CN113707820A - Display device - Google Patents

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Publication number
CN113707820A
CN113707820A CN202010434855.0A CN202010434855A CN113707820A CN 113707820 A CN113707820 A CN 113707820A CN 202010434855 A CN202010434855 A CN 202010434855A CN 113707820 A CN113707820 A CN 113707820A
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electron
light
unit
emitting
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孙明晓
金南德
乔明胜
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Hisense Visual Technology Co Ltd
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Hisense Visual Technology Co Ltd
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K2101/00—Properties of the organic materials covered by group H10K85/00
    • H10K2101/10—Triplet emission
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/12—Active-matrix OLED [AMOLED] displays
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass

Abstract

The invention discloses a display device, comprising: the organic light emitting diode device comprises a substrate base plate and an organic light emitting diode device positioned on the substrate base plate; the organic light emitting diode device includes: an anode and a cathode disposed opposite to each other, and a light emitting layer disposed between the anode and the cathode. The organic light emitting diode device is a single-layer white organic light emitting diode device, a light emitting layer in the white organic light emitting diode device is made of delayed fluorescent materials, at least two light emitting units emitting light with different colors are bonded in the delayed fluorescent materials, and emergent light of each light emitting unit is mixed into white light. The white light organic light emitting diode device with the single-layer light emitting layer can be manufactured by adopting the delayed fluorescent material in the light emitting layer, has a simple structure, simplifies the production process and is beneficial to reducing the production cost. Meanwhile, the light-emitting layer made of the polymer is beneficial to further improving the light-emitting efficiency of the single-layer white organic light-emitting diode device.

Description

Display device
Technical Field
The invention relates to the technical field of display, in particular to a display device.
Background
The Organic Light Emitting Diode (OLED) display technology has the advantages of low power consumption, fast response speed, wide viewing angle, Light weight, flexibility, and the like, and is a display technology with great potential.
The white organic light emitting diode device can generate high-efficiency saturated white light, has the characteristics of low driving voltage, good material flexibility, large-area display and the like, and has great application potential in the fields of information display, solid-state lighting and the like. White OLEDs are mainly classified into single light emitting layers, multiple light emitting layers, down-conversion, lamination, and the like.
At present, the high-performance white OLED and the preparation technology thereof have the bottleneck problems of complex device structure and difficult regulation and control of the doping proportion of host and guest materials, so that the problems of high device preparation difficulty, high production equipment investment cost, low yield and the like are caused.
The white light OLED with the single-layer light emitting layer has the advantages of simple structure, simplified process, low cost and the like, and has great process advantages compared with a multi-layer white light OLED. However, the current single-layer white OLED device has low efficiency, which severely restricts the development of the white OLED device.
Disclosure of Invention
In some embodiments of the present invention, the organic light emitting diode device is a single-layer white organic light emitting diode device, a light emitting layer in the white organic light emitting diode device is made of a delayed fluorescent material, at least two light emitting units emitting light with different colors are bonded to the delayed fluorescent material, and light emitted from each light emitting unit is mixed into white light. The white light organic light emitting diode device with the single-layer light emitting layer can be manufactured by adopting the delayed fluorescent material in the light emitting layer, has a simple structure, simplifies the production process and is beneficial to reducing the production cost. Meanwhile, the light-emitting layer made of the polymer is beneficial to further improving the light-emitting efficiency of the single-layer white organic light-emitting diode device.
In some embodiments of the invention, the light-emitting layer comprises different electron-donating groups and electron-withdrawing groups to form delayed fluorescence light-emitting units emitting different colors of light, and the delayed fluorescence light-emitting units emitting different colors of light are bonded in the same polymer, so that white light can be mixed.
In some embodiments of the invention, the electron-withdrawing group comprises an electron-donating group, wherein the electron-withdrawing group includes, but is not limited to: thiophene 5,5,10, 10-tetraoxide groups, dibenzo [ a, c ] bipyridine [3,2-h:2' -j ] phenazine groups, oxadiazole groups, triazine groups, triphenylboron groups, naphthalimide groups, dicyanopyrazine groups, diboron anthracene groups, and acridone groups; electron donating groups include, but are not limited to: diphenylamine, dicarbazole, tricarbazole, tert-butylcarbazole, acridine, phenoxazine, phenothiazine, triphenylamine and dihydrophenazine groups.
In some embodiments of the present invention, the polymer material used in the light-emitting layer bonds two light-emitting units, namely a blue light-emitting unit for emitting blue light and a yellow light-emitting unit for emitting yellow light.
In some embodiments of the invention, the electron-withdrawing group in the blue-emitting unit is a triazine group, and the electron-donating group in the blue-emitting unit is an acridine group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a dicarbazole group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a tricarbazole group.
The electron-withdrawing group in the yellow luminous unit is a thiophene 5,5,10, 10-tetraoxide group, and the electron-donating group in the yellow luminous unit is an acridine group; or the electron-withdrawing group in the yellow luminous unit is a triazine group, and the electron-donating group in the yellow luminous unit is a phenoxazine group; or the electron-withdrawing group in the yellow luminous unit is an acridone group, and the electron-donating group in the yellow luminous unit is a phenothiazine group.
