TWI723909B - Nine-membered fused ring compound and organic photovoltaic cell - Google Patents

Abstract

A nine-membered fused ring compound is shown in chemical formula (I). The nine-membered fused ring compound of the present invention can be used as a non-fullerene electron acceptor material, and can be dissolved in a relatively environmentally friendly non-chlorine solvent, and is suitable for large-area coating. In addition, the organic photovoltaic cell containing the nine-membered fused ring compound of the present invention will also have excellent energy conversion efficiency (PCE).

Description

Nine-membered fused ring compound and organic photovoltaic cell

The present invention relates to a nine-membered fused ring compound and an organic photovoltaic cell, in particular to a nine-membered fused ring compound with thiophene and an organic photovoltaic cell including the aforementioned nine-membered fused ring compound.

As the times evolve, the consumption of energy such as coal, oil, natural gas, and nuclear energy is increasing, and an energy crisis has gradually emerged. Solar power generation is an environmentally friendly power generation method that is renewable and can reduce environmental pollution. The first-generation solar cells are bulk silicon solar cells, which have a high photoelectric conversion rate. The second-generation solar cell is a thin-film cadmium telluride (CdTe) solar cell, and its raw material toxicity and manufacturing method have great environmental pollution. The third generation of organic solar cells followed up, including dye-sensitized solar cells (DSSC), nanocrystalline cells and organic photovoltaics (OPV). Compared with inorganic materials that need to be coated by a vacuum process, organic photovoltaic cells can be made by methods such as dip coating, spin coating, slit coating, screen printing or inkjet printing, which makes it easier to achieve low-cost and large-scale production. . Among them, the new generation of organic photovoltaic cells uses organic electron acceptor materials with conjugated polymers (electron donor materials) as the main photovoltaic absorber layer (active layer) material. The new generation of organic photovoltaic cells has several advantages: (1) light weight and low production cost; (2) flexibility; (3) device structure can be designed; and (4) suitable for liquid-phase process (ie Large area wet coating is possible).

In addition to the aforementioned advantages of the new generation of organic photovoltaic cells, the diversity and development of the electron donor materials (conjugated polymers) in the active layer have enabled the improvement of the energy conversion efficiency of organic photovoltaic cells to reach a certain level. However, most of the existing organic electron acceptor materials are mainly fullerene derivatives (such as PC60BM and PC70BM), and their compatibility with electron donor materials (conjugated polymers) is easily limited. In addition, the fullerene derivatives themselves also have disadvantages such as easy dimerization under light, easy crystallization when heated, weak absorption in the visible light region, difficult structural modification and purification, and high price. Therefore, it is necessary to develop organic electron acceptor materials that are not fullerene derivatives.

Although CN106831815 B discloses a non-fullerene organic electron acceptor material, it can solve the shortcomings produced when fullerene derivatives are used as the electron acceptor material. However, the absorption range of the seven-fused-ring organic electron acceptor material in the aforementioned patent can still be redshifted by increasing the number of fused rings. In addition, if the electron acceptor material has good crystallinity, a chlorine-containing solvent will be needed to increase the solubility of the device, which will increase the difficulty of subsequent coating processing.

Therefore, how to find a non-fullerene electron acceptor material that can be dissolved in a relatively environmentally friendly non-chlorine solvent (such as toluene, o-xylene), and then suitable for large-area coating to facilitate subsequent coating Processing, and the electron acceptor material can also make organic photovoltaic cells have excellent energy conversion efficiency (PCE), which has become the goal of current research and is also one of the important directions for making it industrialized.

Therefore, the first objective of the present invention is to provide a nine-membered fused ring compound. When the nine-membered fused ring compound is used as a non-fullerene electron acceptor material, it can be dissolved in a chlorine-free solvent, and the nine-membered fused ring compound can also enable the organic photovoltaic cell to have excellent energy conversion efficiency.

