Organic semiconductor material containing fluorenecarbazoleamine electron donor, preparation method and application

Abstract

The present invention relates to the technical field of organic semiconductor materials, and is intended to provide an organic semiconductor material, preparation method and application containing a fluorenecarbazole amine electron donor. The organic semiconductor material can be used as a hole transport layer material for a perovskite solar cell, and is composed of a central skeleton comprising four electron acceptors and four electron donors; the electron acceptors are a six-membered ring structure and are symmetrically arranged in the central skeleton; the electron donor is N-(9,9-dimethyl-9H-fluorene-2-yl)-9-methyl-9H-carbazole-3-amine, and is connected in a one-to-one correspondence with the six-membered ring structure. The organic semiconductor material of the present invention has properties such as a high highest occupied molecular orbital energy level, a high glass transition temperature, high electrical conductivity, and solution processability, and can be used to prepare a perovskite solar cell with high energy conversion efficiency and good thermal stability. The average energy conversion efficiency of a perovskite solar cell using the material as a hole transport material and the retention rate of the device energy conversion efficiency after thermal aging are both excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of organic semiconductor materials, and more specifically relates to several organic semiconductor materials containing fluorenecarbazoleamine electron donors, preparation methods and applications. Background Art

[0002] The constituent elements included in the lead halide-based semiconductor materials with a perovskite structure are widely distributed and highly abundant on the earth's surface. Through solution processing methods, polycrystalline semiconductor films with high defect tolerance can be deposited, which have excellent sunlight capture and carrier transport properties. Methylamine lead iodine, formamidinium lead iodine, cesium lead iodine and related alloy perovskites can all be used as light absorption layers of solar cells to achieve efficient conversion of solar energy to electrical energy. In recent years, formamidinium lead iodine, a lead-based perovskite with a wide spectral response and a high thermal decomposition temperature, has been increasingly valued. Thanks to the continuous improvement of processing methods for regulating the properties of formamidinium lead iodine perovskite film composition, crystallinity, grain size and morphology, the energy conversion efficiency of single-junction perovskite solar cells prepared in the laboratory using spiro-OMeTAD as a hole transport material has exceeded 25%.

[0003] According to international testing standards, solar cells must meet high-temperature operating conditions up to 85°C. However, 85°C is too high for current high-efficiency cells to withstand. Although alternative hole transport layers have been used to create perovskite solar cells capable of withstanding 85°C temperatures, the initial efficiencies of these devices are still insufficient. To date, creating perovskite solar cells with long-term thermal stability at 85°C and efficiencies greater than 24% remains a significant challenge.

[0004] For thermally stable and efficient perovskite solar cells, in addition to the perovskite light absorption layer, the selection of appropriate electron transport layer and hole transport layer is also very critical. For perovskite solar cells using oxide electron transport layers such as TiO2 or SnO2, the solution-processable organic hole transport layer should have the following basic characteristics:

[0005] (1) It can form a dense, uniform, and sufficiently thick film on the surface of perovskite to avoid micro-area contact between the metal positive electrode and the perovskite, which would trigger rapid charge recombination.

[0006] (2) The highest occupied molecular orbital energy level should be higher than the valence band top of the perovskite to ensure that the rate at which excited perovskite injects holes into it is fast enough.

[0007] (3) It has a suitable hole concentration, mobility and conductivity to reduce the internal resistance of the battery, while ensuring that the interfacial charge recombination between the perovskite and the hole transport layer is as slow as possible.

[0008] (4) When heated, the mechanical properties of the hole transport layer do not change suddenly and the morphology does not degenerate.

[0009] (5) Can reduce the diffusion and migration of endogenous and exogenous substances.

