WO2018188346A1

WO2018188346A1 - Water and alcohol soluble triple bonded conjugated polymer and application thereof in organic optoelectronic device

Info

Publication number: WO2018188346A1
Application number: PCT/CN2017/112780
Authority: WO
Inventors: 黄飞; 胡志诚; 曹镛
Original assignee: 华南理工大学
Priority date: 2017-04-12
Filing date: 2017-11-24
Publication date: 2018-10-18
Also published as: CN106986982A

Abstract

The present invention relates to a water and alcohol soluble triple bonded conjugated polymer and an application thereof in an organic optoelectronic device. The water and alcohol soluble triple bonded conjugated polymer mainly comprises the four components A, B, C, and D, A and B being conjugated units connected by a triple bond. C and D are side chain groups connected to the A and B units, at least one of C and D being a water and alcohol soluble side chain group. The triple bonded conjugated polyelectrolyte can be processed using a strong polarity solvent like alcohol, and is suitable for manufacturing multi-layer optoelectronic devices. The main bonds of the water and alcohol soluble triple bonded conjugated polymer have good rigidity and planarity, improving the migration rate of the polymer film. The present water and alcohol soluble triple bonded conjugated polymer can be used as a cathode interface modification material for use in an optoelectronic device, improving the performance of the device.

Description

Three-bond water-soluble alcohol-soluble conjugated polymer and its application in organic optoelectronic devices

Technical field

The invention relates to the field of polymer photoelectric materials, in particular to a kind of triple-linked water alcohol-soluble conjugated polymer and its application in organic photoelectric devices.

Background technique

As the global demand for energy increases year by year, the traditional energy sources such as oil and coal are depleted, and the need to protect the earth's ecological environment, more and more scientists around the world are focusing on the development and utilization of hydrogen and solar energy. Inexhaustible renewable energy.

As an innovative thin-film photovoltaic cell technology, organic/polymer solar cells based on organic/polymer materials have the advantages of being all solid, translucent, and flexible. In addition, organic/polymer solar cells can be processed using a low-cost roll-to-roll process to produce large-area devices. The use of organic/polymer solar cells is virtually independent of environmental and site constraints, and is highly complementary to inorganic semiconductor solar cells, with great commercial development value and market competitiveness. Organic materials have a wide range of photovoltaic properties, and can be chemically controlled for materials, electronic energy levels, carrier mobility, and solution processing. Therefore, research on organic/polymer solar cells has attracted wide attention, and scientific research centered on organic/polymer solar cells has become a highly competitive field of material science research in the world.

Electron transport materials are important to improve the performance of organic/polymer solar cells. Excellent electron transport materials can improve the charge collection capacity of organic/polymer solar cells, improve the filling factor of battery devices, and improve the energy conversion efficiency of battery devices. Electron transport materials with high mobility characteristics also have good solution processing characteristics, effectively reducing the dependence of device performance on the thickness of the electron transport layer. The invention develops a kind of triple-linked water alcoholic conjugated polycondensation As an electron transport material for organic/polymer solar cells, the compound improves the charge collection capability of the organic/polymer solar cell device, and improves the filling factor and energy conversion efficiency of the battery device.

Summary of the invention

The object of the present invention is to provide a kind of triple-bonded hydroalcohol-soluble conjugated polymer and its use in organic optoelectronic devices. The main chain of the triple-linked hydroalcohol-soluble conjugated polymer has good rigidity and planarity. It is beneficial to increase the mobility of the polymer film, can improve the charge collection ability of the organic/polymer solar cell device, and improve the filling factor and energy conversion efficiency of the battery device.

The technical scheme of the present invention is as follows:

A three-bond water-soluble alcohol-soluble conjugated polymer having the following structure:

Wherein, 1<n<1000000; the A, B are conjugated units constituting a conjugated polymer, and the conjugated unit is thiophene, furan, benzene, anthracene, carbazole, silicon germanium, benzodithiophene, benzene And selenophene, benzodifuran, phenothiazine, phenoxazine, bithiophene, thiophene, thienocyclopentadiene, thienopyrrole, thienothiol, indole, oxazole, pyrrole One or more of naphthalimide, phthalimide or a derivative thereof; the C, D is a side chain group bonded to the A and B units, and at least one of C and D is a hydroalcohol Soluble side chain groups; said C, D are linked to A, B via an alkyl chain, respectively.

