Trans-perovskite solar cell and preparation method and application thereof

Abstract

The invention provides a trans-perovskite solar cell and a preparation method and application thereof. The preparation method comprises the following steps: sequentially depositing the hole transport layer and the perovskite light absorption layer on the transparent conductive substrate; depositing C60 on the upper surface of the perovskite light absorption layer to obtain a C60 electron transport layer; performing steam annealing on the battery semi-finished product with the C60 electron transport layer in a steam atmosphere formed by the mixed solvent to obtain an interface modified battery semi-finished product; wherein the mixed solvent comprises a solvent for dissolving C60 and a solvent for dissolving perovskite crystals; and depositing an electrode layer on the C60 electron transport layer side of the cell semi-finished product obtained in the step to obtain the trans-perovskite solar cell. According to the method, a mixed solvent steam annealing strategy is adopted, the crystallization behavior of C60 and perovskite at the interface is regulated and controlled, the interface contact quality is improved, the efficiency of the trans-perovskite solar cell is improved, and the service life of the trans-perovskite solar cell is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to an inverted perovskite solar cell, its preparation method, and its application. Background Technology

[0002] The photovoltaic cell industry is an important component of the new energy technology industry, and it has been a key focus of academic and industry attention since its inception.

[0003] Perovskite solar cells, due to their low manufacturing cost, simple synthesis process, high photoelectric conversion efficiency, and ability to be mass-produced, are expected to become a new generation of solar cells to replace crystalline silicon solar cells. Since 2009, after more than a decade of exploration, the photoelectric conversion efficiency of perovskite solar cells has now exceeded 26%. Their commercialization process has also developed rapidly, with several companies currently building GW-level perovskite mass production lines. With the development of scale-up processes and upstream and downstream industries, perovskite solar cells have become one of the most promising solar cell modules for large-area commercial production.

[0004] In the commercialization field, inverted perovskite solar cell structures are the most competitive. Currently, in large-area inverted solar cells, the electron transport layer is mostly prepared using carbon ion exchange deposition. 60 Layer, but due to C 60 Its own spherical molecular structure, lacking functional group modification, makes it prone to self-aggregation, thus C 60 Numerous interface defects exist between the perovskite layer and the perovskite surface, resulting in poor contact quality. This accelerates battery aging and reduces device efficiency, which has always been a key issue affecting battery efficiency and lifespan. Furthermore, current commonly used perovskite surface passivation strategies primarily rely on functional groups and intermolecular interactions to improve perovskite surface defects, but C... 60 The nonradiative recombination loss of charge carriers caused by poor contact quality between the agglomeration layer and the perovskite surface was not improved.

[0005] Therefore, how to effectively improve C 60 The poor contact quality between the electron transport layer and the perovskite surface is a key technical challenge that urgently needs to be addressed in order to improve the efficiency and lifespan of inverted perovskite solar cells. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an inverted perovskite solar cell, its fabrication method, and its applications. This invention employs a mixed solvent vapor annealing strategy, utilizing the solubility of the mixed solvent vapor in both materials to optimize the interaction between the upper surface of the perovskite light-absorbing layer and C. 60 The interface of the electron transport layer improves C 60Hole and electron recombination losses due to self-aggregation on the perovskite surface, and C losses induced by mixed solvents. 60 The self-assembly behavior of perovskite molecules optimizes the molecular crystallization state at the interface, effectively improves the residual stress at the interface, and ultimately enhances the efficiency and lifetime of inverted perovskite solar cells.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing an inverted perovskite solar cell, the method comprising the following steps:

[0009] (1) A hole transport layer and a perovskite light-absorbing layer are sequentially deposited on a transparent conductive substrate;

[0010] (2) Deposit C on the upper surface of the perovskite light-absorbing layer 60 , to obtain C 60 Electron transport layer;

[0011] (3) Under the vapor atmosphere formed by the mixed solvent, for C 60 The battery semi-finished product with electron transport layer is steam annealed to obtain a battery semi-finished product with interface modification.

