Perovskite layer and preparation method thereof, perovskite cell and preparation method thereof

Abstract

The invention provides a perovskite layer, a preparation method of the perovskite layer, a perovskite battery and a preparation method of the perovskite battery, and belongs to the technical field of perovskite batteries. The perovskite layer comprises a compound with a structure as shown in a formula 1, and a methyl oxime tripolymer or a salt thereof; the formula 1 of the AmPbnX3 is shown in the specification; wherein A comprises at least one of methylamine cations and formamidine cations; x comprises at least one of chlorine anions, bromine anions and iodine anions; m is from 0.95 to 1.05; n ranges from 0.95 to 1.05; the mass ratio of the compound with the structure as shown in the formula 1 to the methyl oxime tripolymer or the salt thereof is 100: (0.22-0.29). According to the invention, by adopting the metoxime tripolymer or the salt thereof and controlling the mass ratio of the metoxime tripolymer or the salt thereof to the compound with the structure as shown in the formula 1, the grain uniformity of the perovskite layer can be adjusted, so that the cell efficiency and the stability of the perovskite cell are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite battery, in particular to a perovskite layer and a preparation method thereof, a perovskite battery and a preparation method thereof. BACKGROUND

[0002] The perovskite battery has the advantages of low raw material cost and broad market prospect. At present, the core light absorption layer (perovskite layer) of the perovskite battery is mostly prepared by a two-step method, i.e., a porous lead iodide layer is first deposited, and then an organic salt is added to diffuse into the lead iodide, and a perovskite layer is formed by heat annealing to optimize the crystalline quality. However, the perovskite layer still has the problem of poor grain uniformity, which seriously affects the battery efficiency and stability of the perovskite battery. Therefore, how to improve the grain uniformity of the perovskite layer has become a technical problem to be solved. SUMMARY

[0003] Based on this, the main purpose of the present application is to provide a perovskite layer and a preparation method thereof, and a perovskite battery and a preparation method thereof, so as to improve the grain uniformity of the perovskite layer, passivate grain boundary defects, and improve the battery performance.

[0004] In a first aspect, the present application provides a perovskite layer, comprising a compound with a structure shown in Formula 1, and methoxime trimer or a salt thereof.

[0005] A m Pb n X3Formula 1;

[0006] wherein A comprises at least one of methylamine cation and formamidinium cation;

[0007] X comprises at least one of chloride anion, bromide anion and iodide anion;

[0008] m is 0.95-1.05;

[0009] n is 0.95-1.05;

[0010] The mass ratio of the compound with the structure shown in Formula 1 to the methoxime trimer or the salt thereof is 100: (0.22-0.29).

[0011] In some embodiments, the methoxime trimer or the salt thereof comprises methoxime trimer or methoxime trimer hydrochloride.

[0012] In a second aspect, the present application provides a preparation method of a perovskite layer, comprising the following steps:

[0013] depositing a solution containing lead iodide and methoxime trimer or a salt thereof to prepare a lead iodide layer;

[0014] An organic halide solution was deposited on the lead iodide layer, and then annealed to prepare a perovskite layer.

[0015] In the solution containing lead iodide and formoxime trimer or its salt, the mass ratio of lead ions to formoxime trimer or its salt is 100:(0.56-0.74, based on the mass of lead ions in lead iodide.

[0016] In some embodiments, the organic halide solution contains an organic halide of type A; wherein A includes at least one of methylamine cation and formamidinium cation; and X includes at least one of chloride anion, bromide anion and iodide anion.

[0017] In some embodiments, the molar ratio of A ions to lead ions in the perovskite layer is (0.95-1.05):(0.95-1.05), based on the molar amounts of A ions and lead ions.

[0018] In some embodiments, the oxime trimer or a salt thereof includes oxime trimer or oxime trimer hydrochloride.

[0019] In some implementations, the annealing conditions include: a temperature of 90°C-150°C and a time of 10 min-40 min.