[0010] Spiro-OMeTAD was first reported in 1997 by researchers from the Max Planck Institute for Polymer Research and Hoechst AG in Germany. Spiro-OMeTAD is composed of a spirobifluorene (SBF) central skeleton and four dimethoxydiphenylamine (OMeDPA) electron donors. The structural origins of spiro-OMeTAD can be traced back to the early 20th century. As early as 1910, Nobel Prize winner in Chemistry, German chemist Professor Wieland and others first synthesized OMeDPA. In 1930, Clarkson and Gomberg of the University of Michigan reported the synthesis of SBF. In 1998, Gratzel et al. at the École Polytechnique Fédérale de Lausanne in Switzerland achieved a breakthrough in the efficiency of solid-state dye-sensitized solar cells by doping spiro-OMeTAD with an oxidant during the deposition of an amorphous film. Since 2012, using spiro-OMeTAD as a hole transport layer, research teams from home and abroad have repeatedly set records for energy conversion efficiency in perovskite solar cells. The reason for this is not only that spiro-OMeTAD is commercially available, but also that its doped films possess suitable energy levels, hole concentration, hole mobility, morphology, and slow interfacial charge recombination. However, a crucial fact is that the glass transition temperature of spiro-OMeTAD is only slightly above 120°C. After doping, the glass transition temperature is typically lower, and upon prolonged heating at 85°C, the spiro-OMeTAD-based hole transport layer is susceptible to crystallization and cracking. This severe morphological degradation leads to a significant decrease in device efficiency. In recent years, several new hole transport materials based on spirobifluorene and other electron donors have been reported, but these materials still lack comprehensive quality factors, including film formation, energy levels, hole transport properties, and glass transition temperature. For example, Jeon et al. reported a hole transport material (DM) composed of SBF and the electron donor fluorenylmethoxyamine. DM-based perovskite solar cells exhibited thermal stability at 60°C. Compared with spiro-OMeTAD, DM has a higher glass transition temperature of 161°C, but its hole transport performance is reduced. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide an organic semiconductor material containing a fluorenecarbazoleamine electron donor, a preparation method and an application thereof.

[0012] To solve the technical problem, the solution of the present invention is:

[0013] Provided is an organic semiconductor material containing a fluorenecarbazole amine electron donor, comprising a central skeleton comprising four electron acceptors and four electron donors; the electron acceptors are six-membered ring structures and are symmetrically arranged in the central skeleton; the electron donors are N-(9,9-dimethyl-9H-fluoren-2-yl)-9-methyl-9H-carbazole-3-amine, and are connected to the six-membered ring structures in a one-to-one correspondence.

[0014] As a preferred embodiment of the present invention, the central skeleton is any one of spirobifluorene, difluorene, dibenzochrysene or tetraphenylene.

[0015] As a preferred embodiment of the present invention, the general structural formula of the organic semiconductor material is any one of formula (I), formula (II), formula (III), and formula (IV):

[0016]

[0017] In the formula, R1, R2, and R3 are optionally methyl, ethyl, or propyl.

[0018] As a preferred embodiment of the present invention, the organic semiconductor material is composed of spirobifluorene, difluorene, dibenzochrysene or tetraphenylene as a central skeleton, and N-(9,9-dimethyl-9H-fluoren-2-yl)-9-methyl-9H-carbazole-3-amine as an electron donor; its general structural formula is any one of Formula (IA), Formula (II-A), Formula (III-A), and Formula (IV-A):

[0019]

[0020]

[0021] The present invention further provides a method for preparing the aforementioned organic semiconductor material containing a fluorenecarbazole amine electron donor, comprising: under nitrogen protection, adding a central skeleton halide, N-(9,9-dimethyl-9H-fluoren-2-yl)-9-methyl-9H-carbazole-3-amine, tris(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate, and sodium tert-butoxide to toluene in a molar ratio of 1:5:0.2:0.4:5; heating to 120° C. while stirring, and reacting for 12 hours; after the reaction is completed, allowing the mixture to stand, cooling to room temperature, and separating and purifying the mixture by column chromatography to obtain a solid, which is the organic semiconductor material.

[0022] As a preferred embodiment of the present invention, the central skeleton halogenated compound is any one of the following: 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 2,2',7,7'-tetrabromo-9,9'-difluorene, 3,6,11,14-tetrabromodibenzochrysene or 2,7,10,15-tetrachlorotetraphenylene.

