Co-SAM molecular interface modification-based trans-broadband gap perovskite solar cell and preparation method thereof

Abstract

The invention discloses a trans-broadband gap perovskite solar cell based on Co-SAM molecular interface modification and a preparation method of the trans-broadband gap perovskite solar cell. According to the trans-broadband gap perovskite solar cell based on Co-SAM molecular interface modification, an interface modification layer is prepared from a modified interface modification material, the interface modification layer is arranged between a hole transport layer and a perovskite thin film, and the modified interface modification material is triphenylphosphine salt doped self-assembly molecules. According to the method, TPBr is introduced into the SAM precursor solution, then the SAM thin film based on doping is obtained, and due to the fact that the uniformity, hydrophilicity and conductivity of the Co-SAM thin film are optimized, the efficiency of trans-wide-band-gap PSCs based on doped HTL and the efficiency of a perovskite-silicon laminated solar cell are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell technology, and in particular to an inverse wide-bandgap perovskite solar cell based on Co-SAM molecular interface modification and its preparation method. Background Technology

[0002] Inverse wide-bandgap perovskite solar cells have become a focus of current research due to their broad application prospects. Perovskite solar cells based on self-assembled monolayers (SAMs) as hole transport layers (HTLs) exhibit excellent performance. However, HTLs prepared based on SAM materials (e.g., 2PACz, Me-4PACz) still face a series of problems that need to be solved. First, these hole transport layers often have low hydrophilicity, which is not conducive to the spreading and wetting of perovskite precursor solutions on their surface. Second, SAM layers usually exhibit poor uniformity, which directly affects the quality of subsequent perovskite film deposition. Finally, the energy level matching between the SAM layer and the perovskite layer also needs further optimization to promote carrier transport and improve efficiency. Due to these problems, severe interfacial losses occur at the SAM-PVK interface after depositing a perovskite film (PVK) on the SAM surface. This interfacial loss greatly limits further improvement in device performance. Therefore, it is urgent to address the shortcomings of HTLs prepared based on SAM materials. Summary of the Invention

[0003] This invention solves the problems existing in the prior art and provides an inverted wide-bandgap perovskite solar cell based on Co-SAM molecular interface modification and its preparation method. This invention introduces TPBr into the SAM precursor solution and then obtains a SAM-based thin film (i.e., HTL of Co-SAM). Due to the optimization of the uniformity, hydrophilicity and conductivity of the Co-SAM thin film, the properties of HTL and PVK themselves and at the HTL / PVK interface are improved, which ultimately leads to a significant enhancement in the performance of inverted PSCs (perovskite solar cells) based on HTL.

[0004] The first objective of this invention is to provide a modified interface material Co-SAM, wherein the modified interface material is prepared by mixing a triphenylphosphine salt (A) with a nitrogen-containing heterocyclic self-assembled SAM molecule (B) dissolved in an alcohol solution, wherein the triphenylphosphine salt (A) is selected from one of (2-aminoethyl)triphenylphosphine bromide (AETPBr), (3-aminopropyl)triphenylphosphine bromide (APTPBr), and (2-hydroxyethyl)triphenylphosphine bromide (HETPBr).

[0005] Nitrogen-containing heterocyclic self-assembled SAM molecules and triphenylphosphine salts were dissolved in alcohol solutions to prepare SAM precursor solutions and TPBr precursor solutions, respectively. The concentrations of both SAM precursor solutions and TPBr precursor solutions were 0.15-1.0 mg / mL.

[0006] Preferably, the alcohol solution is anhydrous ethanol.

[0007] Preferably, the concentrations of the SAM precursor solution and the TPBr precursor solution are the same, both being 0.3-0.8 mg / mL; the volume ratio of the TPBr precursor solution to the SAM precursor solution is 1:9-1:1.

[0008] Further preferably, the volume ratio of the TPBr precursor solution to the SAM precursor solution is 1:4.

[0009] Preferably, the material of the nitrogen-containing heterocyclic self-assembled SAM molecule (B) is selected from one of (2-(9H-carbazole-9-yl)ethyl)phosphonic acid (2PACz), (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid (Me-4PACz) and [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid (4PADCB).

