Method for regulating and controlling performance of PeLEDs by waiting time before spin coating

Abstract

The invention relates to a method for regulating and controlling the performance of PeLEDs by waiting time before spin-coating, which comprises the following steps: step 1, dropwise adding a perovskite precursor solution to a zinc-magnesium-oxygen electron transport layer which is prepared in advance and has acetate on the surface, standing and waiting for 8-15 seconds on the electron transport layer, the perovskite precursor solution and the electron transport layer are subjected to a pre-reaction; 2, carrying out spin-coating film formation on the perovskite precursor solution subjected to the pre-reaction treatment, and then carrying out annealing treatment on the perovskite film; the perovskite thin film is an FAPbBr3 thin film; the perovskite precursor comprises FABr and PbBr2, and the molar ratio of the FABr to the PbBr2 is greater than 2: 1. According to the method, the perovskite thin film with a smooth surface is prepared by using specific waiting time before spin coating, so that local electric injection nonuniformity is inhibited, the efficiency roll-off of the device is reduced, and the brightness of about 590000 cd m <-2 > is finally realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite light-emitting diodes, and in particular relates to a method for regulating the performance of PeLEDs by waiting time before spin coating. Background Art

[0002] Perovskite light-emitting diodes (PeLEDs) have been demonstrated to be promising candidates for achieving high-efficiency electroluminescence. However, the maximum external quantum efficiency (EQE) of state-of-the-art PeLEDs is typically achieved at relatively low current densities and they exhibit severe efficiency roll-off under strong electrical excitation, thus limiting their potential for high-power and near-eye display applications.

[0003] For example, the inventor previously applied for a Chinese patent, which disclosed a preparation technology for a high-performance green perovskite light-emitting diode (publication number: CN117858591A), which disclosed that a perovskite precursor solution was added to a zinc magnesium oxide electron transport layer, and a film was formed by spin coating at a speed of 2000-5000 rpm for 10-70 seconds, and then the perovskite film was annealed to obtain a perovskite light-emitting layer. Figure 1 As shown in Figure 2, when the current density continues to increase to 100 mA cm -2 When the current density is increased to more than 125 mA cm, the rate of external quantum efficiency (EQE) growth slows down significantly and reaches a plateau. -2 Above this value, the external quantum efficiency (EQE) begins to show a clear downward trend, making it difficult to apply it under strong electrical excitation (high current density, high power) conditions with maximum external quantum efficiency (EQE), thus limiting its potential in high-power and near-eye display applications.

[0004] The inventors of this case considered how to make secondary improvements based on the original technology, and designed and optimized the process methods so that perovskite light-emitting diodes (PeLEDs) can still have the maximum external quantum efficiency (EQE) under strong electrical excitation, so there is room for improvement. Summary of the Invention

[0005] This paper proposes a method for regulating the performance of PeLEDs based on a waiting time before spin coating. This method uses a specific waiting time before spin coating to produce a perovskite film with a smooth surface, thereby suppressing local electrical injection non-uniformity, reducing device efficiency roll-off, and ultimately achieving approximately 590,000 cd m -2 brightness.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for regulating the performance of PeLEDs by waiting time before spin coating, comprising the following steps:

[0008] Step 1: Add the perovskite precursor solution dropwise onto a pre-prepared zinc magnesium oxide electron transport layer having acetate groups on its surface, and leave it in a waiting state on the electron transport layer for 8-15 seconds to promote a pre-reaction between the perovskite precursor solution and the electron transport layer;

[0009] Step 2: spin coating the perovskite precursor solution that has undergone the above-mentioned pre-reaction treatment to form a film, and then annealing the perovskite film;

[0010] The perovskite film is a FAPbBr3 film;

[0011] The perovskite precursor includes FABr and PbBr2, and the molar ratio of FABr to PbBr2 is greater than 2:1.