[0020] In some embodiments, after depositing the solution containing lead iodide and formoxime trimer or its salt, a first annealing step is further included; the conditions for the first annealing include: a temperature of 80°C-120°C and a time of 1 min-10 min.

[0021] In some embodiments, the solvent in the solution containing lead iodide and formoxime trimer or its salt includes at least one of N,N-dimethylformamide and dimethyl sulfoxide.

[0022] In some embodiments, the solvent in the organic halide solution includes at least one of ethanol and isopropanol.

[0023] In a third aspect of this application, a perovskite layer is provided, which is prepared by the method for preparing a perovskite layer described in the second aspect.

[0024] In a fourth aspect, this application provides a perovskite solar cell, including a perovskite layer;

[0025] The perovskite layer includes the perovskite layer described in the first aspect, the perovskite layer prepared by the method described in the second aspect, or the perovskite layer described in the third aspect.

[0026] In some embodiments, the perovskite solar cell includes a conductive substrate, an electron transport layer, a perovskite layer, a passivation layer, a hole transport layer, and an electrode layer stacked sequentially.

[0027] In a fifth aspect, the application provides a method for preparing the perovskite cell according to the fourth aspect, comprising the following steps:

[0028] Preparation of an electron transport layer, a perovskite layer, a passivation layer, a hole transport layer and an electrode layer on a conductive substrate to prepare a perovskite cell.

[0029] Compared with the prior art, the application has at least the following beneficial effects:

[0030] The perovskite layer described in the application is doped with a compound having the structure shown in Formula 1 and a methoxyl trimer or a salt thereof, and the mass ratio of the two is controlled, so as to improve the grain uniformity of the perovskite layer, passivate grain boundary defects, and thus improve the cell efficiency and stability of the perovskite cell. DETAILED DESCRIPTION

[0031] The application will be further described in detail below with reference to the embodiments and examples. These embodiments and examples are only used to illustrate the application and are not used to limit the scope of the application. The purpose of providing these embodiments and examples is to make the disclosure of the application more thorough and comprehensive. It should also be understood that the application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or changes without departing from the spirit of the application, and the equivalent forms obtained thereby also fall within the protection scope of the application. In addition, in the following description, a large number of specific details are given in order to provide a more complete understanding of the application. It should be understood that the application can be implemented without one or more of these details.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs. The terminology used in the specification of the application herein is only for the purpose of describing specific embodiments and is not intended to limit the application. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0033] In view of the problem that poor grain uniformity in the perovskite layer leads to reduced cell efficiency and stability, the application dopes a compound having the structure shown in Formula 1 and a methoxyl trimer or a salt thereof, and controls the mass ratio of the two, so as to improve the grain uniformity of the perovskite layer, passivate grain boundary defects, and thus improve the cell efficiency and stability of the perovskite cell.

[0034] In a first aspect, the application provides a perovskite layer comprising a compound having the structure shown in Formula 1 and a methoxyl trimer or a salt thereof.

[0035] A m Pb n X3Formula 1

[0036] wherein A comprises at least one of methylamine cation and formamidinium cation;

[0037] X comprises at least one of chloride anion, bromide anion and iodide anion;

[0038] m is 0.95-1.05;

[0039] n is 0.95-1.05;

[0040] the mass ratio of the compound of the structure shown in Formula 1 to methanolic trimer or salt thereof is 100: (0.22-0.29).

[0041] The present application can improve the grain uniformity of the perovskite layer, passivate the grain boundary defects, and thus improve the battery efficiency and stability of the perovskite battery by controlling the mass ratio of the compound of the structure shown in Formula 1 to methanolic trimer or salt thereof.

[0042] In some embodiments, the methanolic trimer or salt thereof comprises methanolic trimer or methanolic trimer hydrochloride.

[0043] In a second aspect, the present application provides a preparation method of a perovskite layer, comprising the following steps:

[0044] depositing a solution containing lead iodide and methanolic trimer or salt thereof to prepare a lead iodide layer;

[0045] depositing an organic halide salt solution on the lead iodide layer and annealing to prepare a perovskite layer;

[0046] wherein in the solution containing lead iodide and methanolic trimer or salt thereof, the mass ratio of lead ions to methanolic trimer or salt thereof, based on the mass of lead ions in lead iodide, is 100: (0.56-0.74).