Further, wherein the conjugated units A, B have one or more of the following structures:

Further, the hydroalcoholic side chain group has one of the following structures:

Further, the alkyl chain is a linear, branched or cyclic alkyl chain having 1 to 20 carbon atoms.

Further, one or more carbon atoms in the linear, branched or cyclic alkyl chain having 1 to 20 carbon atoms are bonded to an oxygen atom, an alkenyl group, an alkynyl group, an aryl group, a hydroxyl group, an amino group, a carbonyl group, Carboxy, ester, cyano or nitro substituted.

Further, the hydrogen atom in the linear, branched or cyclic alkyl chain having 1 to 20 carbon atoms is substituted by a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

A three-bonded water-alcohol-soluble conjugated polymer is used as a cathode interface modifying material in an organic photovoltaic device.

The three-bonded water-alcohol-soluble conjugated polymer is synthesized by the following method. First, a three-bonded hydroalcohol-soluble neutral conjugated polymer is obtained by Sonogashira polymerization of a conjugated unit A and a conjugated unit B, and then passed through a quaternary ammonium. The cyclization or quaternization reaction results in a three-bonded hydroalcohol conjugated polymer containing a quaternary ammonium salt or a quaternary phosphonium salt group. A water-soluble conjugated polymer containing a triple bond of different counter ions can also be obtained by ion exchange.

As shown in Fig. 1, the organic/polymer solar cell used in the present invention is formed by laminating a substrate 1, an anode 2, an anode interface layer 3, a light absorbing layer 4, a cathode interface layer 5, and a cathode 6 in this order. The cathode interface layer consists of a three-bonded hydroalcohol conjugated polymer synthesized in accordance with the present invention.

In the solar cell of the present invention, the anode material is preferably aluminum, silver, gold, calcium/aluminum alloy or calcium/silver alloy.

The anode interface layer of the present invention is preferably an organic conjugated polymer (such as poly 3,4-ethylenedioxythiophene/polystyrene sulfonate) or an inorganic semiconductor.

The cathode of the present invention is preferably a metal, a metal oxide (such as an indium tin oxide conductive film (ITO), doped tin dioxide (FTO), zinc oxide (ZnO), indium gallium zinc oxide (IGZO)) and graphene. At least one of its derivatives.

The substrate of the present invention is preferably a glass, flexible material (such as polyimide, polyethylene terephthalate, ethylene terephthalate, polyethylene naphthalate or other polyester materials). At least one of a metal, an alloy, and a stainless steel film.

The present invention has the following advantages over the prior art:

(1) The three-bonded hydroalcohol-soluble conjugated polymer synthesized by the present invention has a good rigidity and planarity in the main chain, and is advantageous for increasing the mobility of the polymer film and facilitating charge transport.

(2) The triple-linked hydroalcohol-conjugated conjugated polymer synthesized by the present invention has a high mobility, and can be processed into a thick film in a polymer solar cell, which is advantageous for processing a large area of a polymer solar cell device.

(3) The polymer synthesized by the present invention can be dissolved in a polar solvent (e.g., methanol, ethanol), and the light absorbing layer material is generally insoluble in such a solvent, and thus between the light absorbing layer and the electron injecting layer when constructing the multilayer device There is no mutual mixing.

(4) The triple-linked hydroalcohol-soluble conjugated polymer synthesized by the invention has excellent charge extraction performance and can be applied to a polymer solar cell to improve the filling factor and energy conversion efficiency of the battery device.

DRAWINGS

Figure 1 is a schematic view showing the structure of an organic/polymer solar cell;

2 is an ultraviolet-visible absorption spectrum of a representative three-bonded water-soluble NDI-based conjugated polymer;

Figure 3 is a graph showing the ultraviolet-visible absorption spectrum of a representative three-bonded water-soluble PDI-based conjugated polymer.

detailed description

The invention is further illustrated by the following examples, which are intended to facilitate a better understanding of the present invention, including synthesis, characterization, and device preparation, but the specific embodiments do not limit the scope of the invention in any way.

