Self-assembly modifier based on phthalimide as well as preparation method and application of self-assembly modifier

Abstract

The invention relates to the technical field of solar cells, in particular to a phthalimide-based self-assembly modifier and a preparation method and application thereof, the structural formula is shown as any one of formulas I, II and III, in the formula, R1, R2, R3 and R4 are independently selected from one of F, Cl, Br, CN, Ph and H, and n is selected from an integer from 1 to 4. The phosphate group in the modifier can anchor the surface of the perovskite to reduce various defects on the interface, and the phthalimide can provide a template for a subsequently deposited charge transport layer (such as C60) to realize uniform film formation, so that the defects on the perovskite interface are reduced to the greatest extent, and non-radiative recombination is reduced. The compound can be applied to the field of batteries as a passivator, and can better hinder interface reaction and improve the stability of devices. The perovskite solar cell can be applied to the field of cells as a transmission layer, and can perform electron selective transmission on the surface of perovskite and optimize interface carrier distribution, thereby reducing non-radiative recombination and effectively increasing the open-circuit voltage of a device.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a phthalimide-based self-assembly modifier, its preparation method, and its application. Background Technology

[0002] Organic-inorganic metal halide perovskite materials have become a research hotspot in the photovoltaic field due to their excellent light absorption coefficient, long carrier diffusion length and tunable band gap.

[0003] The certified efficiency of single-junction solar cells based on this material has reached 26.9%, and its broad spectral response characteristics make it an ideal candidate material for tandem cells to break the single-junction Shockley-Queisser limit.

[0004] In the prior art, the perovskite surface and interface contain a large number of uncoordinated lead clusters and halogen vacancy defects, which lead to significant open-circuit voltage loss and efficiency degradation.

[0005] Current mainstream solutions improve device efficiency by introducing two-dimensional perovskite or organic small molecules to passivate the three-dimensional perovskite surface, but still face two major technical drawbacks: First, the inorganic perovskite layer and the charge transport organic layer (such as C...) 60 First, a new heterogeneous interface is formed between the two, and its band matching characteristics and carrier transport mechanism are not yet clear. Second, the small molecule ammonium salt passivator introduces iodine ions, which accelerates ion migration in the device and causes instability. Summary of the Invention Based on the above problems, one of the objectives of this invention is to provide a phthalimide-based self-assembly modifier to solve the problem of the interface between the perovskite layer and the charge transport layer in related technologies. Such molecules can be applied to a variety of optoelectronic devices.

[0006] The second objective of this invention is to provide a method for preparing a self-assembled modifier based on phthalimide, which is simple and easy to adjust.

[0007] A third objective of this invention is to provide an application of a phthalimide-based self-assembly modifier.

[0008] To achieve one of the objectives, the technical solution adopted by this invention is as follows: a self-assembly modifier based on phthalimide is provided, the structural formula of which is shown in any one of formulas I, II, and III: ; In the formula: R1, R2, R3, and R4 are independently chosen from one of F, Cl, Br, CN, and H, and n is an integer from 1 to 4.

[0009] CN stands for cyano, and Ph stands for phenyl.

[0010] n can be an integer from 1 to 4 to achieve different chain lengths and different molecular stacking.

[0011] R1, R2, R3, and R4 are independently selected from at least one of F, Cl, Br, CN, Ph, and H. That is, the hydrogen atom on the corresponding benzene ring may or may not be substituted. When the hydrogen atom on the corresponding benzene ring is substituted, the substituent group is selected from at least one of F, Cl, Br, CN, Z, and H.

[0012] Preferably, the self-assembly surface modifier is any one of the following compounds:

[0013] The second technical solution for achieving the objective of this invention is as follows: a method for preparing the self-assembly modifier based on phthalimide, comprising the following steps: (1) Compound 1 is reacted with dibromoalkane to prepare compound 2. The specific reaction formula is as follows: , , ; (2) When compound 2 reacts with triethyl phosphite, compound 3 is generated. The specific reaction formula is as follows: , , ; (3) The self-assembled surface modifier is prepared by reacting compound 3-bromotrimethylsilane in a solvent, and the specific reaction formula is as follows: , , .

