Perovskite solar cell and preparation method thereof

Abstract

The invention relates to the technical field of solar cells, in particular to a perovskite solar cell and a preparation method thereof. The perovskite solar cell comprises a substrate, a transparent conductive cathode, a hole transport layer, a perovskite active layer, an electron transport layer and a metal anode which are sequentially arranged from bottom to top, and an ion barrier layer is arranged between the perovskite active layer and the transparent conductive cathode. The ion barrier layer comprises one or a combination of a dielectric polymer 2-vinylnaphthalene and poly N-ethylaniline. According to the perovskite solar cell, the ion barrier layer is arranged, so that migration of halogen elements in perovskite is effectively inhibited, the risk of structural decomposition of the perovskite is reduced, and the overall stability of a device is enhanced.

Description

[0001] The present application relates to the technical field of solar cells, and in particular to a perovskite solar cell and a preparation method thereof. Background Art

[0002] Among many emerging energy sources, solar energy is an unlimited and widely distributed natural resource. Its unique advantages make it increasingly prominent in the process of global energy transformation. Perovskite solar cells are widely cited due to their amazing efficiency growth rate, significant cost advantages and easy large-scale production.

[0003] However, iodine ion migration is prone to occur in perovskite solar cells, which can lead to the decomposition of perovskite devices and corrosion of electrodes, resulting in poor stability of perovskite solar cells. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the purpose of the present application is to provide a perovskite solar cell, which effectively suppresses the migration problem of iodine ions and improves the stability of the perovskite solar cell.

[0005] To achieve the above-mentioned purpose, a perovskite solar cell is provided, characterized in that it includes a substrate, a transparent conductive cathode, a hole transport layer, a perovskite active layer, an electron transport layer and a metal anode arranged in sequence from bottom to top, an ion blocking layer is arranged between the perovskite active layer and the transparent conductive cathode, and the ion blocking layer includes one or a combination of dielectric polymers 2-vinylnaphthalene and poly-N-ethylaniline.

[0006] Furthermore, the ion blocking layer is located between the hole transport layer and the perovskite active layer.

[0007] Furthermore, the ion blocking layer and the hole transport layer are mixed into one layer.

[0008] Furthermore, the ion barrier layer has a thickness of 1-20 nm.

[0009] To achieve the above objectives, the present application also provides a method for preparing a perovskite solar cell, comprising: cleaning the substrate composed of the substrate and the transparent conductive cathode, and drying; Preparing a hole transport layer on the upper surface of the substrate; Preparing a perovskite active layer on the upper surface of the substrate; Preparing an electron transport layer on the upper surface of the substrate; Preparing a metal anode on the upper surface of the substrate; Before preparing the perovskite active layer, an ion blocking layer is prepared on the upper surface of the substrate using a solution comprising one or a combination of dielectric polymers 2-vinylnaphthalene and poly-N-ethylaniline.

[0010] Furthermore, after the hole transport layer is prepared, an ion blocking layer is prepared on the upper surface of the substrate using a solution comprising one or a combination of dielectric polymers 2-vinylnaphthalene and poly-N-ethylaniline.

[0011] Furthermore, when preparing the hole transport layer, a solution including one or a combination of dielectric polymers 2-vinylnaphthalene and poly-N-ethylaniline is mixed to prepare a mixed layer forming the hole transport layer and the ion blocking layer.

[0012] Furthermore, the concentration of the dielectric polymer 2-vinylnaphthalene and / or poly-N-ethylaniline in the solution is 5-20 mg / ml, and the thickness of the ion barrier layer is 1-20 nm.

[0013] Furthermore, it also includes: The ion barrier layer is thermally annealed at a temperature of 60-100°C.

[0014] To achieve the above objectives, the present application also provides a perovskite solar cell, which is prepared using the perovskite solar cell preparation method as described above.

[0015] A perovskite solar cell of the present application effectively inhibits the migration of halogen elements in the perovskite by setting an ion barrier layer, fundamentally reduces the risk of perovskite structure decomposition, and significantly enhances the overall stability of the device.

[0016] A perovskite solar cell of the present application can isolate the direct contact between the organic transport layer and the halogen element, thereby avoiding possible adverse reactions between the two, and thereby greatly improving the stability of the organic transport layer.

