Solar cell electron transport layer, solar cell and preparation method

Abstract

The invention discloses a solar cell electron transport layer, a solar cell and a preparation method, and is applied to the technical field of perovskite solar cells. The solar cell electron transport layer comprises a complex generated by complexing a transport material and tetrachloro aluminate ions; the transmission material comprises fullerene and a fullerene derivative. By using the complex as the electron transport layer of the perovskite solar cell, when the perovskite solar cell discharges during working, the complex can be decomposed into superhalogens AlCl4 <-> and Cl <->, and the superhalogens can passivate vacancy defects of organic cations on the surface of perovskite, so that the efficiency and stability of the perovskite solar cell are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite solar cells, in particular to a perovskite solar cell electron transport layer, a preparation method of the perovskite solar cell electron transport layer, a perovskite solar cell and a preparation method of the perovskite solar cell. BACKGROUND

[0002] The perovskite solar cell is a new type of solar cell taking perovskite nanocrystalline grains as a photosensitive material. It is concerned due to its high conversion efficiency, low manufacturing cost and diversified application potential. The perovskite solar cell realizes solar energy conversion through the following working principle: when the perovskite grains are irradiated by sunlight, electron-hole pairs, i.e. carriers, are generated. Since the carriers move in opposite directions under the action of an electric field, the electrons move to the anode and the holes move to the cathode, generating a small photocurrent. By connecting an external load, solar energy can be converted into usable electrical energy.

[0003] Compared with the traditional silicon-based solar cell, the perovskite solar cell has a wider spectral response range and a relatively simple manufacturing process. However, it also has some challenges. The organic-inorganic hybrid perovskite material has a soft lattice and is an ionic crystal, which is easy to ionize under the interference of external environment, forming a large number of vacancy defects, thus inducing lattice collapse and component decomposition, so that it no longer has excellent photoelectric conversion capability. Organic cation vacancies are universally present on the surface and grain boundaries of perovskite due to their low defect formation energy. Such vacancy defects not only affect the working efficiency of the solar cell, but also induce further degradation of the perovskite crystal, forming more bulk defects.

[0004] Therefore, how to reduce the generation of defects in the use process of the perovskite solar cell is a problem that needs to be solved by those skilled in the art. SUMMARY

[0005] The purpose of the present application is to provide a perovskite solar cell electron transport layer and a preparation method thereof, which can effectively improve the efficiency and stability of the perovskite solar cell in the use process. Another purpose of the present application is to provide a perovskite solar cell and a preparation method thereof, which can effectively improve the efficiency and stability of the perovskite solar cell in the use process.

[0006] To solve the above technical problems, the present application provides a perovskite solar cell electron transport layer, which comprises a complex generated by complexing a transport material with a tetrachloroaluminate ion.

[0007] The transport material comprises fullerene and a fullerene derivative.

[0008] Optionally, the transport material comprises any one or any combination of the following:

[0009] Fullerene C 60 Fullerene C 70 , mono-adduct fullerene derivative, di-adduct fullerene derivative, multi-adduct fullerene derivative.

[0010] Optionally, the complex comprises fullerene C 70 complexed with tetrachloroaluminate ion C 70 · [AlCl4]5Cl 16 .

[0011] Optionally, a first electron transport layer formed based on the complex is included, and a second electron transport layer is located on one side surface of the first electron transport layer; the second electron transport layer is made of tin dioxide.

[0012] The application further provides a preparation method of an electron transport layer of a perovskite solar cell, comprising:

[0013] The transmission material comprises fullerene and fullerene derivative.

[0014] The battery is charged to generate, at the cathode, a complex formed by complexing the transmission material with tetrachloroaluminate ion.

[0015] Optionally, the transmission material comprises:

[0016] fullerene C 70 as the cathode.

[0017] The battery is charged to generate, at the cathode, a complex formed by complexing the transmission material with tetrachloroaluminate ion.

[0018] The battery is charged to generate, at the cathode, complex C 70 · [AlCl4]5Cl 16 .

[0019] The application further provides a perovskite solar cell comprising an electron transport layer, wherein the electron transport layer is an electron transport layer made based on the complex according to any one of the above.

[0020] The application further provides a preparation method of a perovskite solar cell, comprising:

[0021] A first substrate is made.

[0022] An electron transport layer is arranged on a surface of the first substrate to make a second substrate; the electron transport layer is an electron transport layer made based on the complex according to any one of the above.

[0023] The perovskite solar cell is made based on the second substrate.

[0024] Optionally, the surface of the first substrate is provided with an electron transport layer, including:

[0025] The complex is evaporated on the surface of the first substrate based on an evaporation process to form the electron transport layer.

