NanoESCA III

Energy Filtered Photoemission Electron Microscopy (PEEM)

The PEEM mode maps the sample surface through photoelectrons. Photon energies can be in either the UV or the X-ray range. Due to its wide range of accessible photon energies for PEEM operation, the NanoESCA III can map either the UPS-based sample surface geometry or the XPS-based distribution of chemical elements within the field of view. The NanoESCA III in the University of Arizona has a lateral resolution of 30.4 nm, the field of view spans from 1mm to 6µm.

Dark field imaging is also possible, which involves mapping the sample surface with a select electron momentum. Users will need to discuss with the instrument operator in order to carry out dark field imaging.

Work Function Mapping

By measuring the work function of select points on the surface with a spatial resolution of up to 30 nm, the NanoESCA III can produce high-resolution real-space work function maps. These maps combine electronic structure information with the spatial geometry information that is also captured by PEEM mode.

Chemical Imaging at the Nanoscale

Harnessing the double hemispherical analyzer's energy filtering capability, the NanoESCA III can create a real-space map with chemical elements distinguished. Using advanced image processing techniques, users can create a chemical composition map.

MicroARPES (Micro Angle-Resolved Photoemission Spectroscopy)

MicroARPES maps electronic band structure by measuring electron momentum. The He-based UV source in the NanoESCA III has a focusing mirror, producing small beam spot size, as small as a micron-sized spot. A small beam spot size helps minimize sample surface contamination, thus improving the quality of angle-resolved photoemission spectra. Momentum resolution: 7.5/milliAngstrom at 290K. Energy Resolution: 14meV at 43K. Sample temperatures can go as low as 30 Kelvin.