阅读说明：本技术 一种全光谱钙钛矿纳米线阵列及其制备方法 (Full-spectrum perovskite nanowire array and preparation method thereof ) 是由 付悦 吴雨辰 江雷 于 2021-01-18 设计创作，主要内容包括：本发明公开了一种全光谱钙钛矿纳米线阵列及其制备方法,所述全光谱钙钛矿纳米线阵列制备方法包括以下步骤：配制卤素基团为溴的钙钛矿前驱体溶液；利用钙钛矿前驱体溶液制备钙钛矿纳米线阵列；配制溶质分别含氯、含碘的两种离子交换溶液；将钙钛矿纳米线阵列的一端浸泡在其一离子交换溶液中,并持续提拉钙钛矿纳米线阵列；取出一端形成异质结的钙钛矿纳米线阵列,并清洗、烘干；将钙钛矿纳米线阵列的另一端浸泡在另一离子交换溶液中,并持续提拉钙钛矿纳米线阵列；取出另一端也形成异质结的钙钛矿纳米线阵列,并清洗、烘干。该制备方法可直接在宏观角度下简便地制造出具有全波段光谱的特性谱钙钛矿纳米线阵列。(The invention discloses a full-spectrum perovskite nanowire array and a preparation method thereof, wherein the preparation method of the full-spectrum perovskite nanowire array comprises the following steps: preparing a perovskite precursor solution with bromine as a halogen group; preparing a perovskite nanowire array by using a perovskite precursor solution; preparing two ion exchange solutions with solutes respectively containing chlorine and iodine; soaking one end of the perovskite nanowire array in an ion exchange solution of the perovskite nanowire array, and continuously lifting the perovskite nanowire array; taking out the perovskite nanowire array with one end forming a heterojunction, cleaning and drying; soaking the other end of the perovskite nanowire array in another ion exchange solution, and continuously lifting the perovskite nanowire array; and taking out the perovskite nanowire array with the other end also forming the heterojunction, and cleaning and drying the perovskite nanowire array. The preparation method can directly and simply manufacture the perovskite nanowire array with the characteristic spectrum of the full-wave-band spectrum under a macroscopic angle.)

1. A preparation method of a full-spectrum perovskite nanowire array is characterized by comprising the following steps:

s1, preparing a perovskite precursor solution with bromine as a halogen group;

s2, preparing a perovskite nanowire array by using the perovskite precursor solution;

s3, preparing two ion exchange solutions with solutes respectively containing chlorine and iodine;

s4, soaking one end of the perovskite nanowire array in an ion exchange solution of the perovskite nanowire array, and continuously lifting the perovskite nanowire array;

s5, taking out the perovskite nanowire array with one end forming the heterojunction, cleaning and drying;

s6, soaking the other end of the perovskite nanowire array in another ion exchange solution, and continuously pulling the perovskite nanowire array;

and S7, taking out the other end of the perovskite nanowire array which also forms the heterojunction, and cleaning and drying the perovskite nanowire array.

2. The method for preparing a full-spectrum perovskite nanowire array as claimed in claim 1, wherein step S1 comprises the following sub-steps:

s11, mixing a bromine-containing organic substance and a bromine-containing inorganic substance in a molar mass ratio of 1:1, or mixing two bromine-containing inorganic substances in a molar mass ratio of 1:1 to be used as solutes of the precursor solution;

s12, preparing an organic solvent of N, N-dimethylformamide, dimethyl sulfoxide and a combination thereof;

s13, dissolving the solute of the precursor solution in the step S11 in the organic solvent in the step S12 to prepare the precursor solution with the concentration of 5-50 mg/mL.

3. The method for preparing a full-spectrum perovskite nanowire array as claimed in claim 1, wherein step S2 comprises the following sub-steps:

s21, taking a proper amount of precursor solution and dripping the precursor solution on the substrate;

s22, covering a silicon column template containing a silicon column array on a substrate to form a sandwich assembly system of the substrate, the perovskite precursor solution and the silicon column template;

s23, heating and drying the sandwich assembly system, and forming a nano single crystal array in the process of infiltrating and removing the perovskite precursor solution;

s24, disassembling the sandwich assembly system to obtain the perovskite nanowire array.

4. The method for preparing a full-spectrum perovskite nanowire array as claimed in claim 3, wherein the heating temperature in step S23 is 60-70 ℃ and the heating time is 8-24 hours.

5. The method of making a full-spectrum perovskite nanowire array of claim 1, wherein the length of the perovskite nanowire array immersed in the ion exchange solution in steps S4 and S6 is less than half the overall length of the perovskite nanowire array.