[0047] Currently, in the process of preparing a perovskite layer by a two-step method, uneven diffusion of organic salt and incomplete perovskite conversion lead to uneven perovskite crystallization, thereby affecting the battery efficiency and stability of the perovskite battery. The methanolic trimer or salt thereof used in the present application contains a nitrogen heterocyclic structure and multiple oxime groups. The oxygen atoms in the oxime groups can form a Pb-O bond with lead ions in lead iodide through coordination. After lead iodide and methanolic trimer or salt thereof are co-dissolved, they form a hydrogen bond complex through hydrogen bond interaction, which is conducive to improving the pore structure of the lead iodide layer and effectively promoting the uniform diffusion of the organic halide salt, adjusting the perovskite crystallization rate and grain uniformity, and passivating the grain boundary defects, thereby improving the battery efficiency and stability of the perovskite battery. Further, by controlling the mass ratio of lead ions to methanolic trimer or salt thereof, the grain uniformity of the perovskite layer can be improved, thereby significantly improving the battery efficiency and stability of the perovskite layer.

[0048] In some embodiments, the concentration of lead iodide in the solution containing lead iodide and formonitrile trimer or a salt thereof is 1 mol / L-1.5 mol / L, which can be 1.3 mol / L.

[0049] In some embodiments, the concentration of formonitrile trimer or a salt thereof in the solution containing lead iodide and formonitrile trimer or a salt thereof is 1.5 mg / mL-2 mg / mL.

[0050] In some embodiments, the organic halide salt in the solution of organic halide salt is AX; wherein A includes at least one of methylamine cation and formamidine cation; and X includes at least one of chloride anion, bromide anion and iodide anion.

[0051] In some embodiments, the molar ratio of A ion to lead ion in the perovskite layer is (0.95-1.05):(0.95-1.05) based on the molar amount of A ion and the molar amount of lead ion, which can be 1:1.

[0052] In some embodiments, the organic halide salt includes at least one of FAI, MABr and MACl.

[0053] In some embodiments, the organic halide salt includes FAI, MABr and MACl, and the molar ratio of the FAI, MABr and MACl is 1:(0.1-0.3):(0.02-0.08), which can be 1:0.18:0.05.

[0054] In some embodiments, the concentration of organic halide salt in the solution of organic halide salt is 50 mg / mL-120 mg / mL, which can be 80 mg / mL.

[0055] In some embodiments, the formonitrile trimer or a salt thereof includes formonitrile trimer or formonitrile trimer hydrochloride.

[0056] The formonitrile trimer hydrochloride has a molecular formula of C3H9N3O3·HCl (molecular weight of 171.6 g / mol) and a structure as follows:

[0057] .

[0058] In some embodiments, the annealing conditions include a temperature of 90℃-150℃, which can be 90℃, 100℃, 110℃, 120℃, 130℃, 140℃ or 150℃; and a time of 10 min-40 min, which can be 10 min, 20 min, 30 min or 40 min.

[0059] In some embodiments, after the solution containing lead iodide and methylnitroxide trimer or salt thereof is deposited, a step of first annealing is further included; the first annealing is performed at a temperature of 80-120°C, which can be 80°C, 90°C, 100°C, 110°C or 120°C, for a time of 1-10 minutes, which can be 1 minute, 2 minutes, 5 minutes, 8 minutes or 10 minutes.

[0060] In some embodiments, the solvent in the solution containing lead iodide and methylnitroxide trimer or salt thereof includes at least one of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0061] In some embodiments, the solvent in the solution containing lead iodide and methylnitroxide trimer or salt thereof includes N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the volume ratio of DMF to DMSO is (10-7):(0-3), which can be 9:1.

[0062] In some embodiments, the solvent in the organic halide salt solution includes at least one of ethanol and isopropanol.

[0063] In a third aspect of the present application, a perovskite layer is provided, which is prepared by the method for preparing a perovskite layer according to the second aspect.

