Preparation method of super-long perovskite single crystal wire

Abstract

The application provides a preparation method of an ultralong perovskite single crystal wire, and the preparation method comprises the following steps: dropping a precursor solution of perovskite A a B b X c onto a stacked porous aerogel, standing, and then growing the porous aerogel in a ventilated environment to obtain the ultralong perovskite single crystal wire. The preparation method is simple, low in cost and low in energy consumption, can synthesize perovskite single crystal wires doped with different elements, and the prepared perovskite single crystal wire is monodisperse and transferable, has a length of 0.5-3 mm, a thickness of 30 nm-30 mu m, a rectangular morphology and a smooth and flat surface.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor optoelectronic material preparation technology, and particularly relates to a method for preparing ultra-long perovskite single crystal wires. Background Technology

[0002] In recent years, metal halide perovskite materials have attracted great attention from researchers in fields such as solar cells, light-emitting diodes, photodetectors and lasers due to their high crystal quality, high fluorescence quantum yield, high absorption coefficient, bipolar carrier transport, long carrier diffusion length and solution handleability.

[0003] To improve device performance, current research largely focuses on synthesizing high-quality perovskite materials, such as polycrystalline perovskite films or single crystals. Compared to polycrystalline perovskite films, highly crystalline single crystals have fewer defects, stronger luminescence, and faster carrier migration. Furthermore, the one-dimensional structure of perovskite single crystal wires can confine photon or carrier transmission radially without scattering loss, which can benefit high-performance integrated photonic circuits. Compared to organic-inorganic hybrid single crystal wires, all-inorganic peroxide single crystal wires have better thermal stability and high-energy radiation stability, making them more suitable for applications in heat-generating devices such as lasers, light-emitting diodes, and high-energy detectors.

[0004] Currently, the main methods for synthesizing perovskite single crystal wires include chemical vapor deposition (CVD), template-assisted growth, spin coating, solution synthesis, and suspension growth. CVD and template-assisted growth require expensive vapor deposition equipment or precision templates, hindering their widespread application. Spin coating is simple, but the limited amount of precursor solvents used results in a large number of nanowires, leading to insufficient lengths (only a few hundred micrometers). Solution synthesis often requires additional factors such as heat, ultrasound, light, high pressure, and polar solvents to promote the directional adhesion of quantum dots. Even then, the obtained single crystal wire length is limited, and the wires are mixed in the solution, making it difficult to extract single wires for device fabrication and research, thus hindering further development of this material in device applications.

[0005] CN111058085A discloses a method for growing perovskite single crystals, employing a suspension growth method. The method involves dissolving AX and PbX2 in a 1:1 ratio, adding an anti-solvent to near saturation, then using a one-dimensional micro-template as a one-dimensional seed crystal, placing it in a growth flask, sealing it, and placing it in an incubator. By heating, a perovskite APbX3 single crystal with complete crystal faces is grown, and high-quality micro-curved APbX3 crystals are obtained by stripping the template. However, this method requires the use of organic solvents, polluting the environment, and results in short single crystal lengths.

[0006] In conclusion, synthesizing ultra-long and dispersed perovskite single crystal wires remains a significant challenge. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preparing ultralong perovskite single crystal wires. Compared with the existing CVD method, template method and solution synthesis method, the preparation method has the advantages of not requiring large equipment or precision templates, low energy consumption, low cost, long length of grown single crystal wires, and transferability.

[0008] To achieve this objective, the present invention employs the following technical solution:

[0009] This invention provides a method for preparing ultralong perovskite single crystal wires, the method comprising: preparing perovskite A... a B b X c The precursor solution was dropped onto the stacked porous aerogel, left to stand, and then the porous aerogel was placed in a ventilated environment to grow, thus obtaining the ultralong perovskite single crystal wire.

[0010] This invention utilizes inexpensive porous aerogel powder as a growth substrate, adds a perovskite precursor solution dropwise, and then places it in a ventilated environment for several days to synthesize a large number of dispersed, transferable, ultra-long perovskite single crystal wires. The preparation method is simple, low-cost, low-energy, and environmentally friendly, and can synthesize perovskite single crystal wires doped with any element.

