A two-dimensional hybrid perovskite based on amino carboxylic acid, preparation method thereof and applications thereof

Abstract

The present invention relates to an amino-carboxylic acid-based two-dimensional hybrid perovskite, a preparation method thereof, and applications thereof. The chemical formula of the amino-carboxylic acid-based two-dimensional hybrid perovskite is C 16 H 32 Br4N2O4Pb. The present invention creatively proposes an amino-carboxylic acid-based two-dimensional hybrid perovskite. The synthesis method of the amino-carboxylic acid-based two-dimensional hybrid perovskite is simple, low in cost, mild in reaction conditions, and relatively high in stability. It is an organic molecular antiferroelectric compound with excellent optoelectronic properties and has good application prospects in the fields of photodetectors, photovoltaic devices, light-emitting diodes, and neutron detection.

Description

Technical Field

[0001] The present invention belongs to the field of functional materials, and particularly relates to a two-dimensional hybrid perovskite based on amino carboxylic acid, a preparation method thereof, and an application thereof. Background Art

[0002] Neutron detection is an important radiation detection method, which is indirectly realized by using high-energy secondary charged particles generated after the interaction between neutrons and the atomic nuclei of detection materials. Neutrons are uncharged and have strong penetration ability, and can measure the internal structure of substances. Therefore, neutron detection has very wide applications in military and civilian fields such as nuclear power generation, nuclear detection, particle physics research, nuclear medicine, and non-destructive detection. Neutron detection can be divided into two types: direct detection and indirect detection. Direct detection means that semiconductor materials ionize and excite a large number of electrons and holes under the irradiation of high-energy rays. These carriers are collected under the action of an electric field, and then an electric signal is generated to realize the direct detection of high-energy rays. In indirect detection, a large number of electrons and holes ionized and excited by a scintillator material under the irradiation of high-energy rays recombine to emit visible light or ultraviolet light, and then an amplified electric signal is generated through detection by a photomultiplier tube to realize the indirect detection of high-energy rays. Indirect detection has the advantages of fast response speed, mature technology, and strong environmental adaptability compared with direct detection, and is the mainstream of current market applications. As one of the most commonly used inorganic scintillation crystals for neutron detection, LiI:Eu crystal has a high light yield (50000 photons MeV -1 ), but its decay time is very long (1400 ns), and this crystal is extremely prone to moisture decomposition. Although organic scintillators have the advantage of short luminescence lifetime compared with inorganic scintillators, their light yield is low. In 2021, J. Perego et al. constructed an organic plastic scintillator Zr-DPA@PDMS by adding metal-organic framework (MOF) nanocrystals into a PDMS matrix. Its light yield during γ-ray detection is only 920 photons MeV -1 . So far, most traditional inorganic scintillators used for radiation detection have a long luminescence lifetime, while organic scintillators, although suitable for fast neutron detection using the nuclear recoil method due to their high hydrogen atom density, have the disadvantage of low light yield. Therefore, there is an urgent need to develop new scintillator materials with high light yield and short luminescence lifetime and to expand their practical applications. Summary of the Invention

[0003] The present invention provides a two-dimensional hybrid perovskite based on amino carboxylic acid, a preparation method thereof, and an application thereof. The present invention creatively proposes a two-dimensional hybrid perovskite based on amino carboxylic acid. The synthesis method of this two-dimensional hybrid perovskite based on amino carboxylic acid is simple, low in cost, mild in reaction conditions, and high in stability. It is an organic molecular antiferroelectric compound with excellent optoelectronic properties. It has good application prospects in the fields of photodetectors, photovoltaic devices, light-emitting diodes, and neutron detection.

[0004] The present invention is achieved through the following technical solutions:

[0005] Solution 1)

[0006] A two-dimensional hybrid perovskite based on amino carboxylic acid, the chemical formula of the two-dimensional hybrid perovskite based on amino carboxylic acid is C 16 H 32 Br4N2O4Pb, and the molecular structural formula is:

[0007]

[0008] Further, when the temperature of the two-dimensional hybrid perovskite based on amino carboxylic acid is 298 - 400K, it is in the polar orthorhombic crystal system, space group Pca21, and the unit cell parameters are Z = 4,

[0009] Solution 2)

[0010] A method for preparing a two-dimensional hybrid perovskite based on amino carboxylic acid, comprising the following steps: at room temperature, add tranexamic acid and lead acetate to an aqueous hydrobromic acid solution in a molar ratio of 1 - 1.5:1, heat to 80 - 100 °C, and then stir until completely dissolved to form a clear solution. Subsequently, keep the obtained solution at a constant temperature of 80 - 85 °C for 24 - 36h, and then slowly cool to 30 - 40 °C to obtain the two-dimensional hybrid perovskite based on amino carboxylic acid.

