A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterojunction perovskite solar cell and preparation method

Abstract

The application discloses a CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3‑x Heterojunction type perovskite solar cell and preparation method thereof, mainly solve the problem of poor light absorption and low photoelectric conversion efficiency of the existing solar cell. It includes transparent conductive substrate, electron transport layer, CsPbBr3 light absorption layer, hole transport layer, protective layer and electrode layer from bottom to top. The transparent conductive substrate adopts conductive glass, the electron transport layer adopts high light transmission material in n-type semiconductor, and the hole transport layer adopts high light transmission material in p-type semiconductor. Its characteristics are that CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3‑x Heterostructure layer is arranged between the CsPbBr3 light absorption layer and the hole transport layer, which is used for adjusting the band gap of the perovskite light absorption layer and enhancing the light absorption capacity. The application improves the photoelectric conversion efficiency and can be used for intelligent photovoltaic glass, photovoltaic automobile and building integrated photovoltaic.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device technology, and specifically relates to a perovskite solar cell that can be applied to smart photovoltaic glass, photovoltaic vehicles, and building-integrated photovoltaics. Background Technology

[0002] Solar cells are semiconductor devices that convert sunlight into electrical energy based on the photovoltaic effect of semiconductor materials. Depending on the semiconductor materials used, solar cells can be divided into crystalline silicon solar cells and thin-film solar cells. Organic-inorganic hybrid perovskite solar cells, a type of thin-film solar cell, have received widespread attention since their first report in 2009, with their photoelectric conversion efficiency increasing from 3.8% to 26% within fifteen years. Despite this significant improvement in efficiency, the poor stability of organic-inorganic hybrid perovskite solar cells hinders their commercialization. Inorganic cesium ions (Cs) are used... + It can completely replace organic cations in hybrid perovskites, such as MA + The resulting all-inorganic perovskite exhibits higher stability under conditions of high humidity, high temperature, and light exposure. Among all-inorganic perovskite systems, CsPbBr3 perovskite possesses the best stability, allowing for a balance between efficiency and stability in solar cell fabrication. Furthermore, CsPbBr3 perovskite exhibits excellent light transmittance in the long-wavelength visible light range, making it a promising candidate for semi-transparent solar cells in applications such as smart photovoltaic glass, photovoltaic vehicles, and building-integrated photovoltaics.

[0003] Existing CsPbBr3 solar cell structures consist of a transparent conductive substrate / electron transport layer / CsPbBr3 light-absorbing layer / hole transport layer / electrode. However, due to the large bandgap of CsPbBr3 material (~2.3 eV), its absorption spectrum is narrow, only 350 nm to 550 nm, further resulting in a significantly lower photocurrent than other perovskite solar cells. Most studies have focused on improving the photocurrent of CsPbBr3 solar cells by introducing highly absorbent organic polymers to form a CsPbBr3 / organic polymer heterostructure. For example, Zhao Yuanyuan et al. published an article titled "10.34%-efficient integrated CsPbBr3 / bulk-heterojunction solar cells" in the *Journal of Power Sources* in 2019, disclosing a high-performance CsPbBr3 / J... 61 -ITIC heterostructure solar cells, which are fabricated on CsPbBr3 surfaces using J... 61-ITIC enhances the overall light absorption ability. Although it can improve the photocurrent of CsPbBr3 solar cells to a certain extent, due to the J used in it 61 -ITIC is an organic polymer and is prone to oxidation and hydrolysis to lose its activity in high-temperature and high-humidity environments, thus resulting in CsPbBr3 / J 61 -ITIC heterostructures with poor stability. The solar cells prepared with it will have serious energy losses and attenuation of the photoelectric conversion efficiency after long-term operation, and cannot meet the practical requirements of long-term stability. Summary of the Invention

[0004] In view of the defects of the above-mentioned prior art, the present invention proposes a CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterojunction-type perovskite solar cell, aiming to improve the photocurrent of CsPbBr3 solar cells while maintaining excellent moisture and heat resistance stability, and meeting the practical requirements of long-term stability of solar cells.

