TW202237690A - Perovskite photoelectric element including benzothiadiazole polymer which improves an energy level matching with fullerene derivatives - Google Patents

Abstract

A benzothiadiazole polymer, an electron transport complex comprising the benzothiadiazole polymer, and a perovskite photoelectric element comprising the electron transport complex are disclosed. The benzothiadiazole polymer comprises a repeating unit represented by formula (I). The benzothiadiazole polymer of the invention can improve an energy level matching with fullerene derivatives, and can be mixed with the fullerene derivatives to form an electron transport complex. If the electron transport complex is used as a carrier transport material on a perovskite photoelectric element, both of the power conversion efficiency (PCE) and stability of the perovskite photoelectric element can be improved.

Description

Benzothiadiazole polymers, electron transport complexes and perovskite optoelectronic devices

The present invention relates to a polymer, an electron transport compound comprising the aforementioned polymer, and a perovskite photoelectric element comprising the aforementioned electron transport compound, in particular to a benzothiadiazole polymer, comprising the aforementioned benzothiadiazole An electron transport complex of an oxadiazole polymer, and a perovskite photovoltaic element comprising the aforementioned electron transport complex.

Perovskite photoelectric materials have developed rapidly in recent years. Because of their good optical and electrical properties and can be used in wet coating processes, they are used to make low-cost and high-functional perovskite photoelectric components, such as solar cells, Light emitting diodes or light sensors, etc.

Commonly used as upper carrier transport materials in perovskite photoelectric components are fullerene derivatives, such as [6,6]-phenyl-C61-butyric acid methyl ester {[6,6]-phenyl-C61-butyric acid methyl ester, referred to as PCBM}. However, PCBM is a small molecule material, which has poor film-forming properties when used in wet coating, which often leads to the occurrence of shunt leakage in perovskite photoelectric devices and low performance, and may also cause perovskite photoelectric devices The main cause of poor life expectancy hinders the process of its commercialization.

CN106449882 A and CN107994121 A have disclosed that the film-forming properties of upper carrier transport materials are improved by doping PCBM with polymers. However, in addition to improving the film-forming properties, the role of the polymer is also very important to match the energy levels of the fullerene derivatives, which will affect the conductivity of the carrier and the electrical properties of the device. Generally speaking, the closer the energy of the lowest unoccupied molecular orbital (LUMO) of the doped polymer is to that of the fullerene derivative, the better. Otherwise, the performance of the device may be reduced, and even the energy barrier defect may be caused. It causes charge accumulation and adversely affects the life of the component.

Therefore, how to design a polymer that can be doped with fullerene derivatives to improve the film-forming properties of fullerene derivatives during wet coating, and at the same time improve the energy level matching of materials and increase the calcium The power conversion efficiency (PCE) and stability of titanium photovoltaic components are particularly important for the technological development and commercialization of perovskite photovoltaic components.

Therefore, the first object of the present invention is to provide a benzothiadiazole polymer. The benzothiadiazole polymer of the present invention is a copolymer, which can improve the energy level matching with the fullerene derivatives, and can be mixed with the fullerene derivatives to form an electron transport complex. If the electron transport complex is used as the carrier transport material on the perovskite photoelectric device, the power conversion efficiency (PCE) and stability of the perovskite photoelectric device can be improved at the same time.

其中， p與q分別為0、1或2； X ¹與X ²分別為H、F或Cl，且X ¹與X ²至少其中一者為F或Cl；及； Ar ¹、Ar ²與Ar ³分別為亞芳基(arylene)或亞雜芳基(heteroarylene)。 Thus, the benzothiadiazole polymer of the present invention comprises a repeating unit represented by the following formula (I): [Formula (I)]

Wherein, p and q are 0, 1 or 2 respectively; X ¹ and X ² are H, F or Cl respectively, and at least one of X ¹ and X ² is F or Cl; and; Ar ¹ , Ar ² and Ar ³ are respectively arylene or heteroarylene.

Therefore, the second object of the present invention is to provide an electron transport complex.

Thus, the electron transport complex of the present invention comprises the aforementioned benzothiadiazole polymer and fullerene derivatives.

Therefore, the third object of the present invention is to provide a perovskite photoelectric device.

Thus, the perovskite photovoltaic element of the present invention comprises the aforementioned electron transport complex.

The effect of the present invention lies in that the energy of the material can be properly adjusted by controlling the chemical structure (Ar ¹ , Ar ² , Ar ³ , X ¹ and X ² ) of the benzothiadiazole polymer of the present invention. order, so that it has better energy level matching with various fullerene derivatives.

In addition, the benzothiadiazole polymer of the present invention can obtain the required molecular ratio in the material synthesis stage, so compared with the prior art (CN107994121 A), the present invention can save the need to mix different polymers with each other. steps, not only saves the complexity of the manufacturing process, but also reduces the doubts about the uneven distribution of materials caused by subsequent mixing.

In addition, when the benzothiadiazole polymer of the present invention is mixed with a fullerene derivative to form an electron transport compound, the carrier transport material prepared from the electron transport compound will have better film-forming properties and energy Order matching, and at the same time, it can improve the power conversion efficiency (PCE) and stability of perovskite photovoltaic devices.