[0023] The present invention also provides an application method of the organic semiconductor material containing the fluorenecarbazoleamine electron donor, which is to use the organic semiconductor material as a hole transport layer material of a perovskite solar cell.

[0024] As a preferred embodiment of the present invention, when preparing a perovskite solar cell, the organic semiconductor material, tert-butylpyridinium bis(trifluorosulfonyl)imide, and tert-butylpyridine are first added to chlorobenzene to obtain a hole transport layer solution; then, the solution is rotated at 4000 rpm for 30 seconds by dynamic spin coating to deposit the organic semiconductor material on the perovskite layer to obtain a hole transport layer.

[0025] The present invention also provides a perovskite solar cell device using the aforementioned organic semiconductor material containing the fluorenecarbazole amine electron donor as the hole transport layer material. The perovskite solar cell device has a multilayer structure, which comprises, from bottom to top, an ITO conductive glass layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer, and a metal electrode.

[0026] Brief description of the invention principle:

[0027] The present invention discloses several organic semiconductor materials, each with a spirobifluorene, difluorene, dibenzochrysene, or tetraphenylene as the core skeleton and four fluorenylcarbazole amines as electron donors. For example, the present invention's organic semiconductor material (SBF-FC) has a spirobifluorene as the core skeleton and four N-(9,9-dimethyl-9H-fluoren-2-yl)-9-methyl-9H-carbazole-3-amines as electron donors. Replacing dimethoxydiphenylamine with the rigid fluorenylcarbazole amine electron donor makes the SBF-FC molecule less susceptible to twisting or torsional motion, resulting in a significantly higher glass transition temperature than spiro-OMeTAD. Furthermore, the fluorenylcarbazole amine electron donor has a larger conjugated system, resulting in a larger average molecular center-of-mass distance, a smaller reorganization energy, and a lower energy disorder, resulting in a higher hole mobility than spiro-OMeTAD. In addition, tests have shown that SBF-FC has a higher highest occupied molecular orbital energy level, and the fluorenylcarbazole amine electron donor does not affect the solubility of the SBF-FC molecule. Under the same material processing conditions, SBF-FC presents a complete and uniform film. In sharp contrast, the spiro-OMeTAD hole transport layer presents a small number of nanoscale holes.

[0028] Testing has shown that when the SBF-FC product of this invention is used as the hole transport layer in perovskite solar cells, the average energy conversion efficiency of the cells reaches 24.5%. This is likely due to the excellent hole transport properties of SBF-FC and the slow charge recombination at the perovskite / hole transport layer interface. Furthermore, the cells exhibit good tolerance to temperatures of 85°C, which can be attributed to the fact that the hole transport layer based on the SBF-FC product of this invention maintains its morphological integrity after aging and effectively inhibits the degradation of the perovskite light absorption layer.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The several organic semiconductor materials containing fluorenecarbazole amine provided by the present invention have properties such as a high highest occupied molecular orbital energy level, a high glass transition temperature, high conductivity, and solution processability, and can be used to prepare perovskite solar cells with high energy conversion efficiency and good thermal stability.

[0031] 2. The average energy conversion efficiency of perovskite solar cells using several organic semiconductor materials containing fluorenecarbazole amine electron donors prepared by the present invention as hole transport materials reaches 24.5%, and the energy conversion efficiency retention rate of the device after 500 hours of thermal aging at 85°C is greater than 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 DSC curves of organic semiconductor materials containing fluorenecarbazole amine electron donors of formula (IA), formula (II-A), formula (III-A) and formula (IV-A) measured by differential scanning calorimetry (DSC);

[0033] Figure 2 The measured cyclic voltammetry curves of the organic semiconductor materials of formula (IA), formula (II-A), formula (III-A) and formula (IV-A) containing the fluorenecarbazoleamine electron donor and the calculated highest occupied molecular orbital energy level;

[0034] Figure 3 This is a schematic diagram of the device structure of the perovskite solar cell provided by the present invention.

