Formamidinium lead-based perovskite material, preparation method and application thereof

Abstract

The application belongs to the field of solar cells, and relates to a formamidinium lead-based perovskite material and a preparation method and application thereof. The preparation method of the formamidinium lead-based perovskite material mainly comprises the following steps: S1, dissolving formamidinium iodide (FAI) and lead iodide (PbI2) in a solvent according to a certain molar ratio and stirring and dissolving; S2, washing and drying the mixed solution stirred and dissolved to obtain FAPbI3 material; and S3, adding the FAPbI3 material into a quaternary ammonium salt solution to obtain quaternary ammonium salt modified FAPbI3 material. The application has the following advantages: the FAPbI3 perovskite material containing the quaternary ammonium salt has better stability; the FAPbI3 thin film prepared contains a low-dimensional structure formed by quaternary ammonium salt molecules, which can significantly improve the quality and stability of the thin film; and the carbon-based perovskite solar cell prepared by using the FAPbI3 material has the advantages of good repeatability, easy operation and low cost, and the device efficiency reaches 16.82%.

Description

TECHNICAL FIELD

[0001] The application relates to a formamidinium lead-based perovskite material and a preparation method and application thereof, and belongs to the technical field of solar cells. BACKGROUND

[0002] Organic-inorganic hybrid perovskite materials are very suitable for being used as light absorption materials of solar cells due to high carrier mobility, long carrier diffusion length, high extinction coefficient and adjustable band gap. The solar cell is a device for converting light energy into electrical energy by using a photovoltaic effect, and the authentication efficiency has reached 25.7%, reaching the efficiency level similar to that of traditional silicon solar cells. The perovskite solar cell has developed rapidly in a short time, fully demonstrating its great potential in the field of solar cells. At present, high-efficiency perovskite solar cells are mainly based on formamidinium lead-based perovskite (FAPbI3) materials, which have excellent photoelectric properties, thermal stability, high extinction coefficient and suitable band gap, and exhibit excellent application potential. However, the FAPbI3 material is prone to phase transition in air, which adversely affects the performance and stability of the device. Therefore, it is crucial to develop high-quality and phase-stable FAPbI3 materials for preparing high-efficiency and stable perovskite solar cells.

[0003] Therefore, it is necessary to provide a formamidinium lead-based perovskite material and a preparation method and application thereof to solve the above problems. SUMMARY

[0004] The application aims to provide a preparation method of a formamidinium lead-based perovskite material and a formamidinium lead-based perovskite thin film, so that the prepared FAPbI3 perovskite thin film has a more stable phase structure and higher film quality.

[0005] To achieve the above-mentioned purpose, the application provides a preparation method of a formamidinium lead-based perovskite material, which mainly comprises the following steps:

[0006] Step S1, iodine formamidinium (FAI) and lead iodide (PbI2) are dissolved in a solvent according to a certain molar ratio and are stirred and dissolved;

[0007] Step S2, the mixed solution stirred and dissolved is washed and dried to obtain a FAPbI3 material;

[0008] Step S3, the FAPbI3 material is added into a quaternary ammonium salt solution to obtain a quaternary ammonium salt modified FAPbI3 material.

[0009] As a further improvement of the application, in step S1, the molar ratio of the formamidinium (FAI) to the lead iodide (PbI2) is (1-1.8):1.

[0010] 10As a further improvement of the present application, in step S1, the solvent is at least one of acetonitrile, gamma-butyrolactone, 2-methoxyethanol.

[0011] As a further improvement of the present application, in step S3, the quaternary ammonium salt is at least one of phenyltrimethylammonium iodide (PTAI), ethyltripropylammonium iodide (EPAI), tetrahexylammonium iodide (THAI), tetrabutylammonium iodide (TBAI).

[0012] As a further improvement of the present application, in step S3, the concentration of the quaternary ammonium salt solution is 0.1 mg / mL-20 mg / mL.

[0013] As a further improvement of the present application, in step S3, the solvent in the quaternary ammonium salt solution is one of hexafluoroisopropanol, chloroform, chlorobenzene, toluene, etc. or a mixed solution thereof.

[0014] To achieve the above-mentioned purpose, the present application further provides a formamidinium lead-based perovskite thin film, which is applied to the preparation method of the aforementioned formamidinium lead-based perovskite material.

[0015] As a further improvement of the present application, the formamidinium lead-based perovskite thin film contains a low-dimensional phase structure formed by a quaternary ammonium salt.

[0016] The purpose of the present application is also to provide a formamidinium lead-based perovskite solar cell to improve the efficiency and stability of the perovskite solar cell.

[0017] To achieve the above-mentioned purpose, the present application provides a formamidinium lead-based perovskite solar cell, which comprises the aforementioned formamidinium lead-based perovskite thin film.

