Blue-light perovskite light-emitting diode based on hydrogen bond network and preparation method of blue-light perovskite light-emitting diode

Abstract

The invention discloses a blue-light perovskite light-emitting diode based on a hydrogen bond network and a preparation method thereof, 3-(5-fluoropyridine-2-yl) acrylic acid hydrochloride molecules are added into a perovskite precursor solution, non-radiative recombination is reduced by passivating defects, and the molecules cooperate with ligands and octahedrons to construct the hydrogen bond network in the crystallization process, so that the blue-light perovskite light-emitting diode based on the hydrogen bond network is obtained. The stability of the octahedral framework is enhanced, ion migration is effectively inhibited, the high-efficiency and high-stability blue-light PeLED is finally obtained, and the external quantum efficiency and the operation stability of the blue-light PeLED are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of blue perovskite light-emitting diode technology, specifically to a blue perovskite light-emitting diode based on a hydrogen bond network and its fabrication method. Background Technology

[0002] Metal halide perovskite materials have become a research hotspot in the fields of light-emitting displays and solid-state lighting due to their advantages of high color purity, narrow emission half-width, continuously tunable emission wavelength, and low cost brought about by solution-based fabrication. Currently, the external quantum efficiencies of red, green, and blue perovskite light-emitting diodes (PeLEDs) have reached 32.14%, 32.1%, and 26.4%, respectively, demonstrating excellent luminescent performance in laboratory settings. However, these devices still face severe stability bottlenecks in practical applications, with the stability problem of blue PeLEDs being particularly prominent. During device fabrication or under high bias conditions, the lattice periodicity of perovskite crystals is easily disrupted, leading to the formation of numerous defect states (such as halogen vacancies and uncoordinated metal cations). These defects act as non-radiative recombination centers, significantly reducing carrier utilization efficiency and directly causing rapid decay of device luminescent performance. Furthermore, halide ions (such as Cl-) in blue PeLEDs... - ,Br - Under the influence of an electric field, these particles (such as perovskites) have extremely strong migration capabilities and are prone to cross-interface diffusion. This can not only cause component imbalance, phase separation, and the formation of non-perovskite phases in the perovskite active layer, thus damaging the integrity of the luminescent center and causing wavelength shift and color purity reduction, but also potentially penetrate the charge transport layer and react chemically with the metal electrode, accelerating the degradation of the electrode-transport layer interface and ultimately leading to rapid device failure.

[0003] Although existing technologies have proposed improvements such as optimizing the perovskite composition ratio, designing functionalized charge transport layers, and constructing interface modification layers, these strategies still significantly lag behind red and green PeLEDs in improving the operational stability of blue PeLEDs, making it difficult to meet the core requirements of device lifetime in practical applications. Therefore, developing a blue PeLED that can suppress the formation of perovskite lattice defects, prevent halide ion migration, and enhance crystal structure stability has become a key technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of existing blue perovskite LEDs, such as numerous defects, ion migration, and insufficient stability. It provides a blue perovskite LED based on a hydrogen bond network and its fabrication method. 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecules are added to the perovskite precursor solution. This reduces non-radiative recombination by passivating defects. Furthermore, during crystallization, this molecule synergistically constructs a hydrogen bond network with ligands and octahedrons, enhancing the stability of the octahedral framework and effectively suppressing ion migration. Ultimately, a high-efficiency, high-stability blue perovskite LED is obtained, significantly improving its external quantum efficiency and operational stability.

