A collection of 4,10-chrysene derivatives was prepared via the BHQ (Bull-Hutchings- Quayle) reaction, their electronic and morphological properties analysed and assessed for suitability as organic semiconductor (OSC) materials. Larger polycyclic aromatic hydrocarbons (PAHs) such as benzo[k]tetraphenes and dinaphtho[1,2,-b:1',2'- k]chrysenes were then prepared and similarly characterised. An acene-based OSC material TMTES-pentacene was also prepared. It is proposed that non-linear PAH- based OSC materials may provide an alternative to popular acene-based materials; offering advantages in stability, diversity and handling.

L’organique électronique, qui repose sur l’utilisation de molécules et macromolécules fi-conjuguées comme semi-conducteurs dans divers dispositifs électroniques, connaît un essor considérable depuis une vingtaine d’années. L’utilisation de molécules organiques octroie de nombreux avantages vis-à-vis du silicium actuellement largement utilisé comme semi-conducteur. Citons par exemple la facilité de mise en oeuvre et la flexibilité méca- nique. La synthèse de nouvelles structures moléculaires est un axe important pour la mise au point de semi-conducteurs organiques plus performants mais aussi pour fournir les systèmes physiques nécessaires à la compréhension des processus physico-chimiques inhérents au transport de charges. Le paramètre primordial pour déterminer la qualité des semi-conducteurs est la mobilité des charges (μ), soit l’efficacité avec laquelle les charges se déplacent au sein des matériaux pi-conjugués. Il n’est pas impossible, qu’un jour, les performances des semi-conducteurs organiques dépassent celles du silicium en raison de la grande diversité de structures moléculaires accessibles via la synthèse organique. Le contrôle de la dimensionnalité de la structure électronique dans les solides organiques moléculaires est crucial pour le développement des dispositifs électroniques organiques à hautes performances. La dimensionnalité correspond au nombre de dimensions de l’espace (1D, 2D, 3D) dans lesquelles les charges peuvent se déplacer, plus celle-ci sera faible, plus le transport de charges sera sensible aux défauts. Dans ce contexte, nous nous sommes basés sur l’étude menée par Schweicher et al. sur le 2,7-di-tert-butyl[1]benzothiéno[3,2- b]benzothiophène, présentant une dimensionnalité des propriétés du transport de charges proche de deux. Ce travail repose sur la synthèse et la caractérisation de semi-conducteurs moléculaires sur base du [1]benzothiéno[3,2-b]benzothiophène (BTBT) dans le but d’augmenter la dimensionnalité du transport de charges. Pour ce faire, différents groupements aromatiques mais également plusieurs substituants dont le tert-butyle ont été greffés au BTBT. Ce travail a permis de voir que la relation structure-propriétés est difficilement prédictible mais il s’avère que la présence des groupements tert-butyles permet d’augmenter la dimensionnalité dans la plupart des cas. Cependant, lorsque des groupements 2-méthylnonyles sont utilisés à la place des tert-butyles, la structure cristalline des semi-conducteurs présentent généralement du désordre structural, néfaste aux propriétés du transport de charges. Du polymorphisme a aussi été décelé pour quelques semi-conducteurs munis de chaînes octyles. En plus de différents substituants, des groupements aromatiques ont été greffés au BTBT tels que des phényles, des thiényles, des bithiényles et également une unité BTBT pour former le dimère. Contre toute attente, l’allongement du système pi n’a pas conduit à la diminution du potentiel d’ionisation. Néanmoins, l’ajout de longues chaînes alkyles induit le rapprochement spatial des systèmes conjugués au sein de la maille cristalline, octroyant aux semi-conducteurs un potentiel d’ionisation plus faible ainsi que des intégrales de transport plus élevées, propices au transport de charges. Ce travail a permis également de faire une étude préliminaire du transport de charges au sein de monocristaux sur trois semi-conducteurs dont deux nouvellement synthétisés. