Receptor containing three-dimensional structure unit and preparation method and application thereof

Abstract

The invention discloses a receptor containing a three-dimensional structural unit, the chemical structural general formula of the receptor is as shown in formula I. In the formula I, Ar is selected from the structural unit as shown in formula i or formula ii. Compared with an existing acceptor, after a three-dimensional structure unit is introduced into an A'unit of the acceptor, the fluorescence quantum yield of the acceptor is remarkably improved, and then the voltage loss of a corresponding photovoltaic device is effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaic materials, and in particular relates to a receptor containing a three-dimensional structural unit. Background Art

[0002] Organic solar cells with organic semiconductor materials as active layers can be printed to prepare large-area flexible devices. They have the characteristics of low cost, colorfulness, and translucency. They are a photovoltaic technology with great development prospects. The active layer of organic solar cells is generally composed of a blend of electron donors and electron acceptors. Since Zou Yingping's research group at Central South University reported the high-performance Y6 small molecule acceptor in 2019, this A-DA'DA type electron acceptor (based on 2,1,3-benzothiadiazole (BT) as the core, with nitrogen atoms and two thieno[3,2-b]thiophene (TT) connected in parallel on both sides of the benzene ring of BT) has been widely used. ) has attracted widespread attention. Due to its ease of synthesis, structural modifications of the side chains of these A-DA'DA receptor molecules have been systematically studied. Existing research has demonstrated that increasing the fluorescence quantum yield of the receptor material can effectively reduce the voltage loss of the corresponding photovoltaic device. Summary of the Invention

[0003] The purpose of the present invention is to improve the A' unit in the structure of the above-mentioned A-DA'DA type receptor material and obtain a higher fluorescence quantum yield by introducing a three-dimensional structural unit.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A receptor containing a three-dimensional structural unit, wherein the general chemical structure of the receptor is shown in Formula I:

[0006] , wherein R1, R2, R3 and R4 are each independently selected from hydrogen or substituted or unsubstituted C6-C 20 Alkyl, A1 and A2 are each independently selected from any one of the groups shown in Formula A to Formula G:

[0007] , X1, X2, X3 and X4 are each independently selected from hydrogen, deuterium, halogen, nitro, cyano, C1-C 30 Alkyl, C3-C 30 Cycloalkyl, C1-C 30 Alkoxy, halogenated C1-C 30 Alkyl or halogenated C1-C 30 Alkoxy, X5 is substituted or unsubstituted C1-C 30 Alkyl, substituted or unsubstituted C3-C30 Cycloalkyl, substituted or unsubstituted C6-C 30 Aryl or substituted or unsubstituted C4-C 30 Heteroaryl, the substituent for said substitution is selected from deuterium, halogen, nitro, cyano, C1-C 10 Alkyl, C1-C 10 Alkoxy, C3-C 10 Cycloalkyl, C6-C 12 Aryl or C4-C 12 heteroaryl,

[0008] Its characteristic point is that Ar is selected from the structural unit shown in formula i or formula ii:

[0009] ,

[0010] X6, X7, X8 and X9 are each independently selected from hydrogen, deuterium, halogen, nitro, cyano, C1-C 30 Alkyl, C3-C 30 Cycloalkyl, C1-C 30 Alkoxy, halogenated C1-C 30 Alkyl or halogenated C1-C 30 Alkoxy.

[0011] Preferably, the receptor is

[0012] .

[0013] The preparation method of the above receptor comprises:

[0014] (1) reacting the compound represented by formula II with the diketone represented by formula i-1 or formula ii-1 to obtain the compound represented by formula III;

[0015] (2) The compound represented by Formula III is subjected to a Vilsmeier reaction to obtain a compound represented by Formula IV;

[0016] (3) The compound represented by Formula IV is reacted with one or two compounds selected from the group consisting of Formulas A-1 to G-1 by Knoevenagel reaction to obtain the receptor;

[0017] ,

[0018] ,

[0019] ,

[0020] ,

[0021] .

[0022] Preferably, the reaction temperature of step (1) is 60-80°C.

