IWO composite layer and preparation method and application thereof

Abstract

The invention discloses an IWO composite layer and a preparation method and application thereof, and belongs to the technical field of new energy. The IWO composite layer provided by the invention comprises a SnO2 seed layer and an IWO layer which are superposed, and the IWO layer comprises a first IWO sub-layer and a second IWO sub-layer; and the first IWO sub-layer and the second IWO sub-layer are arranged in a superposed manner. According to the invention, the SnO2 seed layer and the IWO layer which are superposed are introduced, the SnO2 seed layer provides uniform nucleation sites for the growth of the IWO layer, the uniform growth of the IWO film is promoted, defects and pores in the film are effectively reduced, the superposed arrangement of the first IWO sub-layer and the second IWO sub-layer optimizes the energy level matching between the buffer layer and the perovskite layer, and the performance of the perovskite solar cell is improved. And the carrier extraction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to an IWO composite layer and a preparation method and application thereof. Background Art

[0002] Indium tungsten oxide (IWO) is a novel transparent conductive material widely used in transparent conductive films and transparent electronic devices due to its excellent transparency and conductivity. IWO is a metal oxide material composed of indium (In), tungsten (W), and oxygen (O). Its application in perovskite solar cells is primarily as a buffer layer, inserted between the electron transport layer and the electrode. This buffer layer not only reduces damage to the electron transport layer during electrode deposition but also effectively blocks water and oxygen in the air, thereby preventing degradation of the perovskite layer and improving the stability and lifespan of the cell. Although IWO exhibits significant advantages in transparency and conductivity and is considered a potential alternative to traditional tin oxide (SnO2) buffer layers, its practical application still faces numerous challenges. First, the complex preparation process and high cost of IWO materials limit their large-scale production and commercial application. Second, while IWO can theoretically improve the photoelectric conversion efficiency and stability of perovskite solar cells, its performance in actual cells still requires further experimental research to verify and optimize. In addition, the existing technology has not yet achieved an IWO buffer layer film with high mobility and high transmittance that can adapt to single-junction perovskite solar cells and significantly improve their efficiency. Summary of the Invention

[0003] The present invention aims to address at least one of the technical problems existing in the prior art. To this end, the present invention introduces a stacked SnO2 seed layer and an IWO layer. The SnO2 seed layer provides uniform nucleation sites for the growth of the IWO layer, promoting uniform growth of the IWO film and effectively reducing defects and pores in the film. The stacked arrangement of the first and second IWO sublayers optimizes the energy level matching between the buffer layer and the perovskite layer, improving carrier extraction efficiency.

[0004] The present invention also provides a method for preparing the IWO composite layer.

[0005] The present invention also provides a perovskite solar cell.

[0006] The present invention also provides applications of the perovskite solar cell.

[0007] According to a first aspect of the present invention, there is provided an IWO composite layer, the IWO composite layer comprising a SnO2 seed layer and an IWO layer stacked together;

[0008] The IWO layer consists of a first IWO sub-layer and a second IWO sub-layer;

[0009] The first IWO sub-layer and the second IWO sub-layer are stacked.

[0010] According to the first aspect of the present invention, there are at least the following beneficial effects:

[0011] The SnO2 seed layer provides uniform nucleation sites for the growth of the IWO layer, promoting uniform growth of the IWO film and effectively reducing defects and pores in the film. Simultaneously, the interface between the SnO2 seed layer and the IWO layer is more tightly bonded, significantly reducing interface defects and carrier recombination losses. Furthermore, the stacking of the SnO2 seed layer and the IWO layer further optimizes the energy level matching between the buffer layer and the perovskite layer, significantly improving carrier extraction efficiency. The first IWO sublayer provides uniform nucleation sites for the growth of the second IWO sublayer, promoting uniform growth of the film and reducing defects and pores. The stacking of the first and second IWO sublayers optimizes the energy level matching between the buffer layer and the perovskite layer, improving carrier extraction efficiency. The aforementioned thickness promotes uniform film growth, reduces defects and pores, while optimizing the energy level matching between the layers and improving carrier extraction efficiency.

[0012] According to some embodiments of the present invention, the thickness of the first IWO sub-layer is 5-15 nm; the thickness of the second IWO sub-layer is 10-20 nm.

[0013] According to some embodiments of the present invention, in the IWO layer, the first IWO sub-layer and the second IWO sub-layer are stacked and arranged for at least one cycle.

[0014] According to a second aspect of the present invention, a method for preparing an IWO composite layer is provided, the method comprising:

[0015] A1. Cyclic deposition of SnO2 seed layer in an atomic layer deposition apparatus;

[0016] A2. Obtaining an IWO layer by coating the SnO2 seed layer;

[0017] In the IWO layer, the first IWO sublayer is obtained by oxygen-free deposition, and the second IWO sublayer is obtained by oxygen-containing deposition.

