Display panel and manufacturing method thereof, and display device

Abstract

The present invention provides a display panel and a preparation method thereof, and a display device, which relate to the field of display technology, so as to improve the transmittance of a transparent OLED display screen. The display panel includes a display substrate and a reflection enhancement layer. The display substrate includes a substrate, a pixel circuit, a flat layer, and a plurality of light-emitting devices. The reflection enhancement layer is located between the flat layer and the first electrode of the light-emitting device, and includes a plurality of reflection enhancement parts, and the plurality of reflection enhancement parts correspond to the plurality of first electrodes one by one. Each reflection enhancement part includes at least one composite reflection enhancement part, and each composite reflection enhancement part includes a first reflection enhancement part and a second reflection enhancement part. The refractive index of the first reflection enhancement part and the first electrode is greater than the refractive index of the second reflection enhancement part or the refractive index of the flat layer. In the direction from the flat layer to the light-emitting device, the first reflection enhancement part in each composite reflection enhancement part is closer to the flat layer, and the second reflection enhancement part in each composite reflection enhancement part is closer to the first electrode.

Description

Technical Field

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

[0002] In recent years, organic light-emitting diode (OLED) displays have been popular for their bendability, high brightness, low power consumption, and thinness. In addition to using OLED displays to make flexible displays, OLED displays can also be used to make transparent displays. For example, transparent displays can be used in store windows, service hall windows, and car windows, so that people can not only watch the images displayed on the transparent display, but also observe the objects behind the transparent display through the transparent display.

[0003] However, the overall transmittance of the current transparent OLED display is relatively low due to various reasons. For example, when the light-emitting device in the transparent OLED display is made of opaque material, the transmittance of the transparent OLED display will be reduced. Summary of the invention

[0004] Embodiments of the present disclosure provide a display panel and a method for manufacturing the same, and a display device, which are used to solve the problem of low overall transmittance of a transparent OLED display screen.

[0005] To achieve the above objectives, the embodiments of the present disclosure adopt the following technical solutions:

[0006] In a first aspect, a display panel is provided. The display panel includes a display substrate and a reflection enhancement layer. The display substrate includes a substrate, a pixel circuit, a flat layer, and a plurality of light-emitting devices. The pixel circuit is located on the substrate. The flat layer is located on a side of the pixel circuit away from the substrate. Each light-emitting device includes a first electrode, a light-emitting function layer, and a second electrode. The first electrode and the second electrode are both transparent or semi-transparent conductive films, and the first electrode is electrically connected to the pixel circuit through a via in the flat layer. The reflection enhancement layer is located between the flat layer and the first electrode, and includes a plurality of reflection enhancement portions, and the plurality of reflection enhancement portions correspond to a plurality of first electrodes one by one. Each reflection enhancement portion includes at least one composite reflection enhancement portion, and the at least one composite reflection enhancement portion is stacked in a direction along the flat layer pointing to the light-emitting device, and each composite reflection enhancement portion includes a first reflection enhancement portion and a second reflection enhancement portion. The refractive index of the first reflection enhancement portion and the first electrode is greater than the refractive index of the second reflection enhancement portion or the refractive index of the flat layer. In a direction along the planar layer pointing toward the light emitting device, the first reflection enhancing portion in each composite reflection enhancing portion is closer to the planar layer, and the second reflection enhancing portion in each composite reflection enhancing portion is closer to the first electrode.

[0007] In some embodiments, the optical thickness of the first reflection enhancing portion and the optical thickness of the second reflection enhancing portion satisfy the following formula:

[0008]

[0009]

[0010] Among them, n 1 is the refractive index of the first reflective enhancement portion, d 1 is the physical thickness of the first reflective enhancement portion, n 2 is the refractive index of the second reflective enhancement portion, d 2 is the physical thickness of the second reflection enhancing portion, λ 0 is the wavelength of the incident light, and i and j are both greater than or equal to zero.

[0011] In some embodiments, both i and j are integers greater than or equal to zero, so that the optical thicknesses of the first reflection enhancing portion and the second reflection enhancing portion are both λ 0 / Odd multiple of 4.

[0012] In some embodiments, the multiple reflection enhancing parts include a first color light reflection enhancing part, a second color light reflection enhancing part and a third color light reflection enhancing part; the first color light reflection enhancing part corresponds to a light emitting device that emits a first color light, the second color light reflection enhancing part corresponds to a light emitting device that emits a second color light, and the third color light reflection enhancing part corresponds to a light emitting device that emits a third color light; the first color light, the second color light and the third color light are different from each other, and the physical thicknesses of the first color light reflection enhancing part, the second color light reflection enhancing part and the third color light reflection enhancing part are different from each other.

[0013] In some embodiments, the display panel also includes a pixel defining layer; the pixel defining layer is arranged on a side of the first electrode away from the substrate, the pixel defining layer includes a plurality of opening areas and a retaining wall surrounding each of the opening areas; the first electrode and the light-emitting functional layer are separated by the retaining wall; and the retaining wall is also arranged between adjacent reflection enhancing portions and is configured to fill the gap between adjacent reflection enhancing portions.

[0014] In some embodiments, the material of the second reflection enhancing part in the at least one composite reflection enhancing part that is closest to the first electrode is transparent resin, and the second reflection enhancing layer formed by multiple second reflection enhancing parts made of transparent resin is a whole layer; the second reflection enhancing layer made of transparent resin is configured to fill the gap between adjacent reflection enhancing parts.

[0015] In some embodiments, the optical thickness of the second reflection enhancing portion made of transparent resin is λ 0An odd multiple of / 2.

[0016] In some embodiments, each reflection enhancing portion includes at least four layers of composite reflection enhancing portions.

[0017] In some embodiments, the material of the first reflective enhancement portion includes ITO, ZrO 2 、TiO 2 or ZnS; the material of the second reflection enhancing portion includes SiO 2 , LiF or MgF 2 .

[0018] In some embodiments, the display panel further includes an encapsulation layer, and the reflection enhancing layer located between the flat layer and the first electrode is replaced by a reflection enhancing layer located between the second electrode and the encapsulation layer. The reflection enhancing layer includes a plurality of reflection enhancing portions, and the plurality of reflection enhancing portions correspond to a plurality of first electrodes one by one; each reflection enhancing portion includes at least one composite reflection enhancing portion, and the at least one composite reflection enhancing portion is stacked in a direction from the light emitting device to the encapsulation layer, and each composite reflection enhancing portion includes a first reflection enhancing portion and a second reflection enhancing portion. The refractive index of the first reflection enhancing portion and the second electrode is greater than the refractive index of the second reflection enhancing portion or the refractive index of the encapsulation layer; and in the direction from the light emitting device to the encapsulation layer, the first reflection enhancing portion in each composite reflection enhancing portion is closer to the encapsulation layer, and the second reflection enhancing portion in each composite reflection enhancing portion is closer to the second electrode.

[0019] In a second aspect, a display device is provided, comprising the above-mentioned display panel.

[0020] In a third aspect, a method for manufacturing a display panel is provided, comprising: forming the pixel circuit and a planar layer located on a side of the pixel circuit away from the substrate on one side of the substrate; forming the reflection enhancement layer on a side of the planar layer away from the substrate; and forming a plurality of light-emitting devices on a side of the reflection enhancement layer away from the substrate.

[0021] In some embodiments, forming a reflection enhancing layer on a side of the flat layer away from the substrate includes: depositing a first material layer covering the flat layer on a side of the flat layer away from the substrate; exposing, developing, ashing and etching the first material layer using a half-tone mask process to form a plurality of first reflection enhancing portions with different physical thicknesses; depositing a second material layer covering the plurality of first reflection enhancing portions on a side of the plurality of first reflection enhancing portions away from the substrate; exposing, developing, ashing and etching the second material layer using a half-tone mask process to form a plurality of second reflection enhancing portions with different physical thicknesses; and sequentially preparing at least one layer of composite reflection enhancing portions on a side of the plurality of second reflection enhancing portions away from the substrate.

[0022] In some embodiments, at least one layer of composite reflection enhancing portion is sequentially prepared on a side of the plurality of second reflection enhancing portions away from the substrate, including: preparing a second reflection enhancing portion of the last composite reflection enhancing portion in the reflection enhancing portions by a coating process.

[0023] In a fourth aspect, a method for manufacturing a display panel is provided. The manufacturing method includes: forming the pixel circuit and a flat layer located on a side of the pixel circuit away from the substrate on one side of the substrate; forming a plurality of light-emitting devices on a side of the flat layer away from the substrate; forming a reflection enhancement layer on a side of the plurality of light-emitting devices away from the substrate; and forming an encapsulation layer on the substrate to cover the reflection enhancement layer and the plurality of light-emitting devices.