[0026] Optionally, the surface of the first substrate is provided with an electron transport layer, including:

[0027] The complex is evaporated on the surface of the first substrate based on an evaporation process to form a first electron transport layer;

[0028] A tin dioxide film is provided on the surface of the first electron transport layer based on an atomic deposition process to form a second electron transport layer.

[0029] The perovskite solar cell electron transport layer provided by the application includes a complex generated by complexing a transport material with a tetrachloroaluminate ion; the transport material includes fullerene and fullerene derivatives. By using the complex as the electron transport layer of the perovskite solar cell, when the perovskite solar cell is discharged in operation, the complex will decompose into superhalogen AlCl4 - and Cl - The superhalogen will passivate the vacancy defects of the organic cations on the surface of the perovskite, thereby improving the efficiency and stability of the perovskite solar cell.

[0030] The application also provides a preparation method of a perovskite solar cell electron transport layer, a perovskite solar cell and a preparation method of a perovskite solar cell, which also have the beneficial effects described above, and will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0032] Figure 1 A ball-and-stick model diagram of the complex in the perovskite solar cell electron transport layer provided by the application;

[0033] Figure 2 A flowchart of the preparation method of the perovskite solar cell electron transport layer provided by the application;

[0034] Figure 3A structure schematic diagram of a first perovskite solar cell provided by an embodiment of the present application;

[0035] Figure 4 A structure schematic diagram of a second perovskite solar cell provided by an embodiment of the present application;

[0036] Figure 5 A flow chart of a perovskite solar cell preparation method provided by an embodiment of the present application;

[0037] Figure 6 A graph of the change of the normalized PCE of the perovskite solar cell in Example 1 and the perovskite solar cell in Comparative Example 1 with the increase of the use time;

[0038] Figure 7 A graph of the change of the normalized PCE of the perovskite crystalline silicon laminated solar cell in Example 2 and the perovskite crystalline silicon laminated solar cell in Comparative Example 2 with the increase of the use time. DETAILED DESCRIPTION

[0039] The core of the present application is to provide a perovskite solar cell electron transport layer. In the prior art, the organic-inorganic hybrid perovskite material has a relatively soft lattice and is an ionic crystal, which is easy to migrate under the interference of the external environment, form a large number of vacancy defects, and thus induce lattice collapse and component decomposition, so that it no longer has excellent photoelectric conversion capability. Organic cation vacancies are generally present on the perovskite surface and grain boundaries due to their low defect formation energy. Such vacancy defects not only affect the working efficiency of the solar cell, but also induce further degradation of the perovskite crystal to form more bulk defects.

[0040] The perovskite solar cell electron transport layer provided by the present application is characterized in that it comprises a complex generated by complexing a transport material with a tetrachloroaluminate ion; the transport material comprises fullerene and a fullerene derivative. By using the complex as the electron transport layer of the perovskite solar cell, the complex will decompose into hyperhalogen AlCl4 - and Cl - when the perovskite solar cell is working and discharging. The hyperhalogen can passivate the organic cation vacancy defects on the surface of the perovskite, thereby improving the efficiency and stability of the perovskite solar cell.

[0041] In order for those skilled in the art to better understand the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0042] Please refer to Figure 1 , Figure 1 A ball-and-stick model diagram of a complex in an electron transport layer of a perovskite solar cell provided in an embodiment of the present invention.

[0043] In an embodiment of the present invention, the electron transport layer of the perovskite solar cell includes a complex formed by complexing a transport material with tetrachloroaluminate ions; the transport material includes fullerene and fullerene derivatives.

[0044] The transmission materials selected in this embodiment include fullerene C 60 , fullerene C 70 Fullerene materials, including single addition fullerene derivatives (such as PC 61 BM, PC 71 BM), double addition fullerene derivatives (such as bis-PC 61 BM, bis-PC 71 BM, bis-ThC 61 BM, bis-ThC 71 BM, IC 60 BA, NC 60 BA, NC 70 BA), polyaddition fullerene derivatives (such as tris-PC 61 BM, IC 60 TA) and other fullerene derivatives, the output material selected in this embodiment is generally spherical, and its exterior can be combined with other materials.

[0045] In this embodiment, the above-mentioned transmission material needs to be combined with tetrachloroaluminate ions (AlCl4 - ) are complexed with each other to obtain the corresponding complex. For example, if fullerene C is selected 70 As a transport material, fullerene C 70 Complex C is obtained by complexation with tetrachloroaluminate ion. 70 ·[AlCl4]5Cl 16 , that is, the complex in this embodiment includes fullerene C 70 Complex C formed by complexation with tetrachloroaluminate ion 70 ·[AlCl4]5Cl 16 , its structure is as follows Figure 1 As shown, the sphere in the middle is fullerene C 70 , which is surrounded by AlCl4 - and Cl - Depending on the transmission material, different complexes will be generated, and the specific content needs to be determined according to the actual situation and is not specifically limited here.