[0018] The introduction of a SnO2 seed layer and the alternating anaerobic and oxygen-free preparation method in the present invention can significantly promote the uniform growth of the IWO film, making the film denser. The improved film density increases the stress of the film layer. The mechanism mainly includes the reduction of defects and pores, the optimization of interface bonding, and the enhancement of the close arrangement of crystals. Under the combined action of these factors, the mechanical stability and photoelectric performance of the film are optimized, thereby significantly improving the efficiency and stability of perovskite solar cells.

[0019] The alternating deposition of oxygen-free and oxygen-containing deposition to prepare the IWO layer, on the one hand, forms a smooth energy level gradient, reducing the potential barrier and recombination loss of carriers at the interface; on the other hand, the alternating deposition of oxygen-free and oxygen-containing deposition promotes the uniform growth of the IWO film and reduces defects and pores. Specifically, the crystal structure of the IWO film layer generated by oxygen-free deposition is more compact, while oxygen-containing deposition further fills the defects and pores that may form under oxygen-free conditions, optimizing the carrier transmission path; on the other hand, it also optimizes the interface bonding between the IWO film layer and the SnO2 seed layer, reducing interface defects and carrier recombination. Specifically, the SnO2 seed layer provides uniform nucleation sites for the growth of the IWO film, promoting the uniform growth of the film. The alternating deposition of oxygen-free and oxygen-containing deposition optimizes the interface bonding between the IWO film layer and the seed layer, reducing interface defects and carrier recombination.

[0020] According to some embodiments of the present invention, the temperature of the cyclic deposition is 70-80°C.

[0021] At the above-mentioned cyclic deposition temperature, precise control at the atomic level can be achieved to generate a uniform and dense SnO2 seed layer, reducing defects and pores in the film. At the same time, the energy level position of the SnO2 seed layer can be precisely regulated, providing a good energy level matching foundation for the subsequent growth of the IWO film and maintaining energy level stability.

[0022] According to some embodiments of the present invention, the precursor source of the SnO2 seed layer includes: tetrakis(dimethylamino)tin and water.

[0023] According to some embodiments of the present invention, the cyclic deposition step includes: using tetradimethylaminotin as a precursor source, maintaining the sample and chamber temperature at 70-80°C, and using H2O as an oxygen precursor source. When the deposition chamber pressure reaches 4-5×10 -3After the temperature drops below 100 Torr, the temperature is raised to 70-80°C. A tin precursor source is introduced into the reaction chamber along with a nitrogen pulse at a nitrogen flow rate of 5-15 sccm. The tin precursor source is exposed for 0.12-0.15 seconds, and the flushing time is 5-15 seconds. The oxygen precursor source is exposed for 0.01-0.03 seconds, and the flushing time is 5-15 seconds. After the oxygen precursor source reacts with the tin precursor source, a flushing gas is introduced to purge excess oxygen precursor source and reaction byproducts. The flushing gas is nitrogen at a flow rate of 5-15 sccm. The above is one cycle. After 10-15 cycles, the ALD-SnO2 seed layer is obtained.

[0024] According to some embodiments of the present invention, the oxygen-free deposition method includes: a plasma deposition method under oxygen-free conditions.

[0025] According to some embodiments of the present invention, the plasma deposition under oxygen-free conditions is performed in a plasma deposition coating device, and the plasma deposition method under oxygen-free conditions satisfies at least one of the following conditions:

[0026] a. The atmosphere of the chamber of the plasma deposition coating equipment is an inert gas, and the flow rate of the inert gas is 90 to 100 sccm;

[0027] b. The gas pressure in the chamber of the plasma deposition coating equipment is 4×10 -4 ~5×10 -4 Pa;

[0028] c. The gun current of plasma deposition is 120~165A.

[0029] Under these conditions, a stable plasma environment can be maintained, promoting uniform deposition of thin films, reducing defects and pores, maintaining the smoothness and chemical stability of the interface, and stabilizing energy levels. At the same time, collisions between gas molecules can be reduced, improving the density and uniformity of the film and reducing interfacial reactions.

[0030] According to some embodiments of the present invention, the aerobic deposition method includes: a plasma deposition method under aerobic conditions.

[0031] According to some embodiments of the present invention, the plasma deposition under aerobic conditions is performed in a plasma deposition coating device, and the plasma deposition method under aerobic conditions satisfies at least one of the following conditions:

[0032] a. The atmosphere of the chamber of the plasma deposition coating apparatus comprises a mixture of oxygen and an inert gas, the flow rate of the mixed gas being 100 to 120 sccm;

[0033] b. The gun current of plasma deposition is 120~180A.

