Method for preparing MAPbIxBr3-x.DMF perovskite microwire forest by room-temperature gas phase method

Abstract

The invention discloses a method for preparing MAPbIxBr3-x.DMF perovskite microwire forest by a room temperature gas phase method. The method comprises the following steps: S1, mixing perovskite precursors, and uniformly grinding to obtain mixed powder; s2, putting the mixed powder into a glass bottle; s3, at the room temperature, organic solvent gas is introduced into the glass bottle, and the gas makes full contact with the mixed powder; s4, after the reaction is finished, a white one-dimensional structure, namely the perovskite microwire forest, appears in the glass bottle. The preparation method disclosed by the invention is simple, relatively low in cost and convenient for industrial production, and the prepared perovskite microwire forest is complete in structure, controllable in morphology and orderly in arrangement, can be further applied to the fields of photoelectric detection, high-energy ray detection, optical waveguides, optical fibers and the like in the photovoltaic field, and is wide in application range.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor optoelectronic materials, in particular to a room temperature gas phase method for preparing MAPbI x Br 3-x · DMF perovskite microwire forest approach. Background Art

[0002] Organic metal halide perovskite materials have excellent optoelectronic properties, such as high light absorption coefficient, adjustable band gap, high carrier mobility and long carrier diffusion length, and have shown great potential in the fields of solar cells, photodetectors, lasers, etc. In practical applications, their performance and stability still face many challenges, especially the preparation of perovskite materials at the micro-nano scale has certain technical difficulties.

[0003] As a typical low-dimensional structure, microwires have unique advantages in light capture and carrier transport, and have high optical gain and strong optical waveguide capabilities. The high-density microwire forest is not only highly consistent and orderly in morphology, but also has excellent electrical, thermal and optical properties. These properties make it have great application potential in the fields of gas sensors, biomarkers and optoelectronic components. Perovskite microwire forests can be used to construct optical sensors, photodetectors, optical waveguide devices, high-efficiency solar cells and other applications, and are considered to be one of the key materials for the development of high-efficiency perovskite optoelectronic devices.

[0004] Traditional methods for preparing perovskite microwire forests include solution method, chemical vapor deposition (CVD) method and template-assisted method, among which the solution method is to dissolve the perovskite precursor in an appropriate solvent to form a solution, and then apply the solution to the substrate by spin coating, drop casting, dip pulling and other techniques, and form a perovskite microstructure after a certain temperature treatment or solvent volatilization. For the formation of microwires, the solution method usually requires further induction or control of the crystallization process, such as the use of additives, changing annealing conditions or using directional freezing to guide the growth of one-dimensional structures. Chemical vapor deposition (CVD) is a thermally activated chemical reaction process in which a gaseous precursor is introduced to the heated substrate surface, decomposes, adsorbs and reacts on the substrate surface to generate solid products and deposit them. For the preparation of perovskite microwires, the growth in a specific direction can be promoted by adjusting the reaction parameters (such as temperature, pressure, gas flow rate, etc.), thereby obtaining a one-dimensional nanostructure. The template-assisted method uses a pre-made porous membrane or other types of templates as a supporting structure to fill the perovskite precursor into the template pores, and then uses physical or chemical means to promote the crystallization and growth of the perovskite material inside the template, eventually forming micrometer wires with regular shapes. After removing the template, independent perovskite micrometer wires can be obtained.

[0005] Although the above-mentioned method for preparing the perovskite micron wire forest can prepare the corresponding product, it has the following disadvantages: (1) The preparation process is complex and the operating conditions are harsh, making it impossible to achieve large-scale production; (2) Since the nucleation and growth processes are difficult to fully control, the quality of the prepared crystals is average; (3) The length, diameter and arrangement density of the obtained microwires are difficult to control precisely, and the morphology is difficult to control.

[0006] Therefore, a simple, controllable, and environmentally friendly method for preparing perovskite microwire forests is urgently needed. Summary of the invention

[0007] The purpose of the present invention is to provide a room temperature gas phase method for preparing MAPbI x Br 3-x The present invention provides a method for preparing MAPbI by a room temperature vapor phase method. x Br 3-x The DMF perovskite micron wire forest method solves the problem of complex CVD process for preparing perovskite micron wires and low quality of solution-grown perovskite micron wire crystals, and achieves the preparation of relatively high-quality perovskite micron wires under low-cost and simple process conditions. The prepared perovskite micron wire forest has a complete structure, controllable morphology and orderly arrangement, which can be further used in photovoltaic field for photoelectric detection, high-energy ray detection, optical waveguide, optical fiber and other fields.