[0012] The mixed solvent includes solvents for dissolving C 60 Solvents and solvents for dissolving perovskite crystals;

[0013] (4) The C of the battery semi-finished product obtained in step (3) 60 An electrode layer is deposited on the electron transport layer side to obtain the inverted perovskite solar cell.

[0014] This invention employs a mixed solvent vapor annealing strategy, utilizing the solubility of the mixed solvent vapor in two materials to optimize the interaction between the upper surface of the perovskite light-absorbing layer and C. 60 The interface of the electron transport layer improves C 60 Hole and electron recombination losses due to self-aggregation on the perovskite surface, and C losses induced by mixed solvents. 60 The self-assembly behavior of perovskite molecules optimizes the molecular crystallization state at the interface, effectively improves the residual stress at the interface, and ultimately enhances the efficiency and lifetime of inverted perovskite solar cells.

[0015] The preparation method provided by this invention has a simple process operation, which is conducive to large-scale commercial production.

[0016] It should be noted that C 60 It is a carbon atom cluster composed of 60 carbon atoms forming a 32-sided polyhedron shaped like a soccer ball, consisting of 20 hexagons and 12 pentagons.

[0017] Preferably, the dissolution of C in step (3) 60 The solvent includes any one or a combination of at least two of chlorobenzene, carbon disulfide, m-xylene, toluene, or cumene. For example, chlorobenzene is used with C... 60 The material has high solubility and is often used as an antisolvent to induce the crystallization of perovskite.

[0018] Preferably, the solvent for dissolving the perovskite crystals in step (3) comprises any one or a combination of at least two of acetonitrile, N-methylpyrrolidone, N,N-dimethylformamide, or dimethyl sulfoxide. For example, acetonitrile is effective against C... 60 It has poor solubility, but it has some ability to dissolve perovskite crystals.

[0019] In this invention, by means of dissolving C 60 The polarity difference between the solvent and the solvent that dissolves the perovskite crystals allows them to be miscible in any proportion.

[0020] Preferably, in the steam atmosphere described in step (3), dissolved C 60 The volume ratio of the solvent for dissolving the perovskite crystals to the solvent for dissolving the perovskite crystals is (0.05-0.15):(0.85-0.95). This volume ratio can be any value within this range; for example, the volume ratio of the solvent for dissolving C... 60 The volume ratio of the solvent can be any value within the range of 0.05-0.15, such as 0.05, 0.07, 0.1, 0.12 or 0.15, etc. The volume ratio of the solvent for dissolving perovskite crystals can be any value within the range of 0.85-0.95, such as 0.85, 0.87, 0.9, 0.92 or 0.95, etc.

[0021] In this invention, if C is dissolved 60 The volume ratio of the solvent to the solvent used to dissolve the perovskite crystals is too small, i.e., the dissolution of C... 60 The relatively small volume of the solvent can cause partial rearrangement of the perovskite crystals at the interface, but it is not conducive to improving C. 60 C at the perovskite interface 60 Molecular aggregation occurs, interfacial recombination cannot be effectively controlled, and the interfacial passivation effect cannot be highlighted; if C is dissolved... 60 The volume ratio of the solvent to the solvent used to dissolve the perovskite crystals is too large, i.e., the volume ratio of C to the volume of C is too high. 60 If the volume of the solvent is relatively too large, it may lead to C 60 Excessive dissolution can easily cause interface C 60 Excessive dissolution and re-aggregation after escaping the solvent environment increase vacancies and defects at the interface, ultimately leading to increased carrier recombination and decreased battery efficiency.

[0022] Preferably, the vapor pressure of the steam atmosphere in step (3) is atmospheric pressure.

[0023] It should be noted that atmospheric pressure refers to one atmosphere. Choosing to process under atmospheric pressure eliminates the need for special pressure control, which simplifies the operation.

