Application of Ultraviolet Photoemission Spectroscopy to Surface Studies.

摘要

Within the past 2-3 years, ultraviolet photoemission spectroscopy (UPS) has rapidly developed as a technique for probing the electronic energy levels of surface complexes. He (21.2 and 40.8 eV) and Ne(16.8 eV) resonance lamps have proven to be particularly useful radiation sources. Various applications of UPS to date include studies of chemisorption, sorption (e.g., oxidation), intrinsic surface states, and formation of very thin overlayers. UPS surface studies have also been extended to angular measurements on single crystal surfaces which can yield significantly more information, e.g., symmetries of adsorbate-induced 'molecular complexes' and/or clearer delineations of 'surface' versus 'bulk' features. Such angular studies place greater importance on surface preparation and characterization (e.g., smoothness). (Author)