Perovskite solar cell based on synergistic effect of additive and passivation agent and preparation method thereof

Abstract

The application provides a perovskite solar cell based on synergistic effect of an additive and a passivation agent and a preparation method thereof, the perovskite solar cell based on synergistic effect of the additive and the passivation agent comprising: conductive electrodes FTO, a first hole transport layer, a second hole transport layer, a perovskite active layer, a passivation layer, an electron transport layer, an interface modification layer and a metal electrode layer arranged in sequence; wherein the perovskite active layer is added with an additive fluoropyridine; the passivation layer is added with a passivation agent diammonium hydriodate; the additive and the passivation agent can simultaneously interact with constituent components in the perovskite. Through synergistic effect of the fluoropyridine additive and the diammonium hydriodate passivation agent, formation of lead iodide and a delta phase in the perovskite thin film is inhibited, crystallinity of the perovskite thin film is improved, and defect density is reduced, and finally a perovskite solar cell with high performance and high stability is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite solar cells, and particularly relates to a perovskite solar cell based on synergistic effect of an additive and a passivation agent and a preparation method thereof. BACKGROUND

[0002] Since the 21st century, non-renewable energy based on fossil fuels has been increasingly exhausted, and people are facing an unprecedented energy crisis. It is urgent to solve the problem of energy shortage and seek pollution-free renewable new energy. Among numerous renewable energies, solar energy is currently the safest and most promising one, and photovoltaic devices can convert solar energy into electrical energy, which is an important strategy for human society to cope with energy crisis and seek sustainable development.

[0003] Perovskite solar cells have become a hot spot in the field of photovoltaics due to their high efficiency, low cost and ease of manufacture. However, the stability problem of perovskite materials has always been a key factor restricting their commercial application. The introduction of additives in the preparation of perovskite solar cells is an effective means to improve the film quality of perovskite crystals and inhibit the migration of lead ions. Additives can usually inhibit the release of lead ions from the perovskite lattice by coordinating with lead ions, improving the chemical stability of perovskite thin films. In addition, effective additives can also improve the overall performance of perovskite solar cells by passivating lattice defects, adjusting energy level structure, relieving interface stress, and reducing the enthalpy of perovskite crystal formation. In summary, the exploration of efficient perovskite additives is an important way to improve the performance of perovskite devices.

[0004] However, most of the existing researches are limited to exploring the effect of additives on perovskite thin films, but they generally ignore the synergistic effect with other functional layers of the device. This lack of research perspective makes it difficult to fully exploit the potential value of additives in interface energy level matching, carrier transport regulation and interface stress relief, and it is difficult to achieve synergistic optimization and systematic improvement of performance from the overall architecture of the device.

[0005] In summary, there is an urgent need for a new technical solution to solve the problems existing in the prior art. SUMMARY

[0006] Based on this, the application provides a perovskite solar cell based on the synergistic effect of an additive and a passivation agent and a preparation method thereof.

[0007] One object of the application is to provide a perovskite solar cell based on the synergistic effect of an additive and a passivation agent, comprising: conductive electrodes FTO, a first hole transport layer, a second hole transport layer, a perovskite active layer, a passivation layer, an electron transport layer, an interface modification layer and a metal electrode layer arranged in sequence.

[0008] The perovskite active layer is formed by an additive and a perovskite precursor.

[0009] The additive is a fluoropyridine.

[0010] The additive is a fluoropyridine.

[0011] The passivation layer is formed by a passivation agent.

[0012] The passivation agent comprises diammonium hydroiodide.

[0013] The additive and the passivation agent can simultaneously interact with the constituent components in the perovskite.

[0014] Further, the fluoropyridine is selected from one or more of monofluoropyridine, difluoropyridine, trifluoropyridine, tetrafluoropyridine or pentafluoropyridine; preferably 3,5-difluoropyridine (DFPy).

[0015] Further, the diammonium hydroiodide is selected from one or more of methyldiammonium hydroiodide, ethyldiammonium hydroiodide, propyldiammonium hydroiodide, butyldiammonium hydroiodide, pentyldiammonium hydroiodide, hexyldiammonium hydroiodide or octyldiammonium hydroiodide; preferably butyldiammonium hydroiodide (BDADI).

[0016] Further, the material of the first hole transport layer is NiO x ; and the material of the second hole transport layer is [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (Me-4pacz).

