Display panel and display device

Abstract

Provided in the present disclosure are a display panel and a display device. The display panel comprises: a base substrate and a plurality of light-emitting devices arranged on the base substrate, wherein each light-emitting device comprises an internal micro-cavity structure and an external micro-cavity structure; each external micro-cavity structure is located between the corresponding internal micro-cavity structure and the base substrate; each internal micro-cavity structure comprises a first electrode layer, a light-emitting functional layer and a second electrode layer, which are stacked in sequence in a direction away from the base substrate; and each external micro-cavity structure comprises a total reflection layer, an optical buffer layer and a semi-transparent and semi-reflective layer made of a metal material, which layers are stacked in sequence in the direction away from the base substrate.

Description

Display panel and display device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410362126.7 filed in China on March 27, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of display technology, and in particular to a display panel and a display device. Background Art

[0004] The material system of existing organic light-emitting diode (OLED) devices uses new phosphorescent materials and thermally activated delayed fluorescent materials to achieve that both singlet and triplet excitons can return to the ground state in the form of radiative transitions, which can increase the internal quantum efficiency of the device to 100%. However, due to the limitation of the light extraction efficiency of the microcavity structure of existing devices, the external quantum efficiency of the device always remains at a low level. At the same time, the BT.2020 standard also puts forward requirements for OLED devices to have narrower monochrome half-width and wider color gamut. Therefore, how to improve the external quantum efficiency of the device and realize that the device has a narrower monochrome half-width and a wider color gamut has become an urgent problem to be solved. Summary of the Invention

[0005] An object of the present disclosure is to provide a display panel and a display device.

[0006] In order to achieve the above objectives, the present disclosure provides the following technical solutions:

[0007] A first aspect of the present disclosure provides a display panel, comprising: a base substrate and a plurality of light-emitting devices disposed on the base substrate; the light-emitting devices include an internal microcavity structure and an external microcavity structure, wherein the external microcavity structure is located between the internal microcavity structure and the base substrate;

[0008] The internal microcavity structure includes a first electrode layer, a light-emitting functional layer, and a second electrode layer stacked in sequence in a direction away from the base substrate;

[0009] The external microcavity structure includes a total reflection layer, an optical buffer layer and a semi-transmissive and semi-reflective layer made of a metal material, which are sequentially stacked in a direction away from the base substrate.

[0010] Optionally, one of the first electrode layer and the second electrode layer includes an anode layer, and the other of the first electrode layer and the second electrode layer includes a cathode layer; at least part of the membrane layer in the external microcavity structure and the first electrode layer together form a multilayer electrode structure.

[0011] Optionally, the first electrode layer is reused as the semi-transmissive and semi-reflective layer.

[0012] Optionally, the first electrode layer includes an anode layer, the second electrode layer includes a cathode layer, and the external microcavity structure and the anode layer together form a multi-layer anode structure; or

[0013] The first electrode layer includes a cathode layer, the second electrode layer includes an anode layer, and the external microcavity structure and the cathode layer together form a multi-layer cathode structure.

[0014] Optionally, the outer microcavity structure further includes: a transparent conductive compensation film layer, wherein the transparent conductive compensation film layer is located between the semi-transmissive and semi-reflective layer and the optical buffer layer.

[0015] Optionally, in the case that the first electrode layer includes the anode layer, the transparent conductive compensation film layer and the first electrode layer are made of the same material, and the transparent conductive compensation film layer and the first electrode layer have the same thickness.

[0016] Optionally, the display panel further includes a driving circuit layer, the driving circuit layer includes a plurality of driving circuits; and the semi-transmissive and semi-reflective layers are coupled to corresponding driving circuits.

[0017] Optionally, the display panel further includes a driving circuit layer, which includes multiple driving circuits; the external microcavity structure further includes a conductive connection layer, which is located between the total reflection layer and the base substrate, and the conductive connection layer is coupled to the corresponding driving circuit.

[0018] Optionally, the material of the semi-transmissive and semi-reflective layer includes a mixture of metal magnesium and metal silver; and / or, the material of the optical buffer layer includes indium tin oxide or indium zinc oxide; and / or, the material of the total reflection layer includes metal silver.

[0019] Optionally, the thickness of the semi-transmissive and semi-reflective layer is between 10 nm and 20 nm, the thickness of the optical buffer layer is between 60 nm and 140 nm, and the thickness of the total reflection layer is between 85 nm and 110 nm.

