PhotoEmission Electron Microscopy Xrays CCD Electron Optical Column

Photo-Emission Electron Microscopy X-rays CCD Electron Optical Column Tunable x-rays or UV light Transfer - Full field imaging of electrons (ie. parallel detection) - Real time - UV or tunable synchrotron x-rays - < 5 nm (UV) and 25 nm (x-ray) resolution

Electron Yield Sampling Depth 3 -10 nm

UV Photo-Emission Electron Microscopy -UV imaging - work function contrast - < 10 nm resolution - variable energy - measure of yield (energy) - extract local work function 266 nm image of LCLS copper cathode, 30 x 30 microns

UV Photo-Emission Electron Microscopy 50 nm holes on 248 nm pitch, Al (FIB: Hyuck Choo) p: 266 nm light PEEM image 7: 1 hole to background contrast s: 266 nm light PEEM image 1. 5: 1 hole to background contrast - local measurement of field strength - local measurement of Fowler curves…. work function - image as function of photon energy to 1 e. V above work function

Synchrotron PEEM: Elemental Contrast from Jo Stohr

Synchrotron PEEM: Chemical / Magnetic Contrast from Jo Stohr

Magnetic and Antiferromagnetic Domains In Co-La. Fe. O 3 E 5 mm Scholl et al. , Science, 2000 p s FM A Co [010] 45° c La. Fe. O 3 c [100] AFM La. Fe. O 3 Nolting et al. , Nature 2000

100 psec pump probe PEEM magnetic domains Gradient image Cho et al. , Science 2004

• Image of electron yield as a function of time • image surface using PEEM; Ag polycrystalline film • pump - probe geometry using 100 MHz laser oscillator, 10 fsec, 3 e. V photons • launch SPP, then 2 photon photoemission image at delay d. T • temporal resolution ~ 15 fsec • Image shows propagation of the plasmon wavepacket + dispersion + damping Apply to plasmonic nanostructures (coupled to photovoltaic materials)

Photo-Electron Emission Microscopy - Full field…. 50 microns - 5 - 20 MV/m - Secondary electron imaging - Variable UV photon energy…. . local Fowler plots……local work function - Variable SR x-rays…. local elemental and chemical speciation - 10 nm resolution with UV, 25 nm with x-rays - can be combined with pump probe time resolved studies