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Quantum coherence plays a vital role in the excitonic properties of organic semiconductors. Several theoretical and experimental studies have shown an unprecedented role of coherence in charge transfer and transport processes, which in turn can improve the performance of electronic devices. Specifically, an enhancement of exciton coherence size can result in fast energy transport and efficient charge separation. The ability to tailor the design and performance of organic electronics based on exciton coherence effects represents the possibility of ultrafast electronic applications in communication and information technology. The objective of this thesis is the excitonic coherence studies of 1D crystalline thin films of phthalocyanine-based organic semiconductors using steady-state and time-resolved photoluminescence spectroscopy (TRPL). One of the main focuses of this work is on investigating the correlation of intermolecular interactions, $\pi$ orbital overlap and dynamic disorders on the excitonic coherent behaviors in crystalline thin films of various phthalocyanine derivatives (i.e. H$_2$TPP, H$_2$OBPc, H$_2$OCPc, and H$_2$OBNc). Specifically, coherence lengths, exciton-phonon coupling strengths and the nearest neighbor (NN) interaction strengths are determined via: (1) the PL ratio of the excitonic coherence transition and its first vibrational replica and (2) the temperature evolution of radiative recombination lifetimes of coherent excitons. This study showed that the optimum coherence size and the robustness of excitonic coherence can be achieved by a complex interplay between NN interaction, vibrational energies and the coupling to vibrational modes. In particular, it is shown that the shortest NN distance does not ensure the achievement of maximum coherence length within the four investigated phthalocyanine species. Instead, the largest coherence length is measured in the octabutoxy derivative, where the saddle shape of the molecule and crystalline packing results in weaker coupling to the acoustic phonons modes despite having larger intermolecular NN distance. In addition, the effect of static and dynamic disorders on the behavior of exciton coherence is explored by alloying two phthalocyanine derivatives that are close in band gap energies and possess large coherence lengths, H$_2$OBPc and H$_2$OBNc. This study demonstrated the successful tuning of exciton coherence lengths and excitonic parameters in organic analogues of semiconductor alloys, H$_2$OBNc$_x$H$_2$OBPc$_{1-x}$. Furthermore, the correlation of exciton-phonon coupling and radiative recombination rate of coherent excitons with increasing alloy concentration or static disorders are successfully revealed.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20933号 / 理博第4385号 / 新制||理||1630(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 長谷川 健, 教授 倉田 博基, 教授 小野 輝男 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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Der Schwerpunkt dieser Arbeit liegt auf der Simulation, Entwicklung und Realisierung organischer Halbleiterbauelemente für Anwendungen im Bereich der Sensorik. Unter dem Gesichtspunkt der Fertigung sollen die organischen lichtemittierenden Dioden (OLEDs) und die organischen Photodioden (OPDs) einfach konzeptioniert sein. Je nach Bauelementetyp stehen für die Herstellung der organischen Schichten die Vakuumtechnologie oder lösungsmittelbasierte Prozesse zur Verfügung. Eine Besonderheit der Arbeit ist die Integration der OLEDs bzw. der OPDs auf Silizium-Substraten. Zudem wird die Integration von optischen Filtern für die OLEDs sowie die Etablierung einer Dünnschichtverkapselung für die OLEDs und OPDs gezeigt. Im ersten Teil der Arbeit wird anhand von Simulationen der Dünnschichtoptik erarbeitet, welche Möglichkeiten vorhanden sind, die Charakteristik der OLEDEmission bzw. die Absorptionseigenschaften der OPDs zu beeinflussen. Die Besonderheit der OLEDs für die Sensorikanwendungen liegt hierbei in der Licht-Emission mit geringen Halbwertsbreiten. Es wird anhand von Fluoreszenzmarkern (Rhodamin 6G und Nah-IR Alzheimer Farbstoff-4) und einem Chromoprotein (PAS-GAF-64) verdeutlicht, welche Möglichkeiten für die Sensorik durch die Anregung mit der OLED bestehen. Für die OPDs hingegen wird gezeigt, welche Möglichkeiten es für das Rodamin 6G gibt, mit dielektrischen Spiegeln die Absorptionseigenschaften so zu beeinflussen, dass die gewünschten spektralen Bereiche des Lichtes absorbiert bzw. reflektiert werden. Der zweite Teil widmet sich der Entwicklung der OLEDs anhand der Integrationsmöglichkeiten der dielektrischen Filter sowie deren Optimierung. Es wird am Beispiel des Rhodamin 6G gezeigt, dass für die OLED-Emission eine Halbwertsbreite von 18 nm beim Maximum von 530 nm hat. Durch die Verwendung von Entlastungsschichten zwischen OLED und dielektrischem Spiegel können die Kennwerte der OLED positiv beeinflusst werden und weiterhin werden das Temperaturverhalten der OLEDs sowie die Verspannungseigenschaften der dielektrischen