Diketopyrrolopyrrole polymers for use in organic semiconductor devices

Abstract

The present invention relates to polymers comprising one or more (repeating) unit(s) of the formula (I) which are characterized in that Ar.sup.1 and Ar.sup.1 are independently of each other are an annulated (aromatic) heterocyclic ring system, containing at least one thiophene ring, which may be optionally substituted by one, or more groups, and their use as organic semiconductor in organic devices, especially in organic photovoltaics (solar cells) and photodiodes, or in a device containing a diode and/or an organic field effect transistor. The polymers according to the invention have excellent solubility in organic solvents and excellent film-forming properties. In addition, high efficiency of energy conversion, excellent field-effect mobility, good on/off current ratios and/or excellent stability can be observed, when the polymers according to the invention are used in organic field effect transistors, organic photovoltaics (solar cells) and photodiodes. ##STR00001##

Claims

1. An organic semiconductor material, layer or component, comprising a polymer comprising one or more (repeating) unit(s) of the formula ##STR00113## wherein a is 1, 2, or 3, a is 0, 1, 2, or 3; b is 0, 1, 2, or 3; b is 0, 1, 2, or 3; c is 0, 1, 2, or 3; c is 0, 1, 2, or 3; d is 0, 1, 2, or 3; d is 0, 1, 2, or 3; with the proviso that b is not 0, if a is 0; R.sup.1 and R.sup.2 may be the same or different and are selected from hydrogen, a C.sub.1-C.sub.100alkyl group, COOR.sup.103, a C.sub.1-C.sub.100alkyl group which is substituted by one or more halogen atoms, hydroxyl groups, nitro groups, CN, or C.sub.6-C.sub.18aryl groups and/or interrupted by O, COO, OCO, or S; a C.sub.7-C.sub.100arylalkyl group, which can be substituted one to three times with C.sub.1-C.sub.8alkyl and/or C.sub.1-C.sub.8alkoxy; a carbamoyl group, C.sub.5-C.sub.12cycloalkyl, which can be substituted one to three times with C.sub.1-C.sub.8alkyl and/or C.sub.1-C.sub.8alkoxy; a C.sub.6-C.sub.24aryl group, which can be substituted one to three times with C.sub.1-C.sub.8alkyl, C.sub.1-C.sub.8thioalkoxy, and/or C.sub.1-C.sub.8alkoxy, or pentafluorophenyl, Ar.sup.1 and Ar.sup.1 are independently of each other an annulated (aromatic) heterocyclic ring system, containing at least one thiophene ring, which may be optionally substituted by one, or more groups, Ar.sup.2, Ar.sup.2, Ar.sup.3, Ar.sup.3, Ar.sup.4 and Ar.sup.4 have the meaning of Ar.sup.1, or are independently of each other ##STR00114## wherein one of X.sup.3 and X.sup.4 is N and the other is CR.sup.99, R.sup.99, R.sup.104 and R.sup.104 are independently of each other hydrogen, halogen, or a C.sub.1-C.sub.25alkyl group, which may optionally be interrupted by one or more oxygen or sulphur atoms, C.sub.7-C.sub.25arylalkyl, or a C.sub.1-C.sub.25alkoxy group, R.sup.105, R.sup.105, R.sup.106 and R.sup.106 are independently of each other hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms; C.sub.7-C.sub.25arylalkyl, or C.sub.1-C.sub.18alkoxy, R.sup.107 is C.sub.7-C.sub.25arylalkyl, C.sub.6-C.sub.18aryl; C.sub.6-C.sub.18aryl which is substituted by C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.18perfluoroalkyl, or C.sub.1-C.sub.18alkoxy; C.sub.1-C.sub.18alkyl; C.sub.1-C.sub.18alkyl which is interrupted by O, or S; or COOR.sup.103; R.sup.103 is C.sub.1-C.sub.50alkyl; R.sup.108 and R.sup.109 are independently of each other H, C.sub.1-C.sub.25alkyl, C.sub.1-C.sub.25alkyl which is substituted by E and/or interrupted by D, C.sub.7-C.sub.25arylalkyl, C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24aryl which is substituted by G, C.sub.2-C.sub.20heteroaryl, C.sub.2-C.sub.20heteroaryl which is substituted by G, C.sub.2-C.sub.18alkenyl, C.sub.2-C.sub.18alkynyl, C.sub.1-C.sub.18alkoxy, C.sub.1-C.sub.18alkoxy which is substituted by E and/or interrupted by D, or C.sub.7-C.sub.25aralkyl, or R.sup.108 and R.sup.109 together form a group of formula CR.sup.110R.sup.111, wherein R.sup.110 and R.sup.111 are independently of each other H, C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.18alkyl which is substituted by E and/or interrupted by D, C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24aryl which is substituted by G, or C.sub.2-C.sub.20heteroaryl, or C.sub.2-C.sub.20 heteroaryl which is substituted by G, or R.sup.108 and R.sup.109 together form a five or six membered ring, which optionally can be substituted by C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.18alkyl which is substituted by E and/or interrupted by D, C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24aryl which is substituted by G, C.sub.2-C.sub.20heteroaryl, C.sub.2-C.sub.20heteroaryl which is substituted by G, C.sub.2-C.sub.18alkenyl, C.sub.2-C.sub.18alkynyl, C.sub.1-C.sub.18alkoxy, C.sub.1-C.sub.18alkoxy which is substituted by E and/or interrupted by D, or C.sub.7-C.sub.25aralkyl, D is CO, COO, S, O, or NR.sup.112, E is C.sub.1-C.sub.8thioalkoxy, C.sub.1-C.sub.8alkoxy, CN, NR.sup.112R.sup.113, CONR.sup.112R.sup.113, or halogen, G is E, or C.sub.1-C.sub.18alkyl, and R.sup.112 and R.sup.113 are independently of each other H; C.sub.6-C.sub.18aryl; C.sub.6-C.sub.18aryl which is substituted by C.sub.1-C.sub.18alkyl, or C.sub.1-C.sub.18alkoxy; C.sub.1-C.sub.18alkyl; or C.sub.1-C.sub.18alkyl which is interrupted by O.