[0023] Preferably, the formylating agent in the Vilsmeier reaction in step (2) is N,N-dimethylformamide, the catalyst is POCl3, and the reaction temperature is 60-90°C.

[0024] Preferably, the catalyst for the Knoevenagel reaction in step (3) is boron trifluoride etherate.

[0025] Application of the above-mentioned acceptor in the preparation of organic solar cells.

[0026] An organic solar cell comprises a hole collection layer, an active layer and an electron collection layer. The active layer is a blend of an acceptor material and a donor material. The organic solar cell is characterized in that the acceptor material comprises the acceptor described above.

[0027] Preferably, the donor material is selected from at least one of PBDB-T, PM6, D18, and PTQ-10.

[0028] Preferably, the hole collection layer is (2-(9H-carbazol-9-yl)ethyl)phosphonic acid.

[0029] Preferably, the electron collection layer is PDINN.

[0030] Preferably, the mass ratio of the acceptor material to the donor material is 1:0.5 to 1:2, more preferably 1:1.2.

[0031] Preferably, the active layer is a blend of D18, L8-BO and the above-mentioned acceptor in a mass ratio of 1:1:0.2. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 UV-visible absorption spectra of the acceptor LLZ1 solution (solvent: chloroform) and film.

[0033] Figure 2 Figure 2 is the fluorescence quantum yield diagram of the receptor LLZ1 (a) and the receptor L8-BO (b).

[0034] Figure 3 The current density-voltage (JV) curve of the organic solar cell prepared based on the acceptor LLZ1. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described in detail below with reference to the embodiments.

[0036] PBDB-T: CAS number is 1415929-80-4

[0037] PM6: CAS number is 1802013-84-8

[0038] D18: CAS number is 2433725-54-1

[0039] PTQ-10: CAS number is 2269476-13-1

[0040] 2PACz: (2-(9H-carbazol-9-yl)ethyl)phosphonic acid, CAS number 20999-38-6

[0041] PDINN: CAS number is 1020180-01-1

[0042] Example 1: Synthesis of Compound 3

[0043] Compound 1 (CAS: 2962942-91-0):

[0044]

[0045] Compound 2:

[0046]

[0047] Diketone:

[0048]

[0049] Compound 3:

[0050]

[0051] Compound 1 (200 mg, 0.2 mmol) was dissolved in 20 mL of acetic acid, and zinc powder (261 mg, 4 mmol) was added under nitrogen. The mixture was then heated to 80°C for 3 hours. After cooling to room temperature, the mixture was filtered to remove solids. The mixed solution was extracted with ethyl acetate. The solvent was then removed under reduced pressure to obtain compound 2 as a dark solid, which was not further purified.

[0052] Compound 2 (194 mg, 0.2 mmol) and the diketone (60 mg, 0.4 mmol) were added to 5 mL of pyridine. The mixture was heated to 75°C overnight, cooled to room temperature, and then extracted with dichloromethane. The solvent was removed under reduced pressure. The organic phase was purified by silica gel column chromatography to obtain compound 3 as an orange solid (120 mg, 55% yield). 1H NMR (600 MHz, Chloroform-d) δ 6.96 (s, 2H), 5.83 (s, 2H), 4.63 (m, 4H), 4.33 (d, 2H), 3.42(s, 2H), 2.77 (d, 4H), 2.13 (d, 1H), 2.09-2.04 (m, 4H), 1.95 (d, 1H), 1.37-1.26 (m, 48H), 0.91-0.87 (m, 12H), 0.66-0.60 (m, 12H).