In some embodiments of the present invention, the light-emitting layer employs a copolymer having a ratio of blue light-emitting units to yellow light-emitting units of 1: 1; alternatively, the light-emitting layer adopts a ratio of blue light-emitting units to yellow light-emitting units of n1:n2The block copolymer of (1).
In some embodiments of the present invention, the polymer material used in the light emitting layer bonds three light emitting units, namely a blue light emitting unit for emitting blue light, a red light emitting unit for emitting red light, and a green light emitting unit for emitting green light.
In some embodiments of the invention, the electron-withdrawing group in the blue-emitting unit is a triazine group, and the electron-donating group in the blue-emitting unit is an acridine group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a dicarbazole group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a tricarbazole group.
An electron-withdrawing group in the red luminescent unit is a dibenzo [ a, c ] bipyridine [3,2-h:2' -j ] phenazine group, and an electron-donating group in the red luminescent unit is a phenoxazine group; or the electron-withdrawing group in the red luminescent unit is a naphthalimide group, and the electron-donating group in the red luminescent unit is an acridine group; or the electron-withdrawing group in the red luminescent unit is a triazine group, and the electron-donating group in the red luminescent unit is a dihydrophenazine group.
The electron-withdrawing group in the green luminescent unit is a triazine group, and the electron-donating group in the green luminescent unit is a diphenylamine carbazole group; or the electron-withdrawing group in the green luminescent unit is a thioxanthene tetroxide group, and the electron-donating group in the green luminescent unit is an acridine group; or the electron-withdrawing group in the green luminescent unit is a diboron anthracene group, and the electron-donating group in the green luminescent unit is a tert-butyl carbazole group.
In some embodiments of the present invention, the light-emitting layer employs a copolymer having a ratio of blue light-emitting units, green light-emitting units, and red light-emitting units of 1:1: 1; or the proportion of the blue light-emitting unit, the green light-emitting unit and the red light-emitting unit in the light-emitting layer is n1:n2:n3The block copolymer of (1).
In some embodiments of the present invention, the organic light emitting diode device further comprises: a hole injection layer, a hole transport layer, and an electron transport layer. The hole injection layer, the hole transport layer and the light-emitting layer are manufactured by a solution method, so that the cost is reduced.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic cross-sectional structure diagram of a display device according to an embodiment of the present invention;
fig. 2 is a schematic cross-sectional view of an organic light emitting diode device according to an embodiment of the present invention;
fig. 3 is a second schematic cross-sectional view illustrating an organic light emitting diode device according to an embodiment of the invention;
fig. 4 is a flowchart of a method for manufacturing a display device according to an embodiment of the invention.
Among them, 11-substrate, 12-organic light emitting diode device, 121-anode, 122-cathode, 123-light emitting layer, 124-hole injection layer, 125-hole transport layer, 126-electron transport layer.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, the present invention is further described with reference to the accompanying drawings and examples. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their repetitive description will be omitted. The words expressing the position and direction described in the present invention are illustrated in the accompanying drawings, but may be changed as required and still be within the scope of the present invention. The drawings of the present invention are for illustrative purposes only and do not represent true scale.
The OLED display device has the advantages of being light and thin, high in brightness, low in power consumption, fast in response, high in definition, good in flexibility, high in luminous efficiency and the like, and occupies an increasingly important position in the display field.
The OLED display device comprises an array substrate and an encapsulation cover plate.
The array substrate comprises a substrate and a Thin Film Transistor (TFT) driving circuit formed on the substrate, wherein the OLED device is formed on the TFT driving circuit and is electrically connected with the TFT circuit.
The packaging cover plate is arranged opposite to the array substrate and used for packaging the OLED device.
The OLED device includes an anode, a light emitting layer, and a cathode. The anode, the light-emitting layer and the cathode form a sandwich structure, after an electric field is generated between the anode and the cathode, electrons and holes can move to the light-emitting layer and are combined into excitons in the light-emitting layer, and the excitons excite light-emitting molecules to finally generate visible light.
The White Organic Light Emitting Diode (WOLED) can generate high-efficiency saturated white light, has the characteristics of low driving voltage, good material flexibility, large-area display and the like, and has huge application potential in the fields of information display, solid-state lighting and the like. The WOLED is mainly divided into a single light emitting layer, a multiple light emitting layer, a down-conversion layer, a lamination layer, and the like. At present, the bottleneck problems of complicated device structure and difficult regulation and control of the doping proportion of a host material and a guest material exist in the high-performance WOLED and the preparation technology thereof, so that the problems of high device preparation difficulty, high production equipment input cost, low yield and the like are caused. The single-layer WOLED has the advantages of simple structure, simplified process, low cost and the like, and has great process advantages compared with the multilayer WOLED. However, the efficiency of the current single-layer WOLED is low, and the development of WOLED devices is severely restricted.
In view of the above, embodiments of the present invention provide a display device, in which a light emitting layer of an organic light emitting diode device has a single-layer structure, and the organic light emitting diode device has high efficiency, so as to effectively solve the above problems.
