A compound based on purine polycyclic skeleton and application thereof

Abstract

This invention belongs to the field of organic-inorganic lead halide perovskite solar cell fabrication technology, specifically relating to a compound based on a purine polycyclic skeleton and its application. Using a purine polycyclic skeleton as the core and phosphonic acid and carboxylic acid as anchoring groups, the synthesized compound serves as a self-assembled monolayer hole transport material, exhibiting a multi-site anchoring effect. The nitrogen atoms, rich in lone pair electrons, connect with the Pb atoms on the perovskite substrate. 2+ A strong multidentate coordination network is formed to lock the chemical bonds of the lattice, thereby effectively resisting strong ultraviolet radiation and suppressing the generation of radiation-induced deep level defects. It has a suitable HOMO energy level, which can be well matched with the perovskite absorber layer, which is conducive to hole transport. When used as a hole transport layer in an inverted perovskite solar cell, it can achieve excellent photoelectric conversion efficiency without doping, and has excellent stability and resistance to ultraviolet radiation.

Description

Technical Field

[0001] This invention specifically relates to a compound based on a purine polycyclic skeleton and its application, belonging to the field of organic-inorganic lead halide perovskite solar cell fabrication technology. Background Technology

[0002] Perovskite solar cells, as a representative of the next generation of photovoltaic devices, have achieved rapid development in recent years due to their advantages such as high light absorption coefficient, long carrier lifetime, low processing temperature, and high power conversion efficiency. However, many challenges remain in realizing the commercialization of perovskite cells, among which interface engineering is considered one of the key factors restricting device performance and stability. Especially in inverted perovskite solar cells, the performance of hole transport materials directly affects the efficiency and stability of the device.

[0003] Traditional hole transport materials, such as polymeric hole transport materials (e.g., poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) and poly(3,4-ethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS)), while widely used, suffer from low decomposition temperatures and low hole mobility. Furthermore, commonly used small-molecule organic hole transport materials (e.g., 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD)) are difficult to coat over large areas, prone to water absorption, and have poor thermal stability, significantly hindering the large-scale fabrication of perovskite solar cells. In practical applications, perovskite solar cells also face problems such as interfacial instability, band mismatch, and ion migration, which severely impact device lifetime and large-area uniformity. Meanwhile, commonly used hole transport layers (HTLs) (such as Spiro-OMeTAD, PTAA) require the addition of hygroscopic lithium salts (such as lithium bis(trifluoromethanesulfonyl)imide, Li-TFSI) as dopants. Under strong ultraviolet radiation, these dopants are highly volatile and can induce violent halide ion migration in the perovskite layer, leading to rapid device failure. Although existing commercially available self-assembled monolayer materials (SAMs) achieve doping-free operation, they lack effective passivation capabilities for deep defects in the perovskite lattice under strong ultraviolet radiation, and cannot provide a long-lasting physical barrier against ultraviolet radiation.

[0004] Therefore, developing a high-performance hole transport material suitable for large-scale fabrication is of great significance for promoting the commercial application of perovskite solar cells. An ideal hole transport material not only needs to possess excellent hole transport performance but should also be able to effectively passivate perovskite layer defects, improving device stability and uniformity. Furthermore, due to the application requirements of perovskite solar cells in space environments, developing hole transport materials with high UV absorption resistance has become a current research hotspot. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing compounds based on purine polycyclic skeletons and their applications. These compounds, as self-assembled monolayer hole transport materials, possess suitable HOMO energy levels and can be well matched with perovskite absorber layers, facilitating hole transport. When used as hole transport layers in inverted perovskite solar cells, they achieve excellent photoelectric conversion efficiency without doping and exhibit excellent stability and UV resistance.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a compound based on a purine polycyclic skeleton, the compound having the structural formula shown in formula (I):

[0007] Wherein, X is any one of halogen atoms, R1 group, -OR2 group, -SR2 group, -NHR2 group, -N(R2)2 group, and Ar group; Y is selected from hydrogen, halogen, C1-C3 alkyl, trifluoromethyl, perfluoroalkyl, trialkylsilyl, C6-C 40 Substituted or unsubstituted aryl groups, C4-C 40 Any one of the heteroaryl groups; L is selected from C1-C4 alkyl groups, -(CH2CH2O) n - any of the phenyl groups, where n = 2-4; A is selected from either phosphoric acid or carboxylic acid; R1 is hydrogen, deuterium, tritium, cyano, haloalkyl, or C1-C. 40 Alkyl or heteroalkyl, C3-C 40 cycloalkyl, C2-C 40 Heterocyclic alkyl, C7-C 40 Aryl alkyl, C2-C 40 Any one of the heteroaryl alkyl groups; R2 is any one of hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, aryl, C1-C6 acyl, and aryl(C1-C6) alkyl; Ar is any one of substituted or unsubstituted aryl or heteroaryl groups.

[0008] Further, R1 is any one of hydrogen, deuterium, tritium, cyano, -CF3, methyl, ethyl, propyl, tert-butyl, cyclopentyl, cyclohexyl, methoxymethyl, methoxyethyl, benzyl, and phenethyl.

[0009] Furthermore, R2 is any one of hydrogen, methyl, ethyl, propyl, tert-butyl, allyl, ethynyl, aryl, acetyl, propionyl, benzyl, and phenethyl.

[0010] Furthermore, Ar can be any one of the following structural formulas Ar1 to Ar20:

[0011] The R3 group is independently selected from H, halogen group, -OR', -OCOR', -NHCOR', -NR'2, -R'; The R' group is selected from any one of hydrogen, substituted or unsubstituted phenyl, thiophene, and C1-C5 alkyl groups; The W group is selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2-), and R is -CH3 or -H.