[0020] Optionally, the thickness d of the optical buffer layer satisfies: nd=kλ, where n represents the refractive index of the optical buffer layer, k is a positive integer, and λ is the wavelength of light emitted by the light-emitting device.

[0021] Optional,

[0022] The plurality of light-emitting elements include a red light-emitting element, a green light-emitting element and a blue light-emitting element; the light-emitting functional layer in the red light-emitting element includes a red light-emitting functional layer; the light-emitting functional layer in the green light-emitting element includes a green light-emitting functional layer; and the light-emitting functional layer in the blue light-emitting element includes a blue light-emitting functional layer;

[0023] The optical buffer layer in the red light-emitting element includes a red optical buffer layer, the optical buffer layer in the green light-emitting element includes a green optical buffer layer, and the optical buffer layer in the blue light-emitting element includes a blue optical buffer layer;

[0024] The thicknesses of the red optical buffer layer, the green optical buffer layer, and the blue optical buffer layer are different.

[0025] Optionally, when the first electrode layer includes an anode layer and the second electrode layer includes a cathode layer, the light-emitting functional layer includes a hole transport layer, an organic light-emitting material layer, a hole blocking layer and an electron transport layer stacked in sequence in a direction away from the base substrate; or

[0026] When the first electrode layer includes a cathode layer and the second electrode layer includes an anode layer, the light-emitting functional layer includes an electron transport layer, a hole blocking layer, an organic light-emitting material layer and a hole transport layer stacked in sequence in a direction away from the base substrate.

[0027] Optionally, the light-emitting functional layer further includes a hole injection layer and an electron injection layer; the hole injection layer is located between the anode layer and the hole transport layer; and the electron injection layer is located between the cathode layer and the electron transport layer.

[0028] Based on the technical solution of the above-mentioned display panel, a second aspect of the present disclosure provides a display device including the above-mentioned display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:

[0030] FIG1 is a schematic diagram showing the relationship between the optical power spectrum of a dipole emission and the in-plane wave vector in the related art;

[0031] FIG2 is a schematic diagram showing the relationship between the optical power spectrum of a dipole emission and the in-plane wave vector provided by an embodiment of the present disclosure;

[0032] FIG3 is a schematic diagram showing a comparison of electroluminescence spectra of three primary color organic light emitting diodes provided by an embodiment of the present disclosure using conventional technology and a dual microcavity structure;

[0033] FIG4 is a schematic diagram of a color gamut in a CIE chromaticity diagram provided by an embodiment of the present disclosure;

[0034] FIG5 is a comparison diagram of optical power density distribution using conventional technology and a dual microcavity structure according to an embodiment of the present disclosure;

[0035] FIG6 is a schematic diagram of a first structure of a light emitting device provided in an embodiment of the present disclosure;

[0036] FIG7 is a second structural diagram of a light emitting device provided in an embodiment of the present disclosure;

[0037] FIG8 is a third structural schematic diagram of a light emitting device provided in an embodiment of the present disclosure;

[0038] FIG9 is a fourth structural schematic diagram of a light emitting device provided in an embodiment of the present disclosure;

[0039] FIG10 is a fifth structural schematic diagram of the light-emitting device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0040] In order to further illustrate the display panel and display device provided by the embodiments of the present disclosure, they are described in detail below with reference to the accompanying drawings.

[0041] Referring to FIG. 6 to FIG. 10 , an embodiment of the present disclosure provides a display panel, comprising: a base substrate and a plurality of light-emitting devices disposed on the base substrate; the light-emitting devices include an internal microcavity structure 10 and an external microcavity structure 20, wherein the external microcavity structure 20 is located between the internal microcavity structure 10 and the base substrate;

[0042] The internal microcavity structure 10 includes a first electrode layer (including one of the anode layer Ano and the cathode layer Cath), a light-emitting functional layer, and a second electrode layer (including the other of the anode layer Ano and the cathode layer Cath) stacked in sequence in a direction away from the substrate;

[0043] The external microcavity structure 20 includes a total reflection layer 201 , an optical buffer layer 202 and a semi-transmissive and semi-reflective layer 203 made of a metal material, which are sequentially stacked in a direction away from the base substrate.

