A thionium salt and its application

Abstract

This application provides a thiatonium salt and its application, relating to the field of carbocyclic compounds. This application provides a thiatonium salt of formula (I), which, when applied to perovskite solar cells, can simultaneously passivate both cation and anion defects on the perovskite surface. By effectively suppressing surface defect states, it reduces nonradiative recombination of charge carriers, thereby significantly improving the open-circuit voltage (Vo) of the solar cell. OC By adjusting the fill factor (FF) and fill factor (FF), a higher power conversion efficiency (PCE) was ultimately achieved. Experimental results show that the open-circuit voltage (V0) of the perovskite solar cell fabricated with the thionium salt described in formula (Ⅰ) as the passivation layer is significantly improved. OC The voltage can reach 1.172V, and the short-circuit current density (J) is [missing information]. SC It can reach 26.36 mA / cm 2 The fill factor (FF) can reach 85.12%, and the photoelectric conversion efficiency (PCE) can reach 26.30%. (I).

Description

Technical Field

[0001] This application relates to the field of carbocyclic compounds, and more particularly to a thioonium salt and its applications. Background Technology

[0002] Perovskite solar cells (PSCs), as outstanding representatives of third-generation photovoltaic technology, have made breakthrough progress in the past decade due to their superior photoelectric conversion efficiency (PCE), low manufacturing cost, and solution-processable advantages. Their certified efficiency has exceeded 26%, which is comparable to that of traditional crystalline silicon solar cells.

[0003] However, the inherent defects in perovskite materials are one of the main obstacles to their commercialization. During the crystallization process, perovskite films inevitably generate a large number of defect states on their surface and at grain boundaries due to ion volatilization, grain boundary formation, and interactions with the environment.

[0004] To address these issues, defect passivation technology has emerged as a key strategy for improving the performance and stability of perovskite solar cells. For example, existing technologies utilize the synergistic effect of quaternary ammonium salts (such as tetrabutylammonium bromide) and Lewis base additives (such as thiourea) to passivate defects; others employ fluorinated phenylethylamine derivatives to simultaneously passivate both cation and anion defects. While these methods have improved device performance to some extent, they still have limitations, such as single functionality and the conflict between steric hindrance and coordination ability.

[0005] Therefore, developing a method that can simultaneously and efficiently passivate multiple defects on the perovskite surface is of great significance for promoting the further development of perovskite solar cells. Summary of the Invention

[0006] In view of this, this application provides a thionium salt and its application. The thionium salt provided in this application, when applied to perovskite solar cells, can improve the photoelectric conversion efficiency and operational stability of perovskite solar cells.

[0007] This application provides a thionium salt having the structure of formula (I): (I).

[0008] This application also provides a perovskite solar cell, comprising: a passivation layer prepared from a thionium salt as shown in formula (I) above.

[0009] In some specific implementations, the perovskite solar cell further includes: Base; A perovskite active layer is formed on the surface of the substrate, and the passivation layer is formed on the surface of the perovskite active layer; An electrode layer is formed on the surface of the passivation layer.

[0010] In some specific implementations, the thickness of the passivation layer is 1 nm to 10 nm.

[0011] In some specific implementations, the material of the perovskite active layer has the atomic ratio shown in formula (II): AMX3 (II); A is selected from one or more of formamidine ions, methylamine ions, cesium ions, and rubidium ions; M is selected from one or more of lead ions, tin ions, and germanium ions; X is a halide ion; The thickness of the perovskite active layer is 400 nm to 800 nm.

[0012] In some specific implementations, the material of the electrode layer is selected from a metal back electrode, a carbon-based back electrode, or a transparent bottom electrode; The thickness of the electrode layer is 50nm~100nm.

[0013] In some specific implementations, the substrate is an ITO glass substrate or an FTO glass substrate; The thickness of the substrate is 1mm to 1.5mm.

[0014] In some specific implementations, the perovskite solar cell further includes: A first transport layer is formed between the substrate and the perovskite active layer; A second transport layer is formed between the passivation layer and the electrode layer; The first transport layer and the second transport layer are each independently a hole transport layer and an electron transport layer, and the first transport layer is different from the second transport layer.

[0015] In some specific implementations, the hole transport layer is made of one or more of the following materials: [2-(9,9-dimethyl-9H-fluoren-2-yl)ethyl]phosphonic acid, (4-(3,6-dimethoxy-9H-carbazole-9-yl)butylphosphonic acid), (4-(9H-carbazole-9-yl)butylphosphonic acid), and (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid; the thickness of the hole transport layer is 1 nm to 5 nm. The electron transport layer is made of fullerene C. 60 One or more of SnO2, TiO2, isomethyl [6,6]-phenyl-C61-butyrate and isomethyl [6,6]-phenyl-C71-butyrate; the thickness of the electron transport layer is 15 nm to 70 nm.

[0016] This application also provides an electrical device, including the perovskite solar cell described in any of the above technical solutions.

