Perovskite precursor solution, perovskite thin film prepared from perovskite precursor solution, preparation method and solar cell

Abstract

The invention discloses a perovskite precursor solution, a perovskite thin film prepared from the perovskite precursor solution, a preparation method and a solar cell, the perovskite precursor solution comprises a solute, a DDS additive and an organic solvent, the solute comprises methylamine halide plumbate and / or formamidine halide plumbate, and the DDS additive is complexed with lead ions in the solute. According to the method, the DDS additive is introduced into the perovskite precursor solution to control the volatilization rate of the solvent, so that uniform crystal growth is realized, the quality and the stability of the perovskite film are improved, and the performance of a photoelectric device is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a perovskite precursor solution, a perovskite film prepared therefrom, a preparation method and a solar cell. Background Art

[0002] As an emerging optoelectronic semiconductor material, perovskite materials have attracted widespread attention in the field of solar cells in recent years due to their excellent light absorption characteristics, high photoelectric conversion efficiency, and low-cost preparation process. However, the crystallization process of perovskite materials has a crucial influence on the quality of their films and the performance of the final devices. The perovskite crystallization process is easily affected by factors such as environmental humidity, solvent evaporation rate, and temperature, which can lead to problems such as uneven film quality, high porosity, or incomplete crystallization. These problems directly affect the optoelectronic properties and stability of perovskite films, limiting their widespread promotion in practical applications.

[0003] At present, the quality of perovskite crystallization is mainly improved by regulating solvent engineering, introducing additives and optimizing deposition process to improve device efficiency. However, the crystallization process still needs to be further optimized to improve the uniformity, crystallinity and long-term stability of perovskite films. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, embodiments of the present invention provide a perovskite precursor solution, a perovskite film prepared therefrom, a preparation method, and a solar cell.

[0006] In a first aspect, the present invention provides a perovskite precursor solution, comprising:

[0007] a solute, wherein the solute comprises methylamine halide plumbate and / or formamidine halide plumbate;

[0008] A DDS additive that complexes with lead ions in the solute;

[0009] Organic solvents.

[0010] Furthermore, the halogen element in the solute is one or more of chlorine, bromine and iodine.

[0011] Furthermore, the added amount of the DDS additive is 0.01-10 mg / ml.

[0012] Furthermore, the organic solvent includes one or more of DMF, DMSO, NMP and GBL.

[0013] In a second aspect, the present invention provides a method for preparing a perovskite film, using the perovskite precursor solution provided in the first aspect, comprising the following steps:

[0014] (a) Prepare a clean and dry substrate;

[0015] (b) coating a perovskite precursor solution on the substrate;

[0016] (c) The substrate is placed on a heating stage and annealed in an inert gas atmosphere to obtain a perovskite film.

[0017] Furthermore, the substrate is a substrate to which a solution film can be attached.

[0018] Furthermore, the coating method in step (b) includes one of spin coating, spray coating, blade coating, screen printing, air knife coating, and slit extrusion coating.

[0019] Furthermore, in the step (c), the annealing temperature is 100 to 300° C., and the annealing time is 10 to 60 minutes.

[0020] In a third aspect, the present invention proposes a perovskite film prepared by the method proposed in the second aspect.

[0021] In a fourth aspect, the present invention proposes a solar cell comprising the perovskite film proposed in the third aspect or the perovskite film prepared by the method proposed in the second aspect, wherein the solar cell also comprises a conductive substrate, an electron transport layer, a hole transport layer and a metal electrode, wherein the conductive substrate, the electron transport layer, the perovskite film, the hole transport layer and the metal electrode are arranged in sequence.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The present invention introduces a DDS additive into a perovskite precursor solution to control the volatilization rate of the solvent, thereby achieving uniform crystal growth, improving the quality and stability of the perovskite film, and further improving the performance of the optoelectronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0025] Figure 1 The flowchart of the method for preparing the perovskite film of the present invention;

[0026] Figure 2 Schematic diagram of the structure of the DDS additive of the present invention. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0028] The perovskite precursor solution, the perovskite film prepared therefrom, the preparation method and the solar cell of the present invention are described below in conjunction with the accompanying drawings.