[0046] Fullerene C60 Compared with fullerene C 70 Two transport materials as a comparison, fullerene C 70 Compared with superhalogen AlCl4 - And superhalogen Cl - The binding capacity is stronger than fullerene C 60 , and superhalogen AlCl4 - And Cl - The number of combinations on the surface of fullerene C 70 It is also stronger than fullerene C 60 Therefore, fullerene C 70 As a transport material is preferred in this embodiment. During the discharge process of perovskite solar cell, the complex C 70 ·[AlCl4]5Cl 16 Will decompose into superhalogen AlCl4 - , superhalogen Cl - And fullerene C 70 Among them, superhalogen AlCl4 - And Cl - Will passivate the organic cation vacancy defects on the surface of perovskite, thereby improving the efficiency and stability of the battery.

[0047] In the perovskite solar cell of the present application, the electron transport layer is usually two layers, that is, in this embodiment, the electron transport layer specifically includes a first electron transport layer and a second electron transport layer, wherein the second electron transport layer is located on one side of the surface of the first electron transport layer. In this embodiment, the first electron transport layer is an electron transport layer formed from the above-mentioned complex as a raw material, which is usually directly arranged on the surface of the light-absorbing layer so as to passivate the organic cation vacancies. The second transport layer will be specifically located on the surface of the side of the first electron transport layer away from the light-absorbing layer. In this embodiment, the second electron transport layer can be specifically an electron transport layer made of tin dioxide. Of course, in this embodiment, the material of the second electron transport layer is not specifically limited, which can also be titanium dioxide and the like, which is not specifically limited here.

[0048] The perovskite solar cell electron transport layer provided in this embodiment includes a complex formed by complexing a transport material with tetrachloroaluminate ion; the transport material includes fullerene and fullerene derivative. By using the complex as the electron transport layer of the perovskite solar cell, when the perovskite solar cell is discharged during operation, the complex will decompose into superhalogen AlCl4 - And Cl - , which passivates the organic cation vacancy defects on the surface of perovskite, thereby improving the efficiency and stability of the perovskite solar cell.

[0049] The preparation method of the perovskite solar cell electron transport layer will be described in detail in the following inventive examples.

[0050] Please refer to Figure 2 , Figure 2 The flowchart of the preparation method of the perovskite solar cell electron transport layer provided in the present application is shown in the following.

[0051] Please refer to Figure 2 In the present example, the preparation method of the perovskite solar cell electron transport layer comprises:

[0052] S101: A battery is prepared by using a transport material as the cathode and 1-ethyl-3-methylimidazolium aluminum chloride as the electrolyte.

[0053] In the present example, the transport material comprises fullerene and fullerene derivatives. The specific content of the transport material has been described in detail in the above inventive examples, and will not be repeated here.

[0054] In the present example, a battery based on the electrochemical reaction to generate the above complex will be prepared, and the transport material will be used to prepare the cathode of the battery in this step, for example, fullerene C 70 is used as the cathode, and the anode can be selected from aluminum foil and the like to avoid the introduction of impurities into the electrolyte in the subsequent process. Of course, other materials can also be selected as the anode in the present example, and the type of the material for the anode of the battery is not specifically limited in the present example.

[0055] In the present example, 1-ethyl-3-methylimidazolium aluminum chloride (AlCl3: [EMIm]Cl = 1.3 by mole) is specifically selected as the electrolyte to provide the necessary aluminum chlorate ions for the reaction to prepare the battery.

[0056] S102: The battery is charged to generate a complex of the transport material and the aluminum chlorate ion at the cathode.

[0057] In this step, the above battery needs to be charged for electrochemical reaction, and the chlorine ions in the electrolyte will react with aluminum chloride to generate aluminum chlorate ions (AlCl4 - ), which can be specifically charged at a voltage of 2.4V in the present example. When fullerene C 70 is used as the cathode, AlCl4 - will complex with the fullerene C 70 at the cathode side under the charging condition to generate C 70 ·[AlCl4]5Cl 16 complex, that is, the present step can specifically include charging the battery to generate the complex C 70 ·[AlCl4]5Cl16 The reaction formula is as follows:

[0058]

[0059] Of course, when other types of transport materials are selected in the present embodiment, other similar structure complexes are generated. After the step, the battery is disassembled, and then the complex generated on the cathode of the battery is scraped off, which is used as an electron transport layer material of a perovskite solar cell to prepare an electron transport layer for preparing a perovskite solar cell.

