Perovskite hybrid fiber, perovskite hybrid fiber coating and preparation method and application thereof

Abstract

The invention discloses a perovskite hybrid fiber, a perovskite hybrid fiber coating and a preparation method and application thereof. The preparation method of the perovskite hybrid fiber comprises the following steps: S1, mixing a perovskite precursor and a perovskite precursor good solvent, and carrying out ultrasonic treatment to obtain a mixed solution I; mixing a carbon nanotube and a solvent, and carrying out ultrasonic treatment to obtain a mixed solution II; s2, adding the mixed solution I into the mixed solution II, mixing and reacting; performing solid-liquid separation to obtain a solid; and annealing the solid to obtain the product. The good solvent and the solvent are mutually insoluble. According to the method, the perovskite hybrid fiber is prepared in a confinement mode through the double-solvent liquid phase method, the perovskite precursor is subjected to mass transfer and diffusion by the good solvent to enter the inner cavity of the carbon nano tube, the method is high in filling efficiency and high in universality, and the prepared perovskite hybrid fiber is high in stability in a high-humidity or high-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite materials, and in particular to a perovskite hybrid fiber, a perovskite hybrid fiber coating, and a preparation method and application thereof. Background Art

[0002] The chemical formula of metal halide perovskite is generally ABX3, where A is a monovalent cation (CH3NH3 + 、CH(NH2)2 + 、Cs + ), B is a metal cation, and X is a halogen anion. Metal halide perovskites can combine high-atomic-number atoms to form a dense structure, resulting in high X-ray attenuation coefficients. They also possess high absorption coefficients, easily tunable band gaps, high carrier mobility, and defect tolerance. Their carrier mobility and lifetime product are hundreds of times higher than those of traditional semiconductors. Lead-based halide perovskites have high effective atomic numbers (50-60) and strong X-ray absorption. Consequently, X-ray detection research based on lead-based perovskites has garnered widespread attention in recent years.

[0003] Currently, the most common method to improve metal halide perovskite devices is to passivate the perovskite coating and encapsulate it with a polymer to isolate moisture and oxygen in the air and prevent the decomposition of the perovskite. In addition, X-ray detectors based on perovskite films also face the problem of random orientation, which leads to inefficient charge collection. Therefore, it is of great significance to develop environmentally friendly, specifically oriented, and structurally stable perovskite materials for high-sensitivity X-ray detection. Nanopore confined assembly, as an emerging synthesis method, can provide a nano-reaction cavity and improve the controllability of the synthesis through the confinement effect of nanopores, which is conducive to the precise control of the structure of crystalline materials at the atomic scale. However, the synthesis methods in related technologies have the defects of poor filling efficiency and poor filling effect.

[0004] Therefore, it is necessary to develop a preparation method for perovskite hybrid fibers with high filling efficiency and good filling effect. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for preparing perovskite hybrid fibers, which has high filling efficiency and filling quality, and the prepared perovskite hybrid fibers have high stability.

[0006] The second aspect of the present invention further provides a perovskite hybrid fiber.

[0007] The third aspect of the present invention further provides a perovskite hybrid fiber coating.

[0008] A fourth aspect of the present invention further provides an X-ray detector.

[0009] The fifth aspect of the present invention also provides an application of a perovskite hybrid fiber coating.

[0010] According to an embodiment of the first aspect of the present invention, a method for preparing a perovskite hybrid fiber is provided, comprising the following steps:

[0011] S1, mixing a perovskite precursor and a good solvent for the perovskite precursor and sonicating to obtain a mixed solution I; mixing a carbon nanotube dispersion and a poor solvent for the perovskite precursor and sonicating to obtain a mixed solution II;

[0012] S2, adding the mixed solution I to the mixed solution II to mix and react; solid-liquid separation to obtain a solid; and annealing the solid to obtain.

