Electron transport material, solar cell, power utilization device, and power generation device

Abstract

The invention discloses an electron transport material, a solar cell, a power utilization device and a power generation device, the electron transport material is used for an electron transport layer of the solar cell, the electron transport material comprises a first fullerene derivative and a second fullerene derivative, the first fullerene derivative has an electron donating group, and the second fullerene derivative has an electron donating group. The second fullerene derivative has an electron withdrawing group, and the mass of the second fullerene derivative accounts for 1-10% of the total mass of the first fullerene derivative and the second fullerene derivative, so that the electron transport material has relatively high conductivity and stability. When the electron transport material is used as the electron transport layer of the solar cell, the electron transport material has excellent electron transport performance, and the photoelectric conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to an electron transport material, a solar cell, an electrical device and a power generation device. Background Art

[0002] In existing solar cell devices, the electron transport layer (ETL) exhibits poor conductivity and low stability, resulting in low photoelectric conversion efficiency and hindering the industrialization of solar cells. Therefore, providing an electron transport material, solar cell, power-consuming device, and power generation device that can improve the photoelectric conversion efficiency of solar cells is a pressing technical challenge. Summary of the Invention

[0003] In view of the above technical problems, the present application provides an electron transport material, a solar cell, an electrical device and a power generation device to improve the photoelectric conversion efficiency of the solar cell.

[0004] The first technical solution adopted in this application is: to provide an electron transport material, the electron transport material includes a first fullerene derivative and a second fullerene derivative, the first fullerene derivative has an electron-donating group, the second fullerene derivative has an electron-withdrawing group, and the second fullerene derivative accounts for 1% to 10% of the total mass of the first fullerene derivative and the second fullerene derivative.

[0005] In the technical solution of the embodiment of the present application, a first fullerene derivative having an electron-donating group and a second fullerene derivative having an electron-withdrawing group are used as electron transport materials, wherein the second fullerene derivative accounts for 1% to 10% of the total mass of the first fullerene derivative and the second fullerene derivative, so that the electron transport material has high conductivity and stability. Using this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0006] At the same time, the first fullerene derivative and the second fullerene derivative are both fullerene derivatives with similar structures. Therefore, by doping the second fullerene derivative into the first fullerene derivative as an electron transport material, the second fullerene derivative is less likely to disrupt the original arrangement of the first fullerene derivative during doping. The electron transport film layer formed by the two not only has a high density, which is conducive to improving the stability of the electron transport material, but also has good flatness, thereby improving the transport performance of the electron transport layer and further improving the photoelectric conversion efficiency of the solar cell.

[0007] In some embodiments, the electron-withdrawing group of the second fullerene derivative includes at least one of a carboxylic acid group, a phosphate group, a sulfate group, and an alcoholic hydroxyl group.

[0008] In the technical solution of the embodiment of the present application, the electron-withdrawing group of the second fullerene derivative is within the above-mentioned range. When the second fullerene derivative having the above-mentioned electron-withdrawing group is doped into the first fullerene derivative, it is beneficial to charge transfer, so that the conductive performance of the electron transport material is greatly improved. The application of this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0009] In some embodiments, the second fullerene derivative is a fullerene pyrrolidine derivative, and the electron-withdrawing group is directly or via a carbon chain connected to the fullerene pyrrolidine host.

[0010] In the technical solution of the embodiment of the present application, the second fullerene derivative is a fullerene pyrrolidine derivative, so the material has greater stability. The above-mentioned electron-withdrawing group is directly or through a carbon chain connected to the fullerene pyrrolidine body, so the second fullerene derivative can improve the conductivity of the electron transport material. Using this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0011] In some embodiments, the second fullerene derivative comprises At least one of .

[0012] The second fullerene derivative in the technical solution of the embodiment of the present application can improve the conductivity of the electron transport material. Applying this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0013] In some embodiments, the first fullerene derivative comprises a fullerene pyrrolidine derivative, and the electron-donating group is a nitrogen atom of the fullerene pyrrolidine derivative attached to the fullerene.