Fig. 1 is a schematic cross-sectional structure diagram of a display device according to an embodiment of the present invention.
Referring to fig. 1, a display device according to an embodiment of the present invention includes: a substrate 11 and an organic light emitting diode device 12 located on the substrate 11.
The substrate base plate 11 is generally located at the bottom of the display device for supporting and carrying all the elements in the display device. The shape of the substrate 11 is adapted to the shape of the display device, and the display devices currently applied to the fields of televisions, mobile terminals, and the like are all rectangular, so that the substrate 11 can also be rectangular; in addition, if the display device is applied to a special-shaped display device such as a smart watch, the substrate base plate can be correspondingly set to be in a shape of a circle or the like, which is not limited herein.
The display device in the embodiment of the invention can be a rigid display device or a flexible display device. When the substrate 11 of the rigid display device is made of a rigid material such as glass, the substrate 11 of the flexible display device is made of a flexible material such as Polyimide (PI).
Before the OLED is fabricated on the substrate 11, a driving circuit needs to be fabricated on the substrate, and a thin film transistor array may be formed on the substrate 11 by a thin film fabrication process to form the driving circuit. In the embodiment of the present invention, the OLED may be driven by a passive driving method or an active driving method.
The organic light emitting diode device 12 is located on the substrate base plate 11. The organic light emitting diode device 12 functions as a sub-pixel in the display apparatus. The organic light emitting diode device 12 in the embodiment of the present invention is a white organic light emitting diode device, and can be used in combination with a color filter in practical applications.
Fig. 2 is a schematic cross-sectional view of an organic light emitting diode device according to an embodiment of the present invention.
Referring to fig. 2, the organic light emitting diode device 12 includes at least an anode 121, a cathode 122, and an emission layer 123.
The anode 121 is located above the substrate 11 and electrically connected to a driving circuit on the substrate 11.
The sub-pixels in the display panel are OLEDs, and the area of each anode defines a light emitting area of the OLED, i.e., an open area of the sub-pixel. The size of the anode 121 may be determined according to the design and resolution of the display device, and is not limited herein. The anode may be generally rectangular in shape. The anode is made of Indium Tin Oxide (ITO) or the like.
The cathode 122 is located on a side of the anode 121 facing away from the substrate base plate 11, the cathode 122 is disposed opposite to the anode 121, and an electric field is generated between the cathode 122 and the anode 121 when an electric signal is applied.
The cathode 122 is typically disposed over the entire surface, and need not be individually disposed for each sub-pixel. The cathode 122 has a shape corresponding to the shape of the base substrate 11, and may be generally rectangular. The size of the cathode is determined by the footprint of all the OLEDs, with cathode 122 overlying all the OLEDs. The cathode is made of silver Ag or aluminum Al and the like.
The light-emitting layer 123 is located between the anode 121 and the cathode 122, and when an electric signal is applied to the anode 121 and the cathode 122 to form an electric field between the anode 121 and the cathode 122, electrons and holes move to the light-emitting layer 123 and combine into an excitation in the light-emitting layer 123, so that the light-emitting material is excited to emit light.
The light emitted from the light emitting layer 123 in the embodiment of the present invention is white light, so the light emitting layer 123 may be disposed in a whole layer, or the light emitting layer 123 may be disposed on the anode 121 only, and no matter which manufacturing method is adopted, the white light organic light emitting diode device is used in cooperation with the color filter, and different sub-pixels may be controlled to emit light of different colors.
Fig. 3 is a second schematic cross-sectional view of an organic light emitting diode device according to an embodiment of the invention.
Referring to fig. 3, the organic light emitting diode device 12 according to the embodiment of the present invention further includes: a hole injection layer 124, a hole transport layer 125, and an electron transport layer 126.
A hole injection layer 124 is located on the surface of the anode 121 on the side facing away from the substrate base 11.
The hole injection layer 124 may be provided as a whole layer or may be provided only over the anode 121.
The entire layer of the hole injection layer 124 may provide holes for all OLED devices, and the process of disposing the hole injection layer 124 entirely is relatively simple.
However, only holes injected to the position of the anode 121 contribute to light emission of the OLED device, and thus the hole injection layer 124 may be formed only on the anode 121, which saves cost.
According to the embodiment of the invention, the hole injection layer 124 is arranged on the anode 121, so that the hole injection capability of the device can be improved, the stability of the device is increased, and the service life is prolonged.
The hole injection layer 124 is formed by a solution method using a polymer material. For example, poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonic acid) (PEDOT: PSS) and other materials can be used for the hole injection layer 124.
Hole transport layer 125 is located on the surface of hole injection layer 124 on the side facing away from anode 121.
The hole transport layer 125 may be provided as a whole layer, or may be provided only at a position corresponding to the anode 121.
The hole transport layer 125 can improve hole transport ability, and facilitate transport of carriers to the light emitting layer 123. Meanwhile, the hole transport layer 125 also has the function of blocking electrons, so that the transport of carriers can be balanced, and the efficiency of the device can be improved.
The hole transport layer 125 is formed by a solution method using a polymer material. For example, Poly-bis (4-phenyl) (4-butylphenyl) amine (Poly-TPD) or the like can be used as the hole transport layer 125.
