CN117794306A

CN117794306A - Light-emitting device, preparation method thereof and display device

Info

Publication number: CN117794306A
Application number: CN202211147962.0A
Authority: CN
Inventors: 贾聪聪; 董婷
Original assignee: Guangdong Juhua Printing Display Technology Co Ltd
Current assignee: Guangdong Juhua Printing Display Technology Co Ltd
Priority date: 2022-09-19
Filing date: 2022-09-19
Publication date: 2024-03-29

Abstract

The application relates to a light-emitting device, which comprises a bottom electrode, a pixel unit and a top electrode, wherein the bottom electrode, the pixel unit and the top electrode are arranged in a stacked mode, and each pixel unit comprises a red sub-pixel unit, a green sub-pixel unit and a blue sub-pixel unit; the red sub-pixel unit corresponds to a first optical path, the blue sub-pixel unit corresponds to a second optical path, and the first optical path is smaller than the second optical path; the green sub-pixel unit corresponds to a third optical path, which is smaller than the second optical path. The application also relates to a preparation method of the light-emitting device and a display device. According to the method, the red sub-pixel unit corresponds to the first optical path, the green sub-pixel unit corresponds to the third optical path, the blue sub-pixel unit corresponds to the second optical path, and the first optical path and the third optical path are smaller than the second optical path, so that microcavity effects corresponding to the red sub-pixel unit and the green sub-pixel unit are weakened, the brightness attenuation degree difference of the three is reduced under a large viewing angle, and the brightness attenuation speed of white light formed by mixing red light, green light and blue light is reduced under the large viewing angle.

Description

Light-emitting device, preparation method thereof and display device

Technical Field

The application relates to the technical field of display, and in particular relates to a light emitting device, a preparation method thereof and a display device.

Background

An Organic Light-Emitting Diode (OLED) emits Light by injection of carriers and recombination of released energy, and its Light emission intensity is proportional to the injected current. OLEDs are lighter and thinner than conventional Liquid Crystal Display (LCD) devices, and have advantages of wider viewing angle, faster response speed, richer colors, better contrast ratio, and flexible display realization, and thus have received much attention.

For OLED products, a positive viewing angle or a viewing angle close to the positive viewing angle, which refers to the corresponding viewing angle when facing the screen, is generally referred to as a small viewing angle; the viewing angle when the screen is side-to-side is referred to as a large viewing angle, and a normal viewing angle is generally 0 ° and the large viewing angle is 40 ° to 70 °. In the current OLED products, the optical paths corresponding to the red sub-pixel unit, the green sub-pixel unit and the blue sub-pixel unit are the same, so that when an observer looks at the OLED products (such as a screen and a television) in a side view, especially when the observer looks at the OLED products at a large viewing angle, the problems that the brightness of the OLED products is low and the brightness of white light is attenuated too fast often occur, and the experience is affected.

Disclosure of Invention

At least one embodiment of the application provides a light emitting device, a preparation method thereof and a display device, which are used for solving the problems that the light emitting device in the prior art has low brightness or the white light brightness decay too fast under a large viewing angle.

In order to solve the above technical problems, at least one embodiment of the present application provides a light emitting device, which adopts the following technical scheme:

a light emitting device comprising a bottom electrode, a pixel unit and a top electrode which are stacked, wherein the pixel unit comprises a red sub-pixel unit, a green sub-pixel unit and a blue sub-pixel unit;

the red sub-pixel unit corresponds to a first optical path, the blue sub-pixel unit corresponds to a second optical path, and the first optical path is smaller than the second optical path;

the green sub-pixel unit corresponds to a third optical path, which is smaller than the second optical path.

In the light emitting device provided in at least one embodiment of the present application, the red sub-pixel unit, the green sub-pixel unit, and the blue sub-pixel unit include pixel functional layers, and the thickness of the pixel functional layer in the red sub-pixel unit and/or the thickness of the pixel functional layer in the green sub-pixel unit are smaller than the thickness of the pixel functional layer in the blue sub-pixel unit.

In the light emitting device provided in at least one embodiment of the present application, the thickness of the pixel functional layer in the red subpixel unit is 110 to 140 nanometers; optionally, the thickness of the pixel functional layer in the red sub-pixel unit is 110 to 135 nm, 110 to 130 nm, 110 to 125 nm, 110 to 120 nm, 110 to 115 nm, 115 to 140 nm, 115 to 135 nm, 115 to 130 nm, 115 to 125 nm, 115 to 120 nm, 120 to 140 nm, 120 to 135 nm, 120 to 130 nm, 120 to 125 nm, 125 to 140 nm, 125 to 135 nm, 125 to 130 nm, 130 to 140 nm, 130 to 135 nm, 135 to 140 nm; and/or the number of the groups of groups,

The thickness of the pixel functional layer in the green sub-pixel unit is 70-100 nanometers; optionally, the thickness of the pixel functional layer in the green sub-pixel unit is 70 to 95 nm, 70 to 90 nm, 70 to 85 nm, 70 to 80 nm, 70 to 75 nm, 75 to 100 nm, 75 to 95 nm, 75 to 90 nm, 75 to 85 nm, 75 to 80 nm, 80 to 100 nm, 80 to 95 nm, 80 to 90 nm, 80 to 85 nm, 85 to 100 nm, 85 to 95 nm, 85 to 90 nm, 90 to 100 nm, 95 to 100 nm; and/or the number of the groups of groups,

the thickness of the pixel functional layer in the blue sub-pixel unit is 180-220 nanometers; optionally, the thickness of the pixel functional layer in the blue sub-pixel unit is 180 to 220 nm, 180 to 215 nm, 180 to 210 nm, 180 to 205 nm, 180 to 200 nm, 180 to 195 nm, 180 to 190 nm, 180 to 185 nm, 185 to 220 nm, 185 to 215 nm, 185 to 210 nm, 185 to 205 nm, 185 to 200 nm, 185 to 195 nm, 185 to 190 nm, 190 to 220 nm, 190 to 215 nm, 190 to 210 nm, 190 to 205 nm, 190 to 200 nm, 190 to 195 nm, 195 to 220 nm, 195 to 215 nm, 195 to 210 nm, 195 to 205 nm, 195 to 200 nm, 200 to 220 nm, 200 to 215 nm, 200 to 205 nm, 205 to 220 nm, 205 to 215 nm, 205 to 210 nm, 210 to 220 nm, 210 to 215 nm, 215 to 220 nm.

In the light emitting device provided in at least one embodiment of the present application, the pixel functional layer includes a light emitting layer, a first optical path adjusting layer disposed between the top electrode and the light emitting layer, and/or a second optical path adjusting layer disposed between the bottom electrode and the light emitting layer;

the thickness of the first optical path regulating layer in the red sub-pixel unit is smaller than that of the first optical path regulating layer in the blue sub-pixel unit; and/or the thickness of the first optical path regulating layer in the green sub-pixel unit is smaller than the thickness of the first optical path regulating layer in the blue sub-pixel unit; and/or the thickness of the second optical path regulating layer in the red sub-pixel unit is smaller than the thickness of the second optical path regulating layer in the blue sub-pixel unit; and/or the thickness of the second optical path regulating layer in the green sub-pixel unit is smaller than that of the second optical path regulating layer in the blue sub-pixel unit.