[0044] It should be noted that FIG6 to FIG10 also illustrate the cover layer CPL.

[0045] Exemplarily, the carriers generated by the first electrode layer and the carriers generated by the second electrode layer recombine and emit light in the light-emitting functional layer, thereby realizing the light-emitting function of the light-emitting device.

[0046] Illustratively, the material of the semi-transmissive and semi-reflective layer 203 includes a mixture of metal magnesium and metal silver, that is, the semi-transmissive and semi-reflective layer 203 is formed by using the mixture of metal magnesium and metal silver; and / or the material of the total reflection layer 201 includes metal silver.

[0047] Exemplarily, the external microcavity structure 20 is configured to include the semi-transparent and semi-reflective layer 203, so that a portion of the light generated by the internal microcavity structure 10 can be reflected back into the internal microcavity structure 10 by the semi-transparent and semi-reflective layer 203, and the other portion can pass through the semi-transparent and semi-reflective layer 203 and enter the external microcavity structure 20.

[0048] It should be noted that there are three recombination paths for dipole emission, namely radiative recombination, non-radiative recombination and excitation of the metal cathode by SP (the internal quantum efficiency is assumed to be 100% here, that is, there is no non-radiative recombination). There are three optical modes generated by radiative recombination, namely external mode, substrate mode and waveguide mode. The excitation of the metal cathode by SP will produce a surface plasmon (SP) mode. The SP mode usually produces ohmic damping within a short lifetime. It is worth noting that when discussing the optoelectronic technology of light-emitting diodes, "dipole" often refers to those occasions where excitons are formed when electrons and hole pairs recombine. Excitons are a quasiparticle that represents a bound state formed by electrons and holes and has dipole characteristics. The radiative recombination of excitons can lead to the emission of light. The dipole emission is describing the process of such exciton radiative recombination and light emission.

[0049] However, when the horizontal wave vector of the SP mode matches that of the waveguide mode, the SP mode may be re-emitted. Therefore, there are two approaches to reducing SP losses. One is to suppress the generation of plasmons themselves, and the other is to combine plasmons with propagating waves and return them to radiation. The former method uses a thick hole-transport layer to separate the dipole and metal, which significantly increases the driving voltage and, in turn, the power consumption of the device, making this approach undesirable. Therefore, the second approach is considered, which re-emits the SP mode and couples it with the microcavity effect, thus creating a double microcavity structure.

[0050] In a detailed optical analysis, it was found that since the semi-transparent and semi-reflective layer 203 is very thin, the evanescent wave emitted by the dipole will reach the side of the semi-transparent and semi-reflective layer 203 facing the optical buffer layer 202. Therefore, on the side of the semi-transparent and semi-reflective layer 203 facing the internal microcavity structure 10, and on the side of the semi-transparent and semi-reflective side layer facing the external microcavity structure 20, the two SPs couple and interact in the semi-transparent and semi-reflective layer 203, and are then converted into waveguide modes, which significantly reduces SP losses. As shown in Figures 1 and 2, the solid lines in the figures represent transverse electric waves and the dotted lines represent transverse magnetic waves. It can be found that the existing light-emitting devices also include a large number of transverse magnetic waves in the SP mode, and the light-emitting device disclosed in the present invention can convert the transverse electric waves and transverse magnetic waves in the SP mode into waveguide modes, so as to increase the light extraction efficiency during the light extraction process. It should be noted that in the figure, M1 represents the external mode, M2 represents the substrate mode, M3 represents the waveguide mode, and M4 represents the SP mode. It is worth noting that the abscissa in Figures 1 and 2 represents the in-plane wave vector, and the ordinate represents the optical power density of the dipole emission. Furthermore, the interference of the light waves between the internal microcavity structure 10 and the external microcavity structure 20 produces stronger forward emission, further improving the external quantum efficiency and thus achieving higher light extraction efficiency for the light-emitting device.

