the first direction. In some exemplary embodiments, the light-emitting structure 1 can be a top-emitting device. The optical thickness of the organic layer between the first electrode and the second electrode needs to meet the optical path requirements of the optical micro-resonator, so as to obtain the optimal light emission intensity and the desired color. The internal optical path of the light-emitting structure 1 can be adjusted by changing the thickness of the hole transport layer 13, which has a smaller impact on the voltage.

[0101] In some exemplary embodiments, as shown in FIG4, the hole mobility of the exciton blocking layer 12 is μ p1 The hole mobility of hole transport layer 13 is μ p2 The hole mobility of the red electron blocking layer 17 is μ p3 , of which 10 -3 ≤μ p1 / μ p2 ≤1, 1≤μ p1 / μ p3 ≤10 3The exciton blocking layer 12 has an energy level of H1, the hole transport layer 13 has an energy level of H2, and the red electron blocking layer 17 has an energy level of H3, wherein |H1-H2| ≤ 0.15 eV, and |H1| ≤ |H3|. In some exemplary embodiments, the hole transport layer 13 and the exciton blocking layer 12 are spaced apart in a direction perpendicular to the substrate (a first direction), the exciton blocking layer 12 has an energy level of H1, the hole transport layer 13 has an energy level of H2, and |H1-H2| ≥ 0.15 eV.

[0102] In some exemplary embodiments, as shown in FIG4, the T1 energy of the hole blocking layer 10 is greater than the T1 energy of the TADF-characteristic material in the adjacent green emitting layer 15, and the difference in T1 energy between the two is not less than 0.2 eV. The absolute value of the HOMO of the material of the hole blocking layer 10 is greater than the absolute value of the HOMO of all materials in the connected emitting layers, optimized to exceed 0.2 eV. The absolute value of the LUMO (lowest unoccupied orbital level in a molecule) of the material of the hole blocking layer 10 is less than the absolute value of the LUMO of all materials in the connected emitting layers.

[0103] In some exemplary embodiments, as shown in FIG4, the light-emitting structure 1 further includes an electron injection layer 19 and an electron output layer 20 located between the first electrode 5 and the light-emitting unit 4. The electron injection layer 19 is located on the side of the electron output layer 20 closer to the first electrode 5 in a first direction. The material of the electron injection layer 19 may include a low work function metal, such as Li, Ca, or Yb, or may include a metal salt, such as LiF, LiQ, etc., formed by vapor deposition. The thickness of the electron injection layer 19 may be 0.5 nm to 2 nm, and the thickness of the electron injection layer 19 may be the minimum dimension of the electron injection layer 19 in the first direction. The electron output layer 20 may be formed by vapor deposition of a material with good electron transport properties, or may be formed by doping an electron transport material with materials such as LiQ, Li, Ca, etc., in a predetermined ratio. The absolute LUMO value of the material of the electron output layer 20 is greater than the absolute LUMO value of the material of the connected hole blocking layer 10.

[0104] In some exemplary embodiments, as shown in FIG4, the light-emitting structure 1 further includes a hole injection layer 7 located between the second electrode and the light-emitting unit 4. The material of the hole injection layer 7 can be an injection material such as CuPc, HATCN, or MoO3. However, it is not limited to this. For example, the material of the hole injection layer 7 can also be formed by p-type doping of a hole transport material. The p-type dopant can be an oxide-based inorganic material, or it can be an axialene-based organic material. The thickness of the hole injection layer 7 can be from 1 nm to 30 nm, and the thickness of the hole injection layer 7 can be the minimum dimension of the hole injection layer 7 in the first direction. The hole injection layer 7 can be formed by multi-source co-evaporation.

[0105] Figure 5 is a schematic diagram of the pixel arrangement of a display panel according to an exemplary embodiment of this invention. In some exemplary embodiments, as shown in Figures 4 and 5, the light-emitting structure 1 emits light after being powered on. The red light-emitting layer 14 emits red light and forms a red sub-pixel 21 on the display panel. The portion of the light-emitting structure 1 that emits red light constitutes a red light-emitting device. The green light-emitting layer 15 emits green light and forms a green sub-pixel 22 on the display panel. The portion of the light-emitting structure 1 that emits green light constitutes a green light-emitting device. The blue light-emitting layer 16 emits blue light and forms a blue sub-pixel 23 on the display panel. The portion of the light-emitting structure 1 that emits blue light constitutes a blue light-emitting device. A red sub-pixel 21, a green sub-pixel 22, and a blue sub-pixel 23 constitute a pixel group. Multiple pixel groups are arrayed on a plane formed by a second direction and a third direction. The first direction and the second direction are both perpendicular to the first direction and mutually perpendicular, and the second direction and the third direction are both parallel to the substrate. A red sub-pixel 21 and a green sub-pixel 22 constitute a first pixel group, and a blue sub-pixel 23 constitutes a second pixel group. The first and second pixel groups are arranged alternately in a third direction. The red sub-pixel 21 and the green sub-pixel 22 are arranged alternately along a second direction. The red sub-pixel 21 and the green sub-pixel 22 share an exciton blocking layer, which simplifies the structure and reduces the number of vapor deposition chambers and fine metal masks (FMMs), thus reducing manufacturing difficulty and cost. The light-emitting structure 1 has a partition structure between adjacent light-emitting devices. The partition structure can be an isolation pillar between adjacent light-emitting devices. The partition structure can isolate the connection of the charge generation layers of adjacent light-emitting devices, thereby reducing or eliminating the amount of leakage current flowing between adjacent light-emitting devices.

[0106] Figure 6 is a schematic diagram of the pixel arrangement of another display panel according to this exemplary embodiment. In some exemplary embodiments, as shown in Figures 4 and 6, the light-emitting structure 1 emits light after being powered on. The red light-emitting layer 14 emits red light and forms a red sub-pixel 21 on the display panel; the green light-emitting layer 15 emits green light and forms a green sub-pixel 22 on the display panel; and the blue light-emitting layer 16 emits blue light and forms a blue sub-pixel 23 on the display panel. One red sub-pixel 21, two green sub-pixels 22, and one blue sub-pixel 23 constitute a pixel group. Multiple pixel groups are arrayed on a plane formed by the second direction and the third direction. The first direction and the second direction are both perpendicular to the first direction and perpendicular to each other, and the second direction and the third direction are both parallel to the substrate.

