Display panel and method for manufacturing the same

Abstract

The present application provides a display panel and a method for manufacturing the same. The display panel includes a substrate and a plurality of light-emitting units arranged on one side of the substrate, wherein the light-emitting unit has a light-emitting area and a light adjustment area, and the light-emitting unit includes a light-emitting layer located in the light-emitting area, and a light adjustment layer located in the light adjustment area, and the light adjustment layer is used to adjust the light emitted by the light-emitting unit. Since the light adjustment layer can scatter light at a large angle, light at a large or extremely large angle will be adjusted to a smaller viewing angle after being scattered by the light adjustment layer and emitted through the light-emitting layer, which is equivalent to reducing the waveguide loss of light at a large viewing angle from the light source, and enhancing the light output at a positive viewing angle, thereby achieving the purpose of improving the performance of the display panel.

Description

Technical Field

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

[0002] Organic Light-Emitting Diode (OLED) is known as a new generation of flat panel display devices. Compared with the current mainstream liquid crystal display (LCD), it has the advantages of self-luminescence, wide viewing angle, high contrast, fast response time, thin panel thickness (flat panel), etc. Due to the different refractive indices of various functional film layers in OLED devices, there will be a large amount of optical total reflection phenomenon. Therefore, most of the light will be lost in the form of waveguide and cannot be coupled into the air, resulting in low coupling light efficiency. Summary of the invention

[0003] In view of this, the present application provides a display panel and a method for manufacturing the same to solve the problem of low light coupling efficiency of the display panel.

[0004] In a first aspect, the present application provides a display panel, which includes: a substrate; a plurality of light-emitting units arranged on one side of the substrate; wherein the light-emitting unit has a light-emitting area and a light adjustment area, the light-emitting unit includes a light-emitting layer located in the light-emitting area, and a light adjustment layer located in the light adjustment area, the light adjustment layer being used to adjust the light emitted by the light-emitting unit.

[0005] In a specific implementation of the first aspect of the present application, the light-emitting unit further includes a stacked anode and a cathode, the light-emitting layer is located between the anode and the cathode, and the light-adjusting layer and the light-emitting layer are arranged in the same layer.

[0006] In a specific implementation of the first aspect of the present application, the light adjustment layer includes a scattering layer, the scattering layer includes a plurality of scattering particles, and the scattering particles are used to scatter the light emitted by the light emitting unit.

[0007] In a specific embodiment of the first aspect of the present application, the light adjustment layer further includes a polymer, and the scattering particles are dispersed in the polymer.

[0008] In a specific implementation of the first aspect of the present application, the wavelength range of the localized surface plasmon resonance spectrum of the scattering particles at least partially overlaps with the wavelength range of the luminescence spectrum of the luminescent layer.

[0009] In a specific implementation of the first aspect of the present application, the scattering particles include a metal core and a shell layer encapsulating the metal core.

[0010] In a specific implementation of the first aspect of the present application, the material of the metal core includes one or more of gold, silver, aluminum, copper, titanium, platinum, nickel, and chromium, and the material of the shell includes at least one of silicon dioxide, aluminum oxide, and graphene.

[0011] In a specific implementation of the first aspect of the present application, a plurality of the light-emitting areas and a plurality of the light adjustment areas in a light-emitting unit are arranged at intervals in the first direction and / or the second direction; and / or the light adjustment area is arranged around the light-emitting area, and the first direction and the second direction intersect.

[0012] A second aspect of the present application provides a method for preparing a display panel, which includes providing a substrate; forming a plurality of light-emitting units on the substrate; wherein the light-emitting unit has a light-emitting area and a light adjustment area, the light-emitting unit includes a light-emitting layer located in the light-emitting area, and a light adjustment layer located in the light adjustment area, the light adjustment layer being used to adjust the light emitted by the light-emitting unit.

