WO2023082964A1 - Complex, preparation method for complex, and electroluminescent device - Google Patents

Abstract

The present application discloses a complex, a preparation method for the complex and an electroluminescent device; the complex comprises: a P-type semiconductor material and an N-type semiconductor material which are covalently bound; the P-type semiconductor material comprises black phosphorus nanosheets, and the N-type semiconductor material comprises a component A and a component B; component A comprises inorganic nanoparticles, component B comprises one or more of fullerene and fullerene derivatives, and the complex can be used for preparing a charge generation layer of an electroluminescent device.

Description

Composite, preparation method of composite and electroluminescent device

This application requires the application number filed at the China Patent Office on November 15, 2021.

202111346703.6, the priority of the Chinese patent application titled "composite, compound preparation method, electroluminescent device and display device", the entire content of which is incorporated in this application by reference.

technical field

The application relates to the field of optoelectronic technology, in particular to a compound, a preparation method of the compound and an electroluminescent device.

Background technique

Black phosphorus nanosheets are a highly efficient P-type semiconductor material, which has the advantages of large specific surface area, abundant adsorption sites, high carrier mobility, excellent mechanical strength and thermal conductivity, and its surface has phosphorus atoms carrying lone pairs of electrons. , phosphorus atoms serve as highly reactive sites of black phosphorus nanosheets, and the surface of black phosphorus nanosheets can form phosphorus atom-metal atom chemical bond bridging, phosphorus atom-oxygen atom-carbon atom chemical bond bridging, or phosphorus atom-oxygen atom -Silicon atom chemical bond bridging.

technical problem

Phosphorus atoms serve as highly reactive sites of black phosphorus nanosheets, which makes the black phosphorus nanosheets have unsatisfactory chemical stability. Therefore, how to improve the chemical stability of black phosphorus nanosheets is of great significance to the application of black phosphorus nanosheets.

technical solution

In view of this, the present application provides a compound, a preparation method of the compound and an electroluminescent device, so as to improve the chemical stability of black phosphorus nanosheets.

In a first aspect, the present application provides a composite, the composite includes a P-type semiconductor material and an N-type semiconductor material, and the P-type semiconductor material is connected to the N-type semiconductor material through a covalent chemical bond; the P Type semiconductor materials include black phosphorus nanosheets; the N-type semiconductor materials include:

Component A: inorganic nanoparticles; and

Component B: one or more of fullerenes and fullerene derivatives.

Optionally, calculated by weight percentage, the compound includes: 5% to 80% of N-type semiconductor material and 20% to 95% of P-type semiconductor material.

Optionally, calculated by weight percentage, the compound includes: 5% to 40% of N-type semiconductor material and 60% to 95% of P-type semiconductor material.

Optionally, calculated by weight percentage, the N-type semiconductor material includes: 80% to 99% of component A, and 1% to 20% of component B.

Optionally, the compound is composed of a P-type semiconductor material and an N-type semiconductor material, and the P-type semiconductor material is connected to the N-type semiconductor material through a covalent chemical bond; the P-type semiconductor material is a black phosphorus nanosheet ; The N-type semiconductor material is composed of component A and component B.

Optionally, the thickness of the black phosphorus nanosheets is 0.5nm to 10nm.

Optionally, the energy level difference between the highest occupied orbital of the P-type semiconductor material and the lowest unoccupied orbital of the N-type semiconductor material is -1.0eV to 1.0eV, and the band gap of the compound is 1.0 eV to 2.5eV.

Optionally, the inorganic nanoparticles are selected from one or more of metal oxide nanoparticles and metal sulfide nanoparticles, and the phosphorus atoms of the black phosphorus nanosheets coordinate with the metal atoms of the inorganic nanoparticles Bond.

Optionally, the inorganic nanoparticles are selected from ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO, ZnSnO, ZnLiO, InSnO, AlZnO, CdS, ZnS, MoS, WS and at least one of CuS.

Optionally, the fullerene derivative contains an alkyl chain with 10 to 40 carbon atoms, and the alkyl chain contains one or more of nitro groups, aromatic groups, ester groups and fluorine atoms.

Optionally, the fullerene derivative is [60]PCBM or [70]PCBM.

In a second aspect, the present application provides a method for preparing a complex, the preparation method comprising the following steps:

A mixed solution is provided, the mixed solution includes black phosphorus nanosheets and component B, and the component B is one or more of fullerenes and fullerene derivatives;

placing the mixed solution at a first preset temperature to react to obtain a solution containing black phosphorus nanosheet-fullerene composite material, and removing the solvent of the solution to obtain a solid black phosphorus nanosheet-fullerene composite material; as well as

Provide a dispersion comprising component A, the component A is inorganic nanoparticles, mix the black phosphorus nanosheet-fullerene composite material with the dispersion, and react at a second preset temperature to obtain the complex.

Optionally, the first preset temperature is 100°C to 200°C, and the first reaction time is 1h to 12h;

The second preset temperature is -15°C to 80°C, and the second reaction time is 0.5h to 24h.

Optionally, in the mixed liquid, the mass ratio of the black phosphorus nanosheets: the component B is 1: (0.01˜0.10).

Optionally, in the step of mixing the black phosphorus nanosheet-fullerene composite with the dispersion, the black phosphorus nanosheet-fullerene composite: the mass ratio of the component A It is 1: (0.01～0.64).

In a third aspect, the present application provides an electroluminescent device, the electroluminescent device comprising:

anode;

a cathode disposed opposite to the anode;

N light-emitting layers are arranged at intervals between the anode and the cathode; and

(N-1) charge generation layers are arranged at intervals between the anode and the cathode, and each of the charge generation layers is respectively arranged between two adjacent light-emitting layers, and N is greater than or equal to 2 positive integer;

Wherein, the material of the charge generation layer includes black phosphorus nanosheets and inorganic nanoparticles; or, the material of the charge generation layer includes a P-type semiconductor material and an N-type semiconductor material, and the P-type semiconductor material and the N-type semiconductor material The semiconductor materials are connected by covalent chemical bonds, the P-type semiconductor materials include black phosphorus nanosheets, the N-type semiconductor materials include component A and component B, the component A is inorganic nanoparticles, and the component B One or more of fullerenes and fullerene derivatives; or, the material of the charge generation layer is prepared by the following method:

A mixed solution is provided, the mixed solution includes black phosphorus nanosheets and component B, and the component B is one or more of fullerenes and fullerene derivatives;

placing the mixed solution at a first preset temperature to react to obtain a solution containing black phosphorus nanosheet-fullerene composite material, and removing the solvent of the solution to obtain a solid black phosphorus nanosheet-fullerene composite material; as well as

Provide a dispersion comprising component A, the component A is inorganic nanoparticles, mix the black phosphorus nanosheet-fullerene composite material with the dispersion, and react at a second preset temperature to obtain the complex.

Optionally, calculated by weight percentage, the compound includes: 5% to 80% of N-type semiconductor material and 20% to 95% of P-type semiconductor material;

Preferably, calculated by weight percentage, the compound includes: 5% to 40% of N-type semiconductor material and 60% to 95% of P-type semiconductor material.

Optionally, calculated by weight percentage, the N-type semiconductor material includes: 80% to 99% of component A, and 1% to 20% of component B.

Optionally, the energy level difference between the highest occupied orbital of the P-type semiconductor material and the lowest unoccupied orbital of the N-type semiconductor material is -1.0eV to 1.0eV, and the band gap of the compound is 1.0 eV to 2.5eV.