6. The method for preparing a full-spectrum perovskite nanowire array according to claim 1, wherein the cleaning and drying processes in steps S5 and S7 comprise: and (3) cleaning the surface of the perovskite nanowire array by using chlorobenzene and normal hexane, and drying by using a hot table to remove the residual organic solution on the surface of the perovskite nanowire array.

7. The method of claim 1, wherein the solute of the ion exchange solution is one of oleylamine chloride, oleylamine iodide, lead chloride, lead iodide, chloromethane, iodomethylamine, and the solvent of the ion exchange solution is one of octadecene, toluene, and isopropanol.

8. The method for preparing a full-spectrum perovskite nanowire array as claimed in claim 1, wherein the soaking time in steps S4 and S6 is 16-24 hours, and the soaking temperature is normal temperature.

9. The method of claim 1, wherein the pulling step of steps S4 and S6 is performed by using a square-shaped pulling jig, and the perovskite nanowire array is fixed to four sides of the square-shaped pulling jig.

10. The full-spectrum perovskite nanowire array is characterized in that two heterojunctions are arranged on a nanowire of the nanowire array, the two heterojunctions divide the nanowire into three crystal segments, and the three crystal segments are respectively composed of perovskite single crystals with halogen groups respectively being chlorine, bromine and iodine.

Technical Field

The invention relates to the technical field of photoelectric materials, and mainly relates to a full-spectrum perovskite nanowire array and a preparation method thereof.

Background

The perovskite is an artificially synthesized material with the same crystal form as calcium titanate, and the molecular general formula of the perovskite is ABX₃Wherein the a and B sites are different sized cations and X is a halide anion (X ═ Cl, Br, I); the organic-inorganic hybrid perovskite material has variable components and dimensions and excellent photoelectric and photovoltaic characteristics, and is widely applied to the field of photoelectric devices such as solar cells, light-emitting diodes, photoelectric detection, nano lasers and the like. In the perovskite material system, the nano crystal can carry out rapid anion exchange reaction in a solid-liquid or solid-gas state, and the component proportion and the electrical and optical properties of the nano crystal can be regulated, so that the perovskite single crystal containing different halogen groups can be obtained by an ion exchange method.

The perovskite single crystal nanowire has no crystal boundary and a unique one-dimensional geometrical structure, so that the perovskite single crystal nanowire with different halogen ion ratios is generated by ion exchange by a solid-liquid method, and an ideal thought is provided for researching a heterojunction.

However, in the prior art, the work of obtaining the full-spectrum perovskite nanowire by ion exchange of the single crystal nanowire needs the assistance of an electron beam lithography method and needs to be carried out under a microscope system, the operation process is complicated, and the preparation under a macroscopic angle cannot be carried out.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, an object of the embodiments of the present application is to provide a full-spectrum perovskite nanowire array and a method for manufacturing the same, which can directly and easily manufacture a perovskite nanowire array having a characteristic spectrum of a full-band spectrum under a macroscopic angle.

In a first aspect, an embodiment of the present application provides a method for preparing a full-spectrum perovskite nanowire array, including the following steps:

s1, preparing a perovskite precursor solution with bromine as a halogen group;

s2, preparing a perovskite nanowire array by using the perovskite precursor solution;

s3, preparing two ion exchange solutions with solutes respectively containing chlorine and iodine;

s4, soaking one end of the perovskite nanowire array in an ion exchange solution of the perovskite nanowire array, and continuously lifting the perovskite nanowire array;

s5, taking out the perovskite nanowire array with one end forming the heterojunction, cleaning and drying;

s6, soaking the other end of the perovskite nanowire array in another ion exchange solution, and continuously pulling the perovskite nanowire array;

and S7, taking out the other end of the perovskite nanowire array which also forms the heterojunction, and cleaning and drying the perovskite nanowire array.

The preparation method of the full-spectrum perovskite nanowire array comprises the following steps of S1:

s11, mixing a bromine-containing organic substance and a bromine-containing inorganic substance in a molar mass ratio of 1:1, or mixing two bromine-containing inorganic substances in a molar mass ratio of 1:1 to be used as solutes of the precursor solution;

s12, preparing an organic solvent of N, N-dimethylformamide, dimethyl sulfoxide and a combination thereof;

s13, dissolving the solute of the precursor solution in the step S11 in the organic solvent in the step S12 to prepare the precursor solution with the concentration of 5-50 mg/mL.

