Perovskite solar cell passivated and modified by inorganic metal oxide nanoparticles and preparation method thereof

Abstract

The invention discloses a perovskite solar cell passivated and modified by inorganic metal oxide nanoparticles and a preparation method of the perovskite solar cell, and belongs to the technical field of perovskite solar cells. According to the invention, magnesium oxide, aluminum oxide, silicon oxide, zirconium oxide and other non-nano particles are applied to interface modification of the perovskite light absorption layer and the electrode layer. The corresponding inorganic metal oxide layer effectively passivates interface defects through chemical passivation, and serves as a compact physical barrier to block erosion of water vapor, oxygen and ion migration to perovskite and inhibit phase change of the perovskite and loss of volatile components, so that the photoelectric conversion efficiency and stability of the perovskite solar cell are improved. The cost of required materials is low, the preparation process is simple, good contact between the perovskite light absorption layer and the electrode layer is achieved, and a good scheme is provided for practical application of the perovskite solar cell.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite solar cells, and particularly to a perovskite solar cell passivated and modified with inorganic metal oxide nanoparticles and a preparation method thereof. Background Art

[0002] Perovskite solar cells are a new type of photovoltaic material, which are based on compounds with a perovskite structure and usually use organic-inorganic lead halides as the light absorption layer. Perovskite materials have attracted much attention due to their excellent optoelectronic properties and relatively low production costs, and have made remarkable progress in the field of solar cells in recent years. However, in the materials of conventional perovskite solar cells, although the widespread use of the hole transport layer has high efficiency, it is expensive and has poor stability. The cost of the metal electrode is high, and halogen atoms will migrate from the perovskite phase and combine with the electrode to form metal halides, thereby reducing the performance, which has become the biggest obstacle to the industrialization of perovskite solar cells. Using inexpensive, chemically stable, and highly conductive polyaniline and carbon materials to prepare electrodes to replace metal electrodes can further reduce costs and simplify the manufacturing process. At the same time, it can also improve the battery stability. However, the interface problem between the perovskite layer and the electrode is one of the key factors affecting the battery efficiency and stability, especially when using polyaniline electrodes or carbon electrodes. Therefore, it is necessary to develop a method to improve the interface contact between the perovskite layer and the electrode layer. Summary of the Invention

[0003] In view of the above-mentioned defects of the prior art, in the first aspect of the present invention, there is provided a perovskite solar cell passivated and modified with inorganic metal oxide nanoparticles, which has low material price, high photoelectric conversion efficiency, and strong stability. The battery structure is, from bottom to top, a transparent conductive substrate, an electron transport layer, a perovskite light absorption layer, an inorganic metal oxide layer, and an electrode layer; the inorganic metal oxide layer is one of magnesium oxide (MgO), aluminum oxide (Al2O3), silicon dioxide (SiO2), and zirconium oxide (ZrO2) nanoparticles.

[0004] Preferably, the transparent conductive substrate includes one of an ITO glass substrate, an FTO glass substrate, and an ITO flexible substrate, and its thickness is 0.1 - 2 mm.

[0005] Preferably, the electron transport layer is SnO2, and its thickness is 1 - 20 nm.

[0006] Preferably, the perovskite light absorption layer is an ABX3 perovskite crystal, and its thickness is 300 - 1000 nm; in the ABX3 perovskite crystal, A is cesium ion (Cs + ), methylammonium cation (MA + ), or formamidinium cation (FA +), and B is Pb 2+ or Sn 2+ , X is I - or Br - .

[0007] Preferably, the thickness of the inorganic metal oxide layer is 5 - 500 nm; the particle size of the nanoparticles is 5 - 500 nm.

[0008] Preferably, the electrode layer is one of a polyaniline electrode, a carbon electrode, a polyaniline - carbon nanotube composite electrode, and a hole transport layer / metal electrode, and its thickness is 0.1 - 50 μm.

[0009] More preferably, the metal electrode in the hole transport layer / metal electrode includes one of a gold electrode, a silver electrode, a copper electrode, and an aluminum electrode.

[0010] In the second aspect of the present invention, a preparation method of a perovskite solar cell passivated and modified with the inorganic metal oxide nanoparticles of the first aspect of the present invention, which has a simple process, is provided, and includes the following steps: S1: Clean the transparent conductive substrate, and perform drying and ultraviolet - ozone treatment; S2: Coat a precursor solution on the surface of the transparent conductive substrate, and then anneal to obtain an electron transport layer; S3: Prepare and filter a perovskite precursor solution, coat the perovskite precursor solution on the surface of the electron transport layer, and anneal to obtain a perovskite light - absorbing layer; S4: Prepare and filter an inorganic metal oxide nanoparticle precursor solution, coat the inorganic metal oxide nanoparticle precursor solution on the surface of the perovskite light - absorbing layer, and anneal to obtain an inorganic metal oxide layer; S5: Complete the preparation of the electrode layer on the surface of the inorganic metal oxide layer to obtain a perovskite solar cell passivated and modified with inorganic metal oxide nanoparticles.

