NiS QDs modified silicon-based perovskite solar cell and preparation method thereof

Abstract

The invention provides a NiS QDs modified silicon-based perovskite solar cell. The NiS QDs modified silicon-based perovskite solar cell comprises a top electrode, an electron transport layer, a NiS QDs layer, a perovskite layer, a first transition layer, a hole transport layer, a second transition layer, a Si substrate and a back electrode from top to bottom. Perovskite is used as a top cell, and NiS QDs are introduced to the surface of a perovskite film; the silicon-based perovskite solar cell is modified through NiS QDs, so that the light current density is increased, the conversion efficiency is greatly improved, and the device performance is improved. The preparation process is simple and can be implemented, extremely high conversion efficiency is achieved, meanwhile, the manufacturing cost is greatly reduced, the method can be applied to industrial preparation, and a thought is provided for large-scale production.

Description

Technical Field

[0001] The present application belongs to the technical field of solar cells, and in particular relates to a NiS QDs-modified silicon-based perovskite solar cell and a preparation method thereof. Background Art

[0002] In recent years, with the continuous development of photovoltaic technology, perovskite materials have gradually become a research hotspot in the field of solar cells due to their tunable band gap and high absorption coefficient, demonstrating excellent optoelectronic properties. Their low cost and ease of preparation have made them a research hotspot. Since their first application in solar cells in 2009, the efficiency of perovskite solar cells has rapidly increased from an initial 3% to nearly 25%, making them a representative example of the third generation of solar cells.

[0003] However, single-junction perovskite cells are limited by the Shockley-Queisser (SQ) limit, and their photoelectric conversion efficiency has reached a bottleneck. In order to further improve the conversion efficiency, researchers have begun to explore combining materials with different band gaps through multi-junction stacked structures to absorb a wider spectrum and break through the efficiency limit of single-junction cells. In particular, silicon-based perovskite stacked cells have become an important development direction for silicon-based cells. They stack perovskite cells with silicon-based cells to form an efficient multi-junction structure. Currently, the efficiency of silicon-based perovskite stacked cells has exceeded 34.6% and is expected to reach a higher theoretical limit.

[0004] In addition to improving efficiency, key future research directions include long-term stability, simplified manufacturing processes, and cost reduction for silicon-based perovskite tandem cells. While the combination of silicon and perovskite improves spectral absorption efficiency, it also faces challenges such as interface defects and light stability. Furthermore, the compatibility of perovskite and silicon-based cell fabrication processes—particularly the potential for damage to crystalline silicon-based cells during perovskite deposition—is a bottleneck in current technological development.

[0005] Therefore, how to optimize the band gap, thickness and interface design of the perovskite absorption layer, solve the stability problem of perovskite materials, and ensure the long-term stable operation of the battery will be the focus of future research in this field. Summary of the Invention

[0006] The present invention provides a NiS QDs-modified silicon-based perovskite solar cell and a preparation method thereof to solve the problems existing in the related art. The technical solution is as follows:

[0007] In a first aspect, an embodiment of the present application provides a NiS QDs-modified silicon-based perovskite solar cell, comprising a top electrode, an electron transport layer, a NiS QDs layer, a perovskite layer, a first transition layer, a hole transport layer, a second transition layer, a Si substrate, and a back electrode from top to bottom.

[0008] In one embodiment, the top electrode is Au; the electron transport layer is SnO2; the back electrode is Al; the first transition layer is CoO x ; The second transition layer is ZrO2; the hole transport layer is PTCBI.

[0009] In one embodiment, the back electrode has a thickness of 100-200 nm; the Si substrate is single crystal silicon with a thickness of 90-200 μm; the second transition layer has a thickness of 10-80 nm; the hole transport layer has a thickness of 20-100 nm; the first transition layer has a thickness of 10-60 nm; the electron transport layer has a thickness of 10-50 nm; and the top electrode has a thickness of 30-150 nm.

[0010] In one embodiment, the perovskite layer is a CsPbI3 thin film; the thickness is 100-400 nm; the roughness is less than 50 nm; and the band gap width ranges from 1.2 eV to 2.5 eV.

[0011] In one embodiment, the preparation method of the CsPbI3 thin film is:

[0012] DMAPbI3 and CsI are dissolved in DMF to prepare a precursor solution, which is then stirred evenly and preheated to 60°C to 80°C for spin coating; then dried; and then heated at 100°C to 200°C to obtain a perovskite layer film.

[0013] In one embodiment, the NiS QDs in the NiS QDs layer are prepared by a high-temperature reaction of sodium sulfide and nickel chloride or its hydrate; and the particle size of the NiS QDs is 5-20 nm.

