Die enormen Fortschritte im Bereich der organischen Elektronik in den letzten Jahrzehnten haben zur Entwicklung effizienter optoelektronischer Bauelemente geführt wie z. B. organische Leuchtdioden (OLEDs), organische Feldeffekttransistoren (OFETs) und organische Photovoltaikzellen (OPV). Darüber hinaus ermöglichen halbleitende Polymere die Herstellung kostengünstiger, großflächiger elektronischer Bauelemente mit Hilfe von Niedertemperatur Lösungsverfahren auf flexiblen Substraten. Der erste Teil dieser Arbeit befasste sich mit der Entwicklung von Host-Materialien für die emittierende Schicht (EML) von OLEDs. Effiziente Host-Materialien sollten bestimmte Eigenschaften aufweisen, z. B. eine hohe Triplett-Energie, einen hohen und ausgeglichenen Ladungsträgertransport, geeignete Grenzorbitalniveaus, die mit denen der Nachbarschichten übereinstimmen, und morphologische Stabilität. Zu diesem Zweck wurden Polymere auf Carbazolbasis mit einer elektronenziehenden Gruppe (EWG) an verschiedenen Stellen der Kette entworfen und durch Suzuki Kupplung synthetisiert. Die Polymere wurden chemisch und optisch charakterisiert, bevor sie nach Dotierung mit Tris(2-phenylpyridin)iridium(III) (Ir(ppy)3) in eine funktionierende grüne OLED eingebaut wurden. Zusätzlich wurden die Ladungstransporteigenschaften durch die Herstellung von Einzelträgergeräte untersucht. Der zweite Teil widmete sich der Herstellung von Halbleitermaterialien für OFET Anwendungen. Nach einem neuartigen Moleküldesign wurde eine Reihe von Verbindungen auf der Basis von Diketopyrrolopyrrol (DPP) und Thiophen durch Stille-Kupplung und phosphinfreie direkte Heteroarylierung synthetisiert. Dieses molekulare Design erwies sich als flexibel für die Synthese neuartiger Derivate durch Modifikation der Endgruppen. Die Korrelation zwischen Struktur und Morphologie wurde ebenfalls untersucht. Die Mobilität der Ladungsträger, welche von der chemischen Struktur und Morphologie des Halbleiters beeinflusst wird, ist einer der wichtigsten Parameter eines OFET. Daher wurden die erhaltenen Materialien mit niedriger Bandlücke in Transistoren verschiedener Architekturen integriert, die durch Lösungsverfahren wie Spin-Coating und Scherbeschichtung hergestellt wurden. Die Mobilität sowie andere OFET-Parameter wurden im p- und n-Typ-Betrieb gemessen.:1 Theoretical background 1.1 Introduction 1.2 Organic semiconductors 1.3 Organic Light Emitting Diodes 1.3.1 Physics of OLEDs 1.3.2 Solution processable OLEDs 1.3.3 Polymer Light-Emitting Diodes 1.4 Organic Field-Effect Transistors 1.4.1 Device operation 1.4.2 Ambipolar transistors 1.5 Synthesis of π-conjugated polymers 1.6 Characterisation methods 1.6.1 Chemical structure characterisation 1.6.2 Optical characterisation 1.6.3 Morphology and microstructure 2 Motivation and aim 3 Results and discussion 3.1 Polymers for ambipolar semiconductors 3.1.1 Molecular design 3.1.2 (N-carbazole)triphenylphosphine oxide polymers 3.1.3 Bis(carbazol-3-yl)triphenylphosphine oxide polymers 3.1.4 ((Carbazol-3-yl)phenoxy)hexyl diphenylphosphinate polymers 3.1.5 ((Phenothiazin-10-yl)phenyl)diphenylphosphine oxide polymers 3.1.6 Device integration 3.1.7 Summary 3.2 DPP based molecules for OFETs 3.2.1 Molecular design 3.2.2 DBT-I series 3.2.3 DBT-II 3.2.4 Device integration 3.2.5 Summary 4 Conclusions and outlook 5 Experimental part 6 Supporting Information 7 Bibliography / Staggering progress in the field of organic electronics over the past decades has led to the development of efficient optoelectronic devices, such as organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs)and organic photovoltaic cells (OPV). Moreover, semiconducting polymers enable the fabrication of low-cost, large-area electronic devices using low-temperature solution-processing methodologies on flexible substrates. The first part of this thesis focused on the development of host materials for the emitting layer (EML) of an OLED. Efficient hosts should possess a number of properties, such as high triplet energy, good and balanced charge-carrier transport, suitable frontier orbital levels that match those of the neighbouring layers, and morphological stability. To this end, carbazole-based polymers featuring an electron-withdrawing group (EWG) at different positions of the chain were designed and synthesised by Suzuki coupling. Chemical and optical characterisations of the polymers were performed prior to their incorporation into a functioning green OLED upon doping with tris(2-phenylpyridine)iridium(III) (Ir(ppy)3). Additionally, the charge-transport properties were studied through the fabrication of single-carrier devices. The second part was dedicated to the production of semiconductor materials for OFET