其中， X為NR ³、C(R ⁴) ₂或Si(R ⁵) ₂； R ¹為氫、C ₁~C ₃₀烷基、C ₁~C ₃₀烷氧基、C ₁~C ₃₀烷基芳基或C ₁~C ₃₀烷基雜芳基； R ²為C ₁~C ₃₀烷基或C ₁~C ₃₀烷氧基； E為拉電子基團；及 R ³、R ⁴與R ⁵分別為氫、C ₁~C ₃₀烷基或C ₁~C ₃₀烷氧基。 Therefore, the nine-membered fused ring compound of the present invention is shown in the following chemical formula (I): [Chemical formula (I)]

Wherein, X is NR ³ , C(R ⁴ ) ₂ or Si(R ⁵ ) ₂ ; R ¹ is hydrogen, C ₁ ~C ₃₀ alkyl, C ₁ ~C ₃₀ alkoxy, C ₁ ~C ₃₀ alkyl Aryl or C ₁ to C ₃₀ alkyl heteroaryl; R ² is C ₁ to C ₃₀ alkyl or C ₁ to C ₃₀ alkoxy; E is an electron withdrawing group; and R ³ , R ⁴ and R ⁵ Respectively hydrogen, C ₁ ~C ₃₀ alkyl or C ₁ ~C ₃₀ alkoxy.

Therefore, the second objective of the present invention is to provide an organic photovoltaic cell.

Therefore, the organic photovoltaic cell of the present invention includes the aforementioned nine-membered fused ring compound.

The effect of the present invention is that the nine-membered fused ring compound of the present invention can be used as a non-fullerene electron acceptor material, and because of its introduction of alkyl or alkoxy (ie R ² ) in the structure, it is suitable for non-chlorine solvents. It has a certain solubility, so it can be dissolved in a relatively environmentally friendly non-chlorine solvent, which is suitable for large-area coating to facilitate subsequent coating processing, and the organic photovoltaic cell containing the nine-membered fused ring compound of the present invention is also Will have excellent energy conversion efficiency (PCE).

The content of the present invention will be described in detail below:

[ Nine-membered fused ring compound ]

The nine-membered fused ring compound of the present invention is represented by the following chemical formula (I). [Chemical formula (I)]

X is NR ³ , C(R ⁴ ) ₂ or Si(R ⁵ ) ₂ and R ³ , R ⁴ and R ⁵ are hydrogen, C ₁ to C ₃₀ alkyl group or C ₁ to C ₃₀ alkoxy group, respectively. Preferably, X is NR ³ and R ³ is C ₁ to C ₃₀ alkyl or C ₁ to C ₃₀ alkoxy. More preferably, R ³ is a C ₁ to C ₃₀ alkyl group. Still more preferably, R ³ is a C ₁₂ to C ₂₂ alkyl group. More preferably, R ³ is a C ₁₄ to C ₂₀ alkyl group.

It should be noted that the “alkylaryl”, “alkylheteroaryl” and “alkylphenyl” in the present invention refer to “aryl substituted with alkyl” and “alkyl substituted with alkyl”, respectively. "Heteroaryl substituted with alkyl" and "phenyl substituted with alkyl". In addition, the carbon number before "alkylaryl", "alkylheteroaryl" or "alkylphenyl" refers to the carbon number of the alkyl group. For example, C ₁ ~C ₃₀ alkylphenyl refers to the carbon number of the alkyl group. C ₁ ~C ₃₀ alkyl substituted phenyl group.

R ¹ is hydrogen, C ₁ to C ₃₀ alkyl, C ₁ to C ₃₀ alkoxy, C ₁ to C ₃₀ alkyl aryl, or C ₁ to C ₃₀ alkyl heteroaryl. Preferably, R ¹ is a C ₁ to C ₃₀ alkyl group, a C ₁ to C ₃₀ alkyl phenyl group, or a C ₁ to C ₃₀ alkyl heteroaryl group. More preferably, R ¹ is a C ₁ to C ₃₀ alkylphenyl group. Still more preferably, R ¹ is a C ₃ to C ₁₃ alkylphenyl group. Still more preferably, R ¹ is a C ₄ to C ₁₁ alkylphenyl group. Still more preferably, R ¹ is a phenyl group substituted with a C ₄ to C ₁₁ alkyl group at the para position.

R ² is a C ₁ to C ₃₀ alkyl group or a C ₁ to C ₃₀ alkoxy group. Preferably, R ² is a C ₆ -C ₁₆ alkyl group. More preferably, R ² is a C ₆ to C ₁₂ alkyl group. Still more preferably, R ² is a C ₆ to C ₁₀ alkyl group.