[0014] In one embodiment, sodium sulfide and nickel chloride or its hydrate are mixed in a certain proportion, stirred evenly, and then transferred to a high-temperature furnace for high-temperature reaction. After the reaction is completed, the NiS QDs are obtained. The high-temperature reaction conditions are: temperature 100-300°C, reaction time 60-180min.

[0015] In a second aspect, the present invention provides a method for preparing a silicon-based perovskite solar cell modified with NiS QDs, comprising the following steps:

[0016] A back electrode is deposited on the back of a Si substrate; a second transition layer, a hole transport layer, a first transition layer, a perovskite film, a NiS QDs layer, and an electron transport layer are sequentially deposited on the front; and a top electrode is prepared on the electron transport layer; thus, the NiS QDs-modified silicon-based perovskite solar cell is obtained.

[0017] In one embodiment, the top electrode is Au; the electron transport layer is SnO2; the back electrode is Al; the first transition layer is CoO x The second transition layer is ZrO2; the hole transport layer is PTCBI; the perovskite layer is a CsPbI3 thin film;

[0018] The Al back electrode and Au top electrode were deposited by vacuum evaporation.

[0019] ZrO2 layer, PTCBI layer, CoO x The layer, perovskite film, NiS QDs layer, and SnO2 layer were deposited by spin coating.

[0020] In one embodiment, the ZrO2 layer is spin-coated using a ZrO2 precursor solution and then annealed at 300-500°C to deposit the ZrO2 layer;

[0021] CoO x CoO layer x The precursor solution was spin-coated and then annealed at 100-200 ° C to deposit CoO x layer;

[0022] The SnO2 layer is spin-coated using a SnO2 precursor solution and then annealed at 300-500° C. to deposit the SnO2 layer.

[0023] The advantages or beneficial effects of the above technical solution include at least:

[0024] The NiS QDs-modified silicon-based perovskite solar cell of the present application uses perovskite as the top cell and introduces NiS QDs on the surface of the perovskite film. By modifying the silicon-based perovskite solar cell with NiS QDs, the surface state of the perovskite is effectively passivated, non-radiative recombination is reduced, thereby increasing the photocurrent density and greatly improving the conversion efficiency. The energy band structure of the perovskite film is improved, the absorption spectrum range of the solar cell is broadened, and the photoelectric conversion efficiency under weak light conditions is enhanced.

[0025] It also optimizes the energy band matching between the perovskite layer and the electron transport layer, reduces interface defects and carrier recombination, and improves device performance. It also enhances the stability of the device in harsh environments such as high temperature and high humidity, extending its service life. It comprehensively improves the optoelectronic performance and stability of perovskite solar cells, enhancing the overall performance of the device.

[0026] The preparation method of the NiS QDs-modified silicon-based perovskite solar cell of the present application has a simple and feasible preparation process, which significantly reduces the manufacturing cost while achieving extremely high conversion efficiency. It can be applied to industrial preparation and provides a solution for large-scale production.

[0027] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0029] Figure 1 Schematic diagram of the structure of the silicon-based perovskite solar cell modified with NiS QDs in this application;

[0030] Figure 2 The current-voltage relationship diagram of the silicon-based perovskite solar cell modified with NiS QDs in Example 1, where the test conditions are a sunlight simulation test system and the effective area is 0.64 cm 2 , the radiation power under AM 1.5G conditions is 100mWcm -2 , using standard Si solar cells as calibration;

[0031] Figure 3 This is a structural comparison diagram of a comparative example silicon-based perovskite solar cell and a silicon-based solar cell modified with NiS QDs in this application;

[0032] Figure 4 The current-voltage relationship comparison diagram of the silicon-based perovskite solar cell in comparative example 1 and the silicon-based solar cell modified with NiS QDs in example 1 of the present application is shown in FIG. 1 , wherein the test conditions are a sunlight simulation test system with an effective area of ​​0.64 cm2 and a radiation power of 100 mW cm2 under AM 1.5G conditions. -2 , using standard Si solar cells as calibration;

[0033] Figure 5 The stability comparison chart of the silicon-based perovskite solar cell in comparative example 1 and the silicon-based solar cell modified with NiS QDs in example 1 of the present application is shown in FIG. 1 , wherein the test conditions are a sunlight simulation test system with AM 1.5G (100mW cm -2 ) conditions to record the corresponding photocurrent It curve; the test device should be stored in a dry and sealed environment to avoid the influence of surface dust and air humidity; the test environment is: room temperature 25-28℃, humidity 40-60%. DETAILED DESCRIPTION

[0034] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0035] Silicon-based perovskites are unstable in space and do not fully utilize sunlight. However, silicon-based perovskite tandem solar cells, with their theoretical efficiency, low cost, and good photoelectric performance, have shown great application potential and are expected to become an important technological path to improve the overall performance of the photovoltaic industry in the future. Therefore, this application provides a silicon-based perovskite solar cell modified with NiS QDs and a preparation method thereof.

