KR20150111094A - Diketopyrrolopyrrole polymer and organic electronic device using the same - Google Patents

Abstract

The present invention relates to a diketopyrrolopyrrole polymer which is an organic semiconductor compound for an organic electronic device, and to an organic electronic device comprising the same. The diketopyrrolopyrrole polymer of the present invention, as a novel organic semiconductor compound having high π-electron stacking, and an organic electronic device using the same has excellent charge mobility and a remarkable on/off ratio.

Description

TECHNICAL FIELD [0001] The present invention relates to a dicetopyrrolopyrrole polymer and an organic electronic device employing the same,

The present invention relates to a diketopyrrolopyrrole polymer which is an organic semiconductor compound for an organic electronic device and an organic electronic device including the same. The diketopyrrolopyrrole polymer of the present invention is a novel organic semiconductor compound having a high pi electron-ply chip, and the organic electronic device employing it is excellent in charge mobility and flickering ratio.

The development of information communication in the 21st century and the desire for personal portable communication devices are required for ultra-fine processing that enables information communication devices that are small in size, light in weight, thin in thickness, and easy to use, Electronic materials, and new information communication materials that enable new concept display. Among them, the organic thin film transistor (OTFT) can be applied to a display device such as a portable computer, an organic EL device, a smart card, an electric tag, a pager, a cellular phone, The possibility of being used as an important component of the plastic circuit part has been the subject of much research.

Organic thin film transistors using organic semiconductors have advantages over conventional amorphous silicon and polysilicon organic thin film transistors because they are simple to manufacture and can be manufactured at low cost. Compatibility with plastic substrates for the implementation of flexible displays And the advantages such as the superiority of the recent research is being done. In particular, when a polymer organic semiconductor is used, the manufacturing cost can be reduced as compared with a low molecular weight organic semiconductor compound because it can easily form a thin film by a solution process.

Typical semiconductor compounds for polymeric organic thin film transistors developed to date include P3HT [poly (3-hexylthiophene)] and F8T2 [poly (9,9-dioctylfluorene-co-bithiophene)]. The performance of OTFT is various, but important evaluation scale is charge mobility and on / off ratio, and the most important evaluation measure is charge mobility. The charge mobility varies depending on the kind of the semiconductor material, the thin film forming method (structure and morphology), the driving voltage, and the like.

Generally, an organic thin film transistor has a structure including a substrate / gate / insulating layer / electrode layer (source, drain) / organic semiconductor layer, and a gate electrode is formed on the substrate. An insulating layer is formed on the gate electrode, and an organic semiconductor layer, a source and a drain electrode are sequentially formed on the insulating layer. The driving principle of the organic thin film transistor having the above structure will be described as an example of a p-type semiconductor as follows. First, when a voltage is applied between a source and a drain to flow a current, a current proportional to the voltage flows under a low voltage. When a positive voltage is applied to the gate, the positive charges are all pushed up to the top of the semiconductor layer by the electric field due to the applied voltage. Therefore, a depletion layer having no conduction charge is generated in a portion close to the insulating layer, and in such a situation, a low amount of current will flow because a potential carrier between the source and the drain is reduced even when a conduction charge carrier is reduced . On the contrary, when a negative voltage is applied to the gate, an accumulation layer is formed in which a positive charge is induced in the vicinity of the insulating layer by the effect of the electric field by the applied voltage. At this time, since there are many conduction charge carriers between the source and the drain, more current can flow. Therefore, the current flowing between the source and the drain can be controlled by alternately applying a positive voltage and a negative voltage to the gate while a voltage is applied between the source and the drain.

Electrodes (sources and drains), substrates and gate electrodes requiring high thermal stability, insulators having high dielectric constant and dielectric constant, and semiconductors capable of transferring charges well can be used for organic thin film transistors having the above- There are many problems to be overcome, but the key material is organic semiconductors. Organic semiconductors can be classified into low-molecular organic semiconductors and polymeric organic semiconductors according to molecular weight, and classified into n-type organic semiconductors or p-type organic semiconductors depending on whether electrons or holes are delivered. In general, when a low-molecular organic semiconductor is used in the formation of an organic semiconductor layer, the low-molecular organic semiconductor is easy to purify and can remove impurities hardly, so that the charge transfer property is excellent. However, such an organic semiconductor can not be spin- Therefore, the manufacturing process is complicated and costly as compared with the polymer organic semiconductor, because the thin film must be manufactured through vacuum deposition. In the case of polymer organic semiconductors, purification with high purity is difficult, but heat resistance is excellent, and spin coating and printing are possible, which is advantageous in manufacturing process, cost, and mass production.