[0017] A perovskite solar cell of the present application can effectively inhibit the corrosion of halogen elements on metal electrodes, improve the anti-oxidation ability of metal electrodes, and ensure its reliability under long-term operating conditions.

[0018] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings: Figure 1This is a schematic diagram of the structure of the perovskite solar cell according to Example 1 of the present application; Figure 2 This is a schematic diagram of the structure of a perovskite solar cell according to Example 2 of the present application; Figure 3 A schematic diagram showing the performance comparison of the perovskite solar cells of the present application; Figure 4 This is a schematic diagram of a process for preparing a perovskite solar cell according to Example 3 of the present application; Figure 5 This is a schematic diagram of the results of the silver corrosion experiment of this application; Figure 6 The JV performance curve of the perovskite solar cell of this application; Figure 7 A schematic diagram showing the comparison of thermal stability of the perovskite solar cell of the present application and that of a standard device under extreme conditions; Figure 8 A schematic diagram showing the comparison of the working stability of the perovskite solar cell of the present application and the standard device at the maximum power output point; In the figure: 10-substrate, 20-transparent conductive cathode, 30-hole transport layer, 40-ion blocking layer, 50-perovskite active layer, 60-electron transport layer, 70-metal anode, 80-hole transport & ion blocking layer. DETAILED DESCRIPTION

[0020] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes and are not intended to limit the scope of protection of the present application.

[0021] It should be understood that the various steps described in the method implementation of the present application can be performed in different orders and / or performed in parallel. In addition, the method implementation may include additional steps and / or omit the steps shown. The scope of the present application is not limited in this respect.

[0022] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0023] It should be noted that the modifications of "one" and "plurality" mentioned in this application are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more". "Plurality" should be understood as two or more.

[0024] Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0025] Example 1 An embodiment of the present application provides a perovskite solar cell, referring to Figure 1 , including a substrate 10, a transparent conductive cathode 20, a hole transport layer 30, a perovskite active layer 50, an electron transport layer 60 and a metal anode 70 arranged in sequence from bottom to top, and also including: The ion blocking layer 40 includes one or a combination of dielectric polymers 2-vinylnaphthalene (PVN) and poly-N-ethylaniline (PVK). The chemical structures of PVN and PVK are shown below: .

[0026] In this embodiment, the ion blocking layer 40 is disposed between the hole transport layer 30 and the perovskite active layer 50 .

[0027] In the present embodiment, the ion blocking layer 40 is formed by wet coating using a doctor blade coating method.

[0028] In some other embodiments, the ion blocking layer 40 may be formed by any wet coating method including spin coating, slit coating and spray coating.

[0029] In this embodiment, the concentration of the ion blocking layer 40 can also be prepared using a solution with a concentration of 5-20 mg / ml according to actual needs.

[0030] In this embodiment, the thickness of the ion blocking layer 40 can be set to 1-20 nm according to actual needs.

[0031] In this embodiment, the hole transport layer 30 includes one or more of PTAA, PEDOT:PSS, F4-TCNQ, 2-PACZ or metal oxides.

[0032] In this embodiment, the concentration of the solution for preparing the hole transport layer 30 is 1-20 mg / ml, and the thickness is set in the range of 1-100 nm.

[0033] In this embodiment, the perovskite active layer 50 includes a perovskite material with an ABX3 structure, wherein A is Cs+, HN=CHNH3+, CH3NH3+, Rb+ or a combination thereof; B is Sn2+, Pb2+ or a combination thereof; and X is Cl-, Br-, I- or a combination thereof.

[0034] In this embodiment, the thickness of the perovskite active layer 50 is set in the range of 100-1500 nm.

[0035] In this embodiment, the electron transport layer 60 is one or more of C60, BCP, PCBM, Bphen, Alq3, ZnO, SnO2, and has a thickness ranging from 1 to 100 nm.

[0036] In this embodiment, the metal anode 70 is Au, Ag, Al or Cu, and has a thickness ranging from 50 to 300 nm.

[0037] It should be noted that the substrate 10 is a glass substrate, and after an ITO cathode is provided on the glass substrate, it can be called an ITO substrate.

[0038] Example 2 An embodiment of the present application provides a perovskite solar cell, referring to Figure 2 The difference between Example 2 of the present application and Example 1 is that: In Example 2 of the present application, the ion blocking layer 40 can be mixed with the hole transport layer 30 into one layer to form a hole transport & ion blocking layer 80 .

