Self-assembled hole transport materials containing phenanthrotriazole moieties, synthesis methods and applications

Abstract

The invention provides a self-assembled hole transport material containing phenanthrotriazole motifs, a synthesis method and an application thereof. Phenanthrotriazole is selected as a mother core and a phosphonic acid motif is selected as an anchoring group, wherein the phenanthrotriazole has a larger conjugated plane, which is beneficial to the stacking and charge transport between molecules, and due to the introduction of triazole, the whole molecule has a larger dipole moment relative to carbazole, which is beneficial to the transport of charges to a substrate. The self-assembled hole transport material is used as a self-assembled hole selection material for an inverted perovskite solar cell, has good solubility and wettability, is suitable for large-scale solvent processing, and can be used as a self-assembled hole selection material for an inverted perovskite solar cell.

Description

Technical Field

[0001] The invention relates to the field of novel self-assembled hole selection materials for trans-perovskite solar cells, and in particular to a self-assembled hole transport material containing phenanthrotriazole moieties, a synthesis method and an application thereof. Background Art

[0002] Energy is the foundation of the development of human civilization and the driving force for the rapid growth of the world economy. At present, the global energy supply is accelerating its transformation to new energy. Clean, low-carbon, safe, efficient and sustainable are its distinctive features. The new energy sources that have been developed and utilized include nuclear energy, wind energy, hydropower, geothermal energy and solar energy. Of course, their use also has limitations, such as: thermal pollution accompanied by nuclear reactions in nuclear power generation, improper handling of nuclear waste will cause air crash consequences; wind energy and hydropower are restricted by natural factors such as ecology and geography, and it is difficult to promote and utilize them on a large scale. Solar energy has always been the most important source of energy for mankind. The energy of sunlight reaching the earth's surface every year reaches 1.5×10 18 kW·h, which is about 10,000 times more than the energy required by the entire earth. As one of the core technologies for the development of new renewable energy, photovoltaic technology has become an international key and cutting-edge research field. However, due to the constraints of the photoelectric conversion efficiency and cost of photovoltaic devices, the use of solar energy currently accounts for only 2% of the world's energy supply.

[0003] Perovskite Solar Cells (PSCs), as a new type of third-generation solar cell, have attracted extensive attention from many scientists and companies due to their low cost and high efficiency. In just over a decade, the certified photoelectric conversion efficiency (PCE) of a single perovskite solar cell has rapidly increased from 3.9% to 26.7%, which is comparable to crystalline silicon solar cells.

[0004] Hole transport materials (HTMs) are an important component of PSCs and play a key role in the efficiency and stability of the battery. In trans-PSCs, the quality of perovskite films is largely determined by the hole transport materials, and the selection or design of HTMs is particularly important for the device performance. At present, the classical hole transport materials widely used in high-efficiency perovskite solar cells are 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA). Such hole transport materials have the advantages of energy level matching and excellent hole transport performance. Among them, PTAA is the most commonly used HTMs in high-efficiency trans-PSCs, but its synthesis steps are complicated and the cost is high; as a polymer, the batch difference is large, which is not conducive to the reproducible optimization of device performance. At the same time, PTAA itself has poor conductivity, and P-type dopants and additives are needed to improve the conductivity of the hole transport layer, such as 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone (F4TCNQ), lithium bis(trifluoromethanesulfonimide) (Li-TFSI), etc. The use of these dopants and additives not only reduces the stability of the battery, but also further increases the production cost of the battery, limiting its practicality in industrial production.

[0005] Therefore, in order to promote the large-scale commercialization of efficient and low-cost trans-PSCs, it is urgent to develop inexpensive, readily available, and high-mobility self-assembled hole transport materials. Summary of the invention

[0006] The purpose of the present invention is to provide a self-assembled hole transport material containing phenanthrotriazole motifs, a synthesis method and an application thereof. The phenanthrotriazole motifs are used as the parent core, have a larger dipole moment and a larger conjugated plane, improve the efficiency and quality of charge transport, are suitable for large-scale solvent processing, and can be used as a self-assembled hole selection material for inverse perovskite solar cells.