[0005] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0006] A method for fabricating a blue perovskite light-emitting diode based on a hydrogen bond network includes the following steps:

[0007] S1. Prepare a hole transport layer on a conductive substrate;

[0008] S2. Cesium bromide (CsBr), lead bromide (PbBr2), lead chloride (PbCl2), and p-fluorophenylethylamine bromide (pF-PEABr) are dissolved in an organic solvent to obtain a perovskite precursor solution; 3-(5-fluoropyridin-2-yl)acrylate hydrochloride is dissolved in a solvent to obtain a 3-(5-fluoropyridin-2-yl)acrylate hydrochloride solution with a concentration of 5-15 mg / mL; the perovskite precursor solution and the 3-(5-fluoropyridin-2-yl)acrylate hydrochloride solution are mixed at a volume ratio of 1:(0.02-0.06) to obtain a perovskite doped solution; the perovskite doped solution is coated on the hole transport layer described in S1 to obtain a perovskite thin film;

[0009] S3. An electron transport layer, an electrode modification layer, and an electrode are sequentially fabricated on the perovskite thin film described in S2 to obtain the blue perovskite light-emitting diode based on a hydrogen bond network.

[0010] The preparation method provided by this invention is simple and convenient. By introducing doped 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecules into the perovskite film to construct a dense hydrogen bond network, a synergistic effect of defect passivation and ion migration suppression is achieved, thus preparing a perovskite film with high crystallinity, low defects, and high stability, which significantly improves the luminous efficiency and operational stability of blue perovskite light-emitting diodes.

[0011] Furthermore, in S1, the conductive substrate comprises an indium tin oxide (ITO) substrate.

[0012] Furthermore, S1 also includes the steps of cleaning and drying the conductive substrate.

[0013] In a specific embodiment, the conductive substrate is cleaned sequentially with detergent, high-purity water, ethanol and isopropanol, and then dried until the solvent and moisture are completely removed.

[0014] Furthermore, in S1, the material of the hole transport layer includes poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS).

[0015] Further, in S1, the hole transport layer is spin-coated onto the conductive substrate and then annealed.

[0016] Furthermore, the spin coating method is as follows: spin coating at a speed of 5000-7000 rpm for 50-70 s.

[0017] Furthermore, the annealing treatment is performed at a temperature of 130-150 °C for a time of 10-20 min.

[0018] Further, in S2, the organic solvent is dimethylformamide (DMF) and / or dimethyl sulfoxide (DMSO).

[0019] Furthermore, in S2, the molar ratio of CsBr, PbBr2, PbCl2 and pF-PEABr is (10-20):(5-7):(3-5):(4-6).

[0020] Furthermore, in S2, the concentration of CsBr in the perovskite precursor solution is 0.1-0.2 M.

[0021] In a specific embodiment, CsBr, PbBr2, PbCl2 and pF-PEABr are dissolved in an organic solvent and stirred at 35-45℃ for 3-4 h until the powder is completely dissolved to obtain a perovskite precursor solution.

[0022] Further, in S2, the solvent is dimethylformamide (DMF) and / or dimethyl sulfoxide (DMSO).

[0023] If the doping amount of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride is too low, the number of molecules is insufficient, and a dense hydrogen bond network cannot be formed, resulting in insufficient defect passivation and weak ion migration suppression. If the doping amount is too high, excessive molecules will accumulate in the perovskite lattice, hindering crystal growth, leading to a decrease in crystallinity, and introducing additional interface defects, which in turn reduces device performance.

[0024] Further, in S2, the perovskite doping solution is spin-coated onto the hole transport layer, and after annealing, a perovskite thin film is obtained.

[0025] Furthermore, the spin coating method is as follows: spin coating at a speed of 3000-5000 rpm for 50-70 s.

[0026] Furthermore, the annealing treatment is performed at a temperature of 60-80 ℃ for 5-10 min.

[0027] Further, in S3, the electron transport layer comprises a 2,4,6-tris[3-(diphenylphosphino)phenyl]-1,3,5-triazine (PO-T2T) layer and a 2,2',2''-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) (TPBi) layer.

[0028] Furthermore, the thickness of the PO-T2T layer is 1-2 nm, and the thickness of the TPBi layer is 35-45 nm.

[0029] Furthermore, in S3, the material of the electrode modification layer is lithium fluoride (LiF).