Example 1

The synthetic route for representative water-soluble conjugated polymers containing triple bonds is as follows:

(1) Monomer M _{1 was} synthesized according to the method disclosed in the literature [Chem. Mater. 2011, _23, 4563.].

(2) Monomer M _{2 was} synthesized according to the method disclosed in the literature [J. Am. Chem. Soc. 2009, 129, 7246].

(3) Synthesis of monomer M0:

Synthesis of 1,4-dibromo-2,5-bis((6-bromohexyl)oxy)benzene (A1):

2,5-Dibromobenzene-1,4-diol (5.35 g, 20 mmol) and dibromohexane (19.5 g, 80 mmol) were placed in a 150 mL round bottom flask, followed by the addition of 80 mL of acetone. After flowing through N ₂ for 15 minutes, K ₂ CO ₃ (11.1 g, 80 mmol) was added portionwise. The reaction solution was refluxed for 24 hours, then the mixture was concentrated. Water and dichloromethane were added. The organic phase was then separated and concentrated under reduced pressure. Separation of the pure A1 was obtained as a white solid (7.7 g, 65%). ^{_{1 H NMR (500MHz, CDCl 3}} , δ): 7.08 (s, 2H), 3.96 (t, J = 6.3Hz, 4H), 3.43 (t, J = 6.8Hz, 4H), 2.02-1.72 (m, 8H ), 1.63-1.45 (m, 8H).

Synthesis of (2,5-bis((6-bromohexyl)oxy)-1,4-phenylene)bis(acetylene-2,1diyl))bis(trimethylsilane)(A2): A1 (2.37 g, 4 mmol) and trimethylsilylacetylene (1 g, 10 mmol) were added to a 50 mL round bottom flask. 20 mL of toluene and 8 mL of diisopropylamine were added, and then the reaction liquid was cooled to 0 ° C, and nitrogen gas was passed for 20 minutes. 80 mg of CuI and 462 mg of Pd(PPh ₃ ) _{4 were added} , and the reaction solution was heated to 70 ° C and stirred for 12 hours. The crude product was then concentrated under reduced pressure and purified using a chromatography column. The pure A2 obtained was a white solid (2.25 g, 89.6%). ^{_{1 H NMR (500MHz, CDCl 3}} , δ): 6.89 (s, 2H), 3.95 (t, J = 6.2Hz, 4H), 3.42 (t, J = 6.8Hz, 4H), 1.89 (dt, J = 13.9 , 6.8 Hz, 4H), 1.81 (tt, J = 12.7, 6.2 Hz, 4H), 1.63-1.39 (m, 8H), 0.25 (s, 18H). ¹³ C NMR (126 MHz, CDCl ₃ , δ): 153.94 , 117.27, 113.99, 100.99, 100.22, 69.15, 33.79, 32.78, 29.16, 27.96, 25.26, 0.00.

6,6'-((2,5-Diethynyl-1,4-phenylene)bis(oxy))bis(N,N-diethylhexylamine-1-amine)(M ₀ ) synthesis:

1 g of the substrate A2 was added to a mixed solution of 20 ml of THF and 2 ml of DMF, and then 1 ml of diethylamine was added. The reaction was stirred at 50 ° C for 24 hours. After completion of the reaction, the mixture was concentrated with a rotary evaporator and dissolved again in THF, and then a mixture of 10 ml of 20% aqueous KOH and 10 ml of methanol was added and stirred at room temperature for 2 hours. The organic layer was combined and washed with water several times, and the solvent was evaporated. ^{_{1 H NMR (500MHz, CDCl 3}} , δ): 6.94 (s, 1H), 3.97 (t, J = 6.6Hz, 2H), 3.32 (s, 1H), 2.52 (q, J = 7.2Hz, 4H), 2.47-2.31 (m, 2H), 1.79 (dd, J = 14.8, 6.9 Hz, 2H), 1.61-1.39 (m, 4H), 1.39-1.27 (m, 2H), 1.02 (t, J = 7.2 Hz, 6H). ¹³ C NMR (126MHz, CDCl ₃ , δ): 153.95, 117.75, 113.26, 82.46, 79.76, 69.56, 52.85, 46.91, 29.13, 27.43, 26.88, 25.94, 11.63.