[0017] This application provides a thionium salt as shown in formula (I). Applying this thionium salt to perovskite solar cells enables simultaneous passivation of both cation and anion defects on the perovskite surface. By effectively suppressing surface defect states, it reduces nonradiative recombination of charge carriers, thereby significantly improving the open-circuit voltage (V) of the solar cell. OC By adjusting the fill factor (FF) and fill factor (FF), a higher power conversion efficiency (PCE) was ultimately achieved. Experimental results show that the open-circuit voltage (V) of the perovskite solar cell fabricated with the thionium salt described in formula (Ⅰ) as the passivation layer is significantly improved. OC The voltage can reach 1.172V, and the short-circuit current density (J) is [missing information]. SC It can reach 26.36 mA / cm 2 The fill factor (FF) can reach 85.12%, and the photoelectric conversion efficiency (PCE) can reach 26.30%. Attached Figure Description

[0018] Figure 1 This is the 1H NMR spectrum of p-methoxyphenyl dimethylthionium trifluoromethanesulfonate in Example 1 of this application; Figure 2 This is the carbon NMR spectrum of p-methoxyphenyl dimethylthionium trifluoromethanesulfonate in Example 1 of this application; Figure 3 The nuclear magnetic resonance fluorine spectrum of p-methoxyphenyl dimethylthionium trifluoromethanesulfonate in Example 1 of this application; Figure 4 The diagram shows the structure of the perovskite solar cell prepared in Example 2. Figure 5 The current density-voltage (JV) curves of the perovskite solar cells in Example 2 and Comparative Examples 1-3 of this application are shown. Detailed Implementation

[0019] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0020] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0021] It should be understood that the order of steps or the sequence of actions is not important as long as this application remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0022] The use of any and all instances or exemplary language such as “e.g.” or “including” herein is merely intended to better illustrate the application and does not constitute a limitation on the scope of the application unless the claims are made. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of this application.

[0023] Furthermore, the numerical ranges and parameters used to define this application are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any numerical value inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise explicitly stated, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately." Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.

[0024] This application provides a thionium salt having the structure of formula (I): (I).

[0025] The synergistic effect of cations and anions in the thioonium salt provided in this application enables bifunctional synergistic passivation: 1. Passivation of cation defects by anions: Anions [OTf] - The oxygen atom in the perovskite contains a lone pair of electrons and can act as a Lewis base, interacting with lead ions (Pb) exposed on the surface of perovskite (e.g., (FA,MA,Cs)Pb(I,Br)3 due to coordination unsaturation. 2 + A Lewis acid (Pb-O) forms a stable coordination bond. This strong interaction effectively fills lead vacancies or saturates lead ion coordination sites, thereby suppressing nonradiative recombination caused by these deep-level defect sites and significantly reducing the device's open-circuit voltage (V). OC )loss.

[0026] 2. Passivation of anion defects by cations: cation [CH3-O-C6H4-S(CH3)2] + Positively charged ions can be firmly anchored to negatively charged defect sites on the perovskite surface through electrostatic attraction, particularly iodine vacancies or weakly bound halide ions at grain boundaries. This electrostatic shielding effect not only fills the vacancies but also increases the barrier to ion migration, thereby effectively suppressing ion migration problems that lead to device performance lag and long-term instability.

[0027] This application also provides a method for preparing a thionium salt, comprising the following steps: The reaction of p-methoxybenzyl sulfide with methyl trifluoromethanesulfonate yields a thioonium salt.

[0028] Specifically, p-methoxyanisole is dissolved in a solvent, and methyl trifluoromethanesulfonate is slowly added dropwise under stirring to react and obtain a thioonium salt.

[0029] In some specific implementations, the solvent for the reaction is one or more of 1,2-dichloroethane, toluene, and tetrahydrofuran, preferably 1,2-dichloroethane. In some specific implementations, the volume ratio of p-methoxyanisole to the solvent is 1:15~40, preferably 1:20~35, more preferably 1:25~30. In some specific implementations, the volume ratio of p-methoxyanisole to methyl trifluoromethanesulfonate is 1:0.5~2, preferably 1:0.7~1.5. In some specific implementations, the reaction temperature is 40℃~80℃, preferably 50℃~70℃; the reaction time is 10h~14h, preferably 11h~13h.

[0030] After the reaction is complete, the reaction mixture is preferably cooled and filtered to obtain a solid crude product. This application does not impose any particular limitation on the filtration method; any method well-known to those skilled in the art is acceptable. In some specific implementations, a Buchner funnel is used for vacuum filtration.

[0031] The obtained crude solid product is washed with a small amount of diethyl ether to remove unreacted raw materials and soluble impurities; finally, the obtained white solid is dried, preferably under vacuum, to obtain the final product with a yield of up to 97%.

[0032] This application also provides a perovskite solar cell, comprising: a passivation layer, wherein the passivation layer is prepared from the thioonium salt described in any of the above technical solutions.

[0033] The passivation layer provided in this application includes the cation [CH3-O-C6H4-S(CH3)2]. + and anions [OTf] - The oxygen atom in the anion contains a lone pair of electrons and can act as a Lewis base, reacting with lead ions (Pb) exposed on the surface of perovskite (e.g., (FA,MA,Cs)Pb(I,Br)3) due to coordination unsaturation. 2+The perovskite cations form stable coordination bonds (Pb-O) with Lewis acids. The positively charged cations, through electrostatic attraction, can firmly anchor to negatively charged defect sites on the perovskite surface, particularly iodine vacancies or weakly bound halide ions at grain boundaries. Therefore, the passivation layer described in this application can simultaneously target and neutralize both cation and anion defects on the perovskite surface through a "dual-function synergistic passivation" mechanism, effectively suppressing non-radiative recombination and ion migration, thereby significantly improving the photoelectric conversion efficiency and operational stability of perovskite solar cells.

