Synthèse et relation structure-propriétés de copolymères alternés π-conjugués

Tout au long du siècle dernier, l’électronique s’est révélé être un progrès technologique majeur, et ses applications sont tellement nombreuses qu’elles ont envahi notre vie de tous les jours. De par leurs propriétés bien spécifiques, les semi-conducteurs organiques représentent une remarquable alternative aux matériaux inorganiques utilisés actuellement. Cependant, leurs propriétés électriques peuvent être limitées, et l’efficacité des dispositifs composés de tels matériaux ne permet pas encore de rivaliser avec ceux basés sur des matériaux inorganiques. Dans ce contexte, ce travail de thèse a pour objectif de synthétiser et caractériser de nouveaux polymères conjugués et d’étudier leurs propriétés, dans le but d’ajouter de nouveaux matériaux au déjà riche catalogue de polymères semi-conducteurs disponibles, ainsi que de permettre une meilleure compréhension de la relation structure-propriétés dans les systèmes conjugués. Des copolymères alternés composés de motifs carbazole, benzothiadiazole ou encore squaraine ont été synthétisés et caractérisés. De plus, des polymérisations originales et sans catalyseurs métalliques ont été développées.Within the last century, electronics have become a major technological breakthrough and the resulting applications are so numerous that it has invaded our every-day life. Due to their properties, organic semiconductors have attracted much attention and represent a great alternative to the nowadays used inorganic materials. However, their electrical properties can be limited, and the efficiencies of the resulting devices are still not completely competitive against the inorganic-based ones. In this context, this PhD goal was to synthesize novel conjugated polymers (CPs) and investigate their properties, in order to add novel materials to the already wide catalogue of semiconducting polymers and allow a better comprehension of the structure-properties relationship in conjugated systems. Alternated copolymers based on carbazole, benzothiadiazole, or squaraine were synthesized and characterized. Furthermore, original and metal catalyst-free polymerizations were successfully developed

Synthèse et relation structure-propriétés de copolymères alternés π-conjugués

Tout au long du siècle dernier, l’électronique s’est révélé être un progrès technologique majeur, et ses applications sont tellement nombreuses qu’elles ont envahi notre vie de tous les jours. De par leurs propriétés bien spécifiques, les semi-conducteurs organiques représentent une remarquable alternative aux matériaux inorganiques utilisés actuellement. Cependant, leurs propriétés électriques peuvent être limitées, et l’efficacité des dispositifs composés de tels matériaux ne permet pas encore de rivaliser avec ceux basés sur des matériaux inorganiques. Dans ce contexte, ce travail de thèse a pour objectif de synthétiser et caractériser de nouveaux polymères conjugués et d’étudier leurs propriétés, dans le but d’ajouter de nouveaux matériaux au déjà riche catalogue de polymères semi-conducteurs disponibles, ainsi que de permettre une meilleure compréhension de la relation structure-propriétés dans les systèmes conjugués. Des copolymères alternés composés de motifs carbazole, benzothiadiazole ou encore squaraine ont été synthétisés et caractérisés. De plus, des polymérisations originales et sans catalyseurs métalliques ont été développées.Within the last century, electronics have become a major technological breakthrough and the resulting applications are so numerous that it has invaded our every-day life. Due to their properties, organic semiconductors have attracted much attention and represent a great alternative to the nowadays used inorganic materials. However, their electrical properties can be limited, and the efficiencies of the resulting devices are still not completely competitive against the inorganic-based ones. In this context, this PhD goal was to synthesize novel conjugated polymers (CPs) and investigate their properties, in order to add novel materials to the already wide catalogue of semiconducting polymers and allow a better comprehension of the structure-properties relationship in conjugated systems. Alternated copolymers based on carbazole, benzothiadiazole, or squaraine were synthesized and characterized. Furthermore, original and metal catalyst-free polymerizations were successfully developed

Synthesis and structure-properties relationship of alternated π-conjugated copolymers