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

[ Benzothiadiazole polymer ]

其中， p與q分別為0、1或2； X ¹與X ²分別為H、F或Cl，且X ¹與X ²至少其中一者為F或Cl；及； Ar ¹、Ar ²和Ar ³分別為亞芳基或亞雜芳。 The benzothiadiazole polymer of the present invention comprises a repeating unit represented by the following formula (I): [Formula (I)]

Wherein, p and q are 0, 1 or 2 respectively; X ¹ and X ² are H, F or Cl respectively, and at least one of X ¹ and X ² is F or Cl; and; Ar ¹ , Ar ² and Ar ³ are respectively arylene or heteroarylene.

Preferably, p and q are 0 or 1 respectively.

、

、

或

， 其中， R ¹至R ⁵分別為H、R ⁶、‒(CH ₂)n ₁OR ⁷、‒(CH ₂)n ₁SR ⁸、 ‒(CH ₂)n ₁C(=O)OR ⁹、‒(CH ₂)n ₁Si(R ₁₀) ₃、‒(CH ₂)n ₁N(CH ₃) ₂、 ‒(CH ₂)n ₁N ⁺R ¹¹(CH ₃) ₂X¯、‒(CH ₂)n ₁N ⁺H(CH ₃) ₂X¯或 ‒(C ₂H ₄O)n ₁R ¹¹； R ⁶至R ¹⁰分別為未經取代或經至少一R ¹⁶取代的C ₁~C ₄₀直鏈烷基、未經取代或經至少一R ¹⁶取代的C ₄~C ₄₀支鏈烷基、未經取代或經至少一R ¹⁶取代的C ₄~C ₄₀環狀烷基、未經取代或經至少一R ¹⁶取代的C ₂~C ₄₀烯基、或未經取代或經至少一R ¹⁶取代的C ₂~C ₄₀炔基； R ¹¹為甲基或乙基； n ₁為1~8； X為Cl、Br或I； R ¹⁶為鹵素、‒CN、芳基、雜芳基或‒SiR ¹⁷R ¹⁸R ¹⁹；及 R ¹⁷至R ¹⁹分別為C ₁~C ₄₀烷基。 Preferably, Ar ¹ is

,

,

or

, wherein, R ¹ to R ⁵ are H, R ⁶ , ‒(CH ₂ )n ₁ OR ⁷ , ‒(CH ₂ )n ₁ SR ⁸ , ‒(CH ₂ )n ₁ C(=O)OR ⁹ , ‒(CH ₂ )n ₁ Si(R ₁₀ ) ₃ , ‒(CH ₂ )n ₁ N(CH ₃ ) ₂ , ‒(CH ₂ )n ₁ N ⁺ R ¹¹ (CH ₃ ) ₂ X¯, ‒(CH ₂ )n ₁ N ⁺ H(CH ₃ ) ₂ X ¯ or ‒(C ₂ H ₄ O)n ₁ R ¹¹ ; R ⁶ to R ¹⁰ are respectively unsubstituted or substituted by at least one R ¹⁶ C ₁ ~C ₄₀ straight chain alkyl, C ₄ ~C ₄₀ branched alkyl unsubstituted or substituted by at least one R ¹⁶ , C ₄ ~C ₄₀ cyclic alkyl unsubstituted or substituted by at least one R ¹⁶ , unsubstituted C ₂ ~C ₄₀ alkenyl substituted or substituted by at least one R ¹⁶ , or C ₂ ~C ₄₀ alkynyl unsubstituted or substituted by at least one R ¹⁶ ; R ¹¹ is methyl or ethyl; n ₁ is 1 ~8; X is Cl, Br or I; R ¹⁶ is halogen, ‒CN, aryl, heteroaryl or ‒SiR ¹⁷ R ¹⁸ R ¹⁹ ; and R ¹⁷ to R ¹⁹ are respectively C ₁ ~C ₄₀ alkyl.

。 More preferably, Ar ¹ is

.

Still more preferably, R ¹ and R ² are R ⁶ . Still more preferably, R ¹ and R ² are respectively unsubstituted or substituted by at least one R ¹⁶ C ₁ ~C ₄₀ straight chain alkyl, unsubstituted or substituted by at least one R ¹⁶ C ₄ ~C ₄₀ branched Alkanyl, or C ₄ ~C ₄₀ cyclic alkyl that is unsubstituted or substituted by at least one R ¹⁶ . Still more preferably, R ¹ and R ² are C ₁ -C ₄₀ linear alkyl groups that are unsubstituted or substituted by at least one R ¹⁶ . Still more preferably, R ¹ and R ² are respectively unsubstituted C ₁ -C ₄₀ linear alkyl groups. Still more preferably, R ¹ and R ² are respectively unsubstituted C ₁ -C ₁₅ linear alkyl groups. Still more preferably, R ¹ and R ² are respectively unsubstituted C ₅ -C ₁₃ linear alkyl groups.

或

，其中，n ₂與n ₃分別為1、2或3；及R ¹²至R ¹⁵分別為H、F、Cl、Br、R ⁶、‒CN、‒OR ⁷、‒SR ⁸、‒C(=O)OR ⁹、‒Si(R ¹⁰) ₃、芳基或雜芳基。 More preferably, Ar ² and Ar ³ are

or

, wherein, n ₂ and n ₃ are 1, 2 or 3 respectively; and R ¹² to R ¹⁵ are H, F, Cl, Br, R ⁶ , ‒CN, ‒OR ⁷ , ‒SR ⁸ , ‒C (= O)OR ⁹ , -Si(R ¹⁰ ) ₃ , aryl or heteroaryl.

。 And more preferably, Ar ² and Ar ³ are respectively

.

