A ferrocene-peryleneimide complex small molecule compound, its preparation method and application
By preparing a composite small molecule compound of ferrocene and perylene imide as an electron transport layer material, the problems of film formation and low conductivity of small molecule electron transport layers were solved, thereby improving the performance and commercial potential of organic solar cells.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ENERGY RES INST OF JIANGXI ACAD OF SCI
- Filing Date
- 2023-10-23
- Publication Date
- 2026-06-30
AI Technical Summary
Existing small molecule electron transport layers have poor film-forming properties, low electron mobility, and low conductivity in organic solar cells, which limits their development in the field of organic solar cells.
Ferrocene and perylene imide composite small molecule compounds are used as electron transport layer materials. They are prepared by esterification and quaternization reactions. The high electron mobility and high conductivity of perylene imide and ferrocene units are combined, and ester groups are introduced into the molecular structure to improve film-forming properties.
It achieves good film formation and thickness insensitivity of the electron transport layer, improves the energy conversion efficiency and conductivity of organic solar cells, and is suitable for commercial applications.
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Figure CN117417386B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic solar cell technology, and in particular to a ferrocene-perylene imide composite small molecule compound, its preparation method, and its application. Background Technology
[0002] In organic solar cells, improving energy conversion efficiency requires not only continuous innovation in donor and acceptor materials but also optimization of the performance of the hole or electron transport layer. In recent years, electron transport layers have made rapid progress in organic solar cells, primarily consisting of polymer and small molecule types. Although most high-efficiency organic solar cell devices currently employ polymer electron transport layers, batch-to-batch inconsistencies in polymer materials lead to unstable device performance. In contrast, small molecule electron transport layers offer advantages such as precise structure and simple synthesis, attracting considerable attention from researchers. However, existing small molecule electron transport layers still face challenges such as poor film-forming properties, low electron mobility, and low conductivity, hindering the fabrication of thick-film devices and limiting their development in the field of organic solar cells. Summary of the Invention
[0003] The purpose of this invention is to provide a ferrocene-perylene imide composite small molecule compound, its preparation method, and its application. The ferrocene-perylene imide composite small molecule compound provided by this invention is used to prepare the electron transport layer of organic solar cells. It has the characteristics of good film-forming properties, high electron mobility and conductivity, and is not sensitive to thickness, which is beneficial for commercial application.
[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:
[0005] This invention provides a ferrocene-peryleneimide complex small molecule compound having the structure shown in Formula I:
[0006]
[0007] In Formula I, n and m are independently integers from 1 to 12, R1 is hydrogen, methyl, ethyl, propyl, butyl, fluorine, chlorine or bromine; R2 and R3 are independently hydrogen, fluorine, chlorine or bromine.
[0008] Preferably, it has the structure shown in Formula II:
[0009]
[0010] This invention provides a method for preparing the ferrocene-perylene imide complex small molecule compound described above, comprising the following steps:
[0011] Compound 1, a first polar organic solvent, a dehydrating agent, a basic catalyst, and compound 2 were mixed and subjected to an esterification reaction to obtain compound 3;
[0012] Compound 3 was mixed with compound 4 and a second polar organic solvent to carry out a quaternization reaction, resulting in a small molecule compound of ferrocene and perylene imide with the structure shown in Formula I.
[0013]
[0014] Preferably, the molar ratio of compound 1 to compound 2 is 1:(1.1 to 10).
[0015] Preferably, the dehydrating agent comprises N,N'-dicyclohexylcarbodiimide or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide; the molar ratio of compound 1 to the dehydrating agent is 1:(1.1-10).
[0016] Preferably, the alkaline catalyst comprises 4-dimethylaminopyridine; the molar ratio of compound 1 to the alkaline catalyst is 1:(0.1-10).
[0017] Preferably, the temperature of the esterification reaction is 30–70°C.
[0018] Preferably, the molar ratio of compound 4 to compound 3 is 1:(2.1 to 10).
[0019] Preferably, the quaternization reaction is carried out at a temperature of 40–120°C for a time of 24–96 hours.
[0020] This invention provides the application of the ferrocene-perylene-imide composite small molecule compound described in the above-described scheme or the ferrocene-perylene-imide composite small molecule compound prepared by the above-described preparation method in the electron transport layer of organic solar cells.