In the light emitting device provided in at least one embodiment of the present application, the first optical path adjustment layer in the red sub-pixel unit, the first optical path adjustment layer in the green sub-pixel unit, and the first optical path adjustment layer in the blue sub-pixel unit have the same formation material; and/or the second optical path regulating layer in the red sub-pixel unit, the second optical path regulating layer in the green sub-pixel unit and the second optical path regulating layer in the blue sub-pixel unit are formed by the same material.

In the light emitting device provided in at least one embodiment of the present application, the light emitting layer is a quantum dot light emitting layer or an organic light emitting layer, and a material of the quantum dot light emitting layer includes at least one of quantum dots with a single structure and quantum dots with a core-shell structure;

the material of the single-structure quantum dot is selected from at least one of II-VI compound, IV-VI compound, III-V compound and I-III-VI compound, wherein the II-VI compound is selected from at least one of CdS, cdSe, cdTe, znS, znSe, znTe, znO, hgS, hgSe, hgTe, cdSeS, cdSeTe, cdSTe, znSeS, znSeTe, znSTe, hgSeS, hgSeTe, hgSTe, cdZnS, cdZnSe, cdZnTe, cdHgS, cdHgSe, cdHgTe, hgZnS, hgZnSe, hgZnTe, cdZnSeS, cdZnSeTe, cdZnSTe, cdHgSeS, cdHgSeTe, cdHgSTe, hgZnSeS, hgZnSeTe and HgZnSTe, the IV-VI compound is selected from at least one of SnS, snSe, snTe, pbS, pbSe, pbTe, snSeS, snSeTe, snSTe, pbSeS, pbSeTe, pbSTe, snPbS, snPbSe, snPbTe, snPbSSe, snPbSeTe and SnPbSTe, the III-V compound is selected from at least one of GaN, gaP, gaAs, gaSb, alN, alP, alAs, alSb, inN, inP, inAs, inSb, gaNP, gaNAs, gaNSb, gaPAs, gaPSb, alNP, alNAs, alNSb, alPAs, alPSb, inNP, inNAs, inNSb, inPAs, inPSb, gaAlNP, gaAlNAs, gaAlNSb, gaAlPAs, gaAlPSb, gaInNP, gaInNAs, gaInNSb, gaInPAs, gaInPSb, inAlNP, inAlNAs, inAlNSb, inAlPAs or InAlPSb, and the I-III-VI compound is selected from at least one of CuInS2, cuInSe2 and AgInS 2; and/or the number of the groups of groups,

The core of the quantum dot with the core-shell structure comprises any one of the quantum dots with the single structure, and the shell material of the quantum dot with the core-shell structure comprises CdS, cdTe, cdSeTe, cdZnSe, cdZnS, cdSeS, znSe, znSeS, znS and at least one of the quantum dots with the single structure; and/or the number of the groups of groups,

the material of the organic light emitting layer comprises at least one of 4,4' -bis (N-carbazole) -1,1' -biphenyl, tris [2- (p-tolyl) pyridine-C2, N) iridium (III), 4' -tris (carbazole-9-yl) triphenylamine, tris [2- (p-tolyl) pyridine-C2, N) iridium, diaryl anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and derivatives thereof, poly-p-benzene and derivatives thereof, polythiophene and derivatives thereof, polyfluorene and derivatives thereof.

In the light emitting device provided in at least one embodiment of the present application, the first optical path adjustment layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer sequentially stacked between the bottom electrode and the light emitting layer;

the material of at least one of the hole transport layer, the hole injection layer, and the electron blocking layer includes at least one of TFB, cuPc, PVK, poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT: PSS, TAPC, MCC, F4-TCNQ, HAT-CN, 4' -tris (N-3-methylphenyl-N-phenylamino) triphenylamine, polyaniline, a transition metal oxide, a transition metal sulfide, a transition metal tin compound, doped graphene, undoped graphene, and C60.

In the light emitting device provided in at least one embodiment of the present application, the second optical path adjustment layer includes at least one of a hole blocking layer, an electron transport layer, and an electron injection layer sequentially stacked between the light emitting layer and the top electrode;

the material of the electron transport layer and/or the electron injection layer comprises an inorganic material and/or an organic material; the inorganic material is selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, titanium lithium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, zinc lithium oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc stannate, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, barium titanate and lithium fluoride, and the doped element comprises one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium and gadolinium; the organic material is selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene compounds and hydroxyquinoline compounds; and/or the number of the groups of groups,

the material of the hole blocking layer is one or more selected from aromatic compounds, carbazole compounds, DPEPO and TPDI.

In the light emitting device provided in at least one embodiment of the present application, the bottom electrode and/or the top electrode is a common electrode or a non-common electrode shared by the red sub-pixel unit, the green sub-pixel unit, and the blue sub-pixel unit.

In the light emitting device provided in at least one embodiment of the present application, the material of the top electrode and/or the bottom electrode includes one or more of a metal, a carbon material, and a metal oxide, and the metal includes one or more of Al, ag, cu, mo, au, ba, ca, yb and Mg; the carbon material comprises one or more of graphite, carbon nanotubes, graphene and carbon fibers; the metal oxide comprises one or more of doped or undoped metal oxide, ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, or a composite electrode comprising one or more of AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/Al/ITO, znO/Ag/ZnO, znO/Al/ZnO, znS/Ag/ZnS, znS/Al/ZnS, tiO2/Ag/TiO2 and TiO2/Al/TiO2, wherein the metal is sandwiched between the doped or undoped transparent metal oxide.

In order to solve the above technical problems, at least one embodiment of the present application provides a method for manufacturing a light emitting device, which adopts the following technical scheme:

A method of manufacturing a light emitting device, comprising the steps of:

providing a substrate, and forming a bottom electrode on the substrate;

forming a pixel unit on the bottom electrode, wherein the pixel unit comprises a red sub-pixel unit, a green sub-pixel unit and a blue sub-pixel unit, the red sub-pixel unit corresponds to a first optical path, the blue sub-pixel unit corresponds to a second optical path, and the first optical path is smaller than the second optical path; the green sub-pixel unit corresponds to a third optical path, which is smaller than the second optical path;

and forming a top electrode on the pixel unit to obtain the light-emitting device.

In order to solve the above technical problems, at least one embodiment of the present application provides a display device, which adopts the following technical schemes:

a display apparatus comprising an encapsulation film, and a light emitting device as described above or a light emitting device manufactured by a manufacturing method of a light emitting device as described above, the encapsulation film encapsulating the light emitting device.

Compared with the prior art, the embodiment of the application has the following main beneficial effects: the brightness of blue light in white light is less, the red sub-pixel unit and the green sub-pixel unit are both corresponding to the first optical path, the blue sub-pixel unit is corresponding to the second optical path, and the first optical path is smaller than the second optical path, so that the micro-cavity effect corresponding to the red sub-pixel unit and the green sub-pixel unit is weakened, the scattering degree of the red light beam emitted by the red sub-pixel unit and the green light beam emitted by the green sub-pixel unit is higher than that of the blue light beam emitted by the blue sub-pixel unit, the brightness difference of the red light beam emitted by the red sub-pixel unit, the green light beam emitted by the green sub-pixel unit and the blue light beam emitted by the blue sub-pixel unit is reduced under the small visual angle and the large visual angle, the white light brightness attenuation speed is reduced under the large visual angle, and the user experience is improved.

