Light-emitting element and display panel

Abstract

The present application provides a light-emitting element and a display panel. The light-emitting element includes a first electrode, a light-emitting layer, a hole blocking layer, an electron transport layer, two or more scattering particle layers, and a second electrode. The hole blocking layer and the electron transport layer are disposed between the light-emitting layer and the second electrode. One of the two or more scattering particle layers is disposed between the hole blocking layer and the electron transport layer, and at least one other is disposed between the electron transport layer and the second electrode. The scattering particle layer includes a plurality of scattering particles. The embodiments of the present application can improve the light extraction efficiency, while improving color shift and simplifying the manufacturing process.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a light-emitting element and a display panel. Background Art

[0002] With the rapid development of organic light-emitting diode (OLED) display technology, higher requirements are also put forward for OLED display technology.

[0003] In existing OLED light-emitting elements, in order to improve the light extraction efficiency, a top-emission structure is often adopted, and an opaque metal anode and a cathode metal are selected to form a resonant cavity. However, due to the different carrier mobilities of each functional layer and the influence of the resonant cavity, the paths of light rays passing through are different at different viewing angles, that is, the brightness and chromaticity are different at different viewing angles, and there is a serious problem of viewing angle color shift.

[0004] In addition, zinc oxide nanoparticles are often doped in the electron transport layer or other functional layers of the light-emitting element to improve the light-emitting efficiency. However, this method has poor effect in improving the light-emitting efficiency, and the process is complex and the manufacturing difficulty is large. Summary of the Invention

[0005] Embodiments of the present application provide a light-emitting element and a display panel, which can improve the light extraction efficiency, simultaneously improve color shift and simplify the manufacturing process.

[0006] On the one hand, embodiments of the present application propose a light-emitting element, including a first electrode, a light-emitting layer, a hole blocking layer, an electron transport layer, two or more scattering particle layers, and a second electrode. The hole blocking layer and the electron transport layer are disposed between the light-emitting layer and the second electrode. One of the two or more scattering particle layers is disposed between the hole blocking layer and the electron transport layer, and at least one more is disposed between the electron transport layer and the second electrode. The scattering particle layer includes a plurality of scattering particles.

[0007] On the other hand, embodiments of the present application also provide a display panel, including the light-emitting element of the first aspect.

[0008] An illuminating element and a display panel provided by an embodiment of the present application. The illuminating element includes two or more scattering particle layers, and each of the two or more scattering particle layers includes a plurality of scattering particles. Since the scattering particles can scatter light, they can increase the propagation direction of the light and the light output in different directions, thereby improving the light extraction efficiency. By providing two or more scattering particle layers with scattering particles, the two or more scattering particles act together, which can further increase the propagation direction of the light and the light output in different directions, better improve the light extraction efficiency, and thus improve color shift. Moreover, the two or more scattering particle layers are separate layer structures, which are easy to fabricate and have a simple process. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The features, advantages, and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0010] Figure 1 is a schematic plan view of a display panel provided by an embodiment of the present application;

[0011] Figure 2 is a schematic cross-sectional view of an illuminating element provided by an embodiment of the present application;

[0012] Figure 3 is Figure 2 an enlarged schematic view of area P;

[0013] Figure 4 is a schematic cross-sectional view of another illuminating element provided by an embodiment of the present application;

[0014] Figure 5 is Figure 4 an enlarged schematic view of area Q;

[0015] Figure 6 and Figure 7 is a schematic partial view of an illuminating element provided by an embodiment of the present application;

[0016] Figure 8 and Figure 9 is a schematic cross-sectional view of yet another illuminating element provided by an embodiment of the present application.

[0017] MARKING DESCRIPTION:

[0018] AA1 - display area; AA2 - non-display area;

[0019] 11 - first electrode; 12 - light-emitting layer; 13 - hole blocking layer; 14 - electron transport layer; 15 - scattering particle layer; 151 - first scattering particle layer; 151a - first scattering particle; 152 - second scattering particle layer; 152a - second scattering particle; 16 - second electrode; 17 - hole injection layer; 18 - hole transport layer; 19 - electron injection layer;

[0020] X - thickness direction.

[0021] In the drawings, like reference numerals are used for like components. The drawings are not drawn to scale. Detailed implementation manners

[0022] The features and exemplary embodiments of various aspects of the present application will be described in detail below. To make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application.

