Light-emitting substrate and light-emitting apparatus

Abstract

A light-emitting substrate. The light-emitting substrate comprises: a base and a plurality of light-emitting devices, wherein the plurality of light-emitting devices are located on one side of the base, each light-emitting device comprises a first electrode, a light-emitting layer, and a second electrode which are stacked, and the first electrode is closer to the base than the second electrode; the first electrode includes a reflective electrode, and the second electrode includes a transparent electrode; at least one light-emitting device comprises an optical adjustment structure, the optical adjustment structure comprises an optical control layer and a transparent reflective layer, the optical control layer is located on the side of the second electrode distant from the base, and the transparent reflective layer is located on the side of the optical control layer distant from the base; the conductivity of the optical control layer is less than that of the transparent reflective layer, and the optical control layer and the transparent reflective layer have different thicknesses.

Description

Light-emitting substrate and light-emitting device

[0001] This application claims priority to Chinese Patent Application No. 202411047984.9, filed on July 31, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of display, and in particular, to a light-emitting substrate and a light-emitting device. BACKGROUND

[0003] Quantum dots (QDs) as a new type of light-emitting material have the advantages of high light color purity, high light-emitting quantum efficiency, adjustable light-emitting color, and long service life, and have become a research hotspot of new LED (Light Emitting Diode) light-emitting materials. Therefore, quantum dot light-emitting diodes (QLED) using quantum dot materials as light-emitting layers have become the main direction of current research on new display devices. SUMMARY

[0004] In one aspect, a light-emitting substrate is provided, which includes a substrate and a plurality of light-emitting devices located on one side of the substrate, each of the light-emitting devices including a first electrode, a light-emitting layer, and a second electrode stacked in order, the first electrode being closer to the substrate than the second electrode; the first electrode including a reflective electrode, and the second electrode including a transparent electrode; wherein at least one of the light-emitting devices includes an optical adjustment structure including an optical adjustment layer and a transparent reflective layer, the optical adjustment layer being located on a side of the second electrode away from the substrate, and the transparent reflective layer being located on a side of the optical adjustment layer away from the substrate; the optical adjustment layer having an electrical conductivity less than that of the transparent reflective layer, and the optical adjustment layer and the transparent reflective layer having different thicknesses.

[0005] In some embodiments, the optical adjustment layer has a light transmittance greater than or equal to that of the transparent reflective layer, and the light transmittance of the optical adjustment layer is greater than or equal to 90%.

[0006] In some embodiments, the optical adjustment layer has an extinction coefficient in the range of 0.001m -1 ~ 0.005m -1 .

[0007] In some embodiments, the material of the optical modulation layer is selected from at least one of 4,4,4,-tris(9H-carbazol-9-yl)phenylamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, 4,4'-bis(9-carbazol) biphenyl, silicon oxide, silicon nitride, and silicon oxynitride.

[0008] In some embodiments, the plurality of light emitting devices comprises: a first light emitting device configured to emit first color light; the optical modulation layer comprises: a first modulation portion arranged corresponding to the first light emitting device; wherein the thickness of the first modulation portion ranges from 55 nm to 65 nm.

[0009] In some embodiments, the light emitting substrate further comprises: a light extraction layer located on the side of the transparent reflective layer away from the substrate; the light extraction layer comprises: a first light extraction portion arranged corresponding to the first light emitting device; wherein the thickness of the first light extraction portion ranges from 85 nm to 115 nm.

[0010] In some embodiments, the first light emitting device further comprises: a first hole transport layer; the first hole transport layer is located between the first electrode and the light emitting layer of the first light emitting device, or the first hole transport layer is located between the light emitting layer and the second electrode of the first light emitting device; wherein the thickness of the first hole transport layer ranges from 20 nm to 30 nm.

[0011] In some embodiments, the first light emitting device further comprises: a first electron transport layer; the first electron transport layer is located between the first electrode and the light emitting layer of the first light emitting device, or the first electron transport layer is located between the light emitting layer and the second electrode of the first light emitting device; wherein the thickness of the first electron transport layer ranges from 30 nm to 70 nm.

[0012] In some embodiments, the first light emitting device further comprises: a first hole transport layer and a first electron transport layer; the first electrode, the first hole transport layer, the light emitting layer, the first electron transport layer, and the second electrode of the first light emitting device are arranged in a direction away from the substrate; or, the first electrode, the first electron transport layer, the light emitting layer, the first hole transport layer, and the second electrode of the first light emitting device are arranged in a direction away from the substrate; wherein the thickness of the first hole transport layer ranges from 20 nm to 30 nm; the thickness of the first electron transport layer ranges from 30 nm to 70 nm.

[0013] In some embodiments, the plurality of light emitting devices comprises: a second light emitting device configured to emit second color light; the optical regulation layer comprises: a second regulation portion arranged corresponding to the second light emitting device; wherein the thickness of the second regulation portion ranges from 95nm to 115nm.

[0014] In some embodiments, the light emitting substrate further comprises: a light extraction layer; the light extraction layer comprises: a second light extraction portion arranged corresponding to the second light emitting device; wherein the thickness of the second light extraction portion ranges from 105nm to 145nm.

[0015] In some embodiments, the second light emitting device further comprises: a second hole transport layer; the second hole transport layer is located between the first electrode of the second light emitting device and the light emitting layer of the second light emitting device, or the second hole transport layer is located between the light emitting layer of the second light emitting device and the second electrode of the second light emitting device; wherein the thickness of the second hole transport layer ranges from 20nm to 30nm.

[0016] In some embodiments, the second light emitting device further comprises: a second electron transport layer; the second electron transport layer is located between the first electrode of the second light emitting device and the light emitting layer of the second light emitting device, or the second electron transport layer is located between the light emitting layer of the second light emitting device and the second electrode of the second light emitting device; wherein the thickness of the second electron transport layer ranges from 30nm to 70nm.

[0017] In some embodiments, the second light emitting device further comprises: a second hole transport layer and a second electron transport layer; the first electrode of the second light emitting device, the second hole transport layer, the light emitting layer of the second light emitting device, the second electron transport layer and the second electrode of the second light emitting device are arranged in a direction away from the substrate; or, the first electrode of the second light emitting device, the second electron transport layer, the light emitting layer of the second light emitting device, the second hole transport layer and the second electrode of the second light emitting device are arranged in a direction away from the substrate; wherein the thickness of the second hole transport layer ranges from 20nm to 30nm; the thickness of the second electron transport layer ranges from 30nm to 70nm.

[0018] In some embodiments, the plurality of light emitting devices comprises: a third light emitting device configured to emit third color light; the optical regulation layer comprises: a third regulation portion arranged corresponding to the third light emitting device; wherein the thickness of the third regulation portion ranges from 5nm to 15nm.

[0019] In some embodiments, the light-emitting substrate further comprises: a light extraction layer; the light extraction layer comprises: a third light extraction portion, the third light extraction portion is arranged corresponding to the third light-emitting device; wherein the thickness of the third light extraction portion ranges from 55 nm to 85 nm.

[0020] In some embodiments, the third light-emitting device further comprises: a third hole transport layer; the third hole transport layer is located between the first electrode of the third light-emitting device and the light-emitting layer of the third light-emitting device; or, the third hole transport layer is located between the light-emitting layer of the third light-emitting device and the second electrode of the third light-emitting device; wherein the thickness of the third hole transport layer ranges from 20 nm to 40 nm.

[0021] In some embodiments, the third light-emitting device further comprises: a third electron transport layer; the third electron transport layer is located between the first electrode of the third light-emitting device and the light-emitting layer of the third light-emitting device; or, the third electron transport layer is located between the light-emitting layer of the third light-emitting device and the second electrode of the third light-emitting device; wherein the thickness of the third electron transport layer ranges from 40 nm to 80 nm.

[0022] In some embodiments, the third light-emitting device further comprises: a third hole transport layer and a third electron transport layer; the first electrode of the third light-emitting device, the third hole transport layer, the light-emitting layer of the third light-emitting device, the third electron transport layer and the second electrode of the third light-emitting device are arranged in a direction away from the substrate; or, the first electrode of the third light-emitting device, the third electron transport layer, the light-emitting layer of the third light-emitting device, the third hole transport layer and the second electrode of the third light-emitting device are arranged in a direction away from the substrate; wherein the thickness of the third hole transport layer ranges from 20 nm to 40 nm; the thickness of the third electron transport layer ranges from 40 nm to 80 nm.

[0023] In some embodiments, the light transmittance of the transparent reflective layer ranges from greater than or equal to 60% to less than or equal to 90%; and / or, in the wavelength range of 400 nm to 700 nm, the light transmittance of the second electrode ranges from greater than or equal to 85%.

[0024] In some embodiments, the material of the transparent reflective layer and the material of the second electrode are independently selected from at least one of gold, silver, magnesium-silver alloy, molybdenum oxide, indium tin oxide, indium zinc oxide, indium tin zinc oxide, indium gallium oxide and aluminum-doped zinc oxide.

[0025] In another aspect, a light-emitting device is provided. The light-emitting device comprises: the light-emitting substrate as described in any of the above embodiments. The light-emitting device further comprises: a driving chip, the driving chip is used to drive the light-emitting substrate to emit light. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings 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, the actual process of the method, etc. involved in the embodiments of this disclosure.

[0027] Figure 1 is a structural diagram of a light-emitting device according to some embodiments of the present disclosure;

[0028] Figure 2 is a structural diagram of a light-emitting substrate according to some embodiments of the present disclosure;

[0029] Figure 3 is a light path diagram of a light-emitting substrate according to some embodiments of the present disclosure;

[0030] Figure 4 is a light emission brightness diagram of a light-emitting device according to some embodiments of the present disclosure;

[0031] Figure 5 is a graph showing the relationship between the front current efficiency and voltage of a light-emitting device according to some embodiments of the present disclosure;

[0032] Figure 6 is a graph showing the relationship between the external quantum efficiency and voltage of a light-emitting device according to some embodiments of the present disclosure;

[0033] Figure 7 is a light emission angle distribution diagram of the light-emitting device according to Example 1 of this disclosure;

[0034] Figure 8 is a light emission angle distribution diagram of the light-emitting device according to Example 2 of this disclosure;

[0035] Figure 9 is a graph showing the relationship between the light output brightness and voltage of a light-emitting device according to some embodiments of the present disclosure;

[0036] Figure 10 is a light emission angle distribution diagram of the light-emitting device according to Example 3 of this disclosure;

[0037] Figure 11 is a graph showing the relationship between the light output brightness and voltage of the light-emitting device according to Example 3 of this disclosure;

[0038] Figure 12 is a graph showing the relationship between the external quantum efficiency and voltage of the light-emitting device according to Example 3 of this disclosure;

[0039] Figure 13 is another structural diagram of a light-emitting substrate according to some embodiments of the present disclosure;

[0040] Figure 14 is another light path diagram of a light-emitting substrate according to some embodiments of the present disclosure;

[0041] FIG. 15 is a light output luminance map of a first light emitting device according to some embodiments of the present disclosure;

[0042] FIG. 16 is yet another structure diagram of a light emitting substrate according to some embodiments of the present disclosure;

[0043] FIG. 17 is yet another structure diagram of a light emitting substrate according to some embodiments of the present disclosure;

[0044] FIG. 18 is yet another structure diagram of a light emitting substrate according to some embodiments of the present disclosure;

[0045] FIG. 19 is yet another structure diagram of a light emitting substrate according to some embodiments of the present disclosure;

[0046] FIG. 20 is yet another structure diagram of a light emitting substrate according to some embodiments of the present disclosure;

[0047] FIG. 21 is a light output luminance map of a second light emitting device according to some embodiments of the present disclosure;

[0048] FIG. 22 is a light output luminance map of a third light emitting device according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0049] The technical solutions in some embodiments of the present disclosure will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments provided in the present disclosure, all other embodiments obtained by a person of ordinary skill in the art belong to the scope of protection of the present disclosure.