、

、

、

、

、

、

、

或

， 其中，R ⁶為氫或鹵素；及R ⁷為氫、C ₁~C ₃₀烷基或C ₁~C ₃₀烷氧基。較佳地，E為

且R ⁶為鹵素。 E is an electron withdrawing group. Preferably, E is

,

,

,

,

,

,

,

or

, Wherein, R ⁶ is hydrogen or halogen; and R ⁷ is hydrogen, C ₁ to C ₃₀ alkyl or C ₁ to C ₃₀ alkoxy. Preferably, E is

And R ⁶ is halogen.

[ Organic photovoltaic cells ]

The organic photovoltaic cell of the present invention contains the aforementioned nine-membered fused ring compound.

Preferably, the organic photovoltaic cell includes a substrate, a first electrode laminated on the substrate, an electron transport layer laminated on the first electrode, an active layer laminated on the electron transport layer, and a laminated layer A hole transport layer above the active layer, and a second electrode layered above the hole transport layer, and the active layer includes the nine-membered fused ring compound.

Preferably, the organic photovoltaic cell includes a substrate, a first electrode laminated on the substrate, a hole transport layer laminated on the first electrode, an active layer laminated on the hole transport layer, An electron transport layer laminated on the active layer, and a second electrode laminated on the electron transport layer, and the active layer includes the nine-membered fused ring compound.

> Example 1>

Preparation of nine-membered fused ring compound

化合物 3

化合物 3 的製備方法：將3,4-二溴噻吩(50 g, 20.7 mmol)溶於二氯甲烷(200 mL)，冰浴下，加入三氯化鋁(26.2 g, 19.6 mmol )後，慢慢滴加癸醯氯(39.4 g, 20.7 mmol)，進行反應2小時。以二氯甲烷、水與碳酸氫鈉水溶液萃取，有機層以無水硫酸鎂乾燥及過濾，接著以迴旋濃縮機濃縮抽乾，即可得到液體化合物 1。隨後，將化合物 1溶於二甲基甲醯胺(400 ml)，加入碳酸鉀(42.9 g ,31 mmol)並滴入氫硫乙酸乙酯(27.2 ml, 24.8 mmol)，再加熱至60℃ ^oC 攪拌16小時，用水和庚烷萃取，有機層再以無水硫酸鎂乾燥及過濾，接著以迴旋濃縮機濃縮抽乾，得到化合物 2。將所得化合物 2溶於乙醇(500 mL)，加入氫氧化鈉(50 g)，加熱迴流16小時，待回溫後，倒入冰鹽酸水溶液，使固體析出。最後，過濾收集固體，以真空烘箱除水與溶劑後，得到化合物 3(48.8 g；產率:60%)。 化合物 4

化合物 4 的製備方法：將化合物 3(30 g, 77 mmol)加入喹啉(150 mL)與亞鉻酸銅Cu ₂Cr ₂O ₅(1.19 g, 3.8 mmol)，並加熱至180℃ 2小時，待反應結束後冷卻。接著，先以庚烷萃取，再依序用6M 鹽酸、水與鹽水萃取，再用無水硫酸鎂乾燥。最後，經矽膠過濾後，以迴旋濃縮機濃縮抽乾得淡黃色液體化合物 4(26 g；產率:97 %)。 化合物 5

化合物 5 的製備方法：將化合物 4(21.2 g, 61.5 mmol)溶於四氫呋喃(220 mL)中，接著在常溫下加入1.3M ⁱ PrMgCl•LiCl (94.6 mL, 123.0 mmol)，並在室溫下攪拌1小時。隨後，降溫至-20℃下加入氰甲酸乙酯(24.4 mL, 246.0 mmol)，半小時後回溫。待反應結束後，先以庚烷與飽和氯化銨水溶液萃取，有機層再以無水硫酸鎂乾燥。經濃縮後，粗產物以矽膠管柱層析(石油醚/乙酸乙酯)進行純化，再經真空乾燥後得到淡黃色液體化合物 5(16.3 g；產率:78 %)。 化合物 6

化合物 6 的製備方法：將化合物 5(5.0 g, 14.8 mmol)溶於四氫呋喃(50 mL)中，降溫至-20℃後，加入1.3M ⁱ PrMgCl•LiCl (19.3 mL, 25.1 mmol)於反應瓶中，並在-20℃下攪拌1小時。隨後，加入1,2-二溴四氯乙烷(9.6 g, 29.6 mmol)，半小時後回溫。待反應結束後，先用庚烷與水萃取，有機層再以無水硫酸鎂乾燥。經濃縮後，粗產物以矽膠管柱層析(石油醚/二氯甲烷)進行純化。最後，經真空乾燥後得到淡黃色液體化合物 6(3.4 g；產率:55.6 %)。 化合物 8

