CN113471392A

CN113471392A - Display device

Info

Publication number: CN113471392A
Application number: CN202010241512.2A
Authority: CN
Inventors: 孙明晓; 金南德; 乔明胜
Original assignee: Hisense Visual Technology Co Ltd
Current assignee: Hisense Visual Technology Co Ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2021-10-01

Abstract

The invention discloses a display device, comprising: a substrate base plate and a light-emitting electrochemical cell device located over the substrate base plate; a light-emitting electrochemical cell device comprising: the light emitting diode comprises a first electrode, a second electrode and a light emitting layer positioned between the first electrode and the second electrode. The luminous layer adopts ion conduction type delayed fluorescence material. The ion conduction type delayed fluorescent material is used as a light emitting layer, so that the high exciton utilization rate and the high light emitting efficiency of the delayed fluorescent material are achieved, the ion conduction characteristic is also achieved, and the conduction of anions and cations in the ion conduction type delayed fluorescent material is beneficial to the injection of carriers, so that the turn-on voltage is reduced.

Description

Display device

Technical Field

The invention relates to the technical field of display, in particular to a display device.

Background

The Light-Emitting Electrochemical Cell (LEC) is developed on the basis of an organic Light-Emitting Diode (OLED), has a sandwich structure similar to that of an OLED device, but has a simpler structure compared with the OLED device, and has a wider application prospect in the fields of low cost and large-area display.

Currently, the luminescent materials used by LECs mainly include ionic transition metal complexes or polymers. The polymer luminescent material is difficult to prepare and purify, and the luminescent efficiency is relatively low; the ionic transition metal complex material has high luminous efficiency, but contains heavy metal elements, so that the material cost is high, and the industrialization of a light-emitting device is restricted.

Disclosure of Invention

In some embodiments of the present invention, the light emitting layer in the light emitting electrochemical cell device employs an ion-conducting delayed fluorescent material, and the ion-conducting delayed fluorescent material has high exciton utilization rate and high light emitting efficiency of the delayed fluorescent material, and also has an ion-conducting characteristic, which is beneficial to injection of carriers and reduction of turn-on voltage.

In some embodiments of the present invention, the molecular structural general formula of the ion-conducting delayed fluorescent material is [ n ]₁Cz·A][n₂PF₆ ^-](ii) a Wherein Cz represents a carbazole group, n₁Denotes the number of carbazole groups, A denotes an electron-withdrawing group, PF₆ ^-Represents a hexafluorophosphate ion, n₂Indicates the number of hexafluorophosphate ions. The ion transmission capability of a molecular system is regulated and controlled by changing the number of anions and cations in molecules, so that the ion transmission capability of the LEC device is optimized.

In some embodiments of the present invention, the electron-withdrawing group is any one of a thioxanthone group, a dibenzothiophene-s, s-dioxide group, a triazine group, a thioxanthene tetraoxide group, an oxadiazole group, and a triphenylboron group.

In some embodiments of the present invention, the light emitting layer comprises: a red light emitting layer, a green light emitting layer, a blue light emitting layer, and a white light emitting layer.

In some embodiments of the present invention, the ion-conducting delayed fluorescence material used in the red light emitting layer is [ n ]₁Cz·Anthraquinone][n₂PF₆ ^-](ii) a Wherein n is₁Denotes the number of carbazole groups, n₂Indicates the number of hexafluorophosphate ions.

In some embodiments of the present invention, the ion-conducting delayed fluorescence material used in the red light emitting layer is [ n ]₁Cz·Diboraanthracene][n₂PF₆ ^-](ii) a Wherein n is₁Denotes the number of carbazole groups, n₂Indicates the number of hexafluorophosphate ions.

In some embodiments of the present invention, the ion-conducting delayed fluorescence material used in the blue light emitting layer is [ n ]₁Cz·Benzoyl][n₂PF₆ ^-](ii) a Wherein n is₁Denotes the number of carbazole groups, n₂Indicates the number of hexafluorophosphate ions.

