Novel SFX polymer hole transport material and application thereof

Abstract

The invention provides a novel spirofluorene xanthene (SFX) polymer hole transport material, the main chain of the polymer hole transport material is composed of spirofluorene xanthene (SFX) or a repetitive unit formed by connecting triphenylamine and spirofluorene xanthene (SFX), and the triphenylamine in the structure ensures that the material has proper HOMO energy level and good hole transport performance; meanwhile, due to the rigid structure of the SFX, the material has excellent thermal stability and uniform film-forming property. In addition, alkoxy is introduced into a side chain, so that the solubility of the material can be further improved, and the material is suitable for manufacturing devices based on a solution method. The novel spirofluorene xanthene polymer hole transport material disclosed by the invention has the advantages of good film-forming property and hole transport property, low cost and strong interface passivation effect, and is suitable for preparing large-area electron transport devices such as perovskite solar cells and perovskite quantum dot light-emitting diodes.

Description

Technical Field

[0001] The present invention relates to the fields of perovskite solar cells and quantum dot light-emitting diodes, and particularly to a novel polymer hole transport material containing spirofluorene oxadiazole in the main chain and its application as a hole transport material. In addition, the present invention also relates to a perovskite solar cell and a perovskite quantum dot light-emitting diode. Background Art

[0002] As a clean and renewable energy source, solar energy has gradually become a good choice to replace traditional fossil fuels and an important means to boost the development of the green economy and achieve the transformation of the energy structure. Research shows that the energy in the sun is sufficient to drive the operation of the solar system for 5 billion years. The energy the sun brings to the earth every day is more than 10,000 times the energy consumed by humans every day, but most of the energy is not utilized. A solar cell is an optoelectronic device that converts solar energy into electrical energy and is a cheap and efficient way to obtain clean electrical energy. Perovskite solar cells have attracted extensive attention due to their high photoelectric conversion efficiency, good low-light performance, low raw material cost, simple and convenient production, etc. At present, the photoelectric conversion efficiency of perovskite solar cells has reached 27.1%, significantly higher than that of traditional silicon cells.

[0003] With the development of technology, people's living standards are increasing day by day, and the requirements for light sources in life are also gradually increasing, such as high efficiency, energy saving, environmental protection, etc. In 2023, the Nobel Prize in Chemistry was awarded to three researchers, the Franco-Tunisian-American chemist Moungi Bawendi, the American chemist Louis Brus, and the Russian physicist Alexei Ekimov, who have done pioneering work in the field of quantum dots. Subsequently, quantum dot light-emitting diodes have developed rapidly. Quantum dot semiconductor materials have the advantages of high color purity, adjustable bandgap, low cost, solution processing at low temperature, and good stability, and can meet the display requirements of low cost, wide color gamut, and ultra-high definition, showing great application potential in the field of new displays.

[0004] The efficiency and long-term stability of devices such as perovskite solar cells and quantum dot light-emitting diodes strongly depend on hole transport materials. Polymer hole transport materials (HTMs) have excellent electrical conductivity, film-forming properties, and thermal stability, and have now become the mainstream hole transport materials in perovskite solar cells and quantum dot light-emitting diodes. Traditional polymer hole transport materials, such as poly(triarylamine) (PTAA), poly[bis(4-phenyl)(4-butylphenyl)amine] (poly-TPD), poly(9,9-dioctylfluorene-alt-N-(4-sec-butylphenyl)-diphenylamine) (TFB), etc., although having excellent hole mobilities, have a HOMO energy level of only -5.20 eV. In perovskite quantum dot light-emitting diodes and perovskite solar cells, the valence band of perovskite usually reaches -5.80 eV. Therefore, there is a problem of energy level mismatch for traditional polymers in devices. Secondly, traditional polymers have no passivating groups and cannot passivate perovskite with numerous defect states, reduce its defect state density, and thereby improve the device efficiency. In addition, the synthesis of PTAA and poly-TPD is complex and the purification is cumbersome, resulting in their high prices and significant differences between different production batches, which limits their large-scale commercial applications. Therefore, it is of great significance to develop new polymer hole transport materials with excellent performance and low cost. Summary of the Invention

[0005] One of the objectives of the present invention is to provide a novel SFX-based polymer hole transport material. The main chain of the polymer hole transport material is composed of repeating units formed by connecting spirofluorene oxazine (SFX) or triphenylamine and spirofluorene oxazine (SFX). Triphenylamine ensures that the material has a suitable HOMO energy level and good hole transport performance. At the same time, due to the rigidity of the structure of SFX, the material can have excellent thermal stability and uniform film-forming properties. The introduction of alkoxy groups in the side chain can improve the solubility of the material and is suitable for device fabrication based on solution methods. The hole transport polymer material provided by the present invention has the advantages of good film-forming properties, good hole transport properties, low cost, and strong interfacial passivation effect, and is suitable for large-area electron transport devices.