[0034] Under these conditions, a stable plasma environment can be maintained, promoting uniform deposition of thin films, reducing defects and pores, maintaining the smoothness and chemical stability of the interface, and stabilizing energy levels. At the same time, collisions between gas molecules can be reduced, improving the density and uniformity of the film and reducing interfacial reactions.

[0035] The combination of ALD cyclic deposition of the SnO2 seed layer and plasma deposition of the IWO film has the following beneficial effects:

[0036] Thin film growth optimization: The SnO2 seed layer generated by the ALD process provides uniform nucleation sites for the growth of the IWO film, promoting the uniform growth of the IWO film; the IWO film generated by the plasma deposition method further reduces defects and pores in the film, improving the density of the film.

[0037] Optimized interface properties: The interface between the SnO2 seed layer generated by the ALD process and the IWO film generated by the plasma deposition method is more tightly bonded, reducing interface defects and carrier recombination. The optimized interface bonding can effectively transfer stress and reduce the possibility of film cracking or delamination.

[0038] Energy level matching optimization: The energy level matching between the SnO2 seed layer generated by the ALD process and the IWO film generated by the plasma deposition method optimizes the carrier transmission path, reduces the potential barrier and recombination loss of carriers at the interface; by optimizing the energy level matching, the carrier extraction efficiency is improved.

[0039] Improved photoelectric performance: Comprehensive optimization significantly improved the photoelectric performance of perovskite solar cells, including reducing square resistance, increasing carrier concentration, transmittance, mobility and overall efficiency.

[0040] According to a third aspect of the present invention, a perovskite solar cell is provided, comprising a stacked FTO glass substrate, a hole transport layer, a self-assembled monolayer, a perovskite layer, a passivation layer, an electron transport layer, an IWO composite layer, and an electrode layer.

[0041] In the IWO composite layer, the SnO2 seed layer is in contact with the electron transport layer.

[0042] According to some embodiments of the present invention, the preparation method of the FTO conductive glass includes: ultrasonically cleaning with glass water, IPA, deionized water, and ethanol for 30 to 40 minutes respectively, and then blowing it dry with nitrogen for standby use; placing the dried FTO glass substrate in an ultraviolet ozone machine for 15 to 20 minutes to remove organic impurities on its surface.

[0043] According to some embodiments of the present invention, the method for preparing the hole transport layer includes: dispersing nickel oxide, spin-coating the nickel oxide on an FTO glass substrate, and then annealing the nickel oxide. The spin-coating speed is 2500 to 4500 rpm, for example, approximately 2000 rpm. The spin-coating time is 20 to 40 seconds, for example, approximately 30 seconds. The annealing temperature is 150 to 200°C, for example, approximately 150°C. The annealing time is 20 to 40 minutes, for example, approximately 30 minutes.

[0044] According to some embodiments of the present invention, the concentration of the nickel oxide solution is 20-30 mg / mL.

[0045] According to some embodiments of the present invention, the method for preparing the self-assembled monolayer includes: dispersing 4-(9H-carbazole-9-yl)butylphosphonic acid to obtain a 4-(9H-carbazole-9-yl)butylphosphonic acid solution, spin-coating the solution on the hole transport layer, and then annealing the solution. The spin-coating speed is 2500 to 4500 rpm, for example, approximately 3000 rpm. The spin-coating time is 20 to 40 seconds, for example, approximately 30 seconds. The annealing temperature is 100 to 200° C., for example, approximately 100° C., and the annealing time is 20 to 40 seconds, for example, approximately 30 seconds.

[0046] According to some embodiments of the present invention, the concentration of the 4-(9H-carbazol-9-yl)butylphosphonic acid solution is 0.5 to 1 mol / L.

[0047] According to some embodiments of the present invention, in step S2, the method for preparing the perovskite optical layer includes coating a perovskite slurry on the surface of the self-assembled monolayer and performing perovskite annealing.

[0048] According to some embodiments of the present invention, the solutes in the perovskite slurry include the reaction raw materials of ammonium salt, methylammonium iodide, cesium iodide, and lead iodide. The specific addition amount can be selected according to the target material of the perovskite light absorbing layer.

[0049] According to some embodiments of the present invention, the solvent of the perovskite slurry includes DMF and DMSO, wherein the volume ratio of DMF to DMSO is 4 to 8:1, for example, about 5:1, 6:1, or about 7:1.

[0050] According to some embodiments of the present invention, the concentration of the perovskite slurry is 1.3 to 1.8 mol / mL, for example, about 1.4 mol / mL, 1.5 mol / mL, 1.6 mol / mL, or about 1.7 mol / mL.