化合物 8 的製備方法：將化合物 6(2.8 g, 6.7 mmol)、化合物 7(2.0 g, 3.0 mmol)、三(2-呋喃基)膦(93 mg, 0.3 mmol)、Pd ₂(dba) ₃(70 mg, 0.08 mmol)與磷酸鉀(1.9 g, 9.1 mmol)加入至圓底瓶中。隨後，加入甲苯 (20 mL)、水(5 mL)與Aliquat 336(1 mL)。在氮氣保護下，加熱迴流攪拌一晚。冷卻後先使用迴旋濃縮機移除溶劑，接著使用庚烷與水萃取，有機層再以無水硫酸鎂乾燥。經濃縮後，粗產物矽膠管柱層析(石油醚/二氯甲烷)進行純化。最後經真空乾燥後得到淡黃色液體化合物 8(3.0 g；產率:92%)。 化合物 10

化合物 10 的製備方法：將鎂粉(0.14 mg, 6.02 mmol)加入至100 mL的圓底瓶中，隨後加入無水四氫呋喃(20 mL)。在常溫下，滴入1 -溴 -4 -己基苯(1.42 g, 5.9 mmol)並在 70℃下攪拌1小時。隨後，降溫至30℃，加入化合物 8(0.65 g, 0.60 mmol)，緩慢升至70℃，攪拌16小時。待反應結束後降溫，隨後加入氯化銨水溶液 (50 mL)及乙酸乙酯 (50 mL)進行萃取，有機層以無水硫酸鎂乾燥及過濾，接著以迴旋濃縮機濃縮抽乾，得到化合物 9。將化合物 9加入100 mL圓底瓶中，隨後加入醋酸(20 mL)，緩慢升溫至迴流，攪拌4小時。冷卻後以二氯甲烷進行萃取，有機層以無水硫酸鎂乾燥與過濾，先經迴旋濃縮機抽乾，再以矽膠管柱層析(石油醚/二氯甲烷)進行純化。最後經真空乾燥後得到淡黃色化合物 10(0.45g,；產率:47%)。 化合物 11

化合物 11 的製備方法：於100 mL的圓底瓶當中，加入化合物 10(0.45 g, 0.28 mmol) 及無水二甲基甲醯胺(1.29 mL, 16.8 mmol)溶於1,2-二氯乙烷(10 mL)。冰浴下，緩慢加入三氯氧磷 (0.82 mL, 5.63 mmol)，隨後緩慢升溫至迴流，攪拌16小時。待反應結束後，以二氯甲烷加入進行萃取，有機層先以無水硫酸鎂乾燥及過濾，再以迴旋濃縮機濃縮抽乾。最後以矽膠管柱層析(石油醚/二氯甲烷)進行純化，經真空乾燥後得到橘色之化合物 11(0.24 g；產率:51%)。 實施例 1

實施例 1 的製備方法：取化合物 11(0.24 g, 0.15 mmol)及化合物 12(0.15 g, 0.58 mmol)於100 mL圓底瓶中，加入氯仿(20 mL)，緩慢滴入吡啶2 mL，在氮氣保護下，常溫攪拌2小時。待反應結束後，以迴旋濃縮機濃縮抽乾，接著以甲醇析出固體後，再以矽膠管柱層析(石油醚/氯仿)進行純化。最後經真空乾燥後得到深藍色固體即為實施例 1(0.19 g；產率:62%)。 The preparation process of the nine-membered fused ring compound of Example 1 is shown in the following reaction formula I. [Reaction formula I]