[0024] In the display panel provided by the first aspect above, a reflection-enhancing layer is arranged between the flat layer and the first electrode of the display panel, or between the second electrode and the encapsulation layer, and the number of layers and the physical thickness of the reflection-enhancing part in the reflection-enhancing layer, as well as the refractive index and stacking direction of the first reflection-enhancing part and the second reflection-enhancing part in the reflection-enhancing part, are set, so as to achieve high reflectivity of the reflection-enhancing part to light of a specific wavelength and high transmittance to light of other wavelengths; in this way, the anode of the top-emitting light-emitting device or the cathode of the bottom-emitting light-emitting device can be made of transparent or translucent materials, thereby improving the light transmittance of the light-emitting device itself; in addition, when a light-emitting device emits light, the reflection-enhancing part corresponding to the light-emitting device can reflect the light emitted by the light-emitting device, thereby allowing the display panel to display normally; and when the light-emitting device does not emit light, the reflection-enhancing part corresponding to the light-emitting device can transmit the external ambient light; thereby, without affecting the normal display of the display panel, the overall transmittance of the display panel is improved, and the overall transparency of the transparent OLED display is ensured.

[0025] It can be understood that the display device provided in the second aspect includes the above-mentioned display panel, and the preparation methods provided in the third and fourth aspects can prepare the above-mentioned display panel. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the display panel provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. However, the drawings described below are only drawings of some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not intended to limit the actual size of the product involved in the embodiments of the present disclosure, the actual process of the method, the actual timing of the signal, etc.

[0027] Figure 1 is a structural diagram of a display device according to some embodiments;

[0028] Figure 2 is a structural diagram of a display panel according to some embodiments;

[0029] Figure 3 is a cross-sectional view of a display panel according to some embodiments;

[0030] Figure 4 is a cross-sectional view of another display panel according to some embodiments;

[0031] Figure 5 is a structural diagram of a pixel circuit according to some embodiments;

[0032] Figure 6 is a cross-sectional view of yet another display panel according to some embodiments;

[0033] Figure 7 is a cross-sectional view of yet another display panel according to some embodiments;

[0034] Figure 8 is a structural diagram of a reflection enhancement unit according to some embodiments;

[0035] Fig. 9 A schematic diagram of a reflection enhancing portion enhancing reflected light according to some embodiments;

[0036] Fig.10 is a graph showing the reflectivity of the reflection enhancing portion with different numbers of layers and physical thicknesses according to some embodiments;

[0037] Fig.11 is a structural diagram of another reflection enhancing portion according to some embodiments;

[0038] Fig.12 is a cross-sectional view of yet another display panel according to some embodiments;

[0039] Fig.13 is a flow chart of a method for preparing a display panel according to some embodiments;

[0040] Fig.14 A structural diagram of a planar layer and a pixel circuit prepared according to some embodiments;

[0041] Fig.15A is a diagram showing the position relationship between the first material layer and the half-tone mask during the exposure process according to some embodiments;

[0042] Fig. 15B is a structural diagram of the first material layer after development according to some embodiments;

[0043] Fig. 15C is a structural diagram of the first material layer after the first etching according to some embodiments;

[0044] Fig.15D is a structural diagram of the first material layer after the first ashing according to some embodiments;

[0045] Fig.15E is a structural diagram of the first material layer after the second etching according to some embodiments;

[0046] Fig.15F is a structural diagram of the first material layer after the second ashing according to some embodiments;

[0047] Figure 15G is a structural diagram of the first material layer after the third etching according to some embodiments;

[0048] Fig.15H is a structural diagram of the first material layer after the third ashing according to some embodiments;

[0049] Fig.15I is a structural diagram of the first material layer after the fourth etching according to some embodiments;

[0050] Fig.16 A structural diagram of a first layer of a composite reflection enhancing portion in a reflection enhancing portion prepared according to some embodiments;

[0051] Fig.17A A structural diagram of a reflection enhancement portion prepared according to some embodiments;

[0052] Fig. 17B is another structural diagram of a reflection enhancement portion prepared according to some embodiments;

[0053] Fig.18 is a flow chart of another method for preparing a display panel according to some embodiments. DETAILED DESCRIPTION

[0054] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0055] Unless the context requires otherwise, throughout the specification and claims, the term "include" and its other forms, such as the third person singular form "include" and the present participle form "include", are to be interpreted as open, inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0056] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0057] When describing some embodiments, the term "connected" and its derivative expressions may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0058] “At least one of A, B, and C” has the same meaning as “at least one of A, B, or C” and both include the following combinations of A, B, and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0059] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0060] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [a stated condition or event] is detected" are optionally interpreted to mean "upon determining that" or "in response to determining that" or "upon detecting [a stated condition or event]" or "in response to detecting [a stated condition or event]," depending on the context.

[0061] The use of "adapted to" or "configured to" herein is meant to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0062] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0063] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of variation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0064] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within the acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism may be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity may also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality may be, for example, the difference between the two equalities is less than or equal to 5% of either one.

[0065] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0066] like Figure 1 As shown, some embodiments of the present disclosure provide a display device 1000, which includes a display panel 2000, a cover plate 3000, a circuit board 4000, and a driver chip (Integrated Circuit Chip, IC) ( Figure 1 Not shown), frame 5000 and other electronic accessories.

[0067] The longitudinal section of the frame 5000 is U-shaped, and the display panel 2000, the circuit board 4000 and other electronic components are all arranged in the frame 5000. The circuit board 4000 is arranged on the non-display side of the display panel 2000, and the cover plate 3000 is arranged on the side of the display panel 2000 away from the circuit board 4000.

[0068] The cover plate 3000 may be rigid, in which case the material of the cover plate 3000 may be glass. The cover plate 3000 may also be flexible, in which case the material of the cover plate 3000 may be polyimide (PI) or the like. In this case, the frame 5000 is a foldable or rollable frame. In some embodiments, the cover plate 3000 may also be omitted.

[0069] The display device 1000 may be a watch, a tablet computer, a laptop computer, a display, a television, a billboard, a digital photo frame, a printer with a display function, a telephone, a mobile phone, a personal digital assistant (PDA), a digital camera, a portable camcorder, a viewfinder, a navigator, a home appliance, a shop window, a baffle of a service hall, a car window or glass, an information query device (such as a business query device of e-government, a bank, a hospital, a power station, a post office, etc.), or any other component with a display function. The embodiment of the present disclosure does not impose any special restrictions on the specific form of the display device 1000.

[0070] The display panel 2000 is used to display images and may be an OLED display panel. Figure 2 As shown, the display panel 2000 includes a display area 11 and a peripheral area 12 located on at least one side of the display area 11. The display area 11 includes a plurality of sub-pixels (Sub Pixel) P defined by a gate line GL (Gate Line) and a data line DL (Data Line). For the convenience of explanation, the following description is made by taking a plurality of sub-pixels P arranged in a matrix form as an example, and the sub-pixels P arranged in a row along the horizontal direction X are called sub-pixels in the same row, and the sub-pixels P arranged in a row along the vertical direction Y are called sub-pixels in the same column. Each sub-pixel P includes a pixel circuit 100 and a light-emitting device M electrically connected to the pixel circuit 100. The pixel circuit 100 can drive the light-emitting device M electrically connected thereto to emit light.

[0071] like Figure 3 and Figure 4 As shown, the display panel 2000 includes a display substrate 101 having a plurality of stacked pattern layers and an encapsulation layer 102. The encapsulation layer 102 is used to prevent water vapor and oxygen from invading the display substrate 101 to prevent display defects and the like.

[0072] The display substrate 101 includes a substrate 1011 . The gate lines GL, the data lines DL, the pixel circuits 100 , and the light emitting devices M are all disposed on the substrate 1011 .

[0073] By way of example, the substrate 1011 may be a flexible substrate. The constituent material of the flexible substrate 1011 may be one or more of polyimide (PI), polyethylene terephthalate (PET), and polyethylene naphthalate diformic acid glycol ester (PEN).

[0074] For example, the substrate 1011 may be a rigid substrate. The rigid substrate 1011 may be made of one or more materials selected from the group consisting of glass and polymethyl methacrylate (PMMA).

[0075] The gate lines GL are insulated from and cross the data lines DL, and the common power lines VDD may be parallel to the data lines DL.

[0076] like Figure 2 to Figure 4 As shown, the pixel circuit 100 includes at least one thin film transistor TFT and at least one capacitor C, and each thin film transistor TFT may adopt a top gate structure or a bottom gate structure.

[0077] In some embodiments, Figure 3 As shown, when the thin film transistor TFT is a top gate structure, it includes an active layer AL (Active Layer) arranged on one side of the substrate 1011, a gate insulation layer GI (Gate Insulation), a gate metal pattern layer GM (Gate Metal, forming a gate 1012), an interlayer dielectric layer ILD (Interlayer), and a source-drain metal pattern layer SD (forming a source 1013 and a drain 1014).

[0078] In other embodiments, Figure 4 As shown, when the thin film transistor TFT is a bottom gate structure, it includes a gate metal pattern layer GM (forming a gate electrode 1012), a gate insulating layer GI, an active layer AL, and a source-drain metal pattern layer SD (forming a source electrode 1013 and a drain electrode 1014) arranged on one side of a substrate 1011.