[0007] To achieve the above objectives, the present technical solution provides a self-assembled hole transport material containing a phenanthrotriazole moiety, which can be used as a self-assembled hole selection material for a trans-perovskite solar cell. The phenanthrotriazole moiety is a parent core, and the phosphonic acid moiety is an anchoring group. The chemical structure is shown in the following formula (I):

[0008]

[0009] Wherein R1 and RR2 are independently selected from any one of the following groups: hydrogen, chain alkyl, chain alkenyl, chain alkynyl, chain alkoxy, cyclic alkyl, cyclic alkenyl, cyclic alkoxy, aryl, heteroaryl, wherein the group contains substituents or does not contain substituents.

[0010] When R1 and R2 are chain alkyl groups, the chain alkyl group is selected from methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl, eicosyl, tricosyl or tetracosyl groups which may or may not contain substituents.

[0011] When R1 and R2 are chain alkenyl groups, the chain alkenyl groups are selected from vinyl, propenyl, butadienyl, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tetradecene, hexadecene and heptadecene, which may contain substituents or not.

[0012] When R1 and R2 are chain alkynyl groups, the chain alkynyl group is selected from propynyl, butadiynyl, pentyn, hexyn, heptyn, octyne, nonyn, decyn, undecyn, tridecyn, tetradecyn, pentadecyn and hexadecane, which may contain substituents or not.

[0013] When R1 and R2 are chain alkoxy groups, the chain alkoxy groups are selected from C1-C16 alkoxy groups which may have substituents or not.

[0014] When R1 and R2 are cyclic alkyl groups, the cyclic alkyl group is selected from cyclopentyl, cyclohexyl and cyclooctyl groups which may or may not contain substituents.

[0015] When R1 and R2 are cyclic alkenyl groups, the cyclic alkenyl groups are selected from cyclopentene, cyclooctene, cycloheptatriene, cyclooctatetraene, and cyclododecene, which may contain substituents or not.

[0016] When R1 and R2 are cyclic alkoxy groups, the cyclic alkoxy groups are selected from propylene oxide groups, epoxyhexyl groups, epoxypentyl groups, dioxolane groups, and dioxane groups, which may contain substituents or not.

[0017] When R1 and R2 are heteroaryl, the heteroaryl is selected from thienyl, furyl, pyrrolyl, pyridyl, and quinolyl, which may or may not contain a substituent.

[0018] The substituents mentioned in the above hydrogen, chain alkyl, chain alkenyl, chain alkynyl, chain alkoxy, cyclic alkyl, cyclic alkenyl, cyclic alkoxy, aryl, and heteroaryl are selected from methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, hydroxyl, carboxyl, mercapto, fluorine atom, chlorine atom, bromine atom, cyano, amino, aldehyde group or one of them.

[0019] As a preferred solution, the phenanthrotriazole-containing moiety of this solution has good self-assembly and π-π stacking properties, and the structures of the self-assembled hole transport materials are shown in the following NPA-1 to NPA-4:

[0020]

[0021] Regarding the self-assembled hole transport material of NPA-1, a substituent-free phenanthrotriazine core, it can be used to study the intrinsic properties of the molecule.

[0022] Regarding the self-assembled hole transport material of NPA-2, this material introduces electron-donating methyl substituents at the 6,9-positions of the parent core to study the regulation of molecular energy levels.

[0023] Regarding the self-assembled hole transport materials of NPA-3 and NPA-4, methoxy groups were introduced at different sites of the parent nucleus to study and compare the influence of the positioning group effect on the electron cloud distribution and dipole moment of the molecular parent nucleus, and then to study the hole transport performance of the molecule.