[0064] In a fourth aspect of the present application, a perovskite battery is provided, which includes a perovskite layer.

[0065] The perovskite layer includes the perovskite layer according to the first aspect, the perovskite layer prepared by the method for preparing a perovskite layer according to the second aspect, or the perovskite layer according to the third aspect.

[0066] In some embodiments, the perovskite battery includes, in sequence, a conductive substrate, an electron transport layer, a perovskite layer, a passivation layer, a hole transport layer and an electrode layer.

[0067] In some embodiments, the conductive substrate includes at least one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO) and aluminum-doped zinc oxide (AZO).

[0068] In some embodiments, the electron transport layer includes tin oxide.

[0069] In some embodiments, the passivation layer includes phenethylamine iodide (PEAI).

[0070] In some embodiments, the hole transport layer includes 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD).

[0071] In some embodiments, the electrode layer comprises Au.

[0072] In a fifth aspect, the application provides a method for preparing the perovskite cell according to the fourth aspect, comprising the following steps:

[0073] Preparation of an electron transport layer, a perovskite layer, a passivation layer, a hole transport layer and an electrode layer on a conductive substrate to prepare a perovskite cell.

[0074] In some embodiments, the preparation of an electron transport layer, a perovskite layer, a passivation layer, a hole transport layer and an electrode layer on a conductive substrate specifically comprises the following steps:

[0075] Deposition of a tin oxide solution on a conductive substrate by spin coating to prepare an electron transport layer;

[0076] Deposition of a solution containing lead iodide and formamidinium trimer or its salt on the electron transport layer by spin coating to prepare a lead iodide layer, and then deposition of an organic halide salt solution on the lead iodide layer by spin coating, and annealing to prepare a perovskite layer;

[0077] Deposition of a PEAI solution on the perovskite layer by spin coating to prepare a passivation layer;

[0078] Deposition of a Spiro-OMeTAD solution on the passivation layer by spin coating to prepare a hole transport layer;

[0079] Deposition of Au on the hole transport layer by thermal evaporation to prepare an electrode layer.

[0080] The embodiments of the application will be described in detail below with reference to the examples. It should be understood that these examples are only used to illustrate the application and not to limit the scope of the application. The experimental methods in the following examples are not specified, and the priority is given to the instructions given in the application. The experimental methods can also be carried out according to the experimental manual or conventional conditions in the art, or according to the conditions recommended by the manufacturer, or according to the known experimental methods in the art.

[0081] Example 1

[0082] The preparation method of the perovskite cell is as follows:

[0083] (1) Substrate pretreatment:

[0084] The ITO substrate was cleaned, specifically, washed with neutral cleaning agent, deionized water, acetone and isopropanol for 10 min respectively, dried with nitrogen, and then treated with ultraviolet-ozone (UV-O3) for 15 min;

[0085] (2) Preparation of an electron transport layer:

[0086] An electron transport layer (30 nm in thickness) was prepared by spin-coating a 2.67 wt% SnO2 colloid solution on an ITO substrate at a rotation speed of 3000 rpm for 30 s, and then annealing at 150°C for 30 min;

[0087] (3) Preparation of a perovskite layer:

[0088] A solution containing lead iodide and formamidinium trihydrate hydrochloride was prepared, wherein the concentration of lead iodide was 1.3 mol / L (599.3 mg / mL), the concentration of formamidinium trihydrate hydrochloride (molecular weight: 171.6 g / mol) was 1.5 mg / mL, the mass ratio of lead ions to formamidinium trihydrate or a salt thereof was 100:0.56, and the solvent was DMF and DMSO in a volume ratio of 9:1;

[0089] FAI, MABr and MACl were dissolved in 1 mL of isopropanol according to a molar ratio of 1:0.18:0.05 to prepare an organic halide salt solution of 80 mg / mL;

[0090] A lead iodide layer was prepared by spin-coating 70 μL of the solution containing lead iodide and formamidinium trihydrate hydrochloride on the electron transport layer at a rotation speed of 2000 rpm for 20 s and then at a rotation speed of 4000 rpm for 30 s, and then annealing at 100°C for 5 min;

