Composite film, method for preparing the same, and use thereof
Patent Information
- Application Number
- CN202510219240.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2026-08-28
AI Technical Summary
[0002]尽管钙钛矿太阳能电池的功率转换效率超过了许多传统的薄膜太阳能技术，但由于其脆弱的界面，钙钛矿太阳能电池难以实现长期稳定性
[0039] (1) The present invention uses plasma deposition to prepare a composite thin film as the electron transport layer of perovskite solar cells. By controlling the oxygen content in the target material and the oxygen partial pressure during the deposition process, a small amount of oxygen vacancies are introduced to activate the interface carriers and promote electron extraction, thereby improving the photoelectric performance of the composite electron transport layer.
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Figure CN122648867A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of solar cell technology, and relates to a composite thin film, its preparation method, and its application. Background Technology
[0002] Although perovskite solar cells offer higher power conversion efficiencies than many traditional thin-film solar technologies, their fragile interfaces make long-term stability challenging. Some contacts degrade under the combined effects of various environmental stressors, such as humidity, oxygen, temperature variations, and sunlight, thus reducing cell performance and lifespan.
[0003] In inverted PIN perovskite solar cells, the interface between the perovskite light-absorbing layer and the electron transport layer significantly leads to efficiency loss and the formation of deep well states. The high cost and poor mechanical properties of fullerene electron transport layers have prompted the search for alternatives.
[0004] CN116916666A discloses a perovskite solar cell and its fabrication method. The solar cell includes an electron transport layer, the material of which is SnO2 modified with a polysaccharide compound.
[0005] CN115172602A discloses an atomic layer deposition (ALD) doped metal oxide composite layer structure. This invention provides a wide bandgap doped metal oxide tunneling junction based on continuous ALD deposition. This structure includes an ALD-deposited metal oxide electron transport layer (including TiO2, ZnO, or SnO2) and an ALD-deposited doped nickel oxide hole transport layer.
[0006] The above scheme prepares SnO directly on the perovskite surface via atomic layer deposition (ALD). x As a durable electron transport layer (ETL), research has shown that the limiting factor for perovskite stability is the interaction between organic cations and ALD metal-organic precursors in the case of tin oxide grown via tetratetra(dimethylamino)tin (TDMASn) and water. Conventional ALD deposition of SnO... x The tin-based TDMASn precursor has a stronger effect on PbI2 formation than water exposure or 150°C thermal annealing, and will greatly promote the degradation of perovskite. Summary of the Invention
[0007] The purpose of this invention is to provide a composite thin film, its preparation method, and its application. This invention uses plasma deposition to prepare the composite thin film. By controlling the oxygen content in the target material and the oxygen partial pressure during the deposition process, a trace amount of oxygen vacancies is introduced to activate interfacial charge carriers and promote electron extraction, thereby improving the photoelectric performance and stability of the composite thin film.
[0008] To achieve this objective, the present invention adopts the following technical solution:
[0009] In a first aspect, the present invention provides a method for preparing a composite thin film, the method comprising the following steps:
[0010] (1) A first plasma deposition process is performed using a composite tin target to obtain a first tin oxide layer;
[0011] (2) Using a composite tin target, a second plasma deposition process is performed on the surface of the first tin oxide layer to form a second tin oxide layer, thereby obtaining the composite film;
[0012] The composite tin target material includes tin suboxide and tin oxide;
[0013] The oxygen partial pressure of the first plasma deposition treatment is less than the oxygen partial pressure of the second plasma deposition treatment.
[0014] This invention introduces trace amounts of oxygen vacancies by controlling the oxygen partial pressure of the target material during plasma deposition (RPD) and the oxygen partial pressure during the deposition process to activate interfacial charge carriers and promote electron extraction, thereby producing a composite thin film. This composite thin film serves as the electron transport layer of a perovskite solar cell and exhibits excellent photoelectric performance. The preparation method of the composite thin film is simple, and compared to traditional inverted perovskite solar cells, the composite thin film prepared by the method of this invention also demonstrates excellent stability. Even without encapsulation, the perovskite solar cell containing the composite thin film still shows excellent performance in stability tests.
