A reverse-type perovskite cell containing a self-assembled monolayer and a preparation method thereof

Abstract

The present application relates to a kind of reverse perovskite battery containing self-assembled monolayer and preparation method thereof, perovskite battery includes the hole transport layer, perovskite layer, electron transport layer and electrode layer sequentially arranged from substrate side, light is incident on perovskite layer from hole transport layer side, hole transport layer is self-assembled monolayer material, connecting layer is further provided between hole transport layer and perovskite layer, inorganic material is provided in connecting layer, inorganic material is the combination of one or more of nitride, sulfide, oxide.The reverse perovskite battery uses self-assembled monolayer material as hole transport layer material, can satisfy the energy level matching and conductivity requirement of reverse perovskite, depositing connecting layer on hole transport layer material, on the one hand, hole transport layer material can be tightly pressed on substrate or electrode layer, on the other hand, keying action can be formed between hole transport layer material and perovskite layer, and the connecting strength between connecting layer and perovskite layer is enhanced.

Description

Technical Field

[0001] This invention relates to an inverted perovskite solar cell containing a self-assembled monolayer and its preparation method, belonging to the field of photovoltaics. Background Technology

[0002] As a clean energy source, solar energy can meet the growing global energy demand. Among numerous optoelectronic devices, perovskite solar cells have attracted much attention due to their high photoelectric conversion efficiency and low manufacturing cost. The theoretical efficiency limit of single-junction perovskite solar cells is approximately 31%, while the current laboratory record efficiency is 26.8%, reaching a level comparable to crystalline silicon cells. Crystalline silicon cells have a lifespan of 20-30 years, while the same perovskite cell only lasts 3-5 years, severely limiting the reduction of the levelized cost of electricity (LCOE). Therefore, improving the stability of perovskite cells is currently the focus.

[0003] Perovskite solar cells are classified into two structures based on their stacked configuration: positive (nip) and negative (pin). In the positive structure, the hole transport material, Spiro, is unavoidable. However, Spiro exhibits significant hygroscopicity and instability, resulting in poor stability. In contrast, negative pin cells eliminate the use of Spiro, employing other hole layers such as PTAA and SAMs. SAMs have garnered significant attention due to their thinness, low dosage, energy level matching, and good conductivity, achieving optimal conversion efficiency in perovskite solar cells. Compared to Spiro, SAMs offer improved stability. However, compared to PTAA (another commonly used hole layer in negative structures, this polymer), SAMs still lag significantly in stability. Therefore, maintaining the high efficiency of SAMs in perovskite solar cells while further improving their stability is crucial to enabling perovskite solar cells to achieve a competitive advantage comparable to crystalline silicon in real-world applications. Summary of the Invention

[0004] To improve the stability of inverted perovskite solar cells, this invention provides an inverted perovskite solar cell containing a self-assembled monolayer and a method for its fabrication. This inverted perovskite solar cell uses a self-assembled monolayer material as the hole transport layer material, which meets the energy level matching and conductivity requirements of inverted perovskites. A bonding layer is deposited on the hole transport layer material, which on the one hand firmly presses the hole transport layer material onto the substrate or electrode layer, and on the other hand forms a bonding interaction with the perovskite layer, enhancing the connection strength between the bonding layer and the perovskite layer.

[0005] The technical solution adopted in this invention is as follows: an inverted perovskite solar cell containing a self-assembled monolayer, comprising a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer arranged sequentially from the substrate side. The substrate can be a silicon cell, conductive glass or other films. Light passes through the electrode layer and the hole transport layer and is incident on the perovskite layer, where photogenerated carriers are generated. Holes then enter the hole transport layer and electrons enter the electron transport layer. The hole transport layer is a self-assembled monolayer material (SAMs material). As a hole transport layer material, the self-assembled monolayer material (SAMs material) (1) can provide excellent hole conductivity, improve the photoelectric conversion efficiency of the cell, (2) form a stable interface between the perovskite interfaces, reduce defects, reduce non-radiative recombination, thereby enhancing the overall performance and stability of the cell, (3) has strong adjustability, and its electronic properties can be optimized by changing the molecular structure, further improving the cell efficiency, and (4) has good film-forming properties and exhibits strong durability under harsh environmental conditions, ensuring the long-term stable operation of the cell. (5) The preparation process of SAMs materials is environmentally friendly and simple, and has a low cost in industrial applications.