[0017] Further, the passivation agent further comprises 3-methylthiopropyl-1-amine hydroiodide salt (3MTPAI).

[0018] Further, the material of the electron transport layer is [6,6]-phenyl-C61-butyric acid methyl ester (PCBM).

[0019] Further, the material of the interface modification layer is Bicmnyl (BCP).

[0020] Another object of the present application is to provide a preparation method of the above-mentioned perovskite solar cell based on the synergistic effect of additives and passivation agents, comprising the following steps:

[0021] S1, cleaning the conductive electrode FTO to obtain the conductive electrode FTO;

[0022] S2, dissolving the hole transport layer material in a first solvent to form a first hole transport layer solution and a second hole transport layer solution; spin coating the first hole transport layer solution on the conductive electrode FTO, annealing to form a first hole transport layer; spin coating the second hole transport layer solution on the first hole transport layer, annealing to form a second hole transport layer;

[0023] S3, dissolving the perovskite precursor material and the additive in a second solvent to form a perovskite precursor solution, then spin coating on the second hole transport layer, adding an anti-solvent, and annealing to form a perovskite active layer;

[0024] S4, dissolving the passivation agent in a third solvent to form a passivation layer solution; spin coating the passivation layer solution on the perovskite active layer, annealing to form a passivation layer;

[0025] S5, dissolving the electron transport layer material in a fourth solvent to form an electron transport layer solution; spin coating the electron transport layer solution on the passivation layer, annealing to form an electron transport layer;

[0026] S6, dissolving the interface modification layer material in a fifth solvent to form an interface modification layer solution; spin coating the interface modification layer solution on the electron transport layer to form an interface modification layer;

[0027] S7, evaporating a metal electrode on the surface of the interface modification layer to form a metal electrode layer, thereby obtaining a perovskite solar cell based on the synergistic effect of additives and passivation agents.

[0028] Further, in step S3, the second solvent is a mixed solution of DMF and DMSO, and the volume ratio is (5-15):1; preferably the volume ratio is 10:1.

[0029] Further, in step S3, the anti-solvent is selected from chlorobenzene solvents, toluene solvents or ester solvents, or derivatives of the above-mentioned solvents.

[0030] Further, in step S3, the perovskite precursor material comprises monovalent cation halide, divalent metal cation halide and methylamine chloride; the monovalent cation halide is selected from one or more of formamidinium iodide, methylammonium iodide or cesium iodide; the divalent metal cation halide is selected from one or more of lead iodide or lead bromide; the molar ratio of the monovalent cation halide, divalent metal cation halide, methylamine chloride and additive is (0.5-1.5):1:(0.1-0.5):(1-5); preferably, the molar ratio of the monovalent cation halide, divalent metal cation halide, methylamine chloride and additive is 0.95:1:0.15:2.

[0031] Further, in step S4, the passivation agent comprises di-ammonium hydriodide, and the concentration of the di-ammonium hydriodide in the passivation layer solution is (10-15) mM; preferably, the concentration of the di-ammonium hydriodide in the passivation layer solution is 12 mM.

[0032] Compared with the prior art, the main advantages of the present application are as follows:

[0033] The present application provides a perovskite solar cell based on the synergistic effect of an additive and a passivation agent and a preparation method thereof. In the present application, a fluoropyridine additive is added to a perovskite precursor solution, and a FAPbI3 perovskite thin film is prepared by one-step solution spin coating. A di-ammonium hydriodide is used as a passivation agent, and the synergistic effect of the fluoropyridine additive and the di-ammonium hydriodide passivation agent inhibits the formation of lead iodide (PbI2) and δ phase in the FAPbI3 perovskite thin film, improves the crystallinity of the perovskite thin film and reduces the defect density, and finally a perovskite solar cell with high performance and high stability is obtained. Under this synergistic effect, the power conversion efficiency (PCE) of the perovskite solar cell is significantly higher than that of the perovskite solar cell obtained by using the fluoropyridine additive or the di-ammonium hydriodide passivation agent alone. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The structure of the perovskite solar cell based on the synergistic effect of an additive and a passivation agent of the present application is shown.

[0035] Figure 2 The XRD patterns of the perovskite active layers prepared in Example 1 and Comparative Examples 1-2 are shown.

[0036] Figure 3 The J-V curves of the perovskite solar cells prepared in Example 1 and Comparative Example 1 of the present application are shown.

