CsPbBr3 / CsPb0. 6Sn0. 4IxBr3-x heterojunction perovskite solar cell and preparation method thereof

Abstract

The invention discloses a CsPbBr3 / CsPb0. 6Sn0. 4IxBr3-x heterojunction perovskite solar cell and a preparation method thereof, and mainly solves the problems of poor light absorption capability and low photoelectric conversion efficiency of the existing solar cell. The solar cell comprises a transparent conductive substrate, an electron transport layer, a CsPbBr3 light absorption layer, a hole transport layer, a protective layer and an electrode layer from bottom to top, the transparent conductive substrate is made of conductive glass, the electron transport layer is made of a high-light-transmittance material in an n-type semiconductor, and the hole transport layer is made of a high-light-transmittance material in a p-type semiconductor. The perovskite solar cell is characterized in that a CsPbBr3 / CsPb0. 6Sn0. 4IxBr3-x heterostructure layer is arranged between the CsPbBr3 light absorption layer and the hole transport layer and used for adjusting the forbidden bandwidth of the perovskite light absorption layer and enhancing the light absorption capacity of the perovskite light absorption layer, the photoelectric conversion efficiency is improved, and the perovskite solar cell can be used for intelligent photovoltaic glass, photovoltaic automobiles and photovoltaic building integration.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor devices, and in particular relates to a perovskite solar cell, which can be applied to the integration of smart photovoltaic glass, photovoltaic vehicles and photovoltaic buildings. Background Art

[0002] Solar cells are semiconductor devices that absorb sunlight and convert it 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 in thin-film solar cells have received widespread attention since they were first reported in 2009. In fifteen years, the photoelectric conversion efficiency of the cells has increased from 3.8% to 26%. Although the efficiency of organic-inorganic hybrid perovskite solar cells has been greatly improved, their poor stability has hindered their commercialization. Using inorganic cesium ions (Cs + ) can completely replace the organic cations in the hybrid perovskite, such as MA + The all-inorganic perovskite formed has higher stability under conditions of high humidity, high temperature, and light. 3 Perovskite has the best stability and can be used to prepare solar cells to achieve a balance between efficiency and stability. 3 Perovskite has good light transmittance in the long-wave band of visible light. Preparing it into semi-transparent cells has great application prospects in smart photovoltaic glass, photovoltaic vehicles and photovoltaic building integration.

[0003] Existing CsPbBr 3 The solar cell structure is transparent conductive substrate / electron transport layer / CsPbBr 3 Light absorbing layer / hole transport layer / electrode, but due to CsPbBr 3 The material itself has a large bandgap (~2.3eV), which results in a narrow absorption spectrum of only 350nm to 550nm, further leading to the CsPbBr 3 The photocurrent of perovskite solar cells is much lower than that of other perovskite solar cells. Most studies have introduced organic polymers with strong light absorption ability to form CsPbBr 3 / organic polymer heterostructures to enhance CsPbBr 3 Photocurrent of solar cells. For example, Zhao Yuanyuan et al. published an article in Journal of Power Sources in 2019 titled “10.34%-efficient integrated CsPbBr 3 / bulk-heterojunction solar cells" discloses a high-performance CsPbBr 3 / J 61 -ITIC heterostructure solar cells, which are based on CsPbBr 3 Surface preparation 61 -ITIC enhances the overall light absorption capacity, although it can improve CsPbBr to a certain extent 3 The photocurrent of the solar cell is 61 -ITIC is an organic polymer, which is easily oxidized and hydrolyzed to lose its activity under high temperature and high humidity environment, thus causing CsPbBr 3 / J 61 -ITIC heterostructure has poor stability. The solar cells prepared by it will have serious energy loss and photoelectric conversion efficiency decay after long-term operation, which cannot meet the long-term stable practical needs. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the present invention proposes a CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterojunction perovskite solar cells aim to improve CsPbBr 3 The solar cell photocurrent maintains excellent moisture and heat stability, 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 CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterojunction perovskite solar cell, from bottom to top, includes transparent conductive substrate, electron transport layer, CsPbBr 3 Perovskite light absorbing layer, hole transport layer, protective layer and electrode layer, characterized in that the CsPbBr 3 CsPbBr is provided between the perovskite light absorbing layer and the hole transport layer. 3 / CsPb 0.6 Sn 0.4 I x Br 3-x The heterostructure layer is used to adjust the bandgap width of the perovskite light-absorbing layer and enhance its light absorption capacity.