Still more preferably, R ¹² and R ¹³ are H or R ⁶ respectively. Still more preferably, R ¹² and R ¹³ are H, unsubstituted or substituted by at least one R ¹⁶ C ₁ ~ C ₄₀ linear alkyl, unsubstituted or substituted by at least one R ¹⁶ C ₄ ~ C ₄₀ branched chain alkyl, or C ₄ ~C ₄₀ cyclic alkyl unsubstituted or substituted by at least one R ¹⁶ . Still more preferably, R ¹² and R ¹³ are respectively H, or C ₁ -C ₄₀ linear alkyl groups that are unsubstituted or substituted by at least one R ¹⁶ . Still more preferably, R ¹² and R ¹³ are H or unsubstituted C ₁ -C ₄₀ linear alkyl groups respectively. Still more preferably, R ¹² and R ¹³ are H or unsubstituted C ₁ -C ₁₁ linear alkyl groups respectively. Still more preferably, R ¹² and R ¹³ are H or unsubstituted C ₃ ~C ₉ straight chain alkyl, respectively.

[ electron transport complex ]

The electron transport complex of the present invention comprises the aforementioned benzothiadiazole polymer and fullerene derivatives.

The fullerene derivatives are, for example but not limited to, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), [6,6]-phenyl-C71-butyric acid methyl ester {[6,6 ]-phenyl- C71-butyric acid methyl ester , referred to as PC71BM}, bis[6,6]-phenyl-C62-butyric acid methyl ester {Bis(1-[3-(methoxycarbonyl)propyl]-1-phenyl)- [6,6]C62, referred to as Bis-PCBM}, indene-carbon sixty double adduct {1',1'',4',4''-tetrahydro-di[1,4]methanonaphthaleno[5, 6] fullerene-C60, referred to as ICBA} or a combination of the aforementioned.

Preferably, the energy difference between the lowest unoccupied molecular orbital (LUMO) of the benzothiadiazole polymer and the lowest unoccupied molecular orbital (LUMO) of the fullerene derivative is less than 1.0 eV. More preferably, the energy difference between the lowest unoccupied molecular orbital (LUMO) of the benzothiadiazole polymer and the lowest unoccupied molecular orbital (LUMO) of the fullerene derivative is less than 0.4 eV

Preferably, based on 100 wt% of the total weight of the electron transport complex, the weight range of the benzothiadiazole polymer is 0.1-99 wt%. More preferably, based on the total weight of the electron transport complex being 100 wt%, the weight range of the benzothiadiazole polymer is 0.5-20 wt%.

[ Perovskite Photovoltaics ]

The perovskite photoelectric element of the present invention comprises the aforementioned electron transport complex.

Preferably, the perovskite photoelectric element comprises a substrate, a lower electrode laminated on the substrate, a carrier transport layer laminated on the lower electrode, a perovskite laminated on the carrier transport layer Active layer, an upper carrier transport unit stacked on the perovskite active layer, an upper electrode stacked on the upper carrier transport unit, the upper carrier transport unit includes the electron transport complex.

More preferably, the upper carrier transport unit includes an upper carrier transport layer, and the upper carrier transport layer contains the electron transport complex.

Still more preferably, the upper carrier transport unit further includes at least one upper carrier modification layer, the upper carrier modification layer is laminated on the perovskite active layer, the upper carrier modification layer is laminated on the upper carrier transport layer, the upper Electrodes are stacked on the upper carrier modification layer.

Still more preferably, the aforementioned upper carrier transport layer has a thickness ranging from 0.1 to 200 nm. Still more preferably, the aforementioned upper carrier transport layer has a thickness ranging from 1 to 100 nm.

< comparative example 1>

Preparation of Benzothiadiazole Polymers

比較例 1 The benzothiadiazole polymer of Comparative Example 1 contained repeating units shown below.

Comparative example 1

芴 化合物 1化合物 1的製備方法： 將芴(50 g, 300.8 mmol)與N-溴代丁二醯亞胺(160.6 g, 902.4 mmol)溶於二甲基甲醯胺(250 mL)中，並加熱至50℃攪拌6小時。待反應結束後，將產物倒入冰水中沉澱出固體。經過濾後，使用甲醇洗滌產物，再經真空乾燥後得到白色固體化合物 1(83.7 g, 產率:86%)。 化合物 2

化合物 1 化合物 2化合物 2的製備方法： 將化合物 1(7.3 g, 22.5 mmol)與1-溴辛烷(13.1 g, 67.5 mmol)溶解於四氫呋喃中。接著，在冰浴下加入叔丁醇鉀(12.6 g. 112.5 mmol)並回到室溫反應1小時。待反應結束後，先以1N鹽酸水溶液中和，再加入二氯甲烷進行萃取。有機層以無水硫酸鎂乾燥後，迴旋濃縮機去除溶劑。最後再以矽膠管柱層析(正庚烷為沖提液)純化，得白色固體化合物 2(9.7 g, 產率:79%)。 化合物 3