[0051] According to the specific structure of the above-mentioned display panel, in the display panel provided by the embodiment of the present disclosure, by setting the light-emitting device to include an internal microcavity structure 10 and an external microcavity structure 20, the light generated in the internal microcavity structure 10 can generate SP on both sides of the semi-transparent and semi-reflective layer 203 respectively, and the SPs located on both sides of the semi-transparent and semi-reflective layer 203 couple and interact in the semi-transparent and semi-reflective layer 203, and are then converted into waveguide modes, thereby significantly reducing the SP loss of the light-emitting device. Therefore, the display panel provided by the embodiment of the present disclosure improves the external quantum efficiency of the light-emitting device by setting the light-emitting device to include a dual microcavity structure combining an internal microcavity structure 10 and an external microcavity structure 20, thereby further improving the light extraction efficiency of the light-emitting device. Specifically, refer to Figure 5. The left side of Figure 5 represents the light power density distribution of a conventional light-emitting device, and the center point A in the figure represents dipole radiation; the right side of Figure 5 represents the light power density distribution of the light-emitting device in the present disclosure, and the part below the dotted line in the figure represents the light power density corresponding to the external microcavity structure. The right side of Figure 5 also illustrates the light power density values ​​corresponding to different colors.

[0052] Moreover, as shown in Figures 3 and 4, the light-emitting device is provided to include a dual microcavity structure, so that the electroluminescence spectrum of the light-emitting device has a narrower half-width and a wider color gamut, effectively enhancing the color display capability of the display panel. It should be noted that the dotted line in Figure 3 represents a conventional light-emitting device, and the solid line represents the light-emitting device in the present disclosure. The abscissa in Figure 3 represents the wavelength, and the ordinate represents the emission intensity. X1 in Figure 4 represents a conventional light-emitting device, X2 represents the light-emitting device in the present disclosure, and X3 represents the BT.2020 standard value.

[0053] In addition, in the display panel provided by the embodiment of the present disclosure, the semi-transmissive and semi-reflective layer 203, the optical buffer layer 202 and the total reflection layer 201 in the external microcavity structure 20 are compatible with the existing display panel manufacturing process, share the FMM mask with the original organic layer in the display panel, and can share the evaporation equipment with the original electrode layer in the display panel. Moreover, the materials selected for each film layer in the external microcavity structure 20 are highly versatile, and there is no need to explore new materials, which effectively simplifies the manufacturing process of the dual microcavity structure.

[0054] As shown in Figures 6 to 10, in some embodiments, one of the first electrode layer and the second electrode layer includes an anode layer Ano, and the other of the first electrode layer and the second electrode layer includes a cathode layer Cath; at least part of the membrane layer in the external microcavity structure 20 and the first electrode layer together form a multilayer electrode structure.

[0055] As shown in FIG7 , illustratively, the first electrode layer includes an anode layer Ano, the second electrode layer includes a cathode layer Cath, and the external microcavity structure 20 and the anode layer Ano together form a multilayer anode structure. For example, the first electrode layer is formed of an indium tin oxide material, the second electrode layer is formed of a mixture of metal magnesium and metal silver, the semi-transparent and semi-reflective layer 203 is formed of a mixture of metal magnesium and metal silver, the optical buffer layer 202 is formed of an indium tin oxide or indium zinc oxide material, and the total reflection layer 201 is formed of a metal silver material. The above-mentioned configuration makes the multilayer anode structure a structure formed by stacking metal oxides and metals, and the multilayer anode structure has good conductivity and transmittance.

[0056] The above-mentioned setting method forms a dual microcavity structure with multiple anodes as the external microcavity structure 20. This structure can not only improve the luminous efficiency of the light-emitting device and the color display capability of the display panel, but also enable the light-emitting device to have a multi-layer anode structure, thereby better improving the connection performance between the anode of the light-emitting device and the driving circuit.

[0057] As shown in FIG6 , the first electrode layer is further reused as the semi-transmissive and semi-reflective layer 203. For example, the anode layer Ano is reused as the semi-transmissive and semi-reflective layer 203. The anode layer Ano can be formed by stacking an indium tin oxide layer and a metal layer, and the metal layer can be formed by a mixture of metal magnesium and metal silver.

[0058] As shown in Figure 9, illustratively, the first electrode layer includes a cathode layer Cath, the second electrode layer includes an anode layer Ano, and the external microcavity structure 20 and the cathode layer Cath together form a multilayer cathode structure. For example, the first electrode layer is formed by a mixture of metal magnesium and metal silver, and the second electrode layer is formed by a stacked indium tin oxide layer, a metal layer, and an indium tin oxide layer. The optical buffer layer 202 is made of indium tin oxide or indium zinc oxide material, and the total reflection layer 201 is made of metal silver material. The above-mentioned setting method makes the multilayer cathode structure a structure formed by stacking metal oxides and metals, and the multilayer cathode structure has good conductivity and transmittance.

