Interface modification layer material, perovskite solar cell and preparation method thereof

Abstract

The invention relates to the technical field of perovskite solar cells, in particular to an interface modification layer material, a perovskite solar cell and a preparation method of the perovskite solar cell. The material of the interface modification layer comprises a sulfonic acid modified aromatic diimide compound. The perovskite solar cell comprises a transparent conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer, wherein an interface modification layer made of the interface modification layer material is arranged between the perovskite layer and the electron transport layer. The interface modification layer prepared from the sulfonic acid modified aromatic diimide compound is introduced between the perovskite layer and the electron transport layer, so that perovskite surface defect passivation and energy level matching can be realized at the same time, the electron extraction efficiency is remarkably improved, the compound loss is reduced, and the photoelectric conversion rate of the cell is improved.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell technology, specifically to an interface modification layer material, a perovskite solar cell, and a method for preparing the same. Background Technology

[0002] Perovskite solar cells (PSCs) have become a core candidate for next-generation photovoltaic technology due to their excellent photoelectric properties, including high absorption coefficient, tunable bandgap, long carrier diffusion length, and relatively low fabrication cost. In recent years, the certified efficiency of single-junction perovskite cells has exceeded 26%. However, the long-term stability of the devices, especially in humid and hot environments, and the interface charge transport efficiency remain key factors restricting their commercialization.

[0003] Interface engineering is a key strategy for improving the performance of power conversion efficiency (PCE) sensors. In high-efficiency inverted PCE sensors, fullerene derivatives [6,6]-phenyl-C61-butyrate methyl ester (PCBM) are often used as electron transport layers (ETLs). However, PCBM suffers from problems such as insufficient passivation, poor surface coverage, and energy level mismatch, which limit further improvements in power conversion efficiency (PCE) and PSC stability. Specifically, there are two core problems at the interface between the perovskite layer and the electron transport layer (such as the PCBM): First, surface defect recombination. Intrinsic defects such as halogen vacancies (such as I⁻ vacancies) and cation interstices (such as Pb²⁺ interstices) are easily formed on the surface of perovskite (such as MAPbI3). These defects, as nonradiative recombination centers, will intensify carrier recombination, leading to a decrease in open-circuit voltage (Voc) and fill factor (FF). Second, energy level mismatch. There is an energy barrier of about 0.3 eV between the bottom of the perovskite conduction band (CBM, about -3.9 eV) and the lowest unoccupied molecular orbital (LUMO, about -4.2 eV) of the PCBM. This energy barrier will hinder the efficient extraction of electrons from the perovskite to the PCBM, thereby limiting the increase of short-circuit current (Jsc).

[0004] Traditional interface modification strategies mostly rely on single-functional materials. For example, Lewis bases (such as NH3BH3I) can achieve defect passivation, but it is difficult to tune the energy levels; fullerene derivatives (such as PCBM) or metal oxides (such as TiO2 and SnO2) can tune the energy levels, but their passivation ability for defects is limited. In view of this, developing interface modification layers that combine defect passivation and energy level matching functions has become a research hotspot in the field of PSCs. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an interface modification layer material comprising a sulfonic acid-modified aromatic diimide compound (R-CO-NH-CO-R', where R and R' are aromatic groups). This material simultaneously achieves perovskite layer surface defect passivation and interface energy level matching, improving the photoelectric conversion efficiency and long-term stability of the battery. The sulfonic acid-modified aromatic diimide compound contains both a sulfonic acid group (-SO3R) and an imine group (-N=) in its molecular structure. The sulfonic acid group (-SO3R) passivates perovskite surface defects through Lewis acid-base interactions, while the imine group (-N=) interacts with electron-rich sites on the perovskite surface using its electron-deficient properties, enhancing the passivation effect. Furthermore, the aromatic diimide compound, through its low LUMO energy level (matching the LUMO of the light absorption layer to ensure electron extraction driving force) and high HOMO energy level (misaligned with the HOMO of the light absorption layer to suppress charge recombination), satisfies the thermodynamic spontaneous conditions and kinetic efficiency of electron transport. This energy level characteristic originates from the conjugation of aromatic rings and imide groups in its molecule. The energy level can be further fine-tuned through chemical modifications (such as changing the size of the aromatic ring or introducing substituents), thereby achieving matching with different types of electron transport layer energy levels.

[0006] Furthermore, the interface modification layer material includes at least one of naphthalenediimide derivatives modified with sulfonic acid groups and naphthalenediphenylimide derivatives modified with sulfonic acid groups. Naphthalenediimide (NDI) and its derivatives, as well as perylenediimide (PDI) derivatives, both possess imine groups (-N=), which can utilize their electron-deficient characteristics and the interaction between them and electron-rich sites on the perovskite surface to improve passivation and thus reduce carrier recombination. Simultaneously, the extended π-conjugated system of NDI and PDI structural units provides efficient electron transport channels, and the energy level positions can be adjusted through alkyl chains (R) to achieve energy level matching with electron transport layers such as PCBMs. Figure 6 The diagram shows the energy level structures of naphthalenediimide (NDI-SO3R) and perylenediimide (PDI-SO3R) and their energy level matching with perovskite and PCBM.