[0012] Furthermore, the compound is selected from at least one of the following SAM1 to SAM72 structures: .

[0013] The present invention also discloses a self-assembled monolayer material, including the compound based on the purine polycyclic skeleton provided by the present invention.

[0014] The present invention also discloses a hole transport layer material, including the self-assembled monolayer material provided by the present invention.

[0015] The present invention also discloses a perovskite solar cell device, wherein the perovskite solar cell includes a conductive glass substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a buffer layer, and a metal electrode.

[0016] Furthermore, the hole transport layer comprises the hole transport layer material provided by the present invention.

[0017] The present invention also discloses an electrical device, including the perovskite solar cell device provided by the present invention.

[0018] The beneficial effects of this invention are: (1) The self-assembled monolayer (SAM) hole transport material based on the purine polycyclic framework provided by the present invention has a multi-site rivet effect, which greatly improves the UV resistance. The material is rich in nitrogen atoms with lone pair electrons and Pb on the perovskite bottom. 2+The chemical bonds that form a strong multidentate coordination network that lock the lattice can effectively resist strong ultraviolet radiation and suppress the generation of radiation-induced deep-level defects. This type of hole transport material has suitable HOMO energy levels, which can be well matched with the perovskite absorption layer, which is conducive to hole transport. At the same time, it has good solubility and film-forming properties.

[0019] (2) The self-assembled monolayer (SAM) based on the purine polycyclic framework provided by this invention is applied to perovskite solar cells for the first time, providing a way to prepare the hole transport layer in perovskite solar cell devices.

[0020] (3) When the self-assembled monolayer (SAM) based on the purine polycyclic framework provided by the present invention is used as the hole transport layer of the inverted perovskite solar cell, it can achieve a photoelectric conversion efficiency of >24% without doping. At the same time, the photoelectric conversion efficiency of the device does not decrease significantly after long-term ultraviolet irradiation, and it has strong anti-ultraviolet radiation performance and broad application prospects. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a typical perovskite solar cell device provided by the present invention; Figure 2 Mass spectrum (a) and 1H NMR spectrum (b) of 4PAClPL-C4Cl prepared in Example 1. Figure 3 Mass spectrum (a) and 1H NMR spectrum (b) of 4PA-ClPL prepared in Synthesis Example 1; Figure 4 Mass spectrum (a) and 1H NMR spectrum (b) of SAM25 prepared in Synthesis Example 1; Figure 5 Mass spectrum (a) and 1H NMR spectrum (b) of PhPL-C4Cl prepared in Synthesis Example 2; Figure 6 Mass spectrum (a) and 1H NMR spectrum (b) of PhPL-C4PA prepared in Synthesis Example 2; Figure 7 Mass spectrum (a) and 1H NMR spectrum (b) of SAM26 prepared in Synthesis Example 2; Figure 8 The JV curves are for the perovskite solar cell devices prepared in Application Example 1 and Application Example 2 of this invention. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below. The present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used is for describing particular embodiments only and is not intended to limit the invention.

[0024] This invention provides a compound based on a purine polycyclic skeleton, the compound having the structural formula shown in formula (I):

[0025] Wherein, X is any one of halogen atoms, R1 group, -OR2 group, -SR2 group, -NHR2 group, -N(R2)2 group, and Ar group; Y is selected from hydrogen, halogen, C1-C3 alkyl, trifluoromethyl, perfluoroalkyl, trialkylsilyl, C6-C 40 Substituted or unsubstituted aryl groups, C4-C 40 Any one of the heteroaryl groups; L is selected from C1-C4 alkyl groups, -(CH2CH2O) n - any of the phenyl groups, where n = 2-4; A is selected from either phosphoric acid or carboxylic acid; R1 is hydrogen, deuterium, tritium, cyano, haloalkyl, or C1-C. 40 Alkyl or heteroalkyl, C3-C 40 cycloalkyl, C2-C 40 Heterocyclic alkyl, C7-C 40 Aryl alkyl, C2-C 40 Any one of the heteroaryl alkyl groups; R2 is any one of hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, aryl, C1-C6 acyl, and aryl(C1-C6) alkyl; Ar is any one of substituted or unsubstituted aryl or heteroaryl groups.

[0026] Specifically, R1 is any one of hydrogen, deuterium, tritium, cyano, -CF3, methyl, ethyl, propyl, tert-butyl, cyclopentyl, cyclohexyl, methoxymethyl, methoxyethyl, benzyl, and phenethyl.

[0027] Specifically, R2 can be any one of hydrogen, methyl, ethyl, propyl, tert-butyl, allyl, ethynyl, aryl, acetyl, propionyl, benzyl, or phenethyl.

[0028] Specifically, Ar can be any one of the following structural formulas from Ar1 to Ar20:

[0029] The R3 group is independently selected from H, halogen group, -OR', -OCOR', -NHCOR', -NR'2, -R'; The R' group is selected from any one of hydrogen, substituted or unsubstituted phenyl, thiophene, and C1-C5 alkyl groups; The W group is selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2-), and R is -CH3 or -H.

[0030] More specifically, the compound is selected from at least one of the following SAM1 to SAM72 structures: .

[0031] It should be noted that the synthesis method of the compound based on the purine polycyclic skeleton provided by the present invention is not particularly limited, and any method known to those skilled in the art can be used for synthesis.