[0036] The present application provides a NiS QDs-modified silicon-based perovskite solar cell, comprising a top electrode, an electron transport layer, a NiS QDs layer, a perovskite layer, a first transition layer, a hole transport layer, a second transition layer, a Si substrate, and a back electrode from top to bottom.

[0037] By introducing NiS QDs on perovskite, not only can the absorption spectrum range of silicon-based perovskite stacked cells be broadened and the dissociation and transmission of photogenerated carriers be promoted, but also the radiation resistance of silicon-based perovskite cells can be effectively improved, greatly improving the photoelectric performance of solar cells in space.

[0038] NiS QDs have a wide light absorption range and can effectively absorb the spectrum in the near-infrared (NIR) region, enhancing photoelectric conversion efficiency under low-light conditions. They also maintain good stability in complex environments and exhibit excellent photoelectrocatalytic properties. NiS QDs can modify the band structure of perovskite films, enabling the material to absorb photons below the band gap, further expanding the absorption range. NiS QDs also have good environmental and thermal stability. Introducing NiS QDs into perovskite solar cells can improve the device's stability in harsh environments such as high temperature and high humidity, extending its service life.

[0039] In one embodiment, the top electrode is Au, the electron transport layer is SnO2, the back electrode is Al, and the first transition layer is CoO x ; The second transition layer is ZrO2; the hole transport layer is PTCBI.

[0040] As one embodiment, the back electrode has a thickness of 100-200nm; the Si substrate is single crystal silicon with a thickness of 90-200μm; the second transition layer has a thickness of 10-80nm; the hole transport layer has a thickness of 20-100nm; the first transition layer has a thickness of 10-60nm; the electron transport layer has a thickness of 10-50nm; and the top electrode has a thickness of 30-150nm.

[0041] In one embodiment, the perovskite layer is a CsPbI3 thin film with a thickness of 100-400 nm. In one embodiment, the roughness of the CsPbI3 thin film is less than 50 nm. In one embodiment, the band gap of the CsPbI3 thin film is in the range of 1.2 eV to 2.5 eV.

[0042] As one embodiment, the preparation method of the CsPbI3 thin film is:

[0043] Dissolve DMAPbI3 and CsI in DMF to prepare a precursor solution, stir evenly, preheat to 60℃-80℃ for spin coating, then dry, and heat at 100℃-200℃ to obtain a perovskite film.

[0044] In one embodiment, the precursor solution has a concentration of 0.5M-1.5M; the precursor solution is stirred at 60°C-80°C for 3-5 hours. In another embodiment, the spin coating speed is 2000-4000 rpm for 20-50 seconds. In another embodiment, the precursor solution is dried at 50-100°C for 5-10 minutes and then heated at 100°C-200°C for 5-20 minutes.

[0045] In one embodiment, DMAPbI3 and CsI are dissolved in DMF to prepare a 0.5M-1.5M precursor solution. The solution is stirred at 60°C-80°C for 3-5 hours, preheated to 60°C-80°C, and spin-coated at a speed of 2000-4000 rpm for 20-50 seconds. The solution is then dried at 50-100°C for 5-10 minutes and then heated at 100°C-200°C for 5-20 minutes to obtain a perovskite film.

[0046] As one embodiment, the NiS QDs in the NiS QDs layer are prepared by a high-temperature reaction of sodium sulfide and nickel chloride or its hydrate.

[0047] As one embodiment, the particle size of the NiS QDs is 5-20 nm.

[0048] In one embodiment, sodium sulfide and nickel chloride or its hydrate are mixed in a molar ratio of 1:1-1.2:1, stirred evenly, and then transferred to a high-temperature furnace for a high-temperature reaction. The NiS QDs are obtained after the reaction is completed. In this embodiment, the high-temperature reaction conditions are: a temperature of 100-300°C and a reaction time of 60-180 minutes.

[0049] As one embodiment, the method further includes a post-processing step of crushing and sieving the NiS QDs prepared by the reaction.

