Passivator composition, perovskite precursor solution, perovskite light-absorbing layer and solar cell

Abstract

The invention belongs to the photovoltaic field, and particularly relates to a passivator composition, a perovskite precursor solution, a perovskite light absorption layer and a solar cell. The passivator composition provided by the invention comprises a tannate substance and an antioxidant. The tannate substance is rich in functional groups, wide in source, low in cost and suitable for synergistic passivation of the perovskite light absorption layer. In addition, through cooperation with the antioxidant, the photo-thermal stability of the tannate substance can be improved, so that composite passivation regulation of internal defects of perovskite is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of photovoltaics, and particularly relates to a passivation agent composition, a perovskite precursor solution, a perovskite light-absorbing layer, and a solar cell. BACKGROUND

[0002] Perovskite materials in the field of photovoltaics are natural ionic substances. The surface and bulk of polycrystalline perovskite thin films prepared by solution method contain many uncoordinated ions, which are prone to decomposition under external erosion. In perovskite solar cells, defects within the perovskite light-absorbing layer, defects within the transport layer, and the lower electrical properties of the transport layer are the main reasons for carrier recombination and energy loss.

[0003] Therefore, it is very important to passivate the defects within the perovskite light-absorbing layer. By passivating the defects, the adverse effects of the defects on the stability of the perovskite solar cell can be reduced, thereby improving the long-term stability of the perovskite solar cell. For example, it has been reported that the introduction of reduced glutathione (GSH) into the perovskite light-absorbing layer can regulate the perovskite crystallization process and improve its resistance to oxidation. Perovskite solar cell devices prepared by this method can still maintain a high proportion of their initial efficiency after being stored for 1000 hours in an indoor environment without packaging. The stability of perovskite solar cells has been one of the key factors restricting their commercialization process. By passivating bulk defects and other strategies, the efficiency and stability of perovskite solar cells can be effectively improved, laying a solid foundation for their commercial application.

[0004] At present, solution coating is the mainstream method for preparing mass-produced high-quality perovskite thin films and high-efficiency perovskite solar cells in the industry. Among them, additive engineering is an important and relatively simple method for passivating bulk defects of perovskite precursors and for rheological control of perovskite precursors.

[0005] The current common bulk passivation methods for perovskite cells include: using ammonium salt for chemical passivation, but the ammonium salt passivation ligand is prone to deprotonation, affecting the passivation effect; using Lewis acid-base, metal cations, etc. to form chemical bond passivation, but the volatility and high migration characteristics of small molecule substances make the stability of the passivation system questionable; using polymer Lewis base to form coordination bond passivation, such as poly succinimide (PSI), which can form strong coordination bonds with metal ions (such as Pb²⁺) in perovskite through its functional groups, thereby effectively passivating the defects at the grain boundaries of perovskite. However, due to its high molecular weight characteristics, a small amount of addition can change the hydrodynamic properties of the perovskite precursor solution, affecting the coating state.

[0006] Conventional small-molecule body-phase passivation reagents are prone to diffusion, volatilization and decomposition under outdoor extreme conditions such as light, heat, oxygen and ultraviolet, which is not conducive to the stability of perovskite solar cells. Polymer-based passivation reagents have better stability due to their larger molecular weight, but they are insufficient in improving the efficiency of perovskite solar cell devices. In addition, due to their large molecular weight, it is very difficult to add and measure them, which is not conducive to the realization of uniform thin films on a large scale and will reduce the yield of the battery. SUMMARY

[0007] The present application is directed to the above-mentioned problems existing in the prior art, and provides a passivation agent composition, a perovskite precursor solution, a perovskite light-absorbing layer and a solar cell.

[0008] Specifically, the present application provides a passivation agent composition for a perovskite light-absorbing layer, which comprises a tannate substance and an antioxidant.

[0009] In one or more embodiments, the tannate substance is a sodium, ammonium and / or potassium salt of one or more acids selected from tannic acid, oleanolic acid, chrysophanol tannic acid, maotan acid, tannin acid, jujube acid, red banana acid, gallic acid, black bitter acid, caesalpinia acid, yellow acid, eucalyptus acid and oxalic acid, preferably a sodium, ammonium and / or potassium salt of one or more acids selected from tannin acid, chrysophanol tannic acid, oleanolic acid and maotan acid, and more preferably one or more selected from ammonium tannin, potassium chrysophanol tannic acid, ammonium oleanolic acid and potassium maotan acid.

[0010] In one or more embodiments, the antioxidant is a sodium, ammonium and / or potassium salt of one or more acids selected from ascorbic acid, sulfurous acid and hypophosphorous acid, preferably one or both of potassium hypophosphite and sodium hypophosphite.

[0011] In one or more embodiments, the mass ratio of the tannate substance to the antioxidant is (3-10):1.

[0012] The present application also provides a perovskite precursor solution, which comprises a perovskite precursor component and a solvent, wherein the perovskite precursor component comprises a perovskite structure substance raw material and the passivation agent composition of any one of the embodiments.

[0013] In one or more embodiments, the solvent is selected from one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methyl pyrrolidone and gamma-butyrolactone.

[0014] In one or more embodiments, the perovskite structure substance raw material comprises a divalent cation, and the concentration of the divalent cation in the perovskite precursor solution is 0.5-2 mol / L.

[0015] In one or more embodiments, the mass of the tannate in the perovskite precursor solution is 0.1wt%-1wt%, preferably 0.1wt%-0.3wt% of the total mass of the perovskite precursor components.