[0032] In some embodiments, the preparation of compounds based on purine polycyclic skeletons can be carried out using the methods shown in the following steps, but is not limited thereto: S1. Under the action of potassium carbonate, compounds based on the purine ring structure react with dihaloalkyl / aryl groups to generate alkyl / aryl halogenated products based on the purine ring structure. S2. Under inert gas conditions, the alkyl / aryl halide obtained in step S1 based on the purine ring structure reacts with triethyl phosphite to generate diethyl alkyl / aryl phosphonate based on the purine ring structure. S3. Under inert gas conditions, the alkyl / arylphosphonate diethyl ester based on the purine ring structure obtained in step S2 reacts with trimethylbromosilane and methanol to generate the target product, a compound based on the purine ring structure. In step S1, the alkyl group in the dihaloalkyl group is any one of C2 to C4, the halogen is substituted at both ends of the alkyl group, the alkyl group is preferably any one of C2 and C4, and the aryl group is a benzene ring.

[0033] More specifically, the synthetic route is as follows: .

[0034] The choices for X and L are as described above.

[0035] Specifically, in step S1, the molar ratio of the compound based on the purine ring structure, the dihaloalkyl / aryl group, and potassium carbonate is 1:(1~5):(1~2.5); preferably 1:(1~2):(1.2~1.5), and more preferably 1:(1~1.5):(1.2~1.5).

[0036] Specifically, in step S2, the molar ratio of the alkyl / aryl halide based on the purine ring structure to triethyl phosphite is 1:(2~20); preferably 1:(8~12), more preferably 1:(10~12).

[0037] Specifically, in step S3, the molar ratio of alkyl / arylphosphonate diethyl ester based on the purine ring structure to trimethylbromosilane is 1:(1~10), preferably 1:(2~5), and more preferably 1:(3~4).

[0038] Specifically, in step S3, the mass ratio of alkyl / arylphosphonate diethyl ester based on the purine ring structure to methanol is 1:(5~10).

[0039] Specifically, in step S1, the reaction temperature is 30~100℃ and the reaction time is 2~10 hours; preferably, the reaction temperature is 40~60℃ and the reaction time is 2~4 hours.

[0040] Specifically, in step S2, the reaction temperature is 120~180℃ and the reaction time is 2~10 hours; preferably, the reaction temperature is 140~170℃ and the reaction time is 4~8 hours; more preferably, the reaction temperature is 150~160℃ and the reaction time is 5~6 hours.

[0041] Specifically, in step S3, the reaction temperature is 40~80℃ and the reaction time is 2~10 hours; preferably, the reaction temperature is 50~70℃ and the reaction time is 4~8 hours; more preferably, the reaction temperature is 50~60℃ and the reaction time is 6~7 hours.

[0042] Specifically, in step S1, the solvent is at least one of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and dioxane; preferably DMF.

[0043] Specifically, in step S3, the solvent is at least one of dichloromethane, dichloroethane, toluene, dioxane, and methanol, preferably dichloromethane or dichloroethane, and more preferably dichloroethane.

[0044] More specifically, there are no particular restrictions on the synthesis methods of compounds based on purine ring structures; any method known to those skilled in the art can be used for synthesis.

[0045] In some embodiments, alkyl / aryl halides with a 6-chloropurine ring / 8-bromo-6-chloropurine ring structure are reacted with reactants containing an X group to obtain a series of compounds based on a purine ring structure; In some embodiments, alkyl / aryl halides with a 6-chloropurine ring / 8-bromo-6-chloropurine ring structure are subjected to a C-coupling reaction with boric acid or boron ester of X under palladium catalysis to prepare compounds with the target purine ring structure. In some embodiments, alkyl / aryl halides with a 6-chloropurine ring / 8-bromo-6-chloropurine ring structure undergo a nucleophilic reaction with a nucleophilic reagent (such as sodium methoxide) to generate a 6-alkoxypurine ring compound; In some embodiments, alkyl / aryl halides with a 6-chloropurine ring / 8-bromo-6-chloropurine ring structure are coupled with a nitrogen-containing compound X via a CN coupling reaction under palladium catalysis to prepare a compound with the target purine ring structure.

[0046] Understandably, when the CC coupling reaction occurs, the catalyst can be at least one of palladium acetate, Pb(PPh3)4, and Pb2(dba)3, preferably Pb(PPh3)4; the solvent can be one or two of toluene, dioxane, THF, and water, preferably toluene and water; the base used can be sodium carbonate, potassium carbonate, or sodium hydroxide, preferably potassium carbonate; the reaction temperature is 70~120℃, and the reaction time is 2~10h, preferably the reaction temperature is 90~110℃, and the reaction time is 5~8h.

[0047] When a nucleophilic substitution reaction occurs, the base used can be sodium carbonate, potassium carbonate, or sodium hydroxide, with potassium carbonate being preferred; the reaction temperature is 30~80℃, and the reaction time is 2~8h, with the preferred reaction temperature being 50~60℃ and the reaction time being 5~6h; the reaction solvent can be one of toluene, THF, dichloroethane, or dioxane, with THF being preferred.

[0048] When the CC coupling reaction occurs, the catalyst can be at least one of palladium acetate, Pb(PPh3)4, and Pb2(dba)3, with palladium acetate being preferred; the solvent can be one of toluene, xylene, and chlorobenzene, with toluene being preferred; the base can be sodium carbonate, potassium carbonate, sodium tert-butoxide, or potassium tert-butoxide, with potassium tert-butoxide being preferred; the reaction temperature is 70~120℃, and the reaction time is 2~10h, with the preferred reaction temperature being 90~110℃ and the reaction time being 5~8h.

[0049] The present invention also provides a self-assembled monolayer material, including compounds based on purine polycyclic skeletons provided in the present invention.

[0050] The present invention also provides a hole transport layer material, including the self-assembled monolayer material provided by the present invention.

[0051] The present invention also provides a perovskite solar cell device, wherein the perovskite solar cell includes a conductive glass substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a buffer layer, and a metal electrode.

[0052] Specifically, the hole transport layer includes the hole transport layer material provided by the present invention.

