Organic-inorganic hybrid perovskite luminescent material and preparation method and application thereof

Abstract

The invention belongs to the technical field of photoelectric materials, and particularly relates to an organic-inorganic hybrid perovskite luminescent material and a preparation method and application thereof. The invention provides a novel conjugated organic additive-conjugated quaternary ammonium salt AX, the conjugated quaternary ammonium salt AX is used as an organic spacer, the carrier mobility is improved by regulating and controlling functional groups on the existing organic spacer, and the conjugated quaternary ammonium salt AX, quaternary ammonium salt PAX, quaternary ammonium salt PEAX, PbX2 and CsX are used as raw materials and are subjected to mixing, film forming and annealing, so that the carrier mobility is improved. A novel organic-inorganic hybrid perovskite luminescent material is synthesized; the organic-inorganic hybrid perovskite luminescent material has smooth film morphology and low defect state density, and more importantly, when the organic-inorganic hybrid perovskite luminescent material is applied to a blue light emitting device, the organic-inorganic hybrid perovskite luminescent material shows high carrier mobility, and plays a good role in promoting transmission of electrons and holes; and the improvement of the carrier transport performance has very high reference to the development of high-efficiency photoelectric devices.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic materials technology, specifically relating to an organic-inorganic hybrid perovskite luminescent material, its preparation method and application, and particularly to an organic-inorganic hybrid perovskite luminescent material using conjugated quaternary ammonium salt AX as an organic additive, its preparation method and application. Background Technology

[0002] Organic-inorganic hybrid lead-based perovskites, as an emerging and highly sought-after material, are unique solution-processable crystalline semiconductors. Their high carrier mobility, long exciton diffusion length, tunable band structure and spectrum varying with composition, high quantum fluorescence yield, high color purity, and low raw material cost have led to extensive research in the field of perovskite light-emitting diodes (LEDs), providing new avenues and opportunities for the fabrication of large-area, low-cost, color-saturated displays and solid-state lighting.

[0003] Currently, although significant progress has been made in the fields of green and red light by organic-inorganic hybrid lead-based perovskites, with green and red LED devices achieving external quantum efficiencies of over 30%, research on blue perovskite light-emitting diodes (LEDs), one of the three primary colors of white light, has lagged behind. The key reason is that the intrinsic wide bandgap emission required for blue light not only increases the difficulty of carrier recombination but also hinders efficient carrier injection in the device. This results in blue perovskite films exhibiting low external quantum efficiency and extremely short luminous lifetime in the device.

[0004] Currently, the construction of organic-inorganic hybrid perovskites is one of the mainstream methods for achieving blue light emission from perovskites. This low-dimensional structure not only possesses a large exciton binding energy to meet the requirements of blue light emission, but also creates a funnel-shaped, highly efficient energy transfer path due to the mixing characteristics from small n-phase to large n-phase. Organic spacers, as essential components for constructing quasi-two-dimensional perovskites, are typically commercially available ammonium salts such as phenylethylammonium salt, ethylammonium salt, and propanemonium salt. The large presence of these insulating organic materials often limits the carrier transfer efficiency between different n-phases, i.e., reduces carrier mobility, which is detrimental to carrier recombination luminescence in thin films and devices. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an organic-inorganic hybrid perovskite luminescent material, its preparation method, and its applications. This invention provides a novel conjugated organic additive—a conjugated quaternary ammonium salt AX—and uses AX as an organic spacer. By regulating the functional groups on existing organic spacers, carrier mobility is specifically improved. A novel organic-inorganic hybrid perovskite luminescent material is synthesized using quaternary ammonium salts AX, PAX, PEAX, PbX2, and CsX as raw materials. This organic-inorganic hybrid perovskite luminescent material exhibits a smooth film morphology and low defect state density. More importantly, it can be applied to blue light emitting devices, demonstrating high carrier mobility and effectively promoting the transport of electrons and holes. The improved carrier transport performance provides valuable insights for the development of high-efficiency optoelectronic devices.

[0006] Based on the above-mentioned technical objectives, the present invention adopts the following technical solution: This invention protects an organic-inorganic hybrid perovskite luminescent material, which is an organic-inorganic hybrid quasi-two-dimensional lead-based perovskite based on a novel conjugated quaternary ammonium salt AX, with the chemical formula A. y PEA z PA 2−y−z (CsPbX3) n−1 PbX4, where A is or PA represents propanediium ion, PEA represents phenylacetium ion, and X represents Cl-. - ,Br - I - A combination of one or more anions, where y + z < 2.

[0007] The organic-inorganic hybrid perovskite luminescent material consists of several insulating organic cation layers and several low-dimensional lead-based perovskite inorganic layers, with the low-dimensional lead-based perovskite inorganic layers located between the insulating organic cation layers.