The electron transport layer 126 is located on the surface of the light-emitting layer 123 on the side facing away from the hole transport layer 125.
The electron transport layer 126 may be provided as a whole layer, or may be provided only at a position corresponding to the anode 121.
The electron transport layer 126 is used for injecting and transporting electrons, which is beneficial for transporting carriers to the light emitting layer 123, and the arrangement of the electron transport layer 126 can improve the efficiency of the device.
The electron transport layer 126 is made of an N-type semiconductor with a wide bandgap, and can ensure a strong carrier transport capability and a high carrier concentration. The electron transport layer 126 may be made of zinc oxide (ZnO) nanoparticles or the like.
In the embodiment of the present invention, the light-emitting layer 123 employs a delayed fluorescent material, which has a light emission mechanism different from that of conventional first-generation fluorescent materials (singlet emission light) and second-generation phosphorescent materials (triplet emission light), and when the energy gap difference between the S1 state (first singlet excited state) and the T1 state (first triplet excited state) is sufficiently small (<0.1eV), excitons of the triplet state can efficiently cross into the singlet state and complete singlet emission light emission, that is, fluorescence is emitted. Due to the channeling effect of the triplet excitons, the exciton utilization rate of the delayed fluorescent material can reach 100%, and the luminous efficiency of the luminescent material can be remarkably improved.
In addition, the delayed fluorescence material is a pure organic material and does not contain noble metal, so the cost is lower, and the preparation of the luminescent material with low cost and high efficiency can be realized.
In the embodiment of the present invention, at least two light emitting units emitting light with different colors are bonded in the delayed fluorescent material used in the light emitting layer 123, and the light emitted from each light emitting unit is mixed into white light.
The light-emitting layer 123 is made of a polymer material, such as polyethylene, polypropylene, etc., and at least two light-emitting units emitting different colors of light are bonded in the polymer material, wherein the light-emitting units include an electron-withdrawing group and an electron-donating group.
According to the embodiment of the invention, the electron donating group and the electron withdrawing group are bonded in the polymer chain segment, and when the space distance between the electron donating group and the electron withdrawing group is less than 0.35nm, the electron donating group and the electron withdrawing group can generate space charge transfer effect. Meanwhile, the highest occupied orbital HOMO and the lowest unoccupied orbital LUMO of the molecule are separated by the electron donating group and the electron withdrawing group which are spatially separated, and the energy gap difference between the singlet state energy level and the triplet state energy level of the molecule is very small due to the separation to a large degree, so that the molecule has remarkable delayed fluorescence property. And the smaller energy gap difference between the single state and the triplet state enables the triplet state exciton of the molecule to rapidly cross to the singlet state excited state, and the singlet state excited state is radiated and transited to the ground state, so that the exciton utilization rate of the luminescent material is greatly improved, namely 75% of the triplet state exciton is fully utilized on the basis of utilizing 25% of the singlet state exciton, and the preparation of a high-efficiency organic light-emitting diode device is facilitated.
When the electron donating group and the electron withdrawing group in the molecule have different electron donating abilities and electron withdrawing abilities respectively, the space charge transfer property between the electron donating group and the electron withdrawing group is changed, and finally the luminescent color of the molecule is changed.
Different electron donating groups and electron withdrawing groups are adopted to construct delayed fluorescence luminescence units emitting different colors of light, and the delayed fluorescence luminescence units emitting different colors of light are bonded in the same polymer, so that white light can be mixed.
In the embodiment of the present invention, the polymer material used in the light-emitting layer 123 is bonded to at least two light-emitting units, and the light-emitting units are composed of electron-withdrawing groups and electron-donating groups. Among these, electron withdrawing groups include, but are not limited to:
Figure BDA0002501848880000091
electron donating groups include, but are not limited to:
Figure BDA0002501848880000092
Figure BDA0002501848880000101
in the embodiment of the present invention, the polymer material used in the light emitting layer 123 bonds two kinds of light emitting units, namely, a blue light emitting unit for emitting blue light and a yellow light emitting unit for emitting yellow light.
Wherein, the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is an acridine group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a dicarbazole group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a tricarbazole group.
The electron-withdrawing group in the yellow luminous unit is a thiophene 5,5,10, 10-tetraoxide group, and the electron-donating group in the yellow luminous unit is an acridine group; or the electron-withdrawing group in the yellow luminous unit is a triazine group, and the electron-donating group in the yellow luminous unit is a phenoxazine group; or the electron-withdrawing group in the yellow luminous unit is an acridone group, and the electron-donating group in the yellow luminous unit is a phenothiazine group.
In addition, the blue light-emitting unit and the yellow light-emitting unit may be of a type other than the electron-withdrawing group and the electron-donating group, and the examples of the present invention are merely illustrative and do not limit the types of the electron-withdrawing group and the electron-donating group in the blue light-emitting unit and the yellow light-emitting unit.