[0053] For convenience, the perovskite solar cell device of the present invention will be described below, but this does not imply any limitation on the scope of protection of the present invention. It is understood that all perovskite solar cell devices using the self-assembled monolayer material of the present invention are within the scope of protection of the present invention.

[0054] For example, Figure 1 This is a schematic diagram of a typical perovskite solar cell device. The hole transport layer (HTL) in the figure is provided by the self-assembled monolayer (SAM) material based on the purine polycyclic framework provided by this invention. The bottom electrode refers to ITO glass or FTO glass, the perovskite layer refers to the film layer obtained after spin coating of perovskite solution, the electron transport layer (ETL) refers to C60, and the back / top electrode refers to Cu.

[0055] The structure of a perovskite solar cell device, from bottom to top, is denoted as glass / hole transport layer / perovskite / C60 / BCP / Cu.

[0056] Specifically, the glass is either FTO glass or ITO glass, with FTO glass being preferred.

[0057] Specifically, the hole transport layer is a compound based on a purine polycyclic skeleton structure provided by this invention.

[0058] Specifically, BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, a hole-blocking material located between the back / top electrode and the electron transport layer.

[0059] Understandable. Figure 1 The structure of a typical perovskite solar cell device is shown only schematically. The present invention is not limited to this structure, and the hole transport layer material of the present invention can be used in any type of perovskite solar cell device.

[0060] There are no particular limitations on the method for preparing the perovskite solar cell device of the present invention, and any method known in the art can be used.

[0061] For example, in some embodiments, the method for fabricating perovskite solar cell devices according to the present invention may include, but is not limited to, the following steps: 1) Pretreatment and cleaning of FTO glass: FTO glass was ultrasonically cleaned for 20 min each time with cleaning agent, deionized water, ethanol and acetone, and then dried with nitrogen.

[0062] 2) Spin-coat a layer of hole transport material ethanol solution onto the FTO glass cleaned in step 1), and anneal it; wherein, the concentration of the hole transport material ethanol solution is 0.3~1.0mg / mL, the amount is 100~150μL; the spin-coating speed is 3000rpm~5000rpm; the annealing temperature is 100~120℃, and the annealing treatment is 10min.

[0063] 3) Spin-coat the perovskite solution onto the surface of the hole transport material and anneal it; the annealing temperature is 100~120℃ and the annealing time is 10min.

[0064] 4) C60 (10-20 nm), BCP (5-10 nm), and Cu (80 nm) were deposited on the perovskite surface to obtain a perovskite solar cell device with an effective area of ​​0.09 cm². 2 .

[0065] It should be noted that the compound based on the purine polycyclic framework structure provided by this invention is used as a hole transport layer in perovskite solar cell devices. The perovskite solar cell devices are prepared using the most traditional preparation method. The hole transport layer mentioned in this invention uses an undoped compound based on the purine polycyclic framework structure, and no other additives are added to the hole transport layer.

[0066] The present invention also provides an electrical device, including the perovskite solar cell device provided by the present invention.

[0067] To better illustrate the embodiments of the present invention, the present invention will be further described in detail below through specific examples.

[0068] The synthesis of compounds based on purine polycyclic skeletons is described in the following synthesis examples 1 to 17.

[0069] Synthesis Example 1 The synthetic route for compound SAM25 is shown below:

[0070] Specifically, the following steps are included: (1) Preparation of 4PAClPL-C4Cl: 46.4g of 6-chloropurine, 10.0g of KI, 62.1g of K2CO3 and 394.4g of DMF were added to a 1L three-necked flask in sequence. Stirring was started, and 1-bromo-4-chlorobutane (51.5g) of DMF solution was added dropwise at room temperature. After the addition was completed, the mixture was kept warm at 40~50℃ for 4h.

[0071] Post-processing: 112.8 g of water was added to the system to quench the reaction, 500 g of DCM was used for three extractions, the organic phase was washed with 100 g of water, dried with anhydrous sodium sulfate, and purified by column chromatography. The organic phase was eluted with DCM, and the column chromatography yielded a pale yellow oily liquid with a yield of 80.1% and a purity greater than 98.5%. The mass spectrum and 1H NMR spectrum of 4PAClPL-C4Cl obtained in this example are shown below. Figure 2 As shown in (a) and (b). 1 H NMR (400MHz, DMSO-) d 6): δ 8.80(s,1H),8.75(s,1H),4.30~4.10(m,2H),3.65(t,2H),2.05~1.95(m,2H),1.78~1.67(m,2H).

[0072] (2) Preparation of 4PA-ClPL: 14.7 g of 4PAClPL-C4Cl, 14.9 g of NaI, and 109.6 g of triethyl phosphite were added sequentially to a 250 mL three-necked flask, and the mixture was stirred and heated. The reaction was maintained at 150~155℃ for 6 h.

[0073] Post-processing: After incubation, the reaction system was subjected to reduced pressure to remove triethyl phosphite, yielding a crude product. The crude product was purified by column chromatography with gradient elution using ethyl acetate as the eluent. After column chromatography, the solvent was removed under reduced pressure to constant weight, yielding a yellow oily liquid with a yield >65.1% and purity of 95.1%. The mass spectrum and 1H NMR spectrum of 4PA-ClPL obtained in this example are shown below. Figure 3 As shown in (a) and (b). 1 H NMR (400 MHz, DMSO-) d 6): δ 8.68 (s, 1H), 8.67 (s, 1H), 4.28 (t, 2H), 3.90~3.88 (m, 4H), 1.95~1.88 (m, 2H), 1.77~1.68 (m, 2H), 1.45~1.36 (m, 2H), 1.12~1.09(t, 6H) 。

[0074] (3) Preparation of SAM25: Add 4.0g 4PA-CIPL, 5.6g TMSBr and 40.0g DCE to a 250mL three-necked flask, heat with stirring, and keep warm at 55~60℃ for 6.0h.