Although many researches have been made so far for the development of organic semiconductor materials, the development of polymer based semiconductor materials has not been developed yet. Therefore, in order to develop an electronic device using an organic thin film transistor which is flexible and has a low manufacturing cost, development of a polymer-based semiconductor material is in urgent need. In general, the charge mobility of polymers is known to be lower than that of low molecular weight materials, but it can be said to be a material that can sufficiently overcome the manufacturing process and cost.

Korean Patent Publication No. 2011-0091711 and Korean Patent Publication No. 2009-0024832 disclose a polymer in which a heteroaromatic ring containing S is directly bonded to a diketopyrrolopyrrole group. However, since it still does not show sufficient expansion of the pi electron, it is necessary to develop a polymer semiconductor material showing sufficient pi electron overlap.

Korean Patent Publication No. 2011-0091711 (2011.08.12.) Korean Patent Publication No. 2009-0024832 (2009.03.09.)

The present invention relates to a process for producing an electron donor material by alternately polymerizing a diketopyrrolopyrrole derivative, which is one of the electron acceptor materials, with thienothiophene or thienocelenophene, which is an electron donor material, to have high thermal stability and increase coplanarity of the main chain, Conjugated structure, thereby providing a diketopyrrolopyrrole polymer exhibiting high electron mobility and high molecular mobility and high charge mobility due to high pi electron pumping.

The present invention also provides a diketopyrrolopyrrole polymer which is an organic semiconductor compound having a high solubility and a viscosity due to a high molecular weight, thereby facilitating spin coating at room temperature and allowing a solution process.

The present invention also provides a diketopyrrolopyrrole polymer which is an organic semiconductor compound having a high charge mobility, which is applied to an organic electronic device.

The present invention also provides an organic electronic device comprising the novel diketopyrrolopyrrole polymer of the present invention.

The present invention relates to an organic semiconductor compound for an organic electronic device such as an organic light emitting device, an organic thin film transistor (OTFT), an organic solar cell, and the use thereof. More specifically, the present invention relates to a p-type polymer used as an active layer material of an organic electronic device configured to alternately polymerize a diketopyrrolopyrrole derivative, which is one of electron acceptor materials, and thienothiophene or thienocelenophen, A diketopyrrolopyrrole polymer which is an organic semiconductor compound, and an organic electronic device using the same.

The present invention provides a novel diketopyrrolopyrrole polymer represented by the following general formula

[Chemical Formula 1]

In Formula 1,

R ₁ and R ₂ are independently a hydrogen or (C1-C50) alkyl group, the alkyl of R ₁ and R ₂ are (C1-C30) alkyl, (C2-C30) alkenyl, respectively, (C2-C30) alkynyl Which may be further substituted with one or more substituents selected from halogen, (C1-C30) alkoxy, amino, hydroxy, halogen, cyano, nitro, trifluoromethyl and tri (C1-C30) alkylsilyl;

X is S or Se; And

n is an integer of 1 to 1000;

The diketopyrrolopyrrole polymer represented by the formula (1) of the present invention can be produced by introducing thienothiophene or thienocelenophen, which is an electron donor, into the diketopyrrolopyrrole derivative, which is one of electron acceptor materials, coplanarity and an extended conjugated structure, thereby increasing the electron density due to the high pi electron pumping, thereby enhancing the intermolecular interaction, and thus the organic electronic device containing the same exhibits a high charge mobility.

인 구조를 가짐으로써 보다 높은 용해도를 가진다. 즉, R₁ 및 R₂의 a가 5 내지 10, 보다 바람직하게는 a가 5 내지 7의 정수를 가지고 말단에 가지쇄 알킬인 구조를 가짐으로써, 말단에 가지쇄를 가지지 않은 알킬에 비해 무려 10배이상 높은 전하이동도를 가지며 동시에 높은 용해도를 가져 용액공정에 보다 유리하여 간단하고 저렴한 공정으로 대면적의 유기 전자 소자를 제작할 수 있다.R ₁ and R _{2, which} are substituents of the diketopyrrolopyrrole derivative,

Lt; RTI ID = 0.0 > solubility. ≪ / RTI > That is, when a in R ₁ and R ₂ has an integer of 5 to 10, more preferably a in the range of 5 to 7 and a branched alkyl at the terminal, It is possible to fabricate a large area organic electronic device with a simple and inexpensive process because it is more advantageous in the solution process because it has high charge mobility which is higher than twice and high solubility.