[0079] There are many types of thin film transistors TFT. For example, the thin film transistor TFT can be an N-type thin film transistor or a P-type thin film transistor, and the only difference is the conduction condition. For the N-type thin film transistor, the high level is turned on and the low level is cut off. For the P-type thin film transistor, the low level is turned on and the high level is cut off. The active layer AL of the thin film transistor TFT can be composed of amorphous silicon, single crystal silicon, polycrystalline silicon or oxide semiconductor. The active layer AL includes a channel region that is not doped with impurities and a source region and a drain region formed by doping impurities on both sides of the channel region. The doped impurities vary with the type of thin film transistor TFT and can be N-type impurities or P-type impurities.

[0080] The capacitor C includes a first plate and a second plate, and an interlayer insulating film as a dielectric is provided between the two plates.

[0081] The structure of the pixel circuit 100 may include multiple structures, which may be selected and set according to actual needs. For example, the structure of the pixel circuit 100 may include a structure such as "2T1C", "6T1C", "7T1C", "6T2C" or "7T2C". Here, "T" represents a thin film transistor TFT, and the number in front of "T" represents the number of thin film transistors TFT in the pixel circuit 100, and "C" represents a capacitor, and the number in front of "C" represents the number of capacitors in the pixel circuit 100.

[0082] Figure 5 Taking a 2T1C structure in which a pixel circuit 100 includes two thin film transistors TFT (ie, a switch thin film transistor T1 and a drive thin film transistor T2) and a capacitor C as an example, the electrical connection relationship between the inside and outside of the pixel circuit is explained. Figure 3 and Figure 4 Only the driving thin film transistor (such as Figure 3 and Figure 4 The structure in the dotted circle) and the structure and connection relationship of the light-emitting device M, but according to the description in the context, those skilled in the art can fully determine the structure of the switching transistor and its connection relationship with other components.

[0083] like Figure 5 As shown, the gate electrode 1012 of the switch thin film transistor T1 is connected to the gate line GL, the source electrode 1013 of the switch thin film transistor T1 is connected to the data line DL, and the drain electrode 1014 of the switch thin film transistor T1 is connected to the gate electrode 1012 of the driving thin film transistor T2. The source electrode 1013 of the driving thin film transistor T2 is connected to the common power line VDD, and the drain electrode 1014 of the driving thin film transistor T2 is connected to the first electrode 1015 of the light emitting device M through a via hole. The first electrode plate of the capacitor C is connected to the gate electrode 1012 of the driving thin film transistor T2, and the second electrode plate is connected to the source electrode 1013 of the driving thin film transistor T2.

[0084] The switching thin film transistor T1 is turned on by the gate voltage applied to the gate line GL, so that the data voltage applied to the data line DL is transmitted to the driving thin film transistor T2. There is a certain difference between the data voltage transmitted from the switching thin film transistor T1 to the driving thin film transistor T2 and the common voltage applied from the common power line VDD to the driving thin film transistor T2, and a voltage corresponding to the absolute value of the difference is stored in the capacitor C, and a current corresponding to the voltage stored in the capacitor C flows into the light emitting device M through the driving thin film transistor T2, so that the light emitting device M emits light.

[0085] In addition, if Figure 3 and Figure 4 As shown, the light emitting device M comprises a first electrode 1015, a light emitting functional layer 1016 and a second electrode 1017. One of the first electrode 1015 and the second electrode 1017 is an anode (for providing holes), and the other is a cathode (for providing electrons). The first electrode 1015 and the second electrode 1017 inject holes and electrons into the light emitting functional layer 1016, respectively, and when the excitons generated by the combination of holes and electrons transition from an excited state to a ground state, light is emitted.

[0086] The first electrode 1015 can be formed of a metal with high reflectivity, and the second electrode 1017 can be formed of a transparent conductive film. In this case, the light of the light-emitting functional layer 1016 is reflected by the first electrode 1015 and emitted to the outside through the second electrode 1017, thereby forming a top-emitting light-emitting device. However, it is not limited to this. When the first electrode 1015 is formed of a transparent conductive film and the second electrode 1017 is formed of a metal with high reflectivity, a bottom-emitting light-emitting device can be formed. Of course, when both the first electrode 1015 and the second electrode 1016 are formed of a transparent conductive film, a double-sided light-emitting device can be formed.

[0087] The material of the transparent conductive film may be, for example, a metal oxide such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide) or IGZO (Indium Gallium Zinc Oxide). The metal with high reflectivity may be, for example, an alloy such as magnesium aluminum alloy (MgAl) and lithium aluminum alloy (LiAl), or a single metal such as magnesium (Mg), aluminum (Al), lithium (Li) and silver (Ag).

[0088] In some embodiments, Figure 3 and Figure 4As shown, the light-emitting functional layer 1016 may include a light-emitting layer 10161. In other embodiments, the light-emitting functional layer 1016 may include, in addition to the light-emitting layer 10161, at least one of a hole injection layer (HIL), a hole transporting layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transporting layer (ETL), and an electron injection layer (EIL). Figure 3 and Figure 4 When the light-emitting functional layer 1016 includes all the above layers, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer 10161, a hole blocking layer, an electron transport layer and an electron injection layer are sequentially stacked on the first electrode 1015 as an anode.

[0089] like Figure 3 and Figure 4 As shown, the display substrate 101 may also include a flat layer 1018 disposed between the thin film transistor TFT and the first electrode 1015, and a pixel defining layer 1019 disposed on the side of the flat layer 1018 away from the substrate 1011. The pixel defining layer 1019 includes a plurality of opening areas, and a retaining wall disposed around each opening area. A light emitting device M is disposed in an opening area, and the first electrode 1015 and the light emitting layer 10161 of the adjacent light emitting device M are separated by the retaining wall of the pixel defining layer 1019. The second electrode 1017 of each light emitting device M is connected as a whole, that is, the second electrode 1017 is a whole layer. The hole injection layer, the hole transport layer, the electron blocking layer, the hole blocking layer, the electron transport layer and the electron injection layer in the light emitting function layer 1016 may be separated by the retaining wall of the pixel defining layer 1019, or may be a whole layer. The material of the pixel defining layer 1019 is, for example, black polyimide, which can absorb the light emitted by one light emitting device M and directed toward another adjacent light emitting device M, thereby preventing light mixing between two adjacent sub-pixels.

[0090] The encapsulation layer 102 may be an encapsulation film. The number of layers of the encapsulation film included in the encapsulation layer 102 is not limited. In some embodiments, the encapsulation layer 102 may include one layer of encapsulation film, or may include two or more layers of encapsulation films stacked in layers. For example, the encapsulation layer 102 includes three layers of encapsulation films stacked in sequence.

[0091] In the case where the encapsulation layer 102 includes three layers of encapsulation films stacked in sequence, the material of the encapsulation film located in the middle layer is an organic material, and the materials of the encapsulation films located on both sides are inorganic materials. The organic material may be, for example, PMMA (Polymethyl methacrylate). The inorganic material may be SiN x (Silicon Nitride), SiO x (Silicon Oxide) or SiO x N y (silicon oxynitride) or one or more thereof.

[0092] In some embodiments, taking a top-emitting light-emitting device as an example, when the first electrode 1015 is an anode and is a transparent or semi-transparent conductive film, and the second electrode 1017 is a cathode and is a transparent or semi-transparent conductive film, as shown in FIG. Figure 6 and Figure 7 As shown, the display panel 2000 further includes a reflection enhancement layer 7 disposed between the first electrode 1015 and the flat layer 1018. The reflection enhancement layer 7 can reflect the light emitted by the light emitting device M, so that the light emitting device is formed as a top-emitting light emitting device. Figure 6 and Figure 7 In the figure, the structure of the display panel 2000 located on the side of the planar layer 1018 away from the light emitting device M is represented by the reference numeral 103.

[0093] The reflection enhancing layer 7 includes a plurality of reflection enhancing portions 71 , and the plurality of reflection enhancing portions 71 correspond one-to-one to the plurality of first electrodes 1015 .

[0094] In some embodiments, Figure 8 As shown, each reflection enhancing portion 71 includes at least one composite reflection enhancing portion 711. When the at least one composite reflection enhancing portion 711 includes a plurality of composite reflection enhancing portions 711, the plurality of composite reflection enhancing portions 711 are stacked and arranged in a direction along the flat layer 1018 pointing toward the light emitting device M. Moreover, in a direction along the flat layer 1018 pointing toward the light emitting device M, each composite reflection enhancing portion 711 includes a first reflection enhancing portion 7111 and a second reflection enhancing portion 7112 stacked in sequence. The refractive index of the flat layer 1018 is less than the refractive index of the first electrode 1015. The refractive index of the first reflection enhancing portion 7111 is greater than the refractive index of the second reflection enhancing portion 7112, and is greater than the refractive index of the flat layer 1018. The refractive index of the second reflection enhancing portion 7112 is less than the refractive index of the first electrode 1015.