[0005] To achieve the above object, the technical solution of the present invention includes:

[0006] 1. A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterojunction-type perovskite solar cell, which includes a transparent conductive substrate, an electron transport layer, a CsPbBr3 perovskite light absorption layer, a hole transport layer, a protective layer and an electrode layer from bottom to top. It is characterized in that a CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterostructure layer is provided between the CsPbBr3 perovskite light absorption layer and the hole transport layer, and is used to adjust the band gap of the perovskite light absorption layer and enhance its light absorption ability.

[0007] Furthermore, the CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterostructure layer can be any one of CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterostructures with 0 < x < 3.

[0008] Furthermore, the transparent conductive substrate is made of conductive glass, and includes any one of fluorine-doped tin oxide FTO, indium tin oxide ITO, and indium tungsten oxide IWO.

[0009] Furthermore, the electron transport layer is made of a high-transmittance material in n-type semiconductors, including any one of titanium oxide (TiO2), tin oxide (SnO2), and zinc oxide (ZnO).

[0010] Furthermore, the hole transport layer is made of a high-transmittance material in a p-type semiconductor, including any one of 3-hexylthiophene P3HT, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]PTAA, and cuprous thiocyanate CuSCN.

[0011] Furthermore, the protective layer employs a high-transmittance material from a p-type oxide semiconductor, including tungsten oxide (WO3) and nickel oxide (NiO). x Any one of molybdenum oxide (MoO3).

[0012] Furthermore, the electrode layer is made of any one of indium zinc oxide (IZO), silver (Ag), gold (Au), copper (Cu), or carbon (C).

[0013] 2. A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x This invention provides two technical solutions for fabricating heterojunction perovskite solar cells:

[0014] Technical solution 1, the implementation steps are as follows:

[0015] S1) Fabrication of an electron transport layer:

[0016] A precursor solution for depositing an electron transport layer on a transparent conductive substrate 1 is annealed and crystallized to obtain an electron transport layer 2.

[0017] S2) Preparation of CsPbBr3 perovskite light-absorbing layer:

[0018] First, a PbBr2 precursor solution was deposited on electron transport layer 2 using a blade coating method, and then PbBr2 thin film was obtained after annealing and crystallization.

[0019] Then, using vapor deposition, a CsBr reaction source was deposited on the PbBr2 film, and CsPbBr3 perovskite light-absorbing layer 3 was formed by in-situ crystallization.

[0020] S3) Preparation of CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterogeneous structure layer:

[0021] Using vapor deposition, a CsI reaction source is first deposited on a CsPbBr3 perovskite light-absorbing layer, followed by in-situ crystallization to form a CsPbBr3 / CsPbI mixture. x Br 3-x Heterogeneous structure;

[0022] Further deposition of the SnCl2 reaction source led to in-situ crystallization to form CsPbBr3 / CsPb. 0.6 Sn 0.4 I x Br 3-x Heterogeneous structure layer 4;

[0023] S4) Preparation of hole transport layer:

[0024] Using the scraping method, on CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x A precursor solution for depositing a hole transport layer on a heterogeneous structure layer is used to obtain hole transport layer 5.

[0025] S5) A protective layer 6 is prepared on the hole transport layer using a thermal evaporation method;

[0026] S6) Electrode 7 is prepared on the protective layer to complete the solar cell preparation.

[0027] Technical solution 2, the implementation steps of which include:

[0028] §1: A precursor solution for depositing an electron transport layer on a transparent conductive substrate 1 is annealed and crystallized to obtain an electron transport layer 2;

[0029] §2: First, a PbBr2 precursor solution is deposited on electron transport layer 2 using a blade coating method, and a PbBr2 film is obtained after annealing and crystallization; then, a CsBr reaction source is deposited on the PbBr2 film using a vapor deposition method, and a CsPbBr3 perovskite light-absorbing layer 3 is formed by in-situ crystallization.

[0030] §3: Using a dual-channel vapor deposition method, CsI and SnCl2 reaction sources are simultaneously deposited on the CsPbBr3 perovskite light-absorbing layer, resulting in in-situ crystallization to form CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterogeneous structure layer 4;

[0031] §4: In CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x A precursor solution for a hole transport layer was deposited on a heterostructure layer using a blade coating method to obtain hole transport layer 5.