In some embodiments of the present invention, the white light emitting layer is made of a mixture of materials used for the red light emitting layer, the green light emitting layer and the blue light emitting layer.

In some embodiments of the present invention, the white light emitting layer includes a red sub-light emitting layer, a green sub-light emitting layer, and a blue sub-light emitting layer; the red sub-luminescent layer adopts a red ion conduction type delayed fluorescent material, the green sub-luminescent layer adopts a green ion conduction type delayed fluorescent material, and the blue sub-luminescent layer adopts a blue ion conduction type delayed fluorescent material.

In some embodiments of the present invention, the light-emitting electrochemical cell device further includes a hole injection layer for improving the hole injection capability of the device and increasing the stability of the device, so as to prolong the service life.

In some embodiments of the invention, the light-emitting electrochemical cell device further comprises a hole transport layer for improving hole transport capability, and the hole transport layer also has an electron blocking effect, so that the transport of an electron carrier can be balanced, and the efficiency of the device can be improved.

In some embodiments of the present invention, the hole injection layer, the hole transport layer and the light emitting layer are formed by a solution method. The LEC device manufactured by the solution method can effectively control the production cost and has higher generation efficiency.

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 a light-emitting electrochemical cell device according to an embodiment of the present invention;

FIG. 3 is a second schematic cross-sectional view of a light-emitting electrochemical cell device according to an embodiment of the present invention;

FIG. 4 is a third schematic cross-sectional view of a light-emitting electrochemical cell device according to an embodiment of the present invention;

fig. 5 is a flowchart of a method for manufacturing a display device according to an embodiment of the invention.

Among them, 11-substrate, 12-light-emitting electrochemical cell, 121-first electrode, 122-second electrode, 123-light-emitting layer, 124-hole injection layer, 125-hole 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.

LECs have been developed on the basis of OLEDs, which have a sandwich structure similar to OLED devices.

The luminous layer of LEC contains a lot of mobile anion and cation with ion conductivity, the luminous mechanism is that the chemical doping action of luminous material is used, when LEC works, the anion and cation move to positive and negative electrodes respectively to form p-i-n junction finally, and the current carrier diffuses from cathode and anode to the inside of luminous layer and finally forms exciton finally, and radiates to give out light.

Compared with the traditional OLED device, the LEC device is insensitive to the work function of an electrode, and stable metal aluminum, gold, silver and the like can be used for the cathode of the device; the LEC device is insensitive to the thickness of the light-emitting layer, so that the preparation process of the device is simplified; the LEC device has a simple structure, and does not need an additional charge injection layer; the LEC device is low in turn-on voltage; the LEC emits light regardless of the direction of the electric field, and emits light under positive and negative bias. Therefore, the LEC has a wide application prospect in the field of low-cost and large-area display.

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, the display device comprises a substrate base plate 11 and a light-emitting electrochemical cell device 12 located on the substrate base plate.

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 quantum dot light-emitting diode is manufactured on the substrate 11, a driving circuit is also required to be manufactured on the substrate, and a thin film transistor array can be formed on the substrate 11 by adopting a thin film manufacturing process for forming the driving circuit. In the embodiment of the present invention, the LEC device may be driven in a passive driving manner or an active driving manner.

A light-emitting electrochemical cell device 12 is located on a substrate base plate 11. Each light-emitting electrochemical cell device 12 acts as a sub-pixel unit, and the structure of each light-emitting electrochemical cell device 12 is identical. After the LEC device is electrically connected with the driving circuit, the light emitting control of the sub-pixel unit can be realized by controlling the electric signal of the driving circuit.

Fig. 2 is a schematic cross-sectional view of a light-emitting electrochemical cell device according to an embodiment of the present invention.

Referring to fig. 2, the light-emitting electrochemical cell device includes opposing first and

second electrodes

121 and 122, and a light-emitting layer 123 sandwiched therebetween.