The preparation method of the full-spectrum perovskite nanowire array comprises the following steps of S2:

s21, taking a proper amount of precursor solution and dripping the precursor solution on the substrate;

s22, covering a silicon column template containing a silicon column array on a substrate to form a sandwich assembly system of the substrate, the perovskite precursor solution and the silicon column template;

s23, heating and drying the sandwich assembly system, and forming a nano single crystal array in the process of infiltrating and removing the perovskite precursor solution;

s24, disassembling the sandwich assembly system to obtain the perovskite nanowire array.

The preparation method of the full-spectrum perovskite nanowire array comprises the step S23, wherein the heating temperature is 60-70 ℃, and the heating time is 8-24 hours.

The preparation method of the full-spectrum perovskite nanowire array comprises the steps of S4 and S6, wherein the length of the perovskite nanowire array immersed in the ion exchange solution is less than half of the whole length of the perovskite nanowire array.

The preparation method of the full-spectrum perovskite nanowire array comprises the following steps of S5 and S7: and (3) cleaning the surface of the perovskite nanowire array by using chlorobenzene and normal hexane, and drying by using a hot table to remove the residual organic solution on the surface of the perovskite nanowire array.

The preparation method of the full-spectrum perovskite nanowire array comprises the steps of preparing an ion exchange solution, wherein a solute of the ion exchange solution is one of oleylamine chloride, oleylamine iodide, lead chloride, lead iodide, chloromethylamine and iodomethylamine, and a solvent of the ion exchange solution is one of octadecene, toluene and isopropanol.

The preparation method of the full-spectrum perovskite nanowire array comprises the steps of S4 and S6, wherein the soaking time is 16-24 hours, and the soaking temperature is normal temperature.

In the preparation method of the full-spectrum perovskite nanowire array, in the pulling process of the step S4 and the step S6, a clamp for pulling is in a cube shape, and the perovskite nanowire array is fixed on four side faces of the cube-shaped clamp.

In a second aspect, an embodiment of the present application further provides a full-spectrum perovskite nanowire array, where the nanowire of the nanowire array has two heterojunctions thereon, two of the heterojunctions separate the nanowire into three crystal segments, and three of the crystal segments are respectively composed of perovskite single crystals in which halogen groups are respectively chlorine, bromine, and iodine.

From the above, the preparation method of the full-spectrum perovskite nanowire array provided by the embodiment of the application has the following beneficial effects:

1. according to the preparation method provided by the invention, the perovskite nanowire array is firstly prepared, and the perovskite nanowire array is subjected to ion exchange twice, so that the full-spectrum perovskite nanowire array is obtained, the visible light band spectrum can be adjusted in the array according to the change of the illumination position, and the full-spectrum perovskite nanowire array has the characteristic of full-band spectrum.

2. The preparation method provided by the invention combines a pulling method and an ion exchange method to prepare the full-spectrum perovskite nanowire, and has the characteristic of convenient and fast operation compared with the preparation of nanowire single crystals by operations such as electron beam etching, vapor deposition and the like.

3. The preparation method provided by the invention can directly carry out ion exchange at a macroscopic angle, and can realize the control of the exchange degree and the exchange position according to the immersion length of the perovskite nanowire in the ion exchange solution, thereby obtaining the perovskite nanowire array of the full-wave-band spectrum.

4. According to the preparation method provided by the invention, in the pulling process, the pulling speed can be adjusted, the soaking time can be changed, the ion exchange effect can be adjusted, the obtained full-spectrum perovskite nanowire array can be ensured to be uniform in light emission and complete in structure, and the physical properties of the prepared heterojunction can be controlled more easily.

5. The method can be used as a pre-preparation for the preparation of more complex patterned devices.

The invention also provides a full-spectrum perovskite nanowire array, wherein the nanowire of the nanowire array is provided with two heterojunctions, the two heterojunctions divide the nanowire into three crystal segments, and the three crystal segments respectively consist of perovskite single crystals of which halogen groups are respectively chlorine, bromine and iodine; according to the change of the illumination position, the adjustability of the visible light band spectrum can be realized in the array, and the array has the characteristic of full-band spectrum.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 shows a full-spectrum perovskite nanowire array positioned in MAPbCl prepared in the preparation method of the full-spectrum perovskite nanowire array in embodiment 1 of the present invention₃-MAPbBr₃Fluorescence photographs of front and rear portions at the heterojunction.

FIG. 2 is a MAPbCl drawing of the full-spectrum perovskite nanowire array prepared in the method for preparing the full-spectrum perovskite nanowire array in embodiment 1 of the invention₃-MAPbBr₃Heterojunction emission spectrum.