For example, the electron donating group of the yellow light-emitting unit is represented by D1, and the electron withdrawing group of the yellow light-emitting unit is represented by a 1; the electron donating group of the blue light-emitting unit is represented by D2, and the electron withdrawing group of the blue light-emitting unit is represented by A2. Wherein D1, D2, A1 and A2 adopt the following groups:
Figure BDA0002501848880000111
D1-A1 is the yellow light emitting unit and can emit yellow light; D2-A2 constituted the blue light emitting cell and was able to emit blue light. The light emitting cells D1-A1 and D2-A2 formed in the polymer used in the light emitting layer 123 can emit white light finally.
In preparing the polymer material of the light emitting layer 123, yellow light emitting units D1-a1 and blue light emitting units D2-a2 may be bonded in the same ratio on the polymer chain to form a copolymer in the following form:
Figure BDA0002501848880000112
wherein x is1Representation D1Number of (2), x2Denotes the number of D2, y1Denotes the number of A1, y2Denotes the number of A2 and n denotes the number of the above-mentioned polymer chains contained. x is the number of1、x2、y1、y2And n is a positive integer greater than or equal to 1.
Alternatively, it is also possible to block-polymerize polymer chains having different proportions of the yellow light-emitting units D1-A1 and the blue light-emitting units D2-A2 bonded thereto to form block copolymers of the following form:
Figure BDA0002501848880000113
wherein x is1Denotes the number, x, of D12Denotes the number of D2, y1Denotes the number of A1, y2Denotes the number of A2, n1Denotes the number of polymer chains comprising D1-A1, n2Indicating the number of polymer chains comprising D2-A2. x is the number of1、x2、y1、y2、n1、n2Are all positive integers greater than or equal to 1.
In the embodiment of the present invention, the material of the light-emitting layer 123 adopts any one of the above forms, and the emission wavelengths of the blue light-emitting unit and the yellow light-emitting unit can be adjusted by adjusting the types of the electron-withdrawing group and the electron-donating group used for the blue light-emitting unit and the yellow light-emitting unit. In addition, the color of the light-emitting layer 123 can be finely adjusted by adjusting the ratio of the blue light-emitting units and the yellow light-emitting units contained in the molecule, so that the light finally emitted from the light-emitting layer 123 is white light that meets the standard.
In another embodiment of the present invention, the polymer material used in the light emitting layer 123 bonds three kinds of light emitting units, namely, a blue light emitting unit for emitting blue light, a red light emitting unit for emitting red light, and a green light emitting unit for emitting green light.
Wherein, the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is an acridine group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a dicarbazole group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a tricarbazole group.
An electron-withdrawing group in the red luminescent unit is a dibenzo [ a, c ] bipyridine [3,2-h:2' -j ] phenazine group, and an electron-donating group in the red luminescent unit is a phenoxazine group; or the electron-withdrawing group in the red luminescent unit is a naphthalimide group, and the electron-donating group in the red luminescent unit is an acridine group; or the electron-withdrawing group in the red luminescent unit is a triazine group, and the electron-donating group in the red luminescent unit is a dihydrophenazine group.
The electron-withdrawing group in the green luminescent unit is a triazine group, and the electron-donating group in the green luminescent unit is a diphenylamine carbazole group; or the electron-withdrawing group in the green luminescent unit is a thioxanthene tetroxide group, and the electron-donating group in the green luminescent unit is an acridine group; or the electron-withdrawing group in the green luminescent unit is a diboron anthracene group, and the electron-donating group in the green luminescent unit is a tert-butyl carbazole group.
In addition, the blue light-emitting unit, the red light-emitting unit, and the green light-emitting unit may be of a type other than the electron-withdrawing group and the electron-donating group described above, and the examples of the present invention are merely illustrative and do not limit the types of the electron-withdrawing group and the electron-donating group in the blue light-emitting unit, the red light-emitting unit, and the green light-emitting unit.
For example, the electron donating group of the blue luminescent unit is represented by D1, and the electron withdrawing group of the blue luminescent unit is represented by a 1; the electron donating group of the green luminescent unit is represented by D2, and the electron withdrawing group of the green luminescent unit is represented by A2; the electron donating group of the red luminescent unit is represented by D3, and the electron withdrawing group of the red luminescent unit is represented by A3. Wherein D1, D2, D3, A1, A2 and A3 adopt the following groups:
Figure BDA0002501848880000131
D1-A1 constituting the blue light-emitting unit and emitting blue light; D2-A2 constitutes the green light emitting unit and can emit green light; D3-A3 constituted the red light emitting cell and allowed emission of red light. The light emitting units D1-A1, D2-A2 and D3-A3 can emit white light finally when the polymer used for the light emitting layer 123 forms.
In preparing the polymer material of the light emitting layer 123, blue light emitting units D1-a1, green blue light emitting units D2-a2, and red light emitting units D3-A3 may be bonded in the same ratio on the polymer chain to form a copolymer of the following form:
Figure BDA0002501848880000132
wherein x is1Denotes the number, x, of D12Denotes the number, x, of D23Denotes the number of D3, y1Denotes the number of A1, y2Denotes the number of A2, y3Denotes the number of A3 and n denotes the number of the above-mentioned polymer chains contained. x is the number of1、x2、x3、y1、y2、y3And n is a positive integer greater than or equal to 1.
