113-type and 125-type composite perovskite multi-stage structure material and preparation method and application thereof
阅读说明：本技术 一种113型和125型复合钙钛矿多级结构材料及其制备方法和应用 (113-type and 125-type composite perovskite multi-stage structure material and preparation method and application thereof ) 是由 赵高凌 李华正 韩高荣 于 2021-08-16 设计创作，主要内容包括：本发明公开了一种113型和125型复合钙钛矿多级结构材料及其制备方法和应用,该复合钙钛矿多级结构材料包括113型钙钛矿纳米材料与125型钙钛矿纳米材料；113型钙钛矿纳米材料为纳米晶,125型钙钛矿纳米材料为纳米片,113型钙钛矿纳米材料嵌合在125型钙钛矿纳米材料中；113型钙钛矿纳米材料的结构分子式为CsPbX-(3),125型钙钛矿纳米材料的结构分子式为CsPb-(2)X-(5),X选自Cl、Br或I。本发明公开的复合钙钛矿多级结构材料,由113型钙钛矿纳米晶嵌入125型钙钛矿纳米片中复合而成,具有高稳定性与载流子迁移距离长等优点,有望在光电探测器、太阳能电池以及LED等光电领域有着广泛的应用前景。(The invention discloses a 113-type and 125-type composite perovskite multilevel structure material and a preparation method and application thereof, wherein the composite perovskite multilevel structure material comprises a 113-type perovskite nano material and a 125-type perovskite nano material; the 113 type perovskite nano material is nanocrystalline, the 125 type perovskite nano material is nanosheet, and the 113 type perovskite nano material is embedded in the 125 type perovskite nano material; the structural molecular formula of the 113 type perovskite nano material is CsPbX 3 The structural molecular formula of the 125 type perovskite nano material is CsPb 2 X 5 And X is selected from Cl, Br or I. The composite perovskite multilevel structure material disclosed by the invention is formed by embedding 113 type perovskite nanocrystals into 125 type perovskite nanosheets in a composite manner, has the advantages of high stability, long carrier migration distance and the like, and is expected to be applied to photoelectricityThe photoelectric field such as detector, solar cell and LED has wide application prospect.)
1. A113 type and 125 type composite perovskite multilevel structure material is characterized by comprising a 113 type perovskite nanometer material and a 125 type perovskite nanometer material;
the 113 type perovskite nano material is a nanocrystal, the 125 type perovskite nano material is a nanosheet, and the 113 type perovskite nano material is embedded in the 125 type perovskite nano material;
the structural molecular formula of the 113 type perovskite nano material is CsPbX3The structural molecular formula of the 125 type perovskite nano material is CsPb2X5And X is selected from Cl, Br or I.
2. The 113-type and 125-type composite perovskite multilevel structure material according to claim 1, wherein:
the particle size of the 113 type perovskite nano material is 2-10 nm;
the 125-type perovskite nano material is square, and the side length is 20-200 nm.
3. A method for preparing a 113-type and 125-type composite perovskite multilevel structure material according to claim 1 or 2, characterized by comprising the steps of:
(1) mixing a cesium precursor, oleic acid and octadecene, and heating until the cesium precursor, the oleic acid and the octadecene are completely dissolved to obtain a solution I;
(2) mixing lead halide, oleic acid and oleylamine, and heating until the lead halide, the oleic acid and the oleylamine are completely dissolved to obtain a solution II;
the volume ratio of the oleic acid to the oleylamine is 2-4: 1;
(3) mixing the solution I and the solution II, heating to 150-180 ℃, and fully reacting for 20-60 min to obtain the 113-type and 125-type composite perovskite multi-stage structure material;
when the temperature is heated to 150-160 ℃, the sufficient reaction time is 30-60 min;
when the temperature is heated to 160-170 ℃, the sufficient reaction time is 25-30 min;
when the temperature is 170-180 ℃, the sufficient reaction time is 20-25 min.
4. The method for producing 113-type and 125-type composite perovskite multilevel structure material according to claim 3, wherein in the step (1):
the precursor of cesium is selected from cesium carbonate or cesium acetate;
in the solution I, the concentration of a precursor of cesium is 0.05-0.1 mol/L;
the mol ratio of the cesium precursor to oleic acid is 1: 2 to 6.
5. The method for preparing 113-type and 125-type composite perovskite multilevel structure material according to claim 3, wherein in the step (1), the heating is performed to 100 ℃ or more.