[0032] §5: Preparation of a protective layer on the hole transport layer using thermal evaporation method 6;

[0033] §6: Fabrication of electrodes on the protective layer 7. Complete the fabrication of the solar cell.

[0034] Furthermore, the precursor solution for depositing the electron transport layer on the transparent conductive substrate 1 is prepared using vapor deposition or spin coating; the electrode 7 is prepared on the protective layer using thermal evaporation, magnetron sputtering, or screen printing.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] Firstly, this invention adds CsPbBr3 / CsPb between the CsPbBr3 perovskite layer and the hole transport layer. 0.6 Sn 0.4 I x Br 3-x The heterostructure layer reduces the bandgap of the perovskite layer, improves the light absorption capacity of the perovskite layer and the photocurrent of the solar cell, and avoids the poor stability of existing CsPbBr3 / organic polymer heterojunction solar cells. Thus, while ensuring high photoelectric conversion efficiency, it effectively improves the long-term stability of heterojunction CsPbBr3 solar cells.

[0037] Secondly, this invention prepares CsPbBr3 / CsPb using a vapor deposition method. 0.6 Sn 0.4 I x Br 3-x The heterostructure layer ensures the complete reaction of the precursor materials required for the preparation of the heterostructure, and induces the surface CsPbBr3 to transform into CsPb with stronger light absorption capacity through gas-phase reaction. 0.6 Sn 0.4 I x Br 3-x Formation of all-inorganic CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x The heterostructure layer retains the excellent damp heat resistance of CsPbBr3 perovskite while improving the photocurrent of solar cells, thereby effectively enhancing the photoelectric conversion efficiency of CsPbBr3 solar cells and meeting the practical requirements for long-term stability of solar cells. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the solar cell structure of the present invention;

[0039] Figure 2Schematic diagram of the implementation process for preparing a solar cell in Embodiment 1 of the present invention;

[0040] Figure 3 Schematic diagram of the implementation process for preparing a solar cell in Embodiment 2 of the present invention;

[0041] Figure 4 Schematic diagram of the implementation process for preparing a solar cell in Embodiment 3 of the present invention. Detailed implementation manners

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Refer to Figure 1 , the solar cell of the present invention includes a transparent conductive substrate 1, an electron transport layer 2, a CsPbBr3 light absorption layer 3, a CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterostructure layer 4, a hole transport layer 5, a protective layer 6, and an electrode layer 7. Among them:

[0044] The transparent conductive substrate 1 uses conductive glass, which includes any one of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), and indium tungsten oxide (IWO), and serves as the bottom layer of the battery.

[0045] The electron transport layer 2 uses a highly transparent material in n-type semiconductors, which includes any one of titanium oxide (TiO2), tin oxide (SnO2), and zinc oxide (ZnO), and is located above the transparent conductive substrate 1.

[0046] The CsPbBr3 light absorption layer 3 is located above the electron transport layer 2.

[0047] CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x The heterostructure layer 4 can be any one of CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterostructures with 0 < x < 3, and is located above the CsPbBr3 light absorption layer 3.

[0048] The hole transport layer 5 uses a highly transparent material in p-type semiconductors, which includes any one of 3-hexylthiophene (P3HT), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and copper thiocyanate (CuSCN), and is located above CsPbBr3 / CsPb 0.6 [[ID=​​​​3-x Above the heterostructure layer 4.

[0049] Protective layer 6 uses a high-transmittance material from p-type oxide semiconductors, including tungsten oxide (WO3) and nickel oxide (NiO). x Any one of molybdenum oxide (MoO3) is located above hole transport layer 5.

[0050] Electrode layer 7 is made of any one of indium zinc oxide (IZO), silver (Ag), gold (Au), copper (Cu), or carbon (C), and it is located on the surface of protective layer 6, i.e., the top layer of the battery.

