Polymer, organic semiconductor and organic electronic device comprising the same

Abstract

The present invention relates to a polymer comprising a repeating unit represented by the following chemical formula 1, an organic semiconductor comprising the same, and an organic electronic device. [Chemical Formula 1] (In the above Chemical Formula 1, R1, R2, and Ar are as described in the specification.)

Description

Technology Field

[0001] The present invention relates to a polymer of a novel structure, an organic semiconductor and an organic electronic device comprising the same. Background Technology

[0002] Organic semiconductors are gaining attention as next-generation materials capable of replacing conventional inorganic semiconductors due to various advantages such as flexibility, lightweight properties, and easy film deposition conditions. In particular, they are widely used as core materials for organic transistors, displays, organic solar cells, organic memory, organic photosensitive materials, and organic photosensors, and the performance requirements for these electronic devices are becoming increasingly sophisticated. Accordingly, there is still a need to develop new organic semiconductor materials with improved charge mobility, light absorption, and durability. Prior art literature

[0003] Republic of Korea Published Patent Application No. 10-2021-0073475 (June 18, 2021) The problem to be solved

[0004] One aspect of the present invention provides a polymer of a novel structure that can be usefully used as a semiconductor material and a method for manufacturing the same.

[0005] Another aspect of the present invention provides an organic electronic device, such as an organic transistor or an organic solar cell, that can satisfy excellent charge mobility, energy conversion efficiency, and durability by employing an organic semiconductor comprising the above polymer. means of solving the problem

[0006] One embodiment of the present invention provides a polymer comprising a repeating unit represented by the following chemical formula 1.

[0007] [Chemical Formula 1]

[0008]

[0009] (In the above chemical formula 1,

[0010] R 1 and R2 Each is independently (C1-C50)alkyl;

[0011] Ar stands for (C6-C20)arylene, (C3-C20)heteroarylene, or *-Ar 1 -L-Ar 2 -* and;

[0012] Ar 1 and Ar 2 Each is independently a (C6-C20)arylene or a (C3-C20)heteroarylene;

[0013] L is (C2-C20)alkenylene or (C2-C20)alkynylene;

[0014] The above Ar, Ar 1 and Ar 2 The arylenes and heteroarylenes of may be further substituted with one or more (C1-C20)alkyl groups.

[0015] The above Ar may be selected from the following structure.

[0016]

[0017] (In the above structural formula,

[0018] Z 1 To Z 5 are each independently S or Se;

[0019] L 1 is a single bond, (C2-C20)alkenylene or (C2-C20)alkynylene;

[0020] R 3 to R 10 Each is independently hydrogen or (C1-C20)alkyl.

[0021] A polymer according to one embodiment may comprise a repeating unit represented by the following chemical formula 2 or chemical formula 3.

[0022] [Chemical Formula 2]

[0023]

[0024] [Chemical Formula 3]

[0025]

[0026] (In the above chemical formulas 2 and 3,

[0027] R 1 and R 2 Each is independently (C1-C50)alkyl;

[0028] R 3 to R 8 Each is independently hydrogen or (C1-C20)alkyl;

[0029] Z 1 To Z 3 Each is independently S or Se.)

[0030] The above R 2 Each can be independently a branched chain (C10-C50)alkyl.

[0031] A polymer according to one embodiment may comprise a repeating unit represented by the following chemical formula 4 or chemical formula 5.

[0032] [Chemical Formula 4]

[0033]

[0034] [Chemical Formula 5]

[0035]

[0036] (In the above chemical formulas 4 and 5,

[0037] R 1 Each is independently (C1-C20)alkyl;

[0038] R 11 to R 14 Each is independently (C1-C20)alkyl;

[0039] n and m are each independently integers from 1 to 10;

[0040] Z 1 To Z 3 Each is independently S or Se.)

[0041] The above R 1 is a (C1-C10)alkyl, and R 11 to R14 Each is independently (C10-C20)alkyl, and n and m can each independently be integers from 1 to 6.

[0042] The repeating unit represented by the above chemical formula 1 may be selected from the following structure.

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] Another aspect of the present invention provides an organic semiconductor comprising the polymer.

[0052] Another aspect of the present invention provides an organic electronic device comprising an organic semiconductor.