[0050] Unless otherwise required by context, the term “comprise” and other forms of the term “comprise”, such as “comprises” and “comprising”, and other forms thereof, are used in an open, inclusive sense, i.e., “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” are intended to mean that a particular feature, structure, material, or characteristic included in at least one embodiment or example of the present disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described can be included in any appropriate manner in any one or more embodiments or examples.

[0051] Hereinafter, the terms "first", "second", etc. are used only for the purpose of description, and should not be construed as indicating or implying relative importance or indicating the number of the technical features indicated. Thus, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0052] In describing some embodiments, "coupled" and "connected", and variations thereof, can be used. The term "connected" should be interpreted broadly, for example, "connected" can be fixed connection, or detachable connection, or integral; can be directly connected, or connected through an intermediate medium. The term "coupled" indicates, for example, that two or more components have direct physical contact or electrical contact. The term "coupled" or "communicatively coupled" can also refer to two or more components that do not have direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content herein.

[0053] "A, B, and C at least one of" has the same meaning as "at least one of A, B, or C", and includes the following combinations of A, B, and C: only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, and a combination of A, B, and C.

[0054] "A and / or B" includes the following three combinations: only A, only B, and a combination of A and B.

[0055] As used herein, "about", "approximately", or "around" includes the stated value and the average value within an acceptable range of deviation from the specific value, as determined by a person of ordinary skill in the art taking into account the measurement being discussed and the error associated with the measurement of the specific quantity (i.e., limitations of the measurement system).

[0056] As used herein, "parallel," "perpendicular," "equal" include the recited condition and conditions that are approximately the recited condition, the range of approximation being within an acceptable deviation range as determined by one of ordinary skill in the art taking into account the measurement being discussed and the error associated with the measurement of the particular quantity (i.e., limitations of the measurement system). For example, "parallel" includes absolute parallel and approximately parallel, where the acceptable deviation range of approximately parallel can be, for example, within 5°; "perpendicular" includes absolute perpendicular and approximately perpendicular, where the acceptable deviation range of approximately perpendicular can also be, for example, within 5°. "Equal" includes absolute equality and approximate equality, where the acceptable deviation range of approximate equality can be, for example, a difference between the two that is less than or equal to 5% of either.

[0057] It will be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers can also be present.

[0058] Exemplary embodiments are described herein with reference to cross-sectional and / or plan view illustrations that are idealized examples of exemplary embodiments. In the interest of clarity, not all of the circular features can be shown in the drawings. It will be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions can be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints. These specific goals will vary from one implementation to another and will vary from one environment to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0059] As shown in FIG. 1, some embodiments of the present disclosure provide a light emitting device 1000, which can be any device that displays both motion (e.g., video) and still (e.g., still images) and both text and graphics. More specifically, it is contemplated that the embodiments can be implemented in or in association with a variety of electronic devices, such as (but not limited to) a mobile phone (e.g., a cell phone), a wireless device, a personal data assistant (PDA), a handheld or portable computer, a GPS receiver / navigator, a camera, an MP4 video player, a camcorder, a game console, a watch, a clock, a calculator, a television monitor, a flat panel display, a computer monitor, an automobile display (e.g., an odometer display, etc.), a navigation instrument, a cockpit controller and / or display, a display of a camera view (e.g., a display of a rear view camera in a vehicle), an electronic photograph, an electronic billboard or sign, a projector, an architectural structure, a package and an aesthetic structure (e.g., a display of an image for a piece of jewelry), etc. The light emitting device 1000 is exemplified as a cell phone in FIG. 1.

[0060] Exemplarily, the light emitting device 1000 can be an electroluminescent display device or a photoluminescent display device. In the case that the light emitting device 1000 is an electroluminescent display device, the electroluminescent display device can be an organic electroluminescent display device (OLED) or a quantum dot electroluminescent display device (QLED). Hereinafter, some embodiments of the present disclosure are exemplarily described by taking the light emitting device 1000 as a QLED display device, but the embodiments of the present disclosure include but are not limited to this, and any other display device can also be considered as long as the same technical idea is applied.

[0061] Please continue to refer to FIG. 1, the light emitting device 1000 described above comprises a light emitting substrate 100.

[0062] In some embodiments, as shown in FIG. 2, the light emitting substrate 100 comprises a substrate 11 and a plurality of light emitting devices 10 located on one side of the substrate 11, each of the plurality of light emitting devices 10 comprises a first electrode 12, a light emitting layer 15 and a second electrode 17 stacked in sequence, and the first electrode 12 is closer to the substrate 11 than the second electrode 17.

[0063] Exemplarily, as shown in FIG. 2, the light emitting substrate 100 further comprises a pixel defining layer 20, and a plurality of openings K are arranged on the pixel defining layer 20, and the plurality of light emitting devices 10 are arranged in the plurality of openings K one by one.

[0064] For example, the plurality of light emitting devices 10 includes a first light emitting device 101, a second light emitting device 102 and a third light emitting device 103, for example, the first light emitting device 101 is configured to emit any one of red light, green light and blue light, the second light emitting device 102 is configured to emit another one of red light, green light and blue light, and the third light emitting device 103 is configured to emit the last one of red light, green light and blue light.

[0065] For example, the first electrode 12 is one of an anode and a cathode, and the second electrode 17 is the other one of the anode and the cathode.

[0066] In some embodiments, as shown in FIG. 2, the light emitting substrate 100 further includes a pixel driving circuit (not shown in the figure) between the substrate 11 and the plurality of light emitting devices 10, the pixel driving circuit is configured to provide an electrical signal to the plurality of light emitting devices 10 to drive the light emitting devices 10 to emit light.

[0067] The light emitting principle of the light emitting device 10 is that, through the circuit connected by the anode and the cathode, the anode injects holes into the light emitting layer 15, and the cathode injects electrons into the light emitting layer 15, the formed electrons and holes form excitons in the light emitting layer 15, and the excitons return to the ground state through radiative transition to emit photons.

[0068] In some embodiments, as shown in FIG. 3, taking the first electrode 12 as an anode and the second electrode 17 as a cathode as an example, the light emitting device 10 further includes a hole injection layer 13 and a hole transport layer 14 between the first electrode 12 and the light emitting layer 15, the hole injection layer 13 and the hole transport layer 14 are arranged in a direction away from the substrate 11, and the light emitting device 10 further includes an electron transport layer 16 between the light emitting layer 15 and the second electrode 17.

[0069] The arrangement of the hole injection layer 13 and the hole transport layer 14 can improve the hole transport efficiency of the light emitting device 10, and the arrangement of the electron transport layer 16 can improve the electron transport efficiency of the light emitting device 10, so as to improve the rate of forming excitons by electrons and holes in the light emitting layer 15, thereby improving the light emitting efficiency of the light emitting device 10.

[0070] For example, the second electrode 17 is provided with a light extraction layer 18 away from the substrate 11. For example, the refractive index of the light extraction layer 18 is less than the refractive index of the second electrode 17 and greater than the refractive index of air, so that due to the influence of the refractive index, the arrangement of the light extraction layer 18 can reduce the total reflection of light at the film layer interface, so as to improve the light extraction efficiency of the light emitting device 10.

[0071] The light emitting device 10 can be classified into a top emission type light emitting device and a bottom emission type light emitting device. For example, the first electrode 12 can be configured as a transparent electrode and the second electrode 17 can be configured as a reflective electrode, or the first electrode 12 can be configured as a reflective electrode and the second electrode 17 can be configured as a transparent electrode. The difference between the two is whether the light emitting device 10 emits light in a direction through the substrate 11 or in a direction away from the substrate 11.

[0072] Since the top emission type light emitting device emits light from the top, it does not need to avoid the metal tracks of the thin film transistor (TFT) array for forming the pixel driving circuit at the bottom, so the pixel design of the top emission type light emitting device is more flexible and has a higher aperture ratio than the bottom emission type light emitting device. Therefore, the embodiments of the present disclosure take the light emitting device 10 as an example of a top emission type light emitting device.

[0073] However, in the top emission type light emitting device, it is a difficult problem that the thicknesses of the functional layers of the light emitting device 10 simultaneously satisfy the better electrical performance and the better optical performance of the light emitting device 10. For example, when the thicknesses of the functional layers of the light emitting device 10 satisfy the better electrical performance of the light emitting device 10, at this time, the carrier (electron and hole) transmission of the light emitting device 10 is more balanced, but the side light emission intensity of the light emitting device 10 is high, resulting in the worse optical performance of the light emitting device 10. When the thicknesses of the functional layers of the light emitting device 10 satisfy the better optical performance of the light emitting device 10, at this time, the front light emission intensity of the light emitting device 10 is high, but the carrier injection of the light emitting device 10 is unbalanced, resulting in the worse electrical performance of the light emitting device 10.

[0074] It should be noted that when the electrical performance of the light emitting device 10 is better, the external quantum efficiency of the light emitting device 10 is higher, wherein the external quantum efficiency (EQE) refers to the efficiency of the light generated in the light emitting layer 15 being extracted to the outside of the light emitting device 10. When the optical performance of the light emitting device 10 is better, the front current efficiency of the light emitting device 10 is higher. Wherein the front current efficiency refers to the ratio of the light emission efficiency and the current at the front of the light emitting device 10.

[0075] As shown in FIG. 3, the front light emission refers to the included angle between the light and the first direction Y being about 0°, and the first direction Y is the direction perpendicular to the substrate 11; the side light emission refers to the light other than the front light emission.