[0013] In a specific implementation of the second aspect of the present application, a plurality of light-emitting units are formed on a substrate, including: preparing a first electrode layer on the substrate; forming a light-emitting layer located in a light-emitting area and a light-adjusting layer located in a light-adjusting area on the first electrode layer, wherein the light-emitting layer is formed by evaporating a light-emitting material, and the light-adjusting layer is formed by spin coating or inkjet printing a polymer doped with scattering particles; and preparing a second electrode layer on the light-emitting layer.

[0014] In the display panel provided in the embodiment of the present application, the light-emitting unit has a light-emitting area and a light adjustment area. The light-emitting unit includes a light-emitting layer located in the light-emitting area and a light adjustment layer located in the light adjustment area. Since the light adjustment layer can scatter light at a large angle, light at a larger or maximum angle will be adjusted to a smaller viewing angle after being scattered by the light adjustment layer and emitted through the light-emitting layer, which is equivalent to reducing the waveguide loss of light at a large viewing angle from the light source. Therefore, the display panel provided in the embodiment of the present application can enhance the light output at a positive viewing angle, thereby further improving the performance of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the planar structure of a display panel provided in one embodiment of the present application.

[0016] Figure 2 for Figure 1 The cross-sectional structure diagram of the display panel along the cutting line AA′ is shown.

[0017] Figure 3 A schematic diagram of the structure of a light-emitting unit provided in one embodiment of the present application.

[0018] Figure 4 This is a schematic top view of a light-emitting layer and a light-adjusting layer provided in one embodiment of the present application.

[0019] Figure 5a This is a schematic top view of a light-emitting layer and a light-adjusting layer provided in another embodiment of the present application.

[0020] Figure 5b This is a schematic top view of a light-emitting layer and a light-adjusting layer provided in another embodiment of the present application.

[0021] Figure 6 A schematic diagram of the structure of scattering particles provided in one embodiment of the present application.

[0022] Figure 7 A schematic flow chart of a method for manufacturing a display panel provided in one embodiment of the present application.

[0023] Figure 8 A schematic flow chart of a method for preparing a display panel provided in another embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0025] In organic electroluminescent devices, total reflection at the interface between the metal layer anode and cathode will lead to energy loss, which in turn causes surface plasma loss near the metal layer (anode or cathode). As a result, after passing through multiple functional film layers, only about 20% of the light emitted from the light-emitting layer can pass through the device into the air and be seen by the user. Most (80%) of the energy is lost, which reduces the external quantum efficiency of the organic electroluminescent device. The external quantum efficiency is the efficiency of light being extracted from the device, also known as light extraction efficiency. For flat display devices, how to improve the external quantum efficiency, that is, how to improve the coupled light extraction efficiency of OLED, is an urgent problem to be solved.

[0026] In view of this, the present application provides a display panel and a manufacturing method thereof, and a display device to solve the problem of low light coupling efficiency in existing display panels.

[0027] It should be noted that an organic electroluminescent device is a device that emits light by being driven by electric current. Specifically, an organic electroluminescent device includes a cathode, an anode, and a light-emitting layer located between the cathode and the anode. When voltage is applied, electrons from the cathode and holes from the anode migrate to the light-emitting layer and combine to generate excitons, thereby emitting light of different wavelengths according to the characteristics of the light-emitting layer.

[0028] Total reflection means that when light enters a medium with a higher refractive index into a medium with a lower refractive index, if the incident angle is greater than a certain critical angle (the light is far away from the normal), the refracted light will disappear and all the incident light will be reflected without entering the medium with a lower refractive index.

[0029] Scattering refers to the phenomenon that when the surface curvature of the object irradiated by the projected wave is large or even not smooth, its secondary radiation wave diffuses and distributes in the angular domain according to a certain rule. It is when molecules or atoms approach each other, due to the strong mutual repulsion between the two sides, they are forced to deviate from their original direction of movement and separate before contact, which is usually called "scattering".

