Perovskite cell, preparation method and method for improving wettability of perovskite layer between hole transport layers

Abstract

The invention relates to a perovskite cell, a preparation method and a method for improving wettability of a perovskite layer between hole transport layers, before the perovskite layer is prepared, a quaternary ammonium salt preparation is adopted to process the deposition side of the hole transport layer, the deposition side is the side, making contact with the perovskite layer, of the hole transport layer, and the quaternary ammonium salt preparation is a solution containing quaternary ammonium salt cations. The quaternary ammonium cation head group carries positive charges, and quaternary ammonium salt is directionally adsorbed on the surface of the hole transport material through cation head group anchoring, so that the surface polarity of the hole transport material is improved, and the wettability between the hole transport material and perovskite is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a perovskite battery, a preparation method and a method for improving the wettability of a perovskite layer between hole transport layers, and belongs to the field of interface processing. BACKGROUND

[0002] Silicon-perovskite tandem solar cells have attracted extensive attention in the academic and photovoltaic industries due to their higher photoelectric conversion efficiency than silicon. During the preparation of the tandem cell, some hole transport layers have strong hydrophobicity, which makes it difficult for the perovskite solution prepared by the solution method to fully wet on them, and it is difficult to obtain a dense and flat perovskite film. The improper interface contact between this hydrophobic passivation layer and the perovskite will cause more holes in the prepared perovskite film, which will adversely affect the performance and stability of the solar device. Therefore, it is urgent to develop a method that can improve the wettability between the perovskite ink and the hole transport layer with low process difficulty and without affecting the electrical transport performance between the perovskite film and the hole transport layer.

[0003] TECHNICAL SCHEME

[0004] In order to improve the interface contact between the perovskite ink and the hole transport layer, the present application provides the following scheme:

[0005] Scheme one: a method for improving the wettability of a perovskite layer between hole transport layers, which is to treat the deposition side of the hole transport layer with a quaternary ammonium salt preparation. The quaternary ammonium cation head group has a positive charge, and the quaternary ammonium salt is adsorbed on the surface of the hole transport material by the anchoring of the cation head group, which improves the polarity of the surface of the hole transport material and further improves the wettability between the perovskite.

[0006] The technical scheme adopted by the present application is: a method for improving the wettability of a perovskite layer between hole transport layers, which uses a quaternary ammonium salt preparation to treat the deposition side of the hole transport layer. The deposition side is the side of the hole transport layer that contacts the perovskite material.

[0007] As a preferred scheme, the quaternary ammonium salt preparation is a quaternary ammonium salt solution obtained by dissolving a quaternary ammonium salt in an organic solvent, and the concentration of the quaternary ammonium salt solution is 0.1-1mmol / L.

[0008] As a preferred scheme, the solvent of the quaternary ammonium salt solution is ethanol.

[0009] As a preferred scheme, the quaternary ammonium salt is [R1R2R3R4N] + X-, wherein X - is Cl - or / and Br - , R1R2R3R4 are respectively substituted NH4 +R1R2R3R4C(CH2)nN(CH2)mR5wherein R1, R2, R3, R4, R5 are independently selected from the group consisting of hydrogen, organic group, short chain alkyl, long chain alkyl, and polar group, n is an integer from 1 to 10, m is an integer from 1 to 10, and at least one of R1, R2, R3, R4 is an organic group, at least one of R1, R2, R3, R4 is a long chain alkyl, the number of carbon atoms in the long chain alkyl is n, 12≤n≤18, at least one of R1, R2, R3, R4 is a short chain alkyl or a polar group, the short chain alkyl is methyl or ethyl, and the polar group is hydroxyl or benzyl.

[0010] As a preferred solution, the quaternary ammonium salt is selected from the group consisting of cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), cetyltrimethylammonium chloride (CTAC), octadecyltrimethylammonium chloride (STAC), and dodecyltrimethylammonium chloride (DTAC).

[0011] As a preferred solution, the quaternary ammonium salt is selected from the group consisting of cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), cetyltrimethylammonium chloride (CTAC), octadecyltrimethylammonium chloride (STAC), and dodecyltrimethylammonium chloride (DTAC).

