Perovskite solar cell based on ion-induced interface electric field and preparation method thereof

Abstract

The invention discloses a perovskite solar cell based on an ion-induced interface electric field, which is characterized in that at least one of an electrode / transmission layer interface and a transmission layer / perovskite layer interface is provided with an interface electric field layer, and the interface electric field layer is composed of ionized functional organic molecules. The ionized functional organic molecules comprise anions and cations, the interface energy level is adjusted through directional distribution of the anions and the cations on the interface under the battery working condition, and electric field induced energy level matching is achieved. The invention further discloses a preparation method of the solar cell, and the ion-induced interface electric field layer is introduced, so that interface carrier transmission is improved, carrier recombination loss is reduced, and interface stability is improved. In addition, the interface electric field layer can also form a surface rich in positive ions or negative ions through deposition of various chemical methods, the interface performance is further optimized, and the working stability of the device is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a perovskite solar cell based on ion-induced interface electric field and a preparation method thereof. Background Art

[0002] In recent years, organic-inorganic lead halide perovskite materials have shown great potential in solar cell applications. The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has rapidly improved in the past decade and has now reached a certified 26.7%, which is comparable to the conversion efficiency of traditional crystalline silicon solar cells. The rapid development of perovskite materials is mainly attributed to their excellent optoelectronic properties, including high optical absorption coefficient (10 5 cm -1 ), longer carrier diffusion length (>1μm), adjustable direct band gap and high defect tolerance.

[0003] However, the inherent defects of perovskite materials, especially traps, vacancies, and uncoordinated ions at perovskite grain boundaries and interfaces, severely limit the optoelectronic performance of PSCs. These defects can lead to non-radiative carrier recombination, thereby reducing the photoelectric conversion efficiency and operational stability of the device. In particular, the number of defects on the surface of perovskite films is two orders of magnitude higher than that in the bulk phase, most of which are deep energy level traps. In addition, the energy level mismatch at the interface increases the recombination loss of carriers, further limiting the performance improvement of the device.

[0004] The overall structure of PSCs has an important influence on their efficiency. The morphology of different functional layers and their interface properties are directly related to the generation and extraction of carriers. Generally, PSCs are composed of a multilayer structure consisting of an anode, a cathode, an electron transport layer (ETL), a hole transport layer (HTL) and a perovskite active layer to form a multi-interface system. Among them, (i) the electrode / ETL interface, (ii) the ETL / perovskite interface, (iii) the perovskite / HTL interface and (iv) the HTL / electrode interface not only affect the optoelectronic performance of the device, but also play an important role in its long-term stability.

[0005] In recent years, interface engineering has made significant progress in improving the performance of PSCs, especially by introducing dipole molecules between the perovskite layer and the carrier transport layer (ETL / HTL) for interface modification. This method effectively improves the photoelectric efficiency and operational stability of the device by adjusting the interface energy level and passivating defects. For example, patent CN118714900A discloses an interface modification method, which uses a naphthyl ammonium bromide dispersion as a passivator at the interface between the hole transport layer and the perovskite layer, and is successfully applied to inverted perovskite solar cells. However, this modification method is limited to specific applications at the interface between the hole transport layer and the perovskite, and cannot be widely applied to other interfaces and materials.

[0006] Generally, the interface modification method for a specific hole transport material is not applicable to other materials. Therefore, it is of great research and practical value to develop a surface modification method applicable to a variety of interfaces and transport materials to improve the interface contact quality and promote the effective transport of carriers. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a perovskite solar cell based on ion-induced interface electric field and a preparation method thereof, which improves interface carrier transport, reduces carrier recombination losses, and improves interface stability by introducing an interface electric field layer at the interface of the perovskite solar cell.

[0008] In order to achieve the above purpose, the technical solution of the present invention is:

[0009] A perovskite solar cell based on ion-induced interface electric field, the perovskite solar cell having an electrode / transport layer interface and a transport layer / perovskite layer interface, wherein at least one of the electrode / transport layer interface and the transport layer / perovskite layer interface is provided with an interface electric field layer, the interface electric field layer is composed of ionized functional organic molecules, the ionized functional organic molecules include anions and cations, and under battery operating conditions, the interface energy level is adjusted by the directional distribution of anions and cations at the interface to achieve electric field induced energy level matching.

