Organic compound and preparation method thereof, display substrate and display device

Abstract

Disclosed are an organic compound and a preparation method thereof, a display substrate and a display device, which relate to the field of display technology and are used to improve the display effect and service life of a display device. The structural formula of the organic compound is shown in the following formula (I): The organic compound provided in the present disclosure is used as a material for an ultraviolet light absorbing layer, and the ultraviolet light absorbing layer is used for a display device.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to an organic compound and a preparation method thereof, a display substrate and a display device. Background Art

[0002] Currently, display devices are easily exposed to ultraviolet light, which will affect the display effect and service life. Summary of the invention

[0003] Embodiments of the present invention provide an organic compound and a preparation method thereof, a display substrate and a display device. The organic compound can be used to improve the display effect and service life of the display device.

[0004] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0005] In one aspect, an embodiment of the present invention provides an organic compound, the structural formula of the organic compound is shown in the following formula (I):

[0006]

[0007] In formula (I), R1 is selected from any one of the following structural formulas:

[0008] Wherein * is a chemical bond connection site; R2 is selected from hydrogen or methyl; R3 is selected from any one of the following structural formulas: Where * is the chemical bond connection site.

[0009] On the other hand, an embodiment of the present invention provides a method for preparing an organic compound, comprising the following reaction steps:

[0010] Compound I and Compound II are dissolved in an organic solvent, and then a catalyst is added and heated to reflux. After the reaction is completed, the mixture is cooled, precipitated and filtered to finally obtain Compound III. The reaction equation is:

[0011]

[0012] Wherein R1, R2 and R3 are selected from the structural formula as described in claim 1.

[0013] The following compounds 1 to 172 are representative structures that conform to the spirit and principle of the present invention. It should be understood that the following compound structures are only for a better understanding of the present invention and are not intended to limit the present invention.

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023] Optionally, the molar ratio of compound I to compound II is 1:(1.0-2.0).

[0024] Optionally, the organic solvent includes at least one of methanol, ethanol, n-propanol and n-butanol, the reaction time is controlled at 10 h-24 h, and the reaction temperature is controlled at 60° C.-120° C.

[0025] Optionally, the catalyst includes trifluoroacetic acid, and the molar ratio of the catalyst to compound I is (0.005-0.05):1.

[0026] On the other hand, an embodiment of the present invention provides a display substrate, comprising a substrate, a circuit structure layer, a light emitting structure layer, an encapsulation layer and an ultraviolet light absorbing layer. The circuit structure layer is located on one side of the substrate. The light emitting structure layer is located on the side of the circuit structure layer away from the substrate. The encapsulation layer is located on the side of the light emitting structure layer away from the substrate. The ultraviolet light absorbing layer is located on the side of the light emitting structure layer away from the substrate. Wherein, the ultraviolet light absorbing layer comprises: one or more organic compounds, and the organic compound is the above-mentioned organic compound.

[0027] Optionally, the ultraviolet light absorbing layer is located on a side of the encapsulation layer away from the substrate, and is in contact with the encapsulation layer.

[0028] Optionally, the ultraviolet light absorbing layer is located between the encapsulation layer and the light emitting structure layer.

[0029] Optionally, the display substrate further comprises: a light extraction layer, which is located on a side of the light-emitting functional layer away from the substrate and in contact with the light-emitting structure layer.

[0030] On the other hand, an embodiment of the present invention provides a display device, including a display substrate; the display substrate is the above-mentioned display substrate.

[0031] An organic compound (E) provided in an embodiment of the present invention can be converted into an organic compound (Z) after absorbing ultraviolet light, completing energy transfer; when irradiated with visible light, the organic compound (Z) can be converted into an organic compound (E) to release energy, as follows:

[0032] In this way, on the one hand, the film structure under the ultraviolet light absorption layer can be protected from ultraviolet light; on the other hand, the energy of ultraviolet light can be transferred, which will not cause the display device to overheat and cause material failure. In addition, the brightness decay rate can be reduced, thereby increasing the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the structure of a display device provided in an embodiment of the present application;

[0034] Figure 2A A cross-sectional structural diagram of a display substrate provided in an embodiment of the present application;