[0012] As a preferred solution, the quaternary ammonium salt is selected from the group consisting of cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), cetyltrimethylammonium chloride (CTAC), octadecyltrimethylammonium chloride (STAC), and dodecyltrimethylammonium chloride (DTAC).

[0013] As a preferred solution, the quaternary ammonium salt is selected from the group consisting of cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), cetyltrimethylammonium chloride (CTAC), octadecyltrimethylammonium chloride (STAC), and dodecyltrimethylammonium chloride (DTAC).

[0014] Solution two: a method for preparing a calcium stacked battery, comprising the following steps S01 depositing a hole transport layer on a substrate or obtaining a substrate with a hole transport layer deposited thereon;

[0015] S02 treating the hole transport layer by the method described in solution one;

[0016] S03 depositing a perovskite material on the hole transport layer;

[0017] obtaining a perovskite layer.

[0018] Further preferably, the preparation method is specifically as follows: (1) obtaining or preparing a bottom cell with a tunneling layer; (2) preparing a hole transport layer on the tunneling layer; (3) treating the hole transport layer with a quaternary ammonium salt solution; (4) preparing a perovskite layer on the hole transport layer; (5) preparing an electron transport layer on the perovskite layer; and (6) preparing an electrode layer on the electron transport layer.

[0019] Further preferably, the bottom cell can be a HJT, HBC, TOPCon, etc.

[0020] Further preferably, the hole transport layer material is a PACs type hole transport material, and the deposition method can be solution coating (spin coating, blade coating, spray coating) or vacuum evaporation, and can be MeO-2PACz, Me-4PACz, 4PADCB, 4-PhCz, 2PACz, 4PACz, Me-2PACz, MeO-4PACz, Br-2PACz, Cl-2PACz, etc., and when prepared using a solution method, the solution concentration is 0.3-1 mg / mL.

[0021] Further preferably, the deposition method of the perovskite layer is a solution method, which can be spin coating, slot coating, blade coating, inkjet printing, etc., and the solute of the perovskite precursor solution is of the ABX3 structural formula, wherein A is any one or more of Cs + , MA + , FA + , B is Pb 2+ , and X is any one or more of halogen elements (Cl, Br, I), and the band gap of the prepared perovskite film layer is 1.6-1.8 eV.

[0022] Further preferably, the deposition method of the electron transport layer is vacuum evaporation. The electron transport layer material includes but is not limited to one of [6,6]-phenyl C61 butyric acid methyl ester (PC 61 BM), carbon 60 (C 60 ).

[0023] Further preferably, a buffer layer is deposited on the electron transport layer, and the buffer layer material includes but is not limited to one of tin oxide (SnO2), titanium dioxide (TiO2), zinc oxide (ZnO), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP). The deposition method can be one of atomic layer deposition (ALD), vacuum evaporation and magnetron sputtering. Further preferably, a TCO material is deposited on the buffer layer to form a transparent electrode layer, which can be ITO or IZO, and the deposition method can be magnetron sputtering or vacuum evaporation.

[0024] Further preferably, a metal electrode layer is deposited on the transparent electrode, which can be at least one of copper (Cu), silver (Ag) and gold (Au), and the deposition method is vacuum evaporation or screen printing.

[0025] Scheme three: a perovskite battery prepared by the preparation method of scheme two.

[0026] The effects of the present application include: the present application improves the wettability of the perovskite material on the surface of the hole transport layer by using a quaternary ammonium salt solution to treat the hole transport layer, reduces the formation of perovskite pores, and improves the battery efficiency.

[0027] In the hollow hole transport layer in the application, the quaternary ammonium cation head group (-N + R1R2R3R4) is positively charged, and forms a "cation-pi" interaction with the pi electron cloud of the carbazole ring in the PACs SAM material, and the quaternary ammonium salt cationic surfactant is oriented and adsorbed on the surface of the SAM material through the cation head group anchoring, which improves the surface polarity of the SAM. The long-chain alkyl group extends vertically to the interface direction, and the steric hindrance thereof can destroy the original tight pi-pi packing of the SAM layer, improve the surface roughness, and further improve the perovskite wettability. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 SEM image of the perovskite layer obtained in Example 1 in the application;

[0029] Figure 2 SEM image of the perovskite layer obtained in Example 2 in the application;

[0030] Figure 3 SEM image of the perovskite layer obtained in Comparative Example 1 in the application;

