AVS 55th International Symposium & Exhibition | |
Surface Science | Wednesday Sessions |
Session SS2+NC-WeM |
Session: | Functional Metal Oxides and Quantum Metal Structures |
Presenter: | L. Tskipuri, Rutgers University |
Authors: | L. Tskipuri, Rutgers University R.A. Bartynski, Rutgers University |
Correspondent: | Click to Email |
We have studied the bonding of the thiol molecule dimethyldisulfide (SCH3)2 on ultrathin Cu and Co films that exhibit metallic quantum well (MQW) states using inverse photoemission (IPE), reflection-absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD). This thiol is similar to more complex organic molecule that exhibits the self-assembled properties on metal surfaces. After a room temperature exposure of the Cu surface to the thiol molecule at a dose of ~ 2.5 L, a c(2 x 2) low energy electron diffraction (LEED) pattern confirmed that the adsorbate forms an ordered overlayer. A large sulfur signal is observed in Auger electron spectroscopy (AES) and the C-H stretch mode was observed in IR with a frequency of 2915 cm-1 confirming molecular adsorption. Changes in the IPE spectrum upon adsorption are dominated by suppression of the substrate-related features, although some weak adsorbate-induced peaks are also observed. Both experimental and theoretical evidence indicates that electronic orbitals involved in molecule-surface bonding are in the same energy range as the MQW states of the substrate and the possible influence of MQW states on molecular adsorption and self-assembly of the thiol molecule will be discussed.