[0050] The present application also provides a method for preparing a NiS QDs-modified silicon-based perovskite solar cell, comprising the following steps:

[0051] A back electrode is deposited on the back of a Si substrate; a second transition layer, a hole transport layer, a first transition layer, a perovskite film, a NiS QDs layer, and an electron transport layer are sequentially deposited on the front; and a top electrode is prepared on the electron transport layer; thus, the NiS QDs-modified silicon-based perovskite solar cell is obtained.

[0052] As one embodiment, the top electrode is Au; the electron transport layer is SnO2; the back electrode is Al; the first transition layer is CoO x The second transition layer is ZrO2; the hole transport layer is PTCBI; the perovskite layer is a CsPbI3 thin film;

[0053] The Al back electrode and Au top electrode were deposited by vacuum evaporation.

[0054] ZrO2 layer, PTCBI layer, CoO x The layer, perovskite film, NiS QDs layer, and SnO2 layer were deposited by spin coating.

[0055] As one embodiment, the back electrode is Al; after preheating the Si substrate to 100-200°C, a vacuum evaporation method is used to deposit an Al film on the back of the silicon wafer, and then the film is cooled to room temperature in the furnace. In this embodiment, the vacuum evaporation system has a vacuum pressure range of 10 -3 -10 -4 Pa, the evaporation rate is 0.1-1 nm / s, and the deposition time is 100-600 s.

[0056] In one embodiment, the second transition layer is ZrO2, which is deposited on the front surface of the Si substrate by spin coating. In this embodiment, a ZrO2 precursor solution is spin-coated on the front surface of the Si substrate by spin coating, and then annealed.

[0057] In one embodiment, the ZrO2 precursor solution is a Zr(OAc) aqueous solution; the concentration of the ZrO2 precursor solution is 0.5-2.0 mol / L; the spin coating conditions are: a rotation speed of 1000-3000 rpm; and the annealing conditions are: a temperature of 300-500°C and an annealing time of 10-20 minutes. In this embodiment, the thickness of the ZrO2 transition layer is 10-80 nm.

[0058] In one embodiment, the hole transport layer is PTCBI, and the PTCBI thin film is deposited on the second transition layer by spin coating. In this embodiment, the PTCBI thin film is deposited on the second transition layer by spin coating and then dried in an oven.

[0059] In one embodiment, the spin coating conditions are: a rotation speed of 2000-4000 rpm; a PTCBI solution concentration of 5 mg / mL-25 mg / mL. In this embodiment, the drying conditions are: a temperature of 70-120°C for 10-30 minutes. In this embodiment, the thickness of the PTCBI hole transport layer is 10-100 nm.

[0060] As one embodiment, the first transition layer is CoO x CoO was deposited on the hole transport layer by spin coating. x In this embodiment, CoO is spin-coated on the hole transport layer by a spin coating method. x of the precursor solution, and then annealing treatment is performed.

[0061] As one embodiment, the CoO x The precursor solution is Co(OAc) aqueous solution; CoO x The concentration of the precursor solution is 0.05-2.0 mol / L; the spin coating condition is: the rotation speed is 3000-4000 r / min; the annealing condition is: the temperature is 100-200 ° C, and the annealing time is 10-20 min. In this embodiment, CoO x The thickness of the transition layer is 10-60 nm.

[0062] In one embodiment, the perovskite layer is a CsPbI3 thin film with a thickness of 100-400 nm. In one embodiment, the roughness of the CsPbI3 thin film is less than 50 nm. In one embodiment, the band gap of the CsPbI3 thin film is in the range of 1.2 eV to 2.5 eV.

[0063] As one embodiment, the preparation method of the CsPbI3 thin film is:

[0064] DMAPbI3 and CsI are dissolved in DMF to prepare a precursor solution, which is stirred evenly and then preheated to 60-80°C for spin coating onto the first transition layer; then dried; and then heated at 100-200°C to obtain a perovskite layer film.

[0065] In one embodiment, the precursor solution has a concentration of 0.5M-1.5M; the precursor solution is stirred at 60°C-80°C for 3-5 hours. In another embodiment, the spin coating speed is 2000-4000 rpm for 20-50 seconds. In another embodiment, the precursor solution is dried at 50-100°C for 5-10 minutes, followed by heating at 100°C-200°C for 5-20 minutes.

[0066] In one embodiment, DMAPbI3 and CsI are dissolved in DMF to prepare a 0.5M-1.5M precursor solution. The solution is stirred at 60°C-80°C for 3-5 hours, preheated to 60°C-80°C, and spin-coated onto the first transition layer at a speed of 2000-4000 rpm for 20-50 seconds. The solution is then dried at 50-100°C for 5-10 minutes and then heated at 100°C-200°C for 5-20 minutes to obtain a perovskite film.