[0011] The synthesis mechanism of this invention is as follows: the surface pores of the porous aerogel can volatilize the precursor solvent, and perovskite seed crystals are generated at the pores. After the seed crystals block the pores, the Bernoulli lift force generated by the airflow at the interface between the seed crystals and the air will lift these seed crystals upward. At the same time, perovskite solutes will be directionally aggregated on the seed crystals at the interface between the seed crystals and the solution inside the porous aerogel, causing the seed crystals to grow. With the continuous repetition of the process, the seed crystals are lifted higher and higher, and the bottom becomes longer and longer, eventually forming an ultra-long perovskite single crystal line.

[0012] As a preferred technical solution of the present invention, the porous aerogel includes any one or a combination of at least two of silica aerogel, organic aerogel, carbon-based aerogel or chalcogenide aerogel, preferably silica aerogel.

[0013] In this invention, the organic aerogel includes resin-based aerogel or cellulose-based aerogel; the carbon-based aerogel includes any one of carbonized plastic aerogel, carbon nanotube aerogel or graphene aerogel.

[0014] Preferably, the packing volume of the porous aerogel is 1-5 cm³. 3 For example, it could be 1cm 3 2cm 3 3cm 3 4cm 3or 5cm 3 The values ​​are not limited to those listed; other unlisted values ​​within the range also apply.

[0015] Preferably, the pore size of the porous aerogel is 20-50 nm, for example, it can be 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] Preferably, the specific surface area of ​​the porous aerogel is >700 m². 2 / g, for example, could be 720m 2 / g、760m 2 / g、800m 2 / g、840m 2 / g、880m 2 / g or 900m 2 / g, etc., but not limited to the listed values, other unlisted values ​​within the range also apply.

[0017] As a preferred technical solution of the present invention, the perovskite A a B b X c In the range 'a' is (0.9-1.1), 'b' is (0.9-1.1), and 'c' is (2.8-3.2). Here, 'a' can be 0.9, 0.95, 1, 1.05, or 1.1, 'b' can be 0.9, 0.95, 1, 1.05, or 1.1, and 'c' can be 2.8, 2.85, 2.9, 2.95, 3, 3.05, 3.1, 3.15, or 3.2, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0018] As a preferred technical solution of the present invention, the perovskite A a B b X c A includes Cs + MA + or FA + Any one or at least two of them.

[0019] In this invention, MA is protonated methylamine (CH3NH3), and FA is protonated formamidin (CH(NH2)2).

[0020] Preferably, the perovskite A a B b X cB includes any one or a combination of at least two of the cations Pb, Sn, Mn or Bi. Typical but non-limiting examples of such combinations include: combinations of Pb cations and Sn cations, combinations of Sn cations and Mn cations, or combinations of Mn cations and Bi cations, etc.

[0021] In this invention, the perovskite A a B b X c B in the text includes divalent, trivalent, or tetravalent metal cations of B.

[0022] In this invention, when B is a combination of trivalent or tetravalent metal cations and divalent metal cations, the molar ratio of trivalent or tetravalent metal cations to divalent metal cations is less than 1:9.

[0023] Preferably, the perovskite A a B b X c X includes any one or at least two of Cl, Br, or I. Typical but non-limiting examples of such combinations include combinations of Cl and Br, combinations of Br and I, or combinations of Cl, Br, and I.

[0024] As a preferred technical solution of the present invention, the concentration of the precursor solution is 0.01-0.1 mol / L, for example, it can be 0.01 mol / L, 0.03 mol / L, 0.05 mol / L, 0.07 mol / L, 0.09 mol / L or 0.1 mol / L, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 0.04-0.06 mol / L.

[0025] Preferably, the volume of the precursor solution is 500-2500 μL, for example, it can be 500 μL, 700 μL, 1000 μL, 1500 μL, 2000 μL or 2500 μL, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] In this invention, the method for preparing the precursor solution of perovskite ABX3 includes: dissolving AX and BX2 in a precursor solvent at a molar ratio of (1-2):1, and heating and stirring to obtain the precursor solution.

[0027] In this invention, the precursor solvent includes N,N dimethylformamide or dimethyl sulfoxide.

[0028] As a preferred technical solution of the present invention, the endpoint of the settling is: the precursor solution is completely absorbed by the porous aerogel.

[0029] As a preferred technical solution of the present invention, the wind speed of the ventilation environment is 1-3m / s, for example, it can be 1m / s, 1.4m / s, 1.8m / s, 2m / s, 2.4m / s, 2.8m / s or 3m / s, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] As a preferred technical solution of the present invention, the growth temperature is 20-40℃, for example, it can be 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, 32℃, 34℃, 36℃, 38℃ or 40℃, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] In this invention, the growth can be carried out at room temperature.