[0095] All the composite reflection enhancing portions 711 corresponding to the plurality of first electrodes 1015 form a composite reflection enhancing layer, and the reflection enhancing layer 7 includes at least one composite reflection enhancing layer. When the at least one composite reflection enhancing layer includes a plurality of composite reflection enhancing layers, the plurality of composite reflection enhancing layers are stacked and arranged in a direction along the flat layer 1018 pointing toward the light emitting device M. All the first reflection enhancing portions 7111 corresponding to the plurality of first electrodes 1015 form a first reflection enhancing layer, and all the second reflection enhancing portions 7112 corresponding to the plurality of first electrodes 1015 form a second reflection enhancing layer, and each composite reflection enhancing layer includes a first reflection enhancing layer and a second reflection enhancing layer.

[0096] For example, the material of the first reflective enhancement portion 7111 is ITO (Indium Tin Oxides, indium tin oxide), ZrO 2 (Zirconium Dioxide, zirconium dioxide), TiO 2 (Titanium Dioxide, titanium dioxide), ZnS (ZincSulfide, zinc sulfide) and other inorganic materials. The material of the second reflection enhancement part 7112 is SiO 2 (Silicon Dioxide, Silicon Dioxide), LiF (Lithium Fluoride, Lithium Fluoride), MgF 2 (Magnesium Fluoride) and other inorganic materials or transparent resin and other organic materials.

[0097] In some embodiments, the optical thicknesses of the first reflection enhancing portion 7111 and the second reflection enhancing portion 7112 satisfy the following formula.

[0098]

[0099]

[0100] In the above formula, n 1 is the refractive index of the first reflective enhancement portion 7111, d 1 is the physical thickness of the first reflective enhancement portion 7111, n 2 is the refractive index of the second reflective enhancement portion 7112, d 2 is the physical thickness of the second reflective enhancement portion 7112, λ 0 is the wavelength of the incident light entering the first reflective enhancement unit 7111 or the second reflective enhancement unit 7112, and i and j are both integers greater than or equal to 0. In some embodiments, λ 0 is the wavelength of the incident light that needs to be reflected by the first reflective enhancement part 7111 or the second reflective enhancement part 7112, while incident light of other wavelengths can be transmitted by the first reflective enhancement part 7111 or the second reflective enhancement part 7112. Generally speaking, the optical thickness is equal to the product of the physical thickness and the refractive index of the medium. Here, the physical thickness refers to the geometric thickness of the object.

[0101] It should be noted that when light is incident from an optically sparse medium to an optically dense medium, the reflected light has a half-wave loss, that is, the phase of the reflected light differs from the phase of the incident light by π, while when light is incident from an optically dense medium to an optically sparse medium, the reflected light does not have a half-wave loss, that is, the phase of the reflected light is the same as the phase of the incident light (that is, in phase); in addition, the transmitted light always has the same phase as the incident light (that is, in phase). Based on these premises, the principle that the first reflective enhancement unit 7111 or the second reflective enhancement unit 7112 reflects light of a specific wavelength and transmits light of other wavelengths will be explained below.

[0102] like Fig. 9 As shown, taking the first electrode 1015 using ITO with a refractive index of about 2.0 and the flat layer 1018 using a material with a refractive index of about 1.5 as an example, a reflection enhancing portion 71 is arranged between the first electrode 1015 and the flat layer 1018, and the reflection enhancing portion 71 includes two layers of composite reflection enhancing portions 711. The first reflection enhancing portion 7111 is made of TiO with a refractive index of about 2.4. 2 The physical thickness d of the first reflective enhancement portion 7111 is 1 Satisfy the formula n 1 ×d 1 =λ 0 / 4 (i.e., i=0). The second reflective enhancement portion 7112 is made of SiO with a refractive index of about 1.48. 2 The physical thickness d of the second reflective enhancement portion 7112 is 2 Satisfy the formula n 2 ×d 2 =λ 0 / 4 (ie, j=0). Generally speaking, the refractive index of an optically denser medium is greater than the refractive index of an optically rarer medium.

[0103] Thus, when the wavelength is λ 0 The incident light 600 is incident vertically from the first electrode 1015 to the second reflective enhancement portion 7112 at the top (ie, the incident light 600 is incident from the optically dense medium ITO to the optically sparse medium SiO 2 ), the reflected light 601 and the incident light 600 at the interface between the first electrode 1015 and the upper second reflection enhancing portion 7112 are in phase with each other.

[0104] When the transmitted light of the incident light 600 that passes through the second reflective enhancement portion 7112 at the top is vertically incident on the first reflective enhancement portion 7111 at the top (i.e., the transmitted light passes through the optically sparse medium SiO 2 The incident light is incident on the dense medium TiO 2 ), the reflected light 602 at the interface between the upper second reflective enhancement portion 7112 and the upper first reflective enhancement portion 7111 will generate λ 0 / 2 half-wave loss, plus the optical path difference between reflected light 601 and reflected light 602 is equal to λ 0 / 2, so the reflected light 602 and the reflected light 601 at the interface between the upper second reflective enhancing portion 7112 and the upper first reflective enhancing portion 7111 are in phase (ie, the phase difference is 2π).

[0105] When the transmitted light of the incident light 600 that passes through the first reflective enhancement part 7111 at the upper part is vertically incident on the second reflective enhancement part 7112 at the lower part (i.e., the transmitted light passes through the optically dense medium TiO 2 The incident light is incident on the light-sparse medium SiO 2 ), since the optical path difference between the reflected light 603 and the reflected light 601 at the interface between the upper first reflective portion 7111 and the lower second reflective portion 7112 is equal to λ 0 , and the transmitted light is always in phase with the incident light 600, and the reflected light 603 does not produce half-wave loss relative to the transmitted light. Therefore, the reflected light 603 at the interface between the upper first reflection enhancing part 7111 and the lower second reflection enhancing part 7112 is in phase with the reflected light 601 (phase difference 2π).

[0106] Similarly, the reflected light 604 and the reflected light 605 are in phase with the reflected light 601 (phase difference 4π).

[0107] It can be seen that when at least one composite reflective enhancement portion 711 is inserted between the first electrode 1015 and the flat layer 1018, the reflected light of the incident light 600 corresponding to the at least one composite reflective enhancement portion 711 is enhanced; for example, the reflected light 601 to 605 constitutes the reflected light of the two composite reflective enhancement portions 711. At this time, the reflective enhancement portion 71 has a wavelength of λ 0 The incident light 600 has a high reflectivity, that is, the reflection enhancement portion 71 has a high reflectivity for the wavelength λ 0 The incident light 600 has a reflection enhancement effect.

[0108] The reflection enhancing portion 71 as described above comprises two layers of composite reflection enhancing portions 711, and the optical thicknesses of the first reflection enhancing portion 7111 and the second reflection enhancing portion 7112 are both equal to their respective minimum values ​​(ie, when i and j are equal to 0, n 1 ×d 1 and n 2 ×d 2 The case where the value of i and j is not equal to 0 is just an example. In some embodiments, the reflection enhancing portion 71 includes one layer, three layers or at least four layers of composite reflection enhancing portions 711. Alternatively, the optical thickness of the first reflection enhancing portion 7111 and the second reflection enhancing portion 7112 are both greater than the respective minimum optical thickness values; for example, the values ​​of i and j are not equal to 0.

[0109] It should be noted that, except for the wavelength λ 0 In addition to the enhanced reflection effect of the incident light, the reflection enhancing portion 71 has an enhanced reflection effect on λ 0The incident light of other wavelengths has a transmission effect. 2 The second reflective enhancement part 7112 is made of SiO 2 , and i and j are equal to each other.

[0110] At the wavelength λ of the incident light 0 is 632nm (i.e., λ 0 = 632 nm), when i = j = 0, the optical thickness of the first reflection enhancing portion 7111 and the second reflection enhancing portion 7112 is the minimum; that is, n 1 ×d 1 =λ 0 / 4, and n 2 ×d 2 =λ 0 / 4. At this time, the reflection effect of the reflection enhancing part 71 with different layers on the light of different wavelengths is simulated. The simulation data is shown in Table 1 below. As the number of layers of the first reflection enhancing part 7111 and the second reflection enhancing part 7112 in the reflection enhancing part 71 increases, the reflection enhancing part 71 on the wavelength λ 0 The wavelength is 632nm and λ 0 The reflectivity of incident light with a wavelength of 530 nm gradually increases, but the reflectivity of incident light with other wavelengths (for example, incident light with a wavelength of 460 nm) remains low.

