KR101513883B1 - Novel polymer and organic electronic device using the same - Google Patents

Abstract

The present invention relates to a polymer and usage thereof. In the present invention, a polymer has high electron mobility, low off rates and high thermal stability and solubility. Organic thin film transistors and solar batteries made of such a polymer provides high efficiency and supports mass production based on the liquid process.

Description

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

 The present invention relates to a novel polymer and an organic electronic device comprising the same, and more particularly to a novel polymer which is a random copolymer containing an electron donor compound containing an electron donor compound and a triple bond and an organic electronic device containing the same .

Organic Thin Film Transistor is an electronic device which research and development has been actively carried out recently due to its many merits. Especially it is easy to manufacture flexible electronic circuit board which is simple and low cost and can be bent or folded without being broken by impact. Lt; / RTI >

In addition, compared with the conventional thin film transistor using amorphous silicon and polysilicon, the organic thin film transistor has a simple manufacturing process, can be manufactured at a low cost, and is excellent in compatibility with substrates mounted with other electronic parts. .

 The organic thin film transistor device comprises a substrate, a gate electrode, an insulating film, a channel layer, a source / drain electrode, and a protective layer for preventing external moisture and oxygen permeation. The organic thin film transistor is fabricated by replacing the existing silicon based inorganic material with the organic compound or the polymer material which exhibits the semiconductor characteristic, which is the key part of the charge transfer which has the greatest influence on the device characteristics.

The organic semiconductor compound constituting the organic thin film transistor can be divided into a low molecular weight and a high molecular weight depending on the molecular weight, and classified into an n-type organic semiconductor or a p-type organic semiconductor depending on whether electrons or holes are delivered.

In general, when a low-molecular organic semiconductor is used for forming an organic semiconductor layer, a low-molecular organic semiconductor can be easily purified and can remove almost any impurities, so that the charge transfer property is excellent. However, since spin coating and printing are impossible, The manufacturing process is complicated and costly compared to the polymer organic semiconductor. 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.

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.

On the other hand, the polymer organic semiconductor compound has a disadvantage of low charge mobility which is an important evaluation measure of the OTFT performance. In order to overcome this disadvantage, Korean Patent Registration No. 1072477 discloses a polymer organic semiconducting compound having a thiophen group substituted with an alkyl group in a side chain ≪ / RTI >

However, development of polymeric organic semiconductors which are advantageous in manufacturing process and cost and capable of solution process, which have high charge mobility and low flicker ratio, which are still advantages of low molecular weight organic semiconductors, are required.

Korean Registered Patent No. 1072477 (October 10, 2011)

The present invention provides a polymer having excellent charge mobility and solubility.

The present invention also provides an organic thin film transistor and an organic solar cell including the polymer of the present invention.

The present invention provides a polymer having excellent charge mobility and solubility, and the polymer of the present invention is represented by the following formula (1).

[Chemical Formula 1]

[In the above formula (1)

A or B independently of one another are (C6-C50) aryl or (C3-C50) heteroaryl;

Ar ₁ to Ar ₄ are independently selected from the following structures;

R ₁ to R ₅ are independently selected from the group consisting of hydrogen, hydroxy, amino, (C 1 -C 50) alkyl, (C 6 -C 50) aryl, (C 1 -C 50) alkoxy, mono- or di (C 1 -C 50) Carbonyl, (C1-C50) alkylcarbonyloxy or (C1-C50) alkoxy substituted (C1-C30)

Z is S, O or Se,

o is an integer from 1 to 4,

Provided that Ar ₁ and Ar ₃ are the same;

The aryl or heteroaryl of A and B may be optionally substituted with one or more substituents selected from the group consisting of (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, An amino group, an amino group, an amino group, an amino group, an amino group, an amino group, an amino group, a nitro group, a trifluoromethyl group, and a silyl group;

and m and n are independently an integer of 1 to 1,000.

The polymer of the present invention is a compound which is electronically and independently of one another comprises a triple bond between the functional groups selected from phenyl, thiophenyl, furanyl, selenophenyl, furanofuranyl, selenophenocelenophene, thionothiophene And the electron accepting compound is alternately polymerized to have high air stability, to increase coplanarity, and to have an extended conjugated structure, so that sufficient pie electron expansion can be exhibited.