[0032] Preferably, the growth time is 3-6 days, for example, it can be 3 days, 3.5 days, 4 days, 4.5 days, 5 days, 5.5 days or 6 days, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0033] As a preferred technical solution of the present invention, the length of the ultra-long perovskite single crystal wire is 0.5-3mm, for example, it can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm or 3mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] Preferably, the thickness of the ultralong perovskite single crystal line is 30nm-30μm, for example, it can be 30nm, 100nm, 500nm, 1μm, 5μm, 10μm, 15μm, 20μm, 25μm or 30μm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] As a preferred embodiment of the present invention, the preparation method includes: preparing perovskite A with a concentration of 0.04-0.06 mol / L and a volume of 500-2500 μL. a B b X c The precursor solution was added dropwise to a volume of 1-5 cm³. 3 On the porous aerogel, after the precursor solution is completely absorbed by the porous aerogel, the porous aerogel is then placed in a ventilated environment and grown at 20-40℃ for 3-6 days to obtain perovskite single crystal wires with a length of 0.5-3mm and a thickness of 30nm-30μm.

[0036] The porous aerogel has a pore size of 20-50 nm and a specific surface area of ​​>700 m². 2 / g.

[0037] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The method for preparing perovskite single crystal wires provided by the present invention is simple, low in cost and low in energy consumption, and can synthesize perovskite single crystal wires doped with different elements.

[0040] (2) The present invention prepares a monodisperse, transferable perovskite single crystal wire with a length of 0.5-3 mm, a thickness of 30 nm-30 μm, a rectangular morphology, and a smooth and flat surface. Attached Figure Description

[0041] Figure 1 An optical microscope image of the perovskite CsPbBr3 single crystal wire prepared in Example 1 of this invention;

[0042] Figure 2 The perovskite CsPb prepared in Example 2 of this invention 0.5 Bi 0.5 Optical microscope image of Br1I2 single crystal line;

[0043] Figure 3 The perovskite Cs prepared in Example 3 of this invention 0.5 MA 0.5 Optical microscope image of PbBr3 single crystal wire;

[0044] Figure 4 This is an optical microscope image of the perovskite CsPbBr3 prepared in Comparative Example 2 of this invention.

[0045] Figure 5 SEM image (40 μm) of the perovskite CsPbBr3 single crystal line prepared in Example 1 of this invention;

[0046] Figure 6 SEM image (10 μm) of the perovskite CsPbBr3 single crystal line prepared in Example 1 of this invention;

[0047] Figure 7 These are growth diagrams of perovskite under different growth environments in Example 1 and Comparative Example 2 of the present invention. Detailed Implementation

[0048] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0049] Example 1

[0050] This embodiment provides a method for preparing ultralong perovskite single crystal wires, the method comprising: preparing wires with a pore size of 30 nm and a specific surface area of ​​800 nm. 2 / g of silica aerogel was placed on a platform and piled up to a depth of 1cm. 3 A small pile was formed, and then a 0.05 mol / L, 500 μL perovskite CsPbBr3 precursor solution was dropped onto the silica aerogel. After the precursor solution was completely absorbed by the silica aerogel, the silica aerogel was placed in a ventilated environment with a wind speed of 1.5 m / s and grown at 30°C for 4 days to obtain ultralong perovskite single crystal wires (the optical microscope image is shown below). Figure 1 (as shown);

[0051] The method for preparing the precursor solution of perovskite CsPbBr3 includes: dissolving CsBr and PbBr2 in N,N dimethylformamide at a molar ratio of 1:1, and heating and stirring to obtain the precursor solution.

[0052] Example 2

[0053] This embodiment provides a method for preparing ultralong perovskite single crystal wires. The preparation method includes: preparing wires with a pore size of 20 nm and a specific surface area of ​​730 m². 2 / g of cellulose-based aerogel was placed on a platform and piled up to a depth of 1cm. 3 A small pile was formed, and then perovskite CsPb with a concentration of 0.05 mol / L and a volume of 500 μL was added. 0.5 Bi 0.5 A Br1I2 precursor solution was dropped onto a silica aerogel. After the silica aerogel completely absorbed the precursor solution, it was placed in a ventilated environment with a wind speed of 2 m / s and grown at 20°C for 6 days to obtain ultralong perovskite single crystal wires (the optical microscope image is shown below). Figure 2 (as shown);

[0054] The perovskite CsPb 0.9 Bi 0.1 Br 2.8 I 0.3 The method for preparing the precursor solution includes: dissolving CsBr, PbBr2 and BiI3 in N,N dimethylformamide at a molar ratio of 1:0.9:0.1, and heating and stirring to obtain the precursor solution.