[0035] Figure 2B A cross-sectional structural diagram of another display substrate provided in an embodiment of the present application;

[0036] Figure 3 An absorption spectrum diagram of a compound 7 provided in an embodiment of the present application and a luminescence spectrum diagram of a display device;

[0037] Figure 4 An absorption spectrum diagram of a compound 95 and a luminescence spectrum diagram of a display device provided in an embodiment of the present application;

[0038] Figure 5 An absorption spectrum diagram of compound 146 and a luminescence spectrum diagram of a display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0040] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and other forms thereof, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open, inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0041] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0042] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0043] “At least one of A, B, and C” has the same meaning as “at least one of A, B, or C” and both include the following combinations of A, B, and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0044] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0045] The use of "adapted to" or "configured to" herein is meant to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0046] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0047] As used herein, "about" or "approximately" includes the stated value and the average value that is within an acceptable range of deviation from the particular value, where the acceptable range of deviation is determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0048] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0049] like Figure 1 As shown, some embodiments of the present disclosure provide a display device 1, which includes a display substrate 100 and may also include other components. For example, it may include a circuit for providing an electrical signal to the display substrate 100 to drive the display substrate 100 to emit light. The circuit may be called a control circuit and may include a circuit board and / or an IC (Integrate Circuit) electrically connected to the display substrate.

[0050] In some embodiments, the display substrate 100 can be used to realize the function of displaying an image (i.e., a picture). The display device 1 may include a display or a product including a display. Among them, the display may be a flat panel display (Flat Panel Display, FPD), a micro display, etc. If divided according to whether the user can see the back of the display, the display may be a transparent display or an opaque display. If divided according to whether the display can be bent or curled, the display may be a flexible display or an ordinary display (which may be called a rigid display). For example, products including displays may include: computer monitors, televisions, billboards, laser printers with display functions, telephones, mobile phones, personal digital assistants (Personal Digital Assistant, PDA), laptop computers, digital cameras, camcorders, viewfinders, vehicles, large-area walls, theater screens or stadium signs, etc.

[0051] In some embodiments, Figure 2A As shown, some embodiments of the present disclosure provide a display substrate 100, which may include a substrate 60, a circuit structure layer 50, a light emitting structure layer 4, an encapsulation layer 10, and an ultraviolet light absorbing layer 20. The circuit structure layer 50 is located on one side of the substrate 60. The light emitting structure layer 4 is located on the side of the circuit structure layer 50 away from the substrate 60. The encapsulation layer 10 is located on the side of the light emitting structure layer 4 away from the substrate 60.

[0052] See also Figure 2A and Figure 2B The ultraviolet light absorbing layer 20 is located on a side of the light emitting structure layer 4 away from the substrate 60 .

[0053] Exemplarily, the ultraviolet light absorbing layer 20 is located between the encapsulation layer 10 and the light emitting structure layer 4, for example, Figure 2A As shown, the ultraviolet light absorbing layer 20 is located between the light extraction layer 30 and the encapsulation layer 10 .

[0054] Another example is Figure 2B As shown, the ultraviolet light absorbing layer 20 is located on a side of the encapsulation layer 10 away from the substrate 60 , and is in contact with the encapsulation layer 10 .

[0055] In other embodiments, Figure 2A and Figure 2B As shown, the display substrate 100 may further include a light extraction layer 30 , which is located on a side of the light emitting functional layer 40 away from the substrate 60 and in contact with the light emitting structure layer 4 .

[0056] In some embodiments, the light emitting structure layer 4 may further include an anode layer 45 , a light emitting functional layer 40 and a cathode layer 41 which are stacked, and the anode layer 45 is in contact with the circuit structure layer 50 .

[0057] The light-emitting principle of the light-emitting structure layer 4 is as follows: through a circuit connected by the anode layer 45 and the cathode layer 41, the anode layer 45 is used to inject holes into the light-emitting functional layer 40, and the cathode layer 41 is used to inject electrons into the light-emitting functional layer 40. The formed electrons and holes form excitons in the light-emitting functional layer 40, and the excitons return to the ground state through radiation transition and emit photons.