[0016] In one or more embodiments, the mass of the antioxidant in the perovskite precursor solution is 0.01wt%-0.1wt%, preferably 0.01wt%-0.05wt%, more preferably 0.01wt%-0.03wt% of the total mass of the perovskite precursor components.

[0017] The present application also provides a perovskite light-absorbing layer comprising a perovskite structured material compound, wherein the perovskite structured material compound comprises a perovskite structured material and the passivation agent composition according to any one of the embodiments.

[0018] In one or more embodiments, the mass of the tannate in the perovskite light-absorbing layer is 0.1wt%-1wt%, preferably 0.1wt%-0.3wt% of the total mass of the perovskite structured material compound.

[0019] In one or more embodiments, the mass of the antioxidant in the perovskite light-absorbing layer is 0.01wt%-0.1wt%, preferably 0.01wt%-0.05wt%, more preferably 0.01wt%-0.03wt% of the total mass of the perovskite structured material compound.

[0020] In one or more embodiments, the thickness of the perovskite light-absorbing layer is 10 nm-100 μm.

[0021] The present application also provides a method for preparing the perovskite light-absorbing layer according to any one of the embodiments, wherein the method comprises coating the perovskite precursor solution according to any one of the embodiments, and then annealing to obtain the perovskite light-absorbing layer.

[0022] In one or more embodiments, the coating is performed by spin coating, blade coating, evaporation, printing, spraying, spray pyrolysis or slot coating.

[0023] In one or more embodiments, the annealing temperature is 70-130 ℃, preferably 100-130 ℃.

[0024] In one or more embodiments, the annealing time is 3-30 min, preferably 10-30 min.

[0025] The present application also provides a solar cell comprising the perovskite light-absorbing layer according to any one of the embodiments.

[0026] The present application also provides the use of tannate or the passivation agent composition described in any embodiment herein in improving the short-circuit current density, open-circuit voltage, fill factor and / or conversion efficiency of a solar cell comprising a perovskite light-absorbing layer.

[0027] The present application finds that tannate contains a large number of phenolic hydroxyl groups (-OH) and can form weak bonds with various ions in the perovskite phase, achieving the purpose of stabilizing the crystal phase and passivating defects. Tannate has abundant functional groups, is widely available and low in cost, and is suitable for synergistic passivation of perovskite solar cell films. In addition, different substituents will increase the rigidity of the molecule, thereby improving its stability. Furthermore, by cooperating with antioxidants, the photothermal stability of tannate and its derivatives can be improved, thereby achieving complex passivation and regulation of internal defects in perovskite. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The figure is a schematic diagram of the structure of a perovskite solar cell in some embodiments of the present application. DETAILED DESCRIPTION

[0029] To enable those skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned herein. Unless otherwise specified, all technical and scientific words used herein have their usual meanings understood by those skilled in the art of the present application, and in the event of a conflict, the definitions in the present specification shall prevail.

[0030] Theories or mechanisms described and disclosed herein, whether correct or not, should not be taken as limiting the scope of the present application, i.e., the present application can be practiced without relying on any particular theory or mechanism.

[0031] In the present application, "comprising", "including", "containing" and similar phrases cover the meanings of "consisting essentially of" and "consisting of", for example, when the present application discloses "A comprising B and C", "A consisting essentially of B and C" and "A consisting of B and C" should be considered to have been disclosed herein.

[0032] In the present application, all features defined in the form of numerical ranges or percentage ranges, such as values, quantities, contents and concentrations, are for the sake of brevity and convenience. Therefore, the description of numerical ranges or percentage ranges should be considered to have covered and specifically disclosed all possible sub-ranges and individual values within the range (including integers and fractions).

[0033] In the present application, unless otherwise specified, percentages refer to mass percentages and ratios refer to mass ratios.

[0034] In the present application, the sum of the percentage contents of each component of the composition is 100%.

[0035] Herein, the description of the embodiments or examples is understood not to limit the present application to these embodiments or examples. Rather, all alternatives, modifications, and equivalents of the methods and materials described herein, can be contemplated as within the scope of the present application.

[0036] Herein, all possible combinations of the technical features in each embodiment or example are not described in order to make the description concise. Therefore, as long as the combinations of the technical features do not contradict each other, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as within the scope of the present specification.

[0037] The present application provides a passivation agent composition for a perovskite light-absorbing layer, which includes a tannate substance and an antioxidant.

[0038] In the present application, the tannate substance is a sodium salt, an ammonium salt, and / or a potassium salt of an acid. In the tannate substance, the acid can be selected from one or more of tannic acid, oleanolic acid, chrysophanol tannic acid, tormentic acid, tannin acid, maslinic acid, red banana acid, gallic acid, black bitter acid, caesalpinia acid, yellow acid, eucalyptus acid, and oxalic acid.

[0039] In some preferred embodiments, the tannate substance can be a sodium salt, an ammonium salt, and / or a potassium salt of one or more acids selected from tannin acid, chrysophanol tannic acid, oleanolic acid, and tormentic acid.

[0040] In some more preferred embodiments, the tannate substance can be selected from one or more of ammonium tannin, potassium chrysophanol tannic acid, ammonium oleanolic acid, and potassium tormentic acid.

[0041] In the present application, the antioxidant is a sodium salt, an ammonium salt, and / or a potassium salt of an acid. In the antioxidant, the acid can be selected from one or more of ascorbic acid, sulfurous acid, and hypophosphorous acid.

[0042] In some preferred embodiments, the antioxidant can be selected from one or both of potassium hypophosphite and sodium hypophosphite.

