A high-performance perovskite nanosheet for direct photolithographic patterning, and a convenient preparation method and application thereof

Abstract

The present invention relates to a high-performance perovskite nanosheet that can be used for direct lithographic patterning, and a convenient preparation method and application thereof. The preparation method includes the following specific steps: Preparation of perovskite nanosheets: Dissolve lead halide, cesium halide and surface ligands together in a polar solvent to prepare a precursor solution; quickly inject the precursor into a non-polar solvent, stir and react, then add a precipitant, centrifugally purify, and disperse the precipitate in a non-polar solvent to obtain a high-performance perovskite nanosheet solution; Crosslinking of perovskite nanosheets: Coat the perovskite nanosheet solution on a clean substrate, and use a mask to induce surface ligand crosslinking in the exposed area by ultraviolet light; then elute the unexposed area with a solvent to obtain a high-performance perovskite nanosheet film that can be used for direct lithographic patterning. Compared with the prior art, the method of the present invention is convenient and controllable, and the prepared perovskite nanosheets have high quantum efficiency and good stability, and can be applied to fields such as optoelectronic display.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor light-emitting materials, and particularly relates to a high-performance perovskite nanosheet that can be used for direct lithographic patterning, and a convenient preparation method and application thereof. Background Art

[0002] As a new type of nanomaterial with a direct bandgap, colloidal perovskite nanomaterials have advantages such as narrow emission spectra, high carrier mobility, and low cost. Among them, nanosheets, as a two-dimensional structure, can effectively tune the wavelength and exciton binding energy through the quantum confinement effect, and thus show great application potential in the field of lighting and display.

[0003] Currently, the synthesis methods of perovskite nanosheets mainly adopt high-temperature thermal injection synthesis or room-temperature multi-step preparation methods. These methods are either energy-consuming or have cumbersome steps, which are not conducive to large-scale preparation. In addition, short-wavelength perovskite nanosheets also face problems such as low fluorescence quantum efficiency and poor stability. Therefore, developing a rapid and convenient method to achieve the controllable preparation of perovskite nanosheets is of great significance for the commercialization process of perovskites.

[0004] In order to realize the application of colloidal perovskite nanomaterials in fields such as flat panel displays, it is crucial to achieve high-resolution perovskite thin film patterning. Currently, methods for realizing perovskite thin film patterning include inkjet printing, template method, transfer printing, and so on. These methods all have deficiencies in process preparation, such as cumbersome steps and insufficient precision. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-performance perovskite nanosheet that can be used for direct lithographic patterning, a convenient preparation method and application thereof, which are convenient and controllable, and the prepared perovskite nanosheets have high quantum efficiency and good stability, so as to overcome at least one of the defects existing in the above-mentioned prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] In order to improve the fluorescence quantum efficiency of perovskite nanosheets and at the same time improve their stability, based on the mature patterning process and high yield of lithography technology, the present invention combines colloidal perovskite nanomaterials with lithography technology to achieve direct lithographic patterning, which is a simple and efficient method. Developing colloidal nanomaterials that can be used for direct lithography can effectively solve the above problems. And due to the crosslinkability of surface ligands, the nanosheets can be used as a new type of lithography material and applied to fields such as optoelectronic display. The specific scheme is as follows:

[0008] A convenient preparation method of a high-performance perovskite nanosheet that can be used for direct lithographic patterning, the method comprising the following specific steps:

[0009] Preparation of perovskite nanosheets: Lead halide, cesium halide and surface ligands are dissolved together in a polar solvent to prepare a precursor solution; the precursor solution is rapidly injected into a non-polar solvent, stirred and reacted, then a precipitant is added, centrifuged and purified, and the precipitate is dispersed in the non-polar solvent to obtain a high-performance perovskite nanosheet solution;

[0010] Crosslinking of perovskite nanosheets: The perovskite nanosheet solution is coated on a clean substrate, and with the aid of a mask, ultraviolet light is used to induce crosslinking of the surface ligands in the exposed area; then the unexposed area is eluted with a solvent to obtain a high-performance perovskite nanosheet thin film that can be used for direct lithographic patterning.

[0011] Further, the halogen element includes one or more of Cl or Br; the surface ligand is an organic acid and an organic amine, the organic acid is an organic acid containing an unsaturated bond, such as C≡C or C=C, and the organic amine is an organic amine containing a cinnamoyl group, a cinnamylideneacetyl group or a benzylideneacetophenone group.