化合物 2 化合物 3化合物 3的製備方法：

將化合物 2(9.6 g, 16.4 mmol)入料於250 mL反應瓶中後，加入100 mL的無水四氫呋喃並降至-78℃。接著，逐滴加入2.5 M的正丁基鋰的正己烷溶液(22 mL, 54.1 mmol)並維持-78℃ 1小時後，再逐滴加入硼酸三甲酯(17.0 g, 164 mmol)。回到室溫後加入4N鹽酸水溶液攪拌1小時。結束後，加入水並用正庚烷萃取及用無水硫酸鎂乾燥。經過濾後，濃縮去除溶劑。以四氫呋喃與正庚烷進行再結晶純化得到中間體白色固體。接著，將中間體與頻哪醇(pinacol)(3.9 g, 32.8 mmol)和甲苯 (100 mL)置入圓底瓶中攪拌隔夜。反應結束後，加入無水硫酸鎂乾燥、濃縮去除溶劑。粗產物以甲苯與甲醇進行再結晶純化得到白色固體化合物 3(4.5 g, 產率：43%)。 比較例 1的製備方法： 在氮氣下將化合物 3(500 mg, 0.78 mmol)、化合物 4(229 mg, 0.78 mmol)、三(2-呋喃基)膦(24 mg, 0.08 mmol)、Pd ₂(dba) ₃(20 mg, 0.02 mmol)、K ₃PO ₄(1.65 g, 7.78 mmol)、Aliquat336 (1mL)溶於甲苯(20 mL)與水(4 mL)的混合液中。接著，加熱迴流攪拌隔夜。待反應結束後，降溫至室溫，先以水與三氯甲烷進行萃取，再使用無水硫酸鎂乾燥。經過濾後，濃縮去除溶劑。以三氯甲烷與甲醇進行再沉澱析出固體。最後，收集沉澱物並將該固體依序以甲醇、丙酮洗滌後，經真空乾燥得到比較例 1(264 mg, 產率:61%)。 The benzothiadiazole polymer of Comparative Example 1 was prepared according to the following method. Compound 1

The preparation method of fluorene compound 1 compound 1 : Dissolve fluorene (50 g, 300.8 mmol) and N-bromosuccinimide (160.6 g, 902.4 mmol) in dimethylformamide (250 mL), and Heat to 50°C and stir for 6 hours. After the reaction was completed, the product was poured into ice water to precipitate a solid. After filtration, the product was washed with methanol, and dried in vacuo to obtain compound 1 (83.7 g, yield: 86%) as a white solid. Compound 2

Compound 1 Compound 2 Preparation method of compound 2 : Compound 1 (7.3 g, 22.5 mmol) and 1-bromooctane (13.1 g, 67.5 mmol) were dissolved in tetrahydrofuran. Next, potassium tert-butoxide (12.6 g. 112.5 mmol) was added under ice-cooling and returned to room temperature to react for 1 hour. After the reaction was completed, it was neutralized with 1N hydrochloric acid aqueous solution, and then dichloromethane was added for extraction. After the organic layer was dried over anhydrous magnesium sulfate, the solvent was removed by whirling concentrator. Finally, it was purified by silica gel column chromatography (n-heptane as the eluent) to obtain compound 2 (9.7 g, yield: 79%) as a white solid. Compound 3

The preparation method of compound 2 compound 3 compound 3 :

After compound 2 (9.6 g, 16.4 mmol) was charged into a 250 mL reaction flask, 100 mL of anhydrous tetrahydrofuran was added and cooled to -78°C. Next, 2.5 M n-butyl lithium in n-hexane (22 mL, 54.1 mmol) was added dropwise and maintained at -78°C for 1 hour, then trimethyl borate (17.0 g, 164 mmol) was added dropwise. After returning to room temperature, 4N aqueous hydrochloric acid solution was added and stirred for 1 hour. After completion, water was added and extracted with n-heptane and dried over anhydrous magnesium sulfate. After filtration, it was concentrated to remove the solvent. Purification by recrystallization with tetrahydrofuran and n-heptane gave the intermediate as a white solid. Next, the intermediate was placed in a round bottom flask with pinacol (3.9 g, 32.8 mmol) and toluene (100 mL) and stirred overnight. After the reaction was completed, anhydrous magnesium sulfate was added to dry and concentrated to remove the solvent. The crude product was purified by recrystallization from toluene and methanol to obtain compound 3 (4.5 g, yield: 43%) as a white solid. Preparation method of Comparative Example 1 : Compound 3 (500 mg, 0.78 mmol), compound 4 (229 mg, 0.78 mmol), tris(2-furyl)phosphine (24 mg, 0.08 mmol), Pd ₂ ( dba) ₃ (20 mg, 0.02 mmol), K ₃ PO ₄ (1.65 g, 7.78 mmol), and Aliquat336 (1 mL) were dissolved in a mixture of toluene (20 mL) and water (4 mL). Then, it was heated to reflux and stirred overnight. After the reaction, cool down to room temperature, extract with water and chloroform, and then dry with anhydrous magnesium sulfate. After filtration, it was concentrated to remove the solvent. A solid was precipitated by reprecipitation with chloroform and methanol. Finally, the precipitate was collected and the solid was washed with methanol and acetone in sequence, and dried in vacuo to obtain Comparative Example 1 (264 mg, yield: 61%).

< Example 1>

Preparation of Benzothiadiazole Polymers

實施例 1 The benzothiadiazole polymer of Example 1 contained the repeating units shown below.

Example 1

實施例 1的製備方法： 在氮氣下，將化合物 3(500 mg, 0.78 mmol)、化合物 5(256 mg, 0.78 mmol)、三(2-呋喃基)膦(24 mg, 0.08 mmol)、Pd ₂(dba) ₃(20 mg, 0.02 mmol)、K ₃PO ₄(1.65 g, 7.78 mmol)、Aliquat336 (1mL)溶於甲苯 (20 mL)與水(4 mL)的混合液中。接著，加熱迴流攪拌隔夜。待反應結束後，降溫至室溫，先以水與三氯甲烷進行萃取，再使用無水硫酸鎂乾燥。經過濾後，濃縮去除溶劑。以三氯甲烷與甲醇進行再沉澱析出固體。收集沉澱物，並將該固體依序以甲醇、丙酮洗滌後，以真空乾燥得到實施例 1(283 mg, 產率:62%)。 The benzothiadiazole polymer of Example 1 was prepared according to the following method.