이고, a는 5 내지 10의 정수이고, R₁₁ 및 R₁₂은 각각 독립적으로 (C10-C30)알킬일 수 있다.In Formula 1 according to an embodiment of the present invention, R ₁ and R ₂ are each independently

, A is an integer from 5 to 10, and R ₁₁ and R ₁₂ are each independently (C 10 -C 30) alkyl.

The diketopyrrolopyrrole polymer according to an embodiment of the present invention is more specific in view of having high solubility and good charge mobility and flicker ratio, and preferably, it is not limited to the following compounds:

And n is an integer of 1 to 1000.

That is, more specifically, the diketopyrrolopyrrole polymer of the present invention is a polyketopyrrolopyrrole polymer of the present invention wherein R ₁ and R ₂ in the above formula (1) have a carbon number of 24 or more and a linear chain of alkyl of 5 to 10, Alkyl has a high solubility but does not cause a decrease in charge mobility or flicker rate, and thus the organic electronic device containing the same has a remarkable effect with high efficiency.

As a method for producing the diketopyrrolopyrrole polymer according to the present invention, the final compound can be prepared through an alkylation reaction, a Grignard coupling reaction, a Suzuki coupling reaction, a styrene coupling reaction or the like. The organic semiconductor compound according to the present invention is not limited to the above-mentioned production method, and can be produced by a conventional organic chemical reaction other than the above-mentioned production method.

Also, the diketopyrrolopyrrole polymer according to the present invention can be used as a material for forming an organic semiconductor layer of an organic electronic device, and the present invention provides an organic electronic device containing a diketopyrrolopyrrole polymer.

The organic electronic device according to an exemplary embodiment of the present invention may be an organic light emitting device, an organic thin film transistor, or an organic solar cell.

The organic light emitting device according to the present invention may be manufactured by the method described below, but the present invention is not limited thereto.

When the organic electronic device according to the present invention is an organic light emitting device, it may have a structure in which a first electrode, one or more organic material layers, and a second electrode are sequentially stacked. The organic material layer may have a multi-layer structure including at least two layers selected from a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer, but is not limited thereto and may have a single layer structure. For example, the organic light emitting device according to the present invention may be formed by depositing a metal or a metal oxide having conductivity or an alloy thereof on a substrate using a physical vapor deposition (PVD) method such as sputtering or electron beam evaporation to form an anode electrode, Forming an organic material layer such as a hole injecting layer, a hole transporting layer, a light emitting layer, or an electron transporting layer thereon, and then vacuum depositing a metal for forming a cathode thereon to form a cathode. In addition to such a method, an organic light emitting device may be manufactured by sequentially depositing a cathode electrode material, an organic material layer, and an anode electrode material on a substrate.

As the substrate, a substrate used in a conventional organic EL device is used, and a glass substrate or a transparent plastic substrate having excellent transparency, surface smoothness, ease of handling, and waterproofness is preferable. As the material for the anode electrode, indium tin oxide (ITO), tin oxide (SnO ₂ ), zinc oxide (ZnO), indium zinc oxide (IZO), antimony tin oxide (ATO) and the like which are transparent and excellent in conductivity are used. The material for forming the hole injection layer is not particularly limited, but CuPc, m-MTDATA, 1I-TNATA, 2T-NATA, NATA, NTNPB, NPNPB and MeO-TPD are used. The hole transport layer material is not particularly limited and may be selected from the group consisting of N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1'- biphenyl] -4,4'- diamine (TPD) NPN), 9,9-bis [4- (N, N-bis-biphenyl-4- (Phenyl) -9H-fluorene (BPAPF), N, N'-bis (phenanthrene-9-yl) -N, N'- (N, N-ditolyl-amino) -phenyl] cyclohexane (TAPC) and N, N, N ', N'-tetra-naphthalene-benzidine (α-TNB). The electron transporting layer may be formed of a material for forming an electron transport layer and may be formed of a metal such as lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al- Ca-Al), lithium fluoride-aluminum (LiF-Al), magnesium-indium (Mg-In), magnesium-silver (Ag-Ag), barium- Ag, copper (Cu), or the like is used.

Further, when the organic electronic device according to the present invention is an organic thin film transistor, a manufacturing method can be specifically exemplified as follows.

As the substrate, n-type silicon used in a typical organic thin film transistor is preferably used. This substrate contains the function of a gate electrode. In addition to the n-type silicon, a glass substrate or a transparent plastic substrate having excellent surface smoothness, ease of handling, and waterproofness may be used as the substrate. In this case, the gate electrode must be added to the substrate. Examples of materials that can be used as the substrate include glass, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl alcohol (PVP), polyacrylate , Polyimide, polynorbornene, and polyethersulfone (PES).