[0035] Figure 4 This is a voltage-current curve of the perovskite solar cell prepared in Example 1 of the present invention before and after aging at 85°C for 500 hours.

[0036] Figure 5 The voltage-current curves of the perovskite solar cell prepared in the comparative example before and after aging at 85°C for 500 hours. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0038] Example 1

[0039] Synthesis of the target compound of formula (IA);

[0040]

[0041] Under the protection of argon, 2,2',7,7'-tetrabromo-9,9'-spirobifluorene (474 ​​mg, 0.75 mmol), N-(9,9-dimethyl-9H-fluoren-2-yl)-9-methyl-9H-carbazole-3-amine (1.46 g, 3.75 mmol), tris(dibenzylideneacetone)dipalladium (137 mg, 0.15 mmol), tri-tert-butylphosphine tetrafluoroborate (87 mg, 0.30 mmol) and sodium tert-butoxide (360 mg, 3.75 mmol) were added together in 50 mL of anhydrous toluene and the reaction mixture was stirred continuously. The system was heated to 120° C. and the reaction was continued for 12 hours. After the reaction was completed, the reaction solution was allowed to stand and cool to room temperature, and the reaction solvent was removed by rotary evaporation under reduced pressure. Subsequently, 100 mL of distilled water was added to the system, and extraction was performed using dichloromethane (extraction was performed three times, with 100 mL of dichloromethane added each time). The organic phases were combined, and the dichloromethane was removed by rotary evaporation under reduced pressure to obtain a crude product. The crude product was separated and purified by chromatography using a mixed solvent of petroleum ether and tetrahydrofuran in a volume ratio of 2:1 as a developing solvent to obtain a white solid product having the compound formula (IA) in a yield of approximately 84% (1.18 g).

[0042] The target organic semiconductor material (IA) was characterized by nuclear magnetic resonance, mass spectrometry and elemental analysis. The results of high-resolution mass spectrometry analysis were as follows: [M] + =1861.8404.

[0043] The NMR characterization data are as follows:

[0044] 1 H NMR(400MHz,THF-d8)δ:8.01(d,J=1.9Hz,4H),7.97(d,J=7.9Hz,4H),7.56(d ,J=7.4Hz,4H),7.52(d,J=8.4Hz,4H),7.45–7.31(m,16H),7.31–7.25(m,12H) ,7.18(td,J=7.5,1.0Hz,4H),7.13(td,J=7.5,1.0Hz,4H),7.09–7.04(m,4H) ,6.99–6.90(m,8H),6.78(dd,J=8.5,2.2Hz,4H),3.78(s,12H),1.55(s,24H).

[0045] 13C NMR(100MHz,THF-d8)δ:155.78,154.51,151.19,149.33,148.49,142.83, 140.63,140.33,139.67,136.40,134.06,127.77,127.01,126.74,126.70 ,124.96,123.75,123.27,122.95,122.61,121.48,121.37,120.80,120.0 9,119.80,119.78,117.78,117.49,110.56,109.54,47.69,29.37,27.90.

[0046] The glass transition temperature of the prepared target organic semiconductor material represented by formula (IA) was measured to be 222°C.

[0047] The conductivity of the prepared target organic semiconductor material formula (IA) was measured, and the conductivity was 0.28 μS cm when naturally doped with air oxidation. -1 , after the introduction of the doping promoter, it is 49 μS cm -1 .

[0048] Example 2

[0049] Synthesis of the target compound of formula (II-A);

[0050] Compared with Example 1, in this example, 2,2',7,7'-tetrabromo-9,9'-spirobifluorene is replaced by 2,2',7,7'-tetrabromo-9,9'-difluoromethylene, and the rest of the reaction process, reagent names, and reagent amounts are consistent with those in Example 1.

[0051] The synthetic route and the final product structure are shown below:

[0052]

[0053] The target compound (II-A) was characterized by nuclear magnetic resonance, mass spectrometry and elemental analysis. The results of high-resolution mass spectrometry analysis were as follows: [M+Na] + =1896.8305.