Compound 3

The preparation method of compound 3 : Dissolve 3,4-dibromothiophene (50 g, 20.7 mmol) in dichloromethane (200 mL), add aluminum trichloride (26.2 g, 19.6 mmol) in an ice bath, slowly Decayl chloride (39.4 g, 20.7 mmol) was slowly added dropwise, and the reaction was carried out for 2 hours. Extract with dichloromethane, water and sodium bicarbonate aqueous solution, and the organic layer is dried and filtered with anhydrous magnesium sulfate, and then concentrated and drained with a cyclonic concentrator to obtain liquid compound 1 . Subsequently, Compound 1 was dissolved in dimethylformamide (400 ml), was added potassium carbonate (42.9 g, 31 mmol) was added dropwise and hydrogen sulfur ethyl acetate (27.2 ml, 24.8 mmol), heated to 60 ℃ ^o C was stirred for 16 hours, extracted with water and heptane, and the organic layer was dried with anhydrous magnesium sulfate and filtered, and then concentrated and drained with a cyclonic concentrator to obtain compound 2 . The obtained compound 2 was dissolved in ethanol (500 mL), sodium hydroxide (50 g) was added, and the mixture was heated to reflux for 16 hours. After the temperature was restored, the mixture was poured into ice-cold hydrochloric acid aqueous solution to precipitate a solid. Finally, the solid was collected by filtration, and after water and solvent were removed in a vacuum oven, compound 3 (48.8 g; yield: 60%) was obtained. Compound 4

The preparation method of compound 4 : add compound 3 (30 g, 77 mmol) to quinoline (150 mL) and copper chromite Cu ₂ Cr ₂ O ₅ (1.19 g, 3.8 mmol), and heat to 180°C for 2 hours, Cool down after the reaction is over. Then, first extract with heptane, then with 6M hydrochloric acid, water and brine in order, and then dry with anhydrous magnesium sulfate. Finally, after filtering with silica gel, it was concentrated and drained by a rotary concentrator to obtain a pale yellow liquid compound 4 (26 g; yield: 97%). Compound 5

Preparation method of compound 5 : Dissolve compound 4 (21.2 g, 61.5 mmol) in tetrahydrofuran (220 mL), then add 1.3M ⁱ PrMgCl•LiCl (94.6 mL, 123.0 mmol) at room temperature and stir at room temperature 1 hour. Subsequently, the temperature was lowered to -20°C and ethyl cyanoformate (24.4 mL, 246.0 mmol) was added, and the temperature returned after half an hour. After the reaction is completed, first extract with heptane and saturated ammonium chloride aqueous solution, and then dry the organic layer with anhydrous magnesium sulfate. After concentration, the crude product was purified by silica gel column chromatography (petroleum ether/ethyl acetate), and then dried under vacuum to obtain a pale yellow liquid compound 5 (16.3 g; yield: 78%). Compound 6

The preparation method of compound 6 : Dissolve compound 5 (5.0 g, 14.8 mmol) in tetrahydrofuran (50 mL), after cooling to -20℃, add 1.3M ⁱ PrMgCl•LiCl (19.3 mL, 25.1 mmol) to the reaction flask , And stirred at -20°C for 1 hour. Subsequently, 1,2-dibromotetrachloroethane (9.6 g, 29.6 mmol) was added, and the temperature was restored after half an hour. After the reaction is over, it is first extracted with heptane and water, and the organic layer is then dried with anhydrous magnesium sulfate. After concentration, the crude product was purified by silica gel column chromatography (petroleum ether/dichloromethane). Finally, after vacuum drying, a pale yellow liquid compound 6 (3.4 g; yield: 55.6%) was obtained. Compound 8

The preparation method of compound 8 : compound 6 (2.8 g, 6.7 mmol), compound 7 (2.0 g, 3.0 mmol), tris(2-furyl)phosphine (93 mg, 0.3 mmol), Pd ₂ (dba) ₃ ( 70 mg, 0.08 mmol) and potassium phosphate (1.9 g, 9.1 mmol) were added to the round bottom flask. Subsequently, toluene (20 mL), water (5 mL) and Aliquat 336 (1 mL) were added. Under the protection of nitrogen, heating under reflux and stirring overnight. After cooling, the solvent was removed with a cyclone concentrator, and then extracted with heptane and water, and the organic layer was dried with anhydrous magnesium sulfate. After concentration, the crude product was purified by silica gel column chromatography (petroleum ether/dichloromethane). Finally, after vacuum drying, a pale yellow liquid compound 8 (3.0 g; yield: 92%) was obtained. Compound 10