[0053] The above organic electronic device may be an organic solar cell, an organic transistor, an organic memory, an organic photosensitive material, or an organic photosensor. Effects of the invention

[0054] A polymer according to one embodiment has an extended conjugation and can achieve a low bandgap and excellent charge mobility. Accordingly, the polymer according to one embodiment can be utilized as a material for various organic optoelectronic devices, such as organic photosensors and organic transistors. Furthermore, the polymer according to one embodiment can effectively absorb light in the long wavelength region compared to conventional diketopyrrolopyrrole-based semiconductor compounds, making it easy to apply to solar cells.

[0055] In addition, the polymer according to one embodiment has excellent solubility in organic solvents, making solution processing easy, and exhibits excellent chemical and thermal stability. That is, an organic electronic device employing the polymer according to one embodiment can have excellent efficiency, durability, and productivity. Brief explanation of the drawing

[0056] Figure 1 is a graph of the UV absorption spectra of the polymers of Examples 1 and 2. Specific details for implementing the invention

[0057] Unless otherwise defined in this specification, all technical and scientific terms have the same meaning as generally understood by those skilled in the art to which the present invention pertains. The terms used in the description herein are merely for the purpose of effectively describing specific embodiments and are not intended to limit the present invention.

[0058] The singular form used in this specification is intended to include the plural form unless specifically indicated otherwise in the context.

[0059] Throughout this specification, the terms “comprising,” “having,” “containing,” or “having” any component mean that, unless specifically stated otherwise, other components are not excluded but may be included, and do not exclude elements, materials, or processes not additionally listed.

[0060] The numerical ranges used herein include lower and upper limits and all values ​​within the range, increments logically derived from the form and width of the defined range, all of which are limited, and all possible combinations of upper and lower limits of the numerical range defined in different forms. Unless otherwise specifically defined in this specification, values ​​outside the numerical range that may occur due to experimental error or rounding are also included in the defined numerical range.

[0061] Unless otherwise specifically defined in this specification, “about” may be considered to be a value within 30%, 25%, 20%, 15%, 10%, or 5% of the specified value.

[0062] The present disclosure will be described in detail below. However, this is merely illustrative and the present disclosure is not limited to the specific embodiments described illustratively.

[0063] One embodiment of the present invention provides a polymer of a novel structure that is usefully usable as an organic semiconductor material, has a low bandgap and excellent charge mobility, and absorbs light in the long wavelength region. Specifically, the polymer according to one embodiment comprises a repeating unit represented by the following chemical formula 1.

[0064] [Chemical Formula 1]

[0065]

[0066] (In the above chemical formula 1,

[0067] R 1 and R 2 Each is independently (C1-C50)alkyl;

[0068] Ar stands for (C6-C20)arylene, (C3-C20)heteroarylene, or *-Ar 1 -L-Ar 2 -* and;

[0069] Ar 1 and Ar 2 Each is independently a (C6-C20)arylene or a (C3-C20)heteroarylene;

[0070] L is (C2-C20)alkenylene or (C2-C20)alkynylene;

[0071] The above Ar, Ar 1 and Ar 2 The arylenes and heteroarylenes of may be further substituted with one or more (C1-C20)alkyl groups.

[0072] A polymer according to one embodiment satisfies the structural features described above, for example, a sequence combination of dithienopyrrole, diketopyrrolopyrrole, dithienopyrrole, and an aromatic ring (Ar), thereby having a low bandgap and significantly improved charge mobility, while simultaneously being able to effectively absorb light in the long wavelength region compared to conventional diketopyrrolopyrrole-based semiconductor compounds. In addition, R 1 and R 2 It has a substituent, so it has excellent solubility in solvents, making solution processing easy.

[0073] For example, the above Ar is (C6-C12)arylene, (C3-C12)heteroarylene, or *-Ar 1 -L-Ar 2 -* and; Ar 1 and Ar 2 Each is independently (C6-C12)arylene or (C3-C12)heteroarylene; L can be (C2-C10)alkenylene or (C2-C10)alkynylene.

[0074] For example, the above L may be (C2-C7)alkenylene or (C2-C7)alkynylene, and may be (C2-C4)alkenylene or (C2-C4)alkynylene.

[0075] For example, the above Ar may be selected from the following structure.

[0076]

[0077] (In the above structural formula, Z 1 To Z 5 are each independently S or Se; L 1 is a single bond, (C2-C20)alkenylene or (C2-C20)alkynylene; R 3 to R 10 Each is independently hydrogen or (C1-C20)alkyl.

[0078] For example, the above L 1It can be a single bond, (C2-C10)alkenylene or (C2-C10)alkynylene, and can be (C2-C4)alkenylene or (C2-C4)alkynylene.