[0034] In some specific implementations, a typical structure of the perovskite solar cell includes: Base; A perovskite active layer is formed on the surface of the substrate; A passivation layer is formed on the surface of the perovskite active layer; An electrode layer is formed on the surface of the passivation layer.

[0035] The perovskite solar cell includes a substrate. The substrate is used to collect and transport photogenerated carriers, and also provides mechanical support for the device. In some specific implementations, the substrate is an ITO glass substrate or an FTO glass substrate, preferably an ITO glass substrate. In some specific implementations, the thickness of the substrate is 1 nm to 1.5 nm, preferably 1 nm to 1.3 nm, and more preferably 1.1 mm.

[0036] The perovskite solar cell includes a perovskite active layer. The perovskite active layer is the core component of the perovskite solar cell, used to absorb sunlight and generate electrons and holes. The material of the perovskite active layer described in this application has the atomic ratio shown in formula (II): AMX3(II), wherein A includes, but is not limited to, formamidinium ions (FA). + ), Methylamine ion (MA) + ), cesium ions (Cs) + ) and rubidium ions (Rb + The ions A can be one or more of these ions. When A is a variety of ions, this application does not impose any special restrictions on the specific proportions of each ion. In some specific implementations, A is preferably a formamidinium ion (FA). + ), Methylamine ion (MA + ) and cesium ions (Cs + B includes, but is not limited to, lead ions (Pb). 2+ ), tin ions (Sn) 2+ ), and germanium ions (Ge 2+ The ions B can be one or more of these, and when B is a variety of ions, this application does not impose any special restrictions on the specific proportions of each ion. In some specific implementations, the B is preferably lead ion (Pb). 2+X is a halide ion, which can be an iodide ion (I). - ), bromide ions (Br) - ) and chloride ions (Cl - X can be one or more of these ions, and when X is a variety of ions, this application does not impose any special restrictions on the specific proportions of each ion. In some specific implementations, X is preferably an iodide ion (I... - ) and bromide ions (Br - In some specific implementations, the perovskite active layer material preferably has the atomic ratio shown in formula (III): FA x MA y Cs 1-x-y Pb(I u Br 1-u )3(Ⅲ), where 0≤x≤1, 0≤y≤1, 0≤u≤1, more preferably FA 0.90 MA 0.05 Cs 0.05 Pb(I 0.95 Br 0.05 3. In some specific implementations, the thickness of the perovskite active layer is 400nm~800nm, preferably 500nm~700nm, and more preferably 600nm.

[0037] The perovskite solar cell includes a passivation layer. The passivation layer in the perovskite solar cell mainly serves to reduce surface and interface defects, suppress nonradiative recombination, and optimize energy level alignment, thereby improving device efficiency and long-term stability. The passivation layer is prepared from the thionium salt described in any of the above technical solutions. Through a "dual-function synergistic passivation" mechanism, the passivation layer can simultaneously target and neutralize cation and anion defects on the perovskite surface, effectively suppressing nonradiative recombination and ion migration, thereby significantly improving the photoelectric conversion efficiency and operational stability of the perovskite solar cell. In some specific implementations, the thickness of the passivation layer is 1 nm to 10 nm, preferably 1 nm to 5 nm, and more preferably 1 nm to 3 nm.

[0038] The perovskite solar cell includes an electrode layer. The electrode layer collects photogenerated carriers and leads them to an external circuit. In some specific implementations, the material of the electrode layer is selected from a metal back electrode, a carbon-based back electrode, or a transparent bottom electrode, preferably a metal back electrode. In some specific implementations, the thickness of the electrode layer is 50 nm to 100 nm, preferably 60 nm to 95 nm, and more preferably 70 nm to 90 nm.

[0039] In some specific implementations, the perovskite solar cell further includes: A first transport layer is formed between the substrate and the perovskite active layer; A second transport layer is formed between the passivation layer and the electrode layer; The first transport layer and the second transport layer are each independently a hole transport layer and an electron transport layer, and the first transport layer is different from the second transport layer.

[0040] When the solar cell structure is a pin structure, in some specific implementations, the hole transport layer is located between the substrate and the perovskite active layer, and the electron transport layer is located between the passivation layer and the electrode layer. In this case, a typical perovskite solar cell structure, from bottom to top, includes: substrate, hole transport layer (HTL), perovskite active layer, passivation layer, electron transport layer (ETL), and electrode layer. When the solar cell structure is a nip structure, in some specific implementations, the electron transport layer is located between the substrate and the perovskite active layer, and the hole transport layer is located between the passivation layer and the electrode layer. In this case, a typical perovskite solar cell structure, from bottom to top, includes: substrate, electron transport layer (ETL), perovskite active layer, passivation layer, hole transport layer (HTL), and electrode layer.