[0010] The modified interface material Co-SAM specifically includes: (2-aminoethyl)triphenylphosphine bromide and (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, (3-aminopropyl)triphenylphosphine bromide and (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, (2-hydroxyethyl)triphenylphosphine bromide and (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, and (2-aminoethyl)triphenylphosphine bromide and (2-(9H-carbazole-9-yl)ethyl)phosphonic acid. Combinations of (3-aminopropyl)triphenylphosphine bromide and (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, (2-hydroxyethyl)triphenylphosphine bromide and (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, (2-aminoethyl)triphenylphosphine bromide and [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid, (3-aminopropyl)triphenylphosphine bromide and [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid, and (2-hydroxyethyl)triphenylphosphine bromide and [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid.

[0011] A second objective of this invention is to provide the application of the modified interface material Co-SAM in the preparation of inverse wide-bandgap perovskite solar cells based on Co-SAM molecular interface modification.

[0012] The third objective of this invention is to provide an inverse wide-bandgap perovskite solar cell based on Co-SAM molecular interface modification, wherein an interface modification layer is prepared using the modified interface modification material Co-SAM, and the interface modification layer is disposed between the hole transport layer and the perovskite thin film.

[0013] This invention incorporates triphenylphosphine salt (TPBr) into a self-assembled material (SAM) precursor solution and co-deposits it onto a hole transport layer. The optimized hole transport layer is more uniform, hydrophilic, and exhibits good conductivity. The quality of the perovskite film deposited on the optimized hole transport material and the properties of the buried interface are improved. This is because, on the one hand, the optimized buried interface improves the nucleation and crystallization process of the perovskite film, resulting in larger film grains and a smoother buried interface. On the other hand, it passivates defects at the buried interface, reducing non-radiative recombination at the interface. Ultimately, this significantly improves the device efficiency of inverted wide-bandgap perovskite solar cells and perovskite-silicon tandem solar cells fabricated based on this doped interface-modified hole transport layer.

[0014] Preferably, the thickness of the interface modification layer is 0.5-1.5 nm. The interface modification layer is a dense self-assembled molecular film, in which molecules form a dense film through π-π stacking and hydrogen bonding.

[0015] Further preferably, the thickness of the interface modification layer is 1 nm.

[0016] This invention also protects the method for preparing the inverse wide-bandgap perovskite solar cell based on Co-SAM molecular interface modification, comprising the following steps:

[0017] S1. Pre-treat the substrate;

[0018] S2. Nickel oxide hole transport layer is prepared by solution method;

[0019] S3. Weigh out nitrogen-containing heterocyclic self-assembled SAM molecules and triphenylphosphine salt TPBr molecules respectively, prepare SAM precursor solution and TPBr precursor solution with anhydrous ethanol respectively, mix the two to prepare Co-SAM solution, deposit the Co-SAM solution on the surface of the nickel oxide hole transport layer obtained in step S2, anneal, and obtain Co-SAM interface modification layer.

[0020] S4. Weigh FAI, CsI, PbI2, PbBr2 and MABr respectively. Use a mixture of DMF and DMSO as a solvent to prepare a perovskite precursor solution. Deposit the perovskite precursor solution onto the surface of the Co-SAM interface modification layer obtained in step S3. Anneal the solution to obtain a perovskite film.

[0021] S5. Spin-coat the interface passivation layer onto the surface of the perovskite thin film obtained in step S4.

[0022] S6. In step S5, an electron transport layer and a blocking layer are sequentially deposited on the surface.

[0023] S7. An electrode layer is then deposited on the surface of the barrier layer obtained in step S6, and finally an inverse wide-bandgap perovskite solar cell based on Co-SAM molecular interface modification is obtained.

[0024] Preferably, the substrate described in step S1 is a transparent conductive substrate Glass / ITO, Glass / FTO, PEN / ITO, or a silicon cell.

[0025] The specific pretreatment steps are as follows: clean the substrate in sequence with cleaning agent, deionized water, ethanol and isopropanol. Then, remove the substrate from the isopropanol solution, dry it with nitrogen gas, and then treat it with ultraviolet ozone equipment.