[0051] The following are three embodiments of the present invention for fabricating the above-mentioned solar cells:

[0052] Example 1: A transparent conductive substrate was fabricated using fluorine-doped tin oxide (FTO), and the electron transport layer was TiO2, CsPbBr3 / CsPb. 0.6 Sn 0.4 I x Br 3-x When the heterostructure layer is CsPbBr3 / CsPb at x=1 0.6 Sn 0.4 A solar cell with IBr2, a hole transport layer of 3-hexylthiophene P3HT, a protective layer of tungsten oxide WO3, and an electrode layer of indium zinc oxide IZO.

[0053] Reference Figure 2 The implementation steps of this example include the following:

[0054] Step 1, prepare the electron transport layer, such as Figure 2 (a).

[0055] First, 8.6 mL of tetrabutyl titanate, 34 mL of anhydrous ethanol, and 2.4 mL of diethanolamine were mixed and stirred for 1.5 h to obtain a TiO2 precursor solution. Then, 80 ± 5 μL of the TiO2 precursor solution was uniformly coated onto the cleaned FTO conductive glass substrate using a spin coating method. The substrate was then coated at 3000 r / min for 30 s and annealed in air at 500 ± 5 °C for 60 min to obtain the TiO2 electron transport layer.

[0056] Step 2, prepare the CsPbBr3 light-absorbing layer, such as Figure 2 (b)

[0057] First, 100±5 μL of a 1 mmol / mL PbBr2 solution was evenly coated onto the blade of a doctor blade coater. The slit width of the doctor blade coater was set to 200 μm, and the blade moving speed was set to 20 mm / s. PbBr2 was deposited on the TiO2 electron transport layer using the doctor blade coating method. Then, it was placed on a hot stage and annealed at 90±5℃ for 30 min to prepare a PbBr2 film. Subsequently, it was placed in a reaction chamber. Next, a 1 mmol / mL CsBr aqueous solution was placed in an atomizer as a gas phase source, and the reaction chamber was heated to 250±10℃. Using the vapor deposition method, the CsBr aqueous solution gas phase source was turned on, and nitrogen gas was introduced into the reaction chamber to react with PbBr2 for 30 min, generating a CsPbBr3 light-absorbing layer on the TiO2 electron transport layer. The atomizer source was then turned off.

[0058] Step 3, Preparation of CsPbBr3 / CsPb 0.6 Sn 0.4 IBr2 heterostructure layers, such as Figure 2 (c)

[0059] Two separate nebulizers were used as gas sources, containing 0.01 mmol / mL CsI aqueous solution and 0.01 mmol / mL SnCl2 aqueous solution. The reaction chamber was heated to 285 ± 5 °C. Using vapor deposition, the CsI aqueous solution gas source was first turned on, and nitrogen gas was introduced into the reaction chamber to allow CsI to react with the surface CsPbBr3 perovskite for 15 min. An in-situ phase transition occurred on the surface, forming the CsPbIBr2 phase and generating a CsPbBr3 / CsPbIBr2 heterostructure. The CsI aqueous solution gas source was then turned off. After the reaction chamber cooled to 185 ± 5 °C, the SnCl2 aqueous solution gas source was turned on again, and nitrogen gas was introduced into the reaction chamber to further react with the CsPbBr3 / CsPbIBr2 heterostructure for 15 min. This resulted in the formation of CsPbBr3 / CsPbBr3 on the CsPbBr3 light-absorbing layer. 0.6 Sn 0.4 IBr2 heterostructure layer.

[0060] Step 4, prepare the hole transport layer, such as Figure 2 (d)

[0061] Prepare a 10 mg / mL P3HT solution. Take 80 ± 5 μL of the P3HT solution and evenly apply it to the blade of a doctor blade coater. Set the slit width of the doctor blade coater to 200 μm and the blade movement speed to 20 mm / s. Apply the doctor blade coater to CsPbBr3 / CsPb. 0.6 Sn 0.4 P3HT was deposited on an IBr2 heterostructure layer in CsPbBr3 / CsPb0.6 Sn 0.4 A P3HT hole transport layer is generated on the IBr2 heterostructure layer.

[0062] Step 5, prepare a protective layer, such as Figure 2 (e).

[0063] WO3 was deposited on the hole transport layer using a thermal evaporation process. The growth pressure of the high-vacuum ion evaporation apparatus was set to 1E-4 Pa, the power to 100 W, and the growth rate to [missing information]. The thickness of the deposited film was set to 20±5 nm, and a WO3 protective layer was generated on the 3-hexylthiophene hole transport layer.