Furthermore, since Ar ₁ and Ar ₃ are different from each other, an asymmetric electron donor group is introduced to increase the irregularity between the polymer chain chains, thereby increasing solubility in solvents.

The polymer represented by the formula (1) of the present invention is a polymer including units of the following formula (2) and units of the formula (3), and may be a block copolymer, a random copolymer, an alternating copolymer, , Tapered copolymers, and the like.

(2)

(3)

(In the above formulas 2 and 3,

A, B, Ar ₁ to Ar ₄ , n and m are as defined in the above formula (1).

Preferably, A and B according to an embodiment of the present invention may be selected from the following structures.

(Wherein,

Z is S, O or Se;

R ₂₁ to R ₃₉ independently of one another are hydrogen, halogen, (C 1 -C 50) alkyl, (C 1 -C 50) alkoxy, (C 1 -C 50) alkoxycarbonyl, (C 6 -C 50) (C1-C50) alkyl;

Alkyl group of R ₂₁ to R _39, alkoxy, alkoxycarbonyl, aryl and aralkyl is (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, (C1-C30) alkoxy, an amino group , A hydroxyl group, a halogen group, a cyano group, a nitro group, a trifluoromethyl group and a silyl group;

R ₄₁ to R ₄₆ are hydrogen or a (C 1 -C 50) alkyl group;

and o is an integer of 1 to 2.)

Preferably, A and B can be selected from the following structures, and by introducing a substituent, particularly an alkyl group, into N in the structures A and B below, the solubility of the polymer of the present invention can be increased,

(In the above structure,

Z is S, O or Se;

R ₄₁ to R ₄₆ are hydrogen or a (C 1 -C 50) alkyl group.

More preferably, A and B according to an embodiment of the present invention can be selected from the following structures, and it is possible to easily increase the solubility by replacing long alkyl with N of the electron accepting material selected from the following structures Preferably R ₄₁ and R ₄₆ independently of one another may be (C 25 -C 50) alkyl. That is, the polymer, which is a random copolymer of the present invention, may be electronically and independently selected from the group consisting of phenyl, thiophenyl, furanyl, selenophenyl, furanofuranyl, selenophenocelenophene, thionothiophene, The solubility can be lowered by such a triple bond. However, such low solubility can be achieved by introducing a substituent for increasing the solubility of the electron acceptor bound to the electron donor, specifically, by introducing a long alkyl group have.

(In the above structure,

Z is S, O or Se;

R ₄₁ to R ₄₆ are (C 25 -C ₅₀ ) alkyl groups.

More preferably, A and B in the polymer of the present invention may have the following structures.

(In the above formula,

Z is independently from each other O, S or Se;

R ₄₃ or R ₄₄ is a (C 25 -C 50) alkyl group.)

일 수 있으며, 이때의 R₄₃ 또는 R₄₄는 용해도를 높이기위한 측면에서 바람직하게는 C30-C50알킬기일 수 있다.Preferably, A and B of the novel polymers of the invention are

And R ₄₃ or R ₄₄ may preferably be a C 30 -C 50 alkyl group in order to increase the solubility.

More specifically, the polymer of the present invention may be selected from the following structures, but is not limited thereto.

[Wherein n is an integer of 1 to 1,000]

The substituents comprising " alkyl ", " alkoxy " and other " alkyl " moieties described in this invention encompass both linear and branched forms. The term " aryl " in the present invention means an organic radical derived from an aromatic hydrocarbon by the removal of one hydrogen, and may be a single or fused ring containing 4 to 7, preferably 5 or 6 ring atoms, A ring system, and a form in which a plurality of aryls are connected by a single bond. Specific examples include, but are not limited to, phenyl, naphthyl, biphenyl, anthryl, indenyl, fluorenyl, and the like. "Heteroaryl" in the present invention includes 1 to 4 heteroatoms selected from B, N, O, S, P (= O), Si and P as aromatic ring skeletal atoms and the remaining aromatic ring skeletal atoms are carbon Means a 5- to 6-membered monocyclic heteroaryl and a polycyclic heteroaryl which is condensed with one or more benzene rings, which may be partially saturated, the partially saturated moiety may have a ketone group, Also included in diketopyrrolopyrrol are heteroaryls. The heteroaryl in the present invention also includes a form in which one or more heteroaryl is connected to a single bond.