[0006] This invention further includes a connecting layer between the hole transport layer and the perovskite layer. The connecting layer contains an inorganic material, or the material of the connecting layer itself is also inorganic, exhibiting high photothermal stability. The inorganic material is selected from at least one or more combinations of nitrides, sulfides, and oxides, i.e., compounds containing -N, -O, or -S. These compounds have minimal impact on charge carriers, thus not affecting the hole tunneling effect, and can form bonds with the perovskite material.

[0007] As a preferred embodiment, the bonding layer is a sulfide and / or oxide, which may contain only sulfides, only oxides, or both. The bonding layer is formed by mixing sulfides and oxides in a predetermined ratio, preferably 1:5 to 5:1; more preferably, it is obtained by mixing one of alumina, titanium dioxide, zinc oxide, and silicon oxide with zinc sulfide. The bonding layer thickness is 1-5 nm.

[0008] As a preferred embodiment, the connecting layer comprises at least two layers: a sulfide layer, preferably zinc sulfide, and an oxide layer, preferably one of alumina, titanium oxide, zinc oxide, and silicon oxide. The sulfide layer connects to the perovskite layer, and the -S bonds have a very strong ability to coordinate with perovskite, especially lead, thus achieving a good passivation effect and promoting perovskite crystallization. The oxide layer connects to the hole transport layer. This material layer has low water vapor permeability and a dense structure, serving as a barrier layer to protect the SAMs material and prevent water vapor from eroding the hole transport layer.

[0009] As a preferred embodiment, the connecting layer comprises two layers: an oxide layer and a sulfide and nitride mixed layer. The oxide is selected from aluminum oxide, titanium oxide, zinc oxide, and silicon oxide; the sulfide is zinc sulfide; and the nitride is selected from aluminum nitride and silicon nitride. The oxide layer has low water vapor permeability and a dense structure, serving as a barrier layer to protect the SAMs material and prevent water vapor from eroding the hole transport layer. The sulfide and nitride mixed layer can form a specific passivation layer, guiding the perovskite orientation crystallization and enhancing the stability of the perovskite layer. On the other hand, it forms coordination bonds with the perovskite, increasing the connection strength between the connecting layer and the perovskite layer, thereby increasing the connection strength between the perovskite layer and the hole transport layer.

[0010] As a preferred approach, the thickness of the connecting layer is 1-5 nm. This thickness can ensure the connection strength between the perovskite layer and the hole transport layer, preventing the hole transport layer from detaching from the perovskite layer, and also ensure the tunneling efficiency of charge carriers in the film layer.

[0011] As a preferred method, the connecting layer is deposited on the hole transport layer in the form of atomic deposition. The atomic deposition structure is dense and can act like a dense "blanket," pressing tightly onto the SAMs layer and preventing it from detaching from the substrate. Moreover, the film layer formed by atomic deposition has fewer defects, resulting in low non-radiative recombination efficiency of charge carriers during transport.

[0012] As a preferred embodiment, the hole transport layer material is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz) or / and (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid (Me-4PACz); poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and the perovskite layer material is a lead-containing material. This material can form strong interactions such as Pb-O / S / N with the connecting layer, further passivating the perovskite interface and improving the interface performance.

[0013] As a preferred embodiment, the inorganic material is selected from one or more of alumina, titanium dioxide, zinc oxide, silicon oxide, aluminum nitride, silicon nitride, and zinc sulfide.

[0014] As a preferred embodiment, the perovskite layer material is a component capable of forming ABX3, wherein A is an organic or inorganic cation, B is a lead ion, X is a halogen, and A is a methylamine ion, formamidinium ion, or Cs. + The preparation method can be one or a combination of spin coating, blade coating, vapor deposition, etc., with preferred perovskite materials being MAPbI3 formed from MAI and PbI2; FAPbI3 formed from FAI and PbI2; and mixed perovskite Cs. 0.05 FA 0.85 MA 0.10 Pb(I 0.95 Br0.05 3.

[0015] This invention also provides a method for preparing an inverted perovskite solar cell containing a self-assembled monolayer, the method comprising the following steps:

[0016] Obtain the substrate;

[0017] A hole transport layer is fabricated on the substrate or a hole transport layer is fabricated after a first spacer layer is fabricated on the substrate.

[0018] Create a connection layer on top of the hole transport layer;

[0019] Fabricate a perovskite layer on the bonding layer;

[0020] An electron transport layer is fabricated on the perovskite layer or an electron transport layer is fabricated after a second spacer layer is fabricated on the perovskite layer.

[0021] An electrode layer is fabricated on the electron transport layer or an electrode layer is fabricated after a third spacer layer is fabricated on the electron transport layer; the connecting layer contains an inorganic material, which is selected from one or more of nitrides, sulfides, and oxides.

