I) Introduction p-Conjugated polymers inherently combine electronic properties of inorganic semiconductor crystals and material characteristics of organic plastics due to their special molecular design. This unique combination has led to developing new unconventional optoelectronic technologies and, further, resulted in the evolution of semiconducting polymers (SCPs) as fundamental components for novel electronic devices, such as organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs) and organic solar cells (OSCs).[1–5] Moreover, the material flexibility, capability for thin-film formation, and solution processibility additionally allow utilizing modern printing technologies for the large-scale fabrication of flexible, light-weight organic electronics. This especially enables to significantly increase the production speed and, moreover, to drastically reduce the costs per unit.[6, 7] In particular, transistors are the most important elements in modern functional electronic devices because of acting as electronic switches in logic circuits or in displays to control pixels. However, due to molecular arrangement and interactions, the electronic performance of SCPs cannot compete with the one of monocrystalline silicon which is used in state-of-the-art high-performance microtechnology.[5, 8] Nonetheless, intensive and continuing efforts of scientists focused on improving the performance of OFETs, with the special focus on the charge carrier mobility, by optimizing the polymer structure, processing conditions and OFET device architecture. By this, it was possible to identify crucial relationships between polymer structure, optoelectronic properties, microstructure, and OFET performance.[8] Nowadays, the interdisciplinary scientific success is represented by high-performance SCPs with charge carrier mobilities exceeding the value of amorphous silicon.[3, 9] However, further research is essential to enable developing the next generation of electronic devices for application in healthcare, safety technology, transportation, and communication. II) Objective and Results Within the scope of this doctoral thesis, current high-performance p-conjugated SCPs should be studied comprehensively to improve the present understanding about the interdependency between molecular structure, material properties and charge transport. Therefore, the extensive research approaches focused on different key aspects of high charge carrier mobility polymers for organic transistors. The performed investigations comprised the impact of, first, novel design concepts, second, precise structural modifications and, third, synthetic and processing conditions and led to the major findings listed below. 1. The design concept of tuning the p-conjugation length allows to gradually modulate physical material properties and demonstrates that a strong localization of frontier molecular orbitals in combination with a high degree of thin-film ordering can provide a favorable platform for charge transport in p-conjugated semiconducting polymers.[1] 2. The replacement of thiophene units with thiazoles in naphthalene diimide-based p- conjugated polymers allows to increase interchain interactions and to lower frontier molecular orbitals. This compensates the potentially detrimental enhancement of backbone torsion and drives the charge transport to unipolar electron transport, whereas mobility values are partially comparable with those of the respective thiophene containing analogs. 3. p-Conjugated diketopyrrolo[3,4-c]pyrrole-based copolymers can be synthesized within fifteen minutes what, in combination with avoiding aqueous washings and optimizing processing conditions, allowed an increase in morphological and energetic order and, thus, improved the charge transport properties significantly. III) Conclusion The key findings of this doctoral thesis provide new significant insights into important aspects of designing, synthesizing and processing high charge carrier mobility polymers. By this, they can guide future research to further improve the performance of organic electronic devices - decisive for driving the development and fabrication of smart, functional and wearable next-generation electronics. References [1] T. Erdmann, S. Fabiano, B. Milián-Medina, D. Hanifi, Z. Chen, M. Berggren, J. Gierschner, A. Salleo, A. Kiriy, B. Voit, A. Facchetti, Advanced Materials 2016, 28 (41), 9169–9174, DOI:10.1002/adma.201602923. [2] Y. Karpov, T. Erdmann, I. Raguzin, M. Al-Hussein, M. Binner, U. Lappan, M. Stamm, K. L. Gerasimov, T. Beryozkina, V. Bakulev, D. V. Anokhin, D. A. Ivanov, F. Günther, S. Gemming, G. Seifert, B. Voit, R. Di Pietro, A. Kiriy, Advanced Materials 2016, 28 (28), 6003–6010, DOI:10.1002/adma.201506295. [3] A. Facchetti, Chemistry of Materials 2011, 23 (3), 733–758, DOI:10.1021/cm102419z. [4] A. J. Heeger, Chemical Society Reviews 2010, 39, 2354–2371, DOI:10.1039/B914956M. [5] H. Klauk, Chemical Society Reviews 2010, 39, 2643–2666, DOI:10.1039/B909902F. [6] S. G. Bucella, A. Luzio, E. Gann, L. Thomsen, C. R. McNeill, G. Pace, A. Perinot, Z. Chen, A. Facchetti, M. Caironi, Nature Communications 2015, 6, 8394, DOI:10.1038/ncomms9394. [7] H. Sirringhaus, T. Kawase, R. H. Friend, T. Shimoda, M. Inbasekaran, W. Wu, E. P. Woo, Science 2000, 290 (5499), 2123–2126, DOI:10.1126/science.290.5499.2123. [8] D. Venkateshvaran, M. Nikolka, A. Sadhanala, V. Lemaur, M. Zelazny, M. Kepa, M. Hurhangee, A. J. Kronemeijer, V. Pecunia, I. Nasrallah, I. Romanov, K. Broch, I. McCulloch, D. Emin, Y. Olivier, J. Cornil, D. Beljonne, H. Sirringhaus, Nature 2014, 515 (7527), 384–388, DOI:10.1038/nature13854. [9] S. Holliday, J. E. Donaghey, I. McCulloch, Chemistry of Materials 2014, 26 (1), 647–663, DOI: 10.1021/cm402421p.