[0053] Example 2: Synthesis of Compound 4

[0054] Compound 4:

[0055]

[0056] Compound 3 (120 mg, 0.1 mmol), N,N-dimethylformamide (2.0 mL), and 1,2-dichloroethane (15 mL) were added to a two-necked flask. Under an N2 atmosphere, 0.1 mL of POCl3 was added, and the mixture was heated to 85°C for 12 h. After completion of the reaction, the mixture was poured into a saturated NaHCO3 solution (500 mL) and stirred for 12 hours. After extraction with dichloromethane, the solution was dried and filtered, and the solvent was removed under reduced pressure. The crude product was purified by silica gel column chromatography to obtain compound 4 (100 mg, 80% yield) as an orange oil. 1 HNMR (600 MHz, Chloroform-d) δ 10.11 (s, 2H), 5.83 (s, 2H), 4.65 (m, 4H), 4.35(d, 2H), 3.44 (s, 2H), 3.12 (d, 4H), 2.15 (d, 1H), 2.11-2.00 (m, 4H), 1.97(d, 1H), 1.42-1.25 (m, 48H), 0.90-0.84 (m, 12H), 0.68-0.60 (m, 12H).

[0057] Example 3: Synthesis of receptor LLZ1

[0058] Receptor LLZ1:

[0059]

[0060] Compound 4 (0.1 mmol) and 5,6-difluoro-3-(dicyanomethylidene)indone (0.25 mmol) were dissolved in toluene (15 mL). Boron trifluoride etherate (0.5 mL) and acetic anhydride (1.0 mL) were added and stirred at room temperature for 2 h. The reaction mixture was poured into water and extracted with dichloromethane. The solvent was evaporated in vacuo and purified by column chromatography. The purified crude product was dissolved in chloroform and precipitated with n-hexane to obtain the receptor LLZ1 (117 mg, 75% yield). 1 H NMR (600 MHz, Chloroform-d) δ9.13 (s, 2H), 8.56 (dd, 2H), 7.71 (t, 2H), 5.81 (s, 2H), 4.78 (s, 4H), 4.37(d, 2H), 3.46 (s, 2H), 3.23 (d, 4H), 2.17 (d, 1H), 2.13 (m, 4H), 1.99 (d, 1H)1.47-1.24 (m, 32H), 1.06 (m, 16H), 0.89-0.83 (m, 12H), 0.78 (m, 6H), 0.69 (m,6H).

[0061] A chloroform solution (10 mg / mL) of the receptor LLZ1 was spin-coated on quartz glass, and the resulting receptor film was used to test the UV-visible absorption spectrum.

[0062] The UV-visible absorption spectra of the chloroform solution and film of the receptor LLZ1 are shown in Figure 2. Figure 1 shown.

[0063] Figure 2 Figure 2 shows the fluorescence quantum yield of LLZ1. The photoluminescence quantum yield (PLQY) of LLZ1 reaches 6.56%, while that of L8-BO is only 3.22%. Experimental results indicate that the introduction of a three-dimensional structural unit into the A' unit of L8-BO significantly improves the fluorescence quantum yield of the receptor.

[0064] Construction of organic solar cells:

[0065] The solar cell structure consists of ITO / 2PACz / donor material:acceptor material / PDINN / Ag. A glass substrate coated with ITO strips (anode) was ultrasonically treated with alkali solution, deionized water, acetone, isopropyl alcohol, and ethanol for 20 minutes. The cleaned ITO glass was dried and then treated with ozone for 20 minutes. The hole-collecting layer, 2PACz, was then spin-coated at 5500 rpm for 25 seconds and annealed at 70°C for 1 minute. The annealed substrate was then transferred to a nitrogen-filled glove box. A chloroform mixture of PBDB-T and LLZ1 (mass ratio 1:1.2) was spin-coated onto the substrate to form a film, which was then annealed on a hot plate at 100°C for 1 minute. The electron-collecting layer, PDINN, was then spin-coated, and finally a 100 nm thick silver electrode was deposited by vacuum evaporation.

[0066] Comparative battery: The preparation process is the same as above, except that L8-BO is used instead of LLZ1.

[0067] The performance test results of the above batteries are shown in Table 1.

[0068] Table 1

[0069]

[0070] The preparation process of the ternary organic solar cell based on D18:L8-BO:LLZ1 is the same as above, except that a chloroform mixed solution of D18, L8-BO and LLZ1 (the mass ratio of the three is 1:1:0.2) is used instead of the chloroform mixed solution of PBDB-T and LLZ1. The JV curve of the ternary organic solar cell is shown in Figure 2. Figure 3 As shown, the corresponding V OC It is 0.922V and PCE is 20.4%.