FIG. 3 shows a full-spectrum perovskite nanowire array positioned at MAPbBr position prepared in the preparation method of the full-spectrum perovskite nanowire array in embodiment 1 of the present invention₃-MAPbI₃Fluorescence photographs of front and rear portions at the heterojunction.

FIG. 4 is a MAPbBr of a full-spectrum perovskite nanowire array prepared in the method for preparing a full-spectrum perovskite nanowire array in embodiment 1 of the present invention₃-MAPbI₃Heterojunction emission spectrum.

FIG. 5 is a CsPbCl-located full-spectrum perovskite nanowire array prepared in the method for preparing a full-spectrum perovskite nanowire array in embodiment 2 of the present invention₃-CsPbBr₃Fluorescence photographs of front and rear portions at the heterojunction.

FIG. 6 is CsPbCl of the full-spectrum perovskite nanowire array prepared in the method for preparing the full-spectrum perovskite nanowire array in embodiment 2 of the invention₃-CsPbBr₃Heterojunction emission spectrum.

FIG. 7 shows CsPbBr-located full-spectrum perovskite nanowire array prepared in the method for preparing full-spectrum perovskite nanowire array in embodiment 2 of the present invention₃-CsPbI₃Fluorescence photographs of front and rear portions at the heterojunction.

FIG. 8 is a full spectrum perovskite nanowire array in example 2 of the present inventionCsPbBr of full-spectrum perovskite nanowire array prepared in preparation method₃-CsPbI₃Heterojunction emission spectrum.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides a method for preparing a full-spectrum perovskite nanowire array by directly and simply manufacturing a characteristic spectrum perovskite nanowire array with a full-wave-band spectrum under a macroscopic angle, so that controllable long-range ordered array preparation of perovskite materials is realized;

specifically, the preparation method of the full-spectrum perovskite nanowire array comprises the following steps:

s1, preparing a perovskite precursor solution with bromine as halogen group, namely preparing a solute with a general molecular formula ABX₃A solution of a perovskite wherein X is Br;

s2, preparing a perovskite nanowire array by using the perovskite precursor solution;

s3, preparing two ion exchange solutions with solutes containing chlorine and iodine respectively, and using the two ion exchange solutions to react and displace bromine groups in the perovskite nanowire array;

s4, soaking one end of the perovskite nanowire array in an ion exchange solution of the perovskite nanowire array, and continuously lifting the perovskite nanowire array; specifically, the perovskite nanowire array is fixed on a lifting rod of a lifting instrument through a clamp, a corresponding ion exchange solution is placed in a crucible of the lifting instrument, and the perovskite nanowire array is subjected to continuous reciprocating lifting motion and rotating motion relative to the crucible in the process of ion exchange reaction; the method comprises the following steps that Br in nanowires of a perovskite nanowire array soaked in an ion exchange solution is replaced by corresponding Cl or I in the ion exchange solution, so that the partial nanowire array forms the perovskite nanowire array containing groups different from original halogen groups, a heterojunction is formed at the boundary of a soaked liquid level, and the perovskite nanowire array is lifted by a pulling method in the reaction process;

s5, taking out the perovskite nanowire array with one end forming the heterojunction, cleaning and drying;

s6, soaking the other end of the perovskite nanowire array in another ion exchange solution, and continuously pulling the perovskite nanowire array; specifically, similarly to step S4, Br of the nanowires in the perovskite nanowire array is displaced by the halogen groups of the ion exchange solution, so that the partial nanowire array forms a perovskite nanowire array containing different halogen groups from the original halogen groups, and a heterojunction is formed at the boundary of the immersed liquid level, so that the perovskite nanowire array is divided into three parts containing different halogen groups;

and S7, taking out the perovskite nanowire array with the other end also forming a heterojunction, cleaning and drying to obtain the full-spectrum perovskite nanowire array.

In certain preferred embodiments, step S1 includes the following sub-steps:

s11, mixing a bromine-containing organic substance and a bromine-containing inorganic substance in a molar mass ratio of 1:1, or mixing two bromine-containing inorganic substances in a molar mass ratio of 1:1, as solutes of the precursor solution, such as a mixture of methylamine bromide and lead bromide, a mixture of methylamine bromide and silver bromide, a mixture of formamidine bromide and lead bromide, a mixture of formamidine bromide and silver bromide, a mixture of cesium bromide and lead bromide, a mixture of cesium bromide and silver bromide, and the like;

s12, preparing an organic solvent of N, N-Dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and a combination thereof, wherein the mixed solution of the DMF and the DMSO can be mixed according to any proportion;

s13, dissolving the solute of the precursor solution in the step S11 in the organic solvent in the step S12 to prepare a precursor solution with the concentration of 5-50mg/mL, thereby preparing the bromine-containing perovskite precursor solution.

