Alcohol-based inkjet printing ink for preparing perovskite layer, napped shape perovskite layer and preparation method and application thereof

Abstract

The application provides an alcohol-based inkjet printing ink for preparing a perovskite layer, a velvet-shaped perovskite layer and a preparation method and application thereof, and the printing ink comprises an alcohol-based solvent, a first functional organic solvent, a second functional organic solvent and an organic ammonium salt; the first functional organic solvent comprises at least one of gamma-valerolactone and propylene carbonate; the second functional organic solvent comprises at least one of triethyl phosphate, ethyl acetate, N-methyl pyrrolidone, isosorbide dimethyl ether and dihydro levoglucosenone; the volume ratio of the alcohol-based solvent, the first functional organic solvent and the second functional organic solvent is (60-98):(1-20):(1-20); the boiling point of the alcohol-based solvent is lower than the boiling points of the first functional organic solvent and the second functional organic solvent, and the problems of nozzle blockage, coffee ring phenomenon, low perovskite phase purity and easy formation of defects in the content of the perovskite layer caused by the organic ammonium salt ink in the prior art are solved.

Description

Technical Field

[0001] This invention relates to perovskite solar cells, and more specifically, to an alcohol-based inkjet printing ink for preparing perovskite layers, a textured conformal perovskite layer, a method for preparing the same, and its applications. Background Technology

[0002] Inkjet printing deposition technology offers advantages such as fine patterning, large-scale production, precise and controllable deposition volume, and high material utilization (nearly 100%). It is used in various industrial applications, including printing posters, signs, textiles, labels, and photographs of different sizes. Currently, inkjet printing technology is also used to deposit thin-film resist patterns in the manufacturing process of electronic liquid crystal display panels, and even in the food industry for decoration and condiments.

[0003] In recent years, academia and industry have shown interest in the application of inkjet printing technology in perovskite solar cells. For example, most existing crystalline silicon / perovskite tandem solar cells are based on polished crystalline silicon substrates. This is because existing perovskite film deposition methods are generally designed for polished substrates. However, the surfaces of most commercially available crystalline silicon cells are textured. Textured surfaces can significantly reduce the reflection of incident light and improve light absorption, which is an indispensable condition for high-efficiency solar cells. To prepare conformally covered perovskite films on textured crystalline silicon substrates, a two-step dry-wet method is generally used: first, conformally covered lead halide is deposited by vapor deposition, and then organic ammonium salts are deposited by wet deposition. Depositing organic ammonium salts using inkjet printing technology is a promising method. However, existing organic ammonium salt ink systems typically use solvents such as ethanol and isopropanol. These solvents evaporate too quickly, easily causing printhead clogging, which affects print quality and can even render expensive printheads unusable. Furthermore, inkjet-prepared films often exhibit the coffee ring effect, resulting in thicker edges and thinner centers, reducing film uniformity and consequently device efficiency. In addition, the rapid evaporation of organic solvents hinders the diffusion of organic ammonium salts in lead halides, leading to incomplete reactions in the perovskite film, resulting in low perovskite phase purity and further reducing device efficiency. Insufficient diffusion of organic ammonium salts in lead halides can also lead to lead iodide residue within the film. This residual lead iodide forms defects within the perovskite film, further reducing device efficiency and long-term battery stability. Summary of the Invention

[0004] The main objective of this invention is to provide an alcohol-based inkjet printing ink for preparing perovskite layers, a textured conformal perovskite layer, its preparation method, and its application, in order to solve the technical problems in the prior art where organic ammonium salt inks easily cause printhead clogging, coffee ring phenomenon, low phase purity of perovskite films, and easy formation of defects in perovskite films.