[0013] The method for preparing the perovskite hybrid fiber according to the embodiment of the present invention has at least the following beneficial effects:

[0014] The present invention adopts a dual-solvent liquid phase method to confine the preparation of perovskite hybrid fibers, so that the perovskite precursor is diffused into the inner cavity of the carbon nanotube by mass transfer of the good solvent. This method has high filling efficiency and high universality, and the prepared perovskite hybrid fibers have high stability.

[0015] Furthermore, the carbon nanotubes described in this invention can form a protective layer on the perovskite surface, preventing the infiltration of water and oxygen molecules, thereby inhibiting the decomposition of the perovskite. They can also be used for extended periods in high-humidity or high-temperature environments. Furthermore, as one-dimensional cavity channels, the carbon nanotubes can control the growth orientation of the perovskite unit cell chains within the cavity. By adjusting this growth orientation, the carrier mobility is increased, ion diffusion is reduced, and device performance is optimized.

[0016] According to some embodiments of the present invention, the perovskite precursor refers to a perovskite precursor salt, for example, including a halide salt.

[0017] According to some embodiments of the present invention, the good solvent includes at least one of dimethyl sulfoxide, N,N-dimethylformamide or N-methylpyrrolidone.

[0018] According to some embodiments of the present invention, the poor solvent includes at least one of dichloromethane, cyclohexane or toluene.

[0019] According to some embodiments of the present invention, the structural formula of the perovskite precursor is selected from ABX3, AB2X3 or A3BX6; wherein A is a monovalent cation; B is a metal ion; and X is a halogen ion.

[0020] According to some embodiments of the present invention, the monovalent cation includes Cs + 、CH3NH3 + 、CH(NH2)2+ .

[0021] According to some embodiments of the present invention, the metal ions include Pb 2+ 、Cu 2+ 、Sn 2+ 、Ge 2+ 、Y 3+ 、Ru 3+ 、Eu 3+ 、Ce 3+ 、Yb 3+ 、Er 3+ 、Gd 3+ .

[0022] According to some embodiments of the present invention, the halogen ions include Cl - Br - , I - .

[0023] According to some embodiments of the present invention, the carbon nanotubes include single-arm carbon nanotubes.

[0024] According to some embodiments of the present invention, the concentration of the carbon nanotubes is 1-10 mg / mL, calculated based on the total mass of the mixed solution II.

[0025] According to some embodiments of the present invention, in the mixed solution I, the concentration of the perovskite precursor is 0.01 to 0.50 mol / L.

[0026] According to some embodiments of the present invention, hydrochloric acid is further included in the mixed solution I. The function of the hydrochloric acid is to prevent the perovskite precursor from decomposing.

[0027] According to some embodiments of the present invention, the volume ratio of the mixed solution I to the mixed solution II is 1:(800-2000).

[0028] According to some embodiments of the present invention, in step S2, the annealing temperature is 200-580°C.

[0029] According to some embodiments of the present invention, in step S2, the annealing time is 1 to 2 hours.

[0030] According to a second aspect of the present invention, an embodiment provides a perovskite hybrid fiber, which is prepared by the preparation method described in any one of the first aspects of the present invention.

[0031] According to some embodiments of the present invention, the width of the perovskite nanowires in the perovskite hybrid fibers is 0.6 to 0.8 nm.

[0032] According to some embodiments of the present invention, the length of the perovskite nanoparticles in the perovskite hybrid fibers is 100 to 1000 nm.

[0033] A third aspect of the present invention provides a perovskite hybrid fiber coating comprising the perovskite hybrid fiber described in the second aspect of the present invention. By assembling and growing perovskites confined within the one-dimensional nanocavities of carbon nanotubes, their composition can be regulated. This provides a template to protect the perovskite and precisely controls the growth orientation of the one-dimensional perovskite, resulting in a more stable perovskite coating in high-temperature or high-humidity environments.

[0034] According to some embodiments of the present invention, the thickness of the perovskite hybrid fiber coating is 2-4 μm.

