Electrical conductivity and magnetism at organic single crystal charge transfer interfaces

• Applicant: Yulia Krupskaya, Ph.D.
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 326645892

Direct contact of two initially insulating organic single crystals can cause significant interfacial electrical conductivity and in some cases can even lead to metallic behaviour. It is known that this enhanced conductivity is mediated by the charge transferred from one material to the other; however there still remains an important scientific question: what are the exact physical mechanisms responsible for the charge transfer and the interfacial conductivity in organic materials? Based on this question, we set the first scientific aim of this project as investigation of the charge transfer and conductivity at organic single crystal interfaces in order to understand the physical mechanisms. On the other hand, our recent study has shown that the charge transfer responsible for the enhanced electrical conductivity at F16CoPc/Rubrene interface involves Co centres of F16CoPc molecules that leads to a change in Co spin. Such an involvement of metal ions into the charge transfer opens a possibility to simultaneously control magnetism and charge transport at organic interfaces. Motivated by this result, we set the second scientific aim of this project as investigation of organic charge transfer interfaces involving magnetic metal-organic molecules in order to understand the interfacial physical processes and to find a connection between charge transport and magnetism. To achieve these aims, we plan to grow high quality organic single crystals, build organic single crystal charge transfer interfaces, as well as interfaces involving magnetic metal-organic molecules and study their charge transport and magnetic properties.

• DFG Programme: Research Grants
• Co-Investigators: Professor Dr. Bernd Büchner; Professor Dr. Karl Leo