[0024] Preferably, the steam annealing temperature in step (3) is 20-100℃, and can be any temperature within this range, such as 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, or 100℃. The steam annealing time in step (3) is 3-15 minutes, and can be any time within this range, such as 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, or 15 minutes.

[0025] In this invention, selecting the above-mentioned temperature and time ranges facilitates the control of the solvent evaporation rate, thereby making it easier to regulate the crystal accumulation effect at the interface. This allows for processing to be completed at a lower temperature and in a shorter time, enabling the corresponding technical effects to be achieved quickly and easily.

[0026] Preferably, the transparent conductive substrate in step (1) is conductive glass. For example, it can be FTO (fluorine-doped tin dioxide) conductive glass or ITO (indium tin oxide) conductive glass.

[0027] Preferably, the hole transport layer in step (1) includes an inorganic hole transport layer.

[0028] In this invention, the inorganic hole transport layer helps to increase battery stability and reduce battery cost.

[0029] Preferably, the inorganic hole transport layer comprises any one or a combination of at least two of the following: a nickel oxide layer, a cuprous oxide layer, a self-assembled monolayer, or a molybdenum oxide layer.

[0030] Preferably, the thickness of the hole transport layer in step (1) is 10-20 nm, for example, it can be 10 nm, 12 nm, 14 nm, 16 nm, 18 nm or 20 nm.

[0031] Preferably, the deposition method of the hole transport layer in step (1) includes magnetron sputtering.

[0032] Preferably, the chemical formula of the perovskite light-absorbing layer in step (1) is ABX3, wherein A includes any one or a combination of at least two of formamidinium ions, methylamine ions or cesium ions, B includes lead ions, and X is a halide ion.

[0033] Preferably, the thickness of the perovskite light-absorbing layer in step (1) is 300-700 nm, for example, it can be 300 nm, 400 nm, 500 nm, 600 nm or 700 nm.

[0034] Preferably, the deposition method of the perovskite light-absorbing layer in step (1) includes any one of spin coating, blade coating or slot coating.

[0035] Preferably, the C in step (2) 60 The thickness of the electron transport layer is 4-40nm, for example, it can be 4nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm or 40nm, etc.

[0036] Preferably, the C in step (2) 60 Deposition methods include vapor deposition.

[0037] Preferably, in the vapor deposition method, C 60 The deposition temperature is 400-550℃, for example, it can be 400℃, 450℃, 500℃, or 550℃, and the deposition rate is... For example, it could be or wait.

[0038] Preferably, the electrode layer in step (4) is a metal electrode. For example, it can be any one or a combination of at least two of the following: Cu electrode, Al electrode, Ag electrode, Ni electrode, Co electrode, Au electrode, Mo electrode, or Cr electrode.

[0039] Preferably, the thickness of the electrode layer in step (4) is 30-110 nm, for example, it can be 30 nm, 50 nm, 70 nm, 90 nm or 110 nm.

[0040] Preferably, the deposition method of the electrode layer in step (4) includes electron beam sputtering or vacuum evaporation.

[0041] Preferably, between the electrode layer deposition steps (4), first in C 60 A buffer layer is deposited on the surface of the electron transport layer.

[0042] Preferably, the buffer layer comprises an IWO (W-doped In2O3) layer and / or an ITO (indium tin oxide) layer.

[0043] Preferably, the thickness of the buffer layer is 40-180nm, for example, it can be 40nm, 60nm, 80nm, 100nm, 120nm, 140nm, 160nm or 180nm, etc.

[0044] Preferably, the deposition method of the buffer layer includes RPD (reactive plasma deposition) and / or electron beam sputtering.

[0045] Preferably, the preparation method includes the following steps:

[0046] (1) A hole transport layer with a thickness of 10-20 nm is deposited on the cleaned conductive glass, and then a perovskite precursor solution is coated on the surface of the hole transport layer to form a perovskite light-absorbing layer with a thickness of 300-700 nm.