[0030] Furthermore, in S3, the thickness of the electrode modification layer is 1-1.5 nm.

[0031] Furthermore, in S3, the electrode is a metal cathode electrode.

[0032] Furthermore, in S3, the electrode is an aluminum (Al) electrode.

[0033] Furthermore, in S3, the thickness of the electrode is 90-110 nm.

[0034] In a specific embodiment, an electron transport layer, an electrode modification layer, and an electrode are sequentially deposited on the perovskite thin film described in S2 using a high-vacuum thermal evaporation method.

[0035] Furthermore, the vacuum degree of the high-vacuum thermal evaporation method is 2 × 10⁻⁶. -4 Pa ~ 4 × 10 -4 Pa.

[0036] Furthermore, the deposition rate of the electron transport layer is 1-3 Å / s, the deposition rate of the electrode modification layer is 1-3 Å / s, and the deposition rate of the electrode is 5-7 Å / s.

[0037] This invention also protects the blue perovskite light-emitting diode based on hydrogen bond network prepared by the above preparation method.

[0038] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0039] The preparation method provided by this invention is simple and convenient. By doping 3-(5-fluoropyridin-2-yl)acrylate hydrochloride into a perovskite film, the 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecule possesses strong adsorption properties. Its high Lewis basicity pyridine nitrogen group and multifunctional carboxylic acid group provide dual interaction sites for regulating the microstructure of perovskite. The pyridine nitrogen group can form hydrogen bonds with halide ions, and the carboxylic acid group can interact with organic ligands. Together, they construct a dense hydrogen bond network in the perovskite lattice. This network can firmly fix halide ions, enhance the structural stability of the perovskite octahedral framework, and fundamentally suppress ion migration behavior under the action of an electric field. At the same time, the two functional groups can also interact with uncoordinated Pb in the perovskite. 2+ By forming stable coordination bonds, the deep-level trap states are effectively passivated and non-radiative recombination losses are reduced. Ultimately, through the above synergistic effect, the luminous efficiency and operational stability of the device are significantly improved, resulting in a high-performance blue PeLED with an external quantum efficiency (EQE) of 24.11% and an operating lifetime of 112.8 min. Attached Figure Description

[0040] Figure 1 The graphs show the performance characteristics of the perovskite thin films prepared in Examples 1-3 and Comparative Example 1; where a is the steady-state photoluminescence spectrum and b is the time-resolved photoluminescence decay curve.

[0041] Figure 2 X-ray photoelectron spectra and density of states calculation diagrams of the perovskite thin films prepared in Example 2 and Comparative Example 1 are shown; where a is the X-ray photoelectron spectrum of the Br 3d orbital, b is the X-ray photoelectron spectrum of the Cl 2p orbital, c is the X-ray photoelectron spectrum of the N 1s orbital, and d is the density of states calculation diagram.

[0042] Figure 3 Figures show the photoelectric performance test results of the blue PeLEDs prepared in Examples 1-3 and Comparative Example 1; where a is the electroluminescence spectrum of the blue PeLED prepared in Example 2, b is the current density-voltage-brightness characteristic curve of the blue PeLEDs prepared in Examples 1-3 and Comparative Example 1, c is the external quantum efficiency (EQE) test result of the blue PeLEDs prepared in Examples 1-3 and Comparative Example 1, and d is the result of the blue PeLEDs prepared in Examples 2 and Comparative Example 1 at a constant current density of 1 mA·cm⁻¹. -2 The following is a graph showing the working half-life test results. Detailed Implementation

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0045] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available.

[0046] Example 1

[0047] A method for fabricating blue PeLEDs based on hydrogen bond networks includes the following steps:

[0048] S1. The ITO substrate is cleaned sequentially with detergent, high-purity water, ethanol and isopropanol, and then dried until the solvent and moisture are completely removed. In a fume hood, PEDOT:PSS is spin-coated onto the dried ITO substrate at 6000 rpm for 60s, and then annealed at 140℃ for 15 min to obtain the PEDOT:PSS layer.