[0010] The ion-induced interfacial electric field layer is formed by the electrical interaction between ions and the interfacial material, and can provide more significant interfacial electric field regulation.

[0011] The anions and cations have a molecular size large enough to avoid cross-layer migration under the action of an electric field, thereby ensuring the long-term stability of the interfacial electric field layer in the perovskite solar cell. Optionally, the anions include sulfonate derivatives, arylsulfonate ions, chloride ions and iodide ions, and the cations include phenylammonium cations, benzoheterocyclyl cations, naphthyl cations, triphenylmethylammonium cations, triarylethylammonium cations and alkyl-substituted phenylammonium cations.

[0012] Optionally, the ionized functional organic molecule further includes a functional group anchored or chelated to any one of the electrodes, transport layers, and perovskite layers forming the interface.

[0013] Optionally, the cation is a protonated 6-aminobenzothiazolium cation, and the anion is a chloride ion or an iodide ion.

[0014] Optionally, the thickness of the interface electric field layer is less than 2 nm, preferably 1 to 2 nm.

[0015] Optionally, the perovskite solar cell includes an upright structure and an inverted structure, and the interface includes a bottom electrode / electron transport layer interface, an electron transport layer / perovskite layer interface, a perovskite layer / hole transport layer interface, and a hole transport layer / top electrode interface in the upright structure, or at least one of a bottom electrode / hole transport layer interface, a hole transport layer / perovskite layer interface, a perovskite layer / electron transport layer interface, and an electron transport layer / top electrode interface in the inverted structure.

[0016] Optionally, the electric field direction of the interface electric field layer is consistent with the built-in electric field direction of the perovskite solar cell to increase the open circuit voltage (V oc ) and photoelectric conversion efficiency (PCE).

[0017] Optionally, the perovskite system uses the cesium formamidinium system FA 0.9 Cs 0.1 PbI3, ternary system (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 )3, Multi-system Rb 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3; The hole transport layer uses organic material PTAA and inorganic material NiO x .

[0018] A method for preparing a perovskite solar cell based on an ion-induced interface electric field as described above, comprising the following steps: forming an interface electric field layer on the surface of a functional layer of the perovskite solar cell by a chemical deposition method, wherein the functional layer is an electrode, a transport layer or a perovskite layer; then forming another functional layer on the interface electric field layer, so that the interface electric field layer is sandwiched between at least one of the electrode / transport layer interface and the transport layer / perovskite layer interface; wherein the chemical deposition method comprises at least one of an ion salt solution post-treatment method, an acid treatment method, an alkali treatment method, an electrodeposition method, and a chemical bath deposition method, so as to form a stable ion distribution at the interface, thereby effectively constructing an interface electric field.

[0019] Optionally, the preparation method comprises:

[0020] S1: dissolving 6-aminobenzothiazole hydrochloride or 6-aminobenzothiazole iodide in a solvent at a ratio of (0.5-1) mg:1 mL to form a solution;

[0021] S2: statically spin coating the solution on the surface of the functional layer at a speed of 3000-5000 rpm for 20-40 seconds to form the interface electric field layer;

[0022] S3: forming the other functional layer on the interface electric field layer.

[0023] Optionally, between step S2 and step S3, a step of annealing at 100° C. for 5 to 15 minutes is also included.

[0024] The beneficial effects of the present invention are:

[0025] Through the ion-induced interface electric field layer, an ion dipole-induced interface built-in electric field can be formed at the interface, effectively promoting the transmission and extraction of carriers, reducing non-radiative recombination losses at the interface, thereby improving the photoelectric conversion efficiency (PCE) of perovskite solar cells; it is applicable to a variety of interfaces and transmission materials, can effectively improve the interface contact quality, has a wide range of applications, and is flexible to use. In addition, the interface electric field layer can also be deposited by a variety of chemical methods to form a surface rich in positive ions or negative ions, further optimizing the interface performance and improving the working stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1(a) is a schematic diagram of the cross-sectional structure of the perovskite solar cell based on the ion-induced interface electric field of Examples 1 to 7, FIG1(b) is a scanning electron microscope (SEM) image of the cross-sectional structure of the perovskite solar cell based on the ion-induced interface electric field of Example 1, FIG1(c) is a schematic diagram of the cross-sectional structure of the perovskite solar cell based on the ion-induced interface electric field of Example 8, and FIG1(d) is a schematic diagram of the cross-sectional structure of the perovskite solar cell based on the ion-induced interface electric field of Example 9;