[0067] As one embodiment, the NiS QDs layer is prepared by a high-temperature reaction of sodium sulfide and nickel chloride or its hydrate, and is spin-coated onto the perovskite layer, followed by annealing.

[0068] As one embodiment, the particle size of the NiS QDs is 5-20 nm.

[0069] In one embodiment, sodium sulfide and nickel chloride or its hydrate are mixed in a molar ratio of 1:1-1.2:1, stirred evenly, and then transferred to a high-temperature furnace for a high-temperature reaction. The NiS QDs are obtained after the reaction is completed. In this embodiment, the high-temperature reaction conditions are: a temperature of 100-300°C and a reaction time of 60-180 minutes.

[0070] As one embodiment, the method further includes a post-processing step of crushing and sieving the NiS QDs prepared by the reaction.

[0071] In one embodiment, the NiS QDs are spin-coated onto the perovskite layer and then annealed. In this embodiment, the NiS QD solution has a concentration of 0.5-2.5 mg / mL, a volume of 25-45 μL, and a spin-coating speed of 1000-1500 rpm. Annealing conditions include an annealing temperature of 90-120°C and an annealing time of 20-30 minutes.

[0072] In one embodiment, the electron transport layer is SnO2, which is deposited on the NiS QDs layer by spin coating. In this embodiment, a SnO2 precursor solution is spin coated on the hole transport layer by spin coating, and then annealed.

[0073] In one embodiment, the SnO2 precursor solution is a SnCl aqueous solution; the concentration of the SnO2 precursor solution is 1.0-2.0 mol / L; the spin coating conditions are: a rotation speed of 1000-3000 rpm; and the annealing conditions are: a temperature of 300-500°C and an annealing time of 10-20 minutes. In this embodiment, the thickness of the SnO2 transition layer is 10-50 nm.

[0074] In one embodiment, the top electrode is Au; after preheating to 100-200°C, the Au electrode is deposited on the electron transport layer by vacuum evaporation, and then cooled to room temperature in the furnace. In this embodiment, the vacuum evaporation system has a vacuum pressure range of 10 -3 -10 -5 Pa, the evaporation rate is 0.1-1 nm / s, and the deposition time is 100-500 s.

[0075] The following is a further description with reference to specific embodiments.

[0076] Example 1

[0077] A NiS QDs-modified silicon-based perovskite solar cell and a preparation method thereof, wherein the preparation process is as follows:

[0078] Al back electrode was deposited on the back of the silicon wafer by vacuum evaporation. After preheating the silicon substrate to 150°C, it was placed in a vacuum evaporation system and the vacuum pressure was 10 -4 Pa, evaporation rate of 0.3 nm / s, deposition time of 500 s, and cooling to room temperature in the furnace;

[0079] A transition layer is constructed by depositing a ZrO2 thin film on the front side of the silicon wafer by spin coating, and then annealing the thin film. The spin coating conditions are: a rotation speed of 2000 r / min; a concentration of the Zr(OAc) solution of 1 mol / L; the annealing conditions are: a temperature of 350°C and an annealing time of 20 minutes; and the thickness of the ZrO2 transition layer is 10-80 nm.

[0080] To construct a hole transport layer, a PTCBI thin film was deposited on the ZrO2 transition layer using spin coating, and then dried in an oven. The spin coating conditions were: a rotation speed of 3000 r / min; a PTCBI solution concentration of 15 mg / mL; and drying conditions: a temperature of 120°C and a drying time of 25 minutes. The PTCBI layer had a thickness of 10-100 nm.

[0081] Construct a transition layer and deposit CoO on the PTCBI layer by spin coating x The film was then annealed, wherein the spin coating conditions were: rotation speed of 3000 r / min; concentration of Co(OAc) solution of 0.1 mol / L; annealing conditions of 200 ° C, annealing time of 20 min; CoO x The thickness of the layer is 10-60 nm;

[0082] The spin coating method was used to coat CoO x The pre-synthesized DMAPbI3 and CsI were dissolved in DMF to prepare a 1.5 mol / L precursor solution, and stirred at 70°C for 3-5 hours before use; the solution preheated to 80°C was then spin-coated onto a CoO layer preheated to 80°C. x The layer was heated at a speed of 2000 r / min for 50 seconds, and then dried at a temperature of 100°C for 10 minutes. Subsequently, the layer was heated at 100°C for 15 minutes to obtain a perovskite layer with a thickness of 100-400 nm.