The first electrode 121 is located on the substrate 11 and electrically connected to a driving circuit on the substrate 11.

The first electrode 121 is typically used as an anode, and the area of each anode defines a light emitting area of the LEC device, i.e., an opening area of the sub-pixel. The size of the anode 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 second electrode 122 is located on a side of the first electrode 121 facing away from the substrate base plate 11.

The second electrode 122 is typically used as a cathode, which is disposed opposite to the bottom anode and generates an electric field therebetween when an electrical signal is applied.

The cathode can be generally arranged on the whole surface, and each sub-pixel does not need to be distinguished to be arranged independently. The cathode 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 LEC devices over which it overlies. The cathode is made of Ag, Al or Au.

The light emitting layer 123 is positioned between the first electrode 121 and the second electrode 122.

The pattern of the first electrode 121 on the substrate base plate 11 is generally a mutually discrete pattern. After the first electrode 121 is formed, a pixel defining layer is formed in the gap of the first electrode 121 to define the position of the sub-pixel. Since the emission colors of different sub-pixel units may be different, the emission layer 123 is only located on the surface of the first electrode 121.

The light-emitting layer 123 in the embodiment of the present invention uses an ion-conductive delayed fluorescent material. The delayed fluorescent material is a novel fluorescent material, the light emission mechanism of which is different from that of the conventional first generation fluorescent material (singlet radiative emission) and second generation phosphorescent material (triplet radiative emission), and when the energy gap difference between the S1 state (first singlet excited state) and the T1 state (first triplet excited state) is very small (<0.1eV), excitons in the triplet state can effectively cross into the singlet state and complete singlet radiative emission, i.e., fluorescence emission. Due to the triplet exciton cross-over effect, the exciton utilization rate of the delayed fluorescent material can reach 100%, and therefore the luminous efficiency of the luminescent material can be remarkably improved. In addition, the delayed fluorescence is a pure organic material and does not contain noble metals, so the cost is lower, and the preparation of the luminescent material with low cost and high efficiency can be realized.

According to the embodiment of the invention, an anion and cation group is introduced on the basis of the traditional delayed fluorescent material, and finally the ion conduction type delayed fluorescent material is prepared. The material has high exciton utilization rate and high luminous efficiency of the delayed fluorescence material, has ion conduction characteristic and can be used as a luminous layer in an LEC device. The conduction of anions and cations in the ion conduction type delayed fluorescent material is beneficial to the injection of carriers, so that the starting voltage is reduced.

In the embodiment of the invention, the molecular structural general formula of the ion conduction type delayed fluorescent material is [ n ]₁Cz·A][n₂PF₆ ^-](ii) a Wherein Cz represents a carbazole group, n₁Denotes the number of carbazole groups, A denotes an electron-withdrawing group, PF₆ ^-Represents a hexafluorophosphate ion, n₂Indicates the number of hexafluorophosphate ions.

Cz · a has a high exciton utilization rate and a high luminous efficiency as a delayed fluorescent material. The carbazole group Cz is an electron donating group, and A is an electron withdrawing group, so that a covalent bond is formed between the carbazole group Cz and the electron withdrawing group A.

Wherein, the electron-withdrawing group A can adopt any one of a thioxanthone group, a dibenzothiophene-s, s-dioxide group, a triazine group, a thioxanthene tetraoxide group, an oxadiazole group and a triphenylboron group.

In the embodiment of the invention, anions and cations are introduced into the delayed fluorescent material, and the delayed fluorescent material is changed into an ionic compound through a chemical reaction and has ion transmission, so that the delayed fluorescent material is used as a light emitting layer of an LEC device.

In the general formula of the prince structure of the ion conduction type delayed fluorescent material, the carbazole group is used as an electron donating group and an electron withdrawing group to jointly act to regulate the band gap of molecules. Wherein n is₁The number of carbazole groups in the molecule is shown, and the change of the number of carbazole groups in the molecule can change the molecular band gap and the HOMO and LUMO energy levels thereof, so that the molecular performance can be regulated and controlled by changing the number of carbazole groups.