[0043] In the passivation agent composition of the present application, the mass ratio of the tannate substance to the antioxidant is preferably (3-10):1, for example, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1. Controlling the mass ratio of the tannate substance to the antioxidant is advantageous for exerting a combined passivation effect of both on internal defects of perovskite.

[0044] The present application also provides a perovskite precursor solution, which comprises a perovskite precursor component and a solvent, wherein the perovskite precursor component comprises a perovskite structure material and the passivation agent composition as described above.

[0045] In the present application, the solvent can be selected from one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl pyrrolidone (NMP) and γ-butyrolactone (γ-GBL). When configuring the perovskite precursor solution, part of the organic components in the perovskite decompose in the presence of water, so the solvent and the powder reagent cannot be mixed with water during the solution preparation process, and the water content is generally less than 100 ppm.

[0046] In the present application, the perovskite structure material comprises a monovalent cation, a divalent cation and a monovalent anion.

[0047] In the present application, the monovalent cation can be selected from one or more of formamidinium ion, cesium ion, methylamine ion, potassium ion and rubidium ion; the divalent cation can be selected from one or more of lead ion, copper ion, zinc ion, gallium ion, tin ion and calcium ion; and the monovalent anion can be selected from one or more of iodine ion, bromine ion, chlorine ion, fluorine ion and thiocyanate ion.

[0048] In the present application, the concentration of the divalent cation in the perovskite precursor solution can be 0.5-2 mol / L, for example, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, 2.0 mol / L.

[0049] In the present application, in the perovskite precursor solution, the mass of the tannate can be 0.1wt%-1wt%, preferably 0.1wt%-0.3wt% of the total mass of the perovskite precursor component, for example, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%.

[0050] In the present application, the mass of the antioxidant in the perovskite precursor solution can be 0.01wt%-0.1wt%, preferably 0.01wt%-0.05wt%, more preferably 0.01wt%-0.03wt% of the total mass of the perovskite precursor components, for example 0.01wt%, 0.02wt%, 0.03wt%, 0.04wt%, 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.1wt%.

[0051] The present application also provides a perovskite light-absorbing layer, which comprises a perovskite structure material composite, and the perovskite structure material composite comprises a perovskite structure material and the passivation agent composition described above.

[0052] In the perovskite light-absorbing layer, the mass of the tannate substance can be 0.1wt%-1wt%, preferably 0.1wt%-0.3wt% of the total mass of the perovskite structure material composite, for example 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%.

[0053] In the perovskite light-absorbing layer, the mass of the antioxidant can be 0.01wt%-0.1wt%, preferably 0.01wt%-0.05wt%, more preferably 0.01wt%-0.03wt% of the total mass of the perovskite structure material composite, for example 0.01wt%, 0.02wt%, 0.03wt%, 0.04wt%, 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.1wt%.

[0054] In the present application, the thickness of the perovskite light-absorbing layer can be 10 nm-100 μm, for example 10 nm, 20 nm, 30 nm, 50 nm, 100 nm, 500 nm, 1 μm, 2 μm, 5 μm, 10 μm, 20 μm, 50 μm, 100 μm.

[0055] In the present application, the band gap of the perovskite light-absorbing layer can be 1.3-2.3 eV, for example 1.3 eV, 1.4 eV, 1.5 eV, 1.6 eV, 1.7 eV, 1.8 eV, 1.9 eV, 2.0 eV, 2.1 eV, 2.2 eV, 2.3 eV.

[0056] In the present application, the chemical formula of the perovskite structure material can be ABX3, the A ion is a monovalent cation, which can be selected from one or more of formamidinium ion, cesium ion, methylamine ion, potassium ion and rubidium ion; the B ion is a divalent cation, which can be selected from one or more of lead ion, copper ion, zinc ion, gallium ion, tin ion and calcium ion; and the X ion is a monovalent anion, which can be selected from one or more of iodine ion, bromine ion, chlorine ion, fluorine ion and thiocyanate ion.

[0057] The present application also provides a method for preparing a perovskite light-absorbing layer, which comprises coating the perovskite precursor solution described above, and then annealing to obtain a perovskite light-absorbing layer.

[0058] In the present application, the coating method can be selected from one or more of spin coating, blade coating, evaporation, printing, spraying, spray pyrolysis and slot coating.

[0059] In the present application, the annealing temperature can be 70-130 ℃, preferably 100-130 ℃, for example 100 ℃, 110 ℃, 120 ℃, 130 ℃.

[0060] In the present application, the annealing time can be 3-30 min, preferably 10-30 min, for example 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 25 min, 30 min.

[0061] The present application also provides a solar cell comprising the perovskite light-absorbing layer of the present application.

[0062] In the present application, the solar cell can be a perovskite solar cell.

[0063] In the present application, the perovskite solar cell can comprise, in order in the thickness direction, glass, a transparent conductive oxide layer (TCO), a first charge transport layer, a perovskite light-absorbing layer, a second charge transport layer, a buffer layer and a back electrode.

[0064] In the present application, the transparent conductive oxide can be one or more of tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO) and cerium-doped indium oxide (ICO), zirconium-doped indium oxide (IZrO).

[0065] In the first and second charge transport layers, one is a hole transport layer (HTL) and the other is an electron transport layer (ETL). In some embodiments, the first charge transport layer is a hole transport layer and the second charge transport layer is an electron transport layer.