[0075] Post-processing: 20.0 g of CH3OH was added to the reaction system to quench the reaction. After quenching, the reaction system was transferred to a 250 mL single-necked flask, and the solvent was dissolved under reduced pressure to obtain crude SAM25. The crude product was reacted with sodium hydroxide solution to form a salt for reverse extraction, followed by acidification and slurrying with ethyl acetate to obtain refined SAM25, with a yield of 67.3% and a purity of 97.9%. The mass spectrum and 1H NMR spectrum of SAM25 obtained in this example are shown below. Figure 4 As shown in (a) and (b). 1 H NMR (400 MHz, D2O): 9.01 (s, 1H), 8.28 (s,1H),4.37 (t, 2H), 2.00~1.94 (m, 2H),1.78~1.69(m, 2H), 1.56~1.49 (m, 2H) 。

[0076] Synthesis Example 2 The synthetic route for compound SAM26 is shown below:

[0077] Specifically, the following steps are included: (1) Preparation of PhPL-C4Cl: 0.246g Pd(OAc)2, 0.903g PCYB, 0.1453g 18-C-6, and 600.0g dioxane were added to a 1.0L three-necked flask and stirred at room temperature. After stirring, 30.00g 4PACIPL-C4Cl and 13.4g (0.011mol) phenylboronic acid were added to the reaction system and stirred at room temperature for 15 min. Then, 23.5g K2CO3 powder was added. After the addition was complete, the mixture was kept warm at 90~95℃ for 6h.

[0078] Post-processing: 100.0 g of water was added to the reaction system to quench the reaction, followed by extraction with 300.0 g of DCM. The organic phase was dried over anhydrous sodium sulfate, and the organic phase was desolventized under reduced pressure to obtain the crude product. The crude product was then purified by alkaline washing and column chromatography using ethyl acetate and petroleum ether as eluents. The eluent was desolventized under reduced pressure to constant weight to obtain the pale yellow target product. Yield: 69.8%, Purity: 97.6%. The mass spectrum and 1H NMR spectrum of PhPL-C4Cl obtained in this example are shown below. Figure 5 As shown in (a) and (b). 1 HNMR (400 MHz, DMSO- d 6): δ 8.67 (s, 1H), 8.81~8.78 (m, 2H), 8.64 (s, 1H), 7.55~7.50 (m, 3H), 4.30 (t, 2H), 3.60 (t, 2H), 2.00~1.90 (m, 2H), 1.71~1.61 (m, 2H).

[0079] (2) Preparation of PhPL-C4PA: 18.8g PhPL-C4Cl, 14.9g NaI, and 109.6g triethyl phosphite were added sequentially to a 250mL three-necked flask, and the mixture was stirred and heated. The reaction was maintained at 150~155℃ for 6h.

[0080] Post-processing: After incubation, the reaction system was subjected to reduced pressure to remove triethyl phosphite, yielding a crude product. The crude product was purified by column chromatography with gradient elution using ethyl acetate as the eluent. After column chromatography, the solvent was removed under reduced pressure until constant weight was achieved, yielding a yellow oily liquid with a yield >70.2% and purity of 95.5%. The mass spectrum and 1H NMR spectrum of PhPL-C4PA obtained in this example are shown below. Figure 6 As shown in (a) and (b). 1 H NMR (400 MHz, DMSO-d6): δ 9.00 (s, 1H), 8.86 (t, 2H), 8.73 (s, 1H), 7.64~7.56 (m, 3H), 4.35 (t, 2H), 3.97~3.91 (m, 4H), 2.02~1.95(m, 2H), 1.84~1.75 (m, 2H), 1.51~1.40(m,2H), 1.20~1.130(m, 6H).

[0081] (3) Preparation of SAM26: Add 3.5g PhPL-C4PA, 35.0g DCE and 4.13g TMSBr to a 250 mL three-necked flask, heat with stirring, and keep the temperature at 55~60℃ for 6.0h.

[0082] Post-processing: 20.0 g of CH3OH was added to the reaction system to quench the reaction. After quenching, the reaction system was transferred to a 250 mL single-necked flask, and the solvent was removed under reduced pressure to obtain crude SAM26. The crude product was reacted with sodium hydroxide solution to form a salt for reverse extraction, followed by acidification and slurrying with ethyl acetate to obtain refined SAM26, with a yield of 59.5% and a purity of 98.2%. The mass spectrum and 1H NMR spectrum of SAM26 obtained in this example are shown below. Figure 7 As shown in (a) and (b). 1H NMR (400 MHz, DMSO-d6): δ 9.03 (s, 1H), 8.87(t, 2H), 8.78(s,1H),7.67~7.57 (m, 3H), 5.27(s,2H), 4.37(t, 2H), 2.04~1.96(m,2H), 1.63~1.46 (m, 4H).

[0083] Synthesis Example 3 This synthesis example uses the same method as in Example 1 to synthesize compound SAM1, except that in step (1), dibromoethane is used instead of 1-bromo-4-chlorobutane, and SAM1 is finally obtained with a purity of 97.2% and a yield of 55.2%. 1 H NMR (400 MHz, DMSO-d6): δ 8.62 (s, 1H), 8.32 (s, 1H), 4.40~4.36 (t, 2H), 2.48~2.44 (t, 2H).

[0084] Synthesis Example 4 This synthesis example uses the same method as Example 2 to synthesize compound SAM2, except that in step (1), dibromoethane is used instead of 1-bromo-4-chlorobutane to finally obtain SAM2 with a purity of 98.1% and a yield of 55.1%. 1 HNMR (400 MHz, DMSO-d6): δ 9.03 (s, 1H), 8.88~8.86 (t, 2H), 8.78(s,1H),7.67~7.57 (m, 3H), 5.27(s,2H), 4.40~4.36 (t, 2H),2.48~2.44 (t, 2H).