[0008] The low-dimensional lead-based perovskite inorganic layer is composed of lead-based perovskite octahedral cells with different numbers of layers; n represents the number of octahedral cells in the lead-based perovskite that are oriented between adjacent insulating organic cation layers.

[0009] The insulating organic cationic layer is made of PA + Ions, PEA + Ions and A + Ionic composition.

[0010] The structural formula of the conjugated quaternary ammonium salt AX is as follows: or R is a substituent at any site on the benzene ring or thiophene ring, and R can be one or more substituents selected from fluorine atoms, methyl groups, or trifluoromethyl groups; X- Selected from Cl - , Br - I - One of them.

[0011] Preferably, the organic-inorganic hybrid perovskite luminescent material has a band gap of 2.50 eV to 2.61 eV and a fluorescence emission wavelength of 475 nm to 495 nm. The band gap and fluorescence emission wavelength are as follows: Figure 20 As shown.

[0012] Preferably, the conjugated quaternary ammonium salt AX is selected from... , , , or .

[0013] Preferred, such as Figure 19 As shown, the center of the octahedral structure is a Pb atom, the atoms at the six vertices of the octahedron are X atoms, the octahedron structure is located inside a cube, and the atoms at the eight vertices of the cube are Cs atoms. + PA + Ions, PEA + Ions or A + ion.

[0014] This invention also protects a method for preparing an organic-inorganic hybrid perovskite luminescent material, comprising the following steps: Using PbX2, CsX, quaternary ammonium salt PAX, quaternary ammonium salt PEAX, and conjugated quaternary ammonium salt AX as raw materials, where X is Cl - ,Br - I - A is one or more of the following combinations, where A is or PA is propanediium ion, PEA is phenylethylammonium ion. Using lead-based halides as the research object can better induce the formation of octahedra, and further form organic-inorganic hybrid perovskite luminescent materials in the form of corner sharing. In an inert atmosphere, PbX2, CsX, quaternary ammonium salt PAX, quaternary ammonium salt PEAX and conjugated quaternary ammonium salt AX are mixed together in an organic solvent, and then insoluble impurities are removed by filtration to obtain the precursor solution.

[0015] A precursor solution was used to prepare a thin film on a substrate by spin coating. During the spin coating process, the crystallization process was controlled by adding an antisolvent. Then, the film was annealed to obtain an organic-inorganic hybrid perovskite luminescent material. This invention uses the preparation of a precursor solution and a simple spin coating method to apply the conjugated quaternary ammonium salt AX to the synthesis of a novel organic-inorganic hybrid perovskite luminescent material. The steps are simple and easy to operate.

[0016] The structural formula of the conjugated quaternary ammonium salt AX is as follows: or R is a substituent at any site on the benzene ring or thiophene ring, and R can be one or more substituents selected from fluorine atoms, methyl groups, or trifluoromethyl groups; X - Selected from Cl - , Br - I - One of them.

[0017] Preferably, the molar ratio of PbX2, CsX, quaternary ammonium salt PAX, and (quaternary ammonium salt PEAX + conjugated quaternary ammonium salt AX) is 1:1.1:0.5:0.6~0.8, and the molar ratio of quaternary ammonium salt PEAX to conjugated quaternary ammonium salt AX is 9:5~13:1. This ratio change affects the light emission performance of the perovskite film, such as the emission wavelength and intensity. The emission wavelength is mainly adjusted by changing the ratio. When the amount of conjugated quaternary ammonium salt AX increases, a red shift occurs, and when the amount of conjugated quaternary ammonium salt AX decreases, a blue shift occurs.

[0018] Preferably, the concentration of the precursor solution is 0.288 mol / L to 0.495 mol / L. This invention can reasonably adjust the emission wavelength and performance of the organic-inorganic hybrid perovskite luminescent material by controlling the amount of solute in the precursor solution.

[0019] Preferably, the concentration of the precursor solution is between 72.2 mg / mL and 123.8 mg / mL (by mass). Adjusting the mass concentration corresponds to adjusting the luminescence properties of the perovskite, and preparation and manipulation are easier through mass conversion.

[0020] Preferably, the precursor solution is obtained by mixing and stirring for 3 to 8 hours, after which all the solute is dissolved.

[0021] Preferably, the solvent in the precursor solution is one or both of N,N-dimethylformamide or dimethyl sulfoxide. Using highly polar aprotic solvents such as N,N-dimethylformamide or dimethyl sulfoxide ensures complete dissolution of both inorganic and organic solutes.

[0022] Preferably, the spin coating speed is 2000 rpm to 5000 rpm, and the time is 30 s to 120 s. The control of spin coating speed and spin coating time has a direct impact on the thickness and morphology of the organic-inorganic hybrid perovskite luminescent material.