[0030] Surface Plasmon (SP) refers to an electron density wave that propagates along the metal surface when the freely vibrating electrons on the metal surface are excited by electrons or light waves and interact with electrons or photons. It is an electromagnetic surface wave that can laterally confine light waves to a sub-wavelength scale, and its dispersion curve is flat near the resonant frequency, the photon state density is large, and its spontaneous radiation can be enhanced when interacting with the surrounding medium. The field intensity of this electron density wave is the largest at the surface, and it decays exponentially in the direction perpendicular to the interface. If the metal surface is very rough or near a curved structure of the metal (such as a sphere, cylinder, etc.), the surface plasma cannot propagate along the interface in the form of a wave, but is localized near the surface of these structures, that is, the localization of the surface plasma. At this time, the surface plasma SP is called localized surface plasma (LSP). When metal particles whose size is close to or smaller than the wavelength of light are illuminated by light, their oscillating electric field causes the electron cloud of the metal particles to shift relative to the nucleus. The Coulomb attraction between the electron cloud and the nucleus generates a restoring force, causing the electron cloud to oscillate around the nucleus. This collective oscillation of the electron cloud is called Localized Surface Plasmon Resonance (LSPR).

[0031] Figure 1 A schematic diagram of the planar structure of a display panel provided in one embodiment of the present application. Figure 2 for Figure 1 The cross-sectional structure diagram of the display panel along the cutting line AA′ is shown. Figure 3 This is a schematic diagram of the structure of a light-emitting unit provided in an embodiment of the present application. Figures 1 to 3As shown, the display panel of this embodiment includes: a substrate 10 and a plurality of light-emitting units 11 arranged on one side of the substrate 10. Among them, the plurality of light-emitting units 11 are arranged in an array. The light-emitting unit 11 can be a light-emitting sub-pixel, which is used to emit light of different colors. The light-emitting unit 11 has a light-emitting area 32 and a light adjustment area 33. The light-emitting unit 11 includes a light-emitting layer 113 located in the light-emitting area 32, and a light adjustment layer 103 located in the light adjustment area 33, and the light adjustment layer 103 is used to adjust the light emitted by the light-emitting unit 11.

[0032] Specifically, due to the different refractive indices of the functional film layers in the display panel, there will be a large number of optical total reflection phenomena. Light with a small viewing angle will not be totally reflected, so the direction of the light with a small viewing angle will not be changed, and it can directly enter the next film layer, while the light with a large viewing angle will be lost in the form of a waveguide, or enter the next functional film layer in a direction close to the total reflection angle, and be lost in the form of a waveguide in other film layers, so that it cannot be coupled to the air, reducing the light extraction efficiency of the display panel. In the prior art, metal nanoparticles are usually doped in the light extraction layer. This method will cause the light at the positive viewing angle to be scattered. In the display panel provided in the embodiment of the present application, the light-emitting unit 11 has a light-emitting area 32 and a light adjustment area 33. The light-emitting unit 11 includes a light-emitting layer 113 located in the light-emitting area 32, and a light-adjusting layer 103 located in the light-adjusting area 33. Since the light-adjusting layer 103 can scatter light at a large angle, light at a larger or maximum angle will be adjusted to a smaller viewing angle after being scattered by the light-adjusting layer 103 and emitted through the light-emitting layer 113, which is equivalent to reducing the waveguide loss of light at a large viewing angle from the light source. Therefore, the display panel provided in the embodiment of the present application can enhance the light output at a positive viewing angle and further improve the performance of the display panel.

[0033] The substrate 10 may be a rigid substrate such as a glass substrate or a silicon substrate, or a flexible substrate such as stainless steel (SUS) or flexible polyimide (PI). In addition, the display panel in the embodiment of the present application may be a non-bendable rigid display panel or a bendable flexible display panel.