Drawings

For a clearer description of the solution of the present application, a brief introduction will be given to the drawings needed in the description of the embodiments, which are some embodiments of the present application, and from which other drawings can be obtained for a person skilled in the art without the inventive effort.

Fig. 1 is a schematic structural view of a light emitting device according to an embodiment of the present application;

fig. 2 is a schematic cross-sectional structure of any one pixel of a red sub-pixel unit, a green sub-pixel unit and a blue sub-pixel unit in the light emitting device according to an embodiment of the present application;

fig. 3 is a flowchart of a method of manufacturing a light emitting device in an embodiment of the present application;

FIG. 4 is a graph showing luminance decay of a red subpixel unit according to one embodiment of the present application;

FIG. 5 is a graph illustrating luminance degradation of a green sub-pixel unit according to one embodiment of the present disclosure;

fig. 6 is a graph of luminance decay of white light in an embodiment of the present application.

Reference numerals:

110. a bottom electrode; 120. a pixel unit; 121. a red sub-pixel unit; 122. a green sub-pixel unit; 123. a blue sub-pixel unit; 124. a light emitting layer; 125. a hole injection layer; 126. a hole transport layer; 127. an electron blocking layer; 128. a hole blocking layer; 129. an electron transport layer; 12A, an electron injection layer; 130. a top electrode.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the applications herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the figures above are intended to cover non-exclusive inclusions. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a sequential or chronological order.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

For ease of understanding, the terms mentioned in the detailed description are first described below:

(1) The white light is formed by mixing red light, green light and blue light, wherein the ratio of the red light to the green light in the white light is highest and reaches 90%, and the blue light is 10%; in practical applications, white light is used to form pictures on a screen/display device.

(2) Optical path is a compromise, which is understood to be the distance that light propagates in vacuum at the same time, and also refers to the product of the path that light travels in the medium at the same time and the refractive index of the medium.

(3) Microcavity effect means that when the optical thickness of the microcavity and the wavelength of the light wave satisfy a certain relationship, the light of a specific wavelength (the wavelength of a certain monochromatic light) is enhanced, and the spectrum is narrowed. The microcavity effect has the functions of selecting, narrowing, strengthening and the like on the light source, and is often used for improving the chromaticity of the OLED, strengthening the emission intensity of specific wavelength, changing the luminous color of the OLED and the like; however, the existence of wide-angle interference affects the viewing angle characteristics of the device, that is, the light emission peak is shifted along with the shift of the viewing angle, so that the problems of brightness difference, chromaticity shift and the like are caused, and especially under a large viewing angle, the optical property is poor and the chromatic aberration is serious.

Referring to fig. 1, an embodiment of the present application provides a light emitting device, including a bottom electrode 110, a pixel unit 120, and a top electrode 130 that are stacked, wherein the pixel unit 120 includes a red sub-pixel unit 121, a green sub-pixel unit 122, and a blue sub-pixel unit 123;

the red sub-pixel unit 121 corresponds to a first optical path, and the blue sub-pixel unit 123 corresponds to a second optical path, the first optical path being smaller than the second optical path;

the green subpixel unit 122 corresponds to a third optical path, which is smaller than the second optical path.

In some embodiments, the red sub-pixel unit 121 corresponds to a red light emitting device in a red pixel region, the green sub-pixel unit 122 corresponds to a green light emitting device in a green pixel region, and the blue sub-pixel unit 123 corresponds to a blue light emitting device in a blue pixel region.

The method for calculating the first optical path is as follows: calculating the product of the thickness of each film layer and the refractive index of the film layer of the red sub-pixel unit 121 to obtain the optical thickness of the film layer, and accumulating the optical thicknesses of the film layers to obtain a first optical path; for example, the optical thickness of the light emitting layer 124 in the red subpixel unit 121 is equal to the film thickness of the light emitting layer 124 multiplied by the refractive index of the light emitting layer 124.

Similarly, the calculation principles of the second optical path and the third optical path are the same as those of the first optical path, and are not described in detail herein, and the difference between the calculation principles of the second optical path, the third optical path and the first optical path is that the second optical path is calculated according to the film layer of the blue sub-pixel unit 123, the third optical path is calculated according to the film layer of the green sub-pixel unit 122, and the first optical path is calculated according to the film layer of the red sub-pixel unit 121.

In practical applications, according to the definition of the optical path, when the refractive indexes of the red sub-pixel unit 121, the green sub-pixel unit 122 and the blue sub-pixel unit 123 are the same, the structural thicknesses (the paths of light) of the red sub-pixel unit 121 and the green sub-pixel unit 122 can be changed, so that the red sub-pixel unit 121 corresponds to the first optical path, the green sub-pixel unit 122 corresponds to the third optical path, and the structural thicknesses (the paths of light) of the blue sub-pixel unit 123 are not changed, so that the blue sub-pixel unit 123 corresponds to the second optical path, and the purposes that both the first optical path and the third optical path are smaller than the second optical path are achieved.

The beneficial effects of this embodiment are as follows: because the brightness of blue light in forming white light is relatively small, based on this, by making the red sub-pixel unit 121 correspond to the first optical path and the green sub-pixel unit 122 correspond to the third optical path, both the first optical path and the third optical path are smaller than the second optical path, so that microcavity effects corresponding to the red sub-pixel unit 121 and the green sub-pixel unit 122 are weakened, scattering degrees of red light beams emitted by the red sub-pixel unit 121 and green light beams emitted by the green sub-pixel unit 122 are higher than scattering degrees of blue light beams emitted by the blue sub-pixel unit 123, and accordingly, brightness differences of red light beams emitted by the red sub-pixel unit 121, green light beams emitted by the green sub-pixel unit 122 and blue light beams emitted by the blue sub-pixel unit 123 are reduced under small viewing angles and large viewing angles, and white light brightness attenuation speeds under large viewing angles are reduced, so that user experience is improved.

In some alternatives of this embodiment, referring to fig. 1, the red sub-pixel unit 121, the green sub-pixel unit 122, and the blue sub-pixel unit 123 include pixel functional layers, and the thickness of the pixel functional layers in the red sub-pixel unit 121 and/or the thickness of the pixel functional layers in the green sub-pixel unit 122 are smaller than the thickness of the pixel functional layers in the blue sub-pixel unit 123.

In some embodiments, due to the reduced thickness of the pixel functional layer in the red sub-pixel unit 121 and the reduced thickness of the pixel functional layer in the green sub-pixel unit 122, the micro-cavity effect corresponding to the red sub-pixel unit 121 and the green sub-pixel unit 122 is reduced, that is, the optical paths corresponding to the red sub-pixel unit 121 and the green sub-pixel unit 122 are reduced, the red sub-pixel unit 121 corresponds to the first optical path and the green sub-pixel unit 122 corresponds to the third optical path, so that the scattering degree of the red light beam emitted by the red sub-pixel unit 121 and the green light beam emitted by the green sub-pixel unit 122 is higher than the scattering degree of the blue light beam emitted by the blue sub-pixel unit 123, and thus the brightness difference of the red light beam emitted by the red sub-pixel unit 121 and the green light beam emitted by the green sub-pixel unit 122 is reduced at the small viewing angle and the large viewing angle, and the white light brightness decay speed is reduced at the large viewing angle.