Alternatively, it is also possible to block-polymerize polymer chains having different proportions of the blue luminescent units D1-A1, the green luminescent units D2-A2, and the red luminescent units D3-A3 bonded thereto to form block copolymers of the following form:
Figure BDA0002501848880000141
wherein x is1Denotes the number, x, of D12Denotes the number, x, of D22Denotes the number of D3, y1Denotes the number of A1, y2Denotes the number of A2, y3Denotes the number of A3, n1Denotes the number of polymer chains comprising D1-A1, n2Denotes the number of polymer chains comprising D2-A2, n3Indicating the number of polymer chains comprising D3-A3. x is the number of1、x2、x3、y1、y2、y3、n1、n2、n3Are all positive integers greater than or equal to 1.
In the embodiment of the present invention, the material of the light-emitting layer 123 adopts any one of the above forms, and the emission wavelengths of the blue light-emitting unit, the green light-emitting unit, and the red light-emitting unit can be adjusted by adjusting the types of the electron-withdrawing group and the electron-donating group used for the blue light-emitting unit, the green light-emitting unit, and the red light-emitting unit. In addition, the color of the light-emitting layer 123 can be finely adjusted by adjusting the ratio of the blue light-emitting unit, the green light-emitting unit, and the red light-emitting unit included in the molecule, so that the light finally emitted from the light-emitting layer 123 is white light that meets the standard.
The light-emitting layer in the embodiment of the invention adopts the delayed fluorescent material, so that a white light organic light-emitting diode device with a single light-emitting layer can be manufactured, the structure of the single white light organic light-emitting diode device is simple, the production process is simplified, and the production cost is favorably reduced. Meanwhile, the light-emitting layer made of the polymer is beneficial to further improving the light-emitting efficiency of the single-layer white organic light-emitting diode device.
Fig. 4 is a flowchart of a method for manufacturing a display device according to an embodiment of the invention.
Referring to fig. 4, a method for manufacturing a display device according to an embodiment of the present invention includes:
s10, forming a pattern of an anode on the substrate base plate;
s20, forming a hole injection layer on one side of the anode, which is far away from the substrate base plate;
s30, forming a hole transport layer on the side of the hole injection layer, which is far away from the anode;
s40, forming a light-emitting layer on the side of the hole transport layer, which is far away from the hole injection layer;
s50, forming an electron transport layer on the side, away from the hole transport layer, of the light-emitting layer;
and S60, forming a cathode on the side of the electron transport layer, which faces away from the light-emitting layer.
The light-emitting layer in the embodiment of the invention adopts the delayed fluorescent material, so that a white light organic light-emitting diode device with a single light-emitting layer can be manufactured, the structure of the single white light organic light-emitting diode device is simple, the production process is simplified, and the production cost is favorably reduced. Meanwhile, the light-emitting layer made of the polymer is beneficial to further improving the light-emitting efficiency of the single-layer white organic light-emitting diode device.
The luminescent layer in the embodiment of the invention adopts organic materials and can be manufactured by a solution method; the hole injection layer and the hole transport layer can also be formed by a solution method. The solution method includes an ink-jet printing method, a spin coating method, a screen printing method, a roll-to-roll process, or the like, and any solution method is not used for the preparation.
Specifically, a pattern of an anode is formed on a substrate on which a driving circuit is formed, the anode may be formed using an etching process, and the anode uses Indium Tin Oxide (ITO).
After the pattern for forming the anode is prepared, the substrate with the anode needs to be washed and dried.
After cleaning the substrate base plate, a hole injection layer is formed on the anode by a solution method. For example, the hole injection layer can be ink-jet printed over the anode. The hole injection layer adopts poly (3, 4-ethylenedioxythiophene) and poly (styrene sulfonic acid) (PEDOT: PSS), and the thickness is 10nm-40 nm.
After the hole injection layer is formed, the substrate is vacuum-dried and baked, and then a hole transport layer is formed over the hole injection layer using a solution method. For example, the hole transport layer may be ink-jet printed over the hole injection layer. The hole transport layer adopts Poly-bis (4-phenyl) (4-butylphenyl) amine (Poly-TPD) with the thickness of 10nm-40 nm.
After the hole transport layer is formed, the substrate is vacuum-dried and baked, and then a light emitting layer is formed over the hole transport layer using a solution method. The light emitting layer is made of delayed fluorescent material, at least two light emitting units emitting light with different colors are bonded in the delayed fluorescent material, and the emergent light of each light emitting unit is mixed into white light. The thickness of the light-emitting layer is 20nm-200 nm.
After the light emitting layer is formed, the substrate is vacuum-dried and baked, and then an electron transport layer is deposited over the light emitting layer. The electron transport layer can adopt zinc oxide nano-particles.
After forming the electron transport layer, a cathode is deposited over the electron transport layer. The cathode can be made of aluminum, silver, copper, and the like, and is not limited herein.
After the organic light emitting diode device is manufactured, the display panel is packaged.
