CN110093665B

CN110093665B - Perovskite crystal growth system and manufacturing method thereof

Info

Publication number: CN110093665B
Application number: CN201910421874.7A
Authority: CN
Inventors: 刘董; 赵一英; 张子明
Original assignee: Institute of Materials of CAEP
Current assignee: Institute of Materials of CAEP
Priority date: 2019-05-16
Filing date: 2019-05-16
Publication date: 2020-08-11
Anticipated expiration: 2039-05-16
Also published as: CN110093665A

Abstract

A perovskite crystal growth system and a manufacturing method thereof belong to the field of functional materials. The perovskite crystal growth system is used to produce single crystals of perovskite at a desired temperature. The crystal growth system includes a first liquid reagent and a second liquid reagent arranged in layers. The first liquid reagent is composed of a first molecule, and the first liquid reagent is capable of remaining in a liquid phase at a desired temperature. The second liquid reagent is composed of a second molecule. The first liquid reagent and the second liquid reagent are immiscible and the second liquid reagent is a perovskite and/or a good solvent for a raw material for producing the perovskite. The first liquid reagent and the second liquid reagent have the following definitions: at the desired temperature, the second liquid reagent is capable of detaching from the crystal growth system as a second molecule through the gaps between the first molecules. The perovskite manufacturing method in the examples enables single crystal perovskite manufacturing in a highly operable manner.

Description

Perovskite crystal growth system and manufacturing method thereof

Technical Field

The application relates to the field of functional materials, in particular to a perovskite crystal growth system and a manufacturing method thereof.

Background

In recent years, Metal Halide Perovskite (MHP) materials have been receiving much attention because they have excellent photoelectric properties such as long carrier lifetime, high optical absorption coefficient, and low defect state density. Based on the excellent properties of materials, MHP has enjoyed great success in the fields of solar cells, optical sensors, light emitting devices and the like.

At present, perovskite photoelectric devices are mostly assembled by MHP polycrystalline thin films. Compared with MHP polycrystalline thin films, single crystals thereof have been one of the important research directions of MHP optoelectronic devices in the following because they have fewer grain boundary defects, better stability and higher crystal quality.

The accurate regulation and control of the MHP single crystal growth are realized, and the method becomes important for improving the quality of the MHP single crystal and the repeatability of a single crystal growth process.

The information disclosed in this background section is only for enhancement of understanding of the general background of the application and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

Based on the defects of the prior art, the application provides a perovskite crystal growth system and a manufacturing method thereof, so as to partially or completely improve and even solve the problem that single crystal perovskite with stable performance cannot be manufactured stably and repeatedly.

The application is realized as follows:

in a first aspect, examples of the present application provide a perovskite crystal growth system.

Such a crystal growth system can be used to produce single crystals of perovskites at a desired temperature.

The crystal growth system includes a first liquid reagent and a second liquid reagent arranged in layers.

Wherein the first liquid reagent is composed of a first molecule and the first liquid reagent is capable of remaining in a liquid phase at a desired temperature.

Wherein the second liquid reagent is comprised of a second molecule.

The first liquid reagent and the second liquid reagent are immiscible and the second liquid reagent is a perovskite and/or a good solvent for a raw material for producing the perovskite.

The first liquid reagent and the second liquid reagent have the following definitions:

at the desired temperature, the second liquid reagent is capable of detaching from the crystal growth system as a second molecule through the gaps between the first molecules.

The above crystal growth system is a liquid phase system capable of dissolving a perovskite or a raw material for producing the perovskite, and precipitating the perovskite as a single crystal by volatilization of a solvent at an appropriate temperature to realize growth of a single crystal perovskite.

In combination with the first aspect, in some alternative examples of the first possible implementation of the first aspect of the present application, the first liquid reagent and the second liquid reagent have the same or different densities.

Optionally, the first liquid reagent and the second liquid reagent have different densities, and the density of the first liquid reagent is greater than the density of the second liquid reagent.

The first liquid reagent and the second liquid reagent may have appropriate density levels depending on their compositions. For example, under normal gravitational forces, the density of the first liquid reagent is greater than the density of the second liquid reagent. Thus, in the container, the first liquid reagent may be located on top of the second liquid reagent, thereby enclosing the second liquid reagent (including the perovskite therein or a material from which it is made) in the container under certain conditions, and if necessary passing the second liquid reagent through the first liquid reagent to achieve the making of a single crystal perovskite.