[0058] like Figure 2A As shown, in order to improve the efficiency of injecting electrons and holes into the light-emitting functional layer 40, the light-emitting functional layer 40 may also include: a hole transport layer (HTL) 44, an electron transport layer (ETL) 42, and a light-emitting layer 43. The hole transport layer 44, the light-emitting layer 43 and the electron transport layer 42 are stacked, and the hole transport layer 44 is in contact with the anode layer 45.

[0059] In some embodiments, the substrate 60 may be of various types, and may be a rigid substrate. The rigid substrate may be, for example, a glass substrate or a PMMA (Polymethyl methacrylate) substrate. In other examples, the substrate 60 may be a flexible substrate. The flexible substrate may be PET (Polyethylene terephthalate), PEN (Polyethylene naphthalate di formic acid glycol ester), or PI (Polyimide).

[0060] The circuit structure layer 50 may include multiple types, which are not limited in the present disclosure. For example, the structure of the pixel driving circuit may be a "6T1C", "7T1C" or "8T1C" structure; wherein "T" represents a thin film transistor, the number before "T" represents the number of thin film transistors, and "C" represents a storage capacitor, and the number before "C" represents the number of storage capacitors. For another example, the thin film transistor included in the pixel driving circuit may be a thin film transistor with a bottom gate structure, or a thin film transistor with a top gate structure.

[0061] The anode layer 45 may be a stacked structure of ITO (Indium Tin Oxides) / Ag / ITO, but is not limited thereto, and is disposed on the upper layer of the TFT by exposure, development, and etching, and has a thickness of to

[0062] The hole transporting layer (HTL) 44 is deposited on the anode layer 45 by vacuum evaporation and has a thickness of to HTL may include carbazole-derived organics such as N-phenylcarbazole and polyvinylcarbazole, fluorene-derived organics, triphenylamine-derived organics such as N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) and 4,4',4"-tri(N-carbazolyl)triphenylamine), N,N-di(1-naphthyl)-N,N-diphenyl-(1,1-biphenyl)-4,4-diamine, 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] or 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl and 1,3-bis(N-carbazolyl)benzene.

[0063] In addition to the aforementioned materials, the hole transport layer 44 may further include a charge generating material to improve conductivity. The charge generating material may be doped in the hole transport layer 44. For example, the charge generating material may be a p-dopant. For example, non-limiting examples of p-dopants may include quinone derivatives such as tetracyanoquinodimethane and 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane and metal oxides such as tungsten oxide and molybdenum oxide, but are not limited thereto.

[0064] The light emitting layer 43 is deposited on the hole transport layer 44 by vacuum evaporation. For example, the thickness of the light emitting layer 43 can be to The light-emitting layer 43 may have a single-layer structure having a single layer formed of a single material, a single-layer structure having a single layer formed of multiple different materials, or a multilayer structure having multiple layers formed of multiple different materials. The light-emitting layer 43 may include a fluorescent material known in the art, and the fluorescent material may also include any one of spiro-DPVBi, 2,2',7,7'-tetra(biphenyl-4-yl)-9,9'-spirobifluorene (spiro-6P), distyrylbenzene, and distyrylarylene compounds. The light-emitting layer 43 includes a phosphorescent material known in the art, and may also include one of an anthracene compound, an aromatic amine compound, or a styryl compound. The light-emitting layer 43 may include a host and a dopant. For example, the host may include tris(8-hydroxyquinoline)aluminum, 4,4'-bis(N-carbazolyl)-1,1'-biphenyl, poly(N-vinylcarbazole), 9,10-di(naphthalene-2-yl)anthracene, 4,4',4"-tri(carbazol-9-yl)-triphenylamine, 1,3,5-tri(N-phenylbenzimidazol-2-yl)benzene, 3-tert-butyl-9,10-di(naphthalene-2-yl)anthracene, 4,4-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl, 2-methyl-9,10-bis(naphthalene-2-yl)anthracene, bis[2-(diphenylphosphino)phenyl]ether oxide, hexaphenylcyclotriphosphazene, 1,4-bis(triphenylsilyl)benzene, octaphenylcyclotetrasiloxane, and 2,8-bis(diphenylphosphino)phenyl]ether oxide. )dibenzofuran, etc. The dopant may be a styryl derivative (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene, 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]styrene, and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalene-2-yl)vinyl)phenyl)-N-phenylaniline), perylene and its derivatives (e.g., 2,5,5,8,11-tetra-tert-butylperylene), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, and 1,4-bis(N,N-diphenylamino)pyrene), [bis-(1-phenylisoquinolyl)iridium(III)acetylacetone], etc.