[0023] Preferably, the antisolvent is one or more of toluene, chlorobenzene, and chloroform, and the volume ratio of the antisolvent to the precursor solution is 100μL~300μL:100μL~200μL, with the antisolvent added at a time of 10s~60s after the start of spin coating. During spin coating, the addition of the antisolvent further promotes the crystallization and formation of perovskite octahedra, controls the crystallization atmosphere and time, and improves the quality of the organic-inorganic hybrid perovskite luminescent material.

[0024] Preferably, the annealing conditions are: annealing at 60℃~150℃ for 0.5min~20min. After spin coating, the coating is quickly transferred to a high-temperature annealing stage for annealing to accelerate solvent evaporation and the crystallization and shaping of the low-dimensional lead-based perovskite inorganic layer.

[0025] This invention also protects the application of organic-inorganic hybrid perovskite luminescent materials in the preparation of blue light emitting devices. The organic-inorganic hybrid perovskite luminescent material is used as the luminescent layer in the blue light emitting device, and the blue light emitting device is ITO / modifiedPEDOT:PSS / perovskite / PO-T2T / LiF / Al, with an external quantum efficiency of over 12%.

[0026] This invention also protects the application of organic-inorganic hybrid perovskite luminescent materials in the fabrication of perovskite solar cell devices, using the organic-inorganic hybrid perovskite luminescent material as the light-absorbing layer in the perovskite solar cell device, wherein the perovskite solar cell device is FTO / NiO. x / perovskite / C 60 / BCP / Cu.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses organic spacers, PbX2, and CsX as raw materials. The organic spacers are composed of quaternary ammonium salt PAX, quaternary ammonium salt PEAX, and conjugated quaternary ammonium salt AX, wherein X is Cl. - ,Br - I - A is one or more of the following combinations, where A is or PA is propanediium ion, and PEA is phenylethylammonium ion. These are mixed, film-formed, and annealed sequentially to prepare an organic-inorganic hybrid perovskite luminescent material. This invention provides a novel functional additive—a conjugated quaternary ammonium salt AX—as an organic spacer. By modifying the functional groups on existing organic spacers, the carrier mobility of perovskites is specifically improved. Specifically, by introducing high-electron-cloud-density alkyne functional groups onto existing organic spacers, not only is the unsaturated lead ion coordinating and passivated, improving the film morphology, but the alkyne group and the aromatic ring of the conjugated quaternary ammonium salt AX molecule can also form a π…π large conjugated system, precisely and effectively improving the carrier mobility in perovskite devices. The use of this additive facilitates the synthesis of a novel organic-inorganic hybrid perovskite luminescent material with enhanced performance, providing an important reference for ligand design and performance improvement of blue light emitting devices or perovskite solar cell devices.

[0028] The conjugated quaternary ammonium salt AX possesses a high-electron-cloud triple-bond system, namely an alkynyl functional group. During film formation, its high electron cloud density allows for delocalization, enabling interactions with uncoordinated lead ions and active hydrogen atoms in the perovskite system. For example, uncoordinated lead ions represent deep-level defects in the perovskite; the alkynyl functional group coordinates with these defects, achieving passivation, reducing the defect state density, and promoting a smoother morphology in the organic-inorganic hybrid perovskite luminescent material. Furthermore, the triple-bond system, together with its own aromatic ring, forms a large conjugated π bond, effectively promoting energy transfer between different n-phase structures and facilitating radiative recombination of charge carriers. More importantly, the synthesis of this novel conjugated quaternary ammonium salt AX utilizes inexpensive commercially available raw materials, demonstrating excellent economic efficiency.

[0029] 2. The structural features of the organic-inorganic hybrid perovskite luminescent material of this invention are as follows: An octahedral structure formed by divalent lead ions and halide ions forms low-dimensional lead-based perovskite inorganic layers of varying thicknesses through angle-sharing. These different low-dimensional lead-based perovskite inorganic layers are separated by conjugated quaternary ammonium salts (AX), forming a multiphase hybrid quasi-two-dimensional lead-based perovskite structure. In this multiphase structure, n=1, n=2, n=3, or n≥4. The advantage of this multiphase structure is that excitons in the perovskite can rapidly form in the small n-phase and quickly transfer to the large n-phase to achieve recombination luminescence, forming a funnel-shaped energy transport path. Furthermore, the octahedral structure formed by divalent lead ions and halide ions is separated by organic ions in the conjugated quaternary ammonium salts (AX), forming a low-dimensional structure. In this low-dimensional organic-inorganic hybrid halide structure, when excited by photons or injected with large energy, electrons and holes combine under the strong confinement of the low n-phase to form excitons. These excitons carry energy and rapidly transfer to the large n-phase, achieving luminescence through radiative recombination. The inherent quantum well of the low-dimensional structure brings about intrinsic strong dielectric and quantum confinement effects, enabling organic-inorganic hybrid halide luminescent materials to have large exciton binding energies. This provides suitable band gaps and carrier recombination conditions for blue light emitting devices. The funnel effect energy transfer method also shows the expected high photoluminescence quantum yield. The conjugated quaternary ammonium salt AX in this organic-inorganic hybrid halide luminescent material significantly improves the carrier mobility. Therefore, organic-inorganic hybrid perovskite luminescent materials have broad market prospects and commercial value.