[0012] By adopting the above solution, the present invention has developed a simple method for controlling the performance of PeLEDs devices. It should be noted that:

[0013] In the traditional process, after adding the perovskite precursor to the substrate, technicians in this field need to immediately spin-coat the film. This is because the precursor added to the substrate will begin to undergo initial nucleation and crystallization reactions during the waiting period. During the waiting period, the precursor in some areas will form crystal nuclei in advance or undergo a certain degree of crystallization, which will destroy the originally planned crystallization process and microstructure, resulting in uneven grain size and increased grain boundaries in the perovskite film formed by the final spin coating, affecting the optical and electrical properties of the film and being detrimental to the efficient luminescence of PeLEDs. Alternatively, after the perovskite precursor is added to the substrate, some of the more active precursors will undergo some preliminary reactions with the substrate surface or the surrounding environment. If the waiting time is too long, these preliminary reactions will change the chemical state and reaction activity of the precursor, resulting in an increase in defects in the synthesized perovskite film, which in turn leads to a decrease in the PL luminescence intensity of the product.

[0014] This negative impact of a waiting time before spin coating has led to a growing technical bias among those skilled in the art, with no published literature worldwide reporting a method for controlling PeLED performance by using a waiting time before spin coating. This is because, under existing technology, a waiting time before spin coating is considered detrimental to PeLED device performance.

[0015] However, the static reaction deposition method provided by the present invention allows the precursor solution to wait for 8-15 seconds on the substrate, allowing the formamidinium cations in the precursor solution to react with the acetate groups on the surface of the ZnMgO substrate. This pre-reaction promotes uniform crystallization of the perovskite. Ultimately, the surface roughness of the perovskite is reduced. This smooth surface roughness suppresses localized electrical injection non-uniformity, reducing device efficiency roll-off and ultimately achieving approximately 59W cd m-2 The experimental data also proves that the present invention can optimize the device efficiency roll-off.

[0016] Furthermore, the spin coating process conditions in step 2 are:

[0017] The film is formed by spin coating at a rotation speed of 2000-5000 rpm and a spin coating time of 10-70 seconds.

[0018] Furthermore, the molar ratio of FABr to PbBr2 is in the range of (2.1-2.3):1.

[0019] Furthermore, the perovskite precursor further comprises decylsulfobetaine (SFB) and benzylamine (BA), and the perovskite precursor solution is prepared as follows:

[0020] Lead bromide (PbBr2), formamidine bromide (FABr), SFB, and BA are weighed and dissolved in N,N-dimethylformamide (DMF) solvent, stirred and set aside; the concentration of the perovskite precursor solution is between 0.1-0.3 mmol / mL, preferably 0.19 mmol / mL.

[0021] Furthermore, the molar ratio of each component in the precursor solution is:

[0022] FABr:PbBr2:SFB:BA=2.2:1:0.2:0.22. This ratio includes rounding of the data.

[0023] Furthermore, the perovskite precursor solution is placed in a waiting state for 15 seconds on the zinc magnesium oxide electron transport layer having acetate groups on the surface.

[0024] Furthermore, the spin coating process in step S2 is performed at an ambient temperature of 20-30° C. That is, the spin coating is performed at room temperature.

[0025] Furthermore, the annealing temperature in step S2 is 50-80° C., and the annealing time is 4-10 minutes, preferably the annealing temperature is 65° C., and the annealing time is 7 minutes.

[0026] Furthermore, the benzylamine (BA) includes 3-chlorobenzylamine (3-ClBA).

[0027] Furthermore, the conventional perovskite light-emitting diode device structure includes the following: ZnMgO electron transport layer / perovskite pattern light-emitting layer / hole transport layer / hole injection layer / electrode are sequentially deposited on ITO.

[0028] The method of the present invention is applied to the preparation of a perovskite patterned light-emitting layer in a green perovskite light-emitting diode.