[0107] Figure 7 is a schematic diagram of a substrate projection of this exemplary embodiment. In some exemplary embodiments, as shown in Figures 4, 5, and 7, a display panel having the light-emitting structure 1 shown in Figure 4 adopts the pixel arrangement structure shown in Figure 5 to obtain the projection structure shown in Figure 7. The area of ​​the light-emitting region of the red light-emitting layer 14 projected onto the substrate is S1, the area of ​​the light-emitting region of the green light-emitting layer 15 projected onto the substrate is S2, and the area of ​​the exciton blocking layer 12 projected onto the substrate is T1, where T1 > (S1 + S2). In some exemplary embodiments, the contact area between the exciton blocking layer 12 and the light-emitting layer 11 is T2, where T2 > S1 and T2 > S2. The area of ​​the hole blocking layer 10 projected onto the substrate is T3, where T1 ≥ T2 and T1 < T3.

[0108] In some exemplary embodiments, as shown in FIG4, the light-emitting structure 1 has two light-emitting units 4, which are arranged sequentially in a first direction and connected in series. However, it is not limited to this. For example, the light-emitting structure 1 may have more than two light-emitting units 4 or may have only one light-emitting unit 4.

[0109] In some exemplary embodiments, as shown in FIG4, the two light-emitting units 4 can be divided into a first light-emitting unit 4-1 and a second light-emitting unit 4-2, with the first light-emitting unit 4-1 located on the side of the second light-emitting unit 4-2 away from the substrate. The hole-blocking layer 10 in the first light-emitting unit 4-1 can be a first hole-blocking layer 10-1, and the hole-blocking layer 10 in the second light-emitting unit 4-2 can be a second hole-blocking layer 10-2. The hole transport layer 13 in the first light-emitting unit 4-1 can be a first hole transport layer 13-1, and the hole transport layer 13 in the second light-emitting unit 4-2 can be a second hole transport layer 13-2. The red light-emitting layer 14 in the first light-emitting unit 4-1 can be a first red light-emitting layer 14-1, and the red light-emitting layer 14 in the second light-emitting unit 4-2 can be a second red light-emitting layer 14-2. The green light-emitting layer 15 in the first light-emitting unit 4-1 can be a first green light-emitting layer 15-1, and the green light-emitting layer 15 in the second light-emitting unit 4-2 can be a second green light-emitting layer 15-2. The blue light-emitting layer 16 in the first light-emitting unit 4-1 can be a first blue light-emitting layer 16-1, and the blue light-emitting layer 16 in the second light-emitting unit 4-2 can be a second blue light-emitting layer 16-2. The red electron blocking layer 17 in the first light-emitting unit 4-1 can be a first red electron blocking layer 17-1, and the red electron blocking layer 17 in the second light-emitting unit 4-2 can be a second red electron blocking layer 17-2. The blue electron blocking layer 18 in the first light-emitting unit 4-1 can be a first blue electron blocking layer 18-1, and the blue electron blocking layer 18 in the second light-emitting unit 4-2 can be a second blue electron blocking layer 18-2. The exciton blocking layer 12 in the first light-emitting unit 4-1 can be a first exciton blocking layer 12-1, and the exciton blocking layer 12 in the second light-emitting unit 4-2 can be a second exciton blocking layer 12-2.

[0110] In some exemplary embodiments, as shown in FIG4, the materials of corresponding components of the first light-emitting unit 4-1 and the second light-emitting unit 4-2 may be the same or different. For example, the materials of the first hole blocking layer 10-1 and the second hole blocking layer 10-2 may be the same or different. As another example, the materials of the first hole transport layer 13-1 and the second hole transport layer 13-2 may be the same or different. As another example, the materials of the first red light-emitting layer 14-1 and the second red light-emitting layer 14-2 may be the same or different. As another example, the materials of the first green light-emitting layer 15-1 and the second green light-emitting layer 15-2 may be the same or different. As another example, the materials of the first blue light-emitting layer 16-1 and the second blue light-emitting layer 16-2 may be the same or different. As another example, the materials of the first red electron blocking layer 17-1 and the second red electron blocking layer 17-2 may be the same or different. As another example, the materials of the first blue electron blocking layer 18-1 and the second blue electron blocking layer 18-2 may be the same or different. For example, the materials of the first exciton blocking layer 12-1 and the second exciton blocking layer 12-2 may be the same or different.

[0111] In some exemplary embodiments, as shown in FIG4, the first light-emitting unit 4-1 and the second light-emitting unit 4-2 are connected in series through a charge generation layer. The charge generation layer is located between the first light-emitting unit 4-1 and the second light-emitting unit 4-2. The charge generation layer includes a P-type charge generation layer 8 and an N-type charge generation layer 9, which are stacked in a first direction. The P-type charge generation layer 8 is located on the side of the N-type charge generation layer 9 away from the second light-emitting unit 4-2. The material of the N-type charge generation layer 9 can be an ET-type material doped with a low work function active metal, such as Li, Ca, Yb, etc.; the material of the P-type charge generation layer 8 can be formed by doping a HT-type material with a P-type dopant, and the P-type dopant can be molybdenum oxide. The proportion of P-type dopant in the P-type charge generation layer 8 is higher than the doping proportion of P-type dopant in the hole injection layer 7, which is beneficial to charge generation.

[0112] In some exemplary embodiments, the light-emitting structure 1 further includes an electron transport layer (not shown), which may be located on the side of the N-type charge generation layer 9 away from the P-type charge generation layer 8 in a first direction. The electron transport layer (not shown) may have the same function as the electron output layer 20, and the material of the electron transport layer (not shown) may be the same as or different from that of the electron output layer 20.

