High-chirality one-dimensional perovskite single crystal and preparation method thereof

Abstract

The invention provides a high-chirality one-dimensional perovskite single crystal and a preparation method thereof, and the preparation method comprises the following steps: 1, using lead oxide, hydriodic acid, hypophosphorous acid and (R)-1-(1-naphthyl) ethylamine to prepare a white precipitate in a glass bottle; 2, heating the glass bottle, and continuously stirring the liquid containing the white precipitate by using magnetons; and 3, cooling the glass bottle to obtain the single crystal. According to the preparation method of the high-chirality one-dimensional perovskite single crystal, provided by the invention, a material (R)-1-(1-naphthyl) ethylamine with ultrahigh chirality is selected as positive ions of perovskite, so that the grown perovskite single crystal also has ultrahigh chirality; the pure one-dimensional chiral perovskite single crystal which is yellow is obtained by adjusting the ratio of lead oxide to (R)-1-(1-naphthyl) ethylamine; and the obtained single crystal has a flat surface, the size can be as long as 6mm, and the application field of the single crystal is widened.

Description

Technical Field

[0001] The invention belongs to the field of optoelectronic materials and devices, and particularly relates to a high-chirality one-dimensional perovskite single crystal and a preparation method thereof. Background Art

[0002] As a photoelectric functional material with broad application prospects, perovskite materials have demonstrated excellent performance in photovoltaic cells, photodiodes, photocatalysis and other fields. Chirality refers to the symmetry property of an object or molecule, that is, they cannot overlap with their mirror image. The chirality phenomenon is particularly important in perovskite materials. In the perovskite lattice, due to the existence of chirality, electrons are affected by rotational forces when moving in the lattice, resulting in a spiral spin vortex structure. This vortex structure has an important influence on electron transport and band structure, and can affect the conductive properties and magnetic behavior of the material. Perovskite materials have a large nonlinear polarization response, which enables them to show excellent performance in optical devices. The introduction of chirality further enhances the nonlinear optical effect. The rotation of chiral molecules or chiral structural units affects the absorption, emission and scattering of light, causing nonlinear changes in optical properties. These nonlinear optical effects make chiral perovskite materials have broad application potential in optical communications, laser technology and optical information processing.

[0003] The commonly used methods for preparing chiral perovskite single crystals are solution method and solid phase method. The solution method is to add chiral molecules to the solution and realize chirality through their interaction with ions during the growth of perovskite crystals. The solution method often requires precise control of conditions such as solution concentration, reaction temperature and pH value. The solution method is relatively simple and easy to operate, and does not require complex equipment and harsh conditions such as high temperature and high pressure. However, due to the fast crystal growth rate of chiral perovskite single crystals prepared by the solution method, it is easy to form polycrystalline or fine particles under supersaturated conditions, and the quality of the prepared single crystals is poor. Poor crystal quality will affect its optoelectronic properties and device stability, limiting the application of one-dimensional chiral perovskite single crystals. The solid phase method is to mix the precursors together and sinter them at high temperature. During the sintering process, the solid phase material undergoes a chemical reaction at high temperature to form a perovskite structure, and then after appropriate temperature control and treatment, it gradually grows into a single crystal structure in the solid phase. Compared with the solution method, the solid-phase method has a high yield, good crystal quality, and is suitable for large-scale production. However, the solid-phase method requires high temperature conditions, which increases energy consumption and places higher requirements on equipment. In addition, the solid-phase reaction rate is slow, and the synthesis of single crystals requires a long reaction time, resulting in low preparation efficiency.

[0004] Therefore, the current challenge is to develop a method to prepare high-quality high-chirality one-dimensional chiral perovskite single crystals to meet their application needs in the fields of photonics, catalysts, detection and quantum computing. Summary of the invention

[0005] In view of the above problems, the present invention provides a high-chirality one-dimensional perovskite single crystal and a preparation method thereof.

[0006] The method for preparing a high-chirality one-dimensional perovskite single crystal provided by the present invention comprises the steps of:

[0007] 1. Prepare a white precipitate in a glass bottle using lead oxide, hydroiodic acid, hypophosphorous acid and (R)-1-(1-naphthyl)ethylamine;

[0008] 2. heating the glass bottle and continuously stirring the liquid containing the white precipitate therein with a magnetic rod;

[0009] 3. Cool the glass bottle to obtain a single crystal.