[0014] Preferably, in step (1), the dibromoalkane includes at least one of dibromomethane, 1,2-dibromoethane, 1,3-dibromopropane, and 1,4-dibromobutane, and the molar ratio of compound 1 to the dibromoalkane is 1:12-18.

[0015] Preferably, in step (1), the reaction temperature is 70-100℃, the reaction is carried out in a solvent atmosphere, and the solvent used is at least one of N-dimethylformamide and dimethyl sulfoxide.

[0016] Preferably, in step (2), the molar ratio of compound 2 to triethyl phosphite is 1:10-25.

[0017] Preferably, in step (3), the molar ratio of compound 3 to trimethylbromosilane is 1:5-15, and the solvent used is a mixture of at least one of 1,4-dioxane, formamide, acetonitrile, methanol, ethanol, propanol, and acetone with water.

[0018] The third technical solution adopted to achieve the objective of this invention is: an application of the phthalimide-based self-assembly modifier, which is applied to the battery field or the lighting device field.

[0019] Preferably, the phthalimide-based self-assembly modifier is used as a passivator or transport layer in the battery field.

[0020] The fourth technical solution adopted to achieve the purpose of this invention is: a perovskite solar cell, wherein a self-assembly surface modifier is disposed between the perovskite inorganic layer and the charge transport organic layer, and the self-assembly surface modifier is the phthalimide-based self-assembly modifier.

[0021] The beneficial effects of this invention are as follows: This invention is based on phthalimide as a self-assembling modifier. The phosphate groups can anchor the perovskite surface to reduce various defects at the interface. Phthalimide will act as a charge transport layer (such as C) for subsequent deposition. 60 It provides a template to achieve uniform film formation, thereby minimizing perovskite interface defects and reducing non-radiative recombination.

[0022] The phthalimide-based self-assembly modifier of the present invention, when used as a passivating agent in the battery field, can better inhibit interfacial reactions and improve device stability.

[0023] The phthalimide-based self-assembly modifier of the present invention is applied as a transport layer in the field of batteries. It can perform electron selective transport on the perovskite surface, optimize the carrier distribution at the interface, thereby reducing non-radiative recombination and effectively increasing the open-circuit voltage of the device. Attached Figure Description

[0024] Figure 1 This is a synthetic route diagram of the present invention; Figure 2 JV curves of perovskite solar cells prepared using the self-assembly modifiers prepared in Examples 1-5 as passivating agents. Detailed Implementation

[0025] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with preferred embodiments, is provided. The purpose is to better understand the content of the present invention and to demonstrate its essential characteristics; therefore, the examples given should not be considered as limitations on the scope of protection of the present invention. It is also specifically noted that, unless otherwise specified, the specific experimental methods and equipment involved in the embodiments are conventional methods or implemented according to the conditions recommended in the manufacturer's instructions, and the reagents involved are commercially available unless otherwise specified.

[0026] This invention discloses a method for preparing a self-assembly modifier based on phthalimide, comprising the following steps: Compound A is reacted with a dibromoalkane in a solvent atmosphere to give compound B. The solvent is N,N-dimethylformamide (DMF) or dimethyl sulfoxide, and the reaction temperature is 70-100℃. The dibromoalkane includes at least one of dibromomethane, 1,2-dibromoethane, 1,3-dibromopropane, and 1,4-dibromobutane. The molar ratio of compound A to the dibromoalkane is 1:(12-18).

[0027] Compound B was reacted with triethyl phosphite to give compound C; the molar ratio of compound B to triethyl phosphite was 1:(10-25).

[0028] Compound C is reacted with trimethylbromosilane in a solvent to obtain a self-assembled modified layer material; the molar ratio of compound C to trimethylbromosilane is 1:(5-15), and the solvent used can be a mixture of at least one of 1,4-dioxane, formamide, acetonitrile, methanol, ethanol, propanol, acetone and water.

[0029] Wherein, compound A is any one of the structural formulas shown in formula (II), compound B is any one of the structural formulas shown in formula (III), compound C is any one of the structural formulas shown in formula (IV), and the self-assembly layer material is any one of the structural formulas shown in formula (V). ; Where R1, R2, R3, and R4 are independently chosen from one of F, Cl, Br, CN, Ph, and H, and n is an integer from 1 to 4.