Optionally, the material of the light-emitting layer is an organic light-emitting material or a quantum dot, and the organic light-emitting material is selected from diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, blue At least one of the TBPe fluorescent material of colored light, the TTPA fluorescent material of green light, the TBRb fluorescent material of orange light and the DBP fluorescent material of red light; the quantum dot is selected from II-VI group compounds, III-V At least one of group compound, IV-VI group compound and I-III-VI group compound, wherein, the II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe , HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZ nSTe, CdHgSeS, CdHgSeTe, CdHgSTe At least one of , HgZnSeS, HgZnSeTe and HgZnSTe, the III-V group compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb , GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb At least one of , InAlPAs and InAlPSb, the IV-VI group compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe , at least one of SnPbSeTe and SnPbSTe, the I-III-VI group compound is selected from at least one of CuInS ₂ , CuInSe ₂ and AgInS ₂ ;

The electroluminescence device also includes an electron transport layer, the electron transport layer is arranged between the cathode and the light-emitting layer, the material of the electron transport layer includes nano-metal oxide, and the nano-metal oxide is selected from At least one of ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnGaO, ZnAlO, ZnMgO, ZnSnO, ZnLiO, InSnO and AlZnO;

The electroluminescence device also includes a hole transport layer, the hole transport layer is arranged between the anode and the light-emitting layer, and the material of the hole transport layer is selected from poly(9,9-dioctyl fluorene-CO-N-(4-butylphenyl) diphenylamine), 3-hexyl substituted polythiophene, poly(9-vinylcarbazole), poly[bis(4-phenyl)(4-butylphenyl base)amine], poly(N,N'-bis(4-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine-CO-9,9-dioctylfluorene) , 4,4',4"-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(9-carbazole)biphenyl, N,N'-diphenyl-N,N'- Bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1 At least one of '-biphenyl-4,4'-diamine, NiO, WO ₃ , MoO ₃ and CuO.

Beneficial effect

The compound of the present application is a bulk heterojunction structure material based on component A, component B and black scale nanosheets, wherein component A is inorganic nanoparticles, and component B is fullerene and/or fullerene Derivatives, component A and component B are used as N-type semiconductor materials, and black scale nanosheets are used as P-type semiconductor materials. Component A is connected to the surface of black phosphorus nanosheets through covalent chemical bonds, thereby effectively passivating black scale nanosheets The phosphorus atoms on the surface improve the stability of the composite; component B is covalently connected to the edge of the black phosphorus nanosheet through the phosphorus atom-carbon atom chemical bond, which further improves the stability of the composite and improves the photocurrent response of the composite rate.

The preparation method of the composite of the present application is to first prepare the black phosphorus nanosheet-fullerene composite material, and then mix the black phosphorus nanosheet-fullerene composite material with a dispersion liquid containing inorganic nanoparticles to obtain the composite, It has the advantages of simple operation, easy control and suitability for industrialized production.

In the electroluminescent device of the present application, the material of the charge generation layer includes a P-type semiconductor material and an N-type semiconductor material, the P-type semiconductor material includes black phosphorus nanosheets, the N-type semiconductor material includes component A, or the N-type semiconductor material Including component A and component B, while effectively improving the stability of the charge generation layer, the photocurrent response rate of the charge generation layer is improved, and electrons and holes can be efficiently injected into the light-emitting layer without doubling the voltage, thereby Significantly improve the luminous brightness and current efficiency of electroluminescent devices; in addition, the charge generation layer can be a single-layer structure prepared by a solution method, which changes the traditional mode of relying on vacuum deposition to prepare charge generation layers, and is suitable for the preparation of large-scale The electroluminescent device is beneficial to reduce manufacturing cost and working voltage, and avoid damage to the light-emitting layer caused by high temperature.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is a schematic flow chart of a preparation method of a complex provided in an example of the present application.

Fig. 2 is a schematic structural diagram of the first electroluminescent device provided in the embodiment of the present application.

Fig. 3 is a schematic structural diagram of a second electroluminescent device provided in the embodiment of the present application.

Fig. 4 is a schematic structural diagram of a third electroluminescent device provided in the embodiment of the present application.

Fig. 5 is a schematic structural diagram of a fourth electroluminescent device provided in the embodiment of the present application.

Fig. 6 is a characteristic curve of current density-voltage of the electroluminescent devices of Examples 6 to 8, Comparative Example 1 and Comparative Example 2 in the experimental examples of the present application.

Fig. 7 is a characteristic curve of current density-voltage of the electroluminescent devices of Example 9, Example 10, Comparative Example 1 and Comparative Example 2 in the experimental examples of the present application.

Fig. 8 is a characteristic curve of current density-voltage of the electroluminescent devices of Examples 11 to 13, Comparative Example 1 and Comparative Example 2 in the experimental examples of the present application.

Embodiment of this application

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

Embodiments of the present application provide a quantum dot light emitting diode device, a manufacturing method thereof, and a display panel. Each will be described in detail below. It should be noted that the description sequence of the following embodiments is not intended to limit the preferred sequence of the embodiments.

In addition, in the description of the present application, the term "including" means "including but not limited to". Various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the application; therefore, the described range should be regarded as The description has specifically disclosed all possible subranges as well as individual values within that range. For example, a description of a range from 1 to 6 should be considered to have specifically disclosed subranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and Single numbers within the stated ranges, eg 1, 2, 3, 4, 5 and 6, apply regardless of the range. Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range.

In this application, the term "and/or" is used to describe the relationship between associated objects, indicating that there may be three relationships, for example, "A and/or B" may indicate three situations: the first situation is that A exists alone ; The second case is the presence of A and B at the same time; the third case is the case of B alone, wherein A and B can be singular or plural respectively.

In this application, the term "at least one" means one or more, and "multiple" means two or more. The terms "at least one", "at least one of the following", "one or more" or similar expressions refer to any combination of these items, including single item(s) or plural item(s) random combination. For example, "at least one (one) of a, b, or c" or "at least one (one) of a, b, and c" can be expressed as: a, b, c, a-b (that is, a and b ), a-c, b-c or a-b-c, wherein, a, b and c can be single or multiple respectively.

An embodiment of the present application provides a compound, the compound includes a P-type semiconductor material and an N-type semiconductor material, the P-type semiconductor material is connected to the N-type semiconductor material through a covalent chemical bond; the P-type semiconductor material includes black Phosphorus nanosheets; N-type semiconductor materials include component A and component B, wherein component A is inorganic nanoparticles, and component B is fullerene and/or fullerene derivatives.

As used in this application, "black phosphorus nanosheets" is a highly efficient P-type semiconductor material with the advantages of large specific surface area, abundant adsorption sites, high carrier mobility, excellent mechanical strength and thermal conductivity, and its surface has A phosphorus atom carrying a lone pair of electrons. Therefore, the phosphorus atom serves as a highly reactive site of the black phosphorus nanosheet. The surface of the black phosphorus nanosheet can form, for example, a phosphorus atom-metal atom chemical bond bridge, phosphorus atom-oxygen atom-carbon atom Chemical bond bridging or phosphorus atom-oxygen atom-silicon atom chemical bond bridging; black phosphorus nanosheets can be either undoped black phosphorus nanosheets, doped black phosphorus nanosheets, or undoped black phosphorus nanosheets A mixture of black phosphorus nanosheets and doped black phosphorus nanosheets, wherein the undoped black phosphorus nanosheets have an energy band gap of 0.3 eV to 2.1 eV and a carrier mobility of about 1000 cm ² V ^-1 s ^{- 1.} The band gap and carrier mobility of undoped black phosphorus nanosheets can be adjusted by means of surface modification and element doping.

"Doped black phosphorus nanosheets" refers to black phosphorus nanosheets having ions of one or more doping elements in the nanolattice. In some embodiments of the present application, the doping element of the doped black phosphorus nanosheet is a metal element, and the metal element is selected from Se, Te, Sb, Bi, As, Co, Fe, Mn, Fe, Pt and at least one of Zn. As an example, in the doped black phosphorus nanosheets, the number of doped metal atoms accounts for no more than 50% of the total number of atoms.

The compound of the embodiment of the present application is a bulk heterojunction structure material based on the covalent combination of a P-type semiconductor material and an N-type semiconductor material, which can be used to prepare a charge generation layer of a stacked electroluminescent device, and can be solution-processed into a film , so as to effectively avoid the negative impact of the charge generation layer formed by the traditional vacuum deposition method on the working performance and service life of the stacked electroluminescent device. In addition, the single-layer thin film formed by the solution method of the composite can be used as the charge generating layer of the stacked electroluminescent device, which effectively reduces the number and thickness of the film layer of the charge generating layer, and is beneficial to improve the efficiency of the stacked electroluminescent device. performance and prolong the service life of stacked electroluminescent devices.