[0027] Figure 2 1 are current-voltage curves of corresponding devices in Example 1 and Comparative Example 1;

[0028] Figure 3 2 are current-voltage curves of corresponding devices in Example 2 and Comparative Example 2;

[0029] Figure 4 3 are the current-voltage curves of the corresponding devices in Example 3 and Comparative Example 3;

[0030] Figure 5 1 are the current-voltage curves of the corresponding devices in Example 4 and Comparative Example 1;

[0031] Figure 6 2 are the current-voltage curves of the corresponding devices in Example 5 and Comparative Example 3;

[0032] Figure 7 2 are the current-voltage curves of the corresponding devices in Example 6 and Comparative Example 4;

[0033] Figure 8 2 are the current-voltage curves of the corresponding devices in Example 7 and Comparative Example 5;

[0034] Fig. 9 2 are the current-voltage curves of the corresponding devices in Example 8 and Comparative Example 3;

[0035] Fig.10 : are the current-voltage curves of the corresponding devices in Example 9 and Comparative Example 3;

[0036] Fig.11 3 are Mott-Schottky curves of the corresponding devices in Example 3 and Comparative Example 3;

[0037] Fig.12 : are the Mott-Schottky curves of the corresponding devices in Example 7 and Comparative Example 5;

[0038] Fig.13 UPS work function spectra corresponding to the buried bottom surface of the perovskite film in Example 3 and Comparative Example 3;

[0039] Fig.14 Scanning electron microscope (SEM) images of the perovskite films in Example 3, Example 5 and Comparative Example 3. DETAILED DESCRIPTION

[0040] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. The various drawings of the present invention are only for illustration to make it easier to understand the present invention, and the specific proportions can be adjusted according to design requirements. The upper and lower relationships of the relative elements and the definitions of the front / back in the figures described in the text should be understood by those skilled in the art to refer to the relative positions of the components, so they can all be flipped to present the same components, which should all fall within the scope disclosed in this specification.

[0041] The perovskite solar cells of Examples 1 to 9 and Comparative Examples 1 to 3 adopt an inverted structure, and their basic structure includes a bottom electrode, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a top metal electrode in sequence. The preparation process of each basic functional layer is consistent, as follows:

[0042] (1) Substrate pretreatment: Substrate pretreatment: Place the etched FTO transparent conductive glass on a cleaning rack and use sodium dodecyl sulfate (or other surfactant) aqueous solution, acetone, and ethanol for ultrasonic cleaning in sequence. Each cleaning time is 20 minutes. After cleaning, take it out and blow it dry with nitrogen, and put it into a UV ozone cleaning machine to clean the glass surface for 25 minutes.

[0043] (2) Preparation of the hole transport layer: There are two preparation methods according to the different hole transport materials:

[0044] 1) NiO x Hole transport layer: 20 mg of nickel oxide nanoparticles were dissolved in 1 mL of deionized water, ultrasonicated for 20 min, and filtered before use; the solution was then statically spin-coated on a clean FTO substrate at a speed of 3000 rpm for 30 s. After the spin coating was completed, the substrate was post-annealed at 100°C for 10 min.

[0045] 2) PTAA hole transport layer: 3 mg of PTAA powder was dissolved in 1 mL of chlorobenzene and shaken for 30 min. The solution was then statically spin-coated on a clean FTO substrate at 3000 rpm for 30 s. After the spin coating was completed, the substrate was post-annealed at 120°C for 3 min.

[0046] (3) Preparation of perovskite layer: There are three preparation methods according to the different perovskite systems:

[0047] 1) Cesium formamidine system FA 0.9 Cs 0.1 PbI3: Dissolve lead iodide, cesium iodide, and iodomethane in a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone, shake in a nitrogen glove box for 3 hours, add an appropriate amount of methylamine chloride 10 minutes before the end of the shaking, and filter before use. The feed ratio of lead iodide, cesium iodide, iodomethane, N,N-dimethylformamide, N-methylpyrrolidone, and methylamine chloride is 311 mg: 13 mg: 113.4 mg: 586 μL: 96 μL: 20 mg.