Schichten betrachtet. Darüber hinaus steht im dritten Teil die Entwicklung der organischen Photodioden im Fokus. Hierbei wurden OPDs auf Glas- und Siliziumsubstraten gefertigt. Inhalt der Entwicklung auf Glassubstraten ist die Variation der absorbierenden Schicht und deren Einfluss auf die elektro-optischen Eigenschaften. Die Entwicklung der OPDs auf Siliziumsubstraten basiert auf der Integration sowie der Optimierung verschiedener Absorbersysteme, einer alternativen Anode und Kathode sowie der Integration einer Dünnschichtverkapselung. Im Ergebnis wurden OPDs entwickelt, die ohne Dünnschichtverkapselung einen Photonen-zu-Elektron-Umwandlungs-wirkungsgrad (IPCE) von ca. 37 % bei 550 nm haben. Der IPCE konnte zudem durch die Modifikation des Kathodenaufbaus um 4 % gesteigert werden. Die OPD-Bauelemente mit integrierter Dünnschichtverkapselung zeigen einen IPCE von ca. 33 % bei 550 nm. Weiterhin wurde die Methode der orthogonalen Photolithographie zur Strukturierung der OPDs verwendet und es erfolgte der Übertrag der OPD-Technologie auf 8-Zoll-Halbleitersubstrate. In diesem Zusammenhang sind zur Bewertung von Einflüssen, wie Wasser oder Sauerstoff, Untersuchungen zur Lebensdauer der OPDs durchgeführt worden. Die Kenntnis über den Einfluss der orthogonalen Photolithographie auf die Kennwerte der OPDs sowie der Einfluss der Dünnschichtverkapselung auf die Eigenschaften der OPDs und OLEDs sind essentiell für weitere Entwicklungen und zur Fertigung von Sensoranwendungen. / This work focuses on the simulation, development and implementation of organic semiconductor devices for applications in the field of sensor technology. From the viewpoint of manufacturing, organic light emitting diodes (OLEDs) as well as organic photodiodes (OPD) should be designed simply. Depending on the type of device vacuum technology or solvent-based processes are available for producing organic layer. A special feature of OLED- and OPD-devices is the integration on silicon substrates. In addition, the integration of optical filters for OLED-devices and the thin-film encapsulation of OLEDs and OPDs is shown. The first part of the work elaborates on simulations of thin film optics, describing options to control the characteristics of the OLED-emission or the absorption properties of the OPD. A special characteristic of OLEDs is the light emission with a small full with half maximum for sensor applications. By using of fluorescent markers Rhodamine 6G and near-IR dye Alzheimer-4 or the Chromoproteins (PAS-GAF-64) clarifies the possibilities for sensors by excitation with the OLED. In contrast, for the OPD is shown which solutions are available, to influence the absorption properties of Rhodamin 6G with dielectric mirrors so that desired spectral ranges of light are absorbed or reflected. The second part is dedicated to the development of OLEDs based on integration of dielectric filters and their optimization. It is shown by the example of Rhodamine 6G that the OLED emission represents a full with at half maximum of 18 nm at 530 nm. Furthermore, the temperature behavior of the OLEDs and the strain properties of the dielectric layers are considered. Organic photodiodes are in the focus of the third part of the development. These OPDs were made on glass and silicon substrates. The main objective of the development on glass substrates is the variation of the absorption layer and its influence to the electro-optical properties to increase the spectral sensitivity of the OPD. The development of OPD on silicon substrates deals with the integration and optimization of different absorber systems, an alternative anode and cathode as well as the integration of a thin-film encapsulation. As a result, the OPDs without a thin-film encapsulation have an incident photon-to-electron conversion efficiency (IPCE) of about 37 % at 550 nm. The IPCE was increased to 4 % by modifying the cathode structure. The OPD devices with integrated thin-film encapsulation showed an IPCE of about 33 % at 550 nm. Furthermore, the method of orthogonal photolithography was used to pattern the OPD and an upscaling of the OPD technology to 8-inch semiconductor substrates have been realized. In this context studies have been carried out to evaluate the influence of process and encapsulation to the lifetime of OPDs. The knowledge about the influence of the orthogonal photolithography to the characteristics of OPDs and the influence of the thin-film encapsulation on the properties of OPD and OLEDs is essential for further development and for the manufacturing of sensor applications.