[0010] further,

[0011] In the step 1,

[0012] First, use a balance to weigh 180-270 mg of lead oxide and put it into a clean and dry 20 ml glass bottle with a lid. Then use a pipette to measure 3-5 ml of hydroiodic acid and put it into the glass bottle. Then use a pipette to measure 400-600 μl of hypophosphorous acid and put it into the glass bottle.

[0013] further,

[0014] In the step 1,

[0015] First, use a balance to weigh 225 mg of lead oxide and put it into the glass bottle, then use a pipette to measure 4 ml of hydroiodic acid and put it into the glass bottle, and then use a pipette to measure 500 μl of hypophosphorous acid and put it into the glass bottle.

[0016] further,

[0017] In the step 1,

[0018] After the white precipitate is formed, the magnetic particle is placed in the glass bottle and the lid is screwed on to seal it.

[0019] further,

[0020] In the step 2,

[0021] The above glass bottle is placed in an oil bath heating magnetic stirring device, and the oil temperature is set to rise evenly to a final temperature of 120-180 degrees Celsius (℃) within one hour. During this period, the magnetic stirring is continued. Finally, it stays at the final temperature for 5-15 minutes, and the solution becomes a clear yellow liquid. The rotation speed during stirring is 400-1200 revolutions per minute.

[0022] further,

[0023] In the step 2,

[0024] The oil temperature was set to rise evenly to a final temperature of 150 degrees Celsius within one hour, and then stay at the final temperature for 10 minutes, with a stirring speed of 800 revolutions per minute.

[0025] further,

[0026] In the step three,

[0027] The glass bottle is transferred to a temperature control device, and the temperature is set to be uniformly cooled from the final temperature to 20-40 degrees Celsius, with an average cooling rate of 2-3 degrees Celsius per hour. After 45-50 hours of cooling, the single crystal is obtained.

[0028] further,

[0029] In the step three,

[0030] The temperature was set to be uniformly cooled from the final temperature to 30 degrees Celsius, with an average cooling rate of 2.5 degrees Celsius per hour. The cooling was completed after 48 hours to obtain the single crystal.

[0031] further,

[0032] The lead oxide has a purity of 99%, the concentration of hydroiodic acid is 57%, the concentration of hypophosphorous acid is 50%, the concentration of n-hexane is 97%, and the concentration of (R)-1-(1-naphthyl)ethylamine is 99%.

[0033] The present invention also provides a high-chirality one-dimensional perovskite single crystal, wherein the high-chirality one-dimensional perovskite single crystal is prepared by the above-mentioned high-chirality one-dimensional perovskite single crystal preparation method.

[0034] The method for preparing a high-chirality one-dimensional perovskite single crystal provided by the present invention selects (R)-1-(1-naphthyl)ethylamine, a material with ultra-high chirality, as a cation of the perovskite, so that the grown perovskite single crystal also has ultra-high chirality.

[0035] The present invention obtains a pure one-dimensional chiral perovskite single crystal in yellow by adjusting the ratio of lead oxide to (R)-1-(1-naphthyl)ethylamine.

[0036] The present invention achieves the preparation of high-quality large-size single crystals by optimizing the cooling time. The surface of the grown single crystal is flat and the size can be up to 6 mm, which broadens its application field.

[0037] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A flow chart of a method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention is shown;

[0040] Figure 2 A physical picture of a one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared according to the method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention is shown;

[0041] Figure 3 An optical micrograph of a one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared according to the method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention is shown;

[0042] Figure 4 An atomic force micrograph of a one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared according to the method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention is shown, and the roughness RMS is 1.04 nm;

[0043] Figure 5 An X-ray diffraction diagram of a one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared according to the method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention is shown;

[0044] Figure 6 The normalized absorption spectra of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 in the ultraviolet and visible light bands prepared by the method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention are shown;

[0045] Figure 7 Circular dichroism spectra of one-dimensional chiral perovskite single crystal (R-NEA) PbI3 in the ultraviolet and visible light bands prepared by the method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention are shown. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", "third", etc. in the specification and claims of this application or the above-mentioned figures are used to distinguish different objects, not to describe a specific order or a primary and secondary relationship. "Multiple" appearing in this application refers to more than two (including two).