In certain preferred embodiments, step S2 includes the following sub-steps:

s21, dropwise adding a proper amount of precursor solution on a substrate, wherein the substrate is a super-hydrophilic substrate and can be one of a silicon wafer, a silicon dioxide sheet, a glass sheet, indium tin oxide conductive glass, a quartz sheet and polyethylene glycol terephthalate;

s22, covering a silicon column template containing a silicon column array on a substrate to form a sandwich assembly system of the substrate, the perovskite precursor solution and the silicon column template;

s23, heating and drying the sandwich assembly system to completely volatilize the solvent of the perovskite precursor solution, wherein the perovskite precursor solution forms a nano single crystal array in the silicon column back infiltration process; specifically, in the process of volatilizing the solvent of the perovskite precursor solution, the perovskite liquid is soaked and removed on the interface of the silicon column template and the substrate to form a stable capillary liquid bridge array to control mass transfer, crystallization and crystal growth, so that a long-range ordered perovskite nanowire array is formed between the substrate and the silicon column template;

s24, disassembling the sandwich assembly system to obtain the perovskite nanowire array.

The perovskite nanowire array prepared by the steps has the thickness of a nanometer level, the ion exchange speed in the subsequent ion exchange reaction can be effectively improved, and the production time of the full-spectrum perovskite nanowire array is effectively shortened.

In step S21, the amount of the precursor solution to be sucked is 7 to 20. mu.L.

The silicon pillar template in step S22 may be manufactured by a photolithography process, and the width of the silicon pillar, the width of the silicon pillar adjacent to the gap between the silicon pillars, and the width of the silicon pillar adjacent to the gap between the silicon pillars are designed and processed by designing a corresponding mask during the design and processing.

Wherein, in the heating and drying process of step S23, at the end edge of the silicon pillar template, the geometric structure level and the wettability level are mutated, in the liquid infiltration removing process, due to the wedge-shaped limited area of the interface near the outward capillary flow and the gas-solid-liquid three-phase contact line, the gas-liquid-solid-three-phase line can be pinned at the edge of the top of the silicon column, the perovskite particles have size separation near the three-phase contact line, the three-phase line pushes the particles kept in the separation state to move from the silicon column gap to the silicon column position, after the liquid bridge is formed, the three-phase line on the surface of the substrate can slide and contract, but the three-phase line on the surface of the silicon column template can not move, and because the evaporation rate of the moving part of the three-phase line is higher, meanwhile, solute molecules are gathered along with capillary liquid flowing to a place with high evaporation rate, so that the perovskite nanowire array is favorably formed.

In addition, solute molecules are gathered along with capillary flow to a place with a high evaporation rate, and the solute in the liquid bridge can be guaranteed to be transported towards the substrate, namely, the perovskite crystals are guaranteed to be completely attached to the substrate as far as possible, so that the perovskite nanowire crystals can be fixed on the substrate when the sandwich assembly system is disassembled in the step S24.

The perovskite nanowire array can be rapidly and effectively prepared by using a dewetting mode, and the perovskite nanowire array can also be prepared at low demand by using a traditional ink-jet printing method or a micro-imprinting method.

In certain preferred embodiments, the heating temperature in step S23 is 60-70 deg.C and the heating time is 8-24 hours.

It should be noted that, before the sandwich assembly system is disassembled in step S24, the sandwich assembly system needs to be left to stand and cooled to room temperature, thereby facilitating the disassembly of the sandwich assembly system.

In certain preferred embodiments, the length of the perovskite nanowire array immersed in the ion exchange solution is less than half of the overall length of the perovskite nanowire array in each of steps S4 and S6, so as to ensure that the perovskite nanowire array has a portion that is not immersed in the ion exchange solution after two immersion times, and to ensure that two heterojunctions are generated to separate the perovskite nanowire array into three portions each having a different halogen group, thereby achieving coverage of the full spectrum of reflected light.

In some preferred embodiments, the washing and drying processes in steps S5 and S7 each include: the surface of the perovskite nanowire array is cleaned by chlorobenzene and n-hexane, the solution on the surface of the perovskite nanowire array can be effectively washed away by the chlorobenzene and n-hexane cleaning, and then the perovskite nanowire array is dried by a hot table, so that the residual organic solution on the surface of the perovskite nanowire array is removed, and the surface cleanness of the perovskite nanowire array is ensured.