[0047] (2) Deposit C on the surface of the perovskite light-absorbing layer 60 C with a thickness of 4-40 nm was obtained. 60 Electron transport layer;

[0048] (3) Having C 60 The battery semi-finished product with electron transport layer is placed in a vapor atmosphere of mixed solvent and annealed under normal pressure at 20-100℃ for 3-15 minutes to obtain the battery semi-finished product with interface modification.

[0049] The mixed solvent comprises a solution of C in a volume ratio of (0.05-0.15):(0.85-0.95). 60 Solvents and solvents for dissolving perovskite crystals;

[0050] (4) A buffer layer with a thickness of 40-180 nm and an electrode layer with a thickness of 30-110 nm are sequentially deposited on the interface modification surface of the battery semi-finished product prepared in step (3) to obtain the inverted perovskite solar cell.

[0051] The buffer layer includes an IWO buffer layer and / or an ITO buffer layer.

[0052] In a second aspect, the present invention provides an inverted perovskite solar cell, which is prepared by the preparation method described in the first aspect.

[0053] Thirdly, the present invention provides an application of the inverted perovskite solar cell as described in the second aspect in the photovoltaic field.

[0054] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] (1) This invention employs a mixed solvent vapor annealing strategy, utilizing the solubility of the mixed solvent vapor in the two materials to optimize the surface of the perovskite light-absorbing layer and C. 60 The interface of the electron transport layer improves C 60 Hole and electron recombination losses due to self-aggregation on the perovskite surface, and C losses induced by mixed solvents. 60 The self-assembly behavior of perovskite molecules optimizes the molecular crystallization state at the interface, effectively improves the residual stress at the interface, and ultimately enhances the efficiency and lifetime of inverted perovskite solar cells.

[0057] (2) The preparation method provided by the present invention has simple process operation and is conducive to large-scale commercial production. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the structure of the perovskite solar cell provided in Example 1 of the present invention.

[0059] Figure 2 This is a schematic diagram of the mixed solvent vapor annealing process provided in Example 1 of the present invention.

[0060] Figure 3 This is a comparison diagram of the air stability of perovskite solar cells provided in Example 1 and Comparative Example 6 of the present invention.

[0061] Among them, 1-FTO conductive glass; 2-hole transport layer; 3-perovskite light-absorbing layer; 4-C 60 Electron transport layer; 5-IWO buffer layer; 6-ITO buffer layer; 7-Metal electrode. Detailed Implementation

[0062] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0063] Example 1

[0064] This embodiment provides a method for fabricating an inverted perovskite solar cell, the method comprising the following steps:

[0065] (1) Nickel oxide material was sputtered and deposited on cleaned FTO conductive glass using magnetron sputtering to form a hole transport layer with a thickness of 15 nm. Then, a perovskite precursor solution was coated onto the surface of the hole transport layer using a blade coating method. After annealing at 70 °C for 10 min, a 450 nm thick perovskite precursor solution with the chemical formula FA was formed. 0.85 Cs 0.15 PbI3 perovskite light-absorbing layer;

[0066] (2) Place the battery semi-finished product with the prepared perovskite light-absorbing layer in the transition chamber of the PVD vacuum evaporation equipment, and evacuate to a vacuum degree of 5×10⁻⁶. -4 Pa, and then transferred to the evaporation source chamber, the vacuum degree of which is 1×10⁻⁶. -4 When Pa, for the placement of C 60 The crucible was heated to 500°C, and the deposition rate was controlled at [value missing]. A C layer with a thickness of 20 nm was deposited on the surface of the perovskite light-absorbing layer. 60 Electron transport layer;

[0067] (3) Mixed solvent vapor annealing process, such as Figure 2 As shown:

[0068] Will have C 60 The battery semi-finished product with electron transport layer is placed in a partially sealed container, and a sufficient amount of mixed solvent is added to the bottom of the container. The mixed solvent evaporates at 30°C to form a vapor atmosphere of mixed solvent. The vapor pressure is atmospheric pressure. Steam annealing is performed for 5 minutes to obtain the battery semi-finished product with interface modification.