[0076] Regarding the relationship between the thicknesses of the functional layers of the light emitting device 10 and the electrical performance and the optical performance of the light emitting device 10, the following embodiments are provided.

[0077] In some embodiments, as shown in FIG. 3, the first electrode 12 is a reflective electrode and the second electrode 17 is a semi-transparent and semi-reflective electrode.

[0078] It should be noted that the reflective electrode is used to reflect light incident on the electrode, and the material of the first electrode 12 is, for example, metal, and the first electrode 12 can be a single-layer structure or a stacked structure. For example, the reflectivity of the reflective electrode is greater than 90%. The semi-reflective and semi-transmissive electrode is used to reflect part of the light incident on the electrode and also to transmit part of the light incident on the electrode.

[0079] In the light emitting device 10, the first electrode 12 and the second electrode 17 form a microcavity (also referred to as a resonant cavity), and the light emitting layer 15 is located between the first electrode 12 and the second electrode 17, i.e., the light emitting layer 15 is located in the microcavity, and the intensity of light of a certain wavelength emitted by the light emitting layer 15 is increased, and the spectrum of light of a certain wavelength is narrowed. The microcavity can cause most of the light emitted by the light emitting layer 15 to be emitted through the second electrode 17, thereby improving the light emitting efficiency of the light emitting device 10.

[0080] That is, the light emitting device 10 has a microcavity effect, specifically, the microcavity effect mainly refers to the optical interference inside the light emitting device 10, and the light will be reflected back and forth inside the light emitting device 10, and only light of a certain wavelength can be emitted outside the light emitting device 10. Moreover, when the light emitting layer 15 of the light emitting device 10 is located in a microcavity formed by a reflective electrode and a semi-reflective and semi-transmissive electrode, when the microcavity length and the wavelength of the light are of the same order of magnitude, light of a certain wavelength is selected and strengthened, and the spectrum is narrowed.

[0081] The microcavity length refers to the size d1 of the microcavity structure in the first direction Y, and can also be understood as the distance between the first electrode 12 and the second electrode 17. The first direction Y is a direction perpendicular to the substrate 11.

[0082] In the top emission type light emitting device, the first electrode 12 and the second electrode 17 produce a Fabry-Perot interference. The Fabry-Perot interference mainly includes two mechanisms. First, the interference between the emitted light L1 directly emitted from the light emitting layer 15 and the reflected light L2 reflected by the first electrode 12 is wide-angle interference. Second, the mutual interference between multiple reflected lights L2 is multi-beam interference.

[0083] Moreover, electromagnetic waves at the dielectric-metal interface L3 are absorbed, and when the light is reflected at the first electrode 12 formed of metal material, a phase shift occurs. Therefore, the microcavity length of the top emission type light emitting device must be determined by considering the difference in the optical path and the phase shift between the beams at the dielectric-metal interface L3. The phase shift refers to the phase difference between the output sine wave and the input sine wave signal.

[0084] The following provides calculation formulas of the wide-angle interference and the multi-beam interference existing in the light emitting device 10.

[0085] wherein equation (1) is wide-angle interference and equation (2) is multi-beam interference. λ is the emission wavelength of the light emitted by the light-emitting layer 15, i represents the film layers between the first electrode 12 and the second electrode 17, and θ is the angle of incidence of the light at one film layer.

[0086] Equation (1) is used to describe the mutual interference between the emitted light L1 and the reflected light L2, n i (λ) is the refractive index of each film layer between the light-emitting layer 15 and the first electrode 12; d i is the dimension between the light-emitting layer 15 and the first electrode 12 in the first direction Y; is the phase shift of the light reflected by the first electrode 12.

[0087] Equation (2) is used to describe the mutual interference between the multiple reflected lights L2, n i (λ) is the refractive index of each film layer in the microcavity structure; d i is the thickness of each film layer; is the phase shift of the light reflected by the first electrode 12, is the phase shift of the light reflected by the second electrode 17.

[0088] m is the order of resonance, when m = 1, it is referred to as a first-order microcavity length; when m = 2, it is referred to as a second-order microcavity length; when m = 3, it is referred to as a third-order microcavity length. The related parameters of the light-emitting device 10 can be brought into the equation to calculate the value of m, and the obtained m is the order of resonance of the light-emitting device 10. Moreover, the thickness of each film layer in the microcavity increases, and the value of m increases.

[0089] In the bottom-emitting light-emitting device, the multi-beam interference is less, because the emitted light of the light-emitting layer 15 is rarely reflected back to the second electrode 17 from the first electrode 12 with high transmittance. In the bottom-emitting light-emitting device, the multi-beam interference is weak, and the multi-beam interference plays a major role in enhancing the light out of the microcavity structure, so that the microcavity effect in the bottom-emitting light-emitting device is weak.

[0090] In the top-emitting light-emitting device structure, both the wide-angle interference and the multi-beam interference exist, and the microcavity resonance can be optimized by properly adjusting the thickness and the refractive index of each film layer. Therefore, the microcavity structure of the top-emitting light-emitting device can narrow the light-emitting spectrum of the light-emitting device 10, so that the red, green and blue colors are purer, thereby improving the purity of the light-emitting color and the light extraction efficiency of the light-emitting device 10, so as to make the color gamut displayed by the light-emitting apparatus 1000 wider. Moreover, the top-emitting light-emitting device can adjust the angular distribution of the light, enhance the front light effect, and be beneficial to reducing the power consumption of the small and medium-sized display applications.

[0091] The optical and electrical properties of the light-emitting device 10 shown in FIG. 3 are described below.

[0092] In some embodiments, as shown in FIG. 3, the light emitting device 10 is configured to emit green light, and the SETFOS simulation software is used to simulate the effect of different thicknesses of the hole transport layer 14 and the electron transport layer 16 on the light emission of the light emitting device 10.

[0093] For example, the structure of the light emitting device 10 is represented as: the first electrode 12 (ITO / Ag / ITO, 7nm / 100nm / 7nm) / hole injection layer 13 (PEDOT, 25nm) / hole transport layer 14 (PF8Cz, xnm) / light emitting layer 15 (QD, 20nm) / electron transport layer 16 (ZnMgO, ynm) / second electrode 17 (Mg:Ag, 10nm) / light extraction layer (60nm).

[0094] The light emitting device 10 is located on one side of the substrate 11, for example, the thickness of the substrate 11 is 0.5mm.

[0095] It should be noted that the first electrode 12 (ITO / Ag / ITO, 7nm / 100nm / 7nm) represents the material of the first electrode 12, and the first electrode 12 is a laminated structure formed by material indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO), and the thickness is 7nm / 100nm / 7nm, the thickness of ITO is 7nm, the thickness of Ag is 100nm, and the rest is described in the same way, which will not be repeated here.

[0096] PEDOT is the abbreviation of poly 3,4-ethylenedioxythiophene, PF8Cz is the abbreviation of poly(9,9-n-dioctyl-2,7-fluorene-alt-9-isooctyl-3,6-carbazole), and QD is the abbreviation of quantum dot.

[0097] FIG. 4 is a light emission brightness diagram of the light emitting device 10, and the color examples on the left side represent the light emission brightness. Wherein, the abscissa represents the thickness x of the hole transport layer 14, and the ordinate represents the thickness y of the electron transport layer 16. When using the SETFOS simulation software to simulate, a plurality of thickness data of the electron transport layer 16 and a plurality of thickness data of the hole transport layer 14 can be simulated respectively, wherein the difference between every two adjacent thickness data of the electron transport layer 16 can be equal, and the difference between every two adjacent thickness data of the hole transport layer 14 can be equal.

[0098] The optical performance of the light emitting device 10 can be seen from FIG. 4. The thickness x of the hole transport layer 14 and the thickness y of the electron transport layer 16 are determined by the light emission brightness of the light emitting device 10.

[0099] In the coordinate shown in FIG. 4, the thickness x and the thickness y of the lower left region are relatively small, and the microcavity length of the light emitting device 10 is first order. The yellow-green region SI represents the light emitting device 10 having a light emitting brightness of about 6500 cd / m 2 , which is the optimal front light emitting brightness of the light emitting device 10. In the region SI, the thickness x of the hole transport layer 14 ranges from 20 nm to 30 nm, and the thickness y of the electron transport layer 16 ranges from 40 nm to 50 nm.

[0100] In the coordinate shown in FIG. 4, the thickness x of the lower right region is relatively large, and the thickness y is relatively small, and the microcavity length of the light emitting device 10 is second order. The red region S2 represents the light emitting device 10 having a light emitting brightness of about 8500 cd / m 2 , which is the optimal front light emitting brightness of the light emitting device 10. In the region S2, the thickness x of the hole transport layer 14 ranges from 150 nm to 170 nm, and the thickness y of the electron transport layer 16 ranges from 40 nm to 70 nm.

[0101] In the coordinate shown in FIG. 4, the thickness x of the upper left region is relatively small, and the thickness y is relatively large, and the microcavity length of the light emitting device 10 is second order. The yellow-green region S3 represents the light emitting device 10 having a light emitting brightness of about 6500 cd / m 2 , which is the optimal front light emitting brightness of the light emitting device 10. In the region S3, the thickness x of the hole transport layer 14 ranges from 20 nm to 30 nm, and the thickness y of the electron transport layer 16 ranges from 180 nm to 200 nm.

[0102] Two examples are provided below, in which the thickness x of the hole transport layer 14 is different, and the optical and electrical properties of the light emitting device 10 are tested by the difference in the thickness x of the hole transport layer 14. The two examples are represented as: Example 1 and Example 2, in which the thickness of the electron transport layer 16 is 50 nm, and the thickness of the hole transport layer 14 is 15 nm in Example 1; and the thickness of the electron transport layer 16 is 50 nm, and the thickness of the hole transport layer 14 is 25 nm in Example 2.

[0103] Fig. 5 is a graph showing the relationship between the front surface current efficiency and the voltage of the light emitting device 10, in which the horizontal axis represents the voltage in V, and the vertical axis represents the front surface current efficiency in cd / A. As shown in Fig. 5, in the example 1 in which the thickness x of the hole transporting layer 14 is 15 nm, the front surface current efficiency of the light emitting device 10 can reach about 120 cd / A in the voltage range of 2 V to 8 V. In the example 2 in which the thickness x of the hole transporting layer 14 is 25 nm, the front surface current efficiency of the light emitting device 10 can reach about 100 cd / A in the voltage range of 2 V to 8 V. Therefore, when the thickness x of the hole transporting layer 14 is 15 nm, the front surface current efficiency of the light emitting device 10 is large, and the light emitting device 10 has better optical performance.

