Preparation of CsPbBr Using Green solvent3Method and device for perovskite thin film
阅读说明：本技术 使用绿色溶剂制备CsPbBr3钙钛矿薄膜的方法和器件 (Preparation of CsPbBr Using Green solvent3Method and device for perovskite thin film ) 是由 曹小兵 张国帅 郝雷 蔡一帆 蒋龙 于 2020-12-28 设计创作，主要内容包括：本发明公开了一种使用绿色溶剂制备CsPbBr-3钙钛矿的方法和器件,该方法包括以下步骤：取苯乙基溴化铵溶于异丙醇,形成PEABr/IPA溶液；取Pb(NO-3)-2水溶液制备形成Pb(NO-3)-2薄膜,然后在Pb(NO-3)-2层上滴加PEABr/IPA溶液,退火形成中间相；在中间相上滴加CsBr水溶液,热处理形成CsPbBr-3钙钛矿。本发明利用苯乙基溴化铵补充溴源,同时苯乙基溴化铵与Pb(NO-3)-2形成的中间相利于制备出覆盖完全、晶粒粗大、表面平整的CsPbBr-3薄膜,本发明的方法完全使用绿色的溶剂,具有环境友好、降低经济成本的优势,在太阳能电池等领域具有较好的应用前景。(The invention discloses a method for preparing CsPbBr by using a green solvent 3 A method and device of perovskite, the method comprising the steps of: dissolving phenethyl ammonium bromide in isopropanol to form PEABr/IPA solution; taking Pb (NO) 3 ) 2 Preparation of aqueous solution to form Pb (NO) 3 ) 2 Film, then in Pb (NO) 3 ) 2 Dripping PEABr/IPA solution on the layer, and annealing to form an intermediate phase; dropwise adding CsBr aqueous solution on the intermediate phase, and carrying out heat treatment to form CsPbBr 3 Perovskite. The invention utilizes phenethyl ammonium bromide to supplement bromine source, and simultaneously, the phenethyl ammonium bromide and Pb (NO) 3 ) 2 The formed intermediate phase is beneficial to preparing the CsPbBr with complete coverage, coarse grains and smooth surface 3 The film and the method of the invention completely use green solvents, have the advantages of environmental protection and economic cost reduction, and have better application prospect in the fields of solar cells and the like.)
1. Preparation of CsPbBr by using green solvent3A method of perovskite thin film, comprising the steps of:
dissolving phenethyl ammonium bromide in isopropanol to form PEABr/IPA solution;
taking Pb (NO)3)2Preparation of aqueous solution to form Pb (NO)3)2Film, then adding said Pb (NO)3)2Reacting the film with a PEABr/IPA solution and forming an intermediate phase by annealing;
adding CsBr aqueous solution into the intermediate phase, and forming CsPbBr by heat treatment3Perovskite.
2. The method of claim 1 wherein the concentration of phenethyl ammonium bromide in the PEABr/IPA solution is 5mg mL-1～30mg mL-1。
3. The method of claim 1, wherein the annealing temperature is 50-150 ℃.
4. The method according to claim 1, wherein the temperature of the heat treatment is 200 to 300 ℃.
5. The method according to any one of claims 1 to 4, wherein the Pb (NO)3)2The concentration of the aqueous solution is 0.8M to 1.5M.
6. The method of any of claims 1 to 4, wherein the CsBr aqueous solution has a concentration of 150mg mL-1～350mg mL-1。
7. The method according to any one of claims 1 to 4, wherein the Pb (NO)3)2The temperature of the aqueous solution is 25-90 ℃.
8. CsPbBr3A perovskite thin film, wherein CsPbBr is3Perovskite thin film preparation of CsPbBr Using Green solvent according to any of claims 1 to 63The perovskite is prepared by a method.
9. A device comprising the CsPbBr of claim 8, wherein the CsPbBr is a semiconductor device3Perovskite.
10. The device of claim 9, wherein the device comprises any one of a solar cell, a light emitting diode, a photodetector, a resistive random access memory, and a random laser emitter.
Technical Field
The invention relates to the technical field of perovskite, in particular to a method for preparing CsPbBr by using a green solvent3Calcium titaniumMethods and devices for mineral films.