Preparation method of Example 1 : Under nitrogen, compound 3 (500 mg, 0.78 mmol), compound 5 (256 mg, 0.78 mmol), tris(2-furyl)phosphine (24 mg, 0.08 mmol), Pd ₂ (dba) ₃ (20 mg, 0.02 mmol), K ₃ PO ₄ (1.65 g, 7.78 mmol), and Aliquat336 (1 mL) were dissolved in a mixture of toluene (20 mL) and water (4 mL). Then, it was heated to reflux and stirred overnight. After the reaction, cool down to room temperature, extract with water and chloroform, and then dry with anhydrous magnesium sulfate. After filtration, it was concentrated to remove the solvent. A solid was precipitated by reprecipitation with chloroform and methanol. The precipitate was collected, and the solid was washed sequentially with methanol and acetone, and dried in vacuo to obtain Example 1 (283 mg, yield: 62%).

< Example 2>

Preparation of Benzothiadiazole Polymers

實施例 2 The benzothiadiazole polymer of Example 2 contained the repeating units shown below.

Example 2

3- 六烷基噻吩 化合物 6化合物 6的製備方法： 將3-六烷基噻吩(10 g, 59 mmol)與150 mL的無水四氫呋喃混合圓底瓶中。在-10 ^oC下，緩慢的加入2.5M正丁基鋰(26 mL, 65 mmol)並在-10 ^oC下持續攪拌1小時。接著，將三甲基氯化錫(15.4 g, 77 mmol)緩慢的加入反應當中，並在0 ^oC下持續攪拌30分鐘。回至室溫後，加入庚烷與去離子水萃取三次。有機層先以無水硫酸鎂乾燥，再經過濾後，以迴旋濃縮機濃縮抽乾得到黃色液體化合物 6(19.6 g, 產率:99%)。

化合物 7的製備方法： 將化合物 5(8.5. g, 25 mmol)、化合物 6(19.6 g, 59 mmol)、三(2-呋喃基)膦(840 mg,  2.7 mmol)及Pd ₂(dba) ₃(710 mg, 0.7 mmol)加入至圓底瓶中。隨後加入85 mL的甲苯，在氮氣保護下50 ^oC下攪拌3小時。冷卻後，先使用迴旋濃縮機移除甲苯，再以矽膠管住層析(石油醚/二氯甲烷)進行純化。最後，經真空乾燥後得到橘黃色固體化合物 7(8.85 g, 產率:68%)。 化合物 8

化合物 7 化合物 8化合物 8的製備方法： 將化合物 7(8.85 g, 17.6 mmol)加入至100 mL的圓底瓶當中後，加入90 mL的四氫呋喃。在避光的條件下，逐步加入NBS(7,45 g, 41.9 mmol)，隨後加熱至55 ^oC攪拌1小時。待反應結束後，先使用迴旋濃縮機移除溶劑，再以矽膠管住層析(石油醚/二氯甲烷)進行純化。最後，經真空乾燥後得到橘紅色固體化合物 8(8.65 g, 產率:74%)。

實施例 2的製備方法： 在氮氣下，將化合物 3(486 mg, 0.75 mmol)、化合物 8(500 mg, 0.76 mmol)、三(2-呋喃基)膦(24 mg, 0.08 mmol)、Pd ₂(dba) ₃(17 mg, 0.018 mmol)、K ₃PO ₄(1.65 g, 7.78 mmol)、Aliquat336 (1mL)溶於甲苯(15 mL)與水(3 mL)的混合液中。接著，加熱迴流攪拌隔夜。待反應結束後，降溫至室溫，先以水與三氯甲烷進行萃取，再使用無水硫酸鎂乾燥。經過濾後，濃縮去除溶劑。以三氯甲烷與甲醇進行再沉澱析出固體。收集沉澱物，並將該固體依序以甲醇、丙酮洗滌後，以真空乾燥得到實施例 2(500 mg, 產率:72%)。 The benzothiadiazole polymer of Example 2 was prepared according to the following method. Compound 6

3 -hexaalkylthiophene compound 6 Preparation method of compound 6 : 3-hexaalkylthiophene (10 g, 59 mmol) was mixed with 150 mL of anhydrous tetrahydrofuran in a round bottom bottle. At -10 ^° C, 2.5M n-butyllithium (26 mL, 65 mmol) was slowly added and stirring was continued at -10 ^° C for 1 hour. Then, trimethyltin chloride (15.4 g, 77 mmol) was slowly added into the reaction, and the stirring was continued at 0 ^o C for 30 minutes. After returning to room temperature, heptane and deionized water were added for extraction three times. The organic layer was first dried with anhydrous magnesium sulfate, and then filtered, concentrated and dried with a cyclone concentrator to obtain yellow liquid compound 6 (19.6 g, yield: 99%).