[0030] 3. The performance characteristics of organic-inorganic hybrid perovskite luminescent materials are: their energy transfer relies on efficient energy transfer from the small n-phase to the large n-phase; the band gap is 2.43 eV~2.61 eV; the fluorescence emission wavelength is 475 nm~495 nm; and the quantum fluorescence yield is high. The external quantum efficiency of blue light emitting devices prepared using organic-inorganic hybrid perovskite luminescent materials reaches over 12%. Furthermore, the introduction of the functional organic additive, the conjugated quaternary ammonium salt AX, enhances the carrier migration characteristics of the organic-inorganic hybrid perovskite luminescent materials. In addition, organic-inorganic hybrid perovskite luminescent materials improve the external quantum efficiency in both blue light emitting devices and perovskite solar cells, which is beneficial for promoting efficient electron injection and thin-film modification in these devices, and is of great significance for improving device performance.

[0031] In summary, the novel organic-inorganic hybrid perovskite luminescent material of this invention effectively improves the quality and morphology of the perovskite thin film and enhances the carrier mobility and performance of the corresponding perovskite devices by introducing the conjugated quaternary ammonium salt AX. Furthermore, the composition and preparation method are simple, easy to operate, and the raw materials are inexpensive and readily available. Attached Figure Description

[0032] Figure 1 The diagram shows the structures of the raw materials PABr, PEABr, and 3FPPYABr in Example 1 of this invention.

[0033] Figure 2 This is the Abs spectrum of the organic-inorganic hybrid perovskite luminescent material of Example 1 of the present invention.

[0034] Figure 3 This is the PL spectrum of the organic-inorganic hybrid perovskite luminescent material of Example 1 of the present invention.

[0035] Figure 4 This is a schematic diagram of the PLQY organic-inorganic hybrid perovskite luminescent material of Embodiment 1 of the present invention.

[0036] Figure 5 The images show SEM images of the blue perovskite luminescent film of Example 1 and the control film of Comparative Example 1 of the present invention.

[0037] Figure 6 The diagram shows the efficiency of devices fabricated using the blue perovskite luminescent thin film of Example 1 and the control thin film of Comparative Example 1.

[0038] Figure 7 This is a schematic diagram of the structure of FPPYABr in Embodiment 2 of the present invention.

[0039] Figure 8 This is the Abs spectrum of the organic-inorganic hybrid perovskite luminescent material of Example 2 of the present invention.

[0040] Figure 9 This is the PL spectrum of the organic-inorganic hybrid perovskite luminescent material of Example 2 of the present invention.

[0041] Figure 10 The images show SEM images of the blue perovskite luminescent film of Example 2 and the control film of Comparative Example 2 of the present invention.

[0042] Figure 11 The efficiency graphs show the devices fabricated using the blue perovskite luminescent thin film of Example 2 and the control thin film of Comparative Example 2.

[0043] Figure 12 This is a schematic diagram of the structure of PPYABr in Embodiment 3 of the present invention.

[0044] Figure 13 This is the Abs spectrum of the organic-inorganic hybrid perovskite luminescent material of Example 3 of the present invention.

[0045] Figure 14 This is the PL spectrum of the organic-inorganic hybrid perovskite luminescent material of Example 3 of the present invention.

[0046] Figure 15 The images show SEM images of the blue perovskite luminescent film of Example 3 and the control film of Comparative Example 3 of the present invention.

[0047] Figure 16 The diagram shows the efficiency of devices fabricated using the blue perovskite luminescent thin film of Example 3 and the control thin film of Comparative Example 3.

[0048] Figure 17 The graph shows the effect of the blue perovskite luminescent films of Examples 1 to 3 and the control film of Comparative Example 1 on electron mobility.

[0049] Figure 18 The diagram shows the effect of the blue perovskite luminescent films of Examples 1 to 3 and the control film of Comparative Example 1 on hole mobility.

[0050] Figure 19 This is a schematic diagram of the structure of a lead-based perovskite octahedron.

[0051] Figure 20 The absorption and emission spectra of the organic-inorganic hybrid perovskite luminescent material in Example 1 are shown. Detailed Implementation

[0052] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.