Background
CsPbBr3The thin film has important potential application value in thin film devices, such as solar cells, photoelectric detectors, light emitting diodes, resistive random access memories and other fields, due to good stability of the thin film. In the thin film devices, CsPbBr with complete coverage, excellent crystallization and single phase is prepared3The film is critical to achieving excellent performance. In the prior literature, CsPbBr has been reported3The film is generally prepared using a typical two-step process. First step, preparation of PbBr2Thin films, usually of PbBr2Dissolving the powder in DMF, forming a film by a spin coating process, and annealing to obtain PbBr2A film; second, PbBr is added2Exposing the film in CsBr/methanol solution to form CsPbBr by controlling reaction time and temperature3A film. In these conventional methods, PbBr2And the formulation of CsBr solution is highly dependent on the toxic DMF and methanol. The use of these toxic solvents in large quantities poses a great threat to the physical health and environmental safety of the workers. To prepare PbBr2The DMF used in the solution is taken as an example, and volatile DMF can enter a human body through the skin and the respiratory tract of the human body and form serious harm to the nervous system, the reproductive development system, the digestive system and the like of the human body, and particularly serious damage is generated to the liver of the human body. In the list of carcinogens published by the international cancer research institute of the world health organization in 2017, the DMF is listed among them, which indicates that DMF has serious harm to the human body. Therefore, the preparation of CsPbBr in a green solvent system is developed3Film pair preparation with CsPbBr3The device with the film as the core has very important significance.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a method for preparing CsPbBr by using green solvent3Method and device for perovskite thin film, the preparation method using water-soluble lead salt Pb (NO)3)2Aqueous solution substituted for PbBr2DMF to provide CsPbBr3Lead source of film, using CsBr water solution to replaceCsBr/methanol solution to provide CsPbBr3Cesium sources for films. Simultaneously supplementing bromine source with PEABr/IPA solution to obtain CsPbBr with the metering ratio of 1:1:33A film. The method adopts nontoxic solvent water and slightly toxic isopropanol as solvents in the whole process, and solves the problem of the existing preparation of CsPbBr3The solvent toxicity problem in the thin film method has potential application value in devices such as solar cells, light emitting diodes, resistive random access memories, photodetectors and random laser emitters.
In a first aspect of the invention, a method for preparing CsPbBr by using green solvent is provided3A process for perovskite comprising the steps of:
dissolving phenethyl ammonium bromide in isopropanol to form PEABr/IPA solution;
taking Pb (NO)3)2Preparation of aqueous solution to form Pb (NO)3)2Film, then adding said Pb (NO)3)2Reacting the film with a PEABr/IPA solution and forming an intermediate phase by annealing;
adding CsBr aqueous solution into the intermediate phase, and forming CsPbBr by heat treatment3Perovskite.
CsPbBr according to embodiments of the invention3The preparation method of the perovskite has at least the following beneficial effects:
the embodiment of the invention utilizes the water-soluble precursor Pb (NO)3)2And CsBr to provide CsPbBr respectively3The lead and cesium sources in the film were supplemented with phenethyl ammonium bromide (PEABr) to obtain a stoichiometric ratio of 1:1:3 CsPbBr3Film, phenylethyl ammonium bromide and Pb (NO)3)2The formed intermediate phase is beneficial to preparing the CsPbBr with complete coverage, coarse grains and smooth surface3A film. In addition, the preparation method provided by the embodiment of the invention adopts green and environment-friendly water and isopropanol as solvents, so that the adverse effects of toxic solvents on the environment and the health of operators can be effectively eliminated. The method provided by the embodiment of the invention completely uses green solvent to prepare CsPbBr3The film has the advantage of environmental protection, and can reduce the preparation of CsPbBr3Economic cost in the thin film process can beA new technical route is provided for the subsequent large-scale production of perovskite, and the subsequent CsPbBr-based method3The large-scale production of relevant devices of the film has important practical significance and economic significance, and has better application prospect in solar cells, light-emitting diodes, photoelectric detectors, resistive random access memories and random laser transmitters.
According to some embodiments of the invention, the concentration of phenethyl ammonium bromide in the PEABr/IPA solution is 5mg mL-1～30mg mL-1。
According to some embodiments of the invention, the annealing is at a temperature of 50 to 150 ℃.