[0113] The applicant discovered that current light-emitting devices employ a sensitized light-emitting mechanism in the green light-emitting layer 15, which comprises three materials. The green light-emitting layer 15 and the hole transport layer 13 require two blocking layers stacked in the first direction. The fabrication of these two blocking layers necessitates separate chambers, leading to an increase in the number of chambers and photomasks, and a more complex fabrication process. The blue electron blocking layer has different requirements than the green electron blocking layer, needing a wider bandgap and slower mobility. The green and red electron blocking layers, being thicker, require faster mobility. Therefore, there are significant differences in the bandgap and mobility between the blue electron blocking layer and the blocking layers for the other two colors. In some exemplary embodiments, as shown in FIG4, this example uses a single exciton blocking layer 12 shared by the red and green light-emitting layers. Furthermore, the first sub-light-emitting layer replaces one blocking layer, reducing the structure between the green light-emitting layer and the hole transport layer 13, simplifying the structure, and improving exciton utilization to a certain extent, thus increasing the device efficiency of green light. Moreover, only one photomask and one evaporation process are needed to fabricate the exciton blocking layer 12, reducing the number of chambers and photomasks. Additionally, the red light-emitting layer adjusts the optical cavity length of the red light by sharing the thickness of the exciton blocking layer and the red electron blocking layer. Therefore, the thickness of the red electron blocking layer can be significantly reduced, allowing for more flexible selection of the hole mobility of the material. Moreover, the structure composed of the red light-emitting layer, the exciton blocking layer, and the red electron blocking layer facilitates the adjustment of charge balance and exciton recombination regions in the red light-emitting layer, improving exciton utilization and increasing the device efficiency of red light. FIG8 is a cross-sectional schematic diagram of another light-emitting structure of this exemplary embodiment. In some exemplary embodiments, as shown in FIG8, the second light-emitting unit 4-2 reduces one exciton blocking layer 12 compared to the first light-emitting unit 4-1. The first light-emitting unit 4-1 in Figure 8 can have the same structure as the first light-emitting unit 4-1 in Figure 4, while the second light-emitting unit 4-2 in Figure 8 can be different from the second light-emitting unit 4-2 in Figure 4. As shown in Figure 8, in the second light-emitting unit 4-2, the end face of the second red electron blocking layer 17-2 near the second hole transport layer 13-2 directly contacts the second hole transport layer 13-2, and the end face of the second green light-emitting layer 15-2 near the second hole transport layer 13-2 directly contacts the second hole transport layer 13-2. However, it is not limited to this. For example, the first light-emitting unit 4-1 reduces one exciton blocking layer 12 compared to the second light-emitting unit 4-2. For another example, the light-emitting structure 1 has m light-emitting units 4, where m is a positive integer greater than or equal to 3. The number of light-emitting units 4 with exciton blocking layers 12 is n, and the number of light-emitting units 4 without exciton blocking layers 12 is (mn), where n ≤ m, and n can be a positive integer greater than or equal to 1.

[0114] Figure 9 is a cross-sectional schematic diagram of another light-emitting structure according to this exemplary embodiment. In some exemplary embodiments, as shown in Figure 9, the second light-emitting unit 4-2 reduces one exciton blocking layer 12 compared to the first light-emitting unit 4-1, and the first light-emitting unit 4-1 omits the red electron blocking layer 17. The first light-emitting unit 4-1 in Figure 8 may be different from the first light-emitting unit 4-1 in Figure 4. The first light-emitting unit 4-1 in Figure 8 reduces the first red electron blocking layer 17-1, so that the first red light-emitting layer 14-1 directly contacts the exciton blocking layer 12. The second light-emitting unit 4-2 in Figure 9 may be different from the second light-emitting unit 4-2 in Figure 4. As shown in Figure 8, in the second light-emitting unit 4-2, the end face of the second red electron blocking layer 17-2 near the second hole transport layer 13-2 directly contacts the second hole transport layer 13-2, and the end face of the second green light-emitting layer 15-2 near the second hole transport layer 13-2 directly contacts the second hole transport layer 13-2.

[0115] Figure 10 is another schematic diagram of substrate projection according to this exemplary embodiment. In some exemplary embodiments, as shown in Figures 9 and 10, a display panel having the light-emitting structure 1 shown in Figure 9 adopts the pixel arrangement structure shown in Figure 5 to obtain the projection structure shown in Figure 10. The area of ​​the light-emitting region of the red light-emitting layer 14 projected onto the substrate is S1, the area of ​​the light-emitting region of the green light-emitting layer 15 projected onto the substrate is S2, and the area of ​​the exciton blocking layer 12 projected onto the substrate is T1, where T1 > (S1 + S2). In some exemplary embodiments, the contact area between the exciton blocking layer 12 and the light-emitting layer 11 is T2, and the sum of the contact area between the exciton blocking layer 12 and the green light-emitting layer 15 and the contact area between the exciton blocking layer 12 and the red light-emitting layer 14 is T2, where T2 > S1 and T2 > S2. The area of ​​the hole blocking layer 10 projected onto the substrate is T3, where T1 ≥ T2 and T1 < T3.

[0116] The applicant conducted tests based on the aforementioned light-emitting structure 1, and the specific test data is shown in Table 1 below.

[0117] Table 1

[0118] In some exemplary embodiments, as shown in Figures 4 and 5, the light-emitting structure in Scheme 1 adopts the pixel arrangement scheme shown in Figure 5 and the structure of the light-emitting structure shown in Figure 4. The components of the light-emitting structure in the direction away from the substrate are as follows:

[0119] Second electrode 6: Metal Ag (100nm thick) / ITO (8nm thick), that is, 100nm thick metal silver is plated with 8nm thick ITO.

[0120] Hole injection layer 7: First transport material HTL(1) (thickness 10nm), the material of the first transport material HTL(1) can also be formed by p-type doping of hole transport material, with a doping ratio of 3%;

[0121] Second hole transport layer 13-2: First transport material HTL(1) (thickness 30nm);

[0122] Second exciton blocking layer 12-2: First hole-type material C-Prime (1), the material of the first hole-type material C-Prime (1) may include a hole-type material with high mobility;

[0123] Second red electron blocking layer 17-2: First red electron blocking material R-EBL(1), the first red electron blocking material R-EBL(1) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives;

[0124] Second blue electron blocking layer 18-2: Blue electron blocking material B-EBL (thickness 5nm), which may include carbazole and its derivatives;

[0125] The second red luminescent layer 14-2 consists of red light host material RH and red light guest material RD, with a thickness of 45nm and a content of 3% for the luminescent guest material RD.

[0126] Second green luminescent layer 15-2: Green light host material GH: Green light guest material GD (99%: 1.0%) (thickness 5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%: 30%: 1.0%) (thickness 30nm);

[0127] Second blue emitting layer 16-2: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0128] Second hole blocking layer 10-2: Hole blocking material HB, thickness 5nm;

[0129] N-type charge generation layer 9: n-CG:Yb, thickness 12nm, Yb doping ratio 1%;

[0130] P-type charge generation layer 8: First transport material HTL(1), thickness 10nm;

[0131] First hole transport layer 13-1: First transport material HTL(1), thickness 40nm;

[0132] First exciton blocking layer 12-1: First hole-type material C-Prime(1);

[0133] First red electron blocking layer 17-1: First red light electron blocking material R-EBL(1);

[0134] First blue electron blocking layer 18-1: First transport material HTL(1);

[0135] First red emitting layer 14-1: Red light host material RH: Red light guest material RD (3%), thickness 45nm;

[0136] First green luminescent layer 15-1: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%), thickness 30nm;

[0137] First blue emitting layer 16-1: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0138] First hole blocking layer 10-1: Hole blocking material HB (thickness 5nm);

[0139] Electron output layer 20: ET:LiQ (thickness 35nm, ratio 50%:50%);

[0140] Electron injection layer 19: Electron injection material EIL (1 nm thick), the electron injection material EIL, the electron injection material EIL may include low work function metals, such as Li, Ca or Yb, or may include metal salts, such as LiF, LiQ, etc., formed by vapor deposition;

[0141] First electrode 5: Metal Mg: Metal Ag, thickness 15nm.