[0053] This invention provides an organic-inorganic hybrid lead-based perovskite luminescent material based on quaternary ammonium salt, the chemical formula of which is: A y PEA z PA 2−y−z (CsPbX3) n−1 PbX4, where A is the organic chain portion of the conjugated quaternary ammonium salt AX, selected from... or PA is the organic chain portion of the small molecule organic ligand quaternary ammonium salt PAX, which is propanediium ion; PEA is the organic chain portion of the small molecule organic spacer quaternary ammonium salt PEAX, which is phenylacetium ion; and X is the halide ion Cl. - , Br - I - One or more of the following, where n represents the number of octahedral cells in the lead-based perovskite between adjacent insulating organic cation layers, and A + PA + and PEA + The total number of the three cations is 2, y and z are correlated, and y+z<2; the lead-based perovskite obtained by the present invention based on the conjugated quaternary ammonium salt AX as an organic additive has the advantages of low defect states, good film morphology and carrier transport, as well as high fluorescence quantum yield.

[0054] The blue light emitting device with a wavelength of 481 nm prepared by this invention can achieve an internal quantum yield of 62.7%, such as... Figure 4 As shown, the blue light emitting device with a wavelength of 490 nm prepared by this invention can achieve an external quantum efficiency of 12.26% and a luminance of 1119 cd / m². 2 This demonstrates a significant improvement in efficiency.

[0055] The structural formula of the conjugated quaternary ammonium salt AX is: or R is a substituent at any site on the benzene ring or thiophene ring, and R can be one or more substituents selected from fluorine atoms, methyl groups, or trifluoromethyl groups; X - Selected from Cl - , Br - I -One of them; in this invention, the conjugated quaternary ammonium salt AX is prepared according to the literature, the literature title is: Direct Asymmetric α-C-H Addition of N-unprotected Propargylic Amines to Trifluoromethyl Ketones by Carbonyl Catalysis, the inventors are: P. Ji, X. Liu, J. Xu, X. Zhang, J. Guo, W.-W.Chen*, B. Zhao*.

[0056] First, prepare or Then, the 1.0 equivalent or The solution dissolved in ethanol to form a colorless solution was titrated with a 1.0 equivalent, 48 wt% HBr ethanol solution under stirring until it turned just yellow. Stirring was continued for 2 hours. After the reaction was complete, the ethanol was removed by vacuum distillation. Then, ethyl acetate was added, and the mixture was ultrasonicated and filtered to obtain... or Finally, recrystallization was performed using an ethanol and ethyl acetate solution to obtain purified product. or It is a white solid. If you want to obtain ammonium iodide or ammonium chloride, replace the HBr solution with the corresponding HI or HCl solution.

[0057] The technical solution of the present invention will be studied below using examples and comparative examples. The specific research methods and results are shown below: Example 1 A method for preparing an organic-inorganic hybrid perovskite luminescent material includes the following steps: Weigh out 36.7 mg of PbBr2, 23.41 mg of CsBr, 7.0 mg of propylammonium bromide (PABr), 10.10 mg of phenethylammonium bromide (PEABr), and 5.32 mg of 3FPPYABr. At this point, the molar ratio of PbBr2, CsBr, PABr, and (PEABr + 3FPPYABr) is 1:1.1:0.5:0.7. Place all components together in a serum bottle. Then, add 1.25 mL of dimethyl sulfoxide as a solvent to the serum bottle, followed by the addition of polytetrafluoroethylene (PTFE). The magnetic flux was thoroughly stirred in a nitrogen-filled glove box. After stirring for 4 hours, insoluble impurities were removed by filtration to obtain a precursor solution. 120 μL of the precursor solution was pipetted onto a clean glass slide, which was then continuously rotated at 4000 rpm for 60 seconds. During this period, 240 μL of the anti-solvent toluene was added 13 seconds after the start of spin coating. The spin-coated glass slide was then transferred to an annealing station and annealed at 130 °C for 1 minute to obtain a blue perovskite luminescent film, i.e., an organic-inorganic hybrid perovskite luminescent material.

[0058] Figure 1 The structural formulas of 3FPPYABr, PABr, and PEABr in Example 1 are shown below.

[0059] Figure 2 The absorption spectrum of the blue perovskite luminescent film prepared in Example 1 shows that the prepared organic-inorganic hybrid perovskite luminescent material has absorption peaks corresponding to different phases at different wavelengths. Among them, the two absorption peaks at 428 nm and 455 nm are more obvious, corresponding to the n=2 and n=3 phases of the organic-inorganic hybrid perovskite luminescent material, respectively.

[0060] Figure 3 The image shows the emission spectrum of the blue perovskite luminescent film prepared in Example 1. There is a strong emission peak at 481 nm with a full width at half maximum (FWHM) of 28 nm.

[0061] Figure 4 This is the fluorescence quantum yield diagram of the blue perovskite luminescent thin film of Example 1, which shows an internal quantum efficiency of over 60% obtained by integration.

[0062] Comparative Example 1 A method for preparing a control film is the same as the preparation steps in Example 1, except that an equal molar amount of PEABr is used instead of 3FPPYABr.