[0030] like Figure 1 The diagram shown is a synthetic route diagram of the present invention.

[0031] Example 1 Synthetic method of compound (3-(1,3-dioxoisoindoline-2-yl)propyl)phosphonic acid 3PDPA: ; Step 1: Compound A, containing a phthalimide unit, undergoes a substitution reaction in a mixed solution of 1,3-dibromopropane and N,N-dimethylformamide (DMF) to give compound B. The molar ratio of compound A to dibromoalkane is 1:4:15. The substitution reaction temperature is 70 °C, and the substitution reaction time is 24 h. After the reaction is complete, the reaction is quenched with water, and the solution is extracted three times with water and dichloromethane. The organic layer is dried with anhydrous sodium sulfate, and the solvent is removed by rotary evaporation to obtain the crude product. The crude product is separated by silica gel column chromatography using a mixed solution of petroleum ether and dichloromethane to obtain compound B with a yield of 85%. 1 H NMR(600 MHz, DMSO-d6) δ 7.85 (ddt, J = 22.2, 5.2, 2.5 Hz, 4H), 3.61 (td, J =7.1, 4.0 Hz, 2H), 1.78 (ddt, J = 15.6, 10.9, 7.3 Hz, 2H), 1.66 – 1.49 (m,2H).

[0032] Step 2: Compound B was subjected to a nucleophilic substitution reaction with a mixed solution of triethyl phosphite to generate compound C. The molar ratio of compound B to triethyl phosphite was 1:20. The substitution reaction was carried out under reflux for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, and petroleum ether was added and stirred under ice bath conditions. The solid was filtered off and washed with petroleum ether to obtain compound C with a yield of 78%.

[0033] Step 3: Compound C was hydrolyzed in a mixed solution of trimethylbromosilane and 1,4-dioxane to prepare a self-assembled layer material. The molar ratio of compound C to trimethylbromosilane was 1:10, the solvent was 1,4-dioxane, the hydrolysis temperature was room temperature, and the hydrolysis time was 24 h. After the reaction was completed, distilled water was added dropwise and stirred for 3 h. The solid was then filtered off and recrystallized from ethyl acetate-petroleum ether. The yield was 75%. 1 H NMR (600 MHz, Chloroform- d ) δ 7.83(dt, J = 6.0, 2.9 Hz, 2H), 7.71 (qd, J = 5.0, 4.3, 1.8 Hz, 2H), 3.76 (t, J =7.0 Hz, 2H), 2.05 – 1.95 (m, 2H), 1.79 (dq, J = 22.2, 7.3, 6.1 Hz, 2H).

[0034] The reaction process is as follows: .

[0035] Example 2 Synthetic method of compound (4-(1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)butyl)phosphonic acid 4PANPD: ; Step 1: Compound D containing a naphthalenedicarboximide unit was subjected to a substitution reaction in a mixed solution of 1,4-dibromobutane and N,N-dimethylformamide (DMF) to give compound E. The molar ratio of compound D to dibromoalkane was 1:4:15. The substitution reaction temperature was 70 °C and the substitution reaction time was 24 h. After the reaction was completed, the reaction was quenched with water, and the solution was extracted three times with water and dichloromethane. The organic layer was dried with anhydrous sodium sulfate, and the solvent was removed by rotary evaporation to obtain the crude product. The crude product was separated by silica gel column chromatography using a mixed solution of petroleum ether and dichloromethane to obtain compound E with a yield of 84%.

[0036] Step 2: Compound E was reacted with a mixed solution of triethyl phosphite to undergo a nucleophilic substitution reaction, yielding compound F. The molar ratio of compound E to triethyl phosphite was 1:20. The substitution reaction was carried out under reflux for 24 hours. After the reaction was complete, the mixture was cooled to room temperature, and petroleum ether was added and stirred under ice bath conditions. The solid was filtered off and washed with petroleum ether to obtain compound F in 80% yield. No purification was required.

