A 3D-printable all-inorganic perovskite flexible light-emitting gel, and a preparation method and application thereof

Abstract

The application discloses a 3D-printable all-inorganic perovskite flexible light-emitting gel and a preparation method and application thereof, and relates to the technical field of perovskite. The method comprises the following steps: dissolving cesium bromide in water to obtain a cesium bromide aqueous solution; adding photo-curing precursor components into the cesium bromide aqueous solution in a certain proportion, and stirring uniformly to obtain a photo-curing precursor mixed solution; obtaining a photo-curing composite hydrogel; obtaining a flexible high polymer gel containing cesium bromide; and performing a spontaneous crystallization reaction, and then performing heat treatment on the gel to remove residual solvents. The perovskite precursors with large solubility difference are introduced into the photo-curing base material in two steps, respectively, so that the compatibility problem of the perovskite and the flexible base material precursor is solved.

Description

Technical Field

[0001] This invention relates to the field of perovskite technology, specifically to a 3D-printable all-inorganic flexible luminescent perovskite gel, its preparation method, and its applications. Background Technology

[0002] Due to their excellent optical properties such as tunable bandgap, long carrier lifetime, and high photoluminescence quantum yield, perovskite materials have broad development prospects in optoelectronic research fields such as solar cells, transistors, and X-ray detectors. However, because organic-inorganic hybrid perovskites exhibit intrinsic thermodynamic instability, their crystal structure is easily disrupted by external perturbations such as light, heat, water, and oxygen. Therefore, inorganic cations (Cs) with high migration barriers... + It is less prone to halide segregation and exhibits superior stability. In addition, all-inorganic perovskites also have advantages such as simple synthesis, flexible dimensional control, high quantum yield, and good monochromaticity, and are considered to be optoelectronic materials with great potential.

[0003] Currently, two main problems exist in the research of all-inorganic perovskite optoelectronic devices: First, the solubility of CsX (X = Cl, Br, I), one of the precursor components of all-inorganic perovskites, is poor. The solubility of the precursor components directly affects the ion transformation and crystallization processes during perovskite preparation. Excessive difference in solubility between the two perovskite precursor components can affect the crystal growth direction and phase structure, thus limiting the perovskite growth content and film quality. Second, with the increasing demand for various flexible and wearable optoelectronic devices, photopolymerization 3D printing technology, as a simple strategy in the manufacture of flexible electronic devices, can adapt to the manufacturing of multifunctional devices for different application scenarios, meeting the needs of technology and optoelectronic application research, and has broad application prospects in rapid prototyping and customization. However, traditional all-inorganic perovskite materials are synthesized through reprecipitation or thermal injection methods, which are not only rigorous and complex with high energy consumption, but also the pre-fabricated all-inorganic perovskite materials are collected in powder form, which limits the material's multi-purpose processing capabilities in subsequent flexible device manufacturing. However, the in-situ crystallization strategy of perovskite is another challenge in the solution-based fabrication of flexible perovskite devices. This is because most photocuring precursor solutions cannot be uniformly mixed with the organic solutions of perovskite precursors; therefore, overcoming the compatibility limitations with photopolymerized flexible substrates is a key technical challenge. Summary of the Invention

[0004] To address the shortcomings of the aforementioned background technologies, this invention primarily solves the technical problems of limited solubility of all-inorganic perovskite components and compatibility issues between perovskite and 3D printing substrates. This invention provides a 3D-printable all-inorganic perovskite flexible luminescent gel, its preparation method, and its applications. This method involves a two-step process to sequentially introduce two perovskite precursor components with significantly different solubilities into a photocurable substrate, thus resolving the compatibility issue between perovskite and the flexible substrate precursor. After self-assembly and spontaneous crystallization, a formable perovskite flexible luminescent gel is obtained, suitable for 3D printing functional manufacturing strategies.

[0005] The first objective of this invention is to provide a method for preparing a 3D-printable, fully inorganic perovskite flexible luminescent gel, comprising the following steps:

[0006] Cesium bromide was dissolved in water to obtain an aqueous solution of cesium bromide.