As a method for producing the 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 polymer 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.

The present invention also provides an organic thin film transistor comprising the novel polymer of the present invention.

A specific example of the production process of the organic thin film transistor according to an embodiment of the present invention is as follows.

As the substrate 11, it is preferable to use n-type silicon used for a typical organic thin film transistor. 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 12 constituting the OTFT device, an insulating material having a large dielectric constant, which is commonly used, may be used. 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 a ferroelectric insulator selected from the group consisting of _{TiO 2, PdZr 0.33 Ti 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, SiN x , and an inorganic insulator selected from the group consisting of AlON, or a polyimide (polyimide), BCB (benzocyclobutene) , parylene ( parylene, polyacrylate, polyvinylalcohol, and polyvinylphenol may be used.

The structure of the organic thin film transistor of the present invention is similar to that of the organic thin film transistor shown in FIG. 1 except that the substrate 11, the gate electrode 16, the insulating layer 12, the organic semiconductor layer 13, the source 14, Contact type of the substrate / gate electrode / insulating layer / source / drain electrode / organic semiconductor layer as well as top-contact. (1,1,1,3,3,3-hexamethyldisilazane), OTS (octadecyltrichlorosilane), or OTDS (octadecyltrichlorosilane) as a surface treatment is applied between the source 14 and the drain electrode 15 and the organic semiconductor layer 13. [ It may or may not be coated.

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 16 and the source and drain electrodes 14 and 15 may be formed of a conductive material and may be formed of a metal such as gold (Au), silver (Ag), aluminum (Al), nickel (Ni), chromium (Cr) Oxide (ITO).

The present invention also provides an organic solar cell comprising the polymer of the present invention.

In general, the organic solar cell according to the present invention can be manufactured by the method described below, but the present invention is not limited thereto.

The solar cell generally comprises a glass substrate / transparent electrode (ITO) / hole transport layer / active layer (electron donor / electron acceptor) / electron transport layer / metal electrode (Al). The driving principle is that when light reaches the active layer through the organic substrate, ITO, and hole transport layer, excitons are generated between the p-type (electron donor) polymer and the n-type (electron acceptor) Electrons move to the metal electrode through hopping and the remaining holes move 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 can be made of PEDOT: PSS [poly (3,4-ethylenedioxythiophene)]: [poly (styrenesulfonate)] and prevents the electrons from moving to the anode ITO layer, help.

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 a plastic substrate such as PET [poly (ethylene terephthalate)] or PES [poly (isosulfone)].

The active layer using the polymer according to the present invention may 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 polymer of the present invention employs a compound containing a triple bond between two functional groups selected from electron donating phenyl, thiophenyl, furanyl, selenophenyl, furanofuranyl, selenophenocelenophene, thiothiophene Thereby improving characteristics such as high charge mobility, thermal stability, threshold voltage, and flicker ratio of the device including the same.

The polymer of the present invention can also be prepared by reacting a compound comprising a triple bond between two functional groups selected from an electron donor phenyl, thiophenyl, furanyl, selenophenyl, furanofuranyl, selenophenocelenophene, thiothiophene and It is a random copolymer of polymers alternately polymerized with electron donor compounds. It is excellent in heat resistance and can be mass-produced by solution process.

The polymer of the present invention may also be prepared by alternating polymerization with a compound comprising a triple bond between two functional groups selected from phenyl, thiophenyl, furanyl, selenophenyl, furanofuranyl, selenophenocelenophene, thionothiophene Various substituents, particularly an alkyl group having more than 25 carbon atoms, than a long alkyl group can be introduced into the N atom of the electron donor compound to increase the solubility and improve the electron characteristics.

Therefore, the polymer of the present invention has a high solubility, and can be mass-produced at a low cost in manufacturing an organic thin film transistor and an organic solar battery including the same, thereby reducing the cost.