[0063] Figure 5 The image shows a scanning electron microscope (SEM) image comparing the blue perovskite luminescent film of Example 1 with the control film of Comparative Example 1. It can be seen that Example 1 yielded a smoother and flatter blue perovskite luminescent film, without the formation of particulate matter or obvious pore coverage.

[0064] Figure 6 This is a schematic diagram of the EQE of the blue perovskite luminescent film of Example 1 and the control film of Comparative Example 1 applied to a perovskite device. The perovskite device is ITO / modified PEDOT:PSS / perovskite / PO-T2T / LiF / Al. Compared with the device prepared using the control film, the external quantum efficiency of the blue perovskite luminescent film prepared using 3FPPYABr and the device prepared using the blue perovskite luminescent film is significantly improved. The external quantum efficiency of the device prepared using the control film is 5.22%, and the external quantum efficiency of the device prepared using the blue perovskite luminescent film is 12.26%.

[0065] Figure 20 The absorption and emission spectra of the organic-inorganic hybrid perovskite luminescent material in Example 1 are shown. Figure 20 The results show that its band gap is 2.50 eV to 2.61 eV and its fluorescence emission wavelength is 475 nm to 495 nm.

[0066] Example 2 A method for preparing an organic-inorganic hybrid perovskite luminescent material includes the following steps: Weigh out 36.7 mg of PbBr2, 23.41 mg of CsBr, 7.0 mg of propylammonium bromide (PABr), 10.10 mg of phenylethylammonium bromide (PEABr), and 4.60 mg of FPPYABr, and place them together in a serum bottle. Then, add 1.25 mL of dimethyl sulfoxide as a solvent to the serum bottle, add a polytetrafluoroethylene magnet, and stir thoroughly in a nitrogen-filled glove box. After stirring for 4 hours, filter to remove insoluble impurities to obtain the precursor solution. Use a pipette to take 120 μL of the precursor solution and drop it onto a clean ITO glass slide. Rotate the ITO glass slide continuously at 4000 rpm for 60 seconds. During this period, add 240 μL of the antisolvent toluene at the 13th second after the spin coating begins. Transfer the spin-coated ITO glass slide to an annealing station and anneal at 130 °C for 1 minute to obtain a blue perovskite luminescent film, i.e., an organic-inorganic hybrid perovskite luminescent material.

[0067] Figure 7 The molecular structure of FPPYABr in Example 2 is shown below.

[0068] Figure 8 The absorption spectrum of the blue perovskite luminescent film prepared in Example 2 shows that the prepared organic-inorganic hybrid perovskite luminescent material has absorption peaks corresponding to different phases at different wavelengths. Among them, the two absorption peaks at 430 nm and 455 nm are more obvious, corresponding to the n=2 and n=3 phases of the organic-inorganic hybrid perovskite luminescent material, respectively.

[0069] Figure 9The image shows the emission spectrum of the blue perovskite luminescent film prepared in Example 2. There is a strong emission peak at 481 nm with a full width at half maximum (FWHM) of 28 nm.

[0070] Comparative Example 2 A method for preparing a control film is the same as the preparation steps in Example 2, except that an equal molar amount of PEABr is used instead of FPPYABr.

[0071] Figure 10 The image shows a scanning electron microscope (SEM) image comparing the blue perovskite luminescent film of Example 2 with the control film of Comparative Example 2. It can be seen that Example 1 has a smoother film surface and the formation of particulate matter is suppressed.

[0072] Figure 11 The diagram shows the EQE of the blue perovskite luminescent film of Example 2 and the control film of Comparative Example 2 in a device. Compared with the device prepared with the control film, the external quantum efficiency of the blue perovskite luminescent film prepared with FPPYABr and the device prepared with the blue perovskite luminescent film is significantly improved. The external quantum efficiency of the device prepared with the control film is 5.22%, and the external quantum efficiency of the device prepared with the blue perovskite luminescent film is 10.99%.

[0073] Example 3 A method for preparing an organic-inorganic hybrid perovskite luminescent material includes the following steps: Weigh 36.7 mg of PbBr2, 23.41 mg of CsBr, 7.0 mg of propylammonium bromide (PABr), 10.10 mg of phenylethylammonium bromide (PEABr), and 4.24 mg of PPYABr, and place them together in a serum bottle. Then, add 1.25 mL of dimethyl sulfoxide as a solvent to the serum bottle, add a polytetrafluoroethylene magnet, and stir thoroughly in a nitrogen-filled glove box. After stirring for 4 hours, filter to remove insoluble impurities to obtain the precursor solution. Use a pipette to take 120 μL of the precursor solution and drop it onto a clean glass slide. Rotate the glass slide continuously at 4000 rpm for 60 seconds. During this period, add 240 μL of the antisolvent toluene at the 13th second after the spin coating begins. Transfer the spin-coated glass slide to an annealing station and anneal at 130 °C for 1 minute to obtain the corresponding blue perovskite luminescent film, i.e., the organic-inorganic hybrid perovskite luminescent material.