[0083] Sodium sulfide and nickel chloride hexahydrate were mixed at a molar ratio of 1:1, stirred evenly, and then transferred to a high-temperature furnace to obtain a NiS QD solution. The synthesis conditions were as follows: temperature adjusted to 400°C, reaction time 100 minutes. NiS QDs were loaded onto the perovskite layer by spin coating, and then annealed. The spin coating conditions were as follows: spin speed of 1500 r / min; NiS QD solution concentration of 0.5 mg / mL; NiS QD solution volume of 25 μL; annealing conditions: annealing temperature of 110°C, annealing time of 25 minutes.

[0084] To construct an electron transport layer, a SnO2 film was deposited on the NiS QDs layer using spin coating, followed by annealing. The spin coating conditions were: a rotation speed of 2000 r / min; a SnCl solution concentration of 1 mol / L; and annealing conditions: a temperature range of 200°C and an annealing time of 15 minutes. The SnO2 film thickness was 10-50 nm.

[0085] The Au electrode was prepared on SnO2 by vacuum evaporation method. It was preheated to 200℃ and then placed in vacuum evaporation system with vacuum pressure of 10 -5 Pa, evaporation rate of 0.1nm / s, deposition time of 400s, cooling to room temperature in the furnace; obtaining the NiS QDs modified silicon-based perovskite solar cell. Figure 1 shown.

[0086] Example 2

[0087] The difference between Example 2 and Example 1 is that the concentration of the NiS QDs solution used is 1.5 mg / mL, and the other preparation methods are the same as those of Example 1.

[0088] Example 3

[0089] The difference between Example 3 and Example 1 is that the concentration of the NiS QDs solution used is 2.5 mg / mL, and the other preparation methods are the same as those of Example 1.

[0090] Comparative Example 1

[0091] The difference between Comparative Example 1 and Example 1 is that there is no NiS QDs layer, specifically as follows:

[0092] Al back electrode was deposited on the back of the silicon wafer by vacuum evaporation. After preheating the silicon substrate to 150°C, it was placed in a vacuum evaporation system and the vacuum pressure was 10 -4 Pa, evaporation rate of 0.3 nm / s, deposition time of 500 s, and cooling to room temperature in the furnace;

[0093] A transition layer is constructed by depositing a ZrO2 thin film on the front side of the silicon wafer by spin coating, and then annealing the thin film. The spin coating conditions are: a rotation speed of 2000 r / min; a concentration of the Zr(OAc) solution of 1 mol / L; the annealing conditions are: a temperature of 350°C and an annealing time of 20 minutes; and the thickness of the ZrO2 transition layer is 10-80 nm.

[0094] To construct a hole transport layer, a PTCBI thin film was deposited on the ZrO2 transition layer using spin coating, and then dried in an oven. The spin coating conditions were: a rotation speed of 3000 r / min; a PTCBI solution concentration of 15 mg / mL; and drying conditions: a temperature of 120°C and a drying time of 25 minutes. The PTCBI layer had a thickness of 10-100 nm.

[0095] Construct a transition layer and deposit CoO on the PTCBI layer by spin coating x The film was then annealed, wherein the spin coating conditions were: rotation speed of 3000 r / min; concentration of Co(OAc) solution of 0.1 mol / L; annealing conditions of 200 ° C, annealing time of 20 min; CoO x The thickness of the layer is 10-60 nm;

[0096] The spin coating method was used to coat CoO x The pre-synthesized DMAPbI3 and CsI were dissolved in DMF to prepare a 1.5 mol / L precursor solution, and stirred at 70°C for 3-5 hours before use; the solution preheated to 80°C was then spin-coated onto a CoO layer preheated to 80°C. x The layer was heated at a speed of 2000 r / min for 50 seconds, and then dried at a temperature of 100°C for 10 minutes. Subsequently, the layer was heated at 100°C for 15 minutes to obtain a perovskite layer with a thickness of 100-400 nm.

[0097] To construct an electron transport layer, a SnO2 film was deposited on the CsPbI3 perovskite layer using spin coating, followed by annealing. The spin coating conditions were: a rotation speed of 2000 r / min; a SnCl solution concentration of 1 mol / L; and annealing conditions: a temperature range of 200°C and an annealing time of 15 minutes. The SnO2 film thickness was 10-50 nm.