The ion transmission capability of a molecular system is regulated and controlled by changing the number of anions and cations in molecules, so that the ion transmission capability of the LEC device is optimized.

In embodiments of the present invention, the LEC devices may be used to emit light of different colors, and accordingly, the LEC devices are classified into red LEC devices, green LEC devices, and blue LEC devices. Every three LEC devices of three colors of red, green and blue form a pixel unit, and image display can be realized by controlling the luminous brightness of the LEC devices of three colors of red, green and blue in each pixel unit.

Wherein, the light-emitting layer in the red LEC device is a red light-emitting layer, the light-emitting layer in the green LEC device is a green light-emitting layer, and the light-emitting layer in the blue LEC device is a blue light-emitting layer. The ion conduction type delayed fluorescence materials used for the light emitting layers of different colors are different.

For example, the molecular structure formula of the ion-conducting delayed fluorescent material used in the red light-emitting layer is [ n ]₁Cz·Anthraquinone][n₂PF₆ ^-]，n₁Different values can be used to include different numbers of carbazole groups in the molecule, thereby providing different numbers of anions and cations in the molecule.

When n is₁When 2, the ion-conducting delayed fluorescent material used for the red light-emitting guide may be any one of the following materials:

when n is₁When 4, the ion-conducting delayed fluorescent material used for the red light-emitting guide may be any one of the following materials:

when n is₁When 6, the ion-conducting delayed fluorescent material used for the red light-emitting guide may be any one of the following materials:

in addition, n₁Other values can be taken, and the embodiment of the invention is only used for illustrating the material adopted by the red light-emitting layer, and does not limit n₁The specific value of (3) is not limited to that the red light-emitting layer adopts other ion conduction type delayed fluorescent materials.

The general molecular structure formula of the ion-conducting delayed fluorescent material adopted by the green luminous layer is [ n ]₁Cz·Diboraanthracene][n₂PF₆ ^-]，n₁Different values can be used to include different numbers of carbazole groups in the molecule, thereby providing different numbers of anions and cations in the molecule.

When n is₁When 2, the ion-conducting delayed fluorescent material used for the green emission guide may be any one of the following materials:

when n is₁When 4, the ion-conducting delayed fluorescent material used for the green emission guide may be any one of the following materials:

when n is₁When 6, the ion-conducting delayed fluorescent material used for the green emission guide may be any one of the following materials:

in addition, n₁Other values can be taken, and the embodiment of the invention is only used for illustrating the material adopted by the green light-emitting layer, and does not limit n₁The specific value of (3) is not limited to that the green light-emitting layer adopts other ion-conducting delayed fluorescent materials.

The general molecular structure formula of the ion conduction type delayed fluorescent material adopted by the blue light-emitting layer is [ n ]₁Cz·Benzoyl][n₂PF₆ ^-]，n₁Different values can be used to include different numbers of carbazole groups in the molecule, thereby providing different numbers of anions and cations in the molecule.

When n is₁When 2, the ion-conducting delayed fluorescent material used for the blue light-emitting guide may be any one of the following materials:

when n is₁When 4, the ion-conducting delayed fluorescent material used for the blue light-emitting guide may be any one of the following materials:

when n is₁When 6, the ion-conducting delayed fluorescent material used for the blue light-emitting guide may be any one of the following materials:

in addition, n₁Other values can be taken, and the embodiment of the invention is only used for illustrating the material adopted by the blue light-emitting layer and is not limited to n₁The specific value of (3) is not limited to that other ion conduction type delayed fluorescence materials are adopted in the blue light-emitting layer.

In another embodiment of the present invention, the LEC device may also be a white LEC device, and the light emitted from the white LEC device is white light, and full color display can be realized by matching with a color filter.

When a white LEC device is used in the display apparatus, then the light emitting layer may be provided in a whole layer without being separately provided for each region where the first electrode 121 is located, whereby the production efficiency may be improved.