[0035] According to some embodiments of the present invention, the perovskite hybrid fiber coating is prepared by the following method:

[0036] The perovskite hybrid fiber and the organic solvent are mixed and ultrasonicated to obtain a mixed solution III; the mixed solution III is coated on a substrate and annealed to obtain the product.

[0037] According to some embodiments of the present invention, the organic solvent includes at least one of N-methylpyrrolidone, toluene, dichloromethane, cyclohexane or anhydrous ethanol.

[0038] A fourth aspect of the present invention provides an X-ray detector comprising the perovskite hybrid fiber coating of the first aspect of the present invention. Because the perovskite hybrid fiber coating of the present invention has high stability, the X-ray detector maintains low dark current and high sensitivity while also having high device stability.

[0039] A fifth aspect of the present invention provides a use of the above-mentioned perovskite hybrid fiber; or the above-mentioned perovskite hybrid fiber coating in the preparation of a photodetector or a solar cell.

[0040] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0042] Figure 1 This is a high-angle annular dark-field electron microscopy image of the perovskite-filled carbon nanotubes of Example 2 of the present invention;

[0043] Figure 2 This is the high-angle annular dark-field electron microscope image of Comparative Example 1;

[0044] Figure 3 A schematic diagram of the structure of an X-ray detector prepared according to an embodiment of the present invention;

[0045] Figure 4 It curves of the X-ray detectors prepared in Example 5 of the present invention and Comparative Example 1;

[0046] Figure 5 The sensitivity and dark current diagram of the X-ray detector prepared in Example 5 of the present invention in a high humidity environment;

[0047] Figure 6 The sensitivity and dark current diagrams of the X-ray detector prepared in Example 5 of the present invention at different temperatures. DETAILED DESCRIPTION

[0048] The embodiments of the present invention are described in detail below. In the description of the present invention, "several" means more than one, "multiple" means more than two, "greater than", "less than", "exceed", etc. are understood as excluding the number itself, and "above", "below", "within", etc. are understood as including the number itself.

[0049] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0050] Some of the raw materials used in the examples and comparative examples of the present invention are as follows:

[0051] Single-walled carbon nanotube (SWCNT): OCSiAI Group, concentration 93%, CAS: 1333-86-4.

[0052] The packing efficiency is calculated by the following formula: Packing efficiency = m1 / M1*M2 / (1-m2); where m1 is the weight of the oxide obtained after thermogravimetry of the precursor salt;

[0053] M1 is the weight of oxide obtained by thermogravimetry of hybrid fibers after loading;

[0054] M2 is the weight of hybrid fibers after filling;

[0055] m2 is the mass of the residual solvent when the carbon tubes are filled.

[0056] Example 1

[0057] This example provides a perovskite hybrid fiber, which is prepared by the following method:

[0058] S1. Dissolve cesium chloride, ytterbium chloride, cerium chloride, erbium chloride, and yttrium chloride in a mixed solvent of 1 mol / L aqueous hydrochloric acid solution and dimethyl sulfoxide in a volume ratio of 1:1, wherein the chloride salt is 0.050 mmol, the hydrochloric acid concentration in the solvent is 0.016 mol / L, and the total volume of the solvent is 3.2 mL; the cesium chloride concentration is 0.048 mol / L and the concentrations of the other chloride salts are all 0.016 mol / L. Place the obtained mixed solution in an ultrasonic bath and sonicate for 30 minutes to obtain the precursor Cs3(CeEuGdYb)1Cl6 mixed solution I. Disperse 40 mg of single-walled carbon nanotubes in 20 mL of cyclohexane to obtain mixed solution II;

[0059] S2. Add 200 μL of the precursor mixture to Mixture II. Stir for 24 hours using a thermostatic magnetic stirrer, centrifuge, and dry in a drying oven at 80°C. The resulting dried carbon nanotube-filled product is annealed at 300°C for 2 hours in an argon atmosphere, followed by repeated additions of deionized water and dimethyl sulfoxide, followed by centrifugation and washing. The calculated filling efficiency is 43%.