[0029] The perovskite precursor solution includes a solute, a DDS additive and an organic solvent, wherein the solute includes methylamine halide lead salt and / or methylammonium halide lead salt, the halogen element in the solute is one or more of chlorine, bromine and iodine, and the organic solvent includes one or more of DMF (dimethylformamide), DMSO (dimethyl sulfoxide), NMP (N-methylpyrrolidone) and GBL (1,4-butyrolactone).

[0030] The structural formula of DDS additive is as follows Figure 2 As shown, the DDS additive complexes with the lead ions in the solute, thereby regulating the evaporation rate of the solvent and the nucleation behavior of the solution, ensuring that the perovskite crystal forms a uniform film during the deposition process, avoiding problems such as uneven crystallization or excessive pores. In addition, the amino groups on the benzene ring of the molecule can also form hydrogen bonds with organic cations in the film to achieve a molecular bridging effect, further regulating the crystallization process of the solute in the precursor solution during the crystallization process.

[0031] The amount of DDS additive added is 0.01-10 mg / ml. In some embodiments, the amount of DDS additive added can be 0.01 mg / ml, 0.1 mg / ml, 0.5 mg / ml, 1 mg / ml, 5 mg / ml, 10 mg / ml, or a value within a range consisting of any two values ​​of the solute mass.

[0032] When the amount of DDS additive added is within an appropriate range, the perovskite crystallization is improved and defects are passivated; when the amount of DDS additive added is too much, the crystallization of the perovskite film is hindered; when the amount of DDS additive added is too little, the defect passivation effect is not obvious and the battery performance improvement is low.

[0033] The preparation method of perovskite film, such as Figure 1 As shown, using a perovskite precursor solution, the following steps are included:

[0034] (a) Prepare a clean and dry substrate;

[0035] (b) coating a perovskite precursor solution on a substrate;

[0036] (c) The substrate is placed on a heating stage and annealed in an inert gas atmosphere to obtain a perovskite film.

[0037] In step (a), the substrate is a substrate to which a solution film can be attached, such as a conductive substrate in a single-junction battery, a silicon battery base in a stacked battery structure, etc.

[0038] The coating method in step (b) includes one of spin coating, spray coating, blade coating, screen printing, air knife coating, and slit extrusion coating.

[0039] In step (c), the annealing temperature is 100-300° C., and the annealing time is 10-60 min. The inert gas atmosphere is provided by nitrogen or argon. In addition, the thickness of the perovskite film is controlled by the concentration of the perovskite precursor solution and the coating thickness.

[0040] The perovskite film prepared by using the perovskite precursor solution can be used in solar cells. The solar cell includes a conductive substrate, an electron transport layer, a hole transport layer and a metal electrode, and the conductive substrate, the electron transport layer, the perovskite film, the hole transport layer and the metal electrode are arranged in sequence upstream and downstream. The electron transport layer can be an n-type inorganic semiconductor or an n-type organic semiconductor. The hole transport layer includes a hole transport material, and the hole transport material is one of Spiro-OMeTAD, PTAA, P3HT or CuSCN.

[0041] The present invention is described below in conjunction with specific examples. The test materials and reagents used in the following examples, unless otherwise specified, can be obtained from commercial sources. If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0042] Example 1

[0043] Preparation of perovskite precursor solution:

[0044] 240.8 mg FAI, 737.6 mg PbI2, 18.2 mg CsI, 33.8 mg MACl and 0.5 mg DDS were dissolved in a mixed solvent of 0.8 mL DMF and 0.2 mL DMSO to prepare a perovskite precursor solution having a molar concentration of 1.47 mol / L for later use.