In the composite, component A is connected to the surface of black phosphorus nanosheets through covalent chemical bonds, thereby effectively passivating the phosphorus atoms on the surface of black phosphorus nanosheets, improving the stability of the composite, and promoting the hole- electronic balance. Component B is covalently linked to the edge of black phosphorus nanosheets through a phosphorus atom-carbon atom chemical bond. Since component B has excellent stability in water, oxygen and air environments, it can further improve the stability of the composite; In addition, component B has an ideal ability to accept electrons, and the electrons excited by light are easily transferred from black phosphorus nanosheets to component B. Therefore, the photogenerated electrons and holes in the composite can be quickly transferred and separated, which is beneficial to improve the complex photocurrent response rate.

In some embodiments of the present application, calculated by weight percentage, the compound includes: 5% to 80% of N-type semiconductor material and 20% to 95% of P-type semiconductor material.

In some embodiments of the present application, calculated by weight percentage, the compound includes: 5% to 40% of N-type semiconductor material and 60% to 95% of P-type semiconductor material. When the compound is used as the charge generation layer material of a laminated electroluminescent device, if the content of the N-type semiconductor material is too small, the protective effect on the P-type semiconductor material will be limited; However, the effect of improving the electron-hole transport imbalance problem of multi-layer electroluminescent devices is limited.

In some embodiments of the present application, calculated by weight percentage, the N-type semiconductor material includes: 80% to 99% of component A, and 1% to 20% of component B. When the compound is used as the charge generation layer material of the stacked electroluminescent device, the content of component B is too small, the effect of improving the stability of the compound is limited, and the effect of improving the stability of the charge generation layer is limited; If the content of component B is too high, the effect of improving the electron-hole transport imbalance of the stacked electroluminescent device is limited.

In order to promote the charge balance between the black phosphorus nanosheets and the N-type semiconductor material in the composite, in some embodiments of the present application, the thickness of the black phosphorus nanosheets is 0.5 nm to 10 nm.

When the compound is used as the charge generation layer material of a stacked electroluminescent device, in order to reduce the energy level barrier difference between the P-type semiconductor material and the N-type semiconductor material in the charge generation layer, to increase the electrons generated by the charge generation layer and hole mobility, in some embodiments of the present application, the energy level difference between the highest occupied orbital of the P-type semiconductor material and the lowest unoccupied orbital of the N-type semiconductor material is -1.0eV to 1.0eV, and the The band gap of the complex is 1.0eV to 2.5eV.

In some embodiments of the present application, the inorganic nanoparticles are selected from metal oxide nanoparticles and/or metal sulfide nanoparticles, and the phosphorus atoms of the black phosphorus nanosheets are coordinated and bonded to the metal atoms of the inorganic nanoparticles .

As used in this application, "metal oxide nanoparticles" can be either undoped metal oxide nanoparticles, doped metal oxide nanoparticles, or undoped metal oxide nanoparticles and Mixture of doped metal oxide nanoparticles. "Doped metal oxide nanoparticles" means metal oxide nanoparticles having ions of one or more doping elements in the crystal lattice, the doping elements being different from the host metal elements of the metal oxide nanoparticles, doped Heteroelements include but are not limited to one or more of Mg, Al, Ga, Li, In, Sn and Mo, and the doped metal oxide nanoparticles can be, for example, molybdenum-doped zinc oxide (MZO), doped magnesium and Lithium zinc oxide (MLZO), gallium and magnesium doped zinc oxide (MGZO), zinc doped magnesium oxide (ZnMgO), zinc doped tin oxide (ZnSnO), zinc doped lithium oxide (ZnLiO), indium doped oxide One or more of tin (InSnO) and aluminum-doped zinc oxide (AlZnO).

As used in this application, "metal sulfide nanoparticles" can be either undoped metal sulfide nanoparticles, doped metal sulfide nanoparticles, or undoped metal sulfide nanoparticles and Mixture of doped metal sulfide nanoparticles. "Doped metal sulfide nanoparticles" means metal sulfide nanoparticles having ions of one or more doping elements in the crystal lattice, the doping elements being different from the host metal elements of the metal oxide nanoparticles, doped Heteroelements include but are not limited to one or more of Mg, Al, Ga, Li, In, Sn, and Mo, and the doped metal sulfide nanoparticles can be, for example, one or more of ZnMgS, AlZnS, and ZnLiS kind.

In some embodiments of the present application, the inorganic nanoparticles are selected from ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO, ZnSnO, ZnLiO, InSnO, AlZnO, CdS, ZnS, At least one of MoS, WS and CuS.

In some embodiments of the present application, the fullerene derivative comprises an alkyl chain with 10 to 40 carbon atoms, and the alkyl chain comprises at least one of a nitro group, an aromatic group, an ester group and a fluorine atom, To further reduce the lowest unoccupied orbital energy level of the fullerene derivatives, thereby improving the electron accepting ability of the fullerene derivatives, and further improving the photocurrent response rate of the composite.

In some embodiments of the present application, the fullerene derivative is [60]PCBM or [70]PCBM.

The embodiment of the present application also provides a preparation method of the complex, as shown in Figure 1, the preparation method includes the following steps:

B101, providing a mixed solution, the mixed solution comprising black phosphorus nanosheets and component B, where component B is fullerene and/or fullerene derivatives;

For B101, it should be noted that the solvents of the mixed solution include but are not limited to acetone, ethanol, methanol, isopropanol, N-methylpyrrolidone, N,N-dimethylformamide, carbon disulfide, cyclohexane, chlorobenzene and at least one of toluene. In some embodiments of the present application, the mass ratio of black phosphorus nanosheets:component B in the mixed solution is 1:(0.01˜0.10).

B102, put the mixed solution of B101 at the first preset temperature to react to obtain a solution containing black phosphorus nanosheet-fullerene composite material, remove the solvent of the solution, and obtain a solid black phosphorus nanosheet-fullerene composite Material;

What needs to be explained for B102 is that the mixed solution is treated with high temperature hydrothermal method to make component B bonded to the edge of black phosphorus nanosheets. In the reaction between component B and black phosphorus nanosheets, due to steric hindrance, Therefore, component B is selectively covalently linked to the edge of black phosphorus nanosheets by carbon atom-phosphorus atom chemical bond. The second preset temperature may be, for example, 100° C. to 200° C., and the reaction time may be, for example, 1 h to 12 h. "Removing the solvent of the solution" refers to everything that can remove the solvent in the solution containing the black phosphorus nanosheet-fullerene composite material to obtain one or more separations of the solid black phosphorus nanosheet-fullerene composite material. In the purification step, for example, the solvent of the solution can be removed by drying under reduced pressure.

B103, providing a dispersion liquid containing component A, component A is inorganic nanoparticles, mixing the black phosphorus nanosheet-fullerene composite material of B102 with the dispersion liquid, and reacting at a second preset temperature to obtain Complex.

For B103, it should be noted that the solvent of the dispersion containing component A includes but not limited to at least one of ethanol, methanol, isopropanol, ethylene glycol methyl ether and acetone. In some embodiments of the present application, the black phosphorus nanosheet-fullerene composite material: the mass ratio of component A is 1: (0.01˜0.64).

In some embodiments of the present application, the second preset temperature is -15°C to 80°C. In an embodiment of the present application, the second preset temperature is -5°C to 60°C, and the reaction time is 0.5h to 24h.

In order to remove impurities in the complex prepared by B103 to improve the purity of the complex, in some embodiments of the present application, the preparation method of the complex further includes step B104: adding a precipitating agent to the complex prepared by B103, solid Liquid separation and collection of the liquid phase, removal of the solvent of the liquid phase, to obtain a purified complex. Wherein, the solid-liquid separation process includes but is not limited to one or more operations in precipitation, centrifugation, decantation, filtration and gravity sedimentation; the precipitant is selected from ethyl acetate, methyl acetate, ethyl formate and methyl formate At least one of the above; "removing the solvent in the liquid phase" refers to one or more separation and purification processes that can remove the solvent in the liquid phase to obtain a solid compound, for example, the decompression drying method can be used to remove the solvent in the liquid phase. solvent.