[0142] The above scheme allows for adjustment of the thicknesses of the second hole transport layer 13-2 and the first hole transport layer 13-1 to correspond to the color coordinates required for blue light. With the thicknesses of the first and second hole transport layers 13-1 and 13-2 fixed, the color coordinates required for green light can be achieved by adjusting the thicknesses of the first and second exciton blocking layers 12-1 and 12-2. With the thicknesses of the first and second exciton blocking layers 12-1 and 12-2 fixed, the color coordinates required for red light can be achieved by adjusting the thicknesses of the first and second red electron blocking layers 17-1 and 17-2.

[0143] In Scheme 1, the light-emitting structure shares an exciton blocking layer 12 between the red and green light-emitting layers. Furthermore, the first sub-light-emitting layer replaces a single blocking layer, reducing the structural gap between the green light-emitting layer and the hole transport layer 13, simplifying the structure, and improving exciton utilization and device efficiency for green light. Moreover, only one photomask and one evaporation process are needed to fabricate the exciton blocking layer 12, reducing the number of cavities and photomasks. Additionally, the red light-emitting layer adjusts the optical cavity length for red light by utilizing the shared thickness of the exciton blocking layer and the red electron blocking layer. Therefore, the thickness of the red electron blocking layer can be significantly reduced, allowing for greater flexibility in selecting the hole mobility of the material. Moreover, the structure composed of the red light-emitting layer, exciton blocking layer, and red electron blocking layer facilitates the adjustment of charge balance and exciton recombination regions within the red light-emitting layer, improving exciton utilization and device efficiency for red light.

[0144] In some exemplary embodiments, as shown in Figures 4 and 5, the light-emitting structure in Scheme 2 adopts the pixel arrangement scheme shown in Figure 5 and the structure of the light-emitting structure shown in Figure 4. The components of the light-emitting structure in the direction away from the substrate are as follows:

[0145] Second electrode 6: Metal Ag (100nm thick) / ITO (8nm thick);

[0146] Hole injection layer 7: First transport material HTL(1), the material of the first transport material HTL(1) can also be formed by p-type doping of hole transport material, with a doping ratio of 3%;

[0147] Second hole transport layer 13-2: First transport material HTL(1), thickness 30nm;

[0148] Second exciton blocking layer 12-2: Second hole-type material C-Prime (2), the second hole-type material C-Prime (2) may include a hole-type material with high mobility;

[0149] Second red electron blocking layer 17-2: First red electron blocking material R-EBL(1), the first red electron blocking material R-EBL(1) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives;

[0150] Second blue electron blocking layer 18-2: Blue electron blocking material B-EBL (thickness 5nm), which may include carbazole and its derivatives;

[0151] Second red luminescent layer 14-2: Red light host material RH: Red light guest material RD (3%) / Hole blocking material HB (5nm) / n-CG: Yb (1%);

[0152] Second green luminescent layer 15-2: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%) (thickness 30nm);

[0153] Second blue emitting layer 16-2: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0154] Second hole blocking layer 10-2: Hole blocking material HB (5nm), thickness 5nm;

[0155] N-type charge generation layer 9: n-CG:Yb, thickness 12nm, Yb doping ratio 1%;

[0156] P-type charge generation layer 8: First transport material HTL(1), thickness 10nm;

[0157] First hole transport layer 13-1: First transport material HTL(1), thickness 40nm;

[0158] First exciton blocking layer 12-1: Second hole-type material C-Prime(2);

[0159] First red electron blocking layer 17-1: First red light electron blocking material R-EBL(1);

[0160] First blue electron blocking layer 18-1: First transport material HTL(1);

[0161] First red emitting layer 14-1: Red light host material RH: Red light guest material RD (3%) / Hole blocking material HB (5nm) / n-CG: Yb (1%), thickness 45nm;

[0162] First green luminescent layer 15-1: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%), thickness 30nm;

[0163] First blue emitting layer 16-1: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0164] First hole blocking layer 10-1: Hole blocking material HB, thickness 5nm;

[0165] Electron output layer 20: ET:LiQ (thickness 35nm, ratio 50%:50%);

[0166] Electron injection layer 19: Electron injection material EIL, electron injection material EIL, thickness 1nm, the electron injection material EIL may include low work function metals, such as Li, Ca or Yb, or may include metal salts, such as LiF, LiQ, etc., formed by vapor deposition;

[0167] First electrode 5: Metal Mg: Metal Ag, thickness 15nm.

[0168] In Scheme 2, compared to Scheme 1, the material of the exciton blocking layer is replaced by the second hole-type material C-Prime (2) instead of the first hole-type material C-Prime (1). The mobility of the second hole-type material C-Prime (2) is greater than that of the first hole-type material C-Prime (1).

[0169] In some exemplary embodiments, as shown in Figures 4 and 5, the light-emitting structure in Scheme 3 adopts the pixel arrangement scheme shown in Figure 5 and the structure of the light-emitting structure shown in Figure 4. The components of the light-emitting structure in the direction away from the substrate are as follows:

[0170] Second electrode 6: Metal Ag (100nm thick) / ITO (8nm thick);

[0171] Hole injection layer 7: First transport material HTL(1) (thickness 10nm), the material of the first transport material HTL(1) can also be formed by p-type doping of hole transport material, with a doping ratio of 3%;

[0172] Second hole transport layer 13-2: First transport material HTL(1) (thickness 30nm);

[0173] Second exciton blocking layer 12-2: First hole-type material C-Prime (1), the material of the first hole-type material C-Prime (1) may include a hole-type material with high mobility;

[0174] Second red electron blocking layer 17-2: First red electron blocking material R-EBL(1), the first red electron blocking material R-EBL(1) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives;

[0175] Second blue electron blocking layer 18-2: Blue electron blocking material B-EBL (thickness 5nm), which may include carbazole and its derivatives;

[0176] The second red luminescent layer 14-2 consists of red light host material RH and red light guest material RD, with a thickness of 45nm and a content of 3% for the luminescent guest material RD.