[0048] 2) Ternary system (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 )3: Dissolve lead iodide, iodoformamidine, iodomethylamine, and cesium iodide in a mixed solution of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone, stir overnight in a nitrogen glove box, and filter before use. The feed ratio of lead iodide, iodoformamidine, iodomethylamine, cesium iodide, N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone is 509.4 mg: 176.6 mg: 33.1 mg: 16.9 mg:

[0049] 800μL:180μL:20μL.

[0050] 3) Multi-system Rb 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05)3: Dissolve rubidium iodide, cesium iodide, methylamine bromide, iodomethane, lead iodide, and lead bromide in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide, stir at room temperature for 3 to 4 hours in a nitrogen glove box, and filter before use. The feed ratio of rubidium iodide, cesium iodide, methylamine bromide, iodomethane, lead iodide, and lead bromide dissolved in N,N-dimethylformamide and dimethyl sulfoxide is: 15.9 mg: 19.5 mg: 8.4 mg:

[0051] 219.5mg: 656.9mg: 21.7mg: 800μL: 200μL.

[0052] (4) Preparation of electron transport layer: 20 mg / mL PC 61 BM powder was dissolved in 1 mL of chlorobenzene and shaken for 20 min; the solution was then statically spin-coated on the perovskite film at a speed of 2000 rpm for 30 s.

[0053] (5) Preparation of hole blocking layer: 0.5 mg of BCP powder was dissolved in 1 mL of isopropanol and shaken for 12 h until the powder was completely dissolved. The solution was then dynamically spin-coated on the electron transport layer at a speed of 4500 rpm for 20 s. Subsequently, the solution was post-annealed on a hot plate at 60 °C for 10 min.

[0054] (6) A 60 nm thick metal electrode was deposited using a vacuum thermal evaporation coating apparatus to obtain an inverted perovskite solar cell device. The effective area of ​​the metal electrode was 0.12 cm 2 .

[0055] Example 1

[0056] The first embodiment of the present invention applied to the hole transport layer / perovskite layer interface modification includes the following steps:

[0057] S1: Weigh 0.5 mg of 6-aminobenzothiazole hydrochloride (6-ABT HCl) and dissolve it in 1 mL of isopropanol. Ultrasonicate for 15 min until the solution is clear.

[0058] S2: The solution prepared in S1 was statically spin-coated at 3000 rpm for 30 seconds on the NiO prepared in the above sequence. x On the hole transport layer;

[0059] S3: the modified layer prepared in S2 is post-annealed at 100° C. for 10 min to remove the solvent, and the obtained dried modified layer is used as the interface electric field layer;

[0060] S4: Spin-coating the perovskite precursor on the dried modified layer prepared in S3 in two steps. The perovskite system used in this step is the cesium formamidinium system (FA 0.9 Cs 0.1 PbI3);

[0061] S5: The perovskite film prepared in S4 was post-annealed at 110° C. for 60 min.

[0062] The subsequent preparation of the electron transport layer and the like is carried out to obtain a complete perovskite solar cell device, as shown in FIG. 1( a ) and FIG. 1( b ), which includes, in sequence, FTO transparent conductive glass 1, hole transport layer 2, interface electric field layer 3, perovskite layer 4, electron transport layer 5, hole blocking layer 6 and top metal electrode 7.

[0063] Example 2

[0064] The second embodiment of the present invention applied to the hole transport layer / perovskite layer interface modification includes the following steps:

[0065] S1: Weigh 0.5 mg of 6-aminobenzothiazole hydrochloride (6-ABT HCl) and dissolve it in 1 mL of isopropanol;

[0066] S2: The solution prepared in S1 was statically spin-coated at 3000 rpm for 30 seconds on the NiO prepared in the above sequence. x On the hole transport layer;

[0067] S3: the modified layer prepared in S2 is post-annealed at 100° C. for 10 min to remove the solvent, and the obtained dried modified layer is used as the interface electric field layer;

[0068] S4: Spin-coating the perovskite precursor on the dried modified layer prepared in S3 in two steps. The perovskite system used in this step is a ternary system (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 )3);

[0069] S5: The perovskite film prepared in S4 is post-annealed at 100° C. for 30 min.

[0070] Subsequent preparation of electron transport layer etc. is carried out to obtain a complete perovskite solar cell device.