[0011] Specifically, the mass fraction of hydrobromic acid in the aqueous hydrobromic acid solution is 40 - 45%.

[0012] Specifically, the cooling rate is 1 - 2 °C / day.

[0013] Solution 3)

[0014] An application of a two-dimensional hybrid perovskite based on amino carboxylic acid in a photodetector, and the photodetector includes the two-dimensional hybrid perovskite based on amino carboxylic acid.

[0015] Solution 4)

[0016] An application of a two-dimensional hybrid perovskite based on amino carboxylic acid in a photovoltaic device, and the photovoltaic device includes the two-dimensional hybrid perovskite based on amino carboxylic acid.

[0017] Solution 5)

[0018] An application of a two-dimensional hybrid perovskite based on amino carboxylic acid in a light-emitting diode, and the light-emitting diode includes the two-dimensional hybrid perovskite based on amino carboxylic acid.

[0019] Solution VI)

[0020] Application of a two-dimensional hybrid perovskite based on amino carboxylic acid in a neutron detector, wherein the neutron detector comprises the two-dimensional hybrid perovskite based on amino carboxylic acid.

[0021] Compared with the prior art, the present invention has the following beneficial effects: A two-dimensional hybrid perovskite based on amino carboxylic acid is creatively proposed. The synthesis method of the two-dimensional hybrid perovskite based on amino carboxylic acid is simple, low-cost, mild in reaction conditions, and has high stability. It is an organic molecular antiferroelectric compound with excellent optoelectronic properties. It has good application prospects in the fields of optoelectronic detectors, photovoltaic devices, light-emitting diodes, and neutron detection. Description of the Drawings

[0022] Figure 1 It is a comparative X-ray powder diffraction diagram of the two-dimensional hybrid perovskite based on amino carboxylic acid of the present invention.

[0023] Figure 2 It is a crystal photo of the two-dimensional hybrid perovskite based on amino carboxylic acid of the present invention (prepared in Example 1).

[0024] Figure 3 It is a molecular schematic diagram of the two-dimensional hybrid perovskite lead bromide tranexamic acid based on amino carboxylic acid of the present invention.

[0025] Figure 4 It is a crystal structure packing diagram of the two-dimensional hybrid perovskite lead bromide tranexamic acid based on amino carboxylic acid of the present invention.

[0026] Figure 5 It is an optical absorption spectrum diagram of the two-dimensional hybrid perovskite lead bromide tranexamic acid based on amino carboxylic acid of the present invention.

[0027] Figure 6 It is a current-voltage curve of the two-dimensional hybrid perovskite lead bromide tranexamic acid based on amino carboxylic acid of the present invention in the dark state and under different light intensities.

[0028] Figure 7 It is an excitation and emission spectrum of the two-dimensional hybrid perovskite lead bromide tranexamic acid based on amino carboxylic acid of the present invention, and a photoluminescence diagram of the crystal. Detailed Embodiments

[0029] The present invention will be further described below in conjunction with the drawings and specific embodiments.

[0030] Example 1

[0031] Preparation and synthesis of amino-carboxylic acid-based two-dimensional hybrid perovskites and crystal growth, including the following steps: At room temperature, tranexamic acid and lead acetate are added to an aqueous hydrobromic acid solution in a molar ratio of 1:1, heated to 80 °C, and then stirred until completely dissolved to form a clear solution. Subsequently, the obtained solution is kept at a constant temperature of 85 °C for 24 h, and then slowly cooled to 30 °C to obtain the amino-carboxylic acid-based two-dimensional hybrid perovskite with a yield of 90%. The mass fraction of hydrobromic acid in the aqueous hydrobromic acid solution is 40%. The cooling rate is 1 °C / day.

[0032] At 65 °C, a part of the obtained amino-carboxylic acid-based two-dimensional hybrid perovskite is dissolved in an aqueous hydrobromic acid solution to form a saturated solution of the amino-carboxylic acid-based two-dimensional hybrid perovskite. Then, it is kept at a constant temperature of 70 °C for 10 h. After that, a single crystal of the obtained amino-carboxylic acid-based two-dimensional hybrid perovskite is immersed on the surface of the saturated solution, and a large-sized single crystal of the amino-carboxylic acid-based two-dimensional hybrid perovskite is prepared by the top-seeded growth method.

[0033] Example 2

[0034] At room temperature, tranexamic acid and lead acetate are added to an aqueous hydrobromic acid solution in a molar ratio of 1.2:1, heated to 90 °C, and then stirred until completely dissolved to form a clear solution. Subsequently, the obtained solution is kept at a constant temperature of 82 °C for 30 h, and then slowly cooled to 35 °C to obtain the amino-carboxylic acid-based two-dimensional hybrid perovskite. The mass fraction of hydrobromic acid in the aqueous hydrobromic acid solution is 42%. The cooling rate is 1.5 °C / day.