In order to control the amount of precipitating agent used to reduce the difficulty of subsequent separation and purification, in an embodiment of the present application, "adding precipitating agent to the complex prepared by B103" includes the steps of: adding dropwise to the compound prepared by B103 Precipitant until no more precipitation occurs.

The embodiment of the present application also provides an electroluminescent device. As shown in FIG. 2 , the electroluminescent device 1 includes an anode 11, a cathode 12, N light-emitting layers and (N-1) charge generation layers, and N is greater than A positive integer equal to 2; N light-emitting layers are arranged at intervals between the anode 11 and the cathode 12; (N-1) charge generation layers are arranged at intervals between the anode 11 and the cathode 12, and each charge generation layer is respectively arranged on the phase Adjacent to the two light-emitting layers; wherein, the material of the charge generation layer includes black phosphorus nanosheets and inorganic nanoparticles, or the material of the charge generation layer includes any one of the compounds described in the embodiments of this application or this application The composite that any one of the preparation methods described in the examples makes.

In some embodiments of the present application, calculated by weight percentage, the material of the charge generation layer includes 20% to 95% of black phosphorus nanosheets and 5% to 80% of inorganic nanoparticles.

In some embodiments of the present application, calculated by weight percentage, the material of the charge generation layer includes 60% to 95% of black phosphorus nanosheets and 5% to 40% of inorganic nanoparticles.

In some embodiments of the present application, the material of the charge generation layer is prepared by the following method:

B201, providing a first solution containing black phosphorus nanosheets and a second solution containing inorganic nanoparticles, mixing the first solution and the second solution to obtain a mixture;

For B201, it should be noted that the solvent of the first solution includes but is not limited to at least one of acetone, ethanol, methanol, isopropanol, N-methylpyrrolidone and N,N-dimethylformamide, the first The concentration of black phosphorus nanosheets in the solution may be, for example, 5 mg/mL to 100 mg/mL. The solvent of the second solution includes but is not limited to at least one of ethanol, methanol, isopropanol, ethylene glycol methyl ether and acetone, and the concentration of inorganic nanoparticles in the second solution can be, for example, 5 mg/mL to 60 mg/mL .

In some embodiments of the present application, the mass ratio of black phosphorus nanosheets:inorganic nanoparticles in the mixture is 1:(0.02˜0.7).

B202, reacting the mixture of B201 at a preset temperature to obtain a reaction product comprising black phosphorus nanosheets and inorganic nanoparticles;

What needs to be explained for B202 is that the preset temperature is -15°C to 80°C. In an embodiment of the present application, the preset temperature is -5°C to 60°C, and the reaction time is 0.5h to 24h.

B203. Purifying the reaction product of B202 to obtain a purified charge generation layer material.

What needs to be explained for B203 is that the reaction product of B202 includes black phosphorus nanosheets, inorganic nanoparticles and impurities, and the purified charge generation layer material can be obtained by purifying the reaction product of B202. The purification process includes but is not limited to solid-liquid Separation process, solid-liquid separation process includes but not limited to one or more operations in sedimentation, centrifugation, decantation, filtration and gravity sedimentation.

In some embodiments of the present application, B203 includes the steps of: adding a precipitating agent to the reaction product of B202, separating the solid from the liquid and collecting the liquid phase, removing the solvent of the liquid phase, and obtaining a purified charge generation layer material. Wherein, the precipitant is selected from at least one of ethyl acetate, methyl acetate, ethyl formate and methyl formate, in an embodiment of the application, in order to control the amount of the precipitant to reduce the difficulty of subsequent separation and purification, The precipitating agent was added dropwise to the reaction product of B202 until no more precipitation occurred. "Removing the solvent in the liquid phase" refers to one or more separation and purification procedures that can remove the solvent in the liquid phase to obtain a solid charge generation layer material. For example, the solvent in the liquid phase can be removed by drying under reduced pressure.

It can be understood that the light-emitting layers and the charge generation layers are stacked alternately. Please continue to refer to 2. The N light-emitting layers respectively correspond to the first light-emitting layer 13-1 to the Nth light-emitting layer 13-N, and (N-1) charges The generation layers correspond to the first charge generation layer 14-1 to the (N-1)th charge generation layer 14-(N-1), the first light-emitting layer 13-1 is close to the anode 11, and the N-th light-emitting layer 13-N is close to Cathode 12, the first charge generation layer 14-1 is arranged between the first light emitting layer 13-1 and the second light emitting layer 13-2, the second charge generation layer 14-2 is arranged between the second light emitting layer 13-2 and the second light emitting layer Between the three light-emitting layers 13-3, and so on, the (N-1)th charge generation layer 14-(N-1) is arranged between the (N-1)-th light-emitting layer 13-(N-1) and the N-th light-emitting layer Between 13-N. When the electroluminescent device is energized, holes are injected into the first light-emitting layer 13-1 from the anode 11, electrons are injected into the N-th light-emitting layer 13-N from the cathode 12, and the (N-1) charge generation layer 14-(N -1) The generated electrons are injected into the (N-1)th light-emitting layer 13-(N-1) toward the anode 11, and the holes generated in the (N-1)th charge generation layer 14-(N-1) toward the cathode 12 directions are injected into the Nth light-emitting layer 13-N, and the Nth light-emitting layer 13-N respectively receives electrons from the cathode 12 and holes from the (N-1)th charge generation layer 14-(N-1), and receives The electrons and the holes in the N-th light-emitting layer 13-N recombine to emit light, and the light-emitting principles of the first light-emitting layer 13-1 to the (N-1)-th light-emitting layer 13-(N-1) are similarly deduced.

In the embodiment of the present application, the materials of the anode 11 and the cathode 12 can be common materials in the field, for example: the materials of the anode 11 and the cathode 12 include but are not limited to one or more of metals, carbon materials and metal oxides The metal can be one or more of Al, Ag, Cu, Mo, Au, Ba, Ca and Mg; the carbon material can be one or more of graphite, carbon nanotube, graphene and carbon fiber, for example. species; metal oxides can be doped or non-doped metal oxides, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, also including doped or non-doped transparent Composite electrodes with metal sandwiched between metal oxides, composite electrodes include but not limited to AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/Al/ITO, ZnO/Ag/ZnO, ZnO /Al/ZnO, TiO ₂ /Ag/TiO ₂ , TiO ₂ /Al/TiO ₂ , ZnS/Ag/ZnS, ZnS/Al/ZnS, TiO ₂ /Ag/TiO ₂ and TiO ₂ /Al/TiO ₂ one or more. The thickness of the anode can be, for example, 40 nm to 160 nm, and the thickness of the cathode can be, for example, 20 nm to 120 nm.

In the embodiment of the present application, the material of the light-emitting layer includes but is not limited to organic light-emitting materials or quantum dots, and the organic light-emitting materials include but not limited to diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or At least one of fluorene derivatives, TBPe fluorescent material emitting blue light, TTPA fluorescent material emitting green light, TBRb fluorescent material emitting orange light and DBP fluorescent material emitting red light. Quantum dots can be at least one of red quantum dots, green quantum dots and blue quantum dots, quantum dots are selected from II-VI group compounds, III-V group compounds, IV-VI group compounds and I-III-VI group compounds At least one of the group I-VI compounds selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe , HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnST At least one of e, the III-V group Compounds selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs , InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and InAlPSb, the IV-VI compound is selected from SnS , SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, the I-III-VI group compound is selected from CuInS _2. At least one of CuInSe ₂ and AgInS ₂ . The thickness of the light emitting layer may be, for example, 10 nm to 30 nm.