[0005] To achieve the above objectives, according to one aspect of the present invention, an alcohol-based inkjet printing ink for preparing perovskite layers is provided, comprising: an alcohol-based solvent, a first functional organic solvent, a second functional organic solvent, and an organic ammonium salt; the first functional organic solvent comprises at least one selected from γ-valerol (GVL) and propylene carbonate (PC); the second functional organic solvent comprises at least one selected from triethyl phosphate (TEP), ethyl acetate, N-methylpyrrolidone (NMP), dimethyl isosorbide dimethyl ether (DMI), and dihydro-L-glucanone; the volume ratio of the alcohol-based solvent, the first functional organic solvent, and the second functional organic solvent is (60–98):(1–20):(1–20); the boiling point of the alcohol-based solvent is lower than the boiling points of the first functional organic solvent and the second functional organic solvent.

[0006] Furthermore, the alcohol-based solvent includes at least one of ethanol, isopropanol, n-propanol, and n-butanol.

[0007] Furthermore, the volume ratio of the alcohol-based solvent, the first functional organic solvent, and the second functional organic solvent is (80-92):(4-10):(4-10).

[0008] Furthermore, the molecular formula of the organic ammonium salt is AX, where A includes HC(NH2)2. + CH3NH3 + At least one of them, X includes I - ,Br - Cl - At least one of them.

[0009] Furthermore, the alcohol-based inkjet printing inks used to prepare the perovskite layer also include iodine reducing agent.

[0010] Furthermore, the iodine reducing agent includes at least one of 3-carboxyphenylhydrazine, sodium formate, potassium formate, sodium hypophosphite, potassium hypophosphite, ammonium hypophosphite, and carbazide.

[0011] Furthermore, the molar ratio of iodine reducing agent to organic ammonium salt is (0.1-1):1.

[0012] Furthermore, in the alcohol-based inkjet printing ink used to prepare the perovskite layer, the molar concentration of the organic ammonium salt is 0.1 mol / L to 1 mol / L.

[0013] According to another aspect of the invention, the use of an alcohol-based inkjet printing ink for preparing a perovskite layer as described above is provided in the preparation of a perovskite layer.

[0014] According to another aspect of the present invention, a method for preparing a textured conformal perovskite layer is provided, comprising the following steps:

[0015] On a lead halide film with a textured surface, an alcohol-based inkjet printing ink, as shown above, for preparing a perovskite layer is deposited by inkjet printing. The perovskite layer is then heat-treated at 120℃~180℃ for 15min~60min to obtain a textured conformal perovskite layer.

[0016] According to another aspect of the present invention, a textured conformal perovskite layer is provided, which is prepared according to the preparation method described above.

[0017] According to another aspect of the present invention, a two-ended crystalline silicon / perovskite tandem solar cell is also provided, comprising the textured conformal perovskite layer as described above.

[0018] By applying the technical solution of this invention, a specific proportion of high-boiling-point, non-volatile first and second functional organic solvents is added to a low-boiling-point alcohol-based solvent, reducing nozzle clogging caused by rapid evaporation of the alcohol-based solvent. Furthermore, the perovskite layer prepared from the ink based on this mixed solvent increases maragonian flow, thereby suppressing the coffee ring effect and improving the uniformity of the perovskite layer. Moreover, the added high-boiling-point solvent is non-volatile and has a moisturizing function, which facilitates the diffusion and penetration of organic ammonium salts into the inorganic phase, improving the purity of the perovskite phase. Additionally, the addition of the second functional organic solvent, such as triethyl phosphate, can form Lewis acid-base adducts with lead halides, significantly slowing down the crystallization rate of lead halide perovskite and improving crystal quality. By controlling the ratio of the first functional organic solvent, such as γ-valerolactone, to the second functional organic solvent, such as triethyl phosphate, the crystallization rate of lead halide perovskite is controlled, resulting in a uniform, highly crystalline perovskite material, improving the quality of the generated perovskite layer, and thus increasing device efficiency.

[0019] The alcohol-based inkjet printing ink of this invention for preparing perovskite layers solves the nozzle clogging problem and produces perovskite layers with uniformity, high purity, and high crystallinity, thereby improving device efficiency. Furthermore, the solvents used, such as γ-valerolactone, are green and environmentally friendly, which is conducive to the large-scale mass production of two-terminal crystalline silicon / perovskite tandem solar cells. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 SEM images of a perovskite layer prepared using the alcohol-based inkjet printing ink from Example 1 for preparing the perovskite layer are shown; and

[0022] Figure 2 SEM images of perovskite layers prepared using the alcohol-based inkjet printing ink used in Comparative Example 1 are shown. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0024] As described in the background section, existing organic ammonium salt inks suffer from problems such as easy nozzle clogging, uneven perovskite film, and easy formation of defects within the perovskite film. To address these issues, this invention provides an alcohol-based inkjet printing ink for preparing a perovskite layer, a perovskite layer, a method for preparing the layer, and its applications.

