Large-area perovskite thin film lossless passivation method, perovskite thin film and solar cell

Abstract

The invention relates to the technical field of solar cells, and particularly discloses a large-area perovskite thin film lossless passivation method, a perovskite thin film and a perovskite solar cell. According to the large-area perovskite thin film lossless passivation method, the surface of a perovskite thin film is coated with passivation modification liquid to form a passivation layer, the passivation modification liquid comprises organic ammonium salt and ethyl acetate, the passivation modification liquid is composed of the organic ammonium salt and the ethyl acetate, and the ratio of the mass of the organic ammonium salt to the volume of the ethyl acetate ranges from 1 mg to 3 mg: 1 ml. According to the lossless passivation method for the large-area perovskite thin film, damage to the perovskite thin film and pollution to the environment in the passivation process can be avoided, meanwhile, the quality of the perovskite thin film can be improved, and then the photoelectric conversion efficiency of a device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and specifically to a large-area perovskite film surface non-destructive passivation method based on a green solvent, a perovskite film and a perovskite solar cell. Background Art

[0002] Perovskite solar cells have attracted a lot of attention and research due to their excellent photovoltaic performance and low manufacturing cost. In the prior art, interface defect passivation is one of the effective methods to obtain high-efficiency perovskite solar cells. Among them, the organic reagent isopropyl alcohol (IPA) is a conventional material used to dissolve the passivation material in the passivation treatment of interface defects in perovskite films. However, when IPA is used to passivate the surface of perovskite films, it will cause irreversible damage to the perovskite crystal structure.

[0003] Existing studies have shown that the adverse effects of IPA on perovskite films can be largely weakened by rapidly volatilizing IPA through rapid spin coating during the preparation of small-area perovskite solar cells (PSCs). However, with the continuous expansion of the area of ​​PSCs, spin coating is no longer suitable for the preparation of large-area perovskite solar modules (PSMs), and only large-scale preparation methods such as slit coating can be used. In actual operation, in the process of large-area slit coating of passivation materials, the above-mentioned problems still exist, that is, the commonly used passivation solvent IPA has high toxicity and low saturated vapor pressure. Without auxiliary treatment, it stays on the perovskite surface for a long time, which will damage the 3D perovskite surface, adversely affect the device performance, and it is difficult to achieve effective surface passivation.

[0004] In order to solve this problem, some researchers use air knife to quickly remove IPA solvent during the coating process of passivation material. However, the blowing process will cause the toxic IPA gas to go uncontrollably and diffuse into the air, causing environmental pollution. Some researchers have also tried different organic solvents to solve this problem, but the results are not ideal.

[0005] Therefore, the present invention aims to develop a large-area perovskite film surface non-destructive passivation method based on green solvents, a perovskite film and a perovskite solar cell to better meet practical needs. Summary of the invention

[0006] The technical problem solved by the present invention is to provide a large-area perovskite film non-destructive passivation method to avoid the damage to the perovskite film and the pollution to the environment caused by the traditional passivation method, while improving the quality of the perovskite film.

[0007] The second technical problem solved by the present invention is to provide a perovskite film with better quality.

[0008] The third technical problem to be solved by the present invention is to provide a solar cell with higher photoelectric conversion efficiency.

[0009] To solve the problems in the above-mentioned background technology.

[0010] The technical problem to be solved by the present invention is realized by adopting the following technical solutions:

[0011] A method for non-destructive passivation of a large-area perovskite thin film, wherein a passivation modification liquid is coated on the surface of the perovskite thin film to form a passivation layer, and the passivation modification liquid includes an organic ammonium salt and ethyl acetate.

[0012] Further, the passivation modification liquid is composed of an organic ammonium salt and ethyl acetate, and the ratio range of the mass of the organic ammonium salt to the volume of ethyl acetate is 1-3 mg:1 ml.

[0013] Further, the coating method is slot coating.

[0014] Further, the organic ammonium salt includes one or more of 2-4-trifluoromethylphenyl hydroiodide, m-fluorophenethylamine hydroiodide, o-fluorophenethylamine hydroiodide, piperazine dihydroiodide, piperazine monoiodide, butylamine hydroiodide, 3-methylthio-1-propylamine hydroiodide.