[0064] Step 6: Prepare electrodes and complete the fabrication of the solar cell, such as... Figure 2 (f).

[0065] Indium zinc oxide (IZO) electrode layers were deposited on a WO3 protective layer using magnetron sputtering. The growth rate of the magnetron sputtering instrument was set to [value missing]. The power was set to 46W, the DC voltage to 99V, and the deposition electrode thickness to 100±5nm. The resulting layers were: an IZO electrode layer, a WO3 protective layer, a P3HT hole transport layer, and a CsPbBr3 / CsPb layer, stacked sequentially from top to bottom. 0.6 Sn 0.4 IBr2 heterostructure layer, CsPbBr3 light-absorbing layer, TiO2 electron transport layer, CsPbBr3 / CsPb on FTO conductive glass substrate 0.6 Sn 0.4 IBr2 heterojunction perovskite solar cells.

[0066] Example 2: A transparent conductive substrate was fabricated using tin-doped indium oxide (ITO), and the electron transport layer was ZnO, CsPbBr3 / CsPb. 0.6 Sn 0.4 I x Br 3-x CsPbBr3 / CsPb with heterostructure layer x=2 0.6 Sn 0.4 A solar cell with an I2Br heterostructure, a hole transport layer of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]PTAA, a protective layer of WO3, and an electrode layer of silver Ag.

[0067] Reference Figure 3 The present invention includes the following steps:

[0068] Step 1: Prepare the electron transport layer, such as... Figure 3 (a).

[0069] 1.1) A 0.025 mmol / mL zinc acetate dihydrate solution was placed in an atomizer as a gas source, and the cleaned ITO conductive glass substrate was placed in the reaction chamber.

[0070] 1.2) Using the vapor deposition method, turn on the zinc acetate dihydrate vapor source, first introduce it into the reaction chamber with nitrogen, then raise the reaction chamber to 200°C in 30 minutes, and finally maintain the reaction chamber temperature at 200°C and continue deposition for 60 minutes to obtain the ZnO electron transport layer, and then turn off the zinc acetate dihydrate vapor source.

[0071] Step two, prepare the CsPbBr3 light-absorbing layer, such as Figure 3 (b)

[0072] 2.1) First, take 100±5μL of PbBr2 solution with a concentration of 1Mmol / mL and spread it evenly on the blade of the doctor blade coater. Set the slit width of the doctor blade coater to 200μm and the blade moving speed to 20mm / s. Deposit PbBr2 on the TiO2 electron transport layer using the doctor blade coating method. Then, place it on a hot stage and anneal at 90±5℃ for 30min to prepare a PbBr2 film. Then, place it in the reaction chamber.

[0073] 2.2) Then, a 1 mmol / mL CsBr aqueous solution was placed in the nebulizer as a gas source, and the reaction chamber was heated to 250±10℃. Using the vapor deposition method, the CsBr aqueous solution gas source was turned on, and nitrogen was introduced into the reaction chamber to react with PbBr2 for 30 min, generating a CsPbBr3 light-absorbing layer on the ZnO electron transport layer. The nebulizer source was then turned off.

[0074] Step 3: Preparation of CsPbBr3 / CsPb 0.6 Sn 0.4 I2Br heterostructure layers, such as Figure 3 (c).

[0075] 3.1) 0.01 mmol / mL CsI aqueous solution and 0.02 mmol / mL SnCl2 aqueous solution were placed in two different nebulizers as gas sources, and the reaction chamber was heated to 285 ± 5 °C.

[0076] 3.2) Using vapor deposition, the CsI aqueous solution vapor source is first turned on and nitrogen is introduced into the reaction chamber to allow CsI to react with the surface CsPbBr3 perovskite. The reaction time is set to 30 min, and the CsPbI2Br phase is formed in situ on the surface, generating a CsPbBr3 / CsPbI2Br heterostructure.