[0024] In a second aspect, the present solution provides an inverted perovskite solar cell, using the self-assembled hole transport material containing phenanthrotriazole moieties mentioned in the first aspect as a self-assembled hole selection material.

[0025] Since the self-assembled hole transport material containing phenanthrotriazole moieties chooses phenanthrotriazole moieties as the mother core, the phenanthrotriazole moieties have a larger conjugated plane, which makes the molecular stacking more compact, which is conducive to the transfer of charge. At the same time, due to the introduction of triazole, the material has a larger dipole moment, which means that the charge is more easily transferred from the material to the bottom electrode, thereby enhancing the charge transfer performance in the self-assembled hole transport material; using the phosphonic acid moieties as anchoring groups can effectively promote the strong bonding between the self-assembled hole transport material and the substrate of the trans-perovskite solar cell, ensuring the stability and functionality of the material. The phenanthrotriazole moieties in the self-assembled hole transport material containing phenanthrotriazole moieties of this scheme have a rigid conjugated plane, and the phenanthrotriazole moieties are modified by groups to regulate the conjugated area and steric hindrance of the conjugated plane. The alkylphosphonic acid as an anchoring group promotes the self-assembled hole transport material to completely cover and bond with the substrate of the trans-perovskite solar cell.

[0026] The structure of the inverted perovskite solar cell is substrate / SAM / perovskite / ETL / electrode from bottom to top, wherein the substrate includes but is not limited to any rigid or flexible substrate such as ATO, ITO, FTO, IZO, CIGS, NiOx, SnO2, ZnO, n-Si, p-Si or PET, and the ETL includes but is not limited to C60, PC 61 BM, PC 71Any single or multiple organic or inorganic material such as BM, BCP, SnO2 or TiO2; the electrode includes but is not limited to any conductive material such as Au, Ag, Cu or Al, and a self-assembled hole transport material containing phenanthrotriazole moieties is used as the SAM layer of the inverse perovskite solar cell.

[0027] In a third aspect, the present invention provides a method for synthesizing a self-assembled hole transport material containing a phenanthrotriazole moiety as described in the first aspect, comprising the following steps:

[0028] Step 1: reacting a phenanthrenequinone monomer of the structural formula (1) with hydroxylamine hydrochloride to obtain a phenanthrene-9,10-dione dioxime monomer of the structural formula (2);

[0029] Step 2: subjecting a phenanthrene-9,10-dione dioxime monomer having a structural formula as shown in formula (2) to a reduction reaction to obtain a phenanthrene-9,10-diamine compound having a structural formula as shown in formula (3);

[0030] Step 3: reacting a phenanthrene-9,10-diamine compound having a structural formula as shown in formula (3) with sodium nitrite to obtain a phenanthrene-triazole compound having a structural formula as shown in formula (4);

[0031] Step 4: reacting a phenanthrotriazole compound having a structural formula as shown in formula (4) with 1,4-dibromobutane to obtain a bromobutane-substituted phenanthrotriazole compound having a structural formula as shown in formula (5);

[0032] Step 5: reacting a phenanthrotriazole derivative substituted with butane having a structural formula as shown in formula (5) with triethyl phosphite to obtain a phenanthrotriazole derivative phosphonate having a structural formula as shown in formula (6);

[0033] Step 6: hydrolyze the phenanthrotriazole phosphonate derivative with the structural formula shown in formula (6) to obtain a self-assembled hole transport material containing a phenanthrotriazole moiety with the structural formula shown in formula (I).

[0034] The reaction process of the synthesis method of the self-assembled hole transport material containing phenanthrotriazole moieties is as follows:

[0035]

[0036] It should be noted that the steps of synthesizing the self-assembled hole transport material containing phenanthrotriazole moieties in this scheme include oximation, reduction, cyclization to form triazole, bromination, phosphonation and hydrolysis, thereby obtaining the self-assembled hole transport material containing phenanthrotriazole moieties.