[0034] The light emitting unit 11 may be a red light emitting unit for emitting red light, a green light emitting unit for emitting green light, or a blue light emitting unit for emitting blue light.

[0035] Exemplarily, the light-emitting layer 113 includes a red light-emitting layer, a green light-emitting layer and a blue light-emitting layer. The light-emitting material of the light-emitting layer 113 may be a blue light-emitting material, so that the light-emitting layer 113 is a blue light-emitting layer. It is understood that, according to actual needs, the light-emitting layer 113 may also be a light-emitting layer of other colors. The light-emitting color requirements of the light-emitting unit 11 are different, and the light-emitting material of the light-emitting layer 113 is also different. The light-emitting material may be an organic material or an inorganic material, and the present application does not make specific restrictions on this.

[0036] The material of the anode 111 can be an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), or any combination of the above materials.

[0037] The material of the cathode 112 can be metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and any combination of the above materials.

[0038] The display panel also has a circuit array layer. The circuit array layer includes a plurality of driving circuits, each of which includes a driving transistor T, such as Figure 2 As shown, the drain of the driving transistor T is electrically connected to the anode 111 of the light emitting unit 11 to transmit a driving signal to the anode 111. It is understandable that the cathode 112 of each light emitting unit 11 is grounded or connected to a low level signal so that there is a voltage difference between the anode 111 and the cathode 112 to drive the light emitting layer 113 to emit light.

[0039] In some embodiments of the present application, the light emitting unit 11 may also include one or more of the following structures. Figure 3 As shown, the light-emitting unit 11 includes: an anode 111, a hole injection layer 116, a hole transport layer 115, an electron blocking layer 114, a light-emitting layer 113 and a light adjustment layer 103, a hole blocking layer 117, an electron transport layer 118, an electron injection layer 119, and a cathode 112 in the stacking direction of the substrate 10 (i.e., the direction in which the anode 111 points to the cathode 112).

[0040] In one embodiment, continue as Figure 2 As shown, each light emitting unit 11 further includes an anode 111 and a cathode 112. The anode 111 and the cathode 112 are arranged in a direction perpendicular to the substrate (i.e. Figure 2 The light emitting layer 113 and the light adjustment layer 103 are both located between the anode 111 and the cathode 112. Figure 3 As shown, the light adjustment layer 103 and the light emitting layer 113 are disposed in the same layer and are located between the electron blocking layer 114 and the hole blocking layer 117. The light emitting layer 113 is used to fill the light emitting material.

[0041] In one embodiment, continue as Figure 3 As shown, the light adjustment layer 103 includes a scattering layer, and the scattering layer includes a plurality of scattering particles 31 . The scattering particles 31 are used to scatter the light emitted by the light emitting unit 11 .

[0042] Figure 4 This is a schematic top view of a light emitting layer and a light adjustment layer provided in one embodiment of the present application. Figure 4 As shown, the light-emitting unit 11 has three light-emitting areas 32 and four light-adjusting areas 33, and the light-adjusting layer 103 located in the light-adjusting area 33 is arranged at intervals from the light-emitting layer 113 located in the light-emitting area 32, so that the LSPR effect of the scattering particles 31 can be applied to the entire light-emitting unit 11. Optionally, the projection areas of the four light-adjusting areas 33 on the substrate 10 are all different, and the projection areas of the three light-emitting areas 32 on the substrate 10 are all different. The number of scattering particles 31 set in each light-adjusting area 33 is also different. The scattering particles 31 are arranged in a grating-like structure.