[0060] The preparation method of the electron transport layer of the perovskite solar cell provided in the present embodiment is used for the perovskite solar cell, and when the perovskite solar cell is discharged during operation, the complex will decompose into superhalogen AlCl4 - and Cl - The superhalogen passivates the organic cation vacancy defects on the perovskite surface, thereby improving the efficiency and stability of the perovskite solar cell.

[0061] The specific content of the perovskite solar cell provided in the present application will be described in detail in the following inventive examples.

[0062] Please refer to Figure 3 and Figure 4 , Figure 3 is a schematic structural diagram of a first perovskite solar cell provided in the present embodiment; Figure 4 is a schematic structural diagram of a second perovskite solar cell provided in the present embodiment.

[0063] In the present embodiment, the perovskite solar cell includes an electron transport layer, and the electron transport layer is specifically an electron transport layer made of a complex provided in any of the above inventive examples. The specific content of the complex has been described in detail in the above inventive examples, and the remaining structure of the perovskite solar cell can refer to the prior art, which will not be described here.

[0064] The present embodiment specifically provides two perovskite solar cells, the first one is a traditional perovskite solar cell, and the second one is a perovskite crystalline silicon stacked cell. Referring to Figure 3For the perovskite solar cell, the structure thereof from bottom to top can be in turn: a conductive substrate, a hole transport layer, a light absorbing layer, an electron transport layer, and an electrode. The electron transport layer in the structure is prepared by the complex generated by the complexation of the transport material and the tetrachloroaluminate ion. The hole transport layer can include a first hole transport layer on the surface of the conductive substrate, and a second hole transport layer on the surface of the first hole transport layer away from the conductive substrate. The electron transport layer can include a first electron transport layer on the surface of the light absorbing layer away from the conductive substrate, and a second electron transport layer on the surface of the first electron transport layer away from the conductive substrate. The first electron transport layer is usually the electron transport layer prepared by the complex.

[0065] In the embodiment, the conductive substrate can be ITO (indium tin oxide) glass, the material of the first hole transport layer can be nickel oxide, the material of the second hole transport layer can be MeO-2PACz [2-(3, 6-dimethoxy-9H-carbazole-9-yl) ethyl] phosphonic acid, the material of the first electron transport layer can be the complex such as C 70 ·[AlCl4]5Cl 16 , and the material of the second electron transport layer can be tin dioxide, and the electrode can be a silver metal electrode. At this time, the perovskite solar cell from bottom to top can be in turn: ITO glass, a nickel oxide hole transport layer, a MeO-2PACz hole transport layer, a light absorbing layer, a C 70 ·[AlCl4]5Cl 16 film electron transport layer, a SnO2 film electron transport layer, and a silver metal electrode.

[0066] Referring to Figure 4 For the perovskite crystalline silicon laminated cell, the structure thereof from bottom to top can be in turn: a back conductive electrode, a back conductive layer, a p-type amorphous silicon layer, a first intrinsic amorphous silicon layer, a silicon wafer, a second intrinsic amorphous silicon layer, an n-type amorphous silicon layer, an intermediate composite layer, a first hole transport layer, a second hole transport layer, a perovskite absorbing layer, a first electron transport layer, a second electron transport layer, a top conductive layer, and a front conductive electrode. From the back conductive electrode to the n-type amorphous silicon layer, it is a crystalline silicon bottom cell structure, which is a semi-finished heterojunction cell used in the embodiment, and the subsequent other structures are prepared based on the semi-finished heterojunction cell.

[0067] The conductive electrode is usually a conductive metal electrode, and the conductive layer is an ITO film or the like transparent conductive layer, and the specific materials of other layers such as the hole transport layers and the electron transport layers can refer to the structure of the perovskite solar cell described above, which will not be described here.

[0068] The perovskite solar cell provided in the embodiment includes the complex provided in the above-mentioned embodiment. When the perovskite solar cell is discharged during operation, the complex is decomposed into superhalogen AlCl4 - and Cl - The superhalogen passivates the vacancy defects of the organic cations on the surface of the perovskite, thereby improving the efficiency and stability of the perovskite solar cell.

[0069] The preparation method of the perovskite solar cell provided in the present application will be described in detail in the following embodiments.

[0070] Please refer to Figure 5 , Figure 5 the flowchart of the preparation method of the perovskite solar cell provided in the embodiment of the present application.

[0071] Please refer to Figure 5 In the embodiment, the preparation method of the perovskite solar cell includes:

[0072] S101: a first substrate is prepared.

[0073] In the embodiment, the first substrate can be a traditional perovskite solar cell substrate provided with a perovskite light-absorbing layer, or a perovskite-silicon tandem cell substrate provided with a perovskite light-absorbing layer based on a crystalline silicon bottom cell. Regardless of the selection of the substrate, it will not affect the preparation of the subsequent electron transport layer. In the embodiment, the first substrate is the substrate before the preparation of the electron transport layer.