[0029] Beneficial effects of the present invention:

[0030] (1) The key to the present invention is to establish a waiting time before spin coating by using an excess of formamidinium cations in the precursor solution, i.e., FA:Pb=(2.1-2.3):1, so that FA and acetate on the substrate surface can pre-react and completely consume acetate, thereby promoting uniform crystallization of perovskite. Both sites in the 3-chlorobenzylamine molecule can effectively bind to lead, passivate halogen defects in the perovskite growth process, and improve the luminous efficiency of the film. The uniform crystal nuclei formed by the pre-reaction and the effective passivation of 3-chlorobenzylamine ultimately achieve a perovskite polycrystalline film with ultra-low surface roughness, thereby achieving uniform electrical injection in the vertical device structure. The present invention increases the uniformity of electrical injection and reduces the LED efficiency roll-off, ultimately achieving high brightness of the perovskite LED.

[0031] (2) The present invention establishes a waiting time before spin coating and uses an excess of formamidinium cations (FA:Pb=(2.1-2.3):1). On the one hand, when the perovskite precursor solution is in a static waiting state, the acetate on the ZnMgO surface at the lower interface continuously consumes FA. + This is because the FA in the perovskite precursor of the present invention + , in fact, they participate in the pre-reaction with the acetate on the surface of ZnMgO and the subsequent FAPbBr3 crystallization. Under the premise of a certain amount of total substances in the perovskite precursor solution, the more formamidinium cations consumed in the pre-reaction, the more A-site components (i.e., FA) used for subsequent crystallization. + ), which also results in the generation of more A-site defects during the crystallization process.

[0032] On the other hand, if the addition ratio of FA cations is too high, it will promote the formation of a quasi-two-dimensional phase in FAPbBr3, reducing the luminescence efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The diagrams are a graph showing the relationship between external quantum efficiency and current density of the perovskite light-emitting diode according to Example 1 of the present invention, as well as a graph showing the relationship between current density, voltage, and brightness of the diode;

[0034] Figure 2 a and Figure 2 b are the external quantum efficiency-current density relationship diagram of the perovskite light-emitting diode of Comparative Example 1 of the present invention and the current density-voltage-brightness relationship diagram of the diode; Figure 2 c and Figure 2 d are the AFM images of the surface roughness of the perovskite films obtained in Comparative Example 1 and Example 1 of the present invention;

[0035] Figure 3The current density-voltage-brightness relationship diagram and the external quantum efficiency-current density relationship diagram of the perovskite light-emitting diode of Comparative Example 2 of the present invention are shown;

[0036] Figure 4 The graphs of the external quantum efficiency-current density relationship of the perovskite light-emitting diode of Comparative Example 3 of the present invention and the current density-voltage-brightness relationship of the diode are shown;

[0037] Figure 5 The graphs of the external quantum efficiency-current density relationship of the perovskite light-emitting diode of Comparative Example 4 of the present invention and the current density-voltage-brightness relationship of the diode are shown;

[0038] Figure 6 This is a comparison of the luminescence of the perovskite films of Example 1 of the present invention and Comparative Example 5. The left picture is FA-based perovskite, and the right picture is Cs-based perovskite;

[0039] Figure 7 This is a comparison chart of the PL luminescence intensities of Examples 1-2, Comparative Example 1, and Comparative Example 6 of the present invention. DETAILED DESCRIPTION

[0040] To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0041] A perovskite light-emitting diode fabrication technology comprises a sequentially arranged ITO layer, a zinc-magnesium-oxide electron transport layer, a perovskite patterned light-emitting layer, a hole transport layer, a hole injection layer, and electrodes. The ITO layer is prepared by ultrasonically cleaning a quartz glass substrate in acetone, deionized water, and anhydrous ethanol for 30 minutes, followed by drying under nitrogen. The dried substrate is then cleaned in an oxygen plasma cleaner for 15 minutes. The zinc-magnesium-oxide electron transport layer contains acetate groups on its surface. The preparation method for this layer is described in our company's prior Chinese patent application, patent number ZL202210599387.1. This is prior art and will not be further elaborated here.