[0021] This invention provides a ferrocene-perylene imide composite small molecule compound with the structure shown in Formula I. This compound combines the high electron mobility and high electrical conductivity of perylene imide and ferrocene units. At the same time, the presence of ester groups in the molecular structure ensures good film-forming properties when the compound is used as an electron transport layer material, and also endows it with thickness insensitivity, which is beneficial to its commercial application.
[0022] This invention also provides a method for preparing the above-mentioned ferrocene and perylene imide complex small molecule compound. This invention utilizes esterification reaction and quaternary ammonium salt reaction, which is green and environmentally friendly and the preparation method is simple. Attached Figure Description
[0023] Figure 1 The image shows the one-dimensional 1H NMR spectrum of compound 3-1 in deuterated chloroform.
[0024] Figure 2 This is the one-dimensional carbon spectrum of compound 3-1 in deuterated trichloromethane;
[0025] Figure 3 The image shows the one-dimensional hydrogen NMR spectrum of compound II in deuterated dimethyl sulfoxide;
[0026] Figure 4 JV curves (a) and EQE curves (b) of the ferrocene-peryleneimide composite small molecule electron transport layer at different thicknesses are shown.
[0027] Figure 5 In the figure, (a) is the UV-Vis absorption spectrum of the ferrocene-peryleneimide composite small molecule electron transport layer material in trifluoroethanol solution with a concentration of 0.01 mg / ml and a thickness of 30 nm; (b) is the UV photoelectron spectrum of the ferrocene-peryleneimide composite small molecule electron transport layer material and the silver electrode; (c) is the electron paramagnetic resonance spectrum of compound II; and (d) is the conductivity test curve, with the test structure being ITO / PDIN-Fc / Ag. Detailed Implementation
[0028] This invention provides a ferrocene-peryleneimide complex small molecule compound having the structure shown in Formula I:
[0029]
[0030] In Formula I, n and m are independently integers from 1 to 12, R1 is hydrogen, methyl, ethyl, propyl, butyl, fluorine, chlorine or bromine; R2 and R3 are independently hydrogen, fluorine, chlorine or bromine.
[0031] In this invention, n and m are preferably integers from 1 to 12, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.
[0032] In this invention, the ferrocene-perylene imide complex small molecule compound preferably has the structure shown in Formula II:
[0033]
[0034] The ferrocene-perylene imide composite small molecule compound provided by this invention combines the high electron mobility and high electrical conductivity of perylene imide and ferrocene units. At the same time, the presence of ester groups in the molecular structure ensures good film-forming properties when the compound is used as an electron transport layer material, and also endows it with thickness insensitivity, which is beneficial to its commercial application.
[0035] This invention provides a method for preparing the ferrocene-perylene imide complex small molecule compound described above, comprising the following steps:
[0036] Compound 1, a first polar organic solvent, a dehydrating agent, a basic catalyst, and compound 2 were mixed and subjected to an esterification reaction to obtain compound 3;
[0037] Compound 3 was mixed with compound 4 and a second polar organic solvent to carry out a quaternization reaction, resulting in a small molecule compound of ferrocene and perylene imide with the structure shown in Formula I.
[0038]
[0039] Unless otherwise specified, all raw materials used in this invention are commercially available products well known in the art.
[0040] In this invention, compound 1, a first polar organic solvent, a dehydrating agent, an alkaline catalyst, and compound 2 are mixed and subjected to an esterification reaction to obtain compound 3.
[0041] In this invention, the first polar organic solvent is preferably dichloromethane, chlorobenzene, or o-dichlorobenzene; the amount of the first organic solvent used in this invention is not particularly required, as long as it can completely dissolve compound 1.
[0042] In this invention, the dehydrating agent preferably includes N,N'-dicyclohexylcarbodiimide (DCC) or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI); the molar ratio of compound 1 to the dehydrating agent is preferably 1:(1.1-10), more preferably 1:(2-8), and even more preferably 1:(4-6).
[0043] In this invention, the alkaline catalyst preferably comprises 4-dimethylaminopyridine (DMAP); the molar ratio of compound 1 to the alkaline catalyst is preferably 1:(0.1-10), more preferably 1:(1-9), and even more preferably 1:(3-6).