In some alternative examples of the second possible implementation of the first aspect of the present application in combination with the first aspect, the first liquid reagent comprises a non-polar organic molecule.

Alternatively, the non-polar organic molecule comprises polydimethylsiloxane.

In combination with the first aspect or the second possible embodiment of the first aspect, in some alternative examples of the third possible embodiment of the first aspect of the present application, the second liquid reagent comprises a polar organic molecule.

Alternatively, the polar organic molecule comprises gamma-hydroxybutyrate lactone, N-dimethylformamide or dimethylsulfoxide.

The selection of the components of the first liquid reagent and the second liquid reagent are mutually limited and adapted. The composition of the second liquid reagent is substantially identified according to the specific characteristics of the composition of the first liquid reagent. Reasonable selection and mutual matching of the two can be better used for manufacturing the single crystal perovskite.

In a second aspect, examples of the present application provide a method of fabricating a perovskite.

The perovskite manufacturing method can be substantially performed by the crystal growth system described above.

The manufacturing method comprises the following steps:

controlling the temperature of the precursor liquid to enable the temperature of the precursor liquid to be at a desired temperature and to be kept for a desired time;

wherein the precursor liquid is obtained by dissolving a perovskite or a raw material for producing a perovskite in a second liquid reagent in a crystal growth system.

The above production method precisely adjusts the supersaturation degree of the solute by the change in the solubility of the solute in the solvent according to the content of the solvent, so as to achieve single crystal growth of perovskite. The manufacturing method has simple process flow and easy implementation, and can grow products with large size.

In combination with the second aspect, in some optional examples of the first possible implementation of the first aspect of the present application, the method of making a precursor liquid includes: and sequentially carrying out a first precursor manufacturing step and a second precursor manufacturing step.

Wherein the first precursor manufacturing step comprises: dissolving the perovskite or a raw material for manufacturing the perovskite in a second liquid reagent, optionally carrying out a filtration treatment, to obtain a first precursor;

wherein the second precursor manufacturing step comprises: a first liquid reagent is added to the first precursor.

The step-by-step process can be selected to implement the above steps based on the difficulty of the process. That is, in the crystal growth system described above, the crystal growth system can be constructed step by step in the process in which the perovskite manufacturing method is performed.

In combination with the second aspect, in some alternative examples of the second possible embodiment of the second aspect of the present application, the desired temperature is 5 to 60 ℃;

optionally, the desired temperature is 12-50 ℃;

optionally, the desired temperature is 23-43 ℃;

alternatively, the desired temperature is 38-47 ℃.

Depending on the second liquid reagent capable of dissolving the perovskite or its manufacturing raw material, the desired temperature may vary accordingly. Generally, the desired temperature may volatilize the second liquid reagent.

In some alternative examples of the third possible embodiment of the second aspect of the present application in combination with the second aspect, the perovskite has the general chemical formula ABX₃；

Wherein A is a monovalent organic cation or inorganic cation;

alternatively, B is a divalent metal cation;

alternatively, X is a monovalent halide anion;

alternatively, the inorganic cation comprises cesium; the organic cation comprises methylamine, methyl ether, ethylamine, dimethylamine and guanamine;

alternatively, the metal cation comprises germanium, tin, lead;

alternatively, the halide anion comprises iodine, bromine, chlorine.

As an alternative to perovskite, it may alternatively be employed with metal-halogenated perovskites. The high-quality single crystal metal halogenated perovskite can be applied to various fields, and the high-quality transformation of electronic components is realized.

In some alternative examples of the fourth possible embodiment of the second aspect of the present application, in combination with the third possible embodiment of the second aspect, the feedstock for making the perovskite comprises separately provided AX and BX₂。

The metal-halogenated perovskite can be formed and produced by the manufacturing raw materials thereof in the process of the manufacturing method. In other words, the methods exemplified herein may be used for polycrystalline to single crystal conversion of perovskites. For polycrystalline metal-halogenated perovskites that are provided directly (purchased or otherwise fabricated), they can also be re-fabricated as single crystal metal-halogenated perovskites by the crystal growth systems and methods provided in the examples of this application. Alternatively, a single crystal perovskite may be produced directly from the raw material.