[0007] The structural formula of naphthalenediimide (NDI-SO3R) is as follows:

[0008]

[0009] The structure of perylene diimide (PDI-SO3R) is as follows:

[0010]

[0011] Furthermore, the thickness of the interface modification layer material is 5~20nm, preferably 5~10nm.

[0012] Furthermore, the perylene diimide derivative may be at least one of perylene diimide, N,N'-dihexylperylene diimide, and tetrachloroperylene diimide.

[0013] Furthermore, the naphthalene diimide derivative may be at least one of naphthonaphthalene diimide, N,N'-dihexylnaphthalene diimide, and tetrachloronaphthalene diimide.

[0014] Another aspect of the present invention provides a perovskite solar cell, comprising a transparent conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer, wherein an interface modification layer is disposed between the perovskite layer and the electron transport layer, and the material of the interface modification layer includes the aforementioned interface modification layer material.

[0015] Furthermore, a hole blocking layer is provided between the electron transport layer and the electrode layer.

[0016] Furthermore, the material of the hole blocking layer includes at least one of BCP, TiO2, SnO2, C60 (fullerene) and its derivatives.

[0017] Furthermore, the material of the electron transport layer includes at least one of (6,6)-phenyl-C61-butyrate methyl ester, tin oxide, titanium dioxide, and zinc oxide.

[0018] Furthermore, the material of the perovskite layer includes a three-dimensional perovskite material or a three-dimensional perovskite material.

[0019] Furthermore, the material of the perovskite layer includes at least one of FAPbI3, MAPbI3, CsPbI3, CsPbBr3, FA0.83MA0.17PbI3, FA0.85Cs0.15PbI3, and FA0.5MA0.5Pb(I0.8Br0.2)3.

[0020] Furthermore, the material of the transparent conductive substrate includes at least one of indium tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, indium-doped cadmium oxide, polyethylene terephthalate, and ITO-PET composite.

[0021] Furthermore, the material of the hole transport layer includes organic conductors or inorganic conductors.

[0022] Furthermore, the material of the electrode layer includes metal electrodes.

[0023] Furthermore, the electrode layer is a silver electrode or a silver-coated copper electrode.

[0024] Furthermore, the perovskite solar cell includes a single-junction cell or a tandem cell.

[0025] This invention also provides a method for preparing a perovskite solar cell, comprising the following steps:

[0026] (1) Preparation of sulfonic acid group-modified naphthalene diimide derivatives, and / or, preparation of sulfonic acid group-modified perylene diimide derivatives;

[0027] (2) Take a transparent substrate and deposit a hole transport layer on one side of its surface;

[0028] (3) Deposit a perovskite layer on the surface of the hole transport layer;

[0029] (4) Apply the sulfonic acid group-modified naphthalene diimide derivative and / or sulfonic acid group-modified perylene diimide derivative obtained in step (1) to the surface of the perovskite layer to form an interface modification layer.

[0030] (5) Deposit an electron transport layer on the surface of the interface modification layer;

[0031] (6) Print an electrode layer on the surface of the electron transport layer.

[0032] Furthermore, in step (5), a hole blocking layer is first deposited on the surface of the electron transport layer, and then an electrode layer is printed on the surface of the hole blocking layer.

[0033] This invention also provides another method for preparing perovskite solar cells, which includes the following steps:

[0034] (1) Preparation of sulfonic acid group-modified naphthalene diimide derivatives, and / or, preparation of sulfonic acid group-modified perylene diimide derivatives;

[0035] (2) Take a transparent substrate and deposit an electron transport layer on one side of its surface;

[0036] (3) Deposit a perovskite layer on the surface of the electron transport layer;

[0037] (4) Apply the sulfonic acid group-modified naphthalene diimide derivative and / or sulfonic acid group-modified perylene diimide derivative obtained in step (1) to the surface of the perovskite layer to form an interface modification layer.

[0038] (5) Deposit a hole transport layer on the surface of the interface modification layer;

[0039] (6) Print an electrode layer on the surface of the hole transport layer.