[0074] S102: an electron transport layer is arranged on the surface of the first substrate to prepare a second substrate.

[0075] In the embodiment of the present application, the electron transport layer is the electron transport layer prepared based on the complex described in any of the above-mentioned embodiments. The specific content of the complex has been described in detail in the above-mentioned embodiments, and will not be repeated here.

[0076] In this step, the electron transport layer is prepared based on the above-mentioned complex. Specifically, this step can specifically include: evaporating the complex on the surface of the first substrate based on an evaporation process to form the electron transport layer. That is, the complex can be prepared by evaporation, so that when the complex is prepared, only the corresponding solid needs to be prepared, and it does not need to be dissolved in a solvent to prepare an electron transport layer ink, etc. The specific evaporation process can refer to the prior art, and will not be repeated here. In this step, the evaporation process is used to directly prepare the complex on the surface of the light-absorbing layer to form the electron transport layer.

[0077] Of course, the multilayer electron transport layer as described in the above embodiment of the application can be prepared in this step, and the step specifically can include: evaporating the complex on the surface of the first substrate based on an evaporation process to form a first electron transport layer; and disposing a tin dioxide film on the surface of the first electron transport layer based on an atomic deposition process to form a second electron transport layer. That is, the electron transport layer formed based on the evaporation process of the complex is the first electron transport layer, and then the tin dioxide film is disposed on the surface of the first electron transport layer based on the atomic deposition process (ALD) as the second electron transport layer, to complete the preparation of the entire electron transport layer. The second substrate is the substrate formed after the preparation of the electron transport layer.

[0078] S103: preparing a perovskite solar cell based on the second substrate.

[0079] In this step, the preparation of the peroviskite solar cell is further completed based on the second substrate.

[0080] Specifically, the embodiment specifically provides two preparation methods of peroviskite solar cells, the first one is a preparation method of a traditional peroviskite solar cell, and the second one is a preparation method of a peroviskite-silicon tandem cell. For the preparation method of the traditional peroviskite solar cell, it generally includes:

[0081] S11: cleaning a glass conductive substrate;

[0082] S12: preparing a hole transport layer of nickel oxide on the glass conductive substrate;

[0083] S13: preparing a hole transport layer of MeO-2PACz

[0084] S14: preparing a peroviskite light absorption layer;

[0085] S15: evaporating a complex electron transport layer;

[0086] S16: preparing a tin dioxide electron transport layer;

[0087] S17: evaporating a silver metal electrode.

[0088] In addition to the electron transport layer prepared in S15 in the embodiment, the material of each film layer can be adjusted as appropriate.

[0089] For the preparation method of the peroviskite-silicon tandem cell, it generally includes:

[0090] S21: preparing an intermediate composite layer on the microcrystalline silicon of the N surface of a silicon cell substrate;

[0091] S22: preparing a hole transport layer of nickel oxide on the ITO intermediate composite layer;

[0092] S23: preparing a MeO-2PACz hole transport layer;

[0093] S24: preparing a perovskite light absorption layer;

[0094] S25: evaporating a complex electron transport layer;

[0095] S26: preparing a tin dioxide electron transport layer;

[0096] S27: preparing an ITO thin film;

[0097] S28: evaporating a silver metal electrode.

[0098] The above crystalline silicon cell substrate is a pre-prepared crystalline silicon bottom cell structure, which is a semi-finished heterojunction cell used in the present embodiment. In the present embodiment, the material of each film layer can be adjusted adaptively in addition to the electron transport layer prepared in S25.

[0099] The present embodiment provides a preparation method of a perovskite solar cell, wherein the electron transport layer uses the complex provided in the above inventive embodiment. When the perovskite solar cell discharges during operation, the complex will decompose into superhalogen AlCl4 - and Cl - The superhalogen passivates the organic cation vacancy defects on the surface of the perovskite, thereby improving the efficiency and stability of the perovskite solar cell.

[0100] Two specific preparation methods of perovskite solar cells and their corresponding comparative examples will be provided below, and the only difference between the two is that the comparative example does not use the above-mentioned complex to prepare the electron transport layer but uses fullerene C 60 to prepare the electron transport layer.

[0101] Embodiment 1

[0102] The present embodiment specifically provides a preparation method of a transverse perovskite solar cell, which specifically comprises:

[0103] First step: cleaning a glass conductive substrate.

[0104] Glass / ITO is used as a conductive substrate, and glass cleaner, deionized water, ethanol, acetone, isopropanol, and ethanol are sequentially ultrasonically cleaned for 15 min. The substrate is blown dry with dry air, and then treated with ultraviolet-ozone for 20 min.

[0105] Second step: preparing a nickel oxide hole transport layer.