In some alternative examples of the fifth possible embodiment of the second aspect of the present application in combination with the second aspect, the perovskite is single crystalline and up to millimeters in size.

In the above implementation, the crystal growth system and the manufacturing method provided in the examples are a solution based on a liquid phase system. Single crystal perovskites can grow progressively from a liquid phase system. The perovskite or a reaction raw material thereof can be dissolved in a liquid phase system and the supersaturation is changed as the second liquid reagent dissolving the perovskite is gradually reduced to achieve growth of a high quality perovskite single crystal.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the prior art of the present application, the drawings used in the description of the embodiments or the prior art will be briefly described below.

FIG. 1 is a schematic structural diagram of a reagent tube in an embodiment of the present application;

FIG. 2 shows a schematic representation of a unit cell of a metal-halogenated perovskite;

FIG. 3 shows a schematic of the layered structure of reagents in a container as provided in example 2 of the present application;

FIG. 4 shows a schematic of a single crystal perovskite grown in a vessel as provided in example 2 of the present application;

FIG. 5 shows an XRD diffraction pattern of the single crystal perovskite in example 2;

fig. 6 shows an XRD diffraction pattern of the {100} crystal plane family of the single-crystal perovskite in example 2.

Icon: 100-reagent tube; 101-a cover body; 102-a tubular body; 201-a first liquid reagent; 202-a second liquid reagent; 301-reserved area; 302-opening; 303-a bottom wall; 401-a first reagent; 402-a second reagent; 403-perovskite single crystals.

Detailed Description

Single crystal perovskites have significantly better properties than polycrystalline perovskites, e.g., fewer grain boundary defects. Therefore, the device manufactured by adopting the single crystal perovskite can obtain some favorable performances, is beneficial to improving the application performance of the device and obtains good performance effect.

It is necessary to produce high quality perovskites. Therefore, in order to obtain high-quality single-crystal perovskites, careful examination of the production scheme thereof is required.

The inventors tried to grow and produce a single crystal perovskite in a liquid phase system. Attempted fabrication methods include low temperature supersaturation, inverse temperature growth, antisolvent-gas phase assisted crystallization, and seed crystal assisted liquid phase growth. In general, the inventors have used temperature and solvent regulation to increase the supersaturation of MHP in the precursor solution to achieve slow ordered growth of MHP single crystals.

Wherein the temperature regulation growth technology is as follows: according to the relation between the solubility of MHP solute in different solvents and the temperature, the supersaturation degree of MHP precursor liquid is changed by heating, cooling, spatial temperature gradient distribution and other modes, and then the ordered growth of MHP crystals is realized.

Wherein, the solvent regulation growth technology is as follows: the supersaturation degree of the MHP precursor solution is changed by natural volatilization or a mode of extracting a second liquid reagent by an anti-solvent, and then the ordered growth of the perovskite single crystal is realized.

However, in practice, the inventors have recognized that the above solution has some problems as follows:

firstly, temperature control growth technology such as temperature reduction, temperature rise, temperature gradient and the like. Although the effective growth of MHP single crystal can be realized, the introduction of thermal convection and temperature gradient in the temperature control process not only can introduce defects in the crystal, but also can influence the regulation and control of the crystal growth process, especially the control of the temperature gradient distribution in the space.

And solvent regulation and control technologies such as solvent volatilization, anti-solvent extraction and the like. Although it is possible to grow an MHP single crystal under a constant temperature condition, it is difficult to grow a large-sized MHP single crystal. In addition, since the method grows a single crystal under the action of air or an anti-solvent gas phase atmosphere, the process thereof is difficult to be precisely controlled.

In view of the above, the inventors tried to research and proposed a scheme for realizing precise control of MHP single crystal growth to improve the quality of MHP single crystal and the repeatability of single crystal growth process.