[0071] Example 3

[0072] The third embodiment of the present invention applied to the hole transport layer / perovskite layer interface modification includes the following steps:

[0073] S1: Weigh 0.5 mg of 6-aminobenzothiazole hydrochloride (6-ABT HCl) and dissolve it in 1 mL of isopropanol;

[0074] S2: The solution prepared in S1 was statically spin-coated at 3000 rpm for 30 seconds on the NiO prepared in the above sequence. x On the hole transport layer;

[0075] S3: the modified layer prepared in S2 is post-annealed at 100° C. for 10 min to remove the solvent, and the obtained dried modified layer is used as the interface electric field layer;

[0076] S4: Spin-coating the perovskite precursor on the dried modified layer prepared in S3 in two steps. The perovskite system used in this step is a multi-element system (Rb 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3);

[0077] S5: The perovskite film prepared in S4 is post-annealed at 100° C. for 20 min.

[0078] Subsequent preparation of electron transport layer etc. is carried out to obtain a complete perovskite solar cell device.

[0079] Example 4

[0080] The fourth embodiment of the present invention applied to the hole transport layer / perovskite layer interface modification comprises the following steps:

[0081] S1: Weigh 0.5 mg of 6-aminobenzothiazole iodate (6-ABT HI) and dissolve it in 1 mL of isopropanol;

[0082] S2: The solution prepared in S1 was statically spin-coated at 3000 rpm for 30 seconds on the NiO prepared in the above sequence. x On the hole transport layer;

[0083] S3: the modified layer prepared in S2 is post-annealed at 100° C. for 10 min to remove the solvent, and the obtained dried modified layer is used as the interface electric field layer;

[0084] S4: Spin-coating the perovskite precursor on the dried modified layer prepared in S3 in two steps. The perovskite precursor system used in this step is the cesium formamidine system (FA 0.9 Cs 0.1 PbI3);

[0085] S5: The perovskite film prepared in S4 was post-annealed at 110° C. for 60 min.

[0086] Subsequent preparation of electron transport layer etc. is carried out to obtain a complete perovskite solar cell device.

[0087] Example 5

[0088] The fifth embodiment of the present invention applied to the hole transport layer / perovskite layer interface modification comprises the following steps:

[0089] S1: Weigh 0.5 mg of 6-aminobenzothiazole iodate (6-ABT HI) and dissolve it in 1 mL of isopropanol;

[0090] S2: The solution prepared in S1 was statically spin-coated at 3000 rpm for 30 seconds on the NiO prepared in the above sequence. x On the hole transport layer;

[0091] S3: the modified layer prepared in S2 is post-annealed at 100° C. for 10 min to remove the solvent, and the obtained dried modified layer is used as the interface electric field layer;

[0092] S4: Spin-coating the perovskite precursor on the dried modified layer prepared in S3 in two steps. The perovskite precursor used in this step is a multi-element system (Rb 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3);

[0093] S6: The perovskite film prepared in S4 is post-annealed at 100° C. for 20 min.

[0094] Subsequent preparation of electron transport layer etc. is carried out to obtain a complete perovskite solar cell device.

[0095] Example 6

[0096] The sixth embodiment of the present invention applied to the hole transport layer / perovskite layer interface modification comprises the following steps:

[0097] S1: Weigh 1.0 mg of 6-aminobenzothiazole iodate (6-ABT HI) and dissolve it in 1 mL of DMF;

[0098] S2: statically spin-coat the solution prepared in S1 on the PTAA hole transport layer prepared in the above sequence at a rotation speed of 4500 rpm, and the obtained modified layer serves as the interface electric field layer;

[0099] S3: Directly spin-coat the perovskite precursor on the wet film prepared in S2 in two steps. The perovskite precursor used in this step is cesium formamidinium system (FA 0.9 Cs 0.1 PbI3);

[0100] S4: The perovskite film prepared in S3 was post-annealed at 110° C. for 60 min.

[0101] Subsequent preparation of electron transport layer etc. is carried out to obtain a complete perovskite solar cell device.

[0102] Example 7

[0103] The seventh embodiment of the present invention applied to the hole transport layer / perovskite layer interface modification comprises the following steps:

[0104] S1: Weigh 1.0 mg of 6-aminobenzothiazole iodate (6-ABT HI) and dissolve it in 1 mL of DMF;

[0105] S2: statically spin-coat the solution prepared in S1 on the PTAA hole transport layer prepared in the above sequence at a rotation speed of 4500 rpm, and the obtained modified layer serves as the interface electric field layer;

[0106] S3: Directly spin-coat the perovskite precursor on the wet film prepared in S2 in two steps. The perovskite precursor used in this step is a multi-element system (Rb 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3);

[0107] S4: The perovskite film prepared in S3 is post-annealed at 100° C. for 20 min.