applications. Following a novel molecular design, a series of compounds based on diketopyrrolopyrrole (DPP) and thiophene were synthesised by Stille coupling and phosphine-free direct heteroarylation. This molecular design was proven to be flexible for the synthesis of novel derivatives by modification of the end-groups. The correlation between structure and morphology was also studied. Mobility, influenced by the chemical structure and morphology of the semiconductor, is one of the most important parameters of an OFET. Thus, the obtained low bandgap materials were integrated into devices of different architectures, fabricated by solution processing methodologies, such as spin coating and shear coating, and the mobility, as well as other OFET parameters, were measured in p- and n-type operation.:1 Theoretical background 1.1 Introduction 1.2 Organic semiconductors 1.3 Organic Light Emitting Diodes 1.3.1 Physics of OLEDs 1.3.2 Solution processable OLEDs 1.3.3 Polymer Light-Emitting Diodes 1.4 Organic Field-Effect Transistors 1.4.1 Device operation 1.4.2 Ambipolar transistors 1.5 Synthesis of π-conjugated polymers 1.6 Characterisation methods 1.6.1 Chemical structure characterisation 1.6.2 Optical characterisation 1.6.3 Morphology and microstructure 2 Motivation and aim 3 Results and discussion 3.1 Polymers for ambipolar semiconductors 3.1.1 Molecular design 3.1.2 (N-carbazole)triphenylphosphine oxide polymers 3.1.3 Bis(carbazol-3-yl)triphenylphosphine oxide polymers 3.1.4 ((Carbazol-3-yl)phenoxy)hexyl diphenylphosphinate polymers 3.1.5 ((Phenothiazin-10-yl)phenyl)diphenylphosphine oxide polymers 3.1.6 Device integration 3.1.7 Summary 3.2 DPP based molecules for OFETs 3.2.1 Molecular design 3.2.2 DBT-I series 3.2.3 DBT-II 3.2.4 Device integration 3.2.5 Summary 4 Conclusions and outlook 5 Experimental part 6 Supporting Information 7 Bibliography

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In this dissertation, we employ a number of computational methods, including Ab Initio, Density Functional Theory, and Molecular Dynamics simulations to investigate key microscopic parameters that govern charge-transport and charge-generation in single-component and bimolecular charge-transfer organic semiconductors. First, electronic (transfer integrals, bandwidths, effective masses) and electron-phonon couplings of single-component organic semiconductors are discussed. In particular, we evaluate microscopic charge-transport parameters in a series of nonlinear acenes with extended pi-conjugated cores. Our studies suggest that high charge-carrier mobilities are expected in these materials, since large electronic couplings are obtained and the formation of self-localized polarons due to local and nonlocal electron-phonon couplings is unlikely. Next, we evaluate charge detrapping due to interaction with intra-molecular crystal vibrations in order to explain changes in experimentally measured electric conductivity generated by pulse excitations in the IR region of a photoresistor based on pentacene/C60 thin film. Here, we directly relate the nonlocal electron-phonon coupling constants with variations in photoconductivity. In terms of charge-generation from an excited manifold, we evaluate the modulation of the state couplings between singlet and triplet excited states due to crystal vibrations, in order to understand the effect of lattice vibrations on singlet fission in tetracene crystal. We find that the state coupling between localized singlet and correlated triplet states is much more strongly affected by the dynamical disorder due to lattice vibrations than the coupling between the charge-transfer singlet and triplet states. Next, the impact of Hartree-Fock exchange in the description of transport properties in crystalline organic semiconductors is discussed. Depending on the nature of the electronic coupling, transfer integrals and bandwidths can show a significant increase as a function of the amount of the Hartree-Fock exchange included in the functional. Similar trend is observed for lattice relaxation energy. It is also shown that the ratio between electronic coupling and lattice relaxation energy is practically independent of the amount of the Hartree-Fock exchange, making this quantity a good candidate for incorporation into tight-binding transport models. We also demonstrate that it is possible to find an amount of the Hartree-Fock exchange that recovers (quasi-particle) band structure obtained from a highly accurate G0W0 approach. Finally, a microscopic understanding of a phase transition in charge-carrier mobility from temperature independent to thermally activated in stilbene-tetrafluoro-tetracyanoquinodimethane crystal is provided.