[0040] The sulfonic acid group-modified naphthalenediimide derivative described in this invention can be prepared by the following method: (N,N-dimethylamino)propanediamine-1,4,5,8-naphthalenetetraic acid dihydrate, dimethylmethylamine, and N,N-dimethyl-1,3-propanediamine are added sequentially and stirred to form a suspension. Triamine is added to the suspension, and the mixture is refluxed for 12-15 hours. After cooling to room temperature, precipitate 1 is collected by filtration and recrystallized with an organic solvent to obtain naphthalenediimide derivative crystals. Methanol is added to the naphthalenediimide derivative crystals, followed by the addition of 1,4-butanesulfonyl lactone. The mixture is stirred at 50°C-55°C for 48-54 hours, and precipitate 2 is collected by filtration. The precipitate 2 is washed with a solvent, dried, and recrystallized with an organic solvent to obtain the sulfonic acid group-modified naphthalenediimide derivative.

[0041] The perylene diimide derivative modified with sulfonic acid groups described in this invention can be prepared by the following method: (N,N-dimethylamino)propanediamine-1,4,5,8-perylenetetracarboxylic acid dihydrate, dimethylmethylamine, and N,N-dimethyl-1,3-propanediamine are added sequentially and stirred to form a suspension. Triamine is added to the suspension, and the mixture is refluxed for 12-15 hours. After cooling to room temperature, precipitate 1 is collected by filtration and recrystallized with an organic solvent to obtain perylene diimide derivative crystals. Methanol is added to the perylene diimide derivative crystals, followed by the addition of 1,4-butanesulfonyl lactone. The mixture is stirred at 50°C-55°C for 48-54 hours, and precipitate 2 is collected by filtration. The precipitate is washed with a solvent, dried, and recrystallized with an organic solvent to obtain the perylene diimide derivative modified with sulfonic acid groups.

[0042] Furthermore, in step (1), the (N,N-dimethylamino)propanediamine-1,4,5,8-perylenetetracarboxylic acid dihydrate is rinsed with helium.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) Highly efficient passivation of perovskite surface defects and reduction of carrier recombination: The interface modification material of this invention is an aromatic diimide compound modified with sulfonic acid, which achieves high efficiency passivation through a dual action. The sulfonic acid group binds to the perovskite surface defects through Lewis acid-base interaction, directly passivating the defects. The electron-deficient characteristics of the imine group (-N=) framework structure of the aromatic diimide are similar to the electron-rich sites (such as I) on the perovskite surface. - The interaction between the vacancy and surrounding cells further enhances the passivation effect. The dual passivation significantly reduces nonradiative recombination of carriers and improves Voc and FF.

[0045] (2) Optimize interface energy level matching to promote efficient electron extraction: In the prior art, the perovskite conduction band bottom (CBM is about -3.9eV) and the LUMO of the commonly used PCBM electron transport layer (about -4.2eV) have a 0.3eV energy overlap, which hinders electron extraction and limits the short-circuit current JSC; The present invention adjusts the energy level position of the interface material by adjusting the alkyl chain, and combined with the conjugation effect of the aromatic ring and the imide group, it can achieve precise energy level matching with the perovskite layer and the electron transport layer, eliminate the electron transport energy barrier, promote the efficient transfer of electrons from the perovskite layer to the electron transport layer, and improve the short-circuit current of the battery.

[0046] (3) Enhanced electron transport capability and improved surface coverage: The present invention further limits the interface modification layer material to naphthalenediimide (NDI) and its derivatives and / or perylenediimide (PDI) and its derivatives. The interface modification layer material has an extended π-conjugated system based on NDI and PDI, which can form a continuous electron transport channel. At the same time, its molecular structure can better cover the perovskite surface, improve the interface contact quality, reduce electron transport resistance, and thus further improve the charge transport efficiency.

[0047] (4) Improved battery stability under high temperature and high humidity conditions: The alkyl chain modification of sulfonic acid groups gives the interface modification layer hydrophobicity, which greatly improves the stability of the battery under 85℃ and 85% humidity conditions. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. The accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0049] Figure 1 These are schematic diagrams of the perovskite solar cells in Examples 1 and 2;

[0050] Figure 2 This is a schematic diagram of the perovskite solar cell in Comparative Example 1.

[0051] Figure 3 SEM image of the perovskite layer in Example 1;

[0052] Figure 4 SEM image of the perovskite layer in Example 2;

[0053] Figure 5 SEM image of the perovskite layer in Comparative Example 1;

[0054] Figure 6Energy level structures of naphthalenediimide (NDI-SO3R) and perylenediimide (PDI-SO3R) and their energy level matching with perovskite and PCBM;

[0055] Figure 7 Stability trend charts of perovskite solar cells of Examples 1-2 and Comparative Example 1 after aging at 85°C and 85% humidity for 500 hours. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0057] This invention proposes a perovskite interface modification layer material, comprising a sulfonic acid-modified aromatic diimide compound. This sulfonic acid-modified aromatic diimide compound not only passivates and repairs surface defects in the perovskite layer but also achieves energy level matching with the electron transport layer.

