TWI385167B - Dyes applied to polymer solar cells and polymer solar cells comprising the same - Google Patents

Description

Dye molecules applied to polymer solar cells and high in the molecules including the dyes Molecular solar cell

The present invention relates to a dye molecule, and more particularly to a dye molecule that absorbs ultraviolet light to emit visible light.

At present, there is still room for improvement in cost and performance regardless of wafer type or thin film solar cell. In contrast, polymer solar cells belonging to the more advanced technology have a comparative advantage in terms of manufacturing cost, and the battery is upgraded in the future. After efficiency and reliability, there will be an opportunity to have a place in the market.

The active layer material of the polymer solar cell mainly utilizes poly(3-hexylthiophene), P3HT/6,6-phenylcarbon 61 methyl butyrate ((6,6)-phenyl). C61-butyric acid methyl ester (PCBM) has a p-n structure, and such active layer materials have the advantages of low cost, light weight, flexibility, and ease of fabrication in large-area components.

However, the ultraviolet light source emitted by the sunlight is one of the culprit destroying the active layer polymer material, which seriously affects the battery efficiency and shortens the life cycle. Therefore, how to effectively protect the active layer polymer material from ultraviolet light damage is a direction worthy of research in an academic community.

An embodiment of the invention provides a dye molecule having the following chemical formula (I):

Wherein Y is sulfur or selenium; R is hydrogen, halogen, alkyl having 6 to 12 carbon atoms or alkoxy having 6 to 18 carbon atoms; K1 and K2 are , a halogen or a fullerene derivative, wherein at least one of K1 and K2 is Wherein X1 is a methoxy group, a thiol group or a hydroxyl group G1 and G2 are independently oxygen or sulfur, and Z1 to Z4 are independently hydrogen, halogen, an alkyl group having 6 to 12 carbon atoms or an alkoxy group having 6 to 18 carbon atoms. Base; and n is 1~200.

An embodiment of the present invention provides a polymer solar cell comprising: a cathode and an anode; and an active layer disposed between the cathode and the anode, which is doped with a dye molecule of the above formula (I).

The invention mixes modified dye molecules in an active layer to improve battery efficiency, and the dye molecules having excited state intramolecular proton transfer characteristics absorb ultraviolet light having a wavelength of 350-400 nm. After that, the molecular structure is isomerized, and the long-wavelength fluorescence in the visible light region is released. Since the absorption wavelength of 350 to 400 nm (S ₀ → S ₁ ) belongs to the electron-conjugated allowed transition, the ultraviolet light absorption coefficient is particularly strong. (>>10 ⁴ M ^-1 cm ^-1 ), effectively protecting the active layer material. The visible light emitted by the dye molecules via the proton transfer in the excited state can be overlapped with the active layer polymer absorption band, resulting in resonance energy transfer. Therefore, in addition to protecting the solar cell component from ultraviolet light damage, the dye molecules blended by the present invention can also take into account the re-conversion of light energy, effectively improving battery efficiency and prolonging the life cycle. In addition, the dye molecules need only be doped in a small amount, and there is no problem that hinders electron/hole transfer.

The above described objects, features and advantages of the present invention will become more apparent and understood.

An embodiment of the invention provides a dye molecule having the following chemical formula (I):

In the formula (I), Y may be sulfur or selenium, and R may be hydrogen, halogen, an alkyl group having 6 to 12 carbon atoms or an alkoxy group having 6 to 18 carbon atoms, and K1 and K2 may be Halogen or a fullerene derivative such as a carbon 60 or carbon 70 derivative. In an embodiment, at least one of K1 and K2 is . Chemical formula In the above, X1 may be a methoxy group, a thiol group or a hydroxyl group, G1 and G2 may independently be oxygen or sulfur, and Z1 to Z4 may independently be hydrogen, halogen, an alkyl group having 6 to 12 carbon atoms or a carbon number of 6~ The alkoxy group of 18, n may be from 1 to 200.

The dye molecules of the invention have an absorption wavelength between 350 and 400 nm.