This thesis describes a number of studies on organic semiconductors focused around using them as gain media for lasers. The photophysical properties of organic semiconductors are studied using a wide range of experimental techniques, allowing the evaluation of new materials and novel excitation schemes for use in organic semiconductor lasers. Polyfluorene is a well-established conjugated polymer laser gain medium and in this thesis its excellent lasing properties are combined with its two photon absorption properties to demonstrate a tunable two-photon pumped solid-state laser based on a commercially available organic semiconductor. A family of bisfluorene dendrimers was studied using a number of photophysical techniques to evaluate their potential as laser materials. Distributed feedback lasers based on one of the dendrimers are demonstrated with lasing thresholds comparable to polyfluorene. The same materials were found to have enhanced two-photon absorption properties in comparison to polyfluorene, leading to the fabrication of tunable two-photon pumped dendrimer lasers. A member of a novel family of star-shaped oligofluorene truxenes was evaluated as a laser gain material and the distributed feedback lasers made from them show some of the lowest lasing thresholds reported for organic semiconductors, partly as a consequence of exceptionally low waveguide losses in comparison to other single-material thin films. Finally, an organic laser dye is blended with a conjugated polymer, where the dye molecules harvest the excitation light of a GaN laser diode and transfer its energy to the polymer molecules. This is the first time such a scheme is used in an organic laser and in combination with a novel surface-emitting distributed Bragg reflector resonator allows the demonstration of a diode-pumped organic laser, a significant step towards simplifying organic lasers.

This work studies various electrical properties of polymer layers of polyaniline, polythiophenes and poly(((benzothiadiazol)4,7-di(thien-2-yl)-5,6-difluoro-2,1,3-benzothiadiazol). Goal of this work is to determine electrical and photoelectrical properties as are electric conductivity, mobility of the free charge carriers, work function of the electrons and diffusion length of excitons. Conductivity was obtained through current and voltage contacts, mobility was measured by CELIV method (charge extraction by linearly increasing voltage). To determine work function a Kelvin probe was built and utilized. Diffusion length of excitons was determined from photovoltage spectrum formed by illuminating space charge region of the polymer.Space charge region on surface of the polymer can arise spontaneously or by laying suitable contact electrode. Powered by TCPDF (www.tcpdf.org)

Das Ziel der Arbeit ist die Herstellung und die Charakterisierung von Heterostrukturen des organischen Halbleiters Pentazen (PEN) mit diversen konjugierten organischen Materialien im Hinblick auf das Anwendungspotenzial im Bereich der organischen Elektronik. Für die Untersuchung von PEN-Heterostrukturen mit (i) Fulleren (C60), (ii) Perfluoropentazen (PFP) und (iii) 6,13-Pentazenchinon (PQ) wurden mehrere komplementäre experimentelle Techniken angewendet: Röntgenbeugung, Schwingungsspektroskopie, Rasterkraftmikroskopie und Photoelektronenspektroskopie. (i) Für PEN - Heterostrukturen mit C60 wurden die elektronischen, strukturellen und morphologischen Eigenschaften mit der Leistung von organischen Solarzellen (OSZ) für geschichtete und gemischte Systeme korreliert. Dabei wurde gezeigt, dass morphologische anstatt struktureller oder energetischer Ursachen die Leistungsunterschiede der beiden untersuchten Zelltypen erklären. (ii) Strukturuntersuchungen wurden an reinen PFP-Filmen, sowie an geschichteten und gemischten Heterostrukturen mit PEN durchgeführt. Es wurde die Struktur der PFP-Dünnfilmphase gelöst und das Wachstum von PEN+PFP Mischkristallen gezeigt, welche erfolgreich angewandt wurden, um die Ionisationsenergie (IE) des Films mit dem Mischungsverhältnis durchzustimmen. Dies wurde durch die Existenz von innermolekularen polaren Bindungen (C-H und C-F für PEN und PFP) erklärt. (iii) Für reine PQ-Filme wurde die Struktur der PQ-Dünnfilmphase gelöst (ein Molekül pro Einheitszelle). Es wurde eine stark orientierungsabhängige IE von PQ und PEN gefunden und gezeigt, dass die Energieniveaulagen für die Anwendung in OSZ geeignet sind. Die Untersuchung von Mischsystemen zeigte phasensepariertes Wachstum ohne Hinweise auf Interkalation, selbst bei PQ Konzentrationen von nur 2%. Weiters wurde gezeigt, dass O2 und Wasser keine nachhaltigen Auswirkungen auf PEN-Filme zeigen, wohingegen Singlett-Sauerstoff und Ozon diese angreifen und flüchtige Reaktionsprodukte liefern. / The scope of this work is the combination of the organic semiconductor pentacene (PEN) with different conjugated organic molecules to form application relevant heterostructures in vacuum sublimed films. Using x-ray diffraction (XRD), vibrational spectroscopy, atomic force microscopy and photoelectron spectroscopy, PEN heterostructures with (i) fullerene (C60), (ii) perfluoropentacene (PFP) and (iii) 6,13-pentacenequinone (PQ) were thoroughly characterized to judge on the respective application potential in organic electronics. (i) PEN heterostructures with C60 were investigated regarding the correlation of energetic, structural and morphological properties with the performance of organic photovoltaic cells (OPVCs) for both layered and mixed structures. Morphological rather than energetic or structural issues account for performance differences of bulk-heterojunction OPVCs compared to layered devices. (ii) XRD investigations were carried out on pure PFP films, on layered and mixed heterostructures with PEN. The thin-film polymorph of PFP was solved and it is shown that blended films form a mixed crystal structure, which led to the finding that the ionization energy (IE) of organic films composed of molecules with intramolecular polar bonds (like C-H and C-F for PEN and PFP, respectively) can be tuned through the mixing ratio. (iii) A so far unknown thin-film polymorph of PQ on SiO2 substrates was solved using XRD reciprocal space mapping evidencing a loss of the herringbone arrangement known from the PQ bulk structure. For PEN heterostructures with PQ a highly molecular-orientation dependent IE and energy level offsets interesting for the use in OPVCs were found. Mixed films of PEN and PQ exhibit phase separation and no intercalation was found even at PQ concentrations as low as 2%. Finally, it is shown that O2 and water do not react noticeably with PEN, whereas singlet oxygen and ozone readily oxidize PEN films producing volatile reaction products instead of PQ.

Made available in DSpace on 2017-07-20T12:40:19Z (GMT). No. of bitstreams: 1 Karine Klider.pdf: 4696661 bytes, checksum: 1625309038e6d64e39214301b4f96f7b (MD5) Previous issue date: 2016-07-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this study, we evaluated the optical and electrochemical properties of organic compounds of different types in order to analyze their potential for application active layer in photovoltaic devices. The work was divided into three parts. The first discloses the preparation and characterization of a derivative of 1,8-naphthalimide chromophore prepared from the reaction with a benzonitrile unit (also synthesized and characterized in this work). The BID-NB compound showed optical and electrochemical properties equivalent of the chromophore with optical and electrochemical band gap of 3.41 eV and 2.19 eV. Photovoltaic devices using bilayer architecture, constructed with the compound as the active layer, reached 0.9% of power conversion efficiency (PCE) and a current density at short circuit of 5.68 mA cm-2 by using the C70 fullerene as electron acceptor layer, and 1,8-diiodoocthane as additive in the solution for active layer deposition. The second part the work described the preparation of conjugated molecules (with electron donor acceptor characteristics) from the indigo dye modification by addiction of thiophene units. It was found that increasing number of thiophene units resulted in better opto-electrochemical properties. The molecule that showed the best behavior, DHT-IND, presented optical and electrochemical band gap of 1.64 and 1.45 eV respectively. Despite the low band gap value, the bulk heterojunction (BHJ) solar cell constructed with a 1: 3 mixture of DHT-IND and PC71BM as active layer, showed PCE of 0.7% and current density at short circuit of -4.59 mA cm-2. The fill factor (FF) was 26%. In the third part of this work we evaluated the photocurrent generation by the copolymer PPV/DCN-PPV formed by DCN-PPV chains attached to PPV chain. The evaluation performed as film deposited on a glass substrate containing ITO coated, which has exposed to a LED ilumination. After irradiation the copolymer generated current of A cm-2 (unstable), and -2 A cm-2 (stable). / Neste trabalho foram avaliadas as propriedades ópticas e eletroquímicas de deferentes compostos orgânicos, e analisar suas potencialidades para aplicação como camada ativa em dispositivos fotovoltaicos. Dividiu-se o trabalho em três partes. A primeira revelou a preparação e caracterização de um derivado do cromóforo 1,8-naftalimida, preparado a partir da reação com uma unidade de benzonitrila previamente preparada e caracterizada. O composto 4-(2-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-il)etoxi)-2,5-dimetilbenzonitrila, ou BID-NB, apresentou propriedades ópticas e eletroquímicas equivalentes às do cromóforo, com band gap óptico de 3,41 eV e eletroquímico de 2,19 eV. Dispositivos