As the gate insulating layer constituting the OTFT device may be a conventional large dielectric constant is used as an insulator, specifically _{Ba 0 .33 Sr 0 .66 TiO 3} (BST), Al 2 O 3, Ta 2 O 5, La ₂ O _5, Y ₂ O ₃ and _0.33 Ti ferroelectric insulators, PdZr selected from the group consisting of _{TiO 2 0.66 O 3 (PZT)} , Bi 4 Ti 3 O 12, BaMgF 4, SrBi 2 (TaNb) 2 O 9, Ba ( _{ZrTi) O 3 (BZT),} BaTiO 3, SrTiO 3, Bi 4 Ti 3 O 12, SiO 2, an inorganic insulator selected from the group consisting of SiN _x and AlON, or a polyimide (polyimide), BCB (benzocyclobutene) , parylene organic conductive materials such as parylene, polyacrylate, polyvinylalcohol and polyvinylphenol can be used.

The structure of the organic thin film transistor of the present invention is not limited to the substrate / gate electrode / insulating layer / organic semiconductor layer / source / drain electrode top-contact, substrate / gate electrode / insulating layer / And the bottom-contact form of the semiconductor layer. Also, HMDS (1,1,1,3,3,3-hexamethyldisilazane), octadecyltrichlorosilane (OTS), or octadecyltrichlorosilane (OTDS) may be coated between the source and drain electrodes and the organic semiconductor layer.

The organic semiconductor layer employing the diketopyrrolopyrrole polymer according to the present invention may be formed into a thin film by a vacuum deposition method, a screen printing method, a printing method, a spin casting method, a spin coating method, a dipping method or an ink jet method, At this time, the deposition of the organic semiconductor layer can be performed using a high-temperature solution at a temperature of 40 ° C or higher, and a thickness of about 500 Å is preferable.

The gate electrode and the source and drain electrodes may be formed of a conductive material but may be formed of a material selected from the group consisting of gold (Au), silver (Ag), aluminum (Al), nickel (Ni), chromium (Cr), and indium tin oxide It is preferably formed of a selected material.

In addition, when the organic electronic device according to the present invention is an organic solar cell, a manufacturing method can be specifically exemplified as follows.

Solar cells generally consist of glass substrate / transparent electrode (ITO) / hole transport layer / active layer (electron acceptor / electron acceptor) / electron transport layer / metal electrode (Al) When the light reaches the active layer through the organic substrate, ITO and the hole transport layer, excitons are generated between the p-type (electrons) and the n-type (electron acceptors) (Hopping) to the metal electrode, and the remaining holes are moved to the ITO layer through the hole transport layer. The separated electrons and holes generate current and voltage and generate power. The hole transport layer is composed of PEDOT: PSS [poly (3,4-ethylenedioxythiophene)]: [poly (styrenesulfonate)] and prevents transport of electrons to the anode ITO layer, give. In addition, the active layer of the present invention preferably has a bulk-heterojunction in which the p-type and n-type interfaces are widened, and excitons generated through the bulk-heterojunction can be easily separated into electrons and holes do.

In addition to the glass substrate, the substrate may be made of a plastic substrate such as polyethylene terephthalate (PET) or polyisophthalon (PES).

The active layer using the organic semiconductor compound according to the present invention can be formed into a thin film by a screen printing method, a printing method, a spin casting method, a spin coating method, a dipping method, or an ink jet method.

The metal electrode may be a conductive material, but may be formed of a material selected from the group consisting of Au, Ag, Al, Ni, Cr, and ITO. .

There is no limitation on the transparent electrode, but ITO (indium tin oxide), ZnO (zinc oxide), MnO (manganese oxide) and the like can be used.

The diketopyrrolopyrrole polymer of the present invention is constituted to alternately polymerize a diketopyrrolopyrrole derivative, which is one of electron acceptor materials, and an electron donor substance, thienothiophene or thienocelenophene, and an electron donor substance, thienothiophene Or thienocelenophene to increase the coplanarity of the main chain and to have an extended conjugated structure, thereby enhancing the electron density due to the high pi electron overlapping, thereby enhancing the intermolecular interaction and exhibiting excellent thermal stability.

In addition, the diketopyrrolopyrrole polymer of the present invention has a low HOMO value, that is, an electron density increases in the repeating unit, so that it has excellent charge mobility and oxidation stability, and thus is extremely useful as an organic semiconductor layer of an organic thin film transistor. .

Therefore, the organic thin film transistor employing them is improved in charge mobility and flickering ratio, and it is possible to make an electronic device having excellent efficiency and performance when using such an organic thin film transistor. Such an organic thin film transistor can also be manufactured by a solution process such as vacuum deposition, spin coating or printing, thereby reducing manufacturing cost of an electronic device using an organic thin film transistor.