In some embodiments of the present application, the electroluminescent device further includes an electron transport layer, the electron transport layer is arranged between the cathode and the light-emitting layer, and the material of the electron transport layer includes a nano-metal oxide, and the nano-metal oxide is selected from ZnO, At least one of TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnGaO, ZnAlO, ZnMgO, ZnSnO, ZnLiO, InSnO, and AlZnO; and/or, the electroluminescent device further includes a hole transport layer, the hole transport layer is arranged between the anode and the light-emitting layer, and the material of the hole transport layer is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine) ( TFB for short, CAS No. 220797-16-0), 3-hexyl substituted polythiophene (CAS No. 104934-50-1), poly(9-vinylcarbazole) (PVK for short, CAS No. 25067-59 -8), poly[bis(4-phenyl)(4-butylphenyl)amine] (referred to as Poly-TPD, CAS No. 472960-35-3), poly(N,N'-bis(4 -Butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine-CO-9,9-dioctylfluorene) (referred to as PFB, CAS No. 223569-28-6), 4,4',4"-Tris(carbazol-9-yl)triphenylamine (abbreviated as TCTA, CAS No. 139092-78-7), 4,4'-bis(9-carbazole)biphenyl (abbreviated as CBP, CAS No. 58328-31-7), N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'- Diamine (TPD for short, CAS No. 65181-78-4) and N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'- At least one of diamines (abbreviated as NPB, CAS No. 123847-85-8), in addition, the material of the hole transport layer can also be selected from inorganic materials with hole transport capabilities, including but not limited to NiO, WO3 , MoO3 and at least one of CuO.

As an example, as shown in FIG. 3, on the basis of the electroluminescent device 1 shown in FIG. between layers 13-1. The thickness of the hole transport layer 15 may be, for example, 10 nm to 50 nm.

As an example, as shown in FIG. 4, on the basis of the electroluminescent device 1 shown in FIG. between the cathodes 12. The thickness of the electron transport layer 16 may be, for example, 10 nm to 60 nm.

It can be understood that the electroluminescent device may also include other layer structures, for example, the electroluminescent device may also include a hole injection layer, for example, the hole injection layer is arranged between the hole transport layer and the anode, and the hole injection layer Materials include but are not limited to 3,4-ethylenedioxythiophene monomer (PEDOT), styrene sulfonate (PSS), copper phthalocyanine (CuPc), 2,3,5,6-tetrafluoro-7,7 ',8,8'-tetracyanodimethyl-p-benzoquinone (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexa One or more of azatriphenylene (HATCN), transition metal oxides and transition metal chalcogenides, wherein the transition metal oxides can be NiO _x , MoO _x , WO _x , CrO _x and CuO One or more, the metal chalcogenide compound may be one or more of MoS _x , MoS _x , WS _x , WS _x and CuS, and the thickness of the hole injection layer may be, for example, 10 nm to 120 nm.

In addition, except for the charge generation layer (prepared by solution method), the preparation method of each layer structure in the electroluminescence device includes but not limited to solution method and deposition method. The solution method includes but not limited to spin coating, coating, inkjet printing, scraping coating, dipping and pulling, soaking, spraying, rolling coating or casting. After the wet film is prepared by the solution method, a drying process needs to be added. The drying process includes all A process in which a wet film obtains higher energy and is transformed into a dry film. The drying process can be, for example, heat treatment, standing to dry naturally, etc.; wherein, "heat treatment" can be a constant temperature heat treatment, or a non-constant temperature heat treatment (for example, the temperature is gradient format change). Deposition methods include chemical methods and physical methods. Chemical methods include but are not limited to chemical vapor deposition, continuous ion layer adsorption and reaction methods, anodic oxidation, electrolytic deposition or co-precipitation methods. Physical methods include but are not limited to thermal evaporation. Coating method, electron beam evaporation coating method, magnetron sputtering method, multi-arc ion coating method, physical vapor deposition method, atomic layer deposition method or pulsed laser deposition method.

In the electroluminescent device of the embodiment of the present application, the material of the charge generation layer includes a P-type semiconductor material and an N-type semiconductor material, the P-type semiconductor material includes black phosphorus nanosheets, and the N-type semiconductor material includes inorganic nanoparticles or N-type semiconductor materials. The materials include fullerene and/or fullerene derivatives and inorganic nanoparticles, which can effectively improve the stability of the charge generation layer and at the same time improve the photocurrent response rate of the charge generation layer, and can efficiently charge the charge generation layer without doubling the voltage. The light-emitting layer injects electrons and holes, thereby significantly improving the luminous brightness and current efficiency of the electroluminescent device. In addition, the charge generation layer can be a single-layer structure prepared by the solution method, which changes the traditional mode of relying on the vacuum deposition method to prepare the charge generation layer, and is suitable for the preparation of large-sized electroluminescent devices, which is conducive to reducing manufacturing costs and operating voltages , and avoid high temperature damage to the light-emitting layer.

An embodiment of the present application further provides a display device, the display device comprising any one of the electroluminescent devices described in the embodiments of the present application. The display device can be any electronic product with a display function, including but not limited to smart phones, tablet computers, notebook computers, digital cameras, digital video cameras, smart wearable devices, smart weighing electronic scales, vehicle displays, televisions Or an e-book reader, wherein the smart wearable device may be, for example, a smart bracelet, a smart watch, a virtual reality (Virtual Reality, VR) helmet, and the like.

The technical solutions and technical effects of the present application will be described in detail below through specific examples. The following examples are only part of the examples of the present application, and do not specifically limit the present application.

Example 1

This embodiment provides a composite and its preparation method. According to the weight percentage, the composite consists of 32% ZnO nanoparticles (6nm particle size), 8% fullerene and 60% black phosphorus nanosheets .

The preparation method of described complex comprises the steps:

S1.1. Take 1.2g of black phosphorus nanosheets and 0.16g of fullerene and dissolve them in 25mL of ethanol-cyclohexane mixed solvent (the molar ratio of ethanol:cyclohexane is 1:0.2) to obtain a mixed solution;

S1.2. Place the mixed solution in step S1.1 at 150°C for 4 hours to react, and the obtained reaction product is a black phosphorus nanosheet-fullerene composite solution, and dry under reduced pressure (at a pressure of -0.1MPa) to remove the black phosphorus A solvent in the nanosheet-fullerene composite solution to obtain a solid black phosphorus nanosheet-fullerene composite material;

S1.3, ZnO nanoparticles (particle diameter is 6nm) is dissolved in ethanol to obtain the dispersion liquid that concentration is 20mg/mL, get the black phosphorus nanosheet-fullerene composite material that 1.36g step S1.2 makes and 16.2mL of the dispersion were mixed, placed at 0°C and stirred for 8 hours to obtain a reaction product containing the complex;

S1.4. At room temperature, add ethyl acetate dropwise to the reaction product in step S1.3, and stir fully at the same time, stop adding ethyl acetate until no white precipitate occurs, let it settle for 5 hours naturally, filter to remove the precipitate and remove The liquid phase was collected, dried under reduced pressure (at a pressure of -0.1 MPa) to remove the solvent of the liquid phase, and a purified compound was obtained.

Example 2

This embodiment provides a composite and its preparation method. According to the weight percentage, the composite consists of 21% ZnO nanoparticles (particle size is 6nm), 4% fullerene and 75% black phosphorus nanosheets .

The preparation method of described complex comprises the steps:

S2.1. Dissolve 1.5g of black phosphorus nanosheets and 0.08g of fullerene in 40mL of ethanol-cyclohexane mixed solvent (the molar ratio of ethanol:cyclohexane is 1:0.2) to obtain a mixed solution;

S2.2. Place the mixed solution in step S2.1 at 150°C for 4 hours to react, and the obtained reaction product is a black phosphorus nanosheet-fullerene composite solution, and dry under reduced pressure (at a pressure of -0.1MPa) to remove the black phosphorus A solvent in the nanosheet-fullerene composite solution to obtain a solid black phosphorus nanosheet-fullerene composite material;

S2.3, dissolving ZnO nanoparticles in ethanol to obtain a dispersion with a concentration of 10 mg/mL, take 0.79 g of the black phosphorus nanosheet-fullerene composite material prepared in step S2.2 and 21.2 mL of the dispersion Mixed, placed at 0°C and stirred for 8 hours to obtain a reaction product containing the complex;

S2.4. At room temperature, add ethyl acetate dropwise to the reaction product in step S2.3, and stir fully at the same time, stop adding ethyl acetate until no white precipitate occurs, let it settle for 5 hours naturally, filter to remove the precipitate and remove The liquid phase was collected, dried under reduced pressure (at a pressure of -0.1 MPa) to remove the solvent of the liquid phase, and a purified compound was obtained.