[0069] The mixed solvent comprises chlorobenzene and acetonitrile in a volume ratio of 0.05:0.95;

[0070] (4) On the interface modification surface of the battery semi-finished product prepared in step (3), a 60 nm thick IWO buffer layer is deposited using reactive plasma deposition equipment. Then, an ITO buffer layer with a thickness of 45 nm and a Cu electrode with a thickness of 70 nm are sequentially deposited on the IWO buffer layer using electron beam sputtering to obtain the inverted perovskite solar cell, the structural schematic diagram of which is shown below. Figure 1 As shown, it includes an FTO conductive glass 1, a hole transport layer 2, a perovskite light-absorbing layer 3, and a C layer stacked sequentially. 60 Electron transport layer 4, IWO buffer layer 5, ITO buffer layer 6, and metal electrode 7.

[0071] Example 2

[0072] This embodiment provides a method for fabricating an inverted perovskite solar cell, the method comprising the following steps:

[0073] (1) Nickel oxide material was sputtered and deposited on cleaned FTO conductive glass using magnetron sputtering to form a hole transport layer with a thickness of 10 nm. Then, a perovskite precursor solution was coated onto the surface of the hole transport layer using a blade coating method. After annealing at 70 °C for 10 min, a 450 nm thick perovskite precursor solution with the chemical formula FA was formed. 0.85 Cs 0.15 PbI3 perovskite light-absorbing layer;

[0074] (2) Place the battery semi-finished product with the prepared perovskite light-absorbing layer in the transition chamber of the PVD vacuum evaporation equipment, and evacuate to a vacuum degree of 5×10⁻⁶. -4 Pa, and then transferred to the evaporation source chamber, the vacuum degree of which is 1×10⁻⁶. -4 When Pa, for the placement of C 60 The crucible was heated to 400°C, and the deposition rate was controlled at [value missing]. A C layer with a thickness of 5 nm was deposited on the surface of the perovskite light-absorbing layer. 60 Electron transport layer;

[0075] (3) Mixed solvent vapor annealing process:

[0076] Will have C 60 The battery semi-finished product with electron transport layer is placed in a partially sealed container, and a sufficient amount of mixed solvent is dropped into the bottom of the container. The mixed solvent evaporates at 60°C to form a vapor atmosphere of mixed solvent. The vapor pressure is atmospheric pressure. Steam annealing is performed for 10 minutes to obtain the battery semi-finished product with interface modification.

[0077] The mixed solvent comprises cumene and N-methylpyrrolidone in a volume ratio of 0.1:0.9;

[0078] (4) A 10 nm thick IWO buffer layer is deposited on the interface modification surface of the battery semi-finished product prepared in step (3) using a reactive plasma deposition device. Then, an ITO buffer layer with a thickness of 30 nm and an Ag electrode with a thickness of 100 nm are deposited sequentially on the IWO buffer layer using an electron beam sputtering method to obtain the inverted perovskite solar cell.

[0079] Example 3

[0080] This embodiment provides a method for fabricating an inverted perovskite solar cell, the method comprising the following steps:

[0081] (1) Nickel oxide material was sputtered and deposited on cleaned FTO conductive glass using magnetron sputtering to form a hole transport layer with a thickness of 20 nm. Then, a perovskite precursor solution was coated onto the surface of the hole transport layer using a blade coating method. After annealing at 70 °C for 10 min, a 450 nm thick perovskite precursor solution with the chemical formula FA was formed. 0.85 Cs 0.15 PbI3 perovskite light-absorbing layer;

[0082] (2) Place the battery semi-finished product with the prepared perovskite light-absorbing layer in the transition chamber of the PVD vacuum evaporation equipment, and evacuate to a vacuum degree of 5×10⁻⁶. -4 Pa, and then transferred to the evaporation source chamber, the vacuum degree of which is 1×10⁻⁶.-4 When Pa, for the placement of C 60 The crucible was heated to 550°C, and the deposition rate was controlled at [value missing]. A C layer with a thickness of 40 nm was deposited on the surface of the perovskite light-absorbing layer. 60 Electron transport layer;