[0111] When i=j=1, the optical thickness of each first reflection enhancing portion 7111 and each second reflection enhancing portion 7112 increases; that is, n 1 ×d 1 =3λ 0 / 4, and n 2 ×d 2 =3λ 0 / 4. At this time, as the number of layers of the first reflection enhancing part 7111 and the second reflection enhancing part 7112 in the reflection enhancing part 71 increases, the reflection enhancing part 71 has a greater wavelength λ 0 The reflectivity of the incident light with a wavelength of 632 nm is significantly improved, and the reflectivity of the incident light with other wavelengths (for example, the incident light with a wavelength of 530 nm and a wavelength of 460 nm) is kept low. That is, compared with the display panel using the opaque first electrode, the display panel 2000 using the reflective enhancement part 71 and the transparent first electrode 1015 has a lower reflectivity for the wavelength λ 0 The reflectivity for incident light of 632 nm is high, and the reflectivity for incident light of other wavelengths is low (that is, the transmittance for incident light of other wavelengths is high).

[0112] For example, when the number of layers of the first reflection-enhancing part 7111 and the second reflection-enhancing part 7112 in the reflection-enhancing part 71 are both 4, the reflectivity of the reflection-enhancing part 71 to the incident light with a wavelength of 632 nm is 92.7%, the reflectivity to the incident light with a wavelength of 530 nm is 2.0%, and the reflectivity to the incident light with a wavelength of 460 nm is 1.9%. The incident light with a wavelength of 632 nm is red light, the incident light with a wavelength of 530 nm is green light, and the incident light with a wavelength of 460 nm is blue light. At this time, the reflection-enhancing part 71 reflects red light and transmits green light and blue light. That is, compared with the display panel using an opaque first electrode, the display panel 2000 using the reflection-enhancing part 71 and the transparent first electrode 1015, the reflection-enhancing part 71 has a reflection-enhancing effect on red light and an anti-transmission effect on green light and blue light.

[0113] Table 1 Effect of the number of layers and physical thickness of the reflective enhancement part on the reflectivity of incident light of different wavelengths

[0114]

[0115] In Table 1, w / o is the abbreviation of the English word without, so "w / o reflection enhancing part" refers to the case where the reflection enhancing part 71 is not provided. The number of layers of the reflection enhancing part 71 refers to the number of layers of the composite reflection enhancing part 711 included in the reflection enhancing part 71; for example, when the reflection enhancing part 71 is 1 layer, it means that the reflection enhancing part 71 includes 1 layer of the composite reflection enhancing part, that is, includes 1 layer of the first reflection enhancing part 7111 (that is, TiO 2 ×1) and a second reflection enhancing portion 7112 (i.e., SiO 2 ×1). i=j=0 indicates that the optical thickness of each layer of the first reflection enhancing portion 7111 and each layer of the second reflection enhancing portion 7112 satisfies the formula n 1 ×d 1 =λ 0 / 4, and n 2 ×d 2 =λ 0 / 4. i=j=1 indicates that the optical thickness of each layer of the first reflection enhancing portion 7111 and each layer of the second reflection enhancing portion 7112 satisfies the formula n 1 ×d 1 =3λ 0 / 4, and n 2 ×d 2 =3λ 0 / 4.

[0116] In addition to Table 1, Fig.10 It also shows that when a specific wavelength λ 0 When the wavelength is equal to 632nm, the reflection effect of the reflection enhancement part 71 with different layers or different physical thicknesses on light of different wavelengths. Fig.10As shown, as the physical thickness of the reflective enhancement portion 71 increases (ie, as the values ​​of i and j change from 0 to 1), the reflectivity curve narrows significantly, for example, toward a specific wavelength λ 0 With the increase of the number of layers of the reflective portion 71 (ie, with the increase of the number of layers of the composite reflective portion 711 contained in the reflective portion 71 changes from 0 to 4), the reflectivity increases significantly, for example, with a specific wavelength λ 0 Thus, by setting the number of layers and physical thickness of the reflection enhancing part 71, the reflectivity of the reflection enhancing part 71 to light of a specific wavelength can be made greater than 90%, while the reflectivity to light of other wavelengths can be made lower, thereby increasing the transmittance of light of other wavelengths and achieving the purpose of increasing the screen transmittance.

[0117] The specific wavelength λ in Table 1 0 For the wavelength of red light, based on the results of Table 1 above, a reflection enhancing portion 71 having a reflection enhancing effect on green light and a transmittance enhancing effect on red and blue light, and a reflection enhancing portion 71 having a reflection enhancing effect on blue light and a transmittance enhancing effect on red and green light can be designed.

[0118] For example, suppose the wavelengths of red light, green light, and blue light are λ 1 , 2 and λ 3 The reflection enhancing portion 71 that has the reflection enhancing effect on red light and the transmittance enhancing effect on green light and blue light is called the red light reflection enhancing portion, the reflection enhancing portion 71 that has the reflection enhancing effect on green light and the transmittance enhancing effect on red light and blue light is called the green light reflection enhancing portion, and the reflection enhancing portion 71 that has the reflection enhancing effect on blue light and the transmittance enhancing effect on red light and green light is called the blue light reflection enhancing portion.

[0119] At this time, the reflection effects of the reflection enhancing parts 71 with different numbers of layers and different physical thicknesses on red light, green light and blue light are simulated. The simulation data are shown in Table 2 below. When i=j=1, the optical thickness of each first reflection enhancing part 7111 and each second reflection enhancing part 7112 in the red light reflection enhancing part satisfies the formula n 1 ×d 1 =3λ 1 / 4 and n 2 ×d 2 =3λ 1 / 4. The optical thickness of each first reflection enhancing portion 7111 and each second reflection enhancing portion 7112 in the green light reflection enhancing portion satisfies the formula n 1 ×d 1 =3λ 2 / 4 and n 2 ×d 2 =3λ 2 / 4. The optical thickness of each first reflection enhancing portion 7111 and each second reflection enhancing portion 7112 in the blue light reflection enhancing portion satisfies the formula n 1 ×d 1 =3λ3 / 4 and n 2 ×d 2 =3λ 3 / 4. And when the number of layers of the first reflection enhancing part 7111 and the second reflection enhancing part 7112 in the red light reflection enhancing part, the green light reflection enhancing part and the blue light reflection enhancing part are all 4, the reflectivity of the red light reflection enhancing part to red light reaches more than 90%, and the reflectivity to green light and blue light is less than 5%; the reflectivity of the green light reflection enhancing part to green light reaches more than 90%, and the reflectivity to red light and blue light is less than 5%; the reflectivity of the blue light reflection enhancing part to blue light reaches more than 90%, and the reflectivity to red light and green light is less than 10%. In general, high reflectivity means low transmittance, and low emissivity means high transmittance.

[0120] Table 2 Reflectivity of the reflective part for red light, green light and blue light corresponding to different wavelengths of light

[0121]

[0122] The embodiments of the present disclosure are not limited to providing a reflection enhancing portion 71 corresponding to red light, green light and blue light, and reflection enhancing portions corresponding to yellow light, cyan light and magenta light may also be provided. Therefore, the above-mentioned red light reflection enhancing portion, green light reflection enhancing portion and blue light reflection enhancing portion may be referred to as a first color light reflection enhancing portion, a second color light reflection enhancing portion and a third color light reflection enhancing portion. The first color, the second color and the third color are different from each other. Moreover, the first color light reflection enhancing portion corresponds to a light emitting device M that emits a first color light, the second color light reflection enhancing portion corresponds to a light emitting device M that emits a second color light, and the third color light reflection enhancing portion corresponds to a light emitting device M that emits a third color light.

[0123] In some embodiments, Figure 6 and Figure 7 As shown, the retaining wall of the pixel defining layer 1019 is disposed between adjacent reflection enhancing portions 71 and is configured to fill the gap between adjacent reflection enhancing portions 71 .

[0124] In summary, in some embodiments of the present disclosure, the reflection-enhancing portion 71 corresponding to the first electrode 1015 is used to achieve high reflectivity for light of a specific wavelength and high transmittance for light of other wavelengths, so that the anode of the top-emitting light-emitting device M can be made of a transparent or translucent material, thereby improving the light transmittance of the light-emitting device M itself. In addition, when a light-emitting device M emits light, the reflection-enhancing portion 71 corresponding to the light-emitting device M can reflect the light emitted by the light-emitting device M, so that the OLED display panel can display normally; and when the light-emitting device M does not emit light, the reflection-enhancing portion 71 corresponding to the light-emitting device M can transmit the external ambient light; thereby, without affecting the normal display of the display panel 2000, the overall transmittance of the display panel 2000 is improved, and the overall transparency of the transparent OLED display screen is ensured.

[0125] It should be noted that, since the wavelengths of the first color light, the second color light, and the third color light are different from each other, according to n 1 ×d 1 =(2i+1)λ 0 / 4 and n 2 ×d 2 =(2j+1)λ 0 According to the optical thickness design principle of 1 / 4, the physical thicknesses of the first color light reflection enhancing part, the second color light reflection enhancing part and the third color light reflection enhancing part are different from each other. This will affect the flatness between the light emitting device of the first color light, the light emitting device of the second color light and the light emitting device of the third color light.