[0026] Preferably, the concentration of the nickel oxide precursor solution in step S2 is 10 mg / mL.

[0027] Preferably, the thickness of the nickel oxide hole transport layer in step S2 is 8-12 nm, the thickness of the perovskite thin film active layer in step S4 is 450-550 nm, and the thickness of the electron transport layer in step S6 is 35-45 nm.

[0028] Further preferably, the thickness of the nickel oxide hole transport layer in step S2 is 10 nm, the thickness of the perovskite thin film active layer in step S4 is 500 nm, and the thickness of the electron transport layer in step S6 is 40 nm.

[0029] Preferably, the concentrations of the SAM precursor solution and the TPBr precursor solution in step S3 are both 0.15-1.0 mg / mL.

[0030] Further preferably, the concentrations of the SAM precursor solution and the TPBr precursor solution mentioned in step S3 are the same, both being 0.3-0.8 mg / mL.

[0031] Preferably, the volume ratio of the TPBr precursor solution to the SAM precursor solution in step S3 is 1:9 to 1:1.

[0032] Further preferably, the volume ratio of the TPBr precursor solution to the SAM precursor solution in step S3 is 1:4.

[0033] Preferably, the doped Co-SAM precursor solution in step S3 is deposited by spin coating at a speed of 3000-5000 rpm, and then annealed at 100℃-125℃ for 5-20 min to form a uniform interface modification layer.

[0034] Further preferred, the preparation conditions in step S3 are spin coating at a speed of 4000 rpm and annealing at 100°C for 10 minutes.

[0035] Preferably, the band gap of the perovskite film described in step S4 is 1.66-1.72 eV.

[0036] Preferably, in step S4, the perovskite precursor solution is deposited on the surface of the optimized hole transport layer using a one-step spin-coating method with antisolvent addition for nucleation or spin-coating followed by transfer to a vacuum chamber for nucleation. Annealing is then performed at 100℃-110℃ for 15-20 minutes. The molar ratio of CsI, MABr, PbBr2, FAI, and PbI2 is 1:3:6:16:14, the volume ratio of DMF to DMSO is 4:1, and the molar concentration of the perovskite precursor solution is 1.3-1.7 mol / L.

[0037] Preferably, in step S5, an interface passivation layer is spin-coated onto the surface of the perovskite film using a dynamic spin-coating method. The passivation layer is one or more mixed materials selected from PEAI, PEACl, PEABr, PI, GACCl, BAI, EAI, EDAI, and PDAI. The concentration of the passivation layer precursor solution is 0.5-1.5 mg / mL. Since vacancies exist within the perovskite film, and defect sites exist on the surface and at grain boundaries, the passivation layer, when modifying the interface of the perovskite film, can simultaneously act on both the surface and internal surface defects of the film through functional group coordination and intergranular penetration. Furthermore, the passivation layer and the perovskite film surface achieve coherent fusion, effectively reducing the defect density of the film.

[0038] Preferably, in step S6, an electron transport layer is deposited on the surface of the passivation layer, specifically using atomic layer deposition (ALD), vapor deposition, or spin coating. The electron transport layer is one or more mixed materials selected from PCBM ([6,6]-phenyl-C61-butyrate), C60, C70, and SnO2. A barrier layer is deposited on the surface of the electron transport layer, specifically using vapor deposition or spin coating. The barrier layer material is BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline).

[0039] Preferably, in step S7, the electrode layer is deposited by vapor deposition or magnetron sputtering, and the electrode material is selected from one or more of ITO, IZO, ICO, Ag, Au, and Cu.

[0040] Compared with existing technologies, this invention has the following advantages: By introducing TPBr into the SAM precursor solution, a doped SAM thin film (i.e., HTL based on Co-SAM) is obtained. Due to the optimized uniformity, hydrophilicity, and conductivity of the Co-SAM thin film, the properties of HTL and PVK themselves, as well as at the HTL / PVK interface, are improved, while the crystallinity of the perovskite thin film on top is also enhanced. Ultimately, this results in a significant increase in the efficiency of inverse wide-bandgap PSCs and perovskite-silicon tandem solar cells based on doped HTL. Attached Figure Description

[0041] Figure 1 The inverted wide-bandgap solar cells prepared in Example 1 based on Co-SAM thin films and Comparative Example 1 based on SAM thin films were tested using a solar simulator (standard light source) with an illumination intensity of 100 mW / cm². 2 The forward and reverse JV curves are shown below, where J is the photocurrent density and V is the photovoltage.