[0066] In the present application, the hole transport layer can be NiO x and one or more of Li, Mg, Cu, etc. doped compounds, PTTA, PEDOT or self-assembled monolayer (SAMs).

[0067] In the present application, the thickness of the hole transport layer can be 5-30 nm, such as 5 nm, 10 nm, 20 nm, 30 nm. When SAMs material is used alone as the hole transport layer, the film thickness is generally less than 2 nm.

[0068] In the present application, the electron transport layer can be one or more of C60, C60 derivatives, tin oxide and titanium dioxide.

[0069] In the present application, the thickness of the electron transport layer can be 10-50 nm, such as 10 nm, 20 nm, 30 nm, 40 nm, 50 nm.

[0070] In the present application, the buffer layer can be SnO2, and the buffer layer is located between the electron transport layer and the back electrode. The thickness of the buffer layer can be 10-30 nm, such as 10 nm, 15 nm, 20 nm, 25 nm, 30 nm.

[0071] In the present application, the back electrode can be one or more of tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), cerium-doped indium oxide (ICO), zirconium-doped indium oxide (IZrO), Au, Ag, Cu, Al and Cr.

[0072] The present application also provides a method for preparing a solar cell, which comprises the following steps: depositing a perovskite light-absorbing layer on the surface of a first charge transport layer.

[0073] Further, the method for preparing a solar cell can further comprise: depositing a second charge transport layer on the surface of the perovskite light-absorbing layer.

[0074] In the present application, the deposition method of the hole transport layer can be spin coating, blade coating, magnetron sputtering or thermal evaporation.

[0075] In the present application, the deposition method of the electron transport layer can be spin coating, blade coating, magnetron sputtering or thermal evaporation.

[0076] The application also provides a use of the tannate or the passivation agent composition described above in improving the short-circuit current density, open-circuit voltage, fill factor and / or conversion efficiency of a solar cell with a perovskite light-absorbing layer.

[0077] The application achieves the following beneficial effects:

[0078] The application finds that the tannate has rich functional groups, is widely available and low in cost, is suitable for synergistic passivation of the perovskite solar cell light-absorbing layer, and different substituents can increase the rigidity of the molecule and thus improve the stability. In addition, through cooperation with the antioxidant, the light-thermal stability of the tannate itself can be improved, thereby achieving complex passivation regulation and control of the internal defects of the perovskite.

[0079] The application will be described below in the manner of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the application. The methods, reagents and materials used in the examples and comparative examples are conventional in the art unless otherwise specified. The raw material compounds in the examples and comparative examples can be purchased through commercial channels.

[0080] Example 1

[0081] This example 1 prepares a perovskite solar cell according to the following steps:

[0082] (1) transparent clean glass with a thickness of 2.2 mm;

[0083] (2) a transparent conductive oxide layer TCO is prepared by a magnetron sputtering method, with a thickness of 100 nm and a material of ITO;

[0084] (3) a hole transport layer HTL is prepared by a magnetron sputtering method, with a thickness of 20 nm and a material of NiO x ;

[0085] (4) preparation of perovskite precursor solution: uniformly mix perovskite structure material raw materials (FAI, MAI, CsBr, PbI2, PbBr2), ammonium tannate, potassium hypophosphite and solvent (solvent includes DMF, DMSO and NMP, the volume ratio of DMF and DMSO is 4:1, and the addition amount of NMP is 10wt% of DMF) to obtain a mixture, forming a perovskite precursor solution. In the perovskite precursor solution, the concentration of Pb 2+ ions is 1.5 mol / L, the mass fraction of ammonium tannate is 0.1wt%, and the mass fraction of potassium hypophosphite is 0.03wt% (herein, the mass fractions of ammonium tannate and potassium hypophosphite are both calculated with respect to the total mass of the perovskite precursor components);

[0086] A perovskite precursor solution was deposited on the surface of the hole transport layer by slit coating, and then annealed to prepare a perovskite light-absorbing layer (a perovskite structure material chemical formula is Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3) with a thickness of 500 nm, in which the mass fraction of ammonium tannate was 0.1wt%, and the mass fraction of potassium hypophosphite was 0.03wt% (herein, the mass fractions of ammonium tannate and potassium hypophosphite were calculated with respect to the total mass of the perovskite precursor components);

[0087] (5) An electron transport layer (ETL) was prepared by a thermal evaporation method, with a thickness of 20 nm and a material of C60;

[0088] (6) A buffer layer was prepared by an atomic layer deposition method, with a thickness of 20 nm and a material of SnO2;

[0089] (7) A back electrode was prepared by a magnetron sputtering method, with a thickness of 200 nm and a material of Cu.

[0090] Example 2

[0091] The perovskite solar cell was prepared according to the following steps in this example 2:

[0092] (1) A transparent clean glass with a thickness of 2.2 mm;

[0093] (2) A transparent conductive oxide layer (TCO) was prepared by a magnetron sputtering method, with a thickness of 100 nm and a material of ITO;

[0094] (3) A hole transport layer (HTL) was prepared by a magnetron sputtering method, with a thickness of 20 nm and a material of NiO x ;

[0095] (4) A perovskite precursor solution was prepared by mixing perovskite structure material raw materials (FAI, MAI, CsBr, PbI2, PbBr2), potassium tannate, sodium hypophosphite and a solvent (the solvent included DMF, DMSO and NMP, the volume ratio of DMF and DMSO was 4:1, and the addition amount of NMP was 10wt% of DMF) uniformly to obtain a mixture, forming a perovskite precursor solution. In the perovskite precursor solution, the mass fraction of Pb 2+The concentration of ions is 1.0 mol / L, the mass fraction of potassium ellagic acid tannate is 0.2wt%, and the mass fraction of sodium hypophosphite is 0.03wt% (herein, the mass fractions of potassium ellagic acid tannate and sodium hypophosphite are calculated with respect to the total mass of the perovskite precursor component);

