Spin-Dependent Processes at Electrodes Detected by Simultaneously Performed EPR, Electrochemistry and EDMR

The electrically detected magnetic resonance (EDMR) results presented in this thesis demonstrate a spin dependence of the charge transfer between an electrode and an electrolyte. These results were found using simultaneous detection of continuous wave electron paramagnetic resonance (CW EPR), EDMR and cyclic voltammetry. The electrochemical cell was located inside a microwave cavity and the electrolyte was saturated withmethyl viologen radicals. Electrodes were either spin polarized using optical spin-pumping in p-GaAs or electrodes functionalized with chiral self-assembled monolayers. Sample preparation and characterization are presented in depth. The measurement and evaluation schemes for combined cyclic voltammogram sweeps and stepwise magnetic field scans are discussed. The resulting detection of spin dependent charge transfer at a spin polarized electrode/electrolyte interface is demonstrated and quantified. The magnitude of this effect is compared with the one observed when using chiral molecules. This brings confirmation of a chirality induced spin selectivity (CISS) effect, based on an experiment in which the spins are excited selectively by magnetic resonance.