[0006] In order to achieve the above objectives, the technical solutions of the present invention are as follows:

[0007] An SFX-based polymer hole transport material, the general chemical structural formula of which is as follows:

[0008]

[0009] Among them, R1-R 12Independently represented as one of the following: hydrogen, halogen, cyano, pyridyl, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 8 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, triarylamino group, carbazolyl group, triaryloxyphosphine group;

[0010] Ar1 and Ar2 are independently represented as one of the following: substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted triarylamine having 3 to 30 carbon atoms;

[0011] A represents O, S, SO, SO2 and Se;

[0012] n is an integer from 2 to 500.

[0013] Preferably, R1 - R 12 Independently represented as hydrogen, halogen, cyano, methyl, ethyl, propyl, tert - butyl, phenyl, tolyl, tert - butylphenyl, pyridyl, methoxy, ethoxy, C1 - C 12 alkoxy, C1 - C 12 thioalkoxy;

[0014] Ar1 and Ar2 are independently represented as phenylene, biphenylene, naphthylene, phenanthrylene, anthrylene, phenylene naphthyl, naphthyl phenylene, 9,9 - dimethylpentylidene, dibenzofuranylidene, dibenzothiophenylene, triarylaminylene, carbazolylene.

[0015] More preferably, it includes any one of the following compounds 1 to 16, including but not limited to:

[0016]

[0017] The second object of the present invention is to provide the application of the above - mentioned SFX - type polymer as an HTM material in a light - emitting device. In particular, perovskite solar cells and quantum dot light - emitting diodes using the polymer of the present invention as the HTM layer (hole - transporting layer) material exhibit excellent efficiency and good device reproducibility.

[0018] The technical solution for the present invention to solve the above problems is as follows: An application of an SFX - type polymer hole - transporting material, characterized in that the HTM layer (hole - transporting layer) of the device contains the spirofluorene - based polymer hole - transporting material of the present invention.

[0019] A perovskite solar cell, whose structure from bottom to top is successively: ITO glass / PEDOT:PSS / HTM / perovskite / C60 / BCP / Al, where the HTM is a hole transport layer containing the spirofluoreneoxanthene polymer hole transport material of the present invention.

[0020] A perovskite quantum dot light-emitting diode, whose structure from bottom to top is successively ITO glass / PEDOT:PSS / HTM / perovskite light-emitting layer / TPBi / LiF / Al, where the HTM is a hole transport layer containing the spirofluoreneoxanthene polymer hole transport material of the present invention. The preparation method of the perovskite quantum dot light-emitting diode is as follows: (1) The ITO glass is successively ultrasonically cleaned with deionized water, isopropanol and acetone, and then subjected to ultraviolet light irradiation. After the PEDOT:PSS solution is filtered through a 0.22 μm filter head, it is spin-coated on the ITO glass at a speed of 3000 rpm, and then annealed at a temperature of 150 °C; (2) The spirofluoreneoxanthene polymer hole transport material of the present invention is dissolved in chlorobenzene, the solution is filtered through a 0.22 μm filter head, and then spin-coated on the PEDOT:PSS at a speed of 4000 rpm, and then annealed at a temperature of 120 °C; (3) The perovskite quantum dots dispersed in n-octane are spin-coated on the hole transport layer at a speed of 2000 rpm, and then annealed at a temperature of 90 °C; (4) Then, a certain thickness of TPBi layer, LiF layer and aluminum electrode are successively evaporated on the surface of the above device.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) The present invention provides a novel SFX class of polymer hole transport materials. The innovation compared with the prior art is that a class of novel chemical structures is designed and synthesized, and it shows excellent efficiency and good device repeatability when used as a material for the HTM layer (hole transport layer) in perovskite solar cells and quantum dot light-emitting diodes. The novel SFX class of polymer hole transport materials provided by the present invention has a triphenylamine main chain, and spirofluoreneoxanthene and pyridine structures are introduced into the side chains. Therefore, it has a high hole mobility, and the HOMO energy level reaches -5.40 eV, effectively solving the problem that the hole mobility and the HOMO energy level cannot be taken into account at the same time. At the same time, the introduction of pyridine in the structure can effectively passivate the defects on the perovskite surface, reduce the defect state density in the device, and improve the device efficiency.

