Solar cells, photovoltaic devices, electrical devices and power generation devices

Abstract

This application discloses a solar cell, a photovoltaic device, an electrical appliance, and a power generation device. The solar cell includes at least a first light-absorbing layer and a hole transport layer, wherein the hole transport layer comprises polythiophene derivative molecules. The polythiophene derivative molecules possess good molecular arrangement and hole transport capability. The ester groups in the polythiophene derivative molecules can modulate the HOMO energy levels of the material without disrupting the molecular arrangement of the polythiophene derivative itself, thereby better matching the molecular energy levels of the hole transport layer and the first light-absorbing layer, thus improving the photoelectric conversion efficiency of the solar cell.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to solar cells, photovoltaic devices, electrical appliances, and power generation devices. Background Technology

[0002] Solar cells have attracted widespread attention because they can directly convert sunlight into electricity without causing environmental pollution, and can be applied to a wide range of fields, including aerospace, industry, commerce, agriculture and communications.

[0003] A solar cell includes at least a first light-absorbing layer and a hole transport layer, with the hole transport layer facilitating hole transport. The energy level difference between the hole transport layer and the first light-absorbing layer affects the extraction and transport of charge carriers, and thus the photoelectric conversion efficiency of the solar cell. Summary of the Invention

[0004] In view of the above-mentioned technical problems, this application provides a solar cell, a photovoltaic device, an electrical device, and a power generation device to reduce the energy level difference between the first light absorption layer and the hole transport layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0005] The first technical solution adopted in this application is: to provide a solar cell, the solar cell including at least a first light-absorbing layer and a hole transport layer, the hole transport layer including polythiophene derivative molecules, the polythiophene derivative molecules including formula (1): R1 and R2 each independently include an alkyl group having 4 to 30 carbon atoms, R3 and R4 each independently include one or more of hydrogen atoms, fluorine atoms, cyano groups, and trifluoromethyl groups, n1 and n2 range from 0 to 2, M1 ranges from 0 or 1, M2 ranges from 1 to 5000, and "---" indicates the linking site of the polythiophene derivative molecule.

[0006] In the technical solution of this application embodiment, the hole transport layer of the solar cell includes polythiophene derivative molecules, and the value range of M1 in formula (1) is 0 or 1, that is, the polythiophene derivative molecules include This type of polythiophene derivative molecule exhibits superior molecular arrangement and hole transport capabilities, thanks to the utilization of ester groups in its structure. Replacing the thiophene group allows for the modulation of the HOMO energy levels of polythiophene derivative molecules without disrupting their molecular arrangement. Replacing thiophene with two ester groups enhances electron-withdrawing ability, leading to better energy level modulation and a more accurate energy match between the hole transport layer and the first light absorption layer, thereby improving the photoelectric conversion efficiency of solar cells. Specifically, the ester group… The C group is linked to the thiophene group, and the O group is linked to R1 or R2.

[0007] R1 and R2 each independently include an alkyl group with 4 to 30 carbon atoms, which can improve the solubility of polythiophene derivative molecules and facilitate the formation of hole transport layers using solution methods such as coating. R3 and R4 each independently include one or more of hydrogen atoms, fluorine atoms, cyano groups, and trifluoromethyl groups. R3 and R4 are used to regulate the arrangement of polythiophene derivative molecules and also play an electron-withdrawing role, further regulating the energy levels of the hole transport layer of polythiophene derivative molecules. The values ​​of n1 and n2 range from 0 to 2, which can also regulate the spatial arrangement of polythiophene derivative molecules.

[0008] By controlling M1 to be 0 or 1, by selecting or setting groups of R1, R2, R3, and R4 with different properties in the polythiophene derivative molecule, and by adjusting the number of n1 and n2, the properties can be controlled. and Between or and The number of thiophene groups between molecules can be precisely controlled to regulate the spatial molecular arrangement and energy level regulation of polythiophene derivative molecules, thereby achieving precise control of the hole transport layer energy level.

[0009] In some embodiments, the polythiophene derivative molecule satisfies one or more of the following conditions:

[0010] (1) The range of values ​​for n1 and n2 is 0 or 1;

[0011] (2) R1 and R2 each independently comprise an alkyl group having 4 to 12 carbon atoms;

[0012] (3) R3 and R4 each independently include one or more of hydrogen atoms, fluorine atoms, and trifluoromethyl groups.

[0013] In the technical solution of this application embodiment, controlling the values ​​of n1 and n2 to be 0 or 1 can regulate the spatial arrangement and hole transport capability of the polythiophene derivative molecules, which is beneficial for hole extraction and transport. Controlling R1 and R2 to independently include alkyl groups with 4 to 12 carbon atoms gives the molecules better solubility and molecular arrangement, facilitating hole extraction and transport. Controlling R3 and R4 to independently include one or more of hydrogen atoms, fluorine atoms, and trifluoromethyl groups can further regulate the energy levels of the hole transport layer of the polythiophene derivative molecules, making it more compatible with the energy difference between the first light absorption layer.

[0014] In some embodiments, the polythiophene derivative molecule includes

[0015]

[0016] At least one of them.

[0017] In the technical solution of this application embodiment, the polythiophene derivative molecule with the above-mentioned structure has better molecular arrangement and hole transport capability. In its structure, the ester group replaces the thiophene group, which can regulate the HOMO energy level of the molecule without destroying the molecular arrangement of the polythiophene derivative molecule itself. The electron-withdrawing ability is better when two ester groups are used to replace thiophene, thereby better regulating the energy level of the molecule, making the energy level between the hole transport layer and the first light absorption layer more matched, thereby improving the photoelectric conversion efficiency of the solar cell.

[0018] In some embodiments, the number-average molecular weight (Mn) of the polythiophene derivative molecules ranges from 2k to 100k, and the molecular weight distribution (PDI) ranges from 1.0 to 4.0.

[0019] In the technical solution of this application embodiment, the number average molecular weight of the polythiophene derivative molecules is within the above range, and its solubility is good, which is beneficial for subsequent solution-based processes such as coating. This type of polythiophene derivative molecule has a low HOMO energy level, which makes the energy levels between the hole transport layer and the first light absorption layer more matched, thereby improving the photoelectric conversion efficiency of the solar cell.

[0020] In some implementations, the thickness of the hole transport layer is 2 nm to 50 nm.

[0021] In the technical solution of this application embodiment, the thickness of the hole transport layer is within the above-mentioned range, which can better transport holes and block electrons, making the energy levels between the hole transport layer and the first light absorption layer more matched, achieving higher charge transfer and transport, thereby improving the photoelectric conversion efficiency of the solar cell.

[0022] In some embodiments, the first light-absorbing layer comprises a perovskite material with the general formula ABX3 or A2CDX6, wherein the A ions comprise inorganic, organic, or mixed organic-inorganic cations, including methylamine cations, ethylamine cations, propylamine cations, butylamine cations, pentamine cations, hexamine cations, formamidin cations, imidazole cations, and Gu... + Cs + 、Rb + Li + Na + K + Cu + Ag + Au + or Hg + One or more of the following; B ions include inorganic cations, including Sn. 2+ C ions include inorganic, organic, or mixed organic-inorganic cations, including Ag. + Cu +Au + FA + Gu + D ions include inorganic cations, including Bi. 3 + Sb 3+ Cr 3+ Fe 3+ Co 3+ Ga 3+ As 3+ Ru 3+ ,Rh 3+ In 3+ Ir 3+ Au 3+ Or Al 3+ One or more of the following; X ions include inorganic, organic, or mixed organic-inorganic anions, including F - Cl - ,Br - I - SCN - CNO - OCN - OSCN - SH - OH - CN - SeCN - One or more of them.