[0039] The solution for preparing the hole transport & ion blocking layer 80 is a solution obtained by mixing the solution for preparing the ion blocking layer 40 and the solution for preparing the hole transport layer 30 .

[0040] In this embodiment, the four structures of the perovskite solar cells and the standard device of the present application are subjected to AM1.5G, 1000 W / m 2 Tested under global standard sunlight, see Figure 3, test schematic diagram of standard devices and several devices equipped with ion transport layers, among which, the structure of the Control device (i.e., standard device) is Glass / ITO / PTAA / perovskite active layer / C60 / BCP / Cu, the difference between the PTAA&PVN device and the standard device is that the hole transport layer is a fused hierarchical structure composed of PTAA and PVN, the difference between the PTAA&PVK device and the standard device is that the hole transport layer is a fused structure composed of PTAA and PVK, the difference between the PTAA / PVN device and the standard device is that the hole transport layer and the ion transport layer composed of PVN are stacked, and the difference between the PTAA / PVK device and the standard device is the structure in which the hole transport layer and the ion transport layer composed of PVN are stacked.

[0041] Example 3 One embodiment of the present application provides a method for preparing a perovskite solar cell, referring to Figure 4 include: Step S101: cleaning the ITO substrate consisting of the substrate and the transparent conductive cathode, and drying it with nitrogen.

[0042] Step S102: preparing a hole transport layer and an ion blocking layer on the surface of the transparent conductive cathode ITO of the ITO substrate, and thermally annealing the formed thin film; In this embodiment, the ion blocking layer is formed by using any one of spin coating, blade coating, slit coating and spray coating wet coating methods.

[0043] In this embodiment, the concentration of the ion barrier layer can also be set at 5-20 mg / ml according to actual needs.

[0044] In this embodiment, the thickness of the ion blocking layer can be set to 1-20 nm according to actual needs.

[0045] In this embodiment, the thermal annealing temperature of the hole transport layer is in the range of 40 to 150°C. In this embodiment, the thermal annealing temperature of the ion barrier layer is 60-100°C.

[0046] In this embodiment, the hole transport layer is one or more of PTAA, PEDOT:PSS, F4-TCNQ, 2-PACZ or metal oxides, the solution concentration is 1-20 mg / ml, and the thickness setting range is 1-100 nm.

[0047] Step S103: preparing a perovskite active layer on the ion barrier layer by evaporation, spin coating, blade coating, or spraying, and performing thermal annealing; In this embodiment, the perovskite active layer includes a perovskite material with an ABX3 structure, wherein A is Cs+, HN=CHNH3+, CH3NH3+, Rb+ or a combination thereof; B is Sn2+, Pb2+ or a combination thereof; X is Cl-, Br-, I- or a combination thereof, and the thickness of the perovskite active layer is set in the range of 100~1500nm.

[0048] In this embodiment, the thermal annealing temperature of the perovskite active layer is in the range of 60-150°C.

[0049] Step S104: evaporating, spin coating, scraping, or spraying an electron transport layer on the perovskite active layer; In this embodiment, the electron transport layer is one or more of C60, BCP, PCBM, Bphen, Alq3, ZnO, SnO2, and has a thickness ranging from 1 to 100 nm.

[0050] In this embodiment, the electron transport layer thermal annealing temperature ranges from 40 to 150°C.

[0051] Step S105: evaporating a metal anode on the electron transport layer.

[0052] In this embodiment, the metal anode is Au, Ag, Al or Cu, and has a thickness ranging from 50 to 300 nm.

[0053] In some other embodiments, the ion blocking layer and the hole transport layer are prepared as one layer by mixing corresponding preparation solutions.

[0054] In this embodiment, silver corrosion experiments were performed on an ITO substrate with an ion barrier layer and an ITO substrate without an ion barrier layer. Figure 5 As shown, when no ion barrier layer is added, the current duration is 890 s, and the current duration of the device containing the PVN thin film (ion barrier layer) is 1470 s.

[0055] In this embodiment, the performance of the prepared perovskite solar cell (i.e., the target device in the figure) and the standard device were tested under the following test conditions: AM 1.5G, 1000 W / m 2 ,like Figure 6 As shown, the open circuit voltage of the target device is measured ( V OC ) is 1.16 V, the short-circuit current ( J SC ) is 24.52 mA / cm 2 , the fill factor (FF) is 81.55% and the photoelectric conversion efficiency (PCE) is 23.19%.