[0023] (2) The SFX-based polymer hole transport material provided by the present invention is significantly simpler in the synthesis process compared to the commercial Spiro-OMeTAD material. Spirofluorene oxanthrene can be synthesized by a one-pot method under the catalysis of an acid, with a yield of over 85%. The raw materials are inexpensive, and the purification process is simple, making it more suitable for large-scale industrial production. For traditional polymer hole transport materials, such as PTAA and Poly-TPD, due to the inability to precisely control the molecular weight distribution range during the synthesis process, there are significant differences in the molecular weight distribution among different batches, which in turn leads to significant differences in device performance. In the post-treatment process of purifying the compounds in the present invention, after washing with n-hexane, methanol, and acetone in sequence for 12 hours, a molecular weight with an extremely narrow distribution range can be obtained, and the PDI is less than 1.5. The SFX-based polymer hole transport material provided by the present invention is applied to the field of quantum dot light-emitting diodes. Based on the good hole transport performance, relatively deep HOMO energy level, excellent passivation effect, etc. of the spirofluorene oxanthrene-based structure, it can promote the large-scale commercial application of perovskite solar cells and perovskite quantum dot light-emitting diodes.

[0024] (3) The SFX-based polymer hole transport material provided by the present invention is superior in terms of the maximum brightness, maximum current efficiency (CE), maximum power efficiency (PE), maximum external quantum efficiency (EQE), etc. of the perovskite quantum dot light-emitting diode device compared to the polymer hole transport materials PTAA and Poly-TPD, which are commercialized and widely used. The performance of the device prepared with the polymer hole transport material of the present invention is comprehensively better than that of the devices prepared with the above two existing materials. The maximum brightness of the device prepared with the polymer hole transport material of the present invention is 35551.34 cd·m -2 to 61103.63 cd·m -2 However, for the devices prepared with the two existing materials, the corresponding maximum brightness is only 24203.24 cd·m -2 and 22573.89 cd·m -2 , that is, the maximum brightness exceeds by at least about 46.89%. Again, for the maximum current efficiency (CE) index, the test data range of the device prepared with the polymer hole transport material of the present invention is 84.22 cd·A -1 to 91.75 cd·A -1 However, the corresponding test data of the devices prepared with the two existing materials are 62.79 cd·A -1 and 60.35 cd·A -1Furthermore, the maximum external quantum efficiency of the devices prepared with the polymer hole transporting materials of the present invention all exceeded 22%, and the maximum external quantum efficiency (EQE) of the device prepared with Compound 6 even reached 24.26%, while the maximum external quantum efficiencies of the two types of existing materials were only 16.81% and 16.16% respectively. Similarly, the photoelectric conversion efficiencies of the perovskite solar cell devices prepared with the polymer hole transporting materials of the present invention all reached over 20%, and the photoelectric conversion efficiency of the device prepared with Compound 2 reached 22.51%, while the photoelectric conversion efficiency of the device prepared with the corresponding existing material PTAA was only 18.30. Therefore, the compound materials of the present invention have better commercial application prospects. Description of the Drawings

[0025] Figure 1 is the current density-voltage-luminance (J-V-L) of perovskite quantum dot light-emitting diode devices prepared with Compound 1, Compound 2, Compound 5, Compound 6, and Compound 9 as hole transporting materials;

[0026] Figure 2 is the current efficiency-current density-power efficiency graph (CE-J-PE) of perovskite quantum dot light-emitting diode devices prepared with Compound 1, Compound 2, Compound 5, Compound 6, and Compound 9 as hole transporting materials;

[0027] Figure 3 is the electroluminescence spectrum of perovskite quantum dot light-emitting diode devices prepared with Compound 1, Compound 2, Compound 5, Compound 6, and Compound 9 as hole transporting materials;

[0028] Figure 4 is the external quantum efficiency-current density graph (EQE-J) of perovskite quantum dot light-emitting diode devices prepared with Compound 1, Compound 2, Compound 5, Compound 6, and Compound 9 as hole transporting materials;

[0029] Figure 5 is the current density-voltage-luminance (J-V-L) of perovskite quantum dot light-emitting diode devices prepared with PTAA and Poly-TPD as hole transporting materials;

[0030] Figure 6 is the current efficiency-current density-power efficiency graph (CE-J-PE) of perovskite quantum dot light-emitting diode devices prepared with PTAA and Poly-TPD as hole transporting materials;

[0031] Figure 7 is the electroluminescence spectrum of perovskite quantum dot light-emitting diode devices prepared with PTAA and Poly-TPD as hole transporting materials;

[0032] Figure 8 External quantum efficiency-current density graph (EQE-J) of a perovskite quantum dot light-emitting diode device prepared with PTAA and Poly-TPD as hole transport materials;

[0033] Figure 9 Current density-voltage graph (J-V) of a perovskite solar cell device prepared with PTAA, Compound 1, Compound 2, Compound 5, Compound 6, and Compound 9 as hole transport materials. Specific implementation manners

[0034] The specific implementation manners, structures, features, and effects of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0035]

Example 1

[0036] Synthesis of Compound 1. The synthesis route is as follows:

[0037]

[0038] Synthesis of intermediate TM1:

[0039]