[0007] Furthermore, the CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x The heterostructure layer can be CsPbBr where 0 < x < 3 3 / CsPb 0.6 Sn 0.4 I x Br 3-x Any one of those in the heterostructure.

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

[0009] Furthermore, for the electron transport layer, a highly transparent material in n-type semiconductors is used, which includes any one of titanium oxide (TiO 2 , tin oxide (SnO 2 , and zinc oxide (ZnO).

[0010] Furthermore, for the hole transport layer, a highly transparent material in p-type semiconductors is used, which includes any one of 3-hexylthiophene (P3HT), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and cuprous thiocyanate (CuSCN).

[0011] Furthermore, for the protective layer, a highly transparent material in p-type oxide semiconductors is used, which includes any one of tungsten oxide (WO 3 , nickel oxide (NiO x , and molybdenum oxide (MoO 3 .

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

[0013] 2. A manufacturing method of a CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterojunction perovskite solar cell, the present invention provides the following two technical solutions:

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

[0015] S1) Prepare the electron transport layer:

[0016] Deposit the precursor solution of the electron transport layer on the transparent conductive substrate 1, and obtain the electron transport layer 2 after annealing and crystallization;

[0017] S2) Prepare CsPbBr 3Perovskite light absorbing layer:

[0018] First, PbBr is deposited on the electron transport layer 2 using a doctor blade coating method. 2 Precursor solution, annealed and crystallized to obtain PbBr 2 film;

[0019] Then, using the vapor deposition method, PbBr 2 CsBr reaction source is deposited on the film, and CsPbBr is formed by in-situ crystallization. 3 Perovskite light absorbing layer 3;

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

[0021] Using the vapor deposition method, first CsPbBr 3 CsI ​​reaction source is deposited on the perovskite light absorbing layer, and CsPbBr is formed by in-situ crystallization. 3 / CsPbI x Br 3-x Heterogeneous structures;

[0022] Continue to deposit SnCl 2 Reaction source, in situ crystallization to form CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterogeneous structure layer 4;

[0023] S4) preparing a hole transport layer:

[0024] Using the doctor blade method, CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x Depositing a precursor solution of a hole transport layer on the heterostructure layer to obtain a hole transport layer 5;

[0025] S5) preparing a protective layer 6 on the hole transport layer by thermal evaporation;

[0026] S6) preparing an electrode 7 on the protective layer to complete the preparation of the solar cell.

[0027] Technical solution 2, its implementation steps include:

[0028] §1: Depositing a precursor solution of an electron transport layer on a transparent conductive substrate 1, and obtaining an electron transport layer 2 after annealing and crystallization;

[0029] §2: First use the scraping method to deposit PbBr on the electron transport layer 2 2 Precursor solution, annealed and crystallized to obtain PbBr 2 Thin film; then using vapor deposition method, on PbBr 2 CsBr reaction source is deposited on the film, and CsPbBr is formed by in-situ crystallization. 3 Perovskite light absorbing layer 3;

[0030] §3: Using dual gas path vapor deposition method, CsPbBr 3 Simultaneous deposition of CsI reaction source and SnCl on the perovskite light absorbing layer 2 Reaction source, in situ crystallization to form CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterogeneous structure layer 4;

[0031] §4: In CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x A precursor solution of a hole transport layer is deposited on the heterogeneous structure layer by a doctor blade coating method to obtain a hole transport layer 5;

[0032] §5: Prepare a protective layer 6 on the hole transport layer by thermal evaporation;

[0033] §6: Prepare electrode 7 on the protective layer to complete the preparation of the solar cell.

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

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

[0036] First, the present invention adopts CsPbBr 3 Add CsPbBr between the perovskite layer and the hole transport layer 3 / CsPb 0.6 Sn 0.4 I x Br 3-x The heterogeneous structure layer reduces the bandgap width of the perovskite layer, improves the light absorption capacity of the perovskite layer and the photocurrent of the solar cell, and avoids the existing CsPbBr 3 / Organic polymer heterojunction solar cells have poor stability, and thus effectively improve the heterojunction CsPbBr while ensuring high photoelectric conversion efficiency. 3 Long-term stability of solar cells.

