Alcohol-based ink-jet printing ink for preparing perovskite layer, suede conformal perovskite layer as well as preparation method and application of suede conformal perovskite layer

Abstract

The invention provides alcohol-based ink-jet printing ink for preparing a perovskite layer, a suede conformal perovskite layer and a preparation method and application thereof. The printing ink comprises an alcohol-based solvent, a first functional organic solvent, a second functional organic solvent and organic ammonium salt, the first functional organic solvent comprises at least one of gamma-valerolactone and propylene carbonate; the second functional organic solvent is prepared from at least one of triethyl phosphate, ethyl acetate, N-methyl pyrrolidone, isosorbide dimethyl ether and dihydrolevoglucose ketone; the volume ratio of the alcohol-based solvent to the first functional organic solvent to 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 point of the first functional organic solvent and the boiling point of the second functional organic solvent. The problems that in the prior art, organic ammonium salt ink is prone to causing nozzle blockage and coffee ring phenomena, the perovskite phase purity is low, and defects are prone to being formed in a perovskite layer are solved.

Description

Technical Field

[0001] The present invention relates to a perovskite solar cell, and in particular to an alcohol-based inkjet printing ink for preparing a perovskite layer, a velvet conformal perovskite layer, and a preparation method and application thereof. Background Art

[0002] Inkjet printing deposition technology has the advantages of fine patterning, large size, precise control of deposition amount and high material utilization rate (close to 100%). Inkjet printing technology is used in various industrial applications, including printing posters, signs, textiles, labels, photos, etc. of different sizes. At present, inkjet printing technology is also used to complete the deposition of thin film resist patterns in the manufacturing process of electronic liquid crystal display panels, and is even used for decoration and seasoning in the food industry.

[0003] In recent years, academia and industry have shown interest in the application of inkjet printing technology in the field of perovskite solar cells. For example, most of the existing crystalline silicon / perovskite tandem solar cells are prepared based on polished crystalline silicon bottom cells. This is because the existing perovskite film formation methods are generally for polished substrates. However, the surfaces of crystalline silicon cells that have been commercialized on a large scale are mostly velvet. Velvet can greatly reduce the reflection of incident light by the device and improve light absorption. It is one of the indispensable conditions for high-efficiency solar cells. In order to prepare conformal and fully covered perovskite films on velvet crystalline silicon substrates, a two-step method combining dry and wet is generally used, that is, first evaporation is used to prepare conformal covered lead halide, and then wet deposition of organic ammonium salts is used. Deposition of organic ammonium salts based on inkjet printing technology is a potential method, but the existing organic ammonium salt ink system, the solvent in the organic ammonium salt ink is generally ethanol, isopropanol, etc., because these solvents evaporate too quickly, it is easy to cause nozzle clogging, thereby affecting the print quality, and even causing the expensive print head to be scrapped, and the film prepared by the inkjet process usually has a coffee ring effect, resulting in a phenomenon of thick edges and thin middles, reducing the uniformity of the film, and thereby reducing the device efficiency. In addition, the organic solvent evaporates too quickly, which is not conducive to the diffusion of the organic ammonium salt in the lead halide, causing the reaction of the perovskite film to be insufficient, causing the perovskite phase purity to be low, thereby reducing the device efficiency, and the insufficient diffusion of the organic ammonium salt in the lead halide is likely to cause residual lead iodide in the film, and the residual lead iodide forms defects in the perovskite film, thereby reducing the device efficiency and the long-term operation stability of the battery. Summary of the invention

[0004] The main purpose of the present invention is to provide an alcohol-based inkjet printing ink for preparing a perovskite layer, a velvet conformal perovskite layer and a preparation method and application thereof, so as to solve the technical problems in the prior art that organic ammonium salt inks easily cause nozzle clogging, coffee ring phenomenon, low phase purity of perovskite films, and defects are easily formed in perovskite films.