[0044] In this invention, the molar ratio of compound 1 to compound 2 is preferably 1:(1.1 to 10), more preferably 1:(2 to 8), and even more preferably 1:(4 to 6).
[0045] In this invention, the mixing of compound 1, the first polar organic solvent, the dehydrating agent, the alkaline catalyst and compound 2 preferably includes: mixing compound 1 with the first polar organic solvent, stirring at 20-50°C for 1-60 minutes, adding the dehydrating agent and the alkaline catalyst, stirring at 20-50°C for 5-120 minutes, adding compound 2, and adjusting to the temperature of the esterification reaction.
[0046] In this invention, the temperature of the esterification reaction is preferably 30–70°C, more preferably 40–60°C, and even more preferably 45–55°C. This invention does not impose a specific time limit on the esterification reaction, but column chromatography is preferably used to monitor the reaction until its completion.
[0047] After the esterification reaction is completed, the present invention preferably performs a first extraction with a mixture of water and dichloromethane on the obtained reaction solution, performs a second extraction with saturated brine on the obtained oil phase, dries the obtained oil phase, filters it, and separates it by column chromatography to obtain compound 3.
[0048] In this invention, the first extraction is preferably performed 2 to 10 times; the volume ratio of water to dichloromethane is preferably (1 to 20):(2 to 40); the second extraction is preferably performed 1 to 5 times; the eluent used for column chromatography is preferably petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is preferably (1 to 100):1.
[0049] After obtaining compound 3, the present invention mixes compound 3 with compound 4 and a second polar organic solvent to carry out a quaternization reaction to obtain a ferrocene-peryleneimide complex small molecule compound having the structure shown in Formula I.
[0050] In this invention, the second polar organic solvent preferably comprises chloroform and trifluoroethanol, or chloroform and methanol; the volume ratio of chloroform to trifluoroethanol (or methanol) is preferably 1:(1-100), more preferably 1:(10-90), and even more preferably 1:(30-60). This invention does not have special requirements on the amount of the second polar organic solvent used, as long as it is sufficient to completely dissolve compounds 3 and 4.
[0051] In this invention, the molar ratio of compound 4 to compound 3 is preferably 1:(2.1 to 10), more preferably 1:(3 to 8), and even more preferably 1:(4 to 6).
[0052] In this invention, the temperature of the quaternization reaction is preferably 40-120°C, more preferably 50-100°C, and even more preferably 60-80°C; the time of the quaternization reaction is preferably 72 hours.
[0053] After the quaternization reaction is completed, the present invention preferably evaporates the obtained reaction solution to 1 / 4 to 1 / 10 of the original volume, adds chloroform to precipitate, centrifuges, and dries to obtain a ferrocene-peryleneimide complex small molecule compound having the structure shown in Formula I.
[0054] In this invention, the centrifugation speed is preferably 1000-10000 rpm, more preferably 2000-8000 rpm, and even more preferably 4000-6000 rpm. In this invention, the number of centrifugations is preferably 2-10, and the duration of each centrifugation is preferably 1-10 minutes. In this invention, the drying temperature is preferably 30-150°C.
[0055] The preparation route of this invention is as follows:
[0056]
[0057] This invention provides the application of the ferrocene-perylene-imide composite small molecule compound described in the above-described scheme or the ferrocene-perylene-imide composite small molecule compound prepared by the above-described preparation method in the electron transport layer of organic solar cells.
[0058] This invention preferably uses the ferrocene-peryleneimide composite small molecule compound as the electron transport layer material. In this invention, the thickness of the electron transport layer is preferably less than 60 nm, more preferably 7–60 nm. This invention does not have special requirements for the specific structure of the organic solar cell; any organic solar cell well-known in the art is acceptable. In an embodiment of this invention, the organic solar cell comprises, in sequence, an indium tin oxide glass substrate, a hole transport layer, an active layer, an electron transport layer, and a metal electrode.
[0059] The following examples illustrate the ferrocene and perylene imide composite small molecule compounds, their preparation methods, and applications provided by this invention. However, these examples should not be construed as limiting the scope of protection of this invention.