[0096] The perovskite precursor solution is deposited on the surface of the hole transport layer by slit coating, and then annealed to prepare a perovskite light-absorbing layer (the chemical formula of the perovskite structure material is Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3) with a thickness of 500 nm, wherein the mass fraction of potassium ellagic acid tannate in the perovskite light-absorbing layer is 0.2wt%, and the mass fraction of sodium hypophosphite is 0.03wt% (herein, the mass fractions of potassium ellagic acid tannate and sodium hypophosphite are calculated with respect to the total mass of the perovskite precursor component);

[0097] (5) The electron transport layer ETL is prepared by a thermal evaporation method, with a thickness of 20 nm and a material of C60;

[0098] (6) The buffer layer (Buffer layer) is prepared by an atomic layer deposition method, with a thickness of 20 nm and a material of SnO2;

[0099] (7) The back electrode (Back electrode) is prepared by a magnetron sputtering method, with a thickness of 200 nm and a material of Cu.

[0100] Example 3

[0101] The perovskite solar cell is prepared according to the following steps in this example 3:

[0102] (1) Transparent clean glass with a thickness of 2.2 mm;

[0103] (2) The transparent conductive oxide layer TCO is prepared by a magnetron sputtering method, with a thickness of 100 nm and a material of ITO;

[0104] (3) The hole transport layer HTL is prepared by a magnetron sputtering method, with a thickness of 20 nm and a material of NiO x ;

[0105] (4) Preparation of perovskite precursor solution: uniformly mix perovskite structure material raw materials (FAI, MAI, CsBr, PbI2, PbBr2), ammonium oleanolate, potassium hypophosphite and solvent (the solvent includes DMF, DMSO and NMP, the volume ratio of DMF and DMSO is 4:1, and the addition amount of NMP is 10wt% of DMF) to obtain a mixture to form a perovskite precursor solution. In the perovskite precursor solution, the concentration of Pb 2+ is 1.5 mol / L, the mass fraction of ammonium oleanolate is 0.3wt%, and the mass fraction of potassium hypophosphite is 0.03wt% (herein, the mass fractions of ammonium oleanolate and potassium hypophosphite are both calculated with respect to the total mass of perovskite precursor components);

[0106] The perovskite precursor solution is deposited on the surface of the hole transport layer in a slit coating manner, and then annealed, with an annealing temperature of 120°C and an annealing time of 30 min, to prepare a perovskite light-absorbing layer with a thickness of 500 nm (the chemical formula of the perovskite structure material is Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3). In the perovskite light-absorbing layer, the mass fraction of ammonium oleanolate is 0.3wt%, and the mass fraction of potassium hypophosphite is 0.03wt% (herein, the mass fractions of ammonium oleanolate and potassium hypophosphite are both calculated with respect to the total mass of perovskite precursor components);

[0107] (5) Electron transport layer ETL is prepared by a thermal evaporation method, with a thickness of 20 nm and a material of C60;

[0108] (6) Buffer layer is prepared by an atomic layer deposition method, with a thickness of 20 nm and a material of SnO2;

[0109] (7) Back electrode is prepared by a magnetron sputtering method, with a thickness of 200 nm and a material of Cu.

[0110] Example 4

[0111] The perovskite solar cell in this example 4 is prepared according to the following steps:

[0112] (1) Transparent clean glass with a thickness of 2.2 mm;

[0113] (2) Transparent conductive oxide layer TCO is prepared by a magnetron sputtering method, with a thickness of 100 nm and a material of ITO;

[0114] (3) Hole transport layer HTL is prepared by a magnetron sputtering method, with a thickness of 20 nm and a material of NiOx ;

[0115] (4) Preparation of perovskite precursor solution: uniformly mix perovskite structure material raw materials (FAI, MAI, CsBr, PbI2, PbBr2), potassium pinenate, potassium hypophosphite and solvent (solvent includes DMF, DMSO and NMP, the volume ratio of DMF and DMSO is 4:1, and the addition amount of NMP is 10wt% of DMF) to obtain a mixture to form a perovskite precursor solution. In the perovskite precursor solution, the concentration of Pb2+ is 1.2 mol / L, the mass fraction of potassium pinenate is 0.15wt%, and the mass fraction of potassium hypophosphite is 0.03wt% (herein, the mass fractions of potassium pinenate and potassium hypophosphite are both calculated with respect to the total mass of perovskite precursor components); 2+

[0116] The perovskite precursor solution is deposited on the surface of the hole transport layer by slit coating, and then annealed, with the annealing temperature being 120°C and the annealing time being 30min, to prepare a perovskite light-absorbing layer with a thickness of 500 nm (the chemical formula of the perovskite structure material is Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3). In the perovskite light-absorbing layer, the mass fraction of potassium pinenate is 0.15wt%, and the mass fraction of potassium hypophosphite is 0.03wt% (herein, the mass fractions of potassium pinenate and potassium hypophosphite are both calculated with respect to the total mass of perovskite precursor components);

[0117] (5) Electron transport layer (ETL) is prepared by thermal evaporation method, with a thickness of 20 nm and a material of C60;

[0118] (6) Buffer layer is prepared by atomic layer deposition method, with a thickness of 20 nm and a material of SnO2;

[0119] (7) Back electrode is prepared by magnetron sputtering method, with a thickness of 200 nm and a material of Cu.