[0065] The electron transport layer 42 is deposited on the light emitting layer 43 by vacuum evaporation. The electron transport layer 42 may include tris(8-hydroxyquinoline)aluminum, 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline, 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq,

[0066] Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-Biphenyl-4-olate)aluminum), bis(benzoquinoline-10-hydroxy)beryllium, 9,10-di(naphthalene-2-yl)anthracene (ADN) and mixtures thereof. The thickness of the electron transport layer 42 is to

[0067] The cathode layer 41 is deposited on the electron transport layer 42 by vacuum evaporation. The cathode layer 41 may include Ag, Mg, Cu, AlPt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (e.g., a mixture of Ag and Mg).

[0068] The light extraction layer 30 is deposited on the cathode layer 41 by vacuum evaporation, and generally uses an organic material with a high refractive index.

[0069] The encapsulation layer 10 may be an encapsulation film (Thin Film Encapsulation, referred to as TFE), or an encapsulation substrate, which is arranged to encapsulate the pixel driving circuit and multiple light-emitting devices on the substrate to block water and oxygen, and prevent water and oxygen from corroding the light-emitting devices, thereby affecting the luminous efficiency and service life of the light-emitting devices. In some examples, the encapsulation layer 10 may include: a first inorganic layer, an organic layer, and a second inorganic layer arranged in sequence from bottom to top. The first inorganic layer and / or the second inorganic layer may, for example, be made of an inorganic insulating material and prepared by a vapor deposition process; the organic layer may, for example, be made of an organic insulating material and prepared by an inkjet printing process.

[0070] The ultraviolet light absorbing layer 20 can be manufactured after the encapsulation layer 10 is manufactured, and can be manufactured by inkjet printing or evaporation. The thickness of the ultraviolet light absorbing layer 20 is to But it is not limited to this and can be adjusted according to needs.

[0071] Inkjet printing method: The ultraviolet light absorbing material (organic compound of the present application) is dissolved in a volatile solvent to prepare a solution with a concentration of 0.1 g / mL to 10 g / mL, and then the solution is evenly printed on the substrate 60 containing the circuit structure layer 50 and the light-emitting device. After leveling and drying, the preparation of the ultraviolet light absorbing layer 20 can be completed. The volatile solvent includes: methyl nitrile, acetonitrile, propionitrile, acetone, cyclohexane, cyclohexanone, n-hexane, toluene. The drying temperature is between 60°C and 100°C.

[0072] Evaporation method: The same as the method for preparing the light-emitting layer 43, vacuum evaporation is adopted, the evaporation temperature is between 280°C and 400°C, and the vacuum degree of evaporation is 1×10 -4 Pa to 1×10 -6 Pa, the evaporation rate is to

[0073] In some embodiments, the ultraviolet light absorbing layer 20 includes: one or more organic compounds, and the organic compound is the following organic compound. The structural formula of the organic compound is shown in the following formula (I):

[0074]

[0075] In formula (I), R1 is selected from any one of the following structural formulas:

[0076]

[0077] Wherein * is a chemical bond connection site; R2 is selected from hydrogen or methyl; R3 is selected from any one of the following structural formulas:

[0078]

[0079] Where * is the chemical bond connection site.

[0080] An organic compound (E) provided in an embodiment of the present invention can be converted into an organic compound (Z) after absorbing ultraviolet light, completing energy transfer; when irradiated with visible light, the organic compound (Z) can be converted into an organic compound (E) to release energy, as follows:

[0081] In this way, on the one hand, the film structure under the ultraviolet light absorbing layer can be protected from ultraviolet light; on the other hand, the energy of ultraviolet light can be transferred, which will not cause the display device 1 to overheat and cause material failure. In addition, the brightness decay rate can be reduced, thereby increasing the service life.