[0108] Subsequent preparation of electron transport layer etc. is carried out to obtain a complete perovskite solar cell device.

[0109] Example 8

[0110] The embodiment of the present invention applied to the bottom electrode (FTO transparent conductive glass) and the hole transport layer includes the following steps:

[0111] S1: Weigh 1.0 mg of 6-aminobenzothiazole iodate (6-ABT HI) and dissolve it in 1 mL of deionized water;

[0112] S2: The solution prepared in S1 is statically spin-coated on a clean FTO substrate at a speed of 3000 rpm. The resulting modified layer is used as the interface electric field layer:

[0113] S3: Directly prepare NiO on the film prepared in S2 x hole transport layer;

[0114] S4: Spin-coat the perovskite precursor on the NiOx hole transport layer prepared in S3 in two steps. The perovskite precursor used in this step is a multi-element system (Rb 0.05 Cs 0.05 MA0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3);

[0115] S5: The perovskite film prepared in S4 was post-annealed at 100° C. for 20 min.

[0116] The subsequent preparation of the electron transport layer etc. is carried out to obtain a complete perovskite solar cell device, the schematic diagram of which is shown in FIG1( c ).

[0117] Example 9

[0118] The first embodiment of the present invention applied to the perovskite layer / electron transport layer includes the following steps:

[0119] S1: Weigh 0.5 mg of 6-aminobenzothiazolidine hydrochloride (6-ABT HI) and dissolve it in 1 mL of isopropanol;

[0120] S2: The solution prepared in S1 is statically spin-coated at 5000 rpm on the perovskite film prepared in the above sequence. The perovskite system used in this step is a multi-element system (Rb 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3);

[0121] S3: The perovskite film prepared in S2 is post-annealed at 100°C for 20 minutes, and the resulting modified layer is used as the interface electric field layer. The subsequent battery preparation steps are continued to obtain a complete perovskite solar cell device, whose structural schematic diagram is shown in Figure 1(d).

[0122] Comparative Example:

[0123] The steps include:

[0124] In the preparation of the above-mentioned inverted structure perovskite solar cell, no interface modification layer is provided, and the following comparative examples are provided according to the system of the hole transport layer and the perovskite active layer:

[0125] Comparative Example 1

[0126] S1: In NiO x Preparation of cesium formamidinium system perovskite film FA on hole transport layer 0.9 Cs 0.1 PbI3.

[0127] Comparative Example 2

[0128] S1: In NiO xPreparation of ternary perovskite film on hole transport layer (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 )3.

[0129] Comparative Example 3

[0130] S1: In NiO x Preparation of multi-system perovskite thin film Rb on hole transport layer 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3.

[0131] Comparative Example 4

[0132] S1: Preparation of cesium formamidinium perovskite film FA on PTAA hole transport layer 0.9 Cs 0.1 PbI3.

[0133] Comparative Example 5

[0134] S1: Preparation of multi-system perovskite Rb on PTAA hole transport layer 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3.

[0135] Performance tests in the embodiments and comparative examples:

[0136] The perovskite solar cell devices in the above embodiments and comparative examples were tested for relevant performance indicators under the same test conditions (all device tests were carried out at room temperature and 40% humidity):

[0137] Table 1 Photoelectric parameters of photoelectric devices

[0138]

[0139] Figure 2 to Figure 10 is a schematic diagram for comparing the current-voltage curves of the embodiment and the comparative example, Figure 2 to Figure 10 As can be seen from Table 1, compared with the comparative example, due to the provision of the interface electric field layer, the open circuit voltage of the perovskite solar cell in each embodiment is significantly improved compared with the comparative example, which indirectly illustrates the successful construction of the interface electric field, thereby reducing the open circuit voltage loss caused by energy level mismatch between adjacent functional layers.

[0140] Fig.11 , Fig.12 Schematic diagram of the comparison of the Mott-Schottky curves of the embodiment and the comparative example. It can be seen from the figure that due to the existence of the interface electric field, the built-in electric field strength inside the battery in the embodiment is increased, which further explains the increase in the open circuit voltage of the battery device in the embodiment.