[0059] As shown in FIG9 , further, the first electrode layer is reused as the semi-transmissive and semi-reflective layer 203 . For example, the cathode layer Cath is reused as the semi-transmissive and semi-reflective layer 203 .

[0060] The above-mentioned setting method forms a light-emitting device with inverted anode and cathode, and a dual microcavity structure with multiple cathodes as the external microcavity structure 20. This structure can not only improve the luminous efficiency of the light-emitting device and improve the color display capability of the display panel, but also enable the light-emitting device to have a multi-layer cathode structure, thereby better improving the connection performance between the cathode of the light-emitting device and the driving circuit.

[0061] As shown in FIG. 8 and FIG. 10 , in some embodiments, the outer microcavity structure further includes: a transparent conductive compensation film layer 204 , and the transparent conductive compensation film layer 204 is located between the semi-transmissive and semi-reflective layer 203 and the optical buffer layer 202 .

[0062] For example, when the first electrode layer includes an anode layer Ano, the anode layer Ano may be made of indium tin oxide, the semi-transparent and semi-reflective layer 203 may be made of a mixture of metal magnesium and metal silver, and the transparent conductive compensation film layer 204 may be made of indium tin oxide.

[0063] Exemplarily, when the first electrode layer includes a cathode layer Cath, the cathode layer Cath can be made of a mixture of metal magnesium and metal silver, and the cathode layer Cath can be reused as the semi-transparent and semi-reflective layer 203, and the transparent conductive compensation film layer 204 can be made of indium tin oxide material.

[0064] This arrangement enhances the overall electrical conductivity of the stacked structure formed by the first electrode layer, the transflective layer 203, and the transparent conductive compensation film layer 204. Furthermore, the transparent conductive compensation film layer 204 on the side closest to the light-emitting functional layer can provide energy level matching, thereby enhancing light extraction.

[0065] As shown in FIG8 , in some embodiments, when the first electrode layer includes the anode layer Ano, the transparent conductive compensation film layer 204 and the first electrode layer are made of the same material and have the same thickness.

[0066] Exemplarily, the transparent conductive compensation film layer 204 has a thickness between 3 nm and 10 nm, including end values.

[0067] The above arrangement enables the anode layer Ano and the transparent conductive compensation layer to form a symmetrical structure on both sides of the semi-transmissive and semi-reflective layer 203, which not only stabilizes the electrical properties of the anode layer Ano, but also helps to convert the SP mode into a waveguide mode, thereby enhancing the light extraction capability.

[0068] As shown in FIG. 10 , in some embodiments, when the first electrode layer includes the cathode layer Cath, the thickness of the transparent conductive compensation film layer 204 may be set between 3 nm and 15 nm, including end values.

[0069] The above configuration can better stabilize the electrical performance of the cathode layer Cath.

[0070] As shown in FIG8 and FIG10 , in some embodiments, the display panel further includes a driving circuit layer, and the driving circuit layer includes a plurality of driving circuits; the transflective layer 203 is coupled to the corresponding driving circuits.

[0071] When the outer microcavity structure also includes the transparent conductive compensation film layer 204, the translucent and semi-reflective layer 203 can be used as an electrode to directly couple to the corresponding drive circuit. This approach not only ensures the device's electrical characteristics but also eliminates the need to specify the material of the optical buffer layer 202. In this case, the optical buffer layer 202 serves only as a microcavity filling layer and only requires excellent transmittance and low material cost. There are no requirements for conductivity. Generally, organic or inorganic materials such as silicon nitride, silicon oxynitride, and silicon oxide can be used as the film layer material.

[0072] This arrangement eliminates the need for the entire outer microcavity structure 20 to function as an electrode, and allows it to be combined with both upright and inverted light-emitting devices. In this case, the inner and outer microcavity structures 10 and 20 share the transflective layer 203, which serves as the first electrode layer.

[0073] As shown in Figures 7 and 9, in some embodiments, the display panel further includes a driving circuit layer, which includes a plurality of driving circuits; the external microcavity structure 20 further includes a conductive connection layer 30, which is located between the total reflection layer 201 and the base substrate, and the conductive connection layer 30 is coupled to the corresponding driving circuit.