According to the first inventive concept, the organic light emitting diode device in the display apparatus provided in the embodiments of the present invention is a single-layer white organic light emitting diode device, a light emitting layer in the white organic light emitting diode device is made of a delayed fluorescent material, at least two light emitting units emitting light with different colors are bonded to the delayed fluorescent material, and light emitted from each light emitting unit is mixed into white light. The white light organic light emitting diode device with the single-layer light emitting layer can be manufactured by adopting the delayed fluorescent material in the light emitting layer, has a simple structure, simplifies the production process and is beneficial to reducing the production cost. Meanwhile, the light-emitting layer made of the polymer is beneficial to further improving the light-emitting efficiency of the single-layer white organic light-emitting diode device.
According to the second inventive concept, the delayed fluorescence light-emitting units emitting different colors of light are constructed by adopting different electron-donating groups and electron-withdrawing groups in the light-emitting layer, and the delayed fluorescence light-emitting units emitting different colors of light are bonded in the same polymer, so that white light can be mixed.
According to a third inventive concept, the light-emitting unit is composed of an electron-withdrawing group and an electron-donating group, wherein the electron-withdrawing group includes, but is not limited to: thiophene 5,5,10, 10-tetraoxide groups, dibenzo [ a, c ] bipyridine [3,2-h:2' -j ] phenazine groups, oxadiazole groups, triazine groups, triphenylboron groups, naphthalimide groups, dicyanopyrazine groups, diboron anthracene groups, and acridone groups; electron donating groups include, but are not limited to: diphenylamine, dicarbazole, tricarbazole, tert-butylcarbazole, acridine, phenoxazine, phenothiazine, triphenylamine and dihydrophenazine groups.
According to the fourth inventive concept, the polymer material employed for the light emitting layer bonds two kinds of light emitting units, a blue light emitting unit for emitting blue light and a yellow light emitting unit for emitting yellow light, respectively.
According to the fifth inventive concept, the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is an acridine group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a dicarbazole group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a tricarbazole group.
The electron-withdrawing group in the yellow luminous unit is a thiophene 5,5,10, 10-tetraoxide group, and the electron-donating group in the yellow luminous unit is an acridine group; or the electron-withdrawing group in the yellow luminous unit is a triazine group, and the electron-donating group in the yellow luminous unit is a phenoxazine group; or the electron-withdrawing group in the yellow luminous unit is an acridone group, and the electron-donating group in the yellow luminous unit is a phenothiazine group.
According to the sixth inventive concept, the light emitting layer employs a copolymer having a ratio of blue light emitting units to yellow light emitting units of 1: 1; alternatively, the light-emitting layer adopts a ratio of blue light-emitting units to yellow light-emitting units of n1:n2The block copolymer of (1).
According to the seventh inventive concept, the emission wavelengths of the blue light-emitting unit and the yellow light-emitting unit are adjusted by adjusting the kinds of electron-withdrawing groups and electron-donating groups used for the blue light-emitting unit and the yellow light-emitting unit. In addition, the color of the light-emitting layer can be finely adjusted by adjusting the ratio of the blue light-emitting unit and the yellow light-emitting unit contained in the molecule, so that the light finally emitted by the light-emitting layer is white light which meets the standard.
According to the eighth inventive concept, the polymer material employed in the light emitting layer bonds three kinds of light emitting units, respectively, a blue light emitting unit for emitting blue light, a red light emitting unit for emitting red light, and a green light emitting unit for emitting green light.
According to the ninth inventive concept, the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is an acridine group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a dicarbazole group; or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a tricarbazole group.
An electron-withdrawing group in the red luminescent unit is a dibenzo [ a, c ] bipyridine [3,2-h:2' -j ] phenazine group, and an electron-donating group in the red luminescent unit is a phenoxazine group; or the electron-withdrawing group in the red luminescent unit is a naphthalimide group, and the electron-donating group in the red luminescent unit is an acridine group; or the electron-withdrawing group in the red luminescent unit is a triazine group, and the electron-donating group in the red luminescent unit is a dihydrophenazine group.
The electron-withdrawing group in the green luminescent unit is a triazine group, and the electron-donating group in the green luminescent unit is a diphenylamine carbazole group; or the electron-withdrawing group in the green luminescent unit is a thioxanthene tetroxide group, and the electron-donating group in the green luminescent unit is an acridine group; or the electron-withdrawing group in the green luminescent unit is a diboron anthracene group, and the electron-donating group in the green luminescent unit is a tert-butyl carbazole group.
According to the tenth inventive concept, the light emitting layer employs a copolymer having a ratio of blue light emitting units, green light emitting units, and red light emitting units of 1:1: 1; or the proportion of the blue light-emitting unit, the green light-emitting unit and the red light-emitting unit in the light-emitting layer is n1:n2:n3The block copolymer of (1).
According to the eleventh inventive concept, emission wavelengths of the blue light-emitting unit, the green light-emitting unit, and the red light-emitting unit are adjusted by adjusting kinds of electron-withdrawing groups and electron-donating groups employed for the blue light-emitting unit, the green light-emitting unit, and the red light-emitting unit. In addition, the color of the light-emitting layer can be finely adjusted by adjusting the proportion of the blue light-emitting unit, the green light-emitting unit and the red light-emitting unit contained in the molecule, so that the light finally emitted by the light-emitting layer is white light which meets the standard.