2. The organic semiconductor material, layer or component comprising a polymer according to claim 1, wherein the polymer comprises one or more (repeating) unit(s) of the formula ##STR00115## ##STR00116## ##STR00117## ##STR00118## wherein R.sup.1 is a C.sub.8-C.sub.36alkyl group, R.sup.3 is hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms, C.sub.7-C.sub.25aralkyl, or C.sub.1-C.sub.25alkoxy; R.sup.4, R.sup.4, R.sup.5, R.sup.5 and R.sup.6 are independently of each other hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms, C.sub.7-C.sub.25aralkyl, or C.sub.1-C.sub.25alkoxy; R.sup.7, R.sup.7, R.sup.9 and R.sup.9 are independently of each other hydrogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one, or more oxygen, or sulphur atoms, or C.sub.7-C.sub.25aralkyl, R.sup.8 is C.sub.7-C.sub.25aralkyl, C.sub.6-C.sub.18aryl; C.sub.6-C.sub.18aryl which is substituted by C.sub.1-C.sub.18alkyl, or C.sub.1-C.sub.18alkoxy; or C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms, and R.sup.12 and R.sup.12 are independently of each other hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one, or more oxygen, or sulphur atoms, C.sub.1-C.sub.25alkoxy, or ##STR00119## wherein R.sup.13 is C.sub.1-C.sub.10alkyl group, or a tri(C.sub.1-C.sub.8alkyl)silyl group.