In addition, the polymer of the present invention can be obtained by reacting a compound containing a triple bond between two functional groups selected from phenyl, thiophenyl, furanyl, selenophenyl, furanofuranyl, selenophenocelenophene and thiothiophene, To increase the coplanarity of the main chain and to have the extended conjugated structure, thereby improving the electron density and increasing the intermolecular interaction to improve the thermal stability.

1 is a cross-sectional view showing the structure of a general organic thin film transistor made of a substrate / gate / insulating layer (source, drain) / semiconductor layer,
Figure 2 is a UV-vis absorption spectrum of a solution phase and film on a polymer (PDPP-SeTh) according to Example 1,
3 is a cyclic voltammetry diagram of the polymer (PDPP-SeTh) according to Example 1,
4 is a differential thermal calorimetry (DSC) curve of the polymer (PDPP-SeTh) according to Example 1,
5 is a thermogravimetric analysis (TGA) curve of the polymer (PDPP-SeTh) according to Example 1,
Figs. 6 and 7 are diagrams showing characteristics (transfer curve, output curve) of the device manufactured by the method of Example 2 using the polymer (PDPP-SeTh) according to Example 1. Fig.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, it should be understood that the present invention is not limited thereto.

[Production Example 1]

Synthesis of trimethyl (5 - ((5- (trimethylstannyl) selenophen-2-yl) ethynyl) thiophen-2-yl) stannane

Preparation of 2- (selenophen-2-ylethynyl) thiophene

2-iodoselenophene (3.56 g, 0.0138 mol), 2-ethynylthiophene (1.00 g, 0.0092 mol), Pd (PPh ₃ ) ₄ (0.213 g, 0.0001842 mol) and CuI , 0.000693 mol) and dissolved in toluene (20 mL). Triethylamine (5 mL) was slowly dropped and then stirred at 90 ^° C for 17 hours. The mixture was cooled to room temperature, filtered through diatomaceous earth and extracted with ether. The organic layer was washed with 10% HCl and water, dried over MgSO _4, and then the solvent was removed using a rotary evaporator. The title compound (1.1 g, 50.4%) was obtained after separation by column chromatography using n- hexane solvent.

^{1 H-NMR (300 MHz,} CD 2 Cl 2): δ 7.70-7.68 (d, 1H), 7.57-7.54 (d, 2H), 7.17-7.13 (d, 2H), 7.10-7.08 (d, 1H) ;

EI, MS m / z (%): 237.9 (100, M < + &

Preparation of trimethyl (5 - ((5- (trimethylstannyl) selenophen-2-yl) ethynyl) thiophen-2-yl) stannane

2- (selenophen-2-ylethynyl) thiophene (1.0 g, 0.0042 mol) was added to a well-dried 100 mL three-neck round bottom flask and dissolved in THF (30 mL). The temperature was lowered to -78 ^° C and n- BuLi (2.5 M in hexane, 3.86 mL, 0.0096 mol) was slowly added dropwise and stirred for 1 hour under a stream of nitrogen. The temperature was then raised to room temperature and stirred for 1 hour. And then lower the temperature to -78 ^o C trimethyltin chloride (1.93 g, 0.0096 mol) was slowly added dropwise and stirred at room temperature for 2 hours. The mixture was poured into ice water and extracted with ether. The organic layer was washed with water, dried over MgSO _4, and then removed at low temperature using a rotary evaporator. Recrystallization was performed using Et-OH (Ethyl alcohol) and filtered to obtain 0.9 g (38.07%) of the title compound.

¹ H-NMR (300 MHz, CD ₂ Cl ₂ ):? 7.57-7.54 (d, 2H), 7.27-7.15, 2H), 0.53-0.32 (m, 18H);

EI, MS m / z (%): 562.7 (100, M < + &

[Preparation Example 2] Preparation of 15- (bromomethyl) hentriacontane

Preparation of 2-tetradecyloctadecan-1-ol

KOH (0.32 g, 0.0057 mol), 0.0625 g of Ni powder, 1.0645 mmol) was added to a well-dried 500 mL three-necked round bottom flask and the temperature was adjusted to 270 ^° C Oligo After stirring for 1 hour under a stream of nitrogen and nitrogen, distillate the water at 270 ^° C for 4 hours using simple distillation. The mixture was cooled to room temperature and extracted with MC (methylene chloride). The organic layer was washed several times with water, and then the solvent was removed using a rotary evaporator. The starting material was then removed using a vacuum distillation apparatus and 34 g of the remaining 2-tetradecyloctadecan-1-ol was obtained in a 70.62% yield.