[0037] Second, the present invention prepares CsPbBr by using a vapor deposition method. 3 / CsPb 0.6 Sn 0.4 I x Br 3-x The heterogeneous structure layer can ensure that the precursor materials required for the preparation of the heterogeneous structure are fully reacted, and the surface CsPbBr 3 Transformed into CsPb with stronger light absorption 0.6 Sn 0.4 I x Br 3-x Formation of all-inorganic CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterostructure layer, retaining CsPbBr 3 The excellent moisture and heat stability of perovskite also improves the photocurrent of solar cells, thereby effectively improving the performance of CsPbBr 3 The photoelectric conversion efficiency of solar energy meets the practical requirements of long-term stability of solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0039] Figure 2 This is a schematic diagram of the implementation process of preparing a solar cell according to Example 1 of the present invention;

[0040] Figure 3 This is a schematic diagram of the implementation process of preparing a solar cell according to Embodiment 2 of the present invention;

[0041] Figure 4 This is a schematic diagram of the implementation process of preparing a solar cell according to Example 3 of the present invention. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0043] Reference Figure 1 The solar cell of the present invention comprises a transparent conductive substrate 1, an electron transport layer 2, a CsPbBr 3 Light absorbing layer 3, CsPbBr 3 / CsPb 0.6 Sn 0.4I x Br 3-x Heterogeneous structure layer 4, hole transport layer 5, protective layer 6, and electrode layer 7. Among them:

[0044] The transparent conductive substrate 1 is made of 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 is made of a highly transparent material in n-type semiconductors, which includes any one of titanium oxide (TiO 2 , tin oxide (SnO 2 , and zinc oxide (ZnO), and is located above the transparent conductive substrate 1.

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

[0047] CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x The heterogeneous structure layer 4 can be any one of CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x in the heterogeneous structure, and is located above the CsPbBr 3 light absorption layer 3.

[0048] The hole transport layer 5 is made of 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 cuprous thiocyanate (CuSCN), and is located above the CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterogeneous structure layer 4.

[0049] The protective layer 6 is made of a highly transparent material in p-type oxide semiconductors, which includes any one of tungsten oxide (WO 3 , nickel oxide (NiO x , and molybdenum oxide (MoO 3 , and is located above the hole transport layer 5.

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

[0051] Three embodiments of the present invention for making the above-mentioned solar cell are given below:

[0052] Example 1: The transparent conductive substrate is made of fluorine-doped tin oxide FTO, and the electron transport layer is made of TiO 2 , CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x CsPbBr when the heterostructure layer is x=1 3 / CsPb 0.6 Sn 0.4 IBr 2 The hole transport layer is 3-hexylthiophene P3HT, and the protective layer is tungsten oxide WO 3 , a solar cell whose electrode layer is indium zinc oxide IZO.

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

[0054] Step 1, prepare an 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 TiO 2 Precursor solution; then spin-coat 80±5μLTiO 2 The precursor solution was evenly applied on the surface of the cleaned FTO conductive glass substrate, and the coating was performed at a coating speed of 3000r / min for 30s, and then annealed in an air atmosphere of 500±5℃ for 60min to obtain TiO 2 Electron transport layer.

[0056] Step 2, preparation of CsPbBr 3 Light absorbing layer, such as Figure 2 (b).

[0057] First take 100±5μL of 1Mmol / mL PbBr 2 The solution was evenly applied to the scraper of the scraper, and the slit width of the scraper was set to 200 μm, and the scraper moving speed was set to 20 mm / s. The TiO 2 Electron transport layer deposition PbBr 2 ; Then place it on a hot plate and anneal it at 90±5℃ for 30min to prepare PbBr 2The film was then placed in the reaction chamber; a 1Mmol / mL CsBr aqueous solution was placed in the atomizer as a gas source, and the reaction chamber was heated to 250±10°C. The CsBr aqueous solution gas source was turned on using a vapor deposition method, and nitrogen was passed into the reaction chamber to make it react with PbBr 2 The reaction took 30 minutes. 2 CsPbBr is generated on the electron transport layer 3 Light absorbing layer, turn off the atomization source.