[0022] The first, second, or third spacer layer is one or more of the following: passivation layer, modification layer, transition layer, and light modulation layer.

[0023] As a preferred embodiment, one method for preparing the connecting layer is as follows: sulfides, oxides, or nitrides are deposited on the hole transport layer using atomic deposition. Once a certain thickness is reached, deposition is stopped to obtain the connecting layer. Preferably, an alumina film is deposited using atomic deposition with trimethylaluminum as the aluminum source and water as the oxidant. The deposition temperature is 80-300℃. First, a 0.1-5 second TMA (trimethylaluminum) pulse is applied, followed by a 2-100 second inert gas purging, then a 0.1-5 second water pulse, and finally another 2-100 seconds purging to remove byproducts. The working pressure in the reaction chamber is maintained at 1-50 Torr, and deposition is repeated until a 3 nm thick alumina film is formed.

[0024] The second preparation method is as follows: an oxide layer is deposited on the hole transport layer by atomic deposition. After the deposition is completed, the deposition parameters are adjusted, and a sulfide layer is deposited on the oxide layer. After the deposition reaches a certain thickness, the deposition is stopped to obtain the connecting layer. The preferred preparation method is as follows: (1) An alumina film with a thickness of 3 nm is prepared on the hole transport layer by ALD (atomic deposition). Trimethylaluminum is used as the aluminum source and water is used as the oxidant. The deposition temperature is 150℃. First, a 0.3-second TMA pulse is performed, followed by a 15-second inert gas purging, then a 0.3-second water pulse, and finally a 15-second purging to remove byproducts. The working pressure of the reaction chamber is usually maintained at 5 Torr, and a thickness of 3 nm is finally formed. (2) A 2 nm thick sulfide layer is prepared by ALD. The temperature of the reaction chamber is set between 150-250℃ to optimize the adsorption and reaction of the precursor. When introducing a lead source (such as dimethyl lead), the gas flow rate is set to 20-50 sccm for approximately 1-5 seconds to form a monoatomic layer on the substrate. Next, purification is performed using an inert gas (such as nitrogen or argon) at a flow rate typically of 30-60 sccm for 10-20 seconds. Then, a sulfur source (such as hydrogen sulfide) is introduced at a flow rate of 10-30 sccm for 1-5 seconds. This is followed by another inert gas purging at the same flow rate and time as the previous step, and this cycle is repeated until the desired film thickness is achieved, typically between 1-5 nanometers, usually requiring 20-40 cycles. Finally, after deposition, annealing can be performed at 200-300°C to improve the crystallinity and electrical properties of the PbS film. These specific parameters contribute to achieving highly uniform and high-quality lead sulfide films.

[0025] As a preferred option, one method for preparing the hole transport layer is as follows: (1) mix MeO-2PACz with an ethanol solution to obtain a MeO-2PACz solution, filter it with a filter cartridge to remove large particles, and set the filtered solution aside; (2) spin-coat the filtered solution onto a substrate; (3) anneal to obtain the hole transport layer.

[0026] The second preparation method is as follows: (1) Mix Me-4PACz with isopropanol solution to obtain Me-4PACz solution, filter with filter cartridge to remove large particulate matter, and use the filtered solution for later use; (2) slit the filtered solution onto the substrate.

[0027] The third preparation method is as follows: (1) Mix PTAA with chlorobenzene solution to obtain PTAA solution, filter with filter cartridge to remove large particulate matter, and set aside the filtered solution; (2) Spray the filtered solution onto the substrate; (3) Anneal to obtain hole transport layer.

[0028] As a preferred option, one method for preparing the perovskite layer is as follows: (1) Preparing a MAI+PbI2 solution: Dissolving PbI2 and MAI in a mixed solvent of DMF (NN dimethylformamide) and DMSO (dimethyl sulfoxide), heating until completely dissolved, and filtering with a filter cartridge to remove larger particles in the solution to obtain a MAI+PbI2 solution. (2) Spin-coating the prepared MAI+PbI2 solution onto an inorganic modification layer, uniformly adding the antisolvent toluene onto the film layer during the spin-coating process, and then annealing under a nitrogen atmosphere, cooling and storing for later use to form a perovskite film layer of a certain thickness.

[0029] The second preparation method is as follows: (1) Prepare FAI+PbI2 solution: Dissolve PbI2 and FAI in a mixed solvent of DMF (NN dimethylformamide) and DMSO (dimethyl sulfoxide), heat until completely dissolved, and filter with a filter cartridge to remove larger particles in the solution to obtain FAI+PbI2 solution. (2) Spin-coat the prepared FAI+PbI2 solution onto the inorganic modification layer. During the spin-coating process, uniformly add the antisolvent toluene onto the film layer, and then anneal under a nitrogen atmosphere. After cooling, it is ready for use to form a thick perovskite film layer.