[0023] In the technical solution of this application embodiment, the first light absorption layer includes the above-mentioned perovskite material, which has high photoelectric conversion efficiency, low preparation cost, and can be mass-produced by solution method, which is beneficial to reduce the manufacturing cost of solar cells. The band gap of the perovskite material can be adjusted by adjusting the types and proportions of elements A, B, and X, thereby optimizing photoelectric performance and adapting to different application requirements.

[0024] In some embodiments, the band gap of the first light-absorbing layer ranges from 1.2 eV to 1.8 eV.

[0025] In the technical solution of this application embodiment, the band gap of the first light absorption layer is within the above-mentioned range. Optimizing the energy level matching degree between the first light absorption layer and the hole transport layer is beneficial to improving the photoelectric conversion efficiency of the solar cell.

[0026] In some implementations, the HOMO energy level of the hole transport layer ranges from -5.8 eV to -5.0 eV.

[0027] In the technical solution of this application embodiment, the HOMO energy level of the hole transport layer is within the above-mentioned range, which can better match the energy level of the first light absorption layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0028] In some implementations, the HOMO energy level of the first light-absorbing layer ranges from -5.8 eV to -5.2 eV.

[0029] In the technical solution of this application embodiment, the HOMO energy level of the first light absorption layer is within the above range, which can better match the energy level between the hole transport layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0030] In some implementations, the solar cell is a formal solar cell.

[0031] In the technical solution of this application embodiment, the light absorption efficiency of the first light absorption layer of the formal solar cell is relatively high, which is beneficial to improving the photoelectric conversion efficiency of the solar cell.

[0032] The second technical solution adopted in this application is to provide a photovoltaic device, including any of the above-mentioned solar cells.

[0033] Since the photovoltaic device of this application includes the solar cell provided in this application, it has at least the same advantages as the solar cell.

[0034] The third technical solution adopted in this application is: to provide an electrical device, including any of the above-mentioned solar cells or photovoltaic devices as described above.

[0035] Since the power-consuming device of this application includes the solar cell provided in this application, it has at least the same advantages as the solar cell.

[0036] The fourth technical solution adopted in this application is: to provide a power generation device, including any of the above-mentioned solar cells or photovoltaic devices as described above.

[0037] Since the power generation device of this application includes the solar cell provided in this application, it has at least the same advantages as the solar cell.

[0038] The above description is merely an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0039] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0040] Figure 1A first structural schematic diagram of a solar cell provided for an embodiment of this application;

[0041] Figure 2 A schematic diagram of a second structure of a solar cell provided for an embodiment of this application;

[0042] Figure 3 A schematic diagram of the structure of a photovoltaic device provided for an embodiment of this application;

[0043] Figure 4 A schematic diagram of the structure of an electrical device provided for an embodiment of this application;

[0044] Figure 5 A schematic diagram of the structure of a power generation device provided in an embodiment of this application.

[0045] Marker explanation:

[0046] 100-Solar cell, 101-First electrode layer, 102-First light absorption layer, 103-Second electrode layer, 104-Hole transport layer, 105-Electron transport layer, 1000-Photovoltaic device, 2000-Electrical device, 3000-Power generation device. Detailed Implementation

[0047] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0049] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0050] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0051] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0052] In perovskite solar cells, nickel oxide (NiO) is typically used. x (2) PEDOT (a polythiophene derivative polymerized from 3,4-ethylenedioxythiophene monomer): PSS (polystyrene sulfonate) or (3) Spiro (a spirocyclic compound, the structural formula of Spiro in this application is shown in Comparative Example 1) are used as hole transport layer materials. However, nickel oxide (NiOx) has strong oxidizing properties, which will accelerate the degradation of the first light absorption layer in perovskite solar cells. Moreover, nickel oxide has the problem of inflexible energy level control. PEDOT:PSS itself is acidic and corrosive to indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) substrates, which is not conducive to the stability of perovskite solar cells. PEDOT:PSS also has the problem of inflexible energy level control. Spiro has a large molecular volume, high synthesis cost, and poor stability. In current technology, P3HT (a polymer of 3-hexylthiophene) is used as a classic polythiophene derivative for the hole transport layer of perovskite solar cells. It has good molecular arrangement, but the energy level of P3HT cannot be well matched with the first light absorption layer, which is not conducive to improving the performance of perovskite solar cells.

[0053] Therefore, this application provides a solar cell 100, which includes at least a first light-absorbing layer 102 and a hole transport layer 104. The hole transport layer 104 includes polythiophene derivative molecules, which include the formula (1): R1 and R2 each independently include an alkyl group having 4 to 30 carbon atoms, R3 and R4 each independently include one or more of hydrogen atoms, fluorine atoms, cyano groups, and trifluoromethyl groups, n1 and n2 range from 0 to 2, M1 ranges from 0 or 1, M2 ranges from 1 to 5000, and "---" indicates the linking site of the polythiophene derivative molecule.

[0054] The first light-absorbing layer 102 is a core component of the solar cell, and its main function is to absorb solar energy and convert it into electrical energy.

[0055] The hole transport layer 104 is used to facilitate hole transport while blocking the reverse flow of electrons.

[0056] In the technical solution of this application embodiment, the hole transport layer 104 of the solar cell 100 includes polythiophene derivative molecules, and the value of M1 in formula (1) ranges from 0 to 1, that is, the polythiophene derivative molecules include This type of polythiophene derivative molecule not only possesses superior molecular arrangement capabilities similar to P3HT (a polymer of 3-hexylthiophene), but also exhibits superior hole transport capabilities. Its structure utilizes ester groups... Replacing the thiophene group allows for the modulation of the HOMO energy levels of the polythiophene derivative molecule without disrupting its molecular arrangement. Replacing thiophene with two ester groups enhances its electron-withdrawing ability, thereby better modulating the molecular energy levels. This results in a more precise energy level match between the hole transport layer 104 and the first light absorption layer 102, ultimately improving the photoelectric conversion efficiency of the solar cell 100. Specifically, the ester group… The C group is linked to the thiophene group, and the O group is linked to R1 or R2.

[0057] R1 and R2 each independently include an alkyl group with 4 to 30 carbon atoms, which can improve the solubility of polythiophene derivative molecules and facilitate the formation of hole transport layer 104 by solution processing methods such as coating. R3 and R4 each independently include one or more of hydrogen atoms, fluorine atoms, cyano groups, and trifluoromethyl groups. R3 and R4 are used to regulate the arrangement of polythiophene derivative molecules and also play an electron-withdrawing role, further regulating the energy levels of hole transport layer 104 of polythiophene derivative molecules. The values ​​of n1 and n2 range from 0 to 2, which can also regulate the spatial arrangement of polythiophene derivative molecules.