Example 3

This embodiment provides a composite and its preparation method. According to the weight percentage, the composite is composed of 4.95% ZnO nanoparticles (particle size is 6nm), 0.05% fullerene and 95% black phosphorus nanosheets .

The preparation method of described complex comprises the steps:

S3.1. Dissolve 1.9g of black phosphorus nanosheets and 0.001g of fullerene in 45mL of ethanol-cyclohexane mixed solvent (the molar ratio of ethanol:cyclohexane is 1:0.2) to obtain a mixed solution;

S3.2. Place the mixed solution in step S3.1 at 150°C for 4 hours to react, and the obtained reaction product is a black phosphorus nanosheet-fullerene composite solution, and dry under reduced pressure (at a pressure of -0.1MPa) to remove the black phosphorus A solvent in the nanosheet-fullerene composite solution to obtain a solid black phosphorus nanosheet-fullerene composite material;

S3.3, dissolving ZnO nanoparticles in ethanol to obtain a dispersion with a concentration of 5 mg/mL, take 0.951 g of the black phosphorus nanosheet-fullerene composite material prepared in step S3.2 and 10.1 mL of the dispersion Mixed, placed at 0°C and stirred for 8 hours to obtain a reaction product containing the complex;

S3.4. At room temperature, add ethyl acetate dropwise to the reaction product in step S3.3, and stir fully at the same time, stop adding ethyl acetate until no white precipitate occurs, let it settle for 5 hours naturally, remove the precipitate by filtration and remove The liquid phase was collected, dried under reduced pressure (at a pressure of -0.1 MPa) to remove the solvent of the liquid phase, and a purified compound was obtained.

Example 4

This example provides a composite and a preparation method thereof. Compared with the composite of Example 1, the only difference of the composite of this example is that fullerene is replaced by [60]PCBM.

Compared with the preparation method of Example 1, the difference of the preparation method of this example is only that “fullerene” involved in the preparation method is replaced with “[60]PCBM”.

Example 5

This example provides a composite and a preparation method thereof. Compared with the composite of Example 1, the only difference of the composite of this example is that fullerene is replaced by [70]PCBM.

Compared with the preparation method of Example 1, the difference of the preparation method of this example is only that “fullerene” involved in the preparation method is replaced with “[70]PCBM”.

Example 6

The embodiment of the present application provides an electroluminescent device and its preparation method. As shown in FIG. 13-1, the first charge generation layer 14-1, the second light emitting layer 13-2, the electron transport layer 16 and the cathode 12.

The material and thickness of each layer structure in the electroluminescent device 1 are as follows:

The material of the substrate 10 is glass with a thickness of 0.55mm;

The material of the anode 11 is ITO, and the thickness is 50nm;

The material of the cathode 12 is silver, and the thickness is 100nm;

The material of the first light-emitting layer 13-1 is CdSe/ZnS, and the thickness is 15nm;

The material of the first light-emitting layer 13-2 is CdSe/ZnS, and the thickness is 15nm;

The material of the first charge generation layer 14-1 is the composite prepared in Example 1, and the thickness is 30 nm;

The hole transport layer 15 is made of TFB with a thickness of 30nm;

The electron transport layer 16 is made of zinc oxide nanoparticles with a particle size of 6 nm and a thickness of 40 nm.

The preparation method of the electroluminescent device of the present embodiment comprises the following steps:

S6.1. Provide ITO substrate: After cleaning and drying the ITO substrate, treat it with ultraviolet and ozone for 15 minutes to serve as anode and substrate;

S6.2. Under a nitrogen environment at normal temperature and pressure, inkjet printing a TFB (CAS No. 223569-31-1)-chlorobenzene solution with a concentration of 9 mg/mL on one side of the ITO substrate in step S6.1, and then Heat treatment at a constant temperature of 150°C for 30 minutes to obtain a hole transport layer;

S6.3. Under a nitrogen environment at normal temperature and pressure, inkjet print a CdSe/ZnS-n-octane solution with a concentration of 10 mg/mL on the side of the hole transport layer in step 6.2 away from the anode, and then place it at 80°C Heat treatment at constant temperature for 20 minutes to obtain the first luminescent layer;

S6.4. Dissolve the complex prepared in Example 1 in ethanol to obtain a complex solution with a concentration of 30 mg/mL. Under a nitrogen environment at normal temperature and pressure, the first light-emitting layer in step 6.3 is far away from the hole transport One side of the layer is inkjet printed with the composite solution, and then heat-treated at 150° C. for 30 minutes to obtain the first charge generation layer;

S6.5. Under a nitrogen environment at normal temperature and pressure, inkjet print a CdSe/ZnS-n-octane solution with a concentration of 10 mg/mL on the side of the charge generation layer in step 6.4 away from the first light-emitting layer, and then place it at 80 Constant temperature heat treatment at ℃ for 20 minutes to obtain the second light-emitting layer;

S6.6. In a nitrogen environment at normal temperature and pressure, inkjet print a nano-zinc oxide-ethanol solution with a concentration of 30 mg/mL on the side of the second light-emitting layer away from the charge generation layer in step 6.5, and then place it at 80°C Heat treatment for 30min to obtain electron transport layer;

S6.7. Deposit silver on the side of the electron transport layer away from the second light-emitting layer in step 6.6 by vacuum evaporation to obtain a cathode, and then package to obtain an electroluminescent device.

Example 7

This embodiment provides an electroluminescent device. Compared with the electroluminescent device in Embodiment 6, the only difference between the electroluminescent device in this embodiment is that the material of the charge generation layer is replaced with the one in Embodiment 2. The compound produced.

The preparation method of the electroluminescent device of this embodiment is carried out with reference to Example 6.

Example 8

This embodiment provides an electroluminescent device. Compared with the electroluminescent device of Embodiment 6, the only difference between the electroluminescent device of this embodiment is that the material of the charge generation layer is replaced by the material of Embodiment 3. The compound produced.

The preparation method of the electroluminescent device of this embodiment is carried out with reference to Example 6.

Example 9

This embodiment provides an electroluminescent device. Compared with the electroluminescent device of Embodiment 6, the only difference between the electroluminescent device of this embodiment is that the material of the charge generation layer is replaced by the material of Embodiment 4. The compound produced.

The preparation method of the electroluminescent device of this embodiment is carried out with reference to Example 6.

Example 10

This embodiment provides an electroluminescent device. Compared with the electroluminescent device of Embodiment 6, the only difference between the electroluminescent device of this embodiment is that the material of the charge generation layer is replaced by the material of Embodiment 5. The compound produced.

The preparation method of the electroluminescent device of this embodiment is carried out with reference to Example 6.

Example 11

This embodiment provides an electroluminescent device. Compared with the electroluminescent device in Embodiment 6, the only difference of the electroluminescent device in this embodiment is that the material of the charge generation layer is replaced by "by weight Percentage calculation, the composite is composed of 50% ZnO nanoparticles (particle size is 6nm) and 50% black phosphorus nanosheets".

The preparation method of the electroluminescent device of this embodiment is carried out with reference to Example 6.

The preparation method of the material of the charge generating layer in this embodiment is as follows:

S11.1. Dissolving black phosphorus nanosheets in ethanol to obtain a first solution with a concentration of black phosphorus nanosheets of 10 mg/mL, and dissolving ZnO nanoparticles in ethanol to obtain a second solution with a concentration of ZnO nanoparticles of 10 mg/mL Second solution, take 3.0mL of the first solution and 3.0mL of the second solution and mix to obtain a mixture. In the mixture, the mass ratio of black phosphorus nanosheets: ZnO nanoparticles is 1:1;

S11.2, placing the mixture in step S11.1 at 0° C. for 5 h and stirring to react to obtain a reaction product comprising black phosphorus nanosheet-ZnO nanoparticle composite material;

S11.3. At room temperature, add ethyl acetate dropwise to the reaction product in step S11.2, and stir thoroughly at the same time, stop adding ethyl acetate until no white precipitate is produced, let it settle for 5 hours, remove the precipitate by filtration and remove The liquid phase is collected, dried under reduced pressure (the pressure is -0.1 MPa) to remove the solvent of the liquid phase, and a purified charge generation layer material is obtained.