3. The organic semiconductor material, layer or component according to claim 1, wherein the polymer comprises (repeating) unit(s) of the formula ##STR00120## wherein A is a repeating unit of formula (I), and COM.sup.1- is a repeating unit, which is selected from a group of formula Ar.sup.1, such as, for example, ##STR00121## ##STR00122## wherein one of X.sup.5 and X.sup.6 is N and the other is CR.sup.14 R.sup.14, R.sup.14, R.sup.17 and R.sup.17 are independently of each other hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms, C.sub.7-C.sub.25aralkyl, or C.sub.1-C.sub.25alkoxy; R.sup.18 and R.sup.18 independently of each other hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms, C.sub.7-C.sub.25aralkyl, or C.sub.1-C.sub.25alkoxy; R.sup.19 is hydrogen, C.sub.7-C.sub.25aralkyl, C.sub.6-C.sub.18aryl; C.sub.6-C.sub.18aryl which is substituted by C.sub.1-C.sub.18alkyl, or C.sub.1-C.sub.18alkoxy; or C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms; R.sup.20 and R.sup.20 are independently of each other hydrogen, C.sub.7-C.sub.25aralkyl, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one, or more oxygen, or sulphur atoms, and Ar.sup.1 is as defined in claim 1.

4. The organic semiconductor material, layer or component according to claim 3, wherein A is a repeating unit of formula (Ia), (Ib), (Ic), (Id), (Ie), (If), (Ig), (Ih), (Ii), (Ij), (Ik), (H), (Im), (In), (Io), (Ip), (Iq), (Ir), (Is), (It), (Iu) or (Iv) as defined in claim 2.

5. The organic semiconductor material, layer or component according to claim 3, wherein the polymer comprises one or more (repeating) unit(s) of the formula ##STR00123## ##STR00124## ##STR00125## R.sup.1 is a C.sub.8-C.sub.36alkyl group, R.sup.3 is hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms, C.sub.7-C.sub.25aralkyl, or C.sub.1-C.sub.25alkoxy; R.sup.4, R.sup.4 and R.sup.5 are independently of each other hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms, C.sub.7-C.sub.25aralkyl, or C.sub.1-C.sub.25alkoxy; R.sup.7, R.sup.7, R.sup.9 and R.sup.9 are independently of each other hydrogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one, or more oxygen, or sulphur atoms; or C.sub.7-C.sub.25aralkyl, R.sup.8 is C.sub.7-C.sub.25aralkyl, C.sub.6-C.sub.18aryl; C.sub.6-C.sub.18aryl which is substituted by C.sub.1-C.sub.18alkyl, or C.sub.1-C.sub.18alkoxy; or C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms; R.sup.19 is C.sub.7-C.sub.25aralkyl, C.sub.6-C.sub.18aryl; C.sub.6-C.sub.18aryl which is substituted by C.sub.1-C.sub.18alkyl, or C.sub.1-C.sub.18alkoxy; or C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms, one of X.sup.5 and X.sup.6 is N and the other is CR.sup.14, R.sup.14, R.sup.14, R.sup.17 and R.sup.17 are independently of each other hydrogen, halogen, C.sub.1-C.sub.25alkyl, C.sub.1-C.sub.25alkoxy, which may optionally be interrupted by one or more oxygen or sulphur atoms; or C.sub.7-C.sub.25aralkyl, R.sup.18 and R.sup.18 independently of each other hydrogen, halogen, C.sub.1-C.sub.25alkyl, which may optionally be interrupted by one or more oxygen or sulphur atoms; C.sub.7-C.sub.25aralkyl, or C.sub.1-C.sub.25alkoxy.

Description

EXAMPLES

Example 1: Manufacture of the Semiconducting Compound of the Formula 5

(1) ##STR00101##

(2) a) 228.06 g of 2-decyl-1-tetradecanol [58670-89-6] are mixed with 484.51 g 47% hydrolodic acid [10034-85-2] and the mixture is refluxed overnight. The product is extracted with t-butyl-methylether. Then the organic phase is dried and concentrated. The product is purified over a silica gel column to give 211.54 g of the desired compound 1 (73%). .sup.1H-NMR data (ppm, CDCl.sub.3): 3.26 2H d, 1.26-1.12 41H m, 0.88 6H t.