[0058] In some specific embodiments of the present invention, the interface modification layer material includes at least one of naphthalene diimide derivatives modified with sulfonic acid groups and perylene diimide derivatives modified with sulfonic acid groups.

[0059] In some specific embodiments of the present invention, the perylene diimide derivative may be selected from at least one of perylene diimide, N,N'-dihexylperylene diimide, and tetrachloroperylene diimide.

[0060] In some specific embodiments of the present invention, the naphthalene diimide derivative may be selected from at least one of naphthonaphthalene diimide, N,N'-dihexylnaphthalene diimide, and tetrachloronaphthalene diimide.

[0061] A second aspect of the present invention also proposes a perovskite solar cell, which includes a transparent conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer, wherein an interface modification layer made of the perovskite interface modification layer material is disposed between the perovskite layer and the electron transport layer.

[0062] In some specific embodiments of the present invention, a hole blocking layer is provided between the electron transport layer and the electrode layer.

[0063] In some specific embodiments of the present invention, the material of the electron transport layer may be selected from conventional materials in the art, and is not limited herein. Those skilled in the art can select according to actual needs. The material of the electron transport layer includes at least one of (6,6)-phenyl-C61-butyrate, tin oxide, titanium dioxide, and zinc oxide.

[0064] In some specific embodiments of the present invention, the material of the perovskite layer can be selected from conventional materials in the art, and is not limited herein. Those skilled in the art can choose according to actual needs. The material of the perovskite layer includes a three-dimensional perovskite material or a three-dimensional perovskite material.

[0065] Optionally, the material of the perovskite layer includes at least one of FAPbI3, MAPbI3, CsPbI3, CsPbBr3, FA0.83MA0.17PbI3, FA0.85Cs0.15PbI3, and FA0.5MA0.5Pb(I0.8Br0.2)3.

[0066] In some specific embodiments of the present invention, the material of the transparent conductive substrate can be selected from conventional materials in the art, and is not limited herein. Those skilled in the art can select according to actual needs. Preferably, the material of the transparent conductive substrate includes at least one of indium tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, indium-doped cadmium oxide, polyethylene terephthalate, and ITO-PET composite.

[0067] In some specific embodiments of the present invention, the material of the hole transport layer may be selected from conventional materials in the art, and is not limited herein. Those skilled in the art can choose according to actual needs. The material of the hole transport layer includes organic conductors or inorganic conductors.

[0068] In some specific embodiments of the present invention, the electrode material can be selected from conventional materials in the art, and is not limited thereto. Those skilled in the art can choose according to actual needs. Preferably, the electrode layer is a silver electrode or a silver-clad copper electrode.

[0069] In some specific embodiments of the present invention, the perovskite solar cell includes a single-junction cell or a tandem cell.

[0070] Optionally, the tandem cell is a two-junction tandem cell, the bottom cell of which can be a TOPCon cell, a BC cell, a TBC cell, or an HJT cell; the top cell includes the aforementioned perovskite solar cell.

[0071] This invention also proposes a method for preparing perovskite solar cells, which is used to prepare inverted cells, comprising the following steps:

[0072] (1) Preparation of sulfonic acid group-modified naphthalene diimide derivatives, and / or, preparation of sulfonic acid group-modified perylene diimide derivatives;

[0073] (2) Take a transparent substrate and deposit a hole transport layer on one side of its surface;

[0074] (3) Deposit a perovskite layer on the surface of the hole transport layer;

[0075] (4) Apply the sulfonic acid group-modified naphthalene diimide derivative and / or sulfonic acid group-modified perylene diimide derivative obtained in step (1) to the surface of the perovskite layer to form an interface modification layer.

[0076] (5) Deposit an electron transport layer on the surface of the interface modification layer;

[0077] (6) Print an electrode layer on the surface of the electron transport layer.

[0078] In some embodiments of the present invention, in step (5), a hole blocking layer is first deposited on the surface of the electron transport layer, and then an electrode layer is printed on the surface of the hole blocking layer.

[0079] This invention also proposes a method for preparing perovskite solar cells, which is used to prepare positively charged cells, comprising the following steps:

[0080] (1) Preparation of sulfonic acid group-modified naphthalene diimide derivatives, and / or, preparation of sulfonic acid group-modified perylene diimide derivatives;

[0081] (2) Take a transparent substrate and deposit an electron transport layer on one side of its surface;

[0082] (3) Deposit a perovskite layer on the surface of the electron transport layer;

[0083] (4) Apply the sulfonic acid group-modified naphthalene diimide derivative and / or sulfonic acid group-modified perylene diimide derivative obtained in step (1) to the surface of the perovskite layer to form an interface modification layer.

[0084] (5) Deposit a hole transport layer on the surface of the interface modification layer;

[0085] (6) Print an electrode layer on the surface of the hole transport layer.

