Lab-based Photoemission Electron Microscopy: Current Capabilities and Future Directions

Photoemission electron micrscopy (PEEM) is a nanoscale, full-field imaging technique based on the photoelectric effect. PEEM provides real space imaging of surfaces with enhanced contrast mechanism based on topography and electronic properties. Compared to other electron microscopies, PEEM is not as ubiquitous and has been widely associated with synchrotron user facilities. Recent instrument advancements in energy filtering and integration with laser-based photon sources have meant that they are rising in laboratories beyond synchrotron facilities. Here, I will present on the current capabilities and trends of lab-based PEEMs both at NIST and elsewhere. Using epitaxial graphene, I will demonstrate our current instrument capabilities of high-resolution imaging, topographic-electronic contrast due to graphene layer number, and acquiring 3-dimensional E_kinetic, k_x, k_y band structure. I will present on our plan to advance PEEM-based metrology in 2021 by integrating it with an ultraviolet light source generated by a visible laser and non-linear optics. With this new development, it will enable additional, dynamic PEEM imaging modalities to probe new physical phenomena of surfaces and interfaces.