[0041] The hole transport layer efficiently transports holes to the electrodes while blocking electrons from moving to the outer electrodes, thus achieving carrier separation. In some specific implementations, the material of the hole transport layer includes one or more of [2-(9,9-dimethyl-9H-fluoren-2-yl)ethyl]phosphonic acid (2PACz), (4-(3,6-dimethoxy-9H-carbazole-9-yl)butylphosphonic acid (MeO-4PACz), (4-(9H-carbazole-9-yl)butylphosphonic acid (4PACz), and (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (MeO-2PACz), preferably [2-(9,9-dimethyl-9H-fluoren-2-yl)ethyl]phosphonic acid (2PACz). In some specific implementations, the thickness of the hole transport layer is 1 nm to 5 nm, preferably 1.5 nm to 3 nm, and more preferably 2 nm to 2.5 nm.

[0042] The electron transport layer efficiently transports electrons to the electrodes and blocks holes from moving to the outer electrodes, thus achieving carrier separation and preventing direct contact between the perovskite layer and the electrodes, resulting in internal short circuits. In some specific implementations, the electron transport layer includes a main electron transport layer. In some specific implementations, the material of the main electron transport layer is selected from fullerene C. 60 One or more of SnO2, TiO2, isomethyl [6,6]-phenyl-C61-butyrate and isomethyl [6,6]-phenyl-C71-butyrate, preferably fullerene C 60The thickness is 10nm~60nm, preferably 20nm~40nm. In some specific implementations, the electron transport layer further includes a buffer layer. In some specific implementations, the material of the buffer layer is selected from copper bath (BCP) or lithium fluoride (LiF), preferably copper bath (BCP), and the thickness is 5nm~10nm, preferably 7nm~9nm. In some specific implementations, the electron transport layer is preferably C. 60 / BCP. In some specific implementations, the thickness of the electron transport layer is 15nm~70nm, preferably 27nm~49nm, and more preferably 30nm~40nm.

[0043] This application also provides a method for fabricating a perovskite solar cell, comprising the following steps: A perovskite active layer is formed on the substrate; Using the thionium salt described in the above technical solution as a raw material, a passivation layer is formed on the perovskite active layer; An electrode layer is formed on the passivation layer.

[0044] This application first forms a perovskite active layer on a substrate, specifically including the following steps: Pretreatment of the substrate; A perovskite active layer is formed on the pretreated substrate surface.

[0045] This application pre-treats the substrate, which includes cleaning and plasma surface treatment (PLASMA). The selection and thickness of the substrate are as described above and will not be repeated here. In some specific implementations, the cleaning process preferably involves rinsing with detergent and deionized water, followed by ultrasonic cleaning with deionized water, acetone, and ethanol in sequence, and finally drying with a nitrogen air gun. In some specific implementations, the number of ultrasonic cleaning cycles with deionized water is 2 to 4, the number of ultrasonic cleaning cycles with acetone is 1 to 2, and the number of ultrasonic cleaning cycles with ethanol is 1 to 2. The dried substrate is then subjected to plasma surface treatment (PLASMA) to enhance its hydrophilicity and the adhesion of subsequent films. In some specific implementations, the plasma surface treatment (PLASMA) time is 4 to 8 minutes, preferably 5 to 7 minutes.

[0046] A perovskite active layer is formed on the pretreated substrate surface. Specifically, the perovskite material is dissolved in a solvent, stirred to obtain a perovskite precursor solution, and then spin-coated and annealed to form the perovskite active layer. This application can control the proportion of each ion in the perovskite active layer by controlling the molar ratio of A, M, and X. The material selection and thickness of the perovskite active layer are as described above and will not be repeated here. In some specific implementations, the perovskite precursor solution is preferably prepared under a nitrogen atmosphere. In some specific implementations, the solvent is a mixed solvent selected from at least two of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone, preferably N,N-dimethylformamide and dimethyl sulfoxide. This application does not have any special restrictions on the proportion of the above mixed solvent. In some specific implementations, the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide is preferably 2~6:1, more preferably 3~5:1. In some specific implementations, the stirring temperature is 40℃~80℃, preferably 50℃~70℃. This application does not impose any special restrictions on the stirring time, as long as the raw materials are completely dissolved.

[0047] A perovskite precursor solution is obtained, and after spin coating and annealing, a perovskite active layer is formed. In some specific implementations, a perovskite precursor solution of 30 μL to 60 μL is preferably used for the subsequent spin coating process, more preferably 40 μL to 50 μL. The spin coating of the perovskite active layer in this application is divided into two stages: the first stage is a low-speed spreading stage, in which the precursor solution is uniformly covered on the substrate; the second stage is a high-speed forming stage, in which the film thickness is precisely controlled by high-speed rotation, and the crystallization process is precisely controlled by anti-solvent extraction. In some specific implementations, the rotation speed of the first stage is 600 rpm to 1400 rpm, preferably 800 rpm to 1200 rpm, and the time is 2 s to 20 s, preferably 5 s to 15 s. In some specific implementations, the rotation speed of the second stage is 4000 rpm to 8000 rpm, preferably 5000 rpm to 7000 rpm, and the time is 10 s to 50 s, preferably 20 s to 40 s. In some specific implementations, the antisolvent is preferably added rapidly dropwise during the last 5 to 15 seconds of the second-stage spin-coating time. In some specific implementations, the antisolvent is chlorobenzene or ethyl acetate, preferably chlorobenzene, with a volume of 50 μL to 400 μL, preferably 100 μL to 300 μL. In some specific implementations, the acceleration of the spin-coating rotation in the first stage is 200 rpm / s to 800 rpm / s, preferably 400 rpm / s to 600 rpm / s, and the acceleration of the spin-coating rotation in the second stage is 500 rpm / s to 3500 rpm / s, preferably 1000 rpm / s to 3000 rpm / s. After spin-coating, the substrate is preferably annealed quickly. In some specific implementations, the annealing temperature is 80℃ to 120℃, preferably 90℃ to 110℃, and the time is 10 min to 50 min, preferably 20 min to 40 min.