[0056] In this embodiment, the obtained perovskite solar cell is also subjected to an extreme conditions stability test, and a thermal cycle test is performed in accordance with the test requirements listed by the German Rhine TÜV Group in the IEC 61215 standard. The unpackaged perovskite solar cell is subjected to a temperature cycle from -40°C to 85°C in an open circuit state. Each temperature cycle lasts for 2 hours, and the efficiency test is performed every 10 hours.

[0057] like Figure 7 As shown, after 1000 hours of thermal aging test, the perovskite solar cell (target device) can still maintain more than 80% of its initial efficiency, while the standard device has dropped to 48.7% of the initial efficiency.

[0058] like Figure 8 As shown, the target device was subjected to a maximum power output point working stability test. Under the AM1.5G global standard sunlight, the target device can still maintain 80% of the initial efficiency after 600 hours of continuous operation, while the efficiency of the standard device dropped to 39.4% of the initial value.

[0059] In this embodiment, the thermal annealing adopts one or more of constant temperature hot plate heating, oven heating, laser thermal annealing, far infrared heating, hot air heating, or microwave heating.

[0060] Example 4 An embodiment of the present application provides a method for preparing a perovskite solar cell, the process of which is as follows: 10 mg of PVN powder was added to 1 ml of chlorobenzene, and 300 μl of PVN solution was dissolved in 10 mg / ml PTAA solution to form a mixed solution, which was placed under a magnetic stirrer to dissolve for 1 hour; Clean the ITO substrate with a surface roughness less than 1 nm and blow dry it with nitrogen after cleaning; The hole transport and ion blocking layer was prepared on the ITO substrate by blade coating using the mixed solution with a coating thickness of 300 μm and a coating speed of 20 mm / s, and then annealed (annealing temperature 100°C, annealing time 10 min).

[0061] The CsI·RbI·FAPbI3 perovskite (5:5:90, 1.3 mol / L, 80% N,N-dimethylformamide, 20% dimethyl sulfoxide) active layer was prepared by spin coating on the hole transport & ion blocking layer (rotation speed 5000 rpm, 50s, anti-solvent chlorobenzene was added for 45s), and annealed (annealing temperature 150℃, annealing time 15min); An electron transport layer C60 (thickness 30 nm) and BCP (thickness 7 nm) are evaporated on the surface of the active layer; and a metal anode Cu (thickness 100 nm) is evaporated on the electron transport layer to obtain a perovskite solar cell device.

[0062] Under standard test conditions, i.e. AM1.5G, 1000 W / m 2 The device is measured under global standard sunlight. V OC is 1.14 V, J SC 24.27 mA / cm 2 , FF is 80.77% and PCE is 22.35%.

[0063] Example 5 An embodiment of the present application provides a method for preparing a perovskite solar cell, the process of which is as follows: 10 mg PVK powder was added to 1 ml chlorobenzene, and 300 μl PVK solution was dissolved in 10 mg / ml PTAA solution and placed under a magnetic stirrer to dissolve for 1 hour; Clean the ITO substrate with a surface roughness less than 1 nm and blow dry it with nitrogen after cleaning; The hole transport and ion blocking layer was prepared on the ITO substrate by blade coating with a coating thickness of 300 μm and a coating speed of 20 mm / s, and then annealed (annealing temperature 100°C, annealing time 10 min).

[0064] The CsI·RbI·FAPbI3 perovskite (5:5:90, 1.3 mol / L, 80% N,N-dimethylformamide, 20% dimethyl sulfoxide) active layer was prepared by spin coating on the hole transport & ion blocking layer (rotation speed 5000 rpm, 50 s, anti-solvent chlorobenzene was added for 45 s), and annealed (annealing temperature 150 °C, annealing time 15 min); The electron transport layer C is evaporated on the surface of the active layer 60 (thickness 30nm), BCP (thickness 7nm); and evaporate the metal anode Cu (thickness 100nm) on the electron transport layer to obtain a perovskite solar cell device.

[0065] Under standard test conditions, i.e. AM1.5G, 1000 W / m 2 The device is measured under global standard sunlight. V OC is 1.13 V, J SC 23.88 mA / cm 2, FF is 78.26% and PCE is 21.12%.

