Abstract
Film formation of dialkylsulfide (R-S-R) self-assembled monolayers (SAMs) on Au (111) have been investigated by AFM, dynamic contact angle measurement and XPS. AFM images revealed that dialkylsulfide molecules spontaneously aggregate on gold surface at the initial stage of SAM growth. S(2p) XPS spectra changed with the immersing time into the octadecylsulfide solution. For the shorter immersing time for 3h, we detected the strong S(2p) peak at around 163 eV which was assigned to unbound sulfur. On the other hand, after the longer immersing time of 24h, the S(2p) peak position shifted to lower binding energy of 162 eV attributed to bound sulfur. This peak shift indicated that the unbound-bound transition of the sulfurs during the immersion.