[0091] A perovskite layer (550 nm in thickness) was prepared by spin-coating 70 μL of the organic halide salt solution on the lead iodide layer at a rotation speed of 3000 rpm for 30 s, and then annealing at 100°C for 20 min, wherein the perovskite layer was composed of (FA 0.813 MA 0.187 )Pb(I 2.77 Br 0.18 Cl 0.05 ) and formamidinium trihydrate hydrochloride at a mass ratio of 100:0.22;

[0092] (4) Preparation of a passivation layer:

[0093] A passivation layer (10 nm in thickness) was prepared by spin-coating a PEAI solution (PEAI concentration: 3 mg / mL, solvent: isopropanol) on the perovskite layer, and then annealing at 100°C for 5 min;

[0094] (5) Preparation of a hole transport layer:

[0095] spin-coating a Spiro-OMeTAD solution (in which the concentration of Spiro-OMeTAD is 72 mg / mL, and the solvent is chlorobenzene) doped with bis-trifluoromethanesulfonimide lithium (Li-TFSI) and t-butylpyridine (tBP) on the passivation layer, wherein the doping concentration of Li-TFSI acetonitrile stock solution with a concentration of 520 mg / mL in the Spiro-OMeTAD solution is 17.5 µL / mL, and the doping concentration of tBP is 28.5 µL / mL; then aging for 12 h in a dry air at room temperature (25°C) and <10% RH to prepare a hole transport layer (50 nm in thickness);

[0096] (6) Preparing an electrode layer:

[0097] depositing Au on the hole transport layer by thermal evaporation to prepare an electrode layer (100 nm in thickness), thereby obtaining a perovskite battery.

[0098] Example 2

[0099] Example 2 and Example 1 are basically the same in the preparation method, except that the concentration of methoxymethyltrimer hydrochloride is 2 mg / mL, the mass ratio of lead ions to methoxymethyltrimer or its salt is 100:0.74, and the perovskite layer is composed of (FA 0.813 MA 0.187 )Pb(I 2.77 Br 0.18 Cl 0.05 ) and methoxymethyltrimer hydrochloride with a mass ratio of 100:0.29; and the perovskite layer and the perovskite battery are prepared according to the method of Example 1.

[0100] Comparative Example 1

[0101] Comparative Example 1 and Example 2 are basically the same in the preparation method, except that “methoxymethyltrimer hydrochloride” is replaced by “2,4,6-trihydroxy-1,3,5-triazine (molecular weight is 129.07)” with the same mass concentration, and the perovskite layer is composed of (FA 0.813 MA 0.187 )Pb(I 2.77 Br 0.18 Cl 0.05 ) and 2,4,6-trihydroxy-1,3,5-triazine with a mass ratio of 100:0.334; and the perovskite layer and the perovskite battery are prepared according to the method of Example 1.

[0102] Comparative Example 2

[0103] Comparative Example 2 0.813 MA 0.187 )Pb(I 2.77 Br 0.18 Cl 0.05 ) and the hexaazamacrocyclic compound; and the perovskite layer and perovskite cell were prepared according to the method of Example 1.

[0104] Comparative Example 3

[0105] Comparative Example 3 was prepared according to the method of Example 2, except that the "formoxime trimer hydrochloride" was replaced with an equal mass concentration of "trihydroxybenzene", and the perovskite layer consisted of (FA 0.813 MA 0.187 )Pb(I 2.77 Br 0.18 Cl 0.05 ) and trihydroxybenzene in a mass ratio of 100:0.334; and the perovskite layer and perovskite cell were prepared according to the method of Example 2.

[0106] Comparative Example 4

[0107] Comparative Example 4 was prepared according to the method of Example 1, except that the formoxime trimer hydrochloride was not used; and the perovskite layer and perovskite cell were prepared according to the method of Example 1.