[0005] In order to achieve the above-mentioned object, according to one aspect of the present invention, there is provided an alcohol-based inkjet printing ink for preparing a perovskite layer, 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 of γ-valerolactone (GVL) and propylene carbonate (PC); the second functional organic solvent comprises at least one of triethyl phosphate (TEP), ethyl acetate, N-methylpyrrolidone (NMP), dimethyl isosorbide (DMI), and dihydrolevoglucose; 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 point of the first functional organic solvent and the boiling point of 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] Further, the molecular formula of the organic ammonium salt is AX, wherein A comprises HC(NH 2 ) 2 + , CH 3 NH 3 + At least one of X includes I - Br - , Cl - At least one of .

[0009] Furthermore, the alcohol-based inkjet printing ink for preparing the perovskite layer also includes an iodine elemental 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 carbohydrazide.

[0011] Furthermore, the molar ratio of the iodine reducing agent to the 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 present invention, there is provided a use of the alcohol-based inkjet printing ink for preparing a perovskite layer as described above in preparing 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 the lead halide film with a suede structure, the alcohol-based inkjet printing ink for preparing the perovskite layer as described above is deposited by inkjet printing, and heat-treated at 120° C. to 180° C. for 15 min to 60 min to obtain a suede 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 above preparation method.

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

[0018] By applying the technical solution of the present invention, a specific proportion of a high-boiling-point, non-volatile first functional organic solvent and a second functional organic solvent are added to a low-boiling-point alcohol-based solvent, thereby reducing the nozzle clogging phenomenon caused by the rapid volatilization of the alcohol-based solvent. In addition, the perovskite layer prepared by the ink based on the mixed solvent increases the Maragni flow, thereby suppressing the coffee ring effect and improving the uniformity of the perovskite layer. Furthermore, the added high-boiling-point solvent is not easy to volatilize and has a moisturizing function, which is conducive to the diffusion and penetration of organic ammonium salts in the inorganic phase, thereby improving the purity of the perovskite phase. In addition, the addition of the second functional organic solvent triethyl phosphate and the like can form a Lewis acid-base adduct with lead halide, which can significantly delay the crystallization rate of lead halide perovskite and improve the crystallization quality. The crystallization rate of lead halide perovskite is controlled by the ratio of the first functional organic solvent such as γ-valerolactone and the second functional organic solvent such as triethyl phosphate, so as to generate a uniform and high-crystallization perovskite material, improve the quality of the generated perovskite layer, and thus improve the device efficiency.

[0019] The alcohol-based inkjet printing ink for preparing the perovskite layer of the present invention solves the problem of nozzle clogging, and the prepared perovskite layer is uniform, the perovskite phase is high in purity, and the crystallinity is high, thereby improving the efficiency of the device. The solvents such as γ-valerolactone used are green and environmentally friendly, which is conducive to the large-scale mass production of two-terminal crystalline silicon / perovskite stacked solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 shows a SEM image of a perovskite layer prepared by using the alcohol-based inkjet printing ink for preparing a perovskite layer in Example 1; and

[0022] Figure 2An SEM image of a perovskite layer prepared using the alcohol-based inkjet printing ink for preparing a perovskite layer in Comparative Example 1 is shown. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0024] As described in the background technology, the organic ammonium salt ink in the prior art has the technical problems of easily causing nozzle clogging, uneven perovskite film, and easy formation of defects in the perovskite film. In order to solve the above problems, the present invention provides an alcohol-based inkjet printing ink for preparing a perovskite layer, a perovskite layer, and a preparation method and application thereof.

[0025] According to one aspect of the present invention, there is provided an alcohol-based inkjet printing ink for preparing a perovskite layer, 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 of γ-valerolactone (GVL) and propylene carbonate (PC); the second functional organic solvent comprises at least one of triethyl phosphate, ethyl acetate, N-methylpyrrolidone (NMP), dimethyl isosorbide (DMI) and dihydrolevorotatory glucosone; 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 point of the first functional organic solvent and the boiling point of the second functional organic solvent.