[0043] Figure 5a This is a top view schematic diagram of a light emitting layer and a light adjustment layer provided in another embodiment of the present application. Figure 5a As shown, the light-emitting unit 11 has five light adjustment areas 33 and four light-emitting areas 32. The light adjustment area 33 is adjacent to the light-emitting area 32, and the light adjustment layer 103 located in the light adjustment area 33 is arranged at intervals from the light-emitting layer 113 located in the light-emitting area 32. Optionally, the projection areas of the five light adjustment areas 33 on the substrate 10 are the same, and the projection areas of the four light-emitting areas 32 on the substrate 10 are the same. The number of scattering particles 31 set in each light adjustment area 33 is the same. The scattering particles 31 are arranged in a periodic structure of a grating, and this arrangement does not affect the normal optical path of the small-viewing-angle light, and thus does not affect the optical microcavity of the device. In addition, the light adjustment area 33 and the light-emitting area 32 can be arranged at intervals along the first direction and the second direction, that is, arranged at intervals along the row direction and the column direction into an array structure.

[0044] Figure 5b This is a top view schematic diagram of a light emitting layer and a light adjustment layer provided in another embodiment of the present application. Figure 5b As shown, the light adjustment layer 103 can be disposed around the light emitting layer 113 to reduce lateral light emission, thereby further improving the light extraction efficiency of the display panel.

[0045] In other embodiments of the present application, the light adjustment area 33 may also be located in the light emitting direction of the display panel (ie Figure 3It should be understood that the light-emitting unit 11 is equivalent to a point light source, and the light-emitting unit 11 emits light at multiple angles. The light with a small viewing angle will directly enter the next film layer. Since the light adjustment area 33 penetrates the light-emitting layer 113 in the light-emitting direction of the display panel, the light with a large viewing angle emitted by the light-emitting unit 11 can be scattered by the scattering particles 31 of the light adjustment area 33 in the light-emitting layer 113 and return to a small viewing angle so as to be emitted from the light-emitting layer 113, thereby increasing the light extraction efficiency and improving the performance of the OLED device.

[0046] It should be understood that the present application does not specifically limit the number, area size and arrangement of the light adjustment areas 33 and the light emitting areas 32 , as long as the scattering particles 31 in the light adjustment area 33 can scatter the light emitted by the light emitting unit 11 .

[0047] In one embodiment, the interval between two adjacent scattering particles 31 in the light adjustment area 33 is set to a preset distance; the radii of the plurality of scattering particles 31 are all equal. In this way, the plurality of scattering particles 31 can be more evenly distributed in the scattering layer in the light adjustment area 33, which is conducive to uniform light emission in each area of ​​the light-emitting layer 113. The preset distance can be a preset value, which can be set by those skilled in the art according to actual conditions, and the present application embodiment does not limit this.

[0048] It should be understood that in other embodiments of the present application, the scattering layer may also be doped with a plurality of scattering particles 31 with different radii.

[0049] In an embodiment of the present application, the light adjustment region 33 further includes a polymer, and the scattering particles 31 are dispersed in the polymer.

[0050] Specifically, because the scattering particles 31 cannot be directly doped into the light emitting layer 113 and need to be dispersed in a dispersant, the light adjustment area 33 is filled with a polymer used as a dispersant to disperse the scattering particles 31 .

[0051] Exemplarily, the polymer includes one or more of polymethyl methacrylate (PMMA), PC (polycarbonate), polyethylene terephthalate (PET), methyl methacrylate-styrene copolymer (MS), polystyrene (PS), and poly-4-methylpentene-1 (TPX).

[0052] In a specific implementation of the first aspect of the present application, the wavelength range of the localized surface plasmon resonance spectrum of the scattering particles 31 at least partially overlaps with the wavelength range of the luminescence spectrum of the luminescent layer 113. The local field around the scattering particles 31 promotes the excitation of the luminescent material, making it easier for the ground state luminescent molecules to be excited to a high energy level, thereby promoting the luminescence of the luminescent material in the luminescent region.

[0053] Exemplarily, the localized surface plasmon resonance frequency of the scattering particles 31 should be adapted to the light emission wavelength of the light emitting layer 113 to obtain a maximized LSP resonance enhancement effect.