(3) ##STR00102##

(4) b) 5.70 g of the nitril [40985-58-8] are reacted with freshly prepared sodium t-amylate (170 ml t-amylalcohol, 2.22 g sodium and 10 mg FeCl.sub.3) and 5.57 g di-tert-amylsuccinate (DTAS) over night at reflux. Precipitation of the crude DPP from acetic acid affords 5.6 g of the desired compound 2 (79%). MS m/z: 412.

(5) ##STR00103##

(6) c) 4 g of compound 2 and 5.6 g potassium carbonate in 200 ml of dimethylformamide are heated to 90 C. and then 11.82 g of the iodide 1 are added and the mixture is then stirred for 3 hours at 90 C. After cooling the reaction mixture is poured on water and the product is filtered and washed with water. Purification is achieved by column chromatography over silica gel and affords 1.7 g of the desired DPP 3 (15%). .sup.1H-NMR data (ppm, CDCl.sub.3): 9.30 2H s, 7.61 2H d, 7.33 2H d, 4.09 4H d, 2.01 2H m, 1.35-1.20 80H m, 0.89 6H t, 0.87 6H t.

(7) ##STR00104##

(8) d) 2.1 g 3 are dissolved in 40 ml of chloroform, cooled down to 0 C. and after the addition of a drop of perchloric acid 0.68 g of N-bromosuccinimide are then added portion wise over a period of 1 h. The reaction mixture is stirred at 0 C. After the reaction is completed, the mixture is washed with water. The organic phase is extracted, dried and concentrated. The compound is then purified over a silica gel column to give 2 g of the desired compound of the formula 4 (84%). .sup.1H-NMR data (ppm, CDCl.sub.3): 9.21 2H s, 7.33 2H s, 4.05 4H d, 1.97 2H m, 1.35-1.20 80H m, 0.89 6H t, 0.87 6H t.

(9) ##STR00105##

(10) e) 810 mg of compound 4, 208 mg thiophene-di-boronic acid pinacol ester [175361-81-6], 15 mg Pd.sub.2(dba).sub.3 (Tris(dibenzylideneacetone)-di-palladium) and 10 mg tri-tert-butyl-phosphonium-tetrafluoroborate are dissolved in 4 ml of tetrahydrofurane. This solution is degassed with 3 cycles of freeze/pump/thaw (Ar). The reaction mixture is then heated to reflux temperature. Then 418 mg of K.sub.3PO.sub.4 are dissolved in 1.2 ml of water and degassed under Argon. The water solution is added to the THF solution and the reaction mixture is refluxed over night. Then 14 mg of 2-thiophene-mono-boronic-acid-pinacol-ester [193978-23-3] are added, and the mixture is refluxed for another 30 minutes. Then 11 mg of 2-bromo-thiophene [1003-09-4] are added, and the mixture is refluxed for another 30 minutes. The reaction mixture is cooled to room temperature and diluted with water and then extracted with chloroforme. The chloroforme solution is then refluxed with a solution of NaCN in water for 1 hour. The water is separated and the chloroforme solution dried. The residue is then Soxhlet extracted with tetrahydrofurane. The organic phase is precipitated to give 635 mg of the desired polymer 5. Mw=38000, Polydispersity=2.78 (measured by HT-GPC).

Example 2: Application of the Semiconducting Polymer of the Formula 5

(11) The semiconductor thin film is prepared either by spin-coating the polymer of the formula 5 obtained in example 1 in a 0.5% (w/w) solution in chloroform. The spin coating is accomplished at a spinning speed of 3000 rpm (rounds per minute) for about 20 seconds in ambient conditions. The devices are evaluated as deposited and after being annealed at 100 C. for 15 minutes.

(12) Transistor Performance

(13) The transistor behavior is measured on an automated transistor prober (TP-10, CSEM Zrich) and showed clear p-type transistor behavior. From a linear fit to the square root of the saturated transfer characteristics a field effect mobility of 5.610.sup.3 cm.sup.2/Vs with an on/off current ratio of 3.510.sup.5 can be determined.