[0025] According to one aspect of the present invention, an alcohol-based inkjet printing ink for preparing perovskite layers is provided, comprising: an alcohol-based solvent, a first functional organic solvent, a second functional organic solvent, an iodine reducing agent, and an organic ammonium salt; the first functional organic solvent comprises at least one selected from γ-valerol (GVL) and propylene carbonate (PC); the second functional organic solvent comprises at least one selected from triethyl phosphate, ethyl acetate, N-methylpyrrolidone (NMP), dimethyl isosorbide dimethyl ether (DMI), and dihydro-L-glucanone; the volume ratio of the alcohol-based solvent, the first functional organic solvent, and the second functional organic solvent is (60-98):(1-20):(1-20); the boiling point of the alcohol-based solvent is lower than the boiling points of the first functional organic solvent and the second functional organic solvent.

[0026] To obtain a high-quality perovskite layer, this invention provides an alcohol-based inkjet printing ink for preparing perovskite layers. By adding a specific proportion of a high-boiling-point, non-volatile first functional organic solvent and a second functional organic solvent to a low-boiling-point alcohol-based solvent, nozzle clogging caused by rapid evaporation of the alcohol-based solvent is reduced. Furthermore, the perovskite layer prepared based on this mixed solvent increases maragonian flow, thereby suppressing the coffee ring effect and improving the uniformity of the perovskite layer. Moreover, the added high-boiling-point solvent is non-volatile and has a moisturizing function, which facilitates the diffusion and penetration of organic ammonium salts into the inorganic phase, improving the purity of the perovskite phase. Additionally, the addition of the second functional organic solvent, such as triethyl phosphate, can form Lewis acid-base adducts with lead halides, significantly slowing down the crystallization rate of lead halide perovskite and improving crystal quality. By controlling the ratio of the first functional organic solvent, such as γ-valerolactone, and the second functional organic solvent, such as triethyl phosphate, the crystallization rate of lead halide perovskite is controlled, resulting in a uniform, highly crystalline perovskite material, improving the quality of the generated perovskite layer, and thus improving device efficiency. The alcohol-based inkjet printing ink of the present invention for preparing perovskite layers solves the nozzle clogging problem and produces perovskite layers with uniformity, high purity and high crystallinity, thereby improving device efficiency. In addition, the solvents used, such as γ-valerolactone, are green and environmentally friendly, which is conducive to the large-scale mass production of solar cells.

[0027] In some embodiments, the alcohol-based solvent includes at least one of ethanol, isopropanol, n-propanol, and n-butanol. Using the above-mentioned low-boiling-point alcohol-based solvent is beneficial for the efficient preparation of perovskite layers.

[0028] In some embodiments, in order to obtain a more uniform and highly crystalline perovskite material, the volume ratio of the alcohol-based solvent, the first functional organic solvent, and the second functional organic solvent is (80-92):(4-10):(4-10).

[0029] In some embodiments, the organic ammonium salt has the molecular formula AX, wherein A includes HC(NH2)2. + (FA + CH3NH3 + (MA + At least one of the following, X includes I - ,Br - Cl - At least one of them.

[0030] In some embodiments, the alcohol-based inkjet printing ink used to prepare the perovskite layer also includes an iodine reducing agent. Iodine ions in organic ammonium salts are easily oxidized to elemental iodine in air, generating defects in the subsequent perovskite layer and thus reducing device efficiency. Existing technologies can mitigate the impact of impurities in the precursor solution on the quality of the perovskite layer by preparing the precursor solution on a fresh basis. However, this method of preparing the perovskite layer by preparing the solution on a fresh basis does not utilize large-scale perovskite production; and theoretically, once the solution is prepared, the formation of elemental iodine has already partially occurred under light or air exposure, which, from a defect perspective, can already have a significant impact on battery performance. Using the aforementioned iodine reducing agent can prevent iodine ions in iodine-containing organic ammonium salts from being oxidized to elemental iodine in air, avoiding defect generation and thus achieving higher device efficiency.