[0037] Preferably, the reaction of the phenanthrenequinone monomer of formula (1) in step 1 and hydroxylamine hydrochloride is carried out in a reaction solvent under the catalysis of an organic base, wherein the organic base is selected from triethylamine, pyridine, N,N,N,N-tetramethylethylenediamine, and the organic base is preferably pyridine, wherein the reaction solvent is selected from methanol, ethanol, isopropanol, and the reaction solvent is preferably ethanol.

[0038] Preferably, the reaction conditions of step 1 are: reaction time of 1-24 hours, reaction temperature of 0-90° C. Preferably, the reaction time is 3 hours.

[0039] Preferably, the reduction reaction of the phenanthrene-9,10-dione dioxime monomer of the structural formula of step 2 is carried out in a reaction solvent under the protection of an inert gas, wherein the inert gas can be selected as nitrogen or argon, and the reaction solvent can be selected as methanol, ethanol, N,N-dimethylformamide, and the reaction solvent is preferably ethanol.

[0040] In order to complete the reduction of phenanthrene-9,10-dione dioxime monomers, the reaction of step 2 requires the addition of a reducing agent, wherein the reducing agent is selected from borane tetrahydrofuran and palladium / carbon, and the reducing agent is preferably palladium / carbon.

[0041] Preferably, the reaction conditions of step 2 are: reaction time of 1-24 hours, reaction temperature of 0-90° C. Preferably, the reaction time is 2 hours.

[0042] Preferably, in step 3, a phenanthrene-9,10-diamine compound having a structural formula as shown in formula (3) is subjected to a ring-closing reaction with sodium nitrite to obtain a phenanthrene-triazole compound having a structural formula as shown in formula (4), and the ring-closing reaction is carried out in a reaction solvent under the protection of an inert gas. The inert gas can be selected as nitrogen or argon, and the reaction solvent can be selected as hydrochloric acid, sulfuric acid, or acetic acid, and the reaction solvent is preferably acetic acid.

[0043] In order to complete the ring closure, the reaction in step 3 requires the addition of a diazo reagent, wherein the added reagent is sodium nitrite or potassium nitrite, and the added reagent is preferably sodium nitrite.

[0044] Preferably, the reaction of the phenanthrotriazole compound of step 4 shown in formula (4) with 1,4-dibromobutane should be carried out in a reaction solvent under the protection of an inert gas, wherein the inert gas can be selected as nitrogen or argon, and the reaction solvent can be selected as N,N-dimethylformamide, dichloromethane, or chloroform, and the reaction solvent is preferably N,N-dimethylformamide.

[0045] Preferably, the reaction of the phenanthrotriazole compound and 1,4-dibromobutane in step 4 requires the addition of a base to promote the reaction, wherein the base is selected from sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium hydride, and the base is preferably sodium hydride.

[0046] Preferably, the reaction of the bromobutane-substituted phenanthrotriazole-based chemical with triethyl phosphite in step 5 is carried out in a reaction solvent under the protection of an inert gas, wherein the inert gas can be nitrogen or argon, and the reaction solvent is the esterification reactant triethyl phosphite.

[0047] Preferably, the reaction conditions of step 5 are: reaction time of 1-24 hours, reaction temperature of 80-180° C. Preferably, the reaction time is 10 hours.

[0048] Preferably, in step 6, the hydrolysis reaction of hydrolyzing the phenanthrotriazole phosphonate derivative having the structural formula shown in formula (6) is carried out in a reaction solvent under the protection of an inert gas. The inert gas may be nitrogen or argon, and the reaction solvent may be tetrahydrofuran, 1,4-dioxane, toluene, N,N-dimethylformamide, or n-hexane, and the reaction solvent is preferably 1,4-dioxane.

[0049] In order to achieve hydrolysis, the hydrolysis reaction in step 6 requires the addition of a hydrolysis catalyst and a reaction quenching agent, wherein the hydrolysis catalyst is trimethylsilyl bromide and the reaction quenching agent is methanol.