[0079] For example, the above R 3 to R 10 Each can independently be hydrogen or (C1-C10)alkyl, and can be hydrogen or (C1-C7)alkyl.

[0080] Specifically, a polymer according to one embodiment may include repeating units represented by the following chemical formula 2 or chemical formula 3.

[0081] [Chemical Formula 2]

[0082]

[0083] [Chemical Formula 3]

[0084]

[0085] (In the above chemical formulas 2 and 3,

[0086] R 1 and R 2 Each is independently (C1-C50)alkyl;

[0087] R 3 to R 8 Each is independently hydrogen or (C1-C20)alkyl;

[0088] Z 1 To Z 3 Each is independently S or Se.)

[0089] For example, the above R 1 Each can independently be a (C1-C40)alkyl, or a (C1-C30)alkyl, or a (C1-C20)alkyl, or a (C1-C10)alkyl, and can be a straight-chain alkyl.

[0090] For example, the above R 2 Each may independently be a branched-chain (C3-C50)alkyl, a branched-chain (C5-C50)alkyl, a branched-chain (C10-C50)alkyl, or a branched-chain (C20-C50)alkyl.

[0091] Specifically, a polymer according to one embodiment may comprise a repeating unit represented by the following chemical formula 4 or chemical formula 5.

[0092] [Chemical Formula 4]

[0093]

[0094] [Chemical Formula 5]

[0095]

[0096] (In the above chemical formulas 4 and 5,

[0097] R 1 Each is independently (C1-C20)alkyl;

[0098] R 11 to R 14 Each is independently (C1-C20)alkyl;

[0099] n and m are each independently integers from 1 to 10;

[0100] Z 1 To Z 3 Each is independently S or Se.)

[0101] For example, the above R 11 to R 14 Each can independently be a (C5-C20)alkyl or a (C10-C20)alkyl, and n and m can each independently be integers from 1 to 6.

[0102] The repeating unit represented by the above chemical formula 1 according to one embodiment may be selected from, for example, the following structures, but is not limited thereto.

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111] A polymer according to one embodiment can absorb light in the long wavelength region as it has structural features as described above, for example, the maximum absorption wavelength in solution of the polymer may be in the range of 500 to 1,000 nm, or 600 to 1,000 nm, or 700 to 1,000 nm, or 750 to 1,000 nm, or 800 to 1,000 nm.

[0112] The number average molecular weight of the polymer according to one embodiment is not significantly limited as long as the desired effect in the present invention is achieved, but, for example, it may be 5,000 to 100,000 g / mol.

[0113] A polymer according to one embodiment can be prepared as shown in the following reaction scheme, but it is obvious that it can also be prepared through other conventional synthesis methods recognized by those skilled in the art.

[0114] [Reaction Equation]

[0115]

[0116] (In the above reaction equation,

[0117] R 1 , R 2 , Ar is the same as the definition in Chemical Formula 1 above;

[0118] X 1 and X 2 is a halogen;

[0119] R 21 to R 26 Each is independently (C1-C10)alkyl.

[0120] The above reaction may be a Stillie coupling reaction performed under a palladium catalyst, and may be performed for 10 to 50 hours, 20 to 50 hours, or 40 to 50 hours under temperature conditions of 50 to 200 ℃, or 100 to 200 ℃, or 100 to 150 ℃, but is not limited thereto.

[0121] Another aspect of the present invention provides an organic semiconductor comprising the polymer and an organic electronic device comprising the same.

[0122] An organic electronic device according to one embodiment is described below, but it is obvious that, except for including the polymer according to one embodiment as a photoactive layer or semiconductor layer, it can be manufactured into a structure known in the art using conventional manufacturing methods and materials in the art.

[0123] An organic electronic device according to one embodiment is not significantly limited as long as it is a device in which the polymer of the present invention can be used, but non-limiting examples include organic solar cells, organic transistors, organic memories, or organic photosensitive materials, organic photosensors, etc., and preferably may be an organic solar cell or an organic transistor.

[0124] Specifically, a polymer according to one embodiment may be included as an organic semiconductor layer material of an organic transistor, and an organic transistor employing the same may have improved charge mobility, switching ratio, etc.

[0125] A polymer according to one embodiment may be included as a photoactive layer of an organic solar cell, for example, as an electron donor material, and an organic solar cell employing the same can achieve excellent photoelectric conversion efficiency.