[0126] To this end, in some embodiments, such as Figure 7 and Fig.11 As shown, the second reflection enhancing portion 7112' in the composite reflection enhancing portion 711 closest to the first electrode 1015 in the reflection enhancing portion 71 is made of transparent resin, so that the second reflection enhancing layer formed by the plurality of second reflection enhancing portions 7112' becomes a whole layer. At this time, the second reflection enhancing layer fills the gaps between the adjacent reflection enhancing portions 71 and can provide a flat surface for the light emitting device M.

[0127] For example, when the second reflection enhancing portion 7112' is a transparent resin, the optical thickness of the second reflection enhancing portion 7112' is difficult to be determined according to the optical thickness design principle (ie, n 2 ×d 2 =(2j+1)λ 0 / 4, j is an integer greater than or equal to 0) (the above-mentioned whole second reflection enhancing layer is usually prepared by a coating process, which has a low precision compared to magnetron sputtering, vapor deposition, evaporation and other processes, but is suitable for preparing a film layer with a large physical thickness), resulting in the optical thickness of the second reflection enhancing portion 7112' being 3λ 0 / 2 (i.e., j=2.5), 5λ 0 / 2 (i.e., j=4.5) or 7λ 0 / 2 (ie, j=6.5), which results in an unstable reflection-enhancing effect of the second reflection-enhancing portion 7112'.

[0128] To this end, a specific wavelength λ 0 Taking 632nm (i.e., red light) as an example, the influence of the second reflection enhancing portion 7112' on the reflection enhancing effect of the second reflection enhancing portion 7112' when the second reflection enhancing portion 7112' is a transparent resin with a large optical thickness is simulated. The simulation data is shown in Table 3 below, and it can be seen that as the number of layers of the composite reflection enhancing portion 711 included in the reflection enhancing portion 71 increases, the influence of the optical thickness of the second reflection enhancing portion 7112' on the reflectivity gradually decreases.

[0129] For example, when the number of layers of the composite reflection enhancing part 711 included in the reflection enhancing part 71 reaches 4, under the premise that the second reflection enhancing part 7112' has an optical thickness corresponding to when j is not an integer (i.e., j=4.5), the reflectivity of the reflection enhancing part 71 to red light can also reach 89%. It can be seen from this that when the number of layers of the composite reflection enhancing part 711 included in the reflection enhancing part 71 is greater than or equal to 4, the optical thickness of the second reflection enhancing part 7112' does not need to be precisely controlled, and the reflection enhancing part 71 can still reflect the specific wavelength λ 0 The light produced by the reflection effect.

[0130] Table 3 Reflectivity of different layers of reflective enhancement parts when the optical thickness of the second reflective enhancement part 7112' satisfies j=4 or 4.5

[0131] The optical thickness of the second reflective enhancement portion 7112' j＝4 j＝4.5 <![CDATA[1 layer (SiO 2 ×1 + TiO 2 ×1)]]> 27.2％ 10.2％ <![CDATA[2 layers (SiO 2 ×2 + TiO 2 ×2)]]> 61.6％ 44.8％ <![CDATA[3 layers (SiO 2 ×3 + TiO 2 ×3)]]> 83.1％ 73.7％ <![CDATA[4 layers (SiO 2 ×4 + TiO 2 ×4)]]> 93.1％ 89.0％

[0132] It should be noted that when j=4.5, the optical thickness of the second reflective enhancement portion 7112' satisfies n 2 ×d 2 =5λ 0 This makes the optical path difference between the incident light entering the second reflective portion 7112' and the reflected light at the interface between the second reflective portion 7112' and the adjacent first reflective portion 7111 be half a wavelength (λ 0 / 2), destructive interference will occur (ie, the reflection phenomenon is weakened). At this time, the second reflection enhancing portion 7112' has an anti-transmission effect.

[0133] To sum up, in some embodiments of the present disclosure, a whole layer of second reflection enhancing layer is formed by multiple second reflection enhancing portions 7112', and the second reflection enhancing layer is used to provide a flat surface for preparing the first electrode 1015, thereby avoiding the influence of the reflection enhancing portions 71 with different physical thicknesses on the flatness of the first electrode 1015, greatly improving the flatness of the first electrode 1015, and further improving the color deviation symmetry of the display panel 2000.

[0134] The embodiments of the present disclosure are not limited to the case of the top-emitting light-emitting device. In some embodiments, taking a bottom-emitting light-emitting device as an example, when the first electrode 1015 is an anode and a transparent or semi-transparent conductive film, and the second electrode 1017 is a cathode and a transparent or semi-transparent conductive film, as shown in FIG. Fig.12 As shown, the reflection enhancement layer 7 of the display panel 2000 is disposed between the second electrode 1017 and the encapsulation layer 102. Fig.12 In the figure, the structure of the display panel 2000 located on the side of the planar layer 1018 away from the light-emitting device M is also represented by the reference numeral 103.

[0135] The composition structure and number of layers of the above-mentioned reflection enhancing layer 7 can refer to the relevant description of the reflection enhancing layer 7 in the above-mentioned top-emitting light-emitting device, and will not be repeated here.

[0136] It should be noted that when the refractive index of the encapsulation layer 102 is less than the refractive index of the second electrode 1017, in the direction pointing toward the light-emitting device M along the flat layer 1018, each composite reflective enhancement portion 711 includes a second reflective enhancement portion 7112 and a first reflective enhancement portion 7111 which are stacked in sequence. That is, the first reflective enhancement portion 7111 is in contact with the encapsulation layer 102, and the second reflective enhancement portion 7112 is in contact with the second electrode 1017. In addition, the refractive index of the first reflective enhancement portion 7111 is greater than the refractive index of the second reflective enhancement portion 7112, the refractive index of the first reflective enhancement portion 7111 is greater than the refractive index of the encapsulation layer 102, and the refractive index of the second reflective enhancement portion 7112 is less than the refractive index of the second electrode 1017.

[0137] The materials and optical thicknesses of the first reflection enhancing portion 7111 and the second reflection enhancing portion 7112 can be found in the above-mentioned related descriptions and will not be repeated here.

[0138] Some embodiments of the present disclosure also provide a method for manufacturing a display panel 2000. Fig.13 As shown, the method includes steps 1 to 4.

[0139] In step 1 , a pixel circuit 100 and a planar layer 1018 located on a side of the pixel circuit 100 away from the substrate 1011 are formed on one side of the substrate 1011 .

[0140] Forming the pixel circuit 100 on one side of the substrate 1011 mainly includes forming a thin film transistor on the substrate 1011. The thin film transistor includes an active layer AL, a gate insulating layer GI, a gate metal pattern layer GM (for forming a gate 1012), an interlayer dielectric layer ILD, and a source-drain metal pattern layer SD (forming a source 1013 and a drain 1014) disposed on the substrate 1011.

[0141] The structures of the substrate 1011 and the pixel circuit 100 are not described here. Figure 14-17B The internal structure of the pixel circuit 100 is not shown, and the substrate 1011 and the structure of the pixel circuit 100 thereon are indicated by reference numeral 103 .

[0142] like Fig.14 As shown, a planar layer 1018 is formed on a side of the pixel circuit 100 away from the substrate 1011 .

[0143] In step 2, a reflection enhancing layer 7 is formed on a side of the planar layer 1018 away from the substrate 1011 .

[0144] The reflection enhancing layer 7 includes a plurality of reflection enhancing portions 71. Each reflection enhancing portion 71 includes at least one composite reflection enhancing portion 711. When the at least one composite reflection enhancing portion 711 includes a plurality of composite reflection enhancing portions 711, the plurality of composite reflection enhancing portions 711 are stacked in a direction away from the substrate 1011 along the flat layer 1018. Moreover, in a direction away from the substrate 1011 along the flat layer 1018, each composite reflection enhancing portion 711 includes a first reflection enhancing portion 7111 and a second reflection enhancing portion 7112 stacked in sequence. The refractive index of the first reflection enhancing portion 7111 is greater than the refractive index of the flat layer 1018 and the refractive index of the second reflection enhancing portion 7112.

[0145] The reflection enhancing layer 7 is formed on the side of the planar layer 1018 away from the substrate 1011 , including steps 201 to 205 .

[0146] In step 201 , a first material layer 700 is deposited on a side of the planar layer 1018 away from the substrate 1011 to cover the planar layer 1018 .

[0147] Exemplarily, the first material layer 700 is deposited by a chemical vapor deposition (CVD) process. The first material layer 700 is made of TiO 2 .

[0148] In step 202 , the first material layer 700 is exposed, developed, ashed and etched using a half-tone mask process to form a first reflection enhancing portion 7111 having different physical thicknesses.

[0149] The first reflection enhancing parts 7111 with different physical thicknesses are respectively included in the first color light reflection enhancing part, the second color light reflection enhancing part and the third color light reflection enhancing part. The first color, the second color and the third color are, for example, red, green and blue; or the first color, the second color and the third color are yellow, cyan and magenta.