[0015] Further, after the passivation modification liquid is coated on the surface of the perovskite thin film, it can be naturally volatilized.

[0016] A large-area perovskite thin film is prepared by the method described above.

[0017] A perovskite solar cell includes the perovskite thin film described above.

[0018] Further, the perovskite solar cell sequentially includes an FTO conductive base layer, a hole transport layer, a perovskite active layer, a perovskite thin film layer, a passivation layer, an electron transport layer, a hole blocking layer, a buffer layer, and a cathode electrode from inside to outside.

[0019] Further, the preparation method of the perovskite solar cell includes:

[0020] Pretreatment: Cleaning to remove impurities on the surface of the FTO conductive base layer;

[0021] Preparation of the hole transport perovskite thin film layer: A hole transport layer is formed on the surface of the pretreated FTO conductive base layer by magnetron sputtering, and the hole transport layer is a NiOx layer;

[0022] Preparation of the perovskite active layer: A perovskite precursor solution is coated on the surface of the hole transport layer by slot coating to form a perovskite active layer, and the perovskite active layer is a liquid film layer;

[0023] Preparation of perovskite thin film layer: Place the perovskite active layer in a vacuum crystal preparation device. After crystal preparation, a perovskite intermediate phase thin film is obtained. Then, anneal the perovskite intermediate phase thin film to obtain a solidified and crystallized perovskite thin film;

[0024] Passivation layer: Apply the passivation modification solution by slot coating on the surface of the solidified and crystallized perovskite thin film, and let it volatilize naturally to obtain the passivation layer;

[0025] Then, sequentially deposit an electron transport layer, a dense layer, a buffer layer, and a magnetron sputtered cathode electrode on the surface of the passivation layer.

[0026] Furthermore, the components of the perovskite precursor solution are FA 0.85 Cs 0.15 Pb I( 0.85 Br 0.15 ) 3， The concentration of the perovskite precursor solution is 0.8 - 1.2 M.

[0027] Beneficial effects: For the large - area perovskite thin film non - destructive passivation method of the present invention, the passivation modification solution used combines ethyl acetate and organic ammonium salt. Creatively, ethyl acetate is used as the solvent, and the ratio of ethyl acetate to organic ammonium salt is scientifically formulated. The good solubility of the green solvent for passivation materials, high saturated vapor pressure, and low toxicity are organically combined with other materials, avoiding damage to the perovskite thin film and environmental pollution caused by the passivation process. At the same time, it can improve the quality of the perovskite thin film and thus enhance the photoelectric conversion efficiency of the device.

[0028] For the large - area perovskite thin film non - destructive passivation method of the present invention, it does not require the process of blowing and drying the surface of the perovskite thin film in the traditional process, reducing the requirement for the blowing function of the equipment. Thus, while reducing the manufacturing cost of the equipment, the production efficiency is improved.

[0029] Compared with the perovskite thin film prepared by the traditional process, the perovskite thin film of the present invention has fewer surface defects and better quality.

[0030] The perovskite solar cell of the present invention has better photoelectric conversion efficiency and better performance. Description of the drawings

[0031] Figure 1 It is the electron microscope magnification schematic diagram (40000x) of the large - area perovskite thin film in each example and the control example.

[0032] Figure 2 It is the voltage - current curve graph of the perovskite solar cell in Example 1 and Control Example 6. Detailed implementation manners

[0033] In order to make the technical means, creative features, achieved objectives and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0034] Example 1

[0035] The method for non-destructive passivation of a large-area perovskite thin film in this embodiment includes coating a passivation modification solution on the surface of the perovskite thin film by slit coating to form a passivation layer. The passivation modification solution includes an organic ammonium salt and ethyl acetate. The organic ammonium salt is 2-4-trifluoromethylphenyl hydroiodide. The ratio range of the mass of the organic ammonium salt to the volume of ethyl acetate is 1 mg:1 ml. After the passivation modification solution is coated on the surface of the perovskite thin film, it naturally volatilizes, and the height of the coating slit is 200 μm.

[0036] The perovskite solar cell involved in this embodiment includes, from the inside out, an FTO conductive base layer, a hole transport layer, a perovskite active layer, a perovskite thin film layer, a passivation layer, an electron transport layer, a hole blocking layer, a buffer layer, and a cathode electrode.

