Probing Depth of Ultraviolet Photoelectron Yield Spectroscopy in Hydrocarbon Films

Abstract

In order to clarify the probing depth of ultraviolet photoelectron yield spectroscopy, the escape depth (L) of photo- electrons with kinetic energy (E_k) lower than 1.5eV in hydrocarbon films was determined by using self-assembled monolayers ofn-alkylmercaptane adsorbed on gold. The yield of photoelectrons from the gold substrate decreased exponentially as the chain length of n-alkylmercaptane increased. TheLwas 1.0±0.1nm for electrons with E_k lower than 0.3eV, and increased to 3.0±0.9nm for electrons with the maximumE_k of 1.5eV.