[0018] The purpose of the present application is also to provide a preparation method of a formamidinium lead-based perovskite solar cell to better apply the aforementioned formamidinium lead-based perovskite solar cell.

[0019] To achieve the above-mentioned purpose, the present application provides a preparation method of a formamidinium lead-based perovskite solar cell, which mainly comprises:

[0020] 20Step 1, depositing an electron transport layer on a transparent electrode substrate;

[0021] Step 2, depositing a perovskite light-absorbing layer on the electron transport layer; wherein the perovskite light-absorbing layer is obtained by the aforementioned preparation method;

[0022] Step 3, depositing a hole transport layer on the perovskite light-absorbing layer;

[0023] Step 4, depositing a carbon electrode on the hole transport layer to obtain a formamidinium lead-based perovskite solar cell.

[0024] The beneficial effects of the present application are: compared with the prior art, the present application has the following significant advantages: 1. The FAPbI3 perovskite material containing quaternary ammonium salt modification has better stability. 2. The low-dimensional structure formed by the quaternary ammonium salt molecules in the prepared FAPbI3 thin film can significantly improve the quality and stability of the thin film. 3. The carbon-based perovskite solar cell prepared by using the FAPbI3 material of the present application has a device efficiency of 16.82%, and has the advantages of good repeatability, easy operation and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a graph of FAPbI3 perovskite material in air environment over time in Example 1 and Comparative Example.

[0026] Figure 2 is a curve of the phase transition area size of the FAPbI3 perovskite thin film at different time periods in Example 1 and Comparative Example.

[0027] Figure 3 is an XRD graph of the FAPbI3 perovskite thin film in Example 1 and Comparative Example.

[0028] Figure 4 is an XRD graph of the FAPbI3 perovskite thin film in Example 1 and Comparative Example.

[0029] Figure 5 is a current density-voltage test curve of the FAPbI3 carbon-based perovskite solar cell in Example 1, Example 2, Example 3 and Comparative Example. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be described in detail below in combination with the drawings and specific examples.

[0031] The present application discloses a preparation method of formamidinium lead-based perovskite material, which mainly comprises:

[0032] Step S1, iodine formamidinium (FAI) and lead iodide (PbI2) are dissolved in a solvent in a certain molar ratio and stirred and dissolved;

[0033] Step S2, the mixed solution stirred and dissolved above is washed and dried to obtain FAPbI3 material;

[0034] Step S3, the FAPbI3 material above is added to a quaternary ammonium salt solution to obtain a quaternary ammonium salt modified FAPbI3 material.

[0035] In step S1, the molar ratio of formamidinium (FAI) to lead iodide (PbI2) is (1-1.8): 1.

[0036] In step S1, the solvent is at least one of acetonitrile, gamma-butyrolactone, 2-methoxyethanol.

[0037] In step S3, the quaternary ammonium salt is at least one of phenyltrimethylammonium iodide (PTAI), ethyltripropylammonium iodide (EPAI), tetrahexylammonium iodide (THAI), tetrabutylammonium iodide (TBAI).

[0038] In step S3, the concentration of the quaternary ammonium salt solution is 0.1 mg / mL-20 mg / mL.

[0039] In step S3, the solvent in the quaternary ammonium salt solution is one of hexafluoroisopropanol, chloroform, chlorobenzene, toluene, etc., or a mixed solution thereof.

[0040] The application also discloses a formamidinium lead-based perovskite thin film prepared by the method.

[0041] The formamidinium lead-based perovskite thin film contains a low-dimensional phase structure formed by a quaternary ammonium salt.

[0042] The application also discloses a formamidinium lead-based perovskite solar cell comprising the formamidinium lead-based perovskite thin film.

[0043] The preparation method of the formamidinium lead-based perovskite solar cell mainly comprises the following steps.

[0044] Step 1, depositing an electron transport layer on a transparent electrode substrate;

[0045] Step 2, depositing a perovskite light-absorbing layer on the electron transport layer; wherein the perovskite light-absorbing layer is obtained by the preparation method described above;

[0046] Step 3, depositing a hole transport layer on the perovskite light-absorbing layer;

[0047] Step 4, depositing a carbon electrode on the hole transport layer to obtain a formamidinium lead-based perovskite solar cell.

[0048] In order to more clearly illustrate the technology of the application, the following examples are provided for detailed description.

[0049] Example 1:

[0050] The embodiment relates to a preparation method of a formamidinium lead-based perovskite material, comprising the following steps:

[0051] (1) Synthesis of FAPbI3 material. Formamidinium iodide (FAI) and lead iodide (PbI2) were dissolved in acetonitrile solvent at a molar ratio of 1.4:1, stirred at room temperature for 24 h. After the solution was mixed uniformly, it was washed with diethyl ether and filtered, and then placed in an oven at 140°C for 10 h to dry, to obtain the FAPbI3 material.