[0058] Step 3, preparation of CsPbBr 3 / CsPb 0.6 Sn 0.4 IBr 2 Heterogeneous structural layers, such as Figure 2 (c).

[0059] 0.01 Mmol / mL CsI aqueous solution and 0.01 Mmol / mL SnCl 2 The aqueous solution was placed in two different atomizers as the gas source, and the reaction chamber was heated to 285±5℃. The vapor deposition method was used. The CsI aqueous solution gas source was first opened and nitrogen was passed into the reaction chamber to make CsI and the surface CsPbBr 3 The perovskite reacts for 15 min and forms CsPbIBr in situ on the surface. 2 phase, generating CsPbBr 3 / CsPbIBr 2 Heterogeneous structure, turn off the CsI aqueous solution gas source; wait for the reaction chamber to cool down to 185±5℃, then turn on the SnCl 2 The aqueous solution gas source is introduced into the reaction chamber by nitrogen gas to make SnCl 2 With CsPbBr 3 / CsPbIBr 2 The heterostructure was further reacted, and the reaction time was set to 15 min. 3 CsPbBr is generated on the light-absorbing layer 3 / CsPb 0.6 Sn 0.4 IBr 2 Heterogeneous structural layer.

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

[0061] Prepare 10 mg / mL P3HT solution, take 80±5 μL P3HT solution and evenly apply it to the scraper of the scraper, set the slit width of the scraper to 200 μm, and the scraper moving speed to 20 mm / s. Use the scraper coating method to coat CsPbBr 3 / CsPb 0.6 Sn 0.4 IBr 2 P3HT is deposited on the heterostructure layer, and CsPbBr 3 / CsPb 0.6 Sn 0.4 IBr 2 A P3HT hole transport layer is generated on the heterostructure layer.

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

[0063] Deposition of WO on the hole transport layer using thermal evaporation 3 The growth pressure of the high vacuum ion evaporator was set to 1E-4Pa, the power was set to 100W, and the growth rate was set to The thickness of the deposited film was set to 20 ± 5 nm to generate WO on the 3-hexylthiophene hole transport layer. 3 Protective layer;

[0064] Step 6, prepare electrodes and complete the preparation of solar cells, such as Figure 2 (f).

[0065] Using magnetron sputtering technology, WO 3 The indium zinc oxide (IZO) electrode layer is deposited on the protective layer, and the growth rate of the magnetron sputtering instrument is set to The power was set to 46W, the DC voltage was set to 99V, and the thickness of the deposited electrode was set to 100±5nm. 3 Protective layer, P3HT hole transport layer, CsPbBr 3 / CsPb 0.6 Sn 0.4 IBr 2 Heterostructure layer, CsPbBr 3 Light absorbing layer, TiO 2 Electron transport layer, CsPbBr on FTO conductive glass substrate 3 / CsPb 0.6 Sn 0.4 IBr 2 Heterojunction perovskite solar cells.

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

[0067] Reference Figure 3 , the present invention comprises the following steps:

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

[0069] 1.1) Place 0.025 Mmol / mL zinc acetate dihydrate solution into an atomizer as a gas source, and place the cleaned ITO conductive glass substrate in a reaction chamber;

[0070] 1.2) Using the vapor deposition method, open the zinc acetate dihydrate vapor source, first pass it into the reaction chamber through nitrogen, then raise the reaction chamber temperature to 200°C for 30 minutes, and finally maintain the reaction chamber temperature at 200°C and continue deposition for 60 minutes to obtain a ZnO electron transport layer, and then close the zinc acetate dihydrate vapor source.

[0071] Step 2: Preparation of CsPbBr 3 Light absorbing layer, such as Figure 3 (b).

[0072] 2.1) Take 100±5μL of 1Mmol / mL PbBr 2 The solution was evenly applied to the scraper of the scraper, and the slit width of the scraper was set to 200 μm, and the scraper moving speed was set to 20 mm / s. The TiO 2 Electron transport layer deposition PbBr 2 ; Then place it on a hot plate and anneal it at 90±5℃ for 30min to prepare PbBr 2 film, which is then placed into a reaction chamber;

[0073] 2.2) Then, a 1Mmol / mL CsBr aqueous solution was placed in the atomizer as a gas source, and the reaction chamber was heated to 250±10°C. The CsBr aqueous solution gas source was turned on using a vapor deposition method, and nitrogen was passed into the reaction chamber to make it react with PbBr. 2 The reaction took 30 minutes to generate CsPbBr on the ZnO electron transport layer.3 Light absorbing layer, turn off the atomization source.