[0048] After obtaining the perovskite active layer, a passivation layer is formed on the perovskite active layer using the thionium salt described in the above technical solution as a raw material. Specifically, the thionium salt is dissolved in a solvent to obtain a passivation solution; after spin coating and annealing, a passivation layer is formed. The material and thickness of the passivation layer are as described above and will not be repeated here. In some specific implementations, the solvent is one or more of isopropanol, chlorobenzene, and anhydrous ethanol, preferably isopropanol. In some specific implementations, the concentration of the passivation solution is 0.5 mg / mL to 3 mg / mL, preferably 0.6 mg / mL to 2 mg / mL, more preferably 0.7 mg / mL to 1.5 mg / mL. In some specific implementations, it is preferred to use 30 μL to 60 μL of passivation solution for the subsequent spin coating process, more preferably 40 μL to 50 μL. In some specific implementations, the spin coating speed is 2000 rpm to 6000 rpm, preferably 3000 rpm to 5000 rpm, and the time is 20 s to 60 s, preferably 30 s to 40 s. In some specific implementations, the annealing temperature is 80℃ to 120℃, preferably 90℃ to 110℃, and the time is 5 min to 20 min, preferably 5 min to 15 min.

[0049] After obtaining the passivation layer, an electrode layer is formed on the passivation layer. Specifically, metal is deposited as the back electrode by thermal evaporation. The material selection and thickness of the electrode layer are as described above, and will not be repeated here. In some specific implementations, the vacuum degree during electrode layer deposition is 4 × 10⁻⁶. -4 Pa ~ 8×10 -4 Pa, preferably 5 × 10 -4 Pa ~ 7×10 - 4 Pa, with a deposition rate of 0.1 Å / s to 0.7 Å / s, preferably 0.3 Å / s to 0.5 Å / s.

[0050] Furthermore, in some specific implementations, the fabrication method of the perovskite solar cell includes the following steps: A first transport layer is formed on the substrate; A perovskite active layer is formed on the first transport layer; Using the thionium salt described in the above technical solution as a raw material, a passivation layer is formed on the perovskite active layer; A second transport layer is formed on the passivation layer; An electrode layer is formed on the second transport layer; The first transport layer and the second transport layer are each independently a hole transport layer and an electron transport layer, and the first transport layer is different from the second transport layer.

[0051] In some specific implementations, when the perovskite solar cell has a formal structure (nip), the first transport layer is an electron transport layer and the second transport layer is a hole transport layer. In some specific implementations, when the perovskite solar cell has an inverted structure (pin), the first transport layer is an electron transport layer and the second transport layer is a hole transport layer.

[0052] The preparation of the substrate, perovskite active layer, passivation layer and electrode layer is as described above, and will not be repeated here.

[0053] The method for preparing the hole transport layer (HTL) includes the following steps: Specifically, HTL material is dissolved in a solvent to obtain an HTL solution; after spin coating and annealing, a hole transport layer is formed. The material selection and thickness of the hole transport layer are as described above and will not be repeated here. In some specific implementations, the solvent is one or more of anhydrous ethanol, isopropanol, and chlorobenzene, preferably anhydrous ethanol. In some specific implementations, the concentration of the HTL solution is 0.3 mg / mL to 1.2 mg / mL, preferably 0.3 mg / mL to 1 mg / mL, more preferably 0.3 mg / mL to 0.7 mg / mL. In some specific implementations, 30 μL to 60 μL of HTL solution is preferably selected for the subsequent spin coating process, more preferably 40 μL to 50 μL. In some specific implementations, the spin coating speed is 1000 rpm to 5000 rpm, preferably 2000 rpm to 4000 rpm, and the time is 10 s to 50 s, preferably 20 s to 40 s. In some specific implementations, the annealing temperature is 80℃~120℃, preferably 90℃~110℃, and the time is 5min~20min, preferably 5min~15min.

[0054] The method for preparing the electron transport layer (ETL) includes the following steps: Specifically, a main electron transport layer and a buffer layer are deposited sequentially using a high-vacuum thermal evaporation process. The material selection and thickness of the electron transport layer have been described above and will not be repeated here. In some specific implementations, the vacuum level during electron transport layer deposition is 4 × 10⁻⁶. -4 Pa ~ 8×10 -4 Pa, preferably 5 × 10 -4 Pa ~ 7×10 -4 The deposition rate is 0.1 Å / s to 0.5 Å / s, preferably 0.2 Å / s to 0.4 Å / s. In some specific implementations, the vacuum degree during the deposition of the buffer layer is 4 × 10⁻⁶. -4 Pa ~ 8×10 -4 Pa, preferably 5 × 10 -4Pa ~ 7×10 -4 Pa, with a deposition rate of 0.04 Å / s to 0.16 Å / s, preferably 0.08 Å / s to 0.12 Å / s.