[0042] Figure 2 The perovskite-silicon tandem solar cells prepared in Example 17 based on Co-SAM thin films and Comparative Example 4 based on SAM thin films were tested using a solar simulator (standard light source) with an illumination intensity of 100 mW / cm². 2 The forward and reverse JV curves are shown below, where J is the photocurrent density and V is the photovoltage. Detailed Implementation

[0043] The following embodiments are further illustrations of the present invention, but not limitations thereof.

[0044] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention. Unless otherwise specified, the experimental materials and reagents used herein are commercially available products conventionally available in this technical field.

[0045] The photoelectric conversion efficiency of a perovskite solar cell refers to the efficiency of its operation under a standard light source (illuminance of 100 mW / cm²). 2 Photoelectric conversion efficiency under the given conditions.

[0046] Example 1

[0047] The fabrication method of Glass / ITO / NiOx / Co-SAM / PVK / PEAI / PCBM / BCP / Ag perovskite solar cells includes the following steps:

[0048] S1. Based on the ultrasonic cleaning process, ITO substrate is cleaned in sequence with ITO cleaning agent, deionized water, ethanol and isopropanol. Then, ITO is removed from the isopropanol solution, dried with nitrogen, treated with ultraviolet ozone equipment for 15 minutes and set aside for later use.

[0049] S2. Prepare a NiOx solution with a concentration of 10 mg / mL (the solvent is deionized water), and then spin-coat the NiOx solution onto the above transparent conductive substrate. The spin-coating parameters are 2000 rpm for 30 seconds. Then transfer it to a hot stage at 150 ℃ for annealing for 10 minutes to obtain a nickel oxide hole transport layer with a thickness of 10 nm.

[0050] S3. Weigh (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid (Me-4PACz) and (2-aminoethyl)triphenylphosphine bromide (AETPBr) materials. Prepare 0.3 mg / mL SAM precursor solution and 0.3 mg / mL TPBr precursor solution with anhydrous ethanol, respectively. Then mix the two solutions at a volume ratio of 4:1 to obtain the doped Co-SAM precursor solution. Spin-coat the Co-SAM precursor solution onto the surface of a nickel oxide film at 4000 rpm for 30 seconds. Then transfer it to a hot plate at 100℃ and anneal for 10 minutes to obtain the (2-aminoethyl)triphenylphosphine bromide doped Co-SAM interface modification layer with a thickness of 1 nm.

[0051] S4. Weigh 33.8 mg CsI, 43.6 mg MABr, 286.8 mg PbBr2, 57.8 mg FAI, and 839 mg PbI2. Dissolve them in 1600 μL of DMF and 400 μL of DMSO solvent, and stir for 12 hours to obtain a perovskite precursor solution. Then, drop 60 μL of the perovskite precursor solution onto the surface of the interface modification layer. Spin-coat the perovskite at 1000 rpm for 8 seconds in the first step and 5000 rpm for 30 seconds in the second step. Add ethyl acetate as a reverse solvent dropwise in the 8th second before the end of the second spin-coating process. Transfer the light brown perovskite film to a hot plate at 100 °C for annealing for 15 min to obtain the perovskite film (CsI). 0.05 FA 0.8 MA 0.15 PbI 2.25 Br 0.75 The thickness of the wide-bandgap perovskite thin film is 500 nm.

[0052] S5. Prepare a PEAI solution with a concentration of 1 mg / mL (solvent is IPA) and spin-coat it onto the surface of the perovskite film. That is, first turn on the substrate spin and then drop 80 μL of PEAI solution. The spin-coating parameters are 4000 rpm for 30 seconds, and then transfer it to a 100℃ hot stage for annealing for 5 minutes to obtain the interface passivation layer.