[0054] The NMR characterization data are as follows:

[0055] 1H NMR(400MHz,THF-d8)δ:7.86(s,4H),7.61(d,J=8.2Hz,4H),7.55(s,4H),7.40(d,J=7.9Hz,4H),7.32–7.17(m,20H),7.13(t,J =7.8Hz,4H),7.06(t,J=7.8Hz,4H),6.99–6.93(m,4H),6.90–6.82(m,16H),6.72(d,J=8.7Hz,4H),3.70(s,12H),1.43(s,24H).

[0056] 13 C NMR(100MHz,THF-d8)δ:155.70,154.42,149.94,148.31,142.80,142.76,1 40.77,140.56,140.44,139.36,137.29,133.05,127.71,127.45,126.79,12 6.63,126.28,124.83,123.80,123.74,123.26,121.46,121.40,121.05,120.80,120.03,119.66,119.15,116.19,110.65,109.55,47.53,29.33,27.53.

[0057] The glass transition temperature of the prepared target organic semiconductor material of formula (II-A) was measured and the result was 242°C.

[0058] The conductivity of the prepared target organic semiconductor material (II-A) was measured, and the conductivity was 0.20 μS cm when naturally doped with air oxidation. -1 , after the introduction of the doping promoter, it is 41 μS cm -1 .

[0059] Example 3

[0060] Synthesis of target compound formula (III-A):

[0061] Compared with Example 1, in this example, 2,2',7,7'-tetrabromo-9,9'-spirobifluorene was replaced with 3,6,11,14-tetrabromodibenzochrysene, and the rest of the reaction process, reagent names, and reagent amounts remained the same as in Example 1.

[0062] The synthetic route and the final product structure are shown below:

[0063]

[0064] The target compound (III-A) was characterized by nuclear magnetic resonance, mass spectrometry and elemental analysis. The high-resolution mass spectrometry analysis results showed that [M+Na] + =1896.8311.

[0065] The NMR characterization data are as follows:

[0066] 1 H NMR(400MHz,THF-d8)δ:8.39–8.33(m,8H),7.92(dd,J=10.3,4.7Hz,8H),7.59(d,J=7.4Hz,4H),7.46–7.41(m,12H), 7.38–7.30(m,8H),7.28–7.19(m,8H),7.19–7.06(m,16H),6.90(dd,J=8.5,1.8Hz,4H),3.65(s,12H),1.49(s,24H).

[0067] 13 C NMR(100MHz,THF-d8)δ:155.81,154.44,149.52,147.57,142.76,140.45,1 39.52,133.70,130.86,129.84,129.08,128.82,127.72,127.00,126.92,12 6.62,125.05,124.91,124.64,123.76,123.23,122.15,121.76,121.49,121.40,120.20,119.78,119.65,117.05,110.69,109.56,47.56,29.33,27.53.

[0068] The glass transition temperature of the prepared target organic semiconductor material of formula (III-A) was measured and the result was 246°C.

[0069] The conductivity of the prepared target organic semiconductor material (III-A) was measured, and the conductivity was 0.32 μS cm when naturally doped with air oxidation. -1 , after the introduction of the doping promoter, it is 53 μS cm -1 .

[0070] Example 4

[0071] Synthesis of target compound formula (IV-A)

[0072] Compared with Example 1, in this example, 2,2',7,7'-tetrabromo-9,9'-spirobifluorene was replaced with 2,7,10,15-tetrachlorotetraphenylene, and the rest of the reaction process, reagent names, and reagent amounts remained the same as in Example 1.

[0073] The synthetic route and the final product structure are shown below:

[0074]

[0075] The target compound (IV-A) was characterized by nuclear magnetic resonance, mass spectrometry and elemental analysis. The results of high-resolution mass spectrometry analysis were as follows: [M] + =1849.8448.