fotovoltaicos de bicamada foram construídos com o composto BID-NB como camada ativa, sendo que a eficiência máxima de conversão foi de 0,9% com uma densidade de corrente de curto circuito de -5,68 mA cm-2. O dispositivo que auferiu tais resultados foi construído com o fulereno elétron-aceptor C70, e com o auxilio do aditivo 1,8-diiodooctano na deposição da camada ativa. A segunda parte do trabalho consistiu da preparação de moléculas conjugadas do tipo doador/aceptor de elétrons, a partir da modificação do corante índigo com unidades de tiofenos. Constatou-se que o aumento da quantidade de unidades de tiofenos nas moléculas favoreceu suas propriedades opto-eletroquímicas. O composto 7,14-bis(3``,4`-diexil-[2,2`:5`,2``-tertiofen]-5-il)diindolo[3,2,1-de:3`,2`,1`-il][1,5]naftiridina-6,13-diona, ou DHT-IND, foi o que apresentou os menores valores de band gap óptico e eletroquímico, nos valores de 1,64 e 1,45 eV respectivamente. O dispositivo fotovoltaico de heterojunção, construído a partir da mistura 1:3 de DHT-IND e PC71BM como camada ativa, apresentou eficiência de conversão de 0,7% e densidade de corrente de -4,59 mA cm-2. Na terceira parte deste trabalho avaliou-se geração de fotocorrente em um copolímero formado por blocos de PPV ligados a blocos de DCN-PPV (PPV/DCN-PPV). A avaliação foi efetuada na forma de filme sobre um substrato de vidro contendo ITO, o qual foi exposto a iluminação de LED. O copolímero gerou corrente de até -4 A cm-2 (instável), e de -2 A cm-2 (estável) após iluminação.

This thesis focuses on the synthesis, properties and applications of two types of contorted organic molecules: contorted molecular ribbons and conjugated corrals. We utilized the power of reaction chemistry to writing information into conjugated molecules with contorted structures and studied “structure-property” relationships. The unique properties of the molecules were expressed in electronic and optoelectronic devices such as field-effect transistors, solar cells, photodetectors, etc. In Chapter 2, I describe the design and synthesis of a new graphene ribbon architecture that consists of perylenediimide (PDI) subunits fused together by ethylene bridges. We created a prototype series of oligomers consisting of the dimer, trimer, and tetramer. The steric congestion at the fusion point between the PDI units creates helical junctions, and longer oligomers form helical ribbons. Thin films of these oligomers form the active layer in n-type field effect transistors. UV−vis spectroscopy reveals the emergence of an intense long-wavelength transition in the tetramer. From DFT calculations, we find that the HOMO−2 to LUMO transition is isoenergetic with the HOMO to LUMO transition in the tetramer. We probe these transitions directly using femtosecond transient absorption spectroscopy. The HOMO−2 to LUMO transition electronically connects the PDI subunits with the ethylene bridges, and its energy depends on the length of the oligomer. In Chapter 3, I describe an efficiency of 6.1% for a solution processed non-fullerene solar cell using a helical PDI dimer as the electron acceptor. Femtosecond transient absorption spectroscopy revealed both electron and hole transfer processes at the donor−acceptor interfaces, indicating that charge carriers are created from photogenerated excitons in both the electron donor and acceptor phases. Light-intensity-dependent current−voltage measurements suggested different recombination rates under short-circuit and open-circuit conditions. In Chapter 4, I discuss helical molecular semiconductors as electron acceptors that are on par with fullerene derivatives in efficient solar cells. We achieved an 8.3% power conversion efficiency in a solar cell, which is a record high for non-fullerene bulk heterojunctions. Femtosecond transient absorption spectroscopy revealed both electron and hole transfer processes at the donor-acceptor interfaces. Atomic force microscopy reveals a mesh-like network of acceptors with pores that are tens of nanometers in diameter for efficient exciton separation and charge transport. This study describes a new motif for designing highly efficient acceptors for organic solar cells. In Chapter 5, I compare analogous cyclic and acyclic π-conjugated molecules as n-type electronic materials and find that the cyclic molecules have numerous benefits in organic photovoltaics. We designed two conjugated cycles for this study. Each comprises four subunits; one combines four electron-accepting, redox-active, diphenyl-perylenediimide subunits, and the other alternates two electron-donating bithiophene units with two diphenyl-perylenediimide units. We compare the macrocycles to acyclic versions of these molecules and find that, relative to the acyclic analogs, the conjugated macrocycles have bathochromically shifted UV-vis absorbances and are more easily