[0060] Example 2

[0061] This example provides a perovskite hybrid fiber, prepared by the same method as in Example 1, except that, in step S1, equimolar amounts of cesium iodide and lead iodide are dissolved in a dimethyl sulfoxide solvent, wherein the iodide salt is 0.05 mmol and the total solvent volume is 200 μL; the concentrations of both cesium iodide and lead iodide are 0.25 mol / L. The resulting mixed solution is placed in an ultrasonic bath and sonicated for 30 minutes to obtain a precursor CsPbI3 mixed solution I.

[0062] In step S2, the annealing temperature is changed to 580°C.

[0063] The filling efficiency is 40%.

[0064] Example 3

[0065] This example provides a perovskite hybrid fiber, the preparation method of which is the same as that of Example 1, except that in step S1, dimethyl sulfoxide is replaced by N,N-dimethylformamide. The filling efficiency is 50%.

[0066] Example 4

[0067] This example provides a perovskite hybrid fiber, and its preparation method is the same as that of Example 1, except that in step S1, ruthenium chloride and europium chloride are further added, and the structural formula of the precursor is Cs3(YRuCeEuGdYb)1Cl6.

[0068] The filling efficiency is 43%.

[0069] Examples 5 to 8

[0070] Examples 5 to 8 provide a series of perovskite hybrid fiber coatings with a thickness of 4 μm, prepared by the following method:

[0071] The perovskite hybrid fibers prepared in Examples 1 to 4 were dispersed in toluene at an initial concentration of 0.3 g / L. Ultrasonication was performed using a probe at 500 W for 30 minutes to obtain four dispersed perovskite-carbon nanotube hybrid fiber solutions. A heating plate was preheated to 70°C, and the four perovskite-carbon nanotube hybrid fiber solutions were dropwise added to four silicon substrates (Si / SiO2 substrates) and annealed to form perovskite hybrid fiber coatings I, II, III, and IV.

[0072] Comparative Example 1

[0073] This example provides a perovskite fiber coating, which is prepared by the following method:

[0074] S1. Disperse equimolar amounts of cesium iodide and lead iodide in a cyclohexane solvent at a volume ratio of 1:1000, with 0.05 mmol of iodide salt and a total solvent volume of 200 μL. Place the resulting mixed solution in an ultrasonic bath and sonicate for 30 minutes to obtain a precursor CsPbI3 mixed solution I. Disperse 40 mg of single-walled carbon nanotubes in the CsPbI3 mixed solution I and sonicate for 30 minutes to obtain a mixed solution II.

[0075] S2. Add 200 μL of the precursor mixture to mixed solution II. Stir for 24 hours using a constant temperature magnetic stirrer. Centrifuge and dry in a drying oven at 80°C. The dried carbon nanotube-filled product is annealed at 580°C for 2 hours in an argon atmosphere. Then, wash the product by centrifugation with deionized water and dimethyl sulfoxide multiple times.

[0076] Reload efficiency: 0%.

[0077] Performance Testing

[0078] The perovskite-filled carbon nanotubes of Example 2 of the present invention were subjected to high-angle annular dark-field electron microscopy imaging test, and the results are as follows: Figure 1 As shown, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images reveal the ultrathin nanowire structure inside SWCNTs, and energy-dispersive X-ray (EDX) maps show the uniform distribution of Cs, Pb, and I elements along the tube axis.

[0079] The perovskite-filled carbon nanotubes of Comparative Example 1 were subjected to high-angle annular dark-field electron microscopy imaging test, and the results are as follows: Figure 2As shown, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images reveal that the perovskites are all deposited on the surface of SWCNTs without achieving confined filling.