[0074] Exemplarily, the conductive connection layer 30 is made of indium tin oxide material, but is not limited thereto.

[0075] The above configuration can better ensure the connection performance between the multi-layer electrode structure and the driving circuit.

[0076] In some embodiments, the material of the semi-transmissive and semi-reflective layer 203 includes a mixture of metal magnesium and metal silver; and / or the material of the optical buffer layer 202 includes indium tin oxide or indium zinc oxide; and / or the material of the total reflection layer 201 includes metal silver.

[0077] When the optical buffer layer 202 is provided to form the multi-layer electrode structure, the optical buffer layer 202 needs to have good conductivity and transmittance. The optical buffer layer 202 uses indium tin oxide or indium zinc oxide as the film material, which can well ensure conductivity and transmittance.

[0078] When the total reflection layer 201 is provided to form the multi-layer electrode structure, the total reflection layer 201 needs to have good electrical conductivity and total reflection properties. The material of the total reflection layer 201 includes metallic silver, which can well ensure electrical conductivity and total reflection properties.

[0079] In some embodiments, the thickness of the semi-transmissive and semi-reflective layer 203 is between 10nm and 20nm, which may include endpoint values; the thickness of the optical buffer layer 202 is between 60nm and 140nm, which may include endpoint values; the thickness of the total reflection layer 201 is between 85nm and 110nm, which may include endpoint values.

[0080] The above arrangement enables the formed external microcavity structure 20 to have a good light refraction and reflection effect, which is beneficial to further improve the color display capability of the display panel.

[0081] In some embodiments, the thickness d of the optical buffer layer 202 satisfies: nd=kλ, where n represents the refractive index of the optical buffer layer 202, k is a positive integer, and λ is the wavelength of light emitted by the light emitting device.

[0082] The thickness of the optical buffer layer 202 serves as the cavity length of the external microcavity structure 20 , and can satisfy the microcavity effects of different wavelengths of RGB.

[0083] In some embodiments, the plurality of light-emitting elements include a red light-emitting element, a green light-emitting element, and a blue light-emitting element; the light-emitting functional layer in the red light-emitting element includes a red light-emitting functional layer; the light-emitting functional layer in the green light-emitting element includes a green light-emitting functional layer; and the light-emitting functional layer in the blue light-emitting element includes a blue light-emitting functional layer;

[0084] The optical buffer layer 202 in the red light-emitting element includes a red optical buffer layer, the optical buffer layer 202 in the green light-emitting element includes a green optical buffer layer, and the optical buffer layer 202 in the blue light-emitting element includes a blue optical buffer layer;

[0085] The thicknesses of the red optical buffer layer, the green optical buffer layer, and the blue optical buffer layer are different.

[0086] Exemplarily, the thickness of the red optical buffer layer can be calculated by substituting the wavelength of red light, the thickness of the green optical buffer layer can be calculated by substituting the wavelength of green light, and the thickness of the blue optical buffer layer can be calculated by substituting the wavelength of blue light.

[0087] The above arrangement enables the formed external microcavity structure 20 to have a good light refraction and reflection effect, which is beneficial to further improve the color display capability of the display panel.

[0088] As shown in Figures 6 to 10, in some embodiments, when the first electrode layer includes an anode layer Ano and the second electrode layer includes a cathode layer Cath, the light-emitting functional layer includes a hole transport layer HTL, an organic light-emitting material layer EL, a hole blocking layer HBL and an electron transport layer ETL, which are sequentially stacked in a direction away from the substrate; or, when the first electrode layer includes a cathode layer Cath and the second electrode layer includes an anode layer Ano, the light-emitting functional layer includes an electron transport layer ETL, a hole blocking layer HBL, an organic light-emitting material layer EL and a hole transport layer HTL, which are sequentially stacked in a direction away from the substrate.

[0089] Exemplarily, the light-emitting functional layer further includes a hole injection layer and an electron injection layer; the hole injection layer is located between the anode layer Ano and the hole transport layer HTL; the electron injection layer is located between the cathode layer Cath and the electron transport layer ETL.