[0037] The preparation method of the perovskite solar cell includes:

[0038] Pretreatment: The FTO substrate is cleaned with deionized water and acetone respectively to remove impurities on the surface of the FTO substrate and prevent impurities from having an adverse effect on subsequent processing. After the FTO substrate is ultrasonically cleaned with ethanol, it is dried with a nitrogen gun and reserved for use.

[0039] Preparation of the hole transport perovskite thin film layer: A hole transport layer is formed on the surface of the pretreated FTO conductive base layer by magnetron sputtering. The hole transport layer is a NiOx layer; the thickness of the NiOx layer is 30 nm. When operating, a radio frequency magnetron sputtering device is preferably used.

[0040] Preparation of the perovskite active layer: The perovskite precursor solution is coated on the surface of the hole transport layer by slit coating to form a perovskite active layer, and the perovskite active layer is a liquid film layer.

[0041] The components of the perovskite precursor solution are FA 0.85 Cs 0.15 Pb I( 0.85 Br 0.15 )3. The concentration of the perovskite precursor solution is 1.0 M. Specifically, in the perovskite precursor solution: in a solution with a concentration of 1 M, FAI = 0.1462 g, PbI2 = 0.461 g, CsBr = 0.319 g, and the volume ratio of the solvent components DMF:NMP:2-ME = 6:1:0.5.

[0042] Preparation of perovskite thin film layer: Place the perovskite active layer in a vacuum crystal growth device for crystal growth. Reduce the vacuum degree in the vacuum crystal growth device from atmospheric pressure to 10 Pa within 10 s, and then perform crystal growth for 100 s to obtain a perovskite intermediate phase thin film. Place the perovskite intermediate phase thin film on a hot plate at 80 °C for annealing for 5 min, and then anneal it on a hot plate at 120 °C for 15 min to obtain a solidified and crystallized perovskite thin film;

[0043] Passivation layer: Apply the passivation modification solution by slit coating on the surface of the solidified and crystallized perovskite thin film, and then let it volatilize naturally. The height of the coating slit is 150 μm;

[0044] Then, sequentially evaporate an electron transport layer, deposit a dense layer, evaporate a buffer layer, and magnetron sputter a cathode electrode on the surface of the passivation layer to obtain a metal electrode.

[0045] Example 2

[0046] The method for non-destructive passivation of a large-area perovskite thin film in this example includes applying a passivation modification solution by slit coating on the surface of the perovskite thin film to form a passivation layer. The passivation modification solution includes an organic ammonium salt and ethyl acetate. The organic ammonium salt is m-fluorophenethylamine hydroiodide, and the ratio range of the mass of the organic ammonium salt to the volume of ethyl acetate is 1.5 mg:1 ml. After applying the passivation modification solution on the surface of the perovskite thin film, let it volatilize naturally. The height of the coating slit is 150 μm;

[0047] The perovskite solar cell and the preparation method of the perovskite solar cell in this example are the same as those in Example 1.

[0048] Example 3

[0049] The method for non-destructive passivation of a large-area perovskite thin film in this example includes applying a passivation modification solution by slit coating on the surface of the perovskite thin film to form a passivation layer. The passivation modification solution includes an organic ammonium salt and ethyl acetate. The organic ammonium salt is piperazine dihydroiodide, and the ratio range of the mass of the organic ammonium salt to the volume of ethyl acetate is 1.0 mg:1 ml. After applying the passivation modification solution on the surface of the perovskite thin film, let it volatilize naturally. The height of the coating slit is 100 μm;

[0050] The perovskite solar cell and the preparation method of the perovskite solar cell in this example are the same as those in Example 1.

[0051] Example 4

[0052] The method for non-destructive passivation of a large-area perovskite thin film in this embodiment includes coating a passivation modification liquid on the surface of the perovskite thin film by slit coating to form a passivation layer, where the passivation modification liquid includes an organic ammonium salt and ethyl acetate, the organic ammonium salt is piperazine dihydroiodate, and the ratio range of the mass of the organic ammonium salt to the volume of ethyl acetate is 1.0 mg:1 ml. After the passivation modification liquid is coated on the surface of the perovskite thin film, it volatilizes naturally, and the height of the coating slit is 50 μm;

[0053] The perovskite solar cell and the preparation method of the perovskite solar cell in this embodiment are the same as those in Example 1.