[0040] Weigh SM1 (5.00 g, 22.20 mmol), SM2 (11.02 g, 88.81 mmol), p-TsOH (0.37 g, 0.22 mmol), and toluene (50 mL) and add them to a 150 mL three-necked flask. Heat under reflux, stir, protect with argon, and monitor the reaction progress by TLC plate spotting. After reacting for about 5 h, spot the plate. The spot of raw material SM1 disappears, and then post-treatment begins. Separate by column chromatography to obtain a yellow solid product. After vacuum drying at 100 °C for about 3 h, 8.50 g of the product is obtained, with a yield of 87.5%. 1 1H NMR (400 MHz, DMSO-d6) δ 8.22 (dd, J = 7.5, 1.5 Hz, 1H), 8.02–7.96 (m, 2H), 7.85 (dd, J = 7.3, 1.6 Hz, 1H), 7.38 (td, J = 7.4, 1.6 Hz, 1H), 7.32 (td, J = 7.3, 1.5 Hz, 1H), 7.27 (dd, J = 7.5, 1.8 Hz, 1H), 7.19 (d, J = 7.4 Hz, 2H), 6.65 (dd, J = 7.5, 1.5 Hz, 2H), 6.58 (d, J = 1.4 Hz, 2H), 3.80 (s, 6H).

[0041] Synthesis of intermediate TM2:

[0042]

[0043] Weigh TM1 (6.00 g, 13.72 mmol), stannous chloride (13.00 g, 68.58 mmol), and 1,4-dioxane (60 mL) and add them to a 150 mL single-necked flask. Heat the mixture to 120 °C and monitor the reaction progress by TLC spotting. After stirring for about 10 h, spot the plate and the spot of starting material TM1 disappears. Perform column chromatography separation to obtain a white solid product. Place the product in a vacuum oven to dry and obtain 4.80 g of solid product with a yield of 85.8%. 1 H NMR (600 MHz, DMSO-d6) δ 7.85 (dd, J = 7.4, 1.6 Hz, 1H), 7.62 (d, J = 7.5 Hz, 1H), 7.51–7.46 (m, 1H), 7.34 (dtd, J = 24.5, 7.5, 1.6 Hz, 2H), 7.19 (d, J = 7.5 Hz, 2H), 6.90 (dd, J = 7.5, 1.5 Hz, 1H), 6.70 (dd, J = 7.5, 1.6 Hz, 2H), 6.59 (d, J = 1.5 Hz, 2H), 6.38 (d, J = 1.5 Hz, 1H), 5.40 (d, J = 12.4 Hz, 1H), 5.19 (d, J = 12.5 Hz, 1H), 3.80 (s, 6H).

[0044] Synthesis of intermediate TM3:

[0045]

[0046] Weigh TM2 (4.00 g, 9.82 mmol), p-dibromobenzene (6.95 g, 29.45 mmol), sodium tert-butoxide (2.83 g, 29.45 mmol), Pd2(dba)3 (0.40 g), X-phos (0.80 g), and toluene (40 mL) and add them to a 100 mL single-necked flask. Heat the mixture to 120 °C and monitor the reaction progress by TLC spotting. After stirring for about 10 h, spot the plate and the spot of starting material TM1 disappears. Perform column chromatography separation to obtain a solid product. Place the product in a vacuum oven to dry and obtain 5.70 g of solid product with a yield of 80.9%. 1 HNMR (600 MHz, DMSO-d6) δ 7.85 (dd, J = 7.5, 1.7 Hz, 1H), 7.68 (d, J = 7.5 Hz, 1H), 7.51–7.46 (m, 5H), 7.35 (td, J = 7.4, 1.5 Hz, 1H), 7.32–7.26 (m, 1H), 7.29–7.21 (m, 2H), 7.23–7.15 (m, 1H), 6.87 (d, J = 1.6 Hz, 1H), 6.67 (dd, J = 7.5, 1.5 Hz, 3H), 6.56 (d, J = 1.4 Hz, 3H), 3.80 (s, 6H).

[0047] Synthesis of Compound 1:

[0048]

[0049] Weigh TM3 (1.00 g, 1.39 mmol), Ni(COD)2 (0.16 g, 1.39 mmol), 1,5-COD (0.32 g), and bipy (0.32 g) and add them to a 50 mL three-necked flask. Seal the system, evacuate and replace the air three times with an oil pump to remove the air in the system and fill it with argon. Inject toluene (10 mL) with a syringe, heat at 110 °C under argon protection, stir. After the solid gradually dissolves, the solution quickly turns orange-red. After reacting for about 1 h, the orange-red color fades. After stirring for 48 h, post-treatment begins; after the reaction solution cools to room temperature, add 20 mL of water, extract the aqueous phase three times with DCM, and filter by suction to obtain a yellow solution; when the extraction solution is concentrated to about 5 mL remaining, drop the extraction solution into methanol, and a large amount of flocculent pale yellow solid precipitates; wrap the solid with filter paper, first wash it with n-hexane at 120 °C for about 13 h, and then wash it with acetone at 120 °C for 10 h; after washing with acetone, wash it with chloroform at 100 °C for about 5 h; after washing, concentrate the chloroform, drop the concentrated chloroform solution into methanol, filter by suction, and obtain a flocculent dark yellow solid again; dry it to obtain 0.46 g of a pale yellow product with a yield of 41.5%.