[0108] Comparative Example 5

[0109] Comparative Example 5 was prepared according to the method of Example 1, except that the concentration of the formoxime trimer hydrochloride was 0.5 mg / mL, and the mass ratio of lead ions to formoxime trimer or salt thereof was 100:0.19, and the perovskite layer consisted of (FA 0.813 MA 0.187 )Pb(I 2.77 Br 0.18 Cl 0.05 ) and formoxime trimer hydrochloride in a mass ratio of 100:0.07; and the perovskite layer and perovskite cell were prepared according to the method of Example 1.

[0110] Comparative Example 6

[0111] Comparative Example 6 was prepared according to the method of Example 1, except that the concentration of the formoxime trimer hydrochloride was 1 mg / mL, and the mass ratio of lead ions to formoxime trimer or salt thereof was 100:0.37, and the perovskite layer consisted of (FA 0.813 MA 0.187 )Pb(I2.77 Br 0.18 Cl 0.05 ) and methoxymethyoxymethane hydrochloride; the perovskite layer and perovskite cell are prepared according to the method of Example 1.

[0112] Comparative Example 7

[0113] Comparative Example 7 is substantially the same as the preparation method of Example 1, except that the concentration of methoxymethyoxymethane hydrochloride is 2.5 mg / mL, the mass ratio of lead ions to methoxymethyoxymethane or a salt thereof is 100:0.93, and the perovskite layer consists of (FA 0.813 MA 0.187 ) Pb (I 2.77 Br 0.18 Cl 0.05 ) and methoxymethyoxymethane hydrochloride; the perovskite layer and perovskite cell are prepared according to the method of Example 1.

[0114] Comparative Example 8

[0115] Comparative Example 8 is substantially the same as the preparation method of Example 1, except that the concentration of methoxymethyoxymethane hydrochloride is 3 mg / mL, the mass ratio of lead ions to methoxymethyoxymethane or a salt thereof is 100:1.11, and the perovskite layer consists of (FA 0.813 MA 0.187 ) Pb (I 2.77 Br 0.18 Cl 0.05 ) and methoxymethyoxymethane hydrochloride; the perovskite layer and perovskite cell are prepared according to the method of Example 1.

[0116] Test Example 1

[0117] (1) Under the standard light illumination of AM 1.5G (100 mW·cm - ²), an environment of 25 ± 2 °C, and a metal mask defining an effective area of 0.09 cm 2 , a four-probe source table (Keithley 2400) was used to perform J-V testing (first reverse scan and then forward scan, step 20 mV, residence 20 ms) at a scan rate of 100 mV / s to detect the open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE) of the perovskite cells prepared in Examples 1-2 and Comparative Examples 1-8, and the results are shown in Table 1.

[0118] Table 1 Device performance of perovskite cells

[0119]

[0120] The results in Table 1 show that, compared with the use of 2,4,6-trihydroxy-1,3,5-triazine in Comparative Example 1, the use of methoxymethyltrimer hydrochloride in Example 2 increases the photoelectric conversion efficiency from 24.85% to 26.08%, an increase of 1.23%. This shows that, compared with 2,4,6-trihydroxy-1,3,5-triazine, the oxime group in methoxymethyltrimer hydrochloride is both a hydrogen bond donor (-OH) and a coordination electron pair donor (=NO-), which can achieve stronger Pb 2+ passivation ability and is not prone to decomposition during high-temperature annealing, and has better stability, which can significantly improve the photoelectric conversion efficiency of the perovskite battery.

[0121] In the preparation of the perovskite layer, compared with the use of hexamethylene ketoxime, a saturated six-membered nitrogen-containing ring compound, in Comparative Example 2, the use of methoxymethyltrimer hydrochloride in Example 2 increases the photoelectric conversion efficiency from 24.10% to 26.08%, an increase of 1.98%. This shows that, compared with the use of hexamethylene ketoxime, the use of methoxymethyltrimer hydrochloride with a nitrogen-containing heterocyclic structure in the present application can significantly improve the photoelectric conversion efficiency of the perovskite battery.