[0031] Figure 4 SEM image of the perovskite layer obtained in Comparative Example 2 in the application. DETAILED DESCRIPTION

[0032] The application will be described in more detail below, but should not be understood as the protection scope of the application being limited by the following description. Unless otherwise specified, any range described in the application includes the end values and any numerical value between the end values and any sub-range formed by the end values or any numerical value. The purity of all raw materials in the application is not particularly limited, and the application preferably uses analytical pure. The source and abbreviation of all raw materials in the application belong to the conventional source and abbreviation in the art, and are clear and explicit in the field of their related use. The person skilled in the art can purchase or prepare them by conventional methods according to the abbreviation and the corresponding use.

[0033] “at least one” means one or more, “multiple” means two or more. “And / or” describes the association relationship of associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent: A exists alone, A and B exist together, B exists alone, where A, B can be singular or plural. The character “ / ” generally represents that the front and rear associated objects are in an “or” relationship. “At least one of the following” or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can represent: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0034] Those skilled in the art will understand that perovskite materials are represented by the general formula [A][B][X]3, where [A] is at least one monovalent cation, such as MA + , FA + , Cs + , etc., [B] is at least one divalent cation, such as Pb 2+ , Sn 2+ , etc., and [X] is at least one anion. When the perovskite includes more than one A cation, the different A cations can be distributed in an ordered or disordered manner over the A sites. When the perovskite includes more than one B cation, the different B cations can be distributed in an ordered or disordered manner over the B sites. When the perovskite includes more than one X anion, the different X anions can be distributed in an ordered or disordered manner over the X sites.

[0035] Perovskite cells include p-i-n and n-i-p structures. A single-junction perovskite cell structure consists of a substrate layer, a transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer. The perovskite layer is the core of the entire device, which is responsible for absorbing light energy to generate electron-hole pairs, and the separation, collection and flow of electron-hole pairs are the source of electric energy generation. The specific principle is: when the sunlight is incident from the transparent conductive layer side, reaches the perovskite layer, most of the light energy is absorbed, and the electrons absorb the energy of the photons to form electron-hole pairs. Due to the selection characteristics of the hole transport layer and the electron transport layer, the holes will migrate from the perovskite layer to the hole transport layer, and the electrons will migrate in the opposite direction to the electron transport layer. The holes and electrons flow into the corresponding transport layer and are further collected by the corresponding electrode. In the p-i-n structure, the electrons flow to the back electrode layer, and the holes flow to the transparent conductive layer and are collected on the electrode. The stacked perovskite cell includes a bottom cell and a top cell, the bottom cell is a silicon cell or a perovskite cell, and the top cell is a perovskite cell, which includes a hole transport layer, a perovskite layer, an electron transport layer, and an electrode.

[0036] The present application is aimed at perovskite cells which first deposit a hole transport layer and then deposit a perovskite layer, in order to improve the wettability between the perovskite layer and the hole transport layer when depositing the perovskite layer, the present application uses a quaternary ammonium salt preparation to treat the deposition side of the hole transport layer, the deposition side being the side of the hole transport layer which contacts the perovskite layer, after treatment, the surface polarity of the hole transport layer is enhanced, and after depositing a perovskite material thereon, the hole transport layer and the perovskite material are in close contact, reducing interface defects and improving carrier transport efficiency. When treating the deposition side of the hole transport layer, the substrate on which the hole transport layer is deposited can be immersed in the quaternary ammonium salt preparation, or the quaternary ammonium salt preparation can be coated on the deposition side of the hole transport layer. The above-mentioned substrate can be any substrate material on which the hole transport layer can be deposited, such as conductive glass, PVC, silicon bottom cell, perovskite bottom cell, etc.

[0037] When the hole transport layer material is a PACs type SAM material, this material has phenanthrocarbazole as the core skeleton, and this type of material has a specific structure of a large π conjugated system, which makes the surface of the self-assembled molecular layer (SAM) non-polar, and has poor wettability with a polar perovskite solution. By using a quaternary ammonium salt preparation to treat the hole transport layer, the quaternary ammonium cation head group (-N + R1R2R3R4) in the quaternary ammonium salt preparation is positively charged, and forms a "cation-π" interaction with the π electron cloud of the carbazole ring in the PACs type SAM material, causing the preparation to be adsorbed on the surface of the SAM layer, thereby improving the surface polarity of the SAM.