[0023] It should be noted that, in the present application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover a non - exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0024] With the rapid development of organic light - emitting diode (OLED) display technology, higher requirements are also put forward for OLED display technology.

[0025] In existing OLED light - emitting elements, in order to improve the light extraction efficiency, a top - emission structure is often adopted, and an opaque metal anode and a cathode metal are selected to form a resonant cavity. However, due to the different carrier mobilities of each functional layer and the influence of the resonant cavity, the paths of light rays are different at different viewing angles, that is, the brightness and chromaticity are different at different viewing angles, and there is a serious problem of viewing angle color shift.

[0026] In addition, zinc oxide nanoparticles are usually doped in the electron transport layer or other functional layers of the light-emitting element to improve the light-emitting efficiency. However, this method results in a small total surface area of the nanoparticles and a weak light-scattering effect, so the effect of improving the light-emitting efficiency is not good. Moreover, the setting method of the doped particles is complex in process and difficult to fabricate.

[0027] Based on the above analysis, the embodiments of the present application propose a light-emitting element and a display panel, which can better improve the light-emitting efficiency, while improving color deviation and simplifying the manufacturing process.

[0028] The following will combine the attached Figure 1 to the attached Figure 9 to illustrate the embodiments of the light-emitting element and the display panel. Please refer to Figure 1 . The embodiments of the present application provide a display panel, including a display area AA1 and a non-display area AA2. The light-emitting element is disposed in the area of the display area AA1, so that the display panel of the embodiments of the present application can emit light for display.

[0029] In some embodiments, the display panel further includes a substrate, and the light-emitting elements are stacked on at least one side of the substrate. Optionally, the substrate may include a substrate and a driving circuit disposed on the substrate, and specifically may include an active driving circuit and a passive driving circuit.

[0030] Optionally, the substrate may be a silicon-based substrate, and the silicon-based substrate is more likely to achieve excellent characteristics such as a high number of pixels per inch (PPI), high integration, small volume, easy to carry, good seismic performance, and ultra-low power consumption. Or, the substrate may also be a low temperature poly-silicon (LTPS) substrate, so that the thin film transistors in the substrate have better reliability.

[0031] In order to improve the light-emitting efficiency of the display panel, prevent display defects such as color deviation, ensure the display effect, and reduce the manufacturing difficulty, the embodiments of the present application further provide a novel light-emitting element. The light-emitting element can be produced and sold as an independent component. Of course, it can also be used in the display panels of the above embodiments and be a component of the display panels of the above embodiments.

[0032] Please refer to Figure 2, an embodiment of the present application provides a light-emitting element, including a first electrode 11, a light-emitting layer 12, a hole blocking layer 13, an electron transport layer 14, more than two scattering particle layers 15, and a second electrode 16. The hole blocking layer 13 and the electron transport layer 14 are disposed between the light-emitting layer 12 and the second electrode 16. One of the more than two scattering particle layers 15 is disposed between the hole blocking layer 13 and the electron transport layer 14, and at least one more is disposed between the electron transport layer 14 and the second electrode 16. The scattering particle layer 15 includes a plurality of scattering particles.

[0033] Among them, the first electrode 11 and the second electrode 16 have different polarities. Through the action of the first electrode 11 and the second electrode 16, the light-emitting element can emit light. It can be understood that the light-emitting layer 12 (Emission layer, EML) can emit light such as red, green, and blue through the recombination of holes and electrons.

[0034] Optionally, the first electrode 11 can be located on a substrate, and the first electrode 11 is set as an anode (Anode). Optionally, a material with a relatively high work function can be used to make the first electrode 11 to inject holes into the light-emitting element. Among them, the materials usually selected for the first electrode 11 include ITO, IZO, Au, Pt, Si, etc.

[0035] Optionally, the second electrode 16 is set as a cathode (Cathode), and the second electrode 16 can be made of a transparent conductive material to enable the injection of electrons. Optionally, a material with a low work function can be used to make the second electrode 16, which can not only improve the electron injection efficiency, but also reduce the heat generated during operation and improve the lifespan of the light-emitting element.