[0054] Specifically, when the localized surface plasmon resonance effect occurs, the electromagnetic field around the scattering particles 31 is greatly enhanced. A significant effect of the localized surface plasmon resonance effect is that the surface plasmon generates radiation consistent with the wavelength of the fluorescent molecule radiation under the fluorescence induction of the excitation photon (for example, the luminescent photon of the luminescent layer 113), and at the same time increases the radiation decay rate of the system, reduces the fluorescence lifetime of the photon, increases the fluorescence quantum efficiency, and enhances the fluorescence emission.

[0055] In actual application, for Figure 3 In the organic electroluminescent device shown, excitons recombine in the light-emitting layer 113 and emit photons. When the emitted light acts on the surface of the scattering particles 31, the electrons in the scattering particles 31 will collectively oscillate with the light field. When the electron cloud deviates from the nucleus, the Coulomb attraction between the electron cloud and the nucleus interacts, causing these deviated electron clouds to approach the nucleus again, so that the electron cloud oscillates near the nucleus, which is the localized surface plasma oscillation; when the frequency of the incident light is consistent with the inherent oscillation frequency of the free electrons, a localized surface plasma resonance effect is formed, at which time, light equivalent to the plasma oscillation frequency will be absorbed or scattered, and adjusted to a smaller viewing angle, emitted from the light-emitting layer 113, and enter the next film layer.

[0056] In the display panel provided by the embodiment of the present application, under lighting conditions, localized surface plasmon resonance effect will be generated locally on the scattering particles 31, that is, a local field will be generated. When the wavelength range of the absorption spectrum of the scattering particles 31 at least partially overlaps with the wavelength range of the luminescent spectrum of the light-emitting layer 113, it can promote the excitation of the dye molecules and at the same time reduce the driving voltage.

[0057] In one embodiment, the localized plasma resonance frequency is related to the particle size, particle composition, particle shape and the medium surrounding the scattering particles 31. By adjusting the size, shape and surrounding medium of the scattering particles 31, the purpose of adjusting the surface plasma resonance characteristics of the scattering particles 31 can be achieved. With the help of the localized surface plasma resonance effect of the scattering particles 31, a strong local field is generated around the scattering particles 31, thereby actively promoting the excitation of the luminescent material. The LSPR effect of the scattering particles 31 can increase the quantum yield, excite more molecules to a high energy level, and is beneficial to the luminescence of the luminescent material.

[0058] In one embodiment, the doping concentration of the scattering particles 31 in the light-emitting layer 113 should be set according to actual conditions. If the doping concentration is too high, it will have a certain negative impact on the electrical performance of the light-emitting unit 11. This application does not make any specific restrictions on this, as long as the scattering particles 31 can scatter the light emitted by the light-emitting unit 11 and can ensure that the electrical performance of the light-emitting layer 113 is not affected.

[0059] It should be understood that the scattering particles 31 in the light-emitting unit may be doped uniformly or non-uniformly, for example, embedded in a preset regular pattern.

[0060] Figure 6 This is a schematic diagram of the structure of scattering particles provided in one embodiment of the present application. Figure 6 As shown, the scattering particles 31 are metal nanoparticles with a core-shell structure, and the scattering particles 31 include a metal core 311 and a shell layer 310 that wraps the metal core 311 .

[0061] Exemplarily, the metal core 311 may be a noble metal nanoparticle or nanosphere with a particle size ranging from 10 nm to 100 nm. The metal core 311 includes one or more of gold, silver, aluminum, copper, titanium, platinum, nickel, and chromium; or, the metal core 311 includes one or more of the alloys of gold, silver, aluminum, copper, titanium, platinum, nickel, and chromium.

[0062] Exemplarily, the shell layer 310 encapsulating the metal core 311 may be a material with good optical transparency, and the material of the shell layer includes at least one of silicon dioxide, aluminum oxide, and graphene.

[0063] Exemplarily, the scattering particles 31 may be prepared by the following methods: sputtering, evaporation, photolithography, hydrothermal, chemical synthesis or electrochemical method.