[0012] Further, in the precursor solution, the molar ratio of cesium halide, lead halide and surface ligand is (0.1-2):1:(0.5-5).

[0013] Further, the volume ratio of the precursor solution to the non-polar solvent is 1:(1-10).

[0014] Further, the precipitant is one of methyl acetate, ethyl acetate, acetonitrile or acetone; the volume dosage of the precipitant is 0.1-2 times that of the non-polar solvent; the polar solvent is N,N-dimethylformamide, dimethyl sulfoxide or N-methylpyrrolidone; the non-polar solvent is toluene, n-hexane or n-octane.

[0015] Further, the concentration of the perovskite nanosheets is 10-100 mg / mL.

[0016] Further, the irradiation intensity of the ultraviolet light is 10-500 mW / cm 2 , and the crosslinking time is 5-30 min.

[0017] Further, the substrate includes a glass substrate or a PET flexible substrate; the elution solvent includes toluene, cyclohexane, n-hexane or n-octane.

[0018] A high-performance perovskite nanosheet that can be used for direct lithographic patterning prepared by the method as described above.

[0019] An application of the high-performance perovskite nanosheet as described above, and the perovskite nanosheet is applied to the field of lithography.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) The present invention adopts a room-temperature liquid-phase synthesis method to quickly, conveniently and reliably obtain high-performance perovskite nanosheets. The surface ligands of the perovskite nanosheets have Lewis acid-base properties and specific groups, which can not only significantly improve the optical properties and stability of the perovskite nanosheets, but also further serve as cross-linking units for direct lithographic patterning;

[0022] (2) The method of the present invention is convenient and controllable, and can realize the large-scale and stable preparation of perovskite nanosheets; the perovskite nanosheets obtained by the present invention have good optical properties, with a fluorescence quantum efficiency close to 100%, and can be stably stored at room temperature for more than 3 months; the perovskite nanosheets obtained by the present invention can be cross-linked under the action of ultraviolet light, so as to be applied to the lithography field. Description of the Drawings

[0023] Figure 1 It is a TEM picture of the blue-light perovskite nanosheets prepared in Example 1;

[0024] Figure 2 It is a fluorescence quantum yield diagram of the cyan-light perovskite nanosheets prepared in Example 2;

[0025] Figure 3 It is a schematic diagram showing the change of the fluorescence quantum yield with time during the room-temperature storage of the blue-light perovskite nanosheets prepared in Example 3;

[0026] Figure 4 It is a schematic diagram of the film after photo-crosslinking in Example 3 and the control sample soaked in an organic solvent. Detailed Embodiments

[0027] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0028] A high-performance perovskite nanosheet that can be used for direct lithographic patterning, its convenient preparation method and application, the specific steps are as follows:

[0029] S1: Convenient synthesis of high-performance perovskite nanosheets

[0030] Dissolve lead halide, cesium halide and surface ligands in a polar solvent to prepare a precursor solution; then quickly inject it into a non-polar solvent, stir and react, then add a precipitant, centrifuge and purify, and disperse the precipitate in a non-polar solvent to obtain a high-performance perovskite nanosheet solution; in lead halide, the halogen element is one or more of Cl or Br; in cesium halide, the halogen element is one or more of Cl or Br; the surface ligands are organic acids and organic amine molecules, where the organic acid is characterized by containing an unsaturated bond of "C≡C" or "C=C", and the organic amine is characterized by containing one or more of cinnamoyl, cinnamylideneacetyl or benzylideneacetophenone groups. In the precursor solution, the molar ratio of cesium halide, lead halide, and surface ligand is (0.1-2):1:(0.5-5); the polar solvent is selected from N,N-dimethylformamide, dimethyl sulfoxide or N-methylpyrrolidone; when the precursor solution is injected into the non-polar solvent, the volume ratio of the precursor solution to the non-polar solvent is 1:(1-10); the stirring reaction time is 5-15 minutes; the precipitant is selected from methyl acetate, ethyl acetate, acetonitrile, acetone; the dosage of the precipitant is 0.1-2 times the volume of the aforementioned non-polar solvent; centrifugal purification is centrifugation at 5000-10000 rpm for 2-10 minutes; then disperse the precipitate in a non-polar solvent; the non-polar solvent is selected from toluene, n-hexane or n-octane.