The creation of organic electronics is not only an attractive replacement for amorphous silicon devices, but offers the ability to produce novel technologies such as flexible displays and chemical or biological sensors. Control of the semiconducting film for such devices is of great importance. The fabrication of monolayer devices of a high performance offer a desirable way of creating high sensitivity sensors. Achieving a high level of performance for ultra-thin and monolayer devices, where the charge transport layer is effectively the thickness of the film, requires the careful control of deposition conditions. Thin films of the molecule 5,5'-bis(4-n-hexylphenyl)-2,2'-bithiophene (PTTP) were investigated with respect to their crystal structure, growth dynamics and device performance. Optimised conditions led to the highest reported performance for PTTP, to the best of our knowledge, with mobilities greater than 0.1 cm2V-1s-1. These results allowed the creation of monolayer and multilayer devices, resulting in a saturation thickness of approximately 2.1 monolayers, where the bulk performance was reached. This confirmed the presence of the conduction channel within the first few monolayers and could potentially lead to an optimised device for chemical or biological sensing. The development of a solution processed method for creating monlayers of PTTP was also investigated. Creating a compound with the ability to self assemble on a surface, allowing a controlled monolayer to form, involved the use of a trichlorosilane anchoring group attached to a PTTP core by an alkyl spacer. Solution processed self assembled monolayer field effect transistors (SAMFETs) were formed in less than 10 hours, reaching mobilities as high as 1.7 X 10-2 cm2V-1s-1 . This simple method for creating transistors could further the use of monolayer devices in sensing applications and integrated circuits. Furthermore, the development of solution processed PTTP was undertaken. By blending the small molecule with the insulating polymer PMMA, phase separation of the components led to the creation of thin, crystalline films of PTTP. Working devices were fabricated that required as little as 0.05 \% w/v of the small molecule. This attractive method, of reducing the required material and combination of both insulating and semiconducting components, is a versatile approach to greatly simplify the device processing steps required.

There has been a remarkable progress in the development of organic electronic materials since the discovery of conducting polymers more than three decades ago. Many of these materials can be processed from solution, in the form as inks. This allows for using traditional high-volume printing techniques for manufacturing of organic electronic devices on various flexible surfaces at low cost. Many of the envisioned applications will use printed batteries, organic solar cells or electromagnetic coupling for powering. This requires that the included devices are power efficient and can operate at low voltages. This thesis is focused on organic thin-film transistors that employ electrolytes as gate insulators. The high capacitance of the electrolyte layers allows the transistors to operate at very low voltages, at only 1 V. Polyanion-gated p-channel transistors and polycation-gated n-channel transistors are demonstrated. The mobile ions in the respective polyelectrolyte are attracted towards the gate electrode during transistor operation, while the polymer ions create a stable interface with the charged semiconductor channel. This suppresses electrochemical doping of the semiconductor bulk, which enables the transistors to fully operate in the field-effect mode. As a result, the transistors display relatively fast switching (≤ 100 µs). Interestingly, the switching speed of the transistors saturates as the channel length is reduced. This deviation from the downscaling rule is explained by that the ionic relaxation in the electrolyte limits the channel formation rather than the electronic transport in the semiconductor. Moreover, both unipolar and complementary integrated circuits based on polyelectrolyte-gated transistors are demonstrated. The complementary circuits operate at supply voltages down to 0.2 V, have a static power consumption of less than 2.5 nW per gate and display signal propagation delays down to 0.26 ms per stage. Hence, polyelectrolyte-gated circuits hold great promise for printed electronics applications driven by low-voltage and low-capacity power sources.