[0038] In the present application, the quaternary ammonium salt preparation is a quaternary ammonium salt solution, which is prepared by dissolving a quaternary ammonium salt in an organic solvent, and the preferred organic solvent is an alcohol, and more preferably ethanol, and the concentration of the solution is preferably 0.1-1 mmol / L, such as 0.1 mmol / L, 0.2 mmol / L, 0.3 mmol / L, 0.5 mmol / L, 0.6 mmol / L, 0.8 mmol / L, 0.9 mmol / L, 1 mmol / L.

[0039] In the present application, the preferred treatment method for the hole transport layer is immersion treatment, in which the substrate on which the hole transport layer is deposited is immersed in a quaternary ammonium salt solution, and after immersion is complete, the substrate is removed, rinsed, and air-dried, thereby obtaining the treated hole transport layer. During the immersion process, the temperature of the solution is 40-50℃, such as 40℃, 42℃, 45℃, 48℃, 50℃. Immersion at this temperature can promote the diffusion and molecular motion of the quaternary ammonium salt cations, and accelerate adsorption equilibrium. When the concentration of the solution is 0.1-1 mmol / L and the temperature of the solution is 40-50℃, the immersion time is preferably 10-30 min, and at this immersion time, a single layer of adsorption can be obtained, preventing the quaternary ammonium salt from affecting carrier transport.

[0040] Quaternary ammonium salt is a product obtained by substituting four hydrogens in ammonium ion with organic groups, the four organic groups are R1, R2, R3, R4, respectively, the quaternary ammonium salt cation is expressed as R1R2R3R4N + , N is connected to R1, R2, R3, R4 by covalent bond, R1, R2, R3, R4 can be selected from alkyl, aromatic group or other organic groups, preferably at least one of R1, R2, R3, R4 is long chain alkyl-C n H 2n+1 , wherein 12≤n≤18, at least one is short chain alkyl, such as methyl or ethyl, or polar group, such as hydroxyl or benzyl, long chain alkyl-C n H 2n+1 Short chain alkyl or polar group regulates the water solubility and interfacial activity of quaternary ammonium salt. The quaternary ammonium salt anion is preferably halogen, more preferably Cl - , Br - , and the optional quaternary ammonium salt is hexadecyl trimethyl ammonium bromide (C 16 H 33 (CH3)3NBr, CTAB), dodecyl trimethyl ammonium bromide (C 12 H 25 (CH3)3NBr, DTAB), hexadecyl trimethyl ammonium chloride (C 16 H 33 (CH3)3NCl, CTAC), octadecyl trimethyl ammonium chloride (C 18 H 37 (CH3)3NCl, STAC), dodecyl trimethyl ammonium chloride (C 12 H 25 (CH3)3NCl, DTAC), etc. After the hole transport layer is treated with the quaternary ammonium salt preparation, the long chain alkyl group extends vertically to the interface direction, and the steric hindrance thereof can destroy the original tight π-π packing of the SAM layer, improve the surface roughness, and further improve the wettability of perovskite on the hole transport layer. After the substrate material with the hole transport layer is taken out after the treatment with the quaternary ammonium salt solution, the surface is washed with deionized water for 3 times, and dried with a nitrogen gun.

[0041] The preparation method of the perovskite battery is illustrated by taking a stacked battery as an example, which comprises the following steps: (1) obtaining or preparing a bottom battery with a tunneling layer; (2) preparing a hole transport layer on the tunneling layer; (3) treating the hole transport layer with a quaternary ammonium salt solution; (4) preparing a perovskite layer on the hole transport layer; (5) preparing an electron transport layer on the perovskite layer; and (6) preparing an electrode layer on the electron transport layer. The hole transport layer material is selected from one or a combination of MeO-2PACz, Me-4PACz, 4PADCB, 4-PhCz, 2PACz, 4PACz, Me-2PACz, MeO-4PACz, Br-2PACz and Cl-2PACz, and the deposition method is evaporation, solution method, magnetron sputtering or the like, preferably solution method. The perovskite layer is prepared by solution method, and the solute of the perovskite precursor solution is of the structural formula ABX3, wherein A is any one or more of Cs + , MA + , FA + , B is Pb 2+ , and X is any one or more of halogen elements (Cl - , Br - , I - ). Preferably, the band gap of the prepared perovskite film layer is 1.6-1.8 eV; the electron transport layer material is [6,6]-phenyl C61 butyric acid methyl ester (PC 61 BM) or carbon 60 (C 60 ), and is preferably prepared by vacuum evaporation. An intermediate layer such as a buffer layer, a passivation layer, a light regulation layer or the like can also be arranged between any two adjacent layers of the tunneling layer, the hole transport layer, the perovskite layer, the electron transport layer and the electrode layer.