[0058] By controlling M1 to be 0 or 1, by selecting or setting groups of R1, R2, R3, and R4 with different properties in the polythiophene derivative molecule, and by adjusting the number of n1 and n2, the properties can be controlled. and Between or and The number of thiophene groups between the molecules can be precisely controlled to regulate the spatial molecular arrangement and energy level regulation of polythiophene derivative molecules, thereby achieving precise control of the 104 energy level of the hole transport layer.

[0059] The reverse testing method for polymer additives in solar cells is as follows: The polythiophene derivative molecules in the embodiments of this application can be monitored and analyzed using Fourier transform infrared spectroscopy, hydrogen nuclear magnetic resonance (HNMR), and time-of-flight secondary ion mass spectrometry (TOF-MS). TOF-MS can detect the presence of polythiophene derivative molecules, and the elemental composition of the polythiophene derivative molecules can be identified through mass spectrometry fragment peaks. Fourier transform infrared spectroscopy can detect the characteristic peaks of the polythiophene derivative molecules. In this invention, the characteristic peak of the polythiophene derivative molecules is the ester group, and its characteristic absorption peak in the infrared spectrum appears in the range of 1715 cm⁻¹ to 1750 cm⁻¹. When the polymer is dissolved in deuterated chloroform, the characteristic peak of the polymer thiophene ring appears in the HNMR spectrum.

[0060] Among them, solar cell 100 refers to a device that directly converts light energy into electrical energy through the photovoltaic effect. Generally speaking, solar cell 100 includes first-generation solar cells represented by crystalline silicon solar cells, second-generation solar cells represented by thin-film solar cells made of direct bandgap semiconductors such as copper indium gallium selenide (CIGS), gallium arsenide (GaAs), and cadmium telluride (CdTe), and third-generation solar cells represented by dye-sensitized solar cells (DSSCs), organic photovoltaic cells (OPVs), and perovskite solar cells (PSCs). Taking a single-junction perovskite solar cell as an example, the perovskite solar cell includes a first electrode layer 101, a hole transport layer 104, a first light absorption layer 102, and a second electrode layer 103 stacked together. Alternatively, the perovskite solar cell includes a first electrode layer 101, a first light absorption layer 102, a hole transport layer 104, and a second electrode layer 103 stacked together, wherein at least one of the first electrode layer 101 and the second electrode layer 103 is a light-transmitting electrode, allowing incident photons to pass through the light-transmitting electrode and be absorbed by the first light absorption layer 102. In some embodiments, one of the first electrode layer 101 and the second electrode layer 103 is a light-transmitting electrode layer, and the other is a metal electrode layer. The metal electrode layer is used to reduce the resistivity of the solar cell 100 and improve the cell efficiency of the solar cell 100. The first light absorption layer 102 is a core component of the solar cell, and its main function is to absorb solar energy and convert it into electrical energy. It should be noted that the single-junction perovskite solar cells provided above can be used alone or in devices such as perovskite-perovskite tandem cells, perovskite-crystalline silicon tandem cells, or perovskite-heterojunction tandem cells. This application does not impose any limitations on these applications.

[0061] In some embodiments, n1 and n2 are in the range of 0 or 1, thereby allowing control over the spatial arrangement and hole transport capability of the polythiophene derivative molecules. Furthermore, R1 and R2 each independently comprise an alkyl group having 4 to 12 carbon atoms, resulting in excellent solubility and molecular arrangement, facilitating hole extraction and transport. R3 and R4 each independently comprise one or more of hydrogen atoms, fluorine atoms, and trifluoromethyl groups, enabling further control over the energy levels of the hole transport layer of the polythiophene derivative molecules, resulting in a better match between the energy levels and the first light absorption layer.

[0062] In some embodiments, the polythiophene derivative molecule includes

[0063] At least one of them.

[0064] In the technical solution of this application embodiment, the polythiophene derivative molecule with the above-mentioned structure has better molecular arrangement and hole transport capability. In its structure, the ester group replaces the thiophene group, which can regulate the HOMO energy level of the molecule without destroying the molecular arrangement of the polythiophene derivative molecule itself. The electron-withdrawing ability is better when two ester groups replace thiophene, thereby better regulating the energy level of the molecule, making the energy level between the hole transport layer 104 and the first light absorption layer 102 more matched, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0065] In some embodiments, the number-average molecular weight of the polythiophene derivative molecules ranges from 2k to 100k, and the molecular weight distribution ranges from 1.0 to 4.0.

[0066] Number-average molecular weight is a method for characterizing the molecular weight of polymer molecules. In the embodiments of this application, the number-average molecular weight of polythiophene derivative molecules is determined by high-temperature GPC, using o-dichlorobenzene as the mobile phase, and measuring the molecular weight and molecular weight distribution of the polymer at a temperature of 220°C.

[0067] In the technical solution of this application embodiment, the number average molecular weight of the polythiophene derivative molecules is within the above range, and its solubility is good, which is conducive to subsequent solution-based processes such as coating. This kind of polythiophene derivative molecule can adjust the molecular HOMO energy level of the hole transport layer 104, thereby making the energy levels between the hole transport layer 104 and the first light absorption layer 102 more matched, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0068] The number-average molecular weight of polythiophene derivative molecules can be 2K, 5K, 25K, 50K, 65K, 85K, 90K, 100K, or any range of two of the above values, such as 2K~50K, 50K~85K, 85K~100K, 25K~90K, 65K~90K, etc.

[0069] The molecular weight distribution of polythiophene derivative molecules can be 1.0, 1.6, 1.9, 2.1, 2.5, 2.8, 3.6, 4.0, etc., or a range consisting of any two of the above values, such as 1.0~2.5, 2.5~3.6, 3.6~4.0, 1.9~2.8, 1.6~2.1, etc.

[0070] In one embodiment, the hole transport layer 104 comprises a polythiophene derivative and other hole transport materials. Besides the polythiophene derivative molecules, the other hole transport materials may include at least one of the following materials and their derivatives, or materials obtained by doping or passivation: nickel oxide, 2,2',7,7'-tetratetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene (Spiro-OMeTAD), methoxytriphenylamine-fluoroformamidinium, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), [4-(3,6-phenylamine)-[4,4,6-phenylamine]( ... [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphoric acid (Me-4PACz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphoric acid (MeO-4PACz), poly(3-hexylthiophene) (P3HT), triphenylamine with a triphenylene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-aniline)carbazole-spirobisfluorene, polythiophene, PEDOT:PSS, phosphate monomolecule, carbazole monomolecule, sulfonic acid monomolecule, triphenylamine monomolecule, cuprous iodide and cuprous thiocyanate, or one or more of these.

[0071] In some embodiments, the thickness of the hole transport layer 104 is 2 nm to 50 nm.

[0072] The thickness of the hole transport layer 104 refers to the average vertical distance between the surface of the hole transport layer 104 near the first light absorption layer 102 and the surface of the hole transport layer 104 away from the first light absorption layer 102. The thickness of the hole transport layer 104 is measured by cross-sectional measurement using a high-resolution scanning electron microscope to obtain the calibrated thickness.