[0098] The Au electrode was prepared on SnO2 by vacuum evaporation method. It was preheated to 200℃ and then placed in vacuum evaporation system with vacuum pressure of 10 -5 Pa, evaporation rate 0.1nm / s, deposition time 400s, cooled to room temperature in the furnace; silicon-based perovskite solar cells were obtained. Figure 3 As shown in the left picture.

[0099] Comparative Example 2

[0100] The difference between Comparative Example 2 and Example 1 is that there is no CsPbI3 perovskite layer, specifically as follows:

[0101] Al back electrode was deposited on the back of the silicon wafer by vacuum evaporation. After preheating the silicon substrate to 150°C, it was placed in a vacuum evaporation system and the vacuum pressure was 10 -4 Pa, evaporation rate of 0.3 nm / s, deposition time of 500 s, and cooling to room temperature in the furnace;

[0102] A transition layer is constructed by depositing a ZrO2 thin film on the front side of the silicon wafer by spin coating, and then annealing the thin film. The spin coating conditions are: a rotation speed of 2000 r / min; a concentration of the Zr(OAc) solution of 1 mol / L; the annealing conditions are: a temperature of 350°C and an annealing time of 20 minutes; and the thickness of the ZrO2 transition layer is 10-80 nm.

[0103] To construct a hole transport layer, a PTCBI thin film was deposited on the ZrO2 transition layer using spin coating, and then dried in an oven. The spin coating conditions were: a rotation speed of 3000 r / min; a PTCBI solution concentration of 15 mg / mL; and drying conditions: a temperature of 120°C and a drying time of 25 minutes. The PTCBI layer had a thickness of 10-100 nm.

[0104] Construct a transition layer and deposit CoO on the PTCBI layer by spin coating x The film was then annealed, wherein the spin coating conditions were: rotation speed of 3000 r / min; concentration of Co(OAc) solution of 0.1 mol / L; annealing conditions of 200 ° C, annealing time of 20 min; CoO x The thickness of the layer is 10-60 nm;

[0105] Sodium sulfide and nickel chloride hexahydrate were mixed at a molar ratio of 1:1, stirred evenly, and then transferred to a high-temperature furnace to obtain a NiS QD solution. The synthesis conditions were as follows: temperature adjusted to 400°C, reaction time 100 minutes. NiS QDs were loaded onto the perovskite layer by spin coating, and then annealed. The spin coating conditions were as follows: spin speed of 1500 r / min; NiS QD solution concentration of 0.5 mg / mL; NiS QD solution volume of 25 μL; annealing conditions: annealing temperature of 110°C, annealing time of 25 minutes.

[0106] To construct an electron transport layer, a SnO2 film was deposited on the NiS QDs layer using spin coating, followed by annealing. The spin coating conditions were: a rotation speed of 2000 r / min; a SnCl solution concentration of 1 mol / L; and annealing conditions: a temperature range of 200°C and an annealing time of 15 minutes. The SnO2 film thickness was 10-50 nm.

[0107] The Au electrode was prepared on SnO2 by vacuum evaporation method. It was preheated to 200℃ and then placed in vacuum evaporation system with vacuum pressure of 10 -5 Pa, evaporation rate of 0.1nm / s, deposition time of 400s, cooled to room temperature in the furnace; obtained the NiS QDs modified solar cell. Figure 3 As shown in the picture on the right.

[0108] Performance testing

[0109] The photovoltaic performance of the solar cells of Examples 1-3 and Comparative Examples 1-2 was studied. The JV curves under illumination conditions were as follows: Figure 2 and Figure 4 As shown, Figure 2 For Example 1-3; Figure 4 For comparative examples 1 and 2; the results are shown in Table 1;

[0110] The stability comparison of the silicon-based perovskite solar cell of comparative example 1 and the NiS QDs modified silicon-based solar cell of Example 1 of the present application is shown in the figure. Figure 5 As shown, the test conditions are sunlight simulation test system, AM 1.5G (100mW cm -2 ) conditions to record the corresponding photocurrent It curve; the test device should be stored in a dry and sealed environment to avoid the influence of surface dust and air humidity; the test environment is: room temperature 25-28℃, humidity 40-60%.

[0111] Table 1

[0112] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 <![CDATA[Jsc(mA cm -2 )]]> 23.02 23.89 22.68 20.93 14.84 Voc(V) 0.75 0.78 0.73 0.58 0.4 PCE (%) 15％ 17％ 15％ 8％ 3％

[0113] from Figure 2 and Figure 4 As shown in Table 1, the NiS QDs-modified silicon-based perovskite solar cell of the present application uses perovskite as the top cell and introduces NiS QDs on the surface of the perovskite film. The photocurrent density of the silicon-based perovskite solar cell modified with NiS QDs is increased by 10.0% and the open-circuit voltage Voc is increased by nearly 29.3% as can be seen from Example 1 and Comparative Example 1, improving device performance. The photoelectric conversion efficiency of Example 1 is nearly twice that of Comparative Example 1.