[0106] A layer of nickel oxide hole transport layer with a thickness of 15 nm is sputtered on the ITO glass by using a magnetron sputtering method.

[0107] Third step: Preparation of MeO-2PACz hole transport layer.

[0108] Re-spraying MeO-2PACz hole transport layer on the nickel oxide hole transport layer, the concentration is 1 mM, dissolved in methanol solvent, the rotation speed is 3000 rad / s, and the annealing temperature is 100℃ / 10min.

[0109] Fourth step: Preparation of perovskite light absorption layer

[0110] Using co-evaporation technology, lead iodide, cesium iodide, and lead bromide are evaporated on the ITO composite layer, the evaporation rate of lead iodide is The evaporation rate of cesium iodide lead is The evaporation rate of lead bromide is The total thickness is 350nm-600nm. Then iodomethylidene, bromomethylidene, iodomethylamine, and chloromethylamine are dissolved in a mixed organic solution of isopropyl alcohol and sprayed on the evaporated film layer, the concentration is between 1.0M-1.5M, and annealing is performed, the annealing temperature is 100℃-150℃, the annealing time is 10min-15min, and the perovskite light absorption layer is prepared.

[0111] Fifth step: Evaporation of complex C 70 ·[AlCl4]5Cl 16 Electron transport layer.

[0112] A layer of C 70 ·[AlCl4]5Cl 16 Electron transport layer is prepared on the perovskite light absorption layer obtained in the previous step by evaporation method, and the thickness should be 20nm.

[0113] Sixth step: Preparation of tin dioxide electron transport layer.

[0114] A layer of tin dioxide film is prepared on the C 70 ·[AlCl4]5Cl 16 Electron transport layer by using atomic deposition technology, and the thickness should be 15nm.

[0115] Seventh step: Evaporation of silver metal electrode.

[0116] A layer of silver metal electrode is evaporated on the surface of tin dioxide, and the thickness is 120nm.

[0117] Comparative Example 1

[0118] The embodiment specifically provides a preparation method of a trans perovskite solar cell, which is different from the embodiment 1 only in that the complex C 70 ·[AlCl4]5Cl 16 C 70 ·[AlCl4]5Cl16 electron transport layer, but using fullerene C 60 Preparation of C 60 electron transport layer. It specifically includes:

[0119] First step: cleaning the glass conductive substrate.

[0120] Use glass / ITO as conductive substrate, and use glass cleaner, deionized water, ethanol, acetone, isopropanol, ethanol in turn for 15 min. Use dry air to dry the substrate, and then ultraviolet-ozone treatment for 20 min.

[0121] Second step: preparation of nickel oxide hole transport layer.

[0122] Use magnetron sputtering method to sputter a layer of nickel oxide hole transport layer on ITO glass, thickness is 15 nm.

[0123] Third step: preparation of MeO-2PACz hole transport layer.

[0124] Spin-coat MeO-2PACz hole transport layer on the nickel oxide hole transport layer, its concentration is 1 mM, dissolved in methanol solvent, the rotation speed is 3000 rad / s, and the annealing temperature is 100°C / 10 min.

[0125] Fourth step: preparation of perovskite light absorption layer

[0126] Use co-evaporation technology to evaporate lead iodide, cesium iodide, lead bromide on ITO composite layer, the evaporation rate of lead iodide is The evaporation rate of cesium iodide lead is The evaporation rate of lead bromide is The total thickness is 350 nm-600 nm. Then dissolve methyl iodide, methyl bromide, methyl iodide, methyl amine chloride in isopropanol mixed organic liquid and spin-coat on the evaporated film layer, the concentration is between 1.0M-1.5M, and annealing is carried out, the annealing temperature is 100°C-150°C, the annealing time is 10 min-15 min, and the perovskite light absorption layer is prepared.

[0127] Fifth step: evaporation of complex C 60 electron transport layer.

[0128] Prepare a layer of C 60 electron transport layer on the perovskite light absorption layer obtained in the previous step by evaporation method, the thickness should be 20 nm.

[0129] Sixth step: preparation of tin dioxide electron transport layer.

[0130] Use atomic deposition technology to prepare a layer of tin dioxide electron transport layer on C 60A layer of tin dioxide film is prepared on the upper end of the electron transport layer, and the thickness should be 15 nm.

[0131] Seventh step: evaporation of silver metal electrode.

[0132] A layer of silver metal electrode is evaporated on the surface of tin dioxide, and the thickness is 120 nm.

[0133] Example 2

[0134] The embodiment specifically provides a preparation method of a perovskite crystalline silicon laminated solar cell, and a semi-finished heterojunction cell is specifically used as a crystalline silicon bottom cell, and the method specifically comprises the following steps:

[0135] First step: preparation of intermediate composite layer.