[0073] In the technical solution of this application embodiment, the thickness of the hole transport layer 104 is within the above-mentioned range, which can better transport holes and block electrons, making the energy levels between the hole transport layer 104 and the first light absorption layer 102 more matched, achieving higher charge transfer and transport, thereby improving the photoelectric conversion efficiency of the solar cell 100. The thickness of the hole transport layer 104 can be 2nm, 5nm, 10nm, 15nm, 20nm, 30nm, 38nm, 40nm, 45nm, 50nm, etc., or a range consisting of any two of the above values, such as 2nm~10nm, 10nm~30nm, 30nm~50nm, 5nm~20nm, 15nm~40nm, etc.

[0074] In some embodiments, the first light-absorbing layer 102 comprises a perovskite material with the general formula ABX3 or A2CDX6. The A ions include inorganic, organic, or mixed organic-inorganic cations, including methylamine cations, ethylamine cations, propylamine cations, butylamine cations, pentamine cations, hexamine cations, formamidinium cations, imidazole cations, and Gu... + Cs + 、Rb + Li + Na + K + Cu + Ag + Au + or Hg + One or more of the following; B ions include inorganic cations, including Sn. 2+ C ions include inorganic, organic, or mixed organic-inorganic cations, including Ag. + Cu + Au + FA + Gu + D ions include inorganic cations, including Bi. 3+ Sb 3+ Cr 3+ Fe 3+ Co 3+ Ga 3+ As 3+ Ru 3+ ,Rh 3+ In 3+ Ir 3+ Au 3+ Or Al 3+ One or more of the following; X ions include inorganic, organic, or mixed organic-inorganic anions, including F - Cl - ,Br - I - SCN - CNO - OCN - OSCN - SH - OH - CN - SeCN - One or more of them.

[0075] In the technical solution of this application embodiment, the first light absorption layer 102 includes the above-mentioned perovskite material, which has high photoelectric conversion efficiency, low preparation cost, and can be mass-produced by solution method, which is beneficial to reduce the manufacturing cost of solar cell 100. The band gap of the perovskite material can be adjusted by adjusting the types and proportions of elements A, B, and X, thereby optimizing photoelectric performance and adapting to different application requirements.

[0076] In some embodiments, the band gap of the first light-absorbing layer 102 is in the range of 1.2 eV to 1.8 eV.

[0077] In the technical solution of this application embodiment, the band gap of the first light absorption layer 102 is within the above-mentioned range. Optimizing the energy level matching degree between the first light absorption layer 102 and the hole transport layer 104 is beneficial to improving the photoelectric conversion efficiency of the solar cell 100. The band gap of the first light absorption layer 102 can be 1.2eV, 1.25eV, 1.3eV, 1.36eV, 1.5eV, 1.6eV, 1.65eV, 1.79eV, 1.8eV, etc., or a range composed of any two of the above values, such as 1.2eV~1.36eV, 1.36eV~1.65eV, 1.65eV~1.8eV, 1.3eV~1.5eV, 1.6eV~1.79eV, etc.

[0078] In some implementations, the HOMO energy level of the hole transport layer 104 ranges from -5.8 eV to -5.0 eV.

[0079] The HOMO level of hole transport layer 104 was measured using an electrochemical workstation via electrochemical cyclic voltammetry (CV), as detailed below, with Ag / Ag + The measurement was performed with a reference electrode, a platinum wire electrode as the counter electrode, a glassy carbon electrode as the working electrode, an acetonitrile solution of tetrabutylammonium hexafluorophosphate as the electrolyte, and ferrocene as the standard.

[0080] In the technical solution of this application embodiment, the HOMO energy level of the hole transport layer 104 is within the above-mentioned range, which can better match the energy level of the first light absorption layer 102, thereby improving the photoelectric conversion efficiency of the solar cell 100. The HOMO energy level of the hole transport layer 104 can be -5.8eV, -5.7eV, -5.65eV, -5.5eV, -5.4eV, -5.3eV, -5.2eV, -5.1eV, -5.0eV, etc., or a range consisting of any two of the above values, such as -5.8eV to -5.65eV, -5.65eV to -5.3eV, -5.3eV to -5.0eV, -5.7eV to -5.2eV, -5.5eV to -5.2eV, etc.

[0081] In some embodiments, the HOMO energy level range of the first light-absorbing layer 102 is -5.8 eV to -5.2 eV.

[0082] The HOMO level of the first light absorption layer 102 was measured using an electrochemical workstation via electrochemical cyclic voltammetry (CV), as follows, with Ag / Ag + The measurement was performed with a reference electrode, a platinum wire electrode as the counter electrode, a glassy carbon electrode as the working electrode, an acetonitrile solution of tetrabutylammonium hexafluorophosphate as the electrolyte, and ferrocene as the standard.

[0083] In the technical solution of this application embodiment, the HOMO energy level of the first light absorption layer 102 is within the above-mentioned range, which can better match the energy level of the hole transport layer 104, thereby improving the photoelectric conversion efficiency of the solar cell 100. The HOMO energy level of the first light absorption layer 102 can be -5.8eV, -5.75eV, -5.6eV, -5.52eV, -5.4eV, -5.3eV, -5.2eV, etc., or a range composed of any two of the above values, such as -5.8eV to -5.6eV, -5.6eV to -5.4eV, -5.4eV to -5.2eV, -5.75eV to -5.52eV, -5.3eV to -5.2eV, etc.

[0084] In some embodiments, the solar cell 100 includes a first electrode layer 101, a hole transport layer 104, a first light absorption layer 102, an electron transport layer 105, and a second electrode layer 103.

[0085] Optional, such as Figure 1 As shown, the solar cell 100 is a reverse cell. From bottom to top, the reverse cell includes a first electrode layer 101, a hole transport layer 104, a first light absorption layer 102, an electron transport layer 105, and a second electrode layer 103, arranged sequentially. The direction from bottom to top is the direction of light incidence.

[0086] Optionally, the solar cell 100 is a formal solar cell. In the technical solutions of this application embodiment, as... Figure 2 As shown, the solar cell 100 is a formal solar cell. From bottom to top, the solar cell 100 includes a first electrode layer 101, an electron transport layer 105, a first light absorption layer 102, a hole transport layer 104, and a second electrode layer 103, arranged sequentially. The direction from bottom to top is the light incident direction. The first light absorption layer 102 of the formal solar cell has a high light absorption efficiency, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0087] The electron transport layer 105 serves to transport electrons and block holes. In some embodiments, the electron transport layer 105 may include, but is not limited to, one or more of the following materials and their derivatives: imide compounds, quinone compounds, fullerenes and their derivatives, metal oxides, semiconductor material oxides, titanates, and fluorides. Imide compounds include at least one of perylene imide and its derivatives, naphthylimide and its derivatives, phthalimide, succinimide, N-bromosuccinimide, glutarimide, or maleimide. Quinone compounds include at least one of benzoquinone, naphthylquinone, phenanthrenequinone, or anthraquinone. Fullerenes and their derivatives include at least one of [6,6]-phenyl C61-butyrate methyl ester (PC61BM), [6,6]-phenyl C71-butyrate methyl ester (PC71BM), fullerene C60 (C60), and fullerene C70 (C70). Metal oxides include at least one of the following metallic elements: magnesium (Mg), nickel (Ni), cadmium (Cd), zinc (Zn), indium (In), lead (Pb), molybdenum (Mo), tungsten (W), antimony (Sb), bismuth (Bi), copper (Cu), mercury (Hg), titanium (Ti), silver (Ag), manganese (Mn), iron (Fe), vanadium (V), tin (Sn), zirconium (Zr), strontium (Sr), gallium (Ga), and chromium (Cr). Semiconductor oxides include silicon oxide. Titanates include at least one of strontium titanate and calcium titanate. Fluorides include at least one of lithium fluoride and calcium fluoride.