6. The method for producing 113-type and 125-type composite perovskite multilevel structure material according to claim 3, wherein in the step (2):
in the solution II, the concentration of lead halide is 0.015-0.05 mol/L;
heating to more than or equal to 100 ℃.
7. The method for producing 113-type and 125-type composite perovskite multilevel structure material according to claim 3, wherein in the step (3):
the volume ratio of the solution I to the solution II is 1: 10 to 30.
8. The method for preparing a 113-type and 125-type composite perovskite multilevel structure material according to any one of claims 3 to 7, characterized by comprising the following steps:
in the solution I, the concentration of a precursor of cesium is 0.06-0.08 mol/L;
the mol ratio of the cesium precursor to oleic acid is 1: 3.5 to 4.0;
in the solution II, the concentration of lead halide is 0.015-0.020 mol/L;
the volume ratio of the solution I to the solution II is 1: 25 to 30.
9. The method for preparing a 113-type and 125-type composite perovskite multilevel structure material according to claim 8, wherein:
in the solution I, the concentration of a precursor of cesium is 0.07 mol/L;
the mol ratio of the cesium precursor to oleic acid is 1: 3.67;
in the solution II, the concentration of lead halide is 0.0179 mol/L;
the volume ratio of the solution I to the solution II is 1: 26.25.
10. use of the 113-type and 125-type composite perovskite multilevel structure material according to claim 1 or 2 in the fields of photodetectors, solar cells and LEDs.
Technical Field
The invention relates to a perovskite material, in particular to a 113-type and 125-type composite perovskite multi-stage structure material and a preparation method and application thereof.
Background
All-inorganic cesium-lead halide perovskite nano materialThe material has excellent physical and chemical properties such as wide spectral range, high absorption coefficient, shallow defect level and the like, and has great potential in the fields of photoelectric detectors, solar cells, LEDs and the like. The all-inorganic cesium-lead halogen perovskite structure is mainly CsPbX3(X is selected from Cl, Br or I) and its derivative Cs4PbX6、CsPb2X5Etc. different structures have different photoelectric properties, wherein CsPbX3And CsPb2X5The optical band gap is moderate, the photoelectric property is good, and the stability is strong, so that the method is the key point of the current research.
In addition, the nano material is generally divided into 0-dimensional nano crystal, 1-dimensional nano wire, 2-dimensional nano sheet and the like in dimension, when the dimension is smaller than the wave exciton radius of the material, the quantum confinement effect is obvious, and the nano material has special photoelectric properties such as fluorescence property, absorption property and the like, so that the nano material can be widely applied to the fields of photovoltaic materials, luminescent materials and the like.
The composite multilevel structure of 0 dimension-1 dimension, 0 dimension-2 dimension and the like can change various properties of the material, such as stability, photoelectric property and the like, and is an important way for modifying the material and improving the property. However, the existing preparation method of the perovskite composite multi-stage structure is complex in procedure and high in cost, and the perovskite composite multi-stage structure is a composite structure with the same structure, and a technical scheme that perovskites with different components are compounded to form the multi-stage structure does not exist.
Disclosure of Invention
The invention discloses a 113-type and 125-type composite perovskite multilevel structure material, which is formed by embedding 113-type perovskite nanocrystals into 125-type perovskite nanosheets and compounding, has the advantages of high stability, long carrier migration distance and the like, and is expected to have wide application prospect in the photoelectric fields of photoelectric detectors, solar cells, LEDs and the like.
The specific technical scheme is as follows:
a113 type and 125 type composite perovskite multilevel structure material comprises a 113 type perovskite nanometer material and a 125 type perovskite nanometer material;
the 113 type perovskite nano material is a nanocrystal, the 125 type perovskite nano material is a nanosheet, and the 113 type perovskite nano material is embedded in the 125 type perovskite nano material;
the structural molecular formula of the 113 type perovskite nano material is CsPbX3The structural molecular formula of the 125 type perovskite nano material is CsPb2X5And X is selected from Cl, Br or I.
Preferably:
the particle size of the 113 type perovskite nano material is 2-10 nm;
the 125-type perovskite nano material is square, and the side length is 20-200 nm.