[0042] The steps for preparing the perovskite patterned light-emitting layer are as follows:

[0043] Example 1:

[0044] 0.38 mmol of lead bromide (PbBr2), 0.84 mmol of formamidine bromide (FABr), 0.076 mmol of decylsulfobetaine (SFB), and 0.085 mmol of 3-chlorobenzylamine (3-ClBA) were dissolved in 2 mL of dimethylformamide (DMF) and stirred at room temperature for 6 hours to obtain a perovskite precursor solution. The resulting solution was filtered and set aside. The ITO substrate was ultrasonically cleaned in acetone, deionized water, and anhydrous ethanol for 30 minutes, followed by drying under nitrogen. The dried substrate was then cleaned in an oxygen plasma cleaner for 15 minutes.

[0045] Next, the perovskite patterned light-emitting layer is deposited. A 60μL droplet of the perovskite precursor solution is added to the zinc-magnesium-oxygen electron transport layer. After waiting for 15 seconds, the spin coating process is initiated at 4000r / min for 45 seconds. After the coating is completed, the film is annealed on a hot plate at 65°C for 7 minutes to obtain a high-quality perovskite film. The hole transport layer and subsequent thermal evaporation electrodes are then spin-coated.

[0046] In this embodiment 1, the optimal waiting time and the optimal additive were used to obtain a 590,000 cd m -2 High brightness and low roll-off perovskite light-emitting diodes. The final device performance is as follows Figure 1 shown.

[0047] Example 2:

[0048] The difference from Example 1 is that the waiting time before spin coating is adjusted. Specifically:

[0049] 60 μL of the perovskite precursor solution was added dropwise onto the zinc magnesium oxide electron transport layer, and the spin coating process was started after waiting for 8 seconds. The other steps were the same as those in Example 1.

[0050] Comparative Example 1:

[0051] 0.38 mmol of lead bromide (PbBr2), 0.84 mmol of formamidine bromide (FABr), 0.076 mmol of decylsulfobetaine (SFB), and 0.085 mmol of 3-chlorobenzylamine (3-ClBA) were dissolved in 2 mL of dimethylformamide (DMF) and stirred at room temperature for 6 hours to obtain a perovskite precursor solution. The resulting solution was filtered and set aside. The ITO substrate was ultrasonically cleaned in acetone, deionized water, and anhydrous ethanol for 30 minutes, followed by drying under nitrogen. The dried substrate was then cleaned in an oxygen plasma cleaner for 15 minutes.

[0052] Next, the perovskite patterned light-emitting layer is deposited. A 60μL drop of the perovskite precursor solution is added to the zinc-magnesium-oxygen electron transport layer and immediately spin-coated at 4000r / min for 45 seconds. After the coating is complete, the film is annealed on a hot plate at 65°C for 7 minutes to obtain the perovskite film. The hole transport layer is then spin-coated, followed by the thermal evaporation of the electrode.

[0053] The difference between Comparative Example 1 and Example 1 is that the spin coating process was carried out directly after the precursor solution was added, without waiting. Due to the rapid spin coating process, the small amount of amide generated at random sites of the interface reaction catalyzed the preferential formation of perovskite nuclei at the corresponding sites. The asynchronous nucleation and growth process resulted in the final perovskite film having a higher surface roughness, and the brightness of the device was reduced (210000 cd m -2 ), roll-off deteriorates, surface height maps obtained by atomic force microscopy and device performance such as Figure 2 shown.