According to some embodiments of the invention, the temperature of the heat treatment is 200 to 300 ℃.
According to some embodiments of the invention, the Pb (NO)3)2The concentration of the aqueous solution is 0.8M to 1.5M.
According to some embodiments of the invention, the concentration of the CsBr aqueous solution is 150mg mL-1～350mg mL-1。
According to some embodiments of the invention, the Pb (NO)3)2The temperature of the aqueous solution is 25-90 ℃.
In a second aspect of the invention, CsPbBr is provided3Perovskite thin film, CsPbBr3Perovskite thin film CsPbBr preparation Using Green solvent according to above3The perovskite is prepared by a method.
In a third aspect of the invention, there is provided a device comprising a CsPbBr as described above3Perovskite.
According to some embodiments of the invention, the device comprises any one of a solar cell, a light emitting diode, a photodetector, a resistive random access memory, and a random laser emitter.
Drawings
The invention is further described with reference to the following figures and examples, in which:
FIG. 1 shows the formation of CsPbBr in example 13A schematic diagram of a perovskite preparation process;
FIG. 2 is a schematic structural view of a solar cell in example 1;
FIG. 3 is a drawing showing a mesophase thin film Pb (NO) formed in example 13)2-XRD diffractogram of PEABr;
FIG. 4 shows CsPbBr prepared in example 13XRD diffractogram of perovskite;
FIG. 5 shows CsPbBr prepared in example 13Scanning electron micrographs of perovskites;
fig. 6 is a current-voltage curve of the solar cell prepared in example 1;
FIG. 7 shows Pb (NO) of comparative example 1 in effect comparative example3)2A dissolution state diagram of PEABr, CsBr in water;
FIG. 8 is a photograph of a Cs-Pb-Br film as a real object obtained in comparative example 2;
FIG. 9 shows CsPbBr prepared in example 23Scanning electron microscope photographs of the perovskite thin film;
FIG. 10 shows CsPbBr prepared in example 33Scanning electron microscope photographs of the perovskite thin film;
FIG. 11 shows CsPbBr prepared in example 43Scanning electron microscope photographs of the perovskite thin film;
FIG. 12 shows CsPbBr prepared in example 53Scanning electron microscope photographs of the perovskite thin film;
FIG. 13 shows CsPbBr prepared in example 63Scanning electron micrographs of perovskite thin films.
Detailed Description
The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.
Example 1
The embodiment provides a CsPbBr-based method3A perovskite solar cell as followsThe preparation method comprises the following steps:
(1) sequential preparation of dense TiO on FTO substrates using solution methods2And porous TiO2As an electron transport layer, FTO/TiO was obtained2A substrate.
(2)Pb(NO3)2Aqueous solution: first, 397.5mg of Pb (NO)3)2The powder was dissolved in 1mL of H2O, and stirring at 80 ℃ to obtain clear Pb (NO) with a concentration of 1.2M3)2An aqueous solution.
CsBr aqueous solution: 250mg CsBr powder was dissolved in 1mL H2In O, formed concentration was 250mg mL-1Aqueous CsBr solution.
PEABr/IPA solution: 20mg of phenethyl ammonium bromide (PEABr) powder was dissolved in isopropyl alcohol (IPA) to give a concentration of 20mg mL-1。
(3)CsPbBr3Preparation of perovskite: referring to FIG. 1, the above-mentioned Pb (NO) is taken3)2Aqueous solution (i.e. Pb (NO)3)2/H2O solution) on FTO/TiO by spin coating process2Preparation of Pb (NO) on a substrate3)2A film was formed, and then a PEABr/IPA solution was added dropwise to the film to react for 60 seconds, and then the film was annealed at 100 ℃ to form a mesophase film (Pb (NO)3)2-a PEABr film).
Subsequently, an aqueous CsBr solution (i.e., CsBr/H) was dropped on the film of the intermediate phase2O solution), then heat treated at 250 ℃ for 5min to form CsPbBr3A perovskite thin film.
(4) Preparing a carbon electrode: the purchased carbon paste was knife coated to CsPbBr by a screen printing process3The perovskite thin film is then annealed at 90 ℃ to form a carbon electrode, so that a complete solar cell is formed, and the device structure of the solar cell is shown in figure 2.