[0055] In some specific implementations, when the perovskite solar cell is a pin-structured structure, a typical operating step includes: I. Substrate Pretreatment: 1. Cleaning the substrate: After rinsing the substrate with detergent and deionized water, ultrasonically clean it in sequence with deionized water, acetone and ethanol. After cleaning, dry it with a nitrogen (N2) gas gun.

[0056] 2. Plasma surface treatment of the substrate: The dried substrate is subjected to plasma surface treatment to enhance its hydrophilicity and the adhesion of subsequent films.

[0057] II. Deposition of the Hole Transport Layer (HTL): 1. Preparation of HTL solution: Dissolve HTL material in a solvent to prepare an HTL solution.

[0058] 2. Deposition of HTL layer: Spin-coat the HTL solution onto the substrate. After spin-coating, transfer the substrate to a hot plate for annealing.

[0059] III. Deposition of the perovskite active layer: 1. Preparation of perovskite precursor solution: In a nitrogen glove box, the raw materials A, M, and X are dissolved in a mixed solvent in a molar ratio. The solution is heated and stirred until the raw materials are completely dissolved to obtain a perovskite precursor solution.

[0060] 2. Spin coating of the perovskite active layer: First, set the process parameters for the first spin coating step and spread the precursor solution evenly on the HTL layer; then set the process parameters for the second spin coating step and spin coat further, and add the anti-solvent rapidly in the last 10 seconds of the spin program.

[0061] 3. Annealing of the perovskite active layer: After spin coating, the substrate is quickly transferred to the preheating stage for annealing to promote the growth of perovskite grains and the complete evaporation of solvent.

[0062] IV. Deposition of the passivation layer: 1. Preparation of passivation solution: Dissolve the thionium salt described in this application in a solvent to prepare a passivating agent solution.

[0063] 2. Deposition of passivation layer: After the perovskite active layer cools to room temperature, the passivation agent solution is spin-coated onto its surface; after spin-coating, the substrate is annealed to promote the full interaction between the passivation agent and the perovskite surface.

[0064] V. Deposition of the Electron Transport Layer (ETL): Electron transport layers are deposited sequentially using a high-vacuum thermal evaporation process: 1. Deposition of the main electron transport layer: Under a certain vacuum, the main electron transport layer material is vapor-deposited onto the surface of the passivated perovskite active layer.

[0065] 2. Deposition of the buffer layer: Under the same vacuum level, the buffer layer material is deposited on the surface of the main electron transport layer.

[0066] VI. Deposition of Metal Electrodes: A metal mask with a predetermined electrode pattern is placed on the electron transport layer. Under a certain vacuum, the metal is deposited on the electron transport layer by thermal evaporation as a back electrode.

[0067] This application also provides an electrical device, including the perovskite solar cell described in any of the above technical solutions.

[0068] This application provides a thionium salt as shown in formula (I). Using this thionium salt as a passivating agent to form a passivation layer and applying it to perovskite solar cells enables simultaneous passivation of both cation and anion defects on the perovskite surface. By effectively suppressing surface defect states, it reduces nonradiative recombination of charge carriers, thereby significantly improving the open-circuit voltage (Vo) of the solar cell. OC By adjusting the fill factor (FF) and fill factor (FF), a higher power conversion efficiency (PCE) was ultimately achieved. Experimental results show that the open-circuit voltage (V) of the perovskite solar cell fabricated with the thionium salt described in formula (Ⅰ) as the passivation layer is significantly improved. OC The voltage can reach 1.172V, and the short-circuit current density (J) is [missing information]. SC It can reach 26.36 mA / cm 2 The fill factor (FF) can reach 85.12%, and the photoelectric conversion efficiency (PCE) can reach 26.30%.

[0069] The present invention is further illustrated below with reference to the embodiments. The scope of protection of the present invention is not limited to the following embodiments.

[0070] Example 1

[0071] The preparation method of aryl thioonium salt passivating agents, taking p-methoxyphenyl dimethyl thioonium trifluoromethanesulfonate as an example, involves the following synthesis steps: 1. Add 0.28 mL of p-methoxyanisole (stoichiometry is 1 equivalent, approximately 2 mmol) to the reaction tube, followed by 8 mL of 1,2-dichloroethane (DCE) as a solvent (solution concentration approximately 0.25 M).

[0072] 2. Under magnetic stirring, slowly add 0.3 mL of methyl trifluoromethanesulfonate (MeOTf) (stoichiometry of 1.3 equivalents, approximately 2.6 mmol) to the above solution.

[0073] 3. Place the reaction system at 60℃ for 12 hours. Monitor the reaction progress by thin-layer chromatography (TLC) until the starting material spot disappears.

[0074] 4. After the reaction is complete, cool the reaction mixture and filter it under reduced pressure using a Buchner funnel to collect the precipitated solid product.

[0075] 5. The filter cake was washed three times with a small amount of diethyl ether to remove unreacted raw materials and soluble impurities. The resulting white solid product was then dried under vacuum to obtain the final product p-methoxyphenyl dimethylthionium trifluoromethanesulfonate, the specific structure of which is shown in formula (I). The yield can reach 97%.

[0076] (I).

