UHMob · Ultra-high Charge Carrier Mobility to Elucidate Transport Mechanisms in Molecular Semiconductors

Ultra-high Charge Carrier Mobility to Elucidate Transport Mechanisms in MolecularSemiconductors

Organic electronics is an active field of research that aims to complement silicon with organic semiconductors. The former is energy- and cost-intensive, whereas the latter are cheap to produce and allow additive manufacturing of electronic circuits. The UHMob project objective was twofold. On the one hand, the project aimed to design, synthesise, and assess the performance of a novel generation of organic semiconductors (OSCs) creating a favourable environment for industrial innovations. On the other hand, UHMob delivered the finest quality research training and transfer of knowledge in an interdisciplinary, inter-sectoral, and emerging supra-disciplinary field, to 15 early-stage-researchers (ESRs) to educate them to become future scientific leaders. After 4,5 years of research, UHMob has achieved its objectives by contributing to advancing the field of organic electronics in developing molecular semiconductors with improved charge transport characteristics for unprecedented industrial applications. It has notably been found that chiral OSCs exhibit a surprisingly large magnetoresistance, allowing organic field effect transistors to be switched on/off by an external magnetic field in addition to the usual electric field, paving the way to a double binary computer logics. The charge carrier mobility, which is the figure of merit of semiconductors, remains on the order of 20 cm2/V.s. Thanks to the elucidation of the charge transport mechanism within organic semiconductors performed by a joint spectroscopic and theoretical study, it is now better understood that it is an intrinsic limitation to this class of materials. The inherent sensitivity of charge transport towards ambient conditions was exploited for fabricating state-of-the-art humidity sensors. UHMob also contributed to the general understanding of polymorphism, i.e., the existence of more than crystal form for a given compound. The results obtained on the crystallization of organic semiconductors are transposable to active pharmaceutical ingredients for which polymorphism often determines the therapeutic action mode. Finally, UHMob has explored the revolutionary concept of the coupling of the energy levels of the molecules with quantized states of vacuum. This concept holds great promise for selectively controlling chemical reactivity by external means and thus offers multiple opportunities for chemical process improvements. To reach these goals, academic and industrialist research groups from Belgium (ULB, UMONS), UK (UCAM), France (UNISTRA), Austria (TUGRAZ), Germany (BASF, UBER, MPG), Spain (CSIC), Italy (Polycrystalline) and Japan (KU) selected for their scientific and technological excellence in the field, teamed up to form a world-leading consortium to contribute to the research and training programme. UHMob 15 ESRs could thus take part in a total of 150 trainings delivered by the project and their hosted organisations on different transferable skills and technical aspects of their PhD research. Besides, more than 30 secondments were organized, enabling ESRs to learn complementary techniques. In parallel, ESRs presented their research results in numerous conferences and publications (shorturl.at/rINQX), while additional papers are still being prepared. Finally, ESRs post-graduated since 2022 already joined a research group in their field of research while the majority of ESRs will defend their PhD programme in 2024.

Data: CORDIS, © European Union