[0086] The methods for preparing the transparent conductive substrate, hole transport layer, perovskite layer, electron transport layer, electrode layer, and hole blocking layer of the perovskite solar cell are all conventional methods in the art and are not limited here. Those skilled in the art can choose according to actual needs.

[0087] In some specific embodiments of the present invention, the preparation method of the sulfonic acid group-modified naphthalenediimide derivative is as follows: (N,N-dimethylamino)propanediamine-1,4,5,8-naphthalenetetraic acid dihydrate, dimethylmethylamine and N,N-dimethyl-1,3-propanediamine are added sequentially and stirred to form a suspension. Triamine is added to the suspension and the mixture is refluxed for 12-15 hours. After cooling to room temperature, precipitate 1 is collected by filtration and recrystallized with an organic solvent to obtain naphthalenediimide derivative crystals. Methanol is added to the naphthalenediimide derivative crystals, followed by the addition of 1,4-butanesulfonyl lactone. The mixture is stirred at 50°C-55°C for 48-54 hours. Precipitate 2 is collected by filtration, washed with solvent, and dried. Organic solvent is added to the dried precipitate 2 and recrystallized to obtain the sulfonic acid group-modified naphthalenediimide derivative.

[0088] In some specific embodiments of the present invention, the preparation method of the perylene diimide derivative modified with sulfonic acid groups is as follows: (N,N-dimethylamino)propanediamine-1,4,5,8-perylenetetracarboxylic acid dihydrate, dimethylmethylamine, and N,N-dimethyl-1,3-propanediamine are added sequentially and stirred to form a suspension. Triamine is added to the suspension, and the mixture is refluxed for 12-15 hours. After cooling to room temperature, precipitate 1 is collected by filtration and recrystallized with an organic solvent to obtain perylene diimide derivative crystals. Methanol is added to the perylene diimide derivative crystals, followed by the addition of 1,4-butanesulfonyl lactone. The mixture is stirred at 50°C-55°C for 48-54 hours, and precipitate 2 is collected by filtration. The precipitate is washed with a solvent, dried, and recrystallized with an organic solvent to obtain the perylene diimide derivative modified with sulfonic acid groups.

[0089] In some specific embodiments of the present invention, in step (1), the dehydrated product of (N,N-dimethylamino)propanediamine-1,4,5,8-perylenetetracarboxylic acid is rinsed with helium.

[0090] The embodiments of this application are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0091] Example 1

[0092] This embodiment provides a perovskite solar cell containing a naphthalenediimide (NDI-SO3R) interface modification layer, as shown in the attached figure. Figure 1 As shown, the battery comprises layers of ITO / PTAA / PVSK / NDI-SO3R / PCBM / BCP / Ag, and its fabrication method includes the following steps:

[0093] (1) Take a clean, 100 nm thick transparent conductive indium tin oxide (ITO) substrate and disinfect it in an ultraviolet ozone environment for 25 min, then transfer it to a glove box; (2) Take a 2 mg / mL poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) PTAA toluene solution was spin-coated onto ITO at 4000 rpm / 30 s, and then annealed at 100°C for 10 min on a hot plate to obtain a hole transport layer with a thickness of 20 nm; (3) a perovskite precursor solution (molar ratio: PbI2:MAI=1.2:0.3; solvent: DMF, DMSO) was uniformly spin-coated onto the PTAA film prepared in step (2) at 6000 rpm / 20 s; when the perovskite precursor solution was uniformly spread, an isopropanol solution (40 mg / mL) was rapidly added at 4000 rpm / 40 s and spin-coated onto the spread precursor film, and then annealed at 100°C for 30 min on a hot plate to obtain a perovskite film layer with a thickness of 500 nm. The scanning electron microscope (SEM) image of the perovskite film layer is shown below. Figure 3 Show;

[0094] (4) Take a methanol solution of sulfonic acid group-modified naphthalene diimide (NDI-SO3R) with a concentration of 1 mg / mL and spin-coat it onto the perovskite film layer prepared in step (3) at a speed of 3000 rpm / 30s to obtain an interface modification layer with a thickness of 7 nm; wherein NDI-SO3R can be prepared by the method disclosed above;

[0095] (5) Take a chlorobenzene solution of (6,6)-phenyl-C61-butyrate methyl ester (PCBM) with a concentration of 20 mg / mL and spin coat it onto the NDI-SO3R interface modification layer prepared in step (4) at a speed of 3000 rpm / 20 s. Then place it on a hot plate and anneal at 90 °C for 30 min to obtain a PCBM electron transport layer with a thickness of 30 nm.

[0096] (6) Take a 0.5 mg / mL solution of copper bath (BCP) isopropanol and spin coat the above electron transport layer at a speed of 4000 rpm / 30 s to obtain a hole blocking layer with a thickness of 10 nm.