[0026] In order to obtain a high-quality perovskite layer, the present invention provides an alcohol-based inkjet printing ink for preparing a perovskite layer. 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, the nozzle clogging phenomenon caused by the rapid volatilization of the alcohol-based solvent is reduced; in addition, the perovskite layer prepared by the ink based on the mixed solvent increases the Marragni flow, thereby suppressing the coffee ring effect and improving the uniformity of the perovskite layer; furthermore, the added high-boiling-point solvent is not easy to volatilize and has a moisturizing function, which is conducive to the diffusion and penetration of organic ammonium salts in the inorganic phase, thereby improving the purity of the perovskite phase; and the addition of the second functional organic solvent triethyl phosphate and the like can form a Lewis acid-base adduct with lead halide, which can significantly delay the crystallization rate of lead halide perovskite and improve the crystallization quality; the crystallization rate of lead halide perovskite is controlled by the ratio of the first functional organic solvent such as γ-valerolactone and the second functional organic solvent such as triethyl phosphate, so as to generate a uniform and high-crystallization perovskite material, improve the quality of the generated perovskite layer, and thus improve the device efficiency. The alcohol-based inkjet printing ink for preparing the perovskite layer of the present invention solves the problem of nozzle clogging, and the prepared perovskite layer is uniform, the perovskite phase is high in purity, and the crystallinity is high, thereby improving the efficiency of the device. The solvents such as γ-valerolactone used 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. The use of the above low-boiling point alcohol-based solvent is conducive to the efficient preparation of the perovskite layer.

[0028] In some embodiments, in order to obtain a more uniform, 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 a molecular formula of AX, wherein A comprises HC(NH 2 ) 2 + (FA + ), CH 3 NH 3 + (MA + ), X includes I - Br - , Cl - At least one of .

[0030] In some embodiments, the alcohol-based inkjet printing ink for preparing the perovskite layer also includes an iodine reducing agent. The iodine ions in the organic ammonium salt are easily oxidized to iodine in the air, resulting in defects in the subsequent perovskite layer, thereby reducing the device efficiency. The prior art can reduce the impact of impurities in the precursor solution on the quality of the perovskite layer by using the precursor solution in real time. However, the method of preparing the perovskite layer by using the solution in real time does not utilize the large-scale production of perovskite; and in theory, once the solution is configured, the formation of iodine has partially occurred under light or air exposure. From the defect point of view, it can cause a great impact on the battery performance. The use of the above-mentioned iodine reducing agent can prevent the iodine ions in the iodine-containing organic ammonium salt from being oxidized to iodine in the air, avoiding defects, and thus obtaining a 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 carbohydrazide, including but not limited to the above compounds. Other compounds that can achieve iodine reduction are also suitable for the present invention.

[0032] In some embodiments, the molar ratio of the iodine reducing agent to the organic ammonium salt is (0.1-1):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, and of course other values ​​within the above range are also possible, which are not limited here.

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

[0034] According to another aspect of the present invention, there is provided a use of an alcohol-based inkjet printing ink for preparing a perovskite layer in preparing a perovskite layer.

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

[0037] According to another aspect of the present invention, a two-terminal crystalline silicon / perovskite tandem solar cell is also provided, including the above-mentioned velvet conformal perovskite layer. In a heterojunction single-crystal silicon solar cell, lead halide can be first deposited on a velvet crystalline silicon substrate to form a lead halide film layer with a velvet structure, and then an alcohol-based inkjet printing ink for preparing the perovskite layer is deposited by inkjet printing, so that a high-quality conformal perovskite layer can be deposited on the velvet surface, which can not only well cover the velvet structure and avoid leakage caused by pinholes in the film layer, but also the perovskite layer conformally covers the velvet structure, ensuring the good light trapping effect and anti-reflection effect of the velvet structure, thereby improving the efficiency of the device.

[0038] The present application is further described in detail below in conjunction with specific embodiments. These embodiments 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 a perovskite layer, comprising ethanol, γ-valerolactone, triethyl phosphate, 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, 3-carboxyphenylhydrazine and FA 0.25 MA 0.75 Br 0.25 I 0.75 The molar ratio of FA is 0.5:1. 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 a perovskite layer, comprising ethanol, γ-valerolactone, triethyl phosphate, 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, 3-carboxyphenylhydrazine and FA 0.25 MA 0.75 Br 0.25 I 0.75 The molar ratio of FA is 0.2:1. 0.25 MA 0.75 Br 0.25I 0.75 The molar concentration is 0.4 mol / L.