[0074] Step 3: Preparation of CsPbBr 3 / CsPb 0.6 Sn 0.4 I 2 Br heterostructure layer, such as Figure 3 (c).

[0075] 3.1) 0.01Mmol / mL CsI aqueous solution and 0.02Mmol / mL SnCl 2 The aqueous solution was placed in two different atomizers as gas sources, and the reaction chamber was heated to 285 ± 5 °C;

[0076] 3.2) Using the vapor deposition method, first open the CsI aqueous solution gas source and pass it into the reaction chamber through nitrogen to make CsI and the surface CsPbBr 3 The perovskite reacts, and the reaction time is set to 30 minutes, and the CsPbI is formed in situ on the surface. 2 Br phase, generating CsPbBr 3 / CsPbI 2 Br heterostructure;

[0077] 3.3) Turn off the CsI aqueous solution gas source, wait for the reaction chamber to cool down to 185±5℃, then turn on the SnCl 2 The aqueous solution gas source is introduced into the reaction chamber by nitrogen gas to make SnCl 2 With CsPbBr 3 / CsPbI 2 Br heterostructure was further reacted, and the reaction time was set to 15 min. 3 CsPbBr is generated on the light-absorbing layer 3 / CsPb 0.6 Sn 0.4 I 2 Br heterostructure layer.

[0078] Step 4: prepare a hole transport layer, such as Figure 3 (d).

[0079] 4.1) Prepare 10 mg / mL PTAA solution, take 80±5 μL of PTAA solution and evenly apply it to the scraper of the scraper coater, and set the slit width of the scraper coater to 200 μm and the scraper moving speed to 20 mm / s;

[0080] 4.2) Using the doctor blade method on CsPbBr 3 / CsPb 0.6 Sn 0.4 I 2PTAA is deposited on the Br heterostructure layer. 3 / CsPb 0.6 Sn 0.4 I 2 The Br heterostructure layer generates a PTAA hole transport layer.

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

[0082] Using thermal evaporation process, the growth pressure was set to 1E-4Pa, the power was set to 100W, and the growth rate was Under the process conditions, WO with a thickness of 20±5nm was deposited on the hole transport layer. 3 , to generate WO in the PTAA hole transport layer 3 Protective layer.

[0083] Step 6: Prepare electrodes and complete the preparation of solar cells, such as Figure 3 (f).

[0084] The growth pressure was set to 1E-4Pa, the power was set to 100W, and the growth rate was set to The process conditions are as follows: using thermal evaporation process, on WO 3 A silver electrode layer with a thickness of 100±5nm is deposited on the protective layer to obtain a stacked Ag electrode layer from top to bottom, WO 3 Protective layer, PTAA hole transport layer, CsPbBr 3 / CsPb 0.6 Sn 0.4 I 2 Br heterostructure layer, CsPbBr 3 Light absorbing layer, ZnO electron transport layer, CsPbBr on ITO conductive glass substrate layer 3 / CsPb 0.6 Sn 0.4 I 2 Br heterojunction perovskite solar cells.

[0085] Example 3: The transparent conductive substrate is made of fluorine-doped tin oxide FTO, and the electron transport layer is SnO 2 , CsPbBr 3 Perovskite light absorbing layer, CsPbBr 3 / CsPb 0.6 Sn 0.4 I x Br 3-x CsPbBr with heterostructure layer x=2.5 3 / CsPb 0.6 Sn 0.4 I 2.5 Br0.5 A solar cell with a heterogeneous structure, a hole transport layer of CuSCN, a protective layer and an electrode layer of carbon C.

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

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

[0088] 1 mL SnO 2 The sol was mixed with 2 mL of deionized water and stirred for 1 h to obtain SnO 2 The precursor solution was then spin-coated to obtain 80 ± 5 μL SnO 2 The precursor solution was evenly applied on the surface of the cleaned FTO conductive glass substrate, and the coating was performed at a coating speed of 3000r / min for 30s, and then annealed at 150±5℃ for 30min in air atmosphere to obtain SnO 2 Electron transport layer.