[0064] In actual application, a polymer doped with scattering particles 31 is used to form a light adjustment layer by inkjet printing or spin coating.

[0065] It should be understood that if pure metal nanoparticles are used, the huge absorption loss of the metal material will have a quenching effect on the organic light-emitting material. Therefore, in the display panel provided in the embodiment of the present application, the scattering particles 31 doped in the light-emitting layer 113 include a metal core 311 and a shell 310 that wraps the metal core 311. Since the material of the shell 310 that wraps the metal core 311 is optically transparent, the coated metal core 311 will not only produce a localized surface plasmon resonance effect, but also avoid direct contact with the light-emitting material to avoid a quenching effect.

[0066] Figure 7 A schematic diagram of a method for preparing a display panel according to an embodiment of the present application is shown in FIG. Figure 7As shown, the preparation method includes the following steps.

[0067] Step 700, providing a substrate.

[0068] Step 701, forming a plurality of light-emitting units on a substrate.

[0069] The light-emitting unit has a light-emitting area and a light-adjusting area. The light-emitting unit includes a light-emitting layer located in the light-emitting area and a light-adjusting layer located in the light-adjusting area. The light-adjusting layer is used to adjust the light emitted by the light-emitting unit.

[0070] In the display panel provided in the embodiment of the present application, since the light adjustment layer can scatter light at a large angle, light at a larger or maximum angle will be adjusted to a smaller viewing angle after being scattered by the light adjustment layer and emitted through the light-emitting layer, which is equivalent to reducing the waveguide loss of the light at a large viewing angle from the light source. Therefore, the display panel provided in the embodiment of the present application can enhance the light output at a positive viewing angle, thereby further improving the performance of the display panel.

[0071] Figure 8 A schematic diagram of a method for manufacturing a display panel according to another embodiment of the present application is shown below. Figure 8 As shown, a plurality of light-emitting units are formed on a substrate, including the following steps.

[0072] Step 800: preparing a first electrode layer on a substrate.

[0073] Illustratively, the first electrode layer may be an anode layer, and the anode may be prepared on a substrate, and then a hole injection layer, a hole transport layer, and an electron blocking layer may be formed in sequence on the anode.

[0074] Step 801, forming a light emitting layer in the light emitting area and a light adjusting layer in the light adjusting area on the first electrode layer, wherein the light emitting layer is formed by evaporating a light emitting material, and the light adjusting layer is formed by spin coating or inkjet printing a polymer doped with scattering particles.

[0075] Exemplarily, the light-emitting material is evaporated on the first electrode layer to form the light-emitting layer. The light-emitting material can be evaporated using a high-precision mask or other techniques to form the light-emitting layer located in the light-emitting area.

[0076] Exemplarily, a polymer doped with scattering particles is filled to form a light adjustment layer. The scattering particles in the light adjustment layer can scatter the light emitted by the light-emitting unit and adjust the light at a larger or maximum angle to a smaller viewing angle, which is emitted through the light-emitting layer into the next film layer.

[0077] Step 802: prepare a second electrode layer on the light-emitting layer.

[0078] Illustratively, the second electrode layer may be a cathode layer.

[0079] The method for preparing a display panel provided in an embodiment of the present application comprises vapor-depositing a light-emitting material on a first electrode layer to form a light-emitting layer, and forming a light-adjusting layer by spin coating or inkjet printing of a polymer doped with scattering particles. The light with a large viewing angle emitted by the light-emitting unit is scattered by the light-adjusting layer in the light-emitting layer and can be returned to a small viewing angle to be emitted from the light-emitting layer, thereby increasing the light extraction efficiency and improving the performance of the OLED device.