[0035] At 62 °C, a part of the obtained amino-carboxylic acid-based two-dimensional hybrid perovskite is dissolved in an aqueous hydrobromic acid solution to form a saturated solution of the amino-carboxylic acid-based two-dimensional hybrid perovskite. Then, it is kept at a constant temperature of 71 °C for 11 h. After that, a single crystal of the obtained amino-carboxylic acid-based two-dimensional hybrid perovskite is immersed on the surface of the saturated solution, and a large-sized single crystal of the amino-carboxylic acid-based two-dimensional hybrid perovskite is prepared by the top-seeded growth method.

[0036] Example 3

[0037] At room temperature, tranexamic acid and lead acetate are added to an aqueous hydrobromic acid solution in a molar ratio of 1.5:1, heated to 100 °C, and then stirred until completely dissolved to form a clear solution. Subsequently, the obtained solution is kept at a constant temperature of 80 °C for 36 h, and then slowly cooled to 40 °C to obtain the amino-carboxylic acid-based two-dimensional hybrid perovskite. The mass fraction of hydrobromic acid in the aqueous hydrobromic acid solution is 45%. The cooling rate is 2 °C / day.

[0038] At 67 °C, the obtained partial amino-carboxylic acid-based two-dimensional hybrid perovskite was dissolved in an aqueous hydrobromic acid solution to form a saturated solution of the amino-carboxylic acid-based two-dimensional hybrid perovskite. Then, it was kept at a constant temperature of 72 °C for 10 h. After that, the single crystal of the amino-carboxylic acid-based two-dimensional hybrid perovskite obtained was immersed on the surface of the saturated solution, and a large-sized single crystal of the amino-carboxylic acid-based two-dimensional hybrid perovskite was prepared by the top-seeded growth method.

[0039] Select the single crystal prepared in the above example and grind it into uniform fine particles. Then, the X-ray powder diffraction pattern of the compound was measured by a Miniflex-600 diffractometer, as Figure 1 shown. The experimentally measured X-ray powder diffraction peaks are basically in agreement with the theoretically simulated results, indicating that its phase purity is very high and there are no other obvious impurities.

[0040] As Figure 2 shown are the colorless flaky crystals obtained in Example 1 in this saturated solution.

[0041] The structural characterization of the amino-carboxylic acid-based two-dimensional hybrid perovskite, as Figure 3 and 4 shown, is a polar orthorhombic crystal system with the Pca21 space group at room temperature, and the unit cell parameters are Z = 4, Single crystal structure analysis shows that the two-dimensional hybrid perovskite constructed by the trans-aminomethylcyclohexane carboxylic acid cation (t-ACH + ) has a general two-dimensional RP multi-layer topological structure, including the organic layer composed of t-ACH + and the inorganic perovskite skeleton composed of PbBr6 octahedra. The most significant structural feature is that the adjacent spacer cation layers are connected to each other by strong O-H…O hydrogen bond interactions, which will effectively inhibit the van der Waals gap. Usually, a typical two-dimensional RP-type perovskite contains two organic cation spacer layers, in which the monoammonium cation (R-NH3 + ) is connected to the perovskite layer by a hydrogen bond at one end, so there is a van der Waals gap between the adjacent organic spacer layers. In contrast, strong O-H…O hydrogen bonds connect the adjacent t-ACH + cation layers, which can effectively reduce the energy gap between the adjacent organic layers, thus enhancing the phase stability.

[0042] The absorption spectrum and photoluminescence spectrum tests of the amino-carboxylic acid-based two-dimensional hybrid perovskite, as Figure 5 shown, show that the absorption cut-off edge of the amino-carboxylic acid-based two-dimensional hybrid perovskite is about 430 nm. Based on the Tauc equation ([hvF(R ∞ )] n = A(hv - E g ))), its band gap value was calculated to be about Eg = 2.92 eV.

[0043] For the optoelectronic response test of the two-dimensional hybrid perovskite based on amino carboxylic acid, as Figure 6 shown, we constructed parallel two-probe devices using the grown large single crystals to study their optoelectronic response performance. Under a bias voltage of 10 V, the single crystal optoelectronic device has a very low dark current, which benefits from the high crystal quality and is very conducive to its optoelectronic response. Under the irradiation of a 405 nm laser, when a bias voltage of 10 V is applied, its photocurrent gradually increases with the increase of light intensity, and the optoelectronic response on-off ratio I on / I off can reach 10 3 , which also indicates its potential application value in the field of optoelectronic detection.