[0042] The present application is further described in detail in the form of specific examples, and the examples are all illustrated by the preparation method of the perovskite battery. The method for improving the wettability between the perovskite layer and the hole transport layer is not specifically listed because the method for improving the wettability is covered in the preparation method of the perovskite battery and is not repeated.

[0043] Example 1

[0044] The preparation method of the silicon-perovskite stacked battery comprises the following steps:

[0045] S01 Obtaining a bottom battery

[0046] An HJT battery is taken as the bottom battery. The parameters of the HJT bottom battery used are as follows: the open-circuit voltage (V oc ) is 0.70-0.74 V, the short-circuit current (J sc ) is 38-39.5 mA / cm 2, the fill factor (FF) is 80-85%, and the photoelectric conversion efficiency (PCE) is 24-25%. The size of the bottom cell is 3cm*3cm. The bottom cell is plated with a 15nm ITO tunnel junction on the n-face, and an Ag electrode is provided on the back. The prepared bottom cell is placed in a ultraviolet ozone processor for 15min for standby.

[0047] S02Preparation of hole transport layer, the preparation method is as follows:

[0048] (1) SAM solution preparation: 0.5mg of Me-4PACz is mixed with 1mL of ethanol solution to obtain 1mg / mL of Me-4PACz solution, and 0.45μm filter core is used to filter out large particulate matter, and the filtered solution is standby;

[0049] (2) SAM layer coating: the filtered solution is spin-coated on the bottom cell, the spin-coating rate is 4000r, the time is 30s, and then it is annealed at 120℃ hot table for 20min to obtain Me-4PACz hole transport layer;

[0050] S03Quaternary ammonium salt solution treatment of hole transport layer

[0051] (1) Quaternary ammonium salt solution preparation: 50mL of 0.5mM CTAB ethanol solution is prepared, and it is stirred at room temperature for 2h for standby;

[0052] (4) Quaternary ammonium salt solution soaking: the prepared hole transport layer substrate is soaked in the dissolved CTAB ethanol solution for 20min, and the soaking temperature is 40℃. After soaking, the surface is washed with deionized water for 3 times, and dried with nitrogen gun, to obtain perovskite infiltration good hole transport layer.

[0053] S04Preparation of perovskite layer

[0054] (1) Perovskite solution preparation: 30.5mg of CsI, 34.5mg of MABr, 224.6mg of PbBr2, 312.5mg of FAI and 593.4mg of PbI2 are mixed in a clean 5mL volumetric flask, 800μL and 200μL of DMF and DMSO solution (DMF and DMSO volume ratio is 4:1) are added, and it is stirred at room temperature overnight until completely dissolved, and filtered with a polytetrafluoroethylene filter head with a diameter of 0.22 microns before use;

[0055] (2) Perovskite coating: the process is carried out in a glove box by spin coating. The filtered perovskite solution is spin-coated on the hole transport layer, the spin-coating speed is 1000r / 20s / 200rpm and 5000r / 30s / 1000rpm, and the anti-solvent CB is added at the 10th second, and then the piece is transferred to a 100℃ hot table for heating for 30min annealing. The film is cooled and standby.

[0056] Preparation of the modification layer

[0057] (1) Preparation of the modification layer solution: EDAI2 was configured into a solution with a concentration of 0.5 mg / mL, and dissolved under ultrasonic oscillation for 30 min.

[0058] (2) The EDAI2 solution was spin-coated on the perovskite layer at a speed of 4000 r for 30 s, and then annealed in a glove box at 100°C for 1 min. The film thickness was 3-5 nm.