[0014] In the technical solution of the embodiment of the present application, the first fullerene derivative is a fullerene pyrrolidine derivative, and its electron-donating group is a fullerene pyrrolidine derivative connected to the N atom of the fullerene. Therefore, the first fullerene derivative and the second fullerene derivative are both fullerene pyrrolidine derivatives, and the two have similar structures. The electron transport film layer formed as an electron transport material has a high density and surface flatness, which is beneficial to improving the stability of the electron transport material. At the same time, the first fullerene pyrrolidine derivative is connected to the N atom of the fullerene as an electron-donating group, which improves the conductivity of the electron transport material, thereby improving the transport performance of the electron transport layer and improving the photoelectric conversion efficiency of the solar cell.

[0015] In some embodiments, the first fullerene derivative comprises

[0016] At least one of .

[0017] The first fullerene derivative in the technical solution of the embodiment of the present application can improve the conductivity and stability of the electron transport material. Applying this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0018] The second technical solution adopted in the present application is: providing a solar cell, the solar cell including an electron transport layer, and the electron transport layer including the electron transport material as described above.

[0019] In the technical solution of the embodiment of the present application, the above-mentioned electron transport material is applied as an electron transport layer to a solar cell, which can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0020] In some embodiments, the thickness of the electron transport layer of the solar cell is 20 nm to 25 nm.

[0021] In the technical solution of the embodiment of the present application, the thickness of the electron transport layer is set within the above range, so that the above electron transport material forms a reasonable film thickness, which can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0022] In some embodiments, the solar cell further includes a perovskite layer, and the electron transport layer is located on one side of the perovskite layer.

[0023] In the technical solution of the embodiment of the present application, the above-mentioned electron transport material is applied as an electron transport layer to the perovskite solar cell, which can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0024] The third technical solution adopted in the present application is to provide an electrical device comprising the electron transport material as described above or the solar cell as described above.

[0025] Since the device of the present application includes the electron transport material or solar cell provided by the present application, it has at least the same advantages as the electron transport material or solar cell.

[0026] The fourth technical solution adopted in the present application is: to provide a power generation device, which includes the electron transport material as described above or includes the solar cell as described above.

[0027] Since the device of the present application includes the electron transport material or solar cell provided by the present application, it has at least the same advantages as the electron transport material or solar cell.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0030] Figure 1 This is a schematic structural diagram of a solar cell according to some embodiments of the present application;

[0031] Figure 2 This is a schematic structural diagram of an electrical device according to some embodiments of the present application.

[0032] Figure 3 This is a schematic structural diagram of a power generation device according to some embodiments of the present application.

[0033] In the attached figure:

[0034] 100. Solar cell; 10. First electrode layer; 11. Hole blocking layer; 12. Electron transport layer; 13. Perovskite layer; 14. Hole transport layer; 15. Second electrode layer; 1000. Electrical device; 2000. Power generation device. DETAILED DESCRIPTION

[0035] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0037] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0038] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0040] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0041] Perovskite solar cells are currently a promising solar cell and a hot topic of research due to their outstanding advantages, including high photoelectric conversion efficiency, low cost, and simple fabrication. They can be used in lunar rovers, satellite panels, various sensors and detectors, as well as in civilian products such as wearable electronics and automotive power supplies. Perovskite solar cells are becoming a power source for consumer products in many ways. With the continuous expansion of perovskite solar cell applications and the flexible and foldable nature of perovskite solar cells, market demand is also growing.

[0042] In existing solar cells, C 60 Or the poor conductivity and stability of the electron transport layer formed by PCBM materials lead to poor photoelectric conversion efficiency of solar cells, which restricts the industrial development of solar cells.