[0050]

Example 2

[0051] Synthesis of Compound 2. The synthesis route is as follows:

[0052]

[0053] The synthesis of intermediates TM1 to TM3 has been described in

Example 1

[0054] Synthesis of Intermediate TM4:

[0055]

[0056] Weigh TM4 (1.00 g, 1.39 mmol) and add DCM (10 mL) to a 50 mL single-necked flask, and stir at room temperature until all the solid dissolves. Weigh NIS (0.31 g, 1.39 mmol) and dissolve it in DCM (10 mL), and slowly drip it into the reaction solution with a constant pressure dropping funnel; after reacting for about 30 min, spot-check the plate and the reaction is good; extract the solution with DCM, when the organic phase is concentrated to about 10 mL remaining, add 10 mL of ethanol, stir, and a large amount of solid precipitates; filter by suction to obtain a white solid product, dry it in an oven to obtain 0.81 g with a yield of 69.2%. 1HNMR(500MHz, DMSO-d6) δ 7.86 (d, J = 1.6 Hz, 1H), 7.77 (d, J = 7.5 Hz, 1H), 7.73 (dd, J = 7.5, 1.5 Hz, 1H), 7.64 (d, J = 7.5 Hz, 1H), 7.51–7.46 (m, 4H), 7.29 (s, 1H), 7.28–7.21 (m, 4H), 7.17 (d, J = 7.5 Hz, 2H), 6.98 (d, J = 1.5 Hz, 1H), 6.67 (dd, J = 7.5, 1.5 Hz, 2H), 6.56 (d, J = 1.4 Hz, 2H), 3.80 (s, 6H).

[0057] Synthesis of intermediate TM5:

[0058]

[0059] Weigh TM4 (0.80 g, 0.95 mmol), SM4 (0.14 g, 1.14 mmol), sodium tert-butoxide (0.27 g, 2.85 mmol), Pd(PPh3)4 (0.20 g), and toluene (20 mL) and add them to a 100 mL single-necked flask. Heat the mixture to 120 °C. Monitor the reaction progress by TLC spotting; after stirring for about 10 h, spot the plate and the reaction is complete. Separate by column chromatography to obtain a solid product. Place the product in a vacuum oven to dry and obtain 0.75 g of solid product with a yield of 86.6%. 1 HNMR(500MHz, DMSO-d6) δ 8.81–8.76 (m, 2H), 7.80 (d, J = 7.7 Hz, 1H), 7.78–7.72 (m, 2H), 7.70 (d, J = 7.5 Hz, 1H), 7.60 (dd, J = 7.5, 1.5 Hz, 1H), 7.51–7.46 (m, 4H), 7.40 (d, J = 1.5 Hz, 1H), 7.29–7.21 (m, 5H), 7.17 (d, J = 7.5 Hz, 2H), 6.89 (d, J = 1.5 Hz, 1H), 6.68 (dd, J = 7.4, 1.6 Hz, 2H), 6.56 (d, J = 1.4 Hz, 2H), 3.81 (s, 6H).

[0060] Synthesis of compound 2:

[0061]

[0062] The synthesis of compound 2 is the same as that of compound 1 in [Example 1]. Obtain 0.27 g of light yellow solid product with a yield of 49.7%.

[0063]

Example 3

[0064] The synthesis route of compound 5 is as follows:

[0065]

[0066] The synthesis of intermediates TM1 to TM3 has been described in [Example 1] and will not be repeated here.

[0067] Synthesis of intermediate TM4:

[0068]

[0069] Weigh SM4 (1.00 g, 3.86 mmol), add DCM (10 mL) into a 50 mL single-necked flask, and stir at room temperature until all solids are dissolved. Weigh NBS (1.44 g, 8.10 mmol) and dissolve it in DCM (10 mL), and slowly drip it into the reaction solution using a constant pressure dropping funnel; after about 30 minutes of reaction, tap the plate, and the reaction is good; extract the solution with DCM, concentrate the organic phase to about 10 mL remaining, add 10 mL of ethanol, stir, and a large amount of solids precipitate; filter to obtain a white solid product, and after drying in an oven, obtain 1.11 g, with a yield of 68.9%. 1 H NMR (400MHz, DMSO-d6) δ7.47–7.39(m,4H),7.17(d,J=8.1Hz,2H),7.00–6.94(m,2H),6.93–6.86(m,4H),2.28(s,3H).