In certain preferred embodiments, the solute of the ion exchange solution is one of oleylamine chloride, oleylamine iodide, lead chloride, lead iodide, chloromethane and iodomethylamine, and the solvent of the ion exchange solution is one of octadecene, toluene and isopropanol, wherein oleylamine chloride, lead chloride and chloromethane are chlorine-containing solutes, and oleylamine iodide, lead iodide and iodomethylamine are iodine-containing solutes.

Wherein, both the chlorine-containing ion exchange solution and the iodine-containing ion exchange solution need to be prepared, and the two ion exchange solutions can be prepared in advance or can be prepared before the corresponding perovskite nanowire array is soaked.

The perovskite nanowire array is soaked for ion exchange treatment, chlorine ion exchange can be carried out firstly, iodine ion exchange can also be carried out firstly, and the sequence is not limited.

In certain preferred embodiments, the soaking time in steps S4 and S6 is 16-24 hours, and the soaking temperature is normal temperature; the soaking process does not need to adopt a crucible heating device of a pulling instrument, the ion exchange reaction can be carried out only at normal temperature, the pulling instrument is utilized to carry out pulling motion treatment, the ion exchange reaction is ensured to be complete, and the reaction efficiency is improved, so that the time required for preparing the full-spectrum perovskite nanowire array is shortened, and the quality of the full-spectrum perovskite nanowire array is improved.

In certain preferred embodiments, when the perovskite nanowire array is immersed in the ion exchange solution, the crucible of the pulling apparatus rotates to provide a liquid swirling stirring effect, in order to prevent a single perovskite nanowire array from being placed in the ion solution to interfere with the movement of the ion exchange solution and cause uneven exchange effect, in the pulling process of steps S4 and S6, the clamp for pulling is in a cube shape, and the perovskite nanowire array is fixed on four sides of the cube-shaped clamp, so that the pulling process can simultaneously perform reaction processing on four perovskite nanowire arrays, the reaction processing efficiency can be improved, and the regularity of the flow of the ion exchange solution is ensured and the ion exchange effect of the perovskite nanowire array is ensured.

According to the preparation method of the full-spectrum perovskite nanowire array provided by the embodiment of the application, the perovskite nanowire array is firstly prepared, and then nanowire parts containing different halogen groups, namely the nanowire parts with different spectrum reflection effects are manufactured by an ion exchange method, so that the single perovskite nanowire array has different color emission at different positions; therefore, the perovskite nanowire array obtained by the preparation method can realize the adjustability of visible light band spectrum in the array according to the change of illumination position, and has the characteristic of full-band spectrum.

The preparation method provided by the embodiment of the application combines the pulling method and the ion exchange method to prepare the full-spectrum perovskite nanowire, has the characteristic of convenient operation compared with the preparation of nanowire single crystals by operations such as electron beam etching, vapor deposition and the like, can also directly carry out ion exchange at a macroscopic angle, and can realize the control of the exchange degree and the exchange position according to the immersion length of the perovskite nanowire in an ion exchange solution, thereby obtaining the full-band spectrum perovskite nanowire array.

The method can be used as a pre-preparation for the preparation of more complex patterned devices.

In addition, in the pulling process, the pulling speed can be adjusted, the soaking time can be changed, the ion exchange effect can be adjusted, and the uniform light emission and the complete structure of the obtained full-spectrum perovskite nanowire array can be ensured.

The physical properties (optical, electrical, magnetic, etc.) of the prepared heterojunction are easier to control.

The preparation method provided by the embodiment of the application directly performs ion exchange at a macroscopic angle, is convenient to operate, has controllable exchange degree and position, and can obtain the perovskite nanowire array of the full-wave-band spectrum.

The embodiment of the application also provides a full-spectrum perovskite nanowire array, which can be prepared by the preparation method, wherein the nanowire of the nanowire array is provided with two heterojunctions, the two heterojunctions divide the nanowire into three crystal segments, and the three crystal segments are respectively composed of perovskite single crystals of which halogen groups are respectively chlorine, bromine and iodine; the perovskite single crystal containing the halogen group bromine is partially positioned in the middle of the nanowire, and the full-spectrum perovskite nanowire array can realize the adjustability of visible light band spectrum in the array according to the change of illumination position and has the characteristic of full-band spectrum.

The present invention is further illustrated by the following specific examples.

