Master degree in Materials Science

Photo-initiated charge transfers are central in any process of energy conversion, such as photovoltaics and artificial photosynthesis. The resulting charges – an electron and a hole – are characterised by a spin quantum number S = ½ and can be selectively investigated with Electron Paramagnetic Resonance (EPR) spectroscopy. This experimental thesis will look at the early stages of the charge separation event using Time-Resolved EPR spectroscopy (TR-EPR). TR-EPR monitors the time dependence of paramagnetic species formed upon light irradiation with time resolution of ns and provides a new tool to examine the fate of such species, to name but a few: where they are formed, which sites act as traps or how they travel through the solid. The technique brings together the selectivity of EPR towards paramagnetic species and the time-dependence typical of fast optical spectroscopy