[0104] Fig. 6 is a graph showing the relationship between the external quantum efficiency and the voltage of the light emitting device 10, in which the horizontal axis represents the voltage in V, and the vertical axis represents the external quantum efficiency. As shown in Fig. 6, in the example 1 in which the thickness x of the hole transporting layer 14 is 15 nm, the external quantum efficiency of the light emitting device 10 can reach about 18% in the voltage range of 2 V to 8 V. In the example 2 in which the thickness x of the hole transporting layer 14 is 25 nm, the external quantum efficiency of the light emitting device 10 can reach about 26% in the voltage range of 2 V to 8 V. Therefore, when the thickness x of the hole transporting layer 14 is 25 nm, the external quantum efficiency of the light emitting device 10 is large, and the light emitting device 10 has better electrical performance.

[0105] Fig. 7 is a graph showing the light emitting angle distribution of the light emitting device 10 of the example 1, in which the numerical values on the outside of the semicircle represent the light emitting angles, and the dotted line represents the light emitting intensity on the line is equal. As shown in Fig. 7, the front surface light emitting of the light emitting device 10 represented by the example 1 in which the thickness x of the hole transporting layer 14 is 15 nm is strong. Therefore, when the thickness x of the hole transporting layer 14 is 15 nm, the light emitting device 10 has better optical performance.

[0106] Fig. 8 is a graph showing the light emitting angle distribution of the light emitting device 10 of the example 2. As shown in Fig. 8, the side surface light emitting of the light emitting device 10 represented by the example 2 in which the thickness x of the hole transporting layer 14 is 25 nm is strong, and the front surface light emitting is weak. Therefore, when the thickness x of the hole transporting layer 14 is 25 nm, the light emitting device 10 has poor optical performance.

[0107] Fig. 9 is a graph showing the relationship between the light emitting brightness and the voltage of the light emitting device 10, in which the horizontal axis represents the voltage in V, and the vertical axis represents the light emitting brightness in cd / m 2The light emission brightness of the light emitting device 10 represented by Example 1, in which the thickness x of the hole transport layer 14 is 15 nm, is greater than the light emission brightness of the light emitting device 10 represented by Example 2, in which the thickness x of the hole transport layer 14 is 25 nm. Therefore, when the thickness x of the hole transport layer 14 is 15 nm, the light emission brightness of the light emitting device 10 is great, and the light emitting device 10 has better optical performance.

[0108] Therefore, as can be seen from FIGS. 5-9, under the condition that the thickness y of the electron transport layer 16 of the light emitting device 10 is 50 nm, when the thickness x of the hole transport layer 14 is 15 nm, the light emitting device 10 has greater front surface current efficiency, stronger front surface light emission, and greater light emission brightness, and the light emitting device 10 has better optical performance, as compared to when the thickness x of the hole transport layer 14 is 25 nm. When the thickness x of the hole transport layer 14 is 25 nm, the light emitting device 10 has greater external quantum efficiency, and the light emitting device 10 has better electrical performance. Therefore, the setting of the film layer thickness of the light emitting device 10 has the problem that better electrical performance and better optical performance do not match.

[0109] The influence of increasing the thickness x of the hole transport layer 14 on the optical performance and electrical performance of the light emitting device 10 is described below. This example is represented as Example 3, in which the thickness y of the electron transport layer 16 is 50 nm, and the thickness x of the hole transport layer 14 ranges from 150 nm to 190 nm.

[0110] FIG. 10 is a light emission angle distribution diagram of the light emitting device 10 of Example 3. As can be seen from FIG. 10, the light emitting device 10 has stronger front surface light emission. Therefore, increasing the thickness x of the hole transport layer 14 can improve the front surface light emission effect of the light emitting device 10.

[0111] FIG. 11 is a diagram of the relationship between the light emission brightness and the voltage of the light emitting device 10 of Example 3. As can be seen from FIG. 11, in the range of 10 V to 20 V of the voltage, the light emission brightness of the light emitting device 10 ranges from 100 cd / m 2 to 10000 cd / m 2 In FIG. 9, when the voltage is 6 V, the light emission brightness of the light emitting device 10 can reach 100000 cd / m 2 By comparing FIG. 9 and FIG. 11, it can be seen that increasing the thickness x of the hole transport layer 14 leads to a decrease in the light emission brightness of the light emitting device 10.

[0112] Fig. 12 is a graph showing the relationship between the external quantum efficiency and the voltage of the light emitting device 10 of Example 3. As can be seen from Fig. 12, the external quantum efficiency of the light emitting device 10 is less than 5% in the voltage range of 10 V to 20 V. In Fig. 6, in Example 1 in which the thickness x of the hole transport layer 14 is 15 nm, the external quantum efficiency of the light emitting device 10 is up to about 18% in the voltage range of 2 V to 8 V. In Example 2 in which the thickness x of the hole transport layer 14 is 25 nm, the external quantum efficiency of the light emitting device 10 is up to about 26% in the voltage range of 2 V to 8 V. As can be seen by comparing Fig. 6 and Fig. 12, increasing the thickness x of the hole transport layer 14 results in a decrease in the external quantum efficiency of the light emitting device 10.

[0113] Therefore, increasing the thickness x of the hole transport layer 14 can improve the optical performance of the light emitting device 10, but decreases the electrical performance of the light emitting device 10, and there is a problem that the electrical performance and the optical performance of the light emitting device 10 are not matched.

[0114] Based on this, as shown in Fig. 13, an embodiment of the present disclosure provides a light emitting substrate 100, which includes a substrate 11 and a plurality of light emitting devices 10 located on one side of the substrate 11, each of the light emitting devices 10 including a first electrode 12, a light emitting layer 15 and a second electrode 17 stacked in this order, the first electrode 12 being closer to the substrate 11 than the second electrode 17. The first electrode 12 includes a reflective electrode, and the second electrode 17 includes a transparent electrode.

[0115] Illustratively, the material of the light emitting layer 15 includes quantum dots, and the light emitting substrate 100 containing quantum dots not only has the characteristics of self-light emission and compatibility with flexible processes, but also has the advantages of narrow light emitting spectrum, easy adjustment of light emitting wavelength and high light emitting efficiency.

[0116] Illustratively, the first electrode 12 is a reflective electrode, and the reflective electrode is used to reflect light rays incident on the electrode. The material of the first electrode 12 is, for example, metal, and the first electrode 12 can have a single-layer structure or a stacked structure. For example, the first electrode 12 has a stacked structure formed by indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO).

[0117] Illustratively, the light transmittance of the second electrode 17 is greater than or equal to 85% in the wavelength range of 400 nm to 700 nm. For example, the material of the second electrode 17 is selected from at least one of gold, silver, magnesium-silver alloy, molybdenum oxide, indium tin oxide, indium zinc oxide, indium tin zinc oxide, indium gallium oxide and aluminum-doped zinc oxide.

[0118] Therefore, in an embodiment of the present disclosure, the light emitting direction of the light emitting device 10 is the direction away from the substrate 11, and the light emitting device 10 is a top emission type light emitting device.

[0119] The weak microcavity effect between the first electrode 12 and the second electrode 17 has little effect on the optical performance of the light-emitting device 10. The film layer between the first electrode 12 and the second electrode 17 has a great effect on the electrical performance of the light-emitting device 10, and the thickness of the film layer between the first electrode 12 and the second electrode 17 can be adjusted to improve the balance of carrier transport of the light-emitting device 10, thereby improving the electrical performance of the light-emitting device 10.

[0120] For example, as shown in FIGS. 13 and 14, the at least one light-emitting device 10 includes an optical adjustment structure 110, the optical adjustment structure 110 includes the optical adjustment layer 30 and the transparent reflective layer 40, the optical adjustment layer 30 is located on the side of the second electrode 17 away from the substrate 11, and the transparent reflective layer 40 is located on the side of the optical adjustment layer 30 away from the substrate 11; the conductivity of the optical adjustment layer 30 is less than the conductivity of the transparent reflective layer 40, and the thickness of the optical adjustment layer 30 is different from the thickness of the transparent reflective layer 40.

[0121] It should be noted that the transparent reflective layer 40 can be used to reflect part of the light rays incident on the transparent reflective layer 40, and also can be used to transmit part of the light rays incident on the transparent reflective layer 40.

[0122] For example, FIG. 14 is a light path diagram of the light-emitting substrate 100, the light rays L4 emitted by the light-emitting layer 15 can directly transmit through the transparent reflective layer 40, and the light rays L5 emitted by the light-emitting layer 15 are reflected on the transparent reflective layer 40.

[0123] For example, the material of the transparent reflective layer 40 is selected from at least one of gold, silver, magnesium-silver alloy, molybdenum oxide, tungsten oxide, zinc sulfide, indium tin oxide, indium gallium oxide, aluminum-doped zinc oxide, silver nanowire, copper nanowire, and carbon nanotube. The material of the transparent reflective layer 40 is a conductor, and the conductivity of the transparent reflective layer 40 is large.

[0124] For example, the thickness of the transparent reflective layer 40 ranges from 10 nm to 100 nm. For example, the material of the transparent reflective layer 40 includes magnesium-silver alloy, and the thickness of the transparent reflective layer 40 ranges from 10 nm to 20 nm. The material of the transparent reflective layer 40 includes indium tin oxide, indium gallium oxide, and aluminum-doped zinc oxide, and the thickness of the transparent reflective layer 40 ranges from 50 nm to 100 nm. The material of the transparent reflective layer 40 includes molybdenum oxide and tungsten oxide, and the thickness of the transparent reflective layer 40 ranges from 10 nm to 50 nm. The material of the transparent reflective layer 40 includes silver nanowire, copper nanowire, and carbon nanotube, and the thickness of the transparent reflective layer 40 ranges from 20 nm to 50 nm.

[0125] For example, the material of the optical modulation layer 30 is selected from at least one of 4,4,4,-tris(9H-carbazol-9-yl)phenylamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, 4,4'-bis(9H-carbazol-9-yl)biphenyl, silicon oxide, silicon nitride and silicon oxynitride. The material of the optical modulation layer 30 is an insulator, and the conductivity of the optical modulation layer 30 is small.

[0126] As compared with the material of the transparent reflective layer 40 and the material of the optical modulation layer 30, the conductivity of the optical modulation layer 30 is smaller than the conductivity of the transparent reflective layer 40. Moreover, in the preparation method of the transparent reflective layer 40 and the optical modulation layer 30, the transparent reflective layer 40 can be formed by an evaporation process, and the optical modulation layer 30 can be formed by a deposition process. Generally, the thickness of a film formed by an evaporation process is smaller than the thickness of a film formed by a deposition process. Therefore, the thickness of the transparent reflective layer 40 is generally smaller than the thickness of the optical modulation layer 30.