[0045] Preparation of perovskite thin films:

[0046] Select an area of ​​10*10cm 2The polyvinyl alcohol substrate sheet was cleaned with glass cleaning agent, deionized water, acetone, and ethanol ultrasonically for 20 minutes, dried with nitrogen, and placed in an ozone machine for 5 minutes. The perovskite precursor solution was coated on the polyvinyl alcohol substrate sheet, and the polyvinyl alcohol substrate sheet was transferred to a heating table, and the heating temperature was set to 100°C for 60 minutes. Under the protection of a nitrogen atmosphere, the perovskite crystals were heated to brown, and cooled to room temperature to obtain a perovskite film with a thickness of 600nm.

[0047] Preparation of solar cells:

[0048] An electron transport layer is prepared on a clean and dry polyvinyl alcohol flexible substrate. The material is SnO2. The electron transport layer is prepared on the surface of the polyvinyl alcohol flexible substrate by a spray coating method. A perovskite film layer is directly prepared on the prepared electron transport layer according to the preparation method of the perovskite film.

[0049] A hole transport layer is made on the prepared perovskite film layer. The material is gallium copper oxide. The hole transport layer is prepared on the surface of the perovskite layer by spraying. Then laser etching is used to form the lines required for the battery series connection and lead out the electrodes.

[0050] The metal electrode Al is deposited on the hole transport layer by vacuum thermal evaporation. The thickness of the metal electrode is 80 nm, and the preparation of the perovskite solar cell is completed.

[0051] Example 2

[0052] Preparation of perovskite precursor solution:

[0053] 240.8 mg FAI, 737.6 mg PbI2, 18.2 mg CsI, 33.8 mg MACl and 1 mg DDS were dissolved in a mixed solvent of 0.8 mL DMF and 0.2 ml DMSO to prepare a perovskite precursor solution with a molar concentration of 1.47 mol / L for later use.

[0054] Preparation of perovskite thin films:

[0055] Preparation of perovskite thin films:

[0056] Select an area of ​​10*10cm 2 The polyvinyl alcohol substrate sheet was cleaned with glass cleaning agent, deionized water, acetone, and ethanol ultrasonically for 20 minutes, dried with nitrogen, and placed in an ozone machine for 5 minutes. The perovskite precursor solution was coated on the polyvinyl alcohol substrate sheet, and the polyvinyl alcohol substrate sheet was transferred to a heating table, and the heating temperature was set to 100°C for 60 minutes. Under the protection of a nitrogen atmosphere, the perovskite crystals were heated to brown, and cooled to room temperature to obtain a perovskite film with a thickness of 600nm.

[0057] Preparation of solar cells:

[0058] An electron transport layer is prepared on a clean and dry polyvinyl alcohol flexible substrate. The material is SnO2. The electron transport layer is prepared on the surface of the polyvinyl alcohol flexible substrate by a spray coating method. A perovskite film layer is directly prepared on the prepared electron transport layer according to the preparation method of the perovskite film.

[0059] A hole transport layer is made on the prepared perovskite film layer. The material is gallium copper oxide. The hole transport layer is prepared on the surface of the perovskite layer by spraying. Then laser etching is used to form the lines required for the battery series connection and lead out the electrodes.

[0060] The metal electrode Al is deposited on the hole transport layer by vacuum thermal evaporation. The thickness of the metal electrode is 80 nm, and the preparation of the perovskite solar cell is completed.

[0061] Example 3

[0062] Preparation of perovskite precursor solution:

[0063] 240.8 mg FAI, 737.6 mg PbI2, 18.2 mg CsI, 33.8 mg MACl and 10 mg DDS were dissolved in a mixed solvent of 0.8 mL DMF and 0.2 mL DMSO to prepare a perovskite precursor solution having a molar concentration of 1.47 mol / L for later use.

[0064] Preparation of perovskite thin films:

[0065] Select an area of ​​10*10cm 2 The polyvinyl alcohol substrate sheet was cleaned with glass cleaning agent, deionized water, acetone, and ethanol ultrasonically for 20 minutes, dried with nitrogen, and placed in an ozone machine for 5 minutes. The perovskite precursor solution was coated on the polyvinyl alcohol substrate sheet, and the polyvinyl alcohol substrate sheet was transferred to a heating table, and the heating temperature was set to 100°C for 60 minutes. Under the protection of a nitrogen atmosphere, the perovskite crystals were heated to brown, and cooled to room temperature to obtain a perovskite film with a thickness of 600nm.