The light-emitting layer in a white LEC device is a white light-emitting layer. The white light emitting layer may have a single-layer structure or a stacked-layer structure.

The white light-emitting layer having a single-layer structure is a mixture of ion-conducting delayed phosphors used in the red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer.

The white light emitting layer of the laminated structure is respectively provided with a red sub-light emitting layer, a green sub-light emitting layer and a blue sub-light emitting layer from the bottom side to the top side, wherein the red sub-light emitting layer can adopt the ion conduction type delayed fluorescent material emitting red light, the green sub-light emitting layer can adopt the ion conduction type delayed fluorescent material emitting green light, and the blue sub-light emitting layer can adopt the ion conduction type delayed fluorescent material emitting blue light.

The light-emitting layer in the embodiment of the invention adopts an ion-conducting delayed fluorescent material which is usually an organic material and can be processed by a solution method, so that the light-emitting efficiency is improved, and the production cost is reduced.

Fig. 3 is a second schematic cross-sectional view of a light-emitting electrochemical cell device according to an embodiment of the present invention.

Referring to fig. 3, the light-emitting electrochemical cell device further includes a hole injection layer 124.

The hole injection layer 124 is located on the side of the first electrode facing away from the substrate base plate 11.

The hole injection layer 124 may be provided entirely or only on the first electrode 121.

The entire layer of the hole injection layer 124 can provide holes for all LEC devices, and the process of disposing the hole injection layer 124 entirely is relatively simple.

However, only holes injected to the position of the first electrode 121 contribute to light emission of the LEC device, and therefore, the hole injection layer 124 may be formed only on the first electrode 121, which saves cost.

In the embodiment of the invention, the hole injection layer 124 is arranged on the first electrode 121, so that the hole injection capability of the device can be improved, the stability of the device can be improved, and the service life can be 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.

Fig. 4 is a third schematic cross-sectional view of a light-emitting electrochemical cell device according to an embodiment of the present invention.

Referring to fig. 4, the light-emitting electrochemical cell device further includes a hole transport layer 125.

The hole transport layer 125 is located on a side of the hole injection layer 124 facing away from the first electrode 121.

The hole transport layer 125 may be provided as a whole layer, or may be provided only at a position corresponding to the first electrode 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, polyvinyl carbazole (PVK), bis (4-phenyl) (4-butylphenyl) amine (TPD), poly (9, 9-dioctylfluorene-CO-N- (4-butylphenyl) diphenylamine) (TFB), or the like can be used as the hole transport layer 125.

In the embodiment of the invention, the light-emitting layer and the functional layer in the LEC device can be manufactured by a solution method, so that the cost can be effectively controlled.

Referring to fig. 5, a method for manufacturing a display device includes:

s10, manufacturing a first electrode on the substrate base plate;

s20, forming a hole injection layer on the side of the first electrode, which is far away from the substrate base plate;

s30, forming a hole transport layer on the side, away from the first electrode, of the hole injection layer;

s40, forming a light-emitting layer on the side of the hole transport layer, which is far away from the hole injection layer;

and S50, forming a second electrode on the side of the light-emitting layer, which faces away from the hole transport layer.

The hole injection layer, the hole transport layer and the light-emitting layer are all manufactured by a solution method.

In the embodiment of the invention, the LEC device is manufactured by adopting a solution method, and the solution method comprises an ink-jet printing method, a spin-coating method, a screen printing method or a roll-to-roll preparation process. The LEC device manufactured by the solution method can effectively control the production cost and has higher generation efficiency.

Specifically, a pattern of a first electrode is formed on a substrate on which a driving circuit is formed, the first electrode may be formed using an etching process, and the first electrode uses Indium Tin Oxide (ITO).

After the first electrode is prepared, the substrate with the first electrode needs to be cleaned.