Example 12

This embodiment provides an electroluminescent device. Compared with the electroluminescent device in Embodiment 6, the only difference of the electroluminescent device in this embodiment is that the material of the charge generation layer is replaced by "by weight Calculated in percentage, the composite is composed of 10% ZnO nanoparticles (particle size is 6nm) and 90% black phosphorus nanosheets".

The preparation method of the electroluminescent device of this embodiment is carried out with reference to Example 6.

The preparation method of the material of the charge generation layer in this embodiment is as follows:

S12.1. Dissolving black phosphorus nanosheets in ethanol to obtain a first solution with a concentration of black phosphorus nanosheets of 30 mg/mL, and dissolving ZnO nanoparticles in ethanol to obtain a second solution with a concentration of ZnO nanoparticles of 10 mg/mL Second solution, take 6.0mL of the first solution and 2.0mL of the second solution and mix to obtain a mixture. In the mixture, the mass ratio of black phosphorus nanosheets: ZnO nanoparticles is 1:0.11;

S12.2, placing the mixture in step S12.1 at 0° C. for 5 h and stirring to react to obtain a reaction product comprising black phosphorus nanosheet-ZnO nanoparticle composite material;

S12.3. At room temperature, add ethyl acetate dropwise to the reaction product in step S12.2, and stir fully at the same time, stop adding ethyl acetate until no white precipitate occurs, let it settle for 5 hours naturally, remove the precipitate by filtration and remove The liquid phase is collected, dried under reduced pressure (the pressure is -0.1 MPa) to remove the solvent of the liquid phase, and a purified charge generation layer material is obtained.

Example 13

This embodiment provides an electroluminescent device. Compared with the electroluminescent device in Embodiment 6, the only difference of the electroluminescent device in this embodiment is that the material of the charge generation layer is replaced by "by weight Calculated in percentage, the composite is composed of 40% ZnO nanoparticles (particle size is 6nm) and 60% black phosphorus nanosheets".

The preparation method of the electroluminescent device of this embodiment is carried out with reference to Example 6.

The preparation method of the material of the charge generation layer in this embodiment is as follows:

S13.1. Dissolving black phosphorus nanosheets in ethanol to obtain a first solution with a concentration of black phosphorus nanosheets of 10 mg/mL, and dissolving ZnO nanoparticles in ethanol to obtain a second solution with a concentration of ZnO nanoparticles of 10 mg/mL Second solution, take 3.0mL of the first solution and 2.0mL of the second solution and mix to obtain a mixture. In the mixture, the mass ratio of black phosphorus nanosheets: ZnO nanoparticles is 1:0.67;

S13.2, placing the mixture in step S13.1 at 0° C. for 5 h to react, and obtaining a reaction product comprising black phosphorus nanosheet-ZnO nanoparticle composite material;

S13.3. At room temperature, add ethyl acetate dropwise to the reaction product in step S13.2, and stir fully at the same time, stop adding ethyl acetate until no white precipitate occurs, let it settle for 5 hours naturally, remove the precipitate by filtration and remove The liquid phase is collected, dried under reduced pressure (the pressure is -0.1 MPa) to remove the solvent of the liquid phase, and a purified charge generation layer material is obtained.

Comparative example 1

This comparative example provides an electroluminescent device and a preparation method thereof. Compared with the electroluminescent device of Example 9, the difference between the electroluminescent device of this comparative example is that the structural composition of the charge generation layer is different. Similarly, in this comparative example, the charge generation layer is composed of the first sub-film and the second sub-film stacked, the material of the first sub-film is tris(8-hydroxyquinoline)aluminum (Alq ₃ ), the first sub-film The thickness of the film is 30nm; the material of the second sub-film is molybdenum trioxide (MoO ₃ ), and the thickness of the second sub-film is 25nm, wherein the first sub-film is close to the first light-emitting layer, and the second sub-film is close to the second light-emitting layer layer.

Compared with the preparation method of Example 9, the only difference of the preparation method of this comparative example is that step S9.4 is replaced with "Using the vacuum evaporation method on the side of the first light-emitting layer away from the hole transport layer to depositing to form a first sub-film and a second sub-film”.

Comparative example 2

This comparative example provides an electroluminescent device and its preparation method. Compared with the electroluminescent device of Example 6, the difference between the electroluminescent device of this comparative example is that the material of the charge generation layer is replaced It is the black phosphorus nanosheet-fullerene composite material prepared in step S1.2 in Example 1.

Compared with the preparation method of Example 6, the only difference in the preparation method of this comparative example is: replace step S6.4 with "dissolving the black phosphorus nanosheet-fullerene composite material in ethanol to obtain a concentration of 30mg/mL black phosphorus nanosheet-fullerene composite solution, inkjet printing the composite solution on the side of the first light-emitting layer away from the hole transport layer in step 6.3 under a nitrogen atmosphere at normal temperature and pressure, Then place it at 150°C for constant temperature heat treatment for 30 minutes to obtain a charge generation layer."

Experimental example

The electroluminescent device of embodiment 6 to embodiment 13 and the electroluminescent device of comparative example 1 and comparative example 2 are carried out performance detection, and the project of performance test is: the voltage (U@ 1000nit, V) and the maximum current efficiency (Cd/A), among them, the performance parameters of the electroluminescent device are detected by the optoelectronic instrument composed of CS-2000 and Keithley source meter, and the performance test results are shown in the following table 1: Table 1 The performance testing results of the electroluminescent devices of Example 6 to Example 13 and Comparative Example 1 and Comparative Example 2

As can be seen from Table 1 and Figures 6 to 8, compared with the electroluminescent devices of Comparative Example 1 and Comparative Example 2, the photoelectric performance of the electroluminescent devices of Example 6 to Example 13 has obvious advantages, indicating that the use of this The compound of the application example is used as the material of the charge generation layer, which is beneficial to reduce the operating voltage of the electroluminescent device, and can efficiently inject electrons and holes into the light-emitting layer, thereby significantly improving the current efficiency of the electroluminescent device and effectively improving the efficiency of the electroluminescent device. Optoelectronic properties of electroluminescent devices. In addition, Comparative Example 2 uses black phosphorus nanosheet-fullerene composite material as the material of the charge generation layer. Since fullerene is connected to the edge of the black scale nanosheet through a carbon atom-phosphorus atom chemical bond, only the black scale is passivated. The phosphorus atoms on the edge of the nanosheets, that is, the phosphorus atoms on the surface of the black scale nanosheets have not been effectively passivated. Therefore, the stability of the black phosphorus nanosheet-fullerene composite is not as good as the composite of the embodiment of the present application; further, The electron mobility of fullerene is lower than that of black phosphorus nanosheets, and fullerenes are distributed on the edge of black phosphorus nanosheets, which may cause hole-electron imbalance in black phosphorus nanosheets-fullerene composites Therefore, the overall performance of the electroluminescent device of Comparative Example 2 is not as good as that of the electroluminescent devices of Examples 6 to 13.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For the parts not described in detail in a certain embodiment, you can refer to the relevant descriptions of other embodiments.

A compound, a preparation method of the compound, and an electroluminescent device provided in the embodiments of the present application have been described in detail above. In this paper, specific examples have been used to illustrate the principles and implementation methods of the present application. The above examples The description is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation and scope of application. In summary, The contents of this specification should not be understood as limiting the application.