[0122] In the preparation of the perovskite layer, compared with the use of trihydroxybenzene in Comparative Example 3, the use of methoxymethyltrimer hydrochloride in Example 2 increases the photoelectric conversion efficiency from 23.70% to 26.08%, an increase of 2.38%. This shows that, compared with the use of trihydroxybenzene without an oxime group structure, the use of methoxymethyltrimer hydrochloride with an oxime group structure in the present application can significantly improve the photoelectric conversion efficiency of the perovskite battery.

[0123] Comparing Comparative Examples 1-2 and Comparative Examples 4-8, it can be seen that the use of (FA 0.813 MA 0.187 )Pb(I 2.77 Br 0.18 Cl 0.05 ) and methoxymethyltrimer hydrochloride in Examples 1-2 with a mass ratio of 100: (0.22-0.29) can significantly improve the photoelectric conversion efficiency of the perovskite battery.

[0124] (2) Test the stability of the perovskite batteries prepared in Examples 1-2 and Comparative Examples 1-8

[0125] The perovskite batteries prepared in Examples 1-2 and Comparative Examples 1-8 were encapsulated. The encapsulation conditions were as follows: encapsulation was performed using UV-cured epoxy glue and a glass cover in a nitrogen glove box (O2 / H2O < 0.1 ppm), and the glue was cured under 365 nm ultraviolet light for 120 s. After curing, the glue was allowed to stand for 30 min. After encapsulation, subsequent aging tests were performed.

[0126] The time (T80) required for the PCE of the perovskite cells prepared in Examples 1-2 and Comparative Examples 1-8 to decrease to 80% was detected under the condition of 25°C, 20% RH;

[0127] The time (T80) required for the PCE of the perovskite cells prepared in Examples 1-2 and Comparative Examples 1-8 to decrease to 80% was detected under the condition of 85°C, 85% RH;

[0128] The time (T95) required for the PCE of the perovskite cells prepared in Examples 1-2 and Comparative Examples 1-8 to decrease to 95% was detected under the condition of 45°C, 1 sun, using the continuous MPPT (maximum power point tracking) technology.

[0129] The results are shown in Table 2.

[0130] Table 2 Stability of perovskite cells

[0131]

[0132] The results in Table 2 show that, in the process of preparing the perovskite layer, compared with the use of 2,4,6-trihydroxy-1,3,5-triazine in Comparative Example 1, the use of methoxymethyltrimer hydrochloride in Example 2 improves the T80 of the perovskite cell under the condition of 25°C, 20% RH, packaging by 33%, the T80 under the condition of 85°C, 85% RH by 44%, and the T95 under the condition of 45°C, 1 sun by 38%. 80 80 80 This indicates that, compared with 2,4,6-trihydroxy-1,3,5-triazine, the oxime group in methoxymethyltrimer hydrochloride has both a hydrogen bond donor (-OH) and a coordinate electron pair donor (=NO-), and the stability of the prepared perovskite cell is significantly improved.

[0133] In the process of preparing the perovskite layer, compared with the use of 1,2-cyclohexanedione dioxime in Comparative Example 2, the use of methoxymethyltrimer hydrochloride in Example 2 improves the T80 of the perovskite cell under the condition of 25°C, 20% RH, packaging by 49%, the T80 under the condition of 85°C, 85% RH by 73%, and the T95 under the condition of 45°C, 1 sun by 63%. 80 80 80 This indicates that, compared with the use of 1,2-cyclohexanedione dioxime, the use of methoxymethyltrimer hydrochloride with a nitrogen-containing heterocyclic structure in the present application can significantly improve the stability of the perovskite cell.