I) Introduction p-Conjugated polymers inherently combine electronic properties of inorganic semiconductor crystals and material characteristics of organic plastics due to their special molecular design. This unique combination has led to developing new unconventional optoelectronic technologies and, further, resulted in the evolution of semiconducting polymers (SCPs) as fundamental components for novel electronic devices, such as organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs) and organic solar cells (OSCs).[1–5] Moreover, the material flexibility, capability for thin-film formation, and solution processibility additionally allow utilizing modern printing technologies for the large-scale fabrication of flexible, light-weight organic electronics. This especially enables to significantly increase the production speed and, moreover, to drastically reduce the costs per unit.[6, 7] In particular, transistors are the most important elements in modern functional electronic devices because of acting as electronic switches in logic circuits or in displays to control pixels. However, due to molecular arrangement and interactions, the electronic performance of SCPs cannot compete with the one of monocrystalline silicon which is used in state-of-the-art high-performance microtechnology.[5, 8] Nonetheless, intensive and continuing efforts of scientists focused on improving the performance of OFETs, with the special focus on the charge carrier mobility, by optimizing the polymer structure, processing conditions and OFET device architecture. By this, it was possible to identify crucial relationships between polymer structure, optoelectronic properties, microstructure, and OFET performance.[8] Nowadays, the interdisciplinary scientific success is represented by high-performance SCPs with charge carrier mobilities exceeding the value of amorphous silicon.[3, 9] However, further research is essential to enable developing the next generation of electronic devices for application in healthcare, safety technology, transportation, and communication. II) Objective and Results Within the scope of this doctoral thesis, current high-performance p-conjugated SCPs should be studied comprehensively to improve the present understanding about the interdependency between molecular structure, material properties and charge transport. Therefore, the extensive research approaches focused on different key aspects of high charge carrier mobility polymers for organic transistors. The performed investigations comprised the impact of, first, novel design concepts, second, precise structural modifications and, third, synthetic and processing conditions and led to the major findings listed below. 1. The design concept of tuning the p-conjugation length allows to gradually modulate physical material properties and demonstrates that a strong localization of frontier molecular orbitals in combination with a high degree of thin-film ordering can provide a favorable platform for charge transport in p-conjugated semiconducting polymers.[1] 2. The replacement of thiophene units with thiazoles in naphthalene diimide-based p- conjugated polymers allows to increase interchain interactions and to lower frontier molecular orbitals. This compensates the potentially detrimental enhancement of backbone torsion and drives the charge transport to unipolar electron transport, whereas mobility values are partially comparable with those of the respective thiophene containing analogs. 