[0043] Example 3

[0044] An alcohol-based inkjet printing ink for preparing a perovskite layer, comprising isopropyl alcohol, propylene carbonate, ethyl acetate, FA 0.7 MA 0.3 Br 0.3 I 0.7 , sodium hypophosphite, wherein the volume ratio of isopropyl alcohol, propylene carbonate and ethyl acetate is 8:10:10, and the volume ratio of sodium hypophosphite and FA 0.7 MA 0.3 Br 0.3 I 0.7 The molar ratio of FA is 1:1. 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 a perovskite layer, comprising isopropyl alcohol, γ-valerolactone, triethyl phosphate, 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, 3-carboxyphenylhydrazine and FA 0.85 MA 0.15 Br 0.15 I 0.85 The molar ratio of FA is 0.5:1. 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 a perovskite layer comprises isopropyl alcohol, γ-valerolactone, triethyl phosphate, FAI and potassium formate, wherein the volume ratio of isopropyl alcohol, 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 a perovskite layer, comprising n-propanol, γ-valerolactone, triethyl phosphate, FA 0.85 MA 0.15 Br0.15 I 0.85 , potassium formate, wherein the volume ratio of n-propanol, γ-valerolactone and triethyl phosphate is 90:5:5, potassium formate and FA 0.85 MA 0.15 Br 0.15 I 0.85 The molar ratio of FA is 0.1:1. 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 a perovskite layer, comprising n-propanol, γ-valerolactone, N-methylpyrrolidone, 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 and FA 0.7 MA 0.3 Br 0.3 I 0.7 The molar ratio of FA is 0.1:1. 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 a perovskite layer, comprising n-propanol, γ-valerolactone, isosorbide dimethyl ether, FA 0.7 MA 0.3 Br 0.3 I 0.7 , carbohydrazide, wherein the volume ratio of n-propanol, γ-valerolactone and isosorbide dimethyl ether is 90:5:5, and the volume ratio of carbohydrazide and FA 0.7 MA 0.3 Br 0.3 I 0.7 The molar ratio of FA is 0.5:1. 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 a perovskite layer, comprising n-propanol, γ-valerolactone, dihydrolevorotatory glucosone, FA0.7 MA 0.3 Br 0.3 I 0.7 , sodium hypophosphite, wherein the volume ratio of n-propanol, γ-valerolactone, and dihydro-levulinic acid ketone is 90:5:5, and the volume ratio of sodium hypophosphite and FA 0.7 MA 0.3 Br 0.3 I 0.7 The molar ratio of FA is 0.2:1. 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 the above method 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 from Example 1 is that the solvent does not contain γ-valerolactone.

[0061] Comparative Example 2

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

[0063] Comparative Example 3

[0064] The only difference between the above method 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 from Example 3 is that propylene carbonate is not contained in the solvent.

[0067] Comparative Example 5

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

[0069] Comparative Example 6

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

[0071] Comparative Example 7

[0072] An alcohol-based inkjet printing ink for preparing a perovskite layer, comprising ethanol, FA 0.25 MA 0.75 Br 0.25 I 0.75 , where FA0.25 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 a perovskite layer, comprising isopropyl alcohol, FA 0.25 MA 0.75 Br 0.25 I 0.75 , where 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 a perovskite layer, comprising n-propanol, FA 0.25 MA 0.75 Br 0.25 I 0.75 , where FA 0.25 MA 0.75 Br 0.25 I 0.75 The molar concentration is 0.4 mol / L.

[0077] 1. Preparation of two-terminal crystalline silicon / perovskite tandem solar cells:

[0078] The alcohol-based inkjet printing inks used to prepare the perovskite layer in the embodiment and the comparative example are respectively used to prepare two-terminal crystalline silicon / perovskite tandem solar cells, wherein the two-terminal crystalline silicon / perovskite tandem solar cells include a heterojunction single crystal silicon bottom cell, an ITO middle tunneling layer, a 2PACz self-assembled monolayer hole transport layer, a perovskite layer, a C60 electron transport layer, a SnO 2 Buffer layer, IZO layer, MgF 2 Anti-reflection layer and Ag electrode layer.