[0060] Example 1
[0061]
[0062] Weigh ferrocene (compound 1-1, commercially available, 200 mg, 0.87 mmol) into a 100 mL volumetric flask, add dichloromethane (30 mL) and stir. Add DCC (commercially available, 270 mg, 1.3 mmol) and DMAP (commercially available, 10 mg, 0.087 mmol) and stir for 30 min. Finally, add bromoethanol (compound 2-1, commercially available, 125 mg, 1 mmol) and heat to 30 °C for 8 h. Monitor and confirm the end of the reaction by column chromatography. Extract three times with water and dichloromethane (water to dichloromethane volume ratio 1:1–4), and finally extract once with saturated brine. Purify by column chromatography using petroleum ether:ethyl acetate = 5:1 (volume ratio) as the eluent. The final product is a yellow solid, compound 3 (200 mg, yield 68.25%). The one-dimensional 1H NMR spectrum of compound 3-1 in deuterated trichloromethane is shown below. Figure 1 The one-dimensional carbon spectrum of deuterated trichloromethane is shown below. Figure 2 .Depend on Figure 1 and Figure 2 It can be seen that the present invention successfully prepared compound 3-1.
[0063] Compound 4-1 (commercially available or synthesized according to relevant literature, 0.24 mmol, 135 mg) and compound 3 (0.6 mmol, 200 mg) were added to a reaction flask and dissolved in 20 mL of chloroform:trifluoroethanol = 1:1 (volume ratio). The reaction was carried out at 85 °C for 48 hours. After the reaction was completed, the liquid in the reaction flask was rotary evaporated to one-quarter of its original volume. Then, 20 mL of chloroform was added, and the product precipitated. The product was centrifuged at 9800 rpm for 2 min. The solvent was removed, and the above operation was repeated 3 times. After completion, the product was dried in an oven at 60 °C for 120 min to obtain a red solid (150 mg, yield 50.45%). Its one-dimensional 1H NMR spectrum in deuterated dimethyl sulfoxide is shown in [Figure number missing]. Figure 3 This proves that compound II was indeed obtained.
[0064] Application Example 1
[0065] Application of ferrocene-peryleneimide composite small molecule electron transport layer in organic solar cells:
[0066] The donor material used in the battery device is PM6, and the acceptor material is L8-BO, with the structure shown below:
[0067]
[0068] The specific preparation and performance test results are as follows:
[0069] After cleaning, the indium tin oxide (ITO) glass substrate was treated with a UV ozone instrument for 30 minutes. A PEDOT:PSS aqueous solution diluted 2 times with an equal volume of deionized water was filtered through a 22-micron pore size water-soluble filter and then spin-coated onto the ITO substrate at 4000 rpm. The solution was then annealed at 150°C for 15 minutes to form a uniform and regular thin film as a hole transport layer (30 nm thick). Subsequently, a chloroform solution (with commercially available 1,3-dibromo-5-chlorobenzene (DBCl) as a solid additive at a mass ratio of PM6:L8-BO = 1:1.2 (based on the total donor and acceptor concentration of 16 mg / mL) was spin-coated onto the PEDOT:PSS at 3000 rpm. The spin-coated active layer was then thermally annealed at 80°C for 5 minutes (approximately 110 nm thick). Subsequently, the ferrocene and peryleneimide composite electron transport layer prepared in Example 1 was dissolved in trifluoroethanol solvent and spin-coated onto the active layer at a speed of 3500 rpm (1 mg / mL to 8 mg / mL, thickness of about 7 to 60 nm) as the electron transport layer. Then, 100 nm of Ag was evaporated in a vacuum evaporation chamber as the metal electrode.
[0070] Under optimal device conditions (test area 0.04 cm²), 2 The parameters were measured and are shown in Table 1. (The JV characteristic curve was obtained by testing under simulated sunlight of AM1.5 G and 100mW intensity (instrument model: Enlitech model SS-F5-3A) using a Keithley 2400 current / voltage data source meter. EQE was obtained by testing with a QE-R3011 (Enli Technology Co., Ltd.). The photosensitive layer thickness was measured with a step meter (model: Veeco Dektak XT) at a force of approximately 3mg.)
[0071] Table 1 Performance parameters of solar cell devices
[0072]
[0073]
[0074] Note: In Table 1, the data below are the standard deviations of ten samples, and the data above are the best performance data.