[0126] The above-described embodiment will be explained in more detail below through examples. However, the following examples are for illustrative purposes only and do not limit the scope of the claims.

[0127] [Physical Property Evaluation Methods]

[0128] 1. Molecular weight and molecular weight distribution

[0129] Measurements were performed in chloroform solvent at a rate of 1 mL / min at 40°C using gel permeation chromatography (GPC) consisting of a Waters 1515 isocratic HPLC pump, a temperature control module, and a Waters 2414 differential refractometer, using polystyrene standard material.

[0130] [Preparation Example] Preparation of Compound D

[0131]

[0132] Preparation of Compound A

[0133] 4-octyl-4H-dithieno[3,2-b:2',3'-d]pyrrole-2-carbaldehyde (2.73 g, 8.54 mmol) was dissolved in NMP (N-Methyl-2-pyrrolidone) (50.0 mL), and then hydroxylammonium chloride (0.7 g, 10.1 mmol) was slowly added. The reaction mixture was stirred at 115 °C for 8 hours and then cooled to room temperature. After extraction with dichloromethane and water, the mixture was purified by column chromatography on silica gel using hexane:ethyl acetate (9:1) to obtain compound A, a yellow solid (71%).

[0134] Preparation of Compound B

[0135] Potassium tert-butoxide (2 g, 17.7 mmol) and 15 mL of tert-amyl alcohol were added to a 20 mL reaction flask, and the mixture was heated to 110 °C until all solids were dissolved. Subsequently, Compound A (2.8 g, 8.85 mmol) was added, followed by diisopropyl succinate (0.72 g, 3.54 mmol). After stirring for 12 hours, the reaction mixture was cooled to 40 °C, and methanol (10 mL) and HCl (4 mL) were added. The reaction mixture was filtered and washed with water, methanol, acetone, and hexane to obtain the product, Compound B, as a dark blue solid (64%), which was then used to proceed with the next reaction without further purification.

[0136] Preparation of Compound C

[0137] Compound B (1.7 g, 2.38 mmol), K2CO3 (1.15 g, 8.33 mmol), and DMF (dimethylformamide, 50.0 mL) were dissolved, and then 11-(bromomethyl)tricosane (2.98 g, 7.14 mmol) was slowly added. The reaction mixture was stirred at 120 °C for 24 hours and then cooled to room temperature. After extraction with dichloromethane and water, the product was purified by column chromatography on silica gel using hexane:dichloromethane (9:1) to obtain compound C as a dark blue solid (32%).

[0138] Preparation of Compound D

[0139] Compound C (0.8 g, 0.66 mmol) was dissolved in chloroform (250.0 mL), and then NBS (N-bromosuccinimide (0.26 g, 1.44 mmol)) was slowly added. After stirring at room temperature for 3 hours, the solution was extracted with dichloromethane and washed with water. The extract was dried with MgSO4, concentrated under reduced pressure, and purified by column chromatography on silica gel using hexane:dichloromethane (3:2) to obtain the product compound D as a solid (81%).

[0140] [Example 1] Preparation of Polymer 1

[0141]

[0142] A polymer was prepared using a palladium-catalyzed Stille coupling reaction. Compound D (0.200 g, 0.129 mmol) and 2,5-bis(trimethylstannyl)thiophene (0.052 g, 0.129 mmol) were dissolved in anhydrous toluene (7.0 mL). After degassing under nitrogen for 15 minutes, Pd(PPh3)4 (6 mg, 0.05 mmol) was added to the mixture, and the mixture was stirred at 110 °C for 48 hours. Afterward, the temperature was lowered to room temperature, and the polymer was precipitated in methanol. The unpurified polymer was collected by filtration and then purified by Soxylek extraction in sequence with methanol, acetone, hexane, and toluene. The final product was precipitated in methanol and dried under vacuum to obtain a dark green solid polymer 1 (74%).

[0143] M n : 32kDa, PDI: 2.1

[0144] [Example 2] Preparation of Polymer 2

[0145]

[0146] A dark green solid polymer 2 was obtained by carrying out the same procedure as in Example 1 above, except that 2,5-bis(trimethylstannyl)selenophene was used instead of 2,5-bis(trimethylstannyl)thiophene (74%).