[0070] Synthesis of intermediate TM5:

[0071]

[0072] Weigh KOAc (1.42 g, 14.46 mmol) and toluene (35 mL) and place them in a 50 mL three-necked flask. Protect with nitrogen and distill to remove water. When there is no turbidity on the wall of the flask, start the next step; weigh TM3 (2.00 g, 4.82 mmol), pinacol diboron (2.70 g, 10.60 mmol), Pd2(dba)3 (0.06 g) and tri-tert-butyl phosphine (0.12 g) and add them to the three-necked flask, heat to reflux, stir, and track the progress of the reaction by TLC plate; after stirring for about 5 hours, the TM3 spot disappears; the reaction solution is cooled to room temperature and desalted through a short silica gel column; when the eluent is concentrated to about 10 mL remaining, stop concentrating and stir to crystallize; after stirring for 0.5 hours, a solid is precipitated and filtered; after drying the product for 2 hours, 1.40 g of solid product is obtained with a yield of 56.90%. 1H NMR (400MHz, CDCl3) δ7.66 (d, J=7.8Hz, 4H), 7.05 (dq, J=13.1, 8.0Hz, 8H), 2.33 (s, 3H), 1.33 (s, 24H).

[0073] Synthesis of Compound 5:

[0074]

[0075] Weigh TM3 (1.00 g, 1.39 mmol), TM5 (0.72 g, 1.39 mmol), and t-BuONa (0.40 g, 4.18 mmol), add Pd(OAc)2 (0.10 g) and X-phos (0.20 g) into a 50 mL three-necked flask. Seal the system, evacuate and replace the air three times with an oil pump to remove the air in the system, and then fill it with argon. Inject toluene (10 mL), ethanol (5 mL), and water (5 mL) with a syringe. Heat at 90 °C under argon protection and stir. After the solid gradually dissolves, the solution quickly turns orange-red. After reacting for about 1 h, the orange-red color fades. After stirring for 48 h, start the post-treatment. After the reaction solution cools to room temperature, add 20 mL of water, extract the aqueous phase three times with DCM, and filter to obtain a yellow solution. When the extract is concentrated to about 5 mL remaining, drop the extract into methanol, and a large amount of flocculent pale yellow solid precipitates. Wrap the solid with filter paper, wash it with n-hexane at 120 °C for about 13 h first, and then wash it with acetone at 120 °C for 10 h. After washing with acetone, wash it with chloroform at 100 °C for about 5 h. After washing, concentrate the chloroform, drop the concentrated chloroform solution into methanol, filter, and obtain a flocculent dark yellow solid again. Dry it to obtain 0.51 g of pale yellow product.

[0076]

Example 4

[0077] Synthesis of Compound 6, the synthesis route is as follows:

[0078]

[0079] Synthesis of Compound 6:

[0080]

[0081] Among them, the synthesis of intermediates TM1 to TM3 can be seen in Example 1, the synthesis of TM4 to TM4 can be seen in Example 2, and the synthesis of SM5 can be seen in Example 3. The synthesis conditions of Compound 6 are the same as those in the synthesis process of Compound 5, and 0.47 g of pale yellow solid of Compound 6 is obtained, with a yield of 51.2%.

[0082]

Example 5

[0083] Synthesis of Compound 9, the synthesis route is as follows:

[0084]

[0085] Synthesis of Compound 9:

[0086]

[0087] The intermediate TM5 can be directly purchased. For the synthesis of intermediates TM1 to TM3, see Example 1. The synthesis conditions of Compound 9 are the same as those in the synthesis process of Compound 5, and 0.57 g of pale yellow solid of Compound 9 is obtained, with a yield of 61.2%.

[0088]

Example 6

[0089] Taking the non-doped hole transport material compounds 1, 2, 5, 6, and 9 prepared in Examples 1-5 as examples, perovskite quantum dot light-emitting diode devices are prepared as the hole transport layer, and its structure is ITO / PEDOT:PSS / HTM / CsPbBr3 / TPBi / LiF / Al.

[0090] Device preparation method: The ITO glass is successively ultrasonically cleaned with deionized water, isopropanol, and acetone, and then irradiated with ultraviolet light for 20 min. After the PEDOT:PSS solution is filtered through a 0.22 μm filter head, it is spin-coated on the ITO glass at a speed of 3000 rpm for 45 s (spin-coating concentration 5 mg·mL -1 ), and then annealed at 150 °C for 20 min. Compounds 1, 2, 5, 6, and 9 are dissolved in chlorobenzene (3, 5, 7, 9 mg / mL). After the dissolved chlorobenzene solution is filtered through a 0.22 μm filter head, it is spin-coated on PEDOT:PSS at a speed of 4000 rpm for 45 s, and then annealed at 120 °C for 20 min. The perovskite quantum dots dispersed in n-octane are spin-coated on the hole transport layer at a speed of 2000 rpm for 45 s, and then annealed at 90 °C for 5 min. Immediately afterwards, 45 nm of TPBi, 1.5 nm of LiF, and 100 nm of aluminum electrode are successively evaporated.