[0007] A photocurable precursor component is added to a cesium bromide aqueous solution in a certain proportion and stirred evenly to obtain a photocurable precursor mixed solution; the photocurable precursor component is hydroxyethyl acrylate, metal-diphenyl-(2,4,6-trimethylbenzoyl)phosphine and polyethylene glycol diacrylate;

[0008] The mixed solution was subjected to photocuring treatment to obtain a photocurable composite hydrogel;

[0009] The photocurable composite hydrogel was dehydrated to obtain a flexible polymer gel containing cesium bromide.

[0010] A flexible polymer gel containing cesium bromide is immersed in a lead bromide organic solvent to swell and undergo a spontaneous crystallization reaction. After the reaction, the gel is heat-treated to remove residual solvent, thus obtaining a 3D-printable all-inorganic perovskite flexible luminescent gel.

[0011] Preferably, the concentration of the cesium bromide aqueous solution is 0.1-2.5 mol / L;

[0012] The mass ratio of hydroxyethyl acrylate, metal-diphenyl-(2,4,6-trimethylbenzoyl)oxyphosphine and polyethylene glycol diacrylate is (1-3):(0.01-0.2):(0.01-0.2).

[0013] More preferably, the metal component in the metal-diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide is lithium, sodium, or magnesium.

[0014] Preferably, the volume ratio of water in the photocurable precursor mixture is 30%-80%; and the photocuring time is 10 min to 1 h.

[0015] Preferably, the dehydration treatment method includes freeze drying, vacuum drying, or ordinary annealing; the dehydration treatment time is 30 minutes to 3 days.

[0016] Preferably, during the heat treatment to remove residual solvent, the heat treatment temperature is 60℃~120℃ and the treatment time is 20min~2h.

[0017] Preferably, the lead bromide organic solvent may be one or more of 2-methoxyethanol (2-ME), N,N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF), and N-methylpyrrolidone (NMP); the concentration of the lead bromide organic solvent is 0.01M-0.1M.

[0018] Preferably, the amount of lead bromide organic solution used for the swelling treatment is 0.8 mL to 3 mL per 1 g of gel; and the spontaneous crystallization reaction time is 10 h to 100 h.

[0019] The second objective of this invention is to provide a 3D-printable all-inorganic perovskite flexible luminescent gel.

[0020] The third objective of this invention is to provide an application of a 3D-printable, all-inorganic, flexible, luminescent gel in the optoelectronic field.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This invention discloses a two-step method for preparing 3D-printable all-inorganic flexible perovskite luminescent gel. The method involves sequentially introducing two components of a perovskite precursor with significantly different solubilities into a photocurable substrate, thus resolving the compatibility issue between the perovskite and the flexible substrate precursor. After self-assembly and spontaneous crystallization, a formable flexible perovskite luminescent gel is obtained, suitable for 3D printing functional manufacturing strategies.

[0023] This invention utilizes an environmentally friendly aqueous solution, a good solvent for cesium bromide, which not only significantly improves the solubility of cesium bromide but also allows for uniform mixing with photopolymerization organic solvents. Secondly, after UV curing, the prepared cesium bromide hydrogel undergoes a dehydration step; the escape of water yields a porous polymer gel containing cesium bromide, facilitating subsequent solvent infiltration reactions. Finally, the polymer gel is immersed in a lead bromide organic solution. The gel swells in the solvent, absorbing lead bromide and undergoing a self-assembly crystallization reaction with the cesium bromide within the gel. The spontaneous reaction rate is dependent on the solvent and Pb content. 2+ The coordination strength is related to the strength of the components. This invention can introduce the two components of perovskite separately in a two-step process to carry out a self-assembly crystallization reaction. This not only allows for a wide range of control over the amount of perovskite components added, but also solves the compatibility problem between the perovskite precursor solution and the flexible substrate, enabling a simplified process for manufacturing flexible optoelectronic devices and meeting the functionalization requirements of photopolymerization 3D printing.