[0048] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0049] Figure 1 The present invention provides a flow chart of the method for preparing a high-chirality one-dimensional perovskite single crystal. The materials used in the method for preparing a high-chirality one-dimensional perovskite single crystal include: lead oxide, hydroiodic acid, hypophosphorous acid, n-hexane and (R)-1-(1-naphthyl)ethylamine, wherein the purity of lead oxide is 99%, the concentration of hydroiodic acid is 57%, the concentration of hypophosphorous acid is 50%, the concentration of n-hexane is 97%, and the concentration of (R)-1-(1-naphthyl)ethylamine is 99%. The lead oxide and hydroiodic acid were purchased from Sigma-Aldrich, the hypophosphorous acid and n-hexane were purchased from MacLean, and the (R)-1-(1-naphthyl)ethylamine was purchased from TCI. See Figure 1 The method for preparing a high-chirality one-dimensional perovskite single crystal includes the following steps.

[0050] 1. Use lead oxide, hydroiodic acid, hypophosphorous acid and (R)-1-(1-naphthyl)ethylamine to prepare a white precipitate in a glass bottle: first, use a balance to weigh 180-270 mg, preferably 225 mg of lead oxide and put it into a clean and dry 20 mL glass bottle with a lid, then use a pipette to measure 3-5 mL, preferably 4 mL of hydroiodic acid and put it into the glass bottle, then use a pipette to measure 400-600 microliters (μL), preferably 500 μL of hypophosphorous acid and put it into the glass bottle. The role of adding hypophosphorous acid is that hydroiodic acid is unstable and easily decomposed into hydrogen and iodine, and hypophosphorous acid can reduce iodine to hydroiodic acid. After waiting for the lead oxide to dissolve, add 30-50 μL, preferably 40 μL of (R)-1-(1-naphthyl)ethylamine, and a white precipitate is formed after adding it. After putting in a magnetic, tighten the lid of the glass bottle to seal it.

[0051] Second, heating the glass bottle and continuously stirring the liquid containing the white precipitate with a magnetic device: Place the glass bottle in an oil bath heating magnetic stirring device, set the oil temperature to evenly rise to a final temperature of 120-180 degrees Celsius (℃), preferably 150℃ within one hour, and continuously stir with a magnetic device during this period, in order to allow the reactants to react fully, and by continuously heating, the precipitate gradually dissolves, and finally stays at the final temperature for 5-15 minutes, preferably 10 minutes, and the solution becomes a clear yellow liquid. The speed during stirring is 400-1200 rpm, preferably 800 rpm.

[0052] 3. Cool the glass bottle to obtain a single crystal: transfer the above-mentioned glass bottle to a temperature control device such as a temperature control box, set the temperature to uniformly cool down from the final temperature such as 150°C to 20-40°C, preferably 30°C, and cool down by 2-3°C, preferably 2.5°C per hour on average. After 45-50 hours, preferably 48 hours, the cooling is completed to obtain a single crystal. The slow cooling is to control the solution concentration to be slightly supersaturated. When the solution concentration is largely supersaturated, grains will precipitate in the solution, producing a large number of tiny crystals, and the prepared single crystals will be small in size and poor in quality. However, when the solution is slightly supersaturated, the solution will basically not precipitate grains, but will continue to grow on the original grains to generate large-sized, high-quality single crystals.

[0053] 4. After cleaning the single crystal, dry it: After cooling, take the single crystal obtained in step 3 out of the glass bottle, use n-hexane to fully wash or rinse the surface of the single crystal to clean off the residual solution on the single crystal, and then put the single crystal into a drying oven and dry it at 60 degrees Celsius for 2 hours.

[0054] The present invention also provides a high-chirality one-dimensional perovskite single crystal, and the high-chirality one-dimensional perovskite single crystal is prepared by the high-chirality one-dimensional perovskite single crystal preparation method.

[0055] The morphology, optical absorption and chirality of the high-chirality one-dimensional perovskite single crystal are characterized below.