[0088] In some embodiments, the solar cell 100 may be a tandem perovskite solar cell.

[0089] The solar cell 100 also includes a connecting layer and a second light-absorbing layer. The connecting layer is disposed on the side of the first light-absorbing layer 102 facing the first electrode layer 101, and the second light-absorbing layer is disposed between the connecting layer and the first electrode layer 101. The second light-absorbing layer and the first light-absorbing layer 102 have different band gaps. Thus, a tandem solar cell is obtained. The superposition of the first light-absorbing layer 102 and the second light-absorbing layer can effectively absorb both long-wavelength and short-wavelength light, thereby improving the photoelectric conversion efficiency. The combined use of the first light-absorbing layer 102 and the second light-absorbing layer can optimize the spectral response and has good compatibility with the band gap of the first light-absorbing layer material. The combination of the second light-absorbing layer and the first light-absorbing layer 102 can effectively absorb short-wavelength and long-wavelength light respectively. The tandem solar cell obtained by combining the two can absorb light over a wider spectral range to achieve high solar cell photoelectric conversion efficiency.

[0090] Optionally, the second light-absorbing layer includes any one of a copper indium gallium selenide (CIGS) light-absorbing layer, a cadmium telluride (CdTe) light-absorbing layer, a polycrystalline silicon (PSS) light-absorbing layer, and a perovskite light-absorbing layer. Wherein, if the second light-absorbing layer is a perovskite light-absorbing layer, the perovskite material in the second light-absorbing layer has a different band gap than the perovskite material in the first light-absorbing layer 102.

[0091] Optionally, the connecting layer is a composite layer, where holes from the first light-absorbing layer 102 and electrons from the second light-absorbing layer, or electrons from the first light-absorbing layer 102 and holes from the second light-absorbing layer, recombine and annihilate in the composite layer, thereby achieving the circuit connection of the two battery cells. The connecting layer includes a composite layer, simplifying the fabrication of tandem solar cells. The top cell can be directly deposited on the bottom cell to form a single, complete cell with two electrodes, forming a two-end tandem solar cell. The composite layer comprises one or more of metallic materials, transparent conductive oxides, and carbon materials. Further, the transparent conductive oxide layer comprises, but is not limited to, one or more of FTO (fluorine-doped tin oxide), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), IGZO (indium gallium zinc oxide), and ATO (antimony tin oxide). Further, the metallic materials include, but are not limited to, one or more of gold, copper, silver, platinum, aluminum, and iron. Further, the carbon materials include one or more of graphite, graphene, and carbon nanotubes.

[0092] Optionally, the solar cell includes a first electrode layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, a connecting layer, a first charge transport layer, a first light absorption layer, a second charge transport layer, and a second electrode layer stacked together; wherein the connecting layer is a composite layer. Further, the charge transport layers located on both sides of the connecting layer cannot simultaneously be electron transport layers or hole transport layers. In other words, the first and third charge transport layers are electron transport layers, and the second and fourth charge transport layers are hole transport layers; or, the first and third charge transport layers are hole transport layers, and the second and fourth charge transport layers are electron transport layers.

[0093] Optionally, the connecting layer includes an insulating layer. The solar cell also includes a third electrode layer and a fourth electrode layer, with the third electrode disposed between the first light-absorbing layer and the connecting layer, and the fourth electrode disposed between the connecting layer and the second light-absorbing layer. That is, the solar cell includes a first electrode layer, a second light-absorbing layer, a fourth electrode layer, a connecting layer, a third electrode layer, a first light-absorbing layer, and a second electrode layer. The connecting layer, containing the insulating layer, circuitically isolates the first and second battery cells. Each battery cell has two electrodes, for a total of four electrodes. The circuits of the two battery cells are independent of each other, forming a four-terminal stacked solar cell. In some embodiments, the material of the insulating layer includes, but is not limited to, glass or an insulating adhesive. Further, the glass is transparent glass; further, the insulating adhesive is a transparent adhesive.

[0094] Furthermore, since the third and fourth electrode layers are located in the middle of the tandem solar cell, in order to further increase the light energy utilization of the tandem solar cell and enable the remaining solar energy after absorption by the first light absorption layer to enter the second light absorption layer, the third and fourth electrodes can also be set as light-transmitting electrodes.

[0095] Optionally, the solar cell includes a first electrode layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, a fourth electrode layer, a connecting layer, a third electrode layer, a first charge transport layer, a first light absorption layer, a second charge transport layer, and a second electrode layer stacked together; wherein the connecting layer includes an insulating layer. Since the circuits of the cell units in a four-terminal stacked solar cell are independent, the type of charge transport layers located on both sides of the connecting layer or insulating layer is not limited and can be arbitrarily combined. In other words, the materials of the second charge transport layer and the third charge transport layer can be the same or different, and they can each be independently an electron transport layer or a hole transport layer. Further, one of the first charge transport layer and the second charge transport layer is an electron transport layer, and the other is a hole transport layer; one of the third charge transport layer and the other is an electron transport layer, and the other is a hole transport layer.

[0096] In some embodiments, the solar cell 100 further includes a light-transmitting substrate located on the side of the first electrode layer 101 away from the first light-absorbing layer 102 for supporting the solar cell. The substrate layer can be, but is not limited to, a rigid substrate or a flexible substrate. The rigid substrate is transparent glass, and the flexible substrate is made of materials such as (but not limited to) organic polymer materials. Further, it can be made of one or more of the following materials mixed in different proportions: including but not limited to polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), etc.

[0097] The function of the first electrode layer 101 is to extract photogenerated carriers. The first electrode layer 101 includes one or more of organic conductive materials, inorganic conductive materials, or organic-inorganic mixed conductive materials. It may include one or more of transparent conductive metal oxides, carbon, metals and their alloys, and may include at least one of indium tin oxide (ITO), lanthanide metal-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), zinc aluminum oxide (AZO), indium zinc oxide (IZO), zinc gallium oxide (GZO), indium tungsten oxide (IWO), Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W and their alloys, graphite, graphene, and carbon nanotubes.

[0098] The material of the second electrode layer 103 can be an organic, inorganic, or organic-inorganic mixed conductive material. In some embodiments, the second electrode layer 103 may include transparent conductive oxides, metals, etc. The transparent conductive oxides include one or more of indium tin oxide (ITO), lanthanide-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), aluminum zinc oxide (AZO), indium zinc oxide (IZO), gallium zinc oxide (GZO), and indium tungsten oxide (IWO). The metals include one or more of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, and Mg.

[0099] It should be noted that corresponding modification layers can be inserted between the layers. For example, a passivation layer can be inserted between the first light-absorbing layer 102 and the hole transport layer 104, and / or between the first light-absorbing layer 102 and the electron transport layer 105, to passivate defects in the first light-absorbing layer 102 and further improve the performance of the solar cell 100. Alternatively, a hole-blocking layer can be inserted on the side of the electron transport layer 105 away from the first light-absorbing layer 102 to block holes; the material may include copper bath (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, BCP), etc.