[0037] Figure 4 An EQE diagram of the perovskite solar cell prepared in Example 1 and Comparative Example 1 of the present application is shown. DETAILED DESCRIPTION

[0038] In order to more clearly illustrate the technical solutions of the present application, the following examples are listed. The raw materials, reactions and post-treatment means appearing in the examples are all common raw materials on the market and technical means well known to those skilled in the art, unless otherwise stated.

[0039] Example 1

[0040] A perovskite solar cell based on the synergistic effect of an additive and a passivation agent, comprising: conductive electrodes FTO (500 nm), a first hole transport layer (30 nm), a second hole transport layer (2 nm), a perovskite active layer (480 nm), a passivation layer (5 nm), an electron transport layer (30 nm), an interface modification layer (5 nm) and a metal electrode layer (90 nm) arranged in sequence.

[0041] The preparation method of the above-mentioned perovskite solar cell based on the synergistic effect of an additive and a passivation agent, comprising the following steps:

[0042] S1, wash the FTO conductive glass with washing liquid, deionized water, acetone and alcohol respectively, and perform surface treatment on the FTO conductive glass with a plasma cleaning machine to obtain a conductive electrode FTO;

[0043] S2, dissolve 10 mg of NiO x in deionized water and ultrasonic for 3 min to obtain a first hole transport layer solution with a concentration of 10 mg / ml; dissolve Me-4pacz in anhydrous ethanol, stir at room temperature for 3 h to obtain a second hole transport layer solution, and the concentration of Me-4pacz in the solution is 3 mmol / ml; spin-coat the first hole transport layer solution on the conductive electrode FTO at a speed of 1500 rpm for 30 s, and anneal in ambient air at 150℃ for 10 min to form a first hole transport layer; spin-coat the second hole transport layer solution on the first hole transport layer at a speed of 4000 rpm for 30 s, and anneal at 100℃ for 10 min to form a second hole transport layer;

[0044] S3, 189.2 mg of FAI, 532.5 mg of PbI2, 253.17 mg of 3,5-difluoropyridine and 11.1 mg of MACl (15 mol% of PbI2) are dissolved in a mixed solution of DMF and DMSO (DMF:DMSO = 10:1, v / v) to obtain a 1.1 M FAPbI3 perovskite precursor solution, which is stirred at room temperature for 10 h; spin coating is performed at a speed of 5000 rpm on the second hole transport layer for 30 s, anti-solvent CB is added dropwise, and annealing is performed at 110°C for 20 min to form a perovskite active layer;

[0045] S4, 2.8 mg of 3MTPAI and 2.1 mg of BDADI are dissolved in 1 ml of an IPA and CB mixed solution (IPA:CB = 1:1, v / v), which is stirred at room temperature for 8 h to form a passivation layer solution; the passivation layer solution is spin coated on the perovskite active layer at a speed of 4000 rpm for 25 s, and annealing is performed at 100°C for 5 min to form a passivation layer;

[0046] S5, 20 mg of an electron transport layer material PCBM is dissolved in 1 ml of CB, which is stirred at 70°C for 8 h to form an electron transport layer solution; the electron transport layer solution is spin coated on the passivation layer at a speed of 2000 rpm for 30 s, and annealing is performed at 70°C for 10 min to form an electron transport layer;

[0047] S6, 2 mg of BCP is dissolved in 1 ml of IPA, which is stirred at 70°C for 8 h to form an interface modification layer solution; the interface modification layer solution is spin coated on the electron transport layer at a speed of 2000 rpm for 30 s to form an interface modification layer;

[0048] S7, the perovskite layer solar cell device prepared in the above steps is placed in an evaporation device, the interface modification layer requiring electrode evaporation is placed downward, metal Ag is placed in an evaporation boat for heating and evaporation, the evaporation speed is continuously adjusted during the evaporation process, and the melting of the metal material in the evaporation boat is observed during the evaporation process; finally, the Ag electrode is deposited using the evaporation device to form a metal electrode layer, thereby obtaining a perovskite solar cell based on the synergistic effect of an additive and a passivation agent.

[0049] Figure 1 The structure of the perovskite solar cell based on the synergistic effect of an additive and a passivation agent of the application is shown.

[0050] Example 2-3

[0051] A perovskite solar cell based on the synergistic effect of an additive and a passivation agent, which is different from example 1 in that in step S3, the 3,5-difluoropyridine is replaced by trifluoropyridine or pentafluoropyridine, respectively, and the other steps and amounts are the same as in example 1.