[0083] (3) Mixed solvent vapor annealing process:

[0084] Will have C 60 The battery semi-finished product with electron transport layer is placed in a partially sealed container, and a sufficient amount of mixed solvent is added to the bottom of the container. The mixed solvent forms a vapor atmosphere at 80°C and the vapor pressure is atmospheric pressure. Steam annealing is performed for 5 minutes to obtain the battery semi-finished product with interface modification.

[0085] The mixed solvent comprises m-xylene and dimethyl sulfoxide in a volume ratio of 0.15:0.85;

[0086] (4) On the interface modification surface of the battery semi-finished product prepared in step (3), an IWO buffer layer with a thickness of 120 nm is deposited using a reactive plasma deposition deposition device. Then, an ITO buffer layer with a thickness of 60 nm and an Au electrode with a thickness of 100 nm are deposited sequentially on the IWO buffer layer using an electron beam sputtering method to obtain the inverted perovskite solar cell.

[0087] Example 4

[0088] The difference between this embodiment and embodiment 1 is that the steam annealing time in step (3) is 10 minutes.

[0089] The remaining preparation methods and parameters are consistent with those in Example 1.

[0090] Example 5

[0091] The difference between this embodiment and embodiment 1 is that the volume ratio of chlorobenzene and acetonitrile in step (3) is 0.1:0.9.

[0092] The remaining preparation methods and parameters are consistent with those in Example 1.

[0093] Example 6

[0094] The difference between this embodiment and embodiment 1 is that the volume ratio of chlorobenzene and acetonitrile in step (3) is 0.1:0.9, and the annealing time is 10 min.

[0095] The remaining preparation methods and parameters are consistent with those in Example 1.

[0096] Example 7

[0097] The difference between this embodiment and embodiment 1 is that the volume ratio of chlorobenzene and acetonitrile in step (3) is 0.15:0.85.

[0098] The remaining preparation methods and parameters are consistent with those in Example 1.

[0099] Example 8

[0100] The difference between this embodiment and embodiment 1 is that the volume ratio of chlorobenzene and acetonitrile in step (3) is 0.15:0.85, and the annealing time is 10 min.

[0101] The remaining preparation methods and parameters are consistent with those in Example 1.

[0102] Comparative Example 1

[0103] The difference between this comparative example and Example 1 is that the volume ratio of chlorobenzene and acetonitrile in step (3) is 0.02:0.98.

[0104] The remaining preparation methods and parameters are consistent with those in Example 1.

[0105] Comparative Example 2

[0106] The difference between this comparative example and Example 1 is that the volume ratio of chlorobenzene and acetonitrile in step (3) is 0.5:0.5.

[0107] The remaining preparation methods and parameters are consistent with those in Example 1.

[0108] Comparative Example 3

[0109] The difference between this comparative example and Example 1 is that the volume ratio of chlorobenzene and acetonitrile in step (3) is 0:1.

[0110] The remaining preparation methods and parameters are consistent with those in Example 1.

[0111] Comparative Example 4

[0112] The difference between this comparative example and Example 1 is that the volume ratio of chlorobenzene and acetonitrile in step (3) is 1:0.

[0113] The remaining preparation methods and parameters are consistent with those in Example 1.

[0114] Comparative Example 5

[0115] The difference between this comparative example and Example 1 is that step (3) is performed first after step (1), followed by steps (2) and (4), and the volume ratio of chlorobenzene and acetonitrile in the mixed solvent is 0:1.

[0116] The remaining preparation methods and parameters are consistent with those in Example 1.

[0117] Comparative Example 6

[0118] The difference between this comparative example and Example 1 is that the mixed solvent vapor annealing process in step (3) is replaced by the following steps:

[0119] Will have C 60 The semi-finished battery with the electron transport layer was placed in a glove box under a nitrogen atmosphere and left to stand for 5 minutes.