[0054] Comparative Example 2:

[0055] 0.38 mmol of lead bromide (PbBr2), 0.84 mmol of formamidine bromide (FABr), 0.076 mmol of decylsulfobetaine (SFB), and 0.085 mmol of 3-chlorobenzylamine (3-ClBA) were dissolved in 2 mL of dimethylformamide (DMF) and stirred at room temperature for 6 hours to obtain a perovskite precursor solution. The resulting solution was filtered and set aside. The ITO substrate was ultrasonically cleaned in acetone, deionized water, and anhydrous ethanol for 30 minutes, followed by drying under nitrogen. The dried substrate was then cleaned in an oxygen plasma cleaner for 15 minutes.

[0056] Next, the perovskite patterned light-emitting layer is deposited. 60 μL of the perovskite precursor solution is added to the zinc-magnesium-oxygen electron transport layer. After waiting for 20 seconds, the film is spin-coated at 4000 rpm for 45 seconds. After the coating is complete, the film is annealed on a hot plate at 65°C for 7 minutes to form a perovskite film. The hole transport layer and subsequent thermal evaporation electrodes are then spin-coated.

[0057] The difference between Comparative Example 2 and Example 1 is that the waiting time for the precursor solution is extended to 20 seconds, which proves that even if an excessive amount of FA is added to the precursor solution, the extended reaction time will still lead to excessive consumption of formamidinium cations, and then there will be increased A-site defects in the subsequent growth process, resulting in a decline in the final device performance. The device performance is as follows Figure 3 As shown. The device brightness is about 380000cd m -2 , the efficiency roll-off has increased.

[0058] Comparative Example 3:

[0059] 0.38 mmol of lead bromide (PbBr2), 0.84 mmol of formamidine bromide (FABr), 0.076 mmol of decylsulfobetaine (SFB), and 0.085 mmol of 4-fluorobenzylamine (4-FBA) were dissolved in 2 mL of dimethylformamide (DMF) and stirred at room temperature for 6 hours to obtain a perovskite precursor solution. The resulting solution was filtered and set aside. The ITO substrate was ultrasonically cleaned in acetone, deionized water, and anhydrous ethanol for 30 minutes, followed by drying under nitrogen. The dried substrate was then cleaned in an oxygen plasma cleaner for 15 minutes.

[0060] Next, the perovskite patterned light-emitting layer is deposited. 60 μL of the perovskite precursor solution is added to the zinc-magnesium-oxygen electron transport layer. After waiting for 15 seconds, the film is spin-coated at 4000 rpm for 45 seconds. After the coating is complete, the film is annealed on a hot plate at 65°C for 7 minutes to obtain the perovskite film. The hole transport layer and subsequent thermal evaporation electrodes are then spin-coated.

[0061] In this comparative example 3, the difference from Example 1 is that the additive 4-FBA is replaced. The performance of the prepared device is reduced due to the poor passivation effect of 4-FBA. The maximum brightness of the device is 165189 cd m -2 , but the roll-off is still small after waiting, and the device performance is as follows Figure 4 shown.

[0062] Comparative Example 4:

[0063] 0.38 mmol of lead bromide (PbBr2), 0.84 mmol of formamidine bromide (FABr), 0.076 mmol of decylsulfobetaine (SFB), and 0.085 mmol of 4-fluorobenzylamine (4-FBA) were dissolved in 2 mL of dimethylformamide (DMF) and stirred at room temperature for 6 hours to obtain a perovskite precursor solution. The resulting solution was filtered and set aside. The ITO substrate was ultrasonically cleaned in acetone, deionized water, and anhydrous ethanol for 30 minutes, followed by drying under nitrogen. The dried substrate was then cleaned in an oxygen plasma cleaner for 15 minutes.

[0064] Next, the perovskite patterned light-emitting layer is deposited. A 60μL drop of the perovskite precursor solution is added to the zinc-magnesium-oxygen electron transport layer and immediately spin-coated at 4000r / min for 45 seconds. After the coating is complete, the film is annealed on a hot plate at 65°C for 7 minutes to obtain the perovskite film. The hole transport layer is then spin-coated, followed by the thermal evaporation of the electrode.