[0015] Preferably, in the composite tin target material described in steps (1) and (2), the molar ratio of tin oxide to tin oxide is independently (10-20):(80-90), for example: 10:90, 12:88, 15:85, 18:82 or 20:80, etc., and is not limited to the listed values. Other unlisted values within this range are also applicable.
[0016] In the first and second plasma deposition processes of this invention, the ratio of tin oxide to tin suboxide in the target material can be the same or different, and can be adjusted as needed.
[0017] Preferably, the vacuum degree of the first plasma deposition process in step (1) is ≤5×10⁻⁶. -4 Pa.
[0018] Preferably, the working gas for the first plasma deposition process in step (1) includes argon.
[0019] Preferably, the reaction gas in the first plasma deposition process of step (1) includes oxygen.
[0020] Preferably, the current of the first plasma deposition process in step (1) is 100A to 160A, for example: 100A, 110A, 120A, 130A, 140A, 150A or 160A, etc., not limited to the listed values, and other unlisted values within this range are also applicable.
[0021] Preferably, the substrate temperature of the first plasma deposition treatment in step (1) is 80℃~110℃, for example: 80℃, 85℃, 90℃, 100℃ or 110℃, etc., not limited to the listed values, and other unlisted values within this range are also applicable.
[0022] Preferably, the environmental pressure of the first plasma deposition process in step (1) is 0.3 Pa to 0.5 Pa, for example: 0.3 Pa, 0.35 Pa, 0.4 Pa, 0.45 Pa or 0.5 Pa, etc., not limited to the listed values, and other unlisted values within this range are also applicable.
[0023] Preferably, the oxygen partial pressure of the first plasma deposition process in step (1) is 0% to 2%, for example: 0%, 0.5%, 1%, 1.5% or 2%, etc.
[0024] Preferably, the thickness of the first tin oxide layer in step (1) is 2nm to 5nm, for example: 2nm, 2.5nm, 3nm, 4nm or 5nm, etc., not limited to the listed values, and other unlisted values within this range are also applicable.
[0025] Preferably, in step (2), before introducing the working gas in the second plasma deposition process, the ambient vacuum level is controlled to be ≤5×10⁻⁶. -4 Pa.
[0026] Preferably, the working gas for the second plasma deposition process in step (2) includes argon.
[0027] Preferably, the reaction gas in step (2) of the second plasma deposition process includes oxygen.
[0028] Preferably, the current for the second plasma deposition process in step (2) is 100A to 160A, for example: 100A, 110A, 120A, 130A, 140A, 150A or 160A, etc., and is not limited to the listed values. Other unlisted values within this range are also applicable.
[0029] Preferably, the substrate temperature of the second plasma deposition treatment in step (2) is 80℃~110℃, for example: 80℃, 85℃, 90℃, 100℃ or 110℃, etc., not limited to the listed values, and other unlisted values within this range are also applicable.
[0030] Preferably, the environmental pressure of the second plasma deposition process in step (2) is 0.3 Pa to 0.5 Pa, for example: 0.3 Pa, 0.35 Pa, 0.4 Pa, 0.45 Pa or 0.5 Pa, etc., not limited to the listed values, and other unlisted values within this range are also applicable.
[0031] Preferably, the oxygen partial pressure of the second plasma deposition process in step (2) is 1% to 4%, for example: 1%, 1.5%, 2%, 2.5%, 3%, 3.5% or 4%, etc.
[0032] Preferably, the thickness of the second tin oxide layer in step (2) is 10nm to 20nm, for example: 10nm, 12nm, 15nm, 18nm or 20nm, etc., and is not limited to the listed values. Other unlisted values within this range are also applicable.
[0033] In a second aspect, the present invention provides a composite film, which is prepared by the preparation method described in the first aspect.
[0034] Thirdly, the present invention provides a perovskite solar cell comprising the composite thin film as described in the second aspect;
[0035] The perovskite solar cell includes a perovskite cell or a crystalline silicon perovskite tandem cell.