After the base substrate with the first electrode is cleaned, a hole injection layer is formed on the first electrode by a solution method. For example, the hole injection layer may be ink-jet printed over the first electrode. 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-butyl phenyl) 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 ion conduction type delayed fluorescence material is dissolved in a solvent to prepare luminous ink, and then the luminous ink is sprayed and printed to prepare the luminous layer. The thickness of the light-emitting layer is 20nm-200 nm.

The solvent used in the luminescent ink may be an organic solvent such as acetonitrile, chlorobenzene, dichlorobenzene, and the like, and is not limited herein.

In order to improve the ion conduction capability of the light emitting layer, optimize the injection of carriers and reduce the turn-on voltage, the embodiment of the invention can dope a certain amount of ionic liquid into the light emitting ink and then perform ink jet printing to prepare the light emitting layer. The doped ionic liquid can adopt 1-butyl-3-methylimidazolium hexafluorophosphate ([ BMIM)]PF₆) Etc., without limitation. The doping proportion range of the ionic liquid in the ion conduction type delayed fluorescent material is 1% -25%, and the optimal proportion is selected in the range according to different material systems, and is not limited herein.

After the light emitting layer is formed, the substrate is vacuum-dried and baked, and then a second electrode is deposited over the light emitting layer. The second electrode may be made of aluminum, silver, copper, etc., and is not limited herein.

And after the LEC device is prepared, packaging the display device to finish the manufacture of the display device.

According to the first invention concept, the light-emitting device of the display device in the embodiment of the invention adopts a light-emitting electrochemical cell device, the LEC device is insensitive to the work function of an electrode, and stable metal aluminum, gold, silver and the like can be used for the cathode of the device; the LEC device is insensitive to the thickness of the light-emitting layer, so that the preparation process of the device is simplified; the LEC device has a simple structure, and does not need an additional charge injection layer; the LEC device is low in turn-on voltage; the LEC emits light regardless of the direction of the electric field, and emits light under positive and negative bias. Therefore, the LEC has a wide application prospect in the field of low-cost and large-area display.

According to a second inventive concept, an emitting layer in a light-emitting electrochemical cell device employs an ion-conducting delayed fluorescent material. The ion-conducting delayed fluorescent material has high exciton utilization rate and high luminous efficiency of the delayed fluorescent material, and also has ion-conducting property. The conduction of anions and cations in the ion conduction type delayed fluorescent material is beneficial to the injection of carriers, so that the starting voltage is reduced.

According to the third inventive concept, the molecular structure general formula of the ion-conducting delayed fluorescent material is [ n ]₁Cz·A][n₂PF₆ ^-](ii) a Wherein Cz represents a carbazole group, n₁The number of the carbazole groups is shown, A is an electron-withdrawing group, and the electron-withdrawing group can adopt any one of a thioxanthone group, a dibenzothiophene-s, s-dioxide group, a triazine group, a thioxanthene tetraoxide group, an oxadiazole group and a triphenylboron group. PF (particle Filter)₆ ^-Represents a hexafluorophosphate ion, n₂Indicates the number of hexafluorophosphate ions. The carbazole group is used as an electron donating group and an electron withdrawing group to jointly act to regulate the band gap of the molecule, and the ion transmission capability of a molecule system is regulated by changing the number of anions and cations in the molecule, so that the ion transmission capability of the LEC device is optimized.

According to the fourth inventive concept, the light emitting layer may be divided into a red light emitting layer, a green light emitting layer, a blue light emitting layer, and a white light emitting layer. The red light emitting layer, the green light emitting layer and the blue light emitting layer can be independently used as sub-pixels to realize full-color display. The white light emitting layer can be matched with a color filter to realize full-color display.

According to the fifth inventive concept, the white light emitting layer may employ a mixture of ion-conductive type delayed fluorescent materials employed for the red light emitting layer, the green light emitting layer, and the blue light emitting layer; or the white light emitting layer may include a red sub-light emitting layer, a green sub-light emitting layer, and a blue sub-light emitting layer of a stacked structure; the red sub-luminescent layer adopts red ion conduction type delayed fluorescent material, the green sub-luminescent layer adopts green ion conduction type delayed fluorescent material, and the blue sub-luminescent layer adopts blue ion conduction type delayed fluorescent material.