(4) Synthesis of representative polymers NDIN and PDIN:

0.25 mmol of M ₁ or M ₂ and 0.25 mmol of M _{0 were} added to a 25 ml reaction tube, and 5 ml of toluene and 2 ml of triethylamine were added. After removing oxygen, 2 mg of Pd(PPh3)4 and 1 mg of CuI were added. Heating to 70 ° C, the polymer NDIN required a reaction time of 2 hours, the polymer PDIN required to obtain a reaction time of 6 hours. The solution after the polymerization was allowed to settle in methanol, and the precipitate was dried, and then extracted with methanol, n-hexane and chloroform, and concentrated, and then again, and then dried in methanol to obtain a solid. The NDIN and PDIN obtained were both black solids with yields of 89% and 88%, respectively.

(5) Synthesis of representative polymers NDI-Br and PDI-Br:

100 mg of NDIN or PDIN was dissolved in 25 ml of toluene, 1 ml of ethyl bromide was added, and the mixed solution was added to the reaction at 50 ° C for 48 hours. During the course of this reaction, 5 ml of methanol was added every 8 hours. Finally, the polymer solution is concentrated and sinks in the positive In a mixed solution of hexane and ethyl acetate, the solid was filtered and dried. Both NDI-Br and PDI-Br were black solids with yields of 91% and 90%, respectively.

(6) Synthesis of representative polymers NDI-Ac and PDI-Ac:

NDI-Ac and PDI-Ac are obtained by ion exchange reaction of NDI-Br and PDI-Br. NDI-Br and PDI-Br were dissolved in a mixed solution of methanol and THF, and an excess of sodium acetate in methanol was added thereto, and the reaction was carried out at 45-50 ° C for two days. The solution was concentrated and allowed to settle in a mixed solution of n-hexane and ethyl acetate. The above ion exchange process is carried out once more, and the final solution is dialyzed in water to remove excess salt. After final concentration, it was poured into a mixed solution of n-hexane and ethyl acetate, and the solid was filtered and dried. NDI-Ac and PDI-Ac were both black solids, and the degree of ion exchange was measured by XPS.

The obtained three-bonded hydroalcohol-soluble conjugated polymer was subjected to an ultraviolet-visible absorption test, and the test results are shown in Figs. The absorption of the water-soluble polymer based on the NDI unit in the solid film state is significantly red-shifted relative to the absorption in the solution state, and the red-shift of the water-alcoholic polymerization based on the PDI unit is not so obvious.

Example 2

The three-bonded hydroalcohol conjugated polymer synthesized in Example 1 was used as a cathode interface modifier in an organic/polymer solar cell. The structure of the organic/polymer solar cell is as shown in Fig. 1, which is: substrate 1 / ITO anode 2 / anode interface layer 3 / light absorbing layer 4 / cathode interface layer 5 / cathode 6. The conjugated polyelectrolyte of the present invention is used as a cathode interface layer 5 in an organic/polymer solar cell.

A 40 nm PEDOT:PSS anode interface layer was spin-coated on ITO, and a 100 nm light absorbing layer was spin-coated using a PTB7-Th:PC ₇₁ BM mixed solution, and a representative polymer prepared as a cathode was used as a cathode. The interface material was prepared in a solution of methanol, and a cathode interface layer having a thickness of about 10 nm was prepared. Finally, 80 nm thick aluminum was vapor-deposited as a cathode. The JV curve test was performed, and the relevant parameters of the device were as shown in Table 1. It can be seen from Table 1 that the efficiency of the device is more than 8% after the addition of the cathode interface material. The device efficiency of using NDI-Br and PDI-Br as the cathode interface material is close to 10%, and the short-circuit current is as high as 17.40 and 17.50 mA, respectively. / square centimeter. It can be seen that the three-bonded hydroalcoholic conjugated polymer can be used as a good cathode interface layer in solar cells.