[0120] Comparative Example 1

[0121] Comparative Example 1 prepared a perovskite solar cell according to the following steps:

[0122] (1) Transparent clean glass with a thickness of 2.2 mm;

[0123] (2) Transparent conductive oxide layer (TCO) is prepared by magnetron sputtering method, with a thickness of 100 nm and a material of ITO;

[0124] ​(3) The hole transport layer HTL is prepared by magnetron sputtering method, with a thickness of 20 nm and a material of NiO x ;

[0125] (4) The perovskite precursor solution is prepared by uniformly mixing perovskite structure materials (FAI, MAI, CsBr, PbI2, PbBr2), tannin acid, potassium hypophosphite and solvents (the solvents include DMF, DMSO and NMP, the volume ratio of DMF and DMSO is 4:1, and the addition amount of NMP is 10wt% of DMF) to obtain a mixture, thereby forming the perovskite precursor solution. In the perovskite precursor solution, the concentration of Pb2+ is 1.5 mol / L, the mass fraction of tannin acid is 0.1wt%, and the mass fraction of potassium hypophosphite is 0.03wt% (herein, the mass fractions of tannin acid and potassium hypophosphite are calculated with respect to the total mass of the perovskite precursor components); 2+

[0126] The perovskite precursor solution is deposited on the surface of the hole transport layer in a slit coating manner, and then annealed, with an annealing temperature of 130°C and an annealing time of 30 min, thereby preparing a perovskite light-absorbing layer (the chemical formula of the perovskite structure material is Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3) with a thickness of 500 nm. In the perovskite light-absorbing layer, the mass fraction of tannin acid is 0.1wt%, and the mass fraction of potassium hypophosphite is 0.03wt% (herein, the mass fractions of tannin acid and potassium hypophosphite are calculated with respect to the total mass of the perovskite precursor components);

[0127] (5) The electron transport layer ETL is prepared by thermal evaporation method, with a thickness of 20 nm and a material of C60;

[0128] (6) The buffer layer is prepared by atomic layer deposition method, with a thickness of 20 nm and a material of SnO2;

[0129] (7) The back electrode is prepared by magnetron sputtering method, with a thickness of 200 nm and a material of Cu.

[0130] Comparative Example 2

[0131] The perovskite solar cell of the present comparative example 2 is prepared according to the following steps:

[0132] (1) Transparent clean glass with a thickness of 2.2 mm;

[0133] (2) The transparent conductive oxide layer TCO is prepared by magnetron sputtering method, with a thickness of 100 nm and a material of ITO;​

[0134] (3) The hole transport layer HTL is prepared by magnetron sputtering method, with a thickness of 20 nm and a material of NiO. x ;

[0135] (4) The perovskite precursor solution is prepared by uniformly mixing perovskite structure materials (FAI, MAI, CsBr, PbI2, PbBr2), potassium hypophosphite and solvents (the solvents include DMF, DMSO and NMP, the volume ratio of DMF and DMSO is 4:1, and the addition amount of NMP is 10wt% of DMF) to obtain a mixture, forming a perovskite precursor solution. In the perovskite precursor solution, the concentration of Pb2+ is 1.3 mol / L, and the mass fraction of potassium hypophosphite is 0.03wt% (herein, the mass fraction of potassium hypophosphite is calculated with respect to the total mass of the perovskite precursor components); 2+

[0136] The perovskite precursor solution is deposited on the surface of the hole transport layer by slot coating, and then annealed, with an annealing temperature of 120℃ and an annealing time of 30 min, to prepare a perovskite light-absorbing layer with a thickness of 500 nm (the chemical formula of the perovskite structure material is Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3), and the mass fraction of potassium hypophosphite in the perovskite light-absorbing layer is 0.03wt% (herein, the mass fraction of potassium hypophosphite is calculated with respect to the total mass of the perovskite precursor components);

[0137] The isopropanol solution of emodin ammonium tannate with a concentration of 0.5 mg / mL is deposited on the surface of the perovskite light-absorbing layer by slot coating, to prepare a passivation layer with a thickness of 2 nm, and the material of the passivation layer is emodin ammonium tannate;

[0138] (5) The electron transport layer ETL is prepared by thermal evaporation method, with a thickness of 20 nm and a material of C60;

[0139] (6) The buffer layer is prepared by atomic layer deposition method, with a thickness of 20 nm and a material of SnO2;

[0140] (7) The back electrode is prepared by magnetron sputtering method, with a thickness of 200 nm and a material of Cu.

[0141] Comparative Example 3

[0142] The perovskite solar cell of Comparative Example 3 is prepared according to the following steps:

[0143] ​(1) transparent clean glass, thickness of 2.2 mm;

[0144] (2) a transparent conductive oxide layer TCO is prepared by a magnetron sputtering method, thickness of 100 nm, material of ITO;

[0145] (3) a hole transport layer HTL is prepared by a magnetron sputtering method, thickness of 20 nm, material of NiO x ;

[0146] (4) a perovskite precursor solution is prepared: perovskite structure material raw materials (FAI, MAI, CsBr, PbI2, PbBr2), ammonium tannate and solvent (solvent includes DMF, DMSO and NMP, the volume ratio of DMF and DMSO is 4:1, and the addition amount of NMP is 10wt% of DMF) are uniformly mixed to obtain a mixture, forming a perovskite precursor solution. In the perovskite precursor solution, the concentration of Pb 2+ ion is 1.5 mol / L, and the mass fraction of ammonium tannate is 0.1wt% (herein, the mass fraction of ammonium tannate is calculated with respect to the total mass of the perovskite precursor components);