[0079] The preparation steps of the 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 pyramid velvet substrate;

[0081] The second step is to deposit an ITO intermediate tunneling layer with a thickness of 10 nm on the velvet substrate of the heterojunction single crystal silicon bottom cell, and 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 is to deposit lead iodide by evaporation to form a lead iodide film layer with a suede structure, with a thickness of 600 nm;

[0083] The fourth step is to deposit the alcohol-based inkjet printing ink used to prepare the perovskite layer on the lead iodide film layer by using inkjet printing technology;

[0084] Step 5: heat treatment at 160°C for 30 min to obtain a perovskite layer with a thickness of 1 μm;

[0085] Step 6: Deposit a C60 electron transport layer by evaporation with a thickness of 10 nm;

[0086] Step 7: Prepare SnO using atomic layer deposition equipment 2 Buffer layer, thickness 10nm;

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

[0088] Step 9: Prepare MgF 2 Anti-reflection layer (100nm) and Ag electrode layer (15μm).

[0089] 2. Performance test:

[0090] 1) The perovskite layer prepared by the alcohol-based inkjet printing ink for preparing the perovskite layer in Example 1 and Comparative Example 1 was characterized by SEM. 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 is prepared by printing ink in Example 1, and the film layer is uniform and dense; Figure 2 It can be seen that the perovskite layer prepared by the printing ink in Comparative Example 1 has many holes, the film is not dense, uniform, and the shape retention effect is poor.

[0091] 2) The performance of the two-terminal crystalline silicon / perovskite tandem solar cell prepared by the alcohol-based inkjet printing ink for preparing the perovskite layer in the above-mentioned embodiment and comparative example was tested, and the photoelectric conversion efficiency (PCE), fill factor (FF), open circuit voltage (V 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 is not added.

[0097] From the above description, it can be seen that by preparing the alcohol-based inkjet printing ink according to the embodiment of the present invention for preparing the perovskite layer, a uniformly covered conformal perovskite layer is obtained, the film layer is regular, compact, uniform and dense, and the device efficiency is significantly improved compared with the comparative example.

[0098] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An alcohol-based inkjet printing ink for preparing a perovskite layer, characterized in that: include: An alcohol-based solvent, a first functional organic solvent, a second functional organic solvent and an organic ammonium salt; The first functional organic solvent includes at least one of γ-valerolactone and propylene carbonate; The second functional organic solvent includes at least one of triethyl phosphate, ethyl acetate, N-methyl pyrrolidone, dimethyl isosorbide, and dihydro-levoglucose; 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 point of the first functional organic solvent and the boiling point of the second functional organic solvent.

2. The alcohol-based inkjet printing ink for preparing a perovskite layer according to claim 1, characterized in that: The alcohol-based solvent includes at least one of ethanol, isopropanol, n-propanol, and n-butanol; and / or, 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 a perovskite layer according to claim 1, characterized in that: The molecular formula of the organic ammonium salt is AX, wherein A comprises HC(NH2)2 + 、CH3NH3 + At least one of X includes I - Br - , Cl - At least one of .

4. The alcohol-based inkjet printing ink for preparing a perovskite layer according to claim 1, characterized in that: The alcohol-based inkjet printing ink for preparing the perovskite layer also includes an iodine elemental reducing agent.

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

1.

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

7. Use of the alcohol-based inkjet printing ink for preparing a perovskite layer according to any one of claims 1 to 6 in preparing a perovskite layer.

8. A method for preparing a textured conformal perovskite layer, characterized in that: The steps include: On a lead halide film having a velvet structure, the alcohol-based inkjet printing ink for preparing a perovskite layer according to any one of claims 1 to 6 is deposited by inkjet printing, and heat-treated at 120° C. to 180° C. for 15 min to 60 min to obtain the velvet conformal perovskite layer.

9. A textured conformal perovskite layer, characterized in that: Prepared according to the preparation method according to claim 8.

10. A two-terminal crystalline silicon / perovskite tandem solar cell, characterized in that: Comprising the textured conformal perovskite layer as claimed in claim 9.

Images