[0075] Figure 4 In the figure, (a) is the JV curve of the ferrocene-perylene-imide composite small molecule electron transport layer at different thicknesses; (b) is the EQE curve of the ferrocene-perylene-imide composite small molecule electron transport layer at different thicknesses.
[0076] As shown in Table 1 and the JV and EQE plots, the ferrocene-peryleneimide composite small molecule electron transport layer can achieve good energy conversion efficiency, reaching 18.45%, and exhibits good thickness insensitivity. At a thickness of 60 nm, the energy conversion efficiency of this small molecule electron transport layer is 17.00%, maintaining the highest efficiency of 92%. This is mainly due to the good film-forming properties, good energy level matching, and high conductivity of the small molecule electron transport layer.
[0077] Figure 5 In the table, (a) is the UV-Vis absorption spectrum of the ferrocene-peryleneimide composite small molecule electron transport layer material in trifluoroethanol solution at a concentration of 0.01 mg / ml and a thickness of 30 nm; (b) is the UV photoelectron spectrum of the ferrocene-peryleneimide composite small molecule electron transport layer material and the silver electrode; (c) is the electron paramagnetic resonance spectrum of compound II; and (d) is the conductivity test curve, with the test structure being ITO / PDIN-Fc / Ag.
[0078] Depend on Figure 5 As shown in (a), PDIN-Fc has an absorption range of 400–550 nm in solution, while its absorption range widens to 300–700 nm in thin film, indicating that the aggregation intensity of this small molecule material is enhanced in thin film, leading to a wider absorption range. Ultraviolet photoelectron spectroscopy (b) shows that PDIN-Fc can effectively reduce the work function of the silver electrode, thereby effectively improving electron transport and extraction in organic solar cells; (c) shows that PDIN-Fc has a significant self-doping effect, which helps to improve the electron mobility and conductivity of the material, thus improving the electron transport layer material's ability to transport and extract electrons; (d) shows that PDIN-Fc has high conductivity, which is attributed to the material's self-doping effect and the large conjugated system of perylene imide.
[0079] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A small molecule compound composed of ferrocene and perylene imide, having the structure shown in Formula I: Formula I; In Formula I, n and m are independent integers from 1 to 12, R1 is hydrogen, methyl, ethyl, propyl, butyl, fluorine, chlorine or bromine; R2 and R3 are independent hydrogen, fluorine, chlorine or bromine.
2. The ferrocene and perylene imide complex type small molecule compound according to claim 1, characterized by, It has the structure shown in Equation II: Formula II.
3. The method for preparing the ferrocene and perylene imide complex type small molecule compound according to claim 1, characterized in that, Includes the following steps: Compound 1, a first polar organic solvent, a dehydrating agent, a basic catalyst, and compound 2 were mixed and subjected to an esterification reaction to obtain compound 3; Compound 3 was mixed with compound 4 and a second polar organic solvent to carry out a quaternization reaction, resulting in a small molecule compound of ferrocene and perylene imide with the structure shown in Formula I. 、 、 、 。 4. The preparation method according to claim 3, characterized in that, The molar ratio of compound 1 to compound 2 is 1:(1.1~10).
5. The preparation method according to claim 3, characterized in that, The dehydrating agent includes N,N'-dicyclohexylcarbodiimide or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide; the molar ratio of compound 1 to the dehydrating agent is 1:(1.1~10).
6. The preparation method according to claim 3, characterized in that, The alkaline catalyst includes 4-dimethylaminopyridine; the molar ratio of compound 1 to the alkaline catalyst is 1:(0.1~10).
7. The preparation method according to any one of claims 3 to 6, characterized in that, The esterification reaction is carried out at a temperature of 30~70℃.
8. The preparation method according to claim 3, characterized in that, The molar ratio of compound 4 to compound 3 is 1:(2.1~10).
9. The preparation method according to claim 3 or 8, characterized in that, The quaternization reaction is carried out at a temperature of 40~120℃ for a time of 24~96 hours.
10. The application of the ferrocene-perylene-imide composite small molecule compound according to claim 1 or 2, or the ferrocene-perylene-imide composite small molecule compound prepared by the preparation method according to any one of claims 3 to 9, in the electron transport layer of an organic solar cell.