[0177] Second green luminescent layer 15-2: Green light host material GH (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%);

[0178] Second blue emitting layer 16-2: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0179] Second hole blocking layer 10-2: Hole blocking material HB (5nm);

[0180] N-type charge generation layer 9: n-CG:Yb, thickness 12nm, Yb doping ratio 1%;

[0181] P-type charge generation layer 8: First transport material HTL(1), thickness 10nm;

[0182] First hole transport layer 13-1: First transport material HTL(1), thickness 40nm;

[0183] First exciton blocking layer 12-1: First hole-type material C-Prime(1);

[0184] First red electron blocking layer 17-1: First red light electron blocking material R-EBL(1);

[0185] First blue electron blocking layer 18-1: First transport material HTL(1);

[0186] First red emitting layer 14-1: Red light host material RH: Red light guest material RD (3%), thickness 45nm;

[0187] First green luminescent layer 15-1: Green light host material GH (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%), thickness 30nm;

[0188] First blue emitting layer 16-1: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0189] First hole blocking layer 10-1: Hole blocking material HB (thickness 5nm);

[0190] Electron output layer 20: ET:LiQ (thickness 35nm, ratio 50%:50%);

[0191] Electron injection layer 19: Electron injection material EIL (1 nm thick), the electron injection material EIL, the electron injection material EIL may include low work function metals, such as Li, Ca or Yb, or may include metal salts, such as LiF, LiQ, etc., formed by vapor deposition;

[0192] First electrode 5: Metal Mg: Metal Ag (thickness 15nm).

[0193] In Scheme 3, compared to Scheme 1, the second sub-emissive layer of the green luminescent layer uses the green light host material GH.

[0194] In some exemplary embodiments, as shown in Figures 4 and 5, the light-emitting structure in Scheme 4 adopts the pixel arrangement scheme shown in Figure 5 and the structure of the light-emitting structure shown in Figure 4. The components of the light-emitting structure in the direction away from the substrate are as follows:

[0195] Second electrode 6: Metal Ag (100nm thick) / ITO (8nm thick);

[0196] Hole injection layer 7: First transport material HTL(1) (thickness 10nm), the material of the first transport material HTL(1) can also be formed by p-type doping of hole transport material, with a doping ratio of 3%;

[0197] Second hole transport layer 13-2: First transport material HTL(1) (thickness 30nm);

[0198] Second exciton blocking layer 12-2: First hole-type material C-Prime (1), the material of the first hole-type material C-Prime (1) may include a hole-type material with high mobility;

[0199] Second red electron blocking layer 17-2: First red electron blocking material R-EBL(1), the first red electron blocking material R-EBL(1) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives;

[0200] Second blue electron blocking layer 18-2: Blue electron blocking material B-EBL (thickness 5nm), which may include carbazole and its derivatives;

[0201] The second red luminescent layer 14-2 consists of red light host material RH and red light guest material RD, with a thickness of 45nm and a content of 3% for the luminescent guest material RD.

[0202] Second green luminescent layer 15-2: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (79%:20%:1.0%) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%), thickness 30nm;

[0203] Second blue emitting layer 16-2: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0204] Second hole blocking layer 10-2: Hole blocking material HB (thickness 5nm);

[0205] N-type charge generation layer 9: n-CG:Yb, thickness 12nm, Yb doping ratio 1%;

[0206] P-type charge generation layer 8: First transport material HTL(1), thickness 10nm;

[0207] First hole transport layer 13-1: First transport material HTL(1), thickness 40nm;

[0208] First exciton blocking layer 12-1: First hole-type material C-Prime(1);

[0209] First red electron blocking layer 17-1: First red light electron blocking material R-EBL(1);

[0210] First blue electron blocking layer 18-1: First transport material HTL(1);

[0211] First red emitting layer 14-1: Red light host material RH: Red light guest material RD (3%), thickness 45nm;

[0212] First green luminescent layer 15-1: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (79%:20%:1.0%) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%), thickness 30nm;

[0213] First blue emitting layer 16-1: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0214] First hole blocking layer 10-1: Hole blocking material HB (thickness 5nm);

[0215] Electron output layer 20: ET:LiQ (thickness 35nm, ratio 50%:50%);

[0216] Electron injection layer 19: Electron injection material EIL (1 nm thick), the electron injection material EIL, the electron injection material EIL may include low work function metals, such as Li, Ca or Yb, or may include metal salts, such as LiF, LiQ, etc., formed by vapor deposition;

[0217] First electrode 5: Metal Mg: Metal Ag (thickness 15nm).

[0218] Compared to Scheme 1, the light-emitting structure in Scheme 4 adds a third sub-light-emitting layer to the green light-emitting layer. The third sub-light-emitting layer adopts a green light host material GH: green light TADF characteristic material G-TADF: green light guest material GD (79%:20%:1.0%), which promotes the widening of the exciton recombination region, reduces the exciton density, reduces exciton quenching, and effectively improves the device lifetime.

[0219] In some exemplary embodiments, as shown in Figures 4 and 5, the light-emitting structure in scheme 5 adopts the pixel arrangement scheme shown in Figure 5 and the structure of the light-emitting structure shown in Figure 4. The components of the light-emitting structure in the direction away from the substrate are as follows:

[0220] Second electrode 6: Metal Ag (100nm thick) / ITO (8nm thick);

[0221] Hole injection layer 7: First transport material HTL(1) (thickness 10nm), the material of the first transport material HTL(1) can also be formed by p-type doping of hole transport material, with a doping ratio of 3%;

[0222] Second hole transport layer 13-2: First transport material HTL(1) (thickness 30nm);

[0223] Second exciton blocking layer 12-2: First hole-type material C-Prime (1), the material of the first hole-type material C-Prime (1) may include a hole-type material with high mobility;

[0224] Second red electron blocking layer 17-2: First red electron blocking material R-EBL(1), the first red electron blocking material R-EBL(1) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives;

[0225] Second blue electron blocking layer 18-2: Blue electron blocking material B-EBL (thickness 5nm), which may include carbazole and its derivatives;

[0226] The second red luminescent layer 14-2 consists of red light host material RH and red light guest material RD, with a thickness of 45nm and a content of 3% for the luminescent guest material RD.