The invention discloses a composite perovskite multilevel structure material with a novel structure, which has the unique appearance that small-size 113 type perovskite nanocrystals are embedded into large-size 125 type perovskite nanosheets, and the small-size 113 type perovskite nanocrystals with the particle size of 2-10 nm have a quantum size effect, and the 125 type perovskite nanosheets simultaneously play a role in protecting and transmitting current carriers, so that the multilevel structure has the advantages of excellent photoelectric property, high stability, long migration distance of the current carriers and the like, and the photo-generated current carriers can be generated and transmitted more efficiently. Is expected to be applied to the fields of photoelectric detectors, solar cells and LEDs.
The invention also discloses a preparation method of the 113-type and 125-type composite perovskite multi-stage structure material, which comprises the following steps:
(1) mixing a cesium precursor, oleic acid and octadecene, and heating until the cesium precursor, the oleic acid and the octadecene are completely dissolved to obtain a solution I;
(2) mixing lead halide, oleic acid and oleylamine, and heating until the lead halide, the oleic acid and the oleylamine are completely dissolved to obtain a solution II;
the volume ratio of the oleic acid to the oleylamine is 2-4: 1;
(3) and mixing the solution I and the solution II, heating to 150-180 ℃, and fully reacting for 20-60 min to obtain the 113-type and 125-type composite perovskite multi-stage structure material.
Existing fully inorganic CsPbX3In the preparation process of the perovskite nano material, a thermal injection method is mostly adopted, oleic acid and oleylamine are taken as ligands, octadecene is taken as a solvent, but in the synthesis process, CsPbX is adopted3Perovskite nanomaterialsThe nucleation and growth speed of (2) are very fast, and it is difficult to obtain small-sized nanocrystals. The inventor of the invention unexpectedly finds that in the experiment, when the lead halide precursor solution is prepared, octadecene is not added, but oleic acid and oleylamine with a specific ratio are added (the volume ratio of the oleic acid to the oleylamine is 2-4: 1), and the oleic acid and the oleylamine are used as a ligand and a solvent, so that 113-type and 125-type composite perovskite multilevel structures with unique shapes and performances can be prepared at one time.
Tests show that the key points for obtaining the special appearance are two points: first, the volume ratio of oleic acid oleylamine; the second is the reaction temperature and time in the step (3). In the preparation process of the invention, the reaction temperature and the reaction time in the step (3) need to be reasonably matched, if the two choices are not matched, no product is obtained, or the prepared 113 type perovskite material and 125 type perovskite material are separated.
The reaction temperature is inversely proportional to the choice of the reaction time, i.e. the higher the reaction temperature is, the shorter the reaction time is, specifically:
when the temperature is heated to 150-160 ℃, the sufficient reaction time is 30-60 min;
when the temperature is heated to 160-170 ℃, the sufficient reaction time is 25-30 min;
when the temperature is 170-180 ℃, the sufficient reaction time is 20-25 min.
Preferably, in step (1):
the precursor of cesium is selected from cesium carbonate and cesium acetate;
in the solution I, the concentration of a precursor of cesium is 0.05-0.1 mol/L;
the mol ratio of the cesium precursor to oleic acid is 1: 2 to 6.
And heating the raw materials in the step (1) to more than or equal to 100 ℃ until the raw materials are completely dissolved, preferably heating to 110-130 ℃.
Preferably, in step (2):
in the solution II, the concentration of lead halide is 0.015-0.05 mol/L;
and heating the raw materials in the step (2) to more than or equal to 100 ℃ until the raw materials are completely dissolved, preferably heating to 110-130 ℃.
Preferably, in step (3):
the volume ratio of the solution I to the solution II is 1: 10 to 30.
Further preferably:
in the solution I, the concentration of a precursor of cesium is 0.06-0.08 mol/L;
the mol ratio of the cesium precursor to oleic acid is 1: 3.5 to 4.0;
in the solution II, the concentration of lead halide is 0.015-0.020 mol/L;
the volume ratio of the solution I to the solution II is 1: 25 to 30.
Further preferably:
in the solution I, the concentration of a precursor of cesium is 0.07 mol/L;
the mol ratio of the cesium precursor to oleic acid is 1: 3.67;
in the solution II, the concentration of lead halide is 0.0179 mol/L;
the volume ratio of the solution I to the solution II is 1: 26.25.
compared with the prior art, the invention has the following advantages:
the invention can obtain the 113-type and 125-type composite perovskite multi-stage structure material at one time only by accurately regulating the volume ratio of oleic acid to oleylamine in the preparation process of lead halide precursor solution and accurately matching the reaction temperature and the reaction time by using the traditional thermal injection method. The preparation process is simple and controllable, does not need additional equipment investment, and is easy to realize industrial production.