¹ H-NMR (300 MHz, CDCl ₃ ):? 4.86-4.85 (s, 1H), 3.67-3.53 (m, 2H), 1.58-155 (d, 1H), 1.28-1.21 H), 0.91-0.87 (t, 6H)

EI, MS m / z (%): 466.8 (100, M < + &

Preparation of 15- (bromomethyl) hentriacontane

Triphenylphosphine (17.9 g, 0.06544 mol) was dissolved in MC in a well-dried 500 mL three-necked round bottom flask and the temperature was lowered to 0 ^° C. Bromine (10.5 g, 0.06544 mol) was added dropwise and stirred for about 10 minutes. 2-tetradecyloctadecan-1-ol (25.5 g, 0.05462 mol) dissolved in MC was added dropwise thereto and stirred for 16 hours. The organic layer was extracted with MC. The organic layer was washed with water, dried over MgSO _4, and then the solvent was removed using a rotary evaporator. The solvent was dissolved in hexane and the solution was filtered with hexane. The solvent was removed using a rotary evaporator to remove the solvent. The product was isolated by column chromatography using n- hexane as a solvent to obtain 22.56 g (78%) of yield.

¹ H-NMR (300 MHz, CDCl ₃ ):? 3.67-3.53 (m, 2H), 1.58-155 (d, 1H), 1.28-1.21 (m, 56H), 0.91-0.87 )

EI, MS m / z (%): 529.7 (100, M < + &

[Example 1]

Preparation of 2,5-bis (2-tetradecyloctadecyl) -3,6-di (thiophen-2-yl) pyrrolo [3,4-c] pyrrole-

A well-dried 250 mL three-necked round bottom flask was charged with DPP (3,6-di (thiophen-2-yl) pyrrolo [3,4-c] pyrrole- mol), K ₂ CO ₃ (3.68 g, 0.0266 mol) was added, dissolved in 60 mL of DMF, the temperature was raised to 150 ^° C, and the mixture was stirred for 6 hours. Then 15- (bromomethyl) hentriacontane (21.16 g, 0.0399 mol) was added in portions and stirred for 16 hours under a stream of nitrogen. DMF (dimethylformamide) was first blown and extracted with ether. The organic layer was washed several times with water, and then the solvent was removed using a rotary evaporator. n- Hexane / MC (1: 3) solvent to obtain 1.2 g, 17% yield.

^{1 H-NMR (300 MHz,} CDCl 3): δ 8.89-8.88 (d, 2H), 7.64-7.62 (d, 2H), 7.30-7.29 (d, 2 H), 4.04-4.02 (d, 2 H) , 3.66 (s, 2H), 1.93-188 (m, 2H), 1.30-1.22 (m, 106 H)

EI, MS m / z (%): 1198.0 (100, M < + &

Preparation of 3,6-bis (5-bromothiophen-2-yl) -2,5-bis (2-tetradecyloctadecyl) pyrrolo [3,4-c] pyrrole-

A well-dried 150 mL three-neck round bottom flask was charged with 2,5-bis (2-tetradecyloctadecyl) -3,6-di (thiophen-2-yl) pyrrolo [ ) -dione (0.72 g, 0.6009 mmol) was dissolved in chloroform (40 mL) and blocked with aluminum foil. NBS (N-Bromosuccinimide) (0.22 g, 1.2319 mmol) was slowly added dropwise and stirred for 8 hours. The reaction mixture was extracted with MC (methylene chloride), the organic layer was washed with water, dried over MgSO _4, and then the solvent was removed using a rotary evaporator. n- Hexane / EA (15: 1) solvent, and recrystallized from MC and hexane to obtain 0.65 g, 80% yield.