Table 1 device structure is ITO / PEDOT: PSS (40nm) / PTB7-Th: PC ₇₁ BM (100nm) / cathode interface layer

Performance parameters of (10nm)/Al (80nm) devices

Example 3

The three-bonded hydroalcohol-conjugated conjugated polymers NDI-Br and PDI-Br synthesized in Example 1 were used as cathode interface modifiers in organic/polymer solar cells. The structure of the organic/polymer solar cell is as shown in Fig. 1, which is: substrate 1 / ITO anode 2 / anode interface layer 3 / light absorbing layer 4 / cathode interface layer 5 / cathode 6. The three-bonded hydroalcoholic conjugated polymers NDI-Br and PDI-Br synthesized in Example 1 of the present invention were used as the cathode interface layer 5 in an organic/polymer solar cell. The device structure is ITO/PEDOT: PSS (40 nm) / NT812: PC ₇₁ BM (300 nm) / cathode interface layer / Al (80 nm), the device fabrication process is similar to that of the second embodiment, but the light absorbing layer is mixed with NT812: PC ₇₁ BM. The film has a thickness of 300 nm. The cathode interface layer was prepared by using a solution of NDI-Br and PDI-Br in methanol to prepare a cathode interface layer of 10 nm and 60 nm thick respectively, and the device efficiency was as shown in Table 2.

It can be seen from Table 2 that when the active layer is NT812:PC ₇₁ BM and the cathode interface layer is 10 nm thick, compared with the first case, the photoelectric conversion efficiency of the device is relatively improved, and the short-circuit current is relatively high, among which PDI-Br is used. The device efficiency for the cathode interface layer is over 10%. At the same time, when the film thickness is 60 nm, the device efficiency based on NDI-Br can be maintained at 7.35%, while the device efficiency based on PDI-Br is maintained at 9.25%. It can be seen that the three-bonded water-soluble conjugated polymer can be used not only as a good cathode interface layer in solar cells, but also to improve the performance of various polymer batteries while being relatively insensitive to film thickness. It has great advantages in the large-area preparation of devices in the future.

Table 2 device structure is ITO / PEDOT: PSS (40nm) / NT812: PC ₇₁ BM (300nm) / cathode interface layer / Al (80nm), performance parameters of the device

The above-described embodiments of the present invention are merely illustrative of the present invention and are not intended to limit the embodiments of the present invention. Other variations or modifications of the various forms may be made by those skilled in the art in light of the above description. There is no need and no way to exhaust all of the implementations. Any modifications, equivalent substitutions and improvements made within the spirit and scope of the invention are intended to be included within the scope of the appended claims.

Claims

A three-bond water-soluble alcohol-soluble conjugated polymer having the following structure:

Wherein, 1<n<1000000; the A, B are conjugated units constituting a conjugated polymer, and the conjugated unit is thiophene, furan, benzene, anthracene, carbazole, silicon germanium, benzodithiophene, benzene And selenophene, benzodifuran, phenothiazine, phenoxazine, bithiophene, thiophene, thienocyclopentadiene, thienopyrrole, thienothiol, indole, oxazole, pyrrole One or more of naphthalimide, phthalimide or a derivative thereof; the C, D is a side chain group bonded to the A and B units, and at least one of C and D is a hydroalcohol Soluble side chain groups; said C, D are linked to A, B via an alkyl chain, respectively.
The triple-linked water-alcohol-soluble conjugated polymer according to claim 1, wherein the conjugated units A and B have one or more of the following structures:
The triple-linked hydroalcohol-soluble conjugated polymer according to claim 1, wherein the hydroalcoholic side chain group has one of the following structures:
The triple-linked hydroalcohol-conjugated conjugated polymer according to claim 1, wherein the alkyl chain is a linear, branched or cyclic alkyl chain having 1 to 20 carbon atoms.
The triple-linked hydroalcohol-conjugated conjugated polymer according to claim 1, wherein one or more carbon atoms of said linear, branched or cyclic alkyl chain having 1 to 20 carbon atoms It is substituted by an oxygen atom, an alkenyl group, an alkynyl group, an aryl group, a hydroxyl group, an amino group, a carbonyl group, a carboxyl group, an ester group, a cyano group or a nitro group.
The triple-linked water-alcohol-soluble conjugated polymer according to claim 1, wherein the hydrogen atom in the linear, branched or cyclic alkyl chain having 1 to 20 carbon atoms is a fluorine atom, The chlorine atom, the bromine atom, and the iodine atom are substituted.
The three-bonded hydroalcohol-soluble conjugated polymer according to any one of claims 1 to 6 is used as an electron transporting material in an organic photoelectric device.