One embodiment of the present invention provides a polymer solar cell comprising a cathode and an anode, and an active layer disposed between the cathode and the anode, which is doped with a dye molecule of the above formula (I).

The active layer of the polymer solar cell of the present invention may be high by, for example, poly(3-hexylthiophene), P3HT or poly(p-phenylene vinylene) (PPV). The molecular semiconductor is composed of a fullerene derivative such as 6,6-phenyl C61-butyric acid methyl ester (PCBM). The weight percentage of the above dye molecules in the active layer is between 5 and 30% or 8 to 25%.

The invention mixes modified dye molecules in an active layer to improve battery efficiency, and the dye molecules having excited state intramolecular proton transfer characteristics absorb ultraviolet light having a wavelength of 350-400 nm. After that, the molecular structure is isomerized, and the long-wavelength fluorescence in the visible region is released. Since the absorption wavelength of 350 to 400 nm (S ₀ → S ₁ ) belongs to the electron-conjugated allowed transition, the ultraviolet light absorption coefficient is particularly strong. (>>10 ⁴ M ^-1 cm ^-1 ), effectively protecting the active layer material. The visible light emitted by the dye molecules via the proton transfer in the excited state can be overlapped with the active layer polymer absorption band, resulting in resonance energy transfer. Therefore, in addition to protecting the solar cell component from ultraviolet light damage, the dye molecules blended by the present invention can also take into account the re-conversion of light energy, effectively improving battery efficiency and prolonging the life cycle. In addition, the dye molecules need only be doped in a small amount, and there is no problem that hinders electron/hole transfer.

[Examples] [Example 1]

Chemical formula I-1 synthesis

Synthesis steps:

(1) First, 1.2 ml of 2-hydroxyacetonphenol was dissolved in ethanol, and NaOH and 1.2 ml of 5-bromothiophene-2-carbaldehyde were added, and the mixture was stirred at 50 ° C for 6 hours. After the solvent was drained by a rotary concentrator, water and dichloromethane were added for extraction. The concentrated organic layer product was subjected to column chromatography (dichloromethane: n-hexane = 1:4) to obtain Compound 1 .

(2) 0.77 g of Compound 1 was dissolved in 50 ml of a mixed solution of ethanol and tetrahydrofuran (1:1 by volume), and 5 ml of an aqueous NaOH solution (2 M) was added, and 35% of hydrogen peroxide was slowly added thereto in an ice bath. After stirring to room temperature for 6 hours, an aqueous solution of hydrochloric acid was added to bring the pH of the solution to 7. After the solvent was drained by a rotary concentrator, water and dichloromethane were added for extraction. The concentrated organic layer product was subjected to column chromatography (dichloromethane: n-hexane = 1:1) to obtain Compound 2 .

(3) Compound 2 was dissolved in anhydrous tetrahydrofuran, and 10 equivalents of NaH and 2.5 equivalents of chloro(methoxy)methane were added under ice bath. After stirring to room temperature for 2 hours, deionized water was added to terminate the reaction. After extracting with dichloromethane, the concentrated organic layer product was subjected to column chromatography (ethyl acetate: n-hexane = 1:1) to obtain Compound 3 .

(4) 3.2 mmole of compound 3 , 1.6 mmole of thiophene-2, 5-diyldiboronic acid and 0.1 mmole of Pd(PPh ₃ ) ₄ were placed in a reaction flask, and 50 ml of tetrahydrofuran and 15 ml of sodium carbonate aqueous solution (2M) were added. ), heated to reflux and stirring was continued for 48 hours. After cooling to room temperature, 30 ml of deionized water was added. After extracting with dichloromethane, the concentrated organic layer product was subjected to column chromatography (ethyl acetate: n-hexane = 1:1) to obtain compound 4 .

(5) Compound 4 was dissolved in 25 ml of methanol, and 5 ml of aqueous hydrochloric acid (3N) was added thereto, and the mixture was stirred at room temperature for 2 hours. After the solvent was drained by a rotary concentrator, water and dichloromethane were added for extraction. The concentrated organic layer product was subjected to column chromatography (ethyl acetate: n-hexane = 1:1) to obtain compound 5 .