[0050] Preferably, the reaction conditions of step 6 are: reaction time of 1-48 hours, reaction temperature of 0-40° C. Preferably, the reaction time is 20 hours.

[0051] Compared with the prior art, this technical solution has the following characteristics and beneficial effects:

[0052] About the structure: The self-assembled hole transport material containing phenanthrotriazole motif provided by the present invention uses phenanthrotriazole motif with a rigid conjugated plane as the mother core, which gives the molecule good charge transport properties and stability, and can modify the phenanthrotriazole motif to regulate the conjugated area and steric hindrance of the conjugated motif, thereby promoting π-π stacking between single molecules, thereby facilitating the transmission of holes; using the phosphonic acid motif as the anchoring group, the self-assembled hole selection material is completely covered and bonded on the substrate surface. It should be noted that this scheme emphasizes the selection of phenanthrotriazole motif as the mother core, which has a larger conjugated plane and dipole moment than carbazole, is conducive to the stacking and charge transfer between molecules, and the introduction of triazole brings a larger dipole moment, which is conducive to the transmission of charges to the substrate; relative to the benzotriazole mother core, it also has a larger conjugated plane.

[0053] About the preparation method: The present invention adopts simplified synthesis steps, mild synthesis conditions, low cost of substrates and catalysts, simple post-treatment, and high yield of target products. The synthesized self-assembled hole transport material containing phenanthrotriazole moieties is used as a self-assembled hole selection material for a trans-perovskite solar cell to obtain an energy conversion efficiency of >18%. Therefore, the phosphonic acid derivative of phenanthrotriazole of the present invention as a self-assembled hole selection material for a trans-perovskite solar cell promotes charge transfer and improves the energy conversion efficiency and stability of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is the hydrogen spectrum of M2 prepared by the present invention.

[0055] Figure 2 This is the hydrogen spectrum of M3 prepared in the present invention.

[0056] Figure 3 This is the hydrogen spectrum of M4 prepared in the present invention.

[0057] Figure 4 This is the hydrogen spectrum of M5 prepared in the present invention.

[0058] Figure 5 It is the carbon spectrum of M5 prepared by the present invention.

[0059] Figure 6 It is the phosphorus spectrum of M5 prepared by the present invention.

[0060] Figure 7 This is the hydrogen spectrum of NPA-1 prepared in the present invention.

[0061] Figure 8 It is the carbon spectrum of NPA-1 prepared by the present invention.

[0062] Fig. 9 It is the phosphorus spectrum of NPA-1 prepared by the present invention.

[0063] Fig.10 Density functional theory calculations for NPA-1 prepared in the present invention.

[0064] Fig.11 This is a cross-sectional view of the preparation of the perovskite film according to the present invention.

[0065] Fig.12 JV curve of NPA-1 prepared in the present invention used as a hole transport material for perovskite solar cells. DETAILED DESCRIPTION

[0066] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0067] Example 1: Synthesis of NPA-1:

[0068]

[0069] Synthesis of intermediate M1:

[0070] Compound M0 (14.4 mmol) and pyridine (9 mL) were added to a 250 mL two-necked flask in sequence, and anhydrous ethanol (150 mL) was added to the reaction flask. After reflux reaction at 90 ° C for 3 h, heating was stopped, and the solvent of the reaction system was vacuum dried. After drying, methanol (10 mL) and deionized water (100 mL) were added to obtain a mixture, and then the obtained mixture was filtered under reduced pressure, and the filter cake was dried to obtain a crude product M1, which was directly used for the next step of reaction.