[0085] Synthesis Example 5 This synthesis example uses the same method as in Example 4 to synthesize compound SAM4, except that in step (2), 2-furanboronic acid is used instead of phenylboronic acid, and SAM4 is finally obtained with a purity of 97.5% and a yield of 45.1%. 1 H NMR (400MHz, DMSO-d6): δ 8.75 (s, 1H), 8.33 (s, 1H), 7.61~7.57 (m, 1H), 6.97 (dd, 1H), 6.68 (dd, 1H), 4.41 (td, 2H), 2.48 (dt, 2H).

[0086] Synthesis Example 6 This synthesis example uses the same method as in Example 4 to synthesize compound SAM8, except that in step (2), 4-phenylphenylboronic acid is used instead of phenylboronic acid, and SAM8 is finally obtained with a purity of 98.0% and a yield of 49.3%. 1 H NMR (400 MHz, DMSO-d6): δ 8.76 (s, 1H), 8.33 (s, 1H), 7.68~7.62 (m, 2H), 7.62~7.56(m, 2H), 7.56 ~7.49 (m, 2H), 7.48~ 7.41 (m, 2H), 7.41 ~7.33 (m, 1H), 4.41(td, 2H), 2.48 (dt, 2H) Synthesis Example 7 This synthesis example uses the same method as in Example 4 to synthesize compound SAM10, except that in step (2), carbazole is used instead of phenylboronic acid, potassium carbonate is replaced with sodium tert-butoxide, and the solvent is replaced with toluene. Finally, SAM10 is obtained with a purity of 97.5% and a yield of 41.2%. 1 H NMR (400 MHz, DMSO-d6): δ 8.53 (s, 1H), 8.26 (s, 1H), 8.24~8.18 (m, 2H), 7.73~7.66 (m, 2H), 7.43 (dd, 1H), 7.39 ~7.31 (m, 3H), 4.40 (td, 2H), 2.48 (dt, 2H).

[0087] Synthesis Example 8 This synthesis example uses the same method as in Example 4 to synthesize compound SAM14, except that in step (2), 1-pyrene boronic acid ester is used instead of phenylboronic acid, and SAM14 is finally obtained with a purity of 97.0% and a yield of 35.2%. 1 H NMR (400 MHz, DMSO-d6): δ 9.12 (s, 2H), 8.79 (s, 1H), 8.34~8.20 (m, 5H), 8.11~7.98 (m, 4H), 7.57 (dd, 1H), 4.24 (td, 2H), 1.99~1.85 (m, 4H), 1.80 ~1.69 (m, 2H).

[0088] Synthesis Example 9 This synthesis example uses the same method as Example 2 to synthesize compound SAM31, except that in step (2), 2-indolephenylboronic acid is used instead of phenylboronic acid, and SAM31 is finally obtained with a purity of 96.9% and a yield of 45.5%. 1HNMR (400 MHz, DMSO-d6): δ 9.84 (s, 1H), 9.12 (s, 2H), 9.00 (s, 1H), 8.31 (t, 1H), 7.48 (dd, 1H), 7.45~7.39 (m, 1H), 7.31 (s, 1H), 7.11 (dd, 1H), 7.04 (td,1H), 4.24 (td, J = 6.9, 0.9 Hz, 2H), 1.99~1.85 (m, 4H), 1.80~1.69 (m, 2H).

[0089] Synthesis Example 10 This synthesis example uses the same method as in Example 2 to synthesize compound SAM39, except that in step (2), 1-naphthoboric acid is used instead of phenylboronic acid, and SAM39 is finally obtained with a purity of 98.0% and a yield of 42.5%. 1H NMR (400MHz, DMSO-d6): δ 9.12 (s, 2H), 8.78 (s, 1H), 8.29 (s, 1H), 8.06~7.87 (m, 4H), 7.76~7.59 (m, 1H), 7.58~7.43 (m, 2H), 4.24 (td, 2H), 2.06~1.82 (m, 4H), 1.82~1.63 (m, 2H).

[0090] Synthesis Example 11 This synthesis example uses the same method as Example 2 to synthesize compound SAM40, except that in step (2), 4-diphenylaminophenylboronic acid is used instead of phenylboronic acid, and SAM40 is finally obtained with a purity of 97.5% and a yield of 39.5%. 1 HNMR (400 MHz, DMSO-d6): δ 9.12 (s, 2H), 8.76 (s, 1H), 8.25 (s, 1H), 7.85~7.79(m, 2H), 7.28 ~7.21 (m, 6H), 7.11~ 7.06 (m, 4H), 7.06~ 6.99 (m, 2H), 4.24(td, 2H), 1.99 ~ 1.85 (m, 4H), 1.80~1.69 (m, 2H).

[0091] Synthesis Example 12 This synthesis example uses the same method as Example 2 to synthesize compound SAM41, except that in step (2), 4-diphenylphosphine-phenylboronic acid is used instead of phenylboronic acid, and SAM41 is finally obtained with a purity of 97.1% and a yield of 29.5%. 1 HNMR (400 MHz, DMSO-d6): δ 9.12 (s, 2H), 8.76 (s, 1H), 8.25 (s, 1H), 7.86 (td,2H), 7.65~7.56 (m, 2H), 7.37~7.33 (m, 2H), 7.28~7.21 (m, 8H), 4.24 (t, 2H), 2.04~1.85 (m, 4H), 1.81~ 1.68 (m, 2H).