[0043] In order to solve the above technical problems, the present application provides an electron transport material, which includes a first fullerene derivative and a second fullerene derivative, the first fullerene derivative has an electron-donating group, the second fullerene derivative has an electron-withdrawing group, and the second fullerene derivative accounts for 1% to 10% of the total mass of the first fullerene derivative and the second fullerene derivative.

[0044] In the technical solution of the embodiment of the present application, a first fullerene derivative having an electron-donating group and a second fullerene derivative having an electron-withdrawing group are used as electron transport materials, wherein the second fullerene derivative accounts for 1% to 10% of the total mass of the first fullerene derivative and the second fullerene derivative, so that the electron transport material has high conductivity and stability. Using this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0045] At the same time, the first fullerene derivative and the second fullerene derivative are both fullerene derivatives with similar structures. Therefore, by doping the second fullerene derivative into the first fullerene derivative as an electron transport material, the second fullerene derivative is less likely to disrupt the original arrangement of the first fullerene derivative during doping. The electron transport film layer formed by the two not only has a high density, which is conducive to improving the stability of the electron transport material, but also has good flatness, thereby improving the transport performance of the electron transport layer and further improving the photoelectric conversion efficiency of the solar cell.

[0046] The solar cells disclosed in the embodiments of the present application can be used in electrical devices that utilize photoelectric conversion. The electrical devices may include, but are not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery-powered vehicles, electric vehicles, ships, spacecraft, and the like. The electric toys may include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, and the spacecraft may include airplanes, rockets, space shuttles, and spacecraft, among others.

[0047] In some embodiments, the electron-withdrawing group of the second fullerene derivative includes at least one of a carboxylic acid group, a phosphate group, a sulfate group, and an alcoholic hydroxyl group.

[0048] In the technical solution of the embodiment of the present application, the electron-withdrawing group of the second fullerene derivative is within the above-mentioned range. When the second fullerene derivative having the above-mentioned electron-withdrawing group is doped into the first fullerene derivative, it is beneficial to charge transfer, so that the conductive performance of the electron transport material is greatly improved. The application of this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0049] In some embodiments, the second fullerene derivative is a fullerene pyrrolidine derivative, and the electron-withdrawing group is directly or via a carbon chain connected to the fullerene pyrrolidine host.

[0050] In the technical solution of the embodiment of the present application, the second fullerene derivative is a fullerene pyrrolidine derivative, so the material has greater stability. The above-mentioned electron-withdrawing group is directly or through a carbon chain connected to the fullerene pyrrolidine body, so the second fullerene derivative can improve the conductivity of the electron transport material. Using this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0051] In some embodiments, the second fullerene derivative comprises

[0052] (Sigma-Aldrich no.709085), At least one of (CAS: 155116-19-1).

[0053] In the technical solution of the embodiment of the present application, the second fullerene derivative is within the above-mentioned range, so that the second fullerene derivative can improve the conductivity of the electron transport material. Applying this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0054] In some embodiments, the first fullerene derivative comprises a fullerene pyrrolidine derivative, and the electron-donating group is a nitrogen atom of the fullerene pyrrolidine derivative attached to the fullerene.

[0055] In the technical solution of the embodiment of the present application, the first fullerene derivative is a fullerene pyrrolidine derivative, and its electron-donating group is a fullerene pyrrolidine derivative connected to the N atom of the fullerene. Therefore, the first fullerene derivative and the second fullerene derivative are both fullerene pyrrolidine derivatives, and the two have similar structures. The electron transport film layer formed as an electron transport material has a high density and surface flatness, which is beneficial to improving the stability of the electron transport material. At the same time, the first fullerene pyrrolidine derivative is connected to the N atom of the fullerene as an electron-donating group, which improves the conductivity of the electron transport material, thereby improving the transport performance of the electron transport layer and improving the photoelectric conversion efficiency of the solar cell.

[0056] In some embodiments, the first fullerene derivative comprises

[0057] At least one of .