[0091] Using the compounds 1, 2, 5, 6, and 9 prepared in Examples 1-5 as the hole transport layer, perovskite quantum dot light-emitting diode devices are prepared and characterized according to the above procedure. The device performance characteristic curves are shown in Figures 1 to 4 .

[0092] It can be seen from Figures 1 to 4 that for the device prepared with Compound 1, its maximum brightness is 44132.8 cd·m -2 , the maximum current efficiency (CE) is 88.85 cd·A -1 , the maximum power efficiency (PE) is 121.66 lm·W -1 , and the maximum external quantum efficiency (EQE) is 23.98%; for the device prepared with Compound 2, the maximum brightness is 61103.63 cd·m -2, the maximum current efficiency (CE) is 85.21 cd·A -1 , the maximum power efficiency (PE) is 81.89 lm·W -1 , the maximum external quantum efficiency (EQE) is 22.63%; the maximum luminance of the device fabricated with Compound 5 is 42507.13 cd·m -2 , the maximum current efficiency (CE) is 84.22 cd·A -1 , the maximum power efficiency (PE) is 117.19 lm·W -1 , the maximum external quantum efficiency (EQE) is 22.30%; the maximum luminance of the device fabricated with Compound 6 is 35551.34 cd·m -2 , the maximum current efficiency (CE) is 91.75 cd·A -1 , the maximum power efficiency (PE) is 122.55 lm·W -1 , the maximum external quantum efficiency (EQE) is 24.26%; the maximum luminance of the device fabricated with Compound 9 is 44828.59 cd·m -2 , the maximum current efficiency (CE) is 86.97 cd·A -1 , the maximum power efficiency (PE) is 108.77 lm·W -1 , the maximum external quantum efficiency (EQE) is 22.93%.

[0093] For comparison, using the commercially available and widely used polymer hole transport materials PTAA and Poly-TPD as the hole transport layer respectively, perovskite quantum dot light-emitting diode devices were fabricated according to the exactly same procedure above and their performances were tested. The performance characteristic curves of the tested devices are shown in Figures 5 to 8 .

[0094] It can be seen from Figures 5 to 8 that the maximum luminance of the device fabricated with PTAA is 24203.24 cd·m -2 , the maximum current efficiency (CE) is 62.79 cd·A -1 , the maximum power efficiency (PE) is 63.64 lm·W -1 , the maximum external quantum efficiency (EQE) is 16.81%; the maximum luminance of the device fabricated with the commercially available polymer hole transport material Poly-TPD is 22573.89 cd·m -2 , the maximum current efficiency (CE) is 60.35 cd·A -1 , the maximum power efficiency (PE) is 70.39 lm·W -1 , the maximum external quantum efficiency (EQE) is 16.16%.

[0095] The above test results show that the maximum external quantum efficiency of the commercially available polymer hole transport materials PTAA and Poly-TPD is both below 16.9%. For the devices prepared with the compounds provided by the present invention, the corresponding maximum external quantum efficiency all exceeds 20%, and the corresponding device performance significantly surpasses that of PTAA and Poly-TPD, showing good commercial application prospects. The underlying reason is that Compound 1, Compound 2, Compound 5, Compound 6 and Compound 9 of the present invention have deeper HOMO energy levels (more matched with the valence band of perovskite quantum dots), more excellent hole mobilities and good passivation effects on perovskite quantum dots compared with the existing commercial polymer materials.

[0096]

Example 7

[0097] Using Compound 1, Compound 2, Compound 5, Compound 6 and Compound 9 prepared in Examples 1-5 as the non-doped hole transport layer to prepare perovskite solar cells, and its structure is ITO / PEDOT:PSS / HTM / CsPbBr3 / C60 / BCP / Ag.

[0098] Preparation method: The ITO glass is successively ultrasonically cleaned with deionized water, acetone and isopropanol, and then irradiated with ultraviolet light for 20 min. After the PEDOT:PSS solution is filtered through a 0.22 μm filter head, it is spin-coated at a speed of 3000 rpm for 45 s (spin-coating concentration 5 mg·mL -1 ) on the ITO glass, and then annealed at a temperature of 150 °C for 20 min. Compound 1, Compound 2, Compound 5, Compound 6 and Compound 9 are dissolved in chlorobenzene (10 mg / mL), and the dissolved chlorobenzene solution is also filtered through a 0.22 μm filter head, and then spin-coated on PEDOT:PSS at a speed of 3000 rpm for 45 s, and then annealed at a temperature of 120 °C for 15 min. The perovskite layer is deposited by spin-coating the perovskite precursor solution in one step, and this solution is prepared by mixing FAI, PbI2, MABr and PbBr2 in a mixed solvent of DMF and DMSO solution (volume ratio 4:1), and its molar concentration is 1.35 MPb 2+ (PbI2 and PbBr2). PbI2 / PbBr2 = 85 / 15, PbI2 / FAI = 1.05, PbBr2 / MABr = 1 / 1. The DMF / DMSO mixed solution containing the perovskite precursor is spin-coated on the hole transport layer at a speed of 2000 rpm for 45 s, 200 μL of chlorobenzene is quickly added dropwise after 30 s of spin-coating, and then annealed at a temperature of 100 °C for 30 min to evaporate the solvent. Immediately, the device is transferred from the glove box to a vacuum evaporation machine to successively evaporate 20 nm of C60, 5 nm of BCP and 100 nm of silver electrode.