[0031] In some embodiments, the iodine reducing agent includes at least one of 3-carboxyphenylhydrazine, sodium formate, potassium formate, sodium hypophosphite, potassium hypophosphite, ammonium hypophosphite, and carbazide, including but not limited to the above compounds. Other compounds capable of reducing iodine are also applicable to this invention.

[0032] In some embodiments, the molar ratio of iodine reducing agent to organic ammonium salt is (0.1 to 1):1, specifically 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, or other values ​​within the above range, which are not limited here.

[0033] In some embodiments, the molar concentration of the organic ammonium salt in the alcohol-based inkjet printing ink used to prepare the perovskite layer is 0.1 mol / L to 1 mol / L, specifically 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, or 1 mol / L. Other values ​​within the above range are also acceptable and are not limited here. Within the above concentration range, it is beneficial to generate a uniform and highly crystalline lead halide perovskite layer.

[0034] According to another aspect of the present invention, the application of alcohol-based inkjet printing inks for preparing perovskite layers is provided in the preparation of perovskite layers.

[0035] According to another aspect of the present invention, a method for preparing a textured conformal perovskite layer is provided, comprising the following steps: depositing an alcohol-based inkjet printing ink, as described above for preparing a perovskite layer, on a lead halide film having a textured structure by inkjet printing, and heat-treating at 120°C to 180°C for 15 min to 60 min to obtain a textured conformal perovskite layer.

[0036] According to another aspect of the present invention, a textured conformal perovskite layer is provided, which is prepared according to the preparation method described above.

[0037] According to another aspect of the present invention, a two-terminal crystalline silicon / perovskite tandem solar cell is also provided, comprising the textured conformal perovskite layer as described above. In heterojunction monocrystalline silicon solar cells, lead halide can be deposited first on a textured crystalline silicon substrate to form a lead halide film layer with a textured structure, and then an alcohol-based inkjet printing ink for preparing the perovskite layer can be deposited by inkjet printing. This allows for the deposition of a high-quality conformal perovskite layer on the textured surface, which not only effectively covers the textured structure and avoids leakage caused by pinholes in the film layer, but also ensures good light-trapping and anti-reflection effects of the textured structure by conformally covering the perovskite layer on the textured structure, thereby improving device efficiency.

[0038] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0039] Example 1

[0040] An alcohol-based inkjet printing ink for preparing perovskite layers includes ethanol, γ-valerolactone, triethyl phosphate, and FA. 0.25 MA 0.75 Br 0.25 I 0.75 3-Carboxyphenylhydrazine, wherein the volume ratio of ethanol, γ-valerolactone, and triethyl phosphate is 90:5:5, and 3-carboxyphenylhydrazine is mixed with FA. 0.25 MA0.75 Br 0.25 I 0.75 The molar ratio is 0.5:1, FA 0.25 MA 0.75 Br 0.25 I 0.75 The molar concentration is 0.4 mol / L.

[0041] Example 2

[0042] An alcohol-based inkjet printing ink for preparing perovskite layers includes ethanol, γ-valerolactone, triethyl phosphate, and FA. 0.25 MA 0.75 Br 0.25 I 0.75 3-Carboxyphenylhydrazine, wherein the volume ratio of ethanol, γ-valerolactone, and triethyl phosphate is 90:5:5, and 3-carboxyphenylhydrazine is mixed with FA. 0.25 MA 0.75 Br 0.25 I 0.75 The molar ratio is 0.2:1, FA 0.25 MA 0.75 Br 0.25 I 0.75 The molar concentration is 0.4 mol / L.