[0036] Preferably, the perovskite solar cell comprises a substrate, a hole transport layer, a perovskite light-absorbing layer, a composite thin film, and a top electrode layer stacked sequentially.
[0037] Preferably, the perovskite light-absorbing layer is disposed on one side of the first tin oxide layer of the composite film.
[0038] Compared with the prior art, the present invention has the following beneficial effects:
[0039] (1) The present invention uses plasma deposition to prepare a composite thin film as the electron transport layer of perovskite solar cells. By controlling the oxygen content in the target material and the oxygen partial pressure during the deposition process, a small amount of oxygen vacancies are introduced to activate the interface carriers and promote electron extraction, thereby improving the photoelectric performance of the composite electron transport layer.
[0040] (2) The composite film of the present invention does not require C 60 This makes the manufacturing cost of perovskite solar cells more economical and also allows for higher stability of the fabricated perovskite solar cell devices.
[0041] (3) The efficiency of perovskite solar cells fabricated using the composite thin film described in this invention can reach over 21.8%, and the current density can reach 19.8 mA / cm². 2 The open-circuit voltage can reach over 1.2V, the fill factor can reach over 80.1%, and the efficiency retention rate can reach over 91.2%. Attached Figure Description
[0042] Figure 1 This is a schematic diagram of the structure of a PIN perovskite solar cell provided in Application Example 1 of the present invention. 1 is ITO conductive glass, 2 is hole transport layer, 3 is perovskite light-absorbing layer, 4 is first tin oxide layer, 5 is second tin oxide layer, and 6 is top electrode layer.
[0043] Figure 2 This is a comparison chart of the stability of perovskite solar cells prepared in Application Example 1 and Comparative Application Example 4. Detailed Implementation
[0044] 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.
[0045] Example 1
[0046] This embodiment provides a composite film, which is prepared by the following method:
[0047] (1) Plasma deposition was performed using a target material with a SnO and SnO2 molar ratio of 10:90, reducing the vacuum level in the reaction chamber to 5 × 10⁻⁶. -4 Argon gas was introduced into the chamber, and the substrate was transferred to the deposition chamber. The oxygen partial pressure was controlled at 0%, the current at 150A, the vacuum pressure at 0.45Pa, and the substrate heating was controlled at 100℃. A first tin oxide layer with a thickness of 2nm, denoted as SnO, was deposited. x1 ;
[0048] (1) Plasma deposition was performed using a target material with a molar ratio of SnO and SnO2 of 10:90, reducing the vacuum level in the reaction chamber to 5 × 10⁻⁶. -4 Argon gas was introduced into the chamber, and the substrate was transferred to the deposition chamber. The oxygen partial pressure was controlled at 2%, the current at 150A, the vacuum pressure at 0.45Pa, and the substrate heating was controlled at 100℃. A second tin oxide layer with a thickness of 18nm, denoted as SnO, was deposited. x2 The composite film is obtained.
[0049] Example 2
[0050] This embodiment provides a composite film, which is prepared by the following method:
[0051] (1) Plasma deposition was performed using a target material with a molar ratio of SnO and SnO2 of 10:90, reducing the vacuum level in the reaction chamber to 5 × 10⁻⁶. -4 Argon gas was introduced into the chamber, and the substrate was transferred to the deposition chamber. The oxygen partial pressure was controlled at 0%, the current at 120A, the vacuum pressure at 0.4Pa, and the substrate heating at 110℃. A first tin oxide layer with a thickness of 4nm, denoted as SnO, was deposited. x1 ;
[0052] (1) Plasma deposition was performed using a target material with a molar ratio of SnO to SnO2 of 15:85, reducing the vacuum level in the reaction chamber to 5 × 10⁻⁶. -4 Argon gas was introduced into the chamber, and the substrate was transferred to the deposition chamber. The oxygen partial pressure was controlled at 2%, the current at 120A, the vacuum pressure at 0.4Pa, and the substrate heating at 110℃. A second tin oxide layer with a thickness of 15nm, denoted as SnO, was deposited. x2 The composite film is obtained.