Embodiments of the present application will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present application and should not be construed as limiting the scope of the present application. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following description will be made specifically for the perovskite crystal growth system and the method for manufacturing the same in the embodiments of the present application:

as described above, the perovskite crystal growth system proposed in the examples of the present application can be used to produce a single crystal of perovskite under appropriate conditions. The appropriate conditions therein may generally refer to the temperature at which the crystal growth system is at (hereinafter referred to as the desired temperature). During the single crystal fabrication of the perovskite, the temperature may be selected to be a constant temperature. However, the constant temperature may be a certain temperature value arbitrarily selected within a wide range.

The perovskite crystal growth system in the example is a liquid phase system (system).

In practice, when perovskite production is carried out, the liquid phase perovskite crystal growth system is usually housed in a container, and the perovskite production or preparation process may be carried out under an open environment and conditions (e.g., atmospheric air). Such containers may be, for example, test tubes, beakers, reagent bottles, glassware, and the like.

Such containers typically have a bottom wall, side walls connected to the bottom wall, and an opening opposite the bottom wall. The liquid phase system is injected into the vessel and the remaining opening is open to the atmosphere. Alternatively, the opening is closed by a lid, but is able to communicate to some extent with the atmosphere. Further, either the opening is closed off from the atmosphere by a lid, but a portion of the air may be reserved therein or be evacuated (i.e., the evacuated container is filled with the aforementioned liquid phase system). Alternatively, the container is a closed shell structure and may be filled with the aforementioned liquid phase system through holes or gaps, etc.

As mentioned above, the crystal growth system in the examples of the present application is a liquid phase system, and the liquid phase system may also be referred to as a composition for producing single crystal perovskites in some examples. The composition comprises a first component and a second component. The first composition and the second composition are different materials, and both can be single-component materials or multi-component mixtures. In the following discussion, the first composition is referred to as a first liquid reagent and the second composition is referred to as a second liquid reagent.

Further, in conjunction with the aforementioned container, the crystal growth system comprised of the container and the composition may also be considered a kit for conducting single crystal perovskite production. In using the kit, perovskite-related raw materials are added to the kit, and then the kit is subjected to an appropriate temperature to produce single crystal perovskites. Further, a crystal growth system formed by combining a temperature control device (e.g., a heater) with a container and a composition can also be considered as a production cassette for performing single crystal perovskite production.

In an example, a crystal growth system includes a first liquid reagent and a second liquid reagent arranged in layers. A first liquid reagent and a second liquid reagent arranged in layers. And the layered manner of the two is also maintained in the container. For example, in embodiments, the first liquid reagent is located in an upper layer and the second liquid reagent is located in a lower layer. A container (referred to as a reagent tube 100) includes a lid 101 and a tube 102. The second liquid reagent 202 is enclosed in the isolation region between the first liquid reagent 201 and the bottom wall 303, while the first liquid reagent 201 is in the reserve region 301 between the second liquid reagent 202 and the opening 302 (the lid 101). The reserved area 301 may be air filled. For ease of understanding, such a scheme is illustrated in fig. 1.

In an example, the first liquid reagent may be selected as follows. It may be selected to be a non-polar organic polymer. Firstly, the organic polymer exists in a liquid phase state within the temperature range of the growth of the single crystal perovskite; next, the organic polymer is mixed with a perovskite precursor solution (including a second liquid reagent, which may also include dissolved species such as AX and BX)₂A second liquid reagent); third, the density of the organic polymer solution is less than that of the perovskite precursor solution, so that the organic polymer solution floats on the upper layer (or the first liquid reagent is on the second liquid reagent).

In an example, the second liquid reagent may be selected as follows. It may be selected as an organic small molecule solvent. First, it is capable of dissolving perovskite related raw materials (such as AX and BX which will be mentioned later)₂) (ii) a Second, the small organic molecule is a polar molecule, preventing mutual solubility with the first liquid reagent (e.g., a non-polar organic polymer).

For ease of illustration, the first liquid reagent definition is made up of a first molecule and the second liquid reagent definition is made up of a second molecule. It should be noted that the first liquid reagent and the second liquid reagent may be single-component purified substances or may be a composition composed of multiple components. In other words, the first molecule constituting the first liquid reagent may be a defined compound molecule, or may be a combination of various (at least two, such as three, four, five, etc.) compound molecules. Similarly, the second molecules that make up the second liquid reagent may be defined molecules of the compound, or may be a combination of molecules of various compounds (at least two, such as three, six, seven, etc.). In the subsequent examples, both the first and second liquid reagents are provided and used as a single component substance, but this does not mean that both must be single components.