[0082] Some embodiments of the present disclosure provide a method for preparing the above-mentioned organic compound, wherein the organic compound can be prepared through different synthetic routes according to different raw materials obtained, and the preparation route of the organic compound is not specifically limited herein.

[0083] In order to objectively evaluate the technical effects of the embodiments of the present disclosure, the technical solutions provided by the present disclosure will be described in detail and exemplarily through experimental examples below.

[0084] Example 1

[0085] Synthesis of compound 7

[0086]

[0087] S1. Synthesis of intermediate product 7-1: Methyl benzoate (45 mmol) and hydrazine hydrate (4.4 mL, 89 mmol) were dissolved in 100 mL of ethanol solution, heated under reflux for 12 hours, and then cooled to room temperature. The reaction solution was evaporated on a rotary evaporator to remove the solvent, and then 50 mL of toluene was added to the obtained solid. After concentration and drying, the crude product hydrazide 7-1 (45 mmol) was obtained.

[0088] S2. Synthesis of compound 7: Crude hydrazide 7-1 (45 mmol) and 2-acetylthiophene (45 mmol) were dissolved in 45 mL of ethanol solution. Subsequently, two drops of trifluoroacetic acid were added and heated to reflux without stirring until all the product was dissolved. Then, the reaction was cooled to room temperature, and the product precipitated and filtered to obtain compound 7 (36 mmol, yield 80%).

[0089] Compound 7 is used as the ultraviolet light absorbing layer 20. The (E) formula of compound 7 can be converted into the (Z) formula when exposed to ultraviolet light, and the (Z) formula can be converted into the (E) formula when exposed to visible light. The specific process is as follows:

[0090] The absorption spectrum of compound 7 as the ultraviolet light absorbing layer 20 is compared with the luminescence spectrum of the display device 1 as shown in FIG. Figure 3 As shown, through Figure 3 It can be seen that neither the (E) formula nor the (Z) formula of compound 7 will affect the light output of the display device 1 .

[0091] Example 2

[0092] Synthesis of compound 95

[0093]

[0094] S1. Synthesis of compound 95: Crude hydrazide 7-1 (45 mmol) and thiophene aldehyde (45 mmol) were dissolved in 45 mL of ethanol solution. Subsequently, two drops of fluoroacetic acid were added and heated to reflux without stirring until all the product was dissolved. Then, the reaction was cooled to room temperature, and the product precipitated and filtered to obtain compound 95 (36 mmol, yield 80%).

[0095] Compound 95 is used as the ultraviolet light absorbing layer 20. The (E) formula of compound 95 can be converted into the (Z) formula when exposed to ultraviolet light, and the (Z) formula can be converted into the (E) formula when exposed to visible light. The specific process is as follows: The absorption spectrum of compound 95 as the ultraviolet light absorbing layer 20 is compared with the luminescence spectrum of the display device 1 as shown in FIG. Figure 4 As shown, through Figure 4 It can be seen that neither the (E) formula nor the (Z) formula of compound 95 affects the light output of the display device 1 .

[0096] Example 3

[0097] Synthesis of compound 146

[0098]

[0099] S1. Synthesis of intermediate product 146-1: Methyl N,N-dimethylbenzoate (45 mmol) and hydrazine hydrate (4.4 mL, 89 mmol) were dissolved in 100 mL of ethanol solution, heated under reflux for 12 hours, and then cooled to room temperature. The solvent was evaporated from the reaction solution on a rotary evaporator, and then 50 mL of toluene was added to the obtained solid. After concentration and drying, the crude product hydrazide 146-1 (45 mmol) was obtained.

[0100] S2. Synthesis of compound 146: Crude hydrazide 146-1 (45 mmol) and 2-formylpyridine (45 mmol) were dissolved in 45 mL of ethanol solution. Subsequently, two drops of trifluoroacetic acid were added and heated to reflux without stirring until all the product was dissolved. Then, the reaction was cooled to room temperature, and the product precipitated and filtered to obtain a relatively pure compound 146 (38.2 mmol, yield 85%).