[0053] Example 3
[0054] This embodiment provides a composite film, which is prepared by the following method:
[0055] (1) Plasma deposition was performed using a target material with a molar ratio of SnO to SnO2 of 20:80, reducing the vacuum level in the reaction chamber to 5 × 10⁻⁶. -4 Argon gas was introduced into the chamber, and the substrate was transferred to the deposition chamber. The oxygen partial pressure was controlled at 1%, the current at 100A, the vacuum pressure at 0.5Pa, and the substrate heating at 80℃. A first tin oxide layer with a thickness of 5nm, denoted as SnO, was deposited. x1 ;
[0056] (1) Plasma deposition was performed using a target material with a molar ratio of SnO to SnO2 of 15:85, reducing the vacuum level in the reaction chamber to 5 × 10⁻⁶. -4 Argon gas was introduced into the chamber, and the substrate was transferred to the deposition chamber. The oxygen partial pressure was controlled at 3%, the current at 100A, the vacuum pressure at 0.5Pa, and the substrate heating at 80℃. A second tin oxide layer with a thickness of 10nm, denoted as SnO, was deposited. x2 The composite film is obtained.
[0057] Example 4
[0058] The only difference between this embodiment and Embodiment 1 is that the molar ratio of SnO and SnO2 in the plasma deposition process described in steps (1) and (2) is 5:95. All other conditions and parameters are exactly the same as in Embodiment 1.
[0059] Example 5
[0060] The only difference between this embodiment and Embodiment 1 is that the molar ratio of SnO and SnO2 in the plasma deposition process described in steps (1) and (2) is 30:70. All other conditions and parameters are exactly the same as in Embodiment 1.
[0061] Example 6
[0062] The only difference between this embodiment and embodiment 1 is that the oxygen partial pressure of the plasma deposition process in step (1) is 3% and the oxygen partial pressure of the plasma deposition process in step (2) is 4%. Other conditions and parameters are exactly the same as in embodiment 1.
[0063] Example 7
[0064] The only difference between this embodiment and embodiment 1 is that the oxygen partial pressure of the plasma deposition process in step (2) is 0.5%, while the other conditions and parameters are exactly the same as in embodiment 1.
[0065] Example 8
[0066] The only difference between this embodiment and embodiment 1 is that the oxygen partial pressure of the plasma deposition process in step (2) is 5%, while the other conditions and parameters are exactly the same as in embodiment 1.
[0067] Comparative Example 1
[0068] The only difference between this comparative example and Example 1 is that the oxygen partial pressure of the plasma deposition treatment in step (1) and the oxygen partial pressure of the plasma deposition treatment in step (2) are both 2%. All other conditions and parameters are exactly the same as in Example 1.
[0069] Comparative Example 2
[0070] The only difference between this comparative example and Example 1 is that the target material used in the plasma deposition process in steps (1) and (2) is tin oxide. The other conditions and parameters are exactly the same as in Example 1.
[0071] Comparative Example 3
[0072] The only difference between this comparative example and Example 1 is that the target material used in the plasma deposition process described in steps (1) and (2) is tin oxide. All other conditions and parameters are exactly the same as in Example 1.
[0073] Comparative Example 4
[0074] In this comparative example, 20 nm C was prepared by vapor deposition. 60 18nm SnO was prepared by ALD x A composite film was obtained.