[0030] The third preparation method is as follows: (1) Preparation of Cs 0.05 FA 0.85 MA 0.10 Pb(I 0.95 Br 0.05 (3) Solution: Dissolve PbI2, FAI, CsI, CsBr, and PbBr2 in a mixed solvent of DMF (NN dimethylformamide) and DMSO (dimethyl sulfoxide), heat until completely dissolved, and filter using a filter cartridge to remove larger particles in the solution to obtain the solution. (2) Spin-coat the prepared solution onto the inorganic modification layer. During the spin-coating process, uniformly add the anti-solvent chlorobenzene onto the film layer, and then anneal under a nitrogen atmosphere. After cooling, it is ready for use to form a thick perovskite film layer.

[0031] As a preferred option, the method for preparing the electron transport layer is as follows: (1) using vacuum evaporation equipment, C is evaporated by thermal evaporation. 60 The material forms an electron transport layer on the perovskite film, and the evaporation vacuum degree is below 7*10-4Pa.

[0032] As a preferred option, a hole blocking layer is prepared on the electron transport layer after the electron transport layer is prepared. The preparation method is as follows: using a vacuum evaporation equipment, the BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline or copper bath) material is evaporated by thermal evaporation to form a hole blocking layer on the electron transport layer. The evaporation vacuum degree is below 7*10-4 Pa.

[0033] The beneficial effects of this invention include: the use of a self-assembled monolayer as the hole transport layer material of trans-perovskite is beneficial to improving hole transport efficiency and battery photoelectric conversion efficiency.

[0034] The self-assembled monolayer itself degrades under light and heat; and the connection between the self-assembled monolayer and the upper and lower interfaces desorbs and detaches under light, humidity and other environments, which seriously affects the performance of the device. The present invention deposits a bonding layer on the self-assembled monolayer, and the bonding layer is an inorganic material or contains inorganic materials. The structure and composition are stable. Like a blanket, it tightly covers and protects the self-assembled monolayer, so that it can operate stably in the device and will not fall off.

[0035] The inorganic materials used in this invention are nitrides, sulfides, or oxides, which form strong interactions such as Pb-O / S / N with the perovskite components, thereby passivating the perovskite interface.

[0036] The connecting layer in this invention interacts with the perovskite to guide its directional crystallization and improve its crystallization properties.

[0037] This invention employs a single passivating molecule and multiple defects. Each defect and molecule generates a binding energy, which enhances the binding energy between the defect and the passivating molecule, thereby ensuring that the molecule does not fall off under the action of an external field and ensuring that the connecting layer has a continuous passivation effect.

[0038] Unless otherwise specified, any range described in this invention includes the endpoints, any values ​​between the endpoints, and any subranges formed by the endpoints or any values ​​between the endpoints. There are no particular limitations on the purity of any raw materials used in this invention; however, analytical grade is preferred. The sources and abbreviations of all raw materials used in this invention are conventional sources and abbreviations in the art, and are clearly defined in their respective fields of application. Those skilled in the art can obtain them from commercially available sources or prepare them using conventional methods based on their abbreviations and corresponding uses. Unless otherwise specified, all percentages in this invention are mass percentages.

[0039] "At least one" means one or more, while "more" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple. Attached Figure Description

[0040] Figure 1 Structure diagram of perovskite photovoltaic devices;

[0041] Figure 2 Efficiency decay curves of Comparative Example 1 and Example 1 under aging conditions of 85℃ + 85% humidity;

[0042] Figure 3 Efficiency decay curves of Comparative Example 2 and Example 2 under a solar irradiation aging condition;

[0043] In the figure: 1. Substrate; 2. Hole transport layer; 3. Inorganic protective layer; 4. Perovskite layer; 5. Electron transport layer; 6. Hole blocking layer; 7. Electrode. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0045] Unless otherwise specified, any range described in this invention includes the endpoints, any values ​​between the endpoints, and any subranges formed by the endpoints or any values ​​between the endpoints. There are no particular limitations on the purity of any raw materials used in this invention; however, analytical grade is preferred. The sources and abbreviations of all raw materials used in this invention are conventional sources and abbreviations in the art, and are clearly defined in their respective fields of application. Those skilled in the art can obtain them from commercially available sources or prepare them using conventional methods based on their abbreviations and corresponding uses.