[0065] In this comparative example 4, the difference from Example 1 is that the additive 4-FBA is replaced and the waiting process is not performed. The brightness of the prepared device decreases, and the maximum brightness is 76624 cd m -2, compared with comparative example 3, the peak EQE level is similar, but the comparative example 3 device is at 800mAcm- 2 The device still has 4% EQE at the same current density, while the device in comparative example 4 has a serious roll-off, with only 1% EQE at the same current density. Figure 5 shown.

[0066] Comparative Example 5:

[0067] 0.38 mmol of lead bromide (PbBr2), 0.38 mmol of cesium bromide (CsBr), 0.076 mmol of decylsulfobetaine (SFB), and 0.085 mmol of 3-chlorobenzylamine (3-ClBA) were dissolved in 2 mL of dimethylformamide (DMF) and stirred at room temperature for 6 hours to obtain a perovskite precursor solution. The resulting solution was filtered and set aside. The ITO substrate was ultrasonically cleaned in acetone, deionized water, and anhydrous ethanol for 30 minutes, followed by drying under nitrogen. The dried substrate was then cleaned in an oxygen plasma cleaner for 15 minutes.

[0068] Next, the perovskite patterned light-emitting layer was deposited. 60 μL of the perovskite precursor solution was added to the zinc-magnesium-oxygen electron transport layer. After waiting for 15 seconds, the film was spin-coated at 4000 rpm for 45 seconds. After the coating was completed, the film was annealed on a hot plate at 65 degrees Celsius for 7 minutes to obtain the perovskite film.

[0069] Comparative Example 5 differs from Example 1 in that the A-site cation of the perovskite is replaced with Cs. Since Cs cannot pre-react with the zinc magnesium oxide electron transport layer having acetate groups on its surface, the perovskite film quality is low. The film emits a weak green light under 365nm light, and the luminous efficiency is significantly reduced compared to FA-based perovskites, making it impossible to prepare a normal device. This indicates that the system of the present invention is only applicable to FA systems.

[0070] Comparative Example 6:

[0071] The difference from Example 1 is that the waiting time before spin coating is adjusted. Specifically:

[0072] 60 μL of the perovskite precursor solution was added dropwise onto the zinc magnesium oxide electron transport layer, and the spin coating process was started after waiting for 25 seconds. The other steps were the same as those in Example 1.

[0073] In summary: Figure 1 and Figure 2 As shown in the figure, the maximum external quantum efficiency (EQE) of the technical solution without waiting time before spin coating provided by Comparative Example 1 is at a relatively low current density (about 100 mA cm -2 current density) is achieved, with a brightness of 21wcd m -2 .

[0074] The maximum external quantum efficiency (EQE) of the technical solution of waiting 15s before spin coating provided in Example 1 is at a relatively high current density, i.e., 200-600 mA cm -2 The current density establishes a plateau, even at 600 mA cm -2 The maximum external quantum efficiency (EQE) is achieved at the current density, and the brightness is significantly improved to 59wcd m -2 .

[0075] At the same time, the inventors found that Figure 7 As shown, when the waiting time before spin coating is established, the acetate on the ZnMgO surface at the lower interface continues to consume FA during the period when the precursor solution is still. + Pre-react with it. Under the premise of a certain total amount of substances in the perovskite precursor solution, the more formamidinium cations consumed in the pre-reaction, the less A-site components are available for subsequent crystallization, which also causes more A-site defects to be generated during the crystallization process. This leads to a decrease in the PL intensity of the film. However, the present invention achieves a significant improvement in the application of PeLEDs devices under strong electrical excitation and the realization of high brightness by sacrificing a smaller PL luminescence intensity within a waiting time range of 8-15s before spin coating. The waiting time before spin coating is then used to regulate the comprehensive performance of the PeLEDs device.