[0043] Example 3

[0044] An alcohol-based inkjet printing ink for preparing perovskite layers includes isopropanol, propylene carbonate, ethyl acetate, and FA. 0.7 MA 0.3 Br 0.3 I 0.7 Sodium hypophosphite, wherein the volume ratio of isopropanol, propylene carbonate, and ethyl acetate is 8:10:10, and sodium hypophosphite is mixed with FA. 0.7 MA 0.3 Br 0.3 I 0.7 The molar ratio is 1:1, FA 0.7 MA 0.3 Br 0.3 I 0.7 The molar concentration is 0.4 mol / L.

[0045] Example 4

[0046] An alcohol-based inkjet printing ink for preparing perovskite layers includes isopropanol, γ-valerolactone, triethyl phosphate, and FA. 0.85 MA 0.15 Br 0.15 I 0.85 3-Carboxyphenylhydrazine, wherein the volume ratio of isopropanol, γ-valerolactone, and triethyl phosphate is 84:6:10, and 3-carboxyphenylhydrazine is mixed with FA.0.85 MA 0.15 Br 0.15 I 0.85 The molar ratio is 0.5:1, FA 0.85 MA 0.15 Br 0.15 I 0.85 The molar concentration is 0.4 mol / L.

[0047] Example 5

[0048] An alcohol-based inkjet printing ink for preparing perovskite layers includes isopropanol, γ-valerolactone, triethyl phosphate, FAI, and potassium formate, wherein the volume ratio of isopropanol, γ-valerolactone, and triethyl phosphate is 90:5:5, the molar ratio of potassium formate to FAI is 0.1:1, and the molar concentration of FAI is 0.4 mol / L.

[0049] Example 6

[0050] An alcohol-based inkjet printing ink for preparing perovskite layers includes n-propanol, γ-valerolactone, triethyl phosphate, and FA. 0.85 MA 0.15 Br 0.15 I 0.85 Potassium formate, wherein the volume ratio of n-propanol, γ-valerolactone, and triethyl phosphate is 90:5:5, and potassium formate is mixed with FA. 0.85 MA 0.15 Br 0.15 I 0.85 The molar ratio is 0.1:1, FA 0.85 MA 0.15 Br 0.15 I 0.85 The molar concentration is 0.4 mol / L.

[0051] Example 7

[0052] An alcohol-based inkjet printing ink for preparing perovskite layers includes n-propanol, γ-valerolactone, N-methylpyrrolidone, and FA. 0.7 MA 0.3 Br 0.3 I 0.7 Potassium formate, wherein the volume ratio of n-propanol / ethanol, γ-valerolactone, and N-methylpyrrolidone is 90:5:5, and potassium formate is mixed with FA. 0.7 MA 0.3 Br 0.3 I 0.7 The molar ratio is 0.1:1, FA 0.7 MA 0.3 Br 0.3 I 0.7 The molar concentration is 0.4 mol / L.

[0053] Example 8

[0054] An alcohol-based inkjet printing ink for preparing perovskite layers includes n-propanol, γ-valerolactone, isosorbide dimethyl ether, and FA. 0.7 MA 0.3 Br 0.3 I 0.7 The mixture contains carbohydrazine, in which the volume ratio of n-propanol, γ-valerolactone, and isosorbide dimethyl ether is 90:5:5. The carbohydrazine is mixed with FA... 0.7 MA 0.3 Br 0.3 I 0.7 The molar ratio is 0.5:1, FA 0.7 MA 0.3 Br 0.3 I 0.7 The molar concentration is 0.4 mol / L.

[0055] Example 9

[0056] An alcohol-based inkjet printing ink for preparing perovskite layers includes n-propanol, γ-valerolactone, dihydro-L-glucanone, and FA. 0.7 MA 0.3 Br 0.3 I 0.7 Sodium hypophosphite, wherein the volume ratio of n-propanol, γ-valerolactone, and dihydrolevulinone is 90:5:5, and sodium hypophosphite is mixed with FA. 0.7 MA 0.3 Br 0.3 I 0.7 The molar ratio is 0.2:1, FA 0.7 MA 0.3 Br 0.3 I 0.7 The molar concentration is 0.4 mol / L.