[0037] Step 3: Compound F was hydrolyzed in a mixed solution of trimethylbromosilane and 1,4-dioxane to prepare a self-assembled layer material. The molar ratio of compound F to trimethylbromosilane was 1:10, the solvent was 1,4-dioxane, the hydrolysis temperature was room temperature, and the hydrolysis time was 24 h. After the reaction was completed, distilled water was added dropwise and stirred for 3 h. The solid was then filtered off and recrystallized from ethyl acetate-petroleum ether. The yield was 76%. E, F, and 4PABPD were confirmed as the target products by NMR. The NMR data for 4PABPD are as follows: ¹H NMR: δ 1.64–1.80 (4H, 1.70 (quint, J = 7.4 Hz), 1.75 (quint, J = 7.4 Hz)), 2.56 (2H, t, J = 7.4 Hz), 3.81 (2H, t, J = 7.4 Hz), 7.63 (2H, dddd, J = 7.9, 7.3, 2.7, 0.5 Hz), 7.82 (2H, dddt, J = 7.9, 2.7, 1.4, 0.5 Hz), 8.70 (2H, dq, J = 1.4, 0.5 Hz) The reaction process is as follows: .

[0038] Example 3 Synthetic method of compound ((5,6-difluoro-1,3-dioxoisoindololin-2-yl)methyl)phosphonic acid DFPDPA): ; Step 1: Compound G containing phthalimide units undergoes a substitution reaction in a mixed solution of dibromomethane and N,N-dimethylformamide (DMF) to give compound H. The molar ratio of compound G to dibromoalkane is 1:4:15. The substitution reaction temperature is 70 °C, and the substitution reaction time is 24 h. After the reaction is complete, the reaction is quenched with water, and the solution is extracted three times with water and dichloromethane. The organic layer is dried with anhydrous sodium sulfate, and the solvent is removed by rotary evaporation to obtain the crude product. The crude product is separated by silica gel column chromatography using a mixed solution of petroleum ether and dichloromethane to obtain compound H with a yield of 88%.

[0039] Step 2: Compound H was reacted with a mixed solution of triethyl phosphite to undergo a nucleophilic substitution reaction, yielding compound I. The molar ratio of compound H to triethyl phosphite was 1:20. The substitution reaction was carried out under reflux for 24 hours. After the reaction was complete, the mixture was cooled to room temperature, and petroleum ether was added and stirred under ice bath conditions. The solid was filtered off and washed with petroleum ether to obtain compound I in 79% yield. No purification was required.

[0040] Step 3: Compound I was hydrolyzed in a mixed solution of bromotrimethylsilane and 1,4-dioxane to prepare a self-assembled layer material. The molar ratio of compound I to bromotrimethylsilane was 1:10, the solvent was 1,4-dioxane, the hydrolysis temperature was room temperature, and the hydrolysis time was 24 h. After the reaction, distilled water was added dropwise and stirred for 3 h. The solid was then filtered off and recrystallized from ethyl acetate-petroleum ether. The yield was 75%. H, I, and DFPDPA were confirmed as the target products by NMR. The NMR data for DFPDPA are as follows: 1 ¹H NMR: δ 2.67 (2H, t, J = 6.7 Hz), 3.97 (2H, t, J = 6.7Hz), 8.20 (2H, d, J = 0.5 Hz). The reaction process is as follows: .

[0041] Example 4 Synthetic method of compound (2-(5-chloro-1,3-dioxoisoindoline-2-yl)ethyl)phosphonic acid 2CPDPA): ; Step 1: Compound J containing phthalimide units was subjected to a substitution reaction in a mixed solution of 1,2-dibromoethane and N,N-dimethylformamide (DMF) to give compound K. The molar ratio of compound J to dibromoalkane was 1:4:15. The substitution reaction temperature was 70 °C and the substitution reaction time was 24 h. After the reaction was completed, the reaction was quenched with water, and the solution was extracted three times with water and dichloromethane. The organic layer was dried with anhydrous sodium sulfate, and the solvent was removed by rotary evaporation to obtain the crude product. The crude product was separated by silica gel column chromatography using a mixed solution of petroleum ether and dichloromethane to obtain compound K with a yield of 84%.