In some alternatives of this embodiment, referring to fig. 1, the thickness of the pixel functional layer in the red sub-pixel unit 121 is 110 to 140 nm; optionally, the thickness of the pixel functional layer in the red sub-pixel unit 121 is 110 to 135 nm, 110 to 130 nm, 110 to 125 nm, 110 to 120 nm, 110 to 115 nm, 115 to 140 nm, 115 to 135 nm, 115 to 130 nm, 115 to 125 nm, 115 to 120 nm, 120 to 140 nm, 120 to 135 nm, 120 to 130 nm, 120 to 125 nm, 125 to 140 nm, 125 to 135 nm, 125 to 130 nm, 130 to 140 nm, 130 to 135 nm, 135 to 140 nm; and/or the number of the groups of groups,

the thickness of the pixel functional layer in the green sub-pixel unit 122 is 70 to 100 nanometers; optionally, the thickness of the pixel functional layer in the green sub-pixel unit 122 is 70 to 95 nm, 70 to 90 nm, 70 to 85 nm, 70 to 80 nm, 70 to 75 nm, 75 to 100 nm, 75 to 95 nm, 75 to 90 nm, 75 to 85 nm, 75 to 80 nm, 80 to 100 nm, 80 to 95 nm, 80 to 90 nm, 80 to 85 nm, 85 to 100 nm, 85 to 95 nm, 85 to 90 nm, 90 to 100 nm, 95 to 100 nm; and/or the number of the groups of groups,

The thickness of the pixel functional layer in the blue sub-pixel unit 123 is 180 to 220 nanometers; optionally, the thickness of the pixel functional layer in the blue sub-pixel unit 123 is 180 to 220 nm, 180 to 215 nm, 180 to 210 nm, 180 to 205 nm, 180 to 200 nm, 180 to 195 nm, 180 to 190 nm, 180 to 185 nm, 185 to 220 nm, 185 to 215 nm, 185 to 210 nm, 185 to 205 nm, 185 to 200 nm, 185 to 195 nm, 185 to 190 nm, 190 to 220 nm, 190 to 215 nm, 190 to 210 nm, 190 to 205 nm, 190 to 200 nm, 190 to 195 nm, 195 to 220 nm, 195 to 215 nm, 195 to 210 nm, 195 to 205 nm, 195 to 200 nm, 200 to 220 nm, 200 to 215 nm, 200 to 210 nm, 200 to 205 nm, 205 to 215 nm, 205 to 210 nm, 210 to 220 nm, 210 to 215 nm, 215 to 220 nm.

In some embodiments, on the premise that the refractive indexes of the red sub-pixel unit 121, the green sub-pixel unit 122 and the blue sub-pixel unit 123 are the same, the thicknesses of the pixel functional layers in the red sub-pixel unit 121 and the pixel functional layers in the green sub-pixel unit 122 are both smaller than the thickness of the pixel functional layers in the blue sub-pixel unit 123, so that the first optical path of the red sub-pixel unit 121 and the third optical path of the green sub-pixel unit 122 are both smaller than the second optical path of the blue sub-pixel unit 123.

In addition, since the wavelength of the red sub-pixel unit 121 is greater than that of the green sub-pixel unit 122, the thickness of the middle pixel functional layer of the red sub-pixel unit 121 is greater than that of the green sub-pixel unit 122.

In some embodiments, the smaller the thickness of the pixel functional layers of the red sub-pixel unit 121 and the green sub-pixel unit 122, the larger the differences between the first optical path and the third optical path and the second optical path, respectively, the smaller or more consistent the differences between the brightness attenuation degree of the red sub-pixel unit 121 and the green sub-pixel unit 122 and the brightness attenuation degree of the blue sub-pixel unit 123, further reducing the attenuation speed of the white light under a large viewing angle, and improving the brightness of the large viewing angle.

For example, the thickness of the pixel functional layer in the red sub-pixel unit 121 is 125 nm, the thickness of the pixel functional layer in the green sub-pixel unit 122 is 85 nm, and the thickness of the pixel functional layer in the blue sub-pixel unit 123 is 200 nm; on the premise of ensuring the structural performances of the red sub-pixel unit 121, the green sub-pixel unit 122 and the blue sub-pixel unit 123, the display panel manufactured by adopting the light emitting device can still ensure higher brightness under a large viewing angle, and effectively slow down the attenuation of white light brightness under the large viewing angle.

In some alternatives of this embodiment, referring to fig. 1 and 2, the pixel functional layer includes a light emitting layer 124, and a first optical path adjustment layer disposed between the top electrode 130 and the light emitting layer 124 and/or a second optical path adjustment layer disposed between the bottom electrode 110 and the light emitting layer 124;

the thickness of the first optical path adjustment layer in the red sub-pixel unit 121 is smaller than the thickness of the first optical path adjustment layer in the blue sub-pixel unit 123; and/or the thickness of the first optical path adjustment layer in the green sub-pixel unit 122 is smaller than the thickness of the first optical path adjustment layer in the blue sub-pixel unit 123; and/or the thickness of the second optical path adjustment layer in the red sub-pixel unit 121 is smaller than the thickness of the second optical path adjustment layer in the blue sub-pixel unit 123; and/or the thickness of the second optical path adjusting layer in the green sub-pixel unit 122 is smaller than the thickness of the second optical path adjusting layer in the blue sub-pixel unit 123.

In practical applications, the thicknesses of the first optical path adjusting layer and the second optical adjusting layer of the red sub-pixel unit 121 and the green sub-pixel unit 122 can be adjusted separately or simultaneously, so as to adjust the thicknesses of the pixel functional layers in the red sub-pixel unit 121 and the green sub-pixel unit 122; in general, the smaller the thickness of the first/second optical adjustment layers, the higher the brightness of the red light beam emitted from the red sub-pixel unit 121 and the green light beam emitted from the green sub-pixel unit 122, and the more effective the reduction of the brightness of the white light.

In some alternatives of this embodiment, the first optical path adjustment layers in the red sub-pixel unit 121, the green sub-pixel unit 122, and the blue sub-pixel unit 123 are formed of the same material; and/or the number of the groups of groups,

the materials of the second optical path adjusting layers in the red sub-pixel unit 121, the green sub-pixel unit 122, and the blue sub-pixel unit 123 are the same.

In some embodiments, the materials of the first optical path adjustment layers and/or the second optical path adjustment layers of the red sub-pixel unit 121, the green sub-pixel unit 122 and the blue sub-pixel unit 123 are the same, so that the refractive indexes of the first optical path adjustment layers and/or the second optical path adjustment layers of the red sub-pixel unit 121, the green sub-pixel unit 122 and the blue sub-pixel unit 123 are the same, and thus, when the thickness of the first optical path adjustment layer and/or the second optical path adjustment layer in the red sub-pixel unit 121 and the thickness of the first optical path adjustment layer and/or the second optical path adjustment layer in the green sub-pixel unit 122 are changed, the optical paths corresponding to the red sub-pixel unit 121 and the green sub-pixel unit 122 can be changed, so that the red sub-pixel unit 121 corresponds to the corresponding optical path, and the green sub-pixel unit 122 corresponds to the third optical path.