[0053] S6. Prepare a 20 mg / mL PCBM solution (chlorobenzene as solvent) and a 0.5 mg / mL BCP solution (IPA as solvent), and spin-coat them sequentially onto the surface of the interface-modified perovskite film. The spin-coating parameters are 4000 rpm for 30 seconds to obtain an electron transport layer and a barrier layer, respectively. The thickness of the electron transport layer is 40 nm and the thickness of the barrier layer is 8 nm.

[0054] S7. A 100 nm Ag electrode was deposited by vapor deposition to obtain the electrode layer, and finally a trans-wide bandgap perovskite solar cell with optimized buried interface based on the self-assembled molecular layer doped with (2-aminoethyl)triphenylphosphine bromide was obtained.

[0055] The wide-bandgap perovskite solar cell based on Co-SAM molecular interface modification, prepared by the above method, achieved an optimal power conversion efficiency of 23.1%. Figure 1 As shown.

[0056] Example 2

[0057] Similar to Example 1, except that the concentrations of Me-4PACz and AETPBr in the Co-SAM precursor solution were both reduced to 0.15 mg / mL. The perovskite solar cell based on this Co-SAM hole transport layer achieved an efficiency of 21.8%.

[0058] Example 3

[0059] Similar to Example 1, except that the concentrations of Me-4PACz and AETPBr in the Co-SAM precursor solution were increased to 0.8 mg / mL. The perovskite solar cell based on this Co-SAM hole transport layer achieved an efficiency of 22.3%.

[0060] Example 4

[0061] Similar to Example 1, except that the volume ratio of Me-4PACz to AETPBr in the Co-SAM precursor solution is 1:1. The perovskite solar cell based on this Co-SAM hole transport layer achieves an efficiency of 22.1%.

[0062] Example 5

[0063] Similar to Example 1, except that the mixing ratio of Me-4PACz and AETPBr in the Co-SAM precursor solution is 9:1. The perovskite solar cell based on this Co-SAM hole transport layer achieves an efficiency of 22.4%.

[0064] Example 6

[0065] Similar to Example 1, except that the SAM material in the Co-SAM precursor solution is 2PACz. The perovskite solar cell based on this Co-SAM hole transport layer achieves an efficiency of 21.8%.

[0066] Example 7

[0067] Similar to Example 1, except that the SAM material in the Co-SAM precursor solution is 4PADCB. The perovskite solar cell based on this Co-SAM hole transport layer achieves an efficiency of 22.2%.

[0068] Example 8

[0069] Similar to Example 1, except that the TPBr material in the Co-SAM precursor solution is (3-aminopropyl)triphenylphosphine bromide. Based on this Co-SAM hole transport layer, the perovskite solar cell efficiency is 22.5%.

[0070] Example 9

[0071] Similar to Example 1, except that the TPBr material in the Co-SAM precursor solution is (2-hydroxyethyl)triphenylphosphine bromide. Based on this Co-SAM hole transport layer, the perovskite solar cell efficiency is 22.7%.

[0072] Example 10

[0073] Similar to Example 1, except that the annealing temperature of the Co-SAM thin film is 110°C. Based on this Co-SAM hole transport layer, the perovskite solar cell efficiency is 22.9%.

[0074] Example 11

[0075] Similar to Example 1, except that the annealing temperature of the Co-SAM thin film is 125°C. Based on this Co-SAM hole transport layer, the perovskite solar cell efficiency is 22.6%.

[0076] Example 12

[0077] Similar to Example 1, except that the Co-SAM thin film annealing time was 5 minutes. Based on this Co-SAM hole transport layer, the perovskite solar cell efficiency was 22.1%.

[0078] Example 13

[0079] Similar to Example 1, except that the Co-SAM thin film annealing time was 15 minutes. Based on this Co-SAM hole transport layer, the perovskite solar cell achieved an efficiency of 22.7%.

[0080] Example 14

[0081] Similar to Example 1, except that the Co-SAM thin film annealing time was 20 minutes. Based on this Co-SAM hole transport layer, the perovskite solar cell achieved an efficiency of 22.5%.