[0071] Synthesis of intermediate M2:

[0072] Anhydrous ethanol (60 mL) was added to a 250 mL double-necked flask, and M1 (6.3 mmol) was added to the reaction flask after stirring at room temperature for 30 min under a nitrogen environment, and the temperature was raised to 90 ° C for reaction, and then Pd / C (0.75 g) was added to the reaction flask and stirred for 10 min. A mixed solution of hydrazine monohydrate (15 mL) and anhydrous ethanol (15 mL) was then added dropwise to the reaction system, and heated to reflux for 24 h. After the reaction was completed, the reaction system was filtered, and the obtained clear liquid was poured into ice water (500 mL) and floccules were produced. The obtained mixture was then filtered under reduced pressure, and the filter cake was dried to obtain brown powder M2 (660 mg, 3.2 mmol) with a yield of 50%.

[0073] The H NMR spectrum of the intermediate M2 prepared by the above method is as follows: Figure 1 As shown: 1 H NMR (600MHz, DMSO-d6) δ 8.66 (d, J = 8.2 Hz, 2H), 8.02 (d, J = 8.3 Hz, 2H), 7.52 (t, J = 7.5 Hz, 2H), 7.38 (t, J = 7.5 Hz, 2H), 4.96 (s, 4H).

[0074] Synthesis of intermediate M3:

[0075] Add intermediate M2 (3.2 mL) and acetic acid (50 mL) to a 250 mL two-necked flask, stir at room temperature for 10 min, then add an aqueous solution (3 mL) of sodium nitrite (8.0 mmol) dropwise to the reaction system. Stir the reaction at room temperature for 2 h. After the reaction is completed, pour the reaction solution into ice water (150 mL) to obtain a suspended reaction solution. The reaction solution is filtered under reduced pressure, and the filter cake is dried to obtain a light yellow powder M3 (440 mg, 2.0 mmol) with a yield of 63%.

[0076] The H NMR spectrum of the intermediate M3 prepared by the above method is as follows: Figure 2 As shown: 1 H NMR (500MHz, DMSO-d6) δ8.87 (d, J = 7.7Hz, 2H), 8.49–8.28 (m, 2H), 7.81–7.72 (m, 4H).

[0077] Synthesis of intermediate M4:

[0078] Under nitrogen ice bath conditions, intermediate M3 (1.5mmol) and N,N-dimethylformamide (8mL) were added to a 50mL two-necked flask, and sodium hydride (9.6mmol) was added to the reaction body in batches. The reaction was stirred at room temperature for 1h. Then 1,4-dibromobutane was added to the reaction solution and reacted at room temperature for 4h. After the reaction was completed, methanol was dropped into the reaction solution under ice bath conditions to quench the reaction. The extraction reaction system was then washed with dichloromethane and water, the organic phases were combined, and the crude product obtained by spin drying was separated by silica gel column chromatography, the eluents were petroleum ether and ethyl acetate, and the product M4 was separated and purified as a white powder (425mg, 0.85mmol), with a yield of 80%.

[0079] The H NMR spectrum of the intermediate M4 prepared by the above method is as follows: Figure 3 As shown: 1 H NMR(600MHz, CDCl3-d)δ8.60(d,J=7.9Hz,2H),8.50(d,J=6.9Hz,2H),7.69–7.64(m,4H),4 .79(t,J=6.8Hz,2H), 3.48(t,J=6.5Hz,2H), 2.33(p,J=7.0Hz,2H), 1.98(q,J=7.0Hz,2H).

[0080] Synthesis of intermediate M5:

[0081] Compound M4 (1.0 mmol) was added to a 25 mL Schlenk reaction bottle and replaced with argon three times, after which triethyl phosphite (4 mL) was injected into the reaction bottle. The reaction was carried out at 160 ° C for 10 h, and the reaction was stopped after TLC monitoring. The reaction solution was directly dried with a vacuum rotary evaporator. The crude product obtained by drying was separated by silica gel column chromatography, with petroleum ether and acetone as eluents, and the product M5 was separated and purified as a white solid (370 mg, 0.9 mmol), with a yield of 90%.