[0090] Exemplarily, the organic light-emitting material layer includes a first organic light-emitting material layer and a second organic light-emitting material layer stacked together. The first organic light-emitting material layer includes a first red light-emitting material layer R', a first green light-emitting material layer G', and a first blue light-emitting material layer B'. The second organic light-emitting material layer includes a second red light-emitting material layer REML, a second green light-emitting material layer GEML, and a second blue light-emitting material layer BEML.

[0091] The above-mentioned setting of the light-emitting functional layer includes the hole injection layer, the hole transport layer HTL, the organic light-emitting material layer, the hole blocking layer HBL, the electron transport layer ETL and the electron injection layer, which effectively improves the transmission efficiency of carriers such as electrons and holes in the light-emitting functional layer, as well as the luminous efficiency of the organic light-emitting material layer.

[0092] An embodiment of the present disclosure further provides a display device, comprising the display panel provided by the above embodiment.

[0093] Exemplarily, the display device includes an active matrix organic light emitting diode display device, but is not limited thereto.

[0094] It should be noted that the display device can be any product or component with a display function, such as a television, a monitor, a digital photo frame, a mobile phone, a tablet computer, etc., wherein the display device also includes a flexible circuit board, a printed circuit board and a backplane.

[0095] In the display panel provided by the above embodiment, by setting the light-emitting device to include an internal microcavity structure and an external microcavity structure, the light generated in the internal microcavity structure can generate SP on both sides of the semi-transparent and semi-reflective layer respectively. The SPs located on both sides of the semi-transparent and semi-reflective layer couple and interact in the semi-transparent and semi-reflective layer, and are then converted into waveguide modes, thereby significantly reducing the SP loss of the light-emitting device. Therefore, the display panel provided by the above embodiment improves the external quantum efficiency of the light-emitting device by setting the light-emitting device to include a dual microcavity structure combining an internal microcavity structure and an external microcavity structure, thereby further improving the light extraction efficiency of the light-emitting device. Moreover, the light-emitting device is provided with a dual microcavity structure, so that the electroluminescence spectrum of the light-emitting device has a narrower half-width and a wider color gamut, effectively enhancing the color display capability of the display panel. In addition, in the display panel provided by the above embodiment, the semi-transmissive and semi-reflective layer, the optical buffer layer, and the total reflection layer in the external microcavity structure are compatible with the existing display panel manufacturing process, sharing the FMM mask with the original organic layer in the display panel, and can share the evaporation equipment with the original electrode layer in the display panel. Moreover, the materials selected for each film layer in the external microcavity structure are highly versatile, and there is no need to explore new materials, which effectively simplifies the manufacturing process of the dual microcavity structure. The display device provided by the embodiment of the present disclosure also has the above-mentioned beneficial effects when including the above-mentioned display substrate, which will not be repeated here.

[0096] It should be noted that the "same layer" in the embodiment of the present disclosure may refer to a film layer on the same structural layer. Or, for example, a film layer in the same layer may be a film layer formed by using the same film forming process to form a specific pattern, and then patterning the film layer using the same mask through a single composition process to form a layer structure. Depending on the specific pattern, a single composition process may include multiple exposure, development or etching processes, and the specific pattern in the formed layer structure may be continuous or discontinuous. These specific patterns may also be at different heights or have different thicknesses.

[0097] In the various method embodiments of the present disclosure, the serial numbers of the steps cannot be used to limit the order of the steps. For ordinary technicians in this field, without paying any creative work, changes to the order of the steps are also within the scope of protection of the present disclosure.

[0098] It should be noted that the various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences from other embodiments. In particular, the method embodiments are described briefly because they are generally similar to the product embodiments. For relevant parts, refer to the description of the product embodiments.

[0099] Unless otherwise defined, technical or scientific terms used in this disclosure should have the ordinary meaning understood by a person of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are simply used to distinguish different components. Terms such as "include" or "comprising" mean that the element or object preceding the term includes the elements or objects listed after the term and their equivalents, without excluding other elements or objects. Terms such as "connect," "couple," or "connected" are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "below" another element, the element may be "directly" "on" or "below" the other element, or there may be intervening elements.

[0100] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0101] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A display panel, comprising: A base substrate and a plurality of light emitting devices disposed on the base substrate; The light emitting device comprises an inner microcavity structure and an outer microcavity structure, wherein the outer microcavity structure is located between the inner microcavity structure and the base substrate; The internal microcavity structure includes a first electrode layer, a light-emitting functional layer, and a second electrode layer stacked in sequence in a direction away from the base substrate; The external microcavity structure includes a total reflection layer, an optical buffer layer and a semi-transmissive and semi-reflective layer made of a metal material, which are sequentially stacked in a direction away from the base substrate.