[0036] Since the transport rate of holes is generally greater than that of electrons, therefore, an electron transport layer 14 (Electron Transport Layer, ETL) is also provided in the embodiment of the present application to inject or transport the electrons supplied by the second electrode 16 into the light-emitting layer 12. Optionally, the electron transport layer 14 can be made of an organic material having electron transportability and / or electron injectability.

[0037] Optionally, the organic material having electron transportability and / or electron injectability can adopt π-electron system low molecular organic materials such as oxadiazole derivatives (OXD), triazole derivatives (TAZ), phenanthroline derivatives (BCP, Bphen), etc., and the present application does not limit this.

[0038] When electrons and holes migrate into the light-emitting layer 12, due to the existence of an electric field, the electrons can continue to migrate towards the first electrode 11, and the holes can continue to migrate towards the second electrode 16, resulting in a decrease in the electron / hole concentration in the light-emitting region of the light-emitting element and a reduction in the light-emitting efficiency.

[0039] Therefore, an embodiment of the present application further provides a hole blocking layer 13 (Hole Block Layer, HBL). Due to its special energy level structure, a potential barrier for hole migration is formed to prevent further migration of holes.

[0040] In some optional embodiments, the light-emitting element further includes an electron blocking layer (Electron Block Layer, EBL), which is disposed between the light-emitting layer 12 and the first electrode 11 to form a potential barrier for electron migration to prevent further migration of electrons.

[0041] In the embodiment of the present application, the light-emitting element further includes more than two scattering particle layers 15. Optionally, the scattering particle layer 15 can be set to two layers. Of course, it can also be set to multiple layers.

[0042] Exemplarily, the scattering particle layer 15 is set to two layers, one of which is disposed between the hole blocking layer 13 and the electron transport layer 14, and the other is disposed between the electron transport layer 14 and the second electrode 16.

[0043] By providing the scattering particle layer 15, the light emitted from the light-emitting layer 12 can be scattered to increase the scattering direction of light and the light output in different directions, thereby improving the light-emitting efficiency and improving color shift.

[0044] Moreover, the scattering particle layer 15 includes a plurality of scattering particles, and the scattering particles have a scattering function and can scatter the light generated by the light-emitting layer 12. After passing through the scattering particles, the light can be scattered and emitted in various directions, thereby changing the color shift phenomenon.

[0045] Exemplarily, both of the two scattering particle layers 15 include a plurality of scattering particles. When the light emitted from the light-emitting layer 12 passes through the first scattering particle layer 15, its scattering particles can scatter the light to increase the transmission direction of the light and the light output in different directions. The light scattered by the first scattering particle layer 15 passes through the second scattering particle layer 15, and its scattering particles can continue to scatter the light, further increasing the transmission direction of the light and the light output in different directions, improving the light output efficiency, and improving color shift.

[0046] Moreover, since the light scattered by the second scattering particle layer 15 is emitted in different directions, part of the light will be reflected to the first scattering particle layer 15, and its scattering particles will scatter this light again, further increasing the light output, thereby better improving the light output efficiency and improving color shift.

[0047] In the embodiment of the present application, the scattering particle layer 15 is arranged as a separate layer structure. During the manufacturing and forming process, the fabricated scattering particle layer 15 can be directly vapor-deposited onto other layers, which is easy to manufacture and has a simple process.

[0048] Please refer to Figures 2 to 5 , in some alternative embodiments, the scattering particles may include at least one of spherical scattering particles, ellipsoidal scattering particles, and scattering particles of other structural types. Optionally, multiple scattering particles can all be spherical scattering particles, or all be ellipsoidal scattering particles, or a part can be spherical scattering particles and another part can be ellipsoidal scattering particles. The present application does not limit this.

[0049] As an alternative implementation manner, multiple scattering particles include ellipsoidal scattering particles, and the ratio of the major axis length L 1 to the minor axis length L 2 satisfies: 1:1 < L 1 : L 2 ≤ 2:1.

[0050] In some embodiments, the scattering particles can be arranged in an ellipsoidal structure to better achieve the light scattering effect, increase the scattering direction of light and the light output in different directions, thereby better improving the light output efficiency and improving color deviation.

[0051] Optionally, the ratio of the major axis length L 1 to the minor axis length L 2 of the ellipsoidal scattering particles can be any value between 1:1 and 2:1, including one end value of 1:1. Exemplarily, the ratio of the major axis length L 1 to the minor axis length L 2 of the ellipsoidal scattering particles can be selected as 1:1.1, 1:1.2, etc.