[0092] Synthesis Example 13 This synthesis example uses the same method as in Example 2 to synthesize compound SAM46, except that in step (2), 9H-oxanthracene boric acid is used instead of phenylboronic acid, and SAM46 is finally obtained with a purity of 96.2% and a yield of 25.5%. 1 HNMR (400 MHz, DMSO -d6): δ 9.12 (s, 2H), 8.72 (s, 1H), 8.21 (s, 1H), 7.34~7.26(m, 4H), 7.19 (td,2H), 7.01 (dd, 2H), 5.96 (d, 1H), 4.24 (t, 2H), 1.99 ~1.85 (m, 4H), 1.80 ~ 1.69 (m, 2H).

[0093] Synthesis Example 14 This synthesis example uses the same method as in Example 1 to synthesize compound SAM49, except that in step (1), p-dibromobenzene is used instead of 1-chloro-4-bromobutane, and nickel chloride is added as a catalyst during the reaction to finally obtain SAM49 with a purity of 98.0% and a yield of 41.0%. 1 H NMR (400 MHz, DMSO-d6): δ 9.87 (s, 2H), 8.64 (s, 1H), 8.62 (s, 1H), 7.95~7.88 (m, 2H), 7.67~7.61 (m, 2H).

[0094] Synthesis Example 15 This synthesis example uses the same method as Example 2 to synthesize compound SAM50, except that in step (1), p-dibromobenzene is used instead of 1-chloro-4-bromobutane, and nickel chloride is added as a catalyst during the reaction to finally obtain SAM50 with a purity of 97.8% and a yield of 49.2%. 1 H NMR (400 MHz, DMSO-d6): δ 8.86 (s, 1H), 8.61 (s, 1H), 7.96~7.86 (m, 2H), 7.69~7.64 (m, 2H), 7.61~7.53 (m, 2H), 7.39 (ddt,1H), 7.32~7.25 (m, 2H).

[0095] Synthesis Example 16 This synthesis example uses the same method as in Example 1 to synthesize compound SAM57, except that in step (1), 8-bromo-6-chloropurine is used instead of 6-chloropurine, and SAM57 is finally obtained with a purity of 97.0% and a yield of 39.2%. 1 HNMR (400 MHz, DMSO-d6): 1 H NMR (400 MHz, DMSO-) d 6): δ 8.80 (s, 1H), 8.75 (s, 1H), 4.30 ~ 4.10 (m, 2H), 3.65 (t, 2H), 2.05 ~ 1.95 (m, 2H), 1.78 ~ 1.67 (m, 2H).

[0096] Synthesis Example 17 This synthesis example uses the same method as Example 2 to synthesize compound SAM58, except that: in step (1), 8-bromo-6-chloropurine is used instead of 6-chloropurine to obtain the intermediate; in step (2), the reaction conditions are the same, but the amount of phenylboronic acid is increased to 2.2 eq, and finally SAM58 is obtained with a purity of 96.0% and a yield of 29.5%. 1 H NMR (400 MHz, DMSO-d6): δ 9.12 (s, 2H), 8.83 (s, 1H), 7.70 (dt, 2H), 7.62 ~7.52 (m, 4H), 7.52~7.46 (m, 1H), 7.42 ~ 7.35 (m, 1H), 7.33 ~7.25 (m, 2H), 4.30 (t, 2H), 1.99~1.85 (m, 4H), 1.81 ~1.70 (m, 2H).

[0097] Application Example 1 In this Example 1, the self-assembled single-molecule SAM25 hole transport material with a purine polycyclic framework prepared in Synthesis Example 1 is applied to an inverse perovskite solar cell device to fabricate a perovskite solar cell device: FTO / SAM25 / perovskite / C60 / BCP / Cu. The specific preparation steps are as follows: 1) Pre-treatment cleaning of FTO glass: FTO glass was ultrasonically cleaned for 20 minutes each with cleaning agent, deionized water, ethanol and acetone in sequence, and then dried with nitrogen.

[0098] 2) Spin-coat a layer of ethanol solution of the self-assembled monomolecule SAM25 hole transport material with a purine polycyclic backbone prepared in Example 1 onto the FTO glass cleaned in step 1). The concentration of the ethanol solution of the hole transport material is 0.3~1.0 mg / mL, and the amount used is 100~150 μL. The spin-coating speed is 3000 rpm~5000 rpm. Anneal at 100~120℃ for 10 min. Then wash off the excess 2PABZ on the surface with ethanol and anneal at 100~120℃ for 10 min.

[0099] 3) Spin-coat the perovskite solution onto the surface of the SAM25 hole transport material and anneal it at 100~120℃ for 10 min.

[0100] 4) After cooling, C60, BCP, and Cu electrodes are deposited on the surface of the perovskite thin film, respectively. Specifically, 10-20 nm of C60, 5-10 nm of BCP, and 80 nm of Cu electrode are deposited to obtain the perovskite solar cell device. The effective area of ​​the perovskite solar cell device is 0.09 cm². 2 .

[0101] Application Examples 2 to 17 Application Examples 2 to 17 use the same method as Application Example 1 to prepare perovskite solar cell devices, except that the hole transport layer material is replaced with SAM26, SAM1, SAM2, SAM4, SAM8, SAM10, SAM14, SAM31, SAM39, SAM40, SAM41, SAM46, SAM49, SAM50, SAM57, and SAM58 respectively, which are the same as Application Example 1.

[0102] Comparative Example 1 A perovskite solar cell device was prepared using poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) (molecular weight: 7000~10000, polydispersity: 1.8), a commonly used hole transport material, according to the preparation method in Example 1 of this invention.

[0103] Comparative Example 2 This comparative example uses the same method as Application Example 16 to prepare a perovskite solar cell device, except that the hole transport layer uses the material 2PACz to prepare a perovskite cell device.