Preparation of Compound 7 : Compound 5 (8.5. g, 25 mmol), Compound 6 (19.6 g, 59 mmol), Tris(2-furyl)phosphine (840 mg, 2.7 mmol) and Pd ₂ (dba) ₃ (710 mg, 0.7 mmol) was added to a round bottom bottle. Then 85 mL of toluene was added and stirred at 50 ^o C for 3 hours under the protection of nitrogen. After cooling, the toluene was removed using a cyclone concentrator, and then purified by silica gel tube chromatography (petroleum ether/dichloromethane). Finally, orange solid compound 7 (8.85 g, yield: 68%) was obtained after vacuum drying. Compound 8

Compound 7 Compound 8 Preparation method of compound 8 : Compound 7 (8.85 g, 17.6 mmol) was added to a 100 mL round bottom bottle, and 90 mL of tetrahydrofuran was added. Under the condition of protecting from light, NBS (7,45 g, 41.9 mmol) was gradually added, followed by heating to 55 ^o C and stirring for 1 hour. After the reaction was completed, the solvent was removed using a cyclone concentrator, and then purified by silica gel tube chromatography (petroleum ether/dichloromethane). Finally, orange-red solid compound 8 (8.65 g, yield: 74%) was obtained after vacuum drying.

Preparation method of Example 2 : Under nitrogen, compound 3 (486 mg, 0.75 mmol), compound 8 (500 mg, 0.76 mmol), tris(2-furyl)phosphine (24 mg, 0.08 mmol), Pd ₂ (dba) ₃ (17 mg, 0.018 mmol), K ₃ PO ₄ (1.65 g, 7.78 mmol), and Aliquat336 (1 mL) were dissolved in a mixture of toluene (15 mL) and water (3 mL). Then, it was heated to reflux and stirred overnight. After the reaction, cool down to room temperature, extract with water and chloroform, and then dry with anhydrous magnesium sulfate. After filtration, it was concentrated to remove the solvent. A solid was precipitated by reprecipitation with chloroform and methanol. The precipitate was collected, and the solid was washed sequentially with methanol and acetone, and dried in vacuo to obtain Example 2 (500 mg, yield: 72%).

< Comparative example 1 with example 1~2 energy level matching >

The energy levels of the materials in Comparative Example 1, Example 1 and Example 2 were measured by the following method: First, the highest occupied molecular orbital (HOMO) of the material was measured by cyclic voltammetry, and then the ultraviolet The light-visible light spectrometer measures the energy gap (bandgap) of the material, and uses it to calculate the LUMO of the material. Fig. 1 is the energy level diagram of Perovskite (Perovskite), PCBM, Comparative Example 1, and Examples 1-2.

Referring to FIG. 1 , the LUMOs of Example 1 and Example 2 are -3.53 eV and -3.86 eV, respectively. Compared with Comparative Example 1 (-3.42eV), Example 1 and Example 2 are closer to the LUMO (-3.90 eV) of the PCBM and perovskite active layer, thus helping to reduce the energy barrier defects at the material interface.

< Perovskite photoelectric element structure >

Referring to Fig. 2, the first structure of the perovskite photoelectric element of the present invention comprises a substrate 1, a lower electrode 2 laminated on the substrate 1, a carrier transport layer 3 laminated on the lower electrode 2, a laminated layer A perovskite active layer 4 on the carrier transport layer 3 , an upper carrier transport unit 5 stacked on the perovskite active layer 4 , and an upper electrode 6 stacked on the upper carrier transport unit 5 . The uplink subtransmission unit 5 includes an uplink subtransmission layer 51 .

Referring to Fig. 3, the second structure of the perovskite photoelectric element of the present invention comprises a substrate 1, a lower electrode 2 laminated on the substrate 1, a carrier transport layer 3 laminated on the lower electrode 2, a laminated layer A perovskite active layer 4 on the carrier transport layer 3 , an upper carrier transport unit 5 stacked on the perovskite active layer 4 , and an upper electrode 6 stacked on the upper carrier transport unit 5 . The uplink sub-transmission unit 5 includes an uplink subtransmission layer 51 and an uplink subtransmission layer 52 . The upper carrier transport layer 51 is stacked on the perovskite active layer 4 , the upper carrier modification layer 52 is stacked on the upper carrier transport layer 51 , and the upper electrode 6 is stacked on the upper carrier modification layer 52 .

< Comparative application example 1~2 and application examples 1~2＞

Preparation of perovskite photoelectric components

比較例 1 應用例 2

實施例 1 應用例 3

實施例 2 The perovskite photoelectric elements (see Figure 3 for the structure) of comparative application examples 1~2 and application examples 1~2 are based on the benzothiadiene contained in the electron transport compound (as an upper carrier transport material) shown in Table 1 below. Azole polymers were prepared by the following method. Table 1 Benzothiadiazole polymer Comparative application example 1 none Comparative application example 2

Comparative example 1 Application example 2

Example 1 Application example 3

Example 2

Clean the indium tin oxide (ITO) glass substrate (12 Ω/□) sequentially with detergent, deionized water, acetone and isopropanol by ultrasonic vibration for 15 minutes, and then clean the surface of the substrate with a UV ozone cleaner for 30 minutes minute. Wherein, the glass substrate is the substrate 1 , and indium tin oxide (ITO) is the bottom electrode 2 .

Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]{poly [bis(4-phenyl)(2,4,6-trimethylphenyl)amine], PTAA} with solvent Toluene was mixed to form a solution with a solid content of 1.5 wt%. The solution is coated on the lower electrode 2 and baked at 100-120° C. for 10-30 minutes to form a carrier transport layer 3 with a thickness of about 10 nm.