The preparation method of compound 10 : magnesium powder (0.14 mg, 6.02 mmol) was added to a 100 mL round-bottomed flask, and then anhydrous tetrahydrofuran (20 mL) was added. At room temperature, was added dropwise 1-- bromo --4-- hexylbenzene (1.42 g, 5.9 mmol) and stirred at 70 ℃ 1 hour. Subsequently, the temperature was lowered to 30°C, compound 8 (0.65 g, 0.60 mmol) was added, the temperature was slowly raised to 70°C, and the mixture was stirred for 16 hours. After the reaction was completed, the temperature was lowered, and then ammonium chloride aqueous solution (50 mL) and ethyl acetate (50 mL) were added for extraction. The organic layer was dried with anhydrous magnesium sulfate and filtered, and then concentrated and drained with a cyclonic concentrator to obtain compound 9 . Compound 9 was added to a 100 mL round-bottomed flask, followed by acetic acid (20 mL), and slowly heated to reflux, and stirred for 4 hours. After cooling, it was extracted with dichloromethane, and the organic layer was dried and filtered with anhydrous magnesium sulfate, first drained by a rotary concentrator, and then purified by silica gel column chromatography (petroleum ether/dichloromethane). Finally, after vacuum drying, a light yellow compound 10 (0.45g,; yield: 47%) was obtained. Compound 11

Preparation method of compound 11 : In a 100 mL round bottom flask, add compound 10 (0.45 g, 0.28 mmol) and anhydrous dimethylformamide (1.29 mL, 16.8 mmol) and dissolve in 1,2-dichloroethane (10 mL). Under ice bath, slowly add phosphorus oxychloride (0.82 mL, 5.63 mmol), then slowly warm to reflux, and stir for 16 hours. After the reaction is over, dichloromethane is added for extraction, and the organic layer is first dried and filtered with anhydrous magnesium sulfate, and then concentrated and drained with a cyclonic concentrator. Finally, it was purified by silica gel column chromatography (petroleum ether/dichloromethane). After vacuum drying, the orange compound 11 (0.24 g; yield: 51%) was obtained. Example 1

The preparation method of Example 1 : Take compound 11 (0.24 g, 0.15 mmol) and compound 12 (0.15 g, 0.58 mmol) in a 100 mL round bottom flask, add chloroform (20 mL), slowly drop 2 mL of pyridine, Under the protection of nitrogen, stir at room temperature for 2 hours. After the reaction is over, it is concentrated and drained by a cyclone concentrator, and then the solid is precipitated with methanol, and then purified by silica gel column chromatography (petroleum ether/chloroform). Finally, after vacuum drying, a dark blue solid was obtained as Example 1 (0.19 g; yield: 62%).

> Example 2>

Preparation of nine-membered fused ring compound

The chemical structure of the nine-membered fused ring compound of Example 2 is shown below.

It should be noted that the preparation method of Example 2 is similar to that of Example 1, the difference is that in the preparation method of Compound 3, Example 2 is prepared by replacing decanoyl chloride with nonyl chloride, and is used in the preparation of compound 10. the method, based on 1 - bromo - --4-- octylphenyl substituted 1 - bromo - --4-- cyclohexylbenzene, the same method as in Example 1 were carried out.

> UV - Visible light (UV-Vis) Absorption spectrum >

Examples 1 to 2 were dissolved in chloroform and the ultraviolet-visible light absorption spectra measured by the instrument were used, and the obtained results are shown in FIG. 1.

> Organic photovoltaic cell structure >

Figure 2 is a cross-sectional view of the first structure of the organic photovoltaic cell used in the present invention. The organic photovoltaic cell includes a substrate 70, a first electrode 80 laminated on the substrate 70, an organic semiconductor layer 90 laminated on the first electrode 80, and a second electrode laminated on the organic semiconductor layer 90 100. Wherein, the organic semiconductor layer 90 includes an electron transport layer 91 laminated on the first electrode 80, an active layer 92 laminated on the electron transport layer 91, and a hole transport layer laminated on the active layer 92 93. Therefore, the second electrode 100 is laminated on the hole transport layer 93.

Fig. 3 is a cross-sectional view of the second structure of the organic photovoltaic cell used in the present invention. The organic photovoltaic cell includes a substrate 70, a first electrode 80 laminated on the substrate 70, an organic semiconductor layer 90 laminated on the first electrode 80, and a second electrode laminated on the organic semiconductor layer 90 100. Wherein, the organic semiconductor layer 90 includes a hole transport layer 93 laminated on the first electrode 80, an active layer 92 laminated on the hole transport layer 93, and an electron transport layer laminated on the active layer 92 Layer 91. Therefore, the second electrode 100 is laminated on the electron transport layer 91.