In addition, the first liquid reagent can remain in a liquid phase at a desired temperature. That is, in the single crystal production process of perovskite, the first liquid reagent is liquid, so that the second liquid reagent can be covered and enclosed with the first liquid reagent.

Further, the first liquid reagent and the second liquid reagent are immiscible and when mixed together are typically separated into two distinct parts. For example, without limitation, water and oil are generally immiscible; water and ethanol are miscible. Because the first liquid reagent and the second liquid reagent are immiscible, the first liquid reagent and the second liquid reagent can be stored in the container to be separated independently according to the difference of the densities of the first liquid reagent and the second liquid reagent.

Further, the second liquid reagent is a good solvent for the perovskite (first raw material) and/or the raw material for producing the perovskite (second raw material). I.e. the perovskite is capable of being dissolved in the second liquid reagent; alternatively, the raw materials for making the perovskite may be dissolved in a second liquid reagent; alternatively, both the perovskite and the raw material for producing the perovskite may be dissolved in the second liquid reagent. For example, sodium chloride crystals may be dissolved in water and when the water is removed (e.g., thermally evaporated), sodium chloride precipitates as crystals. The first liquid reagent and the second liquid reagent have the same or different densities. In an alternative example, the first and second liquid reagents are selected to have different densities, as desired, and the density of the first liquid reagent is greater than the density of the second liquid reagent. As such, the first liquid reagent is able to float above the second liquid reagent under natural gravitational conditions. For example, oil may float on the surface of seawater.

In an example, the perovskite and its fabrication raw materials are dissolved in the second liquid reagent, and upon removal of the second liquid reagent, a single crystalline perovskite may be formed. The properties of the first liquid reagent and the second liquid reagent are set forth and defined by the following definitions: at the desired temperature, the second liquid reagent is capable of detaching from the crystal growth system as a second molecule through the gaps between the first molecules.

For example, in a system composed of a first liquid reagent, a second liquid reagent, and a raw material for producing perovskite, the second liquid reagent is heated to evaporate at the desired temperature and passes through the first liquid reagent. The perovskite raw material may be reacted to gradually form a single crystal perovskite (solid), which cannot pass through the first liquid reagent but remains (without being dissolved by the first liquid reagent) under the first liquid reagent. And then removing the first liquid reagent or taking out the generated single crystal perovskite from the liquid to obtain the product.

In other words, the second liquid reagent being capable of detaching from the crystal growth system with the second molecules passing through the gaps between the first molecules can be verified by such an assay, and the first liquid reagent and the second liquid reagent can also be screened by such an assay. Namely: the first liquid-phase substance and the second liquid-phase substance which are mixed and can be layered (the first liquid-phase substance is on the upper layer); the second liquid-phase substance may dissolve the perovskite-related raw material; the second liquid phase can be eliminated gradually by heating and the appropriate amount (sufficient) of the first liquid phase is always present in the process.

As a more operative example, the first liquid reagent may optionally comprise a non-polar organic molecule. Such a non-polar organic molecule may be, for example, polydimethylsiloxane. Correspondingly, the second liquid reagent may optionally comprise a polar organic molecule. The polar organic molecule may be, for example, gamma-hydroxybutyrate lactone, N-dimethylformamide or dimethyl sulfoxide. In some such examples, the temperature (desired temperature) for enabling the second liquid reagent to recover while the first liquid reagent is maintained in a liquid state may be selected to be 5 to 60 ℃. Optionally, the desired temperature is 12-50 ℃; optionally, the desired temperature is 23-43 ℃; alternatively, the desired temperature is 38-47 ℃. In addition, it should be recognized that the temperature during the growth of the single crystal can be any value within the foregoing ranges, as well as a range of values. In other words, in the case where the temperature is ensured to be appropriate (the single crystal growth can be performed), the temperature can be appropriately adjusted so as to control the growth rate, the mode, and the like of the single crystal. For example, if the growth temperature (desired temperature) of the single crystal is selected to be 30 ℃. The temperature during the growth of the single crystal can be 30 ℃, or can be properly (intentionally) fluctuated and adjusted between 29 ℃ to 31 ℃ according to the needs.