[Example 2]

Chemical formula I-2 synthesis

Synthesis steps:

(1) First, 5 g of 3-hexylthiophene was dissolved in 100 ml of chloroform, and 90 ml of acetic acid and 10.7 g of NBS were added, and the mixture was stirred at room temperature for 3 hours. After extraction with water, the concentrated organic layer product is subjected to column chromatography (n-hexane) to obtain compound 6 .

(2) 0.64 g of Compound 6 was placed in a reaction flask, and 25 ml of anhydrous tetrahydrofuran and 2 ml of CH ₃ MgBr were added under a nitrogen system. After stirring at room temperature for 1 hour, 0.05 equivalent of Ni(dppp)Cl _{2 was added} and the reaction was overnight. Thereafter, 0.05 equivalent of Pd(PPh ₃ ) ₄ and 0.5 mmole of Compound 3 were added , and the reaction was continued for 24 hours. Thereafter, methanol and a 3N aqueous hydrochloric acid solution were added to terminate the reaction. The resulting filtrate was centrifuged at 3,500 rpm for 3 minutes. After the solid to be filtered, compound 7 can be obtained.

[Example 3]

Synthesis of Chemical Formula I-3

Synthesis steps:

(1) First, 2 mmole of Compound 3 was placed in a reaction flask, and 20 ml of anhydrous tetrahydrofuran was added under a nitrogen system. After cooling to -78 ° C, 1.2 equivalents of B(OMe) ₃ was slowly added dropwise. After returning to room temperature, it was stirred for 5 hours. Thereafter, a saturated aqueous solution of ammonium chloride was added to terminate the reaction. After extracting with dichloromethane, the concentrated organic layer product was subjected to column chromatography (ethyl acetate: n-hexane = 1:3) to obtain compound 8 .

(2) 1 mmole of compound 8 , 1 mmole of [6,6]-Thienyl C ₆₁ butyric acid methyl ester and 0.1 mmole of Pd(PPh ₃ ) ₄ were placed in a reaction flask, and 25 ml of tetrahydrofuran and 7 ml of potassium carbonate were added. The aqueous solution (2M) was heated to reflux and stirring was continued for 24 hours. After cooling to room temperature, 30 ml of deionized water was added. After extraction with methylene chloride, the concentrated organic layer product was subjected to column chromatography (ethyl acetate: n-hexane = 1:1) to afford compound 9 .

[Embodiment 4]

Preparation of the polymer solar cell of the invention (1) (In the active layer, the weight percentage of the dye molecule (I-1) is 8.3%) First, the ITO glass is separately ultrasonically oscillated with water, acetone and isopropyl alcohol. minute. After 5 minutes of application of the plasma, a layer of PEDOT:PSS material having a thickness of about 30 nm was applied and heated at 80 ° C for 10 minutes to complete the fabrication of the composite anode. Thereafter, 15 mg of P3HT, 9 mg of PCMB and 2 mg of the dye molecule (I-1) were dissolved in 1 ml of chlorinated benzene to prepare a solution, and stirring was continued for 24 hours (in a glove box). Next, the above solution was applied onto PEDOT to a thickness of about 90 to 120 nm, and heated at 150 ° C for 10 minutes to complete the production of the active layer. Next, evaporation 5 Lithium fluoride layer with 1,000 The aluminum layer is on the active layer to complete the fabrication of the composite cathode. After the finished product is packaged with UV glue, the battery efficiency is measured with an AM 1.5 G, 1 sun light source.