3. p-Conjugated diketopyrrolo[3,4-c]pyrrole-based copolymers can be synthesized within fifteen minutes what, in combination with avoiding aqueous washings and optimizing processing conditions, allowed an increase in morphological and energetic order and, thus, improved the charge transport properties significantly. III) Conclusion The key findings of this doctoral thesis provide new significant insights into important aspects of designing, synthesizing and processing high charge carrier mobility polymers. By this, they can guide future research to further improve the performance of organic electronic devices - decisive for driving the development and fabrication of smart, functional and wearable next-generation electronics. References [1] T. Erdmann, S. Fabiano, B. Milián-Medina, D. Hanifi, Z. Chen, M. Berggren, J. Gierschner, A. Salleo, A. Kiriy, B. Voit, A. Facchetti, Advanced Materials 2016, 28 (41), 9169–9174, DOI:10.1002/adma.201602923. [2] Y. Karpov, T. Erdmann, I. Raguzin, M. Al-Hussein, M. Binner, U. Lappan, M. Stamm, K. L. Gerasimov, T. Beryozkina, V. Bakulev, D. V. Anokhin, D. A. Ivanov, F. Günther, S. Gemming, G. Seifert, B. Voit, R. Di Pietro, A. Kiriy, Advanced Materials 2016, 28 (28), 6003–6010, DOI:10.1002/adma.201506295. [3] A. Facchetti, Chemistry of Materials 2011, 23 (3), 733–758, DOI:10.1021/cm102419z. [4] A. J. Heeger, Chemical Society Reviews 2010, 39, 2354–2371, DOI:10.1039/B914956M. [5] H. Klauk, Chemical Society Reviews 2010, 39, 2643–2666, DOI:10.1039/B909902F. [6] S. G. Bucella, A. Luzio, E. Gann, L. Thomsen, C. R. McNeill, G. Pace, A. Perinot, Z. Chen, A. Facchetti, M. Caironi, Nature Communications 2015, 6, 8394, DOI:10.1038/ncomms9394. [7] H. Sirringhaus, T. Kawase, R. H. Friend, T. Shimoda, M. Inbasekaran, W. Wu, E. P. Woo, Science 2000, 290 (5499), 2123–2126, DOI:10.1126/science.290.5499.2123. [8] D. Venkateshvaran, M. Nikolka, A. Sadhanala, V. Lemaur, M. Zelazny, M. Kepa, M. Hurhangee, A. J. Kronemeijer, V. Pecunia, I. Nasrallah, I. Romanov, K. Broch, I. McCulloch, D. Emin, Y. Olivier, J. Cornil, D. Beljonne, H. Sirringhaus, Nature 2014, 515 (7527), 384–388, DOI:10.1038/nature13854. [9] S. Holliday, J. E. Donaghey, I. McCulloch, Chemistry of Materials 2014, 26 (1), 647–663, DOI: 10.1021/cm402421p.

Organische Halbleiter werden für viele elektronische Bauteile und Anwendungen wie organische Solarzellen, organische Leuchtdioden und thermoelektrische Generatoren benötigt. Während die Leistung organischer p-Halbleiter in letzter Zeit bereits stark verbessert wurde, hinkt die Entwicklung von guten organischen n-Halbleitern hinterher und konnte bisher nur eingeschränkt vom Innovationsschub profitieren. Um die Effizienten dieser Bauteile weiter zu verbessern werden neue Hochleistungsmaterialien, vor allem im Bereich der n-Halbleiter benötigt. Ein wichtiges Kriterium ist dabei ein genügend tief liegendes LUMO-Energieniveau, welches luftstabile Radikalanionen ermöglicht. In dieser Arbeit werden daher verschiedene konjugierte Materialien auf Basis von Naphthalindiimiden (NDI) synthetisiert und charakterisiert. Anhand von niedermolekularen Modellverbindungen werden zunächst die Einflüsse verschiedener Kernsubstituenten auf die elektronische Struktur, Effizienz der Radikalanionenbildung und Luftstabilität der reduzierten Spezies untersucht. Gemischt mit einer kovalent an NDI