For the convenience of description and understanding, the following uses the structure of the organic photovoltaic element in FIG. 2 as an implementation manner of application examples.

> Application example 1~2>

Preparation of organic photovoltaic cells (OPV)

According to the active layer materials (electron acceptor materials and conjugated polymers) listed in Table 1 below, and the following methods, the organic photovoltaic cells of Application Examples 1 to 2 were prepared. Table 1 Non-fullerene electron acceptor material Conjugated polymer Application example 1 Example 1 Polymer 1 Application example 2 Example 2 Polymer 1

Among them, the specific structure of polymer 1 (conjugated polymer) includes a repeating unit represented by the following chemical formula (A). [Chemical formula (A)]

Before preparing the organic photovoltaic element, the patterned ITO glass substrate (12 Ω/□) was washed in the ultrasonic oscillation tank with detergent, deionized water, acetone and isopropanol for 10 minutes respectively. After the ITO glass substrate was cleaned by ultrasonic vibration, the surface treatment was performed in a UV-ozone cleaning machine for 30 minutes. The glass substrate is the aforementioned substrate 70, and the ITO is the aforementioned first electrode 80, which is the anode in the structure of FIG. 3.

The zinc acetate [Zn(OAc) ₂ ] solution was spin-coated on the ITO glass substrate and baked at 170° C. for 30 minutes to form a ZnO layer (zinc oxide layer), which is the aforementioned electron transport layer 91.

The conjugated polymers listed in Application Examples 1 to 2 in Table 1 are used as electron donor materials, and the weight ratio is 1:1 with the non-fullerene electron acceptor material (Example 1 or 2) After mixing, o-xylene is used as a chlorine-free solvent to prepare an active layer solution. Next, spin-coated the active layer solution on the aforementioned ZnO layer (electron transport layer 91), and baked at 120°C under nitrogen for 10 minutes to form the aforementioned active layer on the ZnO layer (electron transport layer 91) 92. Then, it is sent into a vacuum chamber and heated to deposit a molybdenum trioxide (MoO ₃ ) metal oxide (about 4 nm) to form the aforementioned hole transport layer 93 on the active layer 92. Then, Ag metal (about 100 nm) is heated and deposited as the aforementioned second electrode 100, which is the cathode in the structure of FIG. 2.

> Electrical analysis of organic photovoltaic cells >

The measurement area of the organic photovoltaic cell in application examples 1 to 2 is defined as 0.04 cm ² through a metal mask. This electrical test uses a multi-function power meter (manufacturer model: Keithley 2400) as the power supply and is controlled by a Lab-View computer program. Use the solar light source simulator (manufacturer model: SAN-EI XES-40S3) to illuminate the organic photovoltaic cell with simulated sunlight, and record it with a computer program. The resulting current-voltage curve is shown in Figure 4. Wherein, the illuminance of the aforementioned simulated sunlight is 100 mW/cm ² (AM1.5G).

> Energy conversion efficiency of organic photovoltaic cells (PCE) analysis >

The active layer materials used in organic photovoltaic cells of application examples 1 and 2, and their open voltage (Voc), short-circuit current (Jsc), fill factor (FF) and energy conversion efficiency (PCE) are summarized in Table 2 below. Among them, the open circuit voltage (Voc) and the short circuit current (Jsc) are the intercepts of the current-voltage curve in Fig. 4 on the X-axis (open circuit voltage) and Y-axis (short circuit current), respectively. The fill factor (FF) is the value obtained by dividing the area that can be drawn in the current-voltage curve of FIG. 4 by the product of the short-circuit current and the open-circuit voltage. The energy conversion efficiency (PCE) is obtained by dividing the product of the open circuit voltage, short circuit current, and fill factor by the irradiated simulated sunlight energy, and the higher the value, the better. Table 2 Application example Active layer material Voc (V) Jsc (mA/cm ² ) FF (%) PCE (%) 1 Example 1/Polymer 1 0.92 19.67 72 12.9 2 Example 2 / Polymer 1 0.92 19.65 71 12.9

From the results in Table 2, it can be found that the organic photovoltaic cells of application examples 1 to 2 all have excellent energy conversion efficiency (PCE>12%). In particular, the components of Application Examples 1 and 2 are all made with a chlorine-free solvent (o-xylene). Therefore, it can be seen from the foregoing results that the nine-membered fused ring compound of the present invention is used as an electron acceptor material with the conjugated polymer of formula (A), and a relatively environmentally friendly non-chlorine solvent can be used to dissolve it during the manufacturing process. Large area coating to facilitate subsequent coating processing, and the nine-membered fused ring compound can also enable organic photovoltaic cells to have excellent energy conversion efficiency (PCE).

