Low-energy electron microscopy (LEEM) uses an electron optics similar to a standard transmission electron microscope (TEM). In contrast to TEM, the high-energy electrons are decelerated to a few electron volts in front of the sample. Because of the low penetration depth of such electrons they are diffracted at the sample surface, after which they are re-accelerated in the electron optics. The method gives real-space images of surfaces with a resolution of the order of 10 nm. Time-dependent processes can also be monitored. Photo-emitted electrons can also be used for imaging by the same apparatus (PEEM). We use these methods in the DFG-funded priority programm SPP 1459 "Graphene" in collaboration with T. Seyller (TU Chemnitz). They are also applied in a joint project with S. Günther (TUM) and A. Locatelli (ELETTRA, Trieste).
Movie to appear soon.