[0058] In the technical solution of the embodiment of the present application, the first fullerene derivative is within the above-mentioned range, so that the first fullerene derivative can improve the conductivity and stability of the electron transport material. Applying this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0059] It should be noted that the fullerenes described in this application include but are not limited to C 60 , C 70 wait.

[0060] The second technical solution adopted in the present application is: providing a solar cell 100, wherein the solar cell 100 includes an electron transport layer 12, and the electron transport layer 12 includes the electron transport material as described above.

[0061] In the technical solution of the embodiment of the present application, applying the above-mentioned electron transport material as the electron transport layer 12 to the solar cell 100 can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0062] In some embodiments, reference Figure 1 The solar cell 100 may include a first electrode layer 10, a hole blocking layer 11, an electron transport layer 12, a perovskite layer 13, a hole transport layer 14, and a second electrode layer 15, which are arranged in sequence. In this embodiment, the solar cell 100 has a normal structure; in other embodiments, the solar cell 100 may also have a reverse structure, that is, the solar cell 100 may include a second electrode layer 15, a hole transport layer 14, a perovskite layer 13, an electron transport layer 12, a hole blocking layer 11, and a first electrode layer 10, which are arranged in sequence.

[0063] The first electrode layer 10 may be made of an organic, inorganic, or organic-inorganic hybrid conductive material, including but not limited to the following materials: Ag, Cu, C, Au, Al, ITO, AZO, BZO, IZO, etc. The thickness of the first electrode layer 10 is 10 to 1000 nm, and may be 10 nm, 220 nm, 335 nm, 380 nm, 470 nm, 660 nm, 880 nm, 1000 nm, etc., or a range consisting of any two of the above values, for example, 10 to 970 nm, 240 to 370 nm, 320 to 580 nm, 440 to 770 nm, 280 to 920 nm, 420 to 990 nm, etc.

[0064] The hole blocking layer 11 can transport electrons and block holes, and its material includes BCP and / or SnO2.

[0065] It should be noted that, in some embodiments, the hole blocking layer 11 may not be included.

[0066] In some embodiments, the thickness of the electron transport layer 12 is 20 nm to 25 nm.

[0067] In the technical solution of the embodiment of the present application, the thickness of the electron transport layer 12 is set within the above range, so that the above electron transport material forms a reasonable film thickness, which can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0068] The thickness of the electron transport layer 12 can be 20 nm, 21 nm, 21.5 nm, 22 nm, 23 nm, 23.3 nm, 24 nm, 24.7 nm, 25 nm, etc., or a range consisting of any two of the above values, for example, 20 nm to 21.5 nm, 22 nm to 23.3 nm, 20 nm to 23 nm, 24 nm to 25 nm, etc.

[0069] In some embodiments, the electron transport layer 12 is located on one side of the perovskite layer 13 .

[0070] In the technical solution of the embodiment of the present application, applying the above-mentioned electron transport material as the electron transport layer 12 to the perovskite solar cell 100 can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell 100.

[0071] The electron transport material as described above is used as the electron transport layer 12 . The electron transport material includes a first fullerene derivative having an electron-donating group and a second fullerene derivative having an electron-withdrawing group.

[0072] In some embodiments, during the preparation of the electron transport layer, the electron transport material and the solvent are first mixed to prepare an electron transport layer precursor, and then the electron transport layer 12 can be covered on the surface of the perovskite layer 13 by spin coating, spray coating, blade coating or slit coating. In some embodiments, the solvent can include at least one of dichlorobenzene, chlorobenzene, toluene, and chloroform. In some embodiments, the concentration of the electron transport material can be 10 to 20 mg / mL, which can be 10 mg / mL, 12 mg / mL, 15 mg / mL, 18 mg / mL, 20 mg / mL, etc., or a range consisting of any two of the above values, for example, it can be 10 mg / mL to 12 mg / mL, 12 mg / mL to 18 mg / mL, 18 mg / mL to 20 mg / mL, etc.