[0082] Example 15

[0083] Same as Example 1, except that: the perovskite film composition FA 0.8 Cs 0.2 Pb(I 0.75 Br 0.25 3. The efficiency of perovskite solar cells based on this composition is 22.3%.

[0084] Example 16

[0085] Same as Example 1, except that: the perovskite film component Cs 0.1 FA 0.65 MA 0.25 Pb(I 0.8 Br 0.2 3. The efficiency of perovskite solar cells based on this composition is 22.9%.

[0086] Comparative Example 1

[0087] Similar to Example 1, except that only Me-4PACz was used as the interface modification layer material. Based on this, the efficiency of the HTL perovskite solar cell is 21.5%.

[0088] Comparative Example 2

[0089] Same as Example 1, except that: only Me-4PACz is used as the interface modification layer material, and the perovskite film composition is FA. 0.8 Cs 0.2 Pb(I 0.75 Br 0.25 3. The efficiency of this HTL perovskite solar cell is 20.8%.

[0090] Comparative Example 3

[0091] Same as Example 1, except that: only Me-4PACz is used as the interface modification layer material, and the perovskite film component is Cs. 0.1 FA 0.65 MA 0.25 Pb(I0.8 Br 0.2 3. The efficiency of this HTL perovskite solar cell is 21.2%.

[0092] Example 17

[0093] The fabrication method of Ag / ITO / n-Si / ITO / NiOx / Co-SAM / PVK / GACl+PI / C60 / SnO2 / ITO / Ag perovskite solar cells includes the following steps:

[0094] S1. After ultrasonic cleaning of the silicon cell substrate with sputtered top and bottom ITO, the bottom cell is removed from the ethanol solution, dried with nitrogen, treated with ultraviolet ozone equipment for 5 minutes, and set aside for later use.

[0095] S2. Prepare a NiOx solution with a concentration of 10 mg / mL (the solvent is deionized water), and then spin-coat the NiOx solution onto the above transparent conductive substrate. The spin-coating parameters are 4000 rpm for 30 seconds. Transfer it to a hot stage at 135°C and anneal for 10 minutes to obtain a nickel oxide hole transport layer.

[0096] S3. Weigh (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid and (2-aminoethyl)triphenylphosphine bromide material. Prepare a Me-4PACz precursor solution and an AETPBr precursor solution with a concentration of 0.8 mg / mL using anhydrous ethanol. Then, mix the two solutions at a volume ratio of 4:1 to form a Co-SAM precursor solution. Spin-coat the solution onto the surface of a nickel oxide film at 3000 rpm for 30 seconds. Transfer the solution to a hot plate at 125°C and anneal for 10 minutes to obtain the Co-SAM optimized interface modification layer.

[0097] S4. Weigh 44.2 mg CsI, 57.0 mg MABr, 375.1 mg PbBr2, 467.9 mg FAI, and 1097.2 mg PbI2. Dissolve them in 1600 μL of DMF and 400 μL of DMSO. Stir for 12 hours to obtain a perovskite precursor solution. Then, drop 60 μL of the perovskite precursor solution onto the surface of the interface modification layer. Spin-coat the perovskite at 1000 rpm for 5 seconds in the first step and 3000 rpm for 10 seconds in the second step. Transfer the film to a vacuum chamber and anneal at 0.12 Torr for 20 seconds and 1.6 Torr for 15 seconds. After returning to atmospheric pressure, transfer the film to a hot plate at 110 °C for annealing for 20 min to obtain a perovskite film.

[0098] S5. Prepare a mixed solution of GACl and PI with a concentration of 0.8 mg / mL and 0.2 mg / mL (IPA as solvent) and spin-coat it onto the surface of the perovskite film. The spin-coating parameters are 5000 rpm for 30 seconds. Then transfer it to a hot stage at 100℃ for annealing for 5 minutes to obtain the interface passivation layer.

[0099] S6. A 15 nm C60 electron transport layer is deposited by vapor deposition, and then transferred to an ALD device to deposit an 8 nm SnO2 layer to obtain an electron transport layer and a barrier layer, respectively.