[0046] "At least one" refers to one or more, while "more" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple. The inorganic protective layer mentioned below refers to the connection layer mentioned above.

[0047] Example 1

[0048] This embodiment is a perovskite solar cell with an inverted (pin) conventional bandgap, and the fabrication method includes the following steps:

[0049] S01 Obtaining Base 1

[0050] Using ITO glass as the substrate, the ITO glass substrate was first ultrasonically cleaned for 20 minutes each in detergent and deionized water, then ultrasonically cleaned for 20 minutes in acetone, and finally ultrasonically cleaned for 20 minutes in isopropanol (IPA). After that, it was dried with a nitrogen gun and placed in a UV ozone processor for 15 minutes for later use.

[0051] S02 is used to prepare the hole transport layer 2

[0052] (1) Mix 1 mg of MeO-PACz with 2 mL of ethanol solution to obtain a 0.5 mg / mL MeO-2PACz solution. Use a 0.45 μm filter cartridge to filter out large particles. The filtered solution is ready for use.

[0053] (2) Spin-coat the filtered solution onto ITO glass at a spin rate of 3500 rpm for 40 s.

[0054] (3) Anneal at 125℃ for 10 min to obtain a MeO-2PACz hole transport layer with a thickness of about 2 nm.

[0055] Preparation of SO3 Inorganic Protective Layer 3

[0056] A 3 nm thick alumina film was prepared using ALD (atomic deposition) with trimethylaluminum as the aluminum source and water as the oxidant at a deposition temperature of 150 °C. The deposition process involved a 0.3-second TMA pulse, followed by a 15-second inert gas purging, a 0.3-second water pulse, and finally a 15-second purging to remove byproducts. The working pressure in the reaction chamber was typically maintained at 5 Torr, resulting in a final film thickness of 3 nm.

[0057] Preparation of S04 perovskite film layer 4

[0058] (1) Preparation of MAI+PbI2 solution: 461 mg of PbI2 and 159 mg of MAI were dissolved in 0.85 mL of DMF (NN dimethylformamide) and 0.15 mL of DMSO (dimethyl sulfoxide), heated to 70 °C and stirred for 1 hour until completely dissolved, and filtered with a 0.45 μm filter to remove larger particles in the solution to obtain MAI+PbI2 solution.

[0059] (2) The prepared MAI+PbI2 solution was spin-coated onto the inorganic modification layer at a spin-coating speed of 4000 rpm for 30 s. At the 10th s of spin-coating, 160 μL of the antisolvent toluene was uniformly added to the film. Then, the film was annealed at 100 °C for 30 min under a nitrogen atmosphere and cooled for later use to form a perovskite film with a thickness of 450 nm.

[0060] Fabrication of S05 electron transport layer 5

[0061] Vacuum evaporation equipment is used to evaporate C using a thermal evaporation method. 60 The material forms a 20nm electron transport layer on the perovskite film, with a deposition vacuum of 7*10. -4 Below Pa.

[0062] Preparation of S06 hole blocking layer 6:

[0063] Using vacuum evaporation equipment, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline or copper bath) material was evaporated by thermal evaporation to form an 8nm hole blocking layer on the electron transport layer. The evaporation vacuum degree was 7*10 -4 Below Pa.

[0064] Preparation of S07 electrode 7

[0065] A 100nm copper (Cu) layer was deposited on the surface of the hole blocking layer using thermal evaporation as an electrode.

[0066] Example 2:

[0067] This embodiment is a perovskite solar cell with an inverted (pin) conventional bandgap, and the fabrication method includes the following steps:

[0068] S01 Obtain the substrate

[0069] Using ITO glass as the substrate, the ITO glass substrate was first ultrasonically cleaned for 20 minutes each in detergent and deionized water, then ultrasonically cleaned for 20 minutes in acetone, and finally ultrasonically cleaned for 20 minutes in isopropanol (IPA). After that, it was dried with a nitrogen gun and placed in a UV ozone processor for 15 minutes for later use.

[0070] S02 is used to prepare the hole transport layer.

[0071] (1) Mix 1 mg of MeO-2PACz with 2 mL of ethanol solution to obtain a 0.5 mg / mL MeO-2PACz solution. Use a 0.45 μm filter cartridge to filter out large particles. The filtered solution is ready for use.

[0072] (2) Spin-coat the filtered solution onto ITO glass at a spin rate of 3500 rpm for 40 s.

[0073] (3) Anneal at 125℃ for 10 min to obtain a MeO-2PACz hole transport layer with a thickness of about 2 nm.