[0052] Comparative Example 1

[0053] A perovskite solar cell based on the synergistic effect of additive and passivation agent, the difference between this comparative example and Example 1 is that in step S3, 3,5-difluoropyridine is not added, and other steps and amounts are the same as Example 1.

[0054] Comparative Example 2

[0055] A perovskite solar cell based on the synergistic effect of additive and passivation agent, the difference between this comparative example and Example 1 is that in step S4, BDADI is not added, and other steps and amounts are the same as Example 1.

[0056] Comparative Example 3

[0057] A perovskite solar cell based on the synergistic effect of additive and passivation agent, the difference between this comparative example and Example 1 is that in step S3, 3,5-difluoropyridine is not added, and in step S4, BDADI is not added, and other steps and amounts are the same as Example 1.

[0058] Figure 2 XRD patterns of the perovskite active layers prepared in Example 1, Comparative Examples 1-2 are shown. From the XRD patterns, it can be seen that Example 1 exhibits higher peak intensity and narrower half-height width overall compared to Comparative Examples 1 and 2, reflecting better crystalline quality. Figure 2

[0059] Test Example

[0060] The photovoltaic performance of the perovskite solar cells based on the synergistic effect of additive and passivation agent of Examples 1-3, Comparative Examples 1-2 were tested.

[0061] Test Method:

[0062] X-ray diffraction (XRD) patterns were collected on a Rigaku Ultima-IV instrument using a Cu-Ka radiation source at 2θ = 7-40°. J-V characteristics were measured by a Keithley 2400 source measurement unit under 100 mW cm -2 of AM 1.5G solar light using an Oriel 91192-type solar simulator. The light intensity was determined by a Hamamatsu S1133 monocrystalline silicon reference cell (equipped with a KG-5 visible light filter), which was calibrated by the National Renewable Energy Laboratory (NREL). External quantum efficiency (EQE) was measured using an integrated system QE-R (Enlitech, Taiwan). The device was illuminated by monochromatic light emitted by a 75 W xenon lamp, and the light intensity was determined by a calibrated silicon photodiode.

[0063] ​The test results are shown in Table 1. Figures 3-4 As shown.

[0064] Table 1. Photoelectric performance test results of perovskite solar cells

[0065] Item VOC (V) J SC (mA / cm 2 )]]> FF (%) PCE (%) Example 1 1.17 25.77 85.62 25.90 Example 2 1.18 24.80 84.51 24.73 Example 3 1.18 25.49 83.82 25.20 Comparative Example 1 1.17 24.23 84.75 24.19 Comparative Example 2 1.17 24.14 83.63 23.65 Comparative Example 3 1.18 22.67 82.44 22.12

[0066] Figure 3 The JV diagrams of the perovskite solar cells prepared in Example 1 and Comparative Example 1 of the present invention are shown. Figure 3 It can be seen that the short-circuit current density (J) of the device prepared in Example 1 is... SC Both the fill factor (FF) and the efficiency of the photoelectric conversion (PCE) are better than those of Comparative Example 1.

[0067] Figure 4 The EQE diagrams of the perovskite solar cells prepared in Example 1 and Comparative Example 1 of the present invention are shown. Figure 4 It can be seen that the EQE integral J of Example 1 and Comparative Example 1 SC 24.84 mA cm -2 and 23.80mA cm -2 The value is consistent with the value measured by the JV curve.

[0068] Based on the test results above, it can be seen from the test results of Comparative Example 1 and Comparative Example 3 that the perovskite cell using diammonium hydroiodide passivator has an absolute efficiency improvement of 2.07% compared with the cell without diammonium hydroiodide passivator, and shows significant advantages in open circuit voltage, short circuit current, fill factor and conversion efficiency.

[0069] The test results from Examples 1 and Comparative Examples 1-3 show that the synergistic effect of DFPy and BDADI suppresses the formation of lead iodide (PbI2) and the δ phase in the FAPbI3 perovskite film, improves the crystallinity of the perovskite film, and reduces the defect density, ultimately resulting in a high-performance and highly stable perovskite solar cell. The perovskite solar cell obtained under this synergistic effect exhibits a significantly higher PCE than the perovskite solar cell obtained using DFPy and BDADI alone.