[0077] Nuclear magnetic resonance spectroscopy analysis was performed on the p-methoxyphenyl dimethylthionium trifluoromethanesulfonate described in this embodiment. The results are shown in [reference needed]. Figures 1-3 , Figure 1 This is the 1H NMR spectrum of p-methoxyphenyl dimethylthionium trifluoromethanesulfonate in Example 1 of this application; Figure 2 This is the carbon NMR spectrum of p-methoxyphenyl dimethylthionium trifluoromethanesulfonate in Example 1 of this application; Figure 3 This is the NMR fluorine spectrum of p-methoxyphenyl dimethylthionium trifluoromethanesulfonate from Example 1 of this application. Figures 1-3 As can be seen, p-methoxyphenyl dimethylthionium trifluoromethanesulfonate was prepared in this embodiment, and the structure of the obtained product was confirmed by nuclear magnetic resonance spectroscopy (NMR): 1 HNMR (400MHz, CDCl3) δ7.91(dt,J=10.1,2.7Hz,2H),7.09(dd,J=9.0,2.6Hz,2H),3.85(d,J=2.9Hz,3H),3.25(d,J=3.8Hz,6H).

[0078] 13 CNMR(101MHz,CDCl3)δ164.69,132.12,116.83,114.33,56.05,29.77.

[0079] 19 FNMR (376MHz, CDCl3) δ 78.36.

[0080] Example 2

[0081] The perovskite solar cell with an arylsulfonium salt passivation layer in Example 1 is fabricated using a pin-inverted structure. A typical assembly process includes the following steps: I. Preparation and cleaning of the substrate: 1. Cleaning of ITO glass: Lay the conductive indium tin oxide (ITO) glass flat on a lint-free cloth. The ITO glass thickness is 1.1mm. After rinsing with detergent and deionized water, place it on a cleaning rack and ultrasonically clean it for 20 minutes each time with deionized water (3 times), acetone (1 time), and ethanol (1 time). After cleaning, dry it with a nitrogen (N2) gas gun.

[0082] 2. Plasma surface treatment of the substrate: The dried ITO glass substrate is subjected to plasma surface treatment for 6 minutes to enhance its hydrophilicity and the adhesion of subsequent films.

[0083] II. Deposition of the Hole Transport Layer (HTL): 1. Preparation of HTL solution: Dissolve an appropriate amount of [2-(9,9-dimethyl-9H-fluoren-2-yl)ethyl]phosphonic acid (abbreviated as 2PACz) in anhydrous ethanol to prepare a solution with a concentration of 0.5 mg / mL.

[0084] 2. Deposition of the HTL layer: A hole transport layer with a thickness of 2 nm was deposited on a plasma-treated ITO substrate by spin coating. 45 μL of solution was spin-coated onto the ITO glass at a speed of 3000 rpm for 30 s. After spin coating, the substrate was transferred to a hot stage and annealed at 100 °C for 10 min.

[0085] III. Deposition of the perovskite active layer: 1. Preparation of perovskite precursor solution: In a nitrogen glove box, formamidine iodide (FAI), methylamine bromide (MABr), cesium iodide (CsI), lead iodide (PbI2), and lead bromide (PbBr2) are dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio usually 4:1) according to stoichiometric ratio to prepare the perovskite precursor solution. 0.90 MA 0.05 Cs 0.05 Pb(I 0.95 Br 0.05 )3 Perovskite precursor solution. The solution was heated and stirred at 60°C until the raw material was completely dissolved.

[0086] 2. Spin coating of the perovskite active layer: A two-step spin coating process was used to deposit the perovskite active layer to a thickness of 600 nm. First, 45 μL of the precursor solution was evenly spread on the HTL layer and rotated at 1000 rpm for 10 seconds with an acceleration of 500 rpm / s. Second, the rotation speed was immediately increased to 6000 rpm and continued for 30 seconds with an acceleration of 2000 rpm / s. In the last 10 seconds of the spin process, 200 μL of chlorobenzene antisolvent was rapidly added dropwise.

[0087] 3. Annealing of the perovskite active layer: After spin coating, quickly transfer the substrate to a hot plate preheated to 100°C for annealing treatment for 30 minutes to promote the growth of perovskite grains and complete evaporation of solvent.

[0088] IV. Deposition of the passivation layer: 1. Preparation of passivation solution: Take an appropriate amount of the aryl thioonium salt passivating agent (passivating agent 2) described in Example 1 of this application and dissolve it in isopropanol (IPA) to prepare a passivation layer solution with a concentration of 1 mg / mL.

[0089] 2. Deposition of passivation layer: After the perovskite active layer cools to room temperature, take 45 μL of passivation solution and spin coat it onto the surface at a speed of 4000 rpm for 40 s. The spin coating thickness is controlled at 2 nm. After spin coating, anneal the substrate at 100 °C for 10 min to promote the full interaction between the passivation agent and the perovskite surface.

[0090] V. Deposition of the Electron Transport Layer (ETL): Electron transport layers are deposited sequentially using a high-vacuum thermal evaporation process: 1. C 60 Deposition of layers: at 6×10 -4 Under a vacuum of Pa, fullerene (C 60 The perovskite active layer was vapor-deposited onto the passivated surface, with a deposition thickness controlled at 30 nm and a deposition rate of 0.3 Å / s.