[0101] Compound 146 is used as the ultraviolet light absorbing layer 20. The (E) formula of compound 146 can be converted into the (Z) formula when exposed to ultraviolet light, and the (Z) formula can be converted into the (E) formula when exposed to visible light. The specific process is as follows:

[0102] The absorption spectrum of compound 146 as the ultraviolet light absorbing layer 20 is compared with the luminescence spectrum of the display device 1 as shown in FIG. Figure 5 As shown, through Figure 5 It can be seen that neither the (E) formula nor the (Z) formula of compound 146 affects the light output of the display device 1. The NMR and molecular weight analysis data of compound 7, compound 95 and compound 146 synthesized in the above Examples 1-3 are shown in Table 1 below:

[0103] Table 1

[0104]

[0105]

[0106] From the data in Table 1 above, it can be seen that the present invention has successfully obtained Compound 7, Compound 95 and Compound 146.

[0107] Experimental example

[0108] Experiment 1 is a comparative experiment, using a conventional light-emitting device. Experiment 2 is the same as Experiment 1, except that Experiment 2 has an additional ultraviolet light absorbing layer 20 (the ultraviolet light absorbing layer 20 is made of the compound 146 material) disposed above the encapsulation layer 10. Figure 2B The results of the device before and after 500 hours of UV irradiation are shown in Table 2:

[0109] Table 2

[0110]

[0111] From the results in Table 2, it can be seen that the device prepared by adding a UV absorption layer 20 on the encapsulation layer 10 has relatively small brightness attenuation and color coordinate change after UV irradiation for 500 hours, has excellent UV resistance, and improves the service life of the display device 1.

[0112] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0113] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A display substrate, characterized in that: include: substrate; a circuit structure layer located on one side of the substrate; A light emitting structure layer located on a side of the circuit structure layer away from the substrate; The light emitting structure layer comprises an anode layer, a light emitting function layer and a cathode layer which are stacked, and the anode layer is in contact with the circuit structure layer; An encapsulation layer located on a side of the light emitting structure layer away from the substrate; the encapsulation layer comprises a first inorganic layer, an organic layer and a second inorganic layer arranged in sequence from bottom to top; the organic layer is prepared by inkjet printing process; an ultraviolet light absorbing layer, located on a side of the light emitting structure layer away from the substrate; the ultraviolet light absorbing layer is located on a side of the encapsulation layer away from the substrate and in contact with the encapsulation layer; and A light extraction layer, located on a side of the light-emitting functional layer away from the substrate and in contact with the light-emitting structural layer; The light extraction layer is located between the encapsulation layer and the light emitting structure layer, and is in contact with the encapsulation layer; Wherein, the ultraviolet light absorbing layer comprises: one or more organic compounds, and the structural formula of the organic compound is shown in the following formula (I): In formula (I), R1 is selected from any one of the following structural formulas: Wherein * is a chemical bond connection site; R2 is selected from hydrogen or methyl; R3 is selected from any one of the following structural formulas: Where * is the chemical bond connection site.

2. The display substrate according to claim 1, characterized in that: The method for preparing the organic compound comprises the following reaction steps: Compound I and Compound II are dissolved in an organic solvent, and then a catalyst is added and heated to reflux. After the reaction is completed, the mixture is cooled, precipitated and filtered to finally obtain Compound III. The reaction equation is: Wherein R1, R2 and R3 are selected from the structural formula as described in claim 1.

3. The display substrate according to claim 2, characterized in that: The molar ratio of compound I to compound II is 1:(1.0-2.0).

4. The display substrate according to claim 2, characterized in that: The organic solvent includes at least one of methanol, ethanol, n-propanol and n-butanol, the reaction time is controlled at 10h-24h, and the reaction temperature is controlled at 60°C-120°C.

5. The display substrate according to claim 2, characterized in that: The catalyst includes trifluoroacetic acid, and the molar ratio of the catalyst to compound I is (0.005-0.05):

1.

6. A display device, characterized in that: include: Display substrate; The display substrate is the display substrate according to any one of claims 1 to 5.

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