[0044] For the photoluminescence spectroscopy test of the two-dimensional hybrid perovskite based on amino carboxylic acid, as Figure 7 shown, under the excitation of a 365 nm laser, a strong blue light emission peak appears near 430 nm for the compound, which indicates that the two-dimensional hybrid perovskite based on amino carboxylic acid has great application prospects in the field of neutron detection.

[0045] In summary, the two-dimensional hybrid perovskite based on amino carboxylic acid of the present invention has excellent optoelectronic and photoluminescence properties and has outstanding application potential in the fields of optoelectronic detectors, solar cells, light-emitting diodes, and neutron detectors. The -COOH amino carboxylic acid of the present invention can enrich the action modes of the interlayer organic cation bilayer, such as strong O-H…O hydrogen bond interactions with a certain orientation, which is conducive to the formation of dipoles and effectively inhibits the van der Waals interaction, thereby enhancing the phase stability and structural rigidity. In addition, the strong O-H…O hydrogen bond interaction between the organic cation bilayers can overcome the growth habit of crystal layer stacking, which is beneficial to the preparation and growth of large-sized and high-quality crystals and provides material support for the design and assembly of optoelectronic functional crystal devices.

[0046] Due to the unique quantum well structure of the two-dimensional hybrid perovskite based on amino carboxylic acid of the present invention, the quantum and dielectric confinement effects caused by the dielectric constant difference between the perovskite inorganic framework layer and the organic cation layer can increase the exciton binding energy, making this type of material have a high light yield and a short luminescence lifetime. At the same time, the well edge is conducive to the separation of electron-hole pairs, thereby improving the carrier mobility of perovskite and achieving excellent optoelectronic properties. Therefore, the two-dimensional hybrid perovskite based on amino carboxylic acid of the present invention has a broad chemical space and bright prospects, is expected to become an ideal material system for developing high-performance neutron detection devices, and stimulates the interest of researchers, thus having a continuous impact at the basic and application levels.

[0047] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A two-dimensional hybrid perovskite based on amino carboxylic acid, characterized in that: The chemical formula of the described amino-carboxylic acid-based two-dimensional hybrid perovskite is C 16 H 32 Br4N2O4Pb, and its molecular structural formula is: ; at a temperature of 298 - 400 K, it is a polar orthorhombic system Pca space group 21, and the unit cell parameters are a a = 8.0749(7) Å, b b = 36.117(4) Å, c c = 8.5049(8) Å, Z Z = 4, V V = 2480.4(4) ų 3 .

2. The preparation method of the amino-carboxylic acid-based two-dimensional hybrid perovskite according to claim 1, characterized in that: It includes the following steps: at room temperature, add tranexamic acid and lead acetate into an aqueous hydrobromic acid solution according to a molar ratio of 1 - 1.5:1, then heat to 80 - 100 °C, then stir until completely dissolved to form a clear solution, then keep the obtained solution at a constant temperature of 80 - 85 °C for 24 - 36 h, and then slowly cool to 30 - 40 °C to obtain the amino-carboxylic acid-based two-dimensional hybrid perovskite.

3. The preparation method of the amino-carboxylic acid-based two-dimensional hybrid perovskite according to claim 2, wherein: The mass fraction of hydrobromic acid in the aqueous hydrobromic acid solution is 40 - 45%.

4. The preparation method of the amino-carboxylic acid-based two-dimensional hybrid perovskite according to claim 2, wherein: The cooling rate is 1 - 2 °C / day.

5. The preparation method of the amino-carboxylic acid-based two-dimensional hybrid perovskite according to claim 2, wherein: It also includes the following steps: At 62 - 67 °C, dissolve a part of the obtained amino-carboxylic acid-based two-dimensional hybrid perovskite in an aqueous hydrobromic acid solution to form a saturated solution of the amino-carboxylic acid-based two-dimensional hybrid perovskite, then keep it at a constant temperature of 70 - 72 °C for 10 - 12 h, and then select single crystals from the obtained amino-carboxylic acid-based two-dimensional hybrid perovskite and immerse them on the surface of the saturated solution, and use the top-seeded growth method to prepare large-size single crystals of the amino-carboxylic acid-based two-dimensional hybrid perovskite.

6. Application of an amino-carboxylic acid-based two-dimensional hybrid perovskite in a photodetector, characterized in that: The photodetector described above contains the amino-carboxylic acid-based two-dimensional hybrid perovskite described in claim 1.

7. Application of an amino-carboxylic acid-based two-dimensional hybrid perovskite in a photovoltaic device, characterized in that: The photovoltaic device described above contains the amino-carboxylic acid-based two-dimensional hybrid perovskite described in claim 1.

8. Application of an amino-carboxylic acid-based two-dimensional hybrid perovskite in a light-emitting diode, characterized in that: The light-emitting diode described above contains the amino-carboxylic acid-based two-dimensional hybrid perovskite described in claim 1.

Images