[0071] Receptor L8-BO:

[0072]

[0073] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A receptor comprising a three-dimensional structural unit, wherein the chemical structure of the receptor is shown in Formula I: ， wherein R1, R2, R3 and R4 are each independently selected from hydrogen or substituted or unsubstituted C6-C 20 Alkyl, A1 and A2 are each independently selected from any one of the groups shown in Formula A to Formula G: ， X1, X2, X3 and X4 are each independently selected from hydrogen, deuterium, halogen, nitro, cyano, C1-C 30 Alkyl, C3-C 30 Cycloalkyl, C1-C 30 Alkoxy, halogenated C1-C 30 Alkyl or halogenated C1-C 30 Alkoxy, X5 is substituted or unsubstituted C1-C 30 Alkyl, substituted or unsubstituted C3-C 30 Cycloalkyl, substituted or unsubstituted C6-C 30 Aryl or substituted or unsubstituted C4-C 30 Heteroaryl, the substituent for said substitution is selected from deuterium, halogen, nitro, cyano, C1-C 10 Alkyl, C1-C 10 Alkoxy, C3-C 10 Cycloalkyl, C6-C 12 Aryl or C4-C 12 heteroaryl, Its characteristics are: Ar is selected from the structural units shown in formula i or formula ii: ， X6, X7, X8 and X9 are each independently selected from hydrogen, deuterium, halogen, nitro, cyano, C1-C 30 Alkyl, C3-C 30 Cycloalkyl, C1-C 30 Alkoxy, halogenated C1-C 30 Alkyl or halogenated C1-C 30 Alkoxy.

2. The receptor according to claim 1, characterized in that: The receptor is 。 3. A method for preparing the receptor according to claim 1 or 2, comprising: (1) reacting the compound represented by formula II with the diketone represented by formula i-1 or formula ii-1 to obtain the compound represented by formula III; (2) The compound represented by Formula III is subjected to a Vilsmeier reaction to obtain a compound represented by Formula IV; (3) The compound represented by Formula IV is reacted with one or two compounds selected from the group consisting of Formulas A-1 to G-1 by Knoevenagel reaction to obtain the receptor; ， ， ， ， 。 4. The preparation method according to claim 3, wherein: The reaction temperature of step (1) is 60-80°C; Step (2) The formylation reagent of the Vilsmeier reaction is N,N-dimethylformamide, the catalyst is POCl3, and the reaction temperature is 60-90°C; The catalyst for the Knoevenagel reaction in step (3) is boron trifluoride etherate.

5. Use of the acceptor according to claim 1 or 2 in the preparation of organic solar cells.

6. An organic solar cell comprising a hole collection layer, an active layer, and an electron collection layer, wherein the active layer is a blend of an acceptor material and a donor material, characterized in that: The receptor material comprises the receptor according to claim 1 or 2.

7. The organic solar cell according to claim 6, wherein: The donor material is selected from at least one of PBDB-T, PM6, D18, and PTQ-10.

8. The organic solar cell according to claim 6, wherein: The hole collection layer is (2-(9H-carbazol-9-yl)ethyl)phosphonic acid; The electron collection layer is PDINN.

9. The organic solar cell according to claim 6, wherein: The mass ratio of the acceptor material to the donor material is 1:0.5 to 1:2, preferably 1:1.2; Preferably, the active layer is a blend of D18, L8-BO and the acceptor according to claim 1 or 2 in a mass ratio of 1:1:0.

2.

10. A semiconductor blend for photovoltaic devices, comprising an acceptor material and a donor material, characterized in that: The receptor material comprises the receptor according to claim 1 or 2; Preferably, the donor material is selected from at least one of PBDB-T, PM6, D18, and PTQ-10; Preferably, the mass ratio of the acceptor material to the donor material is 1:0.5 to 1:2, more preferably 1:1.2; Preferably, the semiconductor blend consists of D18, L8-BO and the acceptor according to claim 1 or 2 in a mass ratio of 1:1:0.2.

Images