[0073] The chemical formula of the perovskite layer 13 satisfies ABX3 or A2CDX6, where A includes inorganic or organic or organic-inorganic mixed cations, which may be MA + , FA + 、Cs + At least one of; B includes an inorganic cation, which may be Pb2+ 、Sn 2+ At least one of; C includes inorganic or organic or organic-inorganic mixed cations, commonly Ag + 、Cu + 、Au + , FA + , GA + ; D includes inorganic cations, which can be Bi 3+ 、Sb 3+ , and In 3+ At least one of; X includes an inorganic anion, which may be Cl - Br - , I - At least one of.

[0074] The band gap of the perovskite layer 13 is 1.20 to 2.30 eV.

[0075] The thickness of the perovskite layer 13 is 200-1000 nm, which can be 200 nm, 260 nm, 320 nm, 398 nm, 468 nm, 632 nm, 834 nm, 1000 nm, etc., or a range consisting of any two of the above values, for example, it can be 200-970 nm, 240-370 nm, 360-590 nm, 450-760 nm, 240-990 nm, 480-970 nm, etc.

[0076] The hole transport layer 14 includes but is not limited to at least one of the following materials and their derivatives and materials obtained by doping or passivation: nickel oxide, 2,2',7,7'-tetrakis(N,N-p-anisyl)-9,9'-spirobifluorene (Spiro-OMeTAD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphoric acid (Me-4Pacz), and other materials that have been patented or reported in the literature.

[0077] The second electrode layer 15 includes but is not limited to the following materials: FTO, ITO, AZO, BZO, IZO, etc. The thickness of the second electrode layer 15 is 10 to 1000 nm, which can be 10 nm, 55 nm, 103 nm, 358 nm, 480 nm, 650 nm, 890 nm, 1000 nm, etc., or a range composed of any two of the above values, for example, it can be 10 to 20 nm, 60 to 150 nm, 100 to 520 nm, 400 to 790 nm, 28 to 900 nm, 200 to 980 nm, etc.

[0078] See Figure 2The present application also provides an electrical device 1000 , comprising the electron transport material as described above or the solar cell 100 as described above.

[0079] In the present application, the solar cell 100 serves as a power source for the electrical device 1000; alternatively, the solar cell 100 can serve as an energy storage unit for the electrical device 1000. For example, the electrical device 1000 can be a lighting element, a display element, or a car.

[0080] See Figure 3 The present application further provides a power generation device 2000, comprising the aforementioned electron transport material or the aforementioned solar cell 100. The power generation device 2000 can be used for generating electricity, and comprises at least the solar cell 100.

[0081] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0082] The solar cell 100 of the present application utilizes the aforementioned electron transport material as the electron transport layer 12. This electron transport material comprises a first fullerene derivative having an electron-donating group and a second fullerene derivative having an electron-withdrawing group. The second fullerene derivative accounts for 1% to 10% of the combined mass of the first and second fullerene derivatives. This improves the electron transport performance of the film layer, thereby increasing the photoelectric conversion efficiency of the solar cell. This novel solar cell 100 is suitable for use in both positive and negative solar cells.

[0083] The formal method for preparing the novel solar cell 100 includes the following steps:

[0084] Step 1: Preparation of electron transport materials;

[0085] Step 2: Etching and cleaning the conductive glass substrate, drying it and setting it aside for later use, wherein the conductive glass substrate has a first electrode layer;

[0086] Step 3: preparing a hole blocking layer on a conductive glass substrate;

[0087] Step 4: preparing an electron transport layer on the hole blocking layer;

[0088] Step 5: Preparing a perovskite layer on the electron transport layer;

[0089] Step 6: Prepare hole transport solution for later use;

[0090] Step 7: Prepare a hole transport layer on the perovskite layer and remove the solvent by annealing or vacuum;

[0091] Step 8: Prepare a second electrode layer on the hole transport layer and perform edge cleaning test.