[0227] Second green luminescent layer 15-2: Green phosphorescent host material GPH: Green light guest material GD (99%:1.0%) (5nm) / Green phosphorescent host material GPH: Green phosphorescent material G-PHD: Green light guest material GD (89%:10%:1.0%) (thickness 30nm);

[0228] Second blue emitting layer 16-2: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0229] Second hole blocking layer 10-2: Hole blocking material HB, thickness 5nm;

[0230] N-type charge generation layer 9: n-CG:Yb, thickness 12nm, Yb doping ratio 1%;

[0231] P-type charge generation layer 8: First transport material HTL(1), thickness 10nm;

[0232] First hole transport layer 13-1: First transport material HTL(1), thickness 40nm;

[0233] First exciton blocking layer 12-1: First hole-type material C-Prime(1);

[0234] First red electron blocking layer 17-1: First red light electron blocking material R-EBL(1);

[0235] First blue electron blocking layer 18-1: First transport material HTL(1);

[0236] First red emitting layer 14-1: Red light host material RH: Red light guest material RD (3%), thickness 45nm;

[0237] First green luminescent layer 15-1: Green phosphorescent host material GPH: Green light guest material GD (99%:1.0%) (5nm) / Green phosphorescent host material GPH: Green phosphorescent material G-PHD: Green light guest material GD (89%:10%:1.0%), thickness 30nm;

[0238] First blue emitting layer 16-1: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0239] First hole blocking layer 10-1: Hole blocking material HB (thickness 5nm);

[0240] Electron output layer 20: ET:LiQ (thickness 35nm, ratio 50%:50%);

[0241] Electron injection layer 19: Electron injection material EIL (1 nm thick), the electron injection material EIL, the electron injection material EIL may include low work function metals, such as Li, Ca or Yb, or may include metal salts, such as LiF, LiQ, etc., formed by vapor deposition;

[0242] First electrode 5: Metal Mg: Metal Ag (thickness 15nm).

[0243] In Scheme 5, the green light-emitting layer, compared to Scheme 1, is sensitized using phosphorus photosensitization technology.

[0244] In some exemplary embodiments, as shown in Figures 5 and 8, the light-emitting structure in Scheme 6 adopts the pixel arrangement scheme shown in Figure 5 and the structure of the light-emitting structure shown in Figure 8. The components of the light-emitting structure in the direction away from the substrate are as follows:

[0245] Second electrode 6: Metal Ag (100nm thick) / ITO (8nm thick);

[0246] Hole injection layer 7: Second transport material HTL(2), the material of the second transport material HTL(2) can also be formed by p-type doping of hole transport material, with a doping ratio of 3%;

[0247] Second hole transport layer 13-2: Second transport material HTL(2) (thickness 30nm);

[0248] Second red electron blocking layer 17-2: Second red electron blocking material R-EBL(2), the second red electron blocking material R-EBL(2) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives;

[0249] Second blue electron blocking layer 18-2: Blue electron blocking material B-EBL, with a thickness of 5nm, which may include carbazole and its derivatives.

[0250] The second red luminescent layer 14-2 consists of red light host material RH and red light guest material RD, with a thickness of 45nm and a content of 3% for the luminescent guest material RD.

[0251] Second green luminescent layer 15-2: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%) (thickness 30nm);

[0252] Second blue emitting layer 16-2: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0253] Second hole blocking layer 10-2: Hole blocking material HB, thickness 5nm;

[0254] N-type charge generation layer 9: n-CG:Yb, thickness 12nm, Yb doping ratio 1%;

[0255] P-type charge generation layer 8: First transport material HTL(1), thickness 10nm;

[0256] First hole transport layer 13-1: First transport material HTL(1), thickness 40nm;

[0257] First exciton blocking layer 12-1: First hole-type material C-Prime(1);

[0258] First red electron blocking layer 17-1: First red light electron blocking material R-EBL(1);

[0259] First blue electron blocking layer 18-1: First transport material HTL(1);

[0260] First red emitting layer 14-1: Red light host material RH: Red light guest material RD (3%), thickness 45nm;

[0261] First green luminescent layer 15-1: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%), thickness 30nm;

[0262] First blue emitting layer 16-1: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0263] First hole blocking layer 10-1: Hole blocking material HB (thickness 5nm);

[0264] Electron output layer 20: ET:LiQ (thickness 35nm, ratio 50%:50%);

[0265] Electron injection layer 19: Electron injection material EIL (1 nm thick), the electron injection material EIL, the electron injection material EIL may include low work function metals, such as Li, Ca or Yb, or may include metal salts, such as LiF, LiQ, etc., formed by vapor deposition;

[0266] First electrode 5: Metal Mg: Metal Ag (thickness 15nm).

[0267] In Scheme 6, compared to Scheme 1, the second hole transport layer 13-2 uses a deep HOMO second transport material HTL(2), whose HOMO difference with the host material of the adjacent green light-emitting layer is less than 0.25 eV, thus reducing the hole barrier from the hole transport layer to the light-emitting layer. Therefore, an exciton blocking layer is not required. The first hole transport layer 13-1 still uses the first transport material HTL(1), and the HOMO difference between the first hole transport layer 13-1 and the adjacent green light-emitting layer is relatively large. In the red light region, since hole transport differs in different light-emitting regions, an asymmetric structure of the second red electron blocking material R-EBL(2) combined with the first red electron blocking material R-EBL(1) is used to compensate for the difference of reducing one exciton blocking layer, achieving the same device performance while further reducing the use of materials, chambers, and masks.

[0268] In some exemplary embodiments, as shown in Figures 5 and 9, the light-emitting structure in scheme 7 adopts the pixel arrangement scheme shown in Figure 5 and the structure of the light-emitting structure shown in Figure 9. The components of the light-emitting structure in the direction away from the substrate are as follows:

[0269] Second electrode 6: Metal Ag (100nm thick) / ITO (8nm thick);

[0270] Hole injection layer 7: Second transport material HTL(2), the material of the second transport material HTL(2) can also be formed by p-type doping of hole transport material, with a doping ratio of 3%;

[0271] Second hole transport layer 13-2: Second transport material HTL(2), thickness 30nm;

[0272] Second red electron blocking layer 17-2: Second red electron blocking material R-EBL(2), the second red electron blocking material R-EBL(2) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives;

[0273] Second blue electron blocking layer 18-2: Blue electron blocking material B-EBL, 5nm thick;

[0274] The second red luminescent layer 14-2 consists of red light host material RH and red light guest material RD, with a thickness of 45nm and a content of 3% for the luminescent guest material RD.

[0275] Second green luminescent layer 15-2: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%) (thickness 30nm);

[0276] Second blue emitting layer 16-2: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0277] Second hole blocking layer 10-2: Hole blocking material HB, thickness 5nm;

[0278] N-type charge generation layer 9: n-CG:Yb, thickness 12nm, Yb doping ratio 1%;

[0279] P-type charge generation layer 8: First transport material HTL(1), thickness 10nm;

[0280] First hole transport layer 13-1: First transport material HTL(1), thickness 40nm;

[0281] First exciton blocking layer 12-1: First hole-type material C-Prime(1);

[0282] First blue electron blocking layer 18-1: First transport material HTL(1);

[0283] First red emitting layer 14-1: Red light host material RH: Red light guest material RD (3%), thickness 45nm;

[0284] First green luminescent layer 15-1: Green light host material GH: Green light guest material GD (99%:1.0%) (5nm) / Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%), thickness 30nm;

[0285] First blue emitting layer 16-1: Blue light host material BH: Blue light guest material BD (2%), thickness 20nm;

[0286] First hole blocking layer 10-1: Hole blocking material HB (thickness 5nm);

[0287] Electron output layer 20: ET:LiQ (thickness 35nm, ratio 50%:50%);

[0288] Electron injection layer 19: Electron injection material EIL (1 nm thick), the electron injection material EIL, the electron injection material EIL may include low work function metals, such as Li, Ca or Yb, or may include metal salts, such as LiF, LiQ, etc., formed by vapor deposition;

[0289] First electrode 5: Metal Mg: Metal Ag (thickness 15nm).