[0055] Example 3

[0056] This embodiment provides a method for preparing ultralong perovskite single crystal wires. The preparation method includes: preparing wires with a pore size of 50 nm and a specific surface area of ​​850 nm. 2 / g of silica aerogel was placed on a platform and piled up to a depth of 1cm. 3 A small pile was formed, and then perovskite Cs with a concentration of 0.05 mol / L and a volume of 500 μL was added. 0.5 MA 0.5 The PbBr3 precursor solution was dropped onto the silica aerogel. After the silica aerogel completely absorbed the precursor solution, it was placed in a ventilated environment with a wind speed of 1.5 m / s and grown at 40°C for 3 days to obtain ultralong perovskite single crystal wires (the optical microscope image is shown below). Figure 3 (as shown);

[0057] The perovskite Cs 0.5 MA 0.5 The method for preparing the precursor solution of PbBr3 includes: dissolving CsBr, MABr and PbB2 in dimethyl sulfoxide in a molar ratio of 0.5:0.5:1, and heating and stirring to obtain the precursor solution.

[0058] Example 4

[0059] This embodiment provides a method for preparing ultralong perovskite single crystal wires. The preparation method is the same as in Example 1, except that the "silica aerogel with a pore size of 30 nm" is replaced with "silica aerogel with a pore size of 10 nm".

[0060] Example 5

[0061] This embodiment provides a method for preparing ultralong perovskite single crystal wires. The preparation method is the same as in Example 1, except that the "silica aerogel with a pore size of 30 nm" is replaced with "silica aerogel with a pore size of 70 nm".

[0062] Example 6

[0063] This embodiment provides a method for preparing ultralong perovskite single crystal wires, the method except that "perovskite CsPbBr3" is replaced with "perovskite Cs 0.9 Pb1Br 3.1 Except for the above, all other conditions are the same as in Example 1.

[0064] Example 7

[0065] This embodiment provides a method for preparing ultralong perovskite single crystal wires, the method except that "perovskite CsPbBr3" is replaced with "perovskite Cs 1.1 Pb 1.1 Except for Br3, all other conditions were the same as in Example 1.

[0066] Example 8

[0067] This embodiment provides a method for preparing ultralong perovskite single crystal wires. Except for the concentration of the precursor solution being 0.01 mol / L, the other conditions of the preparation method are the same as those in Example 1.

[0068] Example 9

[0069] This embodiment provides a method for preparing ultralong perovskite single crystal wires. Except for the concentration of the precursor solution being 0.1 mol / L, the other conditions of the preparation method are the same as those in Example 1.

[0070] Example 10

[0071] This embodiment provides a method for preparing ultralong perovskite single crystal wires. Except for the growth temperature of 50°C, the other conditions of the preparation method are the same as those in Example 1.

[0072] Comparative Example 1

[0073] This comparative example provides a method for preparing perovskite single crystal wires. Except for replacing "silica aerogel" with "silica wafer", all other conditions are the same as in Example 1.

[0074] Comparative Example 2

[0075] This comparative example provides a method for preparing perovskite (its optical microscope image is shown below). Figure 4 As shown in the figure, except that the preparation method is the same as in Example 1, except that the silica aerogel is placed in a windless environment (vacuum drying oven) and grown at 30°C for 4 days.

[0076] The perovskite single crystal wires prepared in the above examples and comparative examples were characterized by SEM, and their size results are shown in Table 1.

[0077] in, Figure 5 and Figure 6 All images are SEM images of the perovskite single crystal lines prepared in Example 1. The perovskite CsPbBr3 single crystal lines are rectangular and have smooth surfaces.

[0078] Table 1

[0079]

[0080]

[0081] Where: / indicates that no perovskite single crystal line has grown;

[0082] The following points can be drawn from Table 1:

[0083] (1) The preparation methods provided in Examples 1-3 of the present invention can prepare monodisperse, transferable and ultralong perovskite single crystal wires;

[0084] (2) As can be seen from Examples 1 and 4-5, when the pore size of the porous aerogel is not properly selected, the wind cannot effectively pull the seed crystal up, resulting in a shorter perovskite single crystal line length.