[0082] The intermediate M5 prepared by the above method was characterized by hydrogen, carbon and phosphorus NMR spectra. Figures 4 to 6 As shown: 1 H NMR (600MHz, CDCl3-d) δ8.59(d,J=8.2Hz,2H),8.49(d,J=7.0Hz,2H),7.65(q,J=7.0,6.2Hz,4H),4.77(t,J=7.0 Hz,2H),4.10–4.03(m,4H),2.27(p,J=7.1Hz,2H),1.87–1.81(m,2H),1.76–1.71(m,2H),1.27(t,J=7.1Hz,6H). 13 C NMR (151MHz, CDCl3-d) δ141.00,130.33,127.60,124.62,123.69,123.53,61.56,55.22,30.80,25.50,24.57,19.75,16.40. 31 P NMR (243MHz, CDCl3-d) δ 31.28, where Figure 4 The upper left corner is the H NMR spectrum. Figure 4 The upper right corner is the carbon spectrum. Figure 4 The figure below is the phosphorus spectrum.

[0083] Synthesis of compound NPA-1:

[0084] Compound M5 (1.0 mmol) was added to a 25 mL Schlenk reaction bottle in sequence and replaced with argon three times, after which ultra-dry 1,4-dioxane (8 mL) was injected into the reaction bottle. Trimethylsilyl bromide (1 mL) was slowly added dropwise to the reaction bottle at room temperature, and the reaction was stirred overnight at room temperature. The reaction was completed by TLC monitoring and the reaction was stopped. The reaction solution was directly dried with a vacuum rotary evaporator. Methanol solution (10 mL) and purified water (5 mL) were added dropwise to the obtained solid system, and the reaction system was a white suspension, which was stirred overnight at room temperature. The obtained white suspension was filtered at normal pressure, and the white solid was washed and dried with purified water to obtain compound NPA-1 as a white powder (320 mg, 0.9 mmol) with a yield of 90%.

[0085] The NMR hydrogen spectrum, carbon spectrum and phosphorus spectrum of the compound NPA-1 prepared by the above method are as follows: Figures 7 to 9 As shown: 1 H NMR (600MHz, DMSO-d6) δ8.81(d,J=9.3Hz,2H),8.45–8.40(m,2H),7.76–7.71(m,4H),4.79(t,J=7.0Hz,2H),2.15(p,J=7.1Hz,2H),1.63–1.52(m,4H). 13 C NMR (151MHz, DMSO-d6) δ140.42,130.15,128.58,128.46,124.83,124.29,123.51,55.77,30.98,30.87,27.95,27.05,20.60. 31 P NMR(243MHz,DMSO-d6)δ25.83.HRMS(ESI)Calcd.for C 18 H 18 N3O3P:356.1164,found 356.1168.

[0086] Test Example 1:

[0087] The molecular optimization and density functional theory (DFT) calculations of NPA-1 were performed as Fig.10 As shown in the figure, the calculation results show that the conjugated skeleton of NPA-1 is on one plane, and there is no angle between the conjugated ring planes. The whole molecule has a large dipole moment (1.31D), which is conducive to the stacking of molecules and the charge transfer between molecules and interfaces.