[0008] To achieve the above objectives, the present invention provides a first aspect of a room temperature gas phase method for preparing MAPbI x Br 3-x The method of DMF perovskite microwire forest comprises the following steps: S1: mixing and grinding the perovskite precursors to obtain a mixed powder; S2: Put the mixed powder into a glass bottle; S3: At room temperature, an organic solvent gas is introduced into the glass bottle to allow the gas to fully contact with the mixed powder; S4: After the reaction is completed, a white one-dimensional structure appears in the glass bottle, which is the halogen perovskite microwire forest.

[0009] Preferably, in step S1, the perovskite precursor is one or both of methylamine lead iodine powder and methylamine lead bromide powder.

[0010] Preferably, in step S1, the perovskite precursor includes methylamine lead iodine powder and methylamine lead bromide powder.

[0011] Preferably, in step S1, the molar ratio of methylamine lead iodine powder to methylamine lead bromine powder is (0.8-1.2): (0.8-1.2).

[0012] When methylamine lead iodine powder and methylamine lead bromide powder are used simultaneously as perovskite precursors in the present invention, the molar ratio thereof is not limited to the above range, and may also be (0.1-1.9): (0.1-1.9).

[0013] More preferably, in step S1, the molar ratio of methylamine lead iodine powder to methylamine lead bromine powder is 1:1.

[0014] Preferably, in step S1, the grinding time is not less than 20 min.

[0015] The grinding time in the present invention is usually not less than 20 minutes to ensure that the powdered raw materials are fully mixed.

[0016] Preferably, in step S3, the organic solvent gas is N,N-dimethylformamide gas.

[0017] Preferably, in step S3, the amount of organic solvent gas introduced is 0.1-1 mL.

[0018] The present invention does not require the direct reaction of organic solvents such as N,N-dimethylformamide (DMF) with methylamine lead iodine (MAPbI 3 ) and methylamine lead bromide (MAPbBr 3 ) powder and other perovskite precursor raw materials are mixed to prepare the perovskite precursor solution, and only the introduction of DMF atmosphere is required to realize the one-dimensional MAPbI x Br 3-x The growth of DMF perovskite micron wire forest reduces the use of organic solvents and is more environmentally friendly.

[0019] In step S3 of the present invention, the reaction can occur at room temperature, and there is no need to heat or cool the glass bottle, thereby reducing energy consumption and costs.

[0020] Preferably, in step S4, the reaction time is not less than 3 days.

[0021] The second aspect of the present invention provides a MAPbI x Br 3-x DMF perovskite microwire forest, prepared by the above method.

[0022] Preferably, MAPbI x Br 3-x The diameter of the microwires in the DMF perovskite microwire forest is 10~100μm, the length is 1~5 mm, and the density of the microwires is 0.5×10 4 ~1.5×10 4Root / cm 2 .

[0023] Therefore, the present invention adopts the above-mentioned room temperature gas phase method to prepare MAPbI x Br 3-x The DMF perovskite microwire forest method has the following beneficial effects: (1) Compared with the solution method for preparing perovskite microwires, the present invention does not require the addition of liquid organic solvents to prepare perovskite precursor solutions. Only a small amount of organic atmosphere is required to prepare a higher quality perovskite microwire forest, while reducing the harm of liquid organic solvents to the environment.

[0024] (2) Compared with the CVD method for preparing perovskite microwires, the present invention does not require heating, cooling and other operations, thereby reducing the difficulty of operation and the preparation cost.

[0025] (3) The present invention can prepare a high-density perovskite microwire forest with high consistency and order in morphology. As an excellent photoelectric conversion material, it has practical value in the fields of photoelectric detection and optical waveguide.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the preparation of the present invention; Figure 2 This is an optical photograph of the perovskite microwire forest prepared in Example 1; Figure 3 This is a SEM image of a single perovskite microwire in the perovskite microwire forest prepared in Example 1; Figure 4 This is an EDS image of a single perovskite microwire prepared in Example 1; Figure 5 It curve of the perovskite microwire forest prepared in Example 1. DETAILED DESCRIPTION

[0028] The present invention will be further described below. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and a specific operation process, but the present invention is not limited to this embodiment.

[0029] Unless otherwise specified, the materials, reagents, instruments, etc. used in the examples can be obtained from commercial sources. Experimental methods without specific conditions specified in the examples are usually carried out under conventional conditions or under conditions recommended by the manufacturers.

[0030] Example 1 A room temperature gas phase method for preparing MAPbI xBr 3-x The method of DMF perovskite microwire forest comprises the following steps: S1. 0.623 g (1 mmol) of methylamine lead iodide (MAPbI 3 ) powder and 0.479 g (1 mmol) methylamine lead bromide (MAPbBr 3 ) powders are mixed and ground together for 20 minutes to ensure that they are fully mixed and uniform to obtain a mixed powder.

[0031] S2. Put the fully mixed powder into a glass bottle.