[0074] Figure 12 The molecular structure of PPYABr in Example 3 is shown below.

[0075] Figure 13The absorption spectrum of the blue perovskite luminescent film prepared in Example 3 shows that the prepared organic-inorganic hybrid perovskite luminescent material has absorption peaks corresponding to different phases at different wavelengths. Among them, the two absorption peaks at 430 nm and 455 nm are more obvious, corresponding to the n=2 and n=3 phases of the organic-inorganic hybrid perovskite luminescent material, respectively.

[0076] Figure 14 The image shows the emission spectrum of the blue perovskite luminescent film prepared in Example 3. There is a strong emission peak at 478 nm with a full width at half maximum (FWHM) of 28 nm.

[0077] Comparative Example 3 A method for preparing a control film is the same as the preparation steps in Example 3, except that an equal molar amount of PEABr is used instead of PPYABr.

[0078] Figure 15 The image shows a scanning electron microscope (SEM) image comparing the blue perovskite luminescent film of Example 3 with the control film of Comparative Example 3. It can be seen that Example 3 yielded a film with a smaller roughness and significantly fewer particulate substances on the film surface.

[0079] Figure 16 This is a schematic diagram of the EQE of the blue perovskite luminescent film of Example 3 and the control film of Comparative Example 3 respectively applied in a device. Compared with the device prepared using the control film, the external quantum efficiency of the blue perovskite luminescent film prepared using PPYABr and the device prepared using the blue perovskite luminescent film is significantly improved. The external quantum efficiency of the device prepared using the control film is 5.22%, and the external quantum efficiency of the device prepared using the blue perovskite luminescent film is 8.15%.

[0080] In summary, this invention provides an organic-inorganic hybrid perovskite luminescent material and its preparation method. The core of this method lies in the application of a novel conjugated quaternary ammonium salt AX. After adding this conjugated quaternary ammonium salt AX, the prepared film exhibits a smoother film morphology and a more reasonable phase distribution. More importantly, the improved morphology, altered energy levels, and the construction of the conjugated system result in a film with better carrier mobility. Figure 17 and Figure 18 As shown, the improvement in device performance is quite significant.

[0081] Example 4 A method for preparing an organic-inorganic hybrid perovskite luminescent material includes the following steps: Weigh out 36.7 mg of PbBr2, 23.41 mg of CsBr, 7.0 mg of propylammonium bromide (PABr), 8.26 mg of phenylethylammonium bromide (PEABr), and 5.70 mg of 3FPPYABr. The molar ratio of PEABr to 3FPPYABr is 9:5, and the molar ratio of PbBr2, CsBr, PABr, and (PEABr + 3FPPYABr) is 1:1.1:0.5:0.6. Place all ingredients in a serum bottle, and then add 1.25 mL of dimethyl sulfoxide to the serum bottle as a preservative. Solvent was added to a polytetrafluoroethylene magnet and stirred thoroughly in a nitrogen-filled glove box. After stirring for 3 hours, insoluble impurities were removed by filtration to obtain a precursor solution. 120 μL of the precursor solution was pipetted onto a clean glass slide and rotated continuously at 5000 rpm for 120 seconds. During this period, 240 μL of the anti-solvent toluene was added 60 seconds after the start of spin coating. The spin-coated glass slide was then transferred to an annealing station and annealed at 150 °C for 0.5 min to obtain a blue perovskite luminescent film, i.e., an organic-inorganic hybrid perovskite luminescent material.

[0082] Example 5 A method for preparing an organic-inorganic hybrid perovskite luminescent material includes the following steps: Weigh out 36.7 mg of PbBr2, 23.41 mg of CsBr, 7.0 mg of propylammonium bromide PABr, 15.91 mg of p-phenylethylammonium bromide EABr, and 1.52 mg of 3FPPYABr, with a PEABr:3FPPYABr molar ratio of 13:1 and a PbBr2, CsBr, PABr, (PEABr+3FPPYABr) molar ratio of 1:1.1:0.5:0.8. Place all ingredients in a serum bottle, and then add 1.25 mL of dimethyl sulfoxide to the serum bottle. As a solvent, polytetrafluoroethylene magnetic particles were added and stirred thoroughly in a nitrogen-filled glove box. After stirring for 8 hours, insoluble impurities were removed by filtration to obtain a precursor solution. 120 μL of the precursor solution was pipetted onto a clean glass slide and rotated continuously at 2000 rpm for 30 seconds. During this period, 240 μL of the anti-solvent toluene was added 10 seconds after the spin coating began. The spin-coated glass slide was then transferred to an annealing station and annealed at 60 °C for 20 minutes to obtain a blue perovskite luminescent film, i.e., an organic-inorganic hybrid perovskite luminescent material.