[0290] Compared to Scheme 6, the light-emitting structure in Scheme 7 further reduces the first red disciple blocking layer by using an exciton blocking layer to adjust the length of the green and red optical cavities, thereby maximizing the simplification of the device structure, reducing the use of materials, cavities, and photomasks, and adapting to the process flow to reduce the difficulty of the process.

[0291] The light-emitting structure in Scheme 8 can be the current light-emitting structure.

[0292] Second electrode 6: Metal Ag (100nm thick) / ITO (8nm thick);

[0293] Hole injection layer 7: First transport material HTL(1), the material of the first transport material HTL(1) can also be formed by p-type doping of hole transport material, with a doping ratio of 3%;

[0294] Second hole transport layer 13-2: First transport material HTL(1), thickness 30nm;

[0295] Second red electron blocking layer 17-2: Second red electron blocking material R-EBL(2), the second red electron blocking material R-EBL(2) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives.

[0296] Second blue electron blocking layer 18-2: Blue electron blocking material B-EBL (thickness 5nm), which may include carbazole and its derivatives;

[0297] Second green electron blocking layer: First hole-type material C-Prime(1), thickness 5nm;

[0298] Second red luminescent layer 14-2: Red light host material RH: Red light guest material RD (3%);

[0299] Second green luminescent layer 15-2: Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%);

[0300] Second blue emitting layer 16-2: Blue light host material BH: Blue light guest material BD (2%);

[0301] Second hole blocking layer 10-2: Hole blocking material HB (5nm), thickness 5nm;

[0302] N-type charge generation layer 9: n-CG:Yb, thickness 12nm, Yb doping ratio 1%;

[0303] P-type charge generation layer 8: First transport material HTL(1), thickness 10nm;

[0304] First red electron blocking layer 17-1: Second red electron blocking material R-EBL(2), the second red electron blocking material R-EBL(2) may include triphenylamine, furan, carbazole, thiophene, phenylfluorene and other groups and their derivatives.

[0305] First blue electron blocking layer 18-1: Blue electron blocking material B-EBL (thickness 5nm), which may include carbazole and its derivatives;

[0306] First green electron blocking layer: First hole-type material C-Prime(1), thickness 5nm;

[0307] First red luminescent layer 14-1: Red light host material RH: Red light guest material RD (3%);

[0308] First green luminescent layer 15-1: Green light host material GH: Green light TADF characteristic material G-TADF: Green light guest material GD (69%:30%:1.0%);

[0309] First blue emitting layer 16-1: Blue light host material BH: Blue light guest material BD (2%); First hole blocking layer 10-1: Hole blocking material HB, thickness 5nm;

[0310] Electron output layer 20: ET:LiQ (thickness 35nm, ratio 50%:50%);

[0311] Electron injection layer 19: Electron injection material EIL, electron injection material EIL, thickness 1nm, the electron injection material EIL may include low work function metals, such as Li, Ca or Yb, or may include metal salts, such as LiF, LiQ, etc., formed by vapor deposition;

[0312] First electrode 5: Metal Mg: Metal Ag, thickness 15nm.

[0313] Table 2 below shows the characteristic parameters of each material in Schemes 1 to 8 as follows:

[0314] Table 2

[0315] In some exemplary embodiments, a display panel includes the light-emitting structure 1 described above. The display panel may be an OLED display panel with an integrated touch structure.

[0316] In some exemplary embodiments, a display panel includes: a first pixel group and a second pixel group, wherein the first pixel group includes a first sub-pixel and a second sub-pixel, and the second pixel group includes a third sub-pixel;

[0317] The first sub-pixel and the second sub-pixel are arranged alternately along the second direction, the second pixel group extends along the second direction, the first pixel group and the second pixel group are arranged alternately in the third direction, and the second direction is perpendicular to the third direction;

[0318] The display panel further includes an exciton blocking layer, which is shared by the first sub-pixel and the second sub-pixel.

[0319] In some exemplary embodiments, a display device includes a circuit board and the aforementioned display panel, wherein the circuit board is configured to be electrically connected to the display panel.

[0320] In some exemplary embodiments, a display device includes the display panel of the above embodiments. The display device can be any product or component with display and touch functions, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0321] The accompanying drawings in this disclosure only illustrate the structures involved in this disclosure; other structures can be referred to with common design. Unless otherwise specified, the embodiments of this disclosure, i.e., the features in the embodiments, can be combined with each other to obtain new embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this disclosure without departing from the spirit and scope of the technical solutions of this disclosure, and all such modifications and substitutions should be covered within the scope of the claims of this disclosure.

Claims

1. A light emitting structure, wherein, Includes at least two light-emitting units arranged in series in a direction perpendicular to the substrate; At least one of the light-emitting units includes a light-emitting layer and an exciton blocking layer stacked in a direction perpendicular to the substrate, wherein the exciton blocking layer is located on the side of the light-emitting layer closer to the substrate; The light-emitting layer includes a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer arranged parallel to the direction of the substrate; Two of the red, green, and blue light-emitting layers are disposed on the end face of the exciton blocking layer away from the substrate, and are located between the two ends of the exciton blocking layer in the direction parallel to the substrate.

2. The light emitting structure of claim 1, wherein, The red emitting layer and the green emitting layer are arranged at intervals in a second direction, and the red emitting layer and the green emitting layer are located between the two ends of the exciton blocking layer in the second direction, which is parallel to the substrate.

3. The light emitting structure of claim 2, wherein, The light-emitting unit further includes a hole transport layer, which is located on the side of the exciton blocking layer near the substrate, and the orthographic projection of the exciton blocking layer on the substrate is located within the orthographic projection of the hole transport layer on the substrate.

4. The light emitting structure of claim 3, wherein, It also includes a red electron blocking layer, which is located on the side of the exciton blocking layer away from the substrate, and the red light emitting layer is disposed on the end face of the red electron blocking layer away from the exciton blocking layer; The orthographic projections of the green luminescent layer and the blue luminescent layer onto the substrate do not overlap with the orthographic projection of the red electron blocking layer onto the substrate.