[0011] During the preparation, those skilled in the art can select a suitable coating method according to the actual production conditions, such as spin - coating or blade - coating, etc., which can be used for the preparation of each layer structure.

[0012] Preferably, in S2, the precursor solution is a SnO2 precursor solution, and its concentration range is 1 wt.% - 10 wt.%; the annealing conditions include annealing at 100 - 180 °C for 20 - 60 min.

[0013] Preferably, in S3, the annealing conditions include annealing at 80 - 150 °C for 10 - 60 min.

[0014] Preferably, in S4, the concentration range of the inorganic metal oxide nanoparticle precursor solution is 0.1 - 10 mg / mL; the annealing conditions include annealing at 60 - 150 °C for 5 - 60 min.

[0015] Preferably, in S5, when the electrode layer is one of a polyaniline electrode, a carbon electrode, and a polyaniline - carbon nanotube composite electrode, a conductive plasma is coated on the surface of the inorganic metal oxide layer and annealed to obtain the electrode layer, and the annealing conditions include annealing at 80 - 150 °C for 10 - 60 min; when the electrode layer is a hole - transport layer / metal electrode, a hole - transport layer is coated on the surface of the inorganic metal oxide layer and a metal electrode is deposited.

[0016] Based on the above technical solutions, the design concept and principle of the present invention are as follows: Different from traditional perovskite surface modification materials (various organic small molecules, polymers, and organic halides), the magnesium oxide (MgO), aluminum oxide (Al2O3), silicon oxide (SiO2), and zirconium oxide (ZrO2) nanoparticles used in the present invention have extremely high chemical and mechanical stability. The main function of the obtained metal oxide layer is also different from that of the electron - transport layer (such as SnO2, TiO2, ZnO) or hole - transport layer (such as NiO x ) in the prior art to improve charge transport, but rather plays a role of chemical passivation and physical isolation between the perovskite layer and the electrode layer. These metal oxide layers can form chemical bonds such as Pb - O with lead or halogens on the perovskite surface, effectively passivate the defect states on the perovskite surface and at the interface, enhance the interfacial bonding force, thereby reducing the charge recombination center, inhibiting non - radiative recombination, and increasing the open - circuit voltage. At the same time, it can also act as a dense physical barrier to block the erosion of perovskite by water vapor, oxygen, and ion migration, inhibit perovskite phase change and the loss of volatile components, and improve the stability of the battery. The preparation process of the above - mentioned metal oxide layer is simple and efficient, improving the photoelectric conversion efficiency and stability of perovskite solar cells. Combining electrodes such as polyaniline electrodes, carbon electrodes, and polyaniline - carbon nanotube composite electrodes can significantly reduce the raw material cost and simplify the manufacturing process, providing a feasible solution for the actual production of perovskite solar cells.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention provides a perovskite solar cell passivated and modified with inorganic metal oxide nanoparticles. Its inorganic metal oxide layer effectively passivates the interface defects through chemical passivation and acts as a dense physical barrier to block the erosion of perovskite by water vapor, oxygen, and ion migration and inhibit perovskite phase change and the loss of volatile components, having the advantages of high photoelectric conversion efficiency and strong stability.