[0052] In the embodiment of the present application, when the scattering particles include ellipsoidal scattering particles, the angle α between the major axis direction of the ellipsoidal scattering particles and the thickness direction X of the display panel satisfies: α < 90°.

[0053] Setting the angle α between the major axis direction of the ellipsoidal scattering particles and the thickness direction X of the display panel to be less than 90° can enable more light to be scattered by the ellipsoidal scattering particles, increasing the scattering direction of light and the light output in different directions.

[0054] Exemplarily, the angle α between the major axis direction of the ellipsoidal scattering particles and the thickness direction X of the display panel can be 40°, 45°, etc.

[0055] It can be understood that the particle size of the ellipsoidal scattering particles is the major axis length L 1 .

[0056] As an alternative embodiment, the plurality of scattering particles include spherical scattering particles.

[0057] In some embodiments, the scattering particles may be configured as spherical structures and quasi-spherical structures to better achieve the light scattering effect, increase the light scattering directions and the light output amounts in different directions, thereby better improving the light output efficiency and improving the color shift.

[0058] It can be understood that the particle size of the spherical scattering particles is the diameter.

[0059] Please continue to refer to Figures 2 to 5 , as an alternative embodiment, the number of layers of the scattering particle layer 15 is two. The two scattering particle layers 15 include a first scattering particle layer 151 and a second scattering particle layer 152. The first scattering particle layer 151 is disposed between the hole blocking layer 13 and the electron transport layer 14, and the second scattering particle layer 152 is disposed between the electron transport layer 14 and the second electrode 16.

[0060] Setting the number of layers of the scattering particle layer 15 to two and separating the two scattering particle layers 15 between different layer structures can not only better increase the light scattering directions, but also prevent the scattering particle layer 15 from being too thick, which may lead to too fast electron transport speed, resulting in unbalanced carrier injection and affecting the performance of the light-emitting element.

[0061] The first scattering particle layer 151 includes a plurality of first scattering particles 151a, and the second scattering particle layer 152 includes a plurality of second scattering particles 152a. The average particle size Dv of the plurality of first scattering particles 151a 1 is smaller than the average particle size Dv of the plurality of second scattering particles 152a 2 .

[0062] Since the scattering particles with a smaller particle size have more light scattering directions, while the light scattering direction of the scattering particles with a larger particle size tends to be parallel to the thickness direction X, therefore, setting the scattering particles with a larger average particle size closer to the light output side can make the light scattered by them have a better light output direction, thereby improving the light output efficiency and improving the color shift.

[0063] It can be understood that the scattering particles with a smaller average particle size can also receive the light reflected by the scattering particles with a larger average particle size and scatter it again, avoiding waste of light and increasing the light output amounts in different directions.

[0064] Optionally, the particle sizes of all the first scattering particles 151a may be set to be smaller than those of all the second scattering particles 152a.

[0065] Optionally, the first scattering particle 151a may be an ellipsoidal scattering particle. Of course, it may also be a spherical scattering particle. Similarly, the second scattering particle 152a may be an ellipsoidal scattering particle or a spherical scattering particle.

[0066] Please refer to Figure 6 and Figure 7 , as an alternative embodiment, the thickness d of the first scattering particle layer 151 1 is less than the thickness d of the second scattering particle layer 152 2 , and d 1 ≤Dv 1 , d 2 ≤Dv 2 .

[0067] Exemplarily, when both the first scattering particle 151a and the second scattering particle 152a are spherical scattering particles, the relationship between the thickness d of the first scattering particle layer 151 1 and the average particle size Dv of the first scattering particle 151a 1 is set as d 1 =Dv 1 , and the relationship between the thickness d of the second scattering particle layer 152 2 and the average particle size Dv of the second scattering particle 152a 2 is set as d 2 =Dv 2 , which can make the first scattering particle layer 151 and the second scattering particle layer 152 designed thinner to prevent the scattering particle layer 15 from being too thick, resulting in too fast electron transport speed, thus leading to carrier injection balance, thereby affecting the performance of the light-emitting element and improving the reliability.