[0089] Step B, Preparation of CsPbBr 3 Light absorbing layer, such as Figure 4 (b).

[0090] B1) Take 100±5μL of 1Mmol / mL PbBr 2 The solution was evenly applied to the scraper of the scraper, and the slit width of the scraper was set to 200 μm, and the scraper moving speed was set to 20 mm / s. The TiO 2 Electron transport layer deposition PbBr 2 , and annealed it on a hot stage at 90±5℃ for 30min to obtain PbBr 2 film, which is then placed into a reaction chamber;

[0091] B2) Place 1Mmol / mL CsBr aqueous solution into the atomizer as a gas source, and heat the reaction chamber to 250±10°C. Use a vapor deposition method to open the CsBr aqueous solution gas source and pass nitrogen into the reaction chamber to make it react with PbBr 2 The reaction took 30 minutes. 2 CsPbBr is generated on the electron transport layer 3 Light absorbing layer, turn off the atomization source.

[0092] Step C, Preparation of CsPbBr 3 / CsPb 0.6 Sn 0.4 I 2.5 Br 0.5 Heterogeneous structural layers, such as Figure 4 (c).

[0093] C1) 0.06Mmol / mL CsI aqueous solution and 0.01Mmol / mL SnCl 2 The aqueous solution was placed in two different atomizers as gas sources, and the reaction chamber was heated to 185 ± 5 °C;

[0094] C2) Using the dual-gas path vapor deposition method, the CsI aqueous solution gas source and SnCl 2 The aqueous solution gas source, two gas sources were introduced into the reaction chamber at the same time by nitrogen, and the reaction time was set to 15min to make CsI and SnCl 2 With the surface CsPbBr 3 The perovskite reacts in CsPbBr 3 In-situ ion substitution doping reaction occurs on the perovskite surface to form CsPbBr 3 / CsPb 0.6 Sn 0.4 I 2.5 Br 0.5 Heterogeneous structure.

[0095] Step D, preparing a hole transport layer, such as Figure 4 (d).

[0096] D1) Prepare 35 mg / mL CuSCN solution, take 80±5 μL CuSCN solution and evenly apply it to the scraper of the scraper, and set the slit width of the scraper to 200 μm and the scraper moving speed to 20 mm / s.

[0097] D2) Using the doctor blade method on CsPbBr 3 / CsPb 0.6 Sn 0.4 I 2.5 Br 0.5 CuSCN is deposited on the heterostructure layer, and CsPbBr 3 / 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, preparing a protective layer, such as Figure 4 (e).

[0099] Deposition of WO on the hole transport layer using thermal evaporation 3 The growth pressure of the high vacuum ion evaporator was set to 1E-4Pa, the power was set to 100W, and the growth rate was set to The thickness of the deposited film was set to 20 ± 5 nm, and WO was generated on the cuprous thiocyanate hole transport layer.3 Protective layer;

[0100] Step F, preparing electrodes and completing the preparation of solar cells, such as Figure 4 (f).

[0101] Using screen printing technology, 3 A carbon electrode layer with a thickness of 10±2 μm is deposited on the protective layer. The C electrode layer, WO 3 Protective layer, CuSCN hole transport layer, CsPbBr 3 / CsPb 0.6 Sn 0.4 I 2.5 Br 0.5 Heterostructure layer, CsPbBr 3 Light absorbing layer, SnO 2 Electron transport layer, CsPbBr on FTO conductive glass substrate 3 / CsPb 0.6 Sn 0.4 I 2.5 Br 0.5 Heterojunction perovskite solar cells.

[0102] The above description is only a specific example of the present invention and does not constitute any limitation to the present invention. It is obvious that after understanding the content and principle of the present invention, professionals in the field may make various modifications and changes in form and details without departing from the principle and structure of the invention. For example, in addition to the CsPbBr used in the above example, the heterostructure layer 3 / CsPb 0.6 Sn 0.4 I x Br 3-x In addition to the heterostructure, the ratio of Pb and Sn can be adjusted to form CsPbBr 3 / CsPb y Sn 1- y I x Br 3-x Heterostructure (where 0

Claims

1. A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x A heterojunction perovskite solar cell comprises, from bottom to top, a transparent conductive substrate (1), an electron transport layer (2), a CsPbBr3 light absorbing layer (3), a hole transport layer (5), a protective layer (6) and an electrode layer (7), characterized in that: The CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x The heterostructure layer (4) is used to adjust the bandgap width of the perovskite light absorbing layer and enhance its light absorption capability.