[0042] Step 2: Compound K was reacted with a mixed solution of triethyl phosphite to undergo a nucleophilic substitution reaction, yielding compound L. The molar ratio of compound K to triethyl phosphite was 1:20. The substitution reaction was carried out under reflux for 24 hours. After the reaction was complete, the mixture was cooled to room temperature, and petroleum ether was added and stirred under ice bath conditions. The solid was filtered off and washed with petroleum ether to obtain compound L in 85% yield. No purification was required.

[0043] Step 3: Compound L was hydrolyzed in a mixed solution of bromotrimethylsilane and 1,4-dioxane to prepare a self-assembled layer material. The molar ratio of compound L to bromotrimethylsilane was 1:10, the solvent was 1,4-dioxane, the hydrolysis temperature was room temperature, and the hydrolysis time was 24 h. After the reaction was completed, distilled water was added dropwise and stirred for 3 h. The solid was then filtered off and recrystallized from ethyl acetate-petroleum ether. The yield was 80%. K, L, and 2CPDPA were confirmed as the target products by NMR. The NMR data of 2CPDPA are as follows: 1 ¹H NMR: δ 2.67 (2H, t, J = 6.7 Hz), 3.99 (2H, t, J = 6.7Hz), 7.52 (1H, dd, J = 8.3, 1.7 Hz), 7.89-8.09 (2H, 7.95 (dd, J = 8.3, 0.5 Hz), 8.03 (dd, J = 1.7, 0.5 Hz)). The reaction process is as follows: .

[0044] Example 5 Synthetic method of compound (3-(5,6-dicyano-1,3-dioxoisoindoline-2-yl)propyl)phosphonic acid 3CyPDPA): ; Step 1: Compound M containing phthalimide units was subjected to a substitution reaction in a mixed solution of 1,3-dibromopropane and N,N-dimethylformamide (DMF) to give compound N. The molar ratio of compound M to dibromoalkane was 1:4:15. The substitution reaction temperature was 70 °C and the substitution reaction time was 24 h. After the reaction was completed, the reaction was quenched with water, and the solution was extracted three times with water and dichloromethane. The organic layer was dried with anhydrous sodium sulfate, and the solvent was removed by rotary evaporation to obtain the crude product. The crude product was separated by silica gel column chromatography using a mixed solution of petroleum ether and dichloromethane to obtain compound N with a yield of 81%.

[0045] Step 2: Compound N was subjected to a nucleophilic substitution reaction with a mixed solution of triethyl phosphite to generate compound S. The molar ratio of compound N to triethyl phosphite was 1:20. The substitution reaction was carried out under reflux for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, and petroleum ether was added and stirred under ice bath conditions. The solid was filtered off and washed with petroleum ether to obtain compound S in 92% yield. No purification was required.

[0046] Step 3: Compound S was hydrolyzed in a mixed solution of bromotrimethylsilane and 1,4-dioxane to prepare a self-assembled layer material. The molar ratio of compound S to bromotrimethylsilane was 1:10, the solvent was 1,4-dioxane, the hydrolysis temperature was room temperature, and the hydrolysis time was 24 h. After the reaction was complete, distilled water was added dropwise and stirred for 3 h. The solid was then filtered off and recrystallized from ethyl acetate-petroleum ether. The yield was 88%. The above N, S, and 3CyPDPA were confirmed as the target products by NMR.

[0047] The reaction process is as follows: .