Taking the mesophase film Pb (NO) prepared in the step (3)3)2XRD characterization of PEABr, the results are shown in FIG. 3, from which it can be seen that the diffraction peak of the mesophase film is significantly different from that of Pb (NO)3)2Confirmed the diffraction peak of Pb (NO)3)2A new mesophase is formed after reaction with PEABr.
The CsPbBr prepared by the reaction of the intermediate phase film in the step (3) and CsBr aqueous solution3The perovskite thin film is subjected to XRD characterization, the test result is shown in figure 4, and the result can obviously detect diffraction peaks at 15.3 degrees, 21.7 degrees and 30.8 degrees, and the diffraction peaks respectively correspond to CsPbBr3The (100), (110) and (200) crystal planes of (a) show that CsPbBr with a single component is obtained after reaction by the method of the embodiment of the present invention3A perovskite thin film. FIG. 5 shows CsPbBr prepared in step (3)3Scanning electron microscope photographs of perovskite thin films show that CsPbBr prepared by the embodiment of the invention3The perovskite thin film has a surface which is completely covered and has a flat surface, which is beneficial to preparing a high-performance solar cell. The above characterization results demonstrate that: the method utilizes the water-soluble precursor to obtain the lead source and the cesium source, and can prepare the CsPbBr with complete coverage and single phase by a solution method3A perovskite thin film.
CsPbBr-based material prepared in this example3The perovskite solar cell was exposed to a standard solar simulator and the current-voltage curve is shown in FIG. 6, the result showing the short circuit current density Jsc＝5.92mA/cm2Open circuit voltage Voc1.33V, 0.663 fill factor FF, 5.22% photoelectric conversion efficiency PCE. The results show that the water-soluble precursor Pb (NO) is utilized3)2And CsBr as the lead and cesium sources of Cs-Pb-Br, respectively, with PEABr providing a partial bromine source to obtain CsPbBr in a stoichiometric ratio of 1:1:33The thin film is introduced with PEABr to form a new intermediate phase, and the intermediate phase is assembled into a solar cell, so that excellent photovoltaic performance can be obtained.
This example is CsPbBr3The perovskite preparation is taken as an example for illustrating the formation of a solar cell, and a person skilled in the art will know that the CsPbBr prepared can be formed on the basis of the inventive concept3The perovskite is applied to devices such as light emitting diodes, photoelectric detectors, resistive random access memories, random laser emitters and the like.
Comparative example of Effect
Comparative example 1: comparative example 1 attempted to convert Pb (NO)3)2PEABr and CsBr in a molar ratio of 1:1: 1 dissolved in water at the same time, the dissolution effect is shown in fig. 7. Obviously, although the three precursors can be respectively and effectively dissolved in water, when they are mixed, a new substance insoluble in water is formed through chemical reaction. The water-insoluble substance cannot be used for preparing CsPbBr by a spin coating process3Film, results show that: with Pb (NO)3)2PEABr and CsBr as precursors, CsPbBr could not be prepared by a one-step process using water as a solvent3A film. Thus, comparative example 1 illustrates: the order of preparing the film proposed by the embodiment of the invention is to obtain CsPbBr3The film is essential, namely, the first preparation of Pb (NO)3)2Film, then reacting with PEABr to form mesophase Pb (NO)3)2-PEABr, finally reacted with CsBr and formed CsPbBr by thermal treatment3A film.