In some alternatives of the present embodiment, the light emitting layer 124 is a quantum dot light emitting layer 124 or an organic light emitting layer 124, and the material of the quantum dot light emitting layer 124 includes at least one of quantum dots with a single structure and quantum dots with a core-shell structure;

the material of the organic light emitting layer 124 includes at least one of 4,4' -bis (N-carbazole) -1,1' -biphenyl tris [2- (p-tolyl) pyridine-C2, N) iridium (III), 4',4 "-tris (carbazol-9-yl) triphenylamine tris [2- (p-tolyl) pyridine-C2, N) iridium, biaryl anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and derivatives thereof, poly-p-benzene and derivatives thereof, polythiophene and derivatives thereof, polyfluorene and derivatives thereof.

In some alternatives of this embodiment, the light emitting layer 124 includes a host material and a guest material.

The host material in the red sub-pixel unit 121 is CBP, and the guest material is Ir (piq) 2 (acac) (red phosphorescent material), wherein the doping amount of the guest material in the light emitting layer 124 is any one of 1% to 15%, 3% to 10%, and 5% to 8%.

The host material in the green sub-pixel unit 122 is TCTA, and the guest material is Ir (ppy) 3 (tris (2-phenylpyridine) iridium), wherein the doping amount of the guest material in the light-emitting layer 124 is any one of 1% to 15%, 4% to 11%, and 5% to 8%.

The host material in the blue sub-pixel unit 123 is DPEPO (bis [2- ((oxo) diphenylphosphino) phenyl ] ether), and the guest material is DMAC-DPS (blue thermally-induced delayed fluorescent material), wherein the doping amount of the guest material in the light emitting layer 124 is any one of 1% to 10%, 3% to 8%, and 4% to 6%.

By adding the guest material into the host material, the red sub-pixel unit 121/green sub-pixel unit 122/blue sub-pixel unit 123 has high color uniformity and color accuracy of emitted light in practical application; generally, the larger the doping ratio, the higher the color uniformity and color accuracy of the light emitted from the red/green/blue sub-pixel units 121/122/123.

In some alternatives of the present embodiment, the first optical path adjusting layer includes at least one of a hole injection layer 125, a hole transport layer 126, and an electron blocking layer 127 sequentially stacked between the bottom electrode 110 and the light emitting layer 124;

The material of at least one of the hole transport layer 205, the hole injection layer 206, and the electron blocking layer 127 includes at least one of TFB, cuPc, PVK, poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT: PSS, TAPC, MCC, F4-TCNQ, HAT-CN, 4' -tris (N-3-methylphenyl-N-phenylamino) triphenylamine, polyaniline, a transition metal oxide, a transition metal sulfide, a transition metal stannide, doped graphene, undoped graphene, and C60.

In some alternatives of the present embodiment, the second optical path adjusting layer includes at least one of a hole blocking layer 128, an electron transporting layer 129, and an electron injecting layer 12A sequentially stacked between the light emitting layer 124 and the top electrode 130;

the material of the electron transport layer 129 and/or the electron injection layer 12A includes an inorganic material and/or an organic material; the inorganic material is selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, titanium lithium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, zinc lithium oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc stannate, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, barium titanate and lithium fluoride, and the doped element comprises one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium and gadolinium; the organic material is selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene compounds and hydroxyquinoline compounds; and/or the number of the groups of groups,

The material of the hole blocking layer 128 is selected from one or more of aromatic compounds, carbazole compounds, DPEPO and TPDI.

In some alternatives of this embodiment, the top electrode 130 is a common top electrode 130 or a non-common top electrode 130 that is common to the red, green and blue sub-pixel cells 121, 122 and 123; and/or the number of the groups of groups,

the bottom electrode 110 is a common bottom electrode 110 or an unshared, unshared bottom electrode 110 that is common to the red, green and blue sub-pixel cells 121, 122 and 123.

In some embodiments, the bottom electrode 110 and/or the top electrode 130 are common electrodes, and at this time, the bottom electrode 110 and/or the top electrode 130 in the red sub-pixel unit 121, the bottom electrode 110 and/or the top electrode 130 in the green sub-pixel unit 122, and the bottom electrode 110 and/or the top electrode 130 in the blue sub-pixel unit 123 are made of the same material, so that the compatibility of the materials can be improved, and the stability of the device can be further improved, and meanwhile, the process flow is simplified; in other embodiments, the bottom electrode 110 and/or the top electrode 130 are non-common electrodes, and at this time, the materials of the bottom electrode 110 and/or the top electrode 130 in the red sub-pixel unit 121, the bottom electrode 110 and/or the top electrode 130 in the green sub-pixel unit 122, and the bottom electrode 110 and/or the top electrode 130 in the blue sub-pixel unit 123 may be the same or different, and the red sub-pixel unit 121, the blue sub-pixel unit 123, and the green sub-pixel unit 122 are respectively provided with corresponding non-common electrodes, so that the red sub-pixel unit 121, the blue sub-pixel unit 123, and the green sub-pixel unit 122 are individually powered by the respective corresponding non-common electrodes, thereby ensuring the light emitting effect of the red sub-pixel unit 121, the blue sub-pixel unit 123, and the green sub-pixel unit 122.

In some alternatives of this embodiment, the material of the bottom electrode 110 and/or the top electrode 130 comprises one or more of a metal, a carbon material, and a metal oxide, the metal comprising one or more of Al, ag, cu, mo, au, ba, ca, yb and Mg; the carbon material comprises one or more of graphite, carbon nanotubes, graphene and carbon fibers; the metal oxide comprises one or more of doped or undoped metal oxide, ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, or a composite electrode comprising one or more of AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/Al/ITO, znO/Ag/ZnO, znO/Al/ZnO, znS/Ag/ZnS, znS/Al/ZnS, tiO2/Ag/TiO2 and TiO2/Al/TiO2, wherein the metal is sandwiched between the doped or undoped transparent metal oxide.

The embodiment of the application also provides a display device, which comprises the packaging film and the light-emitting device, wherein the packaging film packages the light-emitting device.

In some embodiments, the display device further comprises a housing, the display panel being loaded in the housing; the display device may be a television, a display, a screen (e.g., a mobile phone screen, a tablet screen, etc.).

The beneficial effects of this embodiment are as follows: because the brightness of blue light in white light is less, based on the fact that the red sub-pixel unit corresponds to the first optical path and the green sub-pixel unit corresponds to the third optical path, the first optical path and the third optical path are smaller than the second optical path, so that micro-cavity effects corresponding to the red sub-pixel unit and the green sub-pixel unit are weakened, the scattering degree of red light beams emitted by the red sub-pixel unit and green light beams emitted by the green sub-pixel unit is higher than that of blue light beams emitted by the blue sub-pixel unit, and therefore brightness differences of the red light beams emitted by the red sub-pixel unit, the green light beams emitted by the green sub-pixel unit and blue light beams emitted by the blue sub-pixel unit are reduced under small visual angles and large visual angles, the white light brightness attenuation speed under the large visual angles is reduced, and user experience is improved.