[0048] Application examples The self-assembly modifiers prepared in Examples 1, 2, 3, 4, and 5 were used as passivating agents to prepare perovskite solar cells and their photovoltaic performance was tested. Its structure is: glass / conductive glass / SAM / perovskite / self-assembling modifier / C 60 / BCP / Cu. The conductive glass was ultrasonically cleaned sequentially with detergent, deionized water, acetone, and isopropanol for 30 min each. After drying with nitrogen, the conductive glass was plasma cleaned for 15 min. The self-assembled layer material dissolved in ethanol (0.5 mg / mL) was filtered before deposition. -1Then, 150 μL of the solution was dropped onto a conductive glass substrate and spin-coated at 3000 rpm for 30 seconds, followed by annealing at 100 °C for 10 minutes. Next, 100 μL of the precursor was dropped onto the SAM layer and rapidly spin-coated in a two-step process: 1000 rpm for 10 seconds and 4000 rpm for 30 seconds, with 150 μL of toluene added as an antisolvent 10 seconds before the end of the second step. The prepared perovskite film was then annealed at 100 °C for 60 minutes, followed by spin-coating of the synthesized 3PDPA / DFPDPA / 4PABPD / 2CPDPA / 3CyPDPA self-assembled modification layer material at 4000 rpm for 30 seconds, and then vacuum-deposited at 0.2 Å s⁻¹. -1 Depositing 20nm C at a high speed 60 , at 0.2 Å s -1 8 nm BCP and 100 nm metallic Cu were deposited at a rate of [missing information - likely a specific velocity or speed] as electrodes. The deposition was performed in air at 100 mW / cm². -2 Current-voltage (ND-V) measurements were performed under simulated AM 1.5 G sunlight irradiance. J - V The curve (2400 Series Source Meter, Keithley Instruments) shows that the effective area of ​​the solar cell, measured under AM 1.5 G conditions, is 0.07 square centimeters, determined by an opaque mask.

[0049] like Figure 2 The figure shows the JV curves of perovskite solar cells prepared by the self-assembly modifiers prepared in Examples 1, 2, 3, 4 and 5 as passivating agents. As can be seen from the figure, all materials applied to the perovskite surface exhibit excellent power conversion efficiency (PCE) and high open-circuit voltage, indicating that the materials have good defect passivation ability and interface matching degree.

[0050] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the content of this specification should be included within the protection scope of the present invention.

Claims

1. A self-assembling modifier based on phthalimide, characterized in that, Its structural formula is shown in any one of formulas I, II, and III: ； In the formula: R1, R2, R3, and R4 are independently chosen from one of F, Cl, Br, CN, and H, and n is an integer from 1 to 4.

2. The phthalimide-based self-assembly modifier as described in claim 1, characterized in that, The self-assembly surface modifier is specifically any one of the following compounds: 。 3. A method for preparing a phthalimide-based self-assembly modifier as described in claim 1 or 2, characterized in that, Includes the following steps: (1) Each , , Reaction with dibromoalkane; (2) React the product of step (1) with triethyl phosphite respectively; (3) The product of step (2) is reacted with bromotrimethylsilane in a solvent to prepare the self-assembled surface modifier.

4. The method for preparing the phthalimide-based self-assembly modifier as described in claim 3, characterized in that, In step (1), the dibromoalkane includes at least one selected from dibromomethane, 1,2-dibromoethane, 1,3-dibromopropane, and 1,4-dibromobutane. , , The molar ratio with dibromoalkane is 1:12-18.

5. The method for preparing the phthalimide-based self-assembly modifier as described in claim 3, characterized in that: In step (1), the reaction temperature is 70-100℃, the reaction is carried out in a solvent atmosphere, and the solvent used is at least one of N-dimethylformamide and dimethyl sulfoxide.

6. The method for preparing the phthalimide-based self-assembly modifier as described in claim 3, characterized in that, In step (2), the molar ratio of the product from step (1) to triethyl phosphite is 1:10-25.

7. The method for preparing the phthalimide-based self-assembly modifier as described in claim 3, characterized in that, In step (3), the molar ratio of the product from step (2) to bromotrimethylsilane is 1:5-15, and the solvent used is a mixture of at least one of 1,4-dioxane, formamide, acetonitrile, methanol, ethanol, propanol, and acetone with water.

8. The application of a phthalimide-based self-assembly modifier according to claim 1 or 2, or a phthalimide-based self-assembly modifier prepared by the preparation method according to any one of claims 3-7, characterized in that: The phthalimide-based self-assembly modifier can be applied to the fields of batteries or lighting devices.

9. The application according to claim 8, characterized in that: The phthalimide-based self-assembly modifier is applied as a passivator or transport layer in the battery field.

10. A perovskite solar cell, characterized in that: A self-assembly surface modifier is disposed between the perovskite inorganic layer and the charge transport organic layer. The self-assembly surface modifier is the phthalimide-based self-assembly modifier as described in claim 1 or 2, or the phthalimide-based self-assembly modifier prepared by the preparation method described in any one of claims 3-7.

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