[0099] Taking the polymer material compounds 1, 2, 5, 6, and 9 prepared in Examples 1-5 as the hole transport layer of the above solar cell as an example, the completed perovskite solar cell was subjected to I-V testing, and the results are as Figure 9 shown. The specific perovskite solar cell data based on Compounds 1, 2, 5, 6, and 9 are shown in Table 1 below.

[0100] Table 1

[0101]

[0102] From Table 1 combined with Figure 9 it can be seen that: (1) Among the device performances of the perovskite solar cells prepared from the compounds 1, 2, 5, 6, and 9 of the present invention, the device performance of Compound 2 is the best, and the photoelectric conversion efficiency reaches 22%. The photoelectric conversion efficiencies of Compounds 1, 5, 6, and 9 all reach 20%, while the photoelectric conversion efficiency of the commercially available polymer PTAA is only 18%. This shows that the compounds provided by the present invention exhibit good application potential. The reason is that compared with the commercially available polymer hole transport material, the novel spirofluorene oxanthrene-based polymer hole transport material provided by the present invention has a greater molecular polarity, better affinity with the upper perovskite thin film, which is beneficial to the growth of high-quality perovskite crystals and the excellent hole mobility of the material itself, and has a deeper HOMO energy level and good passivation effect.

[0103] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention, and does not impose any formal limitations on the present invention. Those skilled in the art can obviously make various modifications to these embodiments easily and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A SFX-based polymeric hole transport material, characterized in that, The general formula of the chemical structural formula is as follows: Among them, R1-R 12 independently represent one of the following: hydrogen, halogen, cyano group, pyridyl group, alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 8 carbon atoms, substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, triarylamino group, carbazolyl group, triaryloxyphosphine group; Ar1 and Ar2 independently represent one of the following: an aryl group having 6 to 30 carbon atoms which may be substituted or unsubstituted, a heteroaryl group having 3 to 30 carbon atoms which may be substituted or unsubstituted, a triarylamine having 3 to 30 carbon atoms which may be substituted or unsubstituted; A represents O, S, SO, SO2 or Se; n is an integer from 2 to 500.

2. The SFX-based polymer hole transport material according to claim 1, characterized in that, R1-R 12 Independently represented as hydrogen, halogen, cyano, methyl, ethyl, propyl, tert-butyl, phenyl, tolyl, tert-butylphenyl, pyridyl, methoxy, ethoxy, C1-C 12 alkoxy or C1-C 12 thioalkoxy; Ar1 and Ar2 independently represent phenylene, biphenylene, naphthylene, phenanthrylene, anthrylene, phenylnaphthylene, naphthylphenyl, 9,9-dimethylpentylene, dibenzofuranyl, dibenzothiophenyl, triarylamino or carbazolyl.

3. The SFX-based polymeric hole transport material according to claim 1 or 2, wherein The general formula (I) includes, but is not limited to, any one of the following compounds 1 to compound 16:

4. Use of the SFX polymer hole transport material according to any one of claims 1 to 3 as a material for the HTM layer.

5. A perovskite solar cell, characterized in that, The HTM layer contains the SFX polymer hole transport material according to any one of claims 1 to 3.

6. The perovskite solar cell according to claim 5, wherein, The structure of the perovskite solar cell is, from bottom to top, ITO glass / PEDOT: PSS / HTM / perovskite / C60 / BCP / Al in sequence.

7. A perovskite quantum dot light-emitting diode, characterized in that, The HTM layer contains the SFX polymer hole transport material according to any one of claims 1 to 3.

8. The perovskite quantum dot light-emitting diode according to claim 7, characterized in that, The structure of the quantum dot light-emitting diode is, from bottom to top, ITO glass / PEDOT: PSS / HTM / perovskite light-emitting layer / TPBi / LiF / Al in sequence.

9. A display device, characterized in that, A perovskite quantum dot light-emitting diode containing claim 7 or 8.

10. The display device according to claim 9, characterized in that, The display device is a display or a display panel.

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