[0147] The perovskite precursor solution is deposited on the surface of the hole transport layer in a slot coating manner, and then annealed, the annealing temperature is 130℃, and the annealing time is 30 min, to prepare a perovskite light-absorbing layer with a thickness of 500 nm (the chemical formula of the perovskite structure material is Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3), and the mass fraction of ammonium tannate in the perovskite light-absorbing layer is 0.1wt% (herein, the mass fraction of ammonium tannate is calculated with respect to the total mass of the perovskite precursor components);

[0148] (5) an electron transport layer ETL is prepared by a thermal evaporation method, thickness of 20 nm, material of C60;

[0149] (6) a buffer layer is prepared by an atomic layer deposition method, thickness of 20 nm, material of SnO2;

[0150] (7) a back electrode is prepared by a magnetron sputtering method, thickness of 200 nm, material of Cu.

[0151] Comparative Example 4

[0152] Comparative Example 4

[0153] (1) transparent clean glass, thickness of 2.2 mm;

[0154] (2) The transparent conductive oxide layer TCO is prepared by magnetron sputtering method, with a thickness of 100 nm and ITO as the material;

[0155] (3) The hole transport layer HTL is prepared by magnetron sputtering method, with a thickness of 20 nm and NiO as the material; x ;

[0156] (4) The perovskite precursor solution is prepared by uniformly mixing perovskite structure materials (FAI, MAI, CsBr, PbI2, PbBr2) and solvents (the solvents include DMF, DMSO and NMP, the volume ratio of DMF and DMSO is 4:1, and the addition amount of NMP is 10wt% of DMF) to obtain a mixture, forming a perovskite precursor solution. In the perovskite precursor solution, the concentration of Pb2+ is 1.5mol / L; 2+ ;

[0157] The perovskite precursor solution is deposited on the surface of the hole transport layer by slot coating, and then annealed, with an annealing temperature of 120℃ and an annealing time of 30 min, to prepare a perovskite light-absorbing layer (the chemical formula of the perovskite structure material is Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3) with a thickness of 500 nm;

[0158] (5) The electron transport layer ETL is prepared by thermal evaporation method, with a thickness of 20 nm and C60 as the material;

[0159] (6) The buffer layer is prepared by atomic layer deposition method, with a thickness of 20 nm and SnO2 as the material;

[0160] (7) The back electrode is prepared by magnetron sputtering method, with a thickness of 200 nm and Cu as the material.

[0161] Test Example

[0162] Performance test of perovskite solar device: at 25℃, using a solar simulator (AM 1.5G standard solar spectrum, incident light power P in is 100 mW / cm 2 ), the voltage range is set to -0.2 V to 1.5 V, the current output of the perovskite solar cells prepared in Examples 1-4 and Comparative Examples 1-4 at different voltages is tested, and the corresponding current-voltage (I-V) characteristic curves are drawn, wherein the effective area of the cell is 1cm 2The open-circuit voltage, short-circuit current density, fill factor, and photoelectric conversion efficiency of the perovskite solar cells prepared from Examples 1-4 and Comparative Examples 1-4 were obtained according to the characteristic curves.

[0163] (1) Open-circuit voltage (V oc ): the voltage value corresponding to the current equal to zero.

[0164] (2) Short-circuit current density (J sc ): the current size (J sc ) per unit area passing through the battery when the voltage across the battery is zero.

[0165] (3) Fill factor (FF): the ratio of the maximum output power (P max ) of the battery to the product of the open-circuit voltage and the short-circuit current, the calculation formula is (P max / V oc *I sc ) * 100%, wherein the maximum power point is the point at which the output power of the battery reaches the maximum value, and I sc is the short-circuit current.

[0166] (4) Photoelectric conversion efficiency (PCE): photoelectric conversion efficiency refers to the ratio of the maximum output power to the incident light power (P in ), the calculation formula is (P max / P in ) * 100%.

[0167] The test results of the open-circuit voltage, short-circuit current density, fill factor, and photoelectric conversion efficiency of the perovskite solar cells prepared from Examples 1-4 and Comparative Examples 1-4 are shown in Table 1.

[0168] Table 1: Short-circuit current density, open-circuit voltage, fill factor, and photoelectric conversion efficiency of perovskite solar cells prepared from Examples 1-4 and Comparative Examples 1-4

[0169]

[0170] As can be seen from Examples 1 and Comparative Example 1 in Table 1, the performance of the solar cells prepared by using tannate as an additive of the perovskite precursor solution is better than that of the solar cells prepared by using tannic acid as an additive of the perovskite precursor solution.

[0171] As can be seen from Examples 1-4 and Comparative Example 2 in Table 1, the performance of the solar cells prepared by using tannate as an additive of the perovskite precursor solution is better than that of the solar cells prepared by using tannate as a passivation layer of perovskite.

[0172] As can be seen from Example 1 and Comparative Example 3 in Table 1, when the perovskite precursor solution only contains tannate without antioxidant, the performance of the solar cell prepared therefrom is slightly lower than that of the solar cell containing both tannate and antioxidant.

[0173] As can be seen from Comparative Example 3 and Comparative Example 4 in Table 1, the solar cell containing only tannate without antioxidant has better performance than the solar cell containing neither tannate nor antioxidant.