[0057] Example 10

[0058] The only difference between it and Example 1 is that the volume ratio of ethanol, γ-valerolactone, and triethyl phosphate is 70:15:15.

[0059] Comparative Example 1

[0060] The only difference between it and Example 1 is that the solvent does not contain γ-valerolactone.

[0061] Comparative Example 2

[0062] The only difference between it and Example 1 is that the solvent does not contain triethyl phosphate.

[0063] Comparative Example 3

[0064] The only difference between it and Example 1 is that the volume ratio of ethanol, γ-valerolactone, and triethyl phosphate is 50:25:25.

[0065] Comparative Example 4

[0066] The only difference between it and Example 3 is that the solvent does not contain propylene carbonate.

[0067] Comparative Example 5

[0068] The only difference between it and Example 4 is that 3-carboxyphenylhydrazine was not added.

[0069] Comparative Example 6

[0070] The only difference between it and Example 5 is that potassium formate was not added.

[0071] Comparative Example 7

[0072] An alcohol-based inkjet printing ink for preparing perovskite layers, comprising ethanol, FA 0.25 MA 0.75 Br 0.25 I 0.75 , among which, FA 0.25 MA 0.75 Br 0.25 I 0.75 The molar concentration is 0.4 mol / L.

[0073] Comparative Example 8

[0074] An alcohol-based inkjet printing ink for preparing perovskite layers includes isopropanol and FA. 0.25 MA 0.75 Br 0.25 I 0.75 , among which, FA 0.25 MA 0.75 Br 0.25 I 0.75 The molar concentration is 0.4 mol / L.

[0075] Comparative Example 9

[0076] An alcohol-based inkjet printing ink for preparing perovskite layers includes n-propanol and FA. 0.25 MA 0.75 Br 0.25 I 0.75 , among which, FA 0.25 MA 0.75 Br 0.25 I 0.75 The molar concentration is 0.4 mol / L.

[0077] I. Fabrication of two-terminal crystalline silicon / perovskite tandem solar cells:

[0078] The alcohol-based inkjet printing inks used in the examples and comparative examples for preparing the perovskite layer were used to prepare two-sided crystalline silicon / perovskite tandem solar cells. The two-sided crystalline silicon / perovskite tandem solar cells include a heterojunction monocrystalline silicon base cell, an ITO intermediate tunneling layer, a 2PACz self-assembled monolayer hole transport layer, a perovskite layer, a C60 electron transport layer, a SnO2 buffer layer, an IZO layer, a MgF2 antireflection layer, and an Ag electrode layer, which are stacked sequentially from bottom to top.

[0079] The fabrication steps of a two-terminal crystalline silicon / perovskite tandem solar cell are as follows:

[0080] The first step is to provide a heterojunction monocrystalline silicon bottom cell with a pyramidal textured substrate;

[0081] The second step is to deposit an ITO intermediate tunneling layer with a thickness of 10 nm on the textured substrate of the heterojunction single crystal silicon bottom cell, and then deposit 2PACz material on the intermediate tunneling layer to obtain a 2PACz self-assembled monolayer with a thickness of 2 nm.

[0082] The third step involves depositing lead iodide using a vapor deposition method to form a lead iodide film with a textured surface and a thickness of 600 nm.

[0083] The fourth step involves using inkjet printing technology to deposit alcohol-based inkjet printing ink, which is used to prepare the perovskite layer, onto the lead iodide film.

[0084] The fifth step is to heat-treat at 160℃ for 30 minutes to obtain a perovskite layer with a thickness of 1μm.

[0085] The sixth step involves depositing a C60 electron transport layer with a thickness of 10 nm using a vapor deposition method.

[0086] Step 7: Prepare a SnO2 buffer layer with a thickness of 10 nm using an atomic layer deposition device;

[0087] Step 8: Prepare an IZO layer with a thickness of 50 nm using magnetron sputtering.

[0088] Step 9: Prepare the MgF2 antireflection layer (100 nm) and the Ag electrode layer (15 μm) sequentially.