[0070] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0071] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature described. The specification can include implicit combinations of explicitly mentioned features and / or explicit combinations of implicitely mentioned features. Each embodiment depends on the explicit combinations of features and / or the implicit combinations of features made specifically within that embodiment, and each such embodiment can be combined with every other such embodiment to create further embodiments.

Claims

1. A perovskite solar cell based on synergistic effect of an additive and a passivating agent, characterized in that, The application relates to a perovskite solar cell based on synergistic effect of an additive and a passivation agent. The perovskite solar cell comprises, in sequence, a conductive electrode FTO, a first hole transport layer, a second hole transport layer, a perovskite active layer, a passivation layer, an electron transport layer, an interface modification layer and a metal electrode layer. The perovskite active layer is formed by an additive and a perovskite precursor; The additive is fluoropyridine; The passivation layer is formed by a passivation agent; The passivation agent comprises diammonium hydriodide; The additive and the passivation agent can simultaneously interact with the constituent components in the perovskite. The fluoropyridine is selected from one or more of monofluoropyridine, difluoropyridine, trifluoropyridine, tetrafluoropyridine or pentafluoropyridine.

2. The perovskite solar cell based on the synergistic effect of an additive and a passivation agent according to claim 1, characterized in that, The diammonium hydriodide is selected from one or more of methyldiammonium hydriodide, ethyldiammonium hydriodide, propyldiammonium hydriodide, butyldiammonium hydriodide, pentyldiammonium hydriodide, hexyldiammonium hydriodide or octyldiammonium hydriodide.

3. The perovskite solar cell based on the synergistic effect of an additive and a passivation agent according to claim 1, characterized in that, The passivation agent further comprises 3-methylthioprop-1-amine hydroiodide.

4. The perovskite solar cell based on the synergistic effect of an additive and a passivation agent according to claim 1, characterized in that, The material of the first hole transport layer is NiO x The material of the second hole transport layer is [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl] phosphonic acid.

5. The perovskite solar cell based on synergistic effect of additive and passivator according to claim 1, characterized in that, The material of the electron transport layer is [6,6]-phenyl-C61-butyric acid methyl ester.

6. The perovskite solar cell based on the synergistic effect of an additive and a passivation agent according to claim 1, characterized in that, The material of the interface modification layer is dicyan imine benzene.

7. The perovskite solar cell based on the synergistic effect of an additive and a passivation agent according to claim 1, characterized in that, The application further discloses a preparation method of the perovskite solar cell.

8. The method for the preparation of perovskite solar cells based on the synergistic effect of additives and passivating agents according to any one of claims 1-7, characterized in that, S1, cleaning the conductive electrode FTO to obtain the conductive electrode FTO; S2, dissolving a hole transport layer material in a first solvent to form a first hole transport layer solution and a second hole transport layer solution; S3, dissolving a perovskite precursor material and an additive in a second solvent to form a perovskite precursor solution, then spin-coating the perovskite precursor solution on the second hole transport layer, adding an anti-solvent and annealing to form the perovskite active layer; S4, dissolving a passivation agent in a third solvent to form a passivation layer solution; S5, dissolving an electron transport layer material in a fourth solvent to form an electron transport layer solution; S6, dissolving an interface modification layer material in a fifth solvent to form an interface modification layer solution; spin-coating the interface modification layer solution on the electron transport layer to form the interface modification layer; S7, evaporating a metal electrode on the surface of the interface modification layer to form a metal electrode layer, thereby obtaining the perovskite solar cell based on the synergistic effect of the additive and the passivation agent. In step S3, the perovskite precursor material comprises monovalent cation halide, divalent metal cation halide and methylamine chloride; the monovalent cation halide is selected from one or more of formamidinium iodide, methylammonium iodide or cesium iodide; the divalent metal cation halide is selected from one or more of lead iodide or lead bromide; and the molar ratio of the monovalent cation halide, the divalent metal cation halide, the methylamine chloride and the additive is (0.5-1.5):1:(0.1-0.5):(1-5). In step S4, the passivation agent comprises diammonium hydriodide, and the concentration of the diammonium hydriodide in the passivation layer solution is (10-15) mM. ​ ​ 9. The method for preparing perovskite solar cells based on the synergistic effect of additives and passivation agents according to claim 8, characterized in that, ​ 10.The method of claim 8, wherein the additive and the passivation agent are simultaneously added to the perovskite solar cell. ​

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