reduced. In blended films, macrocycle-based devices show higher electron mobility and good morphology. All of these factors contribute to the more than doubling of the power conversion efficiency observed in organic photovoltaic devices with these macrocycles as the n-type, electron transporting material. This study highlights the importance of geometric design in creating new molecular semiconductors. In Chapter 6, I describe a new molecular design that enables high performance organic photodetectors. We use a rigid, conjugated macrocycle as the electron acceptor in devices to obtain high photocurrent and low dark current. We directly compare the macrocyclic acceptor devices to an acyclic control device; we find that the superior performance of the macrocycle originates from its rigid, conjugated, and cyclic structure. The macrocycle’s rigid structure reduces the number of charged defects originating from deformed sp2 carbons and covalent defects from photo/thermo-activation. With this molecular design we are able to suppress dark current density while retaining high responsivity in an ultra-sensitive non-fullerene organic photodetector. Importantly, we achieve a detectivity of ~10^14 Jones at near zero bias voltage. This is without the need for extra carrier blocking layers commonly employed in fullerene-based devices. Our devices are comparable to the best fullerene-based photodetectors, and the sensitivity at low working voltages (< 0.1 V) is a record for non-fullerene OPDs.

In recent years, the study of stimulated emission from and by biological systems has gained wide spread attention as a promising technology platform for novel biointegrated laser. However, the photonic properties and the associated physics of many biological laser systems are not yet fully understood and many promising resonator architectures and laser classes have not yet transitioned into the biological world. In this thesis, we investigate the fundamental photonic properties of lasers based on single biological cells and explore the potential of distributed feedback (DFB) gratings as novel biointegrated laser resonators. We show how the easy and flexible fabrication of DFB resonators helps to realize optofluidic and solid-state biological lasers. Lasing characteristics, such as tunable and single mode emission, are investigated and different applications are explored. Fourier-space emission studies on different biological lasers give insight in to the photonic dispersion relation of the system and the fundamental creation of lasing modes and their confinement in living systems. The first purely water based optofluidic DFB laser is demonstrated and novel sensing applications are suggested. This device shows low threshold lasing due to an optimized mode shape, which is achieved by a low refractive index substrate and the use of a mixed-order grating. Next, by integrating a high refractive index interlayer on a DFB resonator, a laser device incorporating the novel solid-state biological gain material green fluorescent protein (GFP) is realized. Lastly, we show how the thickness of organic polymer lasers can be reduced to its fundamental limit (< 500 nm) and the resulting membrane like laser devices can be applied to and operated on various body parts to potentially complement biometric identification.

In the past decade, tremendous progress has been made in organic field effecttransistors. Fused oligothiophenes and anthracene molecules are fascinatingmacromolecules having unique optoelectronic properties. These compounds are successfully employed as active components in optoelectronic devices including field effect transistors. Our goal is to design and synthesize conjugated molecular materials, which are highly functionalized through structural modifications in order to enhance their electronic, photonic, and morphological properties. The main desire is to synthesize novel organic fused-arenes having efficient charge carrier mobilities, as well as to optimize optical properties for organic field effect transistors (OFETs). Novel series of fused arene molecules of 9,10-di(thiophen-3-yl)anthracene (1), trans-2,5-(dianthracene-9- vinyl)thiophene (2), trans-5,5’-(dianthracene-9-yl)vinyl)- 2,2’-bithiophene (3), 5,5’-di(2 thiophene)-2,2’-bithiophene (4) , 9,10-(divinyl)anthracene core with 1- phenylcarboxypyrene (6) and polymers of poly(anthracene-co-bithiophene) (5) and poly(anthracene) (7) have been synthesized as promising materials for organic field effect transistors (OFETs). These compounds were confirmed and characterized by 1H-NMR, FT-IR, and elemental analysis. Their optical, thermal, and electronic properties were investigated using UV-Vis and photoluminescence spectroscopy, and thermogravimetric analysis respectively. Future studies will focus on evaluating OFETs performance of these material.