[0150] When the first color, the second color, and the third color are red, green, and blue respectively, since the wavelength of red light is greater than that of green light, and the wavelength of green light is greater than that of blue light, based on n 1 ×d 1 =(2i+1)λ 0 / 4 optical thickness design principle, the physical thickness of the first reflection enhancing part 7111 corresponding to the red light reflection enhancing part is the largest, the physical thickness of the first reflection enhancing part 7111 corresponding to the green light reflection enhancing part is in the middle, and the physical thickness of the first reflection enhancing part 7111 corresponding to the blue light reflection enhancing part is the smallest.

[0151] For example, FIG. 15A to FIG. 15I As shown, the process of preparing the first reflection enhancing portion 7111 using a halftone mask process is as follows.

[0152] like Fig.15A As shown, after the first material layer 700 is coated with photoresist PR, exposure is performed through a half-tone mask 8. The half-tone mask 8 includes an opaque area, a first partial light-transmitting area, a second partial light-transmitting area, and a completely light-transmitting area, the light transmittances of which increase in sequence. The opaque area corresponds to the red light reflection-enhancing part, the first partial light-transmitting area corresponds to the green light reflection-enhancing part, the second partial light-transmitting area corresponds to the blue light reflection-enhancing part, and the completely light-transmitting area corresponds to the area other than the above-mentioned red light reflection-enhancing part, the green light reflection-enhancing part, and the blue light reflection-enhancing part.

[0153] After the photoresist PR is exposed, the photoresist PR is developed, such as Fig. 15B As shown, the photoresist PR in the completely transparent area is completely removed. In addition, since the transmittances of the opaque area, the first partial transparent area, and the second partial transparent area are different, the physical thickness of the photoresist PR in the opaque area is greater than the physical thickness of the photoresist PR in the first partial transparent area, and the physical thickness of the photoresist PR in the first partial transparent area is greater than the physical thickness of the photoresist PR in the second partial transparent area.

[0154] Then, if Fig. 15C As shown, after the photoresist PR is developed, the first material layer 700 is etched for the first time, and the first material layer 700 in the completely light-transmitting area is completely removed.

[0155] like Fig.15D As shown, after the first etching, the photoresist PR is ashed for the first time, the photoresist PR in the second light-transmitting area is completely removed, and the physical thickness of the photoresist PR in the opaque area and the first light-transmitting area is reduced.

[0156] like Fig.15E As shown, after the first ashing, the first material layer 700 is etched for the second time, the physical thickness of the first material layer 700 in the second partial light-transmitting area is reduced, and the physical thickness of the first material layer 700 in the opaque area and the first partial light-transmitting area remains unchanged.

[0157] like Fig.15F As shown, after the second etching, the photoresist PR is ashed for the second time, so that the photoresist PR in the first part of the light-transmitting area is completely removed and the physical thickness of the photoresist PR in the opaque area is reduced.

[0158] like Figure 15G As shown, after the second ashing, the first material layer 700 is etched for the third time, so that the physical thickness of the first material layer 700 in the second partial light-transmitting area and the first partial light-transmitting area is reduced, and the physical thickness of the first material layer 700 in the opaque area remains unchanged.

[0159] like Fig.15HAs shown, after the third etching, the photoresist PR is ashed for the third time, so that the photoresist PR in the opaque area is completely removed.

[0160] Finally, if Fig.15I As shown, after the third ashing, the first material layer 700 is etched for the fourth time, so that the physical thickness of the first material layer 700 in the opaque area, the first partial light-transmitting area and the second partial light-transmitting area is reduced, thereby forming a first reflection-enhancing portion 7111 with different physical thicknesses.

[0161] Above FIG. 15A to FIG. 15I The process shown is a one-time patterning process, which includes one-time exposure process, one-time development process, multiple etching processes and multiple ashing processes.

[0162] In step 203 , a second material layer covering the first reflection enhancing portion 7111 is deposited on a side of the first reflection enhancing portion 7111 away from the substrate 1011 .

[0163] Exemplarily, the second material layer is deposited by a CVD process. The second material layer is SiO 2 .

[0164] In step 204, the second material layer is exposed, developed, ashed and etched using a half-tone mask process to form a second reflection enhancing portion 7112 with different physical thicknesses.

[0165] At this time, if Fig.16 As shown, in the direction along the flat layer 1018 away from the substrate 1011 , the first reflection enhancing portion 7111 and the second reflection enhancing portion 7112 are stacked in sequence to form a composite reflection enhancing portion 711 .

[0166] The preparation process of forming the second reflection enhancing portion 7112 by using the half-tone mask process can refer to the preparation process of the first reflection enhancing portion 7111, which will not be repeated here.

[0167] In step 205 , three layers of composite reflection enhancing portions 711 are sequentially prepared on the side of the second reflection enhancing portion 7112 away from the substrate 1011 , thereby forming a reflection enhancing portion 71 having four layers of composite reflection enhancing portions 711 .

[0168] The reflection enhancing part 71 having four layers of composite reflection enhancing parts 711 is as follows Fig.17A At this time, a plurality of reflection enhancing portions 71 form a reflection enhancing layer 7 .

[0169] The preparation process of the three-layer composite reflection enhancing portion 711 may refer to the preparation process of the first reflection enhancing portion 7111 and the second reflection enhancing portion 7112 , which will not be described again here.

[0170] The number of layers of the reflection enhancing portion 71 in the above method is only illustrative, and the present disclosure does not limit this, and can be set according to actual needs. For example, the reflection enhancing portion 71 having 2, 3, 5 or more composite reflection enhancing portions 711 can be prepared by 4, 6, 10 or more half-tone mask processes.

[0171] like Fig.17A As shown, since the physical thicknesses of the first color light reflection enhancing portion, the second color light reflection enhancing portion and the third color light reflection enhancing portion are different from each other, the flatness between the light emitting devices of the first color light, the second color light and the third color light is affected.

[0172] To this end, in some embodiments, step 205: sequentially preparing three layers of composite reflection enhancing portions 711 on the side of the second reflection enhancing portion 7112 away from the substrate 1011 to form a reflection enhancing portion 71 having four layers of composite reflection enhancing portions 711, also includes step 2051.

[0173] In step 2051 , the second reflection enhancing portion 7112 ′ of the last layer of the composite reflection enhancing portion 711 in the reflection enhancing portion 71 is prepared by a coating process.

[0174] Exemplarily, the second reflection enhancing portion 7112' is made of transparent resin.

[0175] like Fig. 17B As shown, the second reflection enhancing portion 7112' is a whole layer and fills the gap between adjacent reflection enhancing portions 71. At this time, the second reflection enhancing portion 7112' can provide a flat surface for the preparation of the light emitting device M.

[0176] In step 3, a plurality of light emitting devices M are formed on a side of the reflection enhancing layer 7 away from the substrate 1011 .

[0177] In some embodiments, step 3: forming a plurality of light-emitting devices M on a side of the reflection enhancing layer 7 away from the substrate 1011 , includes steps 31 to 34 .

[0178] In step 31 , a first electrode 1015 is formed on a side of the reflection enhancing layer 7 away from the substrate 1011 .

[0179] The plurality of first electrodes 1015 correspond one-to-one to the plurality of reflection enhancing portions 71. The first electrodes 1015 are transparent or semi-transparent conductive films.

[0180] Illustratively, the first electrode 1015 is manufactured by depositing a first electrode material layer through a magnetron sputtering process, and then exposing, developing and etching the first electrode material layer.

[0181] In step 32 , a pixel defining layer 1019 is formed on a side of the first electrode 1015 away from the substrate 1011 .

[0182] The pixel defining layer 1019 includes a plurality of opening regions and a barrier wall surrounding the plurality of opening regions. The barrier wall of the pixel defining layer 1019 can fill the gap between adjacent reflection enhancing portions 71 and separate the first electrodes 1015 through the barrier wall.

[0183] It should be noted that, when the second reflection enhancing portion 7112 ′ is made of transparent resin, the pixel defining layer 1019 does not need to fill the gap between adjacent reflection enhancing portions 71 .

[0184] In step 33 , a light-emitting functional layer 1016 is formed in the opening region on a side of the first electrode 1015 away from the substrate 1011 .

[0185] Exemplarily, the light-emitting functional layer 1016 is manufactured by an evaporation process.

[0186] In step 34 , a second electrode 1017 is formed on a side of the light-emitting functional layer 1016 away from the substrate 1011 to cover the light-emitting functional layer 1016 and the pixel defining layer 1019 .

[0187] The second electrode 1017 is a transparent or semi-transparent conductive film.

[0188] In step 4 , a packaging layer 102 covering the plurality of light emitting devices M is formed on the substrate 1011 .

[0189] In some embodiments, the reflection enhancement layer 7 may also be disposed between the light emitting device M and the encapsulation layer 102. Fig.18 As shown, the preparation method includes steps 1' to 4'.

[0190] In step 1 ′, a pixel circuit 100 and a planar layer 1018 located on a side of the pixel circuit 100 away from the substrate 1011 are formed on one side of the substrate 1011 .

[0191] In step 2 ′, a plurality of light emitting devices M are formed on a side of the planar layer 1018 away from the substrate 1011 .