[0068] Exemplarily, when both the first scattering particle 151a and the second scattering particle 152a are ellipsoidal scattering particles, the relationship between the thickness d of the first scattering particle layer 151 1 and the average particle size Dv of the first scattering particle 151a 1 is set as d 1 <Dv 1 and the two values are close. The relationship between the thickness d of the second scattering particle layer 152 2 and the average particle size Dv of the second scattering particle 152a 2 is set as d 2 <Dv 2 and the two values are close, which can make the first scattering particle layer 151 and the second scattering particle layer 152 designed thinner to prevent the scattering particle layer 15 from being too thick, resulting in too fast electron transport speed, thus leading to carrier injection balance, thereby affecting the performance of the light-emitting element and improving the reliability.

[0069] As an alternative embodiment, the total volume of the first scattering particles 151a accounts for 40% to 60% of the total volume of the first scattering particle layer 151. The total volume of the second scattering particles 152a accounts for 40% to 60% of the total volume of the second scattering particle layer 152.

[0070] In the embodiment of the present application, the first scattering particle layer 151 can be separately fabricated and disposed on other film layers, and a plurality of first scattering particles 151a are tiled to form the first scattering particle layer 151. It can be understood that the total volume of the first scattering particle layer 151 refers to the volume of a film layer with length, width, and height formed after a plurality of first scattering particles 151a are tiled in space. Similarly, the total volume of the second scattering particle layer 152 represents the volume of a film layer with length, width, and height formed after a plurality of first scattering particles 151a are tiled in space.

[0071] Through the above settings, it can be ensured that the first scattering particles 151a are more densely distributed in the first scattering particle layer 151 and the second scattering particles 152a are more densely distributed in the second scattering particle layer 152, so that the scattering particles in each scattering particle layer 15 have a larger surface area to sufficiently cope with light in more directions and better achieve the scattering effect.

[0072] Optionally, a plurality of first scattering particles 151a can be evenly distributed in the first scattering particle layer 151. Of course, they can also be arranged unevenly. That is to say, the spacing between two adjacent first scattering particles 151a can be equal or unequal.

[0073] Optionally, the spacing between adjacent first scattering particles 151a can be set to be less than the particle size of the first scattering particle 151a with the smallest volume, so that a plurality of first scattering particles 151a are more densely distributed, thereby improving the scattering effect of the first scattering particle layer 151.

[0074] The distribution of the second scattering particles 152a in the second scattering particle layer 152 can be the same as the distribution of the first scattering particles 151a in the first scattering particle layer 151, which will not be elaborated here.

[0075] As an alternative embodiment, the orthographic projection of the first scattering particles 151a in the first scattering particle layer 151 in the thickness direction X of the light-emitting element at least partially overlaps with the orthographic projection of the second scattering particles 152a in the second scattering particle layer 152 in the thickness direction X.

[0076] With the above settings, under the combined action of multiple first scattering particles 151a and multiple second scattering particles 152a, since at least part of their positive projections in the thickness direction X overlap, the overall surface area for light scattering can be increased, the scattering direction of light can be better improved, and the light extraction efficiency can be enhanced.

[0077] Please continue to refer to Figure 6 and Figure 7 , as an alternative implementation, the particle size D of the first scattering particles 151a 1 satisfies: 5nm ≤ D 1 ≤ 15nm. The particle size D of the second scattering particles 152a 2 satisfies: 50nm ≤ D 2 ≤ 120nm.

[0078] With the above settings, the scattering effect on light can be better improved, and the light extraction efficiency can be provided. Moreover, by setting the particle size D of the first scattering particles 151a 1 to be between 5nm and 15nm, and setting the particle size D of the second scattering particles 152a 2 to be between 50nm and 120nm, it can prevent the scattering particle layer 15 from being too thick, resulting in too fast electron transport speed, thus causing carrier injection imbalance and affecting the performance of the light-emitting element, and improving the reliability. It can also ensure that the overall light-emitting element is not too thick, achieving a lightweight design.

[0079] Optionally, the particle size D of the first scattering particles 151a 1 can be any value between 5nm and 15nm, including the two end values of 5nm and 15nm, and can be optionally 5.5nm, 7nm, 8nm, etc.

[0080] Optionally, the particle size D of the second scattering particles 152a 2 can be any value between 50nm and 120nm, including the two end values of 50nm and 120nm, and can be optionally 60nm, 70nm, 80nm, etc.