[0077] 3.3) Turn off the CsI aqueous solution gas source and wait for the reaction chamber to cool to 185±5℃. Then turn on the SnCl2 aqueous solution gas source and introduce nitrogen gas into the reaction chamber to allow SnCl2 to further react with the CsPbBr3 / CsPbI2Br heterostructure. Set the reaction time to 15 min to generate CsPbBr3 / CsPb on the CsPbBr3 light-absorbing layer. 0.6 Sn 0.4 I2Br heterostructure layer.

[0078] Step four, prepare the hole transport layer, such as Figure 3 (d)

[0079] 4.1) Prepare a 10 mg / mL PTAA solution, take 80 ± 5 μL of PTAA solution and apply it evenly to the blade of the scalpel. Set the slit width of the scalpel to 200 μm and the blade moving speed to 20 mm / s.

[0080] 4.2) Using the blade coating method on CsPbBr3 / CsPb 0.6 Sn 0.4 PTAA was deposited on an I2Br heterostructure layer, in CsPbBr3 / CsPb 0.6 Sn 0.4 I2Br heterostructure layer generates PTAA hole transport layer.

[0081] Step 5, prepare a protective layer, such as Figure 3 (e).

[0082] Using a thermal evaporation process, the growth pressure was set to 1E-4Pa, the power to 100W, and the growth rate to be [missing information]. Under the specified process conditions, a WO3 layer with a thickness of 20±5 nm was deposited on the hole transport layer to form a WO3 protective layer on the PTAA hole transport layer.

[0083] Step six: Prepare electrodes and complete the fabrication of the solar cell, such as... Figure 3 (f).

[0084] The growth pressure was set to 1E-4Pa, the power to 100W, and the growth rate to be... Under the specified process conditions, a 100±5 nm thick silver Ag electrode layer was deposited on a WO3 protective layer using thermal evaporation. This resulted in a top-to-bottom stack of Ag electrode layer, WO3 protective layer, PTAA hole transport layer, and CsPbBr3 / CsPb. 0.6 Sn 0.4 I₂Br heterostructure layer, CsPbBr₃ light-absorbing layer, ZnO electron transport layer, CsPbBr₃ / CsPb on ITO conductive glass substrate 0.6 Sn 0.4I2Br heterojunction perovskite solar cells.

[0085] Example 3: A transparent conductive substrate was fabricated using fluorine-doped tin oxide (FTO), an electron transport layer of SnO2, and a CsPbBr3 perovskite light-absorbing layer, forming a CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x CsPbBr3 / CsPb when the heterostructure layer is x = 2.5 0.6 Sn 0.4 I 2.5 Br 0.5 A solar cell with a heterogeneous structure, a hole transport layer of CuSCN, and a protective layer and electrode layer of carbon C.

[0086] Reference Figure 4 The implementation steps of this example include the following:

[0087] Step A: Prepare an electron transport layer, such as... Figure 4 (a).

[0088] 1 mL of SnO2 sol was mixed with 2 mL of deionized water and stirred for 1 h to obtain a SnO2 precursor solution. Then, 80 ± 5 μL of the SnO2 precursor solution was evenly coated onto the cleaned FTO conductive glass substrate using a spin coater. The substrate was then spin-coated at 3000 r / min for 30 s and annealed in air at 150 ± 5 °C for 30 min to obtain the SnO2 electron transport layer.

[0089] Step B, prepare the CsPbBr3 light-absorbing layer, as follows: Figure 4 (b)

[0090] B1) Take 100±5μL of PbBr2 solution with a concentration of 1Mmol / mL and spread it evenly on the blade of the doctor blade. Set the slit width of the doctor blade to 200μm and the blade moving speed to 20mm / s. Deposit PbBr2 on the TiO2 electron transport layer using the doctor blade method. Place it on a hot stage and anneal at 90±5℃ for 30min to obtain a PbBr2 film. Then place it in the reaction chamber.

[0091] B2) Place a 1 mmol / mL CsBr aqueous solution into the nebulizer as a gas source, and heat the reaction chamber to 250±10℃. Using the vapor deposition method, turn on the CsBr aqueous solution gas source and introduce it into the reaction chamber with nitrogen gas to react with PbBr2 for 30 min, generating a CsPbBr3 light-absorbing layer on the SnO2 electron transport layer. Then turn off the nebulizer source.