[0127] For example, as shown in FIG. 14, the first electrode 12 includes a reflective electrode, and the transparent reflective layer 40 can be used to reflect part of the light rays incident on the transparent reflective layer 40 and also to transmit part of the light rays incident on the transparent reflective layer 40. The light ray L4 emitted by the light-emitting layer 15 can be directly emitted by the transparent reflective layer 40; the light ray L6 emitted by the light-emitting layer 15 can be reflected by the first electrode 12 to the transparent reflective layer 40; the light ray L5 emitted by the light-emitting layer 15 can be reflected by the transparent reflective layer 40 to the first electrode 12, which is denoted as the light ray L7, and the light ray L7 can be reflected by the first electrode 12 to the transparent reflective layer 40; the light ray reflected by the first electrode 12 is denoted as the light ray L8. The interference between the light ray L5 and the light ray L8 is wide-angle interference, and the interference between the multiple light rays L8 is multi-beam interference. Therefore, a strong microcavity is formed between the first electrode 12 and the transparent reflective layer 40.

[0128] The embodiment of the present disclosure forms a strong microcavity effect by the provision of the transparent reflective layer 40, and the light-emitting layer 15 is located between the transparent reflective layer 40 and the first electrode 12, i.e., the light-emitting layer 15 is located in the microcavity. Due to the microcavity effect, the intensity of the light of a certain wavelength emitted by the light-emitting layer 15 is increased, so as to improve the light-emitting efficiency of the light-emitting device 10.

[0129] Moreover, the cavity length of the microcavity can be adjusted by adjusting the thickness of the optical modulation layer 30. Since the optical modulation layer 30 is located between the transparent reflective layer 40 and the second electrode 17, the provision of the optical modulation layer 30 does not affect the electrical performance of the light-emitting device 10. For example, after the thicknesses of the film layers between the first electrode 12 and the second electrode 17 are adjusted to be optimal for the electrical performance of the light-emitting device 10, the thickness of the optical modulation layer 30 is adjusted to be optimal for the optical performance of the light-emitting device 10.

[0130] Therefore, the embodiments of the present disclosure achieve the purpose of adjusting the optical performance and the electrical performance of the light-emitting device 10 respectively by arranging the optical adjustment structure 110 on the side of the second electrode 17 away from the substrate 11, so that the light-emitting device 10 has relatively optimal electrical performance and optical performance.

[0131] Further, in the case that the thickness of each film layer between the first electrode 12 and the second electrode 17 is relatively thin, the second-order microcavity effect of the light-emitting device 10 can be achieved by increasing the thickness of the optical adjustment layer 30, so that the light-emitting device 10 has relatively strong light-emitting intensity, and the light-emitting device 10 has relatively optimal optical performance.

[0132] In some embodiments, as shown in FIG. 13, the light transmittance of the optical adjustment layer 30 is greater than or equal to the light transmittance of the transparent reflective layer 40.

[0133] It should be noted that the light transmittance refers to the ratio of the light flux that transmits during the process of the incident light from the irradiated surface of the film layer to the other surface opposite to the irradiated surface of the film layer to the incident light flux. For example, the light transmittance of the film layer can be measured by an ultraviolet-visible absorption spectrometer.

[0134] For example, the light transmittance of the optical adjustment layer 30 is 90%, 92%, 93%, 96%, 97%, 98%, 99% or 100%, etc., which is not limited herein.

[0135] By arranging the light transmittance of the optical adjustment layer 30 in the range of greater than or equal to 90%, the optical adjustment layer 30 has the function of adjusting the microcavity length while having relatively high light transmittance, so as to ensure that the light-emitting device 10 has relatively high light-emitting intensity.

[0136] For example, the light transmittance of the transparent reflective layer 40 is in the range of greater than or equal to 60% and less than or equal to 90%. In this way, the transparent reflective layer 40 can be used to reflect part of the light that reaches the transparent reflective layer 40, and also can transmit part of the light that reaches the transparent reflective layer 40.

[0137] By arranging the light transmittance of the optical adjustment layer 30 to be greater than or equal to the light transmittance of the transparent reflective layer 40, the light can transmit through the optical adjustment layer 30 and further transmit or reflect at the transparent reflective layer 40, so as to cause the light to interfere, thereby improving the optical performance of the light-emitting device 10.

[0138] In some embodiments, as shown in FIG. 13, the extinction coefficient of the optical adjustment layer 30 is in the range of 0.001 m -1 ~0.005 m -1 .

[0139] For example, the extinction coefficient of the optical modulation layer 30 is 0.001 m -1 , 0.002 m -1 , 0.003 m -1 , 0.004 m -1 or 0.005 m -1 , without limitation.

[0140] It should be noted that the extinction coefficient reflects the absorption of the film layer to the light, when the extinction coefficient is large, it means that the film layer will absorb part of the light, resulting in the decrease of the transmittance of the film layer. For example, the extinction coefficient of the film layer can be measured by an ellipsometer.

[0141] By setting the range of the extinction coefficient of the optical modulation layer 30 to 0.001 m -1 ~ 0.005 m -1 , the optical modulation layer 30 has a small extinction coefficient, so that the optical modulation layer 30 has a high light transmittance.

[0142] In some embodiments, as shown in FIG. 13 and FIG. 15, the plurality of light emitting devices 10 includes: a first light emitting device 101, the first light emitting device 101 is configured to emit first color light; the optical modulation layer 30 includes: a first modulation part 301, the first modulation part 301 is arranged corresponding to the first light emitting device 101; wherein the thickness d2 of the first modulation part 301 ranges from 55 nm to 65 nm.

[0143] For example, the first color light is configured to be green light.

[0144] It should be noted that the thickness d2 of the first modulation part 301 is the size of the first modulation part 301 in the first direction Y, and the first direction Y is perpendicular to the substrate 11.

[0145] For example, the thickness d2 of the first modulation part 301 is 55 nm, 57 nm, 59 nm, 60 nm, 61 nm, 62 nm, 64 nm or 65 nm, etc., without limitation.

[0146] By setting the thickness d2 of the first modulation part 301 to range from 55 nm to 65 nm, the first modulation part 301 can adjust the cavity length of the microcavity between the first electrode 12 of the first light emitting device 101 and the transparent reflection layer 40, increase the mutual interference between the light, so that the first light emitting device 101 has a strong light emitting brightness. For the content of the light emitting brightness, please refer to the following description of the light emitting brightness diagram of the first light emitting device 101 of FIG. 15, which will not be described here.

[0147] In some embodiments, as shown in FIG. 13 and FIG. 15, the light-emitting substrate 100 further comprises: a light extraction layer 18, the light extraction layer 18 is located on the side of the transparent reflection layer 40 away from the substrate 11; the light extraction layer 18 comprises: a first light extraction part 181, the first light extraction part 181 is arranged corresponding to the first light-emitting device 101. Wherein, the thickness d3 of the first light extraction part 181 ranges from 85nm to 115nm.

[0148] For example, the thickness d3 of the first light extraction part 181 is 85nm, 90nm, 95nm, 100nm, 105nm, 110nm or 115nm, etc., which is not limited here.

[0149] It should be noted that the difference between the refractive index of the transparent reflection layer 40 and the refractive index of air is large, so that the light will be totally reflected between the transparent reflection layer 40 and the air, resulting in a decrease in the light extraction efficiency of the light-emitting device 10. Therefore, the light extraction layer 18 can be arranged on the side of the transparent reflection layer 40 away from the substrate 11, and the refractive index of the light extraction layer 18 is between the refractive index of the transparent reflection layer 40 and the refractive index of air. In this way, the total reflection of light at the interface between the transparent reflection layer 40 and the light extraction layer 18, and the interface between the light extraction layer 18 and the air can be reduced, which is conducive to light extraction and improves the light extraction efficiency of the light-emitting device 10.

[0150] Therefore, the arrangement of the light extraction layer 18 can improve the front light extraction effect of the light-emitting device 10. Further, by arranging the first light extraction part 181 with a thickness d3 ranging from 85nm to 115nm, the front light extraction of the first light-emitting device 101 can be further increased, so that the first light-emitting device 101 has a stronger light extraction brightness. For details of the light extraction brightness, please refer to the following description of the light extraction brightness diagram of the first light-emitting device 101 in FIG. 15.

[0151] FIG. 15 is a light extraction brightness diagram of the first light-emitting device 101, wherein the abscissa represents the thickness d2 of the first control part 301, and the ordinate represents the thickness d3 of the first light extraction part 181. As shown in FIG. 13, the structure of the first light-emitting device 101 is represented as: the first electrode 12 (ITO / Ag / ITO, 7nm / 100nm / 7nm) / hole injection layer 13 (PEDOT, 25nm) / hole transport layer 14 (PF8Cz, 25nm) / light-emitting layer 15 (QD, 20nm) / electron transport layer 16 (ZnMgO, 50nm) / second electrode 17 (ITO, 50nm) / first control part 301 (d2) / transparent reflection layer 40 (Mg:Ag, 10nm) / first light extraction part 181 (d3).

[0152] As can be seen from FIG. 15, the red region S4 represents that the light emitting brightness of the first light emitting device 101 is about 9000 cd / m2 2 , which is the optimal normal light emitting brightness of the first light emitting device 101. In the region S4, the thickness d2 of the first regulating part 301 ranges from 55 nm to 65 nm, and the thickness d3 of the first light extraction part 181 ranges from 85 nm to 115 nm.

[0153] Therefore, by setting the thickness of the first regulating part 301 ranging from 55 nm to 65 nm and setting the thickness of the first light extraction part 181 ranging from 85 nm to 115 nm, the first light emitting device 101 can have a stronger light emitting brightness.

[0154] In some embodiments, as shown in FIGS. 16 and 17, the first light emitting device 101 further comprises a first hole transport layer 141, which is located between the first electrode 12 and the light emitting layer 15 of the first light emitting device 101, or which is located between the light emitting layer 15 and the second electrode 17 of the first light emitting device 101; wherein the thickness d4 of the first hole transport layer 141 ranges from 20 nm to 30 nm.

[0155] For example, as shown in FIG. 16, the first hole transport layer 141 is located between the first electrode 12 and the light emitting layer 15 of the first light emitting device 101. At this time, the first electrode 12 of the first light emitting device 101 is an anode, and the second electrode 17 of the first light emitting device 101 is a cathode.

[0156] For example, as shown in FIG. 17, the first hole transport layer 141 is located between the light emitting layer 15 and the second electrode 17 of the first light emitting device 101. At this time, the first electrode 12 of the first light emitting device 101 is a cathode, and the second electrode 17 of the first light emitting device 101 is an anode.