[0088] Test example: Preparation and characterization of perovskite devices

[0089] The NPA-1 prepared in Example 1 was used as a self-assembled hole selection material to prepare an inverted perovskite solar cell. Fig.11 As shown, the structure of the inverse perovskite solar cell is glass / ITO / SAM / perovskite / C 60 / BCP / Ag. The ITO conductive glass was ultrasonically cleaned with glass cleaning agent, acetone and isopropanol for 30 min in sequence. The ITO glass was blown clean with a nitrogen gun and then plasma cleaned for 15 min. The NPA-1 obtained in Example 1 was used as the hole selective contact layer to prepare a solution with a concentration of 0.6 mg mL -1 ethanol / NN-dimethylformamide solution (volume ratio of 4:1), 80 μL of NPA-1 solution was pipetted onto the ITO glass, rotated at 3000 rpm for 30 seconds, and thermally annealed at 130°C for 20 minutes.0.05 MA 0.05 FA 0.9 PbI 2.95 Br 0.05 The perovskite solution was spin-coated onto the NPA-1 surface and thermally annealed at 110°C for 20 min. After cooling, 40 nm C 60 Finally, 120nm of Ag was vacuum-evaporated as the top electrode to complete the preparation of the inverse perovskite solar cell device with an effective area of ​​0.095cm 2 The xenon lamp solar simulator was used and the test light intensity was AM 1.5G (100mW cm -2 ), the open circuit voltage, short circuit current and fill factor of inverse perovskite solar cell devices were tested.

[0090] Based on the NPA-1 prepared in Example 1, an inverse perovskite solar cell device was prepared and characterized according to the above method. The current-voltage (JV) characteristic curve of the cell device performance is shown in Fig.12 , where the open circuit voltage (V oc ) is 1.116V, the short-circuit current density J sc 24.48 mA cm -2 , the filling factor FF is 0.694, and the photoelectric conversion efficiency is 18.84%.

[0091] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

[0092] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A self-assembled hole transport material containing a phenanthrotriazine unit, used as a self-assembled hole selection material for an inverse perovskite solar cell, characterized in that: The chemical structures of the self-assembled hole transport materials containing phenanthrotriazole moieties as the parent core and phosphonic acid moieties as the anchoring groups are shown in the following NPA-1 to NPA-4:

2. An inverted perovskite solar cell, characterized in that: The self-assembled hole selection material adopts the self-assembled hole transport material containing phenanthrotriazole moieties as claimed in any one of claim 1.

3. The inverted perovskite solar cell according to claim 2, characterized in that: Self-assembled hole transport materials containing phenanthrotriazole moieties as SAM layers for inverse perovskite solar cells.

4. The inverted perovskite solar cell according to claim 2, characterized in that: The phenanthrotriazole motif has a modifiable conjugated plane. The phenanthrotriazole motif is modified by groups to regulate the conjugated area, charge density, solubility and steric hindrance of the conjugated plane. The alkylphosphonic acid as an anchoring group promotes the anchoring and bonding of the self-assembled hole transport material to the substrate of the inverse perovskite solar cell.

5. A method for synthesizing the self-assembled hole transport material containing phenanthrotriazole moieties according to claim 1, characterized in that: The steps include: Step 1: reacting a phenanthrenequinone monomer with hydroxylamine hydrochloride to obtain a phenanthrene-9,10-dione dioxime monomer; Step 2: subjecting phenanthrene-9,10-dione dioxime monomers to a reduction reaction to obtain phenanthrene-9,10-diamine compounds; Step 3: reacting a phenanthrene-9,10-diamine compound with sodium nitrite to obtain a phenanthrene-triazole compound; Step 4: reacting the phenanthrotriazole compound with 1,4-dibromobutane to obtain a bromobutane-substituted phenanthrotriazole compound; Step 5: reacting the bromobutane-substituted phenanthrophenanthrotriazole with triethyl phosphite to obtain a phenanthrotriazole phosphonate derivative; Step 6: hydrolyze the phenanthrotriazole phosphonate derivative to obtain a self-assembled hole transport material containing a phenanthrotriazole moiety.

6. The method for synthesizing the self-assembled hole transport material containing phenanthrotriazole moieties according to claim 5, characterized in that: The reaction process of the synthesis method is as follows:

7. The method for synthesizing the self-assembled hole transport material containing phenanthrotriazole moieties according to claim 5, characterized in that: The reaction in step 1 is carried out under the condition of adding an organic base, the reaction in step 2 is carried out with the addition of a reducing agent, and the reaction in step 6 is carried out with the addition of a hydrolysis catalyst and a reaction quenching agent.

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