Periodic Reporting for period 1 - TherSpinMol (Exploring Thermoelectric and Spintronic properties of Molecular Devices)
Periodo di rendicontazione: 2017-10-01 al 2019-09-30
TherSpinMol aimed at developing the first molecular thermoelectric devices and discovering new strategies to improve their efficiency. Furthermore, the project worked towards establishing the experimental foundations for molecular spin-caloritronics.
The project has fundamental and applicative significance, aiming at exploring both the physics background of thermoelectric power generation on the single-molecular level and novel ways to create pure spin-currents and their perspective applicability for the reduction of energy consumption in logic elements and energy harvesting.
What is more, a new and highly scalable method to contact single molecules was developed in collaboration with KTH Royal Institute of Technology (published in Nature Communications).
For thermoelectric characterisations of single molecules an ultra-efficient on-chip microheater was developed which can thermally bias single molecules using very low heating powers (published in Applied Physics Letters). This makes the newly developed junctions compatible with very low cryogenic temperatures necessary for detailed thermoelectric characterisations. Using gold as electrode material a high yield of molecular junction formation was achieved. The detailed studies of the thermoelectric properties of single molecules at cryogenic temperatures gave insight into the role of electron-phonon coupling (publication in preparation) or strong correlations like the Kondo regime (publication in preparation) on the thermoelectric efficiency of the device.
Furthermore, I developed a new strategy to fabricate all-graphene thermocouples. These thermocouples can act as ultra-sensitive local thermoemeters which achieve a temperature resolution down to a few tens of µK and have a foot-print on the order of only 1µm. This would make it possible to fabricate about 200 temperature sensors around the circumference of a human hair, or about 100 sensors below the area of a human cell and could pave the way for controlled local temperature management in biological systems to e.g. fight cancer cells.