[0134] ​​​​In the process of preparing perovskite layer, compared with the trihydroxybenzene used in Comparative Example 3, the methoxime trimer hydrochloride used in Example 2, the T of the perovskite battery under the condition of 25℃, 20%RH, packaging 80 increased by 62%, the T under the condition of 85℃, 85%RH increased by 86%, the T under the condition of 45℃, 1sun increased by 73%. This shows that compared with the trihydroxybenzene with no oxime group structure, the methoxime trimer hydrochloride with oxime group structure used in the present application can significantly improve the stability of the perovskite battery. 80 increased by 86%, the T under the condition of 45℃, 1sun increased by 73%. This shows that compared with the trihydroxybenzene with no oxime group structure, the methoxime trimer hydrochloride with oxime group structure used in the present application can significantly improve the stability of the perovskite battery. 80

[0135] Comparative Example 1-2 and Comparative Example 4-8, it can be seen that the mass ratio of (FA 0.813 MA 0.187 )Pb(I 2.77 Br 0.18 Cl 0.05 ) and methoxime trimer hydrochloride used in Examples 1-2 is 100: (0.22-0.29), which can significantly improve the stability of the perovskite battery.

[0136] The technical features of the above-described embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present disclosure.

[0137] The above-described embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as the limitation of the patent application scope. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.​

Claims

1. A perovskite layer, characterized in that, Compounds including those with the structure shown in Formula 1, as well as formoxime trimers or salts thereof; A m Pb n X3 type 1; Wherein, A includes at least one of methylamine cation and formamidinium cation; X includes at least one of chloride anion, bromide anion and iodide anion; m is 0.95-1.05; n is 0.95-1.05; The mass ratio of the compound with the structure shown in Formula 1 to the formoxime trimer or its salt is 100:(0.22-0.29).

2. The perovskite layer according to claim 1, characterized in that, The oxime trimer or its salts include oxime trimer or oxime trimer hydrochloride.

3. A method for preparing a perovskite layer, characterized in that, Includes the following steps: A lead iodide layer is prepared by depositing a solution containing lead iodide and formoxime trimer or its salt. An organic halide solution was deposited on the lead iodide layer, and then annealed to prepare a perovskite layer. In the solution containing lead iodide and formoxime trimer or its salt, the mass ratio of lead ions to formoxime trimer or its salt is 100:(0.56-0.74, based on the mass of lead ions in lead iodide.

4. The method for preparing the perovskite layer according to claim 3, characterized in that, In the organic halide solution, the organic halide is AX; wherein A includes at least one of methylamine cation and formamidinium cation; and X includes at least one of chloride anion, bromide anion and iodide anion.

5. The method for preparing the perovskite layer according to claim 4, characterized in that, In the perovskite layer, the molar ratio of A ions to lead ions is (0.95-1.05):(0.95-1.05), based on the molar amounts of A ions and lead ions.

6. The method for preparing a perovskite layer according to any one of claims 3-5, characterized in that, It meets at least one of the following characteristics: (1) The formoxime trimer or its salt includes formoxime trimer or formoxime trimer hydrochloride; (2) The annealing conditions include: temperature of 90℃-150℃; time of 10min-40min; (3) After depositing the solution containing lead iodide and formoxime trimer or its salt, the process also includes a first annealing step; the conditions for the first annealing include: a temperature of 80℃-120℃ and a time of 1min-10min; (4) In the solution containing lead iodide and formoxime trimer or its salt, the solvent includes at least one of N,N-dimethylformamide and dimethyl sulfoxide; (5) The solvent in the organic halide solution includes at least one of ethanol and isopropanol.

7. A perovskite layer, characterized in that, Prepared by the method for preparing the perovskite layer according to any one of claims 3-6.

8. A perovskite solar cell, characterized in that, Including the perovskite layer; The perovskite layer includes the perovskite layer according to claim 1 or 2, the perovskite layer prepared by the method of preparing the perovskite layer according to any one of claims 3-6, or the perovskite layer according to claim 7.

9. The perovskite solar cell according to claim 8, characterized in that, The perovskite solar cell comprises a conductive substrate, an electron transport layer, a perovskite layer, a passivation layer, a hole transport layer, and an electrode layer stacked sequentially.

10. The method for preparing a perovskite solar cell as described in claim 9, characterized in that, Includes the following steps: An electron transport layer, a perovskite layer, a passivation layer, a hole transport layer, and an electrode layer are sequentially fabricated on a conductive substrate to prepare a perovskite solar cell.

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