2. The display panel according to claim 1, wherein One of the first electrode layer and the second electrode layer includes an anode layer, and the other of the first electrode layer and the second electrode layer includes a cathode layer; at least part of the membrane layer in the external microcavity structure and the first electrode layer together form a multilayer electrode structure.

3. The display panel according to claim 2, wherein: The first electrode layer is reused as the semi-transmissive and semi-reflective layer.

4. The display panel according to claim 2 or 3, wherein: The first electrode layer includes an anode layer, the second electrode layer includes a cathode layer, and the external microcavity structure and the anode layer together form a multi-layer anode structure; or The first electrode layer includes a cathode layer, the second electrode layer includes an anode layer, and the external microcavity structure and the cathode layer together form a multi-layer cathode structure.

5. The display panel according to claim 4, wherein: The outer microcavity structure further includes a transparent conductive compensation film layer, and the transparent conductive compensation film layer is located between the semi-transmissive and semi-reflective layer and the optical buffer layer. The display panel according to claim 5 , wherein: In the case where the first electrode layer includes the anode layer, the transparent conductive compensation film layer and the first electrode layer are made of the same material, and the transparent conductive compensation film layer and the first electrode layer have the same thickness.

7. The display panel according to claim 5, wherein: The display panel further includes a driving circuit layer, which includes a plurality of driving circuits; the transflective layer is coupled to the corresponding driving circuits.

8. The display panel according to any one of claims 1 to 4, wherein: The display panel further includes a driving circuit layer, which includes a plurality of driving circuits; the external microcavity structure further includes a conductive connection layer, which is located between the total reflection layer and the base substrate, and is coupled to the corresponding driving circuit.

9. The display panel according to claim 1, wherein: The material of the semi-transmissive and semi-reflective layer includes a mixture of metal magnesium and metal silver; and / or the material of the optical buffer layer includes indium tin oxide or indium zinc oxide; and / or the material of the total reflection layer includes metal silver.

10. The display panel according to claim 1, wherein The thickness of the semi-transmissive and semi-reflective layer is between 10 nm and 20 nm, the thickness of the optical buffer layer is between 60 nm and 140 nm, and the thickness of the total reflection layer is between 85 nm and 110 nm.

11. The display panel according to claim 10, wherein: The thickness d of the optical buffer layer satisfies: nd=kλ, where n represents the refractive index of the optical buffer layer, k is a positive integer, and λ is the wavelength of the light emitted by the light emitting device.

12. The display panel according to claim 11, wherein: The plurality of light-emitting elements include a red light-emitting element, a green light-emitting element and a blue light-emitting element; the light-emitting functional layer in the red light-emitting element includes a red light-emitting functional layer; the light-emitting functional layer in the green light-emitting element includes a green light-emitting functional layer; and the light-emitting functional layer in the blue light-emitting element includes a blue light-emitting functional layer; The optical buffer layer in the red light-emitting element includes a red optical buffer layer, the optical buffer layer in the green light-emitting element includes a green optical buffer layer, and the optical buffer layer in the blue light-emitting element includes a blue optical buffer layer; The thicknesses of the red optical buffer layer, the green optical buffer layer, and the blue optical buffer layer are different.

13. The display panel according to claim 2 or 3, wherein: In the case where the first electrode layer includes an anode layer and the second electrode layer includes a cathode layer, the light-emitting functional layer includes a hole transport layer, an organic light-emitting material layer, a hole blocking layer and an electron transport layer stacked in sequence in a direction away from the base substrate; or When the first electrode layer includes a cathode layer and the second electrode layer includes an anode layer, the light-emitting functional layer includes an electron transport layer, a hole blocking layer, an organic light-emitting material layer and a hole transport layer stacked in sequence in a direction away from the base substrate.

14. The display panel according to claim 13, wherein: The light-emitting functional layer further includes a hole injection layer and an electron injection layer; the hole injection layer is located between the anode layer and the hole transport layer; and the electron injection layer is located between the cathode layer and the electron transport layer.

15. A display device comprising the display panel according to any one of claims 1 to 14.

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