[0052] (2) Preparation of quaternary ammonium salt modified FAPbI3 material. 1 g of the above FAPbI3 material was weighed and added to a hexafluoroisopropanol solution (2 mg / mL) of PTAI and stirred for 30 min, then filtered and dried to obtain the PTAI modified FAPbI3 material.

[0053] This example relates to a preparation method of a formamidinium lead-based perovskite thin film, comprising the following steps:

[0054] The PTAI modified FAPbI3 material and MACl were dissolved in a mixed solution of 690 μL DMF and 115 μL DMSO, and stirred at room temperature on a magnetic stirrer for 12 h to obtain a PTAI modified FAPbI3 perovskite precursor solution. The PTAI modified FAPbI3 perovskite precursor solution was deposited on a substrate at a spin coating parameter of 6000 rpm for 30 s, and annealed at 100°C on a hot stage for 1 h to obtain a PTAI modified FAPbI3 perovskite thin film.

[0055] This example also relates to a preparation method of a formamidinium lead-based perovskite solar cell, comprising the following steps:

[0056] (1) Depositing a SnO2 electron transport layer on a transparent electrode ITO substrate at a spin coating parameter of 4000 rpm for 30 s, and then annealing at 150°C for 30 min;

[0057] (2) Depositing a perovskite light absorbing layer on the electron transport layer SnO2 substrate, wherein the perovskite light absorbing layer is prepared by the method described above;

[0058] (3) Depositing a Spiro-OMeTAD hole transport layer on the perovskite light absorbing layer at a spin coating parameter of 4000 rpm for 30 s, and then placing it in a drying cabinet for oxidation for 24 h;

[0059] (4) Hot pressing a carbon electrode on the surface of Spiro-OMeTAD at a temperature of 60°C and a hot pressing time of 30 s to obtain a FAPbI3 carbon-based perovskite solar cell.

[0060] Finally, the device was tested under simulated sunlight of 100 mW / cm 2 AM 1.5G light intensity, and the current-voltage change was tested by Keithley 2400, and the test results are as follows:Figure 5 As shown, the photoelectric conversion efficiency of the PTAl-modified FAPbl3 carbon-based perovskite solar cell is 16.82%.

[0061] Example 2

[0062] The steps of this example are the same as those of Example 1 except that the quaternary ammonium salt material used in this example is different. The quaternary ammonium salt material used in this example is EPAI. The device is placed under simulated sunlight of 100 mW / cm2 2 The current-voltage change is tested under the light intensity of AM 1.5G using Keithley 2400, and the test results are as follows: Figure 5 As shown, the photoelectric conversion efficiency of the EPAI-modified FAPbl3 carbon-based perovskite solar cell is 16.01%.

[0063] Example 3

[0064] The steps of this example are the same as those of Example 1 except that the quaternary ammonium salt material used in this example is different. The quaternary ammonium salt material used in this example is THAI. The device is placed under simulated sunlight of 100 mW / cm2 2 The current-voltage change is tested under the light intensity of AM 1.5G using Keithley 2400, and the test results are as follows: Figure 5 As shown, the photoelectric conversion efficiency of the THAI-modified FAPbl3 carbon-based perovskite solar cell is 15.53%.

[0065] Comparative Example

[0066] The steps of this example are the same as those of Example 1 except that the quaternary ammonium salt material used in this example is different. The quaternary ammonium salt material used in this example is THAI. The device is placed under simulated sunlight of 100 mW / cm2 2 The current-voltage change is tested under the light intensity of AM 1.5G using Keithley 2400, and the test results are as follows: Figure 3 As shown, the photoelectric conversion efficiency of the THAI-modified FAPbl3 carbon-based perovskite solar cell is 15.53%.

[0067] Figure 1 The FAPbl3 material in the comparative example and Example 1 is shown in the air environment over time. The FAPbl3 material in the comparative example begins to appear yellow after 2 days in the air, and the yellow material can be clearly observed after 6 days, indicating that the a-FAPbl3 material may have been converted to the δ-FAPbl3 material; while the PTAI-modified FAPbl3 material remains black after 6 days, indicating that PTAI modification can enhance the phase stability of the FAPbl3 material.

