X-RAY PHOTOEMISSION-STUDY OF THE INTERFACE FORMATION BETWEEN CALCIUM AND SELF-ASSEMBLED ALKANETHIOL MONOLAYERS

We have investigated the interface formation of Ca with an alkanethiol CH3(CH3)(17)SH monolayer self-assembled onto gold-coated silicon. Dep osited Ca neither diffused into nor interacted chemically with the mon olayer. Core-level shift and work function changes were observed in th e monolayer as soon as Ca was deposited and they were stabilized after 8 Angstrom of Ca coverage. The shifts are interpreted in terms of cha rge transfer from Ca to the monolayer, creating a dipole layer at the interface. (C) 1995 American Institute of Physics.