[0083] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. An organic-inorganic hybrid perovskite luminescent material, characterized in that, The organic-inorganic hybrid perovskite luminescent material is an organic-inorganic hybrid quasi-two-dimensional lead-based perovskite based on the conjugated quaternary ammonium salt AX, with the chemical formula A. y PEA z PA 2−y−z (CsPbX3) n− 1PbX4, where A is or PA represents propanediium ion, PEA represents phenylacetium ion, and X represents Cl-. - ,Br - I - A combination of one or more anions, where y + z < 2; The organic-inorganic hybrid perovskite luminescent material consists of several insulating organic cation layers and several low-dimensional lead-based perovskite inorganic layers, with the low-dimensional lead-based perovskite inorganic layers located between the insulating organic cation layers. The low-dimensional lead-based perovskite inorganic layer is composed of lead-based perovskite octahedral cells with different numbers of layers; n represents the number of octahedral cells in the lead-based perovskite that are oriented between adjacent insulating organic cation layers. The insulating organic cationic layer is made of PA + Ions, PEA + Ions and A + Ionic composition; The structural formula of the conjugated quaternary ammonium salt AX is as follows: or R is a substituent at any site on the benzene ring or thiophene ring, and R can be one or more substituents selected from fluorine atoms, methyl groups, or trifluoromethyl groups; X - Selected from Cl - , Br - I - One of them.

2. The organic-inorganic hybrid perovskite luminescent material according to claim 1, characterized in that, The organic-inorganic hybrid perovskite luminescent material has a band gap of 2.50 eV to 2.61 eV and a fluorescence emission wavelength of 475 nm to 495 nm.

3. The organic-inorganic hybrid perovskite luminescent material according to claim 1, characterized in that, Conjugated quaternary ammonium salt AX is selected from , , , or .

4. The organic-inorganic hybrid perovskite luminescent material according to claim 1, characterized in that, The center of the octahedral structure is a Pb atom, the atoms at the six vertices of the octahedron are X atoms, the octahedron structure is located inside a cube, and the atoms at the eight vertices of the cube are Cs atoms. + PA + Ions, PEA + Ions or A + ion.

5. A method for preparing the organic-inorganic hybrid perovskite luminescent material according to any one of claims 1 to 4, characterized in that, Includes the following steps: Using PbX2, CsX, quaternary ammonium salt PAX, quaternary ammonium salt PEAX, and conjugated quaternary ammonium salt AX as raw materials, where X is Cl - ,Br - I - A is one or more of the following combinations, where A is or PA is propanediium ion, and PEA is phenylethylammonium ion; under an inert atmosphere, PbX2, CsX, quaternary ammonium salt PAX, quaternary ammonium salt PEAX and conjugated quaternary ammonium salt AX are mixed together in an organic solvent to obtain a precursor solution; The precursor solution was coated into a film. During the coating process, the crystallization process was controlled by adding antisolvent. Then, annealing was performed to obtain an organic-inorganic hybrid perovskite luminescent material. The structural formula of the conjugated quaternary ammonium salt AX is as follows: or R is a substituent at any site on the benzene ring or thiophene ring, and R can be one or more substituents selected from fluorine atoms, methyl groups, or trifluoromethyl groups; X - Selected from Cl - , Br - I - One of them.

6. The method for preparing the organic-inorganic hybrid perovskite luminescent material according to claim 5, characterized in that, The molar ratios of PbX2, CsX, quaternary ammonium salt PAX, and (quaternary ammonium salt PEAX + conjugate quaternary ammonium salt AX) are 1:1.1:0.5:0.6~0.8, and the molar ratio of quaternary ammonium salt PEAX to conjugate quaternary ammonium salt AX is 9:5~13:

1.

7. The method for preparing the organic-inorganic hybrid perovskite luminescent material according to claim 5, characterized in that, The concentration of the precursor solution was 0.288 mol / L to 0.495 mol / L.

8. The method for preparing the organic-inorganic hybrid perovskite luminescent material according to claim 5, characterized in that, The annealing conditions are: annealing at 60℃~150℃ for 0.5min~20min.

9. The application of the organic-inorganic hybrid perovskite luminescent material according to claim 1 in the fabrication of blue light emitting devices, characterized in that, Organic-inorganic hybrid perovskite luminescent materials are used as the luminescent layer in blue light emitting devices.

10. The application of the organic-inorganic hybrid perovskite luminescent material of claim 1 in the fabrication of perovskite solar cell devices, characterized in that, Organic-inorganic hybrid perovskite luminescent materials are used as the light-absorbing layer in perovskite solar cell devices.

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