Example 3: Photovoltaic Application of the Semiconducting Polymer of Formula 5 DPP-Monomer Based Bulk Heterojunction Solar Cell

(14) The solar cell has the following structure: Al electrode/LiF layer/organic layer, including compound of the invention/[poly(3,4-ethylenedioxy-thiophene) (PEDOT)/poly(styrenesulfonic acid) (PSS)]/ITO electrode/glass substrate. The solar cells are made by spin coating a layer of the PEDOT-PSS on a pre-patterned ITO on glass substrate. Then a 1:1 mixture of the polymer of formula 5 (1% by weight): [70]PCBM (a substituted C.sub.70 fullerene) is spin coated (organic layer). LiF and Al are sublimed under high vacuum through a shadow-mask.

(15) Solar Cell Performance

(16) The solar cell is measured under a solar light simulator. Then with the External Quantum Efficiency (EQE) graph the current is estimated under AM1.5 conditions. This leads to a value of J.sub.sc=2.4 mA/cm.sup.2, FF=0.51 and V.sub.oc=0.59 V for an estimated overall efficiency of 0.73%.

Example 4: Synthesis of Polymer 10

(17) ##STR00106##

(18) a) 228.06 g of 2-decyl-1-tetradecanol [58670-89-6] are mixed with 484.51 g 47% hydrolodic acid [10034-85-2] and the mixture is refluxed overnight. The product is extracted with t-butyl-methylether. Then the organic phase is dried and concentrated. The product is purified over a silica gel column to give 211.54 g of the desired compound 6 (73%). .sup.1H-NMR data (ppm, CDCl.sub.3): 3.26 2H d, 1.26-1.12 41H m, 0.88 6H t.

(19) ##STR00107##

(20) b) 5.70 g of the nitril [40985-58-8] are reacted with freshly prepared sodium t-amylate (170 ml t-amylalcohol, 2.22 g sodium and 10 mg FeCl.sub.3) and 5.57 g di-tert-amylsuccinate (DTAS) over night at reflux. Precipitation of the crude DPP from acetic acid affords 5.6 g of the desired compound 7 (79%). MS m/z: 412.

(21) ##STR00108##

(22) c) 4 g of compound 7 and 5.6 g potassium carbonate in 200 ml of dimethylformamide are heated to 90 C. and then 11.82 g of the iodide 6 are added and the mixture is then stirred for 3 hours at 90 C. After cooling the reaction mixture is poured on water and the product is filtered and washed with water. Purification is achieved by column chromatography over silica gel and affords 1.7 g of the desired DPP 8 (15%). .sup.1H-NMR data (ppm, CDCl.sub.3): 9.30 2H s, 7.61 2H d, 7.33 2H d, 4.09 4H d, 2.01 2H m, 1.35-1.20 80H m, 0.89 6H t, 0.87 6H t.

(23) ##STR00109##

(24) d) 2.1 g 8 are dissolved in 40 ml of chloroform, cooled down to 0 C. and after the addition of a drop of perchloric acid 0.68 g of N-bromosuccinimide are then added portion wise over a period of 1 h. The reaction mixture is stirred at 0 C. After the reaction is completed, the mixture is washed with water. The organic phase is extracted, dried and concentrated. The compound is then purified over a silica gel column to give 2 g of the desired compound of the formula 9 (84%). .sup.1H-NMR data (ppm, CDCl.sub.3): 9.21 2H s, 7.33 2H s, 4.05 4H d, 1.97 2H m, 1.35-1.20 80H m, 0.89 6H t, 0.87 6H t.