Mix the perovskite raw material components HC(NH ₂ ) ₂ I, CsI, PbI ₂ , and PbBr ₂ with the solvent DMF/DMSO (9:1 v/v) according to the molar ratio of 0.83:0.17:0.85:0.15 to form a solid content It is 49 wt% perovskite precursor solution. First apply the perovskite precursor solution on the carrier transport layer 3, then remove the solvent by vacuum decompression, and bake at 100-110°C for 30-60 minutes to form a calcium layer with a thickness of about 400 nm. Titanium active layer 4.

According to the benzothiadiazole polymers shown in Table 1, the electron transport complex (including benzothiadiazole polymer and PCBM) was mixed with the solvent chlorobenzene to form a solution with a solid content of 2.5 wt%. Wherein, based on the total weight of the electron transport complex being 100 wt%, the weight of the benzothiadiazole polymer is 5 wt%. The solution is coated on the perovskite active layer 4 and baked at 80-100° C. for 10 minutes to form an upper carrier transport layer 51 with a thickness of about 50 nm.

PEI was mixed with the solvent dibutanol to form a solution with a solid content of 0.05 wt%. The solution is coated on the upper carrier transport layer 51 and baked at 90-100° C. for 6 minutes to form an upper carrier modification layer 52 with a thickness of about 2 nm.

The above-mentioned obtained samples were first sent into a vacuum chamber, and then silver metal was evaporated at 1.0×10 ^‒6 torr to form an upper electrode 6 with a thickness of about 100 nm, and then a perovskite photoelectric element was obtained.

< Energy Conversion Efficiency of Perovskite Photovoltaics (PCE) analyze >

The working area of the perovskite photovoltaic element is defined as 0.04 cm ² via a metal mask. Keithley 2400 is used as a power supply, controlled by Lab-View program, under the irradiation of AM1.5G simulated sunlight (SAN-EI XES-40S3) with a light intensity of 100 mW/cm ² to measure the electrical properties of perovskite photoelectric components , and recorded with a computer program to obtain the current-voltage characteristic parameters.

Application examples 1~2 and comparative application examples 1~2 The electron transport compound used in the perovskite photoelectric element, and the open circuit voltage (open voltage; V _oc ), short-circuit current (short- circuit current; J _sc ), fill factor (fill factor; FF) and power conversion efficiency (PCE) are respectively sorted out in Table 2 below. It should be added that the fill factor FF is considered to be related to the interface defects of the component. Generally speaking, the fewer the defects, the more barrier-free the carrier transfer, and the higher the FF value. Table 2 electron transport complex V _oc (V) J _sc (Ma/cm ^-2 ) FF (%) PCE (%) Comparative application example 1 PCBM 1000 18.0 0.70 12.53 Comparative application example 2 PCBM+ 5wt% Comparative Example 1 1025 18.5 0.66 12.57 Application example 1 PCBM+ 5wt% Example 1 1000 19.4 0.76 14.65 Application example 2 PCBM+ 5wt% Example 2 925 18.6 0.79 13.59

It can be found from Table 2 that, compared with the perovskite photoelectric element (comparative application example 1) that does not contain any polymer in the electron transport compound and the benzothiadiazole polymer of Comparative Example 1 in the electron transport compound and The perovskite optoelectronic element (comparative application example 2) of PCBM, the perovskite optoelectronic element (application example 1 ~ 2) that comprises the benzothiadiazole polymer of the present invention and PCBM in the electronic transport compound will have higher Power Conversion Efficiency (PCE).

It is particularly noted that the fill factor FF of application examples 1-2 is significantly increased compared with comparative application example 2 (the increase range is about 15-20%), which shows that the energy barrier defects at the material interface are reduced, which is conducive to the carrier The transmission ability is improved. The foregoing results fully demonstrate that the electron transport complex comprising the benzothiadiazole polymer of the present invention and PCBM is more suitable as the carrier transport material on the perovskite photoelectric element.

< Continuous Illumination Stability Test of Perovskite Photovoltaic Components >

The perovskite photoelectric elements of application examples 1~2 and comparative application examples 1~2 were continuously illuminated to simulate the actual application situation, and the test results are shown in Figure 4.

It can be found from Figure 4 that, compared with the perovskite photoelectric element (comparative application example 1) that does not contain any polymer in the electron transport compound and the element that includes comparative example 1 and PCBM in the electron transport compound (comparative application example 2 ), the perovskite photoelectric element (application examples 1-2) comprising the benzothiadiazole polymer of the present invention and PCBM in the electron transport compound will have a more stable power conversion efficiency (PCE).

The foregoing is because the electron transport complex comprising the benzothiadiazole polymer of the present invention and a fullerene derivative has excellent film-forming properties, compared to the benzothiadiazole polymer of Comparative Example 1, The benzothiadiazole polymer of the present invention has energy level characteristics that are more compatible with the fullerene derivatives, so it is beneficial to reduce material energy barrier defects and help to improve the service life of components.

In summary, since the benzothiadiazole polymer of the present invention can properly adjust the energy level of the material by controlling the chemical structure (Ar ¹ , Ar ² , Ar ³ , X ¹ and X ² ) of the molecules in the copolymer , so that it has better energy level matching with various fullerene derivatives. In addition, the benzothiadiazole polymer of the present invention can obtain the required molecular ratio in the material synthesis stage, so compared with the prior art, the present invention can save the step of mixing different polymers with each other, not only saving the production process At the same time, it also reduces the doubts about the uneven distribution of materials caused by subsequent mixing. In addition, when the benzothiadiazole polymer of the present invention is mixed with a fullerene derivative to form an electron transport compound, the carrier transport material prepared from the electron transport compound will have better film-forming properties and energy Order matching, and at the same time can improve the power conversion efficiency (PCE) and stability of the perovskite photoelectric element, so the purpose of the present invention can indeed be achieved.