[0024] This invention dissolves cesium bromide in water to obtain a cesium bromide aqueous solution (one of the components of the perovskite precursor). By changing the concentration of the cesium bromide aqueous solution, a perovskite precursor solution that meets the requirements of spontaneous crystallization in a two-step process can be prepared. Based on water, an environmentally friendly and good solvent for cesium bromide, the amount and uniformity of the perovskite precursor components can be controlled. Hydroxyethyl acrylate, metal-diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxide, and polyethylene glycol diacrylate are mixed to obtain a photocurable solution. By changing the material ratio of the photocurable solution, a photocurable solution that is miscible with and can be cured by the cesium bromide aqueous solution can be prepared.

[0025] This invention mixes cesium bromide aqueous solution and photocuring solution according to a specified ratio to obtain a mixed solution, which can achieve compatibility between perovskite and flexible curing substrate solution, and control the perovskite content and crystal morphology in the sample.

[0026] This invention can regulate the degree of cross-linking of polymer gels by changing different curing times, thereby affecting the mechanical properties of the samples; by changing different types of lead bromide solutions (one of the perovskite precursor components) for induction, the self-assembly growth rate of perovskite can be regulated, thereby affecting the grain morphology and final luminescence effect.

[0027] This invention also discloses a flexible luminescent gel prepared by the above-described method. This two-step method addresses the issue of significant differences in the solubility of perovskite precursor components and overcomes the compatibility limitations between the perovskite and the flexible substrate precursor solution, resulting in a moldable flexible perovskite luminescent gel. It is not only applicable to the full-spectrum emission of perovskites but also suitable for 3D printing functionalization strategies, possessing significant application value for flexible device detection, luminescence, and customized functional structures. Attached Figure Description

[0028] Figure 1 SEM images of the cesium bromide flexible polymer gel and the all-inorganic flexible luminescent gel provided in Example 1.

[0029] Figure 2 SEM images of the all-inorganic flexible luminescent gels provided in Examples 2 and 3.

[0030] Figure 3 The photoluminescence fluorescence spectrum of the all-inorganic flexible luminescent gel provided in Example 1.

[0031] Figure 4 The illustration shows the all-inorganic flexible luminescent gel provided in Example 1 3D printed as a kneeling terracotta warrior gel. Detailed Implementation

[0032] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.

[0033] This invention provides a two-step method for preparing 3D-printable all-inorganic flexible perovskite luminescent gel. The method involves sequentially introducing two components of a perovskite precursor with significantly different solubilities into a photocurable substrate, thus resolving the compatibility issue between the perovskite and the flexible substrate precursor. After self-assembly and spontaneous crystallization, a formable flexible perovskite luminescent gel is obtained, suitable for 3D printing functional manufacturing strategies.

[0034] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a 3D-printable all-inorganic perovskite flexible luminescent gel, comprising the following steps:

[0035] Cesium bromide was dissolved in water to obtain an aqueous solution of cesium bromide.

[0036] A photocurable precursor component is added to a cesium bromide aqueous solution in a certain proportion and stirred evenly to obtain a photocurable precursor mixture solution; the photocurable precursor component is hydroxyethyl acrylate, metal-diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxide and polyethylene glycol diacrylate; the volume ratio of water in the photocurable precursor mixture solution is 30%-80%;

[0037] The mixed solution was subjected to photocuring treatment to obtain a photocurable composite hydrogel;

[0038] The photocurable composite hydrogel was dehydrated to obtain a flexible polymer gel containing cesium bromide.

[0039] A flexible polymer gel containing cesium bromide is immersed in a lead bromide organic solvent to swell and undergo a spontaneous crystallization reaction. After the reaction, the gel is heat-treated to remove residual solvent, thus obtaining a 3D-printable all-inorganic perovskite flexible luminescent gel.

[0040] The concentration of the cesium bromide aqueous solution is 0.1-2.5 mol / L; the mass ratio of hydroxyethyl acrylate, metal-diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxyphosphate, and polyethylene glycol diacrylate is (1-3):(0.01-0.2):(0.01-0.2). This environmentally friendly aqueous solution is an excellent solvent for cesium bromide, significantly improving its solubility and allowing for homogeneous mixing with photopolymerization organic solvents.