Referring to fig. 3, the embodiment of the present application further provides a method for manufacturing a light emitting device, which adopts the following technical scheme:

s201, providing a substrate, and forming a bottom electrode on the substrate;

in some embodiments, the material of the bottom electrode comprises one or more of a metal, a carbon material, and a metal oxide, the metal comprising one or more of Al, ag, cu, mo, au, ba, ca, yb and Mg; the carbon material comprises one or more of graphite, carbon nanotubes, graphene and carbon fibers; the metal oxide comprises one or more of doped or undoped metal oxide, ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, or a composite electrode comprising one or more of AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/Al/ITO, znO/Ag/ZnO, znO/Al/ZnO, znS/Ag/ZnS, znS/Al/ZnS, tiO2/Ag/TiO2 and TiO2/Al/TiO2, wherein the metal is sandwiched between the doped or undoped transparent metal oxide.

S202, forming a pixel unit on the bottom electrode, wherein the pixel unit comprises a red sub-pixel unit, a green sub-pixel unit and a blue sub-pixel unit, the red sub-pixel unit corresponds to a first optical path, the blue sub-pixel unit corresponds to a second optical path, and the first optical path is smaller than the second optical path; the green sub-pixel unit corresponds to a third optical path, which is smaller than the second optical path.

In some embodiments, the red, green, and blue sub-pixel cells include a pixel functional layer, and the pixel includes a light emitting layer, and a first optical path adjustment layer disposed between the top electrode and the light emitting layer, and/or a second optical path adjustment layer disposed between the bottom electrode and the light emitting layer. In practical application, the thicknesses of the first optical path adjusting layer and the second optical adjusting layer of the red sub-pixel unit and the green sub-pixel unit can be adjusted independently or simultaneously, so that the thicknesses of the pixel functional layers in the red sub-pixel unit and the green sub-pixel unit can be adjusted; in general, the smaller the thickness of the first/second optical adjustment layers, the higher the brightness of the red light beam emitted from the red sub-pixel unit and the green light beam emitted from the green sub-pixel unit, and the more effective the reduction of the brightness of the white light.

In some embodiments, the first optical path adjustment layer includes a hole transport layer and a hole injection layer disposed between the top electrode and the light emitting layer; in some embodiments, the second optical path adjustment layer includes an electron transport layer and an electron injection layer disposed between the top electrode and the light emitting layer.

The hole injection layer forming material in the red subpixel unit may be any one of HAT-CN, 2,3,5, 6-tetrafluoro-7, 8-tetracyanodimethyl p-benzoquinone (F4 TCNQ), copper phthalocyanine, polyaniline, or 4,4' -tris (N-3-methylphenyl-N-phenylamino) triphenylamine (TDATA); preferably, the hole injection layer of the red sub-pixel unit is made of HAT-CN, and the hole injection layer of the red sub-pixel unit has a thickness of 8 to 15 nanometers, so that electrons of the top electrode are injected into the red sub-pixel unit.

The hole transport layer forming material in the red sub-pixel unit is an aromatic compound, such as NPB, TAPC (4, 4' -cyclohexylbis [ N, N-bis (4-methylphenyl) aniline ]), and the like, and has high hole mobility; preferably, the hole transport layer in the red sub-pixel unit is made of TAPC (4, 4' -cyclohexylbis [ N, N-di (4-methylphenyl) aniline ]), and the hole transport layer of the red sub-pixel unit has a thickness of 10 to 20 nm, so that recombination of electrons and holes injected from the top electrode occurs in the light emitting layer.

The electron blocking layer forming material in the red sub-pixel unit may be the same as or different from the hole transporting layer (e.g., TAPC (4, 4' -cyclohexylbis [ N, N-bis (4-methylphenyl) aniline ]), NPB, etc.); preferably, the electron blocking layer in the red sub-pixel unit may be formed of the same material as the hole transporting layer, and the electron blocking layer of the red sub-pixel unit has a thickness of 5 to 15nm, so as to ensure the transport efficiency of electrons injected from the top electrode and also block electrons of the bottom electrode from migrating to the top electrode.

The light emitting layer in the red sub-pixel unit includes a host material and a guest material, wherein the host material is CBP, the guest material is Ir (piq) 2 (acac) (red phosphorescent material), the doping ratio of the guest material is 1% to 15%, and the thickness of the light emitting layer of the red sub-pixel unit is 30 to 50 nm, so as to generate red light.

The hole blocking layer in the red sub-pixel unit is formed by a material with a deep HOMO energy level (such as HOMO energy level below 6 eV), such as DPEPO or TPDI; preferably, the hole blocking layer forming material in the red sub-pixel unit is DPEPO (bis [2- ((oxo) diphenylphosphino) phenyl ] ether), and the electron blocking layer of the red sub-pixel unit has a thickness of 3 to 5nm for blocking electron migration of the bottom electrode toward the top electrode.

The electron transport layer forming material in the red sub-pixel unit is formed by quinoxaline or imidazole compound material and 8 hydroxyquinoline lithium together, and the doping proportion is 1:9 to 9:1, a step of; preferably, the quinoxaline or imidazole compound material is Bphen (4, 7-diphenyl-1, 10-phenanthridine), and the thickness of the electron transport layer in the red sub-pixel unit is 15 to 30nm, so that the recombination of electrons and holes injected from the bottom electrode occurs in the light emitting layer.

The electron injection layer in the red sub-pixel unit is formed by any one of silver (Ag), magnesium (Mg), ytterbium (Yb), magnesium-silver alloy and ytterbium-silver alloy, and the thickness of the electron injection layer of the red sub-pixel unit is 1 to 4 nanometers so that electrons of the bottom electrode are injected into the red sub-pixel unit.

The hole injection layer in the green sub-pixel unit and the hole injection layer in the red sub-pixel unit have the same material and function, and are not described in detail herein; wherein the thickness of the hole injection layer in the green sub-pixel unit is 8 to 15 nanometers.

The hole transport layer in the green sub-pixel unit and the hole transport layer in the red sub-pixel unit have the same material and function, and are not described in detail herein; wherein the thickness of the hole transport layer in the green sub-pixel unit is 5 to 15 nanometers.

The electron blocking layer in the green sub-pixel unit and the electron blocking layer in the red sub-pixel unit have the same function, and are not described in detail herein; the electron blocking layer in the green sub-pixel unit is formed of TPD, and the thickness of the electron blocking layer of the green sub-pixel unit is 5 to 10 nanometers.

The light emitting layer in the green sub-pixel unit and the light emitting layer in the red sub-pixel unit have the same function, and are not described in detail herein; the light emitting layer in the green sub-pixel unit includes a host material TCTA and a guest material Ir (ppy) 3 (tris (2-phenylpyridine) iridium), the doping ratio of the guest material is 1% to 15%, and the thickness of the light emitting layer of the green sub-pixel unit is 25 to 40 nm.