[0136] A layer of ITO composite layer is sputtered on the microcrystalline silicon on the N face of the crystalline silicon cell substrate by using PVD (Physical Vapor Deposition), and the thickness is 30 nm.

[0137] Second step: preparation of nickel oxide hole transport layer.

[0138] A layer of nickel oxide hole transport layer is sputtered on the ITO composite layer by using a magnetron sputtering method, and the thickness is 15 nm.

[0139] Third step: preparation of MeO-2PACz hole transport layer.

[0140] MeO-2PACz hole transport layer is spin-coated on the nickel oxide hole transport layer, the concentration is 1 mM, the solvent is methanol, the rotation speed is 3000 rad / s, and the annealing temperature is 100 ℃ / 10 min.

[0141] Fourth step: preparation of perovskite light absorption layer.

[0142] Lead iodide, cesium iodide and lead bromide are evaporated on the ITO composite layer by using a co-evaporation technique, the evaporation rate of lead iodide is The evaporation rate of cesium iodide lead is The evaporation rate of lead bromide is The total thickness is 350 nm-600 nm. Then, methyl iodide, methyl bromide, methyl iodide and methyl amine chloride are dissolved in a mixed organic liquid of isopropyl alcohol, spin-coated on the evaporated film layer, the concentration is 1.0 M-1.5 M, and annealing is performed, the annealing temperature is 100 ℃-150 ℃, the annealing time is 10 min-15 min, and the perovskite light absorption layer is prepared.

[0143] Fifth step: evaporation of complex C 70 ·[AlCl4]5Cl 16 Electron transport layer.

[0144] A layer of C 70 [AlCl4]5Cl 16 An electron transport layer with a thickness of 20 nm.

[0145] Step 6: Preparation of a tin dioxide electron transport layer.

[0146] A layer of C 70 [AlCl4]5Cl 16 An electron transport layer with a thickness of 15 nm.

[0147] Step 7: Preparation of an ITO film.

[0148] Sputter a layer of ITO film on the surface of the tin dioxide film layer with a thickness of 120 nm.

[0149] Step 8: Evaporation of silver metal electrode.

[0150] Evaporate a layer of silver metal electrode on the surface of the ITO film with a thickness of 900 nm.

[0151] Comparative Example 2

[0152] The embodiment specifically provides a preparation method of a perovskite crystalline silicon laminated solar cell. The specifically used crystalline silicon bottom cell is a semi-finished heterojunction cell, which is different from the above-mentioned embodiment 2 only in that the complex C 70 [AlCl4]5Cl 16 Preparation of C 70 [AlCl4]5Cl 16 An electron transport layer, but using fullerene C 60 Preparation of C 60 An electron transport layer. Specifically, it includes:

[0153] Step 1: Preparation of intermediate composite layer.

[0154] Sputter a layer of ITO composite layer on the N face microcrystalline silicon of the crystalline silicon cell substrate using PVD (Physical Vapor Deposition), with a thickness of 30 nm.

[0155] Step 2: Preparation of nickel oxide hole transport layer.

[0156] Sputter a layer of nickel oxide hole transport layer on the ITO composite layer by magnetron sputtering, with a thickness of 15 nm.

[0157] Step 3: Preparation of MeO-2PACz hole transport layer.

[0158] Spin coating MeO-2PACz hole transport layer on the nickel oxide hole transport layer, the concentration is 1 mM, dissolved in methanol solvent, the rotation speed is 3000 rad / s, and the annealing temperature is 100℃ / 10 min.

[0159] Fourth step: preparation of perovskite light absorbing layer.

[0160] Using co-evaporation technology, lead iodide, cesium iodide and lead bromide are evaporated on the ITO composite layer, the evaporation rate of lead iodide is The evaporation rate of cesium iodide lead is The evaporation rate of lead bromide is The total thickness is 350 nm-600 nm. Then iodomethyl, bromomethyl, iodomethylamine, chloromethylamine are dissolved in isopropyl alcohol mixed organic liquid and spin coated on the evaporated film layer, the concentration is 1.0 M-1.5 M, and annealing is carried out, the annealing temperature is 100℃-150℃, the annealing time is 10 min-15 min, and the perovskite light absorbing layer is prepared.

[0161] Fifth step: evaporation of complex C 60 Electron transport layer.

[0162] A layer of C 60 Electron transport layer is prepared on the perovskite light absorbing layer obtained in the previous step by evaporation method, and the thickness should be 20 nm.

[0163] Sixth step: preparation of tin dioxide electron transport layer.

[0164] Using atomic deposition technology, a layer of tin dioxide film is prepared on the C 60 Electron transport layer, and the thickness should be 15 nm.

[0165] Seventh step: preparation of ITO thin film.