[0056] Figure 2 The physical picture of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared by the method for preparing a high-chirality one-dimensional perovskite single crystal provided by the present invention is shown. After measurement, the chiral perovskite single crystal prepared by the method for preparing a high-chirality one-dimensional perovskite single crystal provided by the present invention can be 6 mm long and 1.3 mm wide. It shows that high-quality, large-size, pure one-dimensional chiral perovskite single crystals can be prepared by the present invention. Large-area chiral perovskite single crystals are very important for manufacturing large-size and uniform optoelectronic devices.

[0057] Figure 3 An optical micrograph of a one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared by the method for preparing a high-chirality one-dimensional perovskite single crystal provided by the present invention is shown. The morphology of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 can be observed more clearly through optical microscope magnification, and it is observed that the single crystal surface of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 that contacts the bottom of the glass bottle is very flat.

[0058] In order to further characterize the roughness of the surface of one-dimensional chiral perovskite single crystal (R-NEA) PbI3, we used atomic force microscopy (AFM) to test the roughness of the surface of one-dimensional chiral perovskite single crystal (R-NEA) PbI3. AFM is a high-resolution microscopy technique that uses a non-contact probe to scan the sample surface and obtains information about the sample surface by measuring the interaction force between the probe and the sample. Figure 4 The atomic force micrograph of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared according to the method for preparing a high-chirality one-dimensional perovskite single crystal provided by the present invention is shown, and the roughness RMS is 1.04nm. Figure 4, within the selected range of 2×2um, the maximum height difference of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 is only 15nm, and the RMS calculated by data analysis software is only 1.04nm (RMS is usually used to describe the average roughness of the sample surface. The RMS value represents the square root of the deviation of the sample surface from the average height. The specific calculation method is to firstly perform a difference between each data point and the average height of the sample surface, then sum the squares of all the differences and take the average value, and finally square the result to obtain the RMS value). After the above characterization, we can determine that the surface of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 is very flat. A flat chiral perovskite single crystal surface is very important for the performance and preparation process of optoelectronic devices. First of all, the performance of optoelectronic devices will be affected by surface defects. For example, an uneven surface may cause scattering and loss of carriers, reducing the transmission efficiency of the device. In addition, surface defects may also cause problems such as energy level movement and charge recombination, affecting the stability and life of the device. Secondly, when preparing optoelectronic devices, a flat surface helps improve the consistency of the device. During the preparation process, if the surface is not flat, it may lead to uneven deposition or crystallization of materials, resulting in differences in the performance of optoelectronic devices.

[0059] We conducted X-ray diffraction tests on the prepared chiral perovskite single crystals. Figure 5 The X-ray diffraction pattern of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared according to the method for preparing a high-chirality one-dimensional perovskite single crystal provided by the present invention is shown. Figure 5 The X-ray diffraction pattern shows obvious diffraction peaks, and the positions of the diffraction peaks are consistent with the characteristics of one-dimensional perovskite. Therefore, the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 has a very high crystallinity.

[0060] Figure 6 The normalized absorption spectra of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 in the ultraviolet and visible light bands prepared by the method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention are shown. Figure 6 It can be seen that the absorption of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 is basically concentrated in the ultraviolet region, showing strong absorption at 305nm and 375nm, and very little absorption in the visible light region. The absorption characteristics of this material can well avoid the interference of visible light in applications, making it a beneficial material for the preparation of optoelectronic devices, and has broad application prospects in the field of ultraviolet detection.

[0061] Figure 7 Circular dichroism spectra of one-dimensional chiral perovskite single crystal (R-NEA) PbI3 in the ultraviolet and visible light bands prepared by the method for preparing a high-chirality one-dimensional perovskite single crystal according to an embodiment of the present invention are shown. Figure 7 It shows that the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 has a CD value of up to 500 in the ultraviolet region, indicating that it has a very large chirality. The CD peak values ​​of the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 appear at 337nm and 365nm. At these two peaks, the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 also has strong absorption. Therefore, the one-dimensional chiral perovskite single crystal (R-NEA) PbI3 prepared by the present invention has the potential to prepare ultraviolet circularly polarized light detectors.

[0062] The method for preparing a high-chirality one-dimensional perovskite single crystal provided by the present invention selects (R)-1-(1-naphthyl)ethylamine, a material with ultra-high chirality, as a cation of the perovskite, so that the grown perovskite single crystal also has ultra-high chirality.