[0054] Control Example 1

[0055] In this control example, the passivation modification liquid was successively tested with organic ammonium salts such as p-fluorophenethylamine hydroiodide, 2-phenethylamine hydroiodide, 1,4-benzenedimethanamine hydroiodide, piperazine dihydroiodate, piperazine monoiodide, piperidine hydroiodide, guanidine hydrobromide, 1,3-diaminopropane dihydrobromide, 1,3-diaminopropane dihydroiodide, 1,3-diaminopropane dihydrochloride, 1,4-butanediamine dihydrochloride, 1,4-butanediamine hydroiodide, etc. The obtained passivation modification liquid had poor solubility and could not be further coated and processed.

[0056] Control Example 2

[0057] In this control example, the ratio range of the mass of the organic ammonium salt to the volume of ethyl acetate used was 5 mg:1 ml. After coating, it volatilized naturally to obtain a passivation layer. The height of the coating slit was 150 μm, and the rest was the same as in Example 1.

[0058] The perovskite solar cell and the preparation method of the perovskite solar cell in this control example are the same as those in Example 1.

[0059] Control Example 3

[0060] In this control example, the ratio range of the mass of the organic ammonium salt to the volume of ethyl acetate used was 1 mg:4 ml. And after the passivation modification liquid was coated on the surface of the perovskite thin film, it volatilized naturally to obtain a passivation layer. The height of the coating slit was 100 μm. The rest was the same as in Example 1.

[0061] The perovskite solar cell and the preparation method of the perovskite solar cell in this control example are the same as those in Example 1.

[0062] Control Example 4

[0063] In this control example, the passivation modification liquid was the same as that in Example 1. When preparing the perovskite solar cell, in the passivation layer step, after the passivation modification liquid was coated on the surface of the perovskite thin film, it was annealed on a hot plate at 85 °C for 10 minutes. The height of the coating slit was 200 μm. The rest was the same as in Example 1

[0064] Comparative Example 5

[0065] In this comparative example, ethyl acetate was replaced with isopropyl alcohol, and the rest was the same as in Example 1.

[0066] The perovskite solar cell and the preparation method of the perovskite solar cell described in this comparative example were the same as those in Example 1.

[0067] Comparative Example 6

[0068] In this comparative example, isopropyl alcohol was used as the main component of the passivation modification solution, and coating was carried out. During the coating process of the modification solution, air blowing was accompanied, and the height of the coating slit was 200 μm. The rest was the same as in Example 1.

[0069] (1) Comparison of the residence time of the components of the passivation modification solution on the perovskite surface and the damage to the perovskite surface after volatilization in each example and comparative example.

[0070] 1. Test method:

[0071] Timing started after coating, and visual observation was carried out until the solvent in the passivation modification solution was completely volatilized. The results are shown in Table 1. By taking electron microscope photos of the products, the degree of damage was judged, and the results are as attached Figure 1 as shown.

[0072] Table 1 Statistical table of the residence time of the components of the passivation modification solution on the perovskite surface

[0073] Item Residence Time (min) Example 1 2 Example 2 1.5 Example 3 1 Example 4 0.5 Control Example 2 1.5 Control Example 3 1 Control Example 4 2 Control Example 5 5 Control Example 6 0.5

[0074] Referring to Table 1, it can be seen that by using the large-area perovskite thin film non-destructive passivation method described in the present invention, the passivation modification solution can volatilize under natural conditions, and the volatilization time of the solvent in the passivation modification solution is much shorter than that of the traditional passivation modification solution without air blowing operation. Moreover, this application does not require air blowing and annealing operations, simplifies the processing process, and can effectively avoid the safety hazards caused by the emission of toxic isopropyl alcohol due to promoting the volatilization of isopropyl alcohol through air blowing in the traditional process.

[0075] Reference Figure 1 to the enlarged electron microscope schematic diagrams of the perovskite thin films in each example and comparative example in

[0076] (2) Photovoltaic performance detection of perovskite solar cells

[0077] The photovoltaic parameters of the perovskite solar cells obtained in each example and comparative example are shown in Table 2.