[0049] S2. CsBr, PbBr2, PbCl2, and pF-PEABr were dissolved in DMSO and stirred at 40 °C for 3 hours until all the powders were dissolved to obtain a perovskite precursor solution with CsBr concentration of 0.15 M, PbBr2 concentration of 0.06 M, PbCl2 concentration of 0.04 M, and pF-PEABr concentration of 0.05 M. 3-(5-fluoropyridin-2-yl)acrylate hydrochloride was dissolved in a solvent to obtain a 10 mg / mL 3-(5-fluoropyridin-2-yl)acrylate hydrochloride solution. 1 mL of the perovskite precursor solution was mixed with 20 μL of the 3-(5-fluoropyridin-2-yl)acrylate hydrochloride solution to obtain a perovskite doping solution. The perovskite doping solution was spin-coated onto a PEDOT:PSS layer at 4000 rpm for 60 s and annealed at 70 °C for 7 min to form a perovskite film.

[0050] S3. High-vacuum thermal evaporation is performed on perovskite thin films at a vacuum level of 3 × 10⁻⁶. -4A 1.5 nm PO-T2T layer (ν = 1 Å / s), a 40 nm TPBi layer (ν = 2 Å / s), a 1.1 nm LiF layer (ν = 1 Å / s), and a 100 nm Al electrode (ν = 6 Å / s) were sequentially prepared under Pa to obtain a blue PeLED based on a hydrogen bond network.

[0051] Example 2

[0052] A method for preparing blue PeLED based on hydrogen bond network is basically the same as that in Example 1, except that in S2, 1 mL of perovskite precursor solution is mixed with 40 μL of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride solution.

[0053] Example 3

[0054] A method for preparing blue PeLED based on hydrogen bond network is basically the same as that in Example 1, except that in S2, 1 mL of perovskite precursor solution is mixed with 60 μL of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride solution.

[0055] Comparative Example 1

[0056] A method for preparing blue PeLED includes the following steps:

[0057] S1. The ITO substrate is cleaned sequentially with detergent, high-purity water, ethanol and isopropanol, and then dried until the solvent and moisture are completely removed. In a fume hood, PEDOT:PSS is spin-coated onto the dried ITO substrate at 6000 rpm for 60s, and then annealed at 140℃ for 15 min to obtain the PEDOT:PSS layer.

[0058] S2. CsBr, PbBr2, PbCl2 and pF-PEABr are dissolved in DMSO and stirred at 40℃ for 3 hours until all the powders are dissolved to obtain a perovskite precursor solution with the following concentrations: CsBr 0.15 M, PbBr2 0.06 M, PbCl2 0.04 M and pF-PEABr 0.05 M. The perovskite precursor solution is spin-coated onto a PEDOT:PSS layer at 4000 rpm for 60 s and annealed at 70℃ for 7 min to form a perovskite film.

[0059] S3. High-vacuum thermal evaporation is performed on perovskite thin films at a vacuum level of 3 × 10⁻⁶. -4A 1.5 nm PO-T2T layer (ν = 1 Å / s), a 40 nm TPBi layer (ν = 2 Å / s), a 1.1 nm LiF layer (ν = 1 Å / s), and a 100 nm Al electrode (ν = 6 Å / s) were sequentially prepared under Pa to obtain a blue PeLED.