In addition, the diketopyrrolopyrrole polymer of the present invention can be produced by introducing a substituent substituted with N of a diketopyrrolopyrrole derivative, that is, a substituent having a limited number of carbon atoms and a form, to have high solubility without affecting other electrical properties The organic electronic device including the diketopyrrolopyrrole polymer of the present invention can be manufactured by a solution process such as vacuum deposition, spin coating, or printing, thereby achieving a simple process and a large area at a low cost.

1 is a UV-vis absorption spectrum of a solution phase and a film on a diketopyrrolopyrrole polymer (P29DPP-TT) synthesized in Example 3,
2 is a UV-vis absorption spectrum of a solution phase and a film of the diketopyrrolopyrrole polymer (P29DPP-TSe) synthesized in Example 4,
3 is a cyclic voltammetry diagram of the diketopyrrolopyrrole polymer (P29DPP-TT) synthesized in Example 3,
4 is a cyclic voltammetry diagram of the diketopyrrolopyrrole polymer (P29DPP-TSe) synthesized in Example 4,
5 is a thermogravimetric analysis (TGA) curve of the diketopyrrolopyrrole polymer (P29DPP-TT) synthesized in Example 3,
6 is a thermogravimetric analysis (TGA) curve of the diketopyrrolopyrrole polymer (P29DPP-TSe) synthesized in Example 4,
7 is a differential calorimetric (DSC) curve of the diketopyrrolopyrrole polymer (P29DPP-TT) synthesized in Example 3,
8 is a differential thermal calorimetry (DSC) curve of the diketopyrrolopyrrole polymer (P29DPP-TSe) synthesized in Example 4,
FIGS. 9 and 10 show the device characteristics of Example 5 using the diketopyrrolopyrrole polymer (P29DPP-TT) synthesized in Example 3, and the characteristics of the device after 180 ° C. heat treatment (Transfer curve, Output FIG.
FIGS. 11 and 12 show the results of a device manufactured by the method of Example 5 using the diketopyrrolopyrrole polymer (P29DPP-TSe) synthesized in Example 4, and the characteristics of the device after 180 ° C. heat treatment FIG.

The present invention can be more clearly understood by the following examples, and the following examples are merely illustrative of the present invention and are not intended to limit the scope of the invention.

[ Example  1] 2,5-bis ( Trimethylstannyl ) Tieno Preparation of 2,5-bis (trimethylstannyl) thieno [3,2-b] thiophene

2,5-dibromothieno [3,2-b] thiophene (1.0 g, 3.355 mmol) was added to a well-dried 100 mL three- And dissolved in THF (30 mL). The temperature was lowered to -78 ° C and n- BuLi (2.5 M in hexane, 1.61 mL, 4.026 mmol) was slowly added dropwise and stirred for 1 hour under a stream of nitrogen. The temperature was again lowered to -78 ° C and trimethyltin chloride (0.96 g, 4.832 mmol) was slowly added dropwise and stirred at room temperature for 2 hours. The reaction mixture was poured into ice water and extracted with Et ₂ O. The organic layer was washed with water, dried over anhydrous MgSO ₄ , and the solvent was removed at low temperature using a rotary evaporator. The residue was recrystallized from methyl alcohol and filtered to obtain a solid The target compound, 2,5-bis (trimethylstannyl) thieno [3,2-b] thiophene, Was obtained with a yield of 1.25 g (79%).

^{1 H-NMR (300 MHz,} CD 2 Cl 2): δ 7.26 (s, 2 H), 0.53-0.32 (m, 18 H); EI, MS m / z (%): 465.84 (100, M +)

[ Example  2] Selenopheno [3,2-b] thiophene -2,5- Diabis ( Trimethylstannane ) (selenopheno [3,2-b] thiophene-2,5-diylbis (trimethylstannane)

2,5-dibromoselenopheno [3,2-b] thiophene (1.0 g, 2.899 mmol) was added to a well-dried 100 mL three- And dissolved in THF (30 mL). The temperature was lowered to -78 ° C and n- BuLi (2.5 M in hexane, 1.39 mL, 3.479 mmol) was slowly added dropwise and stirred for 1 hour under a stream of nitrogen. The temperature was further lowered to -78 ° C and trimethyltin chloride (0.75 g, 3.769 mmol) was slowly added dropwise and the mixture was stirred at room temperature for 2 hours. The reaction mixture was poured into ice water and extracted with Et ₂ O. The organic layer was washed with water, dried over anhydrous MgSO ₄ , and the solvent was removed at low temperature using a rotary evaporator. The residue was recrystallized from methyl alcohol and filtered to obtain a solid The target compound, selenopheno [3,2-b] thiophene-2,5-diylbis (trimethylstannane) 0.82 g (55%).