[0080] The series of perovskite hybrid fiber coatings prepared in Examples 5 to 8 of the present invention and Comparative Example 1 were prepared into X-ray detectors, the structural diagram of which is shown in FIG. Figure 3 As shown, the steps are as follows:

[0081] An 80 nm gold electrode was obtained by vacuum evaporation deposition on the surface of the series of perovskite hybrid fiber coatings prepared in Examples 5 to 8 and Comparative Example 1.

[0082] Furthermore, the X-ray detectors of Example 5 of the present invention and Comparative Example 1 were directly placed under a 50 kVp X-ray switch and a 200 V bias voltage, and the It curves were measured. The results are as follows: Figure 4 As shown; and the dark current baseline drift is calculated to characterize the degree of ion migration during the operation of the device, so as to characterize the operational stability of the device. The higher the operational stability, the lower the dark current baseline drift value (JD). The JD value of Example 5 is 8.5×10 -7 nA·cm -1 ·s -1 ·V -1 , Comparative Example 1 is 8.7×10 -2 nA·cm -1 ·s -1 ·V -1 , the dark current of Example 5 is much lower than that of Comparative Example 1.

[0083] The X-ray detector prepared in Example 5 was placed directly in an environment with a humidity of 100% RH and the sensitivity and dark current were measured at 0 days (0d) and 4 days (4d). Figure 5 As shown, the X-ray detector prepared in Example 5 is exposed to air for a long time, and its sensitivity and dark current performance remain stable, showing good stability.

[0084] The X-ray detector prepared in Example 5 was placed directly in a temperature environment of 25-100°C to measure the sensitivity and dark current. Figure 6 As shown, the sensitivity of the X-ray detector prepared in Example 5 is basically stable, and the dark current drifts slightly, but the overall change is not large, and it has good stability.

[0085] While the above description is in conjunction with the embodiments of the present invention, the present invention is not limited to the aforementioned embodiments. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. A method for preparing perovskite hybrid fiber, characterized in that: The steps include: S1, mixing a perovskite precursor and a good solvent for the perovskite precursor and ultrasonically obtaining a mixed solution I; mixing carbon nanotubes and a poor solvent for the perovskite precursor and ultrasonically obtaining a mixed solution II; S2, adding the mixed solution I to the mixed solution II to mix and react; solid-liquid separation to obtain a solid; and annealing the solid to obtain.

2. The method for preparing perovskite hybrid fiber according to claim 1, characterized in that: The good solvent includes at least one of dimethyl sulfoxide, N,N-dimethylformamide or N-methylpyrrolidone.

3. The method for preparing perovskite hybrid fiber according to claim 1 or 2, characterized in that: The poor solvent includes at least one of dichloromethane, cyclohexane or toluene.

4. The method for preparing perovskite hybrid fiber according to claim 1 or 2, characterized in that: The structural formula of the perovskite precursor is selected from ABX3, AB2X3 or A3BX6; wherein A is a monovalent cation; B is a metal ion; and X is a halogen ion.

5. A perovskite hybrid fiber, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 4.

6. The perovskite hybrid fiber according to claim 5, characterized in that The width of the perovskite nanowires in the perovskite hybrid fibers is 0.6 to 0.8 nm.

7. A perovskite hybrid fiber coating, characterized in that: Comprising the perovskite hybrid fiber according to claim 5 or 6.

8. The perovskite hybrid fiber coating according to claim 7, characterized in that: The perovskite hybrid fiber coating is prepared by the following method: The perovskite hybrid fiber according to claim 5 or 6 and an organic solvent are mixed and ultrasonically applied to obtain a mixed solution III; the mixed solution III is coated on a substrate and annealed to obtain the product.

9. An X-ray detector, characterized in that: Comprising the perovskite hybrid fiber coating according to claim 7 or 8.

10. Use of the perovskite hybrid fiber according to claim 5 or 6; or the perovskite hybrid fiber coating according to claim 7 or 8 in the preparation of a photodetector or a solar cell.

Images