[0068] Figure 2The phase transition area size of FAPbI3 perovskite film in Comparative Example and Example 1 at different time periods is shown. In Comparative Example, about 35% of the area has phase transition after 2 days, about 58% of the area has phase transition after 4 days, about 76% of the area has phase transition after 6 days, and about 87% of the area has phase transition by the 8th day. In Example 1, phase transition occurs after 6 days, about 11% of the phase transition area, and 23% of the area has phase transition after 8 days. This shows that the phase transition of FAPbI3 can be inhibited after PTAI modification.

[0069] Figure 3 The XRD patterns of FAPbI3 perovskite films in Example 1 and Comparative Example are shown. Compared with Comparative Example, the crystallinity of the perovskite in Example 1 is enhanced after PTAI modification, and a two-dimensional peak appears at 8.42°, which plays a passivation role on the perovskite film

[0070] Figure 4 The XRD patterns of FAPbI3 perovskite films in Example 1 and Comparative Example after being placed in an air environment for 2 days are shown. In Comparative Example, a δ-FAPbI3 peak appears at 11.70° after 2 days, indicating that the film has undergone serious phase transition. In Example 1, there is almost no change after 48 h, and a low-dimensional peak can be observed at 8.42°, indicating that the presence of low-dimensional perovskite can inhibit the phase transition of FAPbI3 perovskite.

[0071] Figure 5 The device efficiency diagrams of FAPbI3 perovskite films in Comparative Example and Examples 1, 2 and 3 are shown. The device performance of FAPbI3 carbon-based perovskite solar cells in Examples 1, 2 and 3 is significantly improved, which is 16.82%, 16.01% and 15.53% respectively, which is significantly higher than the device performance (14.17%) of FAPbI3 carbon-based perovskite solar cells in Comparative Example.

[0072] In summary, compared with the prior art, the present application has the following advantages: 1. The FAPbI3 perovskite material containing quaternary ammonium salt modification has better stability. 2. The low-dimensional structure formed by the quaternary ammonium salt molecules in the prepared FAPbI3 film can significantly improve the quality and stability of the film. 3. The device efficiency of the carbon-based perovskite solar cell prepared by using the FAPbI3 material of the present application reaches 16.82%, which has the advantages of good repeatability, easy operation and low cost.

[0073] The above examples are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A formamidinium lead-based perovskite thin film, characterized in that: The application relates to a preparation method of formamidinium lead-based perovskite material, and mainly comprises the following steps: S1, formamidinium iodide (FAI) and lead iodide (PbI2) are dissolved in a solvent according to a certain molar ratio and are stirred and dissolved; S2, the mixed solution after stirring and dissolving is washed and dried to obtain FAPbI3 material; S3, the FAPbI3 material is added into a quaternary ammonium salt solution to obtain quaternary ammonium salt modified FAPbI3 material; in S3, the quaternary ammonium salt is at least one of phenyltrimethylammonium iodide (PTAI), ethyltripropylammonium iodide (EPAI), tetrahexylammonium iodide (THAI) and tetrabutylammonium iodide (TBAI); The quaternary ammonium salt modified FAPbI3 material is dissolved in a DMF and DMSO mixed solvent, and a formamidinium lead-based perovskite thin film is prepared through solution spin coating; the formamidinium lead-based perovskite thin film contains a low-dimensional phase structure formed by quaternary ammonium salt.

2. The formamidinium lead-based perovskite thin film according to claim 1, characterized in that: In S1, the molar ratio of formamidinium (FAI) to lead iodide (PbI2) is (1-1.8):

1.

3. The formamidinium lead-based perovskite thin film according to claim 2, characterized in that: In S1, the solvent is at least one of acetonitrile, gamma-butyrolactone and 2-methoxyethanol.

4. The formamidinium lead-based perovskite thin film of claim 1, wherein: In S3, the concentration of the quaternary ammonium salt solution is 0.1 mg / mL-20 mg / mL.

5. The formamidinium lead-based perovskite thin film of claim 1, wherein: In S3, the solvent in the quaternary ammonium salt solution is one of hexafluoroisopropanol, chloroform, chlorobenzene, toluene and the like or a mixed solution thereof.

6. A formamidinium lead-based perovskite solar cell, characterized by: The formamidinium lead-based perovskite solar cell comprises the formamidinium lead-based perovskite thin film according to any one of claims 1-5.

7. A method for preparing a formamidinium lead-based perovskite solar cell, characterized in that: The preparation method mainly comprises the following steps: S1, an electron transport layer is deposited on a transparent electrode substrate; S2, a perovskite light-absorbing layer is deposited on the electron transport layer; wherein the perovskite light-absorbing layer is obtained by using the preparation method of the formamidinium lead-based perovskite material according to any one of claims 1-5; S3, a hole transport layer is deposited on the perovskite light-absorbing layer; S4, a carbon electrode is deposited on the hole transport layer to obtain a formamidinium lead-based perovskite solar cell.

Images