[0066] Preparation of solar cells:

[0067] An electron transport layer is prepared on a clean and dry polyvinyl alcohol flexible substrate. The material is SnO2. The electron transport layer is prepared on the surface of the polyvinyl alcohol flexible substrate by a spray coating method. A perovskite film layer is directly prepared on the prepared electron transport layer according to the preparation method of the perovskite film.

[0068] A hole transport layer is made on the prepared perovskite film layer. The material is gallium copper oxide. The hole transport layer is prepared on the surface of the perovskite layer by spraying. Then laser etching is used to form the lines required for the battery series connection and lead out the electrodes.

[0069] The metal electrode Al is deposited on the hole transport layer by vacuum thermal evaporation. The thickness of the metal electrode is 80 nm, and the preparation of the perovskite solar cell is completed.

[0070] Comparative Example 1

[0071] The difference from Example 1 is that no DDS additive is added when preparing the perovskite precursor solution.

[0072] Comparative Example 2

[0073] The difference from Example 1 is that when preparing the perovskite precursor solution, the added amount of the DDS additive is 13 mg.

[0074] Test example

[0075] The perovskite solar cells prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were tested by a solar light simulator to test the photoelectric conversion efficiency of the perovskite solar cells. The test results are shown in Table 1 below.

[0076] Table 1

[0077] Grouping Photoelectric conversion efficiency Example 1 18.2％ Example 2 18.9％ Example 3 17.8％ Comparative Example 1 15.4％ Comparative Example 2 16.5％

[0078] According to Table 1, adding DDS additive can significantly improve the conversion efficiency of solar cells. When no DDS additive is added or the amount of DDS additive added is too much, it is not conducive to improving the conversion efficiency of solar cells.

[0079] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. 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 schematic representations of the above terms may be for different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0080] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0081] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A perovskite precursor solution, characterized in that: include: a solute, wherein the solute comprises methylamine halide plumbate and / or formamidine halide plumbate; A DDS additive that complexes with lead ions in the solute; Organic solvents.

2. The perovskite precursor solution according to claim 1, characterized in that The halogen element in the solute is one or more of chlorine, bromine and iodine.

3. The perovskite precursor solution according to claim 1, characterized in that The added amount of the DDS additive is 0.01-10 mg / ml.

4. The perovskite precursor solution according to claim 1, characterized in that The organic solvent includes one or more of DMF, DMSO, NMP and GBL.

5. A method for preparing a perovskite film, characterized in that: Using the perovskite precursor solution according to any one of claims 1 to 4 comprises the following steps: (a) Prepare a clean and dry substrate; (b) coating a perovskite precursor solution on the substrate; (c) The substrate is placed on a heating stage and annealed in an inert gas atmosphere to obtain a perovskite film.

6. The preparation method according to claim 5, characterized in that: The substrate is a substrate to which a solution film can be attached.

7. The preparation method according to claim 5, characterized in that: The coating method in step (b) includes one of spin coating, spray coating, blade coating, screen printing, air knife coating, and slit extrusion coating.

8. The preparation method according to claim 5, characterized in that: In the step (c), the annealing temperature is 100-300° C. and the annealing time is 10-60 min.

9. A perovskite film, characterized in that: The method is prepared by any one of claims 5 to 8.

10. A solar cell, characterized in that: The solar cell comprises a perovskite film prepared by the method described in any one of claims 5 to 8 or a perovskite film described in claim 9, wherein the solar cell further comprises a conductive substrate, an electron transport layer, a hole transport layer and a metal electrode, wherein the conductive substrate, the electron transport layer, the perovskite film, the hole transport layer and the metal electrode are arranged in sequence.

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