[0081] As an alternative implementation, the scattering particles include metal particles, and the metal particles include one or several of zinc particles, titanium particles, silver particles, and tin particles.

[0082] Optionally, the scattering particles can be made of a light-transmitting material, so as to ensure that the light emitted from the light-emitting layer 12 can pass through the scattering particle layer 15 and be scattered by it.

[0083] Optionally, the scattering particles can include metal particles, and among them, the metal particles can include one of zinc particles, titanium particles, silver particles, and tin particles.

[0084] That is to say, the material of the scattering particles may include a metal oxide material to improve the stability of the scattering particles, prevent the scattering particles from being damaged, and thus improve the service life of the light-emitting element. Exemplarily, the metal oxide material may include zinc oxide (ZnO), titanium oxide (TiO 2 ), tin oxide (SnO 2 ), or a combination of several of ZnO, TiO2, and SnO2.

[0085] Of course, the material of the scattering particles may include a metal sulfide material, which has the same function as the metal oxide material and will not be elaborated here. Exemplarily, the metal oxide material may include ZnS. It can be understood that the forms of metal particles and their oxides and sulfides included in the scattering particles are not limited to this, and the present application does not limit this.

[0086] As an alternative embodiment, the scattering particles include core-shell structure particles, and the core material of the core-shell structure particles includes one of zinc particles, titanium particles, silver particles, and tin particles, and the shell material includes one of zinc particles, titanium particles, silver particles, and tin particles.

[0087] Optionally, the scattering particles may include ZnO@TiO 2 , ZnO@ZnS, ZnO@Ag, TiO 2 @Ag core-shell structure scattering particles.

[0088] Of course, the material of the scattering particles is not limited to this.

[0089] Please refer to Figure 8 and Figure 9 . As an alternative embodiment, the light-emitting element further includes a hole injection layer 17 and a hole transport layer 18. The hole injection layer 17 is disposed on the side of the first electrode 11 close to the light-emitting layer 12, and the hole transport layer 18 is disposed between the light-emitting layer 12 and the hole injection layer 17.

[0090] Among them, the hole injection layer 17 can reduce the barrier for the first electrode 11 to inject holes, so that holes can be effectively injected from the first electrode 11 into the light-emitting element. Optionally, the hole injection layer 17 may be made of oxide materials such as silver (Ag), molybdenum (Mo), chromium (Cr), vanadium (V), tungsten (W), nickel (Ni), iridium (Ir), etc., so that holes can be injected into the light-emitting layer 12 more stably.

[0091] The hole transport layer is disposed on the hole injection layer 17 to transport the holes injected from the hole injection layer 17 to the light-emitting layer 12. Optionally, the hole transport layer may be made of a polymer compound such as polyfluorene or its derivatives or polyarylamine or its derivatives.

[0092] As an alternative embodiment, the light-emitting element further includes an electron injection layer 19 disposed between the scattering particle layer 15 and the second electrode 16. The electron injection layer 19 can reduce the potential barrier for injecting electrons from the second electrode 16, so that electrons can be effectively injected from the second electrode 16 into the light-emitting element. Optionally, the electron injection layer 19 can be made of materials such as LiF, MgP, MgF2, Al2O3, etc.

[0093] Exemplarily, for the light-emitting element provided in the embodiment of the present application, the thickness of the first electrode 11 can be set to 150 nm, the thickness of the hole injection layer 17 can be set to 10 nm, the thickness of the hole transport layer 18 can be set to 120 nm, the thickness of the light-emitting layer 12 can be set to 20 nm, the thickness of the hole blocking layer 13 can be set to 10 nm, the thickness of the first scattering particle layer 151 can be set to 5 - 15 nm, the thickness of the electron transport layer 14 can be set to 20 nm, the thickness of the second scattering particle layer 152 can be set to 50 - 120 nm, the thickness of the electron injection layer 19 can be set to 2 nm, and the thickness of the second electrode 16 can be set to 150 nm.

[0094] Based on the above data, the turn-on voltage and the electron and hole injection rates of the light-emitting element provided in the embodiment of the present application are measured, and it is obtained that the turn-on voltage is reduced by 76% compared with the light-emitting element without the two-layer scattering particle layer 15, and the current efficiency is increased by 2%.