[0078] Table 2 Photovoltaic performance test results of perovskite solar cells

[0079] Voc (V) <![CDATA[Jsc (mA / cm 2 )]]> FF PCE (%) Example 1 14.27 1.63 77.76 18.11 Example 2 14.39 1.58 76.24 17.29 Example 3 14.19 1.64 76.58 17.87 Example 4 14.40 1.61 74.75 17.34 Control Example 2 12.51 1.57 68.66 13.51 Control Example 3 13.41 1.49 68.08 13.59 Control Example 4 14.04 1.48 68.35 14.18 Control Example 5 14.27 1.58 67.29 15.14 Control Example 6 14.37 1.59 73.10 16.74

[0080] As can be seen from Table 2, the perovskite solar cells prepared by the present invention have better photovoltaic performance and are superior to traditional processes.

[0081] (III) Cell-voltage detection

[0082] The current-voltage curves of the perovskite solar cells prepared in Example 1 and Comparative Example 6 are as Figure 2 shown. The results show that, compared with traditional processes, the perovskite solar cells prepared by the technical solution of the present invention have higher improvements in terms of voltage and current.

[0083] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A non-destructive passivation method for large-area perovskite films, characterized in that: A passivation modification solution is coated on the surface of the perovskite film to form a passivation layer, wherein the passivation modification solution comprises an organic ammonium salt and ethyl acetate.

2. The large-area perovskite film non-destructive passivation method according to claim 1, characterized in that: The passivation modification solution is composed of organic ammonium salt and ethyl acetate, and the ratio of the mass of the organic ammonium salt to the volume of the ethyl acetate is in the range of 1-3 mg:1 ml.

3. The large-area perovskite film non-destructive passivation method according to claim 1, characterized in that: The coating method is slit coating.

4. The large-area perovskite film non-destructive passivation method according to claim 1, characterized in that: The organic ammonium salt includes one or more of 2-4-trifluoromethylphenyl hydroiodide, m-fluorophenylethylamine hydroiodide, o-fluorophenylethylamine hydroiodide, piperazine dihydroiodide, piperazine monoiodide, butylamine hydroiodide and 3-methylthio-1-propylamine hydroiodide.

5. The large-area perovskite film non-destructive passivation method according to claim 1, characterized in that: After the passivation modification solution is coated on the surface of the perovskite film, annealing treatment is performed on a hot stage at 80° C. to 100° C. for 1 to 10 minutes.

6. A large-area perovskite film, characterized in that: It is prepared by the non-destructive passivation method as described in any one of claims 1 to 5.

7. A perovskite solar cell, characterized in that: Comprising the perovskite film as claimed in claim 6.

8. The perovskite solar cell according to claim 7, characterized in that From the inside out, perovskite solar cells include FTO conductive substrate layer, hole transport layer, perovskite active layer, perovskite thin film layer, passivation layer, electron transport layer, hole blocking layer, buffer layer, and cathode electrode.

9. The perovskite solar cell according to claim 7, characterized in that: The method for preparing a perovskite solar cell comprises: Pretreatment: Clean and remove impurities on the surface of the FTO conductive substrate layer; Preparation of hole transport perovskite thin film layer: The hole transport layer is formed on the surface of the pre-treated FTO conductive substrate layer by magnetron sputtering, and the hole transport layer is a NiOx layer; Preparation of perovskite active layer: The perovskite precursor solution is coated on the surface of the hole transport layer through a slit to form a perovskite active layer, which is a liquid film layer; Preparation of perovskite thin film layer: placing the perovskite active layer in a vacuum crystallization device to obtain a perovskite intermediate phase thin film after crystallization, and then annealing the perovskite intermediate phase thin film to obtain a solidified and crystallized perovskite thin film; Passivation layer: Slit coating the passivation modification solution on the surface of the solidified and crystallized perovskite film, and then annealing to obtain the passivation layer; Then, the electron transport layer is evaporated on the surface of the passivation layer, a dense layer is deposited, a buffer layer is evaporated, and a cathode electrode is magnetron sputtered.

10. The perovskite solar cell according to claim 9, characterized in that: The components of the perovskite precursor solution are FA 0.85 Cs 0.15 PbI( 0.85 Br 0.15 ) 3， The concentration of the ore precursor solution is 0.8-1.2M.

Images