[0092] The method for preparing the novel inverted solar cell 100 comprises the following steps:

[0093] Step 1: Preparation of electron transport materials;

[0094] Step 2: Etching and cleaning the conductive glass substrate, drying it and setting it aside for later use, wherein the conductive glass substrate has a second electrode layer;

[0095] Step 3: Prepare hole transport solution for later use;

[0096] Step 4: Prepare a hole transport layer on a conductive glass substrate and remove the solvent by annealing or vacuum;

[0097] Step 5: Preparing a perovskite layer on the hole transport layer;

[0098] Step 6: Preparing an electron transport layer on the perovskite layer;

[0099] Step 7: preparing a hole blocking layer on the electron transport layer;

[0100] Step 8: Prepare the first electrode layer on the hole blocking layer and perform edge cleaning test.

[0101] The following is an example of a method for preparing a novel inverted solar cell 100:

[0102] Example 1

[0103] (1) Take a 2.0 cm × 2.0 cm FTO conductive glass and remove 0.35 cm of FTO at each end by laser etching to expose the glass substrate;

[0104] (2) Ultrasonic cleaning of the etched FTO conductive glass was performed several times with water, acetone, and isopropyl alcohol in sequence;

[0105] (3) The FTO conductive glass was blown dry with a nitrogen gun and placed in a UV ozone machine for further cleaning;

[0106] (4) Preparation of NiO on FTO substrate after UV ozone treatment by magnetron sputtering x (20 nm), annealed on a hot plate at 200 °C for 20 min after preparation;

[0107] (5) In NiO x The layer was spin-coated with a 2 mg / mL PTAA solution at 6000 rpm, annealed at 100 °C for 10 minutes, and cooled to room temperature to a thickness of 4 nm.

[0108] (6) Weigh 1.6 mmol of lead iodide, 1.52 mmol of iodomethane, and 0.08 mmol of cesium iodide and dissolve them in 1 ml of a DMF:DMSO mixed solution with a volume ratio of 4:1, stir for 2 h, and filter with a 0.22 μm amphoteric filter membrane to obtain a perovskite precursor solution; spin-coat the perovskite precursor solution on the PTAA layer at 4000 rpm, anneal at 100°C for 10 minutes, and cool to room temperature, wherein the active material of the perovskite layer is a CsFA system and the thickness is 500 nm;

[0109] (7) weighing a certain amount of the first fullerene derivative and the second fullerene derivative in a weight ratio of 99:1 and dissolving them in chlorobenzene to obtain an electron transport layer solution, wherein the total concentration of the electron transport material is 20 mg / ml, and spin coating the solution on the perovskite layer to form an electron transport layer with a thickness of 20 nm;

[0110] (8) Preparing a 20 nm tin oxide layer on the electron transport layer using an ALD device;

[0111] (9) The obtained wafer is placed in a vapor deposition machine and a metal electrode Cu 100 nm is vapor deposited to obtain a battery device 1.

[0112] Examples 2 to 5 are similar to Example 1, except that the weight ratio of the first fullerene derivative to the second fullerene derivative was adjusted. The weight ratios of the first fullerene derivative to the second fullerene derivative in Examples 2 to 5 were 95:5, 90:10, 99.5:0.5, and 85:15, respectively.

[0113] Examples 6 to 9 are similar to Example 1, except for the types and weight ratios of the first fullerene derivative and the second fullerene derivative.

[0114] Comparative Examples 1 to 3 are similar to Example 1, except that the electron transport layer is adjusted. The electron transport layers of Comparative Examples 1 to 3 are PCBM, the first fullerene derivative, and the second fullerene derivative, respectively.

[0115] The battery devices 1 to 12 obtained in the above Examples 1 to 9 and Comparative Examples 1 to 3 were subjected to battery performance tests, and the results are shown in Table 1.

[0116] Test method:

[0117] 1. Conductivity of the electron transport layer

[0118] The actual resistance of the electron transport layer can be measured by connecting two test leads (regardless of positive or negative) to the two end pins of the electron transport layer of the fullerene derivative thin film.