While for single crystalline perovskite products, it can be of various types, selected for use as desired. In the examples of the present application, the perovskite has the general chemical formula ABX₃。

Wherein A is a monovalent organic cation or inorganic cation. Optionally, the inorganic cation comprises cesium (Cs)⁺) (ii) a The organic cation comprises methylamine (CH)₃NH₃ ⁺MA), methyl ether (CH (NH)₂)₂ ⁺FA), ethylamine (CH)₃CH₂NH₃ ⁺EA), dimethylamine (NH)₂(CH₃)₂ ⁺DEA), guanamine (C (NH)₂)₃ ⁺GA), etc.;

wherein B is a divalent metal cation. Optionally, the metal cation comprises germanium (Ge)²⁺) Tin (Sn)²⁺) Lead (Pb)² ⁺) And the like.

Wherein X is a monovalent halide anion. Alternatively, the halide anion comprises iodine (I)^-) Bromine (Br)^-) Chlorine (Cl)^-) And the like.

Thus, by way of example, the perovskite may be, for example, MAPbBr₃、FASnI₃、GAGeBr₃、EAGeBr₃、DEAPbCl₃And so on.

Such perovskites as mentioned above are commonly referred to as metal-halogenated perovskites (general formula ABX)₃) The unit cell is cubic crystal, and the structure is shown in fig. 2. Cation at A position (e.g. Cs)⁺、MA⁺、FA⁺) On the eight vertices of the cubic lattice; divalent metal cations in the B-position (e.g. Ge)²⁺、Sn²⁺、Pb²⁺) At the body center of the cubic lattice; halogen anions monovalent in position X (e.g. I)^-、Br^-、Cl^-) At six face-center positions of the cubic lattice.

The starting materials for the perovskite used to make the single crystal may be AX and BX, which are provided separately₂. Therefore, here, the fact that the second liquid reagent is a good solvent for the raw material for producing the perovskite means that: the second liquid reagent being AX and BX₂A good solvent of (2).

Based on the aforementioned perovskite crystal growth system, a method for producing a (single crystal) perovskite is also provided in the examples. The fabrication method may be implemented by a crystal growth system. It should be noted that: the crystal growth system is prepared in advance before being used for manufacturing the single crystal perovskite; alternatively, the crystal growth system is constructed in a process for making single crystal perovskites.

In one example, a method of making a perovskite includes:

the temperature of the precursor liquid is controlled to be at a desired temperature and maintained for a desired time.

Wherein the precursor solution is prepared by mixing perovskite (polycrystal, first raw material) or raw material for perovskite production (second raw material, such as the aforementioned AX and BX)₂) A second liquid reagent dissolved in the crystal growth system.

In such an example, the crystal growth system is prepared in advance, and the second liquid reagent also dissolves the first raw material or the second raw material. The crystal growth system, which is prepared in advance, is placed in a container, and the container may need to be configured or modified to facilitate subsequent dissolution of the first material or the second material in the second liquid reagent. For example, in the reagent tube 100 shown in fig. 1, the tube 102 may have an opening (not shown) corresponding to the sidewall for accommodating the second liquid reagent 202, and the opening and closing of the opening and closing are controlled by a switch. In this manner, the liquid-phase crystal growth system is injected into the reagent tube 100, and then the second raw material is injected into the tube through the opening as needed, so that it can be mixed with the second liquid reagent by dissolution.

In this embodiment, the precursor solution may be directly heated to control the temperature. For example by providing a heat source for heating by heat convection or by means such as microwaves. The heat convection heat transfer may be performed by blowing hot air to a portion of the container corresponding to the second liquid reagent; alternatively, heating is by a heating wire.

In another approach, the crystal growth system is constructed during the fabrication process of the single crystal perovskite, and then in a suitable step, the second liquid reagent dissolves the first or second raw material. In other words, in such an example, the precursor liquid is distributively produced and carried out during the production method of the single crystal perovskite, and for example, the method of producing the precursor liquid includes: and sequentially carrying out a first precursor manufacturing step and a second precursor manufacturing step.

