In this thesis, the optoelectronic transport at the surface of three-dimensional topological insulators is investigated by photocurrent microscopy. Employing time-resolved photocurrent spectroscopy, we show that surface currents in the topological insulator Bi₂Se₃ can be controlled by circularly polarized light on a picosecond timescale at room temperature. Furthermore, we study the influence of intrinsic local potential fluctuations on the optoelectronic transport in Bi₂Se₃ and BiSbTe₃ films grown by molecular beam epitaxy.     «

In this thesis, the optoelectronic transport at the surface of three-dimensional topological insulators is investigated by photocurrent microscopy. Employing time-resolved photocurrent spectroscopy, we show that surface currents in the topological insulator Bi₂Se₃ can be controlled by circularly polarized light on a picosecond timescale at room temperature. Furthermore, we study the influence of intrinsic local potential fluctuations on the optoelectronic transport in Bi₂Se₃ and BiSbTe₃ films gr...     »