Example 1:

s1, mixing methylamine bromide (MABr) and lead bromide (PbBr)₂) Dissolving the raw materials in a mixed solution of N, N-Dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 1:1 according to a molar mass ratio of 1:1 to prepare a precursor solution with a concentration of 20mg/ml, namely preparing MAPbBr with a halogen group of bromine₃A perovskite precursor solution;

s2, taking 20 mu L MAPbBr₃Directly dripping perovskite precursor solution on a silicon dioxide substrate, covering a silicon column template containing a silicon column array on the substrate to form a substrate-perovskite precursor solution-silicon column template sandwich assembly system, placing the substrate-perovskite precursor solution-silicon column template sandwich assembly system in a vacuum oven at the temperature of 60 ℃, heating for 12 hours, crystallizing by utilizing a dewetting behavior, cooling the sandwich assembly system, and disassembling to obtain MAPBBr₃A nano-single crystal array;

s3, preparing two ion exchange solutions with solutes respectively containing chlorine and iodine, wherein,

the preparation process of the chlorine-containing ion exchange solution comprises the following steps: 10mg of oleylamine chloride was dissolved in 10ml of octadecene to obtain an exchange solution containing halogen chloride ions.

The preparation process of the iodine-containing ion exchange solution comprises the following steps: 10mg of oleylamine iodide was dissolved in 10ml of octadecene to obtain an exchange solution containing a halogen iodide ion.

S4, mixing MAPbBr₃The nano single crystal array is fixed on four sides of a clamp of a pulling instrument, so that the nano wires on the array are vertically extended, one end of the nano wire array is soaked in a crucible of the pulling instrument, an exchange solution containing halogen iodide ions is arranged in the crucible, and the soaking length of the nano wire array is MAPBR₃One third of the nano monocrystal array, continuously pulling the perovskite nanowire array at normal temperature, and soaking and pulling for 16 hours, so that the single crystal at the soaking end is replaced by MAPbCl₃And MAPbCl is formed at the position of the soaking liquid level₃-MAPbBr₃A heterojunction perovskite nanowire array;

s5, taking out the MAPbCl₃-MAPbBr₃Washing the part soaked in the ion exchange solution by using chlorobenzene and normal hexane, and drying by using a hot bench to remove the residual organic solution on the surface;

s6, the nanowire array obtained in the step S5 is fixed at the four sides of the clamp of the pulling instrument after being inverted, namely the nanowire array is provided with MAPBCl₃The lower end of the nanowire array is soaked in a crucible of a pulling instrument, an exchange solution containing halogen iodide ions is arranged in the crucible, the soaking length of the nanowire array is one third of the whole length of the nanowire array, the perovskite nanowire array is continuously pulled at normal temperature, the soaking and pulling time is 16 hours, and therefore single crystals at the soaking end are replaced by MAPbI₃And MAPbBr is formed at the position of the soaking liquid level₃-MAPbI₃A heterojunction perovskite nanowire array;

s7, taking out the perovskite nanowire array, cleaning the part soaked in the ion exchange solution by using chlorobenzene and normal hexane, and drying the part in a hot bench to remove the residual organic solution on the surface.

The preparation method obtains a full-spectrum perovskite nanowire array, and the nanowire array is provided with two heterojunctions which are MAPbCl respectively₃-MAPbBr₃Heterojunctions and MAPbBr₃-MAPbI₃Heterojunctions, two of which separate the nanowire into three crystal segments, namely each separated by MAPBCl₃、MAPbBr₃、MAPbI₃A crystal segment composed of the perovskite single crystal of (a).

FIG. 1 shows the full-spectrum perovskite nanowire array positioned at MAPbCl₃-MAPbBr₃Fluorescence photographs of front and rear portions at the heterojunction.

Performing spectrum test on the full-spectrum perovskite nanowire array to obtain MAPbCl shown in figure 2₃-MAPbBr₃The emission spectrum of the heterojunction can combine and reflect MAPBCl at two sides because the heterojunction is an interface region formed by the contact of two crystals₃、MAPbBr₃Spectral properties of the crystal.

FIG. 3 shows the full spectrum perovskite nanowire array positioned at MAPbBr₃-MAPbI₃Fluorescence photographs of front and rear portions at the heterojunction.

Performing spectrum test on the full-spectrum perovskite nanowire array to obtain MAPbBr shown in FIG. 4₃-MAPbI₃The emission spectrum of the heterojunction can combine and reflect MAPbBr at two sides because the heterojunction is an interface region formed by the contact of two crystals₃、MAPbI₃Spectral properties of the crystal.

The full-spectrum perovskite nanowire array can realize the adjustability of visible light band spectrum in the array according to the change of illumination positions, and has the characteristic of full-band spectrum.