¹ H-NMR (300 MHz, CD ₂ Cl ₂ ):? 7.81 (s, 1H), 7.61 (s, 1H), 0.54-0.32 (m, 18H); EI, MS m / z (%): 512.73 (100, M < + &

[ Example  3] P29DPP - TT's  Produce

The polymer P29DPP-TT can be polymerized through a Stille coupling reaction. 3,4-c] pyrrole-l, 4 (2H, 5H) -dione was used in place of 3,6-bis (5-bromothiophen- 3,4-c] pyrrole-1,4 (2H, 5H) -dione (0.50 g) was added to a solution of 5-bromothiophen- g, 0.0004 mmol) and 2,5-bis (trimethylstannyl) thieno [3,2-b] thiophene (Example 1, 0.183 g, 0.0004 mmol) were dissolved in chlorobenzene (6 mL) After that, Pd ₂ (dba) ₃ (0.007 mg, 2 mol%) and p (o-tol) ₃ (0.095 g, 8 mol%) were added as a catalyst and refluxed at 110 ° C for 48 hours. Then, 2-bromothiophene (0.1 g) was added thereto to reflux for 6 hours, and 2-thiophenemethyltin (0.1 g) was added thereto to reflux for 6 hours. The reaction solution was then slowly precipitated in methanol (300 mL) and the solid was filtered off. The filtered solid was purified through a sohxlet in the order of methanol, hexane, toluene and chloroform. The resulting liquid was precipitated again in methanol, filtered through a filter, and dried to give P29DPP-TT (yield 70%) as a dark green solid.

0.39 g of the obtained amount; Mn = 114,230; Mw = 217,810; PDI = 1.90; ¹ H NMR (300 MHz, CDCl ₃ ) [ppm]: 8.93 (broad, 4H), 6.92-6.73 (broad, 2H), 3.85 (broad, 4H), 2.12 ), 1.07-0.89 (m, 12H).

[ Example  4] P29DPP - TSe  Produce

The polymer P29DPP-TSe can be polymerized through a Stille coupling reaction. 3,4-c] pyrrole-l, 4 (2H, 5H) -dione was used in place of 3,6-bis (5-bromothiophen- 3,4-c] pyrrole-1,4 (2H, 5H) -dione (0.50 g) was added to a solution of 5-bromothiophen- (Example 2, 0.201 g 0.0004 mmol) was dissolved in chlorobenzene (6 mL), and the solution was cooled to 0 [deg.] C. Pd ₂ (dba) ₃ (0.007 mg, 2 mol%) and p (o-tol) ₃ (0.095 g, 8 mol%) were added as a catalyst and refluxed at 110 ° C. for 48 hours . Then, 2-bromothiophene (0.1 g) was added thereto to reflux for 6 hours, and 2-thiophenemethyltin (0.1 g) was added thereto to reflux for 6 hours. The reaction solution was then slowly precipitated in methanol (300 mL) and the solid was filtered off. The filtered solid was purified through a sohxlet in the order of methanol, hexane, toluene and chloroform. The resulting liquid was precipitated again in methanol, filtered through a filter, and dried to give P29DPP-TSe (yield 65%) as a dark green solid.

0.33 g of the obtained amount; Mn = 70, 160; Mw = 120,060; PDI = 1.72; ¹ H NMR (300 MHz, CDCl ₃ ) [ppm]: 8.94 (broad, 4H), 6.98-6.85 (broad, 2H), 3.79 (broad, 4H), 2.15 ), 1.08-0.78 (m, 12H).

In order to test the solubilities of the diketopyrrolopyrrole polymers (P29DPP-TT, P29DPP-TSe) synthesized in Examples 3 and 4, the following methods were used, and the results are shown in Table 1 below.

The solubility test was carried out in the same manner as in Example 1, except that 0.5 wt% of the diketopyrrolopyrrole polymer (P29DPP-TT, P29DPP-TSe) synthesized in Examples 3 and 4 was added to 1 mL of each solvent described in Table 1, And the solution was passed through a scanning filter (0.45 micro-aperture) in order to measure the degree of dissolution.