^{1 H-NMR (300 MHz,} CDCl 3): δ 8.89-8.88 (d, 2H), 7.64-7.62 (d, 2H), 4.04-4.02 (d, 2 H), 3.66 (s, 2 H), 1.93 -188 (m, 2H), 1.30-1.22 (m, 106 H), 0.91-0.87 (t, 12H)

EI, MS m / z (%): 1355.8 (100, M < + &

Preparation of PDPP-SeATh

The polymer can be polymerized through a Stille coupling reaction. Pyrrole- [3,4-c] pyrrole-1,4 (2H, 5H) -dione (0.40 g, 0.295017) was added to a solution of 3,6-bis (5-bromothiophen- 2-yl) stannane (166.03 mg, 0.295017 mmol) was dissolved in Toluene (18 mL) and DMF (3.6 mL), and the solution was treated with trimethyl Nitrogen substitution was performed. Thereafter, Tetrakis (triphenylphosphine) palladium (0) (Pd (pph ₃ ) ₄ ) (0.02727 g, 8 mol%) was added thereto, and the mixture was refluxed at 90 ° C for 10 hours. 2-bromothiophene (0.1 g) was added and stirred for 6 hours. 2-tributyltin thiophene (0.1 g) was added and the reaction solution was end-capped with stirring for 6 hours. The reaction solution was slowly precipitated in methanol The filtered solid was filtered through a sohxlet in the order of methanol, hexane, toluene and chloroform, the precipitated liquid was reprecipitated in methanol, filtered through a filter, and dried to obtain a dark red solid compound PDPP-SeATh. ≪ / RTI >

Mn = 66, 450, Mw = 100, 080, polydispersity = 1.50

[Example 2] Production of organic electronic device

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. The surface was cleaned using piranha cleaning solution (H ₂ SO ₄ : 2H ₂ O ₂ ) and then treated with OD (octadecyltrichlorosilane) (Adrich Co., Ltd.) and treated with SAM (Self Assemble Monolayer). The organic semiconductor layer was coated with a 0.2 wt% chloroform solution at a speed of 2000 rpm for 1 minute using a spin-coater. As the organic semiconductor material, PDPP-SeATh synthesized in Example 1 was used. 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 characteristics of OTFT were measured using Keithley 2400 and 236 source / measure units.

The electric charge mobility of the organic electronic device fabricated in Example 2 was obtained from the following saturation region current equation and a graph obtained by using (I _SD ) ^1/2 and V _G as variables and the slope thereof.

Wherein, I _SD is the source-and-drain current, μ or μ _FET is the charge mobility, and C ₀ is the oxide film electrostatic yongryak, W is a 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 absorbing region of the polymer (PDPP-SeATh) synthesized in Example 1 was measured in a solution state (solution: CHCl ₃ ) and film state, and the results are shown in FIG.

As shown in FIG. 2, it can be seen that the film can be absorbed to a longer wavelength region than in a solution state.

The electrochemical characteristics of the polymer synthesized in Example 1 were measured using a cyclic voltammeter at a flow rate of 50 mV / s in a solvent (Acetonitrile) of Bu ₄ NClO ₄ (0.1 molar concentration) The results are shown in FIG. 3, and a voltage was applied through a coating using a carbon electrode during the measurement.

The electrochemical properties of the polymer synthesized in Example 2 are shown in Table 1 below. Here, the HOMO value was calculated by using the result measured in FIG. 3, and the band gap was obtained at the UV absorption wavelength in the film state.

polymer Electrochemical properties Band gap
(optical)
(eV) Oxidation onset (eV) HOMO (eV) LUMO
(optical) (eV) PDPP-SeTh
(Example 1) 1.20 0.93 -5.36 -4.16

As shown in FIG. 3 and Table 1, the polymer of the present invention has a HOMO energy level value as low as -5.39 eV and thus has a high photooxidative stability. It is also confirmed that the bandgap energy Eg of the semiconductor is lowered by increasing the coplanarity of the main chain and introducing the ethyne bond into the electron acceptor compound, especially diketopyrrolopyrrole, and having an extended conjugated structure have. Therefore, an organic thin film transistor having excellent mobility of both electrons and holes can be manufactured with a low contact resistance with a source / drain electrode due to the low band gap of the polymer of the present invention.

FIG. 4 shows the measurement of the thermal stability of the polymer synthesized in Example 1, wherein the glass transition temperature, melt temperature value and crystallization temperature value were not measured. As a result, it can be seen that it is an amorphous polymer.