[0041] The metal component in the metal-diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxide is lithium, sodium, or magnesium.

[0042] The photocuring time is 10 min to 1 h. After UV curing, the prepared cesium bromide hydrogel undergoes a dehydration step. As water escapes, a porous polymer gel containing cesium bromide is obtained, which is beneficial for subsequent solvent penetration reactions.

[0043] The dehydration treatment method includes freeze drying, vacuum drying, or ordinary annealing; the dehydration treatment time is 30 minutes to 3 days.

[0044] During the heat treatment process to remove residual solvent, the heat treatment temperature is 60℃~120℃ and the treatment time is 20min~2h.

[0045] The lead bromide organic solvent can be one or more of 2-methoxyethanol (2-ME), N,N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF), and N-methylpyrrolidone (NMP); the concentration of the lead bromide solution is 0.01M-0.1M. The amount of lead bromide organic solution used for the swelling treatment is 0.8mL-3mL per 1g of gel; the spontaneous crystallization reaction time is 10h-100h. The polymer gel is immersed in the lead bromide organic solution, and the gel swells in the solvent, absorbing lead bromide and undergoing a self-assembly crystallization reaction with the cesium bromide inside the gel. The spontaneous reaction rate is related to the solvent and Pb content. 2+ The coordination strength is related to the strength of coordination.

[0046] A second aspect of the present invention provides a 3D-printable all-inorganic perovskite flexible luminescent gel.

[0047] A third aspect of this invention provides an application of a 3D-printable all-inorganic perovskite flexible luminescent gel in the optoelectronic field.

[0048] It should be noted that, unless otherwise specified, the experimental methods used in this invention are all conventional methods; and the reagents and materials used, unless otherwise specified, are all commercially available.

[0049] Example 1

[0050] A two-step method for preparing 3D-printable all-inorganic perovskite flexible luminescent gel includes the following steps:

[0051] Step 1: Dissolve 212.8 mg of cesium bromide (CsBr) in 1 mL of ultrapure water and stir at room temperature for 10 min to obtain an aqueous solution of cesium bromide (one of the components of the perovskite precursor);

[0052] A photocurable solution was obtained by mixing 1g of hydroxyethyl acrylate, 0.01g of Li-diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxyphosphate (Li-TPO) and 0.01g of polyethylene glycol diacrylate (PEGDA).

[0053] Cesium bromide aqueous solution and photocuring solution were mixed at a volume ratio of 3:1 and stirred until homogeneous to obtain a mixed solution.

[0054] Step 2: The mixed solution is injected into a custom-shaped polytetrafluoroethylene mold. For example, a rectangular mold groove is 2cm long, 1.5cm wide, and 1mm deep. 600μL of the mixed solution is spread evenly. It is then placed in a UV curing machine for 10 minutes to cure. After demolding, cesium bromide composite hydrogel is obtained.

[0055] Step 3: Freeze-dry the cesium bromide composite hydrogel for 3 days to obtain a flexible polymer gel containing cesium bromide.

[0056] Step 4: The cesium bromide polymer gel was immersed in 0.3 mL of N,N-dimethylformamide (DMF, 98%) containing lead bromide for a spontaneous reaction for 10 h. The concentration of the lead bromide solution was 0.05 M. After the reaction, the photocured composite gel was placed on an 80 °C hot plate for annealing for 2 h. After the residual DMF evaporated, a flexible luminescent gel was obtained.

[0057] Example 2

[0058] A two-step method for preparing 3D-printable all-inorganic perovskite flexible luminescent gel includes the following steps:

[0059] Step 1: Dissolve 21.3 mg of cesium bromide (CsBr) in 1 mL of ultrapure water and stir at room temperature for 10 min to obtain an aqueous solution of cesium bromide (one of the components of the perovskite precursor);

[0060] A photocurable solution was obtained by mixing 1.5g of hydroxyethyl acrylate, 0.01g of Li-diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride (Li-TPO) and 0.02g of polyethylene glycol diacrylate (PEGDA).