[0092] Step C, Preparation of CsPbBr3 / CsPb 0.6Sn 0.4 I 2.5 Br 0.5 Heterogeneous structural layers, such as Figure 4 (c)

[0093] C1) A 0.06 mmol / mL CsI aqueous solution and a 0.01 mmol / mL SnCl2 aqueous solution were placed in two different nebulizers as gas sources, and the reaction chamber was heated to 185 ± 5 °C.

[0094] C2) A dual-gas-path vapor deposition method is used, simultaneously opening both the CsI aqueous solution vapor source and the SnCl2 aqueous solution vapor source. Nitrogen gas is introduced into the reaction chamber simultaneously, and the reaction time is set to 15 minutes. This allows CsI and SnCl2 to react with the surface CsPbBr3 perovskite, resulting in in-situ ion substitution doping of CsPbBr3 / CsPb on the CsPbBr3 perovskite surface. 0.6 Sn 0.4 I 2.5 Br 0.5 Heterogeneous structure.

[0095] Step D, prepare the hole transport layer, such as Figure 4 (d)

[0096] D1) Prepare a 35 mg / mL CuSCN solution. Take 80 ± 5 μL of the CuSCN solution and apply it evenly to the blade of the scalpel. Set the slit width of the scalpel to 200 μm and the blade movement speed to 20 mm / s.

[0097] D2) Using the scraping method on CsPbBr3 / CsPb 0.6 Sn 0.4 I 2.5 Br 0.5 CuSCN was deposited on a heterostructure layer in CsPbBr3 / CsPb 0.6 Sn 0.4 I 2.5 Br 0.5 A CuSCN hole transport layer is generated on the heterostructure layer.

[0098] Step E, prepare a protective layer, such as Figure 4 (e).

[0099] WO3 was deposited on the hole transport layer using a thermal evaporation process. The growth pressure of the high-vacuum ion evaporation apparatus was set to 1E-4 Pa, the power to 100 W, and the growth rate to [missing information]. The thickness of the deposited film was set to 20±5 nm, and a WO3 protective layer was generated on the cuprous thiocyanate hole transport layer.

[0100] Step F involves preparing the electrodes and completing the fabrication of the solar cell, as follows: Figure 4 (f).

[0101] A carbon electrode layer with a thickness of 10±2 μm was deposited on a WO3 protective layer using screen printing. The resulting layers, stacked sequentially from top to bottom, consisted of a C electrode layer, a WO3 protective layer, a CuSCN hole transport layer, and a CsPbBr3 / CsPb layer. 0.6 Sn 0.4 I 2.5 Br 0.5 Heterogeneous structure layer, CsPbBr3 light-absorbing layer, SnO2 electron transport layer, CsPbBr3 / CsPb on FTO conductive glass substrate 0.6 Sn 0.4 I 2.5 Br 0.5 Heterojunction perovskite solar cells.

[0102] The above description is merely a specific example of the present invention and does not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principles of the present invention, may make various modifications and changes in form and detail without departing from the principles and structure of the invention. For example, in addition to the CsPbBr3 / CsPb used in the above example, heterostructure layers may also include other materials. 0.6 Sn 0.4 I x Br 3-x In addition to heterostructures, the ratio of Pb to Sn can be adjusted to form CsPbBr3 / CsPb y Sn 1- y I x Br 3-x Heterogeneous structure (where 0)

Claims

1. A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterojunction type perovskite solar cell, comprising from bottom to top a transparent conductive substrate (1), an electron transport layer (2), a CsPbBr3light absorption layer (3), a hole transport layer (5), a protective layer (6) and an electrode layer (7), characterized in that, CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterostructure layer (4) for adjusting the band gap of the perovskite light-absorbing layer and enhancing its light absorption capacity; CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterostructure layer (4) for adjusting the band gap of the perovskite light-absorbing layer and enhancing its light absorption capacity; CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Any of the heterostructures.

2. The solar cell according to claim 1, characterized in that, The transparent conductive substrate (1) is made of conductive glass, which includes any one of fluorine-doped tin oxide FTO, indium-doped tin oxide ITO, and tungsten-doped indium oxide IWO.