[0059] Preparation of the electron transport layer

[0060] The electron transport layer was prepared by evaporation. For example, C 60 was evaporated at a rate of 15 nm thick.

[0061] Preparation of the buffer layer

[0062] SnO2 was prepared as a buffer layer using an atomic layer deposition device (ALD) with a thickness of 20 nm.

[0063] Preparation of the transparent electrode

[0064] IZO material was prepared as a transparent electrode on the buffer layer using a magnetron sputtering method. The power was controlled at 30-200 W, and the IZO thickness was 30 nm.

[0065] Preparation of the electrode

[0066] A 200 nm Ag grid line was evaporated as an electrode using evaporation at a rate of

[0067] A silicon-perovskite stacked battery was prepared.

[0068] Example 2

[0069] The preparation method of the silicon-perovskite stacked battery includes the following steps:

[0070] S01 Obtaining a base cell

[0071] The base cell conditions were the same as in Example 1, but the size was 210 mm*105 mm.

[0072] S02 Preparation of the hole transport layer

[0073] The hole transport layer material in this example was 2PACz, and the preparation method was as follows:

[0074] (1) SAM solution preparation: 6 mg of 2PACz was mixed with 20 mL of ethanol solution to obtain a 2PACz solution of 0.3 mg / mL, and a 0.45-μm filter cartridge was used to filter out large particulate matter, and the filtered solution was ready for use;

[0075] (2) SAM layer coating: a SAM layer was deposited on a silicon-based cell by using a slot coating method, and the specific parameters were as follows: the gap between the blade and the substrate was 200 μm, the coating speed was 10 mm / s, the injection speed was 4 μL / s, the ambient temperature was 25°C, and the humidity was 30-40%. The film layer obtained after coating was annealed in air for 100 min at a temperature of 120°C. The film layer was ready for use after cooling.

[0076] S03 Quaternary ammonium salt solution treatment of hole transport layer

[0077] (1) Preparation of quaternary ammonium salt solution: 50 mL of 1 mM DTAB ethanol solution was prepared, and stirred at room temperature for 2 h for standby;

[0078] (2) Quaternary ammonium salt solution soaking: the prepared hole transport layer substrate was soaked in the dissolved DTAB ethanol solution for 10 min, and the soaking temperature was 50°C. After soaking, the surface was rinsed with deionized water for 3 times, and dried with a nitrogen gun, to obtain a perovskite infiltration good hole transport layer.

[0079] S04 Preparation of perovskite layer

[0080] (1) Perovskite solution preparation: 0.39 mg of CsI, 0.5 mg of MABr, 3.3 g of PbBr2, 4.13 g of FAI, and 9.68 g of PbI2 were mixed in a clean 20 mL volumetric flask, 16 mL and 4 mL of DMF and DMSO solution (volume ratio of 4:1) were added, and stirred overnight at room temperature until completely dissolved. Before use, filter with a polytetrafluoroethylene filter head with a diameter of 0.22 microns;

[0081] (2) Perovskite coating: this process was carried out by using a slot coating method, and the specific parameters were as follows: 200 μL of organic salt solution was coated on a leaf with the assistance of N2 in air at a rate of 20 mm / s; the gap between the blade and the substrate was 100 μm, the injection speed was 8 μL / s, and the N2 blade pressure was 30 PSI. After completion, the piece was transferred to a hot stage at 105°C and heated for 30 min for annealing, and the film layer was ready for use after cooling. -1

[0082] S05 Preparation of modification layer

[0083] ​(1) Preparation of modification layer solution: This example takes EDAI2 (ethylenediamine dihydroiodide) as an example. EDAI2 is configured into a solution with a concentration of 0.5 mg / mL, and is dissolved for 30 min under ultrasonic oscillation.

[0084] (2) The EDAI2 solution is spin-coated on the perovskite layer at a speed of 4000 r and a time of 30 s, and then annealed in a glove box at 100°C for 1 min. The film thickness is 3-5 nm.

[0085] Preparation of S06 electron transport layer

[0086] The electron transport layer is prepared by evaporation. Taking C 60 as an example, the evaporation rate is The thickness is 15 nm.

[0087] Preparation of S07 buffer layer:

[0088] SnO2 is prepared as a buffer layer using an atomic layer deposition device (ALD) with a thickness of 20 nm.