The hole blocking layer in the green sub-pixel unit and the hole blocking layer in the red sub-pixel unit are formed from the same materials, functions and thicknesses, and are not described in detail herein.

The electron transport layer in the green sub-pixel unit and the electron transport layer in the red sub-pixel unit are formed of the same material, function and thickness, and are not described herein.

The electron injection layer in the green sub-pixel unit and the electron injection layer in the red sub-pixel unit are formed with the same material, function and thickness, and are not described herein.

The hole injection layer in the blue sub-pixel unit and the hole injection layer in the red sub-pixel unit have the same forming materials and functions, and are not described in detail herein; wherein the thickness of the hole injection layer in the blue sub-pixel unit is 8 to 40 nanometers.

The hole transport layer in the blue sub-pixel unit and the hole transport layer in the red sub-pixel unit have the same material and function, and are not described in detail herein; wherein the thickness of the hole transport layer in the blue sub-pixel unit is 80 to 120 nanometers.

The electron blocking layer in the blue sub-pixel unit and the electron blocking layer in the red sub-pixel unit have the same function and are not described in detail herein; the electron blocking layer in the blue sub-pixel unit is formed by CzSi (Czochralski silicon), and the thickness of the electron blocking layer of the blue sub-pixel unit is 5 to 15 nanometers.

The light emitting layer in the blue sub-pixel unit and the light emitting layer in the red sub-pixel unit have the same function and are not described in detail herein; the light emitting layer in the blue sub-pixel unit comprises a host material DEPO (di [2- ((oxo) diphenyl phosphino) phenyl ] ether and a guest material DMAC-DPS (blue thermotropic delayed fluorescent material), wherein the doping proportion of the guest material is 1-15%, and the thickness of the light emitting layer in the blue sub-pixel unit is 25-40 nanometers.

The hole blocking layer in the blue sub-pixel unit and the hole blocking layer in the red sub-pixel unit are the same in forming material, function and thickness, and are not described herein.

The hole transport layer in the blue sub-pixel unit and the electron transport layer in the red sub-pixel unit are formed of the same material, function and thickness, and are not described herein.

The hole injection layer in the blue sub-pixel unit and the electron injection layer in the red sub-pixel unit are formed with the same material, function and thickness, and are not described herein.

And S203, forming a top electrode on the pixel unit to obtain the light-emitting device.

In some embodiments, the material of the top electrode comprises one or more of a metal, a carbon material, and a metal oxide, the metal comprising one or more of Al, ag, cu, mo, au, ba, ca, yb and Mg; the carbon material comprises one or more of graphite, carbon nanotubes, graphene and carbon fibers; the metal oxide comprises one or more of doped or undoped metal oxide, ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, or a composite electrode comprising one or more of AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/Al/ITO, znO/Ag/ZnO, znO/Al/ZnO, znS/Ag/ZnS, znS/Al/ZnS, tiO2/Ag/TiO2 and TiO2/Al/TiO2, wherein the metal is sandwiched between the doped or undoped transparent metal oxide.

In some embodiments, the encapsulation layer may be made of a material with a high refractive index (preferably, a refractive index of 1.59 or more), such as TPD, and the thickness of the encapsulation layer is 50 to 80, so as to ensure uniformity and stability of the color of light emitted by the red sub-pixel unit, the green sub-pixel unit and the blue sub-pixel unit.

In some alternative implementations of the embodiment, the step of forming the red, green, and blue sub-pixel cells on the substrate includes:

and forming a red sub-pixel unit, a green sub-pixel unit and a blue sub-pixel unit on the substrate through an evaporation process or an ink jet printing process.

In some embodiments, the evaporation process is to evaporate the evaporated material into atoms or molecules in vacuum by means of current heating, electron beam bombardment heating, laser heating, etc., and then they can do linear motion with a larger free path, collide with the surface of the substrate to condense, form a thin film layer (such as a hole injection layer, a hole transport layer, etc.), and thus, to evaporate each layer of the red sub-pixel unit, the green sub-pixel unit, and the blue sub-pixel unit sequentially.

The ink jet printing process is to dissolve the OLED organic material into "ink", and then directly jet-print the "ink" of less than several tens of pl (picoliters, one trillion liters) on the surface of the substrate to form a film layer, so that each layer of the red sub-pixel unit, the green sub-pixel unit and the blue sub-pixel unit is sequentially jet-printed.

Compared with the evaporation process, the ink-jet printing process has low processing cost and low processing difficulty.

In order to better understand the technical solutions of the present application, the following description will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings.

The method comprises the steps of respectively preparing a light emitting device and a contrast light emitting device by adopting a first method and a second method, wherein the first method is the preparation method of the light emitting device, the thicknesses of pixel functional layers of a red sub-pixel unit and a green sub-pixel unit in the prepared light emitting device are smaller than those of a blue sub-pixel unit, and a first optical path corresponding to the red sub-pixel unit and a third optical path corresponding to the green sub-pixel unit are smaller than those of the blue sub-pixel unit;

the second method is substantially the same as the first method, except that: and adjusting the thicknesses of the pixel functional layers in the red sub-pixel unit and the green sub-pixel unit in the second method, so that the thicknesses of the pixel functional layers of the red sub-pixel unit and the green sub-pixel unit prepared by the second method are equal to the thicknesses of the pixel functional layers of the blue sub-pixel unit, and the red sub-pixel unit, the green sub-pixel unit and the blue sub-pixel unit correspond to the second optical path.

In the first test, the attenuation degree of the red sub-pixel unit of the light-emitting device and the contrast light-emitting device under different visual angles is compared.

Referring to fig. 4, where the solid line is the attenuation degree of the red sub-pixel unit under the first optical path under the different viewing angles, the dotted line is the attenuation degree of the red sub-pixel unit under the second optical path under the different viewing angles, and it can be seen that the attenuation degree of the red sub-pixel unit in the light emitting device of the present application is substantially identical to the attenuation degree of the red sub-pixel unit of the contrast light emitting device in the range of 0 degrees to 40 degrees (small viewing angles), and the attenuation degree of the red sub-pixel unit in the light emitting device of the present application is significantly smaller than the attenuation degree of the red sub-pixel unit of the contrast light emitting device in the range of 40 degrees to 60 degrees (large viewing angles).

And secondly, comparing the attenuation degree of the green sub-pixel unit of the light-emitting device with that of the contrast light-emitting device under different visual angles.

Referring to fig. 5, where the solid line is the attenuation degree of the green sub-pixel unit under the third optical path under the different viewing angles, and the dotted line is the attenuation degree of the green sub-pixel unit under the second optical path under the different viewing angles, it can be seen that the attenuation degree of the green sub-pixel unit in the light emitting device of the present application is substantially identical to the attenuation degree of the green sub-pixel unit of the contrast light emitting device in the range of 0 degrees to 40 degrees (small viewing angles), and the attenuation degree of the green sub-pixel unit in the light emitting device of the present application is significantly smaller than the attenuation degree of the green sub-pixel unit of the contrast light emitting device in the range of 40 degrees to 60 degrees (large viewing angles).

And thirdly, comparing the attenuation degree of the white light of the light-emitting device with that of the contrast light-emitting device under different visual angles.