[0061] Cesium bromide aqueous solution and photocuring solution were mixed at a volume ratio of 2:1 and stirred until homogeneous to obtain a mixed solution.

[0062] Step 2: The mixed solution is injected into a custom-shaped polytetrafluoroethylene mold. For example, a rectangular mold trough is 2cm long, 1.5cm wide, and 1mm deep. 600μL of the mixed solution is spread evenly. It is then placed in a UV curing machine for 30 minutes to cure. After demolding, cesium bromide composite hydrogel is obtained.

[0063] Step 3: Vacuum dry the cesium bromide composite hydrogel for 2 hours to obtain a flexible polymer gel containing cesium bromide.

[0064] Step 4: The cesium bromide polymer gel was immersed in 0.2 mL of N,N-dimethylacetamide (DMA, 98%) containing lead bromide for a spontaneous reaction for 20 h. The concentration of the lead bromide solution was 0.1 M. After the reaction, the photocured composite gel was placed on a hot plate at 60 °C for annealing for 2 h. After the residual DMA evaporated, a flexible luminescent gel was obtained.

[0065] Example 3

[0066] A two-step method for preparing 3D-printable all-inorganic perovskite flexible luminescent gel includes the following steps:

[0067] Step 1: Dissolve 425.6 mg of cesium bromide (CsBr) in 1 mL of ultrapure water and stir at room temperature for 10 min to obtain an aqueous solution of cesium bromide (one of the components of the perovskite precursor);

[0068] A photocurable solution was obtained by mixing 3g of hydroxyethyl acrylate, 0.2g of Li-diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxyphosphate (Li-TPO) and 0.2g of polyethylene glycol diacrylate (PEGDA).

[0069] Cesium bromide aqueous solution and photocuring solution were mixed at a volume ratio of 1:2 and stirred until homogeneous to obtain a mixed solution.

[0070] Step 2: The mixed solution is injected into a custom-shaped polytetrafluoroethylene mold. For example, a rectangular mold groove is 2cm long, 1.5cm wide, and 1mm deep. 600μL of the mixed solution is spread evenly. It is then placed in a UV curing machine for 40 minutes to cure. After demolding, cesium bromide composite hydrogel is obtained.

[0071] Step 3: The cesium bromide composite hydrogel is freeze-dried for 2 days to obtain a flexible polymer gel containing cesium bromide.

[0072] Step 4: The cesium bromide polymer gel was immersed in 0.4 mL of N-methylpyrrolidone (NMP, 98%) of lead bromide for a spontaneous reaction for 50 h. The concentration of the lead bromide solution was 0.1 M. After the reaction, the photocurable composite gel was placed on a hot plate at 120 °C for annealing for 10 min. After the residual NMP evaporated, a flexible luminescent gel was obtained.

[0073] Example 4

[0074] A two-step method for preparing 3D-printable all-inorganic perovskite flexible luminescent gel includes the following steps:

[0075] Step 1: Dissolve 532.0 mg of cesium bromide (CsBr) in 1 mL of ultrapure water and stir at room temperature for 10 min to obtain an aqueous solution of cesium bromide (one of the components of the perovskite precursor);

[0076] A photocurable solution was obtained by mixing 2g of hydroxyethyl acrylate, 0.02g of Li-diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride (Li-TPO) and 0.05g of polyethylene glycol diacrylate (PEGDA).

[0077] Cesium bromide aqueous solution and photocuring solution were mixed at a volume ratio of 4:1 and stirred until homogeneous to obtain a mixed solution.

[0078] Step 2: The mixed solution is injected into a custom-shaped polytetrafluoroethylene mold. For example, a rectangular mold groove is 2cm long, 1.5cm wide, and 1mm deep. 600μL of the mixed solution is spread evenly. It is then placed in a UV curing machine for 1 hour to cure. After demolding, cesium bromide composite hydrogel is obtained.

[0079] Step 3: Anneal the cesium bromide composite hydrogel for 6 hours to remove water, and obtain a flexible polymer gel containing cesium bromide.