[0074] Preparation of S03 Inorganic Protective Layer

[0075] (1) An alumina film with a thickness of 3 nm was deposited using ALD, with trimethylaluminum as the aluminum source and water as the oxidant. The deposition temperature was 150 °C. A 0.3-second TMA pulse was applied first, followed by a 15-second inert gas purging, then a 0.3-second water pulse, and finally a 15-second purging to remove byproducts. The working pressure in the reaction chamber was typically maintained at 5 Torr, ultimately forming a 3 nm thick alumina film.

[0076] (2) A 2 nm thick sulfide layer was prepared on an alumina film using ALD (atomic deposition). The temperature of the ALD reaction chamber was set at 250 °C to optimize the adsorption and reaction of the precursor. The sulfide deposition steps were as follows:

[0077] A lead source, dimethyl lead, is introduced into the reaction chamber at a flow rate of 50 sccm for approximately 4 seconds, causing it to form a monolayer on the substrate.

[0078] b. The reaction chamber is purified using an inert gas at a flow rate of 60 sccm for 15 seconds.

[0079] c. Hydrogen sulfide is introduced into the reaction chamber at a flow rate of 20 sccm for a reaction time of 3 seconds.

[0080] d. Clean the reaction chamber again with inert gas, using the same flow rate and introduction time as in step b.

[0081] e. Repeat steps a through d until the film thickness reaches 2 nm.

[0082] After deposition, annealing was performed at 200℃ to improve the crystallinity and electrical properties of the PbS film, thereby obtaining a highly uniform and high-quality lead sulfide film.

[0083] Preparation of S04 perovskite film

[0084] (1) Preparation of MAI+PbI2 solution: 461 mg of PbI2 and 159 mg of MAI were dissolved in 0.85 mL of DMF (NN dimethylformamide) and 0.15 mL of DMSO (dimethyl sulfoxide), heated to 70 °C and stirred for 1 hour until completely dissolved, and filtered with a 0.45 μm filter to remove larger particles in the solution to obtain MAI+PbI2 solution.

[0085] (2) The prepared MAI+PbI2 solution was spin-coated onto the inorganic protective layer at a spin-coating speed of 4000 rpm for 30 s. At the 10th s of spin-coating, 160 μL of the antisolvent toluene was uniformly added to the film. Then, the film was annealed at 100 °C for 30 min under a nitrogen atmosphere and cooled for later use to form a perovskite film with a thickness of 450 nm.

[0086] Preparation of S05 electron transport layer

[0087] (1) Using vacuum evaporation equipment, C is evaporated by thermal evaporation. 60 The material forms a 20nm electron transport layer on the perovskite film, with a deposition vacuum of 7*10. -4 Below Pa.

[0088] Preparation of S06 hole blocking layer:

[0089] Using vacuum evaporation equipment, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline or copper bath) material was evaporated by thermal evaporation to form an 8nm hole blocking layer on the electron transport layer. The evaporation vacuum degree was 7*10 -4 Below Pa.

[0090] Preparation of S07 electrode

[0091] A 100nm copper (Cu) layer was deposited on the surface of the hole blocking layer using thermal evaporation as an electrode.

[0092] Example 3

[0093] This embodiment is a perovskite solar cell with an inverted (pin) conventional bandgap, and the fabrication method includes the following steps:

[0094] S01 Obtain the substrate

[0095] Using ITO glass as the substrate, the ITO glass substrate was first ultrasonically cleaned for 20 minutes each in detergent and deionized water, then ultrasonically cleaned for 20 minutes in acetone, and finally ultrasonically cleaned for 20 minutes in isopropanol (IPA). After that, it was dried with a nitrogen gun and placed in a UV ozone processor for 15 minutes for later use.

[0096] S02 is used to prepare the hole transport layer.

[0097] (1) Mix 1 mg of MeO-2PACz with 2 mL of ethanol solution to obtain a 0.5 mg / mL MeO-2PACz solution. Use a 0.45 μm filter cartridge to filter out large particles. The filtered solution is ready for use.

[0098] (2) Spin-coat the filtered solution onto ITO glass at a spin rate of 3500 rpm for 40 s.

[0099] (3) Anneal at 125℃ for 10 min to obtain a MeO-2PACz hole transport layer with a thickness of about 2 nm.

[0100] Preparation of S03 Inorganic Protective Layer

[0101] A 3 nm thick alumina film was prepared using ALD (atomic deposition) with trimethylaluminum as the aluminum source and water as the oxidant at a deposition temperature of 150 °C. The deposition process involved a 0.3-second TMA pulse, followed by a 15-second inert gas purging, a 0.3-second water pulse, and finally a 15-second purging to remove byproducts. The working pressure in the reaction chamber was typically maintained at 5 Torr, resulting in a final film thickness of 3 nm.