Wherein the first precursor manufacturing step comprises: the perovskite or a raw material for making the perovskite is dissolved in a second liquid reagent, optionally subjected to a filtration process, to obtain a first precursor. The second precursor manufacturing step comprises: a first liquid reagent is added to the first precursor.

In the first precursor preparation step, the dissolution of the perovskite in the second liquid reagent or the preparation of the raw material for the perovskite may be carried out under stirring or in the presence of ultrasound. In addition, the first precursor may be subjected to a filtration treatment in combination with consideration of solubility, possible presence of impurities, and the like, to obtain an ideal solution of the first precursor. Without limitation, the dissolution process may be carried out at room temperature (e.g., 20-27 ℃), and the dissolution process may be completed within 24-48 hours.

The addition of the first liquid reagent to the first precursor may be such that the first liquid reagent is added slowly, as may be dropwise.

After dissolving the perovskite or the raw material for producing the perovskite in the second liquid reagent of the crystal growth system, by maintaining the entire system at an appropriate temperature (desired temperature), the second liquid reagent is gradually volatilized and removed by the first liquid reagent. In such a process, the degree of supersaturation of the solute in the (remaining) second liquid reagent is controlled, enabling growth of a high quality perovskite single crystal.

It is contemplated that in some examples, the boiling point of the first liquid reagent may be above the desired temperature and the boiling point of the second liquid reagent may be below or equal to the desired temperature.

Alternatively, in other examples, the boiling point (first boiling point) of the first liquid reagent may be less than or equal to the desired temperature, and the boiling point (first boiling point) of the second liquid reagent may be less than or equal to the desired temperature, but the volatilization rate of the first liquid reagent at the desired temperature is less than the volatilization rate of the second liquid reagent at the desired temperature. In this manner, during the fabrication of single crystal perovskites at the desired temperature, there is always a first liquid reagent coating over a second liquid reagent, isolating the second liquid reagent from the external environment (e.g., air).

The growth of the entire perovskite single crystal may be stopped by completion of volatilization of the second liquid reagent or by complete precipitation of the perovskite single crystal. In some examples, by the above steps, single crystal perovskites up to millimeter in size can be obtained by the foregoing fabrication method. The size of the obtained single crystal perovskite is typically related to a number of factors, such as the amount of raw materials constituting the perovskite (correspondingly also referred to as the amount of the second liquid reagent), the temperature selection during the manufacturing process, the composition of the first liquid reagent and the second liquid reagent, the type selection.

In the example of the application, a method for growing a metal halogenated perovskite single crystal is provided based on that small molecular solvents (organic small molecular solvents) such as GBL (gamma-hydroxy butyrate lactone), DMF (N, N-dimethylformamide) and DMSO (dimethyl sulfoxide) in an MHP precursor solution can effectively pass through the molecular gap of a liquid-phase nonpolar organic polymer material.

Based on the influence of size effect and concentration gradient, small molecules of solvents such as GBL, DMF and DMSO can effectively pass through the gaps of nonpolar organic macromolecules, perovskite precursor solute is blocked in the precursor solution, the volatilization speed of the small molecules of the solvents is regulated and controlled by means of different molecular kinetic energies at different temperatures, the supersaturation degree of a system can be accurately controlled, and then the growth of high-quality perovskite single crystals is realized.

Based on the above description, the perovskite crystal growth system and the manufacturing method in the examples of the present application have at least the following advantages:

(1) the manufacturing method is simple and convenient to operate and high in practicability. The nonpolar organic polymer solution is applied to the growth of MHP single crystals for the first time, and based on the shuttleability of organic solvent micromolecules such as GBL, DMF and DMSO in polymer gaps, the volatilization speed of the solvent micromolecules can be regulated and controlled by means of the influence of temperature on the kinetic energy of the micromolecules, so that the precise control of the volatilization of the solvent micromolecules in the MHP precursor solution is realized.

(2) In the manufacturing method, ABX₃The single crystal growth process has good repeatability.

(3) The scheme in the application example combines the temperature-controlled single crystal growth technology and the solvent volatilization control technology, and realizes the growth of the MHP single crystal under the condition of low temperature (such as 5 ℃) for the first time. The MHP single crystal grows under the low temperature condition, so that the crystal defect caused by the thermal convection to the crystal growth can be effectively avoided, the energy loss of the single crystal growth can be reduced, and the economic cost can be further reduced.