[0031] S2: Photo-crosslinking of perovskite nanosheets

[0032] Coat the perovskite nanosheet solution in S1 on a clean substrate, and with the aid of a mask, use ultraviolet light to induce cross-linking of the surface ligands in the exposed area; then use a polar solvent to elute the unexposed area to obtain a patterned perovskite nanosheet thin film. The concentration of the perovskite nanosheets is 10-100 mg / mL; the irradiation intensity of the ultraviolet light is 10-500 mW / cm 2 , and the cross-linking time is 5-30 min. The non-polar solvents for eluting the unexposed area include but are not limited to non-polar solvents such as toluene, cyclohexane, n-hexane, n-octane, etc.

[0033] Example 1

[0034] A preparation method of crosslinkable blue-light perovskite nanosheets, the specific steps are as follows:

[0035] (1) Synthesis of perovskite nanosheets: Dissolve 0.1 mmol of cesium bromide and 1 mmol of lead bromide in 10 mL of N,N-dimethylformamide, and simultaneously add 3.15 mmol of 2-pentynoic acid, 0.63 mmol of ethyl 4-aminocinnamate and 1 mL of oleylamine; under vigorous stirring, take 1 mL of the above-mentioned dissolved solution and add it to 10 mL of toluene; after 5 minutes, add 2 mL of acetonitrile, centrifuge at 10000 rpm for 2 minutes, and disperse the precipitate in 2 mL of n-hexane to obtain a perovskite nanosheet solution.

[0036] (2) Photo-crosslinking of perovskite nanosheets: Spin-coat 100 μL of the above solution onto a 1.5×1.5 cm 2 glass slide; irradiate under ultraviolet light of 50 mW / cm 2 for 15 min to obtain a photo-crosslinked perovskite nanosheet film.

[0037] Example 2

[0038] A preparation method of crosslinkable blue-green perovskite nanosheets, the specific steps are as follows:

[0039] (1) Synthesis of perovskite nanosheets: Dissolve 0.3 mmol of cesium chloride and 0.6 mmol of lead bromide in 10 mL of dimethyl sulfoxide, and simultaneously add 2 mmol of cinnamic acid, 1 mol of 1-amino-10-undecene, and 0.5 mL of dodecylamine; under vigorous stirring, take 1 mL of the above dissolved solution and add it to 5 mL of toluene; after 15 minutes, add 10 mL of methyl acetate, centrifuge at 6000 rpm for 5 minutes, and disperse the precipitate in 2 mL of toluene to obtain a perovskite nanosheet solution.

[0040] (2) Photo-crosslinking of perovskite nanosheets: Drop 200 μL of the above solution onto a 1.5×1.5 cm 2 glass slide; irradiate under ultraviolet light of 100 mW / cm 2 for 5 min to obtain a photo-crosslinked perovskite nanosheet film.

[0041] Example 3

[0042] A preparation method of crosslinkable green perovskite nanosheets, the specific steps are as follows:

[0043] (1) Synthesis of perovskite nanosheets: Dissolve 0.25 mmol of cesium bromide and 0.25 mmol of lead bromide in 10 mL of N,N-dimethylformamide, and simultaneously add 3 mol of phenylpropiolic acid and 0.5 mL of oleylamine; under vigorous stirring, take 1 mL of the above dissolved solution and add it to 5 mL of toluene; after 10 minutes, add 10 mL of ethyl acetate, centrifuge at 5000 rpm for 10 minutes, and disperse the precipitate in 2 mL of n-octane to obtain a perovskite nanosheet solution.

[0044] (2) Photo-crosslinking of perovskite nanosheets: Drop 100 μL of the above solution onto a 1.5×1.5 cm 2 glass slide; irradiate under ultraviolet light of 200 mW / cm 2 for 5 min to obtain a photo-crosslinked perovskite nanosheet film.

[0045] Figure 1It is the TEM image of the prepared blue-light perovskite nanosheets in Example 1, demonstrating that the morphology of the prepared sample is two-dimensional nanosheets.

[0046] Figure 2 It is the fluorescence quantum yield graph of the prepared cyan-light perovskite nanosheets in Example 2, demonstrating that the perovskite nanosheets prepared by the present invention have a high fluorescence quantum efficiency.