[0102] Preparation of S04 perovskite film

[0103] (1) Preparation of FAI+PbI2 solution: 461 mg of PbI2 and 172 mg of FAI were dissolved in 0.90 mL of DMF (NN dimethylformamide) and 0.10 mL of DMSO (dimethyl sulfoxide), heated to 70 °C and stirred for 1 hour until completely dissolved, and filtered with a 0.45 μm filter to remove larger particles in the solution to obtain FAI+PbI2 solution.

[0104] (2) The prepared solution was spin-coated onto the inorganic modification layer at a spin-coating speed of 4000 rpm for 30 s. At the 15th second of spin-coating, 200 μL of the antisolvent chlorobenzene was uniformly added to the film. Then, the film was annealed at 150 °C for 10 min under a nitrogen atmosphere and annealed at 150 °C for 10 min in air. After cooling, the film was set aside to form a perovskite film with a thickness of 500 nm.

[0105] Preparation of S05 electron transport layer

[0106] Vacuum evaporation equipment is used to evaporate C using a thermal evaporation method. 60 The material forms a 20nm electron transport layer on the perovskite film, with a deposition vacuum of 7*10. -4 Below Pa.

[0107] Preparation of S06 hole blocking layer:

[0108] Using vacuum evaporation equipment, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline or copper bath) material was evaporated by thermal evaporation to form an 8nm hole blocking layer on the electron transport layer. The evaporation vacuum degree was 7*10 -4 Below Pa.

[0109] Preparation of S07 electrode

[0110] A 120nm layer of silver (Ag) was deposited on the surface of the hole blocking layer as an electrode using thermal evaporation.

[0111] Example 4

[0112] This embodiment is a perovskite solar cell with an inverted (pin) conventional bandgap, and the fabrication method includes the following steps:

[0113] S01 Obtain the substrate

[0114] Using FTO glass as the substrate, the ITO glass substrate was first ultrasonically cleaned for 20 minutes each in detergent and deionized water, then ultrasonically cleaned for 20 minutes in acetone, and finally ultrasonically cleaned for 20 minutes in isopropanol (IPA). After that, it was dried with a nitrogen gun and placed in a UV ozone processor for 15 minutes for later use.

[0115] S02 is used to prepare the hole transport layer.

[0116] (1) Mix 0.75 mg of Me-4PACz with 1 mL of isopropanol solution to obtain a 0.75 mg / mL Me-4PACz solution. Use a 0.45 μm filter cartridge to filter out large particles. The filtered solution is ready for use.

[0117] (2) Spin-coat the filtered solution onto FTO glass at a spin rate of 3500 rpm for 40 s.

[0118] (3) Anneal at 125℃ for 10 min to obtain a Me-4PACz hole transport layer with a thickness of about 2nm.

[0119] Preparation of S03 Inorganic Protective Layer

[0120] A 3 nm thick alumina film was prepared using ALD (atomic deposition) with trimethylaluminum as the aluminum source and water as the oxidant at a deposition temperature of 150 °C. The deposition process involved a 0.3-second TMA pulse, followed by a 15-second inert gas purging, a 0.3-second water pulse, and a final 15-second purging to remove byproducts. The working pressure in the reaction chamber was typically maintained at 5 Torr, resulting in a 3 nm thick alumina film.

[0121] Preparation of S04 perovskite film

[0122] (1) Preparation of FAI+PbI2 solution: 461 mg of PbI2 and 172 mg of FAI were dissolved in 0.90 mL of DMF (NN dimethylformamide) and 0.10 mL of DMSO (dimethyl sulfoxide), heated to 70 °C and stirred for 1 hour until completely dissolved, and filtered with a 0.45 μm filter to remove larger particles in the solution to obtain FAI+PbI2 solution.

[0123] (2) The prepared solution was spin-coated onto the inorganic modification layer at a spin-coating speed of 4000 rpm for 30 s. At the 15th second of spin-coating, 200 μL of the antisolvent chlorobenzene was uniformly added to the film. Then, the film was annealed at 150 °C for 10 min under a nitrogen atmosphere and annealed at 150 °C for 10 min in air. After cooling, the film was set aside to form a perovskite film with a thickness of 500 nm.

[0124] Preparation of S05 electron transport layer

[0125] Vacuum evaporation equipment is used to evaporate C using a thermal evaporation method. 60 The material forms a 20nm electron transport layer on the perovskite film, with a deposition vacuum of 7*10. -4 Below Pa.