[0089] II. Performance Testing:

[0090] 1) The perovskite layers prepared using the alcohol-based inkjet printing inks from Example 1 and Comparative Example 1 were characterized by SEM, and the results are as follows: Figure 1 and Figure 2 As shown, by Figure 1 It can be seen that a uniformly covered conformal perovskite layer was prepared using the printing ink in Example 1, and the film layer is uniform and dense; Figure 2It can be seen that the perovskite layer prepared with the printing ink in Comparative Example 1 has many pores, and the film is not dense, uneven, and has poor shape retention.

[0091] 2) The performance of the two-terminal silicon / perovskite tandem solar cells prepared with the alcohol-based inkjet printing inks used to prepare the perovskite layer in the above examples and comparative examples was tested. The photoelectric conversion efficiency (PCE), fill factor (FF), and open-circuit voltage (V) of the two-terminal silicon / perovskite tandem solar cells were measured. oc ) and short-circuit current (J sc As shown in Table 1.

[0092] Table 1

[0093]

[0094]

[0095]

[0096] Note: "—" indicates that the corresponding component was not added.

[0097] As can be seen from the above description, the preparation of a perovskite layer using alcohol-based inkjet printing ink according to the embodiments of the present invention yields a uniformly covered conformal perovskite layer with a regular, compact, and uniform film. Compared with the comparative example, the device efficiency is significantly improved.

[0098] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An alcohol-based inkjet printing ink for preparing perovskite layers, characterized in that, include: Alcohol-based solvents, primary functional organic solvents, secondary functional organic solvents, and organic ammonium salts; The first functional organic solvent includes at least one of γ-valerol and propylene carbonate; The second functional organic solvent includes at least one of triethyl phosphate, ethyl acetate, N-methylpyrrolidone, isosorbide dimethyl ether, and dihydro-L-glucanone; The volume ratio of the alcohol-based solvent, the first functional organic solvent, and the second functional organic solvent is (60-98):(1-20):(1-20). The alcohol-based solvent includes at least one of ethanol, isopropanol, n-propanol, and n-butanol; The organic ammonium salt has the molecular formula AX, wherein A includes HC(NH2)2. + CH3NH3 + At least one of them, X includes I - ,Br - Cl - At least one of them.

2. The alcohol-based inkjet printing ink for preparing perovskite layers according to claim 1, characterized in that, The volume ratio of the alcohol-based solvent, the first functional organic solvent, and the second functional organic solvent is (80-92):(4-10):(4-10).

3. The alcohol-based inkjet printing ink for preparing perovskite layers according to claim 1, characterized in that, The alcohol-based inkjet printing ink used to prepare the perovskite layer also includes an iodine reducing agent.

4. The alcohol-based inkjet printing ink for preparing perovskite layers according to claim 3, characterized in that, The iodine reducing agent includes at least one selected from 3-carboxyphenylhydrazine, sodium formate, potassium formate, sodium hypophosphite, potassium hypophosphite, ammonium hypophosphite, and carbazide; and / or, The molar ratio of the iodine reducing agent to the organic ammonium salt is (0.1~1):

1.

5. The alcohol-based inkjet printing ink for preparing perovskite layers according to any one of claims 1 to 4, characterized in that, In the alcohol-based inkjet printing ink used to prepare the perovskite layer, the molar concentration of the organic ammonium salt is 0.1 mol / L to 1 mol / L.

6. The use of alcohol-based inkjet printing ink for preparing perovskite layers according to any one of claims 1 to 5 in the preparation of perovskite layers.

7. A method for preparing a textured, conformal perovskite layer, characterized in that, Includes the following steps: On a lead halide film with a textured surface, an alcohol-based inkjet printing ink for preparing a perovskite layer according to any one of claims 1 to 5 is deposited by inkjet printing, and the perovskite layer is obtained by heat treatment at 120°C to 180°C for 15 min to 60 min.

8. A textured conformal perovskite layer, characterized in that, It is prepared according to the preparation method described in claim 7.

9. A two-terminal crystalline silicon / perovskite tandem solar cell, characterized in that, Includes the textured conformal perovskite layer as described in claim 8.

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