[0076] The NMR characterization data are as follows:

[0077] 1 H NMR(400MHz,THF-d8)δ:7.86(d,J=6.6Hz,8H),7.51(d,J=7.5Hz,4H),7.45(d,J=8.3Hz,4H),7.37–7.29(m,8H),7.28–7.17(m,16H),7. 13(t,J=7.5Hz,4H),7.06(t,J=7.5Hz,4H),6.98(s,4H),6.91(t,J=7.2Hz,8H),6.86(s,8H),3.79(s,12H),1.43(s,12H),1.35(s,12H).

[0078] 13 C NMR(100MHz,THF-d8)δ:155.91,154.56,149.41,148.77,144.16,142.77 ,140.89,140.33,139.50,136.07,134.39,130.10,127.79,127.06,126.6 5,126.22,124.93,123.71,123.42,123.29,121.83,121.47,121.42,120. 06,119.69,119.25,118.54,110.48,109.46,47.67,29.32,27.93,27.56.

[0079] The glass transition temperature of the prepared target organic semiconductor material of formula (IV-A) was measured and the result was 222°C.

[0080] The conductivity of the prepared target organic semiconductor material (IV-A) was measured, and the conductivity was 0.02 μS cm when naturally doped with air oxidation.-1 , after the introduction of the doping promoter, it is 6.3 μS cm -1 .

[0081] The following examples 5, 6 and 7 illustrate in detail the application method and effect of the organic semiconductor material synthesized in the present invention as a hole transport material in perovskite photoelectric devices.

[0082] Example 5 Preparation of perovskite solar cells

[0083] First, the indium tin oxide (ITO) glass was laser etched, and then a series of ultrasonic cleanings were performed with detergent, deionized water, acetone, and ethanol. The cleaned ITO substrate was then treated with UV ozone. For the electron transport layer, a 3wt% SnO2 colloidal solution was spin-coated onto the ITO substrate and heated at 150°C for 30 minutes. Subsequently, a DMF / DMSO (volume ratio of 9:1) solution containing 1.5MPbI2 and 0.075MRbCl was spin-coated on the electron transport layer and heated at 70°C for 1 minute. After cooling to room temperature, a solution of formamidine iodide: methylamine chloride (90mg:13.5mg in 1ml isopropanol) was spin-coated and heated at 150°C for 30 minutes to obtain a FAPbI3 perovskite layer. For the passivation layer, 5mg of phenylethylamine iodide was dissolved in 1mL of isopropanol and spin-coated onto the perovskite surface. For the hole transport layer, 50mg mL -1 Organic semiconductor material product of formula (IA), formula (II-A), formula (III-A) or formula (IV-A), 8.82 mg mL -1 Tert-butylpyridinium bis(trifluorosulfonyl)imide) and 132 mM tert-butylpyridine were added to 1 mL of chlorobenzene to prepare a hole transport layer solution. The hole transport layer solution was then deposited on the perovskite layer by dynamic spin coating at 4000 rpm for 30 seconds. -4 Pa vacuum thermal evaporation of about 100nm thick gold layer to complete the battery manufacturing. The structure of the perovskite solar cell is shown in the figure below. Figure 3 As shown, the effective area of ​​the battery is 0.258cm 2 .

[0084] Example 6 Energy Efficiency Test

[0085] At a light intensity of 100 mW cm -2 Under AM1.5G simulated sunlight, the voltage-current curve of the perovskite solar cell prepared in Example 5 was tested to obtain the energy conversion efficiency. The results are shown in the following table:

[0086] Organic semiconductor materials Energy conversion efficiency Formula (IA) 24.7％ Formula (II-A) 24.2％ Formula (III-A) 24.1％ Formula (IV-A) 21.0％

[0087] Example 7 Aging test of perovskite solar cells

[0088] The packaged batteries were stored in an oven at 85°C to evaluate long-term thermal stability. The relative humidity outside the oven was 45% to 85%. The batteries were removed from the oven at regular intervals for measurement.