Within the last century, electronics have become a major technological breakthrough and the resulting applications are so numerous that it has invaded our every-day life. Due to their properties, organic semiconductors have attracted much attention and represent a great alternative to the nowadays used inorganic materials. However, their electrical properties can be limited, and the efficiencies of the resulting devices are still not completely competitive against the inorganic-based ones. In this context, this PhD goal was to synthesize novel conjugated polymers (CPs) and investigate their properties, in order to add novel materials to the already wide catalogue of semiconducting polymers and allow a better comprehension of the structure-properties relationship in conjugated systems. Alternated copolymers based on carbazole, benzothiadiazole, or squaraine were synthesized and characterized. Furthermore, original and metal catalyst-free polymerizations were successfully developed.Tout au long du siècle dernier, l’électronique s’est révélé être un progrès technologique majeur, et ses applications sont tellement nombreuses qu’elles ont envahi notre vie de tous les jours. De par leurs propriétés bien spécifiques, les semi-conducteurs organiques représentent une remarquable alternative aux matériaux inorganiques utilisés actuellement. Cependant, leurs propriétés électriques peuvent être limitées, et l’efficacité des dispositifs composés de tels matériaux ne permet pas encore de rivaliser avec ceux basés sur des matériaux inorganiques. Dans ce contexte, ce travail de thèse a pour objectif de synthétiser et caractériser de nouveaux polymères conjugués et d’étudier leurs propriétés, dans le but d’ajouter de nouveaux matériaux au déjà riche catalogue de polymères semi-conducteurs disponibles, ainsi que de permettre une meilleure compréhension de la relation structure-propriétés dans les systèmes conjugués. Des copolymères alternés composés de motifs carbazole, benzothiadiazole ou encore squaraine ont été synthétisés et caractérisés. De plus, des polymérisations originales et sans catalyseurs métalliques ont été développées

Polyisoprene-based block copolymers as supports for metallocene and post-metallocene catalytic systems toward ethylene polymerization

In this work, we report how micellar structures obtained by the self-assembly in heptane of polyisoprene-block-poly(methyl methacrylate) (PI-b-PMMA) and polyisoprene-block-poly(ethylene oxide) (PI-b-PEO) can be effectively used as organic supports for ethylene polymerization catalyzed by metallocene and post-metallocene catalysts. The self-assembly in heptane of these block copolymers was demonstrated by means of dynamic light scattering and the influence of methylaluminoxane (MAO) on this self-assembly was analyzed. The so-formed assemblies, composed of either PMMA or PEO cores and PI corona, were used as organic supports for metallocene or post-metallocene catalysts with methylaluminoxane (MAO) as an activator, to produce micrometric polyethylene bead

Triaryl-1,4-diamine based polysquaraines: effect of co-solvent and monomer insertion on optoelectronic properties

A series of N1,N4-didodecyl-N1,N4-diphenylbenzene-1,4-diamine based polysquaraines have been synthesized under micro-wave irradiation in the absence of any catalyst. The effect of solvent of polymerization, on the squaric acid catenation (1,2 and 1,3 linkages), has been studied and polysquaraines integrating linear chain in their backbone have been advantageously obtained by using di-functional alcohol during the polymerization. Such obtained polymers exhibit a broad emission with a quantum yield up to 18%. The latter were then tested into OLED devices exhibiting a promising white emission

Synthesis of squaraine-based alternated pi-conjugated copolymers: from conventional cross-coupling reactions to metal-free polycondensation

Low band-gap pi-conjugated copolymers based on squaraine units alternated with thiophene or benzothiadiazole moieties were synthesized through Suzuki and Stille cross-coupling reactions, and through a metal-free polycondensation process using squaric acid. The metal-free polymerizations afforded higher molecular weights polymers, showing bright future for the synthesis of small band-gap pi-conjugated polymers via less cost-effective and more environmental-friendly procedures. Additionally, the synthesized materials showed encouraging optoelectronic properties

Photophysics, electronic structure and solar cell performance of a donor-acceptor poly(N-dodecyl-2,7-carbazole-alt-benzothiadiazole) copolymer

In this contribution, we investigate the optoelectronic properties of a donor-acceptor poly(N-Dodecyl-2,7-carbazole-alt-benzothiadiazole (CBZ-BT) copolymer in solutions and thin films, by a combination of complementary optical and electronic spectroscopy techniques including stationary absorption and fluorescence, femtosecond time-resolved and ultraviolet/x-ray photoelectron spectroscopy. Absorption spectroscopy revealed two bands at 322/338 and 445/475 nm for CBZ-BT in solutions/films attributed to the carbazole and benzothiadiazole groups respectively. Photoexcitation either to the absorption band of the carbazole or benzothiadiazole group led to a broad and structureless fluorescence spectrum due to large torsional disorder in the excited state, originating from intramolecular energy transfer between carbazole and benzothiadiazole. Time resolved spectroscopy in solutions reveals a transient red-shift of the emission spectrum within less than 5 ps due to exciton migration and/or conformational relaxation of the polymer backbone. In films, this relaxation is faster accompanied by a quenching of the exciton lifetime