[0100] S7. 60 nm ITO is deposited on top by magnetron sputtering, followed by evaporation deposition of 1 μm Ag grid line electrodes, finally obtaining a perovskite-silicon tandem solar cell based on Co-SAM optimized buried interface.

[0101] The perovskite-silicon tandem solar cell based on Co-SAM molecular interface modification, prepared by the above method, achieved an optimal power conversion efficiency of 32.1%. Figure 2 As shown.

[0102] Comparative Example 4

[0103] Similar to Example 17, except that in step S3, only Me-4PACz is deposited on the surface of the nickel oxide thin film to form a SAM-based hole transport layer. The efficiency of this HTL perovskite silicon tandem solar cell is 31.2%.

[0104] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A modified interface modification material Co-SAM, characterized in that, The modified interface modification material is prepared by mixing a triphenyl phosphonium salt and a nitrogen-containing heterocyclic self-assembled SAM molecule dissolved in an alcohol solution, and the triphenyl phosphonium salt is selected from one of (2-aminoethyl)triphenylphosphonium bromide, (3-aminopropyl)triphenylphosphonium bromide and (2-hydroxyethyl)triphenylphosphonium bromide.

2. The modified interface modification material Co-SAM according to claim 1, characterized in that, The material of the nitrogen-containing heterocyclic self-assembled SAM molecule is selected from one of (2-(9H-carbazol-9-yl)ethyl)phosphonic acid, (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid and [4-(7H-dibenzo carbazole-7-yl)butyl]phosphonic acid.

3. Use of the modified interface modification material Co-SAM in the preparation of a trans wide-bandgap perovskite solar cell based on Co-SAM molecule interface modification.

4. A trans-wide band gap perovskite solar cell based on Co-SAM molecular interface modification, characterized in that, An interface modification layer is prepared by using the modified interface modification material Co-SAM of claim 1 or 2, and the interface modification layer is arranged between a hole transport layer and a perovskite film.

5. The transverse bandgap perovskite solar cell according to claim 4, characterized in that, The thickness of the interface modification layer is 0.5-1.5 nm.

6. The method for preparing a Co-SAM molecular interface modified trans-wide bandgap perovskite solar cell according to claim 4 or 5, characterized in that, The method comprises the following steps: S1, pretreating a substrate; S2, preparing a nickel oxide hole transport layer by a solution method; S3, respectively weighing a nitrogen-containing heterocyclic self-assembled SAM molecule and a triphenyl phosphonium salt TPBr molecule material, preparing a SAM precursor solution and a TPBr precursor solution by using anhydrous ethanol, mixing the two to prepare a Co-SAM solution, depositing the Co-SAM solution on the surface of the nickel oxide hole transport layer obtained in step S2, and annealing to obtain a Co-SAM interface modification layer; S4, respectively weighing FAI, CsI, PbI2, PbBr2 and MABr, using a mixture of DMF and DMSO as a solvent to prepare a perovskite precursor solution, depositing the perovskite precursor solution on the surface of the Co-SAM interface modification layer obtained in step S3, and annealing to obtain a perovskite film; S5, spin-coating an interface passivation layer on the surface of the perovskite film obtained in step S4; S6, sequentially depositing an electron transport layer and a blocking layer on the surface of step S5; S7, depositing an electrode layer on the surface of the blocking layer obtained in step S6 to finally obtain a trans wide-bandgap perovskite solar cell based on Co-SAM molecule interface modification.

7. The preparation method according to claim 6, characterized in that, The concentrations of the SAM precursor solution and the TPBr precursor solution in step S3 are both 0.15-1.0 mg / mL.

8. The production method according to claim 6 or 7, characterized by, The volume ratio of the TPBr precursor solution to the SAM precursor solution in step S3 is 1:9-1:

1.

9. The production method according to claim 6 or 7, characterized by, The annealing conditions in step S3 are as follows: an annealing temperature of 100-125℃ and an annealing time of 5-20 minutes.

10. The production method according to claim 6 or 7, characterized by, The band gap of the perovskite film in step S4 is 1.66-1.72 eV.

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