[0051] According to some embodiments of the present invention, the perovskite slurry is applied by spin coating. The spin coating speed is 1000 to 4500 rpm, for example, approximately 4000 rpm. The spin coating time is 10 to 40 seconds, for example, approximately 40 seconds.

[0052] According to some embodiments of the present invention, step S2 further includes adding an anti-solvent to the surface of the perovskite slurry at 15 to 25 seconds (for example, specifically about 18 seconds, 20 seconds, 22 seconds, 23 seconds, or about 24 seconds) of spin coating the perovskite slurry. The anti-solvent includes chlorobenzene, ethyl acetate, ether, or phenol. The amount of the anti-solvent is 20 to 30 mol / ml. For example, it can be about 20 mol / ml. Thus, the anti-solvent can be fully spread during the spin coating process of the perovskite slurry.

[0053] According to some embodiments of the present invention, the perovskite annealing temperature is 100-110° C., for example, specifically about 100° C.

[0054] According to some embodiments of the present invention, the perovskite annealing time is 20 to 30 minutes, for example, about 30 minutes.

[0055] According to some embodiments of the present invention, the passivation layer preparation method includes: dispersing a polyethyleneimine-polyvinyl chloride copolymer to obtain a polyethyleneimine-polyvinyl chloride copolymer solution, spin-coating the solution on the perovskite layer, and then annealing the solution. The spin-coating speed is 2500 to 4500 rpm, for example, approximately 4000 rpm. The spin-coating time is 20 to 40 seconds, for example, approximately 30 seconds. The annealing temperature is 100 to 200°C, for example, approximately 100°C, and the annealing time is 2 to 5 minutes, for example, approximately 5 minutes.

[0056] According to some embodiments of the present invention, the concentration of the polyethyleneimine-polyvinyl chloride copolymer solution is 0.01 to 0.05 mol / L, for example, about 0.01 mol / mL.

[0057] According to some embodiments of the present invention, the method for preparing the electron transport layer comprises: in a vacuum evaporation machine, -4 A C60 thin film is evaporated on the perovskite layer as an electron transport layer under a vacuum degree of Pa, with an evaporation rate of 0.3 to 5 nm / s.

[0058] According to some embodiments of the present invention, the method for providing the electrode layer includes evaporation. The deposition rate of the metal electrode in the evaporation is 0.08 to 0.12 A / s; for example, it can be about 0.1 A / s.

[0059] The deposition thickness of the electrode layer is 100-120 nm; for example, it may be about 120 nm.

[0060] During evaporation, the vacuum degree of the environment is ≤1×10 -4 Pa.

[0061] According to a fourth aspect of the present invention, a perovskite solar cell is proposed for use in transparent electronic devices, optoelectronic devices, smart windows, and display devices.

[0062] Since the application adopts all the technical solutions of the perovskite solar cell of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0063] Unless otherwise specified, the term “about” in the present invention actually means that the error is allowed to be within the range of ±2%, for example, about 100 actually means 100±2%×100.

[0064] Unless otherwise specified, “between” in the present invention includes the number itself, for example, “between 2 and 3” includes the endpoint values ​​2 and 3.

[0065] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. DETAILED DESCRIPTION

[0066] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0067] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0068] Example 1

[0069] In this example, a perovskite solar cell was prepared. The specific steps are as follows:

[0070] S1. Ultrasonic clean the FTO conductive glass with glass water, IPA, deionized water, and ethanol for 30 minutes each, followed by drying with nitrogen. The dried FTO glass substrate is then treated in a UV-ozone chamber for 15 minutes to remove organic impurities on the surface.

[0071] S2. Dissolve 20 mg of nickel oxide in 2 ml of deionized water and sonicate for 5 minutes. Then, pipette 100 μL of the 20 mg / ml nickel oxide solution and spin-coat it onto an FTO glass substrate at 2000 rpm for 30 seconds. The substrate is then placed on an annealing platform and annealed in air at 150°C for 30 minutes.

[0072] S3. Weigh 1 mg of 4PACz solvent and dissolve it in 2 ml of ethanol to prepare a 0.5 mol / L 4PACz self-assembled monolayer solution. Use a pipette to remove 100 μL of this solution and drop it onto the hole transport layer. Spin-coat the solution at 3000 rpm for 30 seconds and then place it in an annealing station for 100°C in air for 10 minutes.

[0073] S4. Weigh 438 mg of ammonium salt, 47 mg of MAI, 39 mg of cesium iodide, and 1535 mg of lead iodide and dissolve them in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (800 μL of DMF, 200 μL of DMSO). Then, stir the mixture with a magnetic stirrer at 60°C and 1200 rpm to prepare a 1.6 mol / L perovskite precursor solution. Using a multi-step spin coating procedure, spin coat the SAM at 1000 rpm for 10 s and 4000 rpm for 40 s. After 45 s, add 160 μL of a 20 mol / mL chlorobenzene solution. Then, anneal the mixture on a heating plate at 100°C for 30 min.