[0066] Example 6 An embodiment of the present application provides a method for preparing a perovskite solar cell, the process of which is as follows: Clean the ITO substrate with a surface roughness less than 1 nm and blow dry it with nitrogen after cleaning; Then, 5 mg / ml PTAA solution (dissolved in chlorobenzene CB) and 1 mg / ml PVN solution (dissolved in chlorobenzene CB) were mixed in a ratio of 3:1.

[0067] The hole transport layer and ion blocking layer were prepared on the ITO substrate by blade coating with a coating thickness of 300 μm and a coating speed of 20 mm / s, and then annealed (annealing temperature 100°C, annealing time 10 min).

[0068] The CsI·RbI·FAPbI3 perovskite (5:5:90, 1.1 mol / L, 2-methoxyethanol) active layer was prepared by blade coating on the hole transport layer and ion blocking layer (300 μm blade coating thickness, 20 mm / s blade coating speed), and annealed (annealing temperature 150°C, annealing time 15 min); The electron transport layer C is evaporated on the surface of the active layer 60 (thickness 30nm), BCP (thickness 7nm); and evaporate the metal anode Cu (thickness 100nm) on the electron transport layer to obtain a perovskite solar cell device.

[0069] Under standard test conditions, i.e. AM1.5G, 1000 W / m 2 The device is measured under global standard sunlight. V OC is 1.14 V, J SC 22.58 mA / cm 2 , FF is 77.39% and PCE is 19.92%.

[0070] Example 7 One embodiment of the present application provides a perovskite solar cell, which is prepared using the perovskite solar cell preparation method as described above.

[0071] The above description is only a partial embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

[0072] In addition, although each operation is described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in a sequential order. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the application. Some features described in the context of a separate embodiment can also be implemented in a single embodiment in combination. On the contrary, the various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination mode.

[0073] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.

Claims

1. A perovskite solar cell, characterized in that: The invention comprises a substrate, a transparent conductive cathode, a hole transport layer, a perovskite active layer, an electron transport layer and a metal anode which are arranged in sequence from bottom to top. An ion blocking layer is arranged between the perovskite active layer and the transparent conductive cathode. The ion blocking layer comprises one or a combination of dielectric polymers 2-vinylnaphthalene and poly-N-ethylaniline.

2. The perovskite solar cell according to claim 1, characterized in that The ion blocking layer is located between the hole transport layer and the perovskite active layer.

3. The perovskite solar cell according to claim 1, characterized in that The ion blocking layer and the hole transport layer are mixed into one layer.

4. The perovskite solar cell according to claim 1, characterized in that: The thickness of the ion barrier layer is 1-20 nm.

5. A method for preparing a perovskite solar cell, characterized in that: include: cleaning the substrate composed of the substrate and the transparent conductive cathode, and drying; Preparing a hole transport layer on the upper surface of the substrate; Preparing a perovskite active layer on the upper surface of the substrate; Preparing an electron transport layer on the upper surface of the substrate; Preparing a metal anode on the upper surface of the substrate; Before preparing the perovskite active layer, an ion blocking layer is prepared on the upper surface of the substrate using a solution comprising one or a combination of dielectric polymers 2-vinylnaphthalene and poly-N-ethylaniline.

6. The method for preparing a perovskite solar cell according to claim 5, characterized in that: After the hole transport layer is prepared, an ion blocking layer is prepared on the upper surface of the substrate using a solution comprising one or a combination of dielectric polymers 2-vinylnaphthalene and poly-N-ethylaniline.

7. The method for preparing a perovskite solar cell according to claim 5, characterized in that: When preparing the hole transport layer, a solution including one or a combination of dielectric polymers 2-vinylnaphthalene and poly-N-ethylaniline is mixed to prepare a mixed layer forming the hole transport layer and the ion blocking layer.

8. The method for preparing a perovskite solar cell according to claim 5, characterized in that: The concentration of the dielectric polymer 2-vinylnaphthalene and / or poly-N-ethylaniline in the solution is 5-20 mg / ml, and the thickness of the ion barrier layer is 1-20 nm.

9. The method for preparing a perovskite solar cell according to claim 1, characterized in that: Also includes: The ion barrier layer is thermally annealed at a temperature of 60-100°C.

10. A perovskite solar cell, characterized in that: The perovskite solar cell is prepared by the preparation method of any one of claims 5 to 9.

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