[0018] The present invention provides a method for preparing a perovskite solar cell passivated and modified with inorganic metal oxide nanoparticles. The required materials are inexpensive and the preparation process is simple, providing a good solution for expanding the practical application of perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the device structure of a perovskite solar cell passivated and modified with inorganic metal oxide nanoparticles; Figure 2 is a current density-voltage curve graph of the perovskite solar cells prepared in Example 1 and Comparative Example 1; Figure 3 is a current density-voltage curve graph of the perovskite solar cells prepared in Example 2 and Comparative Example 2; Figure 4 is a current density-voltage curve graph of the perovskite solar cells prepared in Example 3 and Comparative Example 3; Figure 5 is a current density-voltage curve graph of the perovskite solar cells prepared in Example 4 and Comparative Example 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples. The experimental methods without specific conditions in the following examples are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0021] Example 1 This example provides a perovskite solar cell passivated and modified with Al2O3 nanoparticles, and its structure is as Figure 1 shown. The preparation method is as follows: S1: Ultrasonically clean the ITO transparent conductive substrate with a cleaner, deionized water, acetone, isopropanol, and ethanol for 5 minutes each in sequence, and blow it dry with a nitrogen gun, and then perform ultraviolet ozone treatment; S2: Prepare a 3 wt.% concentration of SnO2 precursor solution, spin-coat the SnO2 precursor solution on the ITO surface, and then anneal it at 150 °C for 30 minutes to obtain an electron transport layer; S3: Dissolve FAPbI3, CsPbI3, and MAPbBr3 separately in a mixed solvent prepared by mixing N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) at a volume ratio of 4:1, with a concentration of 1.5 M. After complete dissolution, add 5% molar concentration of CsPbI3 and 10% molar concentration of MAPbBr3 to the FAPbI3 solution, and add 25% molar concentration of MACl for crystallization regulation; use a pipette to aspirate 50 μL of the perovskite precursor solution and spin-coat it on the surface of the SnO2 electron transport layer at a rotation speed of 4000 rpm for a total spin-coating duration of 30 s. Drop 400 μL of the green antisolvent ethyl acetate (EA) 5 s before the end of spin-coating, and then anneal at 100 °C for 40 min to obtain the perovskite light-absorbing layer; S4: Prepare a 1 mg / mL isopropanol solution of Al2O3 nanoparticles, stir and filter it, spin-coat it on the surface of the perovskite light-absorbing layer at a rotation speed of 4000 rpm for 30 s, and anneal at 100 °C for 10 min to obtain the inorganic metal oxide layer; S5: Spin-coat the polyaniline conductive paste on the surface of the inorganic metal oxide layer and anneal at 100 °C for 60 min to form the polyaniline electrode, obtaining a perovskite solar cell passivated and modified with Al2O3 nanoparticles.

[0022] Example 2 This example provides a perovskite solar cell passivated and modified with MgO nanoparticles, which is basically the same as the preparation method of Example 1, except that: replace the 1 mg / mL isopropanol solution of Al2O3 nanoparticles in step S4 with a 0.5 mg / mL isopropanol solution of MgO nanoparticles; replace the polyaniline conductive paste in step S5 with a carbon paste; other steps remain unchanged.

[0023] Example 3 This example provides a perovskite solar cell passivated and modified with ZrO2 nanoparticles, which is basically the same as the preparation method of Example 1, except that: replace the 1 mg / mL isopropanol solution of Al2O3 nanoparticles in step S4 with a 0.8 mg / mL isopropanol solution of ZrO2 nanoparticles; replace the polyaniline conductive paste in step S5 with a polyaniline-carbon nanotube composite paste; other steps remain unchanged.

[0024] Example 4 This embodiment provides a perovskite solar cell passivated and modified with SiO2 nanoparticles, which is basically the same as the preparation method of Embodiment 1, except that: the 1 mg / mL Al2O3 nanoparticle isopropanol solution in step S4 is replaced with a 1.2 mg / mL SiO2 nanoparticle isopropanol solution; in step S5, instead of scraping the plasma on the metal oxide surface, a Spiro-OMeTAD hole transport layer is spin-coated at a speed of 5000 rpm, and then a 50 nm gold electrode is deposited on the hole transport layer by thermal evaporation; other steps remain unchanged.

[0025] Comparative Example 1 This comparative example provides a perovskite solar cell, which is basically the same as the preparation method of Embodiment 1, except that: step S4 is cancelled, that is, there is no passivation modification with Al2O3 nanoparticles, and other steps remain unchanged.

[0026] Comparative Example 2 This comparative example provides a perovskite solar cell, which is basically the same as the preparation method of Embodiment 2, except that: step S4 is cancelled, that is, there is no passivation modification with MgO nanoparticles, and other steps remain unchanged.

[0027] Comparative Example 3 This comparative example provides a perovskite solar cell, which is basically the same as the preparation method of Embodiment 2, except that: step S4 is cancelled, that is, there is no passivation modification with ZrO2 nanoparticles, and other steps remain unchanged.

[0028] Comparative Example 4 This comparative example provides a perovskite solar cell, which is basically the same as the preparation method of Embodiment 1, except that: step S4 is cancelled, that is, there is no passivation modification with SiO2 nanoparticles, and other steps remain unchanged.

[0029] The perovskite solar cells prepared in the above embodiments and comparative examples were characterized to obtain their corresponding current density-voltage curves. Figures 2 - 5 The current density-voltage curves of the embodiments and the corresponding comparative examples are respectively shown.