[0091] 2. Deposition of the BCP layer: Under the same vacuum, copper bath (BCP) was continued to be deposited on C. 60 The surface of the layer serves as a buffer layer, with a deposition thickness of 8 nm and a deposition rate of 0.1 Å / s.

[0092] VI. Deposition of Metal Electrodes: A metal mask with a predetermined electrode pattern is placed on the electron transport layer, in a 6×10⁻⁶ area. -4 Under a vacuum of Pa, silver (Ag) was deposited on the electron transport layer as a back electrode by thermal evaporation, with a deposition thickness of 85 nm and a deposition rate controlled between 0.3 Å / s and 0.5 Å / s.

[0093] See the diagram of the perovskite solar cell structure. Figure 4 , Figure 4 This is a structural diagram of the perovskite solar cell prepared in Example 2. Figure 4 In the diagram, 1 is glass, 2 is conductive indium tin oxide, 3 is hole transport layer, 4 is passivation layer, 5 is perovskite active layer, 6 is electron transport layer, and 7 is metal electrode.

[0094] Comparative Example 1

[0095] The difference from Example 2 is that there is no passivation layer.

[0096] Comparative Example 2

[0097] The difference from Example 2 is that in the passivation layer deposition step, phenylethyl ammonium bromide (PEABr) is used as the passivating agent.

[0098] Comparative Example 3

[0099] The difference from Example 2 is that in the passivation layer deposition step, the passivating agent used is passivating agent 1 with the structure shown in formula (Ⅲ); (III).

[0100] The photovoltaic performance parameters of the encapsulated perovskite solar cells were tested under standard test conditions (AM 1.5G spectrum, 100 mW / cm²). 2 Under irradiance conditions, the current density-voltage (JV) curves of the device were recorded using a solar source simulator and a source meter. During testing, a reverse scan was performed from 1.5V to 0.5V, with a scan step size of 0.2V. The photoelectric conversion efficiency (PCE), fill factor (FF), and open-circuit voltage (VJV) of the battery device can be obtained from the test curves. OC ) and short-circuit current density (J SC Key photovoltaic parameters (Note: The effective illumination area of ​​the perovskite solar cell is 0.043 cm²). 2 ).

[0101] See results Figure 5 , Figure 5 The current density-voltage (JV) curves of the perovskite solar cells in Example 2 and Comparative Examples 1-3 of this application are shown. Figure 5 The V of the battery device is obtained OC J SC PCE and FF are shown in Table 1. As can be seen from Table 1, the perovskite solar cell prepared in Example 2 of this application has higher open-circuit voltage, short-circuit current density, fill factor and photoelectric conversion efficiency.

[0102] Table 1. V values ​​of the battery devices in Examples 2 and Comparative Examples 1-3 OC J SC, PCE and FF

[0103] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and inventive concept of this application, should be included within the scope of protection of this application.

Claims

1. A perovskite solar cell, characterized in that, include: A passivation layer, wherein the passivation layer is prepared from a thionium salt with the structure shown in formula (I); （Ⅰ）。 2. The perovskite solar cell according to claim 1, characterized in that, Also includes: Base; A perovskite active layer is formed on the surface of the substrate, and the passivation layer is formed on the surface of the perovskite active layer; An electrode layer is formed on the surface of the passivation layer.

3. The perovskite solar cell according to claim 2, characterized in that, The thickness of the passivation layer is 1 nm to 10 nm.

4. The perovskite solar cell according to claim 2, characterized in that, The material of the perovskite active layer has the atomic ratio shown in formula (II): AMX3 (II); A is selected from one or more of formamidine ions, methylamine ions, cesium ions, and rubidium ions; M is selected from one or more of lead ions, tin ions, and germanium ions; X is a halide ion; The thickness of the perovskite active layer is 400 nm to 800 nm.

5. The perovskite solar cell according to claim 2, characterized in that, The material of the electrode layer is selected from metal back electrode, carbon-based back electrode or transparent bottom electrode; The thickness of the electrode layer is 50nm~100nm.

6. The perovskite solar cell according to claim 2, characterized in that, The substrate is an ITO glass substrate or an FTO glass substrate; The thickness of the substrate is 1mm to 1.5mm.

7. The perovskite solar cell according to claim 2, characterized in that, Also includes: A first transport layer is formed between the substrate and the perovskite active layer; A second transport layer is formed between the passivation layer and the electrode layer; The first transport layer and the second transport layer are each independently a hole transport layer and an electron transport layer, and the first transport layer is different from the second transport layer.

8. The perovskite solar cell according to claim 7, characterized in that, The hole transport layer is made of one or more of the following materials: [2-(9,9-dimethyl-9H-fluoren-2-yl)ethyl]phosphonic acid, (4-(3,6-dimethoxy-9H-carbazole-9-yl)butylphosphonic acid), (4-(9H-carbazole-9-yl)butylphosphonic acid), and (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid; the thickness of the hole transport layer is 1 nm to 5 nm. The electron transport layer is made of fullerene C. 60 One or more of SnO2, TiO2, isomethyl [6,6]-phenyl-C61-butyrate and isomethyl [6,6]-phenyl-C71-butyrate; the thickness of the electron transport layer is 15 nm to 70 nm.

9. An electrical appliance, characterized in that, Including the perovskite solar cell according to any one of claims 1 to 8.

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