[0075] Application Example 1
[0076] This application example provides a perovskite solar cell, the structural schematic of which is shown below. Figure 1 As shown, the perovskite solar cell is fabricated by the following method:
[0077] (1) Cleaning the ITO conductive glass 1, specifically including ultrasonic cleaning with detergent, deionized water, acetone and anhydrous ethanol respectively, each ultrasonic cleaning time is 15min, the glass is dried after cleaning, an ethanol solution of 1mg / mL [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (Meo-4PACz) is prepared and spin-coated on the ITO glass at 3000rpm for 30s, and then dried at 100℃ for 10min to form a hole transport layer 2 on the ITO conductive glass 1;
[0078] (2) MABr, FAI, PbI2, PbBr2 and CsI were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to prepare (CH(NH2)2PbI3) with a concentration of 1.4 mol / L. 0.83 Cs 0.17 Pb(I 0.82 Br 0.18 )3. The perovskite precursor solution, with a DMF:DMSO volume ratio of 4:1, was stirred overnight, spin-coated at 1000 rpm for 40 s, spin-coated at 3000 rpm for 20 s, and 200 μL of ethyl acetate was added in the last 10 s. Then, it was annealed at 100 °C for 20 min to form a 500 nm thick perovskite light-absorbing layer 3 on the hole transport layer 2.
[0079] (3) A composite film is prepared on the perovskite light-absorbing layer 3 using the method described in Example 1, wherein the first tin oxide layer 4 in the composite film is deposited on the perovskite light-absorbing layer 3, and finally an Ag top electrode layer 6 with a thickness of 120 nm is deposited on the second tin oxide layer 5 of the composite film to obtain the perovskite solar cell.
[0080] Application Example 2
[0081] This application example provides a crystalline silicon perovskite tandem solar cell, which is fabricated by the following method:
[0082] (1) A 150μm thick N-type single crystal silicon wafer was sequentially pre-cleaned with ozone and deionized water, post-cleaned with an ozone-hydrofluoric acid mixed solution, and finally cleaned and etched with a hydrofluoric acid / nitric acid mixed solution to form an N-type crystal silicon wafer with a double-sided textured surface. An intrinsic hydrogenated amorphous silicon passivation layer of about 2nm was deposited on both sides of the N-type silicon wafer by PECVD to form the first passivation layer on the front side of the N-type crystal silicon wafer. Then, a 9nm P-type hydrogenated amorphous silicon doped layer and a 6nm P-type doped layer were deposited on both sides respectively. The N-type hydrogenated amorphous silicon doped layer forms a second passivation layer on the back of the N-type crystalline silicon wafer, thereby possessing a symmetrical bifacial cell structure. A 30 nm ITO layer is deposited on the N-type surface amorphous silicon. An ethanol solution of 1 mg / mL [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (Meo-4PACz) is prepared and spin-coated on the ITO at 3000 rpm for 30 s. Then, it is dried at 100 °C for 10 min to obtain the hole transport layer.
[0083] (2) MABr, FAI, PbI2, PbBr2 and CsI were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to prepare (CH(NH2)2PbI3) with a concentration of 1.6 mol / L. 0.83 Cs 0.17 Pb(I 0.82 Br 0.18 )3. The perovskite precursor solution, DMF:DMSO volume ratio of 4:1, was stirred overnight, spin-coated at 1000 rpm for 40 s, spin-coated at 3000 rpm for 20 s, 200 μL of ethyl acetate was added in the last 10 s, and then annealed at 100 °C for 20 min. Then, a 1 nm thick LiF was deposited by vapor deposition to form a 500 nm thick perovskite light-absorbing layer on the hole transport layer.
[0084] (3) A composite film was prepared on the perovskite light-absorbing layer using the method described in Example 1. A 40 nm ITO layer was prepared on the front side of the battery by physical vapor deposition. A 100 nm ITO layer was deposited on the back side (crystalline silicon side) of the battery by physical vapor deposition. An Ag grid line with a thickness of about 180 nm was screen printed on the back side of the battery and sintered and cured. A 1 μm Ag layer and a 90 nm MgF2 layer were deposited on the front side of the battery using a mask to obtain the crystalline silicon perovskite stacked battery.
[0085] Application Example 3
[0086] The only difference between this application example and application example 1 is that the composite film was prepared using example 2, while the other conditions and parameters are exactly the same as in example 1.
[0087] Application Example 4
[0088] The only difference between this application example and application example 1 is that the composite film was prepared using example 3, while the other conditions and parameters are exactly the same as those in example 1.