[0032] S3, from Figure 1 As can be seen from the preparation schematic diagram, at room temperature, 0.5 ml of N,N-dimethylformamide (DMF) gas is introduced into the glass bottle using a glass tube to allow the gas to fully contact with the mixed powder.

[0033] S4. After 5 days of reaction, the complete structure of MAPbI can be observed. x Br 3-x The DMF perovskite microwire forest is produced inside the bottle, showing a white one-dimensional structure.

[0034] The actual product is shown in Figure 2. Figure 2 As shown in Figure 2, the length of the perovskite microwire forest ranges from 1 to 5 mm, the diameter ranges from 10 to 100 μm, and the density is about 1×10 4 Root / cm 2 .

[0035] Single MAPbI x Br 3-x ·DMF perovskite micrometer wire SEM scanning electron microscope image Figure 3 As shown, from Figure 3 It can be seen that its diameter is about 10 μm.

[0036] Single MAPbI x Br 3-x ·DMF perovskite micron line EDS spectrum Figure 4 As shown, its elemental composition is N, Pb, I, Br and C, which is in line with expectations. x Br 3-x DMF perovskite microwire forest has been successfully prepared.

[0037] Example 2 The photoelectric performance of the perovskite microwire forest prepared in Example 1 was tested, specifically the photoelectric response detection was performed, and the It curve was drawn. Figure 5It can be seen that when the applied voltage is 10V, the dark current of the device is in the order of 10-11, and the switching ratio can reach about 450. The perovskite microwire forest prepared by the present invention has a good photoelectric response effect.

[0038] Therefore, compared with the solution method for preparing perovskite microwires, the perovskite microwire forest prepared by the present invention has higher quality; and no liquid organic solvent is required to prepare the perovskite precursor solution, and only a small amount of organic atmosphere is introduced, which reduces the harm of liquid organic solvents to the environment. Compared with the CVD method for preparing perovskite microwires, the present invention does not require heating, cooling and other operations, which reduces the difficulty of operation and preparation cost. The present invention can prepare a high-density perovskite microwire forest with high consistency and order in morphology, rather than a single perovskite microwire, with a density of about 1×10 4 Root / cm 2 The product prepared by the present invention has high crystal quality and complete structure, and its morphology is controllable and arranged in an orderly manner.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A room temperature gas phase method for preparing MAPbI x Br 3-x ·DMF perovskite microwire forest method, characterized by: The following steps are involved: S1: mixing and grinding the perovskite precursors to obtain a mixed powder; S2: Put the mixed powder into a glass bottle; S3: At room temperature, an organic solvent gas is introduced into the glass bottle to allow the gas to fully contact with the mixed powder; S4: After the reaction is completed, a white one-dimensional structure appears in the glass bottle, which is the perovskite microwire forest.

2. Preparation of MAPbI by a room temperature gas phase method according to claim 1 x Br 3-x ·DMF perovskite microwire forest method, characterized by: In step S1, the perovskite precursor is one or both of methylamine lead iodine powder and methylamine lead bromide powder.

3. Preparation of MAPbI by a room temperature gas phase method according to claim 2 x Br 3-x ·DMF perovskite microwire forest method, characterized by: In step S1, the perovskite precursor includes methylamine lead iodine powder and methylamine lead bromide powder.

4. Preparation of MAPbI by a room temperature gas phase method according to claim 3 x Br 3-x ·DMF perovskite microwire forest method, characterized by: In step S1, the molar ratio of methylamine lead iodine powder to methylamine lead bromine powder is (0.8-1.2): (0.8-1.2).

5. Preparation of MAPbI by a room temperature gas phase method according to claim 1 x Br 3-x ·DMF perovskite microwire forest method, characterized by: In step S1, the grinding time is not less than 20 minutes.

6. Preparation of MAPbI by a room temperature gas phase method according to claim 1 x Br 3-x ·DMF perovskite microwire forest method, characterized by: In step S3, the organic solvent gas is N,N-dimethylformamide gas.

7. Preparation of MAPbI by a room temperature gas phase method according to claim 1 x Br 3-x ·DMF perovskite microwire forest method, characterized by: In step S3, the amount of organic solvent gas introduced is 0.1-1 mL.

8. Preparation of MAPbI by a room temperature gas phase method according to claim 1 x Br 3-x ·DMF perovskite microwire forest method, characterized by: In step S4, the reaction time is not less than 3 days.

9. A MAPbI x Br 3-x DMF perovskite microwire forest, characterized by: The method is prepared by any one of claims 1 to 8.

10. A MAPbI according to claim 9. x Br 3-x DMF perovskite microwire forest, characterized by: MAPbI x Br 3-x The diameter of the microwires in the DMF perovskite microwire forest is 10~100μm, the length is 1~5 mm, and the density of the microwires is 0.5×10 4 ~1.5×10 4 Root / cm 2 .

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