In summary, the nine-membered fused ring compound of the present invention can be used as a non-fullerene electron acceptor material, and due to the introduction of alkyl or alkoxy (ie R ² ) in the structure, it is suitable for non-chlorine solvents. It has a certain solubility, so it can be dissolved in a relatively environmentally friendly non-chlorine solvent, which is suitable for large-area coating to facilitate subsequent coating processing, and the organic photovoltaic cell containing the nine-membered fused ring compound of the present invention is also It will have excellent energy conversion efficiency (PCE), so it can indeed achieve the purpose of the invention.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to This invention patent covers the scope.

70: substrate

80: first electrode

90: organic semiconductor layer

91: electron transport layer

92: active layer

93: hole transport layer

100: second electrode

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a spectrum diagram illustrating the ultraviolet-visible light absorption spectra of Examples 1 to 2 in solution; Figure 2 is a schematic cross-sectional view illustrating the first structure of the organic photovoltaic element of the present invention; Figure 3 is a schematic cross-sectional view illustrating the second structure of the organic photovoltaic device of the present invention; and Fig. 4 is a graph illustrating the voltage-current density of the organic photovoltaic cells of application examples 1 to 2.

70: substrate

80: first electrode

90: organic semiconductor layer

91: electron transport layer

92: active layer

93: hole transport layer

100: second electrode

Claims (9)

A nine-membered fused ring compound, as shown in the following chemical formula (I):

Among them, X is NR ³ , C(R ⁴ ) ₂ or Si(R ⁵ ) ₂ ; R ¹ is hydrogen, C ₁ ~C ₃₀ alkyl, C ₁ ~C ₃₀ alkoxy, C ₁ ~C ₃₀ alkyl Aryl or C ₁ ~C ₃₀ alkyl heteroaryl; R ² is C ₁ ~C ₃₀ alkyl or C ₁ ~C ₃₀ alkoxy; R ³ , R ⁴ and R ⁵ are hydrogen, C ₁ ~C ₃₀ alkyl group or C ₁ ~C ₃₀ alkoxy group; and E is an electron withdrawing group, E is

R ⁶ is hydrogen or halogen; and R ⁷ is hydrogen, C ₁ to C ₃₀ alkyl or C ₁ to C ₃₀ alkoxy. The nine-membered fused ring compound according to claim 1, wherein X is NR ³ . The nine-membered fused ring compound according to claim 2, wherein R ³ is a C ₁ to C ₃₀ alkyl group or a C ₁ to C ₃₀ alkoxy group. The nine-membered fused ring compound according to claim 1, wherein R ¹ is a C ₁ to C ₃₀ alkyl group, a C ₁ to C ₃₀ alkyl phenyl group, or a C ₁ to C ₃₀ alkyl heteroaryl group. The nine-membered fused ring compound according to claim 1, wherein R ² is a C ₆ to C ₁₆ alkyl group. The nine-membered fused ring compound according to claim 5, wherein R ² is a C ₆ to C ₁₂ alkyl group. An organic photovoltaic cell comprising the nine-membered fused ring compound as described in claim 1. The organic photovoltaic cell according to claim 7, wherein the organic photovoltaic cell includes a substrate, a first electrode laminated on the substrate, an electron transport layer laminated on the first electrode, and an electron transport layer laminated on the electron An active layer above the transmission layer, a hole transmission layer laminated on the active layer, and a second electrode laminated on the hole transmission layer, and the active layer includes the nine-membered fused ring compound. The organic photovoltaic cell according to claim 7, wherein the organic photovoltaic cell includes a substrate, a first electrode layered on the substrate, a hole transport layer layered on the first electrode, and a hole transport layer layered on the first electrode. An active layer above the hole transport layer, an electron transport layer stacked above the active layer, and a second electrode stacked above the electron transport layer, and the active layer includes the nine-membered fused ring compound.

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