[0097] (7) The thin film prepared in step (6) is transferred to the evaporation chamber to deposit a 100 nm thick silver electrode, resulting in an effective area of ​​0.04 cm². 2 Perovskite solar cells.

[0098] Example 2

[0099] This embodiment provides a perovskite solar cell containing a perylene diimide (PDI-SO3R) interface modification layer, as shown in the attached figure. Figure 1As shown, the battery comprises layers of ITO / PTAA / PVSK / PDI-SO3R / PCBM / BCP / Ag, and its fabrication method includes the following steps:

[0100] (1) Take a clean, 100 nm thick transparent conductive indium tin oxide (ITO) substrate and disinfect it in an ultraviolet ozone environment for 25 min, then transfer it to a glove box; (2) Take a 2 mg / mL poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) PTAA toluene solution was spin-coated onto ITO at 4000 rpm / 30 s, and then annealed at 100°C for 10 min on a hot plate to obtain a hole transport layer with a thickness of 20 nm; (3) An appropriate amount of perovskite precursor solution (molar ratio: PbI2:MAI=1.2:0.3; solvent: DMF, DMSO) was uniformly spin-coated onto the PTAA film prepared in step (2) at 6000 rpm / 20 s; when the perovskite precursor solution was uniformly spread, isopropanol solution (40 mg / mL) was rapidly added at 4000 rpm / 40 s and spin-coated onto the spread precursor film, and then annealed at 100°C for 30 min on a hot plate to obtain a perovskite film layer with a thickness of 500 nm. The scanning electron microscope (SEM) image of the perovskite film layer is shown below. Figure 4 Show;

[0101] (4) Take a sulfonic acid group-modified perylene diimide (PDI-SO3R) methanol solution with a concentration of 1 mg / mL and spin-coat it onto the perovskite thin film layer prepared in step (3) at a speed of 3000 rpm / 30s to obtain an interface modification layer with a thickness of 5 nm; wherein PDI-SO3R can be prepared by the method disclosed above;

[0102] (5) Take a chlorobenzene solution of (6,6)-phenyl-C61-butyrate methyl ester (PCBM) with a concentration of 20 mg / mL and spin coat it onto the NDI-SO3R interface modification layer prepared in step (4) at a speed of 3000 rpm / 20 s. Then place it on a hot plate and anneal at 90 °C for 30 min to obtain a PCBM electron transport layer with a thickness of 30 nm.

[0103] (6) Take a 0.5 mg / mL solution of copper bath (BCP) isopropanol and spin coat the above electron transport layer at a speed of 4000 rpm / 30 s to obtain a hole blocking layer with a thickness of 10 nm.

[0104] (7) The thin film prepared in step (6) is transferred to the evaporation chamber to deposit a 100 nm thick silver electrode, resulting in an effective area of ​​0.04 cm². 2 Perovskite solar cells.

[0105] Example 3

[0106] The perovskite solar cells in Example 3 are basically the same in structure and preparation method as those in Example 1, except that the thickness of the interface modification layer is 5 nm.

[0107] Example 4

[0108] The perovskite solar cells in Example 4 are basically the same in structure and preparation method as those in Example 1, except that the thickness of the interface modification layer is 10 nm.

[0109] Example 5

[0110] The perovskite solar cells in Example 5 are basically the same in structure and preparation method as those in Example 1, except that the thickness of the interface modification layer is 3 nm.

[0111] Example 6

[0112] The perovskite solar cells in Example 6 are basically the same in structure and preparation method as those in Example 1, except that the thickness of the interface modification layer is 20 nm.

[0113] Example 7

[0114] The perovskite solar cells in Example 7 and Example 6 have basically the same structure and preparation method, except that the interface modification layer consists of a 10 nm thick layer of sulfonic acid group-modified naphthalenediimide combined with a 10 nm thick layer of sulfonic acid group-modified perylenediimide.

[0115] Comparative Example 1

[0116] This comparative example provides a perovskite solar cell without an interface modification layer, as shown in the attached figure. Figure 2 As shown, the battery comprises layers of ITO, 2PACz, PVSK, PCBM, BCP, and Ag electrodes, and its fabrication method includes the following steps:

[0117] (1) Take a clean ITO transparent conductive substrate, disinfect it in an ultraviolet ozone environment for 25 min, and then transfer it to a glove box; (2) Take a PTAA toluene solution with a concentration of 2 mg / mL and spin coat it onto the ITO at a speed of 4000 rpm / 30 s, and then place it on a hot stage to anneal at 100 °C for 10 min; (3) Take a perovskite precursor solution (molar ratio: PbI2:MAI=1.2:0.3; solvent: DMF, DMSO) and spin coat it evenly onto the PTAA film prepared in S2 at a speed of 6000 rpm / 20 s; when the perovskite precursor solution is evenly spread, take an isopropanol solution (40 mg / mL) and quickly add it dropwise at 4000 rpm / 40 s and spin coat it onto the spread precursor film, and then place it on a hot stage to anneal at 100 °C for 30 min to obtain a perovskite film layer. The scanning electron microscope (SEM) image of the perovskite film layer is as follows. Figure 5 As shown;