[0100] The second technical solution adopted in this application is: providing a method for preparing a solar cell 100, the method comprising: providing a substrate having a first electrode layer 101; coating a perovskite precursor solution on one side of the first electrode layer 101 to form a first light-absorbing layer 102; coating a hole transport layer solution on one side of the first light-absorbing layer 102 to form a hole transport layer 104, wherein the hole transport layer solution includes polythiophene derivative molecules; and forming a second electrode layer 103 on one side of the hole transport layer 104. Alternatively, providing a substrate having a second electrode layer 103; coating a hole transport layer solution on one side of the second electrode layer 103 to form a hole transport layer 104, wherein the hole transport layer solution includes polythiophene derivative molecules; coating a perovskite precursor solution on one side of the hole transport layer 104 to form a first light-absorbing layer 102; and forming a first electrode layer 101 on one side of the first light-absorbing layer 102. The polythiophene derivative molecules include those of formula (1): R1 and R2 each independently include an alkyl group having 4 to 30 carbon atoms, R3 and R4 each independently include one or more of hydrogen atoms, fluorine atoms, cyano groups, and trifluoromethyl groups, n1 and n2 range from 0 to 2, M1 ranges from 0 or 1, M2 ranges from 1 to 5000, and "---" indicates the linking site of the polythiophene derivative molecule.

[0101] In the technical solution of this application embodiment, the solar cell 100 is prepared using the preparation method provided above.

[0102] See Figure 3 This application also provides a photovoltaic device 1000, including the solar cell 100 as described above.

[0103] See Figure 4 This application also provides an electrical device 2000, including the solar cell 100 as described above or the photovoltaic device 1000 as described above.

[0104] In this application, the solar cell 100 serves as the power source for the aforementioned electrical device 2000; alternatively, the solar cell 100 can serve as an energy storage unit for the aforementioned electrical device 2000. As an example, the electrical device 2000 can be a lighting element, a display element, or an automobile, etc. The electrical device 2000 can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among these, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0105] See Figure 5 This application also provides a power generation device 3000, including the solar cell 100 as described above or the photovoltaic device 1000 as described above. The power generation device 3000 may include the solar cell 100 and an energy storage device, which may be a secondary battery.

[0106] To make the technical problems, technical solutions, and beneficial effects solved by the embodiments of this application clearer, the following will provide a more detailed description in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0107] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0108] Example 1:

[0109] (1) Preparation of the first electrode layer: 20 pieces of ITO conductive glass with a specification of 2.0cm×2.0cm (ITO thickness 150nm, glass thickness 2.5mm) were immersed in detergent, rubbed with a lint-free cloth and placed in a polytetrafluoroethylene rack. Then, they were ultrasonically cleaned twice each in detergent, deionized water, acetone, ethanol and isopropanol, 20min each time. After that, they were dried with a nitrogen gun, placed in glass petri dishes and dried in an 80℃ oven for later use.

[0110] (2) Electron transport layer preparation: 22.6 mg SnCl2·2H2O was dissolved in 1 mL of anhydrous ethanol and stirred at room temperature for 1 hour. Then, the solution was filtered through a 45 mm PTFE membrane to obtain an NP-SnO2 precursor solution. Before spin-coating the NP-SnO2 precursor solution, the ITO conductive glass treated with UV-ozone radiation was preheated at 50 °C for 2 minutes to reduce fogging of the NP-SnO2 film. Then, the NP-SnO2 precursor solution was spin-coated onto the ITO conductive glass at a speed of 4000 rpm for 30 seconds. Finally, the NP-SnO2 electron transport layer with a thickness of 60 nm was prepared by thermal annealing at 150 °C for 30 minutes.

[0111] (3) Preparation of the first light-absorbing layer: 220 mg of PbBr2 (lead bromide), 277 mg of PbI2 (lead iodide), and 312 mg of CsI (cesium iodide) were weighed and mixed in a sample bottle and transferred into a nitrogen glove box. 1 mL of DMSO solvent (dimethyl sulfoxide) was added, and the mixture was heated and stirred on a 70°C hot plate for 6 h to obtain a CsPbI2Br precursor solution with a concentration of 1.2 mol / L. The solution was filtered through a 0.28 mm polytetrafluoroethylene membrane and set aside for later use. The above CsPbI2Br precursor solution was spin-coated at 3500 rpm for 30 seconds, and then the film was treated with a gradient thermal annealing process: annealing at 50°C for 1 minute; annealing at 100°C for 1 minute; and annealing at 160°C for 10 minutes to obtain a CsPbI2Br perovskite light-absorbing layer film with a thickness of 300 nm.

[0112] (4) Hole transport layer preparation: Weigh 6 mg of polythiophene derivative Add 1 mL of chlorobenzene, rotate at 4000 rpm for 40 s to obtain a hole transport layer with a thickness of 12 nm.

[0113] in, The synthetic route is as follows:

[0114]

[0115] In a 50 mL two-necked round-bottom flask, a Br-containing monomer compound was placed... (0.3 mmol, 215 mg) and Sn-containing monomeric compounds (0.3 mmol, 172 mg) was dissolved in 10 mL of dry toluene and 1.5 mL of DMF (N,N-dimethylformamide). Argon gas was then purged into the reaction system for 20 min to remove air. 17 mg of Pd(PPh3)4 was quickly added to the reaction system as a catalyst, followed by another 30 min of argon purging. The reaction system was heated in an oil bath at 110 °C for 10 h under argon protection. The reaction mixture was cooled to room temperature, and then settled in 100 mL of HPLC methanol (HPLC methanol refers to methanol used in high-performance liquid chromatography (HPLC) analysis). The solid was collected by filtration using a Buchner funnel. The solid product was extracted using HPLC methanol, n-hexane, and chloroform, respectively, by Soxhlet extraction. The chloroform extract was collected and concentrated, then settled using HPLC methanol. The final polymer solid was obtained by filtration and dried in a vacuum oven, with a yield of 82%. Wherein, GPC:Mw=72.1K;Mn=34.3K;PDI=2.1.

[0116] (5) Fabrication of the barrier layer and the second electrode layer: The thin film with the hole transport layer spin-coated on it is placed on a mask and then placed in a vacuum coating apparatus at a depth of 4×10⁻⁶. -4 Under pressure of Pa, a 10 nm thick MoO3 and a 60 nm thick silver (Ag) electrode were deposited by thermal evaporation.

[0117] Example 2

[0118] Similar to Example 1, the difference is:

[0119] The hole transport layer preparation in step (4) of Example 1 is adjusted as follows: 6 mg of polymer is weighed... 1 mL of chlorobenzene was added, and the rotation speed was 4000 rpm for 40 s to obtain a hole transport layer with a thickness of 12 nm.