Comparative example 2: comparative example 2 provides a method of preparing a Cs-Pb-Br based thin film, according to the following steps:
(1) preparation of compact TiO by solution process2And porous TiO2As an electron transport layer, FTO/TiO was obtained2A substrate;
(2)Pb(NO3)2aqueous solution: first, 397.5mg of Pb (NO)3)2The powder was dissolved in 1mL of H2O, and stirring at 80 ℃ to obtain clear Pb (NO) with a concentration of 1.2M3)2An aqueous solution;
CsBr aqueous solution: 250mg CsBr powder was dissolved in 1mL H2In O, formed concentration was 250mg mL-1The CsBr aqueous solution of (1);
MABr/IPA solution: 20mg of methylamine bromide (MABr) powder was dissolved in isopropyl alcohol (IPA) to give a concentration of 20mg mL-1；
(3) Preparing a Cs-Pb-Br film: adding the above Pb (NO)3)2The water solution is coated on FTO/TiO by a spin coating process2Preparation of Pb (NO) on a substrate3)2Soaking the film in MABr/IPA solution for 60s, and annealing at 100 deg.C to obtain Pb (NO)3)2-MABr film.Then, in Pb (NO)3)2And dropwise adding a CsBr aqueous solution on the-MABr film, and then carrying out heat treatment at 250 ℃ for 10min to form a Cs-Pb-Br film. As a result, a real photograph of the Cs-Pb-Br film was obtained as shown in FIG. 8. The results show that: substituting MABr for PEABr to provide a bromine source, the resulting film exhibited a non-uniform color, rather than a uniform yellow color. This result shows that: using Pb (NO)3)2And CsBr provides a lead source and a cesium source, and a suitable bromine source (e.g., PEABr) is selected to produce a homogeneous CsPbBr3The thin film is very critical.
Example 2
The embodiment provides a CsPbBr-based method3A perovskite solar cell, prepared according to the following steps:
(1) sequential preparation of dense TiO on FTO substrates using solution methods2And porous TiO2As an electron transport layer, FTO/TiO was obtained2A substrate.
(2)Pb(NO3)2Aqueous solution: first, 397.5mg of Pb (NO)3)2The powder was dissolved in 1mL of H2O, and stirring at 30 ℃ to obtain clear Pb (NO) with a concentration of 1.2M3)2An aqueous solution.
CsBr aqueous solution: 250mg CsBr powder was dissolved in 1mL H2In O, formed concentration was 250mg mL-1Aqueous CsBr solution.
PEABr/IPA solution: 20mg of phenethyl ammonium bromide (PEABr) powder was dissolved in isopropyl alcohol (IPA) to give a concentration of 20mg mL-1。
(3)CsPbBr3Preparation of perovskite: taking the above Pb (NO)3)2The water solution is coated on FTO/TiO by a spin coating process2Preparation of Pb (NO) on a substrate3)2A film was formed, and then a PEABr/IPA solution was added dropwise to the film to react for 60 seconds, and then the film was annealed at 100 ℃ to form a mesophase film (Pb (NO)3)2-a PEABr film).
Subsequently, an aqueous CsBr solution was dropped on the film of the mesophase, followed by heat treatment at 250 ℃ for 5min to form CsPbBr3A perovskite thin film. Prepared CsPbBr3Scanning electron micrograph of perovskite thin film is shown in FIG. 9As can be seen from the figure, CsPbBr3The perovskite film is completely covered, the crystal grains are coarse, and the surface is smooth.
(4) Preparing a carbon electrode: the purchased carbon paste was knife coated to CsPbBr by a screen printing process3And forming a carbon electrode on the perovskite thin film by annealing treatment at 90 ℃ to form a complete solar cell.
The solar cell obtained in this example was irradiated with a standard solar simulator, and the result showed a short-circuit current density Jsc＝5.96mA/cm2Open circuit voltage Voc1.31V, 0.673 fill factor FF, 5.25% photoelectric conversion efficiency PCE. The result shows that the method of the embodiment of the invention can obtain high-quality CsPbBr3The film is assembled into a solar cell, and excellent photovoltaic performance can be obtained.
Example 3
The embodiment provides a CsPbBr-based method3A perovskite solar cell, prepared according to the following steps:
(1) sequential preparation of dense TiO on FTO substrates using solution methods2And porous TiO2As an electron transport layer, FTO/TiO was obtained2A substrate.
(2)Pb(NO3)2Aqueous solution: first, 331.3mg of Pb (NO)3)2The powder was dissolved in 1mL of H2O, and stirring at 80 ℃ to obtain clear Pb (NO) with a concentration of 1.0M3)2An aqueous solution.
CsBr aqueous solution: 250mg CsBr powder was dissolved in 1mL H2In O, formed concentration was 250mg mL-1Aqueous CsBr solution.