[0118] (4) Take a 20 mg / mL PCBM chlorobenzene solution and spin coat it onto the perovskite thin film layer prepared in step (3) at a speed of 3000 rpm / 20 s. Then place it on a hot plate and anneal at 90 °C for 30 min to obtain the PCBM electron transport layer.

[0119] (5) Take an appropriate amount of BCP isopropanol solution with a concentration of 0.5 mg / mL and spin coat the electron transport layer prepared in step (4) at a speed of 4000 rpm / 30 s;

[0120] (6) The thin film prepared in step (5) is transferred to the evaporation chamber to deposit a 100 nm thick silver electrode, ultimately obtaining an effective area of ​​0.04 cm². 2 Perovskite solar cells.

[0121] Comparative Example 2

[0122] The perovskite solar cell of Comparative Example 2 has a basically the same structure as that of Example 1, except that the material of the interface modification layer is p-aminobenzenesulfonic acid (ABSA).

[0123] The structural formula is .

[0124] The perovskite solar cells prepared in Examples 1-7 and Comparative Example 1 were subjected to JV (current-voltage test). The relevant test parameters were open-circuit voltage Voc (V), short-circuit current Isc (mA), fill factor FF (%), and photoelectric conversion efficiency PCE (%). The test method is a conventional test method in the art, and the test results are shown in Table 1.

[0125] Examples 1-2 and Comparative Example 1 were aged for 500 hours at 85°C and 85% humidity. The specific experimental methods were as follows: 1) Initial efficiency testing of the perovskite solar cells; 2) Aging of the perovskite solar cells in a constant temperature and humidity chamber (85°C, 85% humidity) in a dark environment; 3) Every 100 hours, the perovskite solar cells were removed, cooled to room temperature, and then the cell efficiency was tested. The normalized photoelectric conversion efficiency over time was obtained (stability trend graph), as shown below. Figure 7 As shown.

[0126] Table 1

[0127] Group Open-circuit voltage Voc (V) Short-circuit current Isc (mA) Fill factor FF (%) PCE (%) Example 1 1.11 23.41 81.65 21.21 Example 2 1.10 22.89 81.47 20.51 Example 3 1.10 23.25 81.37 20.81 Example 4 1.10 23.17 81.09 20.66 Example 5 1.07 22.15 79.12 18.93 Example 6 1.08 22.29 78.05 18.78 Example 7 1.09 22.74 80.62 19.98 Comparative Example 1 1.08 22.25 78.62 18.89 Comparative Example 2 1.10 22.69 80.53 20.10

[0128] As can be seen from the comparison of Examples 1-7 and Comparative Example 1 in Table 1, the open-circuit voltage, short-circuit current, fill factor, and photoelectric conversion efficiency of the batteries in Examples 1-7 of the present invention are significantly improved. This shows that by setting an interface modification layer made of aromatic diimide compound material modified with sulfonic acid groups between the perovskite layer and the electron transport layer, it is possible to simultaneously passivate and repair defects on the perovskite surface and match the energy level with the electron transport layer, thereby improving the electron transport efficiency; thus, the performance of the perovskite solar cell is significantly optimized.

[0129] As can be seen from the comparison between Comparative Example 2 and Examples 1-7, in perovskite solar cells with interface modification layers, the interface modification layers prepared by the sulfonic acid group-modified aromatic diimide compounds used in this invention, especially the interface modification layers prepared by sulfonic acid group-modified naphthalenediimide and sulfonic acid group-modified perylenediimide, have a significantly better optimization effect on the cell than the interface modification layers prepared by other compounds modified by sulfonic acid groups. The reason for this is that the sulfonic acid group and the imine group (-N=) of the aromatic diimide can synergistically achieve the passivation and repair of defects on the perovskite surface and the energy level matching with the electron transport layer, which significantly improves the electron extraction efficiency and reduces recombination loss.

[0130] From the appendix Figure 7 It can be seen that, compared with Comparative Example 1, Examples 1 and 2 have higher normalized photoelectric conversion efficiency, indicating that they have better stability in humid environments. This significantly improves the battery's lifespan.

[0131] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the nature and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention.

Claims

1. An interface modification layer material, characterized in that, The interface modification layer material includes sulfonic acid-modified aromatic diimide compounds.

