Imaging of light induced carrier transport

Abstract

Imaging of carrier transport is possible due to contactless carrier<br />excitation by means of a small light spot or an electron beam. Besides of<br />electronic transport these techniques allow in addition to investigate other<br />material properties. This is due to the photo-thermoelectric excitation<br />mechanism by illumination and heating. This allows not only the<br />investigation of (thermo-) electric transport but also the imaging of<br />phonon, heat and photo-electric transport. The particles can be<br />distinguished by their reaction upon the application of a magnetic field and<br />by different detection mechanisms.<br /><br />Different kinds of materials have been investigated in different crystal<br />orientations and magnetic field geometries: Such are different types of<br />metals including superconductors, semiconductors in two-dimensional and<br />three-dimensional geometry, intercrystalline boundaries and multi-layer<br />systems. This led to the observation of several new phenomena. Such are<br />Light Induced Electron Focusing (LIEF) at zero magnetic field, Light Induced<br />Transverse Electron Focusing (LITEF), Light Induced Longitudinal Electron<br />Focusing (LILEF), Electron Beam- Induced Electron Focusing (EBIEF),<br />Light Induced Sondheimer Oscillations (LISO), Light Induced Gurevich<br />Oscillations (LIGO), Light Induced Magneto-quantum Oscillations (LIMO) and<br />Light-induces Shubnikov-de Haas oscillations (LISHO). A lot of features have<br />been simulated numerically and the theoretical work mostly allowed to<br />reproduce the experimental data.