PEABr/IPA solution: 20mg of phenethyl ammonium bromide (PEABr) powder was dissolved in isopropyl alcohol (IPA) to give a concentration of 20mg mL-1。
(3)CsPbBr3Preparation of perovskite: taking the above Pb (NO)3)2The water solution is coated on FTO/TiO by a spin coating process2Preparation of Pb (NO) on a substrate3)2Dropping PEABr/IPA solution into the film to react for 60s, and annealing the film at 100 deg.CFilm forming mesophase (Pb (NO)3)2-a PEABr film).
Then, CsBr aqueous solution was dropped on the film of the mesophase to react for 60 seconds, followed by heat treatment at 250 ℃ for 5min to form CsPbBr3A perovskite thin film. Prepared CsPbBr3The scanning electron micrograph of the perovskite thin film is shown in FIG. 10, from which CsPbBr can be seen3The perovskite film is completely covered, the crystal grains are coarse, and the surface is smooth.
(4) Preparing a carbon electrode: the purchased carbon paste was knife coated to CsPbBr by a screen printing process3And forming a carbon electrode on the perovskite thin film by annealing treatment at 90 ℃ to form a complete solar cell.
The solar cell obtained in this example was irradiated with a standard solar simulator, and the results thereof showed: short circuit current density Jsc＝4.95mA/cm2Open circuit voltage Voc1.41V, a fill factor FF of 0.733, and a photoelectric conversion efficiency PCE of 5.12%. The result shows that the method of the embodiment of the invention can obtain high-quality CsPbBr3The film is assembled into a solar cell, and excellent photovoltaic performance can be obtained.
Example 4
The embodiment provides a CsPbBr-based method3A perovskite solar cell, prepared according to the following steps:
(1) sequential preparation of dense TiO on FTO substrates using solution methods2And porous TiO2As an electron transport layer, FTO/TiO was obtained2A substrate.
(2)Pb(NO3)2Aqueous solution: first, 397.5mg of Pb (NO)3)2The powder was dissolved in 1mL of H2O, and stirring at 80 ℃ to obtain clear Pb (NO) with a concentration of 1.2M3)2An aqueous solution.
CsBr aqueous solution: 250mg CsBr powder was dissolved in 1mL H2In O, formed concentration was 250mg mL-1Aqueous CsBr solution.
PEABr/IPA solution: phenethyl ammonium bromide (PEABr) powder was dissolved in Isopropanol (IPA) to a concentration of 8mg mL-1Of PEABr/IPA solution.
(3)CsPbBr3Preparation of perovskite: taking the above Pb (NO)3)2The water solution is coated on FTO/TiO by a spin coating process2Preparation of Pb (NO) on a substrate3)2A film was formed, and then a PEABr/IPA solution was added dropwise to the film to react for 60 seconds, and then the film was annealed at 100 ℃ to form a mesophase film (Pb (NO)3)2-a PEABr film).
Then, CsPbBr aqueous solution was dropped on the film of the mesophase to react, followed by heat treatment at 250 ℃ for 5min to form CsPbBr3A perovskite thin film. Prepared CsPbBr3The scanning electron micrograph of the perovskite thin film is shown in FIG. 11, from which CsPbBr can be seen3The perovskite film is completely covered, the crystal grains are coarse, and the surface is smooth.
(4) Preparing a carbon electrode: the purchased carbon paste was knife coated to CsPbBr by a screen printing process3And forming a carbon electrode on the perovskite thin film by annealing treatment at 90 ℃ to form a complete solar cell.
The solar cell obtained in this example was irradiated with a standard solar simulator, and the result showed a short-circuit current density Jsc＝5.36mA/cm2Open circuit voltage Voc1.39V, 0.665 fill factor FF, 4.95% photoelectric conversion efficiency PCE. The result shows that the method of the embodiment of the invention can obtain high-quality CsPbBr3The film is assembled into a solar cell, and excellent photovoltaic performance can be obtained.
Example 5
The embodiment provides a CsPbBr-based method3A perovskite solar cell, prepared according to the following steps:
(1) sequential preparation of dense TiO on FTO substrates using solution methods2And porous TiO2As an electron transport layer, FTO/TiO was obtained2A substrate.
(2)Pb(NO3)2Aqueous solution: first, 331.3mg of Pb (NO)3)2The powder was dissolved in 1mL of H2O, and stirring at 80 ℃ to obtain clear Pb (NO) with a concentration of 1.0M3)2An aqueous solution.