[0080] Exemplarily, the display panel can be applied to various display device products, including but not limited to display screens of mobile phones, televisions, MP3s, VR glasses, etc. The light-emitting unit of the display device has a light-emitting area and a light adjustment area. On the one hand, the light adjustment layer in the light adjustment area can scatter light at a large angle to reduce the waveguide loss inside the device; on the other hand, the scattering particles in the light adjustment layer have a localized surface plasmon resonance effect, which can generate a strong local field around the scattering particles, actively promoting the excitation of the material, further improving the quantum yield, and exciting more molecules to high energy levels, which is beneficial to the luminescence of the luminescent material to improve product performance.

[0081] The display device provided according to any embodiment of the present application and the display panel provided in the embodiment of the present application belong to the same inventive concept, and have corresponding film layer structures and beneficial effects. Details not fully described in the embodiment of the display device can be found in the embodiment of the display panel, and will not be repeated here.

[0082] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A display panel, characterized in that: include: substrate; A plurality of light emitting units disposed on one side of the substrate; The light-emitting unit has a light-emitting area and a light-adjusting area, the light-emitting unit includes a light-emitting layer located in the light-emitting area, and a light-adjusting layer located in the light-adjusting area, and the light-adjusting layer is used to adjust the light emitted by the light-emitting unit; The light adjustment layer comprises a scattering layer, the scattering layer comprises a plurality of scattering particles, the scattering particles are used to scatter the light emitted by the light emitting unit; the wavelength range of the localized surface plasmon resonance spectrum of the scattering particles at least partially overlaps with the wavelength range of the light emitting spectrum of the light emitting layer; The plurality of light-emitting areas and the plurality of light-adjusting areas in the light-emitting unit are arranged at intervals in the first direction and / or the second direction; and / or the light-adjusting areas are arranged around the light-emitting areas, and the first direction and the second direction intersect.

2. The display panel according to claim 1, characterized in that: The light-emitting unit further includes an anode and a cathode which are stacked, the light-emitting layer is located between the anode and the cathode, and the light-adjusting layer and the light-emitting layer are arranged in the same layer.

3. The display panel according to claim 1, characterized in that: The scattering layer further includes a polymer, and the scattering particles are dispersed in the polymer.

4. The display panel according to claim 1, characterized in that: The scattering particles include a metal core and a shell layer surrounding the metal core.

5. The display panel according to claim 4, characterized in that: The material of the metal core includes one or more of gold, silver, aluminum, copper, titanium, platinum, nickel, and chromium; The material of the shell layer includes at least one of silicon dioxide, aluminum oxide and graphene.

6. A method for preparing a display panel, characterized in that: include: providing a substrate; A plurality of light-emitting units are formed on the substrate; wherein the light-emitting units have a light-emitting area and a light-adjusting area, the light-emitting units include a light-emitting layer located in the light-emitting area, and a light-adjusting layer located in the light-adjusting area, and the light-adjusting layer is used to adjust the light emitted by the light-emitting units; The light adjustment layer comprises a scattering layer, the scattering layer comprises a plurality of scattering particles, the scattering particles are used to scatter the light emitted by the light emitting unit; the wavelength range of the localized surface plasmon resonance spectrum of the scattering particles at least partially overlaps with the wavelength range of the light emitting spectrum of the light emitting layer; The plurality of light-emitting areas and the plurality of light-adjusting areas in the light-emitting unit are arranged at intervals in the first direction and / or the second direction; and / or the light-adjusting areas are arranged around the light-emitting areas, and the first direction and the second direction intersect.

7. The preparation method according to claim 6, characterized in that: The method of forming a plurality of light emitting units on the substrate comprises: preparing a first electrode layer on a substrate; forming a light-emitting layer located in the light-emitting area and a light-adjusting layer located in the light-adjusting area on the first electrode layer, wherein the light-emitting layer is formed by evaporating a light-emitting material, and the light-adjusting layer is formed by spin coating or inkjet printing a polymer doped with scattering particles; A second electrode layer is formed on the light-emitting layer.

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