[0089] Application Example 5
[0090] The only difference between this application example and application example 1 is that the composite film was prepared using example 4, while the other conditions and parameters are exactly the same as in example 1.
[0091] Application Example 6
[0092] The only difference between this application example and application example 1 is that the composite film was prepared using example 5, while the other conditions and parameters are exactly the same as in example 1.
[0093] Application Example 7
[0094] The only difference between this application example and application example 1 is that the composite film was prepared using example 6, while the other conditions and parameters are exactly the same as in example 1.
[0095] Application Example 8
[0096] The only difference between this application example and application example 1 is that the composite film was prepared using example 7, while the other conditions and parameters are exactly the same as in example 1.
[0097] Application Example 9
[0098] The only difference between this application example and application example 1 is that the composite film prepared in example 8 is used; all other conditions and parameters are exactly the same as in example 1.
[0099] Comparative Application Example 1
[0100] The only difference between this comparative application example and application example 1 is that the composite film was prepared using comparative example 1, while the other conditions and parameters are exactly the same as in example 1.
[0101] Comparative Application Example 2
[0102] The only difference between this comparative application example and application example 1 is that the composite film was prepared using comparative example 2, while the other conditions and parameters are exactly the same as in example 1.
[0103] Comparative Application Example 3
[0104] The only difference between this comparative application example and application example 1 is that the composite film was prepared using comparative example 3, while the other conditions and parameters are exactly the same as in example 1.
[0105] Comparative Application Example 4
[0106] The only difference between this comparative application example and application example 1 is that the composite film was prepared using comparative example 4, while the other conditions and parameters are exactly the same as in example 1.
[0107] Comparative Application Example 5
[0108] The only difference between this comparative application example and application example 2 is that the composite film was prepared using comparative example 4, while the other conditions and parameters are exactly the same as in example 1.
[0109] Performance testing:
[0110] At AM1.5, 1000W / m 2 Under the condition of 25±2℃, the current density (mA / cm2), open-circuit voltage (V) and fill factor (%) of the perovskite solar cell were tested, and the efficiency retention rate (compared to the initial efficiency) after 1000h of continuous illumination was also tested. The test results are shown in Table 1.
[0111] Table 1
[0112]
[0113]
[0114] As shown in Table 1, based on Application Examples 1-9, the perovskite solar cells fabricated using the composite thin film described in this invention can achieve an efficiency of over 21.8% and a current density of up to 19.8 mA / cm². 2 The open-circuit voltage can reach over 1.2V, the fill factor can reach over 80.1%, and the efficiency retention rate can reach over 91.2%.
[0115] By comparing Application Example 1 and Application Examples 5-6, it can be seen that during the preparation of the composite thin film of the present invention, the ratio of SnO to SnO2 in the target material affects its performance. Controlling the molar ratio of SnO to SnO2 at (10-20):(80-90) results in a composite thin film with better performance. If the proportion of SnO is too high, the oxygen vacancies in the film layer will be too high. If the proportion of SnO is too low, the oxygen vacancies in the film layer will be too low. Both of these will lead to a decrease in device performance.
[0116] By comparing Application Example 1 and Application Example 7, it can be seen that during the preparation of the composite thin film of the present invention, the oxygen partial pressure of the plasma deposition treatment in step (1) will affect its performance. When the oxygen partial pressure of the plasma deposition treatment in step (1) is controlled at 0% to 2%, the composite thin film has better performance. If the oxygen partial pressure of the plasma deposition treatment in step (1) is too high, the oxygen vacancies in the film layer will be too low, which is not conducive to the electron transport of the device and reduces the device performance.
[0117] By comparing Application Example 1 and Application Examples 8-9, it can be seen that in the preparation process of the composite thin film of the present invention, the oxygen partial pressure of the plasma deposition treatment in step (2) will affect its performance. When the oxygen partial pressure of the plasma deposition treatment in step (2) is controlled at 1% to 4%, the composite thin film has better performance. If the oxygen partial pressure of the plasma deposition treatment in step (2) is too high, the electron transport performance will be reduced. If the oxygen partial pressure of the plasma deposition treatment in step (2) is too low, the band structure of the film layer will be affected, and the device performance will be reduced.