[0074] S5. Weigh 1 mg of PEACL and dissolve it in 1 mL of isopropanol to prepare a 0.01 mol / L PEACL solution. Use a pipette to dispense 100 μL of this solution onto the perovskite layer and spin-coat it at 4000 rpm for 30 seconds. Then, place the perovskite layer on an annealing platform and anneal it in air at 100°C for 5 minutes.

[0075] S6. Place the structure having the perovskite layer, the hole transport layer, and the substrate in a vacuum evaporation machine at 5×10 - 4 Pa, a 20 nm thick C60 film was evaporated on the perovskite layer as an electron transport layer at a rate of 0.3 nm / s;

[0076] S7. Use an atomic layer deposition (ALD) system to deposit a SnO2 seed layer on the electron transport layer. Use tetradimethylaminotin as the precursor source and H2O as the oxygen precursor source. Maintain the sample and chamber temperature at 80°C. When the deposition chamber pressure reaches 5×10 -3 After the temperature drops below 100 Torr, the temperature is raised to 70°C before the process is carried out. The tin precursor source enters the reaction chamber along with the nitrogen pulse. The nitrogen flow rate is 5 sccm. The tin precursor source exposure time is 0.12s, the flushing time is 5s, and the oxygen precursor source exposure time is 0.03s, and the flushing time is 5-15s. After the oxygen precursor source and the tin precursor source react, the flushing gas is introduced to purge the excess oxygen precursor source and reaction by-products. The flushing gas is nitrogen with a flow rate of 5 sccm. The above is one cycle. After 10 cycles, the SnO2 seed layer is obtained.

[0077] S8. Using reactive plasma deposition RPD coating equipment, a 99:1 IWO target was used as the target material (InO:W = 99:1), and the chamber pressure was pumped to 5×10 -4 After Pa, 40 sccm argon was introduced into the plasma gun and 70 sccm argon was introduced into the chamber. The chamber pressure was maintained at 0.3-0.4 Pa. First, a 10 nm oxygen-free IWO film (the first IWO sublayer) was prepared. The gun current was 165 A and the carrier speed was 76.5 mm / s. After the first coating was completed, the carrier was placed in the buffer chamber. The second layer of 15 nm oxygen-containing IWO film (the second IWO sublayer) was prepared. The chamber argon flow was changed to 53.5 sccm and the oxygen flow rate was changed to 16.5 sccm. The second layer coating was started and the carrier speed was 51 mm / s. S7 and S8 prepared an IWO composite layer.

[0078] S9. The composite structure provided with the IWO composite layer is placed in a vacuum deposition chamber, and the vacuum degree of the chamber is 10 - 5 Under the condition of Pa below, 120nm of Ag was evaporated on the IWO layer to obtain a perovskite solar cell.

[0079] Example 2

[0080] In this example, a perovskite solar cell was prepared. The difference between this example and Example 1 is that the structure of the IWO composite layer is a stacked arrangement of a SnO2 seed layer, an oxygen-containing IWO film layer, and an oxygen-free IWO film layer. The specific steps are as follows:

[0081] S1. Ultrasonic clean the FTO conductive glass with glass water, IPA, deionized water, and ethanol for 30 minutes each, followed by drying with nitrogen. The dried FTO glass substrate is then treated in a UV-ozone chamber for 15 minutes to remove organic impurities on the surface.

[0082] S2. Dissolve 20 mg of nickel oxide in 2 ml of deionized water and sonicate for 5 minutes. Then, pipette 100 μL of the 20 mg / ml nickel oxide solution and spin-coat it onto an FTO glass substrate at 2000 rpm for 30 seconds. The substrate is then placed on an annealing platform and annealed in air at 150°C for 30 minutes.

[0083] S3. Weigh 1 mg of 4PACz solvent and dissolve it in 2 ml of ethanol to prepare a 0.5 mol / L 4PACz self-assembled monolayer solution. Use a pipette to remove 100 μL of this solution and drop it onto the hole transport layer. Spin-coat the solution at 3000 rpm for 30 seconds and then place it in an annealing station for 100°C in air for 10 minutes.

[0084] S4. Weigh 438 mg of FAI, 47 mg of MAI, 39 mg of cesium iodide, and 1535 mg of lead iodide and dissolve them in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (800 μL of DMF, 200 μL of DMSO). Then, stir the mixture with a magnetic stirrer at 60°C and 1200 rpm to prepare a 1.6 mol / L perovskite precursor solution. Using a multi-step spin coating procedure, spin coat the SAM at 1000 rpm for 10 s and 4000 rpm for 40 s. Add 160 μL of a 20 mol / mL chlorobenzene solution after 45 s, and anneal on a heating plate at 100°C for 30 min.