[0120] The remaining preparation methods and parameters are consistent with those in Example 1.

[0121] Figure 3 A comparison graph of the air stability of the inverted perovskite solar cells provided in Example 1 and Comparative Example 6 is shown. As can be seen from the graph, the inverted perovskite solar cell prepared by the present invention has high efficiency, and its efficiency only decreases by 6.8% after about 1000 hours in air, indicating that the air stability of the cell is significantly improved.

[0122] Performance testing

[0123] The photoelectric performance of the inverted perovskite solar cells prepared in the above embodiments and comparative examples was tested using the following methods:

[0124] A standard sunlight beam (spectral AM 1.5G, effective area 1 cm²) is emitted using a solar simulator. 2 Incident power 100mW / cm 2 (Temperature 25℃).

[0125] The test results are shown in Table 1.

[0126] Table 1

[0127]

[0128] analyze:

[0129] As shown in the table above, this invention employs a mixed solvent vapor annealing strategy, utilizing the solubility of the mixed solvent vapor in both materials to passivate the surface of the perovskite light-absorbing layer and the C... 60 The interface of the electron transport layer improves C 60 Hole and electron recombination losses due to self-aggregation on the perovskite surface, and C losses induced by mixed solvents. 60 The self-assembly behavior of perovskite molecules optimizes the molecular crystallization state at the interface, effectively improves the residual stress at the interface, and enhances the open-circuit voltage, short-circuit current density, fill factor, and photoelectric conversion efficiency of inverted perovskite solar cells.

[0130] As can be seen from Examples 1, 5, and 7 and Comparative Examples 1-2, the volume ratio of chlorobenzene to acetonitrile affects C. 60Regarding the solubility of perovskite crystals, if the volume ratio of chlorobenzene to acetonitrile is too small, it will cause the aggregated C... 60 If the crystal cannot completely dissolve, carrier recombination increases, and the charge flow factor (FF) will decrease; if the volume ratio of chlorobenzene to acetonitrile is too large, then C will... 60 Excessive dissolution of crystals leads to re-aggregation after leaving the solvent environment, resulting in a poorer interfacial crystallization morphology compared to the control group. Consequently, FF and Voc are significantly reduced, and battery efficiency is noticeably decreased.

[0131] As can be seen from Examples 5 and 6, and Examples 7 and 8, under different volume ratios of chlorobenzene and acetonitrile, increasing the annealing time within a certain range can passivate surface defects and improve series resistance and open-circuit voltage.

[0132] As can be seen from Example 1 and Comparative Examples 3-4, if only one solvent is used for the steam annealing process, the perovskite crystals at the interface and C 60 The original equilibrium of the crystal aggregation state is broken, resulting in an increase in interface defects and a decrease in battery efficiency.

[0133] As can be seen from Example 1 and Comparative Example 5, if the battery semi-finished product with the prepared perovskite light-absorbing layer is placed directly in a container and subjected to a mixed solvent vapor annealing process, the crystallization of the perovskite crystal will be slightly improved and the FF will be improved, but it is still far from the optimal conditions of Example 1.

[0134] As can be seen from Example 1 and Comparative Example 6, if C is present... 60 The battery semi-finished product with the electron transport layer was placed in a glove box under a nitrogen atmosphere and left to stand, but the battery performance was not improved.

[0135] The applicant declares that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a trans-perovskite solar cell, characterized by, The preparation method comprises the following steps: (1) sequentially depositing a hole transport layer and a perovskite light-absorbing layer on a transparent conductive substrate; (2) depositing C on the upper surface of the perovskite light-absorbing layer 60 , obtaining a C 60 electron transport layer; (3) in a vapor atmosphere formed by a mixed solvent, to a C 60 The battery semi-product of the electron transport layer is subjected to vapor annealing to obtain an interface-modified battery semi-product. The mixed solvent includes a solvent dissolving C 60 and a solvent dissolving perovskite crystals. (4) C of the battery semi-finished product obtained in step (3) 60 An electrode layer is deposited on the side of the electron transport layer to obtain the trans-perovskite solar cell.