[0080] Step 4: The cesium bromide polymer gel was immersed in 0.6 mL of N-methylpyrrolidone (NMP, 98%) of lead bromide for a spontaneous reaction for 60 h. The concentration of the lead bromide solution was 0.01 M. After the reaction, the photocured composite gel was placed on a hot plate at 100 °C for annealing for 20 min. After the residual NMP evaporated, a flexible luminescent gel was obtained.

[0081] Example 5

[0082] A two-step method for preparing 3D-printable all-inorganic perovskite flexible luminescent gel includes the following steps:

[0083] Step 1: Dissolve 319.2 mg of cesium bromide (CsBr) in 1 mL of ultrapure water and stir at room temperature for 10 min to obtain an aqueous solution of cesium bromide (one of the components of the perovskite precursor);

[0084] A photocurable solution was obtained by mixing 1.8 g of hydroxyethyl acrylate, 0.12 g of Li-diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxyphosphate (Li-TPO) and 0.12 g of polyethylene glycol diacrylate (PEGDA).

[0085] Cesium bromide aqueous solution and photocuring solution were mixed at a volume ratio of 1:1 and stirred until homogeneous to obtain a mixed solution.

[0086] Step 2: The mixed solution is injected into a custom-shaped polytetrafluoroethylene mold. For example, a rectangular mold groove is 2cm long, 1.5cm wide, and 1mm deep. 600μL of the mixed solution is spread evenly. It is then placed in a UV curing machine for 40 minutes to cure. After demolding, cesium bromide composite hydrogel is obtained.

[0087] Step 3: Vacuum dry the cesium bromide composite hydrogel for 3 hours to obtain a flexible polymer gel containing cesium bromide.

[0088] Step 4: The cesium bromide polymer gel was immersed in 0.4 mL of N,N-dimethylacetamide (DMA, 98%) containing lead bromide for a spontaneous reaction for 60 h. The concentration of the lead bromide solution was 0.07 M. After the reaction, the photocured composite gel was placed on a hot plate at 100 °C for annealing for 30 min. After the residual DMA evaporated, a flexible luminescent gel was obtained.

[0089] Figure 1 (a) shows a scanning electron microscope (SEM) image of the cesium bromide flexible polymer gel prepared in Example 1. Figure 1 (a) It can be seen that the hydrogel has a porous structure after the dehydration step, which is conducive to the permeation reaction of the lead bromide solution in the second step. The cesium bromide crystals are evenly distributed in the porous polymer, indicating that the aqueous solution and the polymer precursor can be uniformly mixed.

[0090] Figure 1 (b) shows a scanning electron microscope (SEM) image of the all-inorganic flexible luminescent gel prepared in Example 1. Figure 1 (b) It can be seen that the all-inorganic perovskite crystals have a spherical structure with stacked layers (about 25 micrometers in diameter) and a single grain size of about 3 micrometers. At the same time, there are also large cubic grains at the bottom of the gel.

[0091] Figure 2 (a) shows a SEM image of the all-inorganic flexible luminescent gel prepared in Example 2. The perovskite exhibits a flower-like structure with stacked layers (approximately 5 micrometers in diameter), partially encapsulated within the polymer. Crystals are densely distributed within the gel. Figure 2 (b) shows a SEM image of the all-inorganic flexible luminescent gel prepared in Example 3. The perovskite is a flower-like structure (approximately 10 micrometers in diameter) with a coexistence of lamellar and cubic crystals, partially encapsulated within the polymer. The crystals are densely distributed within the gel. The differences in crystal size and morphology are due to the different solvents used in step 4. Because the coordination abilities of each solvent with Pb differ, the dissociation rates during the self-assembly crystallization process are unequal.