Solubility test (0.5 wt% / mL) Acetone Methanol THF CHCl ₃ Chlorobenzene
(CB) Dichlorobenzene
(DCB) P29DPP-TT
(Example 3) X X △ o o o P29DPP-TSe
(Example 4) X X o o o o O: dissolves all while heating, and remains dissolved even when cooled to room temperature
Δ: All dissolved during heating, but solidified when cooled to room temperature
X: Not all of them are dissolved during heating, and they do not dissolve even when they are cooled to room temperature

It can be seen that the diketopyrrolopyrrole polymer according to the present invention has an increased irregularity in the polymer chain chain due to the asymmetry of the electron donor monomer.

[ Example  5] Manufacture of organic electronic devices

The OTFT device was fabricated by top-contact method and 100 nm n-doped silicon gate was used and SiO ₂ was used as an insulator. Surface treatment was performed by surface cleaning using piranha cleaning solution (H ₂ SO ₄ : 2H ₂ O ₂ ) and then treating the surface with SAM (Self Assemble Monolayer) using Alfa's ODTS (octadecyltrichlorosilane). The organic semiconductor layer was coated with a 0.5 wt% chloroform solution at a rate of 2000 rpm for 1 minute using a spin-coater. As the organic semiconductor material, P29DPP-TT and P29DPP-TSe synthesized in Examples 3 and 4 were used, respectively. The thickness of the organic semiconductor layer was confirmed to be 50 nm using a surface profiler (Alpha Step 500, Tencor). The gold used as the source and drain was deposited to a thickness of 50 nm at 1 A / s. The channel length is 100 μm and the width is 1000 μm. The OTFT characteristics were measured using Keithley 4800.

The charge mobility of the fabricated organic thin film transistor was obtained from the saturation region current equation and the slope was obtained by plotting (I _SD ) ^1/2 and V _G as variables.

Wherein, I _SD is the source-and-drain current, and Fig μ or μ _FET is charge mobility, and C ₀ is oxide capacitance, W is the channel width, L is channel length, V _G is the gate voltage, V _T is the threshold voltage. In addition, the blocking leakage current (I _off ) is a current flowing when the off state is obtained, and a minimum current is obtained from the off state at the current ratio.

The light absorption regions of the diketopyrrolopyrrole polymers (P29DPP-TT and P29DPP-TSe) synthesized in Examples 3 and 4 were measured in a solution state and a film state, and the results are shown in FIGS. In order to analyze the electrochemical characteristics of the diketopyrrolopyrrole polymers (P29DPP-TT, P29DPP-TSe) synthesized in Examples 3 and 4, the reaction was carried out in a solvent of Bu ₄ NClO ₄ (0.1 molar concentration) at 50 mV / s The results of the measurement using a cyclic voltammetry are shown in FIGS. 3 and 4, and a voltage was applied through a coating using a carbon electrode during the measurement.

The optical and electrochemical properties of the diketopyrrolopyrrole polymers (P29DPP-TT, P29DPP-TSe) synthesized in Examples 3 and 4 are shown in Table 2 below. Here, the HOMO value is a value calculated using the results measured in FIGS. 3 and 4. FIG. The bandgap was also obtained at the UV absorption wavelength in the film state.

Polymer Optical properties Electrochemical properties UV-S (max)
(nm) UV-F (max)
(nm) UV-ann (max)
(nm) UV-edge
(nm) Band gap
(optical)
(eV) LUMO
(optical)
(eV) HOMO
(electrochemical)
(eV) P29DPP-TT
(Example 3) 797
458 801
720 (s)
457 802 954 1.31 -4.01 -5.31 P29DPP-TSe
(Example 4) 818
752 821
752 821 992 1.25 -4.17 -5.42

As shown in Table 2, the diketopyrrolopyrrole polymer of the present invention has a low HOMO level value and has a high oxidation stability, and has a conjugated structure extended by an electron donor-acceptor alternation polymerization and an electron conjugated structure Due to the fuse aroma, it increases the coplanarity, and because it has a pristine conjugate structure, it has a low band gap and the charge mobility of the organic electronic device containing it is high.

In FIGS. 5 and 6, the decomposition temperatures of the diketopyrrolopyrrole polymers (P29DPP-TT and P29DPP-TSe) synthesized in Examples 3 and 4 were measured using TGA. All of them showed excellent thermal stability there can be said that (the P29DPP-TT T _d is 433 ℃; P29DPP-TSe of T _d is 439 ℃).

7 and 8 show the results of measurement using DSC to measure the thermal stability of the diketopyrrolopyrrole polymer (P29DPP-TT, P29DPP-TSe) synthesized in Examples 3 and 4 (P29DPP of -TT T _m is 267 ℃; P29DPP-TSe the T _m is 242 ℃).

 As shown in FIGS. 5 to 8, it can be seen that the organic semiconductor compound synthesized in the present invention has excellent thermal stability and shows an increase in charge mobility when annealed, which is an excellent organic electronic device material have.