[0095] By providing two or more scattering particle layers 15 in the light-emitting element provided in the embodiment of the present application, each scattering particle layer 15 is provided with a plurality of scattering particles, which can not only improve the scattering effect on light, increase the transmission direction of light and the light output in different directions, but also reduce the turn-on voltage, enabling more balanced and stable injection of electrons and holes, thereby better improving color deviation. Moreover, by separately manufacturing the scattering particle layer 15, the process difficulty can be reduced and it is convenient for manufacturing.

[0096] In a second aspect, the embodiment of the present application further provides a display panel including any one of the foregoing light-emitting elements. Due to the advantages of the light-emitting element such as good light transmittance and simple manufacturing, the light-emitting element provided in the embodiment of the present application has uniform and good brightness and chromaticity, ensuring the display effect and improving the manufacturing efficiency.

[0097] Although the disclosed embodiments of the present application are as above, the described content is only an embodiment adopted for the convenience of understanding the present application and is not intended to limit the present invention. Any person skilled in the art within the technical field to which the present application pertains can make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed by the present application. However, the protection scope of the present application shall still be subject to the scope defined by the appended claims.

[0098] As described above, this is only the specific implementation manner of the present application. Those skilled in the art can clearly understand that for the sake of convenience and brevity of description, the replacement of other connection manners described above, etc., can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein. It should be understood that the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various equivalent modifications or replacements, and these modifications or replacements should all be covered within the protection scope of the present application.

Claims

1. A light-emitting element, characterized in that, it includes a first electrode, a light-emitting layer, a hole-blocking layer, an electron transport layer, more than two scattering particle layers, and a second electrode. The hole-blocking layer and the electron transport layer are disposed between the light-emitting layer and the second electrode. One of the more than two scattering particle layers is disposed between the hole-blocking layer and the electron transport layer, and at least one more is disposed between the electron transport layer and the second electrode. The scattering particle layer includes a plurality of scattering particles; the number of the scattering particle layers is two. The two scattering particle layers include a first scattering particle layer and a second scattering particle layer. The first scattering particle layer is disposed between the hole-blocking layer and the electron transport layer, and the second scattering particle layer is disposed between the electron transport layer and the second electrode; The first scattering particle layer includes a plurality of first scattering particles, the second scattering particle layer includes a plurality of second scattering particles, and the average particle size Dv of the plurality of first scattering particles 1 is smaller than the average particle size Dv of the plurality of second scattering particles 2 .

2. The light-emitting element according to claim 1, characterized in that, The plurality of scattering particles includes ellipsoidal scattering particles, and the major axis length L of the ellipsoidal scattering particles 1 and the minor axis length L 2 satisfy the ratio: 1:1 < L 1 :L 2 ≤ 2:

1.

3. The light-emitting element according to claim 1, characterized in that, The thickness d of the first scattering particle layer 1 is less than the thickness d of the second scattering particle layer 2 , and d 1 ≤ Dv 1 , d 2 ≤ Dv 2 .

4. The light-emitting element according to claim 1, characterized in that, the proportion of the total volume of the first scattering particles in the total volume of the first scattering particle layer is 40% - 60%; the proportion of the total volume of the second scattering particles in the total volume of the second scattering particle layer is 40% - 60%.

5. The light-emitting element according to claim 4, characterized in that, the positive projection of the first scattering particles in the first scattering particle layer in the thickness direction of the light-emitting element and the positive projection of the second scattering particles in the second scattering particle layer in the thickness direction at least partially overlap.

6. The light-emitting element according to claim 1, characterized in that, The particle size D of the first scattering particle 1 satisfies: 5 nm ≤ D 1 ≤ 15 nm; The particle size D of the second scattering particle 2 satisfies: 50 nm ≤ D 2 ≤ 120 nm.

7. The light-emitting element according to claim 1, characterized in that, the scattering particles include metal particles, and the metal particles include one or several of zinc particles, titanium particles, silver particles, and tin particles.

8. The light-emitting element according to claim 7, characterized in that, the scattering particles include core-shell structure particles. The core material of the core-shell structure particles includes one of zinc particles, titanium particles, silver particles, and tin particles, and the shell material includes one of zinc particles, titanium particles, silver particles, and tin particles.

9. A display panel, characterized in that, it includes the light-emitting element according to any one of claims 1 to 8.

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