[0085] S5. Weigh 1 mg of PEACL and dissolve it in 1 mL of isopropanol to prepare a 0.01 mol / L PEACL solution. Use a pipette to dispense 100 μL of this solution onto the perovskite layer and spin-coat it at 4000 rpm for 30 seconds. Then, place the perovskite layer on an annealing platform and anneal it in air at 100°C for 5 minutes.

[0086] S6. Place the structure having the perovskite layer, the hole transport layer, and the substrate in a vacuum evaporation machine at 5×10 - 4 Pa, a 20 nm thick C60 film was evaporated on the perovskite layer as an electron transport layer at a rate of 0.3 nm / s;

[0087] S7. A SnO2 seed layer was deposited on the electron transport layer using an atomic layer deposition (ALD) system. Tetramethylaminotin was used as the precursor source. The sample and chamber temperatures were maintained at 80°C. H2O was used as the oxygen precursor source. When the deposition chamber pressure reached 5×10 -3After the temperature drops below 300 Torr, the temperature is raised to 70°C and the process is carried out. The tin precursor source enters the reaction chamber along with the nitrogen pulse. The nitrogen flow rate is 5 sccm. The exposure time of the tin precursor source is 0.12 seconds, and the flushing time is 5 seconds. The exposure time of the oxygen precursor source is 0.03 seconds, and the flushing time is 5-15 seconds. After the reaction of the oxygen precursor source and the tin precursor source is completed, the flushing gas is introduced to purge the excess oxygen precursor source and reaction by-products. The flushing gas is nitrogen with a flow rate of 5 sccm. The above is one cycle. After 10 cycles, the SnO2 seed layer is obtained.

[0088] S8. Using reactive plasma deposition RPD coating equipment, IWO target with a ratio of (97:3) was used as the target material, and the chamber pressure was pumped to 5×10 -4 Pa, a 15nm oxygen-containing IWO film layer (the second IWO sublayer) was prepared, the chamber argon gas was changed to 53.5sccm, the carrier speed was 51mm / s, and the oxygen flow rate was changed to 16.5sccm before coating. After the first coating was completed, the carrier was placed in the buffer chamber to prepare an oxygen-free IWO film layer (the first IWO sublayer). 40sccm argon gas was introduced into the plasma generator gun, 70sccm argon gas was introduced into the chamber, the chamber pressure was maintained at 0.3-0.4Pa, the gun current was 165A, and the carrier speed was 76.5mm / s. S7 and S8 prepared an IWO composite layer;

[0089] S9. The composite structure provided with the IWO composite layer is placed in a vacuum deposition chamber, and the vacuum degree of the chamber is 10 - 5 Under the condition of Pa below, 120nm of Ag was evaporated on the IWO layer to obtain a perovskite solar cell.

[0090] Comparative Example 1

[0091] This example prepares a perovskite solar cell, which differs from Example 1 in that:

[0092] Excluding step S7, in step S8, only oxygen deposition is performed to obtain a 25 nm IWO layer. The IWO composite layer structure of the perovskite solar cell is only the second IWO sublayer. The other conditions are the same as those in Example 1.

[0093] Comparative Example 2

[0094] This example prepares a perovskite solar cell, which differs from Example 1 in that:

[0095] In step S8, only oxygen is deposited to obtain a 25 nm IWO layer. The IWO composite layer structure of the perovskite solar cell is a SnO2 seed layer and a second IWO sublayer stacked in sequence. The other conditions are the same as those in Example 1.

[0096] Comparative Example 3

[0097] This example prepares a perovskite solar cell, which differs from Example 1 in that:

[0098] Excluding step S7, in step S8, only an oxygen-free deposition is performed to obtain a 25 nm IWO layer. The IWO composite layer structure of the perovskite solar cell is only the first IWO sublayer. The other conditions are the same as those in Example 1.

[0099] Comparative Example 4

[0100] This example prepares a perovskite solar cell, which differs from Example 1 in that:

[0101] In step S8, only oxygen-free deposition is performed to obtain a 25 nm thick IWO layer. The IWO composite layer structure of the perovskite solar cell is a SnO2 seed layer and a first IWO sublayer stacked in sequence. The remaining conditions are the same as those in Example 1.

[0102] Comparative Example 5

[0103] This example prepares a perovskite solar cell, which differs from Example 1 in that:

[0104] Excluding step S7, the remaining conditions are the same as those in Example 1.

[0105] Comparative Example 6

[0106] This example prepares a perovskite solar cell, which differs from Example 2 in that:

[0107] Excluding step S7, the remaining conditions are the same as those in Example 1.