[0157] For example, the thickness d4 of the first hole transport layer 141 is 20 nm, 21 nm, 22 nm, 23 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm or 30 nm, etc., which is not limited here.

[0158] By setting the thickness d4 of the first hole transport layer 141 ranging from 20 nm to 30 nm, the hole transport performance of the first light emitting device 101 can be improved, which is conducive to improving the electrical performance of the first light emitting device 101.

[0159] In some embodiments, as shown in FIGS. 18 and 19, the first light-emitting device 101 further comprises: a first electron transport layer 161; the first electron transport layer 161 is located between the first electrode 12 of the first light-emitting device 101 and the light-emitting layer 15 of the first light-emitting device 101, or the first electron transport layer 161 is located between the light-emitting layer 15 of the first light-emitting device 101 and the second electrode 17 of the first light-emitting device 101; wherein the thickness d5 of the first electron transport layer 161 ranges from 30 nm to 70 nm.

[0160] For example, as shown in FIG. 18, the first electron transport layer 161 is located between the first electrode 12 of the first light-emitting device 101 and the light-emitting layer 15 of the first light-emitting device 101. At this time, the first electrode 12 of the first light-emitting device 101 is a cathode, and the second electrode 17 of the first light-emitting device 101 is an anode.

[0161] For example, as shown in FIG. 19, the first electron transport layer 161 is located between the light-emitting layer 15 of the first light-emitting device 101 and the second electrode 17 of the first light-emitting device 101. At this time, the first electrode 12 of the first light-emitting device 101 is an anode, and the second electrode 17 of the first light-emitting device 101 is a cathode.

[0162] For example, the thickness d5 of the first electron transport layer 161 is 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm or 70 nm, etc., which is not limited here.

[0163] By setting the thickness d5 of the first electron transport layer 161 ranging from 30 nm to 70 nm, the electron transport performance of the first light-emitting device 101 can be improved, which is conducive to improving the electrical performance of the first light-emitting device 101.

[0164] In some embodiments, as shown in FIGS. 13 and 20, the first light-emitting device 101 further comprises: a first hole transport layer 141 and a first electron transport layer 161; the first electrode 12 of the first light-emitting device 101, the first hole transport layer 141, the light-emitting layer 15 of the first light-emitting device 101, the first electron transport layer 161 and the second electrode 17 of the first light-emitting device 101 are arranged in a direction away from the substrate 11; or, the first electrode 12 of the first light-emitting device 101, the first electron transport layer 161, the light-emitting layer 15 of the first light-emitting device 101, the first hole transport layer 141 and the second electrode 17 of the first light-emitting device 101 are arranged in a direction away from the substrate 11. Wherein the thickness d4 of the first hole transport layer 141 ranges from 20 nm to 30 nm; the thickness d5 of the first electron transport layer 161 ranges from 30 nm to 70 nm.

[0165] Exemplarily, as shown in FIG. 13, the first electrode 12 of the first light emitting device 101, the first hole transport layer 141, the light emitting layer 15 of the first light emitting device 101, the first electron transport layer 161 and the second electrode 17 of the first light emitting device 101 are arranged in a direction away from the substrate 11. At this time, the first electrode 12 of the first light emitting device 101 is an anode, and the second electrode 17 of the first light emitting device 101 is a cathode.

[0166] Exemplarily, as shown in FIG. 20, the first electrode 12 of the first light emitting device 101, the first electron transport layer 161, the light emitting layer 15 of the first light emitting device 101, the first hole transport layer 141 and the second electrode 17 of the first light emitting device 101 are arranged in a direction away from the substrate 11. At this time, the first electrode 12 of the first light emitting device 101 is a cathode, and the second electrode 17 of the first light emitting device 101 is an anode.

[0167] By setting the thickness d4 of the first hole transport layer 141 in the range of 20 nm to 30 nm and the thickness d5 of the first electron transport layer 161 in the range of 30 nm to 70 nm, the transport performance of holes and electrons of the first light emitting device 101 can be improved, and the balance of electron and hole transport can be improved, which is beneficial to improving the electrical performance of the first light emitting device 101.

[0168] In some embodiments, as shown in FIG. 13 and FIG. 21, the plurality of light emitting devices 10 comprise: a second light emitting device 102, the second light emitting device 102 is configured to emit second color light; the optical regulation layer 30 comprises: a second regulation part 302, the second regulation part 302 is arranged corresponding to the second light emitting device 102; wherein the thickness d6 of the second regulation part 302 ranges from 95 nm to 115 nm.

[0169] Exemplarily, the second color light is configured to be red light.

[0170] Exemplarily, the thickness d6 of the second regulation part 302 is 95 nm, 97 nm, 98 nm, 100 nm, 102 nm, 105 nm, 110 nm or 115 nm, etc., which is not limited here.

[0171] By setting the thickness d6 of the second regulation part 302 in the range of 95 nm to 115 nm, the second regulation part 302 can adjust the cavity length of the microcavity between the first electrode 12 of the second light emitting device 102 and the transparent reflection layer 40, increase the mutual interference between light rays, so that the second light emitting device 102 has stronger light emitting brightness. For details of the light emitting brightness of the second light emitting device 102, please refer to the description of the light emitting brightness diagram of the second light emitting device 102 in FIG. 21 below, which will not be described here.

[0172] In some embodiments, as shown in FIG. 13 and FIG. 21, the light-emitting substrate 100 further comprises: a light extraction layer 18, the light extraction layer 18 is located on the side of the transparent reflective layer 40 away from the substrate 11; the light extraction layer 18 comprises: a second light extraction part 182, the second light extraction part 182 is arranged corresponding to the second light-emitting device 102; wherein the thickness d7 of the second light extraction part 182 ranges from 105 nm to 145 nm.

[0173] For example, the thickness d7 of the second light extraction part 182 is 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm or 145 nm, etc., which is not limited here.

[0174] Through the arrangement of the second light extraction part 182 and the thickness d7 of the second light extraction part 182 ranging from 105 nm to 145 nm, the total reflection of light at the interface between the transparent reflective layer 40 and the second light extraction part 182 and the interface between the second light extraction part 182 and the air can be reduced, which is conducive to light extraction and can increase the front light emission of the second light-emitting device 102, so that the second light-emitting device 102 has stronger light emission brightness. For the content of light emission brightness, please refer to the following introduction of the light emission brightness diagram of the second light-emitting device 102 in FIG. 21.

[0175] FIG. 21 is a light emission brightness diagram of the second light-emitting device 102, wherein the abscissa represents the thickness d6 of the second regulating part 302, and the ordinate represents the thickness d7 of the second light extraction part 182. As shown in FIG. 13, the structure of the second light-emitting device 102 is represented as: the first electrode 12 (ITO / Ag / ITO, 7 nm / 100 nm / 7 nm) / hole injection layer 13 (PEDOT, 25 nm) / hole transport layer 14 (PF8Cz, 25 nm) / light-emitting layer 15 (QD, 20 nm) / electron transport layer 16 (ZnMgO, 50 nm) / second electrode 17 (ITO, 50 nm) / second regulating part 302 (d6) / transparent reflective layer 40 (Mg:Ag, 10 nm) / second light extraction part 182 (d7).

[0176] As can be seen from FIG. 21, the red area S5 represents that the light emission brightness of the second light-emitting device 102 is about 3500 cd / m 2 , which is the optimal front light emission brightness of the second light-emitting device 102. In the area S5, the thickness d6 of the second regulating part 302 ranges from 95 nm to 115 nm, and the thickness d7 of the second light extraction part 182 ranges from 105 nm to 145 nm.

[0177] Therefore, by setting the thickness d6 of the second regulating portion 302 in the range of 95nm-115nm and the thickness d7 of the second light extraction portion 182 in the range of 105nm-145nm, the second light emitting device 102 can have a stronger light extraction brightness.

[0178] In some embodiments, as shown in FIGS. 16 and 17, the second light emitting device 102 further comprises a second hole transport layer 142; the second hole transport layer 142 is located between the first electrode 12 of the second light emitting device 102 and the light emitting layer 15 of the second light emitting device 102, or the second hole transport layer 142 is located between the light emitting layer 15 of the second light emitting device 102 and the second electrode 17 of the second light emitting device 102; wherein the thickness d8 of the second hole transport layer 142 ranges from 20nm to 30nm.

[0179] For example, as shown in FIG. 16, the second hole transport layer 142 is located between the first electrode 12 of the second light emitting device 102 and the light emitting layer 15 of the second light emitting device 102. At this time, the first electrode 12 of the second light emitting device 102 is an anode, and the second electrode 17 of the second light emitting device 102 is a cathode.

[0180] For example, as shown in FIG. 17, the second hole transport layer 142 is located between the light emitting layer 15 of the second light emitting device 102 and the second electrode 17 of the second light emitting device 102. At this time, the first electrode 12 of the second light emitting device 102 is a cathode, and the second electrode 17 of the second light emitting device 102 is an anode.

[0181] For example, the thickness d8 of the second hole transport layer 142 is 20nm, 21nm, 22nm, 23nm, 25nm, 26nm, 27nm, 28nm, 29nm or 30nm, etc., which is not limited here.

[0182] By setting the thickness d8 of the second hole transport layer 142 in the range of 20nm-30nm, the hole transport performance of the second light emitting device 102 can be improved, which is conducive to improving the electrical performance of the second light emitting device 102.

[0183] In some embodiments, as shown in FIGS. 18 and 19, the second light emitting device 102 further comprises a second electron transport layer 162; the second electron transport layer 162 is located between the first electrode 12 of the second light emitting device 102 and the light emitting layer 15 of the second light emitting device 102; or, the second electron transport layer 162 is located between the light emitting layer 15 of the second light emitting device 102 and the second electrode 17 of the second light emitting device 102; wherein the thickness d9 of the second electron transport layer 162 ranges from 30nm to 70nm.

[0184] Exemplarily, as shown in FIG. 18, the second electron transport layer 162 is located between the first electrode 12 of the second light emitting device 102 and the light emitting layer 15 of the second light emitting device 102. At this time, the first electrode 12 of the second light emitting device 102 is a cathode, and the second electrode 17 of the second light emitting device 102 is an anode.

[0185] Exemplarily, as shown in FIG. 19, the second electron transport layer 162 is located between the light emitting layer 15 of the second light emitting device 102 and the second electrode 17 of the second light emitting device 102. At this time, the first electrode 12 of the second light emitting device 102 is an anode, and the second electrode 17 of the second light emitting device 102 is a cathode.

[0186] Exemplarily, the thickness d9 of the second electron transport layer 162 is 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, or 70 nm, etc., which is not limited herein.