In order to make the solution in the examples of the present application easier for those skilled in the art to implement, the perovskite crystal growth system and the manufacturing method thereof are further described in detail below with reference to the examples.

Example 1

For making (single crystal) MAPbBr₃Wherein MA is methylamine (CH)₃NH₃ ⁺) A cation.

The crystal growth system includes N, N-Dimethylformamide (DMF) as the second liquid reagent and Polydimethylsiloxane (PDMS) as the first liquid reagent.

Example 2

This example provides the fabrication of (single crystal) MAPbBr Using the crystal growth System in example 1₃The method of (1), comprising the following steps.

(1) MABr and PbBr in a stoichiometric molar ratio of 1:1₂The medicine is put into a solvent as a solute to prepare MAPbBr with the molar concentration of 0.5-1.5mol/L₃I.e. the first precursor liquid sample.

(2) The first precursor solution sample is placed at room temperature and stirred uniformly for 32 hours until MAPbBr is reached₃The solute is completely dissolved in the DMF solvent, and after filtration, a suitable amount is taken and placed in a clean glass vessel to obtain a second precursor solution sample (first reagent 401).

(3) Liquid phase polydimethylsiloxane (PDMS, second reagent 402) was added to the second precursor solution sample, the liquid phases were layered, and the non-polar organic polymer PDMS solution floated on the top layer, see fig. 3.

(4) Placing the sample obtained in the step (3) at 5 ℃ for heat preservation storage, and after a period of time, MAPbBr₃A single crystal (perovskite single crystal 403) appears, the size of which can be grown to the millimeter scale, as shown in fig. 4.

Experimental example 1

The perovskite single crystal produced from example 2 was ground into powder and tested to obtain its XRD diffraction pattern. As a result, as shown in FIG. 5, MAPbBr was confirmed from the XRD diffraction pattern₃Cubic crystal structure of single crystal.

MAPbBr₃The XRD diffraction pattern obtained for the largest face of the single crystal is shown in fig. 6. Compared with the data of fig. 5, fig. 6 only has the diffraction peak of the {100} crystal plane family, and the peak positions are (100), (200), (300) and (400) crystal planes in sequence from left to right. Comparison of the graphs in FIGS. 5 and 6 shows that the grown crystal is MAPbBr₃And (3) single crystal.

While particular embodiments of the present application have been illustrated and described, it would be appreciated that many other changes and modifications can be made without departing from the spirit and scope of the application. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this application.

Claims

1. A method of producing a perovskite, the method being capable of being carried out by a composition, the method comprising:

controlling the temperature of the precursor liquid to enable the temperature of the precursor liquid to be at a desired temperature and to be kept for a desired time, wherein the desired temperature is 5 ℃;

wherein the precursor liquid is obtained by dissolving the perovskite or a raw material for producing the perovskite in a second liquid reagent in the composition;

the composition includes a first liquid reagent composed of a first molecule capable of remaining in a liquid phase at the desired temperature and a second liquid reagent composed of a second molecule arranged in layers;

the first liquid reagent and the second liquid reagent are immiscible and the second liquid reagent is a good solvent for the perovskite and/or raw materials for making the perovskite;

at the desired temperature, the second liquid reagent is capable of detaching from the composition as the second molecule passes through the gaps between the first molecules;

wherein the first molecule is polydimethylsiloxane;

wherein the second molecule is N, N-dimethylformamide;

wherein the perovskite is MAPbBr₃；

Wherein the raw materials for preparing the perovskite are MABr and PbBr₂。

2. The method of manufacturing the perovskite according to claim 1, wherein the method of manufacturing the precursor liquid includes: a first precursor manufacturing step and a second precursor manufacturing step which are sequentially performed;

the first precursor manufacturing step comprises: dissolving the perovskite or the raw material for manufacturing the perovskite in the second liquid reagent, and filtering to obtain a first precursor;

the second precursor manufacturing step comprises: the first liquid reagent is added to a first precursor.

3. The method of making the perovskite of claim 1, wherein the perovskite is single crystalline and up to millimeters in size.