3. The solar cell of claim 1, wherein The electron transport layer (2) is made of a high-transparency material in an n-type semiconductor, which includes any one of titanium oxide TiO2, tin oxide SnO2, and zinc oxide ZnO.

4. The solar cell of claim 1, wherein The hole transport layer (5) is made of a high-transparency material in a p-type semiconductor, which includes any one of 3-hexylthiophene P3HT, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] PTAA, and cuprous thiocyanate CuSCN.

5. The solar cell of claim 1, wherein The protective layer (6) is made of high light transmission material in p-type oxide semiconductor, including any one of tungsten oxide WO3, nickel oxide NiO, molybdenum oxide MoO3. x , 6. The solar cell of claim 1, wherein The electrode layer (7) is made of any one of indium zinc oxide IZO, silver Ag, gold Au, copper Cu, and carbon C.

7. A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x The method for manufacturing a heterojunction type perovskite solar cell is characterized by comprising the steps of: The method comprises the following steps: S1) preparing an electron transport layer: Depositing a precursor solution of the electron transport layer on the transparent conductive substrate (1), and obtaining the electron transport layer (2) after annealing and crystallization; S2) preparing a CsPbBr3 light-absorbing layer: First, using a blade coating method, depositing a PbBr2 precursor solution on the electron transport layer (2), and obtaining a PbBr2 thin film after annealing and crystallization; Then, using a vapor deposition method, depositing a CsBr reaction source on the PbBr2 thin film to form a CsPbBr3 light-absorbing layer (3) in situ; S3) preparing CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterostructure layer: Using vapor deposition method, first deposit CsI reaction source on CsPbBr3 light absorption layer, in-situ crystallization to form CsPbBr3 / CsPbI x Br 3-x Heterostructure; Continuing to deposit SnCl2 reaction source, in-situ crystallization forms CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterostructure layer (4); the CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterostructure layer (4), CsPbBr3 / CsPb of 0 0.6 Sn 0.4 I x Br 3-x Any one of the heterostructures; S4) preparing a hole transport layer: A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x A precursor solution of a hole transport layer is deposited on the heterostructure layer to obtain a hole transport layer (5). S5) using a thermal evaporation method to prepare a protective layer (6) on the hole transport layer; S6) preparing an electrode layer (7) on the protective layer to complete the preparation of the solar cell.

8. The method of claim 7, wherein: In step S1), the precursor solution of the electron transport layer is deposited on the transparent conductive substrate (1) using a vapor deposition method or a spin coating method; In step S6), the electrode layer (7) is prepared on the protective layer using a thermal evaporation method or a magnetron sputtering method or using a screen printing method.

9. A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x The method for manufacturing a heterojunction type perovskite solar cell is characterized by comprising the steps of: The method comprises the following steps: §1: Depositing a precursor solution of the electron transport layer on the transparent conductive substrate (1), and obtaining the electron transport layer (2) after annealing and crystallization; §2: Preparing a CsPbBr3 light-absorbing layer: First, using a blade coating method, depositing a PbBr2 precursor solution on the electron transport layer (2), and obtaining a PbBr2 thin film after annealing and crystallization; Then, using a vapor deposition method, depositing a CsBr reaction source on the PbBr2 thin film to form a CsPbBr3 light-absorbing layer (3) in situ; §3: using a double gas path vapor deposition method, simultaneously depositing a CsI reaction source and a SnCl2 reaction source on the CsPbBr3 light absorption layer, in-situ crystallizing to form a CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterostructure layer (4); the CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterostructure layer (4), CsPbBr3 / CsPb of 0 0.6 Sn 0.4 I x Br 3-x Any one of the heterostructures; §4: Using a doctor blade method, a precursor solution of a hole transport layer was deposited on the CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x A hole transport layer (5) was obtained by depositing a precursor solution of a hole transport layer on the heterostructure layer. §5: Using a thermal evaporation method to prepare a protective layer (6) on the hole transport layer; §6: Preparing an electrode layer (7) on the protective layer to complete the preparation of the solar cell.

Images