[0187] By setting the thickness d9 of the second electron transport layer 162 in the range of 30 nm to 70 nm, the electron transport performance of the second light emitting device 102 can be improved, which is conducive to improving the electrical performance of the second light emitting device 102.

[0188] In some embodiments, as shown in FIG. 13 and FIG. 20, the second light emitting device 102 further comprises: a second hole transport layer 142 and a second electron transport layer 162; the first electrode 12 of the second light emitting device 102, the second hole transport layer 142, the light emitting layer 15 of the second light emitting device 102, the second electron transport layer 162, and the second electrode 17 of the second light emitting device 102 are arranged in a direction away from the substrate 11; or, the first electrode 12 of the second light emitting device 102, the second electron transport layer 162, the light emitting layer 15 of the second light emitting device 102, the second hole transport layer 142, and the second electrode 17 of the second light emitting device 102 are arranged in a direction away from the substrate 11; wherein the thickness d8 of the second hole transport layer 142 ranges from 20 nm to 30 nm; and the thickness d9 of the second electron transport layer 162 ranges from 30 nm to 70 nm.

[0189] Exemplarily, as shown in FIG. 13, the first electrode 12 of the second light emitting device 102, the second hole transport layer 142, the light emitting layer 15 of the second light emitting device 102, the second electron transport layer 162, and the second electrode 17 of the second light emitting device 102 are arranged in a direction away from the substrate 11. At this time, the first electrode 12 of the second light emitting device 102 is an anode, and the second electrode 17 of the second light emitting device 102 is a cathode.

[0190] Exemplarily, as shown in FIG. 20, the first electrode 12 of the second light emitting device 102, the second electron transport layer 162, the light emitting layer 15 of the second light emitting device 102, the second hole transport layer 142 and the second electrode 17 of the second light emitting device 102 are arranged in a direction away from the substrate 11. At this time, the first electrode 12 of the second light emitting device 102 is a cathode, and the second electrode 17 of the second light emitting device 102 is an anode.

[0191] By arranging the thickness d8 of the second hole transport layer 142 in the range of 20 nm to 30 nm and arranging the thickness d9 of the second electron transport layer 162 in the range of 30 nm to 70 nm, the transport performance of holes and electrons of the second light emitting device 102 can be improved, and the balance of electron and hole transport can be improved, which is beneficial to improving the electrical performance of the second light emitting device 102.

[0192] In some embodiments, as shown in FIG. 13 and FIG. 22, the plurality of light emitting devices 10 comprises: a third light emitting device 103, the third light emitting device 103 is configured to emit third color light; the optical regulation layer 30 comprises: a third regulation part 303, the third regulation part 303 is arranged corresponding to the third light emitting device 103; wherein the thickness d10 of the third regulation part 303 ranges from 5 nm to 15 nm.

[0193] Exemplarily, the third color light is configured as blue light.

[0194] Exemplarily, the thickness d10 of the third regulation part 303 is 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 12 nm or 15 nm, etc., which is not limited here.

[0195] By arranging the thickness d10 of the third regulation part 303 in the range of 5 nm to 15 nm, the third regulation part 303 can adjust the cavity length of the microcavity between the first electrode 12 of the third light emitting device 103 and the transparent reflection layer 40, increase the mutual interference between light, so that the third light emitting device 103 has stronger light emitting brightness. For the content of light emitting brightness, please refer to the following introduction of the light emitting brightness diagram of the third light emitting device 103 in FIG. 22, which will not be described here.

[0196] In some embodiments, as shown in FIG. 13 and FIG. 22, the light emitting substrate 100 further comprises: a light extraction layer 18, the light extraction layer 18 is located on the side of the transparent reflection layer 40 away from the substrate 11; the light extraction layer 18 comprises: a third light extraction part 183, the third light extraction part 183 is arranged corresponding to the third light emitting device 103; wherein the thickness d11 of the third light extraction part 183 ranges from 55 nm to 85 nm.

[0197] Exemplarily, the thickness d11 of the third light extraction part 183 is 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm or 85 nm, etc., which is not limited herein.

[0198] By setting the third light extraction part 183 and the thickness d11 of the third light extraction part 183 in the range of 55 nm to 85 nm, the total reflection of light at the interface between the transparent reflection layer 40 and the third light extraction part 183 and the interface between the third light extraction part 183 and air can be reduced, which is beneficial to light extraction and can increase the front light emission of the third light emitting device 103, so that the third light emitting device 103 has stronger light emission brightness. For details of the light emission brightness, refer to the description of the light emission brightness diagram of the third light emitting device 103 in FIG. 22 below.

[0199] FIG. 22 is a light emission brightness diagram of the third light emitting device 103, wherein the abscissa represents the thickness d10 of the third control part 303, and the ordinate represents the thickness d11 of the third light extraction part 183. As shown in FIG. 13, the structure of the third light emitting device 103 is represented as: the first electrode 12 (ITO / Ag / ITO, 7 nm / 100 nm / 7 nm) / hole injection layer 13 (PEDOT, 25 nm) / hole transport layer 14 (PF8Cz, 25 nm) / light emitting layer 15 (QD, 20 nm) / electron transport layer 16 (ZnMgO, 50 nm) / second electrode 17 (ITO, 50 nm) / third control part 303 (d10) / transparent reflection layer 40 (Mg:Ag, 10 nm) / third light extraction part 183 (d11).

[0200] As can be seen from FIG. 22, the red region S6 represents that the light emission brightness of the third light emitting device 103 is about 170 cd / m 2 , which is the optimal front light emission brightness of the third light emitting device 103. In the region S6, the thickness d10 of the third control part 303 is in the range of 5 nm to 15 nm, and the thickness d11 of the third light extraction part 183 is in the range of 55 nm to 85 nm.

[0201] Therefore, by setting the thickness d10 of the third control part 303 in the range of 5 nm to 15 nm and setting the thickness d11 of the third light extraction part 183 in the range of 55 nm to 85 nm, the third light emitting device 103 can have stronger light emission brightness.

[0202] In some embodiments, as shown in FIGS. 16 and 17, the third light-emitting device 103 further comprises a third hole transport layer 143; the third hole transport layer 143 is located between the first electrode 12 of the third light-emitting device 103 and the light-emitting layer 15 of the third light-emitting device 103; or, the third hole transport layer 143 is located between the light-emitting layer 15 of the third light-emitting device 103 and the second electrode 17 of the third light-emitting device 103; wherein the thickness d12 of the third hole transport layer 143 ranges from 20 nm to 40 nm.

[0203] For example, as shown in FIG. 16, the third hole transport layer 143 is located between the first electrode 12 of the third light-emitting device 103 and the light-emitting layer 15 of the third light-emitting device 103. At this time, the first electrode 12 of the third light-emitting device 103 is an anode, and the second electrode 17 of the third light-emitting device 103 is a cathode.

[0204] For example, as shown in FIG. 17, the third hole transport layer 143 is located between the light-emitting layer 15 of the third light-emitting device 103 and the second electrode 17 of the third light-emitting device 103. At this time, the first electrode 12 of the third light-emitting device 103 is a cathode, and the second electrode 17 of the third light-emitting device 103 is an anode.

[0205] For example, the thickness d12 of the third hole transport layer 143 is 20 nm, 23 nm, 25 nm, 27 nm, 30 nm, 32 nm, 35 nm, 37 nm, 39 nm, or 40 nm, etc., which is not limited here.

[0206] By setting the thickness d12 of the third hole transport layer 143 ranging from 20 nm to 40 nm, the hole transport performance of the third light-emitting device 103 can be improved, which is conducive to improving the electrical performance of the third light-emitting device 103.

[0207] In some embodiments, as shown in FIGS. 18 and 19, the third light-emitting device 103 further comprises a third electron transport layer 163; the third electron transport layer 163 is located between the first electrode 12 of the third light-emitting device 103 and the light-emitting layer 15 of the third light-emitting device 103; or, the third electron transport layer 163 is located between the light-emitting layer 15 of the third light-emitting device 103 and the second electrode 17 of the third light-emitting device 103; wherein the thickness d13 of the third electron transport layer 163 ranges from 40 nm to 80 nm.

[0208] For example, as shown in FIG. 18, the third electron transport layer 163 is located between the first electrode 12 of the third light-emitting device 103 and the light-emitting layer 15 of the third light-emitting device 103. At this time, the first electrode 12 of the third light-emitting device 103 is a cathode, and the second electrode 17 of the third light-emitting device 103 is an anode.

[0209] Exemplarily, as shown in FIG. 19, the third electron transport layer 163 is located between the light-emitting layer 15 of the third light-emitting device 103 and the second electrode 17 of the third light-emitting device 103. At this time, the first electrode 12 of the third light-emitting device 103 is an anode, and the second electrode 17 of the third light-emitting device 103 is a cathode.

[0210] Exemplarily, the thickness d13 of the third electron transport layer 163 is 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, or 80 nm, etc., which is not limited herein.

[0211] By setting the thickness d13 of the third electron transport layer 163 in the range of 40 nm to 80 nm, the electron transport performance of the third light-emitting device 103 can be improved, which is conducive to improving the electrical performance of the third light-emitting device 103.

[0212] In some embodiments, as shown in FIG. 13 and FIG. 20, the third light-emitting device 103 further comprises: a third hole transport layer 143 and a third electron transport layer 163; the first electrode 12 of the third light-emitting device 103, the third hole transport layer 143, the light-emitting layer 15 of the third light-emitting device 103, the third electron transport layer 163, and the second electrode 17 of the third light-emitting device 103 are arranged in a direction away from the substrate 11; or, the first electrode 12 of the third light-emitting device 103, the third electron transport layer 163, the light-emitting layer 15 of the third light-emitting device 103, the third hole transport layer 143, and the second electrode 17 of the third light-emitting device 103 are arranged in a direction away from the substrate 11; wherein the thickness d12 of the third hole transport layer 143 ranges from 20 nm to 40 nm; and the thickness d13 of the third electron transport layer 163 ranges from 40 nm to 80 nm.

[0213] Exemplarily, as shown in FIG. 13, the first electrode 12 of the third light-emitting device 103, the third hole transport layer 143, the light-emitting layer 15 of the third light-emitting device 103, the third electron transport layer 163, and the second electrode 17 of the third light-emitting device 103 are arranged in a direction away from the substrate 11. At this time, the first electrode 12 of the third light-emitting device 103 is an anode, and the second electrode 17 of the third light-emitting device 103 is a cathode.

