Incident Photon Energy Modulated Angle Resolved Photoelectron Spectroscopy

Incident Photon Energy Modulated Angle Resolved Photoelectron Spectroscopy | © Scienta Omicron
Bi0.9Sb0.1 measured with several photon energies between 28 and 32 eV to distinguish between surface states and bulk states.

In an incident photon energy modulated angle resolved photoelectron spectroscopy (IPEM-ARPES) experiment, ARPES data are collected at a series of different photon energies.

Alternative(s): Product(s): R4000

In an incident photon energy modulated angle resolved photoelectron spectroscopy (IPEM-ARPES) experiment, ARPES data are collected at a series of different photon energies. The method serves to obtain information related to the momentum of the electrons (prior to photoexcitation), and in particular the momentum component perpendicular to the surface kz. Although kz is not conserved during the photoemission, it is nevertheless possible to calculate its value amongst other factors, based on the kinetic energy of the photoelectron, the emission angle.  When the incident photon energy is changed, usually over a range of several eV in the typical UPS regime of 20 to 40 eV, the momentum perpendicular to the surface kz will change accordingly. One prominent application for this effect is to distinguish surface from bulk states: True surface states do not show any dispersion (i.e. change of binding energy) with a variation of kz, while bulk states do.

Instruments