[0089] At a light intensity of 100 mW cm -2 The voltage-current curve of the battery was tested under AM1.5G simulated sunlight. Figure 4 The voltage-current curves of the perovskite solar cell prepared in Example 1 of the present invention before and after aging at 85°C for 500 hours. Before aging, the open circuit voltage of the cell was 1.18 V and the short-circuit current density was 25.9 mA cm -2 , the fill factor is 80.9%, the energy conversion efficiency is 24.7%; after 1,000 hours of aging at 85°C, the open circuit voltage of the battery is 1.16V, and the short-circuit current density is 25.2mAcm -2 , the fill factor is 77.3%, the energy conversion efficiency is 22.6%, and the device energy conversion efficiency retention rate is 92%.

[0090] Comparative Example

[0091] Commercially available spiro-OMeTAD was used as the hole transport material. Perovskite solar cells were prepared according to the steps of Example 5. Performance tests were conducted under the same conditions as in Example 6. The results showed that the open circuit voltage of the cell before aging was 1.14 V and the short-circuit current density was 25.9 mA cm -2 , the fill factor is 77.6%, the energy conversion efficiency is 22.9%; after aging at 85℃ for 500 hours, the open circuit voltage of the battery is 0.715V, and the short circuit current density is 13.3mA cm -2 , the fill factor is 43.2%, the energy conversion efficiency is 4.2%, and the device energy conversion efficiency retention rate is 18.3%. Figure 5 The voltage-current curves of the perovskite solar cell prepared in the comparative example before and after aging at 85°C for 500 hours.

[0092] The test results show that the organic semiconductor material of the present invention is used as a hole transport layer for perovskite solar cells, has the characteristics of high glass transition temperature and high electrical conductivity, and far exceeds existing organic semiconductor materials or existing technical solutions in terms of long-term stability at 85°C.

[0093] The above embodiments are provided to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by a person skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An organic semiconductor material containing a fluorenecarbazoleamine electron donor, characterized in that: The organic semiconductor material is composed of spirobifluorene, difluorene, dibenzochrysene or tetraphenylene as a central skeleton, and N-(9,9-dimethyl-9H-fluoren-2-yl)-9-methyl-9H-carbazole-3-amine as an electron donor; the central skeleton has four symmetrically arranged six-membered ring structures, and the four electron donors are connected to the six-membered ring structures used as electron acceptors in a one-to-one correspondence; The general structural formula of the organic semiconductor material is any one of formula (IA), formula (II-A), formula (III-A), and formula (IV-A):

2. The method for preparing the organic semiconductor material containing the fluorenecarbazoleamine electron donor according to claim 1, characterized in that: include: Under nitrogen protection, a central skeleton halide, N-(9,9-dimethyl-9H-fluoren-2-yl)-9-methyl-9H-carbazole-3-amine, tris(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate, and sodium tert-butoxide are added to toluene in a molar ratio of 1:5:0.2:0.4:5; the mixture is heated to 120° C. while stirring, and then reacted for 12 hours; after the reaction is completed, the mixture is allowed to stand, cooled to room temperature, and separated and purified by column chromatography to obtain a solid, which is the organic semiconductor material; The central skeleton halogenated compound is any one of the following: 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 2,2',7,7'-tetrabromo-9,9'-difluorene, 3,6,11,14-tetrabromodibenzochrysene or 2,7,10,15-tetrachlorotetraphenylene.

3. The use of the organic semiconductor material containing the fluorenecarbazoleamine electron donor according to claim 1, characterized in that: It is used as the hole transport layer material of perovskite solar cells.

4. The use according to claim 3, characterized in that When preparing a perovskite solar cell, the organic semiconductor material, tert-butylpyridinium bis(trifluorosulfonyl)imide, and tert-butylpyridine are first added to chlorobenzene to obtain a hole transport layer solution; then, a dynamic spin coating method is used to rotate at 4000 rpm for 30 seconds to deposit the organic semiconductor material on the perovskite layer to obtain a hole transport layer.

5. A perovskite solar cell device using the organic semiconductor material containing the fluorenecarbazoleamine electron donor according to claim 1 as a hole transport layer material, characterized in that: The perovskite solar cell device has a multi-layer structure, which includes, from bottom to top: an ITO conductive glass layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a metal electrode.

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