Example 2:

s1, adding cesium bromide (CsBr) and lead bromide (PbBr)₂) Dissolving the raw materials into a mixed solution of N, N-Dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) according to the molar mass ratio of 1:1 to prepare a precursor solution with the concentration of 20mg/ml, namely preparing CsPbBr with bromine as a halogen group₃A perovskite precursor solution;

s2, 20 mu L CsPbBr₃The perovskite precursor solution is directly dripped on a silicon dioxide substrate, and a silicon column template containing a silicon column array is covered on the substrate to form a sandwich of the substrate, the perovskite precursor solution and the silicon column templateAssembling the system, heating in a vacuum oven at 60 deg.C for 12 hr, crystallizing by degating, cooling, and disassembling to obtain CsPbBr₃A nano-single crystal array;

s3, preparing two ion exchange solutions with solutes respectively containing chlorine and iodine, wherein,

the preparation process of the chlorine-containing ion exchange solution comprises the following steps: 10mg of oleylamine chloride was dissolved in 10ml of octadecene to obtain an exchange solution containing halogen chloride ions.

The preparation process of the iodine-containing ion exchange solution comprises the following steps: 10mg of oleylamine iodide was dissolved in 10ml of octadecene to obtain an exchange solution containing a halogen iodide ion.

S4, mixing CsPbBr₃The nano single crystal array is fixed on four sides of a clamp of a pulling instrument, so that the nano wires on the array are vertically extended, one end of the nano wire array is soaked in a crucible of the pulling instrument, an exchange solution containing halogen iodide ions is arranged in the crucible, and the soaking length of the nano wire array is CsPbBr₃One third of the nano monocrystal array, continuously pulling the perovskite nanowire array at normal temperature, and soaking and pulling for 16 hours to obtain the single crystal at the soaking end replaced by CsPbCl₃And CsPbCl is formed at the position of the soaking liquid level₃-CsPbBr₃A heterojunction perovskite nanowire array;

s5, taking out the CsPbCl₃-CsPbBr₃Washing the part soaked in the ion exchange solution by using chlorobenzene and normal hexane, and drying by using a hot bench to remove the residual organic solution on the surface;

s6, the nanowire array obtained in the step S5 is fixed on the four sides of the clamp of the pulling instrument after being inverted, namely CsPbCl is provided₃The lower end of the nanowire array is soaked in a crucible of a pulling instrument, an exchange solution containing halogen iodide ions is arranged in the crucible, the soaking length of the nanowire array is one third of the whole length of the nanowire array, the perovskite nanowire array is continuously pulled at normal temperature, the soaking and pulling time is 16 hours, and therefore the single crystal at the soaking end is replaced by CsPbI₃And at the level of the soaking liquidFormation of CsPbBr₃-CsPbI₃A heterojunction perovskite nanowire array;

s7, taking out the perovskite nanowire array, cleaning the part soaked in the ion exchange solution by using chlorobenzene and normal hexane, and drying the part in a hot bench to remove the residual organic solution on the surface.

The preparation method obtains a full-spectrum perovskite nanowire array, and the nanowire array has two heterojunctions on the nanowire, namely CsPbCl₃-CsPbBr₃Heterojunction and CsPbBr₃-CsPbI₃Heterojunctions, two of which separate the nanowire into three crystal segments, namely, each of CsPbCl₃、CsPbBr₃、CsPbI₃A crystal segment composed of the perovskite single crystal of (a); the full-spectrum perovskite nanowire array can realize the adjustability of visible light band spectrum in the array according to the change of illumination positions, and has the characteristic of full-band spectrum.

FIG. 5 shows CsPbCl-localized full-spectrum perovskite nanowire array₃-CsPbBr₃Fluorescence photographs of front and rear portions at the heterojunction.

Performing spectrum test on the full-spectrum perovskite nanowire array to obtain CsPbCl shown in FIG. 6₃-CsPbBr₃The emission spectrum at the heterojunction can combine and reflect CsPbCl at two sides because the heterojunction is an interface region formed by the contact of two crystals₃、CsPbBr₃Spectral properties of the crystal.

FIG. 7 shows CsPbBr of the full-spectrum perovskite nanowire array₃-CsPbI₃Fluorescence photographs of front and rear portions at the heterojunction.

Performing spectrum test on the full-spectrum perovskite nanowire array to obtain CsPbBr shown in figure 8₃-CsPbI₃The emission spectrum of the heterojunction can combine and reflect CsPbBr on two sides because the heterojunction is an interface region formed by the contact of two crystals₃、CsPbI₃Spectral properties of the crystal.

The full-spectrum perovskite nanowire array can realize the adjustability of visible light band spectrum in the array according to the change of illumination positions, and has the characteristic of full-band spectrum.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.