[0104] A xenon lamp solar simulator was used for testing in accordance with the national standard IEC61215. A crystalline silicon solar cell was used to correct the light intensity to achieve a solar intensity of AM 1.5. The cell was connected to a digital source meter, and its photoelectric conversion efficiency was measured under illumination. The cells obtained in Application Examples 1-17 and Comparative Examples 1-2 were subjected to cell performance testing. The initial photoelectric efficiency and the photoelectric conversion efficiency after 50 hours of UV lamp (254nm) irradiation were tested. The test data results are shown in Table 1. The JV curves of the perovskite solar cell devices obtained in Application Example 1 and Application Example 2 are shown in Table 1. Figure 8 As shown.

[0105] Table 1 Performance test data of perovskite solar cell devices prepared in Application Examples 1-17 and Comparative Examples 1-2

[0106] As shown in Table 1, the self-assembled single-molecule SAM hole transport material with a purine polycyclic framework provided by this invention, when applied to perovskite solar cell devices, exhibits a significantly higher open-circuit voltage compared to 2PACz and PTAA as hole transport materials. Compared to PTAA as a hole transport material, the fill factor is significantly improved. The solar cell devices using the self-assembled single-molecule SAM hole transport material with a purine polycyclic framework all demonstrate a photoelectric conversion efficiency greater than 23%, with most exceeding 24%, representing a substantial improvement in photoelectric conversion efficiency. This indicates that the undoped self-assembled single-molecule SAM material based on a purine polycyclic framework provided by this invention exhibits excellent photoelectric performance when applied to perovskite solar cells, offering a new approach for the fabrication of hole transport layers in perovskite solar cell devices.

[0107] As shown in Table 1, after 50 hours of UV aging, the photoelectric conversion efficiency of different hole transport layer materials varied significantly. When PTAA was used as the hole transport material, the device efficiency decreased by approximately 25% after UV irradiation, while with 2PACz, the efficiency decreased by approximately 18%. However, when using self-assembled single-molecule SAM with a purine polycyclic framework as the hole transport material, the efficiency decrease was less than 10% after UV aging under the same conditions, demonstrating excellent UV resistance. This material exhibits a multi-site rivet effect, which significantly improves UV resistance, and its nitrogen atoms, rich in lone pair electrons, interact with the Pb atoms on the perovskite substrate. 2+The chemical bonds that form a strong multidentate coordination network that lock the lattice can effectively resist strong ultraviolet radiation and suppress the generation of radiation-induced deep-level defects.

[0108] In summary, the self-assembled monolayer (SAM) hole transport material based on a purine polycyclic framework proposed in this application can improve the photoelectric conversion efficiency and UV resistance of perovskite solar cells.

[0109] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are exhaustively listed. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0110] For those skilled in the art, various modifications and improvements can be made without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A compound based on a purine polycyclic skeleton, characterized in that, The compound has the structural formula shown in formula (I): Wherein, X is any one of halogen atoms, R1 group, -OR2 group, -SR2 group, -NHR2 group, -N(R2)2 group, and Ar group; Y is selected from hydrogen, halogen, C1-C3 alkyl, trifluoromethyl, perfluoroalkyl, trialkylsilyl, C6-C 40 Substituted or unsubstituted aryl groups, C4-C 40 Any one of the heteroaryl groups; L is selected from C1-C4 alkyl groups, -(CH2CH2O) n - any of the phenyl groups, where n = 2-4; A is selected from either phosphoric acid or carboxylic acid; R1 is hydrogen, deuterium, tritium, cyano, haloalkyl, or C1-C. 40 Alkyl or heteroalkyl, C3-C 40 cycloalkyl, C2-C 40 Heterocyclic alkyl, C7-C 40 Aryl alkyl, C2-C 40 Any one of the heteroaryl alkyl groups; R2 is any one of hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, aryl, C1-C6 acyl, and aryl(C1-C6) alkyl; Ar is any one of substituted or unsubstituted aryl or heteroaryl groups.

2. The compound based on a purine polycyclic skeleton according to claim 1, characterized in that, R1 is any one of hydrogen, deuterium, tritium, cyano, -CF3, methyl, ethyl, propyl, tert-butyl, cyclopentyl, cyclohexyl, methoxymethyl, methoxyethyl, benzyl, and phenethyl.

3. The compound based on a purine polycyclic skeleton according to claim 1, characterized in that, R2 is any one of hydrogen, methyl, ethyl, propyl, tert-butyl, allyl, ethynyl, aryl, acetyl, propionyl, benzyl, and phenethyl.

4. The compound based on a purine polycyclic skeleton according to claim 1, characterized in that, Ar can be any one of the following structural formulas from Ar1 to Ar20: The R3 group is independently selected from H, halogen group, -OR', -OCOR', -NHCOR', -NR'2, -R'; The R' group is selected from any one of hydrogen, substituted or unsubstituted phenyl, thiophene, and C1-C5 alkyl groups; The W group is selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2-), and R is -CH3 or -H.

5. The compound based on a purine polycyclic skeleton according to claim 1, characterized in that, The compound is selected from at least one of the following SAM1 to SAM72 structures: 。 6. A self-assembled monolayer material, characterized in that, This includes compounds based on a purine polycyclic skeleton as described in any one of claims 1-5.

7. A hole transport layer material, characterized in that, Including the self-assembled monolayer material as described in claim 6.

8. A perovskite solar cell, characterized in that, The perovskite solar cell includes a conductive glass substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a buffer layer, and a metal electrode.

9. A perovskite solar cell device according to claim 8, characterized in that, The hole transport layer comprises the hole transport layer material of claim 7.

10. An electrical appliance, characterized in that, Includes the perovskite solar cell device according to any one of claims 8-9.

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