5 shows the results of measurement of the decomposition temperature of the polymer synthesized in Example 1 using TGA. It can be seen that the polymer of Example 1 decomposes 5% at 425 ^° C, which is excellent in thermal stability.

6 and 7 are diagrams showing transfer curves of the device fabricated in Example 2 using the polymer synthesized in Example 1 and showing the organic electronic device characteristics of the polymer material, The characteristics of the device are shown.

Example

1 (PDPP-SeATh) Mobility (cm ² / Vs) on / off Vth (V) fresh 0.66 6.98 x 10 ⁴ -4.21 100 ° C ann 1.02 7.44 x 10 ⁴ -3.43 150 ° C ann 1.81 1.28 x 10 ⁶ -2.04 200 ° C ann 2.51 1.33 x 10 ⁶ -3.81

As shown in FIGS. 6, 7 and 2, the device manufactured by annealing at 200 ° C. has a high charge mobility and a flicker ratio of 1.33 × 10 ⁶ , and the threshold voltage Vth (V) is -3.81 V I have. As annealing proceeds, the charge mobility is gradually increased from fresh (un-annealed) to 100 ^° C, 150 ^° C, and 200 ^° C, which is caused by heat treatment (annealing) to N of diketopyrrolopyrrole It is converted into a film with high crystallinity, which results in inter-digitations of the substituted alkyl period. As a result, the migration of the charge is enhanced by the progress of the pi-pile stacking.

Description of the Related Art
11: substrate 12: insulating layer (insulator)
13: organic electronic device channel material 14: source material,
15: drain 16: gate (gate)

Claims (7)

1. A polymer represented by the following formula (1).
[Chemical Formula 1]

[In the above formula (1)
A or B independently of one another are (C6-C50) aryl or (C3-C50) heteroaryl;
Ar ₁ to Ar ₄ are independently selected from the following structures;

R ₁ to R ₅ are independently selected from the group consisting of hydrogen, hydroxy, amino, (C 1 -C 50) alkyl, (C 6 -C 50) aryl, (C 1 -C 50) alkoxy, mono- or di (C 1 -C 50) Carbonyl, (C1-C50) alkylcarbonyloxy or (C1-C50) alkoxy substituted (C1-C30)
Z is S, O or Se,
o is an integer from 1 to 4,
Provided that Ar ₁ and Ar ₃ are the same;
The aryl or heteroaryl of A and B may be optionally substituted with one or more substituents selected from the group consisting of (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, An amino group, an amino group, an amino group, an amino group, an amino group, an amino group, an amino group, a nitro group, a trifluoromethyl group, and a silyl group;
and m and n are independently an integer of 1 to 1,000. The method according to claim 1,
Wherein A and B are independently selected from the following structures.

(Wherein,
Z is S, O or Se;
R ₂₁ to R ₃₉ independently of one another are hydrogen, halogen, (C 1 -C 50) alkyl, (C 1 -C 50) alkoxy, (C 1 -C 50) alkoxycarbonyl, (C 6 -C 50) (C1-C50) alkyl;
R ₂₁ an alkyl group of 1 to R _39, alkoxy, alkoxycarbonyl aryl and aralkyl is (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, (C1-C30) alkoxy, an amino group, Which may further be substituted with at least one substituent selected from a hydroxyl group, a halogen group, a cyano group, a nitro group, a trifluoromethyl group and a silyl group;
R ₄₁ to R ₄₆ are hydrogen or a (C 1 -C 50) alkyl group;
and o is an integer of 1 to 2.) 3. The method of claim 2,
Wherein A and B are the same as each other.

(In the above structure,
Z is S, O or Se;
R ₄₁ to R ₄₆ are hydrogen or a (C 1 -C 50) alkyl group. The method of claim 3,
Wherein R < ₄₁ > and R < ₄₆ > are independently of each other (C25-C50) alkyl. 5. The method of claim 4,
Wherein the polymer is selected from the following compounds.

[Wherein m and n are independently an integer of 1 to 1,000] An organic thin film transistor comprising a polymer according to any one of claims 1 to 5. An organic solar cell comprising a polymer according to any one of claims 1 to 5.

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