[Embodiment 5]

Preparation of the polymer solar cell of the invention (2) (In the active layer, the weight percentage of the dye molecule (I-1) is 25%) First, the ITO glass is separately ultrasonically oscillated with water, acetone and isopropyl alcohol. minute. After 5 minutes of application of the plasma, a layer of PEDOT:PSS material having a thickness of about 30 nm was applied and heated at 80 ° C for 10 minutes to complete the fabrication of the composite anode. Thereafter, 15 mg of P3HT, 9 mg of PCMB and 6 mg of the dye molecule (I-1) were dissolved in 1 ml of chlorinated benzene to prepare a solution, and stirring was continued for 24 hours (in a glove box). Next, the above solution was applied onto PEDOT to a thickness of about 90 to 120 nm, and heated at 150 ° C for 10 minutes to complete the production of the active layer. Next, evaporation 5 Lithium fluoride layer with 1,000 The aluminum layer is on the active layer to complete the fabrication of the composite cathode. After the finished product is packaged with UV glue, the battery efficiency is measured with an AM 1.5 G, 1 sun light source.

[Embodiment 6]

Preparation of the polymer solar cell of the invention (3) (in the active layer, the weight percentage of the dye molecule (I-1) is 16%) First, the ITO glass is separately ultrasonically oscillated with water, acetone and isopropyl alcohol. minute. After 5 minutes of application of the plasma, a layer of PEDOT:PSS material having a thickness of about 30 nm was applied and heated at 80 ° C for 10 minutes to complete the fabrication of the composite anode. Thereafter, 15 mg of P3HT, 9 mg of PCMB and 4 mg of the dye molecule (I-1) were dissolved in 1 ml of chlorinated benzene to prepare a solution, and stirring was continued for 24 hours (in a glove box). Next, the above solution was applied onto PEDOT to a thickness of about 90 to 120 nm, and heated at 150 ° C for 10 minutes to complete the production of the active layer. Next, evaporation 5 Lithium fluoride layer with 1,000 The aluminum layer is on the active layer to complete the fabrication of the composite cathode. After the finished product is packaged with UV glue, the battery efficiency is measured with an AM 1.5 G, 1 sun light source.

Table 1 compares the cell efficiencies of solar cells of the present invention in which a chemical cell of formula (I-1) dye molecules are mixed with a conventional unmixed dye molecule in the active layer.

As shown in Table 1, the polymer solar cell of the present invention is mixed with the dye molecules of the chemical formula (I-1) in the active layer, so that a large amount of ultraviolet light source absorbs it, thereby effectively protecting the active layer of the polymer material. Under the proper protection of the active layer polymer material, the battery performance is significantly better than that of the conventional solar cell without the dye molecule.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the invention may be modified and retouched without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application attached.

Claims (8)

A dye molecule applied to a polymer solar cell having the following chemical formula (I): Wherein Y is sulfur or selenium; R is hydrogen, halogen, alkyl having 6 to 12 carbon atoms or alkoxy having 6 to 18 carbon atoms; K1 and K2 are , halogen or fullerene derivatives, wherein at least one of K1 and K2 is Wherein X1 is a methoxy group, a thiol group or a hydroxyl group, G1 and G2 are independently oxygen or sulfur, and Z1 to Z4 are independently hydrogen, halogen, an alkyl group having 6 to 12 carbon atoms or an alkyl group having 6 to 18 carbon atoms. Oxy; and n is from 1 to 200. Applied to the polymer sun as described in claim 1 A dye molecule of a battery, wherein K1 and K2 are carbon 60 or carbon 70 derivatives. A polymer solar cell comprising: a cathode and an anode; and an active layer disposed between the cathode and the anode, doped with the dye applied to the polymer solar cell according to claim 1 molecule. The polymer solar cell according to claim 3, wherein the active layer is composed of a polymer semiconductor and a fullerene derivative. The polymer solar cell according to claim 4, wherein the polymer semiconductor comprises poly(3-hexylthiophene), P3HT or poly(p-styrene) (poly( P-phenylene vinylene), PPV). The polymer solar cell of claim 4, wherein the fullerene derivative comprises 6,6-phenylcarbon 61-butyric acid methyl ester ((6,6)-phenyl C61-butyric acid) Methyl ester, PCBM). The polymer solar cell of claim 3, wherein the weight percentage of the dye molecule in the active layer is between 5 and 30%. The polymer solar cell of claim 3, wherein the weight percentage of the dye molecule in the active layer is between 8 and 25%.