[0092] The photoluminescence fluorescence spectroscopy (PL) of the all-inorganic perovskite flexible luminescent gel prepared in Example 1 was measured, and the results are as follows: Figure 2 As shown. By Figure 3As can be seen, at an excitation wavelength of 365 nm, the strongest fluorescence emission peak is at 516 nm, indicating a strong fluorescence intensity. This is consistent with the sample exhibiting a bright green color under ultraviolet light. When the flexible luminescent gel film thickness is 1 mm, the fluorescence quantum yield (PLQY) is 39%. Furthermore, the all-inorganic perovskite flexible luminescent gel prepared in Example 1 was fabricated using 3D printing, and the results are as follows... Figure 4 As shown, the example structure is a kneeling terracotta warrior gel with a base diameter of approximately 1 cm. The photoluminescence sites are uniform, enabling the functional fabrication of flexible perovskite optoelectronic materials.

[0093] This invention describes preferred embodiments and their effects. However, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to include both the preferred embodiments and all changes and modifications falling within the scope of this invention.

[0094] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a 3D printable all-inorganic perovskite flexible light-emitting gel, characterized in that, The method comprises the following steps: dissolving cesium bromide in water to obtain a cesium bromide aqueous solution; adding photo-curing precursor components in a certain proportion into the cesium bromide aqueous solution, stirring uniformly to obtain a photo-curing precursor mixed solution; the photo-curing precursor components are hydroxyethyl acrylate, metal-diphenyl-(2,4,6-trimethylbenzoyl) phosphine oxide and polyethylene glycol diacrylate; subjecting the mixed solution to photo-curing treatment to obtain a photo-curing composite hydrogel; subjecting the photo-curing composite hydrogel to water removal treatment to obtain a cesium bromide-containing flexible polymer gel; immersing the cesium bromide-containing flexible polymer gel in a lead bromide organic solvent to swell, performing a spontaneous crystallization reaction, and after the reaction, subjecting the gel to heat treatment to remove residual solvent, thereby obtaining a 3D-printable all-inorganic perovskite flexible light-emitting gel.

2. The process for the preparation of 3D printable all-inorganic perovskite flexible light emitting gel according to claim 1, characterized in that, The concentration of the cesium bromide aqueous solution is 0.1-2.5 mol / L; The mass ratio of the hydroxyethyl acrylate, metal-diphenyl-(2,4,6-trimethylbenzoyl) phosphine oxide and polyethylene glycol diacrylate is (1-3):(0.01-0.2):(0.01-0.2).

3. The process for the preparation of 3D printable all-inorganic perovskite flexible light emitting gel according to claim 2, characterized in that, The metal component in the metal-diphenyl-(2,4,6-trimethylbenzoyl) phosphine oxide is lithium, sodium or magnesium.

4. The process for the preparation of 3D printable all-inorganic perovskite flexible light emitting gel according to claim 1, characterized in that, The volume ratio of water in the photo-curing precursor mixed solution is 30%-80%; and the photo-curing time is 10 min-1 h.

5. The process for the preparation of 3D printable all-inorganic perovskite flexible light emitting gel according to claim 1, wherein, The water removal treatment method comprises freeze-drying, vacuum drying or ordinary annealing; and the water removal treatment time is 30 min-3 days.

6. The process for the preparation of 3D printable all-inorganic perovskite flexible light emitting gel according to claim 1, wherein, The heat treatment temperature is 60 o C~120 o C, and the treatment duration is 20 min~2h.

7. The process for the preparation of 3D printable all-inorganic perovskite flexible light emitting gel according to claim 1, wherein, The lead bromide organic solvent is one or more of 2-methoxyethanol, N,N-dimethylacetamide, N,N-dimethylformamide and N-methylpyrrolidone; and the concentration of the lead bromide organic solvent is 0.01 M-0.1 M.

8. The process for the preparation of 3D printable all-inorganic perovskite flexible light emitting gel according to claim 1, characterized in that, The amount of the lead bromide organic solvent used for swelling treatment per 1 g of the gel is 0.8 mL-3 mL; and the spontaneous crystallization reaction time is 10 h-100 h.

9. A 3D-printable all-inorganic perovskite flexible light-emitting gel prepared by the method of any one of claims 1-8.

10. Application of the 3D-printable all-inorganic perovskite flexible light-emitting gel of claim 9 in the field of optoelectronics.

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