[0076] It is particularly emphasized that: under the electrical excitation of traditional PeLEDs devices, especially under high current density injection, the uneven electrical injection causes the carriers to not be used for radiative recombination and luminescence, but to recombine non-radiatively at the interface between the perovskite and the transport layer. The energy is used for heat generation, which further damages the perovskite. This is the reason why the existing technology has a serious roll-off (such as Figure 2 a, comparative example 1).

[0077] like Figure 2 c and Figure 2 d is an atomic force microscope (AFM) image, which shows the surface roughness of the perovskite film obtained without waiting for the precursor solution (c, comparative example 1) and after waiting for 15 seconds (d, example 1). The RMS root mean square roughness in the lower right corner decreases by an order of magnitude, which proves the great effect of waiting for the precursor solution on reducing the roughness of the film and verifies the effectiveness of the present invention. The fundamental reason why the present invention achieves high brightness is that the carriers are uniformly injected at high current density, and the brightness is improved because the injected carriers are effectively used for luminescence.

[0078] While the present invention is described through the above-described embodiments to illustrate the detailed preparation methods of the present invention, the present invention is not limited to the above-described detailed preparation methods. This does not necessarily mean that the present invention must rely on the above-described products and detailed preparation methods in order to be implemented. Those skilled in the art will appreciate that any improvements to the present invention, or any combination or equivalent substitution of raw materials in the products of the present invention, fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for regulating the performance of PeLEDs by waiting time before spin coating, characterized in that: The steps include: Step 1: Add the perovskite precursor solution dropwise onto a pre-prepared zinc magnesium oxide electron transport layer having acetate groups on its surface, and leave it in a waiting state on the electron transport layer for 8-15 seconds to promote a pre-reaction between the perovskite precursor solution and the electron transport layer; Step 2: spin coating the perovskite precursor solution that has undergone the above-mentioned pre-reaction treatment to form a film, and then annealing the perovskite film; The perovskite film is a FAPbBr3 film; The perovskite precursor includes FABr and PbBr2, and the molar ratio of FABr to PbBr2 is greater than 2:

1.

2. The method for regulating PeLEDs performance by waiting time before spin coating according to claim 1, characterized in that: The spin coating process conditions in step 2 are: The film is formed by spin coating at a rotation speed of 2000-5000 rpm and a spin coating time of 10-70 seconds.

3. The method for regulating PeLEDs performance by waiting time before spin coating according to claim 1, characterized in that: The molar ratio of FABr to PbBr2 is in the range of (2.1-2.3):

1.

4. The method for regulating PeLEDs performance by waiting time before spin coating according to claim 3, characterized in that: The perovskite precursor further includes decylsulfobetaine (SFB) and benzylamine (BA), and the perovskite precursor solution is prepared as follows: Weigh lead bromide (PbBr2), formamidine bromide (FABr), SFB, and BA, dissolve them in N,N-dimethylformamide (DMF) solvent, and stir for later use.

5. The method for regulating PeLEDs performance by waiting time before spin coating according to claim 4, characterized in that: The molar ratio of each component in the precursor solution is: FABr:PbBr2:SFB:BA=2.2:1:0.2:0.

22.

6. The method for regulating PeLEDs performance by waiting time before spin coating according to claim 1, characterized in that: The perovskite precursor solution is placed in a waiting state for 15 seconds on the zinc magnesium oxide electron transport layer having acetate groups on the surface.

7. The method for regulating PeLEDs performance by waiting time before spin coating according to claim 2, characterized in that: The spin coating process in step S2 is performed at an ambient temperature of 20-30°C.

8. The method for regulating PeLEDs performance by waiting time before spin coating according to claim 1, characterized in that: The benzylamine (BA) includes 3-chlorobenzylamine.

9. A method for regulating PeLEDs performance by waiting time before spin coating according to any one of claims 1 to 8, characterized in that: The method is applied to the preparation of a perovskite patterned light-emitting layer in a green perovskite light-emitting diode.

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