[0063] The present invention obtains a pure one-dimensional chiral perovskite single crystal in yellow by adjusting the ratio of lead oxide to (R)-1-(1-naphthyl)ethylamine.

[0064] The present invention achieves the preparation of high-quality large-size single crystals by optimizing the cooling time. The surface of the grown single crystal is flat and the size can be up to 6 mm, which broadens its application field.

[0065] In summary, the solution cooling crystallization method of the present invention overcomes the limitations of traditional methods and achieves high chirality and excellent crystal quality. The method has broad application prospects and is of great significance in the fields of optoelectronic devices and quantum computing. The present invention is expected to promote its practical application in the fields of optoelectronic devices and quantum computing, and bring more opportunities and breakthroughs to the research and application of related fields.

[0066] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high-chirality one-dimensional perovskite single crystal, characterized in that: Includes steps:

1. Prepare a white precipitate in a glass bottle using lead oxide, hydroiodic acid, hypophosphorous acid and (R)-1-(1-naphthyl)ethylamine; 2. heating the glass bottle and continuously stirring the liquid containing the white precipitate therein with a magnetic rod; 3. Cool the glass bottle to obtain a single crystal.

2. The method for preparing a high-chirality one-dimensional perovskite single crystal according to claim 1, characterized in that: In the step 1, First, use a balance to weigh 180-270 mg of lead oxide and put it into a clean and dry 20 ml glass bottle with a lid. Then use a pipette to measure 3-5 ml of hydroiodic acid and put it into the glass bottle. Then use a pipette to measure 400-600 μl of hypophosphorous acid and put it into the glass bottle.

3. The method for preparing a high-chirality one-dimensional perovskite single crystal according to claim 2, characterized in that: In the step 1, First, use a balance to weigh 225 mg of lead oxide and put it into the glass bottle, then use a pipette to measure 4 ml of hydroiodic acid and put it into the glass bottle, and then use a pipette to measure 500 μl of hypophosphorous acid and put it into the glass bottle.

4. The method for preparing a high-chirality one-dimensional perovskite single crystal according to claim 3, characterized in that: In the step 1, After the white precipitate is formed, the magnetic particle is placed in the glass bottle and the lid is screwed on to seal it.

5. The method for preparing a high-chirality one-dimensional perovskite single crystal according to claim 4, characterized in that: In the step 2, The above glass bottle is placed in an oil bath heating magnetic stirring device, and the oil temperature is set to rise evenly to a final temperature of 120-180 degrees Celsius (℃) within one hour. During this period, the magnetic stirring is continued. Finally, it stays at the final temperature for 5-15 minutes, and the solution becomes a clear yellow liquid. The rotation speed during stirring is 400-1200 revolutions per minute.

6. The method for preparing a high-chirality one-dimensional perovskite single crystal according to claim 5, characterized in that: In the step 2, The oil temperature was set to rise evenly to a final temperature of 150 degrees Celsius within one hour, and then stay at the final temperature for 10 minutes, with a stirring speed of 800 revolutions per minute.

7. The method for preparing a high-chirality one-dimensional perovskite single crystal according to claim 6, characterized in that: In the step three, The glass bottle is transferred to a temperature control device, and the temperature is set to be uniformly cooled from the final temperature to 20-40 degrees Celsius, with an average cooling rate of 2-3 degrees Celsius per hour. After 45-50 hours of cooling, the single crystal is obtained.

8. The method for preparing a high-chirality one-dimensional perovskite single crystal according to claim 7, characterized in that: In the step three, The temperature was set to be uniformly cooled from the final temperature to 30 degrees Celsius, with an average cooling rate of 2.5 degrees Celsius per hour. The cooling was completed after 48 hours to obtain the single crystal.

9. The method for preparing a high-chirality one-dimensional perovskite single crystal according to any one of claims 1 to 8, characterized in that: The lead oxide has a purity of 99%, the concentration of hydroiodic acid is 57%, the concentration of hypophosphorous acid is 50%, the concentration of n-hexane is 97%, and the concentration of (R)-1-(1-naphthyl)ethylamine is 99%.

10. A high-chirality one-dimensional perovskite single crystal, characterized in that: The high-chirality one-dimensional perovskite single crystal is prepared by the method for preparing the high-chirality one-dimensional perovskite single crystal according to any one of claims 1 to 9.

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