[0047] Figure 3 It is the schematic diagram of the change of the fluorescence quantum yield of the prepared blue-light perovskite nanosheets with time under room temperature storage in Example 1, demonstrating that the perovskite nanosheets prepared by the present invention have good stability.

[0048] Figure 4 It is the schematic diagram of the film after photo-crosslinking and the control sample soaked in an organic solvent in Example 3. Among them, the uncrosslinked perovskite film has dissolved in the solvent, showing the pattern under the glass slide, while the crosslinked perovskite film has maintained the integrity of the film.

[0049] In summary, the surface ligands of the perovskite nanosheets of the present invention have Lewis acid-base characteristics and specific groups, which can not only significantly improve the optical properties and stability of the perovskite nanosheets, but also further serve as crosslinking units and be applied to direct photolithographic patterning. The method of the present invention is convenient and controllable. The prepared perovskite nanosheets have high quantum efficiency and good stability. Due to the crosslinkability of the surface ligands, the nanosheets can be used as a new type of lithographic material and applied to fields such as optoelectronic display.

[0050] The above are only the preferred embodiments of the present invention, and are not limitations on the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution content of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A convenient preparation method of high-performance perovskite nanosheets for direct photolithographic patterning, characterized in that, The method comprises the following specific steps: Preparation of perovskite nanosheets: Dissolve lead halide, cesium halide and a surface ligand together in a polar solvent to prepare a precursor solution; rapidly inject the precursor into a non-polar solvent, stir and react, then add a precipitant, centrifuge and purify, and disperse the precipitate in a non-polar solvent to obtain a high-performance perovskite nanosheet solution; Crosslinking of perovskite nanosheets: Coat the perovskite nanosheet solution on a clean substrate, and by means of a mask, use ultraviolet light to induce crosslinking of the surface ligand in the exposed area; Then use a solvent to elute the unexposed area to obtain a high-performance perovskite nanosheet thin film that can be used for direct lithographic patterning.

2. The convenient preparation method of a high-performance perovskite nanosheet that can be used for direct lithography patterning according to claim 1, wherein, The halogen element includes one or more of Cl or Br; the surface ligand is an organic acid and an organic amine, the organic acid is an organic acid containing an unsaturated bond, and the organic amine is an organic amine containing a cinnamoyl group, a cinnamylideneacetyl group or a benzylideneacetophenone group.

3. A convenient preparation method of a high-performance perovskite nanosheet for direct lithography patterning according to claim 1, characterized in that, In the precursor solution, the molar ratio of cesium halide, lead halide and the surface ligand is (0.1-2):1:(0.5-5).

4. A convenient preparation method of a high-performance perovskite nanosheet for direct lithography patterning according to claim 1, characterized in that, The volume ratio of the precursor solution to the non-polar solvent is 1:(1-10).

5. The convenient preparation method of a high-performance perovskite nanosheet that can be used for direct lithography patterning according to claim 1, characterized in that, The precipitant is one of methyl acetate, ethyl acetate, acetonitrile or acetone; the volume dosage of the precipitant is 0.1-2 times that of the non-polar solvent; the polar solvent is N,N-dimethylformamide, dimethyl sulfoxide or N-methylpyrrolidone; the non-polar solvent is toluene, n-hexane or n-octane.

6. The convenient preparation method of a high-performance perovskite nanosheet for direct photolithographic patterning according to claim 1, characterized in that, The concentration of the perovskite nanosheets is 10-100 mg / mL.

7. A convenient preparation method of a high-performance perovskite nanosheet for direct photolithographic patterning according to claim 1, characterized in that, The irradiation intensity of the ultraviolet light is 10 - 500 mW / cm 2 , and the crosslinking time is 5 - 30 min.

8. A convenient preparation method of a high-performance perovskite nanosheet for direct photolithographic patterning according to claim 1, characterized in that, The substrate includes a glass substrate or a PET flexible substrate; the eluting solvent includes toluene, cyclohexane, n-hexane or n-octane.

9. A high-performance perovskite nanosheet that can be used for direct lithographic patterning prepared by the method according to any one of claims 1-8.

10. Use of the high-performance perovskite nanosheets as described in claim 9, characterized in that, The perovskite nanosheet is applied to the field of lithography.

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