2. The interface modification layer material according to claim 1, characterized in that, The interface modification layer material includes at least one of naphthalene diimide derivatives modified with sulfonic acid groups and perylene diimide derivatives modified with sulfonic acid groups.

3. The interface modification layer material according to claim 1, characterized in that, The thickness of the interface modification layer material is 5~20nm, preferably 5~10nm.

4. A perovskite solar cell, comprising a transparent conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer, characterized in that, An interface modification layer is disposed between the perovskite layer and the electron transport layer, and the material of the interface modification layer includes the interface modification layer material according to any one of claims 1-3.

5. A perovskite solar cell according to claim 4, characterized in that, A hole blocking layer is provided between the electron transport layer and the electrode layer.

6. A perovskite solar cell according to claim 4, characterized in that, The electron transport layer is made of at least one of (6,6)-phenyl-C61-butyrate, tin oxide, titanium dioxide, and zinc oxide; and / or, The perovskite layer is made of a three-dimensional perovskite material; and / or, The transparent conductive substrate is made of at least one of indium tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, indium-doped cadmium oxide, polyethylene terephthalate, and ITO-PET composite; and / or, The hole transport layer is made of an organic conductor or an inorganic conductor; and / or, The electrode layer is made of metal electrodes.

7. A method for preparing a perovskite solar cell according to any one of claims 4-6, characterized in that, Includes the following steps: (1) Preparation of sulfonic acid group-modified naphthalene diimide derivatives, and / or, preparation of sulfonic acid group-modified perylene diimide derivatives; (2) Take a transparent substrate and deposit a hole transport layer on one side of its surface; (3) Deposit a perovskite layer on the surface of the hole transport layer; (4) Apply the sulfonic acid group-modified naphthalene diimide derivative and / or sulfonic acid group-modified perylene diimide derivative obtained in step (1) to the surface of the perovskite layer to form an interface modification layer. (5) Deposit an electron transport layer on the surface of the interface modification layer; (6) Print an electrode layer on the surface of the electron transport layer.

8. A method for preparing a perovskite solar cell according to any one of claims 4-6, characterized in that, Includes the following steps: (1) Preparation of sulfonic acid group-modified naphthalene diimide derivatives, and / or, preparation of sulfonic acid group-modified perylene diimide derivatives; (2) Take a transparent substrate and deposit an electron transport layer on one side of its surface; (3) Deposit a perovskite layer on the surface of the electron transport layer; (4) Apply the sulfonic acid group-modified naphthalene diimide derivative and / or sulfonic acid group-modified perylene diimide derivative obtained in step (1) to the surface of the perovskite layer to form an interface modification layer. (5) Deposit a hole transport layer on the surface of the interface modification layer; (6) Print an electrode layer on the surface of the hole transport layer.

9. A method for preparing a perovskite solar cell according to claim 7 or 8, characterized in that, The method for preparing the sulfonic acid group-modified naphthalenediimide derivative is as follows: (N,N-dimethylamino)propanediamine-1,4,5,8-naphthalenetetraic acid dihydrate, dimethylmethylamine, and N,N-dimethyl-1,3-propanediamine are added sequentially and stirred to form a suspension. Triamine is added to the suspension, and the mixture is refluxed for 12-15 hours. After cooling to room temperature, precipitate 1 is collected by filtration and recrystallized with an organic solvent to obtain naphthalenediimide derivative crystals. Methanol is added to the naphthalenediimide derivative crystals, followed by the addition of 1,4-butanesulfonyl lactone. The mixture is stirred at 50℃-55℃ for 48-54 hours, and precipitate 2 is collected by filtration. The precipitate 2 is washed with a solvent, dried, and recrystallized with an organic solvent to obtain the sulfonic acid group-modified naphthalenediimide derivative. The preparation method of the perylene diimide derivative modified with sulfonic acid group is as follows: (N,N-dimethylamino)propanediamine-1,4,5,8-perylenetetracarboxylic acid dihydrohydrate, dimethylmethylamine, and N,N-dimethyl-1,3-propanediamine are added sequentially and stirred to form a suspension. Triamine is added to the suspension, and the mixture is refluxed for 12-15 hours. After cooling to room temperature, precipitate 1 is collected by filtration and recrystallized with an organic solvent to obtain perylene diimide derivative crystals. Methanol is added to the perylene diimide derivative crystals, followed by the addition of 1,4-butanesulfonyl lactone. The mixture is stirred at 50℃-55℃ for 48-54 hours, and precipitate 2 is collected by filtration. The precipitate is washed with a solvent, dried, and recrystallized with an organic solvent to obtain the perylene diimide derivative modified with sulfonic acid group.

10. The method for preparing a perovskite solar cell according to claim 7, characterized in that, In step (5), a hole blocking layer is first deposited on the surface of the electron transport layer, and then an electrode layer is printed on the surface of the hole blocking layer.

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