Referring to fig. 6, the attenuation degree of white light obtained by mixing a red sub-pixel unit corresponding to a first optical path and a green sub-pixel unit corresponding to a third optical path and a blue sub-pixel unit corresponding to a second optical path is shown as a solid line under different viewing angles, the attenuation degree of white light obtained by mixing a red sub-pixel unit corresponding to a second optical path and a green sub-pixel unit and a blue sub-pixel unit is shown as a dotted line under different viewing angles, and the attenuation degree of white light in the light emitting device is basically consistent with that of the contrast light emitting device under 0-40 degrees (small viewing angles), and the attenuation degree of white light in the light emitting device is obviously smaller than that of the contrast light emitting device under 40-60 degrees (large viewing angles).

In summary, as can be obtained from the first test and the second test, the red sub-pixel unit corresponds to the first optical path and the green sub-pixel unit corresponds to the third optical path, and the first optical path and the third optical path are smaller than the second optical path corresponding to the blue sub-pixel unit, so that microcavity effects of the red sub-pixel unit and the green sub-pixel unit are weakened, scattering degrees of red light beams emitted by the red sub-pixel unit and green light beams emitted by the green sub-pixel unit are higher than scattering degrees of blue light beams emitted by the blue sub-pixel unit, and brightness attenuation degrees of the red sub-pixel unit and the green sub-pixel unit under a large viewing angle are similar to or the same as those of the blue sub-pixel unit, thereby achieving the purpose of slowing down brightness attenuation of the red sub-pixel unit and the green sub-pixel unit under the large viewing angle; and the third experiment can obtain that, as the brightness attenuation degree of the red sub-pixel unit and the green sub-pixel unit under the large viewing angle is similar or the same as the brightness attenuation degree of the blue sub-pixel unit in the application, the brightness attenuation degree difference of the red sub-pixel unit, the green sub-pixel unit and the blue sub-pixel unit under the large viewing angle is reduced, so that the brightness attenuation degree of white light formed by mixing red light, green light and blue light under the large viewing angle is obviously reduced, and the problems of low brightness and too fast white light brightness attenuation of an OLED product under the large viewing angle are solved.

It is apparent that the embodiments described above are only some embodiments of the present application, but not all embodiments, the preferred embodiments of the present application are given in the drawings, but not limiting the patent scope of the present application. This application may be embodied in many different forms, but rather, embodiments are provided in order to provide a more thorough understanding of the present disclosure. Although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing, or equivalents may be substituted for elements thereof. All equivalent structures made by the specification and the drawings of the application are directly or indirectly applied to other related technical fields, and are also within the protection scope of the application.

Claims

1. A light emitting device comprising a bottom electrode, a pixel unit and a top electrode which are stacked, wherein the pixel unit comprises a red sub-pixel unit, a green sub-pixel unit and a blue sub-pixel unit;

2. The light-emitting device according to claim 1, wherein the red sub-pixel unit, the green sub-pixel unit, and the blue sub-pixel unit include pixel functional layers, and wherein a thickness of the pixel functional layer in the red sub-pixel unit and/or a thickness of the pixel functional layer in the green sub-pixel unit is smaller than a thickness of the pixel functional layer in the blue sub-pixel unit.

3. The light-emitting device according to claim 2, wherein a thickness of the pixel functional layer in the red sub-pixel unit is 110 to 140 nm; and/or the number of the groups of groups,

the thickness of the pixel functional layer in the green sub-pixel unit is 70-100 nanometers; and/or the number of the groups of groups,

the thickness of the pixel functional layer in the blue sub-pixel unit is 180-220 nanometers.

4. A light-emitting device according to claim 2 or 3, wherein the pixel functional layer comprises a light-emitting layer, and a first optical path adjustment layer provided between the top electrode and the light-emitting layer and/or a second optical path adjustment layer provided between the bottom electrode and the light-emitting layer;

the thickness of the first optical path regulating layer in the red sub-pixel unit is smaller than that of the first optical path regulating layer in the blue sub-pixel unit; and/or the number of the groups of groups,

The thickness of the first optical path regulating layer in the green sub-pixel unit is smaller than that of the first optical path regulating layer in the blue sub-pixel unit; and/or the number of the groups of groups,

the thickness of the second optical path regulating layer in the red sub-pixel unit is smaller than that of the second optical path regulating layer in the blue sub-pixel unit; and/or the number of the groups of groups,

the thickness of the second optical path adjusting layer in the green sub-pixel unit is smaller than the thickness of the second optical path adjusting layer in the blue sub-pixel unit.

5. The light-emitting device according to claim 4, wherein the first optical path adjustment layer in the red sub-pixel unit, the first optical path adjustment layer in the green sub-pixel unit, and the first optical path adjustment layer in the blue sub-pixel unit are formed of the same material; and/or the number of the groups of groups,

the second optical path adjusting layer in the red sub-pixel unit, the second optical path adjusting layer in the green sub-pixel unit and the second optical path adjusting layer in the blue sub-pixel unit are formed of the same material.

6. The light-emitting device according to claim 4, wherein the light-emitting layer is a quantum dot light-emitting layer or an organic light-emitting layer, and wherein a material of the quantum dot light-emitting layer comprises at least one of quantum dots of a single structure and quantum dots of a core-shell structure;

The core of the quantum dot with the core-shell structure comprises any one of the quantum dots with the single structure, and the shell material of the quantum dot with the core-shell structure comprises CdS, cdTe, cdSeTe, cdZnSe, cdZnS, cdSeS, znSe, znSeS, znS and at least one of the quantum dots with the single structure;

7. The light-emitting device according to claim 4, wherein the first optical path adjustment layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer sequentially stacked between the bottom electrode and the light-emitting layer;

8. The light-emitting device according to claim 4, wherein the second optical path adjustment layer includes at least one of a hole blocking layer, an electron transport layer, and an electron injection layer sequentially stacked between the light-emitting layer and the top electrode;

9. A light emitting device according to any one of claims 1 to 3 wherein the bottom electrode and/or the top electrode is a common electrode or a non-common electrode common to the red, green and blue sub-pixel cells.

10. A light emitting device according to any one of claims 1 to 3 wherein the material of the bottom electrode and/or top electrode comprises one or more of a metal comprising one or more of Al, ag, cu, mo, au, ba, ca, yb and Mg, a carbon material and a metal oxide; the carbon material comprises one or more of graphite, carbon nanotubes, graphene and carbon fibers; the metal oxide comprises one or more of doped or undoped metal oxide, ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, or a composite electrode comprising one or more of AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/Al/ITO, znO/Ag/ZnO, znO/Al/ZnO, znS/Ag/ZnS, znS/Al/ZnS, tiO2/Ag/TiO2 and TiO2/Al/TiO2, wherein the metal is sandwiched between the doped or undoped transparent metal oxide.

11. A method of manufacturing a light emitting device, comprising the steps of:

providing a substrate, and forming a bottom electrode on the substrate;

12. A display apparatus comprising an encapsulation film, and the light-emitting device according to any one of claims 1 to 10 or the light-emitting device produced by the method for producing a light-emitting device according to claim 11, wherein the encapsulation film encapsulates the light-emitting device.