[0060] Test Example 1

[0061] The properties of the perovskite films prepared in Examples 1-3 and Comparative Example 1 were characterized, and the results are as follows:

[0062] Figure 1 In diagram a, the steady-state photoluminescence spectra of perovskite films with different concentrations of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride, are shown. Figure 1 As can be seen from Figure a, the photoluminescence intensity of the doped perovskite film is significantly improved, and the photoluminescence peak position does not shift. This indicates that the introduction of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride can significantly reduce the defect states in the perovskite film, effectively suppress nonradiative recombination, and at the same time, it does not change the emission wavelength characteristics of the film. Figure 1 In Figure b, time-resolved photoluminescence decay curves of undoped and doped perovskite films with different concentrations of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride are shown. Fitting analysis revealed that the undoped perovskite film had a shorter photoluminescence lifetime and exhibited significant quenching. In contrast, the doped perovskite film showed a significantly longer photoluminescence lifetime and a smoother decay curve. This result perfectly matched the photoluminescence test findings, further validating the passivation effect of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride on internal defects in perovskite. Furthermore, the perovskite films prepared in Examples 1 (low doping concentration) and 3 (high doping concentration) showed lower photoluminescence intensity and lifetime than those in Example 2. This indicates that when the doping concentration is too low, the modification effect of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecules is insufficient, failing to achieve the optimal defect passivation effect; while when the doping concentration is too high, excessive molecules adversely affect the growth of perovskite crystals, thereby impacting the film's crystal quality and optical properties.

[0063] like Figure 2 As shown in Figures a and b, the X-ray photoelectron spectroscopy peaks of the Br 3d and Cl 2p orbitals in perovskite films doped with different concentrations of 3-(5-fluoropyridin-2-yl)acrylate hydrochloride all shift to higher binding energies. This indicates that halide ions, acting as hydrogen bond acceptors, form polydentate hydrogen bonds with the active sites in 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecules and p-fluorophenylethylamine bromide molecules. The formation of hydrogen bonds leads to the elongation of the phase bond length of halide ions, which in turn deepens the halogen orbital vacancies, confirming the existence of hydrogen bond interactions. Figure 2As shown in Figure c, the X-ray photoelectron spectrum of the N 1s orbital splits into two characteristic peaks: the peak at the binding energy of 401.8 eV corresponds to protonated pyridinium nitrogen (N + -H and R4N + The peak shifts to a higher binding energy, indicating the formation of a stable hydrogen bond network between molecules. The peak at 399 eV corresponds to pyridine nitrogen, and its position remains unchanged, suggesting that the chemical structure of pyridine nitrogen has not changed, ensuring the long-term passivation stability of the 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecule. Figure 2 As shown in Figure d, the perovskite film of Comparative Example 1, without 3-(5-fluoropyridin-2-yl)acrylate hydrochloride, exhibits a significant defect state density peak at the bottom of the valence band. In contrast, the perovskite film of Example 2, doped with 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecules, shows a complete disappearance of the defect state density peak at the bottom of the valence band. This indicates that the dopant molecules effectively passivate halogen vacancies in the perovskite through adsorption, significantly reducing the n-type defect density.

[0064] In summary, the characterization results fully demonstrate the synergistic effect between 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecules and perovskite octahedra. 3-(5-fluoropyridin-2-yl)acrylate hydrochloride molecules not only successfully construct a dense hydrogen bond network to lock halide ions and inhibit ion migration, but also efficiently passivate perovskite crystal defects and inhibit nonradiative recombination.

[0065] Test Example 2

[0066] The photoelectric performance of the blue PeLEDs prepared in Examples 1-3 and Comparative Example 1 was tested, and the results are as follows:

[0067] Figure 3 Figure a shows the electroluminescence spectrum of the blue PeLED prepared in Example 2. It can be seen that the blue PeLED doped with 3-(5-fluoropyridin-2-yl)acrylate hydrochloride has a characteristic emission peak at 490 nm, corresponding to the blue light band. Furthermore, when the bias voltage is increased from 3.2 V to 4.8 V, the electroluminescence spectrum of the blue PeLED shows enhanced spectral stability. Figure 3Figure b shows the current density-voltage-brightness characteristic curves of the blue PeLEDs prepared in Examples 1-3 and Comparative Example 1. After introducing 3-(5-fluoropyridin-2-yl)acrylate hydrochloride into the perovskite precursor solution, the leakage current of the blue PeLEDs was significantly reduced due to the reduction of non-radiative defects and the improvement of film coverage, and it also showed a lower turn-on voltage. The turn-on voltages of the blue PeLEDs prepared in Example 1 (low doping concentration) and Example 3 (high doping concentration) were both higher than those in Example 2. This result once again verifies that when the doping concentration is too low, the modification effect is insufficient; when the concentration is too high, it will have an adverse effect on the perovskite film. Neither of these can achieve the ideal device performance regulation. Figure 3 Figure c shows the EQE test results of the blue PeLEDs prepared in Examples 1-3 and Comparative Example 1. The EQE of the blue PeLED prepared in Example 2 can reach 24.11%. Figure 3 In the diagram, d represents the blue PeLED prepared in Example 2 and Comparative Example 1 at a constant current density of 1 mA·cm⁻¹. -2 The operating half-life test curve below can quantitatively evaluate the operational stability of the device. The results show that the operating half-life of the blue PeLED prepared in Example 2 is extended to 112.8 min, and the stability is significantly improved.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art should understand that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for fabricating a blue perovskite light-emitting diode based on a hydrogen bond network, characterized in that, Includes the following steps: S1. Prepare a hole transport layer on a conductive substrate; S2. Cesium bromide, lead bromide, lead chloride, and p-fluorophenylethylamine bromide are dissolved in an organic solvent to obtain a perovskite precursor solution; 3-(5-fluoropyridin-2-yl)acrylate hydrochloride is dissolved in a solvent to obtain a 3-(5-fluoropyridin-2-yl)acrylate hydrochloride solution with a concentration of 5-15 mg / mL; the perovskite precursor solution and the 3-(5-fluoropyridin-2-yl)acrylate hydrochloride solution are mixed at a volume ratio of 1:(0.02-0.06) to obtain a perovskite doped solution; the perovskite doped solution is coated on the hole transport layer described in S1 to obtain a perovskite thin film; S3. An electron transport layer, an electrode modification layer, and an electrode are sequentially fabricated on the perovskite thin film described in S2 to obtain the blue perovskite light-emitting diode based on a hydrogen bond network.

2. The preparation method according to claim 1, characterized in that, In S1, the conductive substrate includes an indium tin oxide substrate; the hole transport layer is made of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid).

3. The preparation method according to claim 1, characterized in that, In S1, the hole transport layer is spin-coated onto a conductive substrate and then annealed. The spin-coating method is as follows: spin-coating at a speed of 5000-7000 rpm for 50-70 s; the annealing temperature is 130-150 ℃ and the time is 10-20 min.

4. The preparation method according to claim 1, characterized in that, In S2, the molar ratio of cesium bromide, lead bromide, lead chloride, and p-fluorophenylethylamine bromide is (10-20):(5-7):(3-5):(4-6); the concentration of cesium bromide in the perovskite precursor solution is 0.1-0.2 M.

5. The preparation method according to claim 1, characterized in that, In step S2, the perovskite doping solution is spin-coated onto the hole transport layer, and after annealing, a perovskite thin film is obtained.

6. The preparation method according to claim 5, characterized in that, The spin coating method is as follows: spin coating at a speed of 3000-5000 rpm for 50-70 s; the annealing treatment temperature is 60-80 ℃ and the time is 5-10 min.

7. The preparation method according to claim 1, characterized in that, In S3, the electron transport layer includes a 2,4,6-tris[3-(diphenylphosphino)phenyl]-1,3,5-triazine layer and a 2,2',2''-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) layer.

8. The preparation method according to claim 1, characterized in that, In S3, the electrode modification layer is made of lithium fluoride; the thickness of the electrode modification layer is 1-1.5 nm.

9. The preparation method according to claim 1, characterized in that, In S3, the electrode is an aluminum electrode; the thickness of the electrode is 90-110 nm.

10. A blue perovskite light-emitting diode based on a hydrogen bond network prepared by the preparation method according to any one of claims 1-9.

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