5. The light emitting structure of claim 4, wherein, The hole mobility of the exciton blocking layer is μ p1 The hole mobility of the hole transport layer is μ p2 The hole mobility of the red electron blocking layer is μ p3 ; wherein 10 -3 ≤ μ p1 / μ p2 ≤ 1, 1 ≤ μ p1 / μ p3 ≤ 10 3 .

6. The light emitting structure of claim 4, wherein, The energy level of the exciton blocking layer is H1, the energy level of the hole transport layer is H2, and the energy level of the red electron blocking layer is H3. Among them, |H1-H2|≤0.15eV, |H1|≤|H3|.

7. The light emitting structure of claim 4, wherein, The hole transport layer and the exciton blocking layer are spaced apart in a direction perpendicular to the substrate. The energy level of the exciton blocking layer is H1, and the energy level of the hole transport layer is H2, with |H1-H2| ≥ 0.15 eV.

8. The light emitting structure of any of claims 1 to 7, wherein, The material of the exciton blocking layer is a hole-type material, which includes triphenylamine, furan, carbazole, thiophene, or phenylfluorene groups.

9. The light emitting structure of claim 2, wherein, The area of ​​the luminescent region of the red luminescent layer projected onto the substrate is S1, the area of ​​the luminescent region of the green luminescent layer projected onto the substrate is S2, and the area of ​​the exciton blocking layer projected onto the substrate is T1, where T1 > (S1 + S2).

10. The light emitting structure of claim 3, wherein, The contact area between the exciton blocking layer and the light-emitting layer is T2, where T2 > S1 and T2 > S2.

11. The light emitting structure of claim 4, wherein, T1≥T2.

12. The light emitting structure of claim 1, wherein, Two of the red, green, and blue light-emitting layers have orthogonal projections onto the substrate that lie within the orthogonal projection of the exciton blocking layer onto the substrate.

13. The light emitting structure of claim 12, wherein, The orthogonal projections of the red and green light-emitting layers onto the substrate lie within the orthogonal projection of the exciton blocking layer onto the substrate.

14. The light emitting structure of claim 2, wherein, It also includes a blue electron blocking layer, which is located on the side of the blue emitting layer closer to the substrate; The orthographic projection of the blue emitting layer on the substrate does not overlap with the orthographic projection of the exciton blocking layer on the substrate, and the orthographic projection of the blue emitting layer on the substrate is located within the orthographic projection of the blue electron blocking layer on the substrate.

15. The light emitting structure of claim 2, wherein, The green luminescent layer includes a first sub-luminescent layer, and the material of the first sub-luminescent layer includes a host material, a sensitizing material, and a guest material. The doping ratio of the sensitizing material in the first sub-emissive layer is less than the doping ratio of the host material in the first sub-emissive layer but greater than the doping ratio of the guest material in the first sub-emissive layer.

16. The light emitting structure of claim 15, wherein, The sensitizing material includes a fluorescent material, or a material with delayed fluorescence properties, or a complex material with a fast intergap crossing rate; The complex material with a fast intergap crossing rate is a material containing transition metal elements; The difference between the lowest singlet and lowest triplet energy levels of the material with delayed fluorescence properties is less than 0.3 eV.

17. The light emitting structure of claim 15, wherein, The doping ratio of the guest material in the green luminescent layer is no higher than 5%.

18. The light emitting structure of claim 15, wherein, The green luminescent layer further includes at least one auxiliary sub-luminescent layer, wherein the at least one auxiliary sub-luminescent layer is located between the first sub-luminescent layer and the substrate, and the material of the auxiliary sub-luminescent layer includes at least one of the host material, the sensitizing material and the guest material.

19. The light emitting structure of claim 18, wherein, At least one of the auxiliary sub-emitting layers includes a second sub-emitting layer, the material of which includes the main material; Alternatively, the material of the second sub-light-emitting layer may include the host material and the guest material. Alternatively, the material of the second sub-luminescent layer may include the host material, the sensitizing material, and the guest material; The doping ratio of the sensitizing material in the first sub-emissive layer is a first ratio, and the doping ratio of the sensitizing material in the second sub-emissive layer is a second ratio, wherein the difference between the first ratio and the second ratio is less than 25%. The doping ratio of the guest material in the first sub-light-emitting layer is a third ratio, and the doping ratio of the guest material in the second sub-light-emitting layer is a fourth ratio, wherein the variation between the third ratio and the fourth ratio is less than 5%.

20. The light emitting structure of claim 18, wherein, At least one of the auxiliary sub-light-emitting layers includes a second sub-light-emitting layer and a third sub-light-emitting layer, wherein the first sub-light-emitting layer, the third sub-light-emitting layer and the second sub-light-emitting layer are arranged sequentially in a direction away from the substrate; The material of the second sub-emissive layer includes at least one of the host material, the sensitizing material, and the guest material, and the material of the third sub-emissive layer includes at least two of the host material, the sensitizing material, and the guest material.

21. The light emitting structure of claim 20, wherein, The material of the third sub-emissive layer includes the host material and the sensitizing material. The doping ratio of the sensitizing material in the first sub-emissive layer is a first ratio, and the doping ratio of the sensitizing material in the third sub-emissive layer is a fifth ratio. The difference between the first ratio and the fifth ratio is less than 20%. Alternatively, the material of the third sub-light-emitting layer comprises the host material, the sensitizing material and the guest material, a doping proportion of the sensitizing material in the first sub-light-emitting layer is a first proportion, a doping proportion of the sensitizing material in the third sub-light-emitting layer is a fifth proportion, and a difference between the first proportion and the fifth proportion is less than 25%; a doping proportion of the guest material in the first sub-light-emitting layer is a third proportion, a doping proportion of the guest material in the third sub-light-emitting layer is a sixth proportion, and a difference between the third proportion and the sixth proportion is less than 5%.

22. A display panel, wherein, The display panel comprises the light-emitting structure as claimed in any one of claims 1 to 21.

23. A display panel, wherein, The display panel comprises: a first pixel group and a second pixel group, the first pixel group comprising a first sub-pixel and a second sub-pixel, and the second pixel group comprising a third sub-pixel; the first sub-pixel and the second sub-pixel are arranged alternately along a second direction, the second pixel group extends along the second direction, the first pixel group and the second pixel group are arranged alternately along a third direction, and the second direction is perpendicular to the third direction; the display panel further comprises an exciton blocking layer, and the first sub-pixel and the second sub-pixel share the exciton blocking layer.

24. A display device comprising: The display panel comprises a circuit board and the display panel as claimed in claim 22 or 23, and the circuit board is arranged to be electrically connected with the display panel.

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