[0141] Fig.13 UPS work function spectra of the buried bottom surface of the perovskite film of the embodiment and the comparative example. It can be seen from the figure that after modification with the ion salt solution, the Fermi level of the perovskite film is further away from the vacuum energy level, and the film as a whole is more P-type, which is conducive to the transfer of photogenerated hole materials from the perovskite to the hole transport layer.

[0142] Fig.14 The scanning electron microscope (SEM) images of the perovskite films of the embodiment and the comparative example show that the crystalline morphology of the perovskite film is not affected after the perovskite film is modified by the ionic salt.

[0143] The above embodiments are only used to further illustrate a perovskite solar cell based on ion-induced interface electric field and a preparation method thereof of the present invention, but the present invention is not limited to the embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the technical solution of the present invention.

Claims

1. A perovskite solar cell based on ion-induced interface electric field, characterized in that: The perovskite solar cell has an electrode / transport layer interface and a transport layer / perovskite layer interface, wherein at least one of the electrode / transport layer interface and the transport layer / perovskite layer interface is provided with an interfacial electric field layer, and the interfacial electric field layer is composed of ionized functional organic molecules, and the ionized functional organic molecules include anions and cations. Under battery operating conditions, the interface energy level is adjusted by the directional distribution of anions and cations at the interface to achieve electric field induced energy level matching.

2. The perovskite solar cell based on ion-induced interface electric field according to claim 1, characterized in that: The anions of the ionized functional organic molecules include sulfonate derivatives, arylsulfonate ions, chloride ions and iodide ions, and the cations of the ionized functional organic molecules include phenylammonium cations, benzoheterocyclyl cations, naphthyl cations, triphenylmethylammonium cations, triarylethylammonium cations and alkyl-substituted phenylammonium cations.

3. The perovskite solar cell based on ion-induced interface electric field according to claim 2, characterized in that: The ionized functional organic molecule further includes a functional group anchored or chelated to any one of the electrodes, the transport layer, and the perovskite layer forming the interface.

4. The perovskite solar cell based on ion-induced interface electric field according to claim 2, characterized in that: The cation of the ionized functional organic molecule is a 6-aminobenzothiazolium cation, and the anion is a chloride ion or an iodide ion.

5. The perovskite solar cell based on ion-induced interface electric field according to claim 1, characterized in that: The thickness of the interface electric field layer is less than 2 nm.

6. The perovskite solar cell based on ion-induced interface electric field according to claim 1, characterized in that: The perovskite solar cell includes an upright structure and an inverted structure, and the interface includes a bottom electrode / electron transport layer interface, an electron transport layer / perovskite layer interface, a perovskite layer / hole transport layer interface, and a hole transport layer / top electrode interface in the upright structure, or at least one of a bottom electrode / hole transport layer interface, a hole transport layer / perovskite layer interface, a perovskite layer / electron transport layer interface, and an electron transport layer / top electrode interface in the inverted structure.

7. The perovskite solar cell based on ion-induced interface electric field according to claim 1, characterized in that: The electric field direction of the interface electric field layer is consistent with the built-in electric field direction of the perovskite solar cell.

8. A method for preparing a perovskite solar cell based on an ion-induced interface electric field according to any one of claims 1 to 7, characterized in that: The following steps are involved: Forming an interfacial electric field layer on a surface of a functional layer of a perovskite solar cell by a chemical deposition method, wherein the functional layer is an electrode, a transmission layer or a perovskite layer; Then, another functional layer is formed on the interface electric field layer, so that the interface electric field layer is sandwiched between at least one of the electrode / transport layer interface and the transport layer / perovskite layer interface; wherein the chemical deposition method includes at least one of ion salt solution post-treatment method, acid treatment method, alkali treatment method, electrodeposition method, and chemical bath deposition method.

9. The preparation method according to claim 8, characterized in that: include: S1: dissolving 6-aminobenzothiazole hydrochloride or 6-aminobenzothiazole iodide in a solvent at a ratio of (0.5-1) mg:1 mL to form a solution; S2: statically spin coating the solution on the surface of the functional layer at a speed of 3000-5000 rpm for 20-40 seconds to form the interface electric field layer; S3: forming the other functional layer on the interface electric field layer.

10. The preparation method according to claim 9, characterized in that: Between step S2 and step S3, an annealing step at 100° C. for 5 to 15 minutes is also included.

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