According to the twelfth inventive concept, the hole injection layer, the hole transport layer, and the light emitting layer in the organic light emitting diode device are manufactured by a solution method, which is advantageous to reduce the cost.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (10)

1. A display device, comprising:
a substrate base plate having a bearing function;
an organic light emitting diode device located on the substrate base plate for emitting white light;
the organic light emitting diode device includes:
an anode located over the substrate base plate;
the cathode is positioned on one side of the anode, which is far away from the substrate base plate;
a light emitting layer between the anode and the cathode;
the light-emitting layer is made of delayed fluorescent materials, at least two light-emitting units emitting light rays with different colors are bonded in the delayed fluorescent materials in a key mode, and the emergent light of each light-emitting unit is mixed into white light;
the luminescent unit includes an electron withdrawing group and an electron donating group.
2. The display device of claim 1, wherein the electron withdrawing group comprises: thiophene 5,5,10, 10-tetraoxide groups, dibenzo [ a, c ] bipyridine [3,2-h:2' -j ] phenazine groups, oxadiazole groups, triazine groups, triphenylboron groups, naphthalimide groups, dicyanopyrazine groups, diboron anthracene groups, and acridone groups.
3. The display device of claim 1, wherein the electron donating group comprises: diphenylamine, dicarbazole, tricarbazole, tert-butylcarbazole, acridine, phenoxazine, phenothiazine, triphenylamine and dihydrophenazine groups.
4. The display device according to claim 1, wherein a blue light emitting unit for emitting blue light and a yellow light emitting unit for emitting yellow light are bonded in the delayed fluorescent material.
5. The display device according to claim 4, wherein the electron-withdrawing group in the blue light-emitting unit is a triazine group, and the electron-donating group in the blue light-emitting unit is an acridine group;
or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a dicarbazole group;
or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a tricarbazole group;
the electron-withdrawing group in the yellow luminous unit is a thiophene 5,5,10, 10-tetraoxide group, and the electron-donating group in the yellow luminous unit is an acridine group;
or the electron-withdrawing group in the yellow luminous unit is a triazine group, and the electron-donating group in the yellow luminous unit is a phenoxazine group;
or the electron-withdrawing group in the yellow luminous unit is an acridone group, and the electron-donating group in the yellow luminous unit is a phenothiazine group.
6. The display device according to claim 4, wherein the delayed fluorescent material is a copolymer containing the blue light-emitting unit and the yellow light-emitting unit in a ratio of 1: 1;
or the delayed fluorescent material contains the blue light-emitting unit and the yellow light-emitting unit in a ratio of n1:n2The block copolymer of (1);
wherein n is1、n2Is a positive integer greater than or equal to 1.
7. The display device according to claim 1, wherein a blue light emitting unit for emitting blue light, a red light emitting unit for emitting red light, and a green light emitting unit for emitting green light are bonded in the delayed fluorescent material.
8. The display device according to claim 7, wherein the electron-withdrawing group in the blue light-emitting unit is a triazine group, and the electron-donating group in the blue light-emitting unit is an acridine group;
or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a dicarbazole group;
or the electron-withdrawing group in the blue luminescent unit is a triazine group, and the electron-donating group in the blue luminescent unit is a tricarbazole group;
an electron-withdrawing group in the red luminescent unit is a dibenzo [ a, c ] bipyridine [3,2-h:2' -j ] phenazine group, and an electron-donating group in the red luminescent unit is a phenoxazine group;
or the electron-withdrawing group in the red luminescent unit is a naphthalimide group, and the electron-donating group in the red luminescent unit is an acridine group;
or the electron-withdrawing group in the red luminescent unit is a triazine group, and the electron-donating group in the red luminescent unit is a dihydrophenazine group;
the electron-withdrawing group in the green luminescent unit is a triazine group, and the electron-donating group in the green luminescent unit is a diphenylamine carbazole group;
or the electron-withdrawing group in the green luminescent unit is a thioxanthene tetroxide group, and the electron-donating group in the green luminescent unit is an acridine group;
or the electron-withdrawing group in the green luminescent unit is a diboron anthracene group, and the electron-donating group in the green luminescent unit is a tert-butyl carbazole group.
9. The display device according to claim 7, wherein the delayed fluorescent material is a copolymer containing the blue light-emitting unit, the red light-emitting unit, and the green light-emitting unit in a ratio of 1:1: 1;
or the ratio of the blue light-emitting unit, the red light-emitting unit and the green light-emitting unit contained in the delayed fluorescent material is n1:n2:n3The block copolymer of (1);
wherein n is1、n2、n3Is a positive integer greater than or equal to 1.
10. The display device according to any one of claims 1 to 9, wherein the organic light emitting diode device further comprises:
a hole injection layer between the anode and the light emitting layer;
a hole transport layer between the hole injection layer and the light emitting layer;
an electron transport layer between the light emitting layer and the cathode;
the hole injection layer, the hole transport layer and the light-emitting layer are prepared by a solution method.
CN202010434855.0A 2020-05-21 2020-05-21 Display device Pending CN113707820A (en)

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