[0118] A comparison between Application Example 1 and Comparative Application Example 1 shows that when the oxygen vacancy rate is too low, the device performance is low.
[0119] A comparison of Application Example 1 and Comparative Application Examples 2-3 shows that both excessively low and excessively high oxygen vacancies will result in lower device performance.
[0120] The stability comparison diagram of the perovskite solar cells prepared in Application Example 1 and Comparative Application Example 4 is shown in the figure below. Figure 2 As shown, by comparing Application Example 1 with Comparative Application Example 4, Application Example 2, and Comparative Application Example 5, it can be seen that the present invention introduces a trace amount of oxygen vacancies to activate interfacial charge carriers and promote electron extraction by controlling the oxygen content of the plasma deposition process (RPD target material) and the oxygen partial pressure during the deposition process. This results in a composite thin film with excellent photoelectric performance while significantly improving the stability of perovskite solar cells.
[0121] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.
Claims
1. A method for preparing a composite thin film, characterized in that, The preparation method includes the following steps: (1) A first plasma deposition process is performed using a composite tin target to obtain a first tin oxide layer; (2) Using a composite tin target, a second plasma deposition process is performed on the surface of the first tin oxide layer to form a second tin oxide layer, thereby obtaining the composite film; The composite tin target material includes tin suboxide and tin oxide; The oxygen partial pressure of the first plasma deposition treatment is less than the oxygen partial pressure of the second plasma deposition treatment.
2. The preparation method according to claim 1, characterized in that, In the composite tin target material described in steps (1) and (2), the molar ratio of tin oxide to tin oxide is independently (10-20):(80-90).
3. The preparation method according to claim 1, characterized in that, Step (1) The vacuum degree of the first plasma deposition process is ≤5×10 -4 Pa; Preferably, the working gas for the first plasma deposition process in step (1) includes argon; Preferably, the current for the first plasma deposition process in step (1) is 100A to 160A; Preferably, the substrate temperature in step (1) of the first plasma deposition treatment is 80°C to 110°C; Preferably, the environmental pressure of the first plasma deposition treatment in step (1) is 0.3 Pa to 0.5 Pa; Preferably, the oxygen partial pressure in the first plasma deposition process of step (1) is 0% to 2%.
4. The preparation method according to any one of claims 1-3, characterized in that, Step (1) The thickness of the first tin oxide layer is 2nm to 5nm.
5. The preparation method according to any one of claims 1-4, characterized in that, Step (2) Before introducing the working gas in the second plasma deposition process, the ambient vacuum level is controlled to be ≤5×10⁻⁶. -4 Pa; Preferably, the working gas for the second plasma deposition process in step (2) includes argon; Preferably, the current for the second plasma deposition process in step (2) is 100A to 160A; Preferably, the substrate temperature in step (2) of the second plasma deposition treatment is 80°C to 110°C; Preferably, the environmental pressure of the second plasma deposition treatment in step (2) is 0.3 Pa to 0.5 Pa; Preferably, the oxygen partial pressure in the second plasma deposition process of step (2) is 1% to 4%.
6. The preparation method according to any one of claims 1-5, characterized in that, In step (2), the thickness of the second tin oxide layer is 10 nm to 20 nm.
7. A composite film, characterized in that, The composite film is prepared by the preparation method according to any one of claims 1-6.
8. A perovskite solar cell, characterized in that, The perovskite solar cell comprises the composite thin film as described in claim 7; The perovskite solar cell includes a perovskite cell or a crystalline silicon perovskite tandem cell.
9. The perovskite solar cell as described in claim 8, characterized in that, The perovskite solar cell comprises a substrate, a hole transport layer, a perovskite light-absorbing layer, a composite thin film, and a top electrode layer, which are stacked sequentially.
10. The perovskite solar cell according to claim 9, characterized in that, The perovskite light-absorbing layer is disposed on one side of the first tin oxide layer of the composite film.