[0192] The light emitting device M includes a first electrode 1015, a light emitting functional layer 1016, and a second electrode 1017 covering the light emitting functional layer 1016 and the pixel defining layer 1019. The first electrode 1015 and the second electrode 1017 are both transparent or semi-transparent conductive films.

[0193] In step 3 ′, a reflection enhancing layer 7 is formed on a side of the plurality of light emitting devices M away from the substrate 1011 .

[0194] The preparation process of the above-mentioned reflection enhancement layer 7 can refer to the related description of the preparation process above, which will not be repeated here.

[0195] In step 4 ′, a packaging layer 102 covering the reflection enhancing layer 7 and the plurality of light emitting devices M is formed on the substrate 1011 .

[0196] In summary, in some embodiments of the present disclosure, a half-tone mask process is used to prepare the reflection-enhancing portion 71 corresponding to the light-emitting devices M of different colors, thereby forming a plurality of reflection-enhancing portions 71 with different physical thicknesses, and then the plurality of reflection-enhancing portions 71 with different physical thicknesses achieve high reflectivity for light of a specific wavelength, and high transmittance for light of other wavelengths. This allows the anode of the top-emitting light-emitting device M or the cathode of the bottom-emitting device M to be made of transparent or translucent materials, thereby improving the light transmittance of the light-emitting device M itself. In addition, when a light-emitting device M emits light, the reflection-enhancing portion 71 corresponding to the light-emitting device M can reflect the light emitted by the light-emitting device M, thereby allowing the OLED display panel to display normally; and when the light-emitting device M does not emit light, the reflection-enhancing portion 71 corresponding to the light-emitting device M can transmit the external ambient light; thereby, without affecting the normal display of the display panel, the overall transmittance of the display panel is improved, and the overall transparency of the transparent OLED display screen is ensured.

[0197] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be thought of by any person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A display panel, characterized in that: include: A display substrate, the display substrate comprising: substrate; A pixel circuit located on the substrate; a planar layer located on a side of the pixel circuit away from the substrate; and A plurality of light-emitting devices, each of which comprises a first electrode, a light-emitting functional layer and a second electrode, wherein the first electrode and the second electrode are both transparent or semi-transparent conductive films, and the first electrode is electrically connected to the pixel circuit through a via hole in the planar layer; A reflection enhancement layer is located between the flat layer and the first electrode, the reflection enhancement layer includes a plurality of reflection enhancement parts, and the plurality of reflection enhancement parts correspond to the plurality of first electrodes one by one; wherein, Each reflection enhancing portion includes at least one composite reflection enhancing portion, the at least one composite reflection enhancing portion is stacked and arranged in a direction along the planar layer pointing toward the light emitting device, and each composite reflection enhancing portion includes a first reflection enhancing portion and a second reflection enhancing portion; The refractive indexes of the first reflective enhancement portion and the first electrode are both greater than the refractive index of the second reflective enhancement portion or the refractive index of the flat layer; and In a direction along the planar layer toward the light emitting device, the first reflector enhancing portion in each composite reflector enhancing portion is closer to the planar layer, and the second reflector enhancing portion in each composite reflector enhancing portion is closer to the first electrode.

2. The display panel according to claim 1, characterized in that: The optical thickness of the first reflection enhancing portion and the optical thickness of the second reflection enhancing portion satisfy the following formula: Among them, n1 is the refractive index of the first reflection enhancing part, d1 is the physical thickness of the first reflection enhancing part, n2 is the refractive index of the second reflection enhancing part, d2 is the physical thickness of the second reflection enhancing part, λ0 is the wavelength of the incident light, and i and j are both greater than or equal to zero.

3. The display panel according to claim 2, characterized in that: The i and j are both integers greater than or equal to zero, so that the optical thicknesses of the first reflection enhancing portion and the second reflection enhancing portion are both odd multiples of λ0 / 4.

4. The display panel according to claim 2, characterized in that: The plurality of reflection enhancing parts include a first color light reflection enhancing part, a second color light reflection enhancing part and a third color light reflection enhancing part; The first color light reflection enhancing portion corresponds to a light emitting device that emits a first color light, the second color light reflection enhancing portion corresponds to a light emitting device that emits a second color light, and the third color light reflection enhancing portion corresponds to a light emitting device that emits a third color light; The first color light, the second color light and the third color light are different from each other, and the physical thicknesses of the first color light reflection enhancing portion, the second color light reflection enhancing portion and the third color light reflection enhancing portion are different from each other.

5. The display panel according to claim 4, characterized in that: The display panel also includes a pixel defining layer; The pixel defining layer is arranged on a side of the first electrode away from the substrate, and the pixel defining layer comprises a plurality of opening areas and a retaining wall surrounding each of the opening areas; the first electrode and the light-emitting functional layer are separated by the retaining wall; Furthermore, the retaining wall is also arranged between adjacent reflection enhancing parts and is configured to fill the gap between the adjacent reflection enhancing parts.

6. The display panel according to claim 4, characterized in that: The material of the second reflection enhancing part in the composite reflection enhancing part closest to the first electrode in the at least one composite reflection enhancing part is transparent resin, and the second reflection enhancing layer formed by the plurality of the second reflection enhancing parts made of transparent resin is a whole layer; The second reflection enhancing layer made of transparent resin is configured to fill the gaps between adjacent reflection enhancing portions.

7. The display panel according to claim 6, characterized in that: The optical thickness of the second reflection enhancing portion made of transparent resin is an odd multiple of λ0 / 2.

8. The display panel according to claim 1, characterized in that: Each reflection enhancing portion includes at least four layers of composite reflection enhancing portions.

9. The display panel according to any one of claims 1 to 5, characterized in that: The material of the first reflection enhancing portion includes ITO, ZrO2, TiO2 or ZnS; the material of the second reflection enhancing portion includes SiO2, LiF or MgF2.

10. The display panel according to any one of claims 1 to 5, characterized in that: The display panel further includes an encapsulation layer, wherein the reflection enhancement layer located between the planar layer and the first electrode is replaced by a reflection enhancement layer located between the second electrode and the encapsulation layer; The reflection enhancement layer includes a plurality of reflection enhancement parts, and the plurality of reflection enhancement parts correspond to the plurality of first electrodes one by one; wherein, Each reflection enhancing portion includes at least one composite reflection enhancing portion, the at least one composite reflection enhancing portion is stacked and arranged in a direction from the light emitting device to the encapsulation layer, and each composite reflection enhancing portion includes a first reflection enhancing portion and a second reflection enhancing portion; The refractive indexes of the first reflective enhancement portion and the second electrode are both greater than the refractive index of the second reflective enhancement portion or the refractive index of the encapsulation layer; and In a direction from the light emitting device to the encapsulation layer, the first reflector enhancing portion in each composite reflector enhancing portion is closer to the encapsulation layer, and the second reflector enhancing portion in each composite reflector enhancing portion is closer to the second electrode.

11. A display device, characterized in that: include: A display panel as claimed in any one of claims 1 to 10.

12. A method for manufacturing a display panel, characterized in that: The display panel is the display panel according to claim 1, and the manufacturing method comprises: forming the pixel circuit on one side of the substrate, and a planar layer located on a side of the pixel circuit away from the substrate; forming the reflection enhancement layer on a side of the planar layer away from the substrate; A plurality of light emitting devices are formed on a side of the reflection enhancing layer away from the substrate.

13. The method for manufacturing a display panel according to claim 12, characterized in that: The step of forming a reflection enhancement layer on a side of the flat layer away from the substrate comprises: Depositing a first material layer covering the planar layer on a side of the planar layer away from the substrate; exposing, developing, ashing and etching the first material layer by using a half-tone mask process to form a plurality of first reflection enhancing portions with different physical thicknesses; Depositing a second material layer covering the plurality of first reflection enhancing portions on a side of the plurality of first reflection enhancing portions away from the substrate; exposing, developing, ashing and etching the second material layer by using a half-tone mask process to form a plurality of second reflection enhancing portions with different physical thicknesses; and At least one layer of composite reflection enhancing portion is sequentially prepared on a side of the plurality of second reflection enhancing portions away from the substrate.

14. The method for manufacturing a display panel according to claim 13, characterized in that: The step of sequentially preparing at least one layer of composite reflection enhancing portion on a side of the plurality of second reflection enhancing portions away from the substrate comprises: The second reflection enhancing portion, which is the last layer of the composite reflection enhancing portion in the reflection enhancing portion, is prepared by a coating process.

15. A method for manufacturing a display panel, characterized in that: The display panel is the display panel according to claim 10, and the manufacturing method comprises: forming the pixel circuit on one side of the substrate, and a planar layer located on a side of the pixel circuit away from the substrate; forming a plurality of light emitting devices on a side of the planar layer away from the substrate; forming a reflection enhancement layer on a side of the plurality of light emitting devices away from the substrate; An encapsulation layer covering the reflection enhancing layer and the plurality of light emitting devices is formed on the substrate.

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