[0120] in, The synthetic route is as follows:

[0121]

[0122] In a 50 mL two-necked round-bottom flask, a Br-containing monomer compound was placed... (0.3 mmol, 215 mg) and Sn-containing monomeric compounds (0.3 mmol, 183 mg) was dissolved in 10 mL of dry toluene and 1.5 mL of DMF. Argon gas was then purged into the reaction system for 20 min to remove air. 17 mg of Pd(PPh3)4 was quickly added to the reaction system as a catalyst, followed by another 30 min of argon gas purging. The reaction system was heated in an oil bath at 110 °C for 8 hours under argon protection. The reaction mixture was cooled to room temperature, and then settled in 100 mL of methanol (HPLC). The solid was collected by filtration using a Buchner funnel. The solid product was extracted using Soxhlet extraction with methanol, n-hexane, and chloroform (HPLC), respectively. The chloroform extract was collected and concentrated, then settled with methanol (HPLC). The final polymer solid was obtained by filtration and dried in a vacuum oven, yielding 80%. GPC: Mw = 57.9 K; Mn = 30.5 K; PDI = 1.9.

[0123] Example 3

[0124] The hole transport layer preparation in step (4) of Example 1 is adjusted as follows: 6 mg of polymer is weighed... 1 mL of chlorobenzene was added, and the rotation speed was 4000 rpm for 40 s to obtain a hole transport layer with a thickness of 12 nm.

[0125] in, The synthetic route is as follows:

[0126]

[0127] In a 50 mL two-necked round-bottom flask, a Br-containing monomer compound was placed... (0.3 mmol / L, 191 mg) and Sn-containing monomeric compounds (0.3 mmol, 158 mg) was dissolved in 10 mL of dry toluene and 1.5 mL of DMF. Argon gas was then purged from the reaction system for 20 min to remove air. 17 mg of Pd(PPh3)4 was quickly added to the reaction system as a catalyst, followed by another 30 min of argon gas purging. The reaction system was heated in an oil bath at 110 °C for 8.5 h under argon protection. The reaction mixture was cooled to room temperature, and then settled in 100 mL of methanol (HPLC). The solid was collected by filtration using a Buchner funnel. The solid product was extracted using Soxhlet extraction with methanol, n-hexane, and chloroform (HPLC), respectively. The chloroform extract was collected and concentrated, then settled with methanol (HPLC). The final polymer solid was obtained by filtration and dried in a vacuum oven, yielding 79%. GPC: Mw = 38.9 K; Mn = 20.5 K; PDI = 1.9.

[0128] Example 4

[0129] The hole transport layer preparation in step (4) of Example 1 is adjusted as follows: 6 mg of polymer is weighed... 1 mL of chlorobenzene was added, and the rotation speed was 4000 rpm for 40 s to obtain a hole transport layer with a thickness of 12 nm.

[0130] in, The synthetic route is as follows:

[0131]

[0132] In a 50 mL two-necked round-bottom flask, a Br-containing monomer compound was placed... (0.3 mmol / L, 191 mg) and Sn-containing monomeric compounds (0.3 mmol, 241 mg) was dissolved in 10 mL of dry toluene and 1.5 mL of LDM. Argon gas was then purged from the reaction system for 20 min to remove air. 17 mg of Pd(PPh3)4 was quickly added to the reaction system as a catalyst, followed by another 30 min of argon purging. The reaction system was heated in an oil bath at 110 °C for 8.5 h under argon protection. The reaction mixture was cooled to room temperature, and then settled in 100 mL of methanol (HPLC). The solid was collected by filtration using a Buchner funnel. The solid product was extracted using Soxhlet extraction with methanol, n-hexane, and chloroform (HPLC), respectively. The chloroform extract was collected and concentrated, then settled with methanol (HPLC). The final polymer solid was obtained by filtration and dried in a vacuum oven, yielding 84%. GPC: Mw = 113.5 K; Mn = 51.6 K; PDI = 2.2.

[0133] Example 5

[0134] The hole transport layer preparation in step (4) of Example 1 is adjusted as follows: 6 mg of polymer is weighed... 1 mL of chlorobenzene was added, and the rotation speed was 4000 rpm for 40 s to obtain a hole transport layer with a thickness of 12 nm.

[0135] in, The synthetic route is as follows:

[0136]

[0137] In a 50 mL two-necked round-bottom flask, a Br-containing monomer compound was placed... (0.3 mmol, 216 mg) and Sn-containing monomeric compounds (0.3 mmol, 266 mg) was dissolved in 10 mL of dry toluene and 1.5 mL of DMF. Argon gas was then purged from the reaction system for 20 min to remove air. 17 mg of Pd(PPh3)4 was quickly added to the reaction system as a catalyst, followed by another 30 min of argon purging. The reaction system was heated in an oil bath at 110 °C for 8.5 h under argon protection. The reaction mixture was cooled to room temperature, and then settled in 100 mL of methanol (HPLC). The solid was collected by filtration using a Buchner funnel. The solid product was extracted using Soxhlet extraction with methanol, n-hexane, and chloroform (HPLC), respectively. The chloroform extract was collected and concentrated, then settled with methanol (HPLC). The final polymer solid was obtained by filtration and dried in a vacuum oven, yielding 85%. GPC: Mw = 111.7 K; Mn = 53.2 K; PDI = 2.1.

[0138] Example 6

[0139] The hole transport layer preparation in step (4) of Example 1 is adjusted as follows: 6 mg of polymer is weighed... 1 mL of chlorobenzene was added, and the rotation speed was 4000 rpm for 40 s to obtain a hole transport layer with a thickness of 12 nm.

[0140] in, The synthetic route is as follows:

[0141]

[0142] In a 50 mL two-necked round-bottom flask, a Br-containing monomer compound was placed... (0.3 mmol) and Sn-containing monomeric compounds (0.3 mmol) was dissolved in 10 mL of dry toluene and 1.5 mL of DMF. Argon gas was then purged from the reaction system for 20 min to remove air. 17 mg of Pd(PPh3)4 was quickly added to the reaction system as a catalyst, followed by another 30 min of argon purging. The reaction system was heated in an oil bath at 110 °C for 8.5 h under argon protection. The reaction mixture was cooled to room temperature, and then settled in 100 mL of methanol (HPLC). The solid was collected by filtration using a Buchner funnel. The solid product was extracted using Soxhlet extraction with methanol, n-hexane, and chloroform (HPLC), respectively. The chloroform extract was collected and concentrated, then settled with methanol (HPLC). The final polymer solid was obtained by filtration and dried in a vacuum oven, yielding 76%. GPC: Mw = 51.1 K; Mn = 23.2 K; PDI = 2.2.

[0143] Comparative Example 1

[0144] Similar to Example 1, the difference is:

[0145] The hole transport layer preparation in step (4) of Example 1 is adjusted as follows: Weigh 25 mg of... (Spiro) was added to 1 mL of chlorobenzene to obtain a solution. Li-TFSI (lithium bis(trifluoromethanesulfonyl)imide) and TBP (tributyl phosphate) were then added to the solution to obtain a hole transport layer mixture. The mixture was placed in an air glove box for 10 h of oxidation. The hole transport layer mixture was then spin-coated at 3000 rpm for 30 s and oxidized in dry air for 12 h to obtain a hole transport layer with a thickness of 40 nm.

[0146] Spiro is a commercial reagent that can be purchased directly from Bailingwei.