Claims (20)

1. A composite, wherein the composite includes a P-type semiconductor material and an N-type semiconductor material, the P-type semiconductor material is connected to the N-type semiconductor material by a covalent chemical bond; the P-type semiconductor material includes black phosphorus Nanosheet; the N-type semiconductor material includes:

   Component A: inorganic nanoparticles; and

   Component B: one or more of fullerenes and fullerene derivatives.
2. The compound according to claim 1, wherein, calculated by weight percentage, the compound comprises: 5% to 80% of N-type semiconductor material and 20% to 95% of P-type semiconductor material.
3. The compound according to claim 1 or 2, wherein, calculated by weight percentage, the compound comprises: 5% to 40% of N-type semiconductor material and 60% to 95% of P-type semiconductor material.
4. The compound according to any one of claims 1 to 3, wherein, calculated by weight percentage, the N-type semiconductor material comprises: 80% to 99% of component A, and 1% to 20% of component A b.
5. The composite according to any one of claims 1 to 4, wherein the composite is composed of a P-type semiconductor material and an N-type semiconductor material, and the P-type semiconductor material and the N-type semiconductor material are covalently chemical bond connection; the P-type semiconductor material is black phosphorus nanosheet; the N-type semiconductor material is composed of component A and component B.
6. The composite according to any one of claims 1 to 5, wherein the thickness of the black phosphorus nanosheets is 0.5nm to 10nm.
7. The compound according to any one of claims 1 to 6, wherein the energy level difference between the highest occupied orbital of the P-type semiconductor material and the lowest unoccupied orbital of the N-type semiconductor material is -1.0eV to 1.0eV, and the band gap of the complex is 1.0eV to 2.5eV.
8. The compound according to any one of claims 1 to 7, wherein the inorganic nanoparticles are selected from one or more of metal oxide nanoparticles and metal sulfide nanoparticles, and the black phosphorus nanosheets The phosphorus atoms of the inorganic nanoparticles are coordinately bonded to the metal atoms of the inorganic nanoparticles.
9. The compound according to any one of claims 1 to 8, wherein the inorganic nanoparticles are selected from ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO, ZnSnO , ZnLiO, InSnO, AlZnO, CdS, ZnS, MoS, WS and one or more of CuS.
10. The compound according to any one of claims 1 to 9, wherein the fullerene derivative comprises an alkyl chain with 10 to 40 carbon atoms, and the alkyl chain comprises a nitro group, an aromatic group, One or more of ester groups and fluorine atoms.
11. The compound according to any one of claims 1 to 10, wherein the fullerene derivative is [60]PCBM or [70]PCBM.
12. A method for preparing a complex, wherein the method for preparing comprises the steps of:

    A mixed solution is provided, the mixed solution includes black phosphorus nanosheets and component B, and the component B is one or more of fullerenes and fullerene derivatives;

    placing the mixed solution at a first preset temperature to react to obtain a solution containing black phosphorus nanosheet-fullerene composite material, and removing the solvent of the solution to obtain a solid black phosphorus nanosheet-fullerene composite material; as well as

    Provide a dispersion comprising component A, the component A is inorganic nanoparticles, mix the black phosphorus nanosheet-fullerene composite material with the dispersion, and react at a second preset temperature to obtain the complex.
13. The preparation method according to claim 12, wherein the first preset temperature is 100°C to 200°C, and the first reaction time is 1h to 12h;

    The second preset temperature is -15°C to 80°C, and the second reaction time is 0.5h to 24h.
14. The preparation method according to claim 12 or 13, wherein, in the mixed solution, the mass ratio of the black phosphorus nanosheets: the component B is 1: (0.01-0.10).
15. According to the preparation method described in any one of claims 12 to 14, wherein, in the step of mixing the black phosphorus nanosheet-fullerene composite material with the dispersion liquid, the black phosphorus nanosheet- Fullerene composite material: the mass ratio of the component A is 1: (0.01-0.64).
16. An electroluminescent device, wherein the electroluminescent device comprises:

    anode;

    a cathode disposed opposite to the anode;

    N light-emitting layers are arranged at intervals between the anode and the cathode; and

    (N-1) charge generation layers are arranged at intervals between the anode and the cathode, and each of the charge generation layers is respectively arranged between two adjacent light-emitting layers, and N is greater than or equal to 2 positive integer;

    Wherein, the material of the charge generation layer includes black phosphorus nanosheets and inorganic nanoparticles; or, the material of the charge generation layer includes a P-type semiconductor material and an N-type semiconductor material, and the P-type semiconductor material and the N-type semiconductor material The semiconductor materials are connected by covalent chemical bonds, the P-type semiconductor materials include black phosphorus nanosheets, the N-type semiconductor materials include component A and component B, the component A is inorganic nanoparticles, and the component B One or more of fullerenes and fullerene derivatives; or, the material of the charge generation layer is prepared by the following method:

    A mixed solution is provided, the mixed solution includes black phosphorus nanosheets and component B, and the component B is one or more of fullerenes and fullerene derivatives;

    placing the mixed solution at a first preset temperature to react to obtain a solution containing black phosphorus nanosheet-fullerene composite material, and removing the solvent of the solution to obtain a solid black phosphorus nanosheet-fullerene composite material; as well as

    Provide a dispersion comprising component A, the component A is inorganic nanoparticles, mix the black phosphorus nanosheet-fullerene composite material with the dispersion, and react at a second preset temperature to obtain the complex.
17. The electroluminescent device according to claim 16, wherein, calculated by weight percentage, the compound comprises: 5% to 80% of N-type semiconductor material and 20% to 95% of P-type semiconductor material;

    Preferably, calculated by weight percentage, the compound includes: 5% to 40% of N-type semiconductor material and 60% to 95% of P-type semiconductor material.
18. The electroluminescent device according to claim 16 or 17, wherein, calculated by weight percentage, the N-type semiconductor material comprises: 80% to 99% of component A, and 1% to 20% of component B.
19. The electroluminescent device according to any one of claims 16 to 18, wherein the energy level difference between the highest occupied orbital of the P-type semiconductor material and the lowest unoccupied orbital of the N-type semiconductor material is -1.0 eV to 1.0eV, and the forbidden band width of the complex is 1.0eV to 2.5eV.
20. The electroluminescent device according to any one of claims 16 to 19, wherein the material of the light-emitting layer is an organic light-emitting material or a quantum dot, and the organic light-emitting material is selected from diarylanthracene derivatives, diphenyl One or more of vinyl aromatic derivatives, pyrene derivatives or fluorene derivatives, TBPe fluorescent materials emitting blue light, TTPA fluorescent materials emitting green light, TBRb fluorescent materials emitting orange light, and DBP fluorescent materials emitting red light Multiple; the quantum dots are selected from one or more of II-VI group compounds, III-V group compounds, IV-VI group compounds and I-III-VI group compounds, wherein the II-VI group The compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe , CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and one or more of HgZnSTe, the III-V group compound is selected from GaN, GaP, GaAs, GaSb , AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs , GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and InAlPSb one or more, the IV-VI group compound is selected from SnS, SnSe, SnTe, PbS , PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe and SnPbSTe, the I-III-VI group compound is selected from CuInS ₂ , One or more of CuInSe ₂ and AgInS ₂ ;

    The electroluminescence device also includes an electron transport layer, the electron transport layer is arranged between the cathode and the light-emitting layer, the material of the electron transport layer includes nano-metal oxide, and the nano-metal oxide is selected from One or more of ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnGaO, ZnAlO, ZnMgO, ZnSnO, ZnLiO, InSnO and AlZnO;

    The electroluminescence device also includes a hole transport layer, the hole transport layer is arranged between the anode and the light-emitting layer, and the material of the hole transport layer is selected from poly(9,9-dioctyl fluorene-CO-N-(4-butylphenyl) diphenylamine), 3-hexyl substituted polythiophene, poly(9-vinylcarbazole), poly[bis(4-phenyl)(4-butylphenyl base)amine], poly(N,N'-bis(4-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine-CO-9,9-dioctylfluorene) , 4,4',4"-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(9-carbazole)biphenyl, N,N'-diphenyl-N,N'- Bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1 One or more of '-biphenyl-4,4'-diamine, NiO, WO ₃ , MoO ₃ and CuO.

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