[0030] It can be found from the above comparison that in a variety of electrode systems, the open-circuit voltage, short-circuit current density, and fill factor of the perovskite solar cells passivated and modified with inorganic metal oxide nanoparticles have been significantly improved. This shows that the inorganic metal oxide layer of the present invention can significantly improve the efficiency, stability, and process compatibility of perovskite devices through multi-dimensional effects such as chemical passivation and physical protection. The combination of the inorganic metal oxide layer with a polyaniline electrode, a carbon electrode, and a polyaniline-carbon nanotube composite electrode can significantly reduce the raw material cost of perovskite solar cells, simplify the manufacturing process, and improve the photoelectric conversion efficiency, providing a feasible solution for the actual production and preparation of perovskite solar cells.

[0031] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in this technical field based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should fall within the protection scope determined by the claims.

Claims

1. A perovskite solar cell modified by passivation of inorganic metal oxide nanoparticles, characterized in that: The battery structure is composed of a transparent conductive substrate, an electron transport layer, a perovskite light absorption layer, an inorganic metal oxide layer and an electrode layer from bottom to top; the inorganic metal oxide layer is one of MgO, Al2O3, SiO2, and ZrO2 nanoparticles.

2. The inorganic metal oxide nanoparticle passivation modified perovskite solar cell according to claim 1, characterized in that: The transparent conductive substrate comprises one of an ITO glass substrate, a FTO glass substrate and an ITO flexible substrate, and has a thickness of 0.1 to 2 mm.

3. The inorganic metal oxide nanoparticle passivation modified perovskite solar cell according to claim 1, characterized in that: The electron transport layer is SnO2, and its thickness is 1-20 nm.

4. The inorganic metal oxide nanoparticle passivation modified perovskite solar cell according to claim 1, characterized in that: The perovskite light-absorbing layer is an ABX3 perovskite crystal with a thickness of 300-1000 nm; in the ABX3 perovskite crystal, A is one of cesium ions, methylammonium cations or formamidinium cations, and B is Pb 2+ or Sn 2+ , X is I - or Br - .

5. The inorganic metal oxide nanoparticle passivation modified perovskite solar cell according to claim 1, characterized in that: The thickness of the inorganic metal oxide layer is 5-500 nm; the particle size of the nanoparticles is 5-500 nm.

6. The inorganic metal oxide nanoparticle passivation modified perovskite solar cell according to claim 1, characterized in that: The electrode layer is one of a polyaniline electrode, a carbon electrode, a polyaniline-carbon nanotube composite electrode, and a hole transport layer / metal electrode, and has a thickness of 0.1-50 μm; The metal electrode in the hole transport layer / metal electrode includes one of a gold electrode, a silver electrode, a copper electrode, and an aluminum electrode.

7. A method for preparing a perovskite solar cell modified by passivation of inorganic metal oxide nanoparticles according to any one of claims 1 to 6, characterized in that: The steps include: S1: Cleaning the transparent conductive substrate, and performing drying and UV-ozone treatment; S2: coating a precursor solution on the surface of a transparent conductive substrate, and then annealing to obtain an electron transport layer; S3: preparing a perovskite precursor solution and filtering it, coating the perovskite precursor solution on the surface of the electron transport layer, and annealing to obtain a perovskite light absorbing layer; S4: preparing an inorganic metal oxide nanoparticle precursor solution and filtering it, coating the inorganic metal oxide nanoparticle precursor solution on the surface of the perovskite light absorbing layer, and annealing to obtain an inorganic metal oxide layer; S5: completing the preparation of the electrode layer on the surface of the inorganic metal oxide layer to obtain a perovskite solar cell modified by passivation of inorganic metal oxide nanoparticles.

8. The method for preparing a perovskite solar cell modified by passivation of inorganic metal oxide nanoparticles according to claim 7, characterized in that: In the S2, the precursor solution is a SnO2 precursor solution, and its concentration ranges from 1 wt.% to 10wt.%, and the annealing conditions include annealing at 100-180°C for 20-60 min; in the S3, the annealing conditions include annealing at 80-150°C for 10-60 min.

9. The method for preparing a perovskite solar cell modified by passivation of inorganic metal oxide nanoparticles according to claim 7, characterized in that: In the S4, the concentration range of the inorganic metal oxide nanoparticle precursor solution is 0.1-10 mg / mL; and the annealing conditions include annealing at 60-150° C. for 5-60 min.

10. The method for preparing a perovskite solar cell modified by passivation of inorganic metal oxide nanoparticles according to claim 7, characterized in that: In S5, when the electrode layer is one of a polyaniline electrode, a carbon electrode, and a polyaniline-carbon nanotube composite electrode, a conductive plasma is coated on the surface of the inorganic metal oxide layer, and annealing is performed to obtain the electrode layer, and the annealing conditions include annealing at 80-150°C for 10-60 min; when the electrode layer is a hole transport layer / metal electrode, a hole transport layer is coated on the surface of the inorganic metal oxide layer and a metal electrode is deposited.

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