Abstract: A large diversity of π-systems exists, nearly all transport electrical charges but only a few molecular structures qualify as best-performing organic semiconductors with μ ≥ 10 cm2/V.s. But charge carrier mobility is more a material than a molecular property. One has, thus, to consider supramolecular order at all length-scales. The best organic semiconductors self-organize into large plate-like single crystals as evidenced in recent papers. Due to their electronic properties but also to their favourable crystalline morphology, thienoacenes derivatives exhibit record charge carrier mobility above 10 cm2/V.s. I will report my latest results on the molecular and supramolecular engineering of novel semiconductors, including: design by theory, synthesis, crystal engineering, calculation and observation of crystal morphology, and processing into single crystal thin films for transistor fabrication. A particular attention will be devoted to the preservation of coherent charge transport via the design of organic semiconductors that are disorder resilient. Finally, I will present chiral organic semiconductors that exhibit a large magnetoresistance.
Bio: Yves Geerts had the chance to be among the first Erasmus students in the eighties. He went to Strasbourg, France, to conduct an undergraduate research project, supervised by the Nobel Laureate Jean-Pierre Sauvage. After working on polymer tribology for DSM, in the Netherlands, he started doctoral researches on the morphology of polymer blends under the supervision of Georges Geuskens. He obtained from ULB his doctoral title in Sciences with summa cum laude, in 1993. Attracted by synthetic polymer chemistry, he was postdoc at the Max-Planck-Institute for Polymer Research in Mainz with Klaus Müllen and at Massachusetts Institute of Technology under the supervision of the Nobel Laureate Richard Schrock. During this period, Yves Geerts was involved in the synthesis of polycatenanes, block copolymers, conjugated oligomers and discotic liquid crystals.
In 1997, he accepted a tenured position of research associate of the National Fund for Scientific Research (FNRS). Since 1999, he is professor of chemistry and the head of the Laboratory of Polymer Chemistry. Soon after, he started to be active at the European level with the coordination of the FP5-DISCEL project (2001-2004) that was followed by the FP6-NAIMO project (2004-2008) to which 22 industrial and academic partners contributed and that generated 360 publications, 12 patents, and 2 industrial technologies. Then, he has coordinated the FP7-ONE-P project (2009-2011) project that has put together 28 industries, universities and research centers to implement a coherent work plan aiming at developing the missing materials for the industrialization of organic electronics in Europe. Currently, he is coordinating two Marie Sklodowska Curie projects UHMob (2019-2023) and CISSE (2023-2026). His scientific interests include the design, the synthesis and the characterization of novel organic materials to study spin, charge, and heat transport, as well as non-equilibrium phenomena, chiral-induced spin selectivity (CISS) effect, and chiral symmetry breaking.