2. The production method according to claim 1, characterized by, The solvent of step (3) dissolves C 60 The solvent includes any one of chlorobenzene, carbon disulfide, m-xylene, toluene, or cumene, or a combination of at least two thereof. Preferably, the solvent for dissolving the perovskite crystals in step (3) comprises any one or a combination of at least two of acetonitrile, N-methylpyrrolidone, N,N-dimethylformamide or dimethyl sulfoxide; Preferably, in the steam atmosphere of step (3), the volume ratio of the solvent dissolving C 60 and the solvent dissolving perovskite crystals is (0.05-0.15):(0.85-0.95).

3. The preparation method according to claim 1, characterized in that, The vapor pressure of the steam atmosphere in step (3) is normal pressure.

4. The preparation method according to claim 1, characterized in that, The temperature of the steam annealing in step (3) is 20-100℃; The time of the steam annealing in step (3) is 3-15min.

5. The preparation method according to claim 1, characterized in that, The transparent conductive substrate in step (1) is conductive glass; The hole transport layer in step (1) comprises an inorganic hole transport layer; Preferably, the inorganic hole transport layer comprises any one or a combination of at least two of a nickel oxide layer, a cuprous oxide layer, a self-assembled monolayer or a molybdenum oxide layer; The thickness of the hole transport layer in step (1) is 10-20nm; Preferably, the perovskite light-absorbing layer in step (1) has a chemical formula of ABX3, wherein A comprises any one or a combination of at least two of formamidinium ion, methylamine ion or cesium ion, B comprises lead ion, and X is halogen ion; The thickness of the perovskite light-absorbing layer in step (1) is 300-700nm.

6. The method of claim 1, wherein, C 60 The thickness of the electron transport layer is 4-40 nm. Preferably, the C 60 Deposition methods include evaporation. In the vapor deposition method, C 60 The deposition temperature is 400-550°C, and the deposition rate is 7. The preparation method according to claim 1, characterized in that, The electrode layer in step (4) is a metal electrode; and the thickness of the electrode layer is 30-110nm; Preferably, before the electrode layer deposition of step (4), a C 60 depositing a buffer layer on the surface of the electron transport layer; Preferably, the buffer layer comprises an IWO buffer layer and / or an ITO buffer layer; and the thickness of the buffer layer is 40-180nm.

8. The method of any one of claims 1-7, wherein, The preparation method comprises the following steps: (1) depositing a hole transport layer with a thickness of 10-20nm on conductive glass, and then coating a perovskite precursor solution on the surface of the hole transport layer to form a perovskite light-absorbing layer with a thickness of 300-700nm; (2) depositing C on the surface of the perovskite light-absorbing layer 60 , to obtain a C layer with a thickness of 4-40 nm 60 electron transport layer (3) the C 60 The battery semi-finished product of the electron transport layer is placed in a vapor atmosphere of the mixed solvent, and vapor annealing is performed at 20-100℃ under normal pressure, the time of vapor annealing is 3-15min, and an interface-modified battery semi-finished product is obtained. The mixed solvent includes a solvent dissolving C 60 and a solvent dissolving perovskite crystals in a volume ratio of (0.05-0.15):(0.85-0.95). (4) sequentially depositing a buffer layer with a thickness of 40-180nm and an electrode layer with a thickness of 30-110nm on the interface modification surface of the battery semi-finished product prepared in step (3) to obtain the trans-perovskite solar cell; Preferably, the buffer layer comprises an IWO buffer layer and / or an ITO buffer layer.

9. A trans-fafium solar cell, characterized by, The trans-perovskite solar cell is prepared by the preparation method in any one of claims 1-8.

10. Use of the trans-perovskite solar cell in claim 9 in the field of photovoltaics.

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