CsBr aqueous solution: 250mg CsBr powder was dissolved in 1mL H2In O, formed concentration was 250mg mL-1Aqueous CsBr solution.
PEABr/IPA solution: phenethyl ammonium bromide (PEABr) powder was dissolved in Isopropanol (IPA) to a concentration of 8mg mL-1Of PEABr/IPA solution.
(3)CsPbBr3Preparation of perovskite: taking the above Pb (NO)3)2The water solution is coated on FTO/TiO by a spin coating process2Preparation of Pb (NO) on a substrate3)2A film was formed, and then a PEABr/IPA solution was added dropwise to the film to react for 60 seconds, and then the film was annealed at 100 ℃ to form a mesophase film (Pb (NO)3)2-a PEABr film).
Then, CsPbBr aqueous solution was dropped on the film of the mesophase to react, followed by heat treatment at 300 ℃ for 10min to form CsPbBr3A perovskite thin film. Prepared CsPbBr3The scanning electron micrograph of the perovskite thin film is shown in FIG. 12, from which CsPbBr can be seen3The perovskite film is completely covered, the crystal grains are coarse, and the surface is smooth.
(4) Preparing a carbon electrode: the purchased carbon paste was knife coated to CsPbBr by a screen printing process3And forming a carbon electrode on the perovskite thin film by annealing treatment at 90 ℃ to form a complete solar cell.
The solar cell obtained in this example was irradiated with a standard solar simulator, and the result showed a short-circuit current density Jsc＝5.16mA/cm2Open circuit voltage Voc1.35V, 0.692 fill factor FF and 4.82% photoelectric conversion efficiency PCE. The result shows that the method of the embodiment of the invention can obtain high-quality CsPbBr3The film is assembled into a solar cell, and excellent photovoltaic performance can be obtained.
Example 6
The embodiment provides a CsPbBr-based method3A perovskite solar cell, prepared according to the following steps:
(1) sequential preparation of dense TiO on FTO substrates using solution methods2And porous TiO2As an electron transport layer, FTO/TiO was obtained2A substrate.
(2)Pb(NO3)2Aqueous solution: first, 331.3mg of Pb (NO)3)2The powder was dissolved in 1mL of H2O, and stirring at 80 ℃ to obtain clear Pb (NO) with a concentration of 1.0M3)2An aqueous solution.
CsBr aqueous solution: 150mg CsBr powder was dissolved in 1mL H2In O, formed concentration was 150mg mL-1Aqueous CsBr solution.
PEABr/IPA solution: phenethyl ammonium bromide (PEABr) powder was dissolved in Isopropanol (IPA) to a concentration of 8mg mL-1Of PEABr/IPA solution.
(3)CsPbBr3Preparation of perovskite: taking the above Pb (NO)3)2The water solution is coated on FTO/TiO by a spin coating process2Preparation of Pb (NO) on a substrate3)2A film was formed, and then a PEABr/IPA solution was added dropwise to the film to react for 60 seconds, and then the film was annealed at 100 ℃ to form a mesophase film (Pb (NO)3)2-a PEABr film).
Then, CsPbBr aqueous solution was dropped on the film of the mesophase to react, followed by heat treatment at 300 ℃ for 10min to form CsPbBr3A perovskite thin film. Prepared CsPbBr3The scanning electron micrograph of the perovskite thin film is shown in FIG. 13, from which CsPbBr can be seen3The perovskite film is completely covered, the crystal grains are coarse, and the surface is smooth.
(4) Preparing a carbon electrode: the purchased carbon paste was knife coated to CsPbBr by a screen printing process3And forming a carbon electrode on the perovskite thin film by annealing treatment at 90 ℃ to form a complete solar cell.
The solar cell obtained in this example was irradiated with a standard solar simulator, and the result showed a short-circuit current density Jsc＝4.68mA/cm2Open circuit voltage Voc1.38V, the fill factor FF is 0.723, and the photoelectric conversion efficiency PCE is 4.67%. The result shows that the method of the embodiment of the invention can obtain high-quality CsPbBr3Film, assembling it into the sunCan be used for a battery, and can obtain excellent photovoltaic performance.