The 113-type and 125-type composite perovskite multilevel structure material prepared by the invention is formed by embedding 113-type perovskite nanocrystals into 125-type perovskite nanosheets and compounding, and has a novel structure. The 113 type perovskite nano crystal is small in size and has excellent photoelectric property, and the nano crystal can well play a role in protection and has high stability when being embedded in a 125 type perovskite nano sheet; in addition, the 125-type perovskite nanosheet is also a photoelectric material with excellent performance, can play a role in separating and transmitting electrons and holes, and has special advantages. The composite perovskite multilevel structure material is expected to be widely applied to the photoelectric fields of photoelectric detection, solar cells, LEDs and the like.
Drawings
FIG. 1 is an XRD pattern of the product prepared in example 1;
FIG. 2 is a TEM picture of the product prepared in example 1;
FIG. 3 is a HRTEM picture of the product prepared in example 1;
FIG. 4 is a TEM picture of the product prepared in comparative example 1;
FIG. 5 is a HRTEM picture of the product prepared in example 2;
figure 6 is an XRD pattern of the product prepared in example 7.
Detailed Description
The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.
Example 1
(1) Fully reacting and dissolving 0.1g of cesium carbonate (0.3mmol), 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 69mg (0.188mmol) of lead bromide, 7mL of oleic acid and 3.5mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 160 ℃, injecting 0.4mL of the solution I into the solution II (10.5mL), and continuing to react and stir;
(4) keeping the same temperature, continuously stirring and reacting for 30min to obtain reaction liquid, and finally centrifuging, separating and washing to obtain a final product.
FIG. 1 is an XRD pattern of the product prepared in this example, from which it can be seen that the product has CsPb at the same time2Br5And CsPbBr3Indicating that the 125 type CsPb is simultaneously present in the obtained product2Br5And 113 type CsPbBr3A perovskite structure;
FIG. 2 is a TEM image of a product prepared in the embodiment, and as can be seen from the TEM image, the main body is a nanosheet, the nanosheet is square, the side length is about 100nm, small nanocrystals exist in the nanosheet, and the particle size is 3-10 nm;
FIG. 3 is an HRTEM image of the product prepared in this example, from which it can be seen that the interplanar spacing of the lamellar structure is 0.30nm, corresponding to a type 125 CsPb2Br5The (220) plane of the perovskite structure is embedded in the nanosheet, the interplanar spacing of the small particles is 0.29nm, and the structure corresponds to 113 type CsPbBr3The (200) plane of the perovskite structure is clearly observed from the figure, and 113 type CsPbBr3Perovskite nanocrystalline embedded in 125 type CsPb2Br5And a composite multilevel structure is formed in the perovskite nanosheet.
Comparative example 1
(1) Fully reacting and dissolving 0.1g of cesium carbonate (0.3mmol), 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 69mg (0.188mmol) of lead bromide, 7mL of oleic acid and 3.5mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 160 ℃, injecting 0.4mL of the solution I into the solution II (10.5mL), and continuing to react and stir;
(4) keeping the same temperature, continuously stirring and reacting for 60min to obtain reaction liquid, and finally centrifuging, separating and washing to obtain a final product.
FIG. 4 is a TEM image of the product prepared in this comparative example, from which it can be seen that both small-particle nanocrystals and sheet structures are present in the product after a long reaction time, but they are not embedded together.
Comparative example 2
(1) Fully reacting and dissolving 0.1g of cesium carbonate (0.3mmol), 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 69mg (0.188mmol) of lead bromide, 7mL of oleic acid and 3.5mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 160 ℃, injecting 0.4mL of the solution I into the solution II (10.5mL), and continuing to react and stir;
(4) keeping the same temperature and continuously stirring for 20min to obtain a reaction solution, and finally centrifuging, wherein the centrifugation time and the centrifugation speed are the same as those of the example 1.
Experiments show that the reaction solution after 20min of reaction time has no product after centrifugation.
Example 2
(1) Fully reacting and dissolving 0.1g of cesium carbonate (0.3mmol), 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 69mg (0.188mmol) of lead bromide, 7mL of oleic acid and 3.5mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 150 ℃, injecting 0.4mL of the solution I into the solution II (10.5mL), and continuing to react and stir;
(4) keeping the same temperature, continuously stirring and reacting for 60min to obtain reaction liquid, and finally centrifuging, separating and washing to obtain a final product.