[0214] Exemplarily, as shown in FIG. 20, the first electrode 12 of the third light-emitting device 103, the third electron transport layer 163, the light-emitting layer 15 of the third light-emitting device 103, the third hole transport layer 143, and the second electrode 17 of the third light-emitting device 103 are arranged in a direction away from the substrate 11. At this time, the first electrode 12 of the third light-emitting device 103 is a cathode, and the second electrode 17 of the third light-emitting device 103 is an anode.

[0215] By setting the thickness d12 of the third hole transport layer 143 in the range of 20-40 nm and the thickness d13 of the third electron transport layer 163 in the range of 40-80 nm, the transport performance of holes and electrons of the third light emitting device 103 can be improved, and the balance of electron and hole transport can be improved, which is beneficial to improving the electrical performance of the third light emitting device 103.

[0216] In some embodiments, as shown in FIG. 13, the light emitting device 10 further comprises a hole injection layer 13, which is located on the side of the hole transport layer 14 away from the light emitting layer 15.

[0217] By setting the hole injection layer 13, the hole injection capability of the light emitting device 10 can be improved, and the electrical performance of the light emitting device 10 can be improved.

[0218] For example, the electron blocking layer is located between the hole transport layer 14 and the light emitting layer 15, the hole blocking layer is located on the side of the electron transport layer 16 close to the light emitting layer 15, and the electron injection layer is located on the side of the electron transport layer 16 away from the light emitting layer 15.

[0219] By setting the electron injection layer, the electron injection capability of the light emitting device 10 can be improved, and by setting the electron blocking layer and the hole blocking layer, the balance of electron and hole transport of the light emitting device 10 can be further improved, which is beneficial to improving the electrical performance of the light emitting device 10.

[0220] As shown in FIG. 1, some embodiments of the present disclosure provide a light emitting apparatus 1000 comprising the light emitting substrate 100 as described in any of the above embodiments.

[0221] Of course, the light emitting apparatus 1000 can further comprise other components, for example, it can comprise a driving chip for providing an electrical signal to the light emitting substrate 100 to drive the light emitting substrate 100 to emit light, which can be a circuit board and / or an integrated circuit (IC).

[0222] In some embodiments, the light emitting apparatus 1000 can be a lighting apparatus, at this time, the light emitting apparatus 1000 serves as a light source to realize the lighting function. For example, the light emitting apparatus 1000 can be a backlight module in a liquid crystal display apparatus, a lamp for internal or external lighting, or various signal lights, etc.

[0223] In other embodiments, the light emitting apparatus 1000 can be a display apparatus, at this time, the light emitting substrate 100 is a display substrate for realizing the display image (i.e. picture) function.

[0224] The above merely provides the specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto, any person skilled in the art can think of the changes or replacements within the technical range disclosed by the present disclosure, which should be covered in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A light-emitting substrate, comprising: a substrate; a plurality of light-emitting devices on one side of the substrate, each of the light-emitting devices comprising a first electrode, a light-emitting layer and a second electrode stacked in order, the first electrode being closer to the substrate than the second electrode; the first electrode comprising a reflective electrode, and the second electrode comprising a transparent electrode; wherein at least one of the light-emitting devices comprises an optical adjustment structure, the optical adjustment structure comprising an optical adjustment layer on a side of the second electrode distal to the substrate, and a transparent reflective layer on a side of the optical adjustment layer distal to the substrate; the optical adjustment layer having an electrical conductivity less than that of the transparent reflective layer, and the optical adjustment layer having a thickness different from that of the transparent reflective layer.

2. The light-emitting substrate according to claim 1, wherein The optical adjustment layer has a light transmittance greater than or equal to that of the transparent reflective layer, and the light transmittance of the optical adjustment layer is greater than or equal to 90%.

3. The light-emitting substrate according to claim 1 or 2, wherein The extinction coefficient of the optical control layer ranges from 0.001 m -1 ~ 0.005 m -1 .

4. The light emitting substrate according to any one of claims 1 to 3, wherein The material of the optical adjustment layer is selected from at least one of 4,4,4,-tris(carbazol-9-yl)triphenylamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, 4,4'-bis(9-carbazol) biphenyl, silicon oxide, silicon nitride and silicon oxynitride.

5. The light emitting substrate of any of claims 1-4, wherein, The plurality of light-emitting devices comprises a first light-emitting device configured to emit light of a first color; the optical adjustment layer comprises a first adjustment portion corresponding to the first light-emitting device; wherein the thickness of the first adjustment portion is in a range of 55 nm to 65 nm.

6. The light-emitting substrate of claim 5, further comprising: a light extraction layer on a side of the transparent reflective layer distal to the substrate; the light extraction layer comprises a first light extraction portion corresponding to the first light-emitting device; wherein the thickness of the first light extraction portion is in a range of 85 nm to 115 nm.

7. The light-emitting substrate according to claim 5 or 6, wherein The first light-emitting device further comprises a first hole transport layer; the first hole transport layer is between the first electrode and the light-emitting layer of the first light-emitting device, or the first hole transport layer is between the light-emitting layer and the second electrode of the first light-emitting device; wherein the thickness of the first hole transport layer is in a range of 20 nm to 30 nm.

8. The light-emitting substrate according to claim 5 or 6, wherein The first light-emitting device further comprises a first electron transport layer; the first electron transport layer is between the first electrode and the light-emitting layer of the first light-emitting device, or the first electron transport layer is between the light-emitting layer and the second electrode of the first light-emitting device; wherein the thickness of the first electron transport layer is in a range of 30 nm to 70 nm.

9. The light-emitting substrate according to claim 5 or 6, wherein The first light-emitting device further comprises a first hole transport layer and a first electron transport layer; The first electrode, the first hole transport layer, the light-emitting layer of the first light-emitting device, the first electron transport layer and the second electrode of the first light-emitting device are arranged in a direction away from the substrate; or the first electrode, the first electron transport layer, the light-emitting layer of the first light-emitting device, the first hole transport layer and the second electrode of the first light-emitting device are arranged in a direction away from the substrate. The thickness of the first hole transport layer ranges from 20 nm to 30 nm, and the thickness of the first electron transport layer ranges from 30 nm to 70 nm.

10. The light emitting substrate of any of claims 1-9, wherein, The plurality of light-emitting devices comprises a second light-emitting device configured to emit second color light; The optical regulation layer comprises a second regulation part arranged corresponding to the second light-emitting device; The thickness of the second regulation part ranges from 95 nm to 115 nm.

11. The light-emitting substrate of claim 10, further comprising: The light extraction layer comprises a second light extraction part arranged corresponding to the second light-emitting device; The thickness of the second light extraction part ranges from 105 nm to 145 nm.

12. The light-emitting substrate according to claim 10 or 11, wherein The second light-emitting device further comprises a second hole transport layer; the second hole transport layer is located between the first electrode of the second light-emitting device and the light-emitting layer of the second light-emitting device, or the second hole transport layer is located between the light-emitting layer of the second light-emitting device and the second electrode of the second light-emitting device; The thickness of the second hole transport layer ranges from 20 nm to 30 nm.

13. The light-emitting substrate according to claim 10 or 11, wherein The second light-emitting device further comprises a second electron transport layer; the second electron transport layer is located between the first electrode of the second light-emitting device and the light-emitting layer of the second light-emitting device, or the second electron transport layer is located between the light-emitting layer of the second light-emitting device and the second electrode of the second light-emitting device; The thickness of the second electron transport layer ranges from 30 nm to 70 nm.

14. The light-emitting substrate according to claim 10 or 11, wherein, The second light-emitting device further comprises a second hole transport layer and a second electron transport layer; The first electrode, the second hole transport layer, the light-emitting layer of the second light-emitting device, the second electron transport layer and the second electrode of the second light-emitting device are arranged in a direction away from the substrate; or the first electrode, the second electron transport layer, the light-emitting layer of the second light-emitting device, the second hole transport layer and the second electrode of the second light-emitting device are arranged in a direction away from the substrate; The thickness of the second hole transport layer ranges from 20 nm to 30 nm, and the thickness of the second electron transport layer ranges from 30 nm to 70 nm.

15. The light emitting substrate of any of claims 1-14, wherein, The plurality of light-emitting devices comprises a third light-emitting device configured to emit third color light; The optical regulation layer comprises a third regulation part arranged corresponding to the third light-emitting device; The thickness of the third regulation part ranges from 5 nm to 15 nm.

16. The light-emitting substrate of claim 14, further comprising: The light extraction layer comprises a third light extraction part arranged corresponding to the third light-emitting device; The thickness of the third light extraction part is in a range of 55 nm to 85 nm.

17. The light-emitting substrate according to claim 15 or 16, wherein The third light emitting device further comprises a third hole transport layer, which is located between the first electrode of the third light emitting device and the light emitting layer of the third light emitting device, or which is located between the light emitting layer of the third light emitting device and the second electrode of the third light emitting device. The thickness of the third hole transport layer is in a range of 20 nm to 40 nm.

18. The light-emitting substrate according to claim 15 or 16, wherein, The third light emitting device further comprises a third electron transport layer, which is located between the first electrode of the third light emitting device and the light emitting layer of the third light emitting device, or which is located between the light emitting layer of the third light emitting device and the second electrode of the third light emitting device. The thickness of the third electron transport layer is in a range of 40 nm to 80 nm.

19. The light-emitting substrate according to claim 15 or 16, wherein, The third light emitting device further comprises a third hole transport layer and a third electron transport layer. The first electrode of the third light emitting device, the third hole transport layer, the light emitting layer of the third light emitting device, the third electron transport layer and the second electrode of the third light emitting device are arranged in a direction away from the substrate, or the first electrode of the third light emitting device, the third electron transport layer, the light emitting layer of the third light emitting device, the third hole transport layer and the second electrode of the third light emitting device are arranged in a direction away from the substrate. The thickness of the third hole transport layer is in a range of 20 nm to 40 nm, and the thickness of the third electron transport layer is in a range of 40 nm to 80 nm.

20. The light emitting substrate according to any one of claims 1 to 19, wherein, The light transmittance of the transparent reflective layer is in a range of greater than or equal to 60% and less than or equal to 90%, and / or The light transmittance of the second electrode is in a range of greater than or equal to 85% in a wavelength range of 400 nm to 700 nm.

21. The light emitting substrate according to claim 20, wherein, The material of the transparent reflective layer and the material of the second electrode are independently selected from at least one of gold, silver, magnesium-silver alloy, molybdenum oxide, indium tin oxide, indium zinc oxide, indium tin zinc oxide, indium gallium oxide and aluminum-doped zinc oxide.

22. A light emitting device comprising: The light emitting substrate according to any one of claims 1 to 21; Further comprising a driving chip for driving the light emitting substrate to emit light. The light emitting substrate according to any one of claims 1 to 21;

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