[0147] Comparative Example 2

[0148] Similar to Example 1, the difference is:

[0149] The hole transport layer preparation in step (4) of Example 1 is adjusted as follows: Weigh 7 mg of Add 1 mL of chlorobenzene to (P3HT), rotate at 4000 rpm for 40 s to obtain a hole transport layer with a thickness of 13 nm.

[0150] P3HT is a commercial reagent and can be purchased directly from Bailingwei.

[0151] The solar cells obtained in Examples 1 to 6, Comparative Examples 1 and 2 were subjected to cell performance tests, and the results are shown in Table 1.

[0152] The testing method is as follows:

[0153] 1. IV measurement method:

[0154] The IV characteristics of the device under test can be obtained by changing the bias voltage point and simultaneously measuring the current.

[0155] a) Place the test fixture containing the sample cell on the sample holder, so that it is in the measurement plane, and ensure that the sample cell is located at the center of the solar simulator's emitted light spot (or the photovoltaic cell normal is parallel to the center line of the solar simulator's emitted light beam).

[0156] b) A solar simulator, conforming to the national standard IEC61215, was used for testing. Crystalline silicon solar cells were used to correct the light intensity to achieve a solar intensity of 1000 W / m². 2Under irradiation conditions, a mask is installed on the sample battery to be tested, and the temperature of the sample battery is controlled by a temperature monitoring device so that the temperature of the sample battery is maintained at (30±5℃) during the measurement process.

[0157] c) Set the scanning direction, voltage range, scanning interval voltage, and scanning interval time. The scanning interval should not exceed 0.02V, and the interval between two adjacent points should not be less than 0.3s. Measure the forward and reverse scanning current-voltage characteristics of the sample battery and record the open-circuit voltage V. OC Short-circuit current J SC .

[0158] Calculation formula: Fill factor FF = J m ×V m / V OC ×J SC Energy conversion efficiency PCE = V OC ×J SC ×FF / P in P in The incident light intensity is 10³ W / m. 2 .

[0159] 2. Method for testing the thickness of the hole transport layer:

[0160] The calibrated thickness was obtained by cross-sectional testing using a high-resolution scanning electron microscope.

[0161]

[0162]

[0163]

[0164] As can be seen from the relevant data in Table 1, the solar cells of Examples 1 to 6 all use polythiophene derivatives in the hole transport layer. The open-circuit voltage, short-circuit current, fill factor and energy conversion efficiency of Examples 1 to 6 are all higher than those of Comparative Examples 1 and 2. This indicates that after using polythiophene derivative molecules in the hole transport layer, the energy levels between the hole transport layer and the first light absorption layer are more matched, thereby improving the photoelectric conversion efficiency of the solar cell.

[0165] This application also conducted energy level tests on different types of polythiophene derivative molecules, as shown in Table 2. The energy level testing method was as follows: the HOMO energy levels of the polythiophene derivative molecules were measured using an electrochemical workstation via electrochemical cyclic voltammetry (CV), specifically as follows, with Ag / Ag... + The measurement was performed with a reference electrode, a platinum wire electrode as the counter electrode, a glassy carbon electrode as the working electrode, an acetonitrile solution of tetrabutylammonium hexafluorophosphate as the electrolyte, and ferrocene as the standard.

[0166] Table 2. HOMO energy level test results of polythiophene derivative molecules.

[0167]

[0168]

[0169] As shown in Table 2, by controlling M1 to be 0 or 1, by selecting or setting R1, R2, R3 or R4 groups with different properties, and by adjusting the number of n1 and n2, the spatial molecular arrangement and energy level regulation ability of polythiophene derivative molecules can be precisely controlled to achieve precise control of the hole transport layer energy level, so that its HOMO energy level is more matched with the energy level of the first light absorption layer, thereby enabling the solar cell to obtain excellent performance.

[0170] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A solar cell, characterized in that, The solar cell includes at least a first light-absorbing layer and a hole transport layer, wherein the hole transport layer comprises polythiophene derivative molecules; the polythiophene derivative molecules comprise formula (1): Wherein, R1 and R2 each independently include an alkyl group having 4 to 30 carbon atoms, R3 and R4 each independently include one or more of hydrogen atoms, fluorine atoms, cyano groups, and trifluoromethyl groups, n1 and n2 range from 0 to 2, M1 ranges from 0 to 1, and M2 ranges from 1 to 5000 natural numbers. This indicates the linking site of the polythiophene derivative molecule.

2. The solar cell as described in claim 1, characterized in that, The polythiophene derivative molecule satisfies one or more of the following conditions: (1) The range of values ​​for n1 and n2 is 0 or 1; (2) R1 and R2 each independently comprise an alkyl group having 4 to 12 carbon atoms; (3) R3 and R4 each independently include one or more of hydrogen atoms, fluorine atoms, and trifluoromethyl groups.

3. The solar cell as described in claim 1 or 2, characterized in that, The polythiophene derivative molecule includes At least one of them.

4. The solar cell according to any one of claims 1 to 3, characterized in that, The number-average molecular weight of the polythiophene derivative molecules ranges from 2k to 100k, and the molecular weight distribution ranges from 1.0 to 4.

0.

5. The solar cell according to any one of claims 1 to 4, characterized in that, The thickness of the hole transport layer is 2nm to 50nm.

6. The solar cell according to any one of claims 1 to 5, characterized in that, The first light-absorbing layer comprises a perovskite material with the general formula ABX3 or A2CDX6. The A ions include inorganic, organic, or mixed organic-inorganic cations, such as methylamine cation, ethylamine cation, propylamine cation, butylamine cation, pentamine cation, hexamine cation, formamidinium cation, imidazole cation, and Gu. + Cs + 、Rb + Li + Na + K + Cu + Ag + Au + or Hg + One or more of the following; B ions include inorganic cations, including Sn. 2+ C ions include inorganic, organic, or mixed organic-inorganic cations, including Ag. + Cu + Au + FA + Gu + D ions include inorganic cations, including Bi. 3+ Sb 3+ Cr 3+ Fe 3+ Co 3+ Ga 3+ As 3+ Ru 3+ ,Rh 3+ In 3 + Ir 3+ Au 3+ Or Al 3+ One or more of the following; X ions include inorganic, organic, or mixed organic-inorganic anions, including F - Cl - ,Br - I - SCN - CNO - OCN - OSCN - SH - OH - CN - SeCN - One or more of them.

7. The solar cell according to any one of claims 1 to 6, characterized in that, The band gap of the first light absorption layer is in the range of 1.2 eV to 1.8 eV.

8. The solar cell according to any one of claims 1 to 7, characterized in that, The HOMO energy level range of the hole transport layer is -5.8 eV to -5.0 eV.

9. The solar cell according to any one of claims 1 to 8, characterized in that, The HOMO energy level range of the first light-absorbing layer is -5.8 eV to -5.2 eV.

10. The solar cell according to any one of claims 1 to 9, characterized in that, The solar cell mentioned is a formal solar cell.

11. A photovoltaic device, characterized in that, Including the solar cell as described in any one of claims 1 to 10.

12. An electrical appliance, characterized in that, This includes the solar cell as described in any one of claims 1 to 10 or the photovoltaic device as described in claim 11.

13. A power generation device, characterized in that, Includes the solar cell as described in any one of claims 1 to 10 and the photovoltaic device as described in claim 11.

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