[0114] from Figure 5It can be seen that the current density of the silicon-based perovskite solar cell decreases rapidly and significantly with the increase of the test time, while the current density of the NiS QDs-modified silicon-based solar cell in Example 1 decreases slightly at the beginning, and then decreases slowly as time goes by. Even after 400h, the current density is still greater than the initial current density of the silicon-based perovskite solar cell, showing excellent stability and photoelectric performance.

[0115] In the description of this specification, the reference terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean 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 application. Moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless they are mutually inconsistent.

[0116] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0117] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A NiS QDs modified silicon-based perovskite solar cell, characterized in that: It includes a top electrode, an electron transport layer, a NiS QDs layer, a perovskite layer, a first transition layer, a hole transport layer, a second transition layer, a Si substrate and a back electrode from top to bottom.

2. The NiS QDs modified silicon-based perovskite solar cell according to claim 1, characterized in that The top electrode is Au; the electron transport layer is SnO2; the back electrode is Al; the first transition layer is CoO x ; The second transition layer is ZrO2; the hole transport layer is PTCBI.

3. The NiS QDs-modified silicon-based perovskite solar cell according to claim 1 or 2, characterized in that: The thickness of the back electrode is 100-200nm; the Si substrate is single crystal silicon with a thickness of 90-200μm; the thickness of the second transition layer is 10-80nm; the thickness of the hole transport layer is 20-100nm; the thickness of the first transition layer is 10-60nm; the thickness of the electron transport layer is 10-50nm; and the thickness of the top electrode is 30-150nm.

4. The NiS QDs modified silicon-based perovskite solar cell according to claim 1, characterized in that The perovskite layer is a CsPbI3 thin film with a thickness of 100-400nm.

5. The NiS QDs modified silicon-based perovskite solar cell according to claim 4, characterized in that: The preparation method of the CsPbI3 film is as follows: DMAPbI3 and CsI are dissolved in DMF to prepare a precursor solution, which is then stirred evenly and preheated to 60-80°C for spin coating. The solution is then dried and heated at 100-200°C to obtain a perovskite film.

6. The NiS QDs modified silicon-based perovskite solar cell according to claim 1, characterized in that The NiS QDs in the NiS QDs layer are prepared by high-temperature reaction of sodium sulfide and nickel chloride or its hydrate; the particle size of the NiS QDs is 5-20 nm.

7. The NiS QDs modified silicon-based perovskite solar cell according to claim 4, characterized in that: Sodium sulfide and nickel chloride or its hydrate are mixed in a certain proportion, stirred evenly, and then transferred to a high-temperature furnace for high-temperature reaction. After the reaction is completed, the NiS QDs are obtained. The high-temperature reaction conditions are: temperature 100-300° C., reaction time 60-180 min.

8. A method for preparing a silicon-based perovskite solar cell modified with NiS QDs, characterized in that: The following steps are involved: A back electrode is deposited on the back of a Si substrate; a second transition layer, a hole transport layer, a first transition layer, a perovskite film, a NiS QDs layer, and an electron transport layer are sequentially deposited on the front; and a top electrode is prepared on the electron transport layer; thus, the NiS QDs-modified silicon-based perovskite solar cell is obtained.

9. The method for preparing a silicon-based perovskite solar cell modified with NiS QDs according to claim 8, wherein: The top electrode is Au; the electron transport layer is SnO2; the back electrode is Al; the first transition layer is CoO x The second transition layer is ZrO2; the hole transport layer is PTCBI; the perovskite layer is a CsPbI3 thin film; The Al back electrode and Au top electrode were deposited by vacuum evaporation. ZrO2 layer, PTCBI layer, CoO x The layer, perovskite film, NiS QDs layer, and SnO2 layer were deposited by spin coating.

10. The method for preparing a silicon-based perovskite solar cell modified with NiS QDs according to claim 9, characterized in that: The ZrO2 layer is spin-coated using a ZrO2 precursor solution and then annealed at 300-500°C to deposit the ZrO2 layer; CoO x CoO layer x The precursor solution was spin-coated and then annealed at 100-200 ° C to deposit CoO x layer; The SnO2 layer is spin-coated using a SnO2 precursor solution and then annealed at 300-500° C. to deposit the SnO2 layer.

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