FIG. 5 is an HRTEM image of the product prepared in this example, and it can be seen from the graph that the small-particle-size 113-type perovskite is embedded in the 125-type perovskite nanosheet, and the morphology is substantially consistent with that of example 1.
However, the increase in reaction time did not affect the product structure, indicating that to obtain the structure, the reaction time is inversely proportional to the reaction temperature.
Example 3
(1) Fully reacting and dissolving 0.1g of cesium carbonate (0.3mmol), 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 69mg (0.188mmol) of lead bromide, 7mL of oleic acid and 3.5mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 170 ℃, injecting 0.4mL of the solution I into the solution II (10.5mL), and continuing to react and stir;
(4) keeping the same temperature, continuously stirring and reacting for 25min to obtain reaction liquid, and finally centrifuging, separating and washing to obtain a final product.
Tests show that the appearance of the reaction product after the reaction time of 25min at 170 ℃ is basically consistent with that of the reaction product in example 1, but the reduction of the reaction time does not affect the structure of the product, which indicates that the reaction time is inversely proportional to the reaction temperature to obtain the structure, and the conclusion of example 2 is consistent.
Example 4
(1) Fully reacting and dissolving 0.1g of cesium carbonate (0.3mmol), 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 69mg (0.188mmol) of lead bromide, 7mL of oleic acid and 3.5mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 180 ℃, injecting 0.4mL of the solution I into the solution II (10.5mL), and continuing to react and stir;
(4) keeping the same temperature, continuously stirring and reacting for 20min to obtain reaction liquid, and finally centrifuging, separating and washing to obtain a final product.
Tests show that the appearance of the reaction product after the reaction time of 20min at 180 ℃ is basically consistent with that of the reaction product in example 1, the reaction time is inversely proportional to the reaction temperature, and the results are consistent with those of examples 2 and 3.
Example 5
(1) Fully reacting and dissolving 0.1g (0.3mmol) of cesium carbonate, 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 52mg (0.188mmol) of lead chloride, 1mL of n-trioctylphosphine oxide, 7mL of oleic acid and 3.5mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 160 ℃, injecting 0.4mL of the solution I into the solution II, and continuing to react and stir;
(4) keeping the same temperature, continuously stirring and reacting for 30min to obtain reaction liquid, and finally centrifuging, separating and washing to obtain a product.
The product prepared in this example was tested to be type 113 CsPbCl3Perovskite nanocrystals and 125 type CsPb2Cl5The morphology of the perovskite nano-sheet composite multilevel structure is basically consistent with that of the embodiment 1.
Example 6
(1) Fully reacting and dissolving 0.1g (0.3mmol) of cesium carbonate, 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 87mg (0.188mmol) of lead iodide, 7mL of oleic acid and 3.5mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 160 ℃, injecting 0.4mL of the solution I into the solution II, and continuing to react and stir;
(4) keeping the same temperature, continuously stirring and reacting for 30min to obtain reaction liquid, and finally centrifuging, separating and washing to obtain a product.
The product prepared in this example was tested to be type 113 CsPbI3Perovskite nanocrystals and 125 type CsPb2I5The morphology of the perovskite nano-sheet composite multilevel structure is basically consistent with that of the embodiment 1.
Example 7
(1) Fully reacting and dissolving 0.1g (0.3mmol) of cesium carbonate, 0.35mL of oleic acid and 3.75mL of octadecene at 120 ℃ in an inert atmosphere to obtain a solution I;
(2) mixing 69mg (0.188mmol) of lead bromide, 8.4mL of oleic acid and 2.1mL of oleylamine, and fully dissolving at 120 ℃ in an inert atmosphere to obtain a solution II;
(3) raising the temperature of the solution II to 160 ℃, injecting 0.4mL of the solution I into the solution II, and continuing to react and stir;
(4) keeping the same temperature, continuously stirring and reacting for 30min to obtain reaction liquid, and finally centrifuging, separating and washing to obtain a product.
FIG. 6 is an XRD pattern of the product prepared in this example, from which it can be seen that the product has CsPb at the same time2Br5And CsPbBr3Is substantially the same as example 1, and has a morphology substantially the same as example 1, CsPb2Br5The side length of the nano-sheet is 200nm, CsPbBr3The grain size of the nanocrystalline is 5-10 nm.