[0119] 2. Short-circuit current, open-circuit voltage, initial efficiency

[0120] Scan the volt-ampere characteristic curve under a sunlight intensity (AM1.5), control the output of the source meter, scan the IV curve, and obtain the main parameters: short-circuit current (I sc ), open circuit voltage (V oc ), initial efficiency (%).

[0121] 3. Efficiency change after 100 hours of maximum power light aging (%)

[0122] Under a sunlight intensity of one sun (AM1.5), control the output voltage of the source meter to the maximum power point, measure the current, obtain the maximum power, and measure the maximum power output every 5 minutes.

[0123]

[0124]

[0125]

[0126]

[0127] As can be seen from the data in Table 1, the battery devices of Examples 1-7 all use an electron transport material comprising a first fullerene derivative doped with a second fullerene derivative as the electron transport layer of the trans-type device. The electron transport layer conductivity and initial efficiency of the devices are higher than or substantially the same as those of Comparative Examples 1-3, and the efficiency after 100 hours of maximum power light aging is also higher than or substantially the same as that of Comparative Examples 1-3. Among them, the device prepared in Example 2, with a weight ratio of the first fullerene derivative to the second fullerene derivative of 95:5, exhibits the highest electron transport layer conductivity and initial efficiency, and the smallest percentage change in efficiency after 100 hours of maximum power light aging. In Examples 1 to 3, the mass of the second fullerene derivative accounts for 1% to 10% of the total mass of the first fullerene derivative and the second fullerene derivative, and the conductivity and initial efficiency of the electron transport layer of the prepared device are higher than or basically the same as those of Examples 4 to 5. This shows that the present application uses the second fullerene derivative having an electron-withdrawing group to dope the first fullerene derivative having an electron-donating group as an electron transport material, wherein the second fullerene derivative accounts for 1% to 10% of the total mass of the first fullerene derivative and the second fullerene derivative, so that the electron transport material has high conductivity and stability. The application of this electron transport material as the electron transport layer of a solar cell can improve the electron transport performance of the film layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0128] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An electron transport material, characterized in that The invention comprises a first fullerene derivative and a second fullerene derivative, wherein the first fullerene derivative has an electron-donating group, the second fullerene derivative has an electron-withdrawing group, and the second fullerene derivative accounts for 1% to 10% of the total mass of the first fullerene derivative and the second fullerene derivative.

2. The electron transport material according to claim 1, wherein The electron-withdrawing group of the second fullerene derivative includes at least one of a carboxylic acid group, a phosphate group, a sulfate group, and an alcoholic hydroxyl group.

3. The electron transport material according to claim 1 or 2, wherein The second fullerene derivative is a fullerene pyrrolidine derivative, and the electron-withdrawing group is connected to the fullerene pyrrolidine main body directly or through a carbon chain.

4. The electron transport material according to any one of claims 1 to 3, wherein The second fullerene derivative includes At least one of .

5. The electron transport material according to any one of claims 1 to 4, characterized in that The first fullerene derivative includes a fullerene pyrrolidine derivative, and the electron-donating group is a nitrogen atom of the fullerene pyrrolidine derivative connected to the fullerene.

6. The electron transport material according to any one of claims 1 to 5, wherein The first fullerene derivative includes At least one of .

7. A solar cell, characterized in that: The method comprises at least an electron transport layer, wherein the electron transport layer comprises the electron transport material according to any one of claims 1 to 6.

8. The solar cell according to claim 7, wherein The thickness of the electron transport layer is 20 nm to 25 nm.

9. The solar cell according to claim 7 or 8, wherein: The solar cell further includes a perovskite layer, and the electron transport layer is located on one side of the perovskite layer.

10. An electrical device comprising the electron transport material according to any one of claims 1 to 6 or the solar cell according to any one of claims 7 to 9.

11. A power generation device comprising the electron transport material according to any one of claims 1 to 6 or the solar cell according to any one of claims 7 to 9.

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