[0108] Test Example 1

[0109] This example tests the performance of the perovskite solar cells obtained in the examples and comparative examples. The specific testing method is as follows:

[0110] Sheet resistance test: Sample preparation: Secure the sample on the test platform to ensure the surface is flat. Calibrate the four-probe tester using a standard sample (known sheet resistance value). Gently touch the four probes to the sample surface to ensure good contact between the probes and the sample. Apply a constant current (usually 1-10mA) and measure the voltage drop between the probes. Calculate the sheet resistance according to the formula: Rs = (π / ln2)·(V / I)·k, where Rs is the sheet resistance, V is the voltage drop, I is the current, and k is the correction factor. Measure at least five different locations on each sample and take the average value as the final result.

[0111] Carrier concentration test:

[0112] Test instrument: Hall Effect Measurement System, test method:

[0113] Make four ohmic contact points on the sample surface (usually using gold or silver paste) to form a Hall test structure to ensure that the contact point resistance is low and stable. The test steps are as follows: place the sample in a magnetic field (usually 0.1-1T), apply a constant current (usually 1-10mA), and measure the Hall voltage V H The carrier concentration is calculated according to the formula: n = (I·B) / (q·t·VH) where n is the carrier concentration, I is the current, B is the magnetic field strength, q is the electron charge (1.6×10-19C), t is the film thickness, and V H = is the Hall voltage. Data recording: Each sample was measured at least 3 times and the average value was taken as the final result.

[0114] Transmittance (%) test:

[0115] Test instrument: UV-Vis Spectrophotometer. Test method: Sample preparation: Cut the sample into a size suitable for the test (usually 1cm×1cm), and ensure that the sample surface is clean, without scratches or contamination. Baseline calibration: Use air or a blank substrate (such as glass) as the baseline to calibrate the instrument. Test steps: Place the sample in the sample chamber, ensure that the light beam passes through the sample vertically, scan within the wavelength range (usually 300-800nm), and record the transmittance data. The transmittance calculation formula is: T (%) = (I / I0) × 100, where I is the light intensity passing through the sample, and I0 is the incident light intensity. Data recording: Calculate the average transmittance in the visible light range (400-700nm) as the final result.

[0116] Mobility (cm 2 / V·s) test:

[0117] Test Instrument: Hall Effect Measurement System. Test Method: As with the carrier concentration test, four ohmic contacts were made. Test Procedure: In the Hall Effect test, the Hall voltage VH and resistance R were measured. Mobility was calculated using the formula: μ = 1 / (q·n·Rs), ​​where μ is mobility, q is electron charge, n is carrier concentration, and Rs is square resistance. Data Recording: Each sample was measured at least three times, and the average value was used as the final result. The test results are shown in Table 1.

[0118] Table 1. Performance test

[0119]

[0120]

[0121] On the one hand, Examples 1 and 2 introduce an IWO composite layer and combine it with an anaerobic + aerobic alternating preparation method to precisely control the energy level position of the IWO film, making it more compatible with the energy level of the perovskite layer, thereby improving device efficiency, reducing carrier scattering at the interface, and reducing square resistance. Examples 1 and 2 introduce a seed layer to provide a uniform nucleation site for the growth of the IWO film, thereby promoting uniform growth of the film. By introducing the seed layer and the anaerobic + aerobic alternating preparation method, the IWO film layer is made denser, defects and pores are reduced, and the improved film quality reduces carrier scattering and recombination during transmission, improves carrier mobility, thereby reducing square resistance and improving device efficiency. Examples 1 and 2 also optimize the interface bonding between the IWO film layer and the seed layer through the anaerobic + aerobic alternating preparation method, thereby effectively transferring stress and reducing defects and lattice mismatch at the interface. Appropriate stress can enhance the crystal structure of the film and improve carrier transmission efficiency. In Examples 1 and 2, the IWO film layers achieved more uniform density and stress distribution, reducing carrier scattering at the interface. This interface optimization reduced carrier scattering and recombination at the interface, improving carrier transport efficiency and thus reducing square resistance and increasing device efficiency.

[0122] Test Example 2

[0123] The test instruments and test conditions used in the examples are as follows:

[0124] JV curve: First, using a standard silicon solar cell (2×2cm 2 , SRC-00019) calibrated to the standard solar spectrum corresponding to 1 sun (AM1.5G, 100mW / cm 2 ) corresponding to the current. The device was then placed under a calibrated test light source using a test fixture (performed in an N2 glove box). The JV characteristic curve of the perovskite semiconductor optoelectronic device was automatically measured using a Keithley 2450 source meter and corresponding software. The open-circuit voltage (VOC), short-circuit current density (JSC), fill factor (FF), and power conversion efficiency (PCE) were then obtained from the curve. The specific formula is as follows:

[0125] FF=Pmax / Voc×Jsc=Vmax×Jmax / Voc*Jsc, PCE=Pmax / Pin=Voc×Jsc×FF / Pin;

[0126] Where Pmax is the maximum output power, VOC and JSC are the voltage and current density at the maximum power point, respectively, and Pin is the incident light power.