According to the fifth inventive concept, the red light emitting layer uses the ion-conducting type delayed fluorescence material of [ n ]₁Cz·Anthraquinone][n₂PF₆ ^-](ii) a Wherein n is₁Denotes the number of carbazole groups, n₂Indicates the number of hexafluorophosphate ions.

According to the sixth inventive concept, the red light emitting layer uses the ion-conducting type delayed fluorescence material of [ n ]₁Cz·Diboraanthracene][n₂PF₆ ^-](ii) a Wherein n is₁Denotes the number of carbazole groups, n₂Indicates the number of hexafluorophosphate ions.

According to the seventh inventive concept, the ion-conducting type delayed fluorescence material adopted in the blue light emitting layer is [ n ]₁Cz·Benzoyl][n₂PF₆ ^-](ii) a Wherein n is₁Denotes the number of carbazole groups, n₂Indicates the number of hexafluorophosphate ions.

According to the eighth inventive concept, the light-emitting electrochemical cell device further comprises a hole injection layer located on the side, away from the substrate, of the first electrode, and the hole injection layer is arranged to improve the hole injection capability of the device, increase the stability of the device and prolong the service life.

According to the ninth inventive concept, the light-emitting electrochemical cell device further comprises a hole transport layer positioned on one side of the hole injection layer, which is far away from the first electrode, the hole transport capability can be improved due to the arrangement of the hole transport layer, and meanwhile, the light-emitting electrochemical cell device has the function of blocking electrons, can balance the transport of carriers, and is beneficial to improving the efficiency of the device.

According to the tenth inventive concept, the hole injection layer, the hole transport layer, and the light emitting layer are formed by a solution method. The LEC device manufactured by the solution method can effectively control the production cost and has higher generation efficiency.

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

1. A display device, comprising:

the substrate base plate has supporting and bearing functions;

a light-emitting electrochemical cell device located over the substrate base plate;

the light-emitting electrochemical cell device comprises:

a first electrode located over the substrate base plate;

the second electrode is positioned on one side of the first electrode, which is far away from the substrate base plate;

a light emitting layer between the first electrode and the second electrode; the luminous layer adopts an ion conduction type delayed fluorescent material.

2. The display device according to claim 1, wherein the ion-conducting delayed fluorescent material has a molecular structure of the general formula [ n ]₁Cz·A][n₂PF₆ ^-]；

Wherein Cz represents a carbazole group, n₁Denotes the number of carbazole groups, A denotes an electron-withdrawing group, PF₆ ^-Represents a hexafluorophosphate ion, n₂Indicates the number of hexafluorophosphate ions.

3. The display device of claim 2, wherein the electron-withdrawing group is any one of a thioxanthone group, a dibenzothiophene-s, s-dioxide group, a triazine group, a thioxanthene tetraoxide group, an oxadiazole group, and a triphenylboron group.

4. The display device according to claim 2, wherein the light-emitting layer comprises: a red light emitting layer, a green light emitting layer, a blue light emitting layer, and a white light emitting layer.

5. The display device according to claim 4, wherein a material of the red light emitting layer is any one of:

6. the display device according to claim 4, wherein a material of the green light emitting layer is any one of:

7. the display device according to claim 4, wherein a material of the blue light emitting layer is any one of:

8. the display apparatus of claim 1, wherein the light-emitting electrochemical cell device further comprises:

and the hole injection layer is positioned on one side of the first electrode, which is far away from the substrate base plate.

9. The display apparatus of claim 8, wherein the light-emitting electrochemical cell device further comprises:

and the hole transport layer is positioned on one side of the hole injection layer, which is far away from the first electrode.

10. The display device according to claim 9, wherein the hole injection layer, the hole transport layer, and the light-emitting layer are formed by a solution method.