(25) ##STR00110##

(26) e) 810 mg of compound 9, 208 mg thiophene-di-boronic acid pinacol ester [175361-81-6], 15 mg Pd.sub.2(dba).sub.3 (tris(dibenzylideneacetone)-di-palladium) and 10 mg tri-tert-butyl-phosphonium-tetrafluoroborate are dissolved in 4 ml of tetrahydrofurane. This solution is degassed with 3 cycles of freeze/pump/thaw (Ar). The reaction mixture is then heated to reflux temperature. Then 418 mg of K.sub.3PO.sub.4 are dissolved in 1.2 ml of water and degassed under Argon. The water solution is added to the THF solution and the reaction mixture is refluxed over night. Then 14 mg of 2-thiophene-mono-boronic-acid-pinacol-ester [193978-23-3] are added, and the mixture is refluxed for another 30 minutes. Then 11 mg of 2-bromo-thiophene [1003-09-4] are added, and the mixture is refluxed for another 30 minutes. The reaction mixture is cooled to room temperature and diluted with water and then extracted with chloroforme. The chloroforme solution is then refluxed with a solution of NaCN in water for 1 hour. The water is separated and the chloroforme solution dried. The residue is then Soxhlet extracted with tetrahydrofurane. The organic phase is precipitated to give 635 mg of the desired polymer 10. Mw=46600, Polydispersity=2.72 (measured by HT-GPC).

Example 5: Synthesis of Compound 12

(27) ##STR00111##

(28) a) A mixture of 5 mg FeCl.sub.3, 1.37 g sodium and 50 ml t-amylalcohol is heated to 110 C. for 30 minutes before a mixture of 3.5 g of nitrile [55219-11-9] and 2.76 g ditertamylsuccinate (DTAS) is added drop wise. The reaction mixture is stirred at 110 C. over night before it is poured onto a water-methanol mixture. Buchner filtration and exhaustive washing with methanol affords 3 g of the desired DPP derivative 11 as dark powder. MS m/z: 400.

(29) ##STR00112##

(30) b) In 10 ml of dry dimethylformamide 1 g of compound 11 is suspended and 220 mg of sodiumhydride (60% in mineral oil) are added. The mixture is heated to 100 C. and then 1.86 g of dimethylsulfate is added and the mixture is stirred over night at 100 C. The crude product is poured on ice, filtered and washed with water. The product is recrystallized from dimethylformamide to give 0.63 g of a compound of formula 12. MS m/z: 428;

Example 6: Application of the Semiconducting Polymer 10

(31) The semiconductor thin film is prepared by spin-coating the polymer 10 obtained in example 1 in a 0.5% (w/w) solution in chloroform. The spin coating is accomplished at a spinning speed of 3000 rpm (rounds per minute) for about 20 seconds in ambient conditions. The devices are evaluated as deposited and after being annealed at 100 C. for 15 minutes.

(32) Transistor Performance

(33) The transistor behavior is measured on an automated transistor prober (TP-10, CSEM Zrich) and showed clear p-type transistor behavior. From a linear fit to the square root of the saturated transfer characteristics a field effect mobility of 5.610.sup.3 cm.sup.2/Vs with an on/off current ratio of 3.510.sup.5 can be determined.

Example 7: Photovoltaic Application of the Semiconducting Polymer 10

(34) The solar cell has the following structure: Al electrode/LiF layer/organic layer, including compound of the invention/[poly(3,4-ethylenedioxy-thiophene) (PEDOT)/poly(styrenesulfonic acid) (PSS)]/ITO electrode/glass substrate. The solar cells are made by spin coating a layer of the PEDOT-PSS on a pre-patterned ITO on glass substrate. Then a 1:1 mixture of the polymer 10 (1% by weight): [70]PCBM (a substituted C.sub.70 fullerene) is spin coated (organic layer). LiF and Al are sublimed under high vacuum through a shadow-mask.

(35) Solar Cell Performance

(36) The solar cell is measured under a solar light simulator. Then with the External Quantum Efficiency (EQE) graph the current is estimated under AM1.5 conditions. This leads to a value of J.sub.sc=2.4 mA/cm.sup.2, FF=0.51 and V.sub.oc=0.59 V for an estimated overall efficiency of 0.73%.