[0089] Preparation of S08 transparent electrode

[0090] IZO material is prepared as a transparent electrode on the buffer layer using a magnetron sputtering method. The control power is 30-200 W, and the IZO thickness is 30 nm.

[0091] Preparation of S09 electrode

[0092] A layer of 200 nm Ag grid line is evaporated as an electrode using evaporation, and the evaporation rate is

[0093] A silicon-perovskite stacked battery is prepared.

[0094] Example 3

[0095] The preparation method of the perovskite battery includes the following steps:

[0096] S01 Obtain a substrate

[0097] The substrate size is the same as in Example 2, but the substrate material is ITO conductive glass

[0098] The hole transport layer material in this example is 4PADCB, and the preparation method is as follows:

[0099] (1) SAM solution preparation: 6 mg of 2PACz is mixed with 20 mL of ethanol solution to obtain a 2PACz solution with a concentration of 0.3 mg / mL. A 0.45 μm filter cartridge is used to filter out large particulate matter, and the filtered solution is ready for use;

[0100] (2) SAM layer coating: SAM layer was deposited on ITO conductive glass by using slot coating method, and the specific parameters were as follows: the gap between the blade and the substrate was 200 μm, the coating speed was 10 mm / s, the injection speed was 4 μL / s, the ambient temperature was 25 °C, and the humidity was 30-40%. The film layer obtained after coating was annealed in air for 100 min at a temperature of 120 °C. The film layer was cooled and ready for use.

[0101] S03 Quaternary ammonium salt solution treatment of hole transport layer

[0102] (1) Preparation of quaternary ammonium salt solution: 50 mL of 1 mM DTAB ethanol solution was prepared, and stirred at room temperature for 2 h for standby;

[0103] (2) Quaternary ammonium salt solution soaking: the prepared hole transport layer substrate was soaked in the dissolved DTAB ethanol solution for 10 min, and the soaking temperature was 50 °C. After soaking, the surface was rinsed with deionized water for 3 times, and dried with a nitrogen gun, to obtain a perovskite infiltration good hole transport layer.

[0104] S04 Preparation of perovskite layer

[0105] (1) Preparation of perovskite solution: 0.39 mg of CsI, 0.5 mg of MABr, 3.3 g of PbBr2, 4.13 g of FAI, and 9.68 g of PbI2 were mixed in a clean 20 mL volumetric flask, 16 mL and 4 mL of DMF and DMSO solution (volume ratio of 4:1) were added, and stirred overnight at room temperature until completely dissolved. Before use, filter with a polytetrafluoroethylene filter head with a diameter of 0.22 microns;

[0106] (2) Perovskite coating: this process was carried out by slot coating, and the specific parameters were as follows: 200 μL of organic salt solution was coated on a leaf at a rate of 20 mm / s in air assisted by N2; the gap between the blade and the substrate was 100 μm, the injection speed was 8 μL / s, and the pressure of the N2 knife was 30 PSI. After the end, the piece was transferred to a hot stage at 105 °C and heated for 30 min for annealing, and the film layer was cooled and ready for use. -1

[0107] S05 Preparation of modification layer

[0108] (1) Preparation of modification layer solution: EDAI2 (ethylenediamine dihydroiodide) was used as an example in this example. EDAI2 was configured into a solution with a concentration of 0.5 mg / mL, and dissolved for 30 min under ultrasonic shaking.

[0109] (2) The EDAI2 solution was spin-coated on the perovskite layer at a speed of 4000 r for 30 s, and then annealed in a glove box at 100 °C for 1 min. The film layer was 3-5 nm thick.​

[0110] Preparation of S06 electron transport layer

[0111] The electron transport layer was prepared by evaporation method. For example, the evaporation rate of C 60 was 0.5 A / s, and the thickness was 15 nm. Preparation of S07 buffer layer

[0112] SnO2 was prepared as a buffer layer by using an atomic layer deposition device (ALD), and the thickness was 20 nm.

[0113] Preparation of S08 electrode

[0114] Ag grid lines with a thickness of 200 nm were evaporated as electrodes by evaporation method, and the evaporation rate was 0.5 A / s.

[0115] The perovskite battery was prepared.