angebundenen tertiären Amin Seitenkette wird photoinduziert ein intermolekularer Dotierungsprozess beobachtet, welcher mit abnehmendem Donorcharakter der Kernsubstituenten, bzw. mit sinkendem HOMO zunimmt. Das elektronenärmste NDI-Derivat mit zwei Cyano-Gruppen zeigt dabei die höchste Radikalanionen-Ausbeute und liefert Radikalanionen, die an Luft stabil sind. Dieses System wurde auf polymere Strukturen übertragen und NDI-Polymere mit niedrigen HOMO- und LUMO-Energieniveaus synthetisiert. Als Comonomer wird 1,4-Phenylen mit nur schwach elektronenschiebendem Charakter mit dem klassischen elektronenreichen Bithiophen verglichen. Die resultierenden Copolymere, jeweils mit und ohne Cyanosubstituenten wurden eingehend charakterisiert. Auch hier können luftstabile Radikalanionen in hohen Ausbeuten generiert werden. Diese Arbeit liefert ein grundlegenderes Verständnis der energetischen und strukturellen Voraussetzungen für Elektronentransferprozesse zwischen tertiären Aminen und elektronenarmen NDI-Derivaten unterschiedlicher Energieniveaus. Sie führt zu einem rationaleren Design von konjugierten Materialien mit selbstdotierenden Eigenschaften, um beispielsweise Radikalanionenkonzentration und Leitfähigkeit von organischen n-Halbleitern zu kontrollieren.:BIBLIOGRAPHISCHE BESCHREIBUNG UND REFERAT 5 I. ABKÜRZUNGSVERZEICHNIS VIII 1. EINLEITUNG 11 1.1 Organische Elektronik 12 1.1.1 Organische Thermoelektrika 14 1.1.2 Organische n Halbleiter auf Rylen Basis 18 1.2 C-C-Kupplungsreaktionen 25 1.2.1 Stille-Kupplung 27 1.2.2 Direkte C-H-Arylierungsreaktion 29 1.3 Dotierung organischer n Halbleiter 31 1.3.1 Selbstdotierung organischer Halbleiter mit Aminen 35 2. AUFGABENSTELLUNG 38 3. ERGEBNISSE UND DISKUSSION 40 3.1 PNDIT2 mit Aminoseitenketten 40 3.1.1 Synthese der Monomere 40 3.1.2 Polymerisation zu DMAP PNDIT2 41 3.1.3 Selbstdotierung von DMAP PNDIT2 42 3.2 DMAP NDI X2-Modellverbindungen 46 3.2.1 Synthesen von DMAP NDI X2 46 3.2.2 Untersuchung der Selbstdotierung von DMAP NDI X2 50 3.3 Kernsubstituierte Alkyl-NDI X2Y2 Modellverbindungen 53 3.3.1 Synthesen von NDI X2Y2 53 3.3.2 Elektronische Charakterisierungen 55 3.3.3 Untersuchung der intermolekularen Dotierung 62 3.3.4 Variation der Alkylseitenketten von Amino NDI und NDI CN2 74 3.4 NDI Copolymere 84 3.4.1 NDI Bipyridin 84 3.4.2 Synthese elektronenarmer NDI Polymere 94 3.4.3 Thermische Charakterisierung der NDI Polymere 99 3.4.4 Elektronische Charakterisierungen der NDI Polymere 101 3.4.5 Intermolekulare Dotierung der NDI Polymere 104 3.4.6 Elektrische Leitfähigkeiten der NDI Polymere 109 4. ZUSAMMENFASSUNG 112 5. AUSBLICK 120 6. EXPERIMENTALTEIL 122 6.1 Methoden und Geräte 122 6.1.1 Magnetische Kernresonanzspektroskopie (NMR) 122 6.1.2 Optische Charakterisierung (UV Vis) 122 6.1.3 UV Bestrahlung 122 6.1.4 Cyclovoltammetrie (CV) 123 6.1.5 Elektronenspinresonanz-Spektroskopie (EPR) 123 6.1.6 Differential-Scanning-Calorimetry (DSC) 123 6.1.7 Thermogravimetrische Analyse (TGA) 124 6.1.8 Gelpermeationschromatographie (GPC) 124 6.1.9 Röntgenweitwinkelstreuung (GIWAXS) 124 6.1.10 Massenspektrometrie (MS) 125 6.1.11 Elektrische Leitfähigkeit 125 6.1.12 Kommerzielle Chemikalien und Ausgangsstoffe 126 6.2 Synthesen 127 7. ANHANG 163 8. LITERATURVERZEICHNIS 175 II. SELBSTSTÄNDIGKEITSERKLÄRUNG 189 III. DANKSAGUNG 191 IV. LEBENSLAUF 192 Ausbildung und beruflicher Werdegang 192 Auszeichnungen 192 V. LISTE DER PUBLIKATIONEN UND VORTRÄGE 193