[pt] O Alq3 é um dos mais importantes semicondutores orgânicos utilizados como transportador de elétrons e emissor em dispositivos eletroluminescentes (OLEDs). Este trabalho apresenta o estudo das propriedades ópticas, eletroquímicas, elétricas e morfológicas de três complexos baseados em íons de terras raras (TR) ligados à 8-hidroxiquinolina (q), Li[TR(q)4] (TR igual a La3mais, Y3mais e Lu3mais). Os espectros de absorção na região UV-Vis possuem máximos em 382nm para os complexos de Y3mais/La3mais e em 388nm para o complexo de Lu3mais. Os espectros de fotoluminescência dos complexos correspondem à emissão da (q) e não exibem as linhas características de emissão dos íons de terras raras. Os dados de analise térmica indicam que os complexos são termicamente estáveis até 325 graus Celsius e que apresentaram H2O absorvida da atmosfera. Os OLEDs fabricados e caracterizados neste trabalho foram de dois tipos: bicamadas e multicamadas.A1)ITO/NPB(25nm)/Li[TR](q)4](40nm)/Al(120nm);A2)ITO/NPB(25nm)/[Eu(DBM)3phen](20nm)/BCP(10nm)/Li[TR(q)4](20nm)/Al(120nm). Os OLEDs bicamadas apresentaram, em seus espectros de eletroluminescência, as bandas de emissão da (q) entre 520 ate 540nm. Os OLEDs multicamadas foram fabricados para testar a eficácia dos complexos Li[TR(q)4] como camadas transportadoras. Este trabalho evidenciou uma interessante dependência entre o pico máximo da emissão eletroluminescente e o raio iônico dos íons de TR. Os OLEDs baseados nos complexos Li[TR(q)4] apresentaram boas características quando comparadas com os OLEDs baseados Alq3, mostrando-se compostos promissores para o desenvolvimento de dispositivos orgânicos. / [en] The Alq3 is one of the most important organic semiconductors used as electron transporting and emitting material in organic electroluminescent devices (OLEDs). This work presents the investigation of the optical, electrochemical, electrical and morphological properties of three complexes based in ions of rare earth (RE) coordinated to 8-hydroxyquinoline (q), Li[RE(q)4] (RE equal La3more, Y3more and Lu3more). The UV-Vis absorption spectrum present the maximum absorption at: 382nm for Y3more/La3more complexes and 388nm for the Lu3more complex. The photoluminescence spectra of the complexes correspond to the emission of the (q) and does no exhibit characteristic lines of the rare earths ions. The thermal analysis data indicate that the complexes are thermally stable until 325 Celsius degrees and that showed H2O molecules absorbed from the atmosphere. The fabricated and characterized OLEDs in this work were of two types: bilayer and multilayer.A1)ITO/NPB(25nm)/Li[TR(q)4](40nm)/Al(120nm);A2)ITO/NPB(25nm)/[Eu(DBM)3phen](20nm)/BCP(10nm)/Li[TR(q)4](20nm)/Al(120nm). The bilayer OLEDs showed, in their electroluminescence spectra, the emission bands of the (q) between 520 until 540nm. The multilayer OLEDs were fabricated to test the efficiency of the complexes Li[TR(q)4] as transport layers. This work showed an interesting dependence between the EL emission peak and the ionic radius of the of RE ions. The OLEDs based on the Li[RE(q)4] complexes presented good characteristics when compared to the OLEDs based on Alq3, showing as promising compounds to the organic devices development.

Organic electronic devices are becoming commonplace in many academic and industrial materials laboratories, and commercial application of these technologies is underway. To maximize our fundamental understanding of organic electronics, a wide array of molecular frameworks is necessary, as it allows for a variety of optical and electronic properties to be systematically investigated. With the ability to further tune each individual scaffold via derivatization, access to a broad spectrum of interesting materials is possible. Of particular interest in the search for organic semiconducting materials are the cyclopenta-fused polyaromatic hydrocarbons, including those based on the fully conjugated indenofluorene (IF) system, which is comprised of five structural isomers. This dissertation represents my recent contributions to this area of research. Chapter I serves as a historical perspective on early indenofluorene research and a review of more current research on their synthesis and applications in organic electronic devices. Chapters II and III cover our early work developing the synthesis of the fully-reduced indeno[1,2-b]fluorene scaffold, with the latter of these chapters showing the first example of its application in an organic electronic device, a field effect transistor. Chapter IV demonstrates the first syntheses of fully-reduced indeno[2,1-c]fluorene derivatives. Chapter V expands our research to encompass isoelectronic heteroatomic derivatives of that same scaffold, introducing the fully-reduced diindeno[2,1-b:1',2'-d]thiophene scaffold and showing that our synthetic methodology also can be used to produce a quinoidal thiophene core. Chapter VI concludes with a review of the similarities between the indeno[2,1-c]fluorene and diindeno[2,1-b:1',2'-d]thiophene molecular architectures and introduces benzo[a]indeno[2,1-b]fluorene derivatives, demonstrating the first example of a fully-reduced indenofluorene that possesses a non-quinoidal core, illustrating that the quinoidal core is not a prerequisite for the strong electron affinities seen across the families of fully-reduced indenofluorenes. This dissertation encompasses previously published and unpublished co-authored material. / 2015-10-10