[0116] Comparative Example 1

[0117] The difference from Example 1 is only that there is no step S03 quaternary ammonium salt solution treatment of the hole transport layer, and the perovskite layer is directly deposited after the hole transport layer is prepared.

[0118] Comparative Example 2

[0119] The difference from Example 2 is only that there is no step S03 quaternary ammonium salt solution treatment of the hole transport layer, and the perovskite layer is directly deposited after the hole transport layer is prepared.

[0120] The scanning electron microscope (SEM) images of the perovskite layers obtained in Example 1, Comparative Example 1, Example 2, and Comparative Example 2 were observed, as shown in FIG. 1. There are many holes in the perovskite in Comparative Example 1 and Comparative Example 2, indicating that the perovskite has poor wettability on the SAM layer. After soaking in the quaternary ammonium salt solution, the wettability of the perovskite on the SAM layer in Example 1 and Example 2 is significantly improved, and the holes disappear. Figure 2 The battery performance of Example 1, Comparative Example 1, Example 2, and Comparative Example 2 was tested, respectively. The test was carried out under one standard sunlight, and the test voltage was 20 V to -0.1 V, and the test step was 100 mV / s. The test results are shown in Table 1. After soaking in the quaternary ammonium salt surfactant, the open circuit voltage, short circuit current, and fill factor of the device are improved.

[0121]

[0122]

[0123] ​The above examples are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalent replaced without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for improving wettability between a perovskite layer and a hole transport layer, the method comprising: The deposition side of the hole transport layer, which is the side of the hole transport layer in contact with the perovskite layer, is treated with a quaternary ammonium salt preparation, which is a solution containing quaternary ammonium cations. ​ 2. The method of claim 1, wherein the method is characterized by: The quaternary ammonium salt preparation is a quaternary ammonium salt solution obtained by dissolving a quaternary ammonium salt in an organic solvent, and the concentration of the quaternary ammonium salt solution is 0.1-1 mmol / L.

3. The method of claim 2, wherein the method is characterized by: The solvent of the quaternary ammonium salt solution is ethanol. 4.The method of claim 1, wherein the method comprises: R1R2R3R4N + , R1, R2, R3, R4 are each an organic radical replacing the four hydrogen atoms of NH4 + +, at least one of R1, R2, R3, R4 is a long-chain alkyl group -C n H 2n+1 , 12 < n < 18, at least one of R1, R2, R3, R4 is a short-chain alkyl group or a polar group, the short-chain alkyl group being methyl or ethyl, the polar group being hydroxyl or benzyl.

5. The method of improving wettability between a perovskite layer and a hole transport layer according to any one of claims 1 to 4, characterized in that: The quaternary ammonium salt is one or more of cetyltrimethylammonium bromide, dodecyltrimethylammonium bromide, cetyltrimethylammonium chloride, octadecyltrimethylammonium chloride, and dodecyltrimethylammonium chloride. 6.The method of claim 1, wherein the method comprises: The quaternary ammonium salt preparation is used to treat the hole transport layer by immersing a substrate on which the hole transport layer is deposited in the quaternary ammonium salt preparation, the temperature of the quaternary ammonium salt preparation is 40-50℃, the immersion time is 10-30 min, and after the immersion is completed, the substrate is removed and rinsed with deionized water. 7.The method of claim 1, wherein the method comprises: The hole transport layer is deposited using a hole transport material, and the hole transport material is a SAM material with phenanthrocarbazole as the core skeleton.

8. The method of improving wettability between a perovskite layer and a hole transport layer according to any one of claims 1 to 7, characterized in that: The material of the hole transport layer includes one or more of a combination of MeO-2PACz, Me-4PACz, 4PADCB, 4-PhCz, 2PACz, 4PACz, Me-2PACz, MeO-4PACz, Br-2PACz, and Cl-2PACz.

9. A method of preparing a perovskite cell, characterized by: The method comprises the following steps S01 depositing a hole transport layer on a substrate or obtaining a substrate on which a hole transport layer is deposited; S02 treating the hole transport layer using the method of any one of claims 1-8; S03 depositing a perovskite material on the hole transport layer; S04 obtaining a perovskite layer.

10. A perovskite cell characterized by: The perovskite layer is prepared using the preparation method of claim 9.

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