But what is described above is only an embodiment of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. Within the scope covered by the patent of the present invention.

1: Substrate 2: Bottom electrode 3: Download sub-transport layer 4: Perovskite active layer 5: Upload subtransmission unit 51:Upload sub-transport layer 52:Upload sub-modification layer 6: Upper electrode

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein: Fig. 1 illustrates the energy level diagram of perovskite (Perovskite), PCBM, comparative example 1, embodiment 1～2; Fig. 2 is a schematic sectional view illustrating the first structure of the perovskite photoelectric element of the present invention; Fig. 3 is a schematic sectional view illustrating the second structure of the perovskite photoelectric element of the present invention; and FIG. 4 is a graph illustrating the stability results of the perovskite photoelectric elements of application examples 1-2 and comparative application examples 1-2 after continuous illumination for simulation.

1: Substrate

2: Bottom electrode

3: Download sub-transport layer

4: Perovskite active layer

5: Upload subtransmission unit

51:Upload sub-transport layer

52:Upload sub-modification layer

6: Upper electrode

Claims (12)

A benzothiadiazole polymer comprising repeating units represented by the following formula (I): [Formula (I)]

Wherein, p and q are 0, 1 or 2 respectively; X ¹ and X ² are H, F or Cl respectively, and at least one of X ¹ and X ² is F or Cl; and Ar ¹ , Ar ² and Ar ³ Arylene or heteroarylene, respectively. The benzothiadiazole polymer as claimed in item 1, wherein Ar ¹ is

,

,

or

, Wherein, R ¹ to R ⁵ are H, R ⁶ , ‒(CH ₂ )n ₁ OR ⁷ , ‒(CH ₂ )n ₁ SR ⁸ , ‒(CH ₂ )n ₁ C(=O)OR ⁹ , ‒ (CH ₂ )n ₁ Si(R ¹⁰ ) ₃ , ‒(CH ₂ )n ₁ N(CH ₃ ) ₂ , ‒(CH ₂ )n ₁ N ⁺ R ¹¹ (CH ₃ ) ₂ X¯, ‒(CH ₂ )n ₁ N ⁺ H(CH ₃ ) ₂ X ¯ or ‒(C ₂ H ₄ O)n ₁ R ¹¹ ; R ⁶ to R ¹⁰ are respectively unsubstituted or substituted by at least one R ¹⁶ C ₁ ~C ₄₀ Straight chain alkyl, C ₄ ~C ₄₀ branched alkyl unsubstituted or substituted by at least one R ¹⁶ , C ₄ ~C ₄₀ cyclic alkyl unsubstituted or substituted by at least one R ¹⁶ , unsubstituted Or C ₂ ~C ₄₀ alkenyl substituted by at least one R ¹⁶ , or C ₂ ~C ₄₀ alkynyl unsubstituted or substituted by at least one R ¹⁶ ; R ¹¹ is methyl or ethyl; n ₁ is 1~ 8; X is Cl, Br or I; R ¹⁶ is halogen, ‒CN, aryl, heteroaryl or ‒SiR ¹⁷ R ¹⁸ R ¹⁹ ; and R ¹⁷ to R ¹⁹ are respectively C ₁ ~C ₄₀ alkyl. The benzothiadiazole polymer as described in claim item 2, wherein Ar ² and Ar ³ are respectively

or

, wherein, n ₂ and n ₃ are 1, 2 or 3 respectively; and R ¹² to R ¹⁵ are H, F, Cl, Br, R ⁶ , ‒CN, ‒OR ⁷ , ‒SR ⁸ , ‒C (= O)OR ⁹ , -Si(R ¹⁰ ) ₃ , aryl or heteroaryl. The benzothiadiazole polymer as claimed in claim 2, wherein Ar ¹ is

. An electron transport complex, comprising the benzothiadiazole polymer and fullerene derivatives as described in claim 1. The electron transport compound as claimed in claim 5, wherein the energy difference between the lowest unoccupied molecular orbital of the benzothiadiazole polymer and the lowest unoccupied molecular orbital of the fullerene derivative is less than 1.0 eV. The electron transport compound as described in Claim 5, wherein, based on the total weight of the electron transport compound being 100 wt%, the weight range of the benzothiadiazole polymer is 0.1-99 wt%. A perovskite photoelectric element, comprising the electron transport compound as described in Claim 5. The perovskite photoelectric element as described in claim 8, wherein the perovskite photoelectric element comprises a substrate, a lower electrode laminated on the substrate, a carrier transport layer laminated on the lower electrode, a laminate A perovskite active layer on the carrier transport layer, an upper carrier transport unit laminated on the perovskite active layer, an upper electrode laminated on the upper carrier transport unit, the upper carrier transport unit includes the Electron transport complex. The perovskite photoelectric element as claimed in claim 9, wherein the upper carrier transport unit includes an upper carrier transport layer, and the upper carrier transport layer includes the electron transport complex. The perovskite photoelectric element according to claim 10, wherein the upper carrier transport unit further includes at least one upper carrier modification layer, the upper carrier transfer layer is laminated on the perovskite active layer, and the upper carrier modification layer is On the upper carrier transport layer, the upper electrode is laminated on the upper carrier modification layer. The perovskite photoelectric element according to claim 10, wherein the upper carrier transport layer has a thickness in the range of 0.1-200 nm.

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