[0085] (3) As can be seen from Examples 1 and 8-9, when the concentration of the precursor solution is too low, the length of the prepared perovskite single crystal line will be shorter due to the less solute contained.

[0086] (4) As can be seen from Examples 1 and 10, when the temperature of the growth environment is too high, perovskite single crystal wires cannot be prepared because the solute crystallization rate is too fast.

[0087] (5) As can be seen from Example 1 and Comparative Example 1, when the substrate is replaced with a silicon dioxide wafer, the silicon dioxide wafer has no pores on its surface and can only support a small amount of precursor solution, resulting in a shorter length of the prepared perovskite single crystal line.

[0088] (6) As can be seen from Example 1 and Comparative Example 2, when growing in a windless environment, the perovskite particles are confined in the aerogel powder and cannot grow, resulting in a mixture of perovskite particles and aerogel powder.

[0089] Figure 7 The images show the growth of perovskite in different growth environments for Examples 1 and Comparative Example 2 of the present invention. When the perovskite solution is grown in a windless environment, the perovskite particles are confined in the aerogel powder and cannot grow, resulting in a mixture of perovskite particles and aerogel powder.

[0090] The applicant declares that the detailed structural features of the present invention are illustrated through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components selected in the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing ultralong perovskite single crystal wires, characterized in that, The preparation method includes: perovskite A a B b X c The precursor solution was dropped onto the stacked porous aerogel, left to stand, and then the porous aerogel was placed in a ventilated environment to grow, thus obtaining the ultralong perovskite single crystal wire. The concentration of the precursor solution is 0.04-0.06 mol / L; The porous aerogel has a pore size of 20-50 nm; The wind speed in the ventilation environment is 1-3 m / s; The growth temperature is 20-40℃.

2. The preparation method according to claim 1, characterized in that, The porous aerogel includes any one or a combination of at least two of silica aerogel, organic aerogel, carbon-based aerogel, or chalcogenide aerogel.

3. The preparation method according to claim 2, characterized in that, The porous aerogel is a silica aerogel.

4. The preparation method according to claim 1, characterized in that, The porous aerogel has a packing volume of 1-5 cm³. 3 .

5. The preparation method according to claim 1, characterized in that, The specific surface area of ​​the porous aerogel is >700m². 2 / g.

6. The preparation method according to claim 1, characterized in that, The perovskite A a B b X c In the equation, a is 0.9-1.1, b is 0.9-1.1, and c is 2.8-3.

2.

7. The preparation method according to claim 1, characterized in that, The perovskite A a B b X c A includes Cs + MA + or FA + Any one or at least two of them.

8. The preparation method according to claim 1, characterized in that, The perovskite A a B b X c B includes any one or a combination of at least two of the cations Pb, Sn, Mn or Bi.

9. The preparation method according to claim 1, characterized in that, The perovskite A a B b X c X includes any one or a combination of at least two of Cl, Br, or I.

10. The preparation method according to claim 1, characterized in that, The volume of the precursor solution is 500-2500 μL.

11. The preparation method according to claim 1, characterized in that, The endpoint of the settling period is when the precursor solution is completely absorbed by the porous aerogel.

12. The preparation method according to claim 1, characterized in that, The growth period is 3-6 days.

13. The preparation method according to claim 1, characterized in that, The length of the ultra-long perovskite single crystal wire is 0.5-3 mm.

14. The preparation method according to claim 1, characterized in that, The thickness of the ultra-long perovskite single crystal line is 30nm-30μm.

15. The preparation method according to claim 1, characterized in that, The preparation method includes: preparing perovskite A with a concentration of 0.04-0.06 mol / L and a volume of 500-2500 μL. a B b X c The precursor solution was added dropwise to a volume of 1-5 cm³. 3 On the porous aerogel, after the precursor solution is completely absorbed by the porous aerogel, the porous aerogel is then placed in a ventilated environment and grown at 20-40℃ for 3-6 days to obtain perovskite single crystal wires with a length of 0.5-3mm and a thickness of 30nm-30μm. The porous aerogel has a pore size of 20-50 nm and a specific surface area >700 m². 2 / g.

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