[0127] During the JV curve test, the test voltage was set to 1.2V (start) to -0.2V (end), the interval was 0.02V, and the delay time was 0.1s.

[0128] The constant temperature and humidity test conditions are as follows: the temperature of the constant temperature and humidity test system is adjusted to 85°C and the humidity is 85% RH. After the first test, the test is performed again at intervals of 100 hours.

[0129] The test results are shown in Table 2.

[0130] Table 2 Performance of perovskite solar cells obtained in Examples and Comparative Examples

[0131]

[0132]

[0133] The Voc value distribution range in Example 1 was relatively narrow, mainly concentrated between 1.14 and 1.155, indicating that the Voc values ​​of this group were relatively stable and had a high overall level. The Voc value distribution range in the RPD group was relatively wide, ranging from 1.135 to 1.155, indicating that the Voc values ​​of this group fluctuated greatly and had poor stability. The Voc value distribution range in the ALD group was the widest, ranging from 1.13 to 1.15, with one obvious outlier (below 1.13), indicating that the Voc values ​​of this group had the greatest fluctuation and the poorest stability.

[0134] The Jsc value distribution range is narrow, mainly concentrated in the range of 25.0~25.2mA / cm 2 The results show that the Jsc value of Example 1 is relatively stable and the overall level is high. Example 1 combines the advantages of ALD (atomic layer deposition) and RPD (reactive plasma deposition), which makes the film quality higher and the interface optimized better, thereby improving the stability of the Jsc value. Example 1 combines the advantages of ALD and RPD (reactive plasma deposition), ALD provides a uniform film substrate, and RPD further optimizes the conductivity and optical properties of the film.

[0135] While the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. An IWO composite layer, characterized in that: The IWO composite layer includes a SnO2 seed layer and an IWO layer stacked together; Wherein, the IWO layer includes a first IWO sublayer and a second IWO sublayer; The first IWO sub-layer and the second IWO sub-layer are stacked.

2. The IWO composite layer according to claim 1, characterized in that: In the IWO layer, the first IWO sub-layer and the second IWO sub-layer are stacked and arranged for at least one cycle.

3. A method for preparing an IWO composite layer according to claim 1 or 2, characterized in that: The preparation method comprises: A1. Cyclic deposition of SnO2 seed layer in an atomic layer deposition apparatus; A2. Obtaining an IWO layer by coating the SnO2 seed layer; In the IWO layer, the first IWO sublayer is obtained by oxygen-free deposition, and the second IWO sublayer is obtained by oxygen-containing deposition.

4. The preparation method according to claim 3, characterized in that The temperature of the cyclic deposition is 70-80°C.

5. The preparation method according to claim 3, characterized in that The oxygen-free deposition method includes: a plasma deposition method under oxygen-free conditions.

6. The preparation method according to claim 5, characterized in that The plasma deposition under oxygen-free conditions is performed in a plasma deposition coating device, and the plasma deposition method under oxygen-free conditions satisfies at least one of the following conditions: a. The atmosphere of the chamber of the plasma deposition coating equipment is an inert gas, and the flow rate of the inert gas is 90 to 110 sccm; b. The gas pressure in the chamber of the plasma deposition coating equipment is 4×10 -4 ~5×10 -4 Pa; c. The gun current of plasma deposition is 120~165A.

7. The preparation method according to claim 3, characterized in that The aerobic deposition method includes: a plasma deposition method under aerobic conditions.

8. The preparation method according to claim 7, characterized in that The plasma deposition under aerobic conditions is performed in a plasma deposition coating device, and the plasma deposition method under aerobic conditions satisfies at least one of the following conditions: a. The atmosphere of the chamber of the plasma deposition coating apparatus comprises a mixture of oxygen and an inert gas, the flow rate of the mixed gas being 100 to 120 sccm; b. The gun current of plasma deposition is 120~165A.

9. A perovskite solar cell, characterized in that: The perovskite solar cell comprises a stacked FTO glass substrate, a hole transport layer, a self-assembled monolayer, a perovskite layer, a passivation layer, an electron transport layer, a composite layer and an electrode layer; Wherein, the composite layer is the IWO composite layer according to claim 1 or 2, and the SnO2 seed layer and the electron transport layer are in contact with each other in the IWO composite layer.

10. Use of the perovskite solar cell according to claim 9 in transparent electronic devices, optoelectronic devices, smart windows and display devices.

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