FIGS. 9 and 10 are schematic diagrams of a device manufactured by the method of Example 5 using the diketopyrrolopyrrole polymer (P29DPP-TT) synthesized in Example 3, followed by transfer curve and out-put curve showing the organic electronic device characteristics of a polymeric material.

FIGS. 11 and 12 are graphs showing the device transfer curve and out-put of the device after heat treatment at 180 ° C. after the device was manufactured by the method of Example 5 using the diketopyrrolopyrrole polymer (P29DPP-TSe) synthesized in Example 4. FIG. curve showing the organic electronic device characteristics of a polymeric material.

As shown in FIGS. 9 to 12, it can be seen that the charge transport mobility is maximally increased when the organic semiconductor compound synthesized in the present invention is annealed at 180 ° C. As a result, it can be seen that the material is excellent in thermal stability at a high temperature of 180 ° C.

The properties of the device fabricated in Example 5 were described in Table 3 below using the diketopyrrolopyrrole polymers (P29DPP-TT, P29DPP-TSe) synthesized in Examples 3 and 4.

The device using P29DPP-TT exhibited excellent charge mobility and flicker rate when annealed at a high temperature of 160 to 200 ° C. The device using P29DPP-TSe exhibited excellent charge mobility and flicker ratio when annealed at a high temperature of 180 to 200 ° C. In particular, the device using P29DPP-TT showed the highest charge mobility about four times higher than annealing temperature at annealing temperature of 180 ° C, and the device using P29DPP-Tt also had annealing temperature of 180 ° C Showed the best charge mobility.

Polymer Heat treatment Surface modification Mobility
(cm ² / (V s)) Flashing Ratio
on / off ratio Threshold voltage (V) P29DPP-TT
(Example 3) Room temperature ODTS 1.22 6.09 x 10 ³ 4.14 100 ℃ ODTS 1.27 1.04 x 10 ⁴ 4.53 120 DEG C ODTS 1.32 1.31 x 10 ⁴ 2.51 140 ° C ODTS 1.48 7.03 x 10 ⁴ 3.64 160 ° C ODTS 4.49 7.97 x 10 ⁴ 2.51 180 DEG C ODTS 4.87 1.19 x 10 ⁴ 2.18 200 ℃ ODTS 4.43 1.26x 10 ⁴ 2.31 220 ℃ ODTS 3.55 1.55x 10 ⁴ 3.07 P29DPP-TSe
(Example 4) Room temperature ODTS 1.35 4.2 X 10 ⁴ 10.3 180 DEG C ODTS 2.94 2.2 X 10 ⁵ 9.3 200 ℃ ODTS 2.67 3.49 x 10 ⁴ 10.2

As shown in Table 3, the organic electronic device manufactured by the method of Example 5 and heat-treated at 180 ° C contains the diketopyrrolopyrrole polymer of the present invention, has a high charge mobility, and has a stable blink rate.

Claims (7)

A diketopyrrolopyrrole polymer represented by the following formula (1): < EMI ID =
[Chemical Formula 1]

In Formula 1,
R ₁ and R ₂ are independently a hydrogen or (C1-C50) alkyl group, the alkyl of R ₁ and R ₂ are (C1-C30) alkyl, (C2-C30) alkenyl, respectively, (C2-C30) alkynyl Which may be further substituted with one or more substituents selected from halogen, (C1-C30) alkoxy, amino, hydroxy, halogen, cyano, nitro, trifluoromethyl and tri (C1-C30) alkylsilyl;
X is S or Se; And
n is an integer of 1 to 1000;
The method according to claim 1,
R ₁ and R ₂ are each independently

, A is an integer from 5 to 10, and R ₁₁ and R ₁₂ are each independently (C 10 -C 30) alkyl.
3. The method of claim 2,
A diketopyrrolopyrrole polymer which is selected from the following compounds:

And n is an integer of 1 to 1000.
An organic electronic device comprising a diketopyrrolopyrrole polymer according to any one of claims 1 to 3.
5. The method of claim 4,
Wherein the organic electronic device is an organic light emitting device having a structure in which a first electrode, at least one organic material layer, and a second electrode are sequentially stacked.
5. The method of claim 4,
Wherein the organic electronic device is an organic thin film transistor having a structure including a substrate, a gate, a gate insulating layer, at least one organic semiconductor layer, and a source electrode and a drain electrode.
5. The method of claim 4,
Wherein the organic electronic device is an organic solar cell and has a structure including a substrate, a transparent electrode, a hole transporting layer, an active layer, an electron transporting layer, and a metal electrode sequentially laminated.

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