[0126] Preparation of S06 Hole Blocking Layer

[0127] Using vacuum evaporation equipment, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline or copper bath) material was evaporated by thermal evaporation to form an 8nm hole blocking layer on the electron transport layer. The evaporation vacuum degree was 7*10 -4 Below Pa.

[0128] Preparation of S07 electrode

[0129] A 120nm layer of silver (Ag) was deposited on the surface of the hole blocking layer as an electrode using thermal evaporation.

[0130] Comparative Example 1

[0131] The difference from Example 1 is that no inorganic protective layer is provided.

[0132] Comparative Example 2

[0133] The difference from Example 2 is that no inorganic protective layer was provided.

[0134] The efficiency changes of Example 1 and Comparative Example 1 were tested under aging conditions of 85°C and 85% humidity, and the results are as follows: Figure 2 It can be seen that the efficiency decays to 86.1% after 568 hours, and to 76.7% in the comparative case. The inorganic protective layer is beneficial to enhancing the stability of the perovskite efficiency.

[0135] The efficiency changes of Example 2 and Comparative Example 2 were tested under sunlight and room temperature conditions, and the results are as follows: Figure 3 It can be seen that the efficiency decays to 84.3% after 800 hours, and to 75.7% in comparison, indicating that the inorganic protective layer is beneficial to enhancing the stability of the perovskite efficiency.

[0136] The efficiency changes of Examples 1 to 4 were tested under aging conditions of 85°C and 85% humidity. After 568 hours, the efficiency decreased to 86.1%, 88.2%, 86.3%, and 87.6% respectively. It can be seen that the batteries with added inorganic protective layers all showed good thermal stability under high temperature conditions.

[0137] The efficiency of Examples 1 to 4 was tested under sunlight and room temperature conditions. After 800 hours, the efficiency decreased to 84.1%, 84.3%, 83.9%, and 83.8% respectively. This shows that the batteries with the added inorganic protective layer all exhibit good photostability under strong light conditions.

[0138] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An inverted perovskite solar cell containing a self-assembled monolayer, comprising a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer sequentially disposed from the substrate side, characterized in that: The hole transport layer is a self-assembled monolayer material. A connecting layer is also provided between the hole transport layer and the perovskite layer. The connecting layer contains inorganic materials and includes a lead sulfide layer connected to the perovskite layer and an alumina layer connected to the hole transport layer. The thickness of the connecting layer is 1-5 nm.

2. The inverse perovskite solar cell containing a self-assembled monolayer according to claim 1, characterized in that: The connecting layer is deposited on the hole transport layer in the form of atomic deposition.

3. The inverse perovskite solar cell containing a self-assembled monolayer according to claim 1, characterized in that: The hole transport layer material is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, or / and (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid; The perovskite layer material is a lead-containing material.

4. The inverse perovskite solar cell containing a self-assembled monolayer according to claim 1, characterized in that: The perovskite layer material includes at least MAPbI3, FAPbI3, and Cs. 0.05 FA 0.85 MA 0.10 Pb(I 0.95 Br 0.05 One of 3.

5. A method for preparing an inverted perovskite solar cell containing a self-assembled monolayer, characterized in that: Includes the following steps Obtain the substrate; Create a hole transport layer; Create a connection layer; Fabrication of perovskite layers; Fabrication of an electron transport layer; Fabrication of electrode layers; The connecting layer contains inorganic materials and includes a lead sulfide layer connected to the perovskite layer and an alumina layer connected to the hole transport layer. The thickness of the connecting layer is 1-5 nm.

6. The preparation method according to claim 5, characterized in that: Both the lead sulfide layer and the alumina layer are formed by atomic deposition. The preparation method of the lead sulfide layer is as follows: (1) A lead source is introduced into the atomic deposition reaction chamber to obtain a single atomic layer. The gas flow rate is set to 20-50 sccm and the time is 1-5s. (2) Inert gas is introduced to purify the reaction chamber; (3) Introduce a sulfur source into the reaction chamber at a gas flow rate of 10-30 sccm for 1-5 seconds; (4) Repeat steps (1) to (3) until the required lead sulfide layer is formed; The method for preparing the alumina layer is as follows: Alumina layer was prepared by using trimethylaluminum as aluminum source and water as oxidant, with a deposition temperature of 150~250°C. (1) Trimethylaluminum was introduced, (2) inert gas was introduced for purging, and (3) water pulse was introduced. Steps (1) to (3) were repeated to obtain an alumina layer of the required thickness.

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