2. The solar cell according to claim 1, characterized in that The described CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x heterostructure layer (4), which can be any one of CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x in the heterostructure where 0 < x < 3.

3. 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, tin-doped indium oxide ITO, and tungsten-doped indium oxide IWO.

4. The solar cell according to claim 1, characterized in that The electron transport layer (2) is made of a highly light-transmitting material in an n-type semiconductor, including any one of titanium oxide TiO2, tin oxide SnO2, and zinc oxide ZnO.

5. The solar cell according to claim 1, characterized in that: The hole transport layer (5) is made of a highly light-transmitting 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.

6. The solar cell according to claim 1, characterized in that The protective layer (6) is made of a highly transparent material in a p-type oxide semiconductor, which includes tungsten oxide WO3, nickel oxide NiO x , any one of molybdenum oxide MoO3.

7. The solar cell according to claim 1, characterized in that The electrode layer (7) is made of any one of indium zinc oxide IZO, silver Ag, gold Au, copper Cu, and carbon C.

8. A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x A method for manufacturing a heterojunction perovskite solar cell, characterized in that: The steps include: S1) Preparation of electron transport layer: Depositing a precursor solution of an electron transport layer on a transparent conductive substrate (1), and obtaining an electron transport layer (2) after annealing and crystallization; S2) Preparation of CsPbBr3 light absorbing layer: First, a PbBr2 precursor solution is deposited on the electron transport layer (2) by a doctor blade method, and a PbBr2 thin film is obtained after annealing and crystallization; Then, a CsBr reaction source is deposited on the PbBr2 film by a vapor deposition method, and a CsPbBr3 light absorbing layer is formed by in-situ crystallization (3); S3) Preparation of CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterogeneous structure layer: Using the vapor deposition method, the CsI reaction source is first deposited on the CsPbBr3 light-absorbing layer, and then in-situ crystallization is formed into CsPbBr3 / CsPbI x Br 3-x Heterogeneous structures; Then continue to deposit SnCl2 reaction source, in situ crystallization to form CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Heterogeneous structure layer (4); S4) preparing a hole transport layer: Using the doctor blade method, CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Depositing a precursor solution of a hole transport layer on the heterostructure layer to obtain a hole transport layer (5); S5) preparing a protective layer (6) on the hole transport layer by thermal evaporation; S6) preparing an electrode (7) on the protective layer to complete the preparation of the solar cell.

9. The method according to claim 8, characterized in that: Step S1) (1) depositing a precursor solution of an electron transport layer on a transparent conductive substrate by vapor deposition or spin coating; In step S6), the electrode (7) is prepared on the protective layer by using a thermal evaporation method, a magnetron sputtering method or a screen printing method.

10. A CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x A method for manufacturing a heterojunction perovskite solar cell, characterized in that: The steps include: §1: Depositing a precursor solution of an electron transport layer on a transparent conductive substrate (1), and obtaining an electron transport layer (2) after annealing and crystallization; §2: Preparation of CsPbBr3 light absorbing layer: First, a PbBr2 precursor solution is deposited on the electron transport layer (2) by a doctor blade method, and a PbBr2 thin film is obtained after annealing and crystallization; Then, a CsBr reaction source is deposited on the PbBr2 film by a vapor deposition method, and a CsPbBr3 light absorbing layer is formed by in-situ crystallization (3); §3: Using the dual-gas path vapor deposition method, CsI reaction source and SnCl2 reaction source are simultaneously deposited on the CsPbBr3 light-absorbing layer, and CsPbBr3 / CsPb is formed by in-situ crystallization. 0.6 Sn 0.4 I x Br 3-x Heterogeneous structure layer (4); §4: Using the scraping method, on CsPbBr3 / CsPb 0.6 Sn 0.4 I x Br 3-x Depositing a precursor solution of a hole transport layer on the heterostructure layer to obtain a hole transport layer (5); §5: Using a thermal evaporation method, a protective layer (6) is prepared on the hole transport layer; §6: Prepare an electrode on the protective layer (7) to complete the preparation of the solar cell.

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