Transient Extreme Ultraviolet Measurement of Element-Specific Charge Transfer Dynamics in Multiple-Material Junctions

摘要

The absorption of solid state materials in complex photonic and optoelectronic devices overlap in the visiblespectrum. Due to the overlap of spectral features, ultrafast measurements of charge carrier dynamics andtransport is obscured. Here, the element specificity of transient extreme ultraviolet (XUV) spectroscopy isadvanced as a probe for studying photoexcited charge transport in multiple-material junctions. The core-holeexcited by the XUV transitions also imparts structural information on to the probed electronic transition.Transient XUV can therefore measure electron and averaged phonon dynamics for each elemental species in ajunction. Application to polaron measurement in α-Fe_2O_3, valley-specific scattering in Si, and charge transfer in ananoscale Ni-TiO_2-Si junction will be discussed.