XPS/UPS Scienta

XPS and UPS (X-ray and UV Photoelectron Spectroscopy) are techniques where the occupied electronic structure, elemental composition and chemical bonds can be probed under ultra high vacuum for solid films and powder samples. The techniques are based on the photoelectric effect, where incident photons of known energy cause emission of electrons from the sample. The samples should preferably be conducting or semiconducting to avoid sample charging problems. Insulating samples can sometimes be studied, but then the analysis of chemical bonds and occupied electronic structure becomes more unreliable. The techniques are highly surface sensitive, we probe down to a depth of less than 100 Å for XPS and less than 25 Å for UPS. Sample surfaces must thus be protected during shipping and handling to avoid spurious results. The preferred sample dimensions for our spectrometer is 1x1 cm2 to 2x2 cm2.