[0166] A layer of ITO thin film is sputtered on the surface of the tin dioxide film layer, and the thickness is 120 nm.

[0167] Eighth step: evaporation of silver metal electrode.

[0168] A layer of silver metal electrode is evaporated on the surface of the ITO thin film, and the thickness is 900 nm.

[0169] Based on the solar cells obtained in example 1, example 2, comparative example 1 and comparative example 2, the open circuit voltage Voc(V), short circuit current Jsc(mA·cm -2 ), fill factor FF(%), and conversion efficiency PCE(%) are measured, and the results are shown in table 1:

[0170] Table 1

[0171]

[0172] The measurement methods of the open-circuit voltage Voc, short-circuit current Jsc, fill factor FF, and conversion efficiency PCE can refer to the prior art, which will not be described here.

[0173] Please refer to Figure 6 and Figure 7 , Figure 6 Figure 1 is a graph showing the change of normalized PCE with time for the perovskite solar cell in Example 1 and the perovskite solar cell in Comparative Example 1. Figure 7 Figure 2 is a graph showing the change of normalized PCE with time for the perovskite crystalline silicon tandem solar cell in Example 2 and the perovskite crystalline silicon tandem solar cell in Comparative Example 2. In combination with Figure 6 , Figure 7 and Table 1, it can be seen that the open-circuit voltage, short-circuit current, fill factor, conversion efficiency of the perovskite solar cell and perovskite crystalline silicon tandem solar cell prepared by the method provided in the present application are all improved compared with the comparative examples, and the conversion efficiency of the solar cell is effectively reduced after long-term use. This is because during the discharge of the battery, the C 70 ·[AlCl4]5Cl 16 The complex will decompose into superhalogen AlCl4 - , Cl - and C 70 , and the superhalogen AlCl4 - and Cl - can passivate the organic cation vacancy defects on the perovskite surface, thereby improving the efficiency and stability of the battery.

[0174] Each of the embodiments in the specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0175] Finally, it should be noted that in this document, relationship terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or equipment including the element.

[0176] The solar cell electron transport layer, the solar cell and the preparation method provided by the present application are described in detail above. The principles and implementation manners of the present application are described by using specific examples in this paper, and the above examples are only used to help understand the method of the present application and the core idea thereof. It should be pointed out that, for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A perovskite solar cell electron transport layer, characterized in that, comprising a complex formed by complexing the transport material with tetrachloroaluminate ions; the transport material comprises fullerene and fullerene derivatives.

2. The perovskite solar cell electron transport layer according to claim 1, characterized in that, the transport material comprises any one or any combination of the following: Fullerene C 60 Fullerene C 70 monoadduct fullerene derivative, diadduct fullerene derivative, polyadduct fullerene derivative.

3. The perovskite solar cell electron transport layer according to claim 2, characterized in that, The complex comprises fullerene C 70 The complex C formed by complexing with tetrachloroaluminate ion 70 • [AlCl4]5Cl 16 .

4. The perovskite solar cell electron transport layer of claim 1, wherein, comprising a first electron transport layer formed from the complex, and a second electron transport layer formed on a side surface of the first electron transport layer; the second electron transport layer is formed from tin dioxide.

5. A method for preparing an electron transport layer of a perovskite solar cell, characterized in that, comprising: a battery formed from the transport material as a cathode, and 1-ethyl-3-methylimidazolium aluminum chloride as an electrolyte; the transport material comprises fullerene and fullerene derivatives; charging the battery to form, in the cathode, a complex formed by complexing the transport material with tetrachloroaluminate ions.

6. The method of claim 5, wherein, the transport material as a cathode comprises: Fullerene C 70 as a cathode; charging the battery to form, in the cathode, a complex formed by complexing the transport material with tetrachloroaluminate ions comprises: charging the cell to generate complex C at the cathode 70 • [AlCl4]5Cl 16 .

7. A perovskite solar cell, characterized by, comprising an electron transport layer formed from the complex according to any one of claims 1 to 4.

8. A method of manufacturing a perovskite solar cell, characterized by, comprising: forming a first substrate; forming a second substrate by disposing an electron transport layer on a surface of the first substrate; the electron transport layer is formed from the complex according to any one of claims 1 to 4; forming a perovskite solar cell based on the second substrate.

9. The method of claim 8, wherein, disposing an electron transport layer on a surface of the first substrate comprises: forming the electron transport layer by evaporating the complex on the surface of the first substrate based on an evaporation process.

10. The method of claim 9, wherein, disposing an electron transport layer on a surface of the first substrate comprises: forming a first electron transport layer by evaporating the complex on the surface of the first substrate based on an evaporation process; forming a second electron transport layer by disposing a tin dioxide film on a surface of the first electron transport layer based on an atomic deposition process.

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