[0174] As can be seen from Example 3 and Comparative Example 4 in Table 1, the solar cell containing both tannate and antioxidant has better performance than the solar cell containing neither tannate nor antioxidant.

[0175] The present application finds that, in bulk passivation, the passivation effect of tannate is better than that of tannic acid. The reason can be that the carboxyl group (-COOH) in tannate can form a strong coordination bond with Pb 2+ in perovskite, regulate the crystal nucleus growth rate, inhibit the formation of small grains, so as to obtain larger grain size, further inhibit non-radiative recombination. In addition, the potassium ion, sodium ion or ammonium ion introduced by tannate can improve the hysteresis effect by occupying the ion migration channel in the lattice, and also can penetrate to the deep defect of the grain boundary by diffusion effect to repair the defect, so as to improve the device efficiency.

[0176] The present application finds that the bulk passivation effect of tannate added to perovskite is better than the passivation effect thereof as a passivation layer. The reason can be that the molecular size of tannate is larger than that of conventional upper interface passivation molecules (such as PI, EDAI2, etc.), and due to the steric hindrance effect, tannate is difficult to achieve effective coverage of the upper interface as a passivation layer. If the thickness of the passivation layer is increased to improve the coverage of the upper interface, the interface transmission efficiency will be affected, thereby causing the device performance to decrease.

Claims

1. A passivating agent composition for a perovskite light-absorbing layer, characterized in that, The passivating agent composition includes tannate substances and antioxidants.

2. The passivating agent composition according to claim 1, characterized in that, The tannate is a sodium, ammonium, and / or potassium salt of one or more acids selected from tannic acid, oleanolic acid, rhein tannic acid, pinoxadenic acid, tannin, hawthorn acid, rutinic acid, gallic acid, picric acid, rutinic acid, succinic acid, eucalyptol, and oxalic acid. Preferably, it is a sodium, ammonium, and / or potassium salt of one or more acids selected from tannin, rhein tannic acid, oleanolic acid, and pinoxadenic acid. More preferably, it is a sodium, ammonium, and / or potassium salt of one or more acids selected from ammonium tannate, potassium rhein tannate, ammonium oleanolic acid, and potassium pinoxadenate.

3. The passivating agent composition according to claim 1, characterized in that, The antioxidant is a sodium, ammonium, and / or potassium salt of one or more acids selected from ascorbic acid, sulfurous acid, and hypophosphite, preferably selected from one or two of potassium hypophosphite and sodium hypophosphite.

4. The passivating agent composition according to claim 1, characterized in that, The mass ratio of the tannate to the antioxidant is (3-10):

1.

5. A perovskite precursor solution, characterized in that, The perovskite precursor solution comprises a perovskite precursor component and a solvent, wherein the perovskite precursor component comprises a perovskite structural material raw material and a passivating agent composition according to any one of claims 1-4.

6. The perovskite precursor solution as described in claim 5, characterized in that, The solvent is selected from one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and γ-butyrolactone.

7. The perovskite precursor solution as described in claim 5, characterized in that, The perovskite structural material raw material includes divalent cations, and the concentration of the divalent cations in the perovskite precursor solution is 0.5-2 mol / L.

8. The perovskite precursor solution as described in claim 5, characterized in that, In the perovskite precursor solution, the mass of the tannate is 0.1wt%-1wt%, preferably 0.1wt%-0.3wt%, of the total mass of the perovskite precursor components.

9. The perovskite precursor solution as described in claim 5, characterized in that, In the perovskite precursor solution, the mass of the antioxidant is 0.01wt%-0.1wt%, preferably 0.01wt%-0.05wt%, and more preferably 0.01wt%-0.03wt% of the total mass of the perovskite precursor components.

10. A perovskite light-absorbing layer, characterized in that, The perovskite light-absorbing layer comprises a perovskite structural material composite, which comprises a perovskite structural material and a passivating agent composition according to any one of claims 1-4.

11. The perovskite light-absorbing layer as described in claim 10, characterized in that, In the perovskite light-absorbing layer, the mass of the tannate substance is 0.1wt%-1wt%, preferably 0.1wt%-0.3wt%, of the total mass of the perovskite structural substance complex.

12. The perovskite light-absorbing layer as described in claim 10, characterized in that, In the perovskite light-absorbing layer, the mass of the antioxidant is 0.01wt%-0.1wt%, preferably 0.01wt%-0.05wt%, and more preferably 0.01wt%-0.03wt% of the total mass of the perovskite structural material composite.

13. The perovskite light-absorbing layer as described in claim 10, characterized in that, The thickness of the perovskite light-absorbing layer is 10 nm-100 μm.

14. A method for preparing a perovskite light-absorbing layer according to any one of claims 10-13, characterized in that, The method includes coating a perovskite precursor solution according to any one of claims 5-9, followed by annealing to obtain a perovskite light-absorbing layer.

15. The method as described in claim 14, characterized in that, The method has one or more of the following characteristics: The coating method is spin coating, blade coating, vapor deposition, printing, spraying, spray pyrolysis, or slot coating; The annealing temperature is 70-130 ℃, preferably 100-130 ℃; The annealing time is 3-30 min, preferably 10-30 min.

16. A solar cell, characterized in that, The solar cell includes the perovskite light-absorbing layer as described in any one of claims 10-13.

17. Use of tannate substances or the passivating agent composition of any one of claims 1-4 in improving the short-circuit current density, open-circuit voltage, fill factor and / or conversion efficiency of solar cells containing perovskite light-absorbing layers.

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