[0147] M n : 17kDa, PDI: 3.2

[0148] <Evaluation Example>

[0149] Evaluation 1. Evaluation of Optical and Electrochemical Properties

[0150] The light absorption regions of the polymers prepared in Examples 1 and 2 above were measured in a solution state (CHCl3) and a film state, and the results are shown in FIG. 1. In addition, the optical properties of compounds (1) to (3) are shown in Table 1 below, and the band gap (Eg) and full width at half maximum (FWHM) were obtained at the UV absorption wavelength in the film state.

[0151] UV-Sol. λ max (nm) FWHM-Film (nm) UV-Film l edge (nm) TO g (house) Example 1 849 198 946 1.31 Example 2 757 233 933 1.33

[0152] Referring to Table 1, the compound according to the embodiment of the present invention can effectively absorb light in the long wavelength region and has a wide range of absorption spectra, so high light absorption efficiency can be expected.

[0153] Fabrication of Organic Transistors

[0154] [Examples 3 and 4]

[0155] Highly n-doped Si ++ After washing the / SiO2 (100 nm) waiter with piranha solution and oxygen plasma, the substrate was deposited with OTS (octadecyltrichlorosilane) and annealed at 120°C for 30 minutes.

[0156] Polymers 1 and 2 prepared in Examples 1 and 2 of the present invention were each dissolved in chlorobenzene to prepare polymer solutions with a concentration of 5 mg / mL. The prepared polymer solutions were spin-coated onto OTS-treated substrates. These were annealed in a nitrogen-filled glove box at 200°C for 20 minutes. Finally, Au electrodes (80 nm) were deposited on active layers with channel lengths of 150 μm and 1500 μm, respectively, to prepare the organic transistors of Examples 3 and 4.

[0157] As described above, the present invention has been explained by limited embodiments, but this is provided merely to aid in a more comprehensive understanding of the invention. The present invention is not limited to the above embodiments, and those skilled in the art can make various modifications and variations from this description.

[0158] Accordingly, the scope of the present invention is not limited to the described embodiments, and all things equivalent to or having equivalent variations to the claims set forth below, as well as the claims set forth below, shall be considered to fall within the scope of the concept of the present invention.

Claims

Claim 1 Polymer comprising repeating units represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, R 1 and R 2 are each independently (C1-C50)alkyl; Ar is (C6-C20)arylene, (C3-C20)heteroarylene, or *-Ar 1 -L-Ar 2 -* and;Ar 1 and Ar 2 is each independently (C6-C20)arylene or (C3-C20)heteroarylene; L is (C2-C10)alkenylene or (C2-C10)alkynylene; and the Ar, Ar 1 and Ar 2 The arylenes and heteroarylenes of may be further substituted with one or more (C1-C20)alkyl groups. Claim 2 In claim 1, the polymer, wherein Ar is selected from the following structures: In the above structural formula, Z 1 To Z 5 are each independently S or Se and;L 1 is a single bond, (C2-C10)alkenylene or (C2-C10)alkynylene; R 3 to R 10 Each is independently hydrogen or (C1-C20)alkyl. Claim 3 The polymer of claim 1, comprising a repeating unit represented by the following chemical formula 2 or chemical formula 3: [Chemical formula 2] [Chemical Formula 3] In the above chemical formulas 2 and 3, R 1 and R 2 are each independently (C1-C50)alkyl and R 3 to R 8 are each independently hydrogen or (C1-C20)alkyl; Z 1 To Z 3 Each is independently S or Se. Claim 4 In paragraph 1, R 2 A polymer, each independently a branched-chain (C10-C50) alkyl. Claim 5 The polymer of claim 1, comprising a repeating unit represented by the following chemical formula 4 or chemical formula 5: [Chemical formula 4] [Chemical Formula 5] In the above chemical formulas 4 and 5, R 1 are each independently (C1-C20)alkyl and R 11 to R 14 are each independently (C1-C20)alkyl; n and m are each independently integers from 1 to 10; and Z 1 To Z 3 Each is independently S or Se. Claim 6 In paragraph 5, the above R 1 is a (C1-C10)alkyl, and R 11 to R 14 A polymer, wherein each is independently (C10-C20)alkyl and n and m are each independently integers from 1 to 6. Claim 7 A polymer according to claim 1, wherein the repeating unit represented by the above chemical formula 1 is selected from the following structures. Claim 8 An organic semiconductor comprising a polymer of any one of claims 1 to 7. Claim 9 An organic